Commit Graph

152 Commits

Author SHA1 Message Date
Xin Long
27af86bb03 sctp: do not pr_err for the duplicated node in transport rhlist
The pr_err in sctp_hash_transport was supposed to report a sctp bug
for using rhashtable/rhlist.

The err '-EEXIST' introduced in Commit cd2b708750 ("sctp: check
duplicate node before inserting a new transport") doesn't belong
to that case.

So just return -EEXIST back without pr_err any kmsg.

Fixes: cd2b708750 ("sctp: check duplicate node before inserting a new transport")
Reported-by: Wei Chen <weichen@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-12 11:39:32 -05:00
Marcelo Ricardo Leitner
b6c5734db0 sctp: fix the handling of ICMP Frag Needed for too small MTUs
syzbot reported a hang involving SCTP, on which it kept flooding dmesg
with the message:
[  246.742374] sctp: sctp_transport_update_pmtu: Reported pmtu 508 too
low, using default minimum of 512

That happened because whenever SCTP hits an ICMP Frag Needed, it tries
to adjust to the new MTU and triggers an immediate retransmission. But
it didn't consider the fact that MTUs smaller than the SCTP minimum MTU
allowed (512) would not cause the PMTU to change, and issued the
retransmission anyway (thus leading to another ICMP Frag Needed, and so
on).

As IPv4 (ip_rt_min_pmtu=556) and IPv6 (IPV6_MIN_MTU=1280) minimum MTU
are higher than that, sctp_transport_update_pmtu() is changed to
re-fetch the PMTU that got set after our request, and with that, detect
if there was an actual change or not.

The fix, thus, skips the immediate retransmission if the received ICMP
resulted in no change, in the hope that SCTP will select another path.

Note: The value being used for the minimum MTU (512,
SCTP_DEFAULT_MINSEGMENT) is not right and instead it should be (576,
SCTP_MIN_PMTU), but such change belongs to another patch.

Changes from v1:
- do not disable PMTU discovery, in the light of commit
06ad391919 ("[SCTP] Don't disable PMTU discovery when mtu is small")
and as suggested by Xin Long.
- changed the way to break the rtx loop by detecting if the icmp
  resulted in a change or not
Changes from v2:
none

See-also: https://lkml.org/lkml/2017/12/22/811
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-08 14:19:13 -05:00
Marcelo Ricardo Leitner
cc35c3d1ed sctp: do not retransmit upon FragNeeded if PMTU discovery is disabled
Currently, if PMTU discovery is disabled on a given transport, but the
configured value is higher than the actual PMTU, it is likely that we
will get some icmp Frag Needed. The issue is, if PMTU discovery is
disabled, we won't update the information and will issue a
retransmission immediately, which may very well trigger another ICMP,
and another retransmission, leading to a loop.

The fix is to simply not trigger immediate retransmissions if PMTU
discovery is disabled on the given transport.

Changes from v2:
- updated stale comment, noticed by Xin Long

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-08 14:19:13 -05:00
Xin Long
8d32503efd sctp: fix some type cast warnings introduced by transport rhashtable
These warnings were found by running 'make C=2 M=net/sctp/'.

They are introduced by not aware of Endian for the port when
coding transport rhashtable patches.

Fixes: 7fda702f93 ("sctp: use new rhlist interface on sctp transport rhashtable")
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-29 18:03:24 +09:00
Xin Long
1cc276cec9 sctp: add the missing sock_owned_by_user check in sctp_icmp_redirect
Now sctp processes icmp redirect packet in sctp_icmp_redirect where
it calls sctp_transport_dst_check in which tp->dst can be released.

The problem is before calling sctp_transport_dst_check, it doesn't
check sock_owned_by_user, which means tp->dst could be freed while
a process is accessing it with owning the socket.

An use-after-free issue could be triggered by this.

This patch is to fix it by checking sock_owned_by_user before calling
sctp_transport_dst_check in sctp_icmp_redirect, so that it would not
release tp->dst if users still hold sock lock.

Besides, the same issue fixed in commit 45caeaa5ac ("dccp/tcp: fix
routing redirect race") on sctp also needs this check.

