linux-toradex.git/net/ipv4, branch v3.2.42

inet: limit length of fragment queue hash table bucket lists

2013-03-27T02:41:07+00:00

[ Upstream commit 5a3da1fe9561828d0ca7eca664b16ec2b9bf0055 ]

This patch introduces a constant limit of the fragment queue hash
table bucket list lengths. Currently the limit 128 is choosen somewhat
arbitrary and just ensures that we can fill up the fragment cache with
empty packets up to the default ip_frag_high_thresh limits. It should
just protect from list iteration eating considerable amounts of cpu.

If we reach the maximum length in one hash bucket a warning is printed.
This is implemented on the caller side of inet_frag_find to distinguish
between the different users of inet_fragment.c.

I dropped the out of memory warning in the ipv4 fragment lookup path,
because we already get a warning by the slab allocator.

Cc: Eric Dumazet 
Cc: Jesper Dangaard Brouer 
Signed-off-by: Hannes Frederic Sowa 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

tcp: fix skb_availroom()

2013-03-27T02:41:06+00:00

[ Upstream commit 16fad69cfe4adbbfa813de516757b87bcae36d93 ]

Chrome OS team reported a crash on a Pixel ChromeBook in TCP stack :

https://code.google.com/p/chromium/issues/detail?id=182056

commit a21d45726acac (tcp: avoid order-1 allocations on wifi and tx
path) did a poor choice adding an 'avail_size' field to skb, while
what we really needed was a 'reserved_tailroom' one.

It would have avoided commit 22b4a4f22da (tcp: fix retransmit of
partially acked frames) and this commit.

Crash occurs because skb_split() is not aware of the 'avail_size'
management (and should not be aware)

Signed-off-by: Eric Dumazet 
Reported-by: Mukesh Agrawal 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

net/ipv4: Ensure that location of timestamp option is stored

2013-03-27T02:41:04+00:00

[ Upstream commit 4660c7f498c07c43173142ea95145e9dac5a6d14 ]

This is needed in order to detect if the timestamp option appears
more than once in a packet, to remove the option if the packet is
fragmented, etc. My previous change neglected to store the option
location when the router addresses were prespecified and Pointer >
Length. But now the option location is also stored when Flag is an
unrecognized value, to ensure these option handling behaviors are
still performed.

Signed-off-by: David Ward 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

tcp: fix double-counted receiver RTT when leaving receiver fast path

2013-03-27T02:40:56+00:00

[ Upstream commit aab2b4bf224ef8358d262f95b568b8ad0cecf0a0 ]

We should not update ts_recent and call tcp_rcv_rtt_measure_ts() both
before and after going to step5. That wastes CPU and double-counts the
receiver-side RTT sample.

Signed-off-by: Neal Cardwell 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

ipv6: use a stronger hash for tcp

2013-03-06T03:24:21+00:00

[ Upstream commit 08dcdbf6a7b9d14c2302c5bd0c5390ddf122f664 ]

It looks like its possible to open thousands of TCP IPv6
sessions on a server, all landing in a single slot of TCP hash
table. Incoming packets have to lookup sockets in a very
long list.

We should hash all bits from foreign IPv6 addresses, using
a salt and hash mix, not a simple XOR.

inet6_ehashfn() can also separately use the ports, instead
of xoring them.

Reported-by: Neal Cardwell 
Signed-off-by: Eric Dumazet 
Cc: Yuchung Cheng 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

ipv4: fix a bug in ping_err().

2013-03-06T03:24:20+00:00

[ Upstream commit b531ed61a2a2a77eeb2f7c88b49aa5ec7d9880d8 ]

We should get 'type' and 'code' from the outer ICMP header.

Signed-off-by: Li Wei 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

tcp: fix for zero packets_in_flight was too broad

2013-02-20T03:15:38+00:00

[ Upstream commit 6731d2095bd4aef18027c72ef845ab1087c3ba63 ]

There are transients during normal FRTO procedure during which
the packets_in_flight can go to zero between write_queue state
updates and firing the resulting segments out. As FRTO processing
occurs during that window the check must be more precise to
not match "spuriously" :-). More specificly, e.g., when
packets_in_flight is zero but FLAG_DATA_ACKED is true the problematic
branch that set cwnd into zero would not be taken and new segments
might be sent out later.

Signed-off-by: Ilpo Järvinen 
Tested-by: Eric Dumazet 
Acked-by: Neal Cardwell 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

tcp: frto should not set snd_cwnd to 0

2013-02-20T03:15:38+00:00

[ Upstream commit 2e5f421211ff76c17130b4597bc06df4eeead24f ]

Commit 9dc274151a548 (tcp: fix ABC in tcp_slow_start())
uncovered a bug in FRTO code :
tcp_process_frto() is setting snd_cwnd to 0 if the number
of in flight packets is 0.

As Neal pointed out, if no packet is in flight we lost our
chance to disambiguate whether a loss timeout was spurious.

We should assume it was a proper loss.

Reported-by: Pasi Kärkkäinen 
Signed-off-by: Neal Cardwell 
Signed-off-by: Eric Dumazet 
Cc: Ilpo Järvinen 
Cc: Yuchung Cheng 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

net: prevent setting ttl=0 via IP_TTL

2013-02-20T03:15:31+00:00

[ Upstream commit c9be4a5c49cf51cc70a993f004c5bb30067a65ce ]

A regression is introduced by the following commit:

	commit 4d52cfbef6266092d535237ba5a4b981458ab171
	Author: Eric Dumazet 
	Date:   Tue Jun 2 00:42:16 2009 -0700

	    net: ipv4/ip_sockglue.c cleanups

	    Pure cleanups

but it is not a pure cleanup...

	-               if (val != -1 && (val < 1 || val>255))
	+               if (val != -1 && (val < 0 || val > 255))

Since there is no reason provided to allow ttl=0, change it back.

Reported-by: nitin padalia 
Cc: nitin padalia 
Cc: Eric Dumazet 
Cc: David S. Miller 
Signed-off-by: Cong Wang 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

tcp: RFC 5961 5.2 Blind Data Injection Attack Mitigation

2013-01-16T01:13:27+00:00

[ Upstream commit 354e4aa391ed50a4d827ff6fc11e0667d0859b25 ]

RFC 5961 5.2 [Blind Data Injection Attack].[Mitigation]

  All TCP stacks MAY implement the following mitigation.  TCP stacks
  that implement this mitigation MUST add an additional input check to
  any incoming segment.  The ACK value is considered acceptable only if
  it is in the range of ((SND.UNA - MAX.SND.WND) <= SEG.ACK <=
  SND.NXT).  All incoming segments whose ACK value doesn't satisfy the
  above condition MUST be discarded and an ACK sent back.

Move tcp_send_challenge_ack() before tcp_ack() to avoid a forward
declaration.

Signed-off-by: Eric Dumazet 
Cc: Neal Cardwell 
Cc: Yuchung Cheng 
Cc: Jerry Chu 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings