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  1. 26 1月, 2011 1 次提交
    • J
      TCP: fix a bug that triggers large number of TCP RST by mistake · 44f5324b
      由 Jerry Chu 提交于 
      This patch fixes a bug that causes TCP RST packets to be generated
on otherwise correctly behaved applications, e.g., no unread data
on close,..., etc. To trigger the bug, at least two conditions must
be met:

1. The FIN flag is set on the last data packet, i.e., it's not on a
separate, FIN only packet.
2. The size of the last data chunk on the receive side matches
exactly with the size of buffer posted by the receiver, and the
receiver closes the socket without any further read attempt.

This bug was first noticed on our netperf based testbed for our IW10
proposal to IETF where a large number of RST packets were observed.
netperf's read side code meets the condition 2 above 100%.

Before the fix, tcp_data_queue() will queue the last skb that meets
condition 1 to sk_receive_queue even though it has fully copied out
(skb_copy_datagram_iovec()) the data. Then if condition 2 is also met,
tcp_recvmsg() often returns all the copied out data successfully
without actually consuming the skb, due to a check
"if ((chunk = len - tp->ucopy.len) != 0) {"
and
"len -= chunk;"
after tcp_prequeue_process() that causes "len" to become 0 and an
early exit from the big while loop.

I don't see any reason not to free the skb whose data have been fully
consumed in tcp_data_queue(), regardless of the FIN flag.  We won't
get there if MSG_PEEK is on. Am I missing some arcane cases related
to urgent data?
Signed-off-by: NH.K. Jerry Chu <hkchu@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      44f5324b
  3. 25 1月, 2011 3 次提交
  5. 20 1月, 2011 1 次提交
  7. 12 1月, 2011 2 次提交
  9. 11 1月, 2011 2 次提交
  11. 10 1月, 2011 1 次提交
  13. 07 1月, 2011 2 次提交
    • P
      netfilter: fix export secctx error handling · cba85b53
      由 Pablo Neira Ayuso 提交于 
      In 1ae4de0c, the secctx was exported
via the /proc/net/netfilter/nf_conntrack and ctnetlink interfaces
instead of the secmark.

That patch introduced the use of security_secid_to_secctx() which may
return a non-zero value on error.

In one of my setups, I have NF_CONNTRACK_SECMARK enabled but no
security modules. Thus, security_secid_to_secctx() returns a negative
value that results in the breakage of the /proc and `conntrack -L'
outputs. To fix this, we skip the inclusion of secctx if the
aforementioned function fails.

This patch also fixes the dynamic netlink message size calculation
if security_secid_to_secctx() returns an error, since its logic is
also wrong.

This problem exists in Linux kernel >= 2.6.37.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      cba85b53
    • E
      ipv4: IP defragmentation must be ECN aware · 6623e3b2
      由 Eric Dumazet 提交于 
      RFC3168 (The Addition of Explicit Congestion Notification to IP)
states :

5.3.  Fragmentation

   ECN-capable packets MAY have the DF (Don't Fragment) bit set.
   Reassembly of a fragmented packet MUST NOT lose indications of
   congestion.  In other words, if any fragment of an IP packet to be
   reassembled has the CE codepoint set, then one of two actions MUST be
   taken:

      * Set the CE codepoint on the reassembled packet.  However, this
        MUST NOT occur if any of the other fragments contributing to
        this reassembly carries the Not-ECT codepoint.

      * The packet is dropped, instead of being reassembled, for any
        other reason.

This patch implements this requirement for IPv4, choosing the first
action :

If one fragment had NO-ECT codepoint
        reassembled frame has NO-ECT
ElIf one fragment had CE codepoint
        reassembled frame has CE
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      6623e3b2
  15. 05 1月, 2011 1 次提交
    • J
      ipv4/route.c: respect prefsrc for local routes · 9fc3bbb4
      由 Joel Sing 提交于 
      The preferred source address is currently ignored for local routes,
which results in all local connections having a src address that is the
same as the local dst address. Fix this by respecting the preferred source
address when it is provided for local routes.

