Commit Graph

661 Commits

Author SHA1 Message Date
Johannes Berg b080db5853 networking: convert many more places to skb_put_zero()
There were many places that my previous spatch didn't find,
as pointed out by yuan linyu in various patches.

The following spatch found many more and also removes the
now unnecessary casts:

    @@
    identifier p, p2;
    expression len;
    expression skb;
    type t, t2;
    @@
    (
    -p = skb_put(skb, len);
    +p = skb_put_zero(skb, len);
    |
    -p = (t)skb_put(skb, len);
    +p = skb_put_zero(skb, len);
    )
    ... when != p
    (
    p2 = (t2)p;
    -memset(p2, 0, len);
    |
    -memset(p, 0, len);
    )

    @@
    type t, t2;
    identifier p, p2;
    expression skb;
    @@
    t *p;
    ...
    (
    -p = skb_put(skb, sizeof(t));
    +p = skb_put_zero(skb, sizeof(t));
    |
    -p = (t *)skb_put(skb, sizeof(t));
    +p = skb_put_zero(skb, sizeof(t));
    )
    ... when != p
    (
    p2 = (t2)p;
    -memset(p2, 0, sizeof(*p));
    |
    -memset(p, 0, sizeof(*p));
    )

    @@
    expression skb, len;
    @@
    -memset(skb_put(skb, len), 0, len);
    +skb_put_zero(skb, len);

Apply it to the tree (with one manual fixup to keep the
comment in vxlan.c, which spatch removed.)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-16 11:48:35 -04:00
David Howells 5f2f97656a rxrpc: Fix several cases where a padded len isn't checked in ticket decode
This fixes CVE-2017-7482.

When a kerberos 5 ticket is being decoded so that it can be loaded into an
rxrpc-type key, there are several places in which the length of a
variable-length field is checked to make sure that it's not going to
overrun the available data - but the data is padded to the nearest
four-byte boundary and the code doesn't check for this extra.  This could
lead to the size-remaining variable wrapping and the data pointer going
over the end of the buffer.

Fix this by making the various variable-length data checks use the padded
length.

Reported-by: 石磊 <shilei-c@360.cn>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Marc Dionne <marc.c.dionne@auristor.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-15 14:23:44 -04:00
David Howells f7aec129a3 rxrpc: Cache the congestion window setting
Cache the congestion window setting that was determined during a call's
transmission phase when it finishes so that it can be used by the next call
to the same peer, thereby shortcutting the slow-start algorithm.

The value is stored in the rxrpc_peer struct and is accessed without
locking.  Each call takes the value that happens to be there when it starts
and just overwrites the value when it finishes.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-14 15:42:45 -04:00
David Howells e754eba685 rxrpc: Provide a cmsg to specify the amount of Tx data for a call
Provide a control message that can be specified on the first sendmsg() of a
client call or the first sendmsg() of a service response to indicate the
total length of the data to be transmitted for that call.

Currently, because the length of the payload of an encrypted DATA packet is
encrypted in front of the data, the packet cannot be encrypted until we
know how much data it will hold.

By specifying the length at the beginning of the transmit phase, each DATA
packet length can be set before we start loading data from userspace (where
several sendmsg() calls may contribute to a particular packet).

An error will be returned if too little or too much data is presented in
the Tx phase.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-06-07 17:15:46 +01:00
David Howells 3ab26a6fd0 rxrpc: Consolidate sendmsg parameters
Consolidate the sendmsg control message parameters into a struct rather
than passing them individually through the argument list of
rxrpc_sendmsg_cmsg().  This makes it easier to add more parameters.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-06-07 17:15:46 +01:00
David Howells 515559ca21 rxrpc: Provide a getsockopt call to query what cmsgs types are supported
Provide a getsockopt() call that can query what cmsg types are supported by
AF_RXRPC.
2017-06-07 17:15:46 +01:00
David Howells 4e255721d1 rxrpc: Add service upgrade support for client connections
Make it possible for a client to use AuriStor's service upgrade facility.

The client does this by adding an RXRPC_UPGRADE_SERVICE control message to
the first sendmsg() of a call.  This takes no parameters.

When recvmsg() starts returning data from the call, the service ID field in
the returned msg_name will reflect the result of the upgrade attempt.  If
the upgrade was ignored, srx_service will match what was set in the
sendmsg(); if the upgrade happened the srx_service will be altered to
indicate the service the server upgraded to.

Note that:

 (1) The choice of upgrade service is up to the server

 (2) Further client calls to the same server that would share a connection
     are blocked if an upgrade probe is in progress.

 (3) This should only be used to probe the service.  Clients should then
     use the returned service ID in all subsequent communications with that
     server (and not set the upgrade).  Note that the kernel will not
     retain this information should the connection expire from its cache.

 (4) If a server that supports upgrading is replaced by one that doesn't,
     whilst a connection is live, and if the replacement is running, say,
     OpenAFS 1.6.4 or older or an older IBM AFS, then the replacement
     server will not respond to packets sent to the upgraded connection.

     At this point, calls will time out and the server must be reprobed.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-06-05 14:30:49 +01:00
David Howells 4722974d90 rxrpc: Implement service upgrade
Implement AuriStor's service upgrade facility.  There are three problems
that this is meant to deal with:

 (1) Various of the standard AFS RPC calls have IPv4 addresses in their
     requests and/or replies - but there's no room for including IPv6
     addresses.

 (2) Definition of IPv6-specific RPC operations in the standard operation
     sets has not yet been achieved.

 (3) One could envision the creation a new service on the same port that as
     the original service.  The new service could implement improved
     operations - and the client could try this first, falling back to the
     original service if it's not there.

     Unfortunately, certain servers ignore packets addressed to a service
     they don't implement and don't respond in any way - not even with an
     ABORT.  This means that the client must then wait for the call timeout
     to occur.

What service upgrade does is to see if the connection is marked as being
'upgradeable' and if so, change the service ID in the server and thus the
request and reply formats.  Note that the upgrade isn't mandatory - a
server that supports only the original call set will ignore the upgrade
request.

In the protocol, the procedure is then as follows:

 (1) To request an upgrade, the first DATA packet in a new connection must
     have the userStatus set to 1 (this is normally 0).  The userStatus
     value is normally ignored by the server.

 (2) If the server doesn't support upgrading, the reply packets will
     contain the same service ID as for the first request packet.

 (3) If the server does support upgrading, all future reply packets on that
     connection will contain the new service ID and the new service ID will
     be applied to *all* further calls on that connection as well.

 (4) The RPC op used to probe the upgrade must take the same request data
     as the shadow call in the upgrade set (but may return a different
     reply).  GetCapability RPC ops were added to all standard sets for
     just this purpose.  Ops where the request formats differ cannot be
     used for probing.

 (5) The client must wait for completion of the probe before sending any
     further RPC ops to the same destination.  It should then use the
     service ID that recvmsg() reported back in all future calls.

 (6) The shadow service must have call definitions for all the operation
     IDs defined by the original service.


To support service upgrading, a server should:

 (1) Call bind() twice on its AF_RXRPC socket before calling listen().
     Each bind() should supply a different service ID, but the transport
     addresses must be the same.  This allows the server to receive
     requests with either service ID.

 (2) Enable automatic upgrading by calling setsockopt(), specifying
     RXRPC_UPGRADEABLE_SERVICE and passing in a two-member array of
     unsigned shorts as the argument:

	unsigned short optval[2];

     This specifies a pair of service IDs.  They must be different and must
     match the service IDs bound to the socket.  Member 0 is the service ID
     to upgrade from and member 1 is the service ID to upgrade to.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-06-05 14:30:49 +01:00
David Howells 28036f4485 rxrpc: Permit multiple service binding
Permit bind() to be called on an AF_RXRPC socket more than once (currently
maximum twice) to bind multiple listening services to it.  There are some
restrictions:

 (1) All bind() calls involved must have a non-zero service ID.

 (2) The service IDs must all be different.

 (3) The rest of the address (notably the transport part) must be the same
     in all (a single UDP socket is shared).

 (4) This must be done before listen() or sendmsg() is called.

This allows someone to connect to the service socket with different service
IDs and lays the foundation for service upgrading.

The service ID used by an incoming call can be extracted from the msg_name
returned by recvmsg().

Signed-off-by: David Howells <dhowells@redhat.com>
2017-06-05 14:30:49 +01:00
David Howells 68d6d1ae5c rxrpc: Separate the connection's protocol service ID from the lookup ID
Keep the rxrpc_connection struct's idea of the service ID that is exposed
in the protocol separate from the service ID that's used as a lookup key.

This allows the protocol service ID on a client connection to get upgraded
without making the connection unfindable for other client calls that also
would like to use the upgraded connection.

The connection's actual service ID is then returned through recvmsg() by
way of msg_name.

Whilst we're at it, we get rid of the last_service_id field from each
channel.  The service ID is per-connection, not per-call and an entire
connection is upgraded in one go.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-06-05 14:30:49 +01:00
Jason A. Donenfeld 89a5ea9966 rxrpc: check return value of skb_to_sgvec always
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-04 23:01:47 -04:00
Colin Ian King 1820dd0633 rxrpc: remove redundant proc_remove call
The proc_remove call is dead code as it occurs after a return and
hence can never be called. Remove it.

Detected by CoverityScan, CID#1437743 ("Logically dead code")

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-04 19:59:11 -04:00
David Howells 2baec2c3f8 rxrpc: Support network namespacing
Support network namespacing in AF_RXRPC with the following changes:

 (1) All the local endpoint, peer and call lists, locks, counters, etc. are
     moved into the per-namespace record.

 (2) All the connection tracking is moved into the per-namespace record
     with the exception of the client connection ID tree, which is kept
     global so that connection IDs are kept unique per-machine.

 (3) Each namespace gets its own epoch.  This allows each network namespace
     to pretend to be a separate client machine.

 (4) The /proc/net/rxrpc_xxx files are now called /proc/net/rxrpc/xxx and
     the contents reflect the namespace.

fs/afs/ should be okay with this patch as it explicitly requires the current
net namespace to be init_net to permit a mount to proceed at the moment.  It
will, however, need updating so that cells, IP addresses and DNS records are
per-namespace also.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-25 13:15:11 -04:00
David Howells 89ca694806 rxrpc: Trace client call connection
Add a tracepoint (rxrpc_connect_call) to log the combination of rxrpc_call
pointer, afs_call pointer/user data and wire call parameters to make it
easier to match the tracebuffer contents to captured network packets.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-04-06 11:10:41 +01:00
David Howells 740586d290 rxrpc: Trace changes in a call's receive window size
Add a tracepoint (rxrpc_rx_rwind_change) to log changes in a call's receive
window size as imposed by the peer through an ACK packet.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-04-06 11:10:41 +01:00
David Howells 005ede286f rxrpc: Trace received aborts
Add a tracepoint (rxrpc_rx_abort) to record received aborts.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-04-06 11:10:41 +01:00
David Howells fb46f6ee10 rxrpc: Trace protocol errors in received packets
Add a tracepoint (rxrpc_rx_proto) to record protocol errors in received
packets.  The following changes are made:

 (1) Add a function, __rxrpc_abort_eproto(), to note a protocol error on a
     call and mark the call aborted.  This is wrapped by
     rxrpc_abort_eproto() that makes the why string usable in trace.

 (2) Add trace_rxrpc_rx_proto() or rxrpc_abort_eproto() to protocol error
     generation points, replacing rxrpc_abort_call() with the latter.

 (3) Only send an abort packet in rxkad_verify_packet*() if we actually
     managed to abort the call.

Note that a trace event is also emitted if a kernel user (e.g. afs) tries
to send data through a call when it's not in the transmission phase, though
it's not technically a receive event.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-04-06 11:09:39 +01:00
David Howells ef68622da9 rxrpc: Handle temporary errors better in rxkad security
In the rxkad security module, when we encounter a temporary error (such as
ENOMEM) from which we could conceivably recover, don't abort the
connection, but rather permit retransmission of the relevant packets to
induce a retry.

Note that I'm leaving some places that could be merged together to insert
tracing in the next patch.

Signed-off-by; David Howells <dhowells@redhat.com>
2017-04-06 10:11:59 +01:00
David Howells 84a4c09c38 rxrpc: Note a successfully aborted kernel operation
Make rxrpc_kernel_abort_call() return an indication as to whether it
actually aborted the operation or not so that kafs can trace the failure of
the operation.  Note that 'success' in this context means changing the
state of the call, not necessarily successfully transmitting an ABORT
packet.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-04-06 10:11:59 +01:00
David Howells 3a92789af0 rxrpc: Use negative error codes in rxrpc_call struct
Use negative error codes in struct rxrpc_call::error because that's what
the kernel normally deals with and to make the code consistent.  We only
turn them positive when transcribing into a cmsg for userspace recvmsg.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-04-06 10:11:56 +01:00
David Howells 4d4a6ac73e rxrpc: Ignore BUSY packets on old calls
If we receive a BUSY packet for a call we think we've just completed, the
packet is handed off to the connection processor to deal with - but the
connection processor doesn't expect a BUSY packet and so flags a protocol
error.

Fix this by simply ignoring the BUSY packet for the moment.

The symptom of this may appear as a system call failing with EPROTO.  This
may be triggered by pressing ctrl-C under some circumstances.

This comes about we abort calls due to interruption by a signal (which we
shouldn't do, but that's going to be a large fix and mostly in fs/afs/).
What happens is that we abort the call and may also abort follow up calls
too (this needs offloading somehoe).  So we see a transmission of something
like the following sequence of packets:

	DATA for call N
	ABORT call N
	DATA for call N+1
	ABORT call N+1

in very quick succession on the same channel.  However, the peer may have
deferred the processing of the ABORT from the call N to a background thread
and thus sees the DATA message from the call N+1 coming in before it has
cleared the channel.  Thus it sends a BUSY packet[*].

[*] Note that some implementations (OpenAFS, for example) mark the BUSY
    packet with one plus the callNumber of the call prior to call N.
    Ordinarily, this would be call N, but there's no requirement for the
    calls on a channel to be numbered strictly sequentially (the number is
    required to increase).

    This is wrong and means that the callNumber in the BUSY packet should
    be ignored (it really ought to be N+1 since that's what it's in
    response to).

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-16 21:27:57 -07:00
David Howells 702f2ac87a rxrpc: Wake up the transmitter if Rx window size increases on the peer
The RxRPC ACK packet may contain an extension that includes the peer's
current Rx window size for this call.  We adjust the local Tx window size
to match.  However, the transmitter can stall if the receive window is
reduced to 0 by the peer and then reopened.

This is because the normal way that the transmitter is re-energised is by
dropping something out of our Tx queue and thus making space.  When a
single gap is made, the transmitter is woken up.  However, because there's
nothing in the Tx queue at this point, this doesn't happen.

To fix this, perform a wake_up() any time we see the peer's Rx window size
increasing.

The observable symptom is that calls start failing on ETIMEDOUT and the
following:

	kAFS: SERVER DEAD state=-62

appears in dmesg.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-10 09:34:23 -08:00
David Howells 6fc166d62c rxrpc: rxrpc_kernel_send_data() needs to handle failed call better
If rxrpc_kernel_send_data() is asked to send data through a call that has
already failed (due to a remote abort, received protocol error or network
error), then return the associated error code saved in the call rather than
ESHUTDOWN.

This allows the caller to work out whether to ask for the abort code or not
based on this.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-09 18:30:10 -08:00
David Howells 146d8fef9d rxrpc: Call state should be read with READ_ONCE() under some circumstances
The call state may be changed at any time by the data-ready routine in
response to received packets, so if the call state is to be read and acted
upon several times in a function, READ_ONCE() must be used unless the call
state lock is held.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-07 13:59:06 -08:00
Linus Torvalds 8d70eeb84a Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) Fix double-free in batman-adv, from Sven Eckelmann.

 2) Fix packet stats for fast-RX path, from Joannes Berg.

 3) Netfilter's ip_route_me_harder() doesn't handle request sockets
    properly, fix from Florian Westphal.

 4) Fix sendmsg deadlock in rxrpc, from David Howells.

 5) Add missing RCU locking to transport hashtable scan, from Xin Long.

 6) Fix potential packet loss in mlxsw driver, from Ido Schimmel.

 7) Fix race in NAPI handling between poll handlers and busy polling,
    from Eric Dumazet.

 8) TX path in vxlan and geneve need proper RCU locking, from Jakub
    Kicinski.

 9) SYN processing in DCCP and TCP need to disable BH, from Eric
    Dumazet.

10) Properly handle net_enable_timestamp() being invoked from IRQ
    context, also from Eric Dumazet.

11) Fix crash on device-tree systems in xgene driver, from Alban Bedel.

12) Do not call sk_free() on a locked socket, from Arnaldo Carvalho de
    Melo.

13) Fix use-after-free in netvsc driver, from Dexuan Cui.

14) Fix max MTU setting in bonding driver, from WANG Cong.

15) xen-netback hash table can be allocated from softirq context, so use
    GFP_ATOMIC. From Anoob Soman.

16) Fix MAC address change bug in bgmac driver, from Hari Vyas.

17) strparser needs to destroy strp_wq on module exit, from WANG Cong.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (69 commits)
  strparser: destroy workqueue on module exit
  sfc: fix IPID endianness in TSOv2
  sfc: avoid max() in array size
  rds: remove unnecessary returned value check
  rxrpc: Fix potential NULL-pointer exception
  nfp: correct DMA direction in XDP DMA sync
  nfp: don't tell FW about the reserved buffer space
  net: ethernet: bgmac: mac address change bug
  net: ethernet: bgmac: init sequence bug
  xen-netback: don't vfree() queues under spinlock
  xen-netback: keep a local pointer for vif in backend_disconnect()
  netfilter: nf_tables: don't call nfnetlink_set_err() if nfnetlink_send() fails
  netfilter: nft_set_rbtree: incorrect assumption on lower interval lookups
  netfilter: nf_conntrack_sip: fix wrong memory initialisation
  can: flexcan: fix typo in comment
  can: usb_8dev: Fix memory leak of priv->cmd_msg_buffer
  can: gs_usb: fix coding style
  can: gs_usb: Don't use stack memory for USB transfers
  ixgbe: Limit use of 2K buffers on architectures with 256B or larger cache lines
  ixgbe: update the rss key on h/w, when ethtool ask for it
  ...
2017-03-04 17:31:39 -08:00
David Howells 37411cad63 rxrpc: Fix potential NULL-pointer exception
Fix a potential NULL-pointer exception in rxrpc_do_sendmsg().  The call
state check that I added should have gone into the else-body of the
if-statement where we actually have a call to check.

Found by CoverityScan CID#1414316 ("Dereference after null check").

Fixes: 540b1c48c3 ("rxrpc: Fix deadlock between call creation and sendmsg/recvmsg")
Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-03 09:48:00 -08:00
Ingo Molnar 174cd4b1e5 sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h>
Fix up affected files that include this signal functionality via sched.h.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:32 +01:00
David Howells 540b1c48c3 rxrpc: Fix deadlock between call creation and sendmsg/recvmsg
All the routines by which rxrpc is accessed from the outside are serialised
by means of the socket lock (sendmsg, recvmsg, bind,
rxrpc_kernel_begin_call(), ...) and this presents a problem:

 (1) If a number of calls on the same socket are in the process of
     connection to the same peer, a maximum of four concurrent live calls
     are permitted before further calls need to wait for a slot.

 (2) If a call is waiting for a slot, it is deep inside sendmsg() or
     rxrpc_kernel_begin_call() and the entry function is holding the socket
     lock.

 (3) sendmsg() and recvmsg() or the in-kernel equivalents are prevented
     from servicing the other calls as they need to take the socket lock to
     do so.

 (4) The socket is stuck until a call is aborted and makes its slot
     available to the waiter.

Fix this by:

 (1) Provide each call with a mutex ('user_mutex') that arbitrates access
     by the users of rxrpc separately for each specific call.

 (2) Make rxrpc_sendmsg() and rxrpc_recvmsg() unlock the socket as soon as
     they've got a call and taken its mutex.

     Note that I'm returning EWOULDBLOCK from recvmsg() if MSG_DONTWAIT is
     set but someone else has the lock.  Should I instead only return
     EWOULDBLOCK if there's nothing currently to be done on a socket, and
     sleep in this particular instance because there is something to be
     done, but we appear to be blocked by the interrupt handler doing its
     ping?

 (3) Make rxrpc_new_client_call() unlock the socket after allocating a new
     call, locking its user mutex and adding it to the socket's call tree.
     The call is returned locked so that sendmsg() can add data to it
     immediately.

     From the moment the call is in the socket tree, it is subject to
     access by sendmsg() and recvmsg() - even if it isn't connected yet.

 (4) Lock new service calls in the UDP data_ready handler (in
     rxrpc_new_incoming_call()) because they may already be in the socket's
     tree and the data_ready handler makes them live immediately if a user
     ID has already been preassigned.

     Note that the new call is locked before any notifications are sent
     that it is live, so doing mutex_trylock() *ought* to always succeed.
     Userspace is prevented from doing sendmsg() on calls that are in a
     too-early state in rxrpc_do_sendmsg().

 (5) Make rxrpc_new_incoming_call() return the call with the user mutex
     held so that a ping can be scheduled immediately under it.

     Note that it might be worth moving the ping call into
     rxrpc_new_incoming_call() and then we can drop the mutex there.

 (6) Make rxrpc_accept_call() take the lock on the call it is accepting and
     release the socket after adding the call to the socket's tree.  This
     is slightly tricky as we've dequeued the call by that point and have
     to requeue it.

     Note that requeuing emits a trace event.

 (7) Make rxrpc_kernel_send_data() and rxrpc_kernel_recv_data() take the
     new mutex immediately and don't bother with the socket mutex at all.

This patch has the nice bonus that calls on the same socket are now to some
extent parallelisable.

Note that we might want to move rxrpc_service_prealloc() calls out from the
socket lock and give it its own lock, so that we don't hang progress in
other calls because we're waiting for the allocator.

We probably also want to avoid calling rxrpc_notify_socket() from within
the socket lock (rxrpc_accept_call()).

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marc Dionne <marc.c.dionne@auristor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-01 09:50:58 -08:00
David Howells d7e15835ab rxrpc: Kernel calls get stuck in recvmsg
Calls made through the in-kernel interface can end up getting stuck because
of a missed variable update in a loop in rxrpc_recvmsg_data().  The problem
is like this:

 (1) A new packet comes in and doesn't cause a notification to be given to
     the client as there's still another packet in the ring - the
     assumption being that if the client will keep drawing off data until
     the ring is empty.

 (2) The client is in rxrpc_recvmsg_data(), inside the big while loop that
     iterates through the packets.  This copies the window pointers into
     variables rather than using the information in the call struct
     because:

     (a) MSG_PEEK might be in effect;

     (b) we need a barrier after reading call->rx_top to pair with the
     	 barrier in the softirq routine that loads the buffer.

 (3) The reading of call->rx_top is done outside of the loop, and top is
     never updated whilst we're in the loop.  This means that even through
     there's a new packet available, we don't see it and may return -EFAULT
     to the caller - who will happily return to the scheduler and await the
     next notification.

 (4) No further notifications are forthcoming until there's an abort as the
     ring isn't empty.

The fix is to move the read of call->rx_top inside the loop - but it needs
to be done before the condition is checked.

Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-26 21:30:12 -05:00
Marc Dionne 774521f353 rxrpc: Fix an assertion in rxrpc_read()
In the rxrpc_read() function, which allows a user to read the contents of a
key, we miscalculate the expected length of an encoded rxkad token by not
taking into account the key length.  However, the data is stored later
anyway with an ENCODE_DATA() call - and an assertion failure then ensues
when the lengths are checked at the end.

Fix this by including the key length in the token size estimation.

The following assertion is produced:

Assertion failed - 384(0x180) == 380(0x17c) is false
------------[ cut here ]------------
kernel BUG at ../net/rxrpc/key.c:1221!
invalid opcode: 0000 [#1] SMP
Modules linked in:
CPU: 2 PID: 2957 Comm: keyctl Not tainted 4.10.0-fscache+ #483
Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
task: ffff8804013a8500 task.stack: ffff8804013ac000
RIP: 0010:rxrpc_read+0x10de/0x11b6
RSP: 0018:ffff8804013afe48 EFLAGS: 00010296
RAX: 000000000000003b RBX: 0000000000000003 RCX: 0000000000000000
RDX: 0000000000040001 RSI: 00000000000000f6 RDI: 0000000000000300
RBP: ffff8804013afed8 R08: 0000000000000001 R09: 0000000000000001
R10: ffff8804013afd90 R11: 0000000000000002 R12: 00005575f7c911b4
R13: 00005575f7c911b3 R14: 0000000000000157 R15: ffff880408a5d640
FS:  00007f8dfbc73700(0000) GS:ffff88041fb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005575f7c91008 CR3: 000000040120a000 CR4: 00000000001406e0
Call Trace:
 keyctl_read_key+0xb6/0xd7
 SyS_keyctl+0x83/0xe7
 do_syscall_64+0x80/0x191
 entry_SYSCALL64_slow_path+0x25/0x25

Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-24 11:42:55 -05:00
David Howells 88c4845d7d rxrpc: Change module filename to rxrpc.ko
Change module filename from af-rxrpc.ko to rxrpc.ko so as to be consistent
with the other protocol drivers.

Also adjust the documentation to reflect this.

Further, there is no longer a standalone rxkad module, as it has been
merged into the rxrpc core, so get rid of references to that.

Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-17 15:09:19 -05:00
David Howells 210f035316 rxrpc: Allow listen(sock, 0) to be used to disable listening
Allow listen() with a backlog of 0 to be used to disable listening on an
AF_RXRPC socket.  This also releases any preallocation, thereby making it
easier for a kernel service to account for all allocated call structures
when shutting down the service.

The socket cannot thereafter have listening reenabled, but must rather be
closed and reopened.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-01-09 11:10:02 +00:00
David Howells 3e018daf04 rxrpc: Show a call's hard-ACK cursors in /proc/net/rxrpc_calls
Show a call's hard-ACK cursors in /proc/net/rxrpc_calls so that a call's
progress can be more easily monitored.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-01-05 11:39:44 +00:00
David Howells b1d9f7fde0 rxrpc: Add some more tracing
Add the following extra tracing information:

 (1) Modify the rxrpc_transmit tracepoint to record the Tx window size as
     this is varied by the slow-start algorithm.

 (2) Modify the rxrpc_rx_ack tracepoint to record more information from
     received ACK packets.

 (3) Add an rxrpc_rx_data tracepoint to record the information in DATA
     packets.

 (4) Add an rxrpc_disconnect_call tracepoint to record call disconnection,
     including the reason the call was disconnected.

 (5) Add an rxrpc_improper_term tracepoint to record implicit termination
     of a call by a client either by starting a new call on a particular
     connection channel without first transmitting the final ACK for the
     previous call.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-01-05 11:39:12 +00:00
David Howells b54a134a7d rxrpc: Fix handling of enums-to-string translation in tracing
Fix the way enum values are translated into strings in AF_RXRPC
tracepoints.  The problem with just doing a lookup in a normal flat array
of strings or chars is that external tracing infrastructure can't find it.
Rather, TRACE_DEFINE_ENUM must be used.

Also sort the enums and string tables to make it easier to keep them in
order so that a future patch to __print_symbolic() can be optimised to try
a direct lookup into the table first before iterating over it.

A couple of _proto() macro calls are removed because they refered to tables
that got moved to the tracing infrastructure.  The relevant data can be
found by way of tracing.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-01-05 10:38:33 +00:00
yuan linyu 1ff8cebf49 scm: remove use CMSG{_COMPAT}_ALIGN(sizeof(struct {compat_}cmsghdr))
sizeof(struct cmsghdr) and sizeof(struct compat_cmsghdr) already aligned.
remove use CMSG_ALIGN(sizeof(struct cmsghdr)) and
CMSG_COMPAT_ALIGN(sizeof(struct compat_cmsghdr)) keep code consistent.

Signed-off-by: yuan linyu <Linyu.Yuan@alcatel-sbell.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-04 13:04:37 -05:00
Matthew Wilcox 444306129a rxrpc: abstract away knowledge of IDR internals
Add idr_get_cursor() / idr_set_cursor() APIs, and remove the reference
to IDR_SIZE.

Link: http://lkml.kernel.org/r/1480369871-5271-65-git-send-email-mawilcox@linuxonhyperv.com
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-14 16:04:10 -08:00
Paolo Abeni 7c13f97ffd udp: do fwd memory scheduling on dequeue
A new argument is added to __skb_recv_datagram to provide
an explicit skb destructor, invoked under the receive queue
lock.
The UDP protocol uses such argument to perform memory
reclaiming on dequeue, so that the UDP protocol does not
set anymore skb->desctructor.
Instead explicit memory reclaiming is performed at close() time and
when skbs are removed from the receive queue.
The in kernel UDP protocol users now need to call a
skb_recv_udp() variant instead of skb_recv_datagram() to
properly perform memory accounting on dequeue.

Overall, this allows acquiring only once the receive queue
lock on dequeue.

Tested using pktgen with random src port, 64 bytes packet,
wire-speed on a 10G link as sender and udp_sink as the receiver,
using an l4 tuple rxhash to stress the contention, and one or more
udp_sink instances with reuseport.

nr sinks	vanilla		patched
1		440		560
3		2150		2300
6		3650		3800
9		4450		4600
12		6250		6450

v1 -> v2:
 - do rmem and allocated memory scheduling under the receive lock
 - do bulk scheduling in first_packet_length() and in udp_destruct_sock()
 - avoid the typdef for the dequeue callback

Suggested-by: Eric Dumazet <edumazet@google.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-07 13:24:41 -05:00
David Howells 07096f612f rxrpc: Fix checking of error from ip6_route_output()
ip6_route_output() doesn't return a negative error when it fails, rather
the ->error field of the returned dst_entry struct needs to be checked.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: 75b54cb57c ("rxrpc: Add IPv6 support")
Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-13 08:43:17 +01:00
David Howells 54fde42345 rxrpc: Fix checker warning by not passing always-zero value to ERR_PTR()
Fix the following checker warning:

	net/rxrpc/call_object.c:279 rxrpc_new_client_call()
	warn: passing zero to 'ERR_PTR'

where a value that's always zero is passed to ERR_PTR() so that it can be
passed to a tracepoint in an auxiliary pointer field.

Just pass NULL instead to the tracepoint.

Fixes: a84a46d730 ("rxrpc: Add some additional call tracing")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-13 08:39:52 +01:00
David Howells bf7d620abf rxrpc: Don't request an ACK on the last DATA packet of a call's Tx phase
Don't request an ACK on the last DATA packet of a call's Tx phase as for a
client there will be a reply packet or some sort of ACK to shift phase.  If
the ACK is requested, OpenAFS sends a REQUESTED-ACK ACK with soft-ACKs in
it and doesn't follow up with a hard-ACK.

If we don't set the flag, OpenAFS will send a DELAY ACK that hard-ACKs the
reply data, thereby allowing the call to terminate cleanly.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 08:11:51 +01:00
David Howells 9749fd2bea rxrpc: Need to produce an ACK for service op if op takes a long time
We need to generate a DELAY ACK from the service end of an operation if we
start doing the actual operation work and it takes longer than expected.
This will hard-ACK the request data and allow the client to release its
resources.

To make this work:

 (1) We have to set the ack timer and propose an ACK when the call moves to
     the RXRPC_CALL_SERVER_ACK_REQUEST and clear the pending ACK and cancel
     the timer when we start transmitting the reply (the first DATA packet
     of the reply implicitly ACKs the request phase).

 (2) It must be possible to set the timer when the caller is holding
     call->state_lock, so split the lock-getting part of the timer function
     out.

 (3) Add trace notes for the ACK we're requesting and the timer we clear.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 08:11:50 +01:00
David Howells cf69207afa rxrpc: Return negative error code to kernel service
In rxrpc_kernel_recv_data(), when we return the error number incurred by a
failed call, we must negate it before returning it as it's stored as
positive (that's what we have to pass back to userspace).

Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 08:11:50 +01:00
David Howells 94bc669efa rxrpc: Add missing notification
The call's background processor work item needs to notify the socket when
it completes a call so that recvmsg() or the AFS fs can deal with it.
Without this, call expiry isn't handled.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 08:11:50 +01:00
David Howells d7833d0091 rxrpc: Queue the call on expiry
When a call expires, it must be queued for the background processor to deal
with otherwise a service call that is improperly terminated will just sit
there awaiting an ACK and won't expire.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 08:11:50 +01:00
David Howells b3156274ca rxrpc: Partially handle OpenAFS's improper termination of calls
OpenAFS doesn't always correctly terminate client calls that it makes -
this includes calls the OpenAFS servers make to the cache manager service.
It should end the client call with either:

 (1) An ACK that has firstPacket set to one greater than the seq number of
     the reply DATA packet with the LAST_PACKET flag set (thereby
     hard-ACK'ing all packets).  nAcks should be 0 and acks[] should be
     empty (ie. no soft-ACKs).

 (2) An ACKALL packet.

OpenAFS, though, may send an ACK packet with firstPacket set to the last
seq number or less and soft-ACKs listed for all packets up to and including
the last DATA packet.

The transmitter, however, is obliged to keep the call live and the
soft-ACK'd DATA packets around until they're hard-ACK'd as the receiver is
permitted to drop any merely soft-ACK'd packet and request retransmission
by sending an ACK packet with a NACK in it.

Further, OpenAFS will also terminate a client call by beginning the next
client call on the same connection channel.  This implicitly completes the
previous call.

This patch handles implicit ACK of a call on a channel by the reception of
the first packet of the next call on that channel.

If another call doesn't come along to implicitly ACK a call, then we have
to time the call out.  There are some bugs there that will be addressed in
subsequent patches.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 08:11:49 +01:00
David Howells a5af7e1fc6 rxrpc: Fix loss of PING RESPONSE ACK production due to PING ACKs
Separate the output of PING ACKs from the output of other sorts of ACK so
that if we receive a PING ACK and schedule transmission of a PING RESPONSE
ACK, the response doesn't get cancelled by a PING ACK we happen to be
scheduling transmission of at the same time.

If a PING RESPONSE gets lost, the other side might just sit there waiting
for it and refuse to proceed otherwise.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 08:11:49 +01:00
David Howells 26cb02aa6d rxrpc: Fix warning by splitting rxrpc_send_call_packet()
Split rxrpc_send_data_packet() to separate ACK generation (which is more
complicated) from ABORT generation.  This simplifies the code a bit and
fixes the following warning:

In file included from ../net/rxrpc/output.c:20:0:
net/rxrpc/output.c: In function 'rxrpc_send_call_packet':
net/rxrpc/ar-internal.h:1187:27: error: 'top' may be used uninitialized in this function [-Werror=maybe-uninitialized]
net/rxrpc/output.c:103:24: note: 'top' was declared here
net/rxrpc/output.c:225:25: error: 'hard_ack' may be used uninitialized in this function [-Werror=maybe-uninitialized]

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 08:11:49 +01:00
David Howells a9f312d98a rxrpc: Only ping for lost reply in client call
When a reply is deemed lost, we send a ping to find out the other end
received all the request data packets we sent.  This should be limited to
client calls and we shouldn't do this on service calls.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 08:11:49 +01:00
David Howells 7212a57e8e rxrpc: Fix oops on incoming call to serviceless endpoint
If an call comes in to a local endpoint that isn't listening for any
incoming calls at the moment, an oops will happen.  We need to check that
the local endpoint's service pointer isn't NULL before we dereference it.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 08:11:49 +01:00
David Howells 19c0dbd540 rxrpc: Fix duplicate const
Remove a duplicate const keyword.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 08:11:48 +01:00
David Howells b63452c11e rxrpc: Accesses of rxrpc_local::service need to be RCU managed
struct rxrpc_local->service is marked __rcu - this means that accesses of
it need to be managed using RCU wrappers.  There are two such places in
rxrpc_release_sock() where the value is checked and cleared.  Fix this by
using the appropriate wrappers.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-10-06 08:11:48 +01:00
David Howells 405dea1deb rxrpc: Fix the call timer handling
The call timer's concept of a call timeout (of which there are three) that
is inactive is that it is the timeout has the same expiration time as the
call expiration timeout (the expiration timer is never inactive).  However,
I'm not resetting the timeouts when they expire, leading to repeated
processing of expired timeouts when other timeout events occur.

Fix this by:

 (1) Move the timer expiry detection into rxrpc_set_timer() inside the
     locked section.  This means that if a timeout is set that will expire
     immediately, we deal with it immediately.

 (2) If a timeout is at or before now then it has expired.  When an expiry
     is detected, an event is raised, the timeout is automatically
     inactivated and the event processor is queued.

 (3) If a timeout is at or after the expiry timeout then it is inactive.
     Inactive timeouts do not contribute to the timer setting.

 (4) The call timer callback can now just call rxrpc_set_timer() to handle
     things.

 (5) The call processor work function now checks the event flags rather
     than checking the timeouts directly.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-30 14:40:11 +01:00
David Howells df0adc788a rxrpc: Keep the call timeouts as ktimes rather than jiffies
Keep that call timeouts as ktimes rather than jiffies so that they can be
expressed as functions of RTT.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-30 14:40:11 +01:00
David Howells c31410ea00 rxrpc: Remove error from struct rxrpc_skb_priv as it is unused
Remove error from struct rxrpc_skb_priv as it is no longer used.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-30 14:39:32 +01:00
David Howells 775e5b71db rxrpc: The offset field in struct rxrpc_skb_priv is unnecessary
The offset field in struct rxrpc_skb_priv is unnecessary as the value can
always be calculated.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-30 14:39:28 +01:00
David Howells 0851115090 rxrpc: Reduce ssthresh to peer's receive window
When we receive an ACK from the peer that tells us what the peer's receive
window (rwind) is, we should reduce ssthresh to rwind if rwind is smaller
than ssthresh.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-30 14:38:59 +01:00
David Howells 8782def204 rxrpc: Switch to Congestion Avoidance mode at cwnd==ssthresh
Switch to Congestion Avoidance mode at cwnd == ssthresh rather than relying
on cwnd getting incremented beyond ssthresh and the window size, the mode
being shifted and then cwnd being corrected.

