Commit graph

1325 commits

Author SHA1 Message Date
Xin Long 5bf35ddfee sctp: change sk state only when it has assocs in sctp_shutdown
Now when users shutdown a sock with SEND_SHUTDOWN in sctp, even if
this sock has no connection (assoc), sk state would be changed to
SCTP_SS_CLOSING, which is not as we expect.

Besides, after that if users try to listen on this sock, kernel
could even panic when it dereference sctp_sk(sk)->bind_hash in
sctp_inet_listen, as bind_hash is null when sock has no assoc.

This patch is to move sk state change after checking sk assocs
is not empty, and also merge these two if() conditions and reduce
indent level.

Fixes: d46e416c11 ("sctp: sctp should change socket state when shutdown is received")
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Tested-by: Andrey Konovalov <andreyknvl@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>
2016-11-14 16:22:33 -05:00
Marcelo Ricardo Leitner 7233bc84a3 sctp: assign assoc_id earlier in __sctp_connect
sctp_wait_for_connect() currently already holds the asoc to keep it
alive during the sleep, in case another thread release it. But Andrey
Konovalov and Dmitry Vyukov reported an use-after-free in such
situation.

Problem is that __sctp_connect() doesn't get a ref on the asoc and will
do a read on the asoc after calling sctp_wait_for_connect(), but by then
another thread may have closed it and the _put on sctp_wait_for_connect
will actually release it, causing the use-after-free.

Fix is, instead of doing the read after waiting for the connect, do it
before so, and avoid this issue as the socket is still locked by then.
There should be no issue on returning the asoc id in case of failure as
the application shouldn't trust on that number in such situations
anyway.

This issue doesn't exist in sctp_sendmsg() path.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Reviewed-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-07 13:18:37 -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
Xin Long cd26da4ff4 sctp: hold transport instead of assoc in sctp_diag
In sctp_transport_lookup_process(), Commit 1cceda7849 ("sctp: fix
the issue sctp_diag uses lock_sock in rcu_read_lock") moved cb() out
of rcu lock, but it put transport and hold assoc instead, and ignore
that cb() still uses transport. It may cause a use-after-free issue.

This patch is to hold transport instead of assoc there.

Fixes: 1cceda7849 ("sctp: fix the issue sctp_diag uses lock_sock in rcu_read_lock")
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
Marcelo Ricardo Leitner bf911e985d sctp: validate chunk len before actually using it
Andrey Konovalov reported that KASAN detected that SCTP was using a slab
beyond the boundaries. It was caused because when handling out of the
blue packets in function sctp_sf_ootb() it was checking the chunk len
only after already processing the first chunk, validating only for the
2nd and subsequent ones.

The fix is to just move the check upwards so it's also validated for the
1st chunk.

Reported-by: Andrey Konovalov <andreyknvl@google.com>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Reviewed-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-29 12:00:10 -04:00
Xin Long ecc515d723 sctp: fix the panic caused by route update
Commit 7303a14750 ("sctp: identify chunks that need to be fragmented
at IP level") made the chunk be fragmented at IP level in the next round
if it's size exceed PMTU.

But there still is another case, PMTU can be updated if transport's dst
expires and transport's pmtu_pending is set in sctp_packet_transmit. If
the new PMTU is less than the chunk, the same issue with that commit can
be triggered.

So we should drop this packet and let it retransmit in another round
where it would be fragmented at IP level.

This patch is to fix it by checking the chunk size after PMTU may be
updated and dropping this packet if it's size exceed PMTU.

Fixes: 90017accff ("sctp: Add GSO support")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@txudriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-26 17:32:19 -04:00
Jiri Slaby a4b8e71b05 net: sctp, forbid negative length
Most of getsockopt handlers in net/sctp/socket.c check len against
sizeof some structure like:
        if (len < sizeof(int))
                return -EINVAL;

On the first look, the check seems to be correct. But since len is int
and sizeof returns size_t, int gets promoted to unsigned size_t too. So
the test returns false for negative lengths. Yes, (-1 < sizeof(long)) is
false.

Fix this in sctp by explicitly checking len < 0 before any getsockopt
handler is called.

Note that sctp_getsockopt_events already handled the negative case.
Since we added the < 0 check elsewhere, this one can be removed.

If not checked, this is the result:
UBSAN: Undefined behaviour in ../mm/page_alloc.c:2722:19
shift exponent 52 is too large for 32-bit type 'int'
CPU: 1 PID: 24535 Comm: syz-executor Not tainted 4.8.1-0-syzkaller #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014
 0000000000000000 ffff88006d99f2a8 ffffffffb2f7bdea 0000000041b58ab3
 ffffffffb4363c14 ffffffffb2f7bcde ffff88006d99f2d0 ffff88006d99f270
 0000000000000000 0000000000000000 0000000000000034 ffffffffb5096422
Call Trace:
 [<ffffffffb3051498>] ? __ubsan_handle_shift_out_of_bounds+0x29c/0x300
...
 [<ffffffffb273f0e4>] ? kmalloc_order+0x24/0x90
 [<ffffffffb27416a4>] ? kmalloc_order_trace+0x24/0x220
 [<ffffffffb2819a30>] ? __kmalloc+0x330/0x540
 [<ffffffffc18c25f4>] ? sctp_getsockopt_local_addrs+0x174/0xca0 [sctp]
 [<ffffffffc18d2bcd>] ? sctp_getsockopt+0x10d/0x1b0 [sctp]
 [<ffffffffb37c1219>] ? sock_common_getsockopt+0xb9/0x150
 [<ffffffffb37be2f5>] ? SyS_getsockopt+0x1a5/0x270

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-sctp@vger.kernel.org
Cc: netdev@vger.kernel.org
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-23 17:43:15 -04:00
David S. Miller b50afd203a Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Three sets of overlapping changes.  Nothing serious.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-02 22:20:41 -04:00
Xin Long 1cceda7849 sctp: fix the issue sctp_diag uses lock_sock in rcu_read_lock
When sctp dumps all the ep->assocs, it needs to lock_sock first,
but now it locks sock in rcu_read_lock, and lock_sock may sleep,
which would break rcu_read_lock.

This patch is to get and hold one sock when traversing the list.
After that and get out of rcu_read_lock, lock and dump it. Then
it will traverse the list again to get the next one until all
sctp socks are dumped.

For sctp_diag_dump_one, it fixes this issue by holding asoc and
moving cb() out of rcu_read_lock in sctp_transport_lookup_process.

Fixes: 8f840e47f1 ("sctp: add the sctp_diag.c file")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-30 02:08:57 -04:00
Xin Long be4947bf46 sctp: change to check peer prsctp_capable when using prsctp polices
Now before using prsctp polices, sctp uses asoc->prsctp_enable to
check if prsctp is enabled. However asoc->prsctp_enable is set only
means local host support prsctp, sctp should not abandon packet if
peer host doesn't enable prsctp.

So this patch is to use asoc->peer.prsctp_capable to check if prsctp
is enabled on both side, instead of asoc->prsctp_enable, as asoc's
peer.prsctp_capable is set only when local and peer both enable prsctp.

Fixes: a6c2f79287 ("sctp: implement prsctp TTL policy")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-30 02:07:05 -04:00
Xin Long 0605483f6a sctp: remove prsctp_param from sctp_chunk
Now sctp uses chunk->prsctp_param to save the prsctp param for all the
prsctp polices, we didn't need to introduce prsctp_param to sctp_chunk.
We can just use chunk->sinfo.sinfo_timetolive for RTX and BUF polices,
and reuse msg->expires_at for TTL policy, as the prsctp polices and old
expires policy are mutual exclusive.

This patch is to remove prsctp_param from sctp_chunk, and reuse msg's
expires_at for TTL and chunk's sinfo.sinfo_timetolive for RTX and BUF
polices.

