| Message ID | da448d7e0a2459519394ab0c398875061f2bf1d0.1583952277.git.dcaratti@redhat.com |
|---|---|
| State | Deferred, archived |
| Delegated to: | Davide Caratti |
| Headers | show |
| Series | [net-next] net: mptcp: don't hang before sending 'MP capable with data' | expand |
From: Davide Caratti <dcaratti@redhat.com> Date: Wed, 11 Mar 2020 19:50:53 +0100 > the following packetdrill script > > socket(..., SOCK_STREAM, IPPROTO_MPTCP) = 3 > fcntl(3, F_GETFL) = 0x2 (flags O_RDWR) > fcntl(3, F_SETFL, O_RDWR|O_NONBLOCK) = 0 > connect(3, ..., ...) = -1 EINPROGRESS (Operation now in progress) > > S 0:0(0) <mss 1460,sackOK,TS val 100 ecr 0,nop,wscale 8,mpcapable v1 flags[flag_h] nokey> > < S. 0:0(0) ack 1 win 65535 <mss 1460,sackOK,TS val 700 ecr 100,nop,wscale 8,mpcapable v1 flags[flag_h] key[skey=2]> > > . 1:1(0) ack 1 win 256 <nop, nop, TS val 100 ecr 700,mpcapable v1 flags[flag_h] key[ckey,skey]> > getsockopt(3, SOL_SOCKET, SO_ERROR, [0], [4]) = 0 > fcntl(3, F_SETFL, O_RDWR) = 0 > write(3, ..., 1000) = 1000 > > doesn't transmit 1KB data packet after a successful three-way-handshake, > using mp_capable with data as required by protocol v1, and write() hangs > forever: > > PID: 973 TASK: ffff97dd399cae80 CPU: 1 COMMAND: "packetdrill" > #0 [ffffa9b94062fb78] __schedule at ffffffff9c90a000 > #1 [ffffa9b94062fc08] schedule at ffffffff9c90a4a0 > #2 [ffffa9b94062fc18] schedule_timeout at ffffffff9c90e00d > #3 [ffffa9b94062fc90] wait_woken at ffffffff9c120184 > #4 [ffffa9b94062fcb0] sk_stream_wait_connect at ffffffff9c75b064 > #5 [ffffa9b94062fd20] mptcp_sendmsg at ffffffff9c8e801c > #6 [ffffa9b94062fdc0] sock_sendmsg at ffffffff9c747324 > #7 [ffffa9b94062fdd8] sock_write_iter at ffffffff9c7473c7 > #8 [ffffa9b94062fe48] new_sync_write at ffffffff9c302976 > #9 [ffffa9b94062fed0] vfs_write at ffffffff9c305685 > #10 [ffffa9b94062ff00] ksys_write at ffffffff9c305985 > #11 [ffffa9b94062ff38] do_syscall_64 at ffffffff9c004475 > #12 [ffffa9b94062ff50] entry_SYSCALL_64_after_hwframe at ffffffff9ca0008c > RIP: 00007f959407eaf7 RSP: 00007ffe9e95a910 RFLAGS: 00000293 > RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007f959407eaf7 > RDX: 00000000000003e8 RSI: 0000000001785fe0 RDI: 0000000000000008 > RBP: 0000000001785fe0 R8: 0000000000000000 R9: 0000000000000003 > R10: 0000000000000007 R11: 0000000000000293 R12: 00000000000003e8 > R13: 00007ffe9e95ae30 R14: 0000000000000000 R15: 0000000000000000 > ORIG_RAX: 0000000000000001 CS: 0033 SS: 002b > > Fix it ensuring that socket state is TCP_ESTABLISHED on reception of the > third ack. > > Fixes: 1954b86016cf ("mptcp: Check connection state before attempting send") > Suggested-by: Paolo Abeni <pabeni@redhat.com> > Signed-off-by: Davide Caratti <dcaratti@redhat.com> Applied, thanks.
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 95007e433109..c0cef07f4382 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1049,6 +1049,10 @@ void mptcp_finish_connect(struct sock *ssk) WRITE_ONCE(msk->write_seq, subflow->idsn + 1); WRITE_ONCE(msk->ack_seq, ack_seq); WRITE_ONCE(msk->can_ack, 1); + if (inet_sk_state_load(sk) != TCP_ESTABLISHED) { + inet_sk_state_store(sk, TCP_ESTABLISHED); + sk->sk_state_change(sk); + } } static void mptcp_sock_graft(struct sock *sk, struct socket *parent)