We need to make sure we switch into CA mode so that we stop marking every
packet for ACK.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-30 14:38:56 +01:00
David Howells ed1e8679d8 rxrpc: Note serial number being ACK'd in the congestion management trace
Note the serial number of the packet being ACK'd in the congestion
management trace rather than the serial number of the ACK packet.  Whilst
the serial number of the ACK packet is useful for matching ACK packet in
the output of wireshark, the serial number that the ACK is in response to
is of more use in working out how different trace lines relate.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-29 22:57:47 +01:00
David Howells b112a67081 rxrpc: Request more ACKs in slow-start mode
Set the request-ACK on more DATA packets whilst we're in slow start mode so
that we get sufficient ACKs back to supply information to configure the
window.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-29 22:57:47 +01:00
David Howells 1e9e5c9521 rxrpc: Reduce the rxrpc_local::services list to a pointer
Reduce the rxrpc_local::services list to just a pointer as we don't permit
multiple service endpoints to bind to a single transport endpoints (this is
excluded by rxrpc_lookup_local()).

The reason we don't allow this is that if you send a request to an AFS
filesystem service, it will try to talk back to your cache manager on the
port you sent from (this is how file change notifications are handled).  To
prevent someone from stealing your CM callbacks, we don't let AF_RXRPC
sockets share a UDP socket if at least one of them has a service bound.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-29 22:57:47 +01:00
David Howells 2629c7fa7c rxrpc: When activating client conn channels, do state check inside lock
In rxrpc_activate_channels(), the connection cache state is checked outside
of the lock, which means it can change whilst we're waking calls up,
thereby changing whether or not we're allowed to wake calls up.

Fix this by moving the check inside the locked region.  The check to see if
all the channels are currently busy can stay outside of the locked region.

Whilst we're at it:

 (1) Split the locked section out into its own function so that we can call
     it from other places in a later patch.

 (2) Determine the mask of channels dependent on the state as we're going
     to add another state in a later patch that will restrict the number of
     simultaneous calls to 1 on a connection.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-29 22:57:47 +01:00
David Howells a1767077b0 rxrpc: Make Tx loss-injection go through normal return and adjust tracing
In rxrpc_send_data_packet() make the loss-injection path return through the
same code as the transmission path so that the RTT determination is
initiated and any future timer shuffling will be done, despite the packet
having been binned.

Whilst we're at it:

 (1) Add to the tx_data tracepoint an indication of whether or not we're
     retransmitting a data packet.

 (2) When we're deciding whether or not to request an ACK, rather than
     checking if we're in fast-retransmit mode check instead if we're
     retransmitting.

 (3) Don't invoke the lose_skb tracepoint when losing a Tx packet as we're
     not altering the sk_buff refcount nor are we just seeing it after
     getting it off the Tx list.

 (4) The rxrpc_skb_tx_lost note is then no longer used so remove it.

 (5) rxrpc_lose_skb() no longer needs to deal with rxrpc_skb_tx_lost.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-29 22:37:15 +01:00
David Howells 8732db67c6 rxrpc: Fix exclusive client connections
Exclusive connections are currently reusable (which they shouldn't be)
because rxrpc_alloc_client_connection() checks the exclusive flag in the
rxrpc_connection struct before it's initialised from the function
parameters.  This means that the DONT_REUSE flag doesn't get set.

Fix this by checking the function parameters for the exclusive flag.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-29 22:37:15 +01:00
David Howells 57494343cb rxrpc: Implement slow-start
Implement RxRPC slow-start, which is similar to RFC 5681 for TCP.  A
tracepoint is added to log the state of the congestion management algorithm
and the decisions it makes.

Notes:

 (1) Since we send fixed-size DATA packets (apart from the final packet in
     each phase), counters and calculations are in terms of packets rather
     than bytes.

 (2) The ACK packet carries the equivalent of TCP SACK.

 (3) The FLIGHT_SIZE calculation in RFC 5681 doesn't seem particularly
     suited to SACK of a small number of packets.  It seems that, almost
     inevitably, by the time three 'duplicate' ACKs have been seen, we have
     narrowed the loss down to one or two missing packets, and the
     FLIGHT_SIZE calculation ends up as 2.

 (4) In rxrpc_resend(), if there was no data that apparently needed
     retransmission, we transmit a PING ACK to ask the peer to tell us what
     its Rx window state is.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 23:49:46 +01:00
David Howells 0d967960d3 rxrpc: Schedule an ACK if the reply to a client call appears overdue
If we've sent all the request data in a client call but haven't seen any
sign of the reply data yet, schedule an ACK to be sent to the server to
find out if the reply data got lost.

If the server hasn't yet hard-ACK'd the request data, we send a PING ACK to
demand a response to find out whether we need to retransmit.

If the server says it has received all of the data, we send an IDLE ACK to
tell the server that we haven't received anything in the receive phase as
yet.

To make this work, a non-immediate PING ACK must carry a delay.  I've chosen
the same as the IDLE ACK for the moment.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 23:49:46 +01:00
David Howells 31a1b98950 rxrpc: Generate a summary of the ACK state for later use
Generate a summary of the Tx buffer packet state when an ACK is received
for use in a later patch that does congestion management.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 23:49:46 +01:00
David Howells df0562a72d rxrpc: Delay the resend timer to allow for nsec->jiffies conv error
When determining the resend timer value, we have a value in nsec but the
timer is in jiffies which may be a million or more times more coarse.
nsecs_to_jiffies() rounds down - which means that the resend timeout
expressed as jiffies is very likely earlier than the one expressed as
nanoseconds from which it was derived.

The problem is that rxrpc_resend() gets triggered by the timer, but can't
then find anything to resend yet.  It sets the timer again - but gets
kicked off immediately again and again until the nanosecond-based expiry
time is reached and we actually retransmit.

Fix this by adding 1 to the jiffies-based resend_at value to counteract the
rounding and make sure that the timer happens after the nanosecond-based
expiry is passed.

Alternatives would be to adjust the timestamp on the packets to align
with the jiffie scale or to switch back to using jiffie-timestamps.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 23:49:46 +01:00
David Howells dd7c1ee59a rxrpc: Reinitialise the call ACK and timer state for client reply phase
Clear the ACK reason, ACK timer and resend timer when entering the client
reply phase when the first DATA packet is received.  New ACKs will be
proposed once the data is queued.

The resend timer is no longer relevant and we need to cancel ACKs scheduled
to probe for a lost reply.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 23:49:46 +01:00
David Howells b69d94d799 rxrpc: Include the last reply DATA serial number in the final ACK
In a client call, include the serial number of the last DATA packet of the
reply in the final ACK.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 23:49:46 +01:00
David Howells a7056c5ba6 rxrpc: Send an immediate ACK if we fill in a hole
Send an immediate ACK if we fill in a hole in the buffer left by an
out-of-sequence packet.  This may allow the congestion management in the peer
to avoid a retransmission if packets got reordered on the wire.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 23:49:46 +01:00
David Howells 805b21b929 rxrpc: Send an ACK after every few DATA packets we receive
Send an ACK if we haven't sent one for the last two packets we've received.
This keeps the other end apprised of where we've got to - which is
important if they're doing slow-start.

We do this in recvmsg so that we can dispatch a packet directly without the
need to wake up the background thread.

This should possibly be made configurable in future.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-24 18:05:26 +01:00
David Howells c6672e3fe4 rxrpc: Add a tracepoint to log which packets will be retransmitted
Add a tracepoint to log in rxrpc_resend() which packets will be
retransmitted.  Note that if a positive ACK comes in whilst we have dropped
the lock to retransmit another packet, the actual retransmission may not
happen, though some of the effects will (such as altering the congestion
management).

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 15:49:19 +01:00
David Howells 9c7ad43444 rxrpc: Add tracepoint for ACK proposal
Add a tracepoint to log proposed ACKs, including whether the proposal is
used to update a pending ACK or is discarded in favour of an easlier,
higher priority ACK.

Whilst we're at it, get rid of the rxrpc_acks() function and access the
name array directly.  We do, however, need to validate the ACK reason
number given to trace_rxrpc_rx_ack() to make sure we don't overrun the
array.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 15:49:19 +01:00
David Howells 89b475abdb rxrpc: Add a tracepoint to log injected Rx packet loss
Add a tracepoint to log received packets that get discarded due to Rx
packet loss.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 15:49:19 +01:00
David Howells be832aecc5 rxrpc: Add data Tx tracepoint and adjust Tx ACK tracepoint
Add a tracepoint to log transmission of DATA packets (including loss
injection).

Adjust the ACK transmission tracepoint to include the packet serial number
and to line this up with the DATA transmission display.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 15:49:19 +01:00
David Howells fc7ab6d29a rxrpc: Add a tracepoint for the call timer
Add a tracepoint to log call timer initiation, setting and expiry.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 15:49:19 +01:00
David Howells b86e218e0d rxrpc: Don't call the tx_ack tracepoint if don't generate an ACK
rxrpc_send_call_packet() is invoking the tx_ack tracepoint before it checks
whether there's an ACK to transmit (another thread may jump in and transmit
it).

Fix this by only invoking the tracepoint if we get a valid ACK to transmit.

Further, only allocate a serial number if we're going to actually transmit
something.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 15:49:19 +01:00
David Howells 70790dbe3f rxrpc: Pass the last Tx packet marker in the annotation buffer
When the last packet of data to be transmitted on a call is queued, tx_top
is set and then the RXRPC_CALL_TX_LAST flag is set.  Unfortunately, this
leaves a race in the ACK processing side of things because the flag affects
the interpretation of tx_top and also allows us to start receiving reply
data before we've finished transmitting.

To fix this, make the following changes:

 (1) rxrpc_queue_packet() now sets a marker in the annotation buffer
     instead of setting the RXRPC_CALL_TX_LAST flag.

 (2) rxrpc_rotate_tx_window() detects the marker and sets the flag in the
     same context as the routines that use it.

 (3) rxrpc_end_tx_phase() is simplified to just shift the call state.
     The Tx window must have been rotated before calling to discard the
     last packet.

 (4) rxrpc_receiving_reply() is added to handle the arrival of the first
     DATA packet of a reply to a client call (which is an implicit ACK of
     the Tx phase).

 (5) The last part of rxrpc_input_ack() is reordered to perform Tx
     rotation, then soft-ACK application and then to end the phase if we've
     rotated the last packet.  In the event of a terminal ACK, the soft-ACK
     application will be skipped as nAcks should be 0.

 (6) rxrpc_input_ackall() now has to rotate as well as ending the phase.

In addition:

 (7) Alter the transmit tracepoint to log the rotation of the last packet.

 (8) Remove the no-longer relevant queue_reqack tracepoint note.  The
     ACK-REQUESTED packet header flag is now set as needed when we actually
     transmit the packet and may vary by retransmission.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 15:49:19 +01:00
David Howells 01a88f7f6b rxrpc: Fix call timer
Fix the call timer in the following ways:

 (1) If call->resend_at or call->ack_at are before or equal to the current
     time, then ignore that timeout.

 (2) If call->expire_at is before or equal to the current time, then don't
     set the timer at all (possibly we should queue the call).

 (3) Don't skip modifying the timer if timer_pending() is true.  This
     indicates that the timer is working, not that it has expired and is
     running/waiting to run its expiry handler.

Also call rxrpc_set_timer() to start the call timer going rather than
calling add_timer().

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 15:49:19 +01:00
David Howells be8aa33806 rxrpc: Fix accidental cancellation of scheduled resend by ACK parser
When rxrpc_input_soft_acks() is parsing the soft-ACKs from an ACK packet,
it updates the Tx packet annotations in the annotation buffer.  If a
soft-ACK is an ACK, then we overwrite unack'd, nak'd or to-be-retransmitted
states and that is fine; but if the soft-ACK is an NACK, we overwrite the
to-be-retransmitted with a nak - which isn't.

Instead, we need to let any scheduled retransmission stand if the packet
was NAK'd.

Note that we don't reissue a resend if the annotation is in the
to-be-retransmitted state because someone else must've scheduled the
resend already.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 15:35:45 +01:00
David Howells dfc3da4404 rxrpc: Need to start the resend timer on initial transmission
When a DATA packet has its initial transmission, we may need to start or
adjust the resend timer.  Without this we end up relying on being sent a
NACK to initiate the resend.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 14:05:12 +01:00
David Howells 98dafac569 rxrpc: Use before_eq() and friends to compare serial numbers
before_eq() and friends should be used to compare serial numbers (when not
checking for (non)equality) rather than casting to int, subtracting and
checking the result.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 14:05:08 +01:00
David Howells 90bd684ded rxrpc: Should be using ktime_add_ms() not ktime_add_ns()
ktime_add_ms() should be used to add the resend time (in ms) rather than
ktime_add_ns().

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 13:23:09 +01:00
David Howells c0d058c21c rxrpc: Make sure sendmsg() is woken on call completion
Make sure that sendmsg() gets woken up if the call it is waiting for
completes abnormally.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 13:23:09 +01:00
David Howells 9aff212bd6 rxrpc: Don't send an ACK at the end of service call response transmission
Don't send an IDLE ACK at the end of the transmission of the response to a
service call.  The service end resends DATA packets until the client sends an
ACK that hard-acks all the send data.  At that point, the call is complete.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 13:23:09 +01:00
David Howells b24d2891cf rxrpc: Preset timestamp on Tx sk_buffs
Set the timestamp on sk_buffs holding packets to be transmitted before
queueing them because the moment the packet is on the queue it can be seen
by the retransmission algorithm - which may see a completely random
timestamp.

If the retransmission algorithm sees such a timestamp, it may retransmit
the packet and, in future, tell the congestion management algorithm that
the retransmit timer expired.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-23 13:17:52 +01:00
David Howells fc943f6777 rxrpc: Reduce the number of PING ACKs sent
We don't want to send a PING ACK for every new incoming call as that just
adds to the network traffic.  Instead, we send a PING ACK to the first
three that we receive and then once per second thereafter.

This could probably be made adjustable in future.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-22 08:49:22 +01:00
David Howells 0d4b103c00 rxrpc: Reduce the number of ACK-Requests sent
Reduce the number of ACK-Requests we set on DATA packets that we're sending
to reduce network traffic.  We set the flag on odd-numbered DATA packets to
start off the RTT cache until we have at least three entries in it and then
probe once per second thereafter to keep it topped up.

This could be made tunable in future.

Note that from this point, the RXRPC_REQUEST_ACK flag is set on DATA
packets as we transmit them and not stored statically in the sk_buff.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-22 08:49:20 +01:00
David Howells 50235c4b5a rxrpc: Obtain RTT data by requesting ACKs on DATA packets
In addition to sending a PING ACK to gain RTT data, we can set the
RXRPC_REQUEST_ACK flag on a DATA packet and get a REQUESTED-ACK ACK.  The
ACK packet contains the serial number of the packet it is in response to,
so we can look through the Tx buffer for a matching DATA packet.

This requires that the data packets be stamped with the time of
transmission as a ktime rather than having the resend_at time in jiffies.

This further requires the resend code to do the resend determination in
ktimes and convert to jiffies to set the timer.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-22 08:21:24 +01:00
David Howells 7aa51da7c8 rxrpc: Expedite ping response transmission
Expedite the transmission of a response to a PING ACK by sending it from
sendmsg if one is pending.  We're most likely to see a PING ACK during the
client call Tx phase as the other side may use it to determine a number of
parameters, such as the client's receive window size, the RTT and whether
the client is doing slow start (similar to RFC5681).

If we don't expedite it, it's left to the background processing thread to
transmit.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-22 08:21:24 +01:00
David Howells 8e83134db4 rxrpc: Send pings to get RTT data
Send a PING ACK packet to the peer when we get a new incoming call from a
peer we don't have a record for.  The PING RESPONSE ACK packet will tell us
the following about the peer:

 (1) its receive window size

 (2) its MTU sizes

 (3) its support for jumbo DATA packets

 (4) if it supports slow start (similar to RFC 5681)

 (5) an estimate of the RTT

This is necessary because the peer won't normally send us an ACK until it
gets to the Rx phase and we send it a packet, but we would like to know
some of this information before we start sending packets.

A pair of tracepoints are added so that RTT determination can be observed.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-22 08:21:24 +01:00
David Howells cf1a6474f8 rxrpc: Add per-peer RTT tracker
Add a function to track the average RTT for a peer.  Sources of RTT data
will be added in subsequent patches.

The RTT data will be useful in the future for determining resend timeouts
and for handling the slow-start part of the Rx protocol.

Also add a pair of tracepoints, one to log transmissions to elicit a
response for RTT purposes and one to log responses that contribute RTT
data.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-22 01:26:25 +01:00
David Howells f07373ead4 rxrpc: Add re-sent Tx annotation
Add a Tx-phase annotation for packet buffers to indicate that a buffer has
already been retransmitted.  This will be used by future congestion
management.  Re-retransmissions of a packet don't affect the congestion
window managment in the same way as initial retransmissions.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-22 01:23:50 +01:00
David Howells 5a924b8951 rxrpc: Don't store the rxrpc header in the Tx queue sk_buffs
Don't store the rxrpc protocol header in sk_buffs on the transmit queue,
but rather generate it on the fly and pass it to kernel_sendmsg() as a
separate iov.  This reduces the amount of storage required.

Note that the security header is still stored in the sk_buff as it may get
encrypted along with the data (and doesn't change with each transmission).

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-22 01:23:50 +01:00
David Howells 8a681c3605 rxrpc: Add config to inject packet loss
Add a configuration option to inject packet loss by discarding
approximately every 8th packet received and approximately every 8th DATA
packet transmitted.

Note that no locking is used, but it shouldn't really matter.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 11:24:04 +01:00
David Howells 71f3ca408f rxrpc: Improve skb tracing
Improve sk_buff tracing within AF_RXRPC by the following means:

 (1) Use an enum to note the event type rather than plain integers and use
     an array of event names rather than a big multi ?: list.

 (2) Distinguish Rx from Tx packets and account them separately.  This
     requires the call phase to be tracked so that we know what we might
     find in rxtx_buffer[].

 (3) Add a parameter to rxrpc_{new,see,get,free}_skb() to indicate the
     event type.

 (4) A pair of 'rotate' events are added to indicate packets that are about
     to be rotated out of the Rx and Tx windows.

 (5) A pair of 'lost' events are added, along with rxrpc_lose_skb() for
     packet loss injection recording.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 11:24:04 +01:00
David Howells ba39f3a0ed rxrpc: Remove printks from rxrpc_recvmsg_data() to fix uninit var
Remove _enter/_debug/_leave calls from rxrpc_recvmsg_data() of which one
uses an uninitialised variable.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 11:24:04 +01:00
David Howells 849979051c rxrpc: Add a tracepoint to follow what recvmsg does
Add a tracepoint to follow what recvmsg does within AF_RXRPC.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 11:24:03 +01:00
David Howells 58dc63c998 rxrpc: Add a tracepoint to follow packets in the Rx buffer
Add a tracepoint to follow the life of packets that get added to a call's
receive buffer.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 11:24:03 +01:00
David Howells f3639df2d9 rxrpc: Add a tracepoint to log ACK transmission
Add a tracepoint to log information about ACK transmission.