Fixes: 55be7a9c60 ("ipv4: Add redirect support to all protocol icmp error handlers")
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-20 12:53:45 +01:00
Xin Long
68d7546946 sctp: remove the typedef sctp_addip_chunk_t
This patch is to remove the typedef sctp_addip_chunk_t, and
replace with struct sctp_addip_chunk in the places where it's
using this typedef.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-03 09:45:47 -07:00
Xin Long
01a992bea5 sctp: remove the typedef sctp_init_chunk_t
This patch is to remove the typedef sctp_init_chunk_t, and replace
with struct sctp_init_chunk in the places where it's using this
typedef.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-01 09:08:42 -07:00
Xin Long
922dbc5be2 sctp: remove the typedef sctp_chunkhdr_t
This patch is to remove the typedef sctp_chunkhdr_t, and replace
with struct sctp_chunkhdr in the places where it's using this
typedef.

It is also to fix some indents and use sizeof(variable) instead
of sizeof(type)., especially in sctp_new.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-01 09:08:41 -07:00
Davide Caratti
804ec7ebe8 sctp: fix ICMP processing if skb is non-linear
sometimes ICMP replies to INIT chunks are ignored by the client, even if
the encapsulated SCTP headers match an open socket. This happens when the
ICMP packet is carried by a paged skb: use skb_header_pointer() to read
packet contents beyond the SCTP header, so that chunk header and initiate
tag are validated correctly.

v2:
- don't use skb_header_pointer() to read the transport header, since
  icmp_socket_deliver() already puts these 8 bytes in the linear area.
- change commit message to make specific reference to INIT chunks.

Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Reviewed-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-26 14:40:46 -04:00
Xin Long
3ebfdf0821 sctp: get sock from transport in sctp_transport_update_pmtu
This patch is almost to revert commit 02f3d4ce9e ("sctp: Adjust PMTU
updates to accomodate route invalidation."). As t->asoc can't be NULL
in sctp_transport_update_pmtu, it could get sk from asoc, and no need
to pass sk into that function.

It is also to remove some duplicated codes from that function.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-05 07:20:06 -07:00
Xin Long
5179b26694 sctp: call rcu_read_lock before checking for duplicate transport nodes
Commit cd2b708750 ("sctp: check duplicate node before inserting a
new transport") called rhltable_lookup() to check for the duplicate
transport node in transport rhashtable.

But rhltable_lookup() doesn't call rcu_read_lock inside, it could cause
a use-after-free issue if it tries to dereference the node that another
cpu has freed it. Note that sock lock can not avoid this as it is per
sock.

This patch is to fix it by calling rcu_read_lock before checking for
duplicate transport nodes.

Fixes: cd2b708750 ("sctp: check duplicate node before inserting a new transport")
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-01 09:50:58 -08:00
Xin Long
cd2b708750 sctp: check duplicate node before inserting a new transport
sctp has changed to use rhlist for transport rhashtable since commit
7fda702f93 ("sctp: use new rhlist interface on sctp transport
rhashtable").

But rhltable_insert_key doesn't check the duplicate node when inserting
a node, unlike rhashtable_lookup_insert_key. It may cause duplicate
assoc/transport in rhashtable. like:

 client (addr A, B)                 server (addr X, Y)
    connect to X           INIT (1)
                        ------------>
    connect to Y           INIT (2)
                        ------------>
                         INIT_ACK (1)
                        <------------
                         INIT_ACK (2)
                        <------------

After sending INIT (2), one transport will be created and hashed into
rhashtable. But when receiving INIT_ACK (1) and processing the address
params, another transport will be created and hashed into rhashtable
with the same addr Y and EP as the last transport. This will confuse
the assoc/transport's lookup.

This patch is to fix it by returning err if any duplicate node exists
before inserting it.

Fixes: 7fda702f93 ("sctp: use new rhlist interface on sctp transport rhashtable")
Reported-by: Fabio M. Di Nitto <fdinitto@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-19 18:19:37 -05:00
Marcelo Ricardo Leitner
b77b7565a6 sctp: add pr_debug for tracking asocs not found
This pr_debug may help identify why the system is generating some
Aborts. It's not something a sysadmin would be expected to use.

