Commit Graph

267 Commits

Author SHA1 Message Date
Eric Dumazet 979402b16c udp: increment UDP_MIB_INERRORS if copy failed
In UDP recvmsg(), we miss an increase of UDP_MIB_INERRORS if the copy
of skb to userspace failed for whatever reason.

Reported-by: Shawn Bohrer <sbohrer@rgmadvisors.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-07 12:56:00 -04:00
Eric Dumazet b5ec8eeac4 ipv4: fix ip_send_skb()
ip_send_skb() can send orphaned skb, so we must pass the net pointer to
avoid possible NULL dereference in error path.

Bug added by commit 3a7c384ffd (ipv4: tcp: unicast_sock should not
land outside of TCP stack)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-10 14:08:57 -07:00
David S. Miller 55be7a9c60 ipv4: Add redirect support to all protocol icmp error handlers.
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-11 21:27:49 -07:00
Eric Dumazet 22911fc581 net: skb_free_datagram_locked() doesnt drop all packets
dropwatch wrongly diagnose all received UDP packets as drops.

This patch removes trace_kfree_skb() done in skb_free_datagram_locked().

Locations calling skb_free_datagram_locked() should do it on their own.

As a result, drops are accounted on the right function.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-27 15:40:57 -07:00
David S. Miller 3639339553 ipv4: Handle PMTU in all ICMP error handlers.
With ip_rt_frag_needed() removed, we have to explicitly update PMTU
information in every ICMP error handler.

Create two helper functions to facilitate this.

1) ipv4_sk_update_pmtu()

   This updates the PMTU when we have a socket context to
   work with.

2) ipv4_update_pmtu()

   Raw version, used when no socket context is available.  For this
   interface, we essentially just pass in explicit arguments for
   the flow identity information we would have extracted from the
   socket.

   And you'll notice that ipv4_sk_update_pmtu() is simply implemented
   in terms of ipv4_update_pmtu()

Note that __ip_route_output_key() is used, rather than something like
ip_route_output_flow() or ip_route_output_key().  This is because we
absolutely do not want to end up with a route that does IPSEC
encapsulation and the like.  Instead, we only want the route that
would get us to the node described by the outermost IP header.

Reported-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-14 22:22:07 -07:00
Tim Bird 31fe62b958 mm: add a low limit to alloc_large_system_hash
UDP stack needs a minimum hash size value for proper operation and also
uses alloc_large_system_hash() for proper NUMA distribution of its hash
tables and automatic sizing depending on available system memory.

On some low memory situations, udp_table_init() must ignore the
alloc_large_system_hash() result and reallocs a bigger memory area.

As we cannot easily free old hash table, we leak it and kmemleak can
issue a warning.

This patch adds a low limit parameter to alloc_large_system_hash() to
solve this problem.

We then specify UDP_HTABLE_SIZE_MIN for UDP/UDPLite hash table
allocation.

Reported-by: Mark Asselstine <mark.asselstine@windriver.com>
Reported-by: Tim Bird <tim.bird@am.sony.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-24 00:28:21 -04:00
Eldad Zack 413c27d869 net/ipv4: replace simple_strtoul with kstrtoul
Replace simple_strtoul with kstrtoul in three similar occurrences, all setup
handlers:
* route.c: set_rhash_entries
* tcp.c: set_thash_entries
* udp.c: set_uhash_entries

Also check if the conversion failed.

Signed-off-by: Eldad Zack <eldad@fogrefinery.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-20 04:06:17 -04:00
Eric Dumazet f545a38f74 net: add a limit parameter to sk_add_backlog()
sk_add_backlog() & sk_rcvqueues_full() hard coded sk_rcvbuf as the
memory limit. We need to make this limit a parameter for TCP use.

No functional change expected in this patch, all callers still using the
old sk_rcvbuf limit.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Maciej Żenczykowski <maze@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Cc: Rick Jones <rick.jones2@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-23 22:28:28 -04:00
Eric Dumazet 95c9617472 net: cleanup unsigned to unsigned int
Use of "unsigned int" is preferred to bare "unsigned" in net tree.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-15 12:44:40 -04:00
Daniel Baluta 5e73ea1a31 ipv4: fix checkpatch errors
Fix checkpatch errors of the following type:
	* ERROR: "foo * bar" should be "foo *bar"
	* ERROR: "(foo*)" should be "(foo *)"

Signed-off-by: Daniel Baluta <dbaluta@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-15 12:37:19 -04:00
Eric Dumazet 447167bf56 udp: intoduce udp_encap_needed static_key
Most machines dont use UDP encapsulation (L2TP)

Adds a static_key so that udp_queue_rcv_skb() doesnt have to perform a
test if L2TP never setup the encap_rcv on a socket.

Idea of this patch came after Simon Horman proposal to add a hook on TCP
as well.

If static_key is not yet enabled, the fast path does a single JMP .

When static_key is enabled, JMP destination is patched to reach the real
encap_type/encap_rcv logic, possibly adding cache misses.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Simon Horman <horms@verge.net.au>
Cc: dev@openvswitch.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-13 13:39:37 -04:00
David Howells 9ffc93f203 Remove all #inclusions of asm/system.h
Remove all #inclusions of asm/system.h preparatory to splitting and killing
it.  Performed with the following command:

perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *`

Signed-off-by: David Howells <dhowells@redhat.com>
2012-03-28 18:30:03 +01:00
Joe Perches afd465030a net: ipv4: Standardize prefixes for message logging
Add #define pr_fmt(fmt) as appropriate.

Add "IPv4: ", "TCP: ", and "IPsec: " to appropriate files.
Standardize on "UDPLite: " for appropriate uses.
Some prefixes were previously "UDPLITE: " and "UDP-Lite: ".

Add KBUILD_MODNAME ": " to icmp and gre.
Remove embedded prefixes as appropriate.

Add missing "\n" to pr_info in gre.c.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-12 17:05:21 -07:00
Pavel Emelyanov 3f518bf745 datagram: Add offset argument to __skb_recv_datagram
This one is only considered for MSG_PEEK flag and the value pointed by
it specifies where to start peeking bytes from. If the offset happens to
point into the middle of the returned skb, the offset within this skb is
put back to this very argument.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-21 14:58:57 -05:00
Erich E. Hoover 76e21053b5 ipv4: Implement IP_UNICAST_IF socket option.
The IP_UNICAST_IF feature is needed by the Wine project.  This patch
implements the feature by setting the outgoing interface in a similar
fashion to that of IP_MULTICAST_IF.  A separate option is needed to
handle this feature since the existing options do not provide all of
the characteristics required by IP_UNICAST_IF, a summary is provided
below.

SO_BINDTODEVICE:
* SO_BINDTODEVICE requires administrative privileges, IP_UNICAST_IF
does not.  From reading some old mailing list articles my
understanding is that SO_BINDTODEVICE requires administrative
privileges because it can override the administrator's routing
settings.
* The SO_BINDTODEVICE option restricts both outbound and inbound
traffic, IP_UNICAST_IF only impacts outbound traffic.

IP_PKTINFO:
* Since IP_PKTINFO and IP_UNICAST_IF are independent options,
implementing IP_UNICAST_IF with IP_PKTINFO will likely break some
applications.
* Implementing IP_UNICAST_IF on top of IP_PKTINFO significantly
complicates the Wine codebase and reduces the socket performance
(doing this requires a lot of extra communication between the
"server" and "user" layers).

bind():
* bind() does not work on broadcast packets, IP_UNICAST_IF is
specifically intended to work with broadcast packets.
* Like SO_BINDTODEVICE, bind() restricts both outbound and inbound
traffic.

Signed-off-by: Erich E. Hoover <ehoover@mines.edu>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-08 15:52:45 -05:00
Pavel Emelyanov fce823381e udp: Export code sk lookup routines
The UDP diag get_exact handler will require them to find a
socket by provided net, [sd]addr-s, [sd]ports and device.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-09 14:14:08 -05:00
David S. Miller b3613118eb Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2011-12-02 13:49:21 -05:00
David S. Miller 59c2cdae27 Revert "udp: remove redundant variable"
This reverts commit 81d54ec847.

If we take the "try_again" goto, due to a checksum error,
the 'len' has already been truncated.  So we won't compute
the same values as the original code did.

