Commit Graph

231 Commits

Author SHA1 Message Date
Thomas Graf 482a8524f8 [NETLINK]: Generic netlink family
The generic netlink family builds on top of netlink and provides
simplifies access for the less demanding netlink users. It solves
the problem of protocol numbers running out by introducing a so
called controller taking care of id management and name resolving.

Generic netlink modules register themself after filling out their
id card (struct genl_family), after successful registration the
modules are able to register callbacks to command numbers by
filling out a struct genl_ops and calling genl_register_op(). The
registered callbacks are invoked with attributes parsed making
life of simple modules a lot easier.

Although generic netlink modules can request static identifiers,
it is recommended to use GENL_ID_GENERATE and to let the controller
assign a unique identifier to the module. Userspace applications
will then ask the controller and lookup the idenfier by the module
name.

Due to the current multicast implementation of netlink, the number
of generic netlink modules is restricted to 1024 to avoid wasting
memory for the per socket multiacst subscription bitmask.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-10 02:26:41 +01:00
Thomas Graf 82ace47a72 [NETLINK]: Generic netlink receive queue processor
Introduces netlink_run_queue() to handle the receive queue of
a netlink socket in a generic way. Processes as much as there
was in the queue upon entry and invokes a callback function
for each netlink message found. The callback function may
refuse a message by returning a negative error code but setting
the error pointer to 0 in which case netlink_run_queue() will
return with a qlen != 0.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-10 02:26:40 +01:00
Thomas Graf a8f74b2288 [NETLINK]: Make netlink_callback->done() optional
Most netlink families make no use of the done() callback, making
it optional gets rid of all unnecessary dummy implementations.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-10 02:26:40 +01:00
Thomas Graf bfa83a9e03 [NETLINK]: Type-safe netlink messages/attributes interface
Introduces a new type-safe interface for netlink message and
attributes handling. The interface is fully binary compatible
with the old interface towards userspace. Besides type safety,
this interface features attribute validation capabilities,
simplified message contstruction, and documentation.

The resulting netlink code should be smaller, less error prone
and easier to understand.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-10 02:26:40 +01:00
Linus Torvalds 236fa08168 Merge master.kernel.org:/pub/scm/linux/kernel/git/acme/net-2.6.15 2005-10-28 08:50:37 -07:00
Al Viro 7d877f3bda [PATCH] gfp_t: net/*
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-28 08:16:47 -07:00
Jayachandran C ea7ce40649 [NETLINK]: Remove dead code in af_netlink.c
Remove the variable nlk & call to nlk_sk as it does not have any side effect.

Signed-off-by: Jayachandran C. <c.jayachandran at gmail.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2005-10-26 00:54:46 -02:00
Al Viro dd0fc66fb3 [PATCH] gfp flags annotations - part 1
- added typedef unsigned int __nocast gfp_t;

 - replaced __nocast uses for gfp flags with gfp_t - it gives exactly
   the same warnings as far as sparse is concerned, doesn't change
   generated code (from gcc point of view we replaced unsigned int with
   typedef) and documents what's going on far better.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-08 15:00:57 -07:00
Patrick McHardy 513c250000 [NETLINK]: Don't prevent creating sockets when no kernel socket is registered
This broke the pam audit module which includes an incorrect check for
-ENOENT instead of -EPROTONOTSUPP.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-09-06 15:43:59 -07:00
Arnaldo Carvalho de Melo 6ed8a48582 [NETLINK]: Fix sparse warnings
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 16:01:35 -07:00
Patrick McHardy 066286071d [NETLINK]: Add "groups" argument to netlink_kernel_create
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 16:01:11 -07:00
Patrick McHardy 9a4595bc7e [NETLINK]: Add set/getsockopt options to support more than 32 groups
NETLINK_ADD_MEMBERSHIP/NETLINK_DROP_MEMBERSHIP are used to join/leave
groups, NETLINK_PKTINFO is used to enable nl_pktinfo control messages
for received packets to get the extended destination group number.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 16:01:07 -07:00
Patrick McHardy f7fa9b10ed [NETLINK]: Support dynamic number of multicast groups per netlink family
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 16:01:02 -07:00
Patrick McHardy ab33a1711c [NETLINK]: Return -EPROTONOSUPPORT in netlink_create() if no kernel socket is registered
This is necessary for dynamic number of netlink groups to make sure we know
the number of possible groups before bind() is called. With this change pure
userspace communication using unused netlink protocols becomes impossible.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 16:00:58 -07:00
Patrick McHardy d629b836d1 [NETLINK]: Use group numbers instead of bitmasks internally
Using the group number allows increasing the number of groups without
beeing limited by the size of the bitmask. It introduces one limitation
for netlink users: messages can't be broadcasted to multiple groups anymore,
however this feature was never used inside the kernel.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 16:00:49 -07:00
Patrick McHardy 77247bbb30 [NETLINK]: Fix module refcounting problems
Use-after-free: the struct proto_ops containing the module pointer
is freed when a socket with pid=0 is released, which besides for kernel
sockets is true for all unbound sockets.

