Commit Graph

207 Commits

Author SHA1 Message Date
Christoph Hellwig 8c918ffbba net: remove compat_sock_common_{get,set}sockopt
Add the compat handling to sock_common_{get,set}sockopt instead,
keyed of in_compat_syscall().  This allow to remove the now unused
->compat_{get,set}sockopt methods from struct proto_ops.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Acked-by: Stefan Schmidt <stefan@datenfreihafen.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:16:40 -07:00
Davide Caratti 8c72894048 mptcp: silence warning in subflow_data_ready()
since commit d47a721520 ("mptcp: fix race in subflow_data_ready()"), it
is possible to observe a regression in MP_JOIN kselftests. For sockets in
TCP_CLOSE state, it's not sufficient to just wake up the main socket: we
also need to ensure that received data are made available to the reader.
Silence the WARN_ON_ONCE() in these cases: it preserves the syzkaller fix
and restores kselftests	when they are ran as follows:

  # while true; do
  > make KBUILD_OUTPUT=/tmp/kselftest TARGETS=net/mptcp kselftest
  > done

Reported-by: Florian Westphal <fw@strlen.de>
Fixes: d47a721520 ("mptcp: fix race in subflow_data_ready()")
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/47
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-17 12:47:00 -07:00
Eric Biggers 5a7a0d9400 mptcp: use sha256() instead of open coding
Now that there's a function that calculates the SHA-256 digest of a
buffer in one step, use it instead of sha256_init() + sha256_update() +
sha256_final().

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Cc: mptcp@lists.01.org
Cc: Mat Martineau <mathew.j.martineau@linux.intel.com>
Cc: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-07-16 21:49:05 +10:00
David S. Miller 71930d6102 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
All conflicts seemed rather trivial, with some guidance from
Saeed Mameed on the tc_ct.c one.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-11 00:46:00 -07:00
Paolo Abeni ac3b45f609 mptcp: add MPTCP socket diag interface
exposes basic inet socket attribute, plus some MPTCP socket
fields comprising PM status and MPTCP-level sequence numbers.

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-09 12:38:41 -07:00
Paolo Abeni 96d890daad mptcp: add msk interations helper
mptcp_token_iter_next() allow traversing all the MPTCP
sockets inside the token container belonging to the given
network namespace with a quite standard iterator semantic.

That will be used by the next patch, but keep the API generic,
as we plan to use this later for PM's sake.

Additionally export mptcp_token_get_sock(), as it also
will be used by the diag module.

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-09 12:38:41 -07:00
Paolo Abeni 9c29e36152 mptcp: fix DSS map generation on fin retransmission
The RFC 8684 mandates that no-data DATA FIN packets should carry
a DSS with 0 sequence number and data len equal to 1. Currently,
on FIN retransmission we re-use the existing mapping; if the previous
fin transmission was part of a partially acked data packet, we could
end-up writing in the egress packet a non-compliant DSS.

The above will be detected by a "Bad mapping" warning on the receiver
side.

This change addresses the issue explicitly checking for 0 len packet
when adding the DATA_FIN option.

Fixes: 6d0060f600 ("mptcp: Write MPTCP DSS headers to outgoing data packets")
Reported-by: syzbot+42a07faa5923cfaeb9c9@syzkaller.appspotmail.com
Tested-by: Christoph Paasch <cpaasch@apple.com>
Reviewed-by: Christoph Paasch <cpaasch@apple.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-07 15:27:37 -07:00
Florian Westphal b416268b7a mptcp: use mptcp worker for path management
We can re-use the existing work queue to handle path management
instead of a dedicated work queue.  Just move pm_worker to protocol.c,
call it from the mptcp worker and get rid of the msk lock (already held).

Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-07 13:02:13 -07:00
Davide Caratti d47a721520 mptcp: fix race in subflow_data_ready()
syzkaller was able to make the kernel reach subflow_data_ready() for a
server subflow that was closed before subflow_finish_connect() completed.
In these cases we can avoid using the path for regular/fallback MPTCP
data, and just wake the main socket, to avoid the following warning:

 WARNING: CPU: 0 PID: 9370 at net/mptcp/subflow.c:885
 subflow_data_ready+0x1e6/0x290 net/mptcp/subflow.c:885
 Kernel panic - not syncing: panic_on_warn set ...
 CPU: 0 PID: 9370 Comm: syz-executor.0 Not tainted 5.7.0 #106
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
 rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
 Call Trace:
  <IRQ>
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0xb7/0xfe lib/dump_stack.c:118
  panic+0x29e/0x692 kernel/panic.c:221
  __warn.cold+0x2f/0x3d kernel/panic.c:582
  report_bug+0x28b/0x2f0 lib/bug.c:195
  fixup_bug arch/x86/kernel/traps.c:105 [inline]
  fixup_bug arch/x86/kernel/traps.c:100 [inline]
  do_error_trap+0x10f/0x180 arch/x86/kernel/traps.c:197
  do_invalid_op+0x32/0x40 arch/x86/kernel/traps.c:216
  invalid_op+0x1e/0x30 arch/x86/entry/entry_64.S:1027
 RIP: 0010:subflow_data_ready+0x1e6/0x290 net/mptcp/subflow.c:885
 Code: 04 02 84 c0 74 06 0f 8e 91 00 00 00 41 0f b6 5e 48 31 ff 83 e3 18
 89 de e8 37 ec 3d fe 84 db 0f 85 65 ff ff ff e8 fa ea 3d fe <0f> 0b e9
 59 ff ff ff e8 ee ea 3d fe 48 89 ee 4c 89 ef e8 f3 77 ff
 RSP: 0018:ffff88811b2099b0 EFLAGS: 00010206
 RAX: ffff888111197000 RBX: 0000000000000000 RCX: ffffffff82fbc609
 RDX: 0000000000000100 RSI: ffffffff82fbc616 RDI: 0000000000000001
 RBP: ffff8881111bc800 R08: ffff888111197000 R09: ffffed10222a82af
 R10: ffff888111541577 R11: ffffed10222a82ae R12: 1ffff11023641336
 R13: ffff888111541000 R14: ffff88810fd4ca00 R15: ffff888111541570
  tcp_child_process+0x754/0x920 net/ipv4/tcp_minisocks.c:841
  tcp_v4_do_rcv+0x749/0x8b0 net/ipv4/tcp_ipv4.c:1642
  tcp_v4_rcv+0x2666/0x2e60 net/ipv4/tcp_ipv4.c:1999
  ip_protocol_deliver_rcu+0x29/0x1f0 net/ipv4/ip_input.c:204
  ip_local_deliver_finish net/ipv4/ip_input.c:231 [inline]
  NF_HOOK include/linux/netfilter.h:421 [inline]
  ip_local_deliver+0x2da/0x390 net/ipv4/ip_input.c:252
  dst_input include/net/dst.h:441 [inline]
  ip_rcv_finish net/ipv4/ip_input.c:428 [inline]
  ip_rcv_finish net/ipv4/ip_input.c:414 [inline]
  NF_HOOK include/linux/netfilter.h:421 [inline]
  ip_rcv+0xef/0x140 net/ipv4/ip_input.c:539
  __netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:5268
  __netif_receive_skb+0x27/0x1c0 net/core/dev.c:5382
  process_backlog+0x1e5/0x6d0 net/core/dev.c:6226
  napi_poll net/core/dev.c:6671 [inline]
  net_rx_action+0x3e3/0xd70 net/core/dev.c:6739
  __do_softirq+0x18c/0x634 kernel/softirq.c:292
  do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1082
  </IRQ>
  do_softirq.part.0+0x26/0x30 kernel/softirq.c:337
  do_softirq arch/x86/include/asm/preempt.h:26 [inline]
  __local_bh_enable_ip+0x46/0x50 kernel/softirq.c:189
  local_bh_enable include/linux/bottom_half.h:32 [inline]
  rcu_read_unlock_bh include/linux/rcupdate.h:723 [inline]
  ip_finish_output2+0x78a/0x19c0 net/ipv4/ip_output.c:229
  __ip_finish_output+0x471/0x720 net/ipv4/ip_output.c:306
  dst_output include/net/dst.h:435 [inline]
  ip_local_out+0x181/0x1e0 net/ipv4/ip_output.c:125
  __ip_queue_xmit+0x7a1/0x14e0 net/ipv4/ip_output.c:530
  __tcp_transmit_skb+0x19dc/0x35e0 net/ipv4/tcp_output.c:1238
  __tcp_send_ack.part.0+0x3c2/0x5b0 net/ipv4/tcp_output.c:3785
  __tcp_send_ack net/ipv4/tcp_output.c:3791 [inline]
  tcp_send_ack+0x7d/0xa0 net/ipv4/tcp_output.c:3791
  tcp_rcv_synsent_state_process net/ipv4/tcp_input.c:6040 [inline]
  tcp_rcv_state_process+0x36a4/0x49c2 net/ipv4/tcp_input.c:6209
  tcp_v4_do_rcv+0x343/0x8b0 net/ipv4/tcp_ipv4.c:1651
  sk_backlog_rcv include/net/sock.h:996 [inline]
  __release_sock+0x1ad/0x310 net/core/sock.c:2548
  release_sock+0x54/0x1a0 net/core/sock.c:3064
  inet_wait_for_connect net/ipv4/af_inet.c:594 [inline]
  __inet_stream_connect+0x57e/0xd50 net/ipv4/af_inet.c:686
  inet_stream_connect+0x53/0xa0 net/ipv4/af_inet.c:725
  mptcp_stream_connect+0x171/0x5f0 net/mptcp/protocol.c:1920
  __sys_connect_file net/socket.c:1854 [inline]
  __sys_connect+0x267/0x2f0 net/socket.c:1871
  __do_sys_connect net/socket.c:1882 [inline]
  __se_sys_connect net/socket.c:1879 [inline]
  __x64_sys_connect+0x6f/0xb0 net/socket.c:1879
  do_syscall_64+0xb7/0x3d0 arch/x86/entry/common.c:295
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 RIP: 0033:0x7fb577d06469
 Code: 00 f3 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89
 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01
 f0 ff ff 73 01 c3 48 8b 0d ff 49 2b 00 f7 d8 64 89 01 48
 RSP: 002b:00007fb5783d5dd8 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
 RAX: ffffffffffffffda RBX: 000000000068bfa0 RCX: 00007fb577d06469
 RDX: 000000000000004d RSI: 0000000020000040 RDI: 0000000000000003
 RBP: 00000000ffffffff R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
 R13: 000000000041427c R14: 00007fb5783d65c0 R15: 0000000000000003

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/39
Reported-by: Christoph Paasch <cpaasch@apple.com>
Fixes: e1ff9e82e2 ("net: mptcp: improve fallback to TCP")
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-06 13:31:12 -07:00
Florian Westphal c9b95a1359 mptcp: support IPV6_V6ONLY setsockopt
Without this, Opensshd fails to open an ipv6 socket listening
socket:
  error: setsockopt IPV6_V6ONLY: Operation not supported
  error: Bind to port 22 on :: failed: Address already in use.

