Commit Graph

31 Commits

Author SHA1 Message Date
Herbert Xu d523a328fb [INET]: Fix inet_diag dead-lock regression
The inet_diag register fix broke inet_diag module loading because the
loaded module had to take the same mutex that's already held by the
loader in order to register the new handler.

This patch fixes it by introducing a separate mutex to protect the
handling of handlers.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-12-03 15:51:25 +11:00
Pavel Emelyanov 076931989f [INET]: Fix inet_diag register vs rcv race
The following race is possible when one cpu unregisters the handler
while other one is trying to receive a message and call this one:

CPU1:                                                 CPU2:
inet_diag_rcv()                                       inet_diag_unregister()
  mutex_lock(&inet_diag_mutex);
  netlink_rcv_skb(skb, &inet_diag_rcv_msg);
    if (inet_diag_table[nlh->nlmsg_type] == 
                               NULL) /* false handler is still registered */
    ...
    netlink_dump_start(idiagnl, skb, nlh,
                           inet_diag_dump, NULL);
           cb = kzalloc(sizeof(*cb), GFP_KERNEL);
                   /* sleep here freeing memory 
                    * or preempt
                    * or sleep later on nlk->cb_mutex
                    */
                                                         spin_lock(&inet_diag_register_lock);
                                                         inet_diag_table[type] = NULL;
    ...                                                  spin_unlock(&inet_diag_register_lock);
                                                         synchronize_rcu();
                                                         /* CPU1 is sleeping - RCU quiescent
                                                          * state is passed
                                                          */
                                                         return;
    /* inet_diag_dump is finally called: */
    inet_diag_dump()
      handler = inet_diag_table[cb->nlh->nlmsg_type];
      BUG_ON(handler == NULL); 
      /* OOPS! While we slept the unregister has set
       * handler to NULL :(
       */

Grep showed, that the register/unregister functions are called
from init/fini module callbacks for tcp_/dccp_diag, so it's OK
to use the inet_diag_mutex to synchronize manipulations with the
inet_diag_table and the access to it.

Besides, as Herbert pointed out, asynchronous dumps should hold 
this mutex as well, and thus, we provide the mutex as cb_mutex one.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-11-30 00:08:14 +11:00
Eric Dumazet 230140cffa [INET]: Remove per bucket rwlock in tcp/dccp ehash table.
As done two years ago on IP route cache table (commit
22c047ccbc) , we can avoid using one
lock per hash bucket for the huge TCP/DCCP hash tables.

On a typical x86_64 platform, this saves about 2MB or 4MB of ram, for
litle performance differences. (we hit a different cache line for the
rwlock, but then the bucket cache line have a better sharing factor
among cpus, since we dirty it less often). For netstat or ss commands
that want a full scan of hash table, we perform fewer memory accesses.

Using a 'small' table of hashed rwlocks should be more than enough to
provide correct SMP concurrency between different buckets, without
using too much memory. Sizing of this table depends on
num_possible_cpus() and various CONFIG settings.

This patch provides some locking abstraction that may ease a future
work using a different model for TCP/DCCP table.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-11-07 04:15:11 -08:00
Jean Delvare 305e1e9691 [INET]: Let inet_diag and friends autoload
By adding module aliases to inet_diag, tcp_diag and dccp_diag, we let
them load automatically as needed. This makes tools like "ss" run
faster.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-22 02:59:54 -07:00
Denis V. Lunev cd40b7d398 [NET]: make netlink user -> kernel interface synchronious
This patch make processing netlink user -> kernel messages synchronious.
This change was inspired by the talk with Alexey Kuznetsov about current
netlink messages processing. He says that he was badly wrong when introduced 
asynchronious user -> kernel communication.

The call netlink_unicast is the only path to send message to the kernel
netlink socket. But, unfortunately, it is also used to send data to the
user.

Before this change the user message has been attached to the socket queue
and sk->sk_data_ready was called. The process has been blocked until all
pending messages were processed. The bad thing is that this processing
may occur in the arbitrary process context.

This patch changes nlk->data_ready callback to get 1 skb and force packet
processing right in the netlink_unicast.

Kernel -> user path in netlink_unicast remains untouched.