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-28 14:26:17 -05:00
Xin Long
7fda702f93 sctp: use new rhlist interface on sctp transport rhashtable
Now sctp transport rhashtable uses hash(lport, dport, daddr) as the key
to hash a node to one chain. If in one host thousands of assocs connect
to one server with the same lport and different laddrs (although it's
not a normal case), all the transports would be hashed into the same
chain.

It may cause to keep returning -EBUSY when inserting a new node, as the
chain is too long and sctp inserts a transport node in a loop, which
could even lead to system hangs there.

The new rhlist interface works for this case that there are many nodes
with the same key in one chain. It puts them into a list then makes this
list be as a node of the chain.

This patch is to replace rhashtable_ interface with rhltable_ interface.
Since a chain would not be too long and it would not return -EBUSY with
this fix when inserting a node, the reinsert loop is also removed here.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-16 23:22:17 -05:00
Xin Long
dae399d7fd sctp: hold transport instead of assoc when lookup assoc in rx path
Prior to this patch, in rx path, before calling lock_sock, it needed to
hold assoc when got it by __sctp_lookup_association, in case other place
would free/put assoc.

But in __sctp_lookup_association, it lookup and hold transport, then got
assoc by transport->assoc, then hold assoc and put transport. It means
it didn't hold transport, yet it was returned and later on directly
assigned to chunk->transport.

Without the protection of sock lock, the transport may be freed/put by
other places, which would cause a use-after-free issue.

This patch is to fix this issue by holding transport instead of assoc.
As holding transport can make sure to access assoc is also safe, and
actually it looks up assoc by searching transport rhashtable, to hold
transport here makes more sense.

Note that the function will be renamed later on on another patch.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-31 16:20:33 -04:00
Xin Long
7c17fcc726 sctp: return back transport in __sctp_rcv_init_lookup
Prior to this patch, it used a local variable to save the transport that is
looked up by __sctp_lookup_association(), and didn't return it back. But in
sctp_rcv, it is used to initialize chunk->transport. So when hitting this,
even if it found the transport, it was still initializing chunk->transport
with null instead.

This patch is to return the transport back through transport pointer
that is from __sctp_rcv_lookup_harder().

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-31 16:20:32 -04:00
David S. Miller
d6989d4bbe Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-09-23 06:46:57 -04:00
Marcelo Ricardo Leitner
e2f036a972 sctp: rename WORD_TRUNC/ROUND macros
To something more meaningful these days, specially because this is
working on packet headers or lengths and which are not tied to any CPU
arch but to the protocol itself.

So, WORD_TRUNC becomes SCTP_TRUNC4 and WORD_ROUND becomes SCTP_PAD4.

Reported-by: David Laight <David.Laight@ACULAB.COM>
Reported-by: David Miller <davem@davemloft.net>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-22 03:13:26 -04:00
Xin Long
715f5552b1 sctp: hold the transport before using it in sctp_hash_cmp
Since commit 4f00878126 ("sctp: apply rhashtable api to send/recv
path"), sctp uses transport rhashtable with .obj_cmpfn sctp_hash_cmp,
in which it compares the members of the transport with the rhashtable
args to check if it's the right transport.

But sctp uses the transport without holding it in sctp_hash_cmp, it can
cause a use-after-free panic. As after it gets transport from hashtable,
another CPU may close the sk and free the asoc. In sctp_association_free,
it frees all the transports, meanwhile, the assoc's refcnt may be reduced
to 0, assoc can be destroyed by sctp_association_destroy.

So after that, transport->assoc is actually an unavailable memory address
in sctp_hash_cmp. Although sctp_hash_cmp is under rcu_read_lock, it still
can not avoid this, as assoc is not freed by RCU.

This patch is to hold the transport before checking it's members with
sctp_transport_hold, in which it checks the refcnt first, holds it if
it's not 0.

Fixes: 4f00878126 ("sctp: apply rhashtable api to send/recv path")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-13 11:44:58 -04:00
Marcelo Ricardo Leitner
4c2f245496 sctp: linearize early if it's not GSO
Because otherwise when crc computation is still needed it's way more
expensive than on a linear buffer to the point that it affects
performance.

