kernel.git/net/core/sock.c, branch linux-2.6.33.y

net: backlog functions rename

2010-04-01T23:02:04Z

[ Upstream commit a3a858ff18a72a8d388e31ab0d98f7e944841a62 ] sk_add_backlog -> __sk_add_backlog sk_add_backlog_limited -> sk_add_backlog Signed-off-by: Zhu Yi Acked-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: add limit for socket backlog

2010-04-01T23:02:02Z

[ Upstream commit 8eae939f1400326b06d0c9afe53d2a484a326871 ] We got system OOM while running some UDP netperf testing on the loopback device. The case is multiple senders sent stream UDP packets to a single receiver via loopback on local host. Of course, the receiver is not able to handle all the packets in time. But we surprisingly found that these packets were not discarded due to the receiver's sk->sk_rcvbuf limit. Instead, they are kept queuing to sk->sk_backlog and finally ate up all the memory. We believe this is a secure hole that a none privileged user can crash the system. The root cause for this problem is, when the receiver is doing __release_sock() (i.e. after userspace recv, kernel udp_recvmsg -> skb_free_datagram_locked -> release_sock), it moves skbs from backlog to sk_receive_queue with the softirq enabled. In the above case, multiple busy senders will almost make it an endless loop. The skbs in the backlog end up eat all the system memory. The issue is not only for UDP. Any protocols using socket backlog is potentially affected. The patch adds limit for socket backlog so that the backlog size cannot be expanded endlessly. Reported-by: Alex Shi Cc: David Miller Cc: Arnaldo Carvalho de Melo Cc: Alexey Kuznetsov Cc: "Pekka Savola (ipv6)" Cc: Patrick McHardy Cc: Vlad Yasevich Cc: Sridhar Samudrala Cc: Jon Maloy Cc: Allan Stephens Cc: Andrew Hendry Signed-off-by: Zhu Yi Signed-off-by: Eric Dumazet Acked-by: Arnaldo Carvalho de Melo Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tcp: update the netstamp_needed counter when cloning sockets

2010-01-08T08:00:09Z

This fixes a netstamp_needed accounting issue when the listen socket has SO_TIMESTAMP set: s = socket(AF_INET, SOCK_STREAM, 0); setsockopt(s, SOL_SOCKET, SO_TIMESTAMP, 1); -> netstamp_needed = 1 bind(s, ...); listen(s, ...); s2 = accept(s, ...); -> netstamp_needed = 1 close(s2); -> netstamp_needed = 0 close(s); -> netstamp_needed = -1 Signed-off-by: Octavian Purdila Signed-off-by: David S. Miller

net: Fix build warning in sock_bindtodevice().

2009-11-06T06:37:11Z

net/core/sock.c: In function 'sock_setsockopt': net/core/sock.c:396: warning: 'index' may be used uninitialized in this function net/core/sock.c:396: note: 'index' was declared here GCC can't see that all paths initialize index, so just set it to the default (0) and eliminate the specific code block that handles the null device name string. Signed-off-by: David S. Miller

net: sock_bindtodevice() RCU-ification

2009-11-06T06:34:24Z

Avoid dev_hold()/dev_put() in sock_bindtodevice() Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: Fix for dst_negative_advice

2009-10-21T01:55:46Z

dst_negative_advice() should check for changed dst and reset sk_tx_queue_mapping accordingly. Pass sock to the callers of dst_negative_advice. (sk_reset_txq is defined just for use by dst_negative_advice. The only way I could find to get around this is to move dst_negative_() from dst.h to dst.c, include sock.h in dst.c, etc) Signed-off-by: Krishna Kumar Signed-off-by: David S. Miller

net: Introduce sk_tx_queue_mapping

2009-10-21T01:55:45Z

Introduce sk_tx_queue_mapping; and functions that set, test and get this value. Reset sk_tx_queue_mapping to -1 whenever the dst cache is set/reset, and in socket alloc. Setting txq to -1 and using valid txq=<0 to n-1> allows the tx path to use the value of sk_tx_queue_mapping directly instead of subtracting 1 on every tx. Signed-off-by: Krishna Kumar Signed-off-by: David S. Miller

net: sk_drops consolidation

2009-10-15T03:40:11Z

sock_queue_rcv_skb() can update sk_drops itself, removing need for callers to take care of it. This is more consistent since sock_queue_rcv_skb() also reads sk_drops when queueing a skb. This adds sk_drops managment to many protocols that not cared yet. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: Generalize socket rx gap / receive queue overflow cmsg

2009-10-12T20:26:31Z

Create a new socket level option to report number of queue overflows Recently I augmented the AF_PACKET protocol to report the number of frames lost on the socket receive queue between any two enqueued frames. This value was exported via a SOL_PACKET level cmsg. AFter I completed that work it was requested that this feature be generalized so that any datagram oriented socket could make use of this option. As such I've created this patch, It creates a new SOL_SOCKET level option called SO_RXQ_OVFL, which when enabled exports a SOL_SOCKET level cmsg that reports the nubmer of times the sk_receive_queue overflowed between any two given frames. It also augments the AF_PACKET protocol to take advantage of this new feature (as it previously did not touch sk->sk_drops, which this patch uses to record the overflow count). Tested successfully by me. Notes: 1) Unlike my previous patch, this patch simply records the sk_drops value, which is not a number of drops between packets, but rather a total number of drops. Deltas must be computed in user space. 2) While this patch currently works with datagram oriented protocols, it will also be accepted by non-datagram oriented protocols. I'm not sure if thats agreeable to everyone, but my argument in favor of doing so is that, for those protocols which aren't applicable to this option, sk_drops will always be zero, and reporting no drops on a receive queue that isn't used for those non-participating protocols seems reasonable to me. This also saves us having to code in a per-protocol opt in mechanism. 3) This applies cleanly to net-next assuming that commit 977750076d98c7ff6cbda51858bb5a5894a9d9ab (my af packet cmsg patch) is reverted Signed-off-by: Neil Horman Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: Fix sock_wfree() race

2009-09-30T23:20:38Z

Commit 2b85a34e911bf483c27cfdd124aeb1605145dc80 (net: No more expensive sock_hold()/sock_put() on each tx) opens a window in sock_wfree() where another cpu might free the socket we are working on. A fix is to call sk->sk_write_space(sk) while still holding a reference on sk. Reported-by: Jike Song Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller