Commit Graph

1054 Commits

Author SHA1 Message Date
Eric Dumazet
aa62d76b6e dccp: rename DCCP_INC_STATS_BH()
Rename DCCP_INC_STATS_BH() to __DCCP_INC_STATS()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-27 22:48:22 -04:00
Hannes Frederic Sowa
1e1d04e678 net: introduce lockdep_is_held and update various places to use it
The socket is either locked if we hold the slock spin_lock for
lock_sock_fast and unlock_sock_fast or we own the lock (sk_lock.owned
!= 0). Check for this and at the same time improve that the current
thread/cpu is really holding the lock.

Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-07 16:44:14 -04:00
Eric Dumazet
3b24d854cb tcp/dccp: do not touch listener sk_refcnt under synflood
When a SYNFLOOD targets a non SO_REUSEPORT listener, multiple
cpus contend on sk->sk_refcnt and sk->sk_wmem_alloc changes.

By letting listeners use SOCK_RCU_FREE infrastructure,
we can relax TCP_LISTEN lookup rules and avoid touching sk_refcnt

Note that we still use SLAB_DESTROY_BY_RCU rules for other sockets,
only listeners are impacted by this change.

Peak performance under SYNFLOOD is increased by ~33% :

On my test machine, I could process 3.2 Mpps instead of 2.4 Mpps

Most consuming functions are now skb_set_owner_w() and sock_wfree()
contending on sk->sk_wmem_alloc when cooking SYNACK and freeing them.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-04 22:11:20 -04:00
Eric Dumazet
e316ea62e3 tcp/dccp: remove obsolete WARN_ON() in icmp handlers
Now SYN_RECV request sockets are installed in ehash table, an ICMP
handler can find a request socket while another cpu handles an incoming
packet transforming this SYN_RECV request socket into an ESTABLISHED
socket.

We need to remove the now obsolete WARN_ON(req->sk), since req->sk
is set when a new child is created and added into listener accept queue.

If this race happens, the ICMP will do nothing special.

Fixes: 079096f103 ("tcp/dccp: install syn_recv requests into ehash table")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Ben Lazarus <blazarus@google.com>
Reported-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-17 21:06:40 -04:00
David S. Miller
b633353115 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/phy/bcm7xxx.c
	drivers/net/phy/marvell.c
	drivers/net/vxlan.c

All three conflicts were cases of simple overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-23 00:09:14 -05:00
Eric Dumazet
7716682cc5 tcp/dccp: fix another race at listener dismantle
Ilya reported following lockdep splat:

kernel: =========================
kernel: [ BUG: held lock freed! ]
kernel: 4.5.0-rc1-ceph-00026-g5e0a311 #1 Not tainted
kernel: -------------------------
kernel: swapper/5/0 is freeing memory
ffff880035c9d200-ffff880035c9dbff, with a lock still held there!
kernel: (&(&queue->rskq_lock)->rlock){+.-...}, at:
[<ffffffff816f6a88>] inet_csk_reqsk_queue_add+0x28/0xa0
kernel: 4 locks held by swapper/5/0:
kernel: #0:  (rcu_read_lock){......}, at: [<ffffffff8169ef6b>]
netif_receive_skb_internal+0x4b/0x1f0
kernel: #1:  (rcu_read_lock){......}, at: [<ffffffff816e977f>]
ip_local_deliver_finish+0x3f/0x380
kernel: #2:  (slock-AF_INET){+.-...}, at: [<ffffffff81685ffb>]
sk_clone_lock+0x19b/0x440
kernel: #3:  (&(&queue->rskq_lock)->rlock){+.-...}, at:
[<ffffffff816f6a88>] inet_csk_reqsk_queue_add+0x28/0xa0

To properly fix this issue, inet_csk_reqsk_queue_add() needs
to return to its callers if the child as been queued
into accept queue.

We also need to make sure listener is still there before
calling sk->sk_data_ready(), by holding a reference on it,
since the reference carried by the child can disappear as
soon as the child is put on accept queue.