Signed-off-by: David Howels <dhowells@redhat.com>
2016-09-17 11:24:03 +01:00
David Howells ec71eb9ada rxrpc: Add a tracepoint to log received ACK packets
Add a tracepoint to log information from received ACK packets.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 11:24:03 +01:00
David Howells a124fe3ee5 rxrpc: Add a tracepoint to follow the life of a packet in the Tx buffer
Add a tracepoint to follow the insertion of a packet into the transmit
buffer, its transmission and its rotation out of the buffer.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 11:24:03 +01:00
David Howells 363deeab6d rxrpc: Add connection tracepoint and client conn state tracepoint
Add a pair of tracepoints, one to track rxrpc_connection struct ref
counting and the other to track the client connection cache state.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 11:24:03 +01:00
David Howells a84a46d730 rxrpc: Add some additional call tracing
Add additional call tracepoint points for noting call-connected,
call-released and connection-failed events.

Also fix one tracepoint that was using an integer instead of the
corresponding enum value as the point type.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 11:24:03 +01:00
David Howells a3868bfc8d rxrpc: Print the packet type name in the Rx packet trace
Print a symbolic packet type name for each valid received packet in the
trace output, not just a number.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 11:24:03 +01:00
David Howells 182f505624 rxrpc: Fix the basic transmit DATA packet content size at 1412 bytes
Fix the basic transmit DATA packet content size at 1412 bytes so that they
can be arbitrarily assembled into jumbo packets.

In the future, I'm thinking of moving to keeping a jumbo packet header at
the beginning of each packet in the Tx queue and creating the packet header
on the spot when kernel_sendmsg() is invoked.  That way, jumbo packets can
be assembled on the spur of the moment for (re-)transmission.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 10:54:32 +01:00
David Howells 2311e327cd rxrpc: Be consistent about switch value in rxrpc_send_call_packet()
rxrpc_send_call_packet() should use type in both its switch-statements
rather than using pkt->whdr.type.  This might give the compiler an easier
job of uninitialised variable checking.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 10:54:21 +01:00
David Howells 27d0fc431c rxrpc: Don't transmit an ACK if there's no reason set
Don't transmit an ACK if call->ackr_reason in unset.  There's the
possibility of a race between recvmsg() sending an ACK and the background
processing thread trying to send the same one.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 10:53:55 +01:00
David Howells dfa7d92040 rxrpc: Fix retransmission algorithm
Make the retransmission algorithm use for-loops instead of do-loops and
move the counter increments into the for-statement increment slots.

Though the do-loops are slighly more efficient since there will be at least
one pass through the each loop, the counter increments are harder to get
right as the continue-statements skip them.

Without this, if there are any positive acks within the loop, the do-loop
will cycle forever because the counter increment is never done.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 10:53:21 +01:00
David Howells d01dc4c3c1 rxrpc: Fix the parsing of soft-ACKs
The soft-ACK parser doesn't increment the pointer into the soft-ACK list,
resulting in the first ACK/NACK value being applied to all the relevant
packets in the Tx queue.  This has the potential to miss retransmissions
and cause excessive retransmissions.

Fix this by incrementing the pointer.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 10:53:21 +01:00
David Howells 78883793f8 rxrpc: Fix unexposed client conn release
If the last call on a client connection is release after the connection has
had a bunch of calls allocated but before any DATA packets are sent (so
that it's not yet marked RXRPC_CONN_EXPOSED), an assertion will happen in
rxrpc_disconnect_client_call().

	af_rxrpc: Assertion failed - 1(0x1) >= 2(0x2) is false
	------------[ cut here ]------------
	kernel BUG at ../net/rxrpc/conn_client.c:753!

This is because it's expecting the conn to have been exposed and to have 2
or more refs - but this isn't necessarily the case.

Simply remove the assertion.  This allows the conn to be moved into the
inactive state and deleted if it isn't resurrected before the final put is
called.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 10:53:21 +01:00
David Howells 357f5ef646 rxrpc: Call rxrpc_release_call() on error in rxrpc_new_client_call()
Call rxrpc_release_call() on getting an error in rxrpc_new_client_call()
rather than trying to do the cleanup ourselves.  This isn't a problem,
provided we set RXRPC_CALL_HAS_USERID only if we actually add the call to
the calls tree as cleanup code fragments that would otherwise cause
problems are conditional.

Without this, we miss some of the cleanup.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 10:53:21 +01:00
David Howells 66d58af7f4 rxrpc: Fix the putting of client connections
In rxrpc_put_one_client_conn(), if a connection has RXRPC_CONN_COUNTED set
on it, then it's accounted for in rxrpc_nr_client_conns and may be on
various lists - and this is cleaned up correctly.

However, if the connection doesn't have RXRPC_CONN_COUNTED set on it, then
the put routine returns rather than just skipping the extra bit of cleanup.

Fix this by making the extra bit of clean up conditional instead and always
killing off the connection.

This manifests itself as connections with a zero usage count hanging around
in /proc/net/rxrpc_conns because the connection allocated, but discarded,
due to a race with another process that set up a parallel connection, which
was then shared instead.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 10:53:20 +01:00
David Howells 0360da6db7 rxrpc: Purge the to_be_accepted queue on socket release
Purge the queue of to_be_accepted calls on socket release.  Note that
purging sock_calls doesn't release the ref owned by to_be_accepted.

Probably the sock_calls list is redundant given a purges of the recvmsg_q,
the to_be_accepted queue and the calls tree.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 10:51:54 +01:00
David Howells e6f3afb3fc rxrpc: Record calls that need to be accepted
Record calls that need to be accepted using sk_acceptq_added() otherwise
the backlog counter goes negative because sk_acceptq_removed() is called.
This causes the preallocator to malfunction.

Calls that are preaccepted by AFS within the kernel aren't affected by
this.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 10:51:54 +01:00
David Howells 816c9fce12 rxrpc: Fix handling of the last packet in rxrpc_recvmsg_data()
The code for determining the last packet in rxrpc_recvmsg_data() has been
using the RXRPC_CALL_RX_LAST flag to determine if the rx_top pointer points
to the last packet or not.  This isn't a good idea, however, as the input
code may be running simultaneously on another CPU and that sets the flag
*before* updating the top pointer.

Fix this by the following means:

 (1) Restrict the use of RXRPC_CALL_RX_LAST to the input routines only.
     There's otherwise a synchronisation problem between detecting the flag
     and checking tx_top.  This could probably be dealt with by appropriate
     application of memory barriers, but there's a simpler way.

 (2) Set RXRPC_CALL_RX_LAST after setting rx_top.

 (3) Make rxrpc_rotate_rx_window() consult the flags header field of the
     DATA packet it's about to discard to see if that was the last packet.
     Use this as the basis for ending the Rx phase.  This shouldn't be a
     problem because the recvmsg side of things is guaranteed to see the
     packets in order.

 (4) Make rxrpc_recvmsg_data() return 1 to indicate the end of the data if:

     (a) the packet it has just processed is marked as RXRPC_LAST_PACKET

     (b) the call's Rx phase has been ended.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 10:51:54 +01:00
David Howells 2e2ea51dec rxrpc: Check the return value of rxrpc_locate_data()
Check the return value of rxrpc_locate_data() in rxrpc_recvmsg_data().

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 10:50:49 +01:00
David Howells 4b22457c06 rxrpc: Move the check of rx_pkt_offset from rxrpc_locate_data() to caller
Move the check of rx_pkt_offset from rxrpc_locate_data() to the caller,
rxrpc_recvmsg_data(), so that it's more clear what's going on there.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 10:50:48 +01:00
David Howells fabf920180 rxrpc: Remove some whitespace.
Remove a tab that's on a line that should otherwise be blank.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-17 10:50:15 +01:00
David Howells d19127473a rxrpc: Make IPv6 support conditional on CONFIG_IPV6
Add CONFIG_AF_RXRPC_IPV6 and make the IPv6 support code conditional on it.
This is then made conditional on CONFIG_IPV6.

Without this, the following can be seen:

   net/built-in.o: In function `rxrpc_init_peer':
>> peer_object.c:(.text+0x18c3c8): undefined reference to `ip6_route_output_flags'

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-17 03:58:45 -04:00
David Howells 75b54cb57c rxrpc: Add IPv6 support
Add IPv6 support to AF_RXRPC.  With this, AF_RXRPC sockets can be created:

	service = socket(AF_RXRPC, SOCK_DGRAM, PF_INET6);

instead of:

	service = socket(AF_RXRPC, SOCK_DGRAM, PF_INET);

The AFS filesystem doesn't support IPv6 at the moment, though, since that
requires upgrades to some of the RPC calls.

Note that a good portion of this patch is replacing "%pI4:%u" in print
statements with "%pISpc" which is able to handle both protocols and print
the port.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-13 23:09:13 +01:00
David Howells 1c2bc7b948 rxrpc: Use rxrpc_extract_addr_from_skb() rather than doing this manually
There are two places that want to transmit a packet in response to one just
received and manually pick the address to reply to out of the sk_buff.
Make them use rxrpc_extract_addr_from_skb() instead so that IPv6 is handled
automatically.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-13 23:09:13 +01:00
David Howells aaa31cbc66 rxrpc: Don't specify protocol to when creating transport socket
Pass 0 as the protocol argument when creating the transport socket rather
than IPPROTO_UDP.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-13 23:09:13 +01:00
David Howells cd5892c756 rxrpc: Create an address for sendmsg() to bind unbound socket with
Create an address for sendmsg() to bind unbound socket with rather than
using a completely blank address otherwise the transport socket creation
will fail because it will try to use address family 0.

We use the address family specified in the protocol argument when the
AF_RXRPC socket was created and SOCK_DGRAM as the default.  For anything
else, bind() must be used.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-13 23:09:13 +01:00
David Howells 75e4212639 rxrpc: Correctly initialise, limit and transmit call->rx_winsize
call->rx_winsize should be initialised to the sysctl setting and the sysctl
setting should be limited to the maximum we want to permit.  Further, we
need to place this in the ACK info instead of the sysctl setting.

Furthermore, discard the idea of accepting the subpackets of a jumbo packet
that lie beyond the receive window when the first packet of the jumbo is
within the window.  Just discard the excess subpackets instead.  This
allows the receive window to be opened up right to the buffer size less one
for the dead slot.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-13 22:38:45 +01:00
David Howells 3432a757b1 rxrpc: Fix prealloc refcounting
The preallocated call buffer holds a ref on the calls within that buffer.
The ref was being released in the wrong place - it worked okay for incoming
calls to the AFS cache manager service, but doesn't work right for incoming
calls to a userspace service.

Instead of releasing an extra ref service calls in rxrpc_release_call(),
the ref needs to be released during the acceptance/rejectance process.  To
this end:

 (1) The prealloc ref is now normally released during
     rxrpc_new_incoming_call().

 (2) For preallocated kernel API calls, the kernel API's ref needs to be
     released when the call is discarded on socket close.

 (3) We shouldn't take a second ref in rxrpc_accept_call().

 (4) rxrpc_recvmsg_new_call() needs to get a ref of its own when it adds
     the call to the to_be_accepted socket queue.

In doing (4) above, we would prefer not to put the call's refcount down to
0 as that entails doing cleanup in softirq context, but it's unlikely as
there are several refs held elsewhere, at least one of which must be put by
someone in process context calling rxrpc_release_call().  However, it's not
a problem if we do have to do that.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-13 22:38:37 +01:00
David Howells cbd00891de rxrpc: Adjust the call ref tracepoint to show kernel API refs
Adjust the call ref tracepoint to show references held on a call by the
kernel API separately as much as possible and add an additional trace to at
the allocation point from the preallocation buffer for an incoming call.

Note that this doesn't show the allocation of a client call for the kernel
separately at the moment.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-13 22:38:30 +01:00
David Howells 01fd074224 rxrpc: Allow tx_winsize to grow in response to an ACK
Allow tx_winsize to grow when the ACK info packet shows a larger receive
window at the other end rather than only permitting it to shrink.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-13 22:38:24 +01:00
David Howells 89a80ed4c0 rxrpc: Use skb->len not skb->data_len
skb->len should be used rather than skb->data_len when referring to the
amount of data in a packet.  This will only cause a malfunction in the
following cases:

 (1) We receive a jumbo packet (validation and splitting both are wrong).

 (2) We see if there's extra ACK info in an ACK packet (we think it's not
     there and just ignore it).

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-13 22:36:22 +01:00
David Howells b25de36053 rxrpc: Add missing unlock in rxrpc_call_accept()
Add a missing unlock in rxrpc_call_accept() in the path taken if there's no
call to wake up.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-13 22:36:22 +01:00
David Howells 33b603fda8 rxrpc: Requeue call for recvmsg if more data
rxrpc_recvmsg() needs to make sure that the call it has just been
processing gets requeued for further attention if the buffer has been
filled and there's more data to be consumed.  The softirq producer only
queues the call and wakes the socket if it fills the first slot in the
window, so userspace might end up sleeping forever otherwise, despite there
being data available.

This is not a problem provided the userspace buffer is big enough or it
empties the buffer completely before more data comes in.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-13 22:36:21 +01:00
David Howells 91c2c7b656 rxrpc: The IDLE ACK packet should use rxrpc_idle_ack_delay
The IDLE ACK packet should use the rxrpc_idle_ack_delay setting when the
timer is set for it.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-13 22:36:21 +01:00
David Howells bc4abfcf51 rxrpc: Add missing wakeup on Tx window rotation
We need to wake up the sender when Tx window rotation due to an incoming
ACK makes space in the buffer otherwise the sender is liable to just hang
endlessly.

This problem isn't noticeable if the Tx phase transfers no more than will
fit in a single window or the Tx window rotates fast enough that it doesn't
get full.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-13 22:36:21 +01:00
David Howells 08a39685a7 rxrpc: Make sure we initialise the peer hash key
Peer records created for incoming connections weren't getting their hash
key set.  This meant that incoming calls wouldn't see more than one DATA
packet - which is not a problem for AFS CM calls with small request data
blobs.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-13 22:36:21 +01:00
David Howells 248f219cb8 rxrpc: Rewrite the data and ack handling code
Rewrite the data and ack handling code such that:

 (1) Parsing of received ACK and ABORT packets and the distribution and the
     filing of DATA packets happens entirely within the data_ready context
     called from the UDP socket.  This allows us to process and discard ACK
     and ABORT packets much more quickly (they're no longer stashed on a
     queue for a background thread to process).

 (2) We avoid calling skb_clone(), pskb_pull() and pskb_trim().  We instead
     keep track of the offset and length of the content of each packet in
     the sk_buff metadata.  This means we don't do any allocation in the
     receive path.

 (3) Jumbo DATA packet parsing is now done in data_ready context.  Rather
     than cloning the packet once for each subpacket and pulling/trimming
     it, we file the packet multiple times with an annotation for each
     indicating which subpacket is there.  From that we can directly
     calculate the offset and length.

 (4) A call's receive queue can be accessed without taking locks (memory
     barriers do have to be used, though).

 (5) Incoming calls are set up from preallocated resources and immediately
     made live.  They can than have packets queued upon them and ACKs
     generated.  If insufficient resources exist, DATA packet #1 is given a
     BUSY reply and other DATA packets are discarded).

 (6) sk_buffs no longer take a ref on their parent call.

To make this work, the following changes are made:

 (1) Each call's receive buffer is now a circular buffer of sk_buff
     pointers (rxtx_buffer) rather than a number of sk_buff_heads spread
     between the call and the socket.  This permits each sk_buff to be in
     the buffer multiple times.  The receive buffer is reused for the
     transmit buffer.

 (2) A circular buffer of annotations (rxtx_annotations) is kept parallel
     to the data buffer.  Transmission phase annotations indicate whether a
     buffered packet has been ACK'd or not and whether it needs
     retransmission.

     Receive phase annotations indicate whether a slot holds a whole packet
     or a jumbo subpacket and, if the latter, which subpacket.  They also
     note whether the packet has been decrypted in place.

 (3) DATA packet window tracking is much simplified.  Each phase has just
     two numbers representing the window (rx_hard_ack/rx_top and
     tx_hard_ack/tx_top).

     The hard_ack number is the sequence number before base of the window,
     representing the last packet the other side says it has consumed.
     hard_ack starts from 0 and the first packet is sequence number 1.

     The top number is the sequence number of the highest-numbered packet
     residing in the buffer.  Packets between hard_ack+1 and top are
     soft-ACK'd to indicate they've been received, but not yet consumed.

     Four macros, before(), before_eq(), after() and after_eq() are added
     to compare sequence numbers within the window.  This allows for the
     top of the window to wrap when the hard-ack sequence number gets close
     to the limit.

     Two flags, RXRPC_CALL_RX_LAST and RXRPC_CALL_TX_LAST, are added also
     to indicate when rx_top and tx_top point at the packets with the
     LAST_PACKET bit set, indicating the end of the phase.

 (4) Calls are queued on the socket 'receive queue' rather than packets.
     This means that we don't need have to invent dummy packets to queue to
     indicate abnormal/terminal states and we don't have to keep metadata
     packets (such as ABORTs) around

 (5) The offset and length of a (sub)packet's content are now passed to
     the verify_packet security op.  This is currently expected to decrypt
     the packet in place and validate it.

     However, there's now nowhere to store the revised offset and length of
     the actual data within the decrypted blob (there may be a header and
     padding to skip) because an sk_buff may represent multiple packets, so
     a locate_data security op is added to retrieve these details from the
     sk_buff content when needed.

 (6) recvmsg() now has to handle jumbo subpackets, where each subpacket is
     individually secured and needs to be individually decrypted.  The code
     to do this is broken out into rxrpc_recvmsg_data() and shared with the
     kernel API.  It now iterates over the call's receive buffer rather
     than walking the socket receive queue.

Additional changes:

 (1) The timers are condensed to a single timer that is set for the soonest
     of three timeouts (delayed ACK generation, DATA retransmission and
     call lifespan).

 (2) Transmission of ACK and ABORT packets is effected immediately from
     process-context socket ops/kernel API calls that cause them instead of
     them being punted off to a background work item.  The data_ready
     handler still has to defer to the background, though.

 (3) A shutdown op is added to the AF_RXRPC socket so that the AFS
     filesystem can shut down the socket and flush its own work items
     before closing the socket to deal with any in-progress service calls.

Future additional changes that will need to be considered:

 (1) Make sure that a call doesn't hog the front of the queue by receiving
     data from the network as fast as userspace is consuming it to the
     exclusion of other calls.

 (2) Transmit delayed ACKs from within recvmsg() when we've consumed
     sufficiently more packets to avoid the background work item needing to
     run.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 11:10:12 +01:00
David Howells 00e907127e rxrpc: Preallocate peers, conns and calls for incoming service requests
Make it possible for the data_ready handler called from the UDP transport
socket to completely instantiate an rxrpc_call structure and make it
immediately live by preallocating all the memory it might need.  The idea
is to cut out the background thread usage as much as possible.

[Note that the preallocated structs are not actually used in this patch -
 that will be done in a future patch.]

If insufficient resources are available in the preallocation buffers, it
will be possible to discard the DATA packet in the data_ready handler or
schedule a BUSY packet without the need to schedule an attempt at
allocation in a background thread.

