linux.git/net/ipv4, branch v3.18-rc3

Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf

2014-10-31T16:29:42+00:00

Pablo Neira Ayuso says:

====================
netfilter/ipvs fixes for net

The following patchset contains fixes for netfilter/ipvs. This round of
fixes is larger than usual at this stage, specifically because of the
nf_tables bridge reject fixes that I would like to see in 3.18. The
patches are:

1) Fix a null-pointer dereference that may occur when logging
   errors. This problem was introduced by 4a4739d56b0 ("ipvs: Pull
   out crosses_local_route_boundary logic") in v3.17-rc5.

2) Update hook mask in nft_reject_bridge so we can also filter out
   packets from there. This fixes 36d2af5 ("netfilter: nf_tables: allow
   to filter from prerouting and postrouting"), which needs this chunk
   to work.

3) Two patches to refactor common code to forge the IPv4 and IPv6
   reject packets from the bridge. These are required by the nf_tables
   reject bridge fix.

4) Fix nft_reject_bridge by avoiding the use of the IP stack to reject
   packets from the bridge. The idea is to forge the reject packets and
   inject them to the original port via br_deliver() which is now
   exported for that purpose.

5) Restrict nft_reject_bridge to bridge prerouting and input hooks.
   the original skbuff may cloned after prerouting when the bridge stack
   needs to flood it to several bridge ports, it is too late to reject
   the traffic.
====================

Signed-off-by: David S. Miller

netfilter: nf_reject_ipv4: split nf_send_reset() in smaller functions

2014-10-31T11:49:05+00:00

That can be reused by the reject bridge expression to build the reject
packet. The new functions are:

* nf_reject_ip_tcphdr_get(): to sanitize and to obtain the TCP header.
* nf_reject_iphdr_put(): to build the IPv4 header.
* nf_reject_ip_tcphdr_put(): to build the TCP header.

Signed-off-by: Pablo Neira Ayuso

net: skb_fclone_busy() needs to detect orphaned skb

2014-10-30T23:58:30+00:00

Some drivers are unable to perform TX completions in a bound time.
They instead call skb_orphan()

Problem is skb_fclone_busy() has to detect this case, otherwise
we block TCP retransmits and can freeze unlucky tcp sessions on
mostly idle hosts.

Signed-off-by: Eric Dumazet 
Fixes: 1f3279ae0c13 ("tcp: avoid retransmits of TCP packets hanging in host queues")
Signed-off-by: David S. Miller

gre: Use inner mac length when computing tunnel length

2014-10-30T23:51:56+00:00

Currently, skb_inner_network_header is used but this does not account
for Ethernet header for ETH_P_TEB. Use skb_inner_mac_header which
handles TEB and also should work with IP encapsulation in which case
inner mac and inner network headers are the same.

Tested: Ran TCP_STREAM over GRE, worked as expected.

Signed-off-by: Tom Herbert 
Acked-by: Alexander Duyck 
Signed-off-by: David S. Miller

ipv4: Do not cache routing failures due to disabled forwarding.

2014-10-30T23:20:40+00:00

If we cache them, the kernel will reuse them, independently of
whether forwarding is enabled or not.  Which means that if forwarding is
disabled on the input interface where the first routing request comes
from, then that unreachable result will be cached and reused for
other interfaces, even if forwarding is enabled on them.  The opposite
is also true.

This can be verified with two interfaces A and B and an output interface
C, where B has forwarding enabled, but not A and trying
ip route get $dst iif A from $src && ip route get $dst iif B from $src

Signed-off-by: Nicolas Cavallari 
Reviewed-by: Julian Anastasov 
Signed-off-by: David S. Miller

inet: frags: remove the WARN_ON from inet_evict_bucket

2014-10-29T19:21:30+00:00

The WARN_ON in inet_evict_bucket can be triggered by a valid case:
inet_frag_kill and inet_evict_bucket can be running in parallel on the
same queue which means that there has been at least one more ref added
by a previous inet_frag_find call, but inet_frag_kill can delete the
timer before inet_evict_bucket which will cause the WARN_ON() there to
trigger since we'll have refcnt!=1. Now, this case is valid because the
queue is being "killed" for some reason (removed from the chain list and
its timer deleted) so it will get destroyed in the end by one of the
inet_frag_put() calls which reaches 0 i.e. refcnt is still valid.