Reported-by: paul bilke <fsmail@conspiracy.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-01 14:12:55 -05:00
Michał Mirosław c8f44affb7 net: introduce and use netdev_features_t for device features sets
v2:	add couple missing conversions in drivers
	split unexporting netdev_fix_features()
	implemented %pNF
	convert sock::sk_route_(no?)caps

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-16 17:43:10 -05:00
Eric Dumazet d826eb14ec ipv4: PKTINFO doesnt need dst reference
Le lundi 07 novembre 2011 à 15:33 +0100, Eric Dumazet a écrit :

> At least, in recent kernels we dont change dst->refcnt in forwarding
> patch (usinf NOREF skb->dst)
>
> One particular point is the atomic_inc(dst->refcnt) we have to perform
> when queuing an UDP packet if socket asked PKTINFO stuff (for example a
> typical DNS server has to setup this option)
>
> I have one patch somewhere that stores the information in skb->cb[] and
> avoid the atomic_{inc|dec}(dst->refcnt).
>

OK I found it, I did some extra tests and believe its ready.

[PATCH net-next] ipv4: IP_PKTINFO doesnt need dst reference

When a socket uses IP_PKTINFO notifications, we currently force a dst
reference for each received skb. Reader has to access dst to get needed
information (rt_iif & rt_spec_dst) and must release dst reference.

We also forced a dst reference if skb was put in socket backlog, even
without IP_PKTINFO handling. This happens under stress/load.

We can instead store the needed information in skb->cb[], so that only
softirq handler really access dst, improving cache hit ratios.

This removes two atomic operations per packet, and false sharing as
well.

On a benchmark using a mono threaded receiver (doing only recvmsg()
calls), I can reach 720.000 pps instead of 570.000 pps.

IP_PKTINFO is typically used by DNS servers, and any multihomed aware
UDP application.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-09 16:36:27 -05:00
Eric Dumazet 0ad92ad03a udp: fix a race in encap_rcv handling
udp_queue_rcv_skb() has a possible race in encap_rcv handling, since
this pointer can be changed anytime.

We should use ACCESS_ONCE() to close the race.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-02 00:51:27 -04:00
Arjan van de Ven 73cb88ecb9 net: make the tcp and udp file_operations for the /proc stuff const
the tcp and udp code creates a set of struct file_operations at runtime
while it can also be done at compile time, with the added benefit of then
having these file operations be const.

the trickiest part was to get the "THIS_MODULE" reference right; the naive
method of declaring a struct in the place of registration would not work
for this reason.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-01 17:56:14 -04:00
Tom Herbert bdeab99191 rps: Add flag to skb to indicate rxhash is based on L4 tuple
The l4_rxhash flag was added to the skb structure to indicate
that the rxhash value was computed over the 4 tuple for the
packet which includes the port information in the encapsulated
transport packet.  This is used by the stack to preserve the
rxhash value in __skb_rx_tunnel.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-17 20:06:03 -07:00
Eric Dumazet 33d480ce6d net: cleanup some rcu_dereference_raw
RCU api had been completed and rcu_access_pointer() or
rcu_dereference_protected() are better than generic
rcu_dereference_raw()

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-12 02:55:28 -07:00
David S. Miller 6a7ebdf2fd Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	net/bluetooth/l2cap_core.c
2011-07-14 07:56:40 -07:00
Eric Dumazet f03d78db65 net: refine {udp|tcp|sctp}_mem limits
Current tcp/udp/sctp global memory limits are not taking into account
hugepages allocations, and allow 50% of ram to be used by buffers of a
single protocol [ not counting space used by sockets / inodes ...]

Lets use nr_free_buffer_pages() and allow a default of 1/8 of kernel ram
per protocol, and a minimum of 128 pages.
Heavy duty machines sysadmins probably need to tweak limits anyway.