To this end:

 (1) Preallocate rxrpc_peer, rxrpc_connection and rxrpc_call structs to a
     maximum number each of the listen backlog size.  The backlog size is
     limited to a maxmimum of 32.  Only this many of each can be in the
     preallocation buffer.

 (2) For userspace sockets, the preallocation is charged initially by
     listen() and will be recharged by accepting or rejecting pending
     new incoming calls.

 (3) For kernel services {,re,dis}charging of the preallocation buffers is
     handled manually.  Two notifier callbacks have to be provided before
     kernel_listen() is invoked:

     (a) An indication that a new call has been instantiated.  This can be
     	 used to trigger background recharging.

     (b) An indication that a call is being discarded.  This is used when
     	 the socket is being released.

     A function, rxrpc_kernel_charge_accept() is called by the kernel
     service to preallocate a single call.  It should be passed the user ID
     to be used for that call and a callback to associate the rxrpc call
     with the kernel service's side of the ID.

 (4) Discard the preallocation when the socket is closed.

 (5) Temporarily bump the refcount on the call allocated in
     rxrpc_incoming_call() so that rxrpc_release_call() can ditch the
     preallocation ref on service calls unconditionally.  This will no
     longer be necessary once the preallocation is used.

Note that this does not yet control the number of active service calls on a
client - that will come in a later patch.

A future development would be to provide a setsockopt() call that allows a
userspace server to manually charge the preallocation buffer.  This would
allow user call IDs to be provided in advance and the awkward manual accept
stage to be bypassed.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 11:10:12 +01:00
David Howells 49e19ec7d3 rxrpc: Add tracepoints to record received packets and end of data_ready
Add two tracepoints:

 (1) Record the RxRPC protocol header of packets retrieved from the UDP
     socket by the data_ready handler.

 (2) Record the outcome of the data_ready handler.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 11:10:12 +01:00
David Howells 2ab27215ea rxrpc: Remove skb_count from struct rxrpc_call
Remove the sk_buff count from the rxrpc_call struct as it's less useful
once we stop queueing sk_buffs.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 11:10:12 +01:00
David Howells de8d6c7401 rxrpc: Convert rxrpc_local::services to an hlist
Convert the rxrpc_local::services list to an hlist so that it can be
accessed under RCU conditions more readily.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 11:10:11 +01:00
David Howells cf13258fd4 rxrpc: Fix ASSERTCMP and ASSERTIFCMP to handle signed values
Fix ASSERTCMP and ASSERTIFCMP to be able to handle signed values by casting
both parameters to the type of the first before comparing.  Without this,
both values are cast to unsigned long, which means that checks for values
less than zero don't work.

The downside of this is that the state enum values in struct rxrpc_call and
struct rxrpc_connection can't be bitfields as __typeof__ can't handle them.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-08 11:10:11 +01:00
David Howells 5a42976d4f rxrpc: Add tracepoint for working out where aborts happen
Add a tracepoint for working out where local aborts happen.  Each
tracepoint call is labelled with a 3-letter code so that they can be
distinguished - and the DATA sequence number is added too where available.

rxrpc_kernel_abort_call() also takes a 3-letter code so that AFS can
indicate the circumstances when it aborts a call.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-07 16:34:40 +01:00
David Howells e8d6bbb05a rxrpc: Fix returns of call completion helpers
rxrpc_set_call_completion() returns bool, not int, so the ret variable
should match this.

rxrpc_call_completed() and __rxrpc_call_completed() should return the value
of rxrpc_set_call_completion().

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-07 16:34:30 +01:00
David Howells 8d94aa381d rxrpc: Calls shouldn't hold socket refs
rxrpc calls shouldn't hold refs on the sock struct.  This was done so that
the socket wouldn't go away whilst the call was in progress, such that the
call could reach the socket's queues.

However, we can mark the socket as requiring an RCU release and rely on the
RCU read lock.

To make this work, we do:

 (1) rxrpc_release_call() removes the call's call user ID.  This is now
     only called from socket operations and not from the call processor:

	rxrpc_accept_call() / rxrpc_kernel_accept_call()
	rxrpc_reject_call() / rxrpc_kernel_reject_call()
	rxrpc_kernel_end_call()
	rxrpc_release_calls_on_socket()
	rxrpc_recvmsg()

     Though it is also called in the cleanup path of
     rxrpc_accept_incoming_call() before we assign a user ID.

 (2) Pass the socket pointer into rxrpc_release_call() rather than getting
     it from the call so that we can get rid of uninitialised calls.

 (3) Fix call processor queueing to pass a ref to the work queue and to
     release that ref at the end of the processor function (or to pass it
     back to the work queue if we have to requeue).

 (4) Skip out of the call processor function asap if the call is complete
     and don't requeue it if the call is complete.

 (5) Clean up the call immediately that the refcount reaches 0 rather than
     trying to defer it.  Actual deallocation is deferred to RCU, however.

 (6) Don't hold socket refs for allocated calls.

 (7) Use the RCU read lock when queueing a message on a socket and treat
     the call's socket pointer according to RCU rules and check it for
     NULL.

     We also need to use the RCU read lock when viewing a call through
     procfs.

 (8) Transmit the final ACK/ABORT to a client call in rxrpc_release_call()
     if this hasn't been done yet so that we can then disconnect the call.
     Once the call is disconnected, it won't have any access to the
     connection struct and the UDP socket for the call work processor to be
     able to send the ACK.  Terminal retransmission will be handled by the
     connection processor.

 (9) Release all calls immediately on the closing of a socket rather than
     trying to defer this.  Incomplete calls will be aborted.

The call refcount model is much simplified.  Refs are held on the call by:

 (1) A socket's user ID tree.

 (2) A socket's incoming call secureq and acceptq.

 (3) A kernel service that has a call in progress.

 (4) A queued call work processor.  We have to take care to put any call
     that we failed to queue.

 (5) sk_buffs on a socket's receive queue.  A future patch will get rid of
     this.

Whilst we're at it, we can do:

 (1) Get rid of the RXRPC_CALL_EV_RELEASE event.  Release is now done
     entirely from the socket routines and never from the call's processor.

 (2) Get rid of the RXRPC_CALL_DEAD state.  Calls now end in the
     RXRPC_CALL_COMPLETE state.

 (3) Get rid of the rxrpc_call::destroyer work item.  Calls are now torn
     down when their refcount reaches 0 and then handed over to RCU for
     final cleanup.

 (4) Get rid of the rxrpc_call::deadspan timer.  Calls are cleaned up
     immediately they're finished with and don't hang around.
     Post-completion retransmission is handled by the connection processor
     once the call is disconnected.

 (5) Get rid of the dead call expiry setting as there's no longer a timer
     to set.

 (6) rxrpc_destroy_all_calls() can just check that the call list is empty.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-07 15:33:20 +01:00
David Howells 6543ac5235 rxrpc: Use rxrpc_is_service_call() rather than rxrpc_conn_is_service()
Use rxrpc_is_service_call() rather than rxrpc_conn_is_service() if the call
is available just in case call->conn is NULL.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-07 15:30:22 +01:00
David Howells 8b7fac50ab rxrpc: Pass the connection pointer to rxrpc_post_packet_to_call()
Pass the connection pointer to rxrpc_post_packet_to_call() as the call
might get disconnected whilst we're looking at it, but the connection
pointer determined by rxrpc_data_read() is guaranteed by RCU for the
duration of the call.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-07 15:30:22 +01:00
David Howells 278ac0cdd5 rxrpc: Cache the security index in the rxrpc_call struct
Cache the security index in the rxrpc_call struct so that we can get at it
even when the call has been disconnected and the connection pointer
cleared.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-07 15:30:22 +01:00
David Howells f4fdb3525b rxrpc: Use call->peer rather than call->conn->params.peer
Use call->peer rather than call->conn->params.peer to avoid the possibility
of call->conn being NULL and, whilst we're at it, check it for NULL before we
access it.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-07 15:30:22 +01:00
David Howells fff72429c2 rxrpc: Improve the call tracking tracepoint
Improve the call tracking tracepoint by showing more differentiation
between some of the put and get events, including:

  (1) Getting and putting refs for the socket call user ID tree.

  (2) Getting and putting refs for queueing and failing to queue the call
      processor work item.

Note that these aren't necessarily used in this patch, but will be taken
advantage of in future patches.

An enum is added for the event subtype numbers rather than coding them
directly as decimal numbers and a table of 3-letter strings is provided
rather than a sequence of ?: operators.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-07 15:30:22 +01:00
David Howells e796cb4192 rxrpc: Delete unused rxrpc_kernel_free_skb()
Delete rxrpc_kernel_free_skb() as it's unused.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-07 14:43:43 +01:00
David Howells 71a17de307 rxrpc: Whitespace cleanup
Remove some whitespace.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-07 14:43:39 +01:00
David Howells 3dc20f090d rxrpc Move enum rxrpc_command to sendmsg.c
Move enum rxrpc_command to sendmsg.c as it's now only used in that file.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-04 21:41:39 +01:00
David Howells df423a4af1 rxrpc: Rearrange net/rxrpc/sendmsg.c
Rearrange net/rxrpc/sendmsg.c to be in a more logical order.  This makes it
easier to follow and eliminates forward declarations.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-04 21:41:39 +01:00
David Howells 0b58b8a18b rxrpc: Split sendmsg from packet transmission code
Split the sendmsg code from the packet transmission code (mostly to be
found in output.c).

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-04 21:41:39 +01:00
David Howells 090f85deb6 rxrpc: Don't change the epoch
It seems the local epoch should only be changed on boot, so remove the code
that changes it for client connections.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-04 21:41:39 +01:00
David Howells 5f2d9c4438 rxrpc: Randomise epoch and starting client conn ID values
Create a random epoch value rather than a time-based one on startup and set
the top bit to indicate that this is the case.

Also create a random starting client connection ID value.  This will be
incremented from here as new client connections are created.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-04 21:41:39 +01:00
David Howells af338a9ea6 rxrpc: The client call state must be changed before attachment to conn
We must set the client call state to RXRPC_CALL_CLIENT_SEND_REQUEST before
attaching the call to the connection struct, not after, as it's liable to
receive errors and conn aborts as soon as the assignment is made - and
these will cause its state to be changed outside of the initiating thread's
control.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-04 13:10:10 +01:00
David Howells 00b5407e42 rxrpc: Fix uninitialised variable warning
Fix the following uninitialised variable warning:

../net/rxrpc/call_event.c: In function 'rxrpc_process_call':
../net/rxrpc/call_event.c:879:58: warning: 'error' may be used uninitialized in this function [-Wmaybe-uninitialized]
    _debug("post net error %d", error);
                                                          ^

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-02 22:39:44 +01:00
Arnd Bergmann 30787a4170 rxrpc: fix undefined behavior in rxrpc_mark_call_released
gcc -Wmaybe-initialized correctly points out a newly introduced bug
through which we can end up calling rxrpc_queue_call() for a dead
connection:

net/rxrpc/call_object.c: In function 'rxrpc_mark_call_released':
net/rxrpc/call_object.c:600:5: error: 'sched' may be used uninitialized in this function [-Werror=maybe-uninitialized]

This sets the 'sched' variable to zero to restore the previous
behavior.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: f5c17aaeb2 ("rxrpc: Calls should only have one terminal state")
Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-02 22:39:44 +01:00
David Howells d001648ec7 rxrpc: Don't expose skbs to in-kernel users [ver #2]
Don't expose skbs to in-kernel users, such as the AFS filesystem, but
instead provide a notification hook the indicates that a call needs
attention and another that indicates that there's a new call to be
collected.

This makes the following possibilities more achievable:

 (1) Call refcounting can be made simpler if skbs don't hold refs to calls.

 (2) skbs referring to non-data events will be able to be freed much sooner
     rather than being queued for AFS to pick up as rxrpc_kernel_recv_data
     will be able to consult the call state.

 (3) We can shortcut the receive phase when a call is remotely aborted
     because we don't have to go through all the packets to get to the one
     cancelling the operation.

 (4) It makes it easier to do encryption/decryption directly between AFS's
     buffers and sk_buffs.

 (5) Encryption/decryption can more easily be done in the AFS's thread
     contexts - usually that of the userspace process that issued a syscall
     - rather than in one of rxrpc's background threads on a workqueue.

 (6) AFS will be able to wait synchronously on a call inside AF_RXRPC.

To make this work, the following interface function has been added:

     int rxrpc_kernel_recv_data(
		struct socket *sock, struct rxrpc_call *call,
		void *buffer, size_t bufsize, size_t *_offset,
		bool want_more, u32 *_abort_code);

This is the recvmsg equivalent.  It allows the caller to find out about the
state of a specific call and to transfer received data into a buffer
piecemeal.

afs_extract_data() and rxrpc_kernel_recv_data() now do all the extraction
logic between them.  They don't wait synchronously yet because the socket
lock needs to be dealt with.

Five interface functions have been removed:

	rxrpc_kernel_is_data_last()
    	rxrpc_kernel_get_abort_code()
    	rxrpc_kernel_get_error_number()
    	rxrpc_kernel_free_skb()
    	rxrpc_kernel_data_consumed()

As a temporary hack, sk_buffs going to an in-kernel call are queued on the
rxrpc_call struct (->knlrecv_queue) rather than being handed over to the
in-kernel user.  To process the queue internally, a temporary function,
temp_deliver_data() has been added.  This will be replaced with common code
between the rxrpc_recvmsg() path and the kernel_rxrpc_recv_data() path in a
future patch.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-01 16:43:27 -07:00
David Howells 4de48af663 rxrpc: Pass struct socket * to more rxrpc kernel interface functions
Pass struct socket * to more rxrpc kernel interface functions.  They should
be starting from this rather than the socket pointer in the rxrpc_call
struct if they need to access the socket.

I have left:

	rxrpc_kernel_is_data_last()
	rxrpc_kernel_get_abort_code()
	rxrpc_kernel_get_error_number()
	rxrpc_kernel_free_skb()
	rxrpc_kernel_data_consumed()

unmodified as they're all about to be removed (and, in any case, don't
touch the socket).

Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-30 16:07:53 +01:00
David Howells ea82aaec98 rxrpc: Use call->peer rather than going to the connection
Use call->peer rather than call->conn->params.peer as call->conn may become
NULL.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-30 16:07:53 +01:00
David Howells 8324f0bcfb rxrpc: Provide a way for AFS to ask for the peer address of a call
Provide a function so that kernel users, such as AFS, can ask for the peer
address of a call:

   void rxrpc_kernel_get_peer(struct rxrpc_call *call,
			      struct sockaddr_rxrpc *_srx);

In the future the kernel service won't get sk_buffs to look inside.
Further, this allows us to hide any canonicalisation inside AF_RXRPC for
when IPv6 support is added.

Also propagate this through to afs_find_server() and issue a warning if we
can't handle the address family yet.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-30 16:07:53 +01:00
David Howells e34d4234b0 rxrpc: Trace rxrpc_call usage
Add a trace event for debuging rxrpc_call struct usage.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-30 16:02:36 +01:00
David Howells f5c17aaeb2 rxrpc: Calls should only have one terminal state
Condense the terminal states of a call state machine to a single state,
plus a separate completion type value.  The value is then set, along with
error and abort code values, only when the call is transitioned to the
completion state.

Helpers are provided to simplify this.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-30 15:58:31 +01:00
David Howells ccbd3dbe85 rxrpc: Fix a potential NULL-pointer deref in rxrpc_abort_calls
The call pointer in a channel on a connection will be NULL if there's no
active call on that channel.  rxrpc_abort_calls() needs to check for this
before trying to take the call's state_lock.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-30 15:56:12 +01:00
David Howells 45025bceef rxrpc: Improve management and caching of client connection objects
Improve the management and caching of client rxrpc connection objects.
From this point, client connections will be managed separately from service
connections because AF_RXRPC controls the creation and re-use of client
connections but doesn't have that luxury with service connections.

Further, there will be limits on the numbers of client connections that may
be live on a machine.  No direct restriction will be placed on the number
of client calls, excepting that each client connection can support a
maximum of four concurrent calls.

Note that, for a number of reasons, we don't want to simply discard a
client connection as soon as the last call is apparently finished:

 (1) Security is negotiated per-connection and the context is then shared
     between all calls on that connection.  The context can be negotiated
     again if the connection lapses, but that involves holding up calls
     whilst at least two packets are exchanged and various crypto bits are
     performed - so we'd ideally like to cache it for a little while at
     least.

 (2) If a packet goes astray, we will need to retransmit a final ACK or
     ABORT packet.  To make this work, we need to keep around the
     connection details for a little while.

 (3) The locally held structures represent some amount of setup time, to be
     weighed against their occupation of memory when idle.


To this end, the client connection cache is managed by a state machine on
each connection.  There are five states:

 (1) INACTIVE - The connection is not held in any list and may not have
     been exposed to the world.  If it has been previously exposed, it was
     discarded from the idle list after expiring.

 (2) WAITING - The connection is waiting for the number of client conns to
     drop below the maximum capacity.  Calls may be in progress upon it
     from when it was active and got culled.

     The connection is on the rxrpc_waiting_client_conns list which is kept
     in to-be-granted order.  Culled conns with waiters go to the back of
     the queue just like new conns.

 (3) ACTIVE - The connection has at least one call in progress upon it, it
     may freely grant available channels to new calls and calls may be
     waiting on it for channels to become available.

     The connection is on the rxrpc_active_client_conns list which is kept
     in activation order for culling purposes.

 (4) CULLED - The connection got summarily culled to try and free up
     capacity.  Calls currently in progress on the connection are allowed
     to continue, but new calls will have to wait.  There can be no waiters
     in this state - the conn would have to go to the WAITING state
     instead.

 (5) IDLE - The connection has no calls in progress upon it and must have
     been exposed to the world (ie. the EXPOSED flag must be set).  When it
     expires, the EXPOSED flag is cleared and the connection transitions to
     the INACTIVE state.

     The connection is on the rxrpc_idle_client_conns list which is kept in
     order of how soon they'll expire.

A connection in the ACTIVE or CULLED state must have at least one active
call upon it; if in the WAITING state it may have active calls upon it;
other states may not have active calls.

As long as a connection remains active and doesn't get culled, it may
continue to process calls - even if there are connections on the wait
queue.  This simplifies things a bit and reduces the amount of checking we
need do.


There are a couple flags of relevance to the cache:

 (1) EXPOSED - The connection ID got exposed to the world.  If this flag is
     set, an extra ref is added to the connection preventing it from being
     reaped when it has no calls outstanding.  This flag is cleared and the
     ref dropped when a conn is discarded from the idle list.

 (2) DONT_REUSE - The connection should be discarded as soon as possible and
     should not be reused.


This commit also provides a number of new settings:

 (*) /proc/net/rxrpc/max_client_conns

     The maximum number of live client connections.  Above this number, new
     connections get added to the wait list and must wait for an active
     conn to be culled.  Culled connections can be reused, but they will go
     to the back of the wait list and have to wait.

 (*) /proc/net/rxrpc/reap_client_conns

     If the number of desired connections exceeds the maximum above, the
     active connection list will be culled until there are only this many
     left in it.

 (*) /proc/net/rxrpc/idle_conn_expiry

     The normal expiry time for a client connection, provided there are
     fewer than reap_client_conns of them around.

 (*) /proc/net/rxrpc/idle_conn_fast_expiry

     The expedited expiry time, used when there are more than
     reap_client_conns of them around.