EINTR processing for in netlink_run_queue was changed. It forces rtnl_lock
drop, but the process remains in the cycle until the message will be fully
processed. So, there is no need to use this kludges now.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Acked-by: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 21:15:29 -07:00
Herbert Xu 0cfad07555 [NETLINK]: Avoid pointer in netlink_run_queue
I was looking at Patrick's fix to inet_diag and it occured
to me that we're using a pointer argument to return values
unnecessarily in netlink_run_queue.  Changing it to return
the value will allow the compiler to generate better code
since the value won't have to be memory-backed.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:51:24 -07:00
Eric W. Biederman b4b510290b [NET]: Support multiple network namespaces with netlink
Each netlink socket will live in exactly one network namespace,
this includes the controlling kernel sockets.

This patch updates all of the existing netlink protocols
to only support the initial network namespace.  Request
by clients in other namespaces will get -ECONREFUSED.
As they would if the kernel did not have the support for
that netlink protocol compiled in.

As each netlink protocol is updated to be multiple network
namespace safe it can register multiple kernel sockets
to acquire a presence in the rest of the network namespaces.

The implementation in af_netlink is a simple filter implementation
at hash table insertion and hash table look up time.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:49:09 -07:00
Ilpo Järvinen 172589ccdd [NET]: DIV_ROUND_UP cleanup (part two)
Hopefully captured all single statement cases under net/. I'm
not too sure if there is some policy about #includes that are
"guaranteed" (ie., in the current tree) to be available through
some other #included header, so I just added linux/kernel.h to
each changed file that didn't #include it previously.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-10-10 16:48:37 -07:00
Patrick McHardy 0a9c730144 [INET_DIAG]: Fix oops in netlink_rcv_skb
netlink_run_queue() doesn't handle multiple processes processing the
queue concurrently. Serialize queue processing in inet_diag to fix
a oops in netlink_rcv_skb caused by netlink_run_queue passing a
NULL for the skb.

BUG: unable to handle kernel NULL pointer dereference at virtual address 00000054
[349587.500454]  printing eip:
[349587.500457] c03318ae
[349587.500459] *pde = 00000000
[349587.500464] Oops: 0000 [#1]
[349587.500466] PREEMPT SMP
[349587.500474] Modules linked in: w83627hf hwmon_vid i2c_isa
[349587.500483] CPU:    0
[349587.500485] EIP:    0060:[<c03318ae>]    Not tainted VLI
[349587.500487] EFLAGS: 00010246   (2.6.22.3 #1)
[349587.500499] EIP is at netlink_rcv_skb+0xa/0x7e
[349587.500506] eax: 00000000   ebx: 00000000   ecx: c148d2a0   edx: c0398819
[349587.500510] esi: 00000000   edi: c0398819   ebp: c7a21c8c   esp: c7a21c80
[349587.500517] ds: 007b   es: 007b   fs: 00d8  gs: 0033  ss: 0068
[349587.500521] Process oidentd (pid: 17943, ti=c7a20000 task=cee231c0 task.ti=c7a20000)
[349587.500527] Stack: 00000000 c7a21cac f7c8ba78 c7a21ca4 c0331962 c0398819 f7c8ba00 0000004c
[349587.500542]        f736f000 c7a21cb4 c03988e3 00000001 f7c8ba00 c7a21cc4 c03312a5 0000004c
[349587.500558]        f7c8ba00 c7a21cd4 c0330681 f7c8ba00 e4695280 c7a21d00 c03307c6 7fffffff
[349587.500578] Call Trace:
[349587.500581]  [<c010361a>] show_trace_log_lvl+0x1c/0x33
[349587.500591]  [<c01036d4>] show_stack_log_lvl+0x8d/0xaa
[349587.500595]  [<c010390e>] show_registers+0x1cb/0x321
[349587.500604]  [<c0103bff>] die+0x112/0x1e1
[349587.500607]  [<c01132d2>] do_page_fault+0x229/0x565
[349587.500618]  [<c03c8d3a>] error_code+0x72/0x78
[349587.500625]  [<c0331962>] netlink_run_queue+0x40/0x76
[349587.500632]  [<c03988e3>] inet_diag_rcv+0x1f/0x2c
[349587.500639]  [<c03312a5>] netlink_data_ready+0x57/0x59
[349587.500643]  [<c0330681>] netlink_sendskb+0x24/0x45
[349587.500651]  [<c03307c6>] netlink_unicast+0x100/0x116
[349587.500656]  [<c0330f83>] netlink_sendmsg+0x1c2/0x280
[349587.500664]  [<c02fcce9>] sock_sendmsg+0xba/0xd5
[349587.500671]  [<c02fe4d1>] sys_sendmsg+0x17b/0x1e8
[349587.500676]  [<c02fe92d>] sys_socketcall+0x230/0x24d
[349587.500684]  [<c01028d2>] syscall_call+0x7/0xb
[349587.500691]  =======================
[349587.500693] Code: f0 ff 4e 18 0f 94 c0 84 c0 0f 84 66 ff ff ff 89 f0 e8 86 e2 fc ff e9 5a ff ff ff f0 ff 40 10 eb be 55 89 e5 57 89 d7 56 89 c6 53 <8b> 50 54 83 fa 10 72 55 8b 9e 9c 00 00 00 31 c9 8b 03 83 f8 0f