Reported-by: Ilya Dryomov <idryomov@gmail.com>
Fixes: ebb516af60 ("tcp/dccp: fix race at listener dismantle phase")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-18 11:35:51 -05:00
Craig Gallek
a583636a83 inet: refactor inet[6]_lookup functions to take skb
This is a preliminary step to allow fast socket lookup of SO_REUSEPORT
groups.  Doing so with a BPF filter will require access to the
skb in question.  This change plumbs the skb (and offset to payload
data) through the call stack to the listening socket lookup
implementations where it will be used in a following patch.

Signed-off-by: Craig Gallek <kraig@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-11 03:54:14 -05:00
Craig Gallek
496611d7b5 inet: create IPv6-equivalent inet_hash function
In order to support fast lookups for TCP sockets with SO_REUSEPORT,
the function that adds sockets to the listening hash set needs
to be able to check receive address equality.  Since this equality
check is different for IPv4 and IPv6, we will need two different
socket hashing functions.

This patch adds inet6_hash identical to the existing inet_hash function
and updates the appropriate references.  A following patch will
differentiate the two by passing different comparison functions to
__inet_hash.

Additionally, in order to use the IPv6 address equality function from
inet6_hashtables (which is compiled as a built-in object when IPv6 is
enabled) it also needs to be in a built-in object file as well.  This
moves ipv6_rcv_saddr_equal into inet_hashtables to accomplish this.

Signed-off-by: Craig Gallek <kraig@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-11 03:54:14 -05:00
David S. Miller
f188b951f3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/renesas/ravb_main.c
	kernel/bpf/syscall.c
	net/ipv4/ipmr.c

All three conflicts were cases of overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-03 21:09:12 -05:00
Eric Dumazet
6bd4f355df ipv6: kill sk_dst_lock
While testing the np->opt RCU conversion, I found that UDP/IPv6 was
using a mixture of xchg() and sk_dst_lock to protect concurrent changes
to sk->sk_dst_cache, leading to possible corruptions and crashes.

ip6_sk_dst_lookup_flow() uses sk_dst_check() anyway, so the simplest
way to fix the mess is to remove sk_dst_lock completely, as we did for
IPv4.

__ip6_dst_store() and ip6_dst_store() share same implementation.

sk_setup_caps() being called with socket lock being held or not,
we have to use sk_dst_set() instead of __sk_dst_set()

Note that I had to move the "np->dst_cookie = rt6_get_cookie(rt);"
in ip6_dst_store() before the sk_setup_caps(sk, dst) call.

This is because ip6_dst_store() can be called from process context,
without any lock held.

As soon as the dst is installed in sk->sk_dst_cache, dst can be freed
from another cpu doing a concurrent ip6_dst_store()

Doing the dst dereference before doing the install is needed to make
sure no use after free would trigger.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-03 11:32:06 -05:00
Eric Dumazet
45f6fad84c ipv6: add complete rcu protection around np->opt
This patch addresses multiple problems :

UDP/RAW sendmsg() need to get a stable struct ipv6_txoptions
while socket is not locked : Other threads can change np->opt
concurrently. Dmitry posted a syzkaller
(http://github.com/google/syzkaller) program desmonstrating
use-after-free.

Starting with TCP/DCCP lockless listeners, tcp_v6_syn_recv_sock()
and dccp_v6_request_recv_sock() also need to use RCU protection
to dereference np->opt once (before calling ipv6_dup_options())

This patch adds full RCU protection to np->opt

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-02 23:37:16 -05:00
Eric Dumazet
9cd3e072b0 net: rename SOCK_ASYNC_NOSPACE and SOCK_ASYNC_WAITDATA
This patch is a cleanup to make following patch easier to
review.

Goal is to move SOCK_ASYNC_NOSPACE and SOCK_ASYNC_WAITDATA
from (struct socket)->flags to a (struct socket_wq)->flags
to benefit from RCU protection in sock_wake_async()

To ease backports, we rename both constants.