Note that I combined the Tx wait queue with the channel grant wait queue to
save space as only one of these should be in use at once.

Note also that, for the moment, the service connection cache still uses the
old connection management code.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-24 15:17:14 +01:00
David Howells 4d028b2c82 rxrpc: Dup the main conn list for the proc interface
The main connection list is used for two independent purposes: primarily it
is used to find connections to reap and secondarily it is used to list
connections in procfs.

Split the procfs list out from the reap list.  This allows us to stop using
the reap list for client connections when they acquire a separate
management strategy from service collections.

The client connections will not be on a management single list, and sometimes
won't be on a management list at all.  This doesn't leave them floating,
however, as they will also be on an rb-tree rooted on the socket so that the
socket can find them to dispatch calls.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-24 15:17:14 +01:00
David Howells df5d8bf70f rxrpc: Make /proc/net/rxrpc_calls safer
Make /proc/net/rxrpc_calls safer by stashing a copy of the peer pointer in
the rxrpc_call struct and checking in the show routine that the peer
pointer, the socket pointer and the local pointer obtained from the socket
pointer aren't NULL before we use them.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-24 15:15:59 +01:00
David Howells 2266ffdef5 rxrpc: Fix conn-based retransmit
If a duplicate packet comes in for a call that has just completed on a
connection's channel then there will be an oops in the data_ready handler
because it tries to examine the connection struct via a call struct (which
we don't have - the pointer is unset).

Since the connection struct pointer is available to us, go direct instead.

Also, the ACK packet to be retransmitted needs three octets of padding
between the soft ack list and the ackinfo.

Fixes: 18bfeba50d ("rxrpc: Perform terminal call ACK/ABORT retransmission from conn processor")
Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-24 13:06:14 +01:00
David Howells 18bfeba50d rxrpc: Perform terminal call ACK/ABORT retransmission from conn processor
Perform terminal call ACK/ABORT retransmission in the connection processor
rather than in the call processor.  With this change, once last_call is
set, no more incoming packets will be routed to the corresponding call or
any earlier calls on that channel (call IDs must only increase on a channel
on a connection).

Further, if a packet's callNumber is before the last_call ID or a packet is
aimed at successfully completed service call then that packet is discarded
and ignored.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-23 16:02:35 +01:00
David Howells 563ea7d5d4 rxrpc: Calculate serial skew on packet reception
Calculate the serial number skew in the data_ready handler when a packet
has been received and a connection looked up.  The skew is cached in the
sk_buff's priority field.

The connection highest received serial number is updated at this time also.
This can be done without locks or atomic instructions because, at this
point, the code is serialised by the socket.

This generates more accurate skew data because if the packet is offloaded
to a work queue before this is determined, more packets may come in,
bumping the highest serial number and thereby increasing the apparent skew.

This also removes some unnecessary atomic ops.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-23 16:02:35 +01:00
David Howells f51b448002 rxrpc: Set connection expiry on idle, not put
Set the connection expiry time when a connection becomes idle rather than
doing this in rxrpc_put_connection().  This makes the put path more
efficient (it is likely to be called occasionally whilst a connection has
outstanding calls because active workqueue items needs to be given a ref).

The time is also preset in the connection allocator in case the connection
never gets used.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-23 16:02:35 +01:00
David Howells df844fd46b rxrpc: Use a tracepoint for skb accounting debugging
Use a tracepoint to log various skb accounting points to help in debugging
refcounting errors.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-23 15:27:24 +01:00
David Howells 01a90a4598 rxrpc: Drop channel number field from rxrpc_call struct
Drop the channel number (channel) field from the rxrpc_call struct to
reduce the size of the call struct.  The field is redundant: if the call is
attached to a connection, the channel can be obtained from there by AND'ing
with RXRPC_CHANNELMASK.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-23 15:27:24 +01:00
David Howells f36b5e444c rxrpc: When clearing a socket, clear the call sets in the right order
When clearing a socket, we should clear the securing-in-progress list
first, then the accept queue and last the main call tree because that's the
order in which a call progresses.  Not that a call should move from the
accept queue to the main tree whilst we're shutting down a socket, but it a
call could possibly move from sequreq to acceptq whilst we're clearing up.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-23 15:27:24 +01:00
David Howells dabe5a7906 rxrpc: Tidy up the rxrpc_call struct a bit
Do a little tidying of the rxrpc_call struct:

 (1) in_clientflag is no longer compared against the value that's in the
     packet, so keeping it in this form isn't necessary.  Use a flag in
     flags instead and provide a pair of wrapper functions.

 (2) We don't read the epoch value, so that can go.

 (3) Move what remains of the data that were used for hashing up in the
     struct to be with the channel number.

 (4) Get rid of the local pointer.  We can get at this via the socket
     struct and we only use this in the procfs viewer.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-23 15:27:24 +01:00
David Howells 26164e77ca rxrpc: Remove RXRPC_CALL_PROC_BUSY
Remove RXRPC_CALL_PROC_BUSY as work queue items are now 100% non-reentrant.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-23 15:27:23 +01:00
David Howells 992c273af9 rxrpc: Free packets discarded in data_ready
Under certain conditions, the data_ready handler will discard a packet.
These need to be freed.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-09 17:13:56 +01:00
David Howells 50fd85a1f9 rxrpc: Fix a use-after-push in data_ready handler
Fix a use of a packet after it has been enqueued onto the packet processing
queue in the data_ready handler.  Once on a call's Rx queue, we mustn't
touch it any more as it may be dequeued and freed by the call processor
running on a work queue.

Save the values we need before enqueuing.

Without this, we can get an oops like the following:

BUG: unable to handle kernel NULL pointer dereference at 000000000000009c
IP: [<ffffffffa01854e8>] rxrpc_fast_process_packet+0x724/0xa11 [af_rxrpc]
PGD 0 
Oops: 0000 [#1] SMP
Modules linked in: kafs(E) af_rxrpc(E) [last unloaded: af_rxrpc]
CPU: 2 PID: 0 Comm: swapper/2 Tainted: G            E   4.7.0-fsdevel+ #1336
Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
task: ffff88040d6863c0 task.stack: ffff88040d68c000
RIP: 0010:[<ffffffffa01854e8>]  [<ffffffffa01854e8>] rxrpc_fast_process_packet+0x724/0xa11 [af_rxrpc]
RSP: 0018:ffff88041fb03a78  EFLAGS: 00010246
RAX: ffffffffffffffff RBX: ffff8803ff195b00 RCX: 0000000000000001
RDX: ffffffffa01854d1 RSI: 0000000000000008 RDI: ffff8803ff195b00
RBP: ffff88041fb03ab0 R08: 0000000000000000 R09: 0000000000000001
R10: ffff88041fb038c8 R11: 0000000000000000 R12: ffff880406874800
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88041fb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000000009c CR3: 0000000001c14000 CR4: 00000000001406e0
Stack:
 ffff8803ff195ea0 ffff880408348800 ffff880406874800 ffff8803ff195b00
 ffff880408348800 ffff8803ff195ed8 0000000000000000 ffff88041fb03af0
 ffffffffa0186072 0000000000000000 ffff8804054da000 0000000000000000
Call Trace:
 <IRQ> 
 [<ffffffffa0186072>] rxrpc_data_ready+0x89d/0xbae [af_rxrpc]
 [<ffffffff814c94d7>] __sock_queue_rcv_skb+0x24c/0x2b2
 [<ffffffff8155c59a>] __udp_queue_rcv_skb+0x4b/0x1bd
 [<ffffffff8155e048>] udp_queue_rcv_skb+0x281/0x4db
 [<ffffffff8155ea8f>] __udp4_lib_rcv+0x7ed/0x963
 [<ffffffff8155ef9a>] udp_rcv+0x15/0x17
 [<ffffffff81531d86>] ip_local_deliver_finish+0x1c3/0x318
 [<ffffffff81532544>] ip_local_deliver+0xbb/0xc4
 [<ffffffff81531bc3>] ? inet_del_offload+0x40/0x40
 [<ffffffff815322a9>] ip_rcv_finish+0x3ce/0x42c
 [<ffffffff81532851>] ip_rcv+0x304/0x33d
 [<ffffffff81531edb>] ? ip_local_deliver_finish+0x318/0x318
 [<ffffffff814dff9d>] __netif_receive_skb_core+0x601/0x6e8
 [<ffffffff814e072e>] __netif_receive_skb+0x13/0x54
 [<ffffffff814e082a>] netif_receive_skb_internal+0xbb/0x17c
 [<ffffffff814e1838>] napi_gro_receive+0xf9/0x1bd
 [<ffffffff8144eb9f>] rtl8169_poll+0x32b/0x4a8
 [<ffffffff814e1c7b>] net_rx_action+0xe8/0x357
 [<ffffffff81051074>] __do_softirq+0x1aa/0x414
 [<ffffffff810514ab>] irq_exit+0x3d/0xb0
 [<ffffffff810184a2>] do_IRQ+0xe4/0xfc
 [<ffffffff81612053>] common_interrupt+0x93/0x93
 <EOI> 
 [<ffffffff814af837>] ? cpuidle_enter_state+0x1ad/0x2be
 [<ffffffff814af832>] ? cpuidle_enter_state+0x1a8/0x2be
 [<ffffffff814af96a>] cpuidle_enter+0x12/0x14
 [<ffffffff8108956f>] call_cpuidle+0x39/0x3b
 [<ffffffff81089855>] cpu_startup_entry+0x230/0x35d
 [<ffffffff810312ea>] start_secondary+0xf4/0xf7

Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-09 17:13:55 +01:00
David Howells 2e7e9758b2 rxrpc: Once packet posted in data_ready, don't retry posting
Once a packet has been posted to a connection in the data_ready handler, we
mustn't try reposting if we then find that the connection is dying as the
refcount has been given over to the dying connection and the packet might
no longer exist.

Losing the packet isn't a problem as the peer will retransmit.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-09 17:13:55 +01:00
David Howells f9dc575725 rxrpc: Don't access connection from call if pointer is NULL
The call state machine processor sets up the message parameters for a UDP
message that it might need to transmit in advance on the basis that there's
a very good chance it's going to have to transmit either an ACK or an
ABORT.  This requires it to look in the connection struct to retrieve some
of the parameters.

However, if the call is complete, the call connection pointer may be NULL
to dissuade the processor from transmitting a message.  However, there are
some situations where the processor is still going to be called - and it's
still going to set up message parameters whether it needs them or not.

This results in a NULL pointer dereference at:

	net/rxrpc/call_event.c:837

To fix this, skip the message pre-initialisation if there's no connection
attached.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-09 17:12:23 +01:00
David Howells 17b963e319 rxrpc: Need to flag call as being released on connect failure
If rxrpc_new_client_call() fails to make a connection, the call record that
it allocated needs to be marked as RXRPC_CALL_RELEASED before it is passed
to rxrpc_put_call() to indicate that it no longer has any attachment to the
AF_RXRPC socket.

Without this, an assertion failure may occur at:

	net/rxrpc/call_object:635

Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-09 17:12:23 +01:00
Arnd Bergmann 55cae7a403 rxrpc: fix uninitialized pointer dereference in debug code
A newly added bugfix caused an uninitialized variable to be
used for printing debug output. This is harmless as long
as the debug setting is disabled, but otherwise leads to an
immediate crash.

gcc warns about this when -Wmaybe-uninitialized is enabled:

net/rxrpc/call_object.c: In function 'rxrpc_release_call':
net/rxrpc/call_object.c:496:163: error: 'sp' may be used uninitialized in this function [-Werror=maybe-uninitialized]

The initialization was removed but one of the users remains.
This adds back the initialization.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 372ee16386 ("rxrpc: Fix races between skb free, ACK generation and replying")
Signed-off-by: David Howells <dhowells@redhat.com>
2016-08-09 10:51:38 +01:00
David Howells 372ee16386 rxrpc: Fix races between skb free, ACK generation and replying
Inside the kafs filesystem it is possible to occasionally have a call
processed and terminated before we've had a chance to check whether we need
to clean up the rx queue for that call because afs_send_simple_reply() ends
the call when it is done, but this is done in a workqueue item that might
happen to run to completion before afs_deliver_to_call() completes.

Further, it is possible for rxrpc_kernel_send_data() to be called to send a
reply before the last request-phase data skb is released.  The rxrpc skb
destructor is where the ACK processing is done and the call state is
advanced upon release of the last skb.  ACK generation is also deferred to
a work item because it's possible that the skb destructor is not called in
a context where kernel_sendmsg() can be invoked.

To this end, the following changes are made:

 (1) kernel_rxrpc_data_consumed() is added.  This should be called whenever
     an skb is emptied so as to crank the ACK and call states.  This does
     not release the skb, however.  kernel_rxrpc_free_skb() must now be
     called to achieve that.  These together replace
     rxrpc_kernel_data_delivered().

 (2) kernel_rxrpc_data_consumed() is wrapped by afs_data_consumed().

     This makes afs_deliver_to_call() easier to work as the skb can simply
     be discarded unconditionally here without trying to work out what the
     return value of the ->deliver() function means.

     The ->deliver() functions can, via afs_data_complete(),
     afs_transfer_reply() and afs_extract_data() mark that an skb has been
     consumed (thereby cranking the state) without the need to
     conditionally free the skb to make sure the state is correct on an
     incoming call for when the call processor tries to send the reply.

 (3) rxrpc_recvmsg() now has to call kernel_rxrpc_data_consumed() when it
     has finished with a packet and MSG_PEEK isn't set.

 (4) rxrpc_packet_destructor() no longer calls rxrpc_hard_ACK_data().

     Because of this, we no longer need to clear the destructor and put the
     call before we free the skb in cases where we don't want the ACK/call
     state to be cranked.

 (5) The ->deliver() call-type callbacks are made to return -EAGAIN rather
     than 0 if they expect more data (afs_extract_data() returns -EAGAIN to
     the delivery function already), and the caller is now responsible for
     producing an abort if that was the last packet.

 (6) There are many bits of unmarshalling code where:

 		ret = afs_extract_data(call, skb, last, ...);
		switch (ret) {
		case 0:		break;
		case -EAGAIN:	return 0;
		default:	return ret;
		}

     is to be found.  As -EAGAIN can now be passed back to the caller, we
     now just return if ret < 0:

 		ret = afs_extract_data(call, skb, last, ...);
		if (ret < 0)
			return ret;

 (7) Checks for trailing data and empty final data packets has been
     consolidated as afs_data_complete().  So:

		if (skb->len > 0)
			return -EBADMSG;
		if (!last)
			return 0;

     becomes:

		ret = afs_data_complete(call, skb, last);
		if (ret < 0)
			return ret;

 (8) afs_transfer_reply() now checks the amount of data it has against the
     amount of data desired and the amount of data in the skb and returns
     an error to induce an abort if we don't get exactly what we want.

Without these changes, the following oops can occasionally be observed,
particularly if some printks are inserted into the delivery path:

general protection fault: 0000 [#1] SMP
Modules linked in: kafs(E) af_rxrpc(E) [last unloaded: af_rxrpc]
CPU: 0 PID: 1305 Comm: kworker/u8:3 Tainted: G            E   4.7.0-fsdevel+ #1303
Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
Workqueue: kafsd afs_async_workfn [kafs]
task: ffff88040be041c0 ti: ffff88040c070000 task.ti: ffff88040c070000
RIP: 0010:[<ffffffff8108fd3c>]  [<ffffffff8108fd3c>] __lock_acquire+0xcf/0x15a1
RSP: 0018:ffff88040c073bc0  EFLAGS: 00010002
RAX: 6b6b6b6b6b6b6b6b RBX: 0000000000000000 RCX: ffff88040d29a710
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88040d29a710
RBP: ffff88040c073c70 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffff88040be041c0 R15: ffffffff814c928f
FS:  0000000000000000(0000) GS:ffff88041fa00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa4595f4750 CR3: 0000000001c14000 CR4: 00000000001406f0
Stack:
 0000000000000006 000000000be04930 0000000000000000 ffff880400000000
 ffff880400000000 ffffffff8108f847 ffff88040be041c0 ffffffff81050446
 ffff8803fc08a920 ffff8803fc08a958 ffff88040be041c0 ffff88040c073c38
Call Trace:
 [<ffffffff8108f847>] ? mark_held_locks+0x5e/0x74
 [<ffffffff81050446>] ? __local_bh_enable_ip+0x9b/0xa1
 [<ffffffff8108f9ca>] ? trace_hardirqs_on_caller+0x16d/0x189
 [<ffffffff810915f4>] lock_acquire+0x122/0x1b6
 [<ffffffff810915f4>] ? lock_acquire+0x122/0x1b6
 [<ffffffff814c928f>] ? skb_dequeue+0x18/0x61
 [<ffffffff81609dbf>] _raw_spin_lock_irqsave+0x35/0x49
 [<ffffffff814c928f>] ? skb_dequeue+0x18/0x61
 [<ffffffff814c928f>] skb_dequeue+0x18/0x61
 [<ffffffffa009aa92>] afs_deliver_to_call+0x344/0x39d [kafs]
 [<ffffffffa009ab37>] afs_process_async_call+0x4c/0xd5 [kafs]
 [<ffffffffa0099e9c>] afs_async_workfn+0xe/0x10 [kafs]
 [<ffffffff81063a3a>] process_one_work+0x29d/0x57c
 [<ffffffff81064ac2>] worker_thread+0x24a/0x385
 [<ffffffff81064878>] ? rescuer_thread+0x2d0/0x2d0
 [<ffffffff810696f5>] kthread+0xf3/0xfb
 [<ffffffff8160a6ff>] ret_from_fork+0x1f/0x40
 [<ffffffff81069602>] ? kthread_create_on_node+0x1cf/0x1cf

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-06 00:08:40 -04:00
Dan Carpenter 7acef60455 rxrpc: checking for IS_ERR() instead of NULL
The rxrpc_lookup_peer() function returns NULL on error, it never returns
error pointers.

Fixes: 8496af50eb ('rxrpc: Use RCU to access a peer's service connection tree')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-15 14:16:25 -07:00
Wei Yongjun 8addc0440b rxrpc: Fix error handling in af_rxrpc_init()
security initialized after alloc workqueue, so we should exit security
before destroy workqueue in the error handing.

Fixes: 648af7fca1 ("rxrpc: Absorb the rxkad security module")
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-12 11:07:38 -07:00
David Howells d440a1ce5d rxrpc: Kill off the call hash table
The call hash table is now no longer used as calls are looked up directly
by channel slot on the connection, so kill it off.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06 11:23:54 +01:00
David Howells 8496af50eb rxrpc: Use RCU to access a peer's service connection tree
Move to using RCU access to a peer's service connection tree when routing
an incoming packet.  This is done using a seqlock to trigger retrying of
the tree walk if a change happened.

Further, we no longer get a ref on the connection looked up in the
data_ready handler unless we queue the connection's work item - and then
only if the refcount > 0.


Note that I'm avoiding the use of a hash table for service connections
because each service connection is addressed by a 62-bit number
(constructed from epoch and connection ID >> 2) that would allow the client
to engage in bucket stuffing, given knowledge of the hash algorithm.
Peers, however, are hashed as the network address is less controllable by
the client.  The total number of peers will also be limited in a future
commit.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06 10:51:14 +01:00
David Howells 1291e9d108 rxrpc: Move data_ready peer lookup into rxrpc_find_connection()
Move the peer lookup done in input.c by data_ready into
rxrpc_find_connection().

Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06 10:51:14 +01:00
David Howells e8d70ce177 rxrpc: Prune the contents of the rxrpc_conn_proto struct
Prune the contents of the rxrpc_conn_proto struct.  Most of the fields aren't
used anymore.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06 10:51:14 +01:00
David Howells 001c112249 rxrpc: Maintain an extra ref on a conn for the cache list
Overhaul the usage count accounting for the rxrpc_connection struct to make
it easier to implement RCU access from the data_ready handler.

The problem is that currently we're using a lock to prevent the garbage
collector from trying to clean up a connection that we're contemplating
unidling.  We could just stick incoming packets on the connection we find,
but we've then got a problem that we may race when dispatching a work item
to process it as we need to give that a ref to prevent the rxrpc_connection
struct from disappearing in the meantime.

Further, incoming packets may get discarded if attached to an
rxrpc_connection struct that is going away.  Whilst this is not a total
disaster - the client will presumably resend - it would delay processing of
the call.  This would affect the AFS client filesystem's service manager
operation.

To this end:

 (1) We now maintain an extra count on the connection usage count whilst it
     is on the connection list.  This mean it is not in use when its
     refcount is 1.

 (2) When trying to reuse an old connection, we only increment the refcount
     if it is greater than 0.  If it is 0, we replace it in the tree with a
     new candidate connection.

 (3) Two connection flags are added to indicate whether or not a connection
     is in the local's client connection tree (used by sendmsg) or the
     peer's service connection tree (used by data_ready).  This makes sure
     that we don't try and remove a connection if it got replaced.

     The flags are tested under lock with the removal operation to prevent
     the reaper from killing the rxrpc_connection struct whilst someone
     else is trying to effect a replacement.

     This could probably be alleviated by using memory barriers between the
     flag set/test and the rb_tree ops.  The rb_tree op would still need to
     be under the lock, however.

 (4) When trying to reap an old connection, we try to flip the usage count
     from 1 to 0.  If it's not 1 at that point, then it must've come back
     to life temporarily and we ignore it.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06 10:50:04 +01:00
David Howells d991b4a32f rxrpc: Move peer lookup from call-accept to new-incoming-conn
Move the lookup of a peer from a call that's being accepted into the
function that creates a new incoming connection.  This will allow us to
avoid incrementing the peer's usage count in some cases in future.

Note that I haven't bother to integrate rxrpc_get_addr_from_skb() with
rxrpc_extract_addr_from_skb() as I'm going to delete the former in the very
near future.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06 10:49:57 +01:00
David Howells 7877a4a4bd rxrpc: Split service connection code out into its own file
Split the service-specific connection code out into into its own file.  The
client-specific code has already been split out.  This will leave just the
common code in the original file.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06 10:49:35 +01:00
David Howells c6d2b8d764 rxrpc: Split client connection code out into its own file
Split the client-specific connection code out into its own file.  It will
behave somewhat differently from the service-specific connection code, so
it makes sense to separate them.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06 10:43:52 +01:00
David Howells a1399f8bb0 rxrpc: Call channels should have separate call number spaces
Each channel on a connection has a separate, independent number space from
which to allocate callNumber values.  It is entirely possible, for example,
to have a connection with four active calls, each with call number 1.

Note that the callNumber values for any particular channel don't have to
start at 1, but they are supposed to increment monotonically for that
channel from a client's perspective and may not be reused once the call
number is transmitted (until the epoch cycles all the way back round).

Currently, however, call numbers are allocated on a per-connection basis
and, further, are held in an rb-tree.  The rb-tree is redundant as the four
channel pointers in the rxrpc_connection struct are entirely capable of
pointing to all the calls currently in progress on a connection.

To this end, make the following changes:

 (1) Handle call number allocation independently per channel.

 (2) Get rid of the conn->calls rb-tree.  This is overkill as a connection
     may have a maximum of four calls in progress at any one time.  Use the
     pointers in the channels[] array instead, indexed by the channel
     number from the packet.

 (3) For each channel, save the result of the last call that was in
     progress on that channel in conn->channels[] so that the final ACK or
     ABORT packet can be replayed if necessary.  Any call earlier than that
     is just ignored.  If we've seen the next call number in a packet, the
     last one is most definitely defunct.

 (4) When generating a RESPONSE packet for a connection, the call number
     counter for each channel must be included in it.

 (5) When parsing a RESPONSE packet for a connection, the call number
     counters contained therein should be used to set the minimum expected
     call numbers on each channel.

To do in future commits:

 (1) Replay terminal packets based on the last call stored in
     conn->channels[].

 (2) Connections should be retired before the callNumber space on any
     channel runs out.

 (3) A server is expected to disregard or reject any new incoming call that
     has a call number less than the current call number counter.  The call
     number counter for that channel must be advanced to the new call
     number.

     Note that the server cannot just require that the next call that it
     sees on a channel be exactly the call number counter + 1 because then
     there's a scenario that could cause a problem: The client transmits a
     packet to initiate a connection, the network goes out, the server
     sends an ACK (which gets lost), the client sends an ABORT (which also
     gets lost); the network then reconnects, the client then reuses the
     call number for the next call (it doesn't know the server already saw
     the call number), but the server thinks it already has the first
     packet of this call (it doesn't know that the client doesn't know that
     it saw the call number the first time).

Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06 10:43:52 +01:00
David Howells 30b515f4d1 rxrpc: Access socket accept queue under right lock
The socket's accept queue (socket->acceptq) should be accessed under
socket->call_lock, not under the connection lock.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06 10:43:51 +01:00
David Howells dee46364ce rxrpc: Add RCU destruction for connections and calls
Add RCU destruction for connections and calls as the RCU lookup from the
transport socket data_ready handler is going to come along shortly.

Whilst we're at it, move the cleanup workqueue flushing and RCU barrierage
into the destruction code for the objects that need it (locals and
connections) and add the extra RCU barrier required for connection cleanup.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06 10:43:51 +01:00
David Howells e653cfe49c rxrpc: Release a call's connection ref on call disconnection
When a call is disconnected, clear the call's pointer to the connection and
release the associated ref on that connection.  This means that the call no
longer pins the connection and the connection can be discarded even before
the call is.

As the code currently stands, the call struct is effectively pinned by
userspace until userspace has enacted a recvmsg() to retrieve the final
call state as sk_buffs on the receive queue pin the call to which they're
related because:

 (1) The rxrpc_call struct contains the userspace ID that recvmsg() has to
     include in the control message buffer to indicate which call is being
     referred to.  This ID must remain valid until the terminal packet is
     completely read and must be invalidated immediately at that point as
     userspace is entitled to immediately reuse it.

 (2) The final ACK to the reply to a client call isn't sent until the last
     data packet is entirely read (it's probably worth altering this in
     future to be send the ACK as soon as all the data has been received).


This change requires a bit of rearrangement to make sure that the call
isn't going to try and access the connection again after protocol
completion:

 (1) Delete the error link earlier when we're releasing the call.  Possibly
     network errors should be distributed via connections at the cost of
     adding in an access to the rxrpc_connection struct.

 (2) Remove the call from the connection's call tree before disconnecting
     the call.  The call tree needs to be removed anyway and incoming
     packets delivered by channel pointer instead.

 (3) The release call event should be considered last after all other
     events have been processed so that we don't need access to the
     connection again.

 (4) Move the channel_lock taking from rxrpc_release_call() to
     rxrpc_disconnect_call() where it will be required in future.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06 10:43:51 +01:00
David Howells d1e858c5a3 rxrpc: Fix handling of connection failure in client call creation
If rxrpc_connect_call() fails during the creation of a client connection,
there are two bugs that we can hit that need fixing:

 (1) The call state should be moved to RXRPC_CALL_DEAD before the call
     cleanup phase is invoked.  If not, this can cause an assertion failure
     later.

 (2) call->link should be reinitialised after being deleted in
     rxrpc_new_client_call() - which otherwise leads to a failure later
     when the call cleanup attempts to delete the link again.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06 10:43:51 +01:00
David Howells 2c4579e4b1 rxrpc: Move usage count getting into rxrpc_queue_conn()
Rather than calling rxrpc_get_connection() manually before calling
rxrpc_queue_conn(), do it inside the queue wrapper.

This allows us to do some important fixes:

 (1) If the usage count is 0, do nothing.  This prevents connections from
     being reanimated once they're dead.

 (2) If rxrpc_queue_work() fails because the work item is already queued,
     retract the usage count increment which would otherwise be lost.

 (3) Don't take a ref on the connection in the work function.  By passing
     the ref through the work item, this is unnecessary.  Doing it in the
     work function is too late anyway.  Previously, connection-directed
     packets held a ref on the connection, but that's not really the best
     idea.

And another useful changes:

 (*) Don't need to take a refcount on the connection in the data_ready
     handler unless we invoke the connection's work item.  We're using RCU
     there so that's otherwise redundant.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06 10:43:51 +01:00
David Howells eb9b9d2275 rxrpc: Check that the client conns cache is empty before module removal
Check that the client conns cache is empty before module removal and bug if
not, listing any offending connections that are still present.  Unfortunately,
if there are connections still around, then the transport socket is still
unexpectedly open and active, so we can't just unallocate the connections.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06 10:43:51 +01:00
David Howells bba304db34 rxrpc: Turn connection #defines into enums and put outside struct def
Turn the connection event and state #define lists into enums and move
outside of the struct definition.

Whilst we're at it, change _SERVER to _SERVICE in those identifiers and add
EV_ into the event name to distinguish them from flags and states.

Also add a symbol indicating the number of states and use that in the state
text array.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06 10:43:51 +01:00
David Howells 5acbee4648 rxrpc: Provide queuing helper functions
Provide queueing helper functions so that the queueing of local and
connection objects can be fixed later.

The issue is that a ref on the object needs to be passed to the work queue,
but the act of queueing the object may fail because the object is already
queued.  Testing the queuedness of an object before hand doesn't work
because there can be a race with someone else trying to queue it.  What
will have to be done is to adjust the refcount depending on the result of
the queue operation.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06 10:43:05 +01:00
Herbert Xu a263629da5 rxrpc: Avoid using stack memory in SG lists in rxkad
rxkad uses stack memory in SG lists which would not work if stacks were
allocated from vmalloc memory.  In fact, in most cases this isn't even
necessary as the stack memory ends up getting copied over to kmalloc
memory.

This patch eliminates all the unnecessary stack memory uses by supplying
the final destination directly to the crypto API.  In two instances where a
temporary buffer is actually needed we also switch use a scratch area in
the rxrpc_call struct (only one DATA packet will be being secured or
verified at a time).

Finally there is no need to split a split-page buffer into two SG entries
so code dealing with that has been removed.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06 10:43:05 +01:00
David Howells 689f4c646d rxrpc: Check the source of a packet to a client conn
When looking up a client connection to which to route a packet, we need to
check that the packet came from the correct source so that a peer can't try
to muck around with another peer's connection.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06 10:43:05 +01:00
David Howells 88b99d0b7a rxrpc: Fix some sparse errors
Fix the following sparse errors:

../net/rxrpc/conn_object.c:77:17: warning: incorrect type in assignment (different base types)
../net/rxrpc/conn_object.c:77:17:    expected restricted __be32 [usertype] call_id
../net/rxrpc/conn_object.c:77:17:    got unsigned int [unsigned] [usertype] call_id
../net/rxrpc/conn_object.c:84:21: warning: restricted __be32 degrades to integer
../net/rxrpc/conn_object.c:86:26: warning: restricted __be32 degrades to integer
../net/rxrpc/conn_object.c:357:15: warning: incorrect type in assignment (different base types)
../net/rxrpc/conn_object.c:357:15:    expected restricted __be32 [usertype] epoch
../net/rxrpc/conn_object.c:357:15:    got unsigned int [unsigned] [usertype] epoch
../net/rxrpc/conn_object.c:369:21: warning: restricted __be32 degrades to integer
../net/rxrpc/conn_object.c:371:26: warning: restricted __be32 degrades to integer
../net/rxrpc/conn_object.c:411:21: warning: restricted __be32 degrades to integer
../net/rxrpc/conn_object.c:413:26: warning: restricted __be32 degrades to integer

Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-06 10:43:05 +01:00
David Howells ac5d26836c rxrpc: Fix processing of authenticated/encrypted jumbo packets
When a jumbo packet is being split up and processed, the crypto checksum
for each split-out packet is in the jumbo header and needs placing in the
reconstructed packet header.

When the code was changed to keep the stored copy of the packet header in
host byte order, this reconstruction was missed.

Found with sparse with CF=-D__CHECK_ENDIAN__:

    ../net/rxrpc/input.c:479:33: warning: incorrect type in assignment (different base types)
    ../net/rxrpc/input.c:479:33:    expected unsigned short [unsigned] [usertype] _rsvd
    ../net/rxrpc/input.c:479:33:    got restricted __be16 [addressable] [usertype] _rsvd

Fixes: 0d12f8a402 ("rxrpc: Keep the skb private record of the Rx header in host byte order")
Signed-off-by: David Howells <dhowells@redhat.com>
2016-07-01 08:35:02 +01:00
David Howells aa390bbe21 rxrpc: Kill off the rxrpc_transport struct
The rxrpc_transport struct is now redundant, given that the rxrpc_peer
struct is now per peer port rather than per peer host, so get rid of it.

Service connection lists are transferred to the rxrpc_peer struct, as is
the conn_lock.  Previous patches moved the client connection handling out
of the rxrpc_transport struct and discarded the connection bundling code.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22 14:00:23 +01:00
David Howells 999b69f892 rxrpc: Kill the client connection bundle concept
Kill off the concept of maintaining a bundle of connections to a particular
target service to increase the number of call slots available for any
beyond four for that service (there are four call slots per connection).

This will make cleaning up the connection handling code easier and
facilitate removal of the rxrpc_transport struct.  Bundling can be
reintroduced later if necessary.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22 09:20:55 +01:00
David Howells 5627cc8b96 rxrpc: Provide more refcount helper functions
Provide refcount helper functions for connections so that the code doesn't
touch local or connection usage counts directly.

Also make it such that local and peer put functions can take a NULL
pointer.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22 09:17:51 +01:00
David Howells 985a5c824a rxrpc: Make rxrpc_send_packet() take a connection not a transport
Make rxrpc_send_packet() take a connection not a transport as part of the
phasing out of the rxrpc_transport struct.

Whilst we're at it, rename the function to rxrpc_send_data_packet() to
differentiate it from the other packet sending functions.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22 09:17:51 +01:00
David Howells f4e7da8cde rxrpc: Calls displayed in /proc may in future lack a connection
Allocated rxrpc calls displayed in /proc/net/rxrpc_calls may in future be
on the proc list before they're connected or after they've been
disconnected - in which case they may not have a pointer to a connection
struct that can be used to get data from there.

Deal with this by using stuff from the call struct in preference where
possible and printing "no_connection" rather than a peer address if no
connection is assigned.

This change also has the added bonus that the service ID is now taken from
the call rather the connection which will allow per-call service upgrades
to be shown - something required for AuriStor server compatibility.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22 09:17:51 +01:00
David Howells f4552c2d24 rxrpc: Validate the net address given to rxrpc_kernel_begin_call()
Validate the net address given to rxrpc_kernel_begin_call() before using
it.

Whilst this should be mostly unnecessary for in-kernel users, it does clear
the tail of the address struct in case we want to hash or compare the whole
thing.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22 09:17:51 +01:00
David Howells 4a3388c803 rxrpc: Use IDR to allocate client conn IDs on a machine-wide basis
Use the IDR facility to allocate client connection IDs on a machine-wide
basis so that each client connection has a unique identifier.  When the
connection ID space wraps, we advance the epoch by 1, thereby effectively
having a 62-bit ID space.  The IDR facility is then used to look up client
connections during incoming packet routing instead of using an rbtree
rooted on the transport.

This change allows for the removal of the transport in the future and also
means that client connections can be looked up directly in the data-ready
handler by connection ID.

The ID management code is placed in a new file, conn-client.c, to which all
the client connection-specific code will eventually move.

Note that the IDR tree gets very expensive on memory if the connection IDs
are widely scattered throughout the number space, so we shall need to
retire connections that have, say, an ID more than four times the maximum
number of client conns away from the current allocation point to try and
keep the IDs concentrated.  We will also need to retire connections from an
old epoch.

Also note that, for the moment, a pointer to the transport has to be passed
through into the ID allocation function so that we can take a BH lock to
prevent a locking issue against in-BH lookup of client connections.  This
will go away later when RCU is used for server connections also.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22 09:10:02 +01:00
David Howells b3f575043f rxrpc: rxrpc_connection_lock shouldn't be a BH lock, but conn_lock is
rxrpc_connection_lock shouldn't be accessed as a BH-excluding lock.  It's
only accessed in a few places and none of those are in BH-context.

rxrpc_transport::conn_lock, however, *is* a BH-excluding lock and should be
accessed so consistently.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22 09:10:02 +01:00
David Howells 42886ffe77 rxrpc: Pass sk_buff * rather than rxrpc_host_header * to functions
Pass a pointer to struct sk_buff rather than struct rxrpc_host_header to
functions so that they can in the future get at transport protocol parameters
rather than just RxRPC parameters.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22 09:10:01 +01:00
David Howells cc8feb8edd rxrpc: Fix exclusive connection handling
"Exclusive connections" are meant to be used for a single client call and
then scrapped.  The idea is to limit the use of the negotiated security
context.  The current code, however, isn't doing this: it is instead
restricting the socket to a single virtual connection and doing all the
calls over that.

This is changed such that the socket no longer maintains a special virtual
connection over which it will do all the calls, but rather gets a new one
each time a new exclusive call is made.

Further, using a socket option for this is a poor choice.  It should be
done on sendmsg with a control message marker instead so that calls can be
marked exclusive individually.  To that end, add RXRPC_EXCLUSIVE_CALL
which, if passed to sendmsg() as a control message element, will cause the
call to be done on an single-use connection.

The socket option (RXRPC_EXCLUSIVE_CONNECTION) still exists and, if set,
will override any lack of RXRPC_EXCLUSIVE_CALL being specified so that
programs using the setsockopt() will appear to work the same.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22 09:10:00 +01:00
David Howells 85f32278bd rxrpc: Replace conn->trans->{local,peer} with conn->params.{local,peer}
Replace accesses of conn->trans->{local,peer} with
conn->params.{local,peer} thus making it easier for a future commit to
remove the rxrpc_transport struct.

This also reduces the number of memory accesses involved.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22 09:10:00 +01:00
David Howells 19ffa01c9c rxrpc: Use structs to hold connection params and protocol info
Define and use a structure to hold connection parameters.  This makes it
easier to pass multiple connection parameters around.

Define and use a structure to hold protocol information used to hash a
connection for lookup on incoming packet.  Most of these fields will be
disposed of eventually, including the duplicate local pointer.

Whilst we're at it rename "proto" to "family" when referring to a protocol
family.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22 09:09:59 +01:00
Arnd Bergmann 2f9f9f5210 rxrpc: fix uninitialized variable use
Hashing the peer key was introduced for AF_INET, but gcc
warns about the rxrpc_peer_hash_key function returning uninitialized
data for any other value of srx->transport.family:

net/rxrpc/peer_object.c: In function 'rxrpc_peer_hash_key':
net/rxrpc/peer_object.c:57:15: error: 'p' may be used uninitialized in this function [-Werror=maybe-uninitialized]

Assuming that nothing else can be set here, this changes the
function to just return zero in case of an unknown address
family.

Fixes: be6e6707f6 ("rxrpc: Rework peer object handling to use hash table and RCU")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22 09:09:58 +01:00
Dan Carpenter 0e4699e4a3 rxrpc: checking for IS_ERR() instead of NULL
rxrpc_lookup_peer_rcu() and rxrpc_lookup_peer() return NULL on error, never
error pointers, so IS_ERR() can't be used.

Fix three callers of those functions.

Fixes: be6e6707f6 ('rxrpc: Rework peer object handling to use hash table and RCU')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-22 09:09:58 +01:00
David Howells 4f95dd78a7 rxrpc: Rework local endpoint management
Rework the local RxRPC endpoint management.

Local endpoint objects are maintained in a flat list as before.  This
should be okay as there shouldn't be more than one per open AF_RXRPC socket
(there can be fewer as local endpoints can be shared if their local service
ID is 0 and they share the same local transport parameters).

Changes:

 (1) Local endpoints may now only be shared if they have local service ID 0
     (ie. they're not being used for listening).

     This prevents a scenario where process A is listening of the Cache
     Manager port and process B contacts a fileserver - which may then
     attempt to send CM requests back to B.  But if A and B are sharing a
     local endpoint, A will get the CM requests meant for B.

 (2) We use a mutex to handle lookups and don't provide RCU-only lookups
     since we only expect to access the list when opening a socket or
     destroying an endpoint.

     The local endpoint object is pointed to by the transport socket's
     sk_user_data for the life of the transport socket - allowing us to
     refer to it directly from the sk_data_ready and sk_error_report
     callbacks.

 (3) atomic_inc_not_zero() now exists and can be used to only share a local
     endpoint if the last reference hasn't yet gone.

 (4) We can remove rxrpc_local_lock - a spinlock that had to be taken with
     BH processing disabled given that we assume sk_user_data won't change
     under us.

 (5) The transport socket is shut down before we clear the sk_user_data
     pointer so that we can be sure that the transport socket's callbacks
     won't be invoked once the RCU destruction is scheduled.

 (6) Local endpoints have a work item that handles both destruction and
     event processing.  The means that destruction doesn't then need to
     wait for event processing.  The event queues can then be cleared after
     the transport socket is shut down.

 (7) Local endpoints are no longer available for resurrection beyond the
     life of the sockets that had them open.  As soon as their last ref
     goes, they are scheduled for destruction and may not have their usage
     count moved from 0.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-15 15:38:17 +01:00
David Howells 875636163b rxrpc: Separate local endpoint event handling out into its own file
Separate local endpoint event handling out into its own file preparatory to
overhauling the object management aspect (which remains in the original
file).

Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-15 15:37:12 +01:00
David Howells f66d749019 rxrpc: Use the peer record to distribute network errors
Use the peer record to distribute network errors rather than the transport
object (which I want to get rid of).  An error from a particular peer
terminates all calls on that peer.

For future consideration:

 (1) For ICMP-induced errors it might be worth trying to extract the RxRPC
     header from the offending packet, if one is returned attached to the
     ICMP packet, to better direct the error.

     This may be overkill, though, since an ICMP packet would be expected
     to be relating to the destination port, machine or network.  RxRPC
     ABORT and BUSY packets give notice at RxRPC level.

 (2) To also abort connection-level communications (such as CHALLENGE
     packets) where indicted by an error - but that requires some revamping
     of the connection event handling first.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-15 10:15:16 +01:00
David Howells fe77d5fc5a rxrpc: Do a little bit of tidying in the ICMP processing
Do a little bit of tidying in the ICMP processing code.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-15 10:15:09 +01:00
David Howells 1c1df86fad rxrpc: Don't assume anything about the address in an ICMP packet
Don't assume anything about the address in an ICMP packet in
rxrpc_error_report() as the address may not be IPv4 in future, especially
since we're just printing these details.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-15 10:15:08 +01:00
David Howells 1a70c05bad rxrpc: Break MTU determination from ICMP into its own function
Break MTU determination from ICMP out into its own function to reduce the
complexity of the error report handler.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-15 10:15:06 +01:00
David Howells abe89ef0ed rxrpc: Rename rxrpc_UDP_error_report() to rxrpc_error_report()
Rename rxrpc_UDP_error_report() to rxrpc_error_report() as it might get
called for something other than UDP.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-15 10:14:37 +01:00
David Howells be6e6707f6 rxrpc: Rework peer object handling to use hash table and RCU
Rework peer object handling to use a hash table instead of a flat list and
to use RCU.  Peer objects are no longer destroyed by passing them to a
workqueue to process, but rather are just passed to the RCU garbage
collector as kfree'able objects.

The hash function uses the local endpoint plus all the components of the
remote address, except for the RxRPC service ID.  Peers thus represent a
UDP port on the remote machine as contacted by a UDP port on this machine.

The RCU read lock is used to handle non-creating lookups so that they can
be called from bottom half context in the sk_error_report handler without
having to lock the hash table against modification.
rxrpc_lookup_peer_rcu() *does* take a reference on the peer object as in
the future, this will be passed to a work item for error distribution in
the error_report path and this function will cease being used in the
data_ready path.

Creating lookups are done under spinlock rather than mutex as they might be
set up due to an external stimulus if the local endpoint is a server.

Captured network error messages (ICMP) are handled with respect to this
struct and MTU size and RTT are cached here.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-15 10:12:33 +01:00
David Howells 0d81a51ab9 rxrpc: Update the comments in ar-internal.h to reflect renames
Update the section comments in ar-internal.h that indicate the locations of
the referenced items to reflect the renames done to the .c files in
net/rxrpc/.

This also involves some rearrangement to reflect keep the sections in order
of filename.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-13 13:38:51 +01:00
David Howells 8c3e34a4ff rxrpc: Rename files matching ar-*.c to git rid of the "ar-" prefix
Rename files matching net/rxrpc/ar-*.c to get rid of the "ar-" prefix.
This will aid splitting those files by making easier to come up with new
names.

Note that the not all files are simply renamed from ar-X.c to X.c.  The
following exceptions are made:

 (*) ar-call.c -> call_object.c
     ar-ack.c -> call_event.c

     call_object.c is going to contain the core of the call object
     handling.  Call event handling is all going to be in call_event.c.

 (*) ar-accept.c -> call_accept.c

     Incoming call handling is going to be here.

 (*) ar-connection.c -> conn_object.c
     ar-connevent.c -> conn_event.c

     The former file is going to have the basic connection object handling,
     but there will likely be some differentiation between client
     connections and service connections in additional files later.  The
     latter file will have all the connection-level event handling.

 (*) ar-local.c -> local_object.c

     This will have the local endpoint object handling code.  The local
     endpoint event handling code will later be split out into
     local_event.c.

 (*) ar-peer.c -> peer_object.c

     This will have the peer endpoint object handling code.  Peer event
     handling code will be placed in peer_event.c (for the moment, there is
     none).

 (*) ar-error.c -> peer_event.c

     This will become the peer event handling code, though for the moment
     it's actually driven from the local endpoint's perspective.

Note that I haven't renamed ar-transport.c to transport_object.c as the
intention is to delete it when the rxrpc_transport struct is excised.

The only file that actually has its contents changed is net/rxrpc/Makefile.

net/rxrpc/ar-internal.h will need its section marker comments updating, but
I'll do that in a separate patch to make it easier for git to follow the
history across the rename.  I may also want to rename ar-internal.h at some
point - but that would mean updating all the #includes and I'd rather do
that in a separate step.

Signed-off-by: David Howells <dhowells@redhat.com.
2016-06-13 12:16:05 +01:00
David Howells 0e119b41b7 rxrpc: Limit the listening backlog
Limit the socket incoming call backlog queue size so that a remote client
can't pump in sufficient new calls that the server runs out of memory.  Note
that this is partially theoretical at the moment since whilst the number of
calls is limited, the number of packets trying to set up new calls is not.
This will be addressed in a later patch.

If the caller of listen() specifies a backlog INT_MAX, then they get the
current maximum; anything else greater than max_backlog or anything
negative incurs EINVAL.

The limit on the maximum queue size can be set by:

	echo N >/proc/sys/net/rxrpc/max_backlog

where 4<=N<=32.

Further, set the default backlog to 0, requiring listen() to be called
before we start actually queueing new calls.  Whilst this kind of is a
change in the UAPI, the caller can't actually *accept* new calls anyway
unless they've first called listen() to put the socket into the LISTENING
state - thus the aforementioned new calls would otherwise just sit there,
eating up kernel memory.  (Note that sockets that don't have a non-zero
service ID bound don't get incoming calls anyway.)

Given that the default backlog is now 0, make the AFS filesystem call
kernel_listen() to set the maximum backlog for itself.

Possible improvements include:

 (1) Trimming a too-large backlog to max_backlog when listen is called.

 (2) Trimming the backlog value whenever the value is used so that changes
     to max_backlog are applied to an open socket automatically.  Note that
     the AFS filesystem opens one socket and keeps it open for extended
     periods, so would miss out on changes to max_backlog.

 (3) Having a separate setting for the AFS filesystem.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-10 18:14:47 -07:00
David Howells bc6e1ea32c rxrpc: Trim line-terminal whitespace
Trim line-terminal whitespace in net/rxrpc/

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-10 18:14:47 -07:00
David S. Miller 1578b0a5e9 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	net/sched/act_police.c
	net/sched/sch_drr.c
	net/sched/sch_hfsc.c
	net/sched/sch_prio.c
	net/sched/sch_red.c
	net/sched/sch_tbf.c

In net-next the drop methods of the packet schedulers got removed, so
the bug fixes to them in 'net' are irrelevant.

A packet action unload crash fix conflicts with the addition of the
new firstuse timestamp.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-10 11:52:24 -07:00
David Howells 2341e07757 rxrpc: Simplify connect() implementation and simplify sendmsg() op
Simplify the RxRPC connect() implementation.  It will just note the
destination address it is given, and if a sendmsg() comes along with no
address, this will be assigned as the address.  No transport struct will be
held internally, which will allow us to remove this later.

Simplify sendmsg() also.  Whilst a call is active, userspace refers to it
by a private unique user ID specified in a control message.  When sendmsg()
sees a user ID that doesn't map to an extant call, it creates a new call
for that user ID and attempts to add it.  If, when we try to add it, the
user ID is now registered, we now reject the message with -EEXIST.  We
should never see this situation unless two threads are racing, trying to
create a call with the same ID - which would be an error.

It also isn't required to provide sendmsg() with an address - provided the
control message data holds a user ID that maps to a currently active call.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-09 23:30:12 -07:00
Wu Fengguang fa54cc70ed rxrpc: fix ptr_ret.cocci warnings
net/rxrpc/rxkad.c:1165:1-3: WARNING: PTR_ERR_OR_ZERO can be used

 Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR

Generated by: scripts/coccinelle/api/ptr_ret.cocci

CC: David Howells <dhowells@redhat.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-07 15:30:21 -07:00
Joe Perches 9b6d53985f rxrpc: Use pr_<level> and pr_fmt, reduce object size a few KB
Use the more common kernel logging style and reduce object size.

The logging message prefix changes from a mixture of
"RxRPC:" and "RXRPC:" to "af_rxrpc: ".

$ size net/rxrpc/built-in.o*
   text	   data	    bss	    dec	    hex	filename
  64172	   1972	   8304	  74448	  122d0	net/rxrpc/built-in.o.new
  67512	   1972	   8304	  77788	  12fdc	net/rxrpc/built-in.o.old

Miscellanea:

o Consolidate the ASSERT macros to use a single pr_err call with
  decimal and hexadecimal output and a stringified #OP argument

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-03 19:41:31 -04:00
Linus Torvalds f4f27d0028 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris:
 "Highlights:

   - A new LSM, "LoadPin", from Kees Cook is added, which allows forcing
     of modules and firmware to be loaded from a specific device (this
     is from ChromeOS, where the device as a whole is verified
     cryptographically via dm-verity).

     This is disabled by default but can be configured to be enabled by
     default (don't do this if you don't know what you're doing).

   - Keys: allow authentication data to be stored in an asymmetric key.
     Lots of general fixes and updates.

   - SELinux: add restrictions for loading of kernel modules via
     finit_module().  Distinguish non-init user namespace capability
     checks.  Apply execstack check on thread stacks"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (48 commits)
  LSM: LoadPin: provide enablement CONFIG
  Yama: use atomic allocations when reporting
  seccomp: Fix comment typo
  ima: add support for creating files using the mknodat syscall
  ima: fix ima_inode_post_setattr
  vfs: forbid write access when reading a file into memory
  fs: fix over-zealous use of "const"
  selinux: apply execstack check on thread stacks
  selinux: distinguish non-init user namespace capability checks
  LSM: LoadPin for kernel file loading restrictions
  fs: define a string representation of the kernel_read_file_id enumeration
  Yama: consolidate error reporting
  string_helpers: add kstrdup_quotable_file
  string_helpers: add kstrdup_quotable_cmdline
  string_helpers: add kstrdup_quotable
  selinux: check ss_initialized before revalidating an inode label
  selinux: delay inode label lookup as long as possible
  selinux: don't revalidate an inode's label when explicitly setting it
  selinux: Change bool variable name to index.
  KEYS: Add KEYCTL_DH_COMPUTE command
  ...
2016-05-19 09:21:36 -07:00
Eric Dumazet 02c223470c net: udp: rename UDP_INC_STATS_BH()
Rename UDP_INC_STATS_BH() to __UDP_INC_STATS(),
and UDP6_INC_STATS_BH() to __UDP6_INC_STATS()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-27 22:48:23 -04:00
David Howells 5ac7eace2d KEYS: Add a facility to restrict new links into a keyring
Add a facility whereby proposed new links to be added to a keyring can be
vetted, permitting them to be rejected if necessary.  This can be used to
block public keys from which the signature cannot be verified or for which
the signature verification fails.  It could also be used to provide
blacklisting.

This affects operations like add_key(), KEYCTL_LINK and KEYCTL_INSTANTIATE.

To this end:

 (1) A function pointer is added to the key struct that, if set, points to
     the vetting function.  This is called as:

	int (*restrict_link)(struct key *keyring,
			     const struct key_type *key_type,
			     unsigned long key_flags,
			     const union key_payload *key_payload),

     where 'keyring' will be the keyring being added to, key_type and
     key_payload will describe the key being added and key_flags[*] can be
     AND'ed with KEY_FLAG_TRUSTED.

     [*] This parameter will be removed in a later patch when
     	 KEY_FLAG_TRUSTED is removed.

     The function should return 0 to allow the link to take place or an
     error (typically -ENOKEY, -ENOPKG or -EKEYREJECTED) to reject the
     link.

     The pointer should not be set directly, but rather should be set
     through keyring_alloc().

     Note that if called during add_key(), preparse is called before this
     method, but a key isn't actually allocated until after this function
     is called.

 (2) KEY_ALLOC_BYPASS_RESTRICTION is added.  This can be passed to
     key_create_or_update() or key_instantiate_and_link() to bypass the
     restriction check.

 (3) KEY_FLAG_TRUSTED_ONLY is removed.  The entire contents of a keyring
     with this restriction emplaced can be considered 'trustworthy' by
     virtue of being in the keyring when that keyring is consulted.

 (4) key_alloc() and keyring_alloc() take an extra argument that will be
     used to set restrict_link in the new key.  This ensures that the
     pointer is set before the key is published, thus preventing a window
     of unrestrictedness.  Normally this argument will be NULL.

 (5) As a temporary affair, keyring_restrict_trusted_only() is added.  It
     should be passed to keyring_alloc() as the extra argument instead of
     setting KEY_FLAG_TRUSTED_ONLY on a keyring.  This will be replaced in
     a later patch with functions that look in the appropriate places for
     authoritative keys.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-04-11 22:37:37 +01:00
David Howells e0e4d82f3b rxrpc: Create a null security type and get rid of conditional calls
Create a null security type for security index 0 and get rid of all
conditional calls to the security operations.  We expect normally to be
using security, so this should be of little negative impact.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-11 15:34:41 -04:00
David Howells 648af7fca1 rxrpc: Absorb the rxkad security module
Absorb the rxkad security module into the af_rxrpc module so that there's
only one module file.  This avoids a circular dependency whereby rxkad pins
af_rxrpc and cached connections pin rxkad but can't be manually evicted
(they will expire eventually and cease pinning).

With this change, af_rxrpc can just be unloaded, despite having cached
connections.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-11 15:34:41 -04:00
David Howells 6dd050f88d rxrpc: Don't assume transport address family and size when using it
Don't assume transport address family and size when using the peer address
to send a packet.  Instead, use the start of the transport address rather
than any particular element of the union and use the transport address
length noted inside the sockaddr_rxrpc struct.

This will be necessary when IPv6 support is introduced.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-11 15:34:41 -04:00
David Howells 843099cac0 rxrpc: Don't pass gfp around in incoming call handling functions
Don't pass gfp around in incoming call handling functions, but rather hard
code it at the points where we actually need it since the value comes from
within the rxrpc driver and is always the same.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-11 15:34:41 -04:00
David Howells dc44b3a09a rxrpc: Differentiate local and remote abort codes in structs
In the rxrpc_connection and rxrpc_call structs, there's one field to hold
the abort code, no matter whether that value was generated locally to be
sent or was received from the peer via an abort packet.

Split the abort code fields in two for cleanliness sake and add an error
field to hold the Linux error number to the rxrpc_call struct too
(sometimes this is generated in a context where we can't return it to
userspace directly).

Furthermore, add a skb mark to indicate a packet that caused a local abort
to be generated so that recvmsg() can pick up the correct abort code.  A
future addition will need to be to indicate to userspace the difference
between aborts via a control message.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-11 15:34:40 -04:00
David Howells 5b3e87f19e rxrpc: Static arrays of strings should be const char *const[]
Static arrays of strings should be const char *const[].

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-11 15:34:40 -04:00
David Howells 8e688d9c16 rxrpc: Move some miscellaneous bits out into their own file
Move some miscellaneous bits out into their own file to make it easier to
split the call handling.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-11 15:34:40 -04:00
David Howells 8f7e6e75d3 rxrpc: Disable a debugging statement that has been left enabled.
Disable a debugging statement that has been left enabled

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-11 15:34:40 -04:00
Willem de Bruijn 4d0fc73ebe rxrpc: do not pull udp headers on receive
Commit e6afc8ace6 modified the udp receive path by pulling the udp
header before queuing an skbuff onto the receive queue.

Rxrpc also calls skb_recv_datagram to dequeue an skb from a udp
socket. Modify this receive path to also no longer expect udp
headers.

Fixes: e6afc8ace6 ("udp: remove headers from UDP packets before queueing")

Signed-off-by: Willem de Bruijn <willemb@google.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-11 15:31:33 -04:00