It's so expensive that netperf test gives a perf output as below:

Overhead  Command         Shared Object       Symbol
  18,62%  netserver       [kernel.vmlinux]    [k] crc32_generic_shift
   2,57%  netserver       [kernel.vmlinux]    [k] __pskb_pull_tail
   1,94%  netserver       [kernel.vmlinux]    [k] fib_table_lookup
   1,90%  netserver       [kernel.vmlinux]    [k] copy_user_enhanced_fast_string
   1,66%  swapper         [kernel.vmlinux]    [k] intel_idle
   1,63%  netserver       [kernel.vmlinux]    [k] _raw_spin_lock
   1,59%  netserver       [sctp]              [k] sctp_packet_transmit
   1,55%  netserver       [kernel.vmlinux]    [k] memcpy_erms
   1,42%  netserver       [sctp]              [k] sctp_rcv

# netperf -H 192.168.10.1 -l 10 -t SCTP_STREAM -cC -- -m 12000
SCTP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.10.1 () port 0 AF_INET
Recv   Send    Send                          Utilization       Service Demand
Socket Socket  Message  Elapsed              Send     Recv     Send    Recv
Size   Size    Size     Time     Throughput  local    remote   local   remote
bytes  bytes   bytes    secs.    10^6bits/s  % S      % S      us/KB   us/KB

212992 212992  12000    10.00      3016.42   2.88     3.78     1.874   2.462

After patch:
Overhead  Command         Shared Object      Symbol
   2,75%  netserver       [kernel.vmlinux]   [k] memcpy_erms
   2,63%  netserver       [kernel.vmlinux]   [k] copy_user_enhanced_fast_string
   2,39%  netserver       [kernel.vmlinux]   [k] fib_table_lookup
   2,04%  netserver       [kernel.vmlinux]   [k] __pskb_pull_tail
   1,91%  netserver       [kernel.vmlinux]   [k] _raw_spin_lock
   1,91%  netserver       [sctp]             [k] sctp_packet_transmit
   1,72%  netserver       [mlx4_en]          [k] mlx4_en_process_rx_cq
   1,68%  netserver       [sctp]             [k] sctp_rcv

# netperf -H 192.168.10.1 -l 10 -t SCTP_STREAM -cC -- -m 12000
SCTP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.10.1 () port 0 AF_INET
Recv   Send    Send                          Utilization       Service Demand
Socket Socket  Message  Elapsed              Send     Recv     Send    Recv
Size   Size    Size     Time     Throughput  local    remote   local   remote
bytes  bytes   bytes    secs.    10^6bits/s  % S      % S      us/KB   us/KB

212992 212992  12000    10.00      3681.77   3.83     3.46     2.045   1.849

Fixes: 3acb50c18d ("sctp: delay as much as possible skb_linearize")
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-19 17:09:42 -07:00
Marcelo Ricardo Leitner
eefc1b1d10 sctp: fix BH handling on socket backlog
Now that the backlog processing is called with BH enabled, we have to
disable BH before taking the socket lock via bh_lock_sock() otherwise
it may dead lock:

sctp_backlog_rcv()
                bh_lock_sock(sk);

                if (sock_owned_by_user(sk)) {
                        if (sk_add_backlog(sk, skb, sk->sk_rcvbuf))
                                sctp_chunk_free(chunk);
                        else
                                backloged = 1;
                } else
                        sctp_inq_push(inqueue, chunk);

                bh_unlock_sock(sk);

while sctp_inq_push() was disabling/enabling BH, but enabling BH
triggers pending softirq, which then may try to re-lock the socket in
sctp_rcv().