Two new helpers, sk_set_bit(int nr, struct sock *sk)
and sk_clear_bit(int net, struct sock *sk) are added so that
following patch can change their implementation.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-01 15:45:05 -05:00
Herbert Xu
1ce0bf50ae net: Generalise wq_has_sleeper helper
The memory barrier in the helper wq_has_sleeper is needed by just
about every user of waitqueue_active.  This patch generalises it
by making it take a wait_queue_head_t directly.  The existing
helper is renamed to skwq_has_sleeper.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-30 14:47:33 -05:00
Eric Dumazet
ce1050089c tcp/dccp: fix ireq->pktopts race
IPv6 request sockets store a pointer to skb containing the SYN packet
to be able to transfer it to full blown socket when 3WHS is done
(ireq->pktopts -> np->pktoptions)

As explained in commit 5e0724d027 ("tcp/dccp: fix hashdance race for
passive sessions"), we must transfer the skb only if we won the
hashdance race, if multiple cpus receive the 'ack' packet completing
3WHS at the same time.

Fixes: e994b2f0fb ("tcp: do not lock listener to process SYN packets")
Fixes: 079096f103 ("tcp/dccp: install syn_recv requests into ehash table")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-02 15:38:26 -05:00
Tina Ruchandani
1032a66871 Use 64-bit timekeeping
This patch changes the use of struct timespec in
dccp_probe to use struct timespec64 instead. timespec uses a 32-bit
seconds field which will overflow in the year 2038 and beyond. timespec64
uses a 64-bit seconds field. Note that the correctness of the code isn't
changed, since the original code only uses the timestamps to compute a
small elapsed interval. This patch is part of a larger attempt to remove
instances of 32-bit timekeeping structures (timespec, timeval, time_t)
from the kernel so it is easier to identify where the real 2038 issues
are.

Signed-off-by: Tina Ruchandani <ruchandani.tina@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-01 17:01:16 -05:00
Eric Dumazet
5e0724d027 tcp/dccp: fix hashdance race for passive sessions
Multiple cpus can process duplicates of incoming ACK messages
matching a SYN_RECV request socket. This is a rare event under
normal operations, but definitely can happen.

Only one must win the race, otherwise corruption would occur.

To fix this without adding new atomic ops, we use logic in
inet_ehash_nolisten() to detect the request was present in the same
ehash bucket where we try to insert the new child.

If request socket was not found, we have to undo the child creation.

This actually removes a spin_lock()/spin_unlock() pair in
reqsk_queue_unlink() for the fast path.

Fixes: e994b2f0fb ("tcp: do not lock listener to process SYN packets")
Fixes: 079096f103 ("tcp/dccp: install syn_recv requests into ehash table")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-23 05:42:21 -07:00
Eric Dumazet
f03f2e154f tcp/dccp: add inet_csk_reqsk_queue_drop_and_put() helper
Let's reduce the confusion about inet_csk_reqsk_queue_drop() :
In many cases we also need to release reference on request socket,
so add a helper to do this, reducing code size and complexity.

Fixes: 4bdc3d6614 ("tcp/dccp: fix behavior of stale SYN_RECV request sockets")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-16 00:52:18 -07:00
Eric Dumazet
ef84d8ce5a Revert "inet: fix double request socket freeing"
This reverts commit c69736696c.

At the time of above commit, tcp_req_err() and dccp_req_err()
were dead code, as SYN_RECV request sockets were not yet in ehash table.

Real bug was fixed later in a different commit.

We need to revert to not leak a refcount on request socket.

inet_csk_reqsk_queue_drop_and_put() will be added
in following commit to make clean inet_csk_reqsk_queue_drop()
does not release the reference owned by caller.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-16 00:52:17 -07:00
Eric Dumazet
4bdc3d6614 tcp/dccp: fix behavior of stale SYN_RECV request sockets
When a TCP/DCCP listener is closed, its pending SYN_RECV request sockets
become stale, meaning 3WHS can not complete.