Note that sctp can't use chunk's sinfo.sinfo_timetolive for TTL policy,
as it needs a u64 variables to save the expires_at time.

This one also fixes the "netperf-Throughput_Mbps -37.2% regression"
issue.

Fixes: a6c2f79287 ("sctp: implement prsctp TTL policy")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-30 02:07:05 -04:00
Jia He 6d4a741cbb net: Suppress the "Comparison to NULL could be written" warnings
This is to suppress the checkpatch.pl warning "Comparison to NULL
could be written". No functional changes here.

Signed-off-by: Jia He <hejianet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-30 01:50:45 -04:00
Jia He 7d64a94be2 proc: Reduce cache miss in sctp_snmp_seq_show
This is to use the generic interfaces snmp_get_cpu_field{,64}_batch to
aggregate the data by going through all the items of each cpu sequentially.

Signed-off-by: Jia He <hejianet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-30 01:50:44 -04:00
Marcelo Ricardo Leitner a3007446e5 sctp: fix the handling of SACK Gap Ack blocks
sctp_acked() is using 32bit arithmetics on 16bits vars, via TSN_lte()
macros, which is weird and confusing.

Once the offset to ctsn is calculated, all wrapping is already handled
and thus to verify the Gap Ack blocks we can just use pure
less/big-or-equal than checks.

Also, rename gap variable to tsn_offset, so it's more meaningful, as
it doesn't point to any gap at all.

Even so, I don't think this discrepancy resulted in any practical bug.

This patch is a preparation for the next one, which will introduce
typecheck() for TSN_lte() macros and would cause a compile error here.

Suggested-by: David Laight <David.Laight@ACULAB.COM>
Reported-by: David Laight <David.Laight@ACULAB.COM>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-23 06:54:58 -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 4a225ce395 sctp: make use of SCTP_TRUNC4 macro
And avoid the usage of '&~3'. This is the last place still not using
the macro.
Also break the line to make it easier to read.

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
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
Christophe Jaillet e8bc8f9a67 sctp: Remove some redundant code
In commit 311b21774f ("sctp: simplify sk_receive_queue locking"), a call
to 'skb_queue_splice_tail_init()' has been made explicit. Previously it was
hidden in 'sctp_skb_list_tail()'

Now, the code around it looks redundant. The '_init()' part of
'skb_queue_splice_tail_init()' should already do the same.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
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>
2016-09-19 01:34:01 -04:00
Xin Long 41001faf95 sctp: not return ENOMEM err back in sctp_packet_transmit
As David and Marcelo's suggestion, ENOMEM err shouldn't return back to
user in transmit path. Instead, sctp's retransmit would take care of
the chunks that fail to send because of ENOMEM.

This patch is only to do some release job when alloc_skb fails, not to
return ENOMEM back any more.

Besides, it also cleans up sctp_packet_transmit's err path, and fixes
some issues in err path:

 - It didn't free the head skb in nomem: path.
 - No need to check nskb in no_route: path.
 - It should goto err: path if alloc_skb fails for head.
 - Not all the NOMEMs should free nskb.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-18 22:02:33 -04:00
Xin Long 83dbc3d4a3 sctp: make sctp_outq_flush/tail/uncork return void
sctp_outq_flush return value is meaningless now, this patch is
to make sctp_outq_flush return void, as well as sctp_outq_fail
and sctp_outq_uncork.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-18 22:02:33 -04:00
Xin Long 645194409b sctp: save transmit error to sk_err in sctp_outq_flush
Every time when sctp calls sctp_outq_flush, it sends out the chunks of
control queue, retransmit queue and data queue. Even if some trunks are
failed to transmit, it still has to flush all the transports, as it's
the only chance to clean that transmit_list.

So the latest transmit error here should be returned back. This transmit
error is an internal error of sctp stack.

I checked all the places where it uses the transmit error (the return
value of sctp_outq_flush), most of them are actually just save it to
sk_err.

Except for sctp_assoc/endpoint_bh_rcv, they will drop the chunk if
it's failed to send a REPLY, which is actually incorrect, as we can't
be sure the error that sctp_outq_flush returns is from sending that
REPLY.

So it's meaningless for sctp_outq_flush to return error back.

This patch is to save transmit error to sk_err in sctp_outq_flush, the
new error can update the old value. Eventually, sctp_wait_for_* would
check for it.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-18 22:02:32 -04:00
Xin Long b61c654f9b sctp: free msg->chunks when sctp_primitive_SEND return err
Last patch "sctp: do not return the transmit err back to sctp_sendmsg"
made sctp_primitive_SEND return err only when asoc state is unavailable.
In this case, chunks are not enqueued, they have no chance to be freed if
we don't take care of them later.

This Patch is actually to revert commit 1cd4d5c432 ("sctp: remove the
unused sctp_datamsg_free()"), commit 69b5777f2e ("sctp: hold the chunks
only after the chunk is enqueued in outq") and commit 8b570dc9f7 ("sctp:
only drop the reference on the datamsg after sending a msg"), to use
sctp_datamsg_free to free the chunks of current msg.

Fixes: 8b570dc9f7 ("sctp: only drop the reference on the datamsg after sending a msg")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-18 22:02:32 -04:00
Xin Long 66388f2c08 sctp: do not return the transmit err back to sctp_sendmsg
Once a chunk is enqueued successfully, sctp queues can take care of it.
Even if it is failed to transmit (like because of nomem), it should be
put into retransmit queue.

If sctp report this error to users, it confuses them, they may resend
that msg, but actually in kernel sctp stack is in charge of retransmit
it already.

Besides, this error probably is not from the failure of transmitting
current msg, but transmitting or retransmitting another msg's chunks,
as sctp_outq_flush just tries to send out all transports' chunks.

This patch is to make sctp_cmd_send_msg return avoid, and not return the
transmit err back to sctp_sendmsg

Fixes: 8b570dc9f7 ("sctp: only drop the reference on the datamsg after sending a msg")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-18 22:02:32 -04:00
Xin Long 2c89791eeb sctp: remove the unnecessary state check in sctp_outq_tail
Data Chunks are only sent by sctp_primitive_SEND, in which sctp checks
the asoc's state through statetable before calling sctp_outq_tail. So
there's no need to check the asoc's state again in sctp_outq_tail.

Besides, sctp_do_sm is protected by lock_sock, even if sending msg is
interrupted by timer events, the event's processes still need to acquire
lock_sock first. It means no others CMDs can be enqueue into side effect
list before CMD_SEND_MSG to change asoc->state, so it's safe to remove it.

This patch is to remove redundant asoc->state check from sctp_outq_tail.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-18 22:02:32 -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
David S. Miller b20b378d49 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts:
	drivers/net/ethernet/mediatek/mtk_eth_soc.c
	drivers/net/ethernet/qlogic/qed/qed_dcbx.c
	drivers/net/phy/Kconfig

All conflicts were cases of overlapping commits.

Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-12 15:52:44 -07:00
Javier Martinez Canillas aebf5de07a sctp: use IS_ENABLED() instead of checking for built-in or module
The IS_ENABLED() macro checks if a Kconfig symbol has been enabled either
built-in or as a module, use that macro instead of open coding the same.

Using the macro makes the code more readable by helping abstract away some
of the Kconfig built-in and module enable details.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-10 21:19:11 -07:00
Marcelo Ricardo Leitner 7303a14750 sctp: identify chunks that need to be fragmented at IP level
Previously, without GSO, it was easy to identify it: if the chunk didn't
fit and there was no data chunk in the packet yet, we could fragment at
IP level. So if there was an auth chunk and we were bundling a big data
chunk, it would fragment regardless of the size of the auth chunk. This
also works for the context of PMTU reductions.

But with GSO, we cannot distinguish such PMTU events anymore, as the
packet is allowed to exceed PMTU.

So we need another check: to ensure that the chunk that we are adding,
actually fits the current PMTU. If it doesn't, trigger a flush and let
it be fragmented at IP level in the next round.

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-09 19:18:33 -07:00
Lorenzo Colitti d545caca82 net: inet: diag: expose the socket mark to privileged processes.
This adds the capability for a process that has CAP_NET_ADMIN on
a socket to see the socket mark in socket dumps.

Commit a52e95abf7 ("net: diag: allow socket bytecode filters to
match socket marks") recently gave privileged processes the
ability to filter socket dumps based on mark. This patch is
complementary: it ensures that the mark is also passed to
userspace in the socket's netlink attributes.  It is useful for
tools like ss which display information about sockets.

Tested: https://android-review.googlesource.com/270210
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-08 16:13:09 -07:00
Lance Richardson 232cb53a45 sctp: fix overrun in sctp_diag_dump_one()
The function sctp_diag_dump_one() currently performs a memcpy()
of 64 bytes from a 16 byte field into another 16 byte field. Fix
by using correct size, use sizeof to obtain correct size instead
of using a hard-coded constant.

Fixes: 8f840e47f1 ("sctp: add the sctp_diag.c file")
Signed-off-by: Lance Richardson <lrichard@redhat.com>
Reviewed-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>
2016-08-23 17:22:53 -07:00
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
Vegard Nossum 54236ab09e net/sctp: always initialise sctp_ht_iter::start_fail
sctp_transport_seq_start() does not currently clear iter->start_fail on
success, but relies on it being zero when it is allocated (by
seq_open_net()).

This can be a problem in the following sequence:

    open() // allocates iter (and implicitly sets iter->start_fail = 0)
    read()
     - iter->start() // fails and sets iter->start_fail = 1
     - iter->stop() // doesn't call sctp_transport_walk_stop() (correct)
    read() again
     - iter->start() // succeeds, but doesn't change iter->start_fail
     - iter->stop() // doesn't call sctp_transport_walk_stop() (wrong)

We should initialize sctp_ht_iter::start_fail to zero if ->start()
succeeds, otherwise it's possible that we leave an old value of 1 there,
which will cause ->stop() to not call sctp_transport_walk_stop(), which
causes all sorts of problems like not calling rcu_read_unlock() (and
preempt_enable()), eventually leading to more warnings like this:

    BUG: sleeping function called from invalid context at mm/slab.h:388
    in_atomic(): 0, irqs_disabled(): 0, pid: 16551, name: trinity-c2
    Preemption disabled at:[<ffffffff819bceb6>] rhashtable_walk_start+0x46/0x150

     [<ffffffff81149abb>] preempt_count_add+0x1fb/0x280
     [<ffffffff83295892>] _raw_spin_lock+0x12/0x40
     [<ffffffff819bceb6>] rhashtable_walk_start+0x46/0x150
     [<ffffffff82ec665f>] sctp_transport_walk_start+0x2f/0x60
     [<ffffffff82edda1d>] sctp_transport_seq_start+0x4d/0x150
     [<ffffffff81439e50>] traverse+0x170/0x850
     [<ffffffff8143aeec>] seq_read+0x7cc/0x1180
     [<ffffffff814f996c>] proc_reg_read+0xbc/0x180
     [<ffffffff813d0384>] do_loop_readv_writev+0x134/0x210
     [<ffffffff813d2a95>] do_readv_writev+0x565/0x660
     [<ffffffff813d6857>] vfs_readv+0x67/0xa0
     [<ffffffff813d6c16>] do_preadv+0x126/0x170
     [<ffffffff813d710c>] SyS_preadv+0xc/0x10
     [<ffffffff8100334c>] do_syscall_64+0x19c/0x410
     [<ffffffff83296225>] return_from_SYSCALL_64+0x0/0x6a
     [<ffffffffffffffff>] 0xffffffffffffffff

Notice that this is a subtly different stacktrace from the one in commit
5fc382d875 ("net/sctp: terminate rhashtable walk correctly").

Cc: Xin Long <lucien.xin@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.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>
2016-08-13 15:10:16 -07:00
Xin Long 1fe323aa1b sctp: use event->chunk when it's valid
Commit 52253db924 ("sctp: also point GSO head_skb to the sk when
it's available") used event->chunk->head_skb to get the head_skb in
sctp_ulpevent_set_owner().

But at that moment, the event->chunk was NULL, as it cloned the skb
in sctp_ulpevent_make_rcvmsg(). Therefore, that patch didn't really
work.

This patch is to move the event->chunk initialization before calling
sctp_ulpevent_receive_data() so that it uses event->chunk when it's
valid.

Fixes: 52253db924 ("sctp: also point GSO head_skb to the sk when it's available")
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>
2016-08-08 14:31:23 -07:00
Phil Sutter 1ba8d77f41 sctp_diag: Respect ss adding TCPF_CLOSE to idiag_states
Since 'ss' always adds TCPF_CLOSE to idiag_states flags, sctp_diag can't
rely upon TCPF_LISTEN flag solely being present when listening sockets
are requested.

Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-08 12:51:58 -07:00
Phil Sutter 12474e8e58 sctp_diag: Fix T3_rtx timer export
The asoc's timer value is not kept in asoc->timeouts array but in it's
primary transport instead.

Furthermore, we must export the timer only if it is pending, otherwise
the value will underrun when stored in an unsigned variable and
user space will only see a very large timeout value.

Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-08 12:51:58 -07:00
Xin Long e08786942e sctp: allow receiving msg when TCP-style sk is in CLOSED state
Commit 141ddefce7 ("sctp: change sk state to CLOSED instead of
CLOSING in sctp_sock_migrate") changed sk state to CLOSED if the
assoc is closed when sctp_accept clones a new sk.

If there is still data in sk receive queue, users will not be able
to read it any more, as sctp_recvmsg returns directly if sk state
is CLOSED.

This patch is to add CLOSED state check in sctp_recvmsg to allow
reading data from TCP-style sk with CLOSED state as what TCP does.

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>
2016-07-30 22:06:22 -07:00
Xin Long a0fc6843f9 sctp: allow delivering notifications after receiving SHUTDOWN
Prior to this patch, once sctp received SHUTDOWN or shutdown with RD,
sk->sk_shutdown would be set with RCV_SHUTDOWN, and all events would
be dropped in sctp_ulpq_tail_event(). It would cause:

1. some notifications couldn't be received by users. like
   SCTP_SHUTDOWN_COMP generated by sctp_sf_do_4_C().

2. sctp would also never trigger sk_data_ready when the association
   was closed, making it harder to identify the end of the association
   by calling recvmsg() and getting an EOF. It was not convenient for
   kernel users.

The check here should be stopping delivering DATA chunks after receiving
SHUTDOWN, and stopping delivering ANY chunks after sctp_close().

So this patch is to allow notifications to enqueue into receive queue
even if sk->sk_shutdown is set to RCV_SHUTDOWN in sctp_ulpq_tail_event,
but if sk->sk_shutdown == RCV_SHUTDOWN | SEND_SHUTDOWN, it drops all
events.

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>
2016-07-30 22:06:22 -07:00
Xin Long 1aa25ec227 sctp: fix the issue sctp requeue auth chunk incorrectly
sctp needs to queue auth chunk back when we know that we are going
to generate another segment. But commit f1533cce60 ("sctp: fix
panic when sending auth chunks") requeues the last chunk processed
which is probably not the auth chunk.

It causes panic when calculating the MAC in sctp_auth_calculate_hmac(),
as the incorrect offset of the auth chunk in skb->data.

This fix is to requeue it by using packet->auth.

Fixes: f1533cce60 ("sctp: fix panic when sending auth chunks")
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>
2016-07-30 22:06:22 -07:00
Vegard Nossum 5fc382d875 net/sctp: terminate rhashtable walk correctly
I was seeing a lot of these:

    BUG: sleeping function called from invalid context at mm/slab.h:388
    in_atomic(): 0, irqs_disabled(): 0, pid: 14971, name: trinity-c2
    Preemption disabled at:[<ffffffff819bcd46>] rhashtable_walk_start+0x46/0x150

     [<ffffffff81149abb>] preempt_count_add+0x1fb/0x280
     [<ffffffff83295722>] _raw_spin_lock+0x12/0x40
     [<ffffffff811aac87>] console_unlock+0x2f7/0x930
     [<ffffffff811ab5bb>] vprintk_emit+0x2fb/0x520
     [<ffffffff811aba6a>] vprintk_default+0x1a/0x20
     [<ffffffff812c171a>] printk+0x94/0xb0
     [<ffffffff811d6ed0>] print_stack_trace+0xe0/0x170
     [<ffffffff8115835e>] ___might_sleep+0x3be/0x460
     [<ffffffff81158490>] __might_sleep+0x90/0x1a0
     [<ffffffff8139b823>] kmem_cache_alloc+0x153/0x1e0
     [<ffffffff819bca1e>] rhashtable_walk_init+0xfe/0x2d0
     [<ffffffff82ec64de>] sctp_transport_walk_start+0x1e/0x60
     [<ffffffff82edd8ad>] sctp_transport_seq_start+0x4d/0x150
     [<ffffffff8143a82b>] seq_read+0x27b/0x1180
     [<ffffffff814f97fc>] proc_reg_read+0xbc/0x180
     [<ffffffff813d471b>] __vfs_read+0xdb/0x610
     [<ffffffff813d4d3a>] vfs_read+0xea/0x2d0
     [<ffffffff813d615b>] SyS_pread64+0x11b/0x150
     [<ffffffff8100334c>] do_syscall_64+0x19c/0x410
     [<ffffffff832960a5>] return_from_SYSCALL_64+0x0/0x6a
     [<ffffffffffffffff>] 0xffffffffffffffff

Apparently we always need to call rhashtable_walk_stop(), even when
rhashtable_walk_start() fails:

 * rhashtable_walk_start - Start a hash table walk
 * @iter:       Hash table iterator
 *
 * Start a hash table walk.  Note that we take the RCU lock in all
 * cases including when we return an error.  So you must always call
 * rhashtable_walk_stop to clean up.

otherwise we never call rcu_read_unlock() and we get the splat above.

Fixes: 53fa1036 ("sctp: fix some rhashtable functions using in sctp proc/diag")
See-also: 53fa1036 ("sctp: fix some rhashtable functions using in sctp proc/diag")
See-also: f2dba9c6 ("rhashtable: Introduce rhashtable_walk_*")
Cc: Xin Long <lucien.xin@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: stable@vger.kernel.org
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-25 17:43:57 -07:00
Marcelo Ricardo Leitner 52253db924 sctp: also point GSO head_skb to the sk when it's available
The head skb for GSO packets won't travel through the inner depths of
SCTP stack as it doesn't contain any chunks on it. That means skb->sk
doesn't get set and then when sctp_recvmsg() calls
sctp_inet6_skb_msgname() on the head_skb it panics, as this last needs
to check flags at the socket (sp->v4mapped).

The fix is to initialize skb->sk for th head skb once we are able to do
it. That is, when the first chunk is processed.

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-25 11:23:27 -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
Xin Long fd2d180a28 sctp: use inet_recvmsg to support sctp RFS well
Commit 486bdee013 ("sctp: add support for RPS and RFS")
saves skb->hash into sk->sk_rxhash so that the inet_* can
record it to flow table.

But sctp uses sock_common_recvmsg as .recvmsg instead
of inet_recvmsg, sock_common_recvmsg doesn't invoke
sock_rps_record_flow to record the flow. It may cause
that the receiver has no chances to record the flow if
it doesn't send msg or poll the socket.