Module refcount leak: when the kernel socket is closed before all user
sockets have been closed the proto_ops struct for this family is
replaced by the generic one and the module refcount can't be dropped.

The second problem can't be solved cleanly using module refcounting in the
generic socket code, so this patch adds explicit refcounting to
netlink_create/netlink_release.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 16:00:45 -07:00
Patrick McHardy db08052979 [NETLINK]: Remove unused groups member from struct netlink_skb_parms
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 16:00:39 -07:00
Harald Welte 4fdb3bb723 [NETLINK]: Add properly module refcounting for kernel netlink sockets.
- Remove bogus code for compiling netlink as module
- Add module refcounting support for modules implementing a netlink
  protocol
- Add support for autoloading modules that implement a netlink protocol
  as soon as someone opens a socket for that protocol

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 15:35:08 -07:00
Victor Fusco 37da647d99 [NETLINK]: Fix "nocast type" warnings
From: Victor Fusco <victor@cetuc.puc-rio.br>

Fix the sparse warning "implicit cast to nocast type"

Signed-off-by: Victor Fusco <victor@cetuc.puc-rio.br>
Signed-off-by: Domen Puncer <domen@coderock.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-07-18 13:35:43 -07:00
David S. Miller b03efcfb21 [NET]: Transform skb_queue_len() binary tests into skb_queue_empty()
This is part of the grand scheme to eliminate the qlen
member of skb_queue_head, and subsequently remove the
'list' member of sk_buff.

Most users of skb_queue_len() want to know if the queue is
empty or not, and that's trivially done with skb_queue_empty()
which doesn't use the skb_queue_head->qlen member and instead
uses the queue list emptyness as the test.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-07-08 14:57:23 -07:00
David S. Miller d470e3b483 [NETLINK]: Fix two socket hashing bugs.
1) netlink_release() should only decrement the hash entry
   count if the socket was actually hashed.

   This was causing hash->entries to underflow, which
   resulting in all kinds of troubles.

   On 64-bit systems, this would cause the following
   conditional to erroneously trigger:

	err = -ENOMEM;
	if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX))
		goto err;

2) netlink_autobind() needs to propagate the error return from
   netlink_insert().  Otherwise, callers will not see the error
   as they should and thus try to operate on a socket with a zero pid,
   which is very bad.

   However, it should not propagate -EBUSY.  If two threads race
   to autobind the socket, that is fine.  This is consistent with the
   autobind behavior in other protocols.

   So bug #1 above, combined with this one, resulted in hangs
   on netlink_sendmsg() calls to the rtnetlink socket.  We'd try
   to do the user sendmsg() with the socket's pid set to zero,
   later we do a socket lookup using that pid (via the value we
   stashed away in NETLINK_CB(skb).pid), but that won't give us the
   user socket, it will give us the rtnetlink socket.  So when we
   try to wake up the receive queue, we dive back into rtnetlink_rcv()
   which tries to recursively take the rtnetlink semaphore.

Thanks to Jakub Jelink for providing backtraces.  Also, thanks to
Herbert Xu for supplying debugging patches to help track this down,
and also finding a mistake in an earlier version of this fix.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-26 15:31:51 -07:00
Thomas Graf 1797754ea7 [NETLINK]: Introduce NLMSG_NEW macro to better handle netlink flags
Introduces a new macro NLMSG_NEW which extends NLMSG_PUT but takes
a flags argument. NLMSG_PUT stays there for compatibility but now
calls NLMSG_NEW with flags == 0. NLMSG_PUT_ANSWER is renamed to
NLMSG_NEW_ANSWER which now also takes a flags argument.

