inet: frags: rename last_in to flags

The last_in field has been used to store various flags different from
first/last frag in so give it a more descriptive name: flags.

Signed-off-by: Nikolay Aleks

inet: frags: rename last_in to flags

The last_in field has been used to store various flags different from
first/last frag in so give it a more descriptive name: flags.

Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

inet: frags: use INC_STATS_BH in the ipv6 reassembly code

Softirqs are already disabled so no need to do it again, thus let's be
consistent and use the IP6_INC_STATS_BH variant.

Signed-off-by: Niko

inet: frags: use INC_STATS_BH in the ipv6 reassembly code

Softirqs are already disabled so no need to do it again, thus let's be
consistent and use the IP6_INC_STATS_BH variant.

Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

inet: frag: set limits and make init_net's high_thresh limit global

This patch makes init_net's high_thresh limit to be the maximum for all
namespaces, thus introducing a global memory limit thresho

inet: frag: set limits and make init_net's high_thresh limit global

This patch makes init_net's high_thresh limit to be the maximum for all
namespaces, thus introducing a global memory limit threshold equal to the
sum of the individual high_thresh limits which are capped.
It also introduces some sane minimums for low_thresh as it shouldn't be
able to drop below 0 (or > high_thresh in the unsigned case), and
overall low_thresh should not ever be above high_thresh, so we make the
following relations for a namespace:
init_net:
high_thresh - max(not capped), min(init_net low_thresh)
low_thresh - max(init_net high_thresh), min (0)

all other namespaces:
high_thresh = max(init_net high_thresh), min(namespace's low_thresh)
low_thresh = max(namespace's high_thresh), min(0)

The major issue with having low_thresh > high_thresh is that we'll
schedule eviction but never evict anything and thus rely only on the
timers.

Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

inet: frag: use seqlock for hash rebuild

rehash is rare operation, don't force readers to take
the read-side rwlock.

Instead, we only have to detect the (rare) case where
the secret was altered whi

inet: frag: use seqlock for hash rebuild

rehash is rare operation, don't force readers to take
the read-side rwlock.

Instead, we only have to detect the (rare) case where
the secret was altered while we are trying to insert
a new inetfrag queue into the table.

If it was changed, drop the bucket lock and recompute
the hash to get the 'new' chain bucket that we have to
insert into.

Joint work with Nikolay Aleksandrov.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

inet: frag: remove periodic secret rebuild timer

merge functionality into the eviction workqueue.

Instead of rebuilding every n seconds, take advantage of the upper
hash chain length limit.

If we

inet: frag: remove periodic secret rebuild timer

merge functionality into the eviction workqueue.

Instead of rebuilding every n seconds, take advantage of the upper
hash chain length limit.

If we hit it, mark table for rebuild and schedule workqueue.
To prevent frequent rebuilds when we're completely overloaded,
don't rebuild more than once every 5 seconds.

ipfrag_secret_interval sysctl is now obsolete and has been marked as
deprecated, it still can be changed so scripts won't be broken but it
won't have any effect. A comment is left above each unused secret_timer
variable to avoid confusion.

Joint work with Nikolay Aleksandrov.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

inet: frag: remove lru list

no longer used.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

inet: frag: move eviction of queues to work queue

When the high_thresh limit is reached we try to toss the 'oldest'
incomplete fragment queues until memory limits are below the low_thresh
value. Th

inet: frag: move eviction of queues to work queue

When the high_thresh limit is reached we try to toss the 'oldest'
incomplete fragment queues until memory limits are below the low_thresh
value. This happens in softirq/packet processing context.

This has two drawbacks:

1) processors might evict a queue that was about to be completed
by another cpu, because they will compete wrt. resource usage and
resource reclaim.

2) LRU list maintenance is expensive.

But when constantly overloaded, even the 'least recently used' element is
recent, so removing 'lru' queue first is not 'fairer' than removing any
other fragment queue.

This moves eviction out of the fast path:

When the low threshold is reached, a work queue is scheduled
which then iterates over the table and removes the queues that exceed
the memory limits of the namespace. It sets a new flag called
INET_FRAG_EVICTED on the evicted queues so the proper counters will get
incremented when the queue is forcefully expired.

When the high threshold is reached, no more fragment queues are
created until we're below the limit again.

The LRU list is now unused and will be removed in a followup patch.

Joint work with Nikolay Aleksandrov.

Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

inet: frag: move evictor calls into frag_find function

First step to move eviction handling into a work queue.

We lose two spots that accounted evicted fragments in MIB counters.

Accounting will b

inet: frag: move evictor calls into frag_find function

First step to move eviction handling into a work queue.

We lose two spots that accounted evicted fragments in MIB counters.

Accounting will be restored since the upcoming work-queue evictor
invokes the frag queue timer callbacks instead.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

inet: frag: remove hash size assumptions from callers

hide actual hash size from individual users: The _find
function will now fold the given hash value into the required range.

Signed-off-by: Flor

inet: frag: remove hash size assumptions from callers

hide actual hash size from individual users: The _find
function will now fold the given hash value into the required range.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

inet: frag: constify match, hashfn and constructor arguments

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv6: split inet6_hash_frag for netfilter and initialize secrets with net_get_random_once

Defer the fragmentation hash secret initialization for IPv6 like the
previous patch did for IPv4.

Because t

ipv6: split inet6_hash_frag for netfilter and initialize secrets with net_get_random_once

Defer the fragmentation hash secret initialization for IPv6 like the
previous patch did for IPv4.

Because the netfilter logic reuses the hash secret we have to split it
first. Thus introduce a new nf_hash_frag function which takes care to
seed the hash secret.

Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

ipv6: drop packets with multiple fragmentation headers

It is not allowed for an ipv6 packet to contain multiple fragmentation
headers. So discard packets which were already reassembled by
fragmentat

ipv6: drop packets with multiple fragmentation headers

It is not allowed for an ipv6 packet to contain multiple fragmentation
headers. So discard packets which were already reassembled by
fragmentation logic and send back a parameter problem icmp.

The updates for RFC 6980 will come in later, I have to do a bit more
research here.

Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

net: drop dst before queueing fragments

Commit 4a94445c9a5c (net: Use ip_route_input_noref() in input path)
added a bug in IP defragmentation handling, as non refcounted
dst could escape an RCU prot

net: drop dst before queueing fragments

Commit 4a94445c9a5c (net: Use ip_route_input_noref() in input path)
added a bug in IP defragmentation handling, as non refcounted
dst could escape an RCU protected section.

Commit 64f3b9e203bd068 (net: ip_expire() must revalidate route) fixed
the case of timeouts, but not the general problem.

Tom Parkin noticed crashes in UDP stack and provided a patch,
but further analysis permitted us to pinpoint the root cause.

Before queueing a packet into a frag list, we must drop its dst,
as this dst has limited lifetime (RCU protected)

When/if a packet is finally reassembled, we use the dst of the very
last skb, still protected by RCU and valid, as the dst of the
reassembled packet.

Use same logic in IPv6, as there is no need to hold dst references.

Reported-by: Tom Parkin <tparkin@katalix.com>
Tested-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

ipv6: implement RFC3168 5.3 (ecn protection) for ipv6 fragmentation handling

Hello!

After patch 1 got accepted to net-next I will also send a patch to
netfilter-devel to make the corresponding chan

ipv6: implement RFC3168 5.3 (ecn protection) for ipv6 fragmentation handling

Hello!

After patch 1 got accepted to net-next I will also send a patch to
netfilter-devel to make the corresponding changes to the netfilter
reassembly logic.

Thanks,

Hannes

-- >8 --
[PATCH 2/2] ipv6: implement RFC3168 5.3 (ecn protection) for ipv6 fragmentation handling

This patch also ensures that INET_ECN_CE is propagated if one fragment
had the codepoint set.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jesper Dangaard Brouer <jbrouer@redhat.com>
Cc: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

inet: limit length of fragment queue hash table bucket lists

This patch introduces a constant limit of the fragment queue hash
table bucket list lengths. Currently the limit 128 is choosen somewhat

inet: limit length of fragment queue hash table bucket lists

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 <eric.dumazet@gmail.com>
Cc: Jesper Dangaard Brouer <jbrouer@redhat.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

ipv6: fix a sparse warning

net/ipv6/reassembly.c:82:72: warning: incorrect type in argument 3 (different base types)
net/ipv6/reassembly.c:82:72: expected unsigned int [unsigned] [usertype] c
net

ipv6: fix a sparse warning

net/ipv6/reassembly.c:82:72: warning: incorrect type in argument 3 (different base types)
net/ipv6/reassembly.c:82:72: expected unsigned int [unsigned] [usertype] c
net/ipv6/reassembly.c:82:72: got restricted __be32 [usertype] id

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

ipv6: optimize inet6_hash_frag()

Use ipv6_addr_hash() and a single jhash invocation.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Add skb_unclone() helper function.