Opensshd opens an ipv4 and and ipv6 listening socket, but because
IPV6_V6ONLY setsockopt fails, the port number is already in use.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-04 17:56:22 -07:00
Florian Westphal fd1452d8ef mptcp: add REUSEADDR/REUSEPORT support
This will e.g. make 'sshd restart' work when MPTCP is used, as we will
now set this option on the listener socket instead of only the mptcp
socket (where it has no effect).

We still need to copy the setting to the master socket so that a
subsequent getsockopt() returns the expected value.

Reported-by: Christoph Paasch <cpaasch@apple.com>
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-04 17:56:22 -07:00
Florian Westphal 83f0c10bc3 net: use mptcp setsockopt function for SOL_SOCKET on mptcp sockets
setsockopt(mptcp_fd, SOL_SOCKET, ...)...  appears to work (returns 0),
but it has no effect -- this is because the MPTCP layer never has a
chance to copy the settings to the subflow socket.

Skip the generic handling for the mptcp case and instead call the
mptcp specific handler instead for SOL_SOCKET too.

Next patch adds more specific handling for SOL_SOCKET to mptcp.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-04 17:56:22 -07:00
Florian Westphal a6b118febb mptcp: add receive buffer auto-tuning
When mptcp is used, userspace doesn't read from the tcp (subflow)
socket but from the parent (mptcp) socket receive queue.

skbs are moved from the subflow socket to the mptcp rx queue either from
'data_ready' callback (if mptcp socket can be locked), a work queue, or
the socket receive function.

This means tcp_rcv_space_adjust() is never called and thus no receive
buffer size auto-tuning is done.

An earlier (not merged) patch added tcp_rcv_space_adjust() calls to the
function that moves skbs from subflow to mptcp socket.
While this enabled autotuning, it also meant tuning was done even if
userspace was reading the mptcp socket very slowly.

This adds mptcp_rcv_space_adjust() and calls it after userspace has
read data from the mptcp socket rx queue.

Its very similar to tcp_rcv_space_adjust, with two differences:

1. The rtt estimate is the largest one observed on a subflow
2. The rcvbuf size and window clamp of all subflows is adjusted
   to the mptcp-level rcvbuf.

Otherwise, we get spurious drops at tcp (subflow) socket level if
the skbs are not moved to the mptcp socket fast enough.

Before:
time mptcp_connect.sh -t -f $((4*1024*1024)) -d 300 -l 0.01% -r 0 -e "" -m mmap
[..]
ns4 MPTCP -> ns3 (10.0.3.2:10108      ) MPTCP   (duration 40823ms) [ OK ]
ns4 MPTCP -> ns3 (10.0.3.2:10109      ) TCP     (duration 23119ms) [ OK ]
ns4 TCP   -> ns3 (10.0.3.2:10110      ) MPTCP   (duration  5421ms) [ OK ]
ns4 MPTCP -> ns3 (dead:beef:3::2:10111) MPTCP   (duration 41446ms) [ OK ]
ns4 MPTCP -> ns3 (dead:beef:3::2:10112) TCP     (duration 23427ms) [ OK ]
ns4 TCP   -> ns3 (dead:beef:3::2:10113) MPTCP   (duration  5426ms) [ OK ]
Time: 1396 seconds

After:
ns4 MPTCP -> ns3 (10.0.3.2:10108      ) MPTCP   (duration  5417ms) [ OK ]
ns4 MPTCP -> ns3 (10.0.3.2:10109      ) TCP     (duration  5427ms) [ OK ]
ns4 TCP   -> ns3 (10.0.3.2:10110      ) MPTCP   (duration  5422ms) [ OK ]
ns4 MPTCP -> ns3 (dead:beef:3::2:10111) MPTCP   (duration  5415ms) [ OK ]
ns4 MPTCP -> ns3 (dead:beef:3::2:10112) TCP     (duration  5422ms) [ OK ]
ns4 TCP   -> ns3 (dead:beef:3::2:10113) MPTCP   (duration  5423ms) [ OK ]
Time: 296 seconds

Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-01 17:47:55 -07:00
Paolo Abeni 6bad912b7e mptcp: do nonce initialization at subflow creation time
This clean-up the code a bit, reduces the number of
used hooks and indirect call requested, and allow
better error reporting from __mptcp_subflow_connect()

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-30 13:38:00 -07:00
Paolo Abeni 8a05661b2b mptcp: close poll() races
mptcp_poll always return POLLOUT for unblocking
connect(), ensure that the socket is a suitable
state.
The MPTCP_DATA_READY bit is never cleared on accept:
ensure we don't leave mptcp_accept() with an empty
accept queue and such bit set.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-29 17:29:38 -07:00
Paolo Abeni 76660afbb7 mptcp: __mptcp_tcp_fallback() returns a struct sock
Currently __mptcp_tcp_fallback() always return NULL
on incoming connections, because MPTCP does not create
the additional socket for the first subflow.
Since the previous commit no __mptcp_tcp_fallback()
caller needs a struct socket, so let __mptcp_tcp_fallback()
return the first subflow sock and cope correctly even with
incoming connections.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-29 17:29:38 -07:00
Paolo Abeni fa68018dc4 mptcp: create first subflow at msk creation time
This cleans the code a bit and makes the behavior more consistent.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-29 17:29:38 -07:00
Paolo Abeni d2f77c5334 mptcp: check for plain TCP sock at accept time
This cleanup the code a bit and avoid corrupted states
on weird syscall sequence (accept(), connect()).

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-29 17:29:38 -07:00
Davide Caratti 8fd738049a mptcp: fallback in case of simultaneous connect
when a MPTCP client tries to connect to itself, tcp_finish_connect() is
never reached. Because of this, depending on the socket current state,
multiple faulty behaviours can be observed:

1) a WARN_ON() in subflow_data_ready() is hit
 WARNING: CPU: 2 PID: 882 at net/mptcp/subflow.c:911 subflow_data_ready+0x18b/0x230
 [...]
 CPU: 2 PID: 882 Comm: gh35 Not tainted 5.7.0+ #187
 [...]
 RIP: 0010:subflow_data_ready+0x18b/0x230
 [...]
 Call Trace:
  tcp_data_queue+0xd2f/0x4250
  tcp_rcv_state_process+0xb1c/0x49d3
  tcp_v4_do_rcv+0x2bc/0x790
  __release_sock+0x153/0x2d0
  release_sock+0x4f/0x170
  mptcp_shutdown+0x167/0x4e0
  __sys_shutdown+0xe6/0x180
  __x64_sys_shutdown+0x50/0x70
  do_syscall_64+0x9a/0x370
  entry_SYSCALL_64_after_hwframe+0x44/0xa9

2) client is stuck forever in mptcp_sendmsg() because the socket is not
   TCP_ESTABLISHED

 crash> bt 4847
 PID: 4847   TASK: ffff88814b2fb100  CPU: 1   COMMAND: "gh35"
  #0 [ffff8881376ff680] __schedule at ffffffff97248da4
  #1 [ffff8881376ff778] schedule at ffffffff9724a34f
  #2 [ffff8881376ff7a0] schedule_timeout at ffffffff97252ba0
  #3 [ffff8881376ff8a8] wait_woken at ffffffff958ab4ba
  #4 [ffff8881376ff940] sk_stream_wait_connect at ffffffff96c2d859
  #5 [ffff8881376ffa28] mptcp_sendmsg at ffffffff97207fca
  #6 [ffff8881376ffbc0] sock_sendmsg at ffffffff96be1b5b
  #7 [ffff8881376ffbe8] sock_write_iter at ffffffff96be1daa
  #8 [ffff8881376ffce8] new_sync_write at ffffffff95e5cb52
  #9 [ffff8881376ffe50] vfs_write at ffffffff95e6547f
 #10 [ffff8881376ffe90] ksys_write at ffffffff95e65d26
 #11 [ffff8881376fff28] do_syscall_64 at ffffffff956088ba
 #12 [ffff8881376fff50] entry_SYSCALL_64_after_hwframe at ffffffff9740008c
     RIP: 00007f126f6956ed  RSP: 00007ffc2a320278  RFLAGS: 00000217
     RAX: ffffffffffffffda  RBX: 0000000020000044  RCX: 00007f126f6956ed
     RDX: 0000000000000004  RSI: 00000000004007b8  RDI: 0000000000000003
     RBP: 00007ffc2a3202a0   R8: 0000000000400720   R9: 0000000000400720
     R10: 0000000000400720  R11: 0000000000000217  R12: 00000000004004b0
     R13: 00007ffc2a320380  R14: 0000000000000000  R15: 0000000000000000
     ORIG_RAX: 0000000000000001  CS: 0033  SS: 002b

3) tcpdump captures show that DSS is exchanged even when MP_CAPABLE handshake
   didn't complete.

 $ tcpdump -tnnr bad.pcap
 IP 127.0.0.1.20000 > 127.0.0.1.20000: Flags [S], seq 3208913911, win 65483, options [mss 65495,sackOK,TS val 3291706876 ecr 3291694721,nop,wscale 7,mptcp capable v1], length 0
 IP 127.0.0.1.20000 > 127.0.0.1.20000: Flags [S.], seq 3208913911, ack 3208913912, win 65483, options [mss 65495,sackOK,TS val 3291706876 ecr 3291706876,nop,wscale 7,mptcp capable v1], length 0
 IP 127.0.0.1.20000 > 127.0.0.1.20000: Flags [.], ack 1, win 512, options [nop,nop,TS val 3291706876 ecr 3291706876], length 0
 IP 127.0.0.1.20000 > 127.0.0.1.20000: Flags [F.], seq 1, ack 1, win 512, options [nop,nop,TS val 3291707876 ecr 3291706876,mptcp dss fin seq 0 subseq 0 len 1,nop,nop], length 0
 IP 127.0.0.1.20000 > 127.0.0.1.20000: Flags [.], ack 2, win 512, options [nop,nop,TS val 3291707876 ecr 3291707876], length 0

force a fallback to TCP in these cases, and adjust the main socket
state to avoid hanging in mptcp_sendmsg().

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/35
Reported-by: Christoph Paasch <cpaasch@apple.com>
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-29 17:29:38 -07:00
Davide Caratti e1ff9e82e2 net: mptcp: improve fallback to TCP
Keep using MPTCP sockets and a use "dummy mapping" in case of fallback
to regular TCP. When fallback is triggered, skip addition of the MPTCP
option on send.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/11
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/22
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-29 17:29:38 -07:00
Paolo Abeni a8ee9c9b58 mptcp: introduce token KUNIT self-tests
Unit tests for the internal MPTCP token APIs, using KUNIT

v1 -> v2:
 - use the correct RCU annotation when initializing icsk ulp
 - fix a few checkpatch issues

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-26 16:21:39 -07:00
Paolo Abeni a00a582203 mptcp: move crypto test to KUNIT
currently MPTCP uses a custom hook to executed unit tests at
boot time. Let's use the KUNIT framework instead.
Additionally move the relevant code to a separate file and
export the function needed by the test when self-tests
are build as a module.

Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-26 16:21:39 -07:00
Paolo Abeni 2c5ebd001d mptcp: refactor token container
Replace the radix tree with a hash table allocated
at boot time. The radix tree has some shortcoming:
a single lock is contented by all the mptcp operation,
the lookup currently use such lock, and traversing
all the items would require a lock, too.

With hash table instead we trade a little memory to
address all the above - a per bucket lock is used.

To hash the MPTCP sockets, we re-use the msk' sk_node
entry: the MPTCP sockets are never hashed by the stack.
Replace the existing hash proto callbacks with a dummy
implementation, annotating the above constraint.

Additionally refactor the token creation to code to:

- limit the number of consecutive attempts to a fixed
maximum. Hitting a hash bucket with a long chain is
considered a failed attempt

- accept() no longer can fail to token management.

- if token creation fails at connect() time, we do
fallback to TCP (before the connection was closed)

v1 -> v2:
 - fix "no newline at end of file" - Jakub

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-26 16:21:39 -07:00
Paolo Abeni d39dceca38 mptcp: add __init annotation on setup functions
Add the missing annotation in some setup-only
functions.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-26 16:21:39 -07:00
David S. Miller 7bed145516 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Minor overlapping changes in xfrm_device.c, between the double
ESP trailing bug fix setting the XFRM_INIT flag and the changes
in net-next preparing for bonding encryption support.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-25 19:29:51 -07:00
Eric Dumazet 9b9e2f250e tcp: move ipv4_specific to tcp include file
Declare ipv4_specific once, in tcp.h were it belongs.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-23 20:10:15 -07:00
Eric Dumazet b03d2142be tcp: move ipv6_specific declaration to remove a warning
ipv6_specific should be declared in tcp include files,
not mptcp.

This removes the following warning :
  CHECK   net/ipv6/tcp_ipv6.c
net/ipv6/tcp_ipv6.c:78:42: warning: symbol 'ipv6_specific' was not declared. Should it be static?

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-23 20:10:15 -07:00
Geliang Tang b562f58bbc mptcp: drop sndr_key in mptcp_syn_options
In RFC 8684, we don't need to send sndr_key in SYN package anymore, so drop
it.

Fixes: cc7972ea19 ("mptcp: parse and emit MP_CAPABLE option according to v1 spec")
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-22 21:06:39 -07:00
Paolo Abeni 9e365ff576 mptcp: drop MP_JOIN request sock on syn cookies
Currently any MPTCP socket using syn cookies will fallback to
TCP at 3rd ack time. In case of MP_JOIN requests, the RFC mandate
closing the child and sockets, but the existing error paths
do not handle the syncookie scenario correctly.

Address the issue always forcing the child shutdown in case of
MP_JOIN fallback.

Fixes: ae2dd71649 ("mptcp: handle tcp fallback when using syn cookies")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-18 20:25:51 -07:00
Paolo Abeni 8fd4de1275 mptcp: cache msk on MP_JOIN init_req
The msk ownership is transferred to the child socket at
3rd ack time, so that we avoid more lookups later. If the
request does not reach the 3rd ack, the MSK reference is
dropped at request sock release time.

As a side effect, fallback is now tracked by a NULL msk
reference instead of zeroed 'mp_join' field. This will
simplify the next patch.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-18 20:25:51 -07:00
Wei Yongjun b8ad540dd4 mptcp: fix memory leak in mptcp_subflow_create_socket()
socket malloced  by sock_create_kern() should be release before return
in the error handling, otherwise it cause memory leak.

unreferenced object 0xffff88810910c000 (size 1216):
  comm "00000003_test_m", pid 12238, jiffies 4295050289 (age 54.237s)
  hex dump (first 32 bytes):
    01 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 2f 30 0a 81 88 ff ff  ........./0.....
  backtrace:
    [<00000000e877f89f>] sock_alloc_inode+0x18/0x1c0
    [<0000000093d1dd51>] alloc_inode+0x63/0x1d0
    [<000000005673fec6>] new_inode_pseudo+0x14/0xe0
    [<00000000b5db6be8>] sock_alloc+0x3c/0x260
    [<00000000e7e3cbb2>] __sock_create+0x89/0x620
    [<0000000023e48593>] mptcp_subflow_create_socket+0xc0/0x5e0
    [<00000000419795e4>] __mptcp_socket_create+0x1ad/0x3f0
    [<00000000b2f942e8>] mptcp_stream_connect+0x281/0x4f0
    [<00000000c80cd5cc>] __sys_connect_file+0x14d/0x190
    [<00000000dc761f11>] __sys_connect+0x128/0x160
    [<000000008b14e764>] __x64_sys_connect+0x6f/0xb0
    [<000000007b4f93bd>] do_syscall_64+0xa1/0x530
    [<00000000d3e770b6>] entry_SYSCALL_64_after_hwframe+0x49/0xb3

Fixes: 2303f994b3 ("mptcp: Associate MPTCP context with TCP socket")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-15 18:08:50 -07:00
Geliang Tang a386bc5b21 mptcp: use list_first_entry_or_null
Use list_first_entry_or_null to simplify the code.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-15 13:04:53 -07:00
Geliang Tang c06c1f87b6 mptcp: drop MPTCP_PM_MAX_ADDR
We have defined MPTCP_PM_ADDR_MAX in pm_netlink.c, so drop this duplicate macro.

Fixes: 1b1c7a0ef7 ("mptcp: Add path manager interface")
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-15 13:01:17 -07:00
Paolo Abeni 4b5af44129 mptcp: don't leak msk in token container
If a listening MPTCP socket has unaccepted sockets at close
time, the related msks are freed via mptcp_sock_destruct(),
which in turn does not invoke the proto->destroy() method
nor the mptcp_token_destroy() function.

Due to the above, the child msk socket is not removed from
the token container, leading to later UaF.

Address the issue explicitly removing the token even in the
above error path.

Fixes: 79c0949e9a ("mptcp: Add key generation and token tree")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-10 16:07:00 -07:00
Paolo Abeni 5969856ae8 mptcp: fix races between shutdown and recvmsg
The msk sk_shutdown flag is set by a workqueue, possibly
introducing some delay in user-space notification. If the last
subflow carries some data with the fin packet, the user space
can wake-up before RCV_SHUTDOWN is set. If it executes unblocking
recvmsg(), it may return with an error instead of eof.

Address the issue explicitly checking for eof in recvmsg(), when
no data is found.

Fixes: 59832e2465 ("mptcp: subflow: check parent mptcp socket on subflow state change")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-10 13:34:14 -07:00
Geliang Tang 8e60eed6b3 mptcp: bugfix for RM_ADDR option parsing
In MPTCPOPT_RM_ADDR option parsing, the pointer "ptr" pointed to the
"Subtype" octet, the pointer "ptr+1" pointed to the "Address ID" octet:

  +-------+-------+---------------+
  |Subtype|(resvd)|   Address ID  |
  +-------+-------+---------------+
  |               |
 ptr            ptr+1

We should set mp_opt->rm_id to the value of "ptr+1", not "ptr". This patch
will fix this bug.

Fixes: 3df523ab58 ("mptcp: Add ADD_ADDR handling")
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-08 19:09:41 -07:00
Linus Torvalds cb8e59cc87 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from David Miller:

 1) Allow setting bluetooth L2CAP modes via socket option, from Luiz
    Augusto von Dentz.

 2) Add GSO partial support to igc, from Sasha Neftin.

 3) Several cleanups and improvements to r8169 from Heiner Kallweit.

 4) Add IF_OPER_TESTING link state and use it when ethtool triggers a
    device self-test. From Andrew Lunn.

 5) Start moving away from custom driver versions, use the globally
    defined kernel version instead, from Leon Romanovsky.

 6) Support GRO vis gro_cells in DSA layer, from Alexander Lobakin.

 7) Allow hard IRQ deferral during NAPI, from Eric Dumazet.

 8) Add sriov and vf support to hinic, from Luo bin.

 9) Support Media Redundancy Protocol (MRP) in the bridging code, from
    Horatiu Vultur.

10) Support netmap in the nft_nat code, from Pablo Neira Ayuso.

11) Allow UDPv6 encapsulation of ESP in the ipsec code, from Sabrina
    Dubroca. Also add ipv6 support for espintcp.

12) Lots of ReST conversions of the networking documentation, from Mauro
    Carvalho Chehab.

13) Support configuration of ethtool rxnfc flows in bcmgenet driver,
    from Doug Berger.

14) Allow to dump cgroup id and filter by it in inet_diag code, from
    Dmitry Yakunin.

15) Add infrastructure to export netlink attribute policies to
    userspace, from Johannes Berg.

16) Several optimizations to sch_fq scheduler, from Eric Dumazet.

17) Fallback to the default qdisc if qdisc init fails because otherwise
    a packet scheduler init failure will make a device inoperative. From
    Jesper Dangaard Brouer.

18) Several RISCV bpf jit optimizations, from Luke Nelson.

19) Correct the return type of the ->ndo_start_xmit() method in several
    drivers, it's netdev_tx_t but many drivers were using
    'int'. From Yunjian Wang.

20) Add an ethtool interface for PHY master/slave config, from Oleksij
    Rempel.

21) Add BPF iterators, from Yonghang Song.

22) Add cable test infrastructure, including ethool interfaces, from
    Andrew Lunn. Marvell PHY driver is the first to support this
    facility.

23) Remove zero-length arrays all over, from Gustavo A. R. Silva.

24) Calculate and maintain an explicit frame size in XDP, from Jesper
    Dangaard Brouer.

25) Add CAP_BPF, from Alexei Starovoitov.

26) Support terse dumps in the packet scheduler, from Vlad Buslov.

27) Support XDP_TX bulking in dpaa2 driver, from Ioana Ciornei.

28) Add devm_register_netdev(), from Bartosz Golaszewski.

29) Minimize qdisc resets, from Cong Wang.

30) Get rid of kernel_getsockopt and kernel_setsockopt in order to
    eliminate set_fs/get_fs calls. From Christoph Hellwig.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2517 commits)
  selftests: net: ip_defrag: ignore EPERM
  net_failover: fixed rollback in net_failover_open()
  Revert "tipc: Fix potential tipc_aead refcnt leak in tipc_crypto_rcv"
  Revert "tipc: Fix potential tipc_node refcnt leak in tipc_rcv"
  vmxnet3: allow rx flow hash ops only when rss is enabled
  hinic: add set_channels ethtool_ops support
  selftests/bpf: Add a default $(CXX) value
  tools/bpf: Don't use $(COMPILE.c)
  bpf, selftests: Use bpf_probe_read_kernel
  s390/bpf: Use bcr 0,%0 as tail call nop filler
  s390/bpf: Maintain 8-byte stack alignment
  selftests/bpf: Fix verifier test
  selftests/bpf: Fix sample_cnt shared between two threads
  bpf, selftests: Adapt cls_redirect to call csum_level helper
  bpf: Add csum_level helper for fixing up csum levels
  bpf: Fix up bpf_skb_adjust_room helper's skb csum setting
  sfc: add missing annotation for efx_ef10_try_update_nic_stats_vf()
  crypto/chtls: IPv6 support for inline TLS
  Crypto/chcr: Fixes a coccinile check error
  Crypto/chcr: Fixes compilations warnings
  ...
2020-06-03 16:27:18 -07:00
Linus Torvalds 81e8c10dac Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto updates from Herbert Xu:
 "API:
   - Introduce crypto_shash_tfm_digest() and use it wherever possible.
   - Fix use-after-free and race in crypto_spawn_alg.
   - Add support for parallel and batch requests to crypto_engine.

  Algorithms:
   - Update jitter RNG for SP800-90B compliance.
   - Always use jitter RNG as seed in drbg.

  Drivers:
   - Add Arm CryptoCell driver cctrng.
   - Add support for SEV-ES to the PSP driver in ccp"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (114 commits)
  crypto: hisilicon - fix driver compatibility issue with different versions of devices
  crypto: engine - do not requeue in case of fatal error
  crypto: cavium/nitrox - Fix a typo in a comment
  crypto: hisilicon/qm - change debugfs file name from qm_regs to regs
  crypto: hisilicon/qm - add DebugFS for xQC and xQE dump
  crypto: hisilicon/zip - add debugfs for Hisilicon ZIP
  crypto: hisilicon/hpre - add debugfs for Hisilicon HPRE
  crypto: hisilicon/sec2 - add debugfs for Hisilicon SEC
  crypto: hisilicon/qm - add debugfs to the QM state machine
  crypto: hisilicon/qm - add debugfs for QM
  crypto: stm32/crc32 - protect from concurrent accesses
  crypto: stm32/crc32 - don't sleep in runtime pm
  crypto: stm32/crc32 - fix multi-instance
  crypto: stm32/crc32 - fix run-time self test issue.
  crypto: stm32/crc32 - fix ext4 chksum BUG_ON()
  crypto: hisilicon/zip - Use temporary sqe when doing work
  crypto: hisilicon - add device error report through abnormal irq
  crypto: hisilicon - remove codes of directly report device errors through MSI
  crypto: hisilicon - QM memory management optimization
  crypto: hisilicon - unify initial value assignment into QM
  ...
2020-06-01 12:00:10 -07:00
David S. Miller 1806c13dc2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
xdp_umem.c had overlapping changes between the 64-bit math fix
for the calculation of npgs and the removal of the zerocopy
memory type which got rid of the chunk_size_nohdr member.

The mlx5 Kconfig conflict is a case where we just take the
net-next copy of the Kconfig entry dependency as it takes on
the ESWITCH dependency by one level of indirection which is
what the 'net' conflicting change is trying to ensure.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-31 17:48:46 -07:00
Paolo Abeni 39884604b1 mptcp: fix NULL ptr dereference in MP_JOIN error path
When token lookup on MP_JOIN 3rd ack fails, the server
socket closes with a reset the incoming child. Such socket
has the 'is_mptcp' flag set, but no msk socket associated
- due to the failed lookup.

While crafting the reset packet mptcp_established_options_mp()
will try to dereference the child's master socket, causing
a NULL ptr dereference.

This change addresses the issue with explicit fallback to
TCP in such error path.

Fixes: 729cd6436f ("mptcp: cope better with MP_JOIN failure")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-30 21:54:03 -07:00
Paolo Abeni c5c79763fa mptcp: remove msk from the token container at destruction time.
Currently we remote the msk from the token container only
via mptcp_close(). The MPTCP master socket can be destroyed
also via other paths (e.g. if not yet accepted, when shutting
down the listener socket). When we hit the latter scenario,
dangling msk references are left into the token container,
leading to memory corruption and/or UaF.

This change addresses the issue by moving the token removal
into the msk destructor.

Fixes: 79c0949e9a ("mptcp: Add key generation and token tree")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-30 21:39:13 -07:00
Paolo Abeni 10f6d46c94 mptcp: fix race between MP_JOIN and close
If a MP_JOIN subflow completes the 3whs while another
CPU is closing the master msk, we can hit the
following race:

CPU1                                    CPU2

close()
 mptcp_close
                                        subflow_syn_recv_sock
                                         mptcp_token_get_sock
                                         mptcp_finish_join
                                          inet_sk_state_load
  mptcp_token_destroy
  inet_sk_state_store(TCP_CLOSE)
  __mptcp_flush_join_list()
                                          mptcp_sock_graft
                                          list_add_tail
  sk_common_release
   sock_orphan()
 <socket free>

The MP_JOIN socket will be leaked. Additionally we can hit
UaF for the msk 'struct socket' referenced via the 'conn'
field.

This change try to address the issue introducing some
synchronization between the MP_JOIN 3whs and mptcp_close
via the join_list spinlock. If we detect the msk is closing
the MP_JOIN socket is closed, too.

Fixes: f296234c98 ("mptcp: Add handling of incoming MP_JOIN requests")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-30 21:39:13 -07:00
Paolo Abeni 41be81a8d3 mptcp: fix unblocking connect()
Currently unblocking connect() on MPTCP sockets fails frequently.
If mptcp_stream_connect() is invoked to complete a previously
attempted unblocking connection, it will still try to create
the first subflow via __mptcp_socket_create(). If the 3whs is
completed and the 'can_ack' flag is already set, the latter
will fail with -EINVAL.

This change addresses the issue checking for pending connect and
delegating the completion to the first subflow. Additionally
do msk addresses and sk_state changes only when needed.

Fixes: 2303f994b3 ("mptcp: Associate MPTCP context with TCP socket")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-30 21:39:13 -07:00
Florian Westphal 4e637c70b5 mptcp: attempt coalescing when moving skbs to mptcp rx queue
We can try to coalesce skbs we take from the subflows rx queue with the
tail of the mptcp rx queue.

If successful, the skb head can be discarded early.

We can also free the skb extensions, we do not access them after this.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-26 20:29:32 -07:00
Paolo Abeni 0a82e230c6 mptcp: avoid NULL-ptr derefence on fallback
In the MPTCP receive path we must cope with TCP fallback
on blocking recvmsg(). Currently in such code path we detect
the fallback condition, but we don't fetch the struct socket
required for fallback.

The above allowed syzkaller to trigger a NULL pointer
dereference:

general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]
CPU: 1 PID: 7226 Comm: syz-executor523 Not tainted 5.7.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:sock_recvmsg_nosec net/socket.c:886 [inline]
RIP: 0010:sock_recvmsg+0x92/0x110 net/socket.c:904
Code: 5b 41 5c 41 5d 41 5e 41 5f 5d c3 44 89 6c 24 04 e8 53 18 1d fb 4d 8d 6f 20 4c 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 ef e8 20 12 5b fb bd a0 00 00 00 49 03 6d
RSP: 0018:ffffc90001077b98 EFLAGS: 00010202
RAX: 0000000000000004 RBX: ffffc90001077dc0 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff86565e59 R09: ffffed10115afeaa
R10: ffffed10115afeaa R11: 0000000000000000 R12: 1ffff9200020efbc
R13: 0000000000000020 R14: ffffc90001077de0 R15: 0000000000000000
FS:  00007fc6a3abe700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004d0050 CR3: 00000000969f0000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 mptcp_recvmsg+0x18d5/0x19b0 net/mptcp/protocol.c:891
 inet_recvmsg+0xf6/0x1d0 net/ipv4/af_inet.c:838
 sock_recvmsg_nosec net/socket.c:886 [inline]
 sock_recvmsg net/socket.c:904 [inline]
 __sys_recvfrom+0x2f3/0x470 net/socket.c:2057
 __do_sys_recvfrom net/socket.c:2075 [inline]
 __se_sys_recvfrom net/socket.c:2071 [inline]
 __x64_sys_recvfrom+0xda/0xf0 net/socket.c:2071
 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3

Address the issue initializing the struct socket reference
before entering the fallback code.

Reported-and-tested-by: syzbot+c6bfc3db991edc918432@syzkaller.appspotmail.com
Suggested-by: Ondrej Mosnacek <omosnace@redhat.com>
Fixes: 8ab183deb2 ("mptcp: cope with later TCP fallback")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-26 20:18:24 -07:00
David S. Miller 13209a8f73 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
The MSCC bug fix in 'net' had to be slightly adjusted because the
register accesses are done slightly differently in net-next.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-24 13:47:27 -07:00
Todd Malsbary bd6972226f mptcp: use untruncated hash in ADD_ADDR HMAC
There is some ambiguity in the RFC as to whether the ADD_ADDR HMAC is
the rightmost 64 bits of the entire hash or of the leftmost 160 bits
of the hash.  The intention, as clarified with the author of the RFC,
is the entire hash.

This change returns the entire hash from
mptcp_crypto_hmac_sha (instead of only the first 160 bits), and moves
any truncation/selection operation on the hash to the caller.

Fixes: 12555a2d97 ("mptcp: use rightmost 64 bits in ADD_ADDR HMAC")
Reviewed-by: Christoph Paasch <cpaasch@apple.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Todd Malsbary <todd.malsbary@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-22 14:21:24 -07:00
Todd Malsbary 12555a2d97 mptcp: use rightmost 64 bits in ADD_ADDR HMAC
This changes the HMAC used in the ADD_ADDR option from the leftmost 64
bits to the rightmost 64 bits as described in RFC 8684, section 3.4.1.

This issue was discovered while adding support to packetdrill for the
ADD_ADDR v1 option.

Fixes: 3df523ab58 ("mptcp: Add ADD_ADDR handling")
Signed-off-by: Todd Malsbary <todd.malsbary@linux.intel.com>
Acked-by: Christoph Paasch <cpaasch@apple.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-19 12:35:51 -07:00
Christoph Hellwig 3986912f6a ipv6: move SIOCADDRT and SIOCDELRT handling into ->compat_ioctl
To prepare removing the global routing_ioctl hack start lifting the code
into a newly added ipv6 ->compat_ioctl handler.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-18 17:35:02 -07:00
Florian Westphal 4930f4831b net: allow __skb_ext_alloc to sleep
mptcp calls this from the transmit side, from process context.
Allow a sleeping allocation instead of unconditional GFP_ATOMIC.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-17 12:35:34 -07:00
Florian Westphal 5c8264435d mptcp: remove inner wait loop from mptcp_sendmsg_frag
previous patches made sure we only call into this function
when these prerequisites are met, so no need to wait on the
subflow socket anymore.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/7
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-17 12:35:34 -07:00
Florian Westphal 17091708d1 mptcp: fill skb page frag cache outside of mptcp_sendmsg_frag
The mptcp_sendmsg_frag helper contains a loop that will wait on the
subflow sk.

It seems preferrable to only wait in mptcp_sendmsg() when blocking io is
requested.  mptcp_sendmsg already has such a wait loop that is used when
no subflow socket is available for transmission.

This is another preparation patch that makes sure we call
mptcp_sendmsg_frag only if the page frag cache has been refilled.

Followup patch will remove the wait loop from mptcp_sendmsg_frag().

The retransmit worker doesn't need to do this refill as it won't
transmit new mptcp-level data.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-17 12:35:34 -07:00
Florian Westphal 149f7c71e2 mptcp: fill skb extension cache outside of mptcp_sendmsg_frag
The mptcp_sendmsg_frag helper contains a loop that will wait on the
subflow sk.

It seems preferrable to only wait in mptcp_sendmsg() when blocking io is
requested.  mptcp_sendmsg already has such a wait loop that is used when
no subflow socket is available for transmission.

This is a preparation patch that makes sure we call
mptcp_sendmsg_frag only if a skb extension has been allocated.

Moreover, such allocation currently uses GFP_ATOMIC while it
could use sleeping allocation instead.

Followup patches will remove the wait loop from mptcp_sendmsg_frag()
and will allow to do a sleeping allocation for the extension.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-17 12:35:34 -07:00
Florian Westphal 72511aab95 mptcp: avoid blocking in tcp_sendpages
The transmit loop continues to xmit new data until an error is returned
or all data was transmitted.

For the blocking i/o case, this means that tcp_sendpages() may block on
the subflow until more space becomes available, i.e. we end up sleeping
with the mptcp socket lock held.

Instead we should check if a different subflow is ready to be used.

This restarts the subflow sk lookup when the tx operation succeeded
and the tcp subflow can't accept more data or if tcp_sendpages
indicates -EAGAIN on a blocking mptcp socket.

In that case we also need to set the NOSPACE bit to make sure we get
notified once memory becomes available.

In case all subflows are busy, the existing logic will wait until a
subflow is ready, releasing the mptcp socket lock while doing so.

The mptcp worker already sets DONTWAIT, so no need to make changes there.

v2:
 * set NOSPACE bit
 * add a comment to clarify that mptcp-sk sndbuf limits need to
   be checked as well.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-17 12:35:34 -07:00
Florian Westphal fb529e62d3 mptcp: break and restart in case mptcp sndbuf is full
Its not enough to check for available tcp send space.

We also hold on to transmitted data for mptcp-level retransmits.
Right now we will send more and more data if the peer can ack data
at the tcp level fast enough, since that frees up tcp send buffer space.

But we also need to check that data was acked and reclaimed at the mptcp
level.

Therefore add needed check in mptcp_sendmsg, flush tcp data and
wait until more mptcp snd space becomes available if we are over the
limit.  Before we wait for more data, also make sure we start the
retransmit timer if we ran out of sndbuf space.

Otherwise there is a very small chance that we wait forever:

 * receiver is waiting for data
 * sender is blocked because mptcp socket buffer is full
 * at tcp level, all data was acked
 * mptcp-level snd_una was not updated, because last ack
   that acknowledged the last data packet carried an older
   MPTCP-ack.

Restarting the retransmit timer avoids this problem: if TCP
subflow is idle, data is retransmitted from the RTX queue.

New data will make the peer send a new, updated MPTCP-Ack.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-17 12:35:34 -07:00
Florian Westphal a0e17064d4 mptcp: move common nospace-pattern to a helper
Paolo noticed that ssk_check_wmem() has same pattern, so add/use
common helper for both places.

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-17 12:35:34 -07:00
Christoph Paasch a0c1d0eafd mptcp: Use 32-bit DATA_ACK when possible
RFC8684 allows to send 32-bit DATA_ACKs as long as the peer is not
sending 64-bit data-sequence numbers. The 64-bit DSN is only there for
extreme scenarios when a very high throughput subflow is combined with a
long-RTT subflow such that the high-throughput subflow wraps around the
32-bit sequence number space within an RTT of the high-RTT subflow.

It is thus a rare scenario and we should try to use the 32-bit DATA_ACK
instead as long as possible. It allows to reduce the TCP-option overhead
by 4 bytes, thus makes space for an additional SACK-block. It also makes
tcpdumps much easier to read when the DSN and DATA_ACK are both either
32 or 64-bit.

Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-16 13:51:10 -07:00
David S. Miller da07f52d3c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Move the bpf verifier trace check into the new switch statement in
HEAD.

Resolve the overlapping changes in hinic, where bug fixes overlap
the addition of VF support.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-15 13:48:59 -07:00
Paolo Abeni 729cd6436f mptcp: cope better with MP_JOIN failure
Currently, on MP_JOIN failure we reset the child
socket, but leave the request socket untouched.

tcp_check_req will deal with it according to the
'tcp_abort_on_overflow' sysctl value - by default the
req socket will stay alive.

The above leads to inconsistent behavior on MP JOIN
failure, and bad listener overflow accounting.

This patch addresses the issue leveraging the infrastructure
just introduced to ask the TCP stack to drop the req on
failure.

The child socket is not freed anymore by subflow_syn_recv_sock(),
instead it's moved to a dead state and will be disposed by the
next sock_put done by the TCP stack, so that listener overflow
accounting is not affected by MP JOIN failure.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Christoph Paasch <cpaasch@apple.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-15 12:30:13 -07:00
Paolo Abeni 90bf45134d mptcp: add new sock flag to deal with join subflows
MP_JOIN subflows must not land into the accept queue.
Currently tcp_check_req() calls an mptcp specific helper
to detect such scenario.

Such helper leverages the subflow context to check for
MP_JOIN subflows. We need to deal also with MP JOIN
failures, even when the subflow context is not available
due allocation failure.

A possible solution would be changing the syn_recv_sock()
signature to allow returning a more descriptive action/
error code and deal with that in tcp_check_req().

Since the above need is MPTCP specific, this patch instead
uses a TCP request socket hole to add a MPTCP specific flag.
Such flag is used by the MPTCP syn_recv_sock() to tell
tcp_check_req() how to deal with the request socket.

This change is a no-op for !MPTCP build, and makes the
MPTCP code simpler. It allows also the next patch to deal
correctly with MP JOIN failure.

v1 -> v2:
 - be more conservative on drop_req initialization (Mat)

RFC -> v1:
 - move the drop_req bit inside tcp_request_sock (Eric)

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Reviewed-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-15 12:30:13 -07:00
Christoph Paasch 64d950ae0b mptcp: Initialize map_seq upon subflow establishment
When the other MPTCP-peer uses 32-bit data-sequence numbers, we rely on
map_seq to indicate how to expand to a 64-bit data-sequence number in
expand_seq() when receiving data.

For new subflows, this field is not initialized, thus results in an
"invalid" mapping being discarded.

Fix this by initializing map_seq upon subflow establishment time.

Fixes: f296234c98 ("mptcp: Add handling of incoming MP_JOIN requests")
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Reviewed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-12 12:08:22 -07:00
Eric Biggers ac0ad93df7 mptcp: use SHA256_BLOCK_SIZE, not SHA_MESSAGE_BYTES
In preparation for naming the SHA-1 stuff in <linux/cryptohash.h>
properly and moving it to a more appropriate header, fix the HMAC-SHA256
code in mptcp_crypto_hmac_sha() to use SHA256_BLOCK_SIZE instead of
"SHA_MESSAGE_BYTES" which is actually the SHA-1 block size.
(Fortunately these are both 64 bytes, so this wasn't a "real" bug...)

Cc: Paolo Abeni <pabeni@redhat.com>
Cc: mptcp@lists.01.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-05-08 15:32:16 +10:00
Paolo Abeni 7d14b0d2b9 mptcp: set correct vfs info for subflows
When a subflow is created via mptcp_subflow_create_socket(),
a new 'struct socket' is allocated, with a new i_ino value.

When inspecting TCP sockets via the procfs and or the diag
interface, the above ones are not related to the process owning
the MPTCP master socket, even if they are a logical part of it
('ss -p' shows an empty process field)

Additionally, subflows created by the path manager get
the uid/gid from the running workqueue.

Subflows are part of the owning MPTCP master socket, let's
adjust the vfs info to reflect this.

After this patch, 'ss' correctly displays subflows as belonging
to the msk socket creator.

Fixes: 2303f994b3 ("mptcp: Associate MPTCP context with TCP socket")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-07 18:16:05 -07:00
David S. Miller 3793faad7b Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Conflicts were all overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-06 22:10:13 -07:00
Paolo Abeni ac2b47fb92 mptcp: fix uninitialized value access
tcp_v{4,6}_syn_recv_sock() set 'own_req' only when returning
a not NULL 'child', let's check 'own_req' only if child is
available to avoid an - unharmful - UBSAN splat.

v1 -> v2:
 - reference the correct hash

Fixes: 4c8941de78 ("mptcp: avoid flipping mp_capable field in syn_recv_sock()")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30 12:34:07 -07:00
Paolo Abeni a77895dbc0 mptcp: initialize the data_fin field for mpc packets
When parsing MPC+data packets we set the dss field, so
we must also initialize the data_fin, or we can find stray
value there.

Fixes: 9a19371bf0 ("mptcp: fix data_fin handing in RX path")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30 12:23:23 -07:00
Paolo Abeni 5a91e32b40 mptcp: fix 'use_ack' option access.
The mentioned RX option field is initialized only for DSS
packet, we must access it only if 'dss' is set too, or
the subflow will end-up in a bad status, leading to
RFC violations.

Fixes: d22f4988ff ("mptcp: process MP_CAPABLE data option")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30 12:23:22 -07:00
Paolo Abeni d6085fe19b mptcp: avoid a WARN on bad input.
Syzcaller has found a way to trigger the WARN_ON_ONCE condition
in check_fully_established().

The root cause is a legit fallback to TCP scenario, so replace
the WARN with a plain message on a more strict condition.

Fixes: f296234c98 ("mptcp: Add handling of incoming MP_JOIN requests")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30 12:23:22 -07:00
Paolo Abeni cfde141ea3 mptcp: move option parsing into mptcp_incoming_options()
The mptcp_options_received structure carries several per
packet flags (mp_capable, mp_join, etc.). Such fields must
be cleared on each packet, even on dropped ones or packet
not carrying any MPTCP options, but the current mptcp
code clears them only on TCP option reset.

On several races/corner cases we end-up with stray bits in
incoming options, leading to WARN_ON splats. e.g.:

[  171.164906] Bad mapping: ssn=32714 map_seq=1 map_data_len=32713
[  171.165006] WARNING: CPU: 1 PID: 5026 at net/mptcp/subflow.c:533 warn_bad_map (linux-mptcp/net/mptcp/subflow.c:533 linux-mptcp/net/mptcp/subflow.c:531)
[  171.167632] Modules linked in: ip6_vti ip_vti ip_gre ipip sit tunnel4 ip_tunnel geneve ip6_udp_tunnel udp_tunnel macsec macvtap tap ipvlan macvlan 8021q garp mrp xfrm_interface veth netdevsim nlmon dummy team bonding vcan bridge stp llc ip6_gre gre ip6_tunnel tunnel6 tun binfmt_misc intel_rapl_msr intel_rapl_common rfkill kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel joydev virtio_balloon pcspkr i2c_piix4 sunrpc ip_tables xfs libcrc32c crc32c_intel serio_raw virtio_console ata_generic virtio_blk virtio_net net_failover failover ata_piix libata
[  171.199464] CPU: 1 PID: 5026 Comm: repro Not tainted 5.7.0-rc1.mptcp_f227fdf5d388+ #95
[  171.200886] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-2.fc30 04/01/2014
[  171.202546] RIP: 0010:warn_bad_map (linux-mptcp/net/mptcp/subflow.c:533 linux-mptcp/net/mptcp/subflow.c:531)
[  171.206537] Code: c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 1d 8b 55 3c 44 89 e6 48 c7 c7 20 51 13 95 e8 37 8b 22 fe <0f> 0b 48 83 c4 08 5b 5d 41 5c c3 89 4c 24 04 e8 db d6 94 fe 8b 4c
[  171.220473] RSP: 0018:ffffc90000150560 EFLAGS: 00010282
[  171.221639] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[  171.223108] RDX: 0000000000000000 RSI: 0000000000000008 RDI: fffff5200002a09e
[  171.224388] RBP: ffff8880aa6e3c00 R08: 0000000000000001 R09: fffffbfff2ec9955
[  171.225706] R10: ffffffff9764caa7 R11: fffffbfff2ec9954 R12: 0000000000007fca
[  171.227211] R13: ffff8881066f4a7f R14: ffff8880aa6e3c00 R15: 0000000000000020
[  171.228460] FS:  00007f8623719740(0000) GS:ffff88810be00000(0000) knlGS:0000000000000000
[  171.230065] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  171.231303] CR2: 00007ffdab190a50 CR3: 00000001038ea006 CR4: 0000000000160ee0
[  171.232586] Call Trace:
[  171.233109]  <IRQ>
[  171.233531] get_mapping_status (linux-mptcp/net/mptcp/subflow.c:691)
[  171.234371] mptcp_subflow_data_available (linux-mptcp/net/mptcp/subflow.c:736 linux-mptcp/net/mptcp/subflow.c:832)
[  171.238181] subflow_state_change (linux-mptcp/net/mptcp/subflow.c:1085 (discriminator 1))
[  171.239066] tcp_fin (linux-mptcp/net/ipv4/tcp_input.c:4217)
[  171.240123] tcp_data_queue (linux-mptcp/./include/linux/compiler.h:199 linux-mptcp/net/ipv4/tcp_input.c:4822)
[  171.245083] tcp_rcv_established (linux-mptcp/./include/linux/skbuff.h:1785 linux-mptcp/./include/net/tcp.h:1774 linux-mptcp/./include/net/tcp.h:1847 linux-mptcp/net/ipv4/tcp_input.c:5238 linux-mptcp/net/ipv4/tcp_input.c:5730)
[  171.254089] tcp_v4_rcv (linux-mptcp/./include/linux/spinlock.h:393 linux-mptcp/net/ipv4/tcp_ipv4.c:2009)
[  171.258969] ip_protocol_deliver_rcu (linux-mptcp/net/ipv4/ip_input.c:204 (discriminator 1))
[  171.260214] ip_local_deliver_finish (linux-mptcp/./include/linux/rcupdate.h:651 linux-mptcp/net/ipv4/ip_input.c:232)
[  171.261389] ip_local_deliver (linux-mptcp/./include/linux/netfilter.h:307 linux-mptcp/./include/linux/netfilter.h:301 linux-mptcp/net/ipv4/ip_input.c:252)
[  171.265884] ip_rcv (linux-mptcp/./include/linux/netfilter.h:307 linux-mptcp/./include/linux/netfilter.h:301 linux-mptcp/net/ipv4/ip_input.c:539)
[  171.273666] process_backlog (linux-mptcp/./include/linux/rcupdate.h:651 linux-mptcp/net/core/dev.c:6135)
[  171.275328] net_rx_action (linux-mptcp/net/core/dev.c:6572 linux-mptcp/net/core/dev.c:6640)
[  171.280472] __do_softirq (linux-mptcp/./arch/x86/include/asm/jump_label.h:25 linux-mptcp/./include/linux/jump_label.h:200 linux-mptcp/./include/trace/events/irq.h:142 linux-mptcp/kernel/softirq.c:293)
[  171.281379] do_softirq_own_stack (linux-mptcp/arch/x86/entry/entry_64.S:1083)
[  171.282358]  </IRQ>

We could address the issue clearing explicitly the relevant fields
in several places - tcp_parse_option, tcp_fast_parse_options,
possibly others.

Instead we move the MPTCP option parsing into the already existing
mptcp ingress hook, so that we need to clear the fields in a single
place.

This allows us dropping an MPTCP hook from the TCP code and
removing the quite large mptcp_options_received from the tcp_sock
struct. On the flip side, the MPTCP sockets will traverse the
option space twice (in tcp_parse_option() and in
mptcp_incoming_options(). That looks acceptable: we already
do that for syn and 3rd ack packets, plain TCP socket will
benefit from it, and even MPTCP sockets will experience better
code locality, reducing the jumps between TCP and MPTCP code.

v1 -> v2:
 - rebased on current '-net' tree

Fixes: 648ef4b886 ("mptcp: Implement MPTCP receive path")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30 12:23:22 -07:00
Paolo Abeni 263e1201a2 mptcp: consolidate synack processing.
Currently the MPTCP code uses 2 hooks to process syn-ack
packets, mptcp_rcv_synsent() and the sk_rx_dst_set()
callback.

We can drop the first, moving the relevant code into the
latter, reducing the hooking into the TCP code. This is
also needed by the next patch.

v1 -> v2:
 - use local tcp sock ptr instead of casting the sk variable
   several times - DaveM

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30 12:23:22 -07:00
Florian Westphal 42c556fef9 mptcp: replace mptcp_disconnect with a stub
Paolo points out that mptcp_disconnect is bogus:
"lock_sock(sk);
looks suspicious (lock should be already held by the caller)
And call to: tcp_disconnect(sk, flags); too, sk is not a tcp
socket".

->disconnect() gets called from e.g. inet_stream_connect when
one tries to disassociate a connected socket again (to re-connect
without closing the socket first).
MPTCP however uses mptcp_stream_connect, not inet_stream_connect,
for the mptcp-socket connect call.

inet_stream_connect only gets called indirectly, for the tcp socket,
so any ->disconnect() calls end up calling tcp_disconnect for that
tcp subflow sk.

This also explains why syzkaller has not yet reported a problem
here.  So for now replace this with a stub that doesn't do anything.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/14
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-29 12:39:49 -07:00
Paolo Abeni 1200832c6e mptcp: fix race in msk status update
Currently subflow_finish_connect() changes unconditionally
any msk socket status other than TCP_ESTABLISHED.