Also converts the users of NLMSG_PUT_ANSWER to use NLMSG_NEW_ANSWER
and fixes the two direct users of __nlmsg_put to either provide
the flags or use NLMSG_NEW(_ANSWER).

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18 22:53:48 -07:00
Tommy S. Christensen aa1c6a6f7f [NETLINK]: Defer socket destruction a bit
In netlink_broadcast() we're sending shared skb's to netlink listeners
when possible (saves some copying). This is OK, since we hold the only
other reference to the skb.

However, this implies that we must drop our reference on the skb, before
allowing a receiving socket to disappear. Otherwise, the socket buffer
accounting is disrupted.

Signed-off-by: Tommy S. Christensen <tommy.christensen@tpack.net>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-05-19 13:07:32 -07:00
Tommy S. Christensen 68acc024ea [NETLINK]: Move broadcast skb_orphan to the skb_get path.
Cloned packets don't need the orphan call.

Signed-off-by: Tommy S. Christensen <tommy.christensen@tpack.net>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-05-19 13:06:35 -07:00
Tommy S. Christensen db61ecc335 [NETLINK]: Fix race with recvmsg().
This bug causes:

assertion (!atomic_read(&sk->sk_rmem_alloc)) failed at net/netlink/af_netlink.c (122)

What's happening is that:

1) The skb is sent to socket 1.
2) Someone does a recvmsg on socket 1 and drops the ref on the skb.
   Note that the rmalloc is not returned at this point since the
   skb is still referenced.
3) The same skb is now sent to socket 2.

This version of the fix resurrects the skb_orphan call that was moved
out, last time we had 'shared-skb troubles'. It is practically a no-op
in the common case, but still prevents the possible race with recvmsg.

Signed-off-by: Tommy S. Christensen <tommy.christensen@tpack.net>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-05-19 12:46:59 -07:00
David Woodhouse bfd4bda097 Merge with master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6.git 2005-05-05 13:59:37 +01:00
Herbert Xu 96c3602343 [NETLINK]: cb_lock does not needs ref count on sk
Here is a little optimisation for the cb_lock used by netlink_dump.
While fixing that race earlier, I noticed that the reference count
held by cb_lock is completely useless.  The reason is that in order
to obtain the protection of the reference count, you have to take
the cb_lock.  But the only way to take the cb_lock is through
dereferencing the socket.

That is, you must already possess a reference count on the socket
before you can take advantage of the reference count held by cb_lock.
As a corollary, we can remve the reference count held by the cb_lock.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-05-03 14:43:27 -07:00
Andrew Morton 54e0f520e7 netlink audit warning fix
scumbags!

net/netlink/af_netlink.c: In function `netlink_sendmsg':
net/netlink/af_netlink.c:908: warning: implicit declaration of function `audit_get_loginuid'

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2005-04-30 07:07:04 +01:00
Serge Hallyn c94c257c88 Add audit uid to netlink credentials
Most audit control messages are sent over netlink.In order to properly
log the identity of the sender of audit control messages, we would like
to add the loginuid to the netlink_creds structure, as per the attached
patch.

Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2005-04-29 16:27:17 +01:00
Al Viro b453257f05 [PATCH] kill gratitious includes of major.h under net/*
A lot of places in there are including major.h for no reason whatsoever.
Removed.  And yes, it still builds. 

The history of that stuff is often amusing.  E.g.  for net/core/sock.c
the story looks so, as far as I've been able to reconstruct it: we used
to need major.h in net/socket.c circa 1.1.early.  In 1.1.13 that need
had disappeared, along with register_chrdev(SOCKET_MAJOR, "socket",
&net_fops) in sock_init().  Include had not.  When 1.2 -> 1.3 reorg of
net/* had moved a lot of stuff from net/socket.c to net/core/sock.c,
this crap had followed... 

Signed-off-by: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-25 18:32:13 -07:00
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00