[  219.187215]  <IRQ>
[  219.187217]  [<ffffffff817ca3e0>] _raw_spin_lock+0x20/0x30
[  219.187223]  [<ffffffffa041888c>] sctp_rcv+0x48c/0xba0 [sctp]
[  219.187225]  [<ffffffff816e7db2>] ? nf_iterate+0x62/0x80
[  219.187226]  [<ffffffff816f1b14>] ip_local_deliver_finish+0x94/0x1e0
[  219.187228]  [<ffffffff816f1e1f>] ip_local_deliver+0x6f/0xf0
[  219.187229]  [<ffffffff816f1a80>] ? ip_rcv_finish+0x3b0/0x3b0
[  219.187230]  [<ffffffff816f17a8>] ip_rcv_finish+0xd8/0x3b0
[  219.187232]  [<ffffffff816f2122>] ip_rcv+0x282/0x3a0
[  219.187233]  [<ffffffff810d8bb6>] ? update_curr+0x66/0x180
[  219.187235]  [<ffffffff816abac4>] __netif_receive_skb_core+0x524/0xa90
[  219.187236]  [<ffffffff810d8e00>] ? update_cfs_shares+0x30/0xf0
[  219.187237]  [<ffffffff810d557c>] ? __enqueue_entity+0x6c/0x70
[  219.187239]  [<ffffffff810dc454>] ? enqueue_entity+0x204/0xdf0
[  219.187240]  [<ffffffff816ac048>] __netif_receive_skb+0x18/0x60
[  219.187242]  [<ffffffff816ad1ce>] process_backlog+0x9e/0x140
[  219.187243]  [<ffffffff816ac8ec>] net_rx_action+0x22c/0x370
[  219.187245]  [<ffffffff817cd352>] __do_softirq+0x112/0x2e7
[  219.187247]  [<ffffffff817cc3bc>] do_softirq_own_stack+0x1c/0x30
[  219.187247]  <EOI>
[  219.187248]  [<ffffffff810aa1c8>] do_softirq.part.14+0x38/0x40
[  219.187249]  [<ffffffff810aa24d>] __local_bh_enable_ip+0x7d/0x80
[  219.187254]  [<ffffffffa0408428>] sctp_inq_push+0x68/0x80 [sctp]
[  219.187258]  [<ffffffffa04190f1>] sctp_backlog_rcv+0x151/0x1c0 [sctp]
[  219.187260]  [<ffffffff81692b07>] __release_sock+0x87/0xf0
[  219.187261]  [<ffffffff81692ba0>] release_sock+0x30/0xa0
[  219.187265]  [<ffffffffa040e46d>] sctp_accept+0x17d/0x210 [sctp]
[  219.187266]  [<ffffffff810e7510>] ? prepare_to_wait_event+0xf0/0xf0
[  219.187268]  [<ffffffff8172d52c>] inet_accept+0x3c/0x130
[  219.187269]  [<ffffffff8168d7a3>] SYSC_accept4+0x103/0x210
[  219.187271]  [<ffffffff817ca2ba>] ? _raw_spin_unlock_bh+0x1a/0x20
[  219.187272]  [<ffffffff81692bfc>] ? release_sock+0x8c/0xa0
[  219.187276]  [<ffffffffa0413e22>] ? sctp_inet_listen+0x62/0x1b0 [sctp]
[  219.187277]  [<ffffffff8168f2d0>] SyS_accept+0x10/0x20

Fixes: 860fbbc343 ("sctp: prepare for socket backlog behavior change")
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-25 11:22:22 -07:00
Marcelo Ricardo Leitner
e7487c86dc sctp: avoid identifying address family many times for a chunk
Identifying address family operations during rx path is not something
expensive but it's ugly to the eye to have it done multiple times,
specially when we already validated it during initial rx processing.

This patch takes advantage of the now shared sctp_input_cb and make the
pointer to the operations readily available.

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-13 18:10:14 -07:00
Marcelo Ricardo Leitner
9e23832379 sctp: allow others to use sctp_input_cb
We process input path in other files too and having access to it is
nice, so move it to a header where it's shared.

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-13 18:10:13 -07:00
Marcelo Ricardo Leitner
90017accff sctp: Add GSO support
SCTP has this pecualiarity that its packets cannot be just segmented to
(P)MTU. Its chunks must be contained in IP segments, padding respected.
So we can't just generate a big skb, set gso_size to the fragmentation
point and deliver it to IP layer.

This patch takes a different approach. SCTP will now build a skb as it
would be if it was received using GRO. That is, there will be a cover
skb with protocol headers and children ones containing the actual
segments, already segmented to a way that respects SCTP RFCs.

With that, we can tell skb_segment() to just split based on frag_list,
trusting its sizes are already in accordance.

This way SCTP can benefit from GSO and instead of passing several
packets through the stack, it can pass a single large packet.

v2:
- Added support for receiving GSO frames, as requested by Dave Miller.
- Clear skb->cb if packet is GSO (otherwise it's not used by SCTP)
- Added heuristics similar to what we have in TCP for not generating
  single GSO packets that fills cwnd.
v3:
- consider sctphdr size in skb_gso_transport_seglen()
- rebased due to 5c7cdf339a ("gso: Remove arbitrary checks for
  unsupported GSO")

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Tested-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-03 19:37:21 -04:00
Marcelo Ricardo Leitner
3acb50c18d sctp: delay as much as possible skb_linearize
This patch is a preparation for the GSO one. In order to successfully
handle GSO packets on rx path we must not call skb_linearize, otherwise
it defeats any gain GSO may have had.

This patch thus delays as much as possible the call to skb_linearize,
leaving it to sctp_inq_pop() moment. For that the sanity checks
performed now know how to deal with fragments.

One positive side-effect of this is that if the socket is backlogged it
will have the chance of doing it on backlog processing instead of
during softirq.

With this move, it's evident that a check for non-linearity in
sctp_inq_pop was ineffective and is now removed. Note that a similar
check is performed a bit below this one.

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Tested-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-03 19:37:21 -04:00
Eric Dumazet
02a1d6e7a6 net: rename NET_{ADD|INC}_STATS_BH()
Rename NET_INC_STATS_BH() to __NET_INC_STATS()
and NET_ADD_STATS_BH() to __NET_ADD_STATS()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-27 22:48:24 -04:00
Eric Dumazet
08e3baef65 net: sctp: rename SCTP_INC_STATS_BH()
Rename SCTP_INC_STATS_BH() to __SCTP_INC_STATS()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-27 22:48:23 -04:00
Eric Dumazet
5d3848bc33 net: rename ICMP_INC_STATS_BH()
Rename ICMP_INC_STATS_BH() to __ICMP_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
Marcelo Ricardo Leitner
3822a5ff4b sctp: align MTU to a word
SCTP is a protocol that is aligned to a word (4 bytes). Thus using bare
MTU can sometimes return values that are not aligned, like for loopback,
which is 65536 but ipv4_mtu() limits that to 65535. This mis-alignment
will cause the last non-aligned bytes to never be used and can cause
issues with congestion control.

So it's better to just consider a lower MTU and keep congestion control
calcs saner as they are based on PMTU.

Same applies to icmp frag needed messages, which is also fixed by this
patch.

One other effect of this is the inability to send MTU-sized packet
without queueing or fragmentation and without hitting Nagle. As the
check performed at sctp_packet_can_append_data():

if (chunk->skb->len + q->out_qlen >= transport->pathmtu - packet->overhead)
	/* Enough data queued to fill a packet */
	return SCTP_XMIT_OK;

with the above example of MTU, if there are no other messages queued,
one cannot send a packet that just fits one packet (65532 bytes) and
without causing DATA chunk fragmentation or a delay.

v2:
 - Added WORD_TRUNC macro

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-20 16:31:12 -04:00
Marcelo Ricardo Leitner
cea8768f33 sctp: allow sctp_transmit_packet and others to use gfp
Currently sctp_sendmsg() triggers some calls that will allocate memory
with GFP_ATOMIC even when not necessary. In the case of
sctp_packet_transmit it will allocate a linear skb that will be used to
construct the packet and this may cause sends to fail due to ENOMEM more
often than anticipated specially with big MTUs.

This patch thus allows it to inherit gfp flags from upper calls so that
it can use GFP_KERNEL if it was triggered by a sctp_sendmsg call or
similar. All others, like retransmits or flushes started from BH, are
still allocated using GFP_ATOMIC.

In netperf tests this didn't result in any performance drawbacks when
memory is not too fragmented and made it trigger ENOMEM way less often.

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-13 22:29:07 -04:00
Xin Long
f46c7011b0 sctp: move rcu_read_lock from __sctp_lookup_association to sctp_lookup_association
__sctp_lookup_association() is only invoked by sctp_v4_err() and
sctp_rcv(), both which run on the rx BH, and it has been protected
by rcu_read_lock [see ip_local_deliver_finish() / ipv6_rcv()].

