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  1. 17 6月, 2008 1 次提交
  3. 15 6月, 2008 1 次提交
  5. 13 6月, 2008 1 次提交
    • D
      tcp: Revert 'process defer accept as established' changes. · ec0a1966
      由 David S. Miller 提交于 
      This reverts two changesets, ec3c0982
("[TCP]: TCP_DEFER_ACCEPT updates - process as established") and
the follow-on bug fix 9ae27e0a
("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: NDavid S. Miller <davem@davemloft.net>
      ec0a1966
  7. 12 6月, 2008 5 次提交
  9. 11 6月, 2008 1 次提交
  11. 02 5月, 2008 1 次提交
  13. 24 4月, 2008 1 次提交
  15. 14 4月, 2008 7 次提交
  17. 10 4月, 2008 1 次提交
    • F
      [Syncookies]: Add support for TCP options via timestamps. · 4dfc2817
      由 Florian Westphal 提交于 
      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: NHagen Paul Pfeifer <hagen@jauu.net>
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      4dfc2817
  19. 04 4月, 2008 6 次提交
  21. 29 3月, 2008 1 次提交
  23. 26 3月, 2008 3 次提交
  25. 25 3月, 2008 1 次提交
  27. 23 3月, 2008 1 次提交
    • P
      [SOCK]: Add udp_hash member to struct proto. · 39d8cda7
      由 Pavel Emelyanov 提交于 
      Inspired by the commit ab1e0a13 ([SOCK] proto: Add hashinfo member to 
struct proto) from Arnaldo, I made similar thing for UDP/-Lite IPv4 
and -v6 protocols.

The result is not that exciting, but it removes some levels of
indirection in udpxxx_get_port and saves some space in code and text.

The first step is to union existing hashinfo and new udp_hash on the
struct proto and give a name to this union, since future initialization 
of tcpxxx_prot, dccp_vx_protinfo and udpxxx_protinfo will cause gcc 
warning about inability to initialize anonymous member this way.
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      39d8cda7
  29. 22 3月, 2008 2 次提交
    • P
      [TCP]: TCP_DEFER_ACCEPT updates - process as established · ec3c0982
      由 Patrick McManus 提交于 
      Change TCP_DEFER_ACCEPT implementation so that it transitions a
connection to ESTABLISHED after handshake is complete instead of
leaving it in SYN-RECV until some data arrvies. Place connection in
accept queue when first data packet arrives from slow path.

Benefits:
  - established connection is now reset if it never makes it
   to the accept queue

 - diagnostic state of established matches with the packet traces
   showing completed handshake

 - TCP_DEFER_ACCEPT timeouts are expressed in seconds and can now be
   enforced with reasonable accuracy instead of rounding up to next
   exponential back-off of syn-ack retry.
Signed-off-by: NPatrick McManus <mcmanus@ducksong.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      ec3c0982
    • P
      [NET]: NULL pointer dereference and other nasty things in /proc/net/(tcp|udp)[6] · 28518fc1
      由 Pavel Emelyanov 提交于 
      Commits f40c81 ([NETNS][IPV4] tcp - make proc handle the network
namespaces) and a91275 ([NETNS][IPV6] udp - make proc handle the
network namespace) both introduced bad checks on sockets and tw
buckets to belong to proper net namespace.

I.e. when checking for socket to belong to given net and family the

	do {
		sk = sk_next(sk);
	} while (sk && sk->sk_net != net && sk->sk_family != family);

constructions were used. This is wrong, since as soon as the
sk->sk_net fits the net the socket is immediately returned, even if it
belongs to other family.

As the result four /proc/net/(udp|tcp)[6] entries show wrong info.
The udp6 entry even oopses when dereferencing inet6_sk(sk) pointer:

static void udp6_sock_seq_show(struct seq_file *seq, struct sock *sp, int bucket)
{
	...
        struct ipv6_pinfo *np = inet6_sk(sp);
	...

        dest  = &np->daddr; /* will be NULL for AF_INET sockets */
	...
	seq_printf(...
	           dest->s6_addr32[0], dest->s6_addr32[1],
                   dest->s6_addr32[2], dest->s6_addr32[3],
	...

Fix it by converting && to ||.
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Acked-by: NDaniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      28518fc1
  31. 21 3月, 2008 2 次提交
  33. 06 3月, 2008 1 次提交
  35. 04 3月, 2008 1 次提交
  37. 01 3月, 2008 2 次提交
  39. 18 2月, 2008 1 次提交