This function will be used in next GRE_GSO patch. This patch does
not change any functionality.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by:

net: Add skb_unclone() helper function.

This function will be used in next GRE_GSO patch. This patch does
not change any functionality.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Eric Dumazet <edumazet@google.com>

show more ...

net: frag, move LRU list maintenance outside of rwlock

Updating the fragmentation queues LRU (Least-Recently-Used) list,
required taking the hash writer lock. However, the LRU list isn't
tied to th

net: frag, move LRU list maintenance outside of rwlock

Updating the fragmentation queues LRU (Least-Recently-Used) list,
required taking the hash writer lock. However, the LRU list isn't
tied to the hash at all, so we can use a separate lock for it.

Original-idea-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

net: frag helper functions for mem limit tracking

This change is primarily a preparation to ease the extension of memory
limit tracking.

The change does reduce the number atomic operation, during f

net: frag helper functions for mem limit tracking

This change is primarily a preparation to ease the extension of memory
limit tracking.

The change does reduce the number atomic operation, during freeing of
a frag queue. This does introduce a some performance improvement, as
these atomic operations are at the core of the performance problems
seen on NUMA systems.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

net: Don't export sysctls to unprivileged users

In preparation for supporting the creation of network namespaces
by unprivileged users, modify all of the per net sysctl exports
and refuse to allow t

net: Don't export sysctls to unprivileged users

In preparation for supporting the creation of network namespaces
by unprivileged users, modify all of the per net sysctl exports
and refuse to allow them to unprivileged users.

This makes it safe for unprivileged users in general to access
per net sysctls, and allows sysctls to be exported to unprivileged
users on an individual basis as they are deemed safe.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

ipv6: unify fragment thresh handling code

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Michal Kubeček <mkubecek@suse.cz>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@r

ipv6: unify fragment thresh handling code

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Michal Kubeček <mkubecek@suse.cz>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

ipv6: make ip6_frag_nqueues() and ip6_frag_mem() static inline

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Michal Kubeček <mkubecek@suse.cz>
Cc: David Miller <davem@davemloft.net>
Signed-off-by

ipv6: make ip6_frag_nqueues() and ip6_frag_mem() static inline

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Michal Kubeček <mkubecek@suse.cz>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

ipv6: unify conntrack reassembly expire code with standard one

Two years ago, Shan Wei tried to fix this:
http://patchwork.ozlabs.org/patch/43905/

The problem is that RFC2460 requires an ICMP Time

ipv6: unify conntrack reassembly expire code with standard one

Two years ago, Shan Wei tried to fix this:
http://patchwork.ozlabs.org/patch/43905/

The problem is that RFC2460 requires an ICMP Time
Exceeded -- Fragment Reassembly Time Exceeded message should be
sent to the source of that fragment, if the defragmentation
times out.

"
If insufficient fragments are received to complete reassembly of a
packet within 60 seconds of the reception of the first-arriving
fragment of that packet, reassembly of that packet must be
abandoned and all the fragments that have been received for that
packet must be discarded. If the first fragment (i.e., the one
with a Fragment Offset of zero) has been received, an ICMP Time
Exceeded -- Fragment Reassembly Time Exceeded message should be
sent to the source of that fragment.
"

As Herbert suggested, we could actually use the standard IPv6
reassembly code which follows RFC2460.

With this patch applied, I can see ICMP Time Exceeded sent
from the receiver when the sender sent out 3/4 fragmented
IPv6 UDP packet.

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Michal Kubeček <mkubecek@suse.cz>
Cc: David Miller <davem@davemloft.net>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: netfilter-devel@vger.kernel.org
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

ipv6: use skb coalescing in reassembly

ip6_frag_reasm() can use skb_try_coalesce() to build optimized skb,
reducing memory used by them (truesize), and reducing number of cache
line misses and overh

ipv6: use skb coalescing in reassembly

ip6_frag_reasm() can use skb_try_coalesce() to build optimized skb,
reducing memory used by them (truesize), and reducing number of cache
line misses and overhead for the consumer.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...