So we can move it to sctp_lookup_association, only let
sctp_lookup_association use rcu_read_lock.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-17 15:41:54 -05:00
Xin Long
1eed677933 sctp: fix the transport dead race check by using atomic_add_unless on refcnt
Now when __sctp_lookup_association is running in BH, it will try to
check if t->dead is set, but meanwhile other CPUs may be freeing this
transport and this assoc and if it happens that
__sctp_lookup_association checked t->dead a bit too early, it may think
that the association is still good while it was already freed.

So we fix this race by using atomic_add_unless in sctp_transport_hold.
After we get one transport from hashtable, we will hold it only when
this transport's refcnt is not 0, so that we can make sure t->asoc
cannot be freed before we hold the asoc again.

Note that sctp association is not freed using RCU so we can't use
atomic_add_unless() with it as it may just be too late for that either.

Fixes: 4f00878126 ("sctp: apply rhashtable api to send/recv path")
Reported-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-28 15:59:32 -08:00
Xin Long
dd7445ad6b sctp: the temp asoc's transports should not be hashed/unhashed
Re-establish the previous behavior and avoid hashing temporary asocs by
checking t->asoc->temp in sctp_(un)hash_transport. Also, remove the
check of t->asoc->temp in __sctp_lookup_association, since they are
never hashed now.

Fixes: 4f00878126 ("sctp: apply rhashtable api to send/recv path")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Reported-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-17 19:11:44 -05:00
Xin Long
65a5124a71 sctp: support to lookup with ep+paddr in transport rhashtable
Now, when we sendmsg, we translate the ep to laddr by selecting the
first element of the list, and then do a lookup for a transport.

But sctp_hash_cmp() will compare it against asoc addr_list, which may
be a subset of ep addr_list, meaning that this chosen laddr may not be
there, and thus making it impossible to find the transport.

So we fix it by using ep + paddr to lookup transports in hashtable. In
sctp_hash_cmp, if .ep is set, we will check if this ep == asoc->ep,
or we will do the laddr check.

Fixes: d6c0256a60 ("sctp: add the rhashtable apis for sctp global transport hashtable")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Reported-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-15 14:41:36 -05:00
Xin Long
b5eff71283 sctp: drop the old assoc hashtable of sctp
transport hashtable will replace the association hashtable,
so association hashtable is not used in sctp any more, so
drop the codes about that.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-05 12:24:01 -05:00
Xin Long
4f00878126 sctp: apply rhashtable api to send/recv path
apply lookup apis to two functions, for __sctp_endpoint_lookup_assoc
and __sctp_lookup_association, it's invoked in the protection of sock
lock, it will be safe, but sctp_lookup_association need to call
rcu_read_lock() and to detect the t->dead to protect it.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-05 12:24:01 -05:00
Xin Long
d6c0256a60 sctp: add the rhashtable apis for sctp global transport hashtable
tranport hashtbale will replace the association hashtable to do the
lookup for transport, and then get association by t->assoc, rhashtable
apis will be used because of it's resizable, scalable and using rcu.

lport + rport + paddr will be the base hashkey to locate the chain,
with net to protect one netns from another, then plus the laddr to
compare to get the target.

this patch will provider the lookup functions:
- sctp_epaddr_lookup_transport
- sctp_addrs_lookup_transport

hash/unhash functions:
- sctp_hash_transport
- sctp_unhash_transport

init/destroy functions:
- sctp_transport_hashtable_init
- sctp_transport_hashtable_destroy

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-05 12:24:00 -05:00
Tom Herbert
202863fe4c sctp: Change sctp to implement csum_levels
CHECKSUM_UNNECESSARY may be applied to the SCTP CRC so we need to
appropriate account for this by decrementing csum_level. This is
done by calling __skb_dec_checksum_unnecessary.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-29 20:41:11 -07:00
Duan Jiong
7304fe4681 net: fix the counter ICMP_MIB_INERRORS/ICMP6_MIB_INERRORS
When dealing with ICMPv[46] Error Message, function icmp_socket_deliver()
and icmpv6_notify() do some valid checks on packet's length, but then some
protocols check packet's length redaudantly. So remove those duplicated
statements, and increase counter ICMP_MIB_INERRORS/ICMP6_MIB_INERRORS in
function icmp_socket_deliver() and icmpv6_notify() respectively.