If an unblocking connect() races with close(), we can end-up
triggering:

IPv4: Attempt to release TCP socket in state 1 00000000e32b8b7e

when the msk socket is disposed.

Be sure to enter the established status only from SYN_SENT.

Fixes: c3c123d16c ("net: mptcp: don't hang in mptcp_sendmsg() after TCP fallback")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-25 20:38:54 -07:00
Florian Westphal 071c8ed6e8 tcp: mptcp: use mptcp receive buffer space to select rcv window
In MPTCP, the receive window is shared across all subflows, because it
refers to the mptcp-level sequence space.

MPTCP receivers already place incoming packets on the mptcp socket
receive queue and will charge it to the mptcp socket rcvbuf until
userspace consumes the data.

Update __tcp_select_window to use the occupancy of the parent/mptcp
socket instead of the subflow socket in case the tcp socket is part
of a logical mptcp connection.

This commit doesn't change choice of initial window for passive or active
connections.
While it would be possible to change those as well, this adds complexity
(especially when handling MP_JOIN requests).  Furthermore, the MPTCP RFC
specifically says that a MPTCP sender 'MUST NOT use the RCV.WND field
of a TCP segment at the connection level if it does not also carry a DSS
option with a Data ACK field.'

SYN/SYNACK packets do not carry a DSS option with a Data ACK field.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-25 20:37:52 -07:00
Bo YU b4e0f9a926 mptcp/pm_netlink.c : add check for nla_put_in/6_addr
Normal there should be checked for nla_put_in6_addr like other
usage in net.

Detected by CoverityScan, CID# 1461639

Fixes: 01cacb00b3 ("mptcp: add netlink-based PM")
Signed-off-by: Bo YU <tsu.yubo@gmail.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-23 15:38:10 -07:00
Paolo Abeni 9a19371bf0 mptcp: fix data_fin handing in RX path
The data fin flag is set only via a DSS option, but
mptcp_incoming_options() copies it unconditionally from the
provided RX options.

Since we do not clear all the mptcp sock RX options in a
socket free/alloc cycle, we can end-up with a stray data_fin
value while parsing e.g. MPC packets.

That would lead to mapping data corruption and will trigger
a few WARN_ON() in the RX path.

Instead of adding a costly memset(), fetch the data_fin flag
only for DSS packets - when we always explicitly initialize
such bit at option parsing time.

Fixes: 648ef4b886 ("mptcp: Implement MPTCP receive path")
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-22 19:46:01 -07:00
Paolo Abeni fca5c82c08 mptcp: drop req socket remote_key* fields
We don't need them, as we can use the current ingress opt
data instead. Setting them in syn_recv_sock() may causes
inconsistent mptcp socket status, as per previous commit.

Fixes: cc7972ea19 ("mptcp: parse and emit MP_CAPABLE option according to v1 spec")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-20 12:59:33 -07:00
Paolo Abeni 4c8941de78 mptcp: avoid flipping mp_capable field in syn_recv_sock()
If multiple CPUs races on the same req_sock in syn_recv_sock(),
flipping such field can cause inconsistent child socket status.

When racing, the CPU losing the req ownership may still change
the mptcp request socket mp_capable flag while the CPU owning
the request is cloning the socket, leaving the child socket with
'is_mptcp' set but no 'mp_capable' flag.

Such socket will stay with 'conn' field cleared, heading to oops
in later mptcp callback.

Address the issue tracking the fallback status in a local variable.

Fixes: 58b0991962 ("mptcp: create msk early")
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-20 12:59:32 -07:00
Florian Westphal 5e20087d1b mptcp: handle mptcp listener destruction via rcu
Following splat can occur during self test:

 BUG: KASAN: use-after-free in subflow_data_ready+0x156/0x160
 Read of size 8 at addr ffff888100c35c28 by task mptcp_connect/4808

  subflow_data_ready+0x156/0x160
  tcp_child_process+0x6a3/0xb30
  tcp_v4_rcv+0x2231/0x3730
  ip_protocol_deliver_rcu+0x5c/0x860
  ip_local_deliver_finish+0x220/0x360
  ip_local_deliver+0x1c8/0x4e0
  ip_rcv_finish+0x1da/0x2f0
  ip_rcv+0xd0/0x3c0
  __netif_receive_skb_one_core+0xf5/0x160
  __netif_receive_skb+0x27/0x1c0
  process_backlog+0x21e/0x780
  net_rx_action+0x35f/0xe90
  do_softirq+0x4c/0x50
  [..]

This occurs when accessing subflow_ctx->conn.

Problem is that tcp_child_process() calls listen sockets'
sk_data_ready() notification, but it doesn't hold the listener
lock.  Another cpu calling close() on the listener will then cause
transition of refcount to 0.

Fixes: 58b0991962 ("mptcp: create msk early")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-20 12:59:32 -07:00
Florian Westphal 9f5ca6a598 mptcp: fix 'Attempt to release TCP socket in state' warnings
We need to set sk_state to CLOSED, else we will get following:

IPv4: Attempt to release TCP socket in state 3 00000000b95f109e
IPv4: Attempt to release TCP socket in state 10 00000000b95f109e

First one is from inet_sock_destruct(), second one from
mptcp_sk_clone failure handling.  Setting sk_state to CLOSED isn't
enough, we also need to orphan sk so it has DEAD flag set.
Otherwise, a very similar warning is printed from inet_sock_destruct().

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-18 15:43:20 -07:00
Florian Westphal df1036da90 mptcp: fix splat when incoming connection is never accepted before exit/close
Following snippet (replicated from syzkaller reproducer) generates
warning: "IPv4: Attempt to release TCP socket in state 1".

int main(void) {
 struct sockaddr_in sin1 = { .sin_family = 2, .sin_port = 0x4e20,
                             .sin_addr.s_addr = 0x010000e0, };
 struct sockaddr_in sin2 = { .sin_family = 2,
	                     .sin_addr.s_addr = 0x0100007f, };
 struct sockaddr_in sin3 = { .sin_family = 2, .sin_port = 0x4e20,
	                     .sin_addr.s_addr = 0x0100007f, };
 int r0 = socket(0x2, 0x1, 0x106);
 int r1 = socket(0x2, 0x1, 0x106);

 bind(r1, (void *)&sin1, sizeof(sin1));
 connect(r1, (void *)&sin2, sizeof(sin2));
 listen(r1, 3);
 return connect(r0, (void *)&sin3, 0x4d);
}

Reason is that the newly generated mptcp socket is closed via the ulp
release of the tcp listener socket when its accept backlog gets purged.

To fix this, delay setting the ESTABLISHED state until after userspace
calls accept and via mptcp specific destructor.

Fixes: 58b0991962 ("mptcp: create msk early")
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/9
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-18 15:43:20 -07:00
Florian Westphal e154659ba3 mptcp: fix double-unlock in mptcp_poll
mptcp_connect/28740 is trying to release lock (sk_lock-AF_INET) at:
[<ffffffff82c15869>] mptcp_poll+0xb9/0x550
but there are no more locks to release!
Call Trace:
 lock_release+0x50f/0x750
 release_sock+0x171/0x1b0
 mptcp_poll+0xb9/0x550
 sock_poll+0x157/0x470
 ? get_net_ns+0xb0/0xb0
 do_sys_poll+0x63c/0xdd0

Problem is that __mptcp_tcp_fallback() releases the mptcp socket lock,
but after recent change it doesn't do this in all of its return paths.

To fix this, remove the unlock from __mptcp_tcp_fallback() and
always do the unlock in the caller.

Also add a small comment as to why we have this
__mptcp_needs_tcp_fallback().

Fixes: 0b4f33def7 ("mptcp: fix tcp fallback crash")
Reported-by: syzbot+e56606435b7bfeea8cf5@syzkaller.appspotmail.com
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-12 21:04:08 -07:00
Geliang Tang c85adced95 mptcp: add some missing pr_fmt defines
Some of the mptcp logs didn't print out the format string:

[  185.651493] DSS
[  185.651494] data_fin=0 dsn64=0 use_map=0 ack64=1 use_ack=1
[  185.651494] data_ack=13792750332298763796
[  185.651495] MPTCP: msk=00000000c4b81cfc ssk=000000009743af53 data_avail=0 skb=0000000063dc595d
[  185.651495] MPTCP: msk=00000000c4b81cfc ssk=000000009743af53 status=0
[  185.651495] MPTCP: msk ack_seq=9bbc894565aa2f9a subflow ack_seq=9bbc894565aa2f9a
[  185.651496] MPTCP: msk=00000000c4b81cfc ssk=000000009743af53 data_avail=1 skb=0000000012e809e1

So this patch added these missing pr_fmt defines. Then we can get the same
format string "MPTCP" in all mptcp logs like this:

[  142.795829] MPTCP: DSS
[  142.795829] MPTCP: data_fin=0 dsn64=0 use_map=0 ack64=1 use_ack=1
[  142.795829] MPTCP: data_ack=8089704603109242421
[  142.795830] MPTCP: msk=00000000133a24e0 ssk=000000002e508c64 data_avail=0 skb=00000000d5f230df
[  142.795830] MPTCP: msk=00000000133a24e0 ssk=000000002e508c64 status=0
[  142.795831] MPTCP: msk ack_seq=66790290f1199d9b subflow ack_seq=66790290f1199d9b
[  142.795831] MPTCP: msk=00000000133a24e0 ssk=000000002e508c64 data_avail=1 skb=00000000de5aca2e

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-03 16:06:32 -07:00
Matthieu Baerts 564cf2f395 mptcp: fix "fn parameter not described" warnings
Obtained with:

  $ make W=1 net/mptcp/token.o
  net/mptcp/token.c:53: warning: Function parameter or member 'req' not described in 'mptcp_token_new_request'
  net/mptcp/token.c:98: warning: Function parameter or member 'sk' not described in 'mptcp_token_new_connect'
  net/mptcp/token.c:133: warning: Function parameter or member 'conn' not described in 'mptcp_token_new_accept'
  net/mptcp/token.c:178: warning: Function parameter or member 'token' not described in 'mptcp_token_destroy_request'
  net/mptcp/token.c:191: warning: Function parameter or member 'token' not described in 'mptcp_token_destroy'

Fixes: 79c0949e9a (mptcp: Add key generation and token tree)
Fixes: 58b0991962 (mptcp: create msk early)
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-02 06:59:21 -07:00
Florian Westphal de06f57392 mptcp: re-check dsn before reading from subflow
mptcp_subflow_data_available() is commonly called via
ssk->sk_data_ready(), in this case the mptcp socket lock
cannot be acquired.