But current behavior is wrong :
incoming packets finding such stale sockets are dropped.

We need instead to cleanup the request socket and perform another
lookup :
- Incoming ACK will give a RST answer,
- SYN rtx might find another listener if available.
- We expedite cleanup of request sockets and old listener socket.

Fixes: 079096f103 ("tcp/dccp: install syn_recv requests into ehash table")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-13 18:26:34 -07:00
Yaowei Bai
45ae74f561 net/dccp: dccp_bad_service_code can be boolean
This patch makes dccp_bad_service_code return bool due to these
particular functions only using either one or zero as their return
value.

dccp_list_has_service is also been made return bool in this patchset.

No functional change.

Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-09 07:49:03 -07:00
Eric Dumazet
a1a5344ddb tcp: avoid two atomic ops for syncookies
inet_reqsk_alloc() is used to allocate a temporary request
in order to generate a SYNACK with a cookie. Then later,
syncookie validation also uses a temporary request.

These paths already took a reference on listener refcount,
we can avoid a couple of atomic operations.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-05 02:45:27 -07:00
Eric Dumazet
079096f103 tcp/dccp: install syn_recv requests into ehash table
In this patch, we insert request sockets into TCP/DCCP
regular ehash table (where ESTABLISHED and TIMEWAIT sockets
are) instead of using the per listener hash table.

ACK packets find SYN_RECV pseudo sockets without having
to find and lock the listener.

In nominal conditions, this halves pressure on listener lock.

Note that this will allow for SO_REUSEPORT refinements,
so that we can select a listener using cpu/numa affinities instead
of the prior 'consistent hash', since only SYN packets will
apply this selection logic.

We will shrink listen_sock in the following patch to ease
code review.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Ying Cai <ycai@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-03 04:32:41 -07:00
Eric Dumazet
0c27171e66 tcp/dccp: constify syn_recv_sock() method sock argument
We'll soon no longer hold listener socket lock, these
functions do not modify the socket in any way.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-29 16:53:09 -07:00
Eric Dumazet
54105f98f5 dccp: constify dccp_create_openreq_child() sock argument
socket no longer needs to be read/write

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-29 16:53:08 -07:00
Eric Dumazet
f76b33c32b dccp: use inet6_csk_route_req() helper
Before changing dccp_v6_request_recv_sock() sock argument
to const, we need to get rid of security_sk_classify_flow(),
and it seems doable by reusing inet6_csk_route_req() helper.

We need to add a proto parameter to inet6_csk_route_req(),
not assume it is TCP.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-29 16:53:08 -07:00
Eric Dumazet
a00e74442b tcp/dccp: constify send_synack and send_reset socket argument
None of these functions need to change the socket, make it
const.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-29 16:53:07 -07:00
David S. Miller
4963ed48f2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	net/ipv4/arp.c

The net/ipv4/arp.c conflict was one commit adding a new
local variable while another commit was deleting one.

Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-26 16:08:27 -07:00
Eric Dumazet
ea3bea3a1d tcp/dccp: constify rtx_synack() and friends
This is done to make sure we do not change listener socket
while sending SYNACK packets while socket lock is not held.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-25 13:00:39 -07:00
Eric Dumazet
802885fc04 dccp: constify dccp_make_response() socket argument
Like tcp_make_synack() the only time we might change the socket is
when calling sock_wmalloc(), which is using atomic operation to
update sk->sk_wmem_alloc

Also use MAX_DCCP_HEADER as both IPv4/IPv6 use this value for max_header.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-25 13:00:39 -07:00
Eric Dumazet
ed2e923945 tcp/dccp: fix timewait races in timer handling
When creating a timewait socket, we need to arm the timer before
allowing other cpus to find it. The signal allowing cpus to find
the socket is setting tw_refcnt to non zero value.

As we set tw_refcnt in __inet_twsk_hashdance(), we therefore need to
call inet_twsk_schedule() first.

This also means we need to remove tw_refcnt changes from
inet_twsk_schedule() and let the caller handle it.