This bug can be demonstrated as follows:

 # ifconfig dummy0 192.168.0.1
 # ip route show table local | grep local.*dummy0
 local 192.168.0.1 dev dummy0  proto kernel  scope host  src 192.168.0.1
 # ip route change table local local 192.168.0.1 dev dummy0 \
     proto kernel scope host src 127.0.0.1
 # ip route show table local | grep local.*dummy0
 local 192.168.0.1 dev dummy0  proto kernel  scope host  src 127.0.0.1

We now establish a local connection and verify the source IP
address selection:

 # nc -l 192.168.0.1 3128 &
 # nc 192.168.0.1 3128 &
 # netstat -ant | grep 192.168.0.1:3128.*EST
 tcp        0      0 192.168.0.1:3128        192.168.0.1:33228 ESTABLISHED
 tcp        0      0 192.168.0.1:33228       192.168.0.1:3128  ESTABLISHED
Signed-off-by: NJoel Sing <jsing@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      9fc3bbb4
  17. 26 12月, 2010 1 次提交
  19. 24 12月, 2010 3 次提交
  21. 21 12月, 2010 2 次提交
  23. 17 12月, 2010 2 次提交
  25. 15 12月, 2010 1 次提交
  27. 14 12月, 2010 2 次提交
  29. 13 12月, 2010 2 次提交
    • D
      ipv4: Don't pre-seed hoplimit metric. · 323e126f
      由 David S. Miller 提交于 
      Always go through a new ip4_dst_hoplimit() helper, just like ipv6.

This allowed several simplifications:

1) The interim dst_metric_hoplimit() can go as it's no longer
   userd.

2) The sysctl_ip_default_ttl entry no longer needs to use
   ipv4_doint_and_flush, since the sysctl is not cached in
   routing cache metrics any longer.

3) ipv4_doint_and_flush no longer needs to be exported and
   therefore can be marked static.

When ipv4_doint_and_flush_strategy was removed some time ago,
the external declaration in ip.h was mistakenly left around
so kill that off too.

We have to move the sysctl_ip_default_ttl declaration into
ipv4's route cache definition header net/route.h, because
currently net/ip.h (where the declaration lives now) has
a back dependency on net/route.h
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      323e126f
    • D
      net: Abstract RTAX_HOPLIMIT metric accesses behind helper. · 5170ae82
      由 David S. Miller 提交于 
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      5170ae82
  31. 11 12月, 2010 1 次提交
  33. 10 12月, 2010 2 次提交
    • E
      net: optimize INET input path further · 68835aba
      由 Eric Dumazet 提交于 
      Followup of commit b178bb3d (net: reorder struct sock fields)

Optimize INET input path a bit further, by :

1) moving sk_refcnt close to sk_lock.

This reduces number of dirtied cache lines by one on 64bit arches (and
64 bytes cache line size).

2) moving inet_daddr & inet_rcv_saddr at the beginning of sk

(same cache line than hash / family / bound_dev_if / nulls_node)

This reduces number of accessed cache lines in lookups by one, and dont
increase size of inet and timewait socks.
inet and tw sockets now share same place-holder for these fields.

Before patch :

offsetof(struct sock, sk_refcnt) = 0x10
offsetof(struct sock, sk_lock) = 0x40
offsetof(struct sock, sk_receive_queue) = 0x60
offsetof(struct inet_sock, inet_daddr) = 0x270
offsetof(struct inet_sock, inet_rcv_saddr) = 0x274

After patch :

offsetof(struct sock, sk_refcnt) = 0x44
offsetof(struct sock, sk_lock) = 0x48
offsetof(struct sock, sk_receive_queue) = 0x68
offsetof(struct inet_sock, inet_daddr) = 0x0
offsetof(struct inet_sock, inet_rcv_saddr) = 0x4

compute_score() (udp or tcp) now use a single cache line per ignored
item, instead of two.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      68835aba
    • D
      net: Abstract away all dst_entry metrics accesses. · defb3519
      由 David S. Miller 提交于 
      Use helper functions to hide all direct accesses, especially writes,
to dst_entry metrics values.

This will allow us to:

1) More easily change how the metrics are stored.

2) Implement COW for metrics.

In particular this will help us put metrics into the inetpeer
cache if that is what we end up doing.  We can make the _metrics
member a pointer instead of an array, initially have it point
at the read-only metrics in the FIB, and then on the first set
grab an inetpeer entry and point the _metrics member there.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
      defb3519
  35. 09 12月, 2010 5 次提交
  37. 07 12月, 2010 2 次提交
  39. 03 12月, 2010 1 次提交
  41. 02 12月, 2010 3 次提交