kernel/git/stable/linux-stable.git/include/net/tcp.h, branch linux-2.6.26.y

tcp: Revert 'process defer accept as established' changes.

2008-06-12T23:34:35+00:00

This reverts two changesets, ec3c0982a2dd1e671bad8e9d26c28dcba0039d87 ("[TCP]: TCP_DEFER_ACCEPT updates - process as established") and the follow-on bug fix 9ae27e0adbf471c7a6b80102e38e1d5a346b3b38 ("tcp: Fix slab corruption with ipv6 and tcp6fuzz"). This change causes several problems, first reported by Ingo Molnar as a distcc-over-loopback regression where connections were getting stuck. Ilpo Järvinen first spotted the locking problems. The new function added by this code, tcp_defer_accept_check(), only has the child socket locked, yet it is modifying state of the parent listening socket. Fixing that is non-trivial at best, because we can't simply just grab the parent listening socket lock at this point, because it would create an ABBA deadlock. The normal ordering is parent listening socket --> child socket, but this code path would require the reverse lock ordering. Next is a problem noticed by Vitaliy Gusev, he noted: ---------------------------------------- >--- a/net/ipv4/tcp_timer.c >+++ b/net/ipv4/tcp_timer.c >@@ -481,6 +481,11 @@ static void tcp_keepalive_timer (unsigned long data) > goto death; > } > >+ if (tp->defer_tcp_accept.request && sk->sk_state == TCP_ESTABLISHED) { >+ tcp_send_active_reset(sk, GFP_ATOMIC); >+ goto death; Here socket sk is not attached to listening socket's request queue. tcp_done() will not call inet_csk_destroy_sock() (and tcp_v4_destroy_sock() which should release this sk) as socket is not DEAD. Therefore socket sk will be lost for freeing. ---------------------------------------- Finally, Alexey Kuznetsov argues that there might not even be any real value or advantage to these new semantics even if we fix all of the bugs: ---------------------------------------- Hiding from accept() sockets with only out-of-order data only is the only thing which is impossible with old approach. Is this really so valuable? My opinion: no, this is nothing but a new loophole to consume memory without control. ---------------------------------------- So revert this thing for now. Signed-off-by: David S. Miller

ipv4: Remove unused declaration from include/net/tcp.h.

2008-06-10T19:37:42+00:00

- The tcp_unhash() method in /include/net/tcp.h is no more needed, as the unhash method in tcp_prot structure is now inet_unhash (instead of tcp_unhash in the past); see tcp_prot structure in net/ipv4/tcp_ipv4.c. - So, this patch removes tcp_unhash() declaration from include/net/tcp.h Signed-off-by: Rami Rosen Signed-off-by: David S. Miller

[TCP]: Increase the max_burst threshold from 3 to tp->reordering.

2008-04-16T09:29:56+00:00

This change is necessary to allow cwnd to grow during persistent reordering. Cwnd moderation is applied when in the disorder state and an ack that fills the hole comes in. If the hole was greater than 3 packets, but less than tp->reordering, cwnd will shrink when it should not have. Signed-off-by: John Heffner Signed-off-by: David S. Miller

Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6

2008-04-14T09:30:23+00:00

Conflicts: drivers/net/ehea/ehea_main.c drivers/net/wireless/iwlwifi/Kconfig drivers/net/wireless/rt2x00/rt61pci.c net/ipv4/inet_timewait_sock.c net/ipv6/raw.c net/mac80211/ieee80211_sta.c

[SKB]: __skb_append = __skb_queue_after

2008-04-14T07:05:09+00:00

This expresses __skb_append in terms of __skb_queue_after, exploiting that __skb_append(old, new, list) = __skb_queue_after(list, old, new). Signed-off-by: Gerrit Renker Signed-off-by: David S. Miller

[TCP]: Remove owner from tcp_seq_afinfo.

2008-04-14T05:13:53+00:00

Move it to tcp_seq_afinfo->seq_fops as should be. Signed-off-by: Denis V. Lunev Signed-off-by: David S. Miller

[TCP]: Place file operations directly into tcp_seq_afinfo.

2008-04-14T05:13:30+00:00

No need to have separate never-used variable. Signed-off-by: Denis V. Lunev Signed-off-by: David S. Miller

[TCP]: Move seq_ops from tcp_iter_state to tcp_seq_afinfo.

2008-04-14T05:12:13+00:00

No need to create seq_operations for each instance of 'netstat'. Signed-off-by: Denis V. Lunev Signed-off-by: David S. Miller

[TCP]: Replace struct net on tcp_iter_state with seq_net_private.

2008-04-14T05:11:14+00:00

Signed-off-by: Denis V. Lunev Signed-off-by: David S. Miller

[Syncookies]: Add support for TCP options via timestamps.

2008-04-10T10:12:40+00:00

Allow the use of SACK and window scaling when syncookies are used and the client supports tcp timestamps. Options are encoded into the timestamp sent in the syn-ack and restored from the timestamp echo when the ack is received. Based on earlier work by Glenn Griffin. This patch avoids increasing the size of structs by encoding TCP options into the least significant bits of the timestamp and by not using any 'timestamp offset'. The downside is that the timestamp sent in the packet after the synack will increase by several seconds. changes since v1: don't duplicate timestamp echo decoding function, put it into ipv4/syncookie.c and have ipv6/syncookies.c use it. Feedback from Glenn Griffin: fix line indented with spaces, kill redundant if () Reviewed-by: Hagen Paul Pfeifer Signed-off-by: Florian Westphal Signed-off-by: David S. Miller