Note that because we use mod_timer_pinned(), we have the guarantee
the timer wont expire before we set tw_refcnt as we run in BH context.

To make things more readable I introduced inet_twsk_reschedule() helper.

When rearming the timer, we can use mod_timer_pending() to make sure
we do not rearm a canceled timer.

Note: This bug can possibly trigger if packets of a flow can hit
multiple cpus. This does not normally happen, unless flow steering
is broken somehow. This explains this bug was spotted ~5 months after
its introduction.

A similar fix is needed for SYN_RECV sockets in reqsk_queue_hash_req(),
but will be provided in a separate patch for proper tracking.

Fixes: 789f558cfb ("tcp/dccp: get rid of central timewait timer")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Ying Cai <ycai@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-21 16:32:29 -07:00
Julia Lawall
20471ed4d4 dccp: drop null test before destroy functions
Remove unneeded NULL test.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression x;
@@

-if (x != NULL)
  \(kmem_cache_destroy\|mempool_destroy\|dma_pool_destroy\)(x);

@@
expression x;
@@

-if (x != NULL) {
  \(kmem_cache_destroy\|mempool_destroy\|dma_pool_destroy\)(x);
  x = NULL;
-}
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-15 16:49:43 -07:00
Sabrina Dubroca
dfbafc9953 tcp: fix recv with flags MSG_WAITALL | MSG_PEEK
Currently, tcp_recvmsg enters a busy loop in sk_wait_data if called
with flags = MSG_WAITALL | MSG_PEEK.

sk_wait_data waits for sk_receive_queue not empty, but in this case,
the receive queue is not empty, but does not contain any skb that we
can use.

Add a "last skb seen on receive queue" argument to sk_wait_data, so
that it sleeps until the receive queue has new skbs.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=99461
Link: https://sourceware.org/bugzilla/show_bug.cgi?id=18493
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1205258
Reported-by: Enrico Scholz <rh-bugzilla@ensc.de>
Reported-by: Dan Searle <dan@censornet.com>
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-27 01:06:53 -07:00
Craig Gallek
3fd22af808 sock_diag: specify info_size per inet protocol
Previously, there was no clear distinction between the inet protocols
that used struct tcp_info to report information and those that didn't.
This change adds a specific size attribute to the inet_diag_handler
struct which defines these interfaces.  This will make dispatching
sock_diag get_info requests identical for all inet protocols in a
following patch.

Tested: ss -au
Tested: ss -at
Signed-off-by: Craig Gallek <kraig@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-15 19:49:22 -07:00
Eric Dumazet
b357a364c5 inet: fix possible panic in reqsk_queue_unlink()
[ 3897.923145] BUG: unable to handle kernel NULL pointer dereference at
 0000000000000080
[ 3897.931025] IP: [<ffffffffa9f27686>] reqsk_timer_handler+0x1a6/0x243

There is a race when reqsk_timer_handler() and tcp_check_req() call
inet_csk_reqsk_queue_unlink() on the same req at the same time.

Before commit fa76ce7328 ("inet: get rid of central tcp/dccp listener
timer"), listener spinlock was held and race could not happen.

To solve this bug, we change reqsk_queue_unlink() to not assume req
must be found, and we return a status, to conditionally release a
refcount on the request sock.

This also means tcp_check_req() in non fastopen case might or not
consume req refcount, so tcp_v6_hnd_req() & tcp_v4_hnd_req() have
to properly handle this.

(Same remark for dccp_check_req() and its callers)

inet_csk_reqsk_queue_drop() is now too big to be inlined, as it is
called 4 times in tcp and 3 times in dccp.

Fixes: fa76ce7328 ("inet: get rid of central tcp/dccp listener timer")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-24 11:39:15 -04:00
Eric Dumazet
789f558cfb tcp/dccp: get rid of central timewait timer
Using a timer wheel for timewait sockets was nice ~15 years ago when
memory was expensive and machines had a single processor.