CC: Florian Westphal 
CC: Eric Dumazet 
CC: Patrick McLean 

Fixes: b13d3cbfb8e8 ("inet: frag: move eviction of queues to work queue")
Reported-by: Patrick McLean 
Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

inet: frags: fix a race between inet_evict_bucket and inet_frag_kill

2014-10-29T19:21:30+00:00

When the evictor is running it adds some chosen frags to a local list to
be evicted once the chain lock has been released but at the same time
the *frag_queue can be running for some of the same queues and it
may call inet_frag_kill which will wait on the chain lock and
will then delete the queue from the wrong list since it was added in the
eviction one. The fix is simple - check if the queue has the evict flag
set under the chain lock before deleting it, this is safe because the
evict flag is set only under that lock and having the flag set also means
that the queue has been detached from the chain list, so no need to delete
it again.
An important note to make is that we're safe w.r.t refcnt because
inet_frag_kill and inet_evict_bucket will sync on the del_timer operation
where only one of the two can succeed (or if the timer is executing -
none of them), the cases are:
1. inet_frag_kill succeeds in del_timer
 - then the timer ref is removed, but inet_evict_bucket will not add
   this queue to its expire list but will restart eviction in that chain
2. inet_evict_bucket succeeds in del_timer
 - then the timer ref is kept until the evictor "expires" the queue, but
   inet_frag_kill will remove the initial ref and will set
   INET_FRAG_COMPLETE which will make the frag_expire fn just to remove
   its ref.
In the end all of the queue users will do an inet_frag_put and the one
that reaches 0 will free it. The refcount balance should be okay.

CC: Florian Westphal 
CC: Eric Dumazet 
CC: Patrick McLean 

Fixes: b13d3cbfb8e8 ("inet: frag: move eviction of queues to work queue")
Suggested-by: Eric Dumazet 
Reported-by: Patrick McLean 
Tested-by: Patrick McLean 
Signed-off-by: Nikolay Aleksandrov 
Reviewed-by: Florian Westphal 
Signed-off-by: David S. Miller

tcp: md5: do not use alloc_percpu()

2014-10-25T20:10:04+00:00

percpu tcp_md5sig_pool contains memory blobs that ultimately
go through sg_set_buf().

-> sg_set_page(sg, virt_to_page(buf), buflen, offset_in_page(buf));

This requires that whole area is in a physically contiguous portion
of memory. And that @buf is not backed by vmalloc().

Given that alloc_percpu() can use vmalloc() areas, this does not
fit the requirements.

Replace alloc_percpu() by a static DEFINE_PER_CPU() as tcp_md5sig_pool
is small anyway, there is no gain to dynamically allocate it.

Signed-off-by: Eric Dumazet 
Fixes: 765cf9976e93 ("tcp: md5: remove one indirection level in tcp_md5sig_pool")
Reported-by: Crestez Dan Leonard 
Signed-off-by: David S. Miller

net: fix saving TX flow hash in sock for outgoing connections

2014-10-22T20:14:29+00:00

The commit "net: Save TX flow hash in sock and set in skbuf on xmit"
introduced the inet_set_txhash() and ip6_set_txhash() routines to calculate
and record flow hash(sk_txhash) in the socket structure. sk_txhash is used
to set skb->hash which is used to spread flows across multiple TXQs.

But, the above routines are invoked before the source port of the connection
is created. Because of this all outgoing connections that just differ in the
source port get hashed into the same TXQ.

This patch fixes this problem for IPv4/6 by invoking the the above routines
after the source port is available for the socket.

Fixes: b73c3d0e4("net: Save TX flow hash in sock and set in skbuf on xmit")

Signed-off-by: Sathya Perla 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller

net: make skb_gso_segment error handling more robust

2014-10-20T16:38:13+00:00

skb_gso_segment has three possible return values:
1. a pointer to the first segmented skb
2. an errno value (IS_ERR())
3. NULL.  This can happen when GSO is used for header verification.

However, several callers currently test IS_ERR instead of IS_ERR_OR_NULL
and would oops when NULL is returned.

Note that these call sites should never actually see such a NULL return
value; all callers mask out the GSO bits in the feature argument.

However, there have been issues with some protocol handlers erronously not
respecting the specified feature mask in some cases.

It is preferable to get 'have to turn off hw offloading, else slow' reports
rather than 'kernel crashes'.

Signed-off-by: Florian Westphal 
Signed-off-by: David S. Miller