References: https://bugzilla.stlinux.com/show_bug.cgi?id=38032
Reported-by: starlight <starlight@binnacle.cx>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-07 00:27:05 -07:00
David S. Miller e12fe68ce3 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2011-07-05 23:23:37 -07:00
Xufeng Zhang 9cfaa8def1 udp/recvmsg: Clear MSG_TRUNC flag when starting over for a new packet
Consider this scenario: When the size of the first received udp packet
is bigger than the receive buffer, MSG_TRUNC bit is set in msg->msg_flags.
However, if checksum error happens and this is a blocking socket, it will
goto try_again loop to receive the next packet.  But if the size of the
next udp packet is smaller than receive buffer, MSG_TRUNC flag should not
be set, but because MSG_TRUNC bit is not cleared in msg->msg_flags before
receive the next packet, MSG_TRUNC is still set, which is wrong.

Fix this problem by clearing MSG_TRUNC flag when starting over for a
new packet.

Signed-off-by: Xufeng Zhang <xufeng.zhang@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-06-21 22:34:27 -07:00
Satoru Moriya 296f7ea75b udp: add tracepoints for queueing skb to rcvbuf
This patch adds a tracepoint to __udp_queue_rcv_skb to get the
return value of ip_queue_rcv_skb. It indicates why kernel drops
a packet at this point.

ip_queue_rcv_skb returns following values in the packet drop case:

rcvbuf is full                 : -ENOMEM
sk_filter returns error        : -EINVAL, -EACCESS, -ENOMEM, etc.
__sk_mem_schedule returns error: -ENOBUF

Signed-off-by: Satoru Moriya <satoru.moriya@hds.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-06-21 16:06:10 -07:00
Dan Rosenberg 71338aa7d0 net: convert %p usage to %pK
The %pK format specifier is designed to hide exposed kernel pointers,
specifically via /proc interfaces.  Exposing these pointers provides an
easy target for kernel write vulnerabilities, since they reveal the
locations of writable structures containing easily triggerable function
pointers.  The behavior of %pK depends on the kptr_restrict sysctl.

If kptr_restrict is set to 0, no deviation from the standard %p behavior
occurs.  If kptr_restrict is set to 1, the default, if the current user
(intended to be a reader via seq_printf(), etc.) does not have CAP_SYSLOG
(currently in the LSM tree), kernel pointers using %pK are printed as 0's.
 If kptr_restrict is set to 2, kernel pointers using %pK are printed as
0's regardless of privileges.  Replacing with 0's was chosen over the
default "(null)", which cannot be parsed by userland %p, which expects
"(nil)".

The supporting code for kptr_restrict and %pK are currently in the -mm
tree.  This patch converts users of %p in net/ to %pK.  Cases of printing
pointers to the syslog are not covered, since this would eliminate useful
information for postmortem debugging and the reading of the syslog is
already optionally protected by the dmesg_restrict sysctl.

Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Cc: James Morris <jmorris@namei.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Thomas Graf <tgraf@infradead.org>
Cc: Eugene Teo <eugeneteo@kernel.org>
Cc: Kees Cook <kees.cook@canonical.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David S. Miller <davem@davemloft.net>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Eric Paris <eparis@parisplace.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-24 01:13:12 -04:00
David S. Miller 79ab053145 ipv4: udp: Eliminate remaining uses of rt->rt_src
We already track and pass around the correct flow key,
so simply use it in udp_send_skb().

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-10 13:32:47 -07:00
David S. Miller f5fca60865 ipv4: Pass flow key down into ip_append_*().
This way rt->rt_dst accesses are unnecessary.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-08 21:24:07 -07:00
David S. Miller 77968b7824 ipv4: Pass flow keys down into datagram packet building engine.
This way ip_output.c no longer needs rt->rt_{src,dst}.

We already have these keys sitting, ready and waiting, on the stack or
in a socket structure.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-08 21:24:06 -07:00
David S. Miller e474995f29 udp: Use flow key information instead of rt->rt_{src,dst}
We have two cases.

Either the socket is in TCP_ESTABLISHED state and connect() filled
in the inet socket cork flow, or we looked up the route here and
used an on-stack flow.

Track which one it was, and use it to obtain src/dst addrs.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-08 21:12:48 -07:00
Eric Dumazet f6d8bd051c inet: add RCU protection to inet->opt
We lack proper synchronization to manipulate inet->opt ip_options

Problem is ip_make_skb() calls ip_setup_cork() and
ip_setup_cork() possibly makes a copy of ipc->opt (struct ip_options),
without any protection against another thread manipulating inet->opt.

Another thread can change inet->opt pointer and free old one under us.

Use RCU to protect inet->opt (changed to inet->inet_opt).

Instead of handling atomic refcounts, just copy ip_options when
necessary, to avoid cache line dirtying.

We cant insert an rcu_head in struct ip_options since its included in
skb->cb[], so this patch is large because I had to introduce a new
ip_options_rcu structure.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-28 13:16:35 -07:00
Eric Dumazet b71d1d426d inet: constify ip headers and in6_addr
Add const qualifiers to structs iphdr, ipv6hdr and in6_addr pointers
where possible, to make code intention more obvious.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-22 11:04:14 -07:00
David S. Miller 1c01a80cfe Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	drivers/net/smsc911x.c
2011-04-11 13:44:25 -07:00
Lucas De Marchi 25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
David S. Miller c0951cbcfd ipv4: Use flowi4_init_output() in udp_sendmsg()
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-31 04:54:27 -07:00
David S. Miller 9cce96df5b net: Put fl4_* macros to struct flowi4 and use them again.
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-12 15:08:54 -08:00
David S. Miller b6f21b2680 ipv4: Use flowi4 in UDP
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-12 15:08:50 -08:00
David S. Miller 9d6ec93801 ipv4: Use flowi4 in public route lookup interfaces.
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-12 15:08:48 -08:00
David S. Miller 6281dcc94a net: Make flowi ports AF dependent.
Create two sets of port member accessors, one set prefixed by fl4_*
and the other prefixed by fl6_*

This will let us to create AF optimal flow instances.

It will work because every context in which we access the ports,
we have to be fully aware of which AF the flowi is anyways.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-12 15:08:46 -08:00
David S. Miller 1d28f42c1b net: Put flowi_* prefix on AF independent members of struct flowi
I intend to turn struct flowi into a union of AF specific flowi
structs.  There will be a common structure that each variant includes
first, much like struct sock_common.

This is the first step to move in that direction.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-12 15:08:44 -08:00
David S. Miller 06dc94b1ed ipv4: Fix crash in dst_release when udp_sendmsg route lookup fails.
As reported by Eric:

[11483.697233] IP: [<c12b0638>] dst_release+0x18/0x60
 ...
[11483.697741] Call Trace:
[11483.697764]  [<c12fc9d2>] udp_sendmsg+0x282/0x6e0
[11483.697790]  [<c12a1c01>] ? memcpy_toiovec+0x51/0x70
[11483.697818]  [<c12dbd90>] ? ip_generic_getfrag+0x0/0xb0

The pointer passed to dst_release() is -EINVAL, that's because
we leave an error pointer in the local variable "rt" by accident.

NULL it out to fix the bug.

Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-03 10:38:01 -08:00
David S. Miller b23dd4fe42 ipv4: Make output route lookup return rtable directly.
Instead of on the stack.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-02 14:31:35 -08:00
David S. Miller 273447b352 ipv4: Kill can_sleep arg to ip_route_output_flow()
This boolean state is now available in the flow flags.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-01 14:27:04 -08:00
David S. Miller 5df65e5567 net: Add FLOWI_FLAG_CAN_SLEEP.
And set is in contexts where the route resolution can sleep.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-01 14:22:19 -08:00
David S. Miller 420d44daa7 ipv4: Make final arg to ip_route_output_flow to be boolean "can_sleep"
Since that is what the current vague "flags" argument means.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-01 14:19:23 -08:00
Herbert Xu 903ab86d19 udp: Add lockless transmit path
The UDP transmit path has been running under the socket lock
for a long time because of the corking feature.  This means that
transmitting to the same socket in multiple threads does not
scale at all.

However, as most users don't actually use corking, the locking
can be removed in the common case.

This patch creates a lockless fast path where corking is not used.

Please note that this does create a slight inaccuracy in the
enforcement of socket send buffer limits.  In particular, we
may exceed the socket limit by up to (number of CPUs) * (packet
size) because of the way the limit is computed.

As the primary purpose of socket buffers is to indicate congestion,
this should not be a great problem for now.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-01 12:35:42 -08:00