This does not scale, code is ugly and source of huge latencies
(Typically 30 ms have been seen, cpus spinning on death_lock spinlock.)

We can afford to use an extra 64 bytes per timewait sock and spread
timewait load to all cpus to have better behavior.

Tested:

On following test, /proc/sys/net/ipv4/tcp_tw_recycle is set to 1
on the target (lpaa24)

Before patch :

lpaa23:~# ./super_netperf 200 -H lpaa24 -t TCP_CC -l 60 -- -p0,0
419594

lpaa23:~# ./super_netperf 200 -H lpaa24 -t TCP_CC -l 60 -- -p0,0
437171

While test is running, we can observe 25 or even 33 ms latencies.

lpaa24:~# ping -c 1000 -i 0.02 -qn lpaa23
...
1000 packets transmitted, 1000 received, 0% packet loss, time 20601ms
rtt min/avg/max/mdev = 0.020/0.217/25.771/1.535 ms, pipe 2

lpaa24:~# ping -c 1000 -i 0.02 -qn lpaa23
...
1000 packets transmitted, 1000 received, 0% packet loss, time 20702ms
rtt min/avg/max/mdev = 0.019/0.183/33.761/1.441 ms, pipe 2

After patch :

About 90% increase of throughput :

lpaa23:~# ./super_netperf 200 -H lpaa24 -t TCP_CC -l 60 -- -p0,0
810442

lpaa23:~# ./super_netperf 200 -H lpaa24 -t TCP_CC -l 60 -- -p0,0
800992

And latencies are kept to minimal values during this load, even
if network utilization is 90% higher :

lpaa24:~# ping -c 1000 -i 0.02 -qn lpaa23
...
1000 packets transmitted, 1000 received, 0% packet loss, time 19991ms
rtt min/avg/max/mdev = 0.023/0.064/0.360/0.042 ms

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-13 16:40:05 -04:00
Fan Du
c69736696c inet: fix double request socket freeing
Eric Hugne reported following error :

I'm hitting this warning on latest net-next when i try to SSH into a machine
with eth0 added to a bridge (but i think the problem is older than that)

Steps to reproduce:
node2 ~ # brctl addif br0 eth0
[  223.758785] device eth0 entered promiscuous mode
node2 ~ # ip link set br0 up
[  244.503614] br0: port 1(eth0) entered forwarding state
[  244.505108] br0: port 1(eth0) entered forwarding state
node2 ~ # [  251.160159] ------------[ cut here ]------------
[  251.160831] WARNING: CPU: 0 PID: 3 at include/net/request_sock.h:102 tcp_v4_err+0x6b1/0x720()
[  251.162077] Modules linked in:
[  251.162496] CPU: 0 PID: 3 Comm: ksoftirqd/0 Not tainted 4.0.0-rc3+ #18
[  251.163334] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  251.164078]  ffffffff81a8365c ffff880038a6ba18 ffffffff8162ace4 0000000000009898
[  251.165084]  0000000000000000 ffff880038a6ba58 ffffffff8104da85 ffff88003fa437c0
[  251.166195]  ffff88003fa437c0 ffff88003fa74e00 ffff88003fa43bb8 ffff88003fad99a0
[  251.167203] Call Trace:
[  251.167533]  [<ffffffff8162ace4>] dump_stack+0x45/0x57
[  251.168206]  [<ffffffff8104da85>] warn_slowpath_common+0x85/0xc0
[  251.169239]  [<ffffffff8104db65>] warn_slowpath_null+0x15/0x20
[  251.170271]  [<ffffffff81559d51>] tcp_v4_err+0x6b1/0x720
[  251.171408]  [<ffffffff81630d03>] ? _raw_read_lock_irq+0x3/0x10
[  251.172589]  [<ffffffff81534e20>] ? inet_del_offload+0x40/0x40
[  251.173366]  [<ffffffff81569295>] icmp_socket_deliver+0x65/0xb0
[  251.174134]  [<ffffffff815693a2>] icmp_unreach+0xc2/0x280
[  251.174820]  [<ffffffff8156a82d>] icmp_rcv+0x2bd/0x3a0
[  251.175473]  [<ffffffff81534ea2>] ip_local_deliver_finish+0x82/0x1e0
[  251.176282]  [<ffffffff815354d8>] ip_local_deliver+0x88/0x90
[  251.177004]  [<ffffffff815350f0>] ip_rcv_finish+0xf0/0x310
[  251.177693]  [<ffffffff815357bc>] ip_rcv+0x2dc/0x390
[  251.178336]  [<ffffffff814f5da3>] __netif_receive_skb_core+0x713/0xa20
[  251.179170]  [<ffffffff814f7fca>] __netif_receive_skb+0x1a/0x80
[  251.179922]  [<ffffffff814f97d4>] process_backlog+0x94/0x120
[  251.180639]  [<ffffffff814f9612>] net_rx_action+0x1e2/0x310
[  251.181356]  [<ffffffff81051267>] __do_softirq+0xa7/0x290
[  251.182046]  [<ffffffff81051469>] run_ksoftirqd+0x19/0x30
[  251.182726]  [<ffffffff8106cc23>] smpboot_thread_fn+0x153/0x1d0
[  251.183485]  [<ffffffff8106cad0>] ? SyS_setgroups+0x130/0x130
[  251.184228]  [<ffffffff8106935e>] kthread+0xee/0x110
[  251.184871]  [<ffffffff81069270>] ? kthread_create_on_node+0x1b0/0x1b0
[  251.185690]  [<ffffffff81631108>] ret_from_fork+0x58/0x90
[  251.186385]  [<ffffffff81069270>] ? kthread_create_on_node+0x1b0/0x1b0
[  251.187216] ---[ end trace c947fc7b24e42ea1 ]---
[  259.542268] br0: port 1(eth0) entered forwarding state

Remove the double calls to reqsk_put()

[edumazet] :

I got confused because reqsk_timer_handler() _has_ to call
reqsk_put(req) after calling inet_csk_reqsk_queue_drop(), as
the timer handler holds a reference on req.

Signed-off-by: Fan Du <fan.du@intel.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Erik Hugne <erik.hugne@ericsson.com>
Fixes: fa76ce7328 ("inet: get rid of central tcp/dccp listener timer")
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-23 21:40:48 -04:00
Eric Dumazet
52036a4305 ipv6: dccp: handle ICMP messages on DCCP_NEW_SYN_RECV request sockets
dccp_v6_err() can restrict lookups to ehash table, and not to listeners.

Note this patch creates the infrastructure, but this means that ICMP
messages for request sockets are ignored until complete conversion.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-23 16:52:26 -04:00
Eric Dumazet
85645bab57 ipv4: dccp: handle ICMP messages on DCCP_NEW_SYN_RECV request sockets
dccp_v4_err() can restrict lookups to ehash table, and not to listeners.

Note this patch creates the infrastructure, but this means that ICMP
messages for request sockets are ignored until complete conversion.

New dccp_req_err() helper is exported so that we can use it in IPv6
in following patch.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-23 16:52:26 -04:00
Eric Dumazet
42cb80a235 inet: remove sk_listener parameter from syn_ack_timeout()
It is not needed, and req->sk_listener points to the listener anyway.
request_sock argument can be const.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-23 16:52:25 -04:00
Eric Dumazet
fa76ce7328 inet: get rid of central tcp/dccp listener timer
One of the major issue for TCP is the SYNACK rtx handling,
done by inet_csk_reqsk_queue_prune(), fired by the keepalive
timer of a TCP_LISTEN socket.

This function runs for awful long times, with socket lock held,
meaning that other cpus needing this lock have to spin for hundred of ms.

SYNACK are sent in huge bursts, likely to cause severe drops anyway.

This model was OK 15 years ago when memory was very tight.

We now can afford to have a timer per request sock.

Timer invocations no longer need to lock the listener,
and can be run from all cpus in parallel.