So this patch fixes it by using inet_recvmsg as .recvmsg
in sctp.

Fixes: 486bdee013 ("sctp: add support for RPS and RFS")
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>
2016-07-25 10:56:28 -07:00
Xin Long 9b97420228 sctp: support ipv6 nonlocal bind
This patch makes sctp support ipv6 nonlocal bind by adding
sp->inet.freebind and net->ipv6.sysctl.ip_nonlocal_bind
check in sctp_v6_available as what sctp did to support
ipv4 nonlocal bind (commit cdac4e0774).

Reported-by: Shijoe George <spanjikk@redhat.com>
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>
2016-07-25 10:46:04 -07:00
Marcelo Ricardo Leitner c5c4e45c4b sctp: fix GSO for IPv6
commit 90017accff ("sctp: Add GSO support") didn't register SCTP GSO
offloading for IPv6 and yet didn't put any restrictions on generating
GSO packets while in IPv6, which causes all IPv6 GSO'ed packets to be
silently dropped.

The fix is to properly register the offload this time.

Fixes: 90017accff ("sctp: Add GSO support")
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-16 22:02:09 -07:00
Marcelo Ricardo Leitner e5b13f3444 sctp: recvmsg should be able to run even if sock is in closing state
Commit d46e416c11 missed to update some other places which checked for
the socket being TCP-style AND Established state, as Closing state has
some overlapping with the previous understanding of Established.

Without this fix, one of the effects is that some already queued rx
messages may not be readable anymore depending on how the association
teared down, and sending may also not be possible if peer initiated the
shutdown.

Also merge two if() blocks into one condition on sctp_sendmsg().

Cc: Xin Long <lucien.xin@gmail.com>
Fixes: d46e416c11 ("sctp: sctp should change socket state when shutdown is received")
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-16 22:02:09 -07:00
Marcelo Ricardo Leitner 2d47fd120d sctp: only check for ECN if peer is using it
Currently only read-only checks are performed up to the point on where
we check if peer is ECN capable, checks which we can avoid otherwise.
The flag ecn_ce_done is only used to perform this check once per
incoming packet, and nothing more.

Thus this patch moves the peer check up.

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 d9cef42529 sctp: do not clear chunk->ecn_ce_done flag
We should not clear that flag when switching to a new skb from a GSO skb
because it would cause ECN processing to happen multiple times per GSO
skb, which is not wanted. Instead, let it be processed once per chunk.
That is, in other words, once per IP header available.

Fixes: 90017accff ("sctp: Add GSO support")
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 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 1f45f78f8e sctp: allow GSO frags to access the chunk too
SCTP will try to access original IP headers on sctp_recvmsg in order to
copy the addresses used. There are also other places that do similar access
to IP or even SCTP headers. But after 90017accff ("sctp: Add GSO
support") they aren't always there because they are only present in the
header skb.

SCTP handles the queueing of incoming data by cloning the incoming skb
and limiting to only the relevant payload. This clone has its cb updated
to something different and it's then queued on socket rx queue. Thus we
need to fix this in two moments.

For rx path, not related to socket queue yet, this patch uses a
partially copied sctp_input_cb to such GSO frags. This restores the
ability to access the headers for this part of the code.

Regarding the socket rx queue, it removes iif member from sctp_event and
also add a chunk pointer on it.

With these changes we're always able to reach the headers again.

The biggest change here is that now the sctp_chunk struct and the
original skb are only freed after the application consumed the buffer.
Note however that the original payload was already like this due to the
skb cloning.

For iif, SCTP's IPv4 code doesn't use it, so no change is necessary.
IPv6 now can fetch it directly from original's IPv6 CB as the original
skb is still accessible.

In the future we probably can simplify sctp_v*_skb_iif() stuff, as
sctp_v4_skb_iif() was called but it's return value not used, and now
it's not even called, but such cleanup is out of scope for this change.

Fixes: 90017accff ("sctp: Add GSO support")
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