Reported by Athanasius <link@miggy.org>

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-09-11 11:33:28 +02:00
Patrick McHardy af65bdfce9 [NETLINK]: Switch cb_lock spinlock to mutex and allow to override it
Switch cb_lock to mutex and allow netlink kernel users to override it
with a subsystem specific mutex for consistent locking in dump callbacks.
All netlink_dump_start users have been audited not to rely on any
side-effects of the previously used spinlock.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25 22:29:03 -07:00
Thomas Graf c702e8047f [NETLINK]: Directly return -EINTR from netlink_dump_start()
Now that all users of netlink_dump_start() use netlink_run_queue()
to process the receive queue, it is possible to return -EINTR from
netlink_dump_start() directly, therefore simplying the callers.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25 22:27:33 -07:00
Thomas Graf ead592ba24 [IPv4] diag: Use netlink_run_queue() to process the receive queue
Makes use of netlink_run_queue() to process the receive queue and
converts inet_diag_rcv_msg() to use the type safe netlink interface.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25 22:27:32 -07:00
Arnaldo Carvalho de Melo dc5fc579b9 [NETLINK]: Use nlmsg_trim() where appropriate
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25 22:26:37 -07:00
Arnaldo Carvalho de Melo b529ccf279 [NETLINK]: Introduce nlmsg_hdr() helper
For the common "(struct nlmsghdr *)skb->data" sequence, so that we reduce the
number of direct accesses to skb->data and for consistency with all the other
cast skb member helpers.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25 22:26:34 -07:00
Arnaldo Carvalho de Melo 27a884dc3c [SK_BUFF]: Convert skb->tail to sk_buff_data_t
So that it is also an offset from skb->head, reduces its size from 8 to 4 bytes
on 64bit architectures, allowing us to combine the 4 bytes hole left by the
layer headers conversion, reducing struct sk_buff size to 256 bytes, i.e. 4
64byte cachelines, and since the sk_buff slab cache is SLAB_HWCACHE_ALIGN...
:-)

Many calculations that previously required that skb->{transport,network,
mac}_header be first converted to a pointer now can be done directly, being
meaningful as offsets or pointers.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25 22:26:28 -07:00
YOSHIFUJI Hideaki e905a9edab [NET] IPV4: Fix whitespace errors.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-10 23:19:39 -08:00
Eric Dumazet dbca9b2750 [NET]: change layout of ehash table
ehash table layout is currently this one :

First half of this table is used by sockets not in TIME_WAIT state
Second half of it is used by sockets in TIME_WAIT state.

This is non optimal because of for a given hash or socket, the two chain heads 
are located in separate cache lines.
Moreover the locks of the second half are never used.

If instead of this halving, we use two list heads in inet_ehash_bucket instead 
of only one, we probably can avoid one cache miss, and reduce ram usage, 
particularly if sizeof(rwlock_t) is big (various CONFIG_DEBUG_SPINLOCK, 
CONFIG_DEBUG_LOCK_ALLOC settings). So we still halves the table but we keep 
together related chains to speedup lookups and socket state change.

In this patch I did not try to align struct inet_ehash_bucket, but a future 
patch could try to make this structure have a convenient size (a power of two 
or a multiple of L1_CACHE_SIZE).
I guess rwlock will just vanish as soon as RCU is plugged into ehash :) , so 
maybe we dont need to scratch our heads to align the bucket...

Note : In case struct inet_ehash_bucket is not a power of two, we could 
probably change alloc_large_system_hash() (in case it use __get_free_pages()) 
to free the unused space. It currently allocates a big zone, but the last 
quarter of it could be freed. Again, this should be a temporary 'problem'.

Patch tested on ipv4 tcp only, but should be OK for IPV6 and DCCP.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-08 14:16:46 -08:00
Patrick McHardy 26932566a4 [NETLINK]: Don't BUG on undersized allocations
Currently netlink users BUG when the allocated skb for an event
notification is undersized. While this is certainly a kernel bug,
its not critical and crashing the kernel is too drastic, especially
when considering that these errors have appeared multiple times in
the past and it BUGs even if no listeners are present.

This patch replaces BUG by WARN_ON and changes the notification
functions to inform potential listeners of undersized allocations
using a unique error code (EMSGSIZE).

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-02-08 12:38:41 -08:00
Al Viro 9f8552996d [IPV4]: inet_diag annotations
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-09-28 18:02:29 -07:00
Panagiotis Issaris 0da974f4f3 [NET]: Conversions from kmalloc+memset to k(z|c)alloc.
Signed-off-by: Panagiotis Issaris <takis@issaris.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-07-21 14:51:30 -07:00
Jörn Engel 6ab3d5624e Remove obsolete #include <linux/config.h>
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-30 19:25:36 +02:00
Arnaldo Carvalho de Melo dff2c03534 [INET_DIAG]: Introduce sk_diag_fill
To be called from inet_diag_get_exact, also rename inet_diag_fill to
inet_csk_diag_fill, for consistency with inet_twsk_diag_fill.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-09 14:56:56 -08:00
Arnaldo Carvalho de Melo c7d58aabdc [INET_DIAG]: Introduce inet_twsk_diag_dump & inet_twsk_diag_fill
To properly dump TIME_WAIT sockets and to reduce complexity a bit by
having per socket class accessor routines.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-09 14:56:38 -08:00
Arnaldo Carvalho de Melo 4e852c0279 [INET_DIAG]: whitespace/simple cleanups
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-09 14:56:19 -08:00
Arnaldo Carvalho de Melo 7dbf075524 [INET_DIAG]: Use inet_twsk() with TIME_WAIT sockets
The fields being accessed in inet_diag_dump are outside sock_common, the
common part of struct sock and struct inet_timewait_sock.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-09 14:56:03 -08:00
Arnaldo Carvalho de Melo 0fa1a53e1f [IPV6]: Introduce inet6_timewait_sock
Out of tcp6_timewait_sock, that now is just an aggregation of
inet_timewait_sock and inet6_timewait_sock, using tw_ipv6_offset in struct
inet_timewait_sock, that is common to the IPv6 transport protocols that use
timewait sockets, like DCCP and TCP.

tw_ipv6_offset plays the struct inet_sock pinfo6 role, i.e. for the generic
code to find the IPv6 area in a timewait sock.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-03 13:10:47 -08:00
Arnaldo Carvalho de Melo ca304b6104 [IPV6]: Introduce inet6_rsk()
And inet6_rsk_offset in inet_request_sock, for the same reasons as
inet_sock's pinfo6 member.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-01-03 13:10:37 -08:00
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
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
Arnaldo Carvalho de Melo 17b085eace [INET_DIAG]: Move the tcp_diag interface to the proper place
With this the previous setup is back, i.e. tcp_diag can be built as a module,
as dccp_diag and both share the infrastructure available in inet_diag.

If one selects CONFIG_INET_DIAG as module CONFIG_INET_TCP_DIAG will also be
built as a module, as will CONFIG_INET_DCCP_DIAG, if CONFIG_IP_DCCP was
selected static or as a module, if CONFIG_INET_DIAG is y, being statically
linked CONFIG_INET_TCP_DIAG will follow suit and CONFIG_INET_DCCP_DIAG will be
built in the same manner as CONFIG_IP_DCCP.

Now to aim at UDP, converting it to use inet_hashinfo, so that we can use
iproute2 for UDP sockets as well.

Ah, just to show an example of this new infrastructure working for DCCP :-)

[root@qemu ~]# ./ss -dane
State      Recv-Q Send-Q Local Address:Port  Peer Address:Port
LISTEN     0      0                  *:5001             *:*     ino:942 sk:cfd503a0
ESTAB      0      0          127.0.0.1:5001     127.0.0.1:32770 ino:943 sk:cfd50a60
ESTAB      0      0          127.0.0.1:32770    127.0.0.1:5001  ino:947 sk:cfd50700
TIME-WAIT  0      0          127.0.0.1:32769    127.0.0.1:5001  timer:(timewait,3.430ms,0) ino:0 sk:cf209620

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 15:57:54 -07:00
Arnaldo Carvalho de Melo a8c2190ee7 [INET_DIAG]: Rename tcp_diag.[ch] to inet_diag.[ch]
Next changeset will introduce net/ipv4/tcp_diag.c, moving the code that was put
transitioanlly in inet_diag.c.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 15:57:48 -07:00