diff options
author | Paolo Abeni <pabeni@redhat.com> | 2020-03-28 00:48:48 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2020-03-30 08:14:48 +0300 |
commit | 3b1d6210a9577369103330b0d802b0bf74b65e7f (patch) | |
tree | ff144be6ae7c006caa879b3581216ddc710dc0e1 /net/mptcp | |
parent | 3f8e0aae1796363442f6d0b7bc2210a6eecffb2d (diff) | |
download | linux-3b1d6210a9577369103330b0d802b0bf74b65e7f.tar.xz |
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>
Diffstat (limited to 'net/mptcp')
-rw-r--r-- | net/mptcp/protocol.c | 98 | ||||
-rw-r--r-- | net/mptcp/protocol.h | 1 |
2 files changed, 95 insertions, 4 deletions
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index b785d4a3766c..8d2777092390 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -283,6 +283,10 @@ static void mptcp_reset_timer(struct sock *sk) void mptcp_data_acked(struct sock *sk) { mptcp_reset_timer(sk); + + if (!sk_stream_is_writeable(sk) && + schedule_work(&mptcp_sk(sk)->work)) + sock_hold(sk); } static void mptcp_stop_timer(struct sock *sk) @@ -900,10 +904,13 @@ static void mptcp_retransmit_handler(struct sock *sk) { struct mptcp_sock *msk = mptcp_sk(sk); - if (atomic64_read(&msk->snd_una) == msk->write_seq) + if (atomic64_read(&msk->snd_una) == msk->write_seq) { mptcp_stop_timer(sk); - else - mptcp_reset_timer(sk); + } else { + set_bit(MPTCP_WORK_RTX, &msk->flags); + if (schedule_work(&msk->work)) + sock_hold(sk); + } } static void mptcp_retransmit_timer(struct timer_list *t) @@ -925,6 +932,37 @@ static void mptcp_retransmit_timer(struct timer_list *t) sock_put(sk); } +/* Find an idle subflow. Return NULL if there is unacked data at tcp + * level. + * + * A backup subflow is returned only if that is the only kind available. + */ +static struct sock *mptcp_subflow_get_retrans(const struct mptcp_sock *msk) +{ + struct mptcp_subflow_context *subflow; + struct sock *backup = NULL; + + sock_owned_by_me((const struct sock *)msk); + + mptcp_for_each_subflow(msk, subflow) { + struct sock *ssk = mptcp_subflow_tcp_sock(subflow); + + /* still data outstanding at TCP level? Don't retransmit. */ + if (!tcp_write_queue_empty(ssk)) + return NULL; + + if (subflow->backup) { + if (!backup) + backup = ssk; + continue; + } + + return ssk; + } + + return backup; +} + /* subflow sockets can be either outgoing (connect) or incoming * (accept). * @@ -958,11 +996,62 @@ static unsigned int mptcp_sync_mss(struct sock *sk, u32 pmtu) static void mptcp_worker(struct work_struct *work) { struct mptcp_sock *msk = container_of(work, struct mptcp_sock, work); - struct sock *sk = &msk->sk.icsk_inet.sk; + struct sock *ssk, *sk = &msk->sk.icsk_inet.sk; + int orig_len, orig_offset, ret, mss_now = 0, size_goal = 0; + struct mptcp_data_frag *dfrag; + u64 orig_write_seq; + size_t copied = 0; + struct msghdr msg; + long timeo = 0; lock_sock(sk); + mptcp_clean_una(sk); __mptcp_flush_join_list(msk); __mptcp_move_skbs(msk); + + if (!test_and_clear_bit(MPTCP_WORK_RTX, &msk->flags)) + goto unlock; + + dfrag = mptcp_rtx_head(sk); + if (!dfrag) + goto unlock; + + ssk = mptcp_subflow_get_retrans(msk); + if (!ssk) + goto reset_unlock; + + lock_sock(ssk); + + msg.msg_flags = MSG_DONTWAIT; + orig_len = dfrag->data_len; + orig_offset = dfrag->offset; + orig_write_seq = dfrag->data_seq; + while (dfrag->data_len > 0) { + ret = mptcp_sendmsg_frag(sk, ssk, &msg, dfrag, &timeo, &mss_now, + &size_goal); + if (ret < 0) + break; + + copied += ret; + dfrag->data_len -= ret; + dfrag->offset += ret; + } + if (copied) + tcp_push(ssk, msg.msg_flags, mss_now, tcp_sk(ssk)->nonagle, + size_goal); + + dfrag->data_seq = orig_write_seq; + dfrag->offset = orig_offset; + dfrag->data_len = orig_len; + + mptcp_set_timeout(sk, ssk); + release_sock(ssk); + +reset_unlock: + if (!mptcp_timer_pending(sk)) + mptcp_reset_timer(sk); + +unlock: release_sock(sk); sock_put(sk); } @@ -1124,6 +1213,7 @@ static int mptcp_disconnect(