Therefore, while we can safely discard subflow data that
was already received up to msk->ack_seq, we cannot be sure
that 'subflow->data_avail' will still be valid at the time
userspace wants to read the data -- a previous read on a
different subflow might have carried this data already.

In that (unlikely) event, msk->ack_seq will have been updated
and will be ahead of the subflow dsn.

We can check for this condition and skip/resync to the expected
sequence number.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-02 06:59:21 -07:00
Florian Westphal 59832e2465 mptcp: subflow: check parent mptcp socket on subflow state change
This is needed at least until proper MPTCP-Level fin/reset
signalling gets added:

We wake parent when a subflow changes, but we should do this only
when all subflows have closed, not just one.

Schedule the mptcp worker and tell it to check eof state on all
subflows.

Only flag mptcp socket as closed and wake userspace processes blocking
in poll if all subflows have closed.

Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-02 06:59:21 -07:00
Florian Westphal 0b4f33def7 mptcp: fix tcp fallback crash
Christoph Paasch reports following crash:

general protection fault [..]
CPU: 0 PID: 2874 Comm: syz-executor072 Not tainted 5.6.0-rc5 #62
RIP: 0010:__pv_queued_spin_lock_slowpath kernel/locking/qspinlock.c:471
[..]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:50 [inline]
 do_raw_spin_lock include/linux/spinlock.h:181 [inline]
 spin_lock_bh include/linux/spinlock.h:343 [inline]
 __mptcp_flush_join_list+0x44/0xb0 net/mptcp/protocol.c:278
 mptcp_shutdown+0xb3/0x230 net/mptcp/protocol.c:1882
[..]

Problem is that mptcp_shutdown() socket isn't an mptcp socket,
its a plain tcp_sk.  Thus, trying to access mptcp_sk specific
members accesses garbage.

Root cause is that accept() returns a fallback (tcp) socket, not an mptcp
one.  There is code in getpeername to detect this and override the sockets
stream_ops.  But this will only run when accept() caller provided a
sockaddr struct.  "accept(fd, NULL, 0)" will therefore result in
mptcp stream ops, but with sock->sk pointing at a tcp_sk.

Update the existing fallback handling to detect this as well.

Moreover, mptcp_shutdown did not have fallback handling, and
mptcp_poll did it too late so add that there as well.

Reported-by: Christoph Paasch <cpaasch@apple.com>
Tested-by: Christoph Paasch <cpaasch@apple.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-02 06:59:21 -07:00
Paolo Abeni 01cacb00b3 mptcp: add netlink-based PM
Expose a new netlink family to userspace to control the PM, setting:

 - list of local addresses to be signalled.
 - list of local addresses used to created subflows.
 - maximum number of add_addr option to react

When the msk is fully established, the PM netlink attempts to
announce the 'signal' list via the ADD_ADDR option. Since we
currently lack the ADD_ADDR echo (and related event) only the
first addr is sent.

After exhausting the 'announce' list, the PM tries to create
subflow for each addr in 'local' list, waiting for each
connection to be completed before attempting the next one.

Idea is to add an additional PM hook for ADD_ADDR echo, to allow
the PM netlink announcing multiple addresses, in sequence.

Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29 22:14:49 -07:00
Florian Westphal fc518953bc mptcp: add and use MIB counter infrastructure
Exported via same /proc file as the Linux TCP MIB counters, so "netstat -s"
or "nstat" will show them automatically.

The MPTCP MIB counters are allocated in a distinct pcpu area in order to
avoid bloating/wasting TCP pcpu memory.

Counters are allocated once the first MPTCP socket is created in a
network namespace and free'd on exit.

If no sockets have been allocated, all-zero mptcp counters are shown.

The MIB counter list is taken from the multipath-tcp.org kernel, but
only a few counters have been picked up so far.  The counter list can
be increased at any time later on.

v2 -> v3:
 - remove 'inline' in foo.c files (David S. Miller)

Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29 22:14:49 -07:00
Davide Caratti 5147dfb508 mptcp: allow dumping subflow context to userspace
add ulp-specific diagnostic functions, so that subflow information can be
dumped to userspace programs like 'ss'.

v2 -> v3:
- uapi: use bit macros appropriate for userspace

Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29 22:14:48 -07:00
Paolo Abeni 3b1d6210a9 mptcp: implement and use MPTCP-level retransmission
On timeout event, schedule a work queue to do the retransmission.
Retransmission code closely resembles the sendmsg() implementation and
re-uses mptcp_sendmsg_frag, providing a dummy msghdr - for flags'
sake - and peeking the relevant dfrag from the rtx head.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29 22:14:48 -07:00
Paolo Abeni 3f8e0aae17 mptcp: rework mptcp_sendmsg_frag to accept optional dfrag
This will simplify mptcp-level retransmission implementation
in the next patch. If dfrag is provided by the caller, skip
kernel space memory allocation and use data and metadata
provided by the dfrag itself.

Because a peer could ack data at TCP level but refrain from
sending mptcp-level ACKs, we could grow the mptcp socket
backlog indefinitely.

We should thus block mptcp_sendmsg until the peer has acked some of the
sent data.

In order to be able to do so, increment the mptcp socket wmem_queued
counter on memory allocation and decrement it when releasing the memory
on mptcp-level ack reception.

Because TCP performns sndbuf auto-tuning up to tcp_wmem_max[2], make
this the mptcp sk_sndbuf limit.

In the future we could add experiment with autotuning as TCP does in
tcp_sndbuf_expand().

v2 -> v3:
 - remove 'inline' in foo.c files (David S. Miller)

Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29 22:14:48 -07:00
Florian Westphal 7948f6cc99 mptcp: allow partial cleaning of rtx head dfrag
After adding wmem accounting for the mptcp socket we could get
into a situation where the mptcp socket can't transmit more data,
and mptcp_clean_una doesn't reduce wmem even if snd_una has advanced
because it currently will only remove entire dfrags.

Allow advancing the dfrag head sequence and reduce wmem,
even though this isn't correct (as we can't release the page).

Because we will soon block on mptcp sk in case wmem is too large,
call sk_stream_write_space() in case we reduced the backlog so
userspace task blocked in sendmsg or poll will be woken up.

This isn't an issue if the send buffer is large, but it is when
SO_SNDBUF is used to reduce it to a lower value.

Note we can still get a deadlock for low SO_SNDBUF values in
case both sides of the connection write to the socket: both could
be blocked due to wmem being too small -- and current mptcp stack
will only increment mptcp ack_seq on recv.

This doesn't happen with the selftest as it uses poll() and
will always call recv if there is data to read.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29 22:14:48 -07:00
Paolo Abeni d027236c41 mptcp: implement memory accounting for mptcp rtx queue
Charge the data on the rtx queue to the master MPTCP socket, too.
Such memory in uncharged when the data is acked/dequeued.

Also account mptcp sockets inuse via a protocol specific pcpu
counter.

Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29 22:14:48 -07:00
Paolo Abeni b51f9b80c0 mptcp: introduce MPTCP retransmission timer
The timer will be used to schedule retransmission. It's
frequency is based on the current subflow RTO estimation and
is reset on every una_seq update

The timer is clearer for good by __mptcp_clear_xmit()

Also clean MPTCP rtx queue before each transmission.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29 22:14:48 -07:00
Paolo Abeni 18b683bff8 mptcp: queue data for mptcp level retransmission
Keep the send page fragment on an MPTCP level retransmission queue.
The queue entries are allocated inside the page frag allocator,
acquiring an additional reference to the page for each list entry.

Also switch to a custom page frag refill function, to ensure that
the current page fragment can always host an MPTCP rtx queue entry.

The MPTCP rtx queue is flushed at disconnect() and close() time

Note that now we need to call __mptcp_init_sock() regardless of mptcp
enable status, as the destructor will try to walk the rtx_queue.

v2 -> v3:
 - remove 'inline' in foo.c files (David S. Miller)

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29 22:14:48 -07:00
Paolo Abeni cc9d256698 mptcp: update per unacked sequence on pkt reception
So that we keep per unacked sequence number consistent; since
we update per msk data, use an atomic64 cmpxchg() to protect
against concurrent updates from multiple subflows.

Initialize the snd_una at connect()/accept() time.

Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29 22:14:48 -07:00
Peter Krystad 926bdeab55 mptcp: Implement path manager interface commands
Fill in more path manager functionality by adding a worker function and
modifying the related stub functions to schedule the worker.

Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29 22:14:48 -07:00
Peter Krystad ec3edaa7ca mptcp: Add handling of outgoing MP_JOIN requests
Subflow creation may be initiated by the path manager when
the primary connection is fully established and a remote
address has been received via ADD_ADDR.

Create an in-kernel sock and use kernel_connect() to
initiate connection.

Passive sockets can't acquire the mptcp socket lock at
subflow creation time, so an additional list protected by
a new spinlock is used to track the MPJ subflows.

Such list is spliced into conn_list tail every time the msk
socket lock is acquired, so that it will not interfere
with data flow on the original connection.

Data flow and connection failover not addressed by this commit.

Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29 22:14:48 -07:00
Peter Krystad f296234c98 mptcp: Add handling of incoming MP_JOIN requests
Process the MP_JOIN option in a SYN packet with the same flow
as MP_CAPABLE but when the third ACK is received add the
subflow to the MPTCP socket subflow list instead of adding it to
the TCP socket accept queue.

The subflow is added at the end of the subflow list so it will not
interfere with the existing subflows operation and no data is
expected to be transmitted on it.

Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29 22:14:48 -07:00
Peter Krystad 1b1c7a0ef7 mptcp: Add path manager interface
Add enough of a path manager interface to allow sending of ADD_ADDR
when an incoming MPTCP connection is created. Capable of sending only
a single IPv4 ADD_ADDR option. The 'pm_data' element of the connection
sock will need to be expanded to handle multiple interfaces and IPv6.
Partial processing of the incoming ADD_ADDR is included so the path
manager notification of that event happens at the proper time, which
involves validating the incoming address information.

This is a skeleton interface definition for events generated by
MPTCP.

Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Co-developed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Co-developed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29 22:14:48 -07:00