In addition, add missed counter in udp6/udplite6 when socket is NULL.

Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-31 22:04:18 -07:00
wangweidong
5bc1d1b4a2 sctp: remove macros sctp_bh_[un]lock_sock
Redefined bh_[un]lock_sock to sctp_bh[un]lock_sock for user
space friendly code which we haven't use in years, so removing them.

Signed-off-by: Wang Weidong <wangweidong1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-21 18:41:36 -08:00
wangweidong
387602dfdc sctp: remove macros sctp_write_[un]_lock
Redefined write_[un]lock to sctp_write_[un]lock for user space
friendly code which we haven't use in years, so removing them.

Signed-off-by: Wang Weidong <wangweidong1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-21 18:40:41 -08:00
wangweidong
79b91130a2 sctp: remove macros sctp_local_bh_{disable|enable}
Redefined local_bh_{disable|enable} to sctp_local_bh_{disable|enable}
for user space friendly code which we haven't use in years, so removing them.

Signed-off-by: Wang Weidong <wangweidong1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-21 18:40:40 -08:00
wangweidong
8d72651d86 sctp: fix checkpatch errors with open brace '{' and trailing statements
fix checkpatch errors below:
ERROR: that open brace { should be on the previous line
ERROR: open brace '{' following function declarations go on the next line
ERROR: trailing statements should be on next line

Signed-off-by: Wang Weidong <wangweidong1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-26 13:47:48 -05:00
wangweidong
f7010e6144 sctp: fix checkpatch errors with indent
fix checkpatch errors below:
ERROR: switch and case should be at the same inden
ERROR: code indent should use tabs where possible

Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Wang Weidong <wangweidong1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-26 13:47:48 -05:00
wangweidong
cb3f837ba9 sctp: fix checkpatch errors with space required or prohibited
fix checkpatch errors while the space is required or prohibited
to the "=,()++..."

Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Wang Weidong <wangweidong1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-26 13:47:47 -05:00
wangweidong
f482f2fcd1 sctp: remove the never used 'return' and redundant 'break'
In switch() had do return, and never use the 'return NULL'. The
'break' after return or goto has no effect. Remove it.

v2: make it more readable as suggested by Neil.

Signed-off-by: Wang Weidong <wangweidong1@huawei.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-22 18:56:51 -05:00
Hannes Frederic Sowa
790e38bc26 ipv6: move ip6_sk_accept_pmtu from generic pmtu update path to ipv6 one
In commit 93b36cf342 ("ipv6: support IPV6_PMTU_INTERFACE on sockets")
I made a horrible mistake to add ip6_sk_accept_pmtu to the generic
sctp_icmp_frag_needed path. This results in build warnings if IPv6 is
disabled which were luckily caught by Fengguang's kbuild bot. But it
also leads to a kernel panic IPv4 frag-needed packet is received.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-21 22:00:59 -05:00
David S. Miller
fc45b45540 Revert "sctp: fix missing include file"
This reverts commit ac0917f250.

Better version of this fix forthcoming.

Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-21 22:00:39 -05:00
sfeldma@cumulusnetworks.com
ac0917f250 sctp: fix missing include file
Compile error reported by Jim Davis on netdev.

ip6_sk_accept_pmtu() needs net/ip6_route.h

Signed-off-by: Scott Feldman <sfeldma@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-21 00:00:33 -05:00
Hannes Frederic Sowa
93b36cf342 ipv6: support IPV6_PMTU_INTERFACE on sockets
IPV6_PMTU_INTERFACE is the same as IPV6_PMTU_PROBE for ipv6. Add it
nontheless for symmetry with IPv4 sockets. Also drop incoming MTU
information if this mode is enabled.

The additional bit in ipv6_pinfo just eats in the padding behind the
bitfield. There are no changes to the layout of the struct at all.

Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-18 17:37:05 -05:00