With following patch increasing somaxconn width to 32 bits,
I tested a listener with more than 4 million active request sockets,
and a steady SYNFLOOD of ~200,000 SYN per second.
Host was sending ~830,000 SYNACK per second.

This is ~100 times more what we could achieve before this patch.

Later, we will get rid of the listener hash and use ehash instead.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-20 12:40:25 -04:00
Eric Dumazet
52452c5425 inet: drop prev pointer handling in request sock
When request sock are put in ehash table, the whole notion
of having a previous request to update dl_next is pointless.

Also, following patch will get rid of big purge timer,
so we want to delete a request sock without holding listener lock.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-20 12:40:25 -04:00
Eric Dumazet
08d2cc3b26 inet: request sock should init IPv6/IPv4 addresses
In order to be able to use sk_ehashfn() for request socks,
we need to initialize their IPv6/IPv4 addresses.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-18 22:00:35 -04:00
Eric Dumazet
77a6a471bc ipv6: get rid of __inet6_hash()
We can now use inet_hash() and __inet_hash() instead of private
functions.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-18 22:00:35 -04:00
Eric Dumazet
d1e559d0b1 inet: add IPv6 support to sk_ehashfn()
Intent is to converge IPv4 & IPv6 inet_hash functions to
factorize code.

IPv4 sockets initialize sk_rcv_saddr and sk_v6_daddr
in this patch, thanks to new sk_daddr_set() and sk_rcv_saddr_set()
helpers.

__inet6_hash can now use sk_ehashfn() instead of a private
inet6_sk_ehashfn() and will simply use __inet_hash() in a
following patch.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-18 22:00:34 -04:00
Eric Dumazet
407640de21 inet: add sk_listener argument to inet_reqsk_alloc()
listener socket can be used to set net pointer, and will
be later used to hold a reference on listener.

Add a const qualifier to first argument (struct request_sock_ops *),
and factorize all write_pnet(&ireq->ireq_net, sock_net(sk));

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-17 22:01:55 -04:00
Eric Dumazet
16f86165bd inet: fill request sock ir_iif for IPv4
Once request socks will be in ehash table, they will need to have
a valid ir_iff field.

This is currently true only for IPv6. This patch extends support
for IPv4 as well.

This means inet_diag_fill_req() can now properly use ir_iif,
which is better for IPv6 link locals anyway, as request sockets
and established sockets will propagate consistent netlink idiag_if.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-14 15:05:10 -04:00
Eric Dumazet
3f66b083a5 inet: introduce ireq_family
Before inserting request socks into general hash table,
fill their socket family.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-12 22:58:13 -04:00
Eric Dumazet
bd337c581b ipv6: add missing ireq_net & ir_cookie initializations
I forgot to update dccp_v6_conn_request() & cookie_v6_check().
They both need to set ireq->ireq_net and ireq->ir_cookie

Lets clear ireq->ir_cookie in inet_reqsk_alloc()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: 33cf7c90fe ("net: add real socket cookies")
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-12 22:58:12 -04:00
Eric Dumazet
d77c555d32 net: fix CONFIG_NET_NS=n compilation
I forgot to use write_pnet() in three locations.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: 33cf7c90fe ("net: add real socket cookies")
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-11 23:28:49 -04:00
Eric Dumazet
33cf7c90fe net: add real socket cookies
A long standing problem in netlink socket dumps is the use
of kernel socket addresses as cookies.

1) It is a security concern.

2) Sockets can be reused quite quickly, so there is
   no guarantee a cookie is used once and identify
   a flow.

3) request sock, establish sock, and timewait socks
   for a given flow have different cookies.

Part of our effort to bring better TCP statistics requires
to switch to a different allocator.

In this patch, I chose to use a per network namespace 64bit generator,
and to use it only in the case a socket needs to be dumped to netlink.
(This might be refined later if needed)

Note that I tried to carry cookies from request sock, to establish sock,
then timewait sockets.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Eric Salo <salo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-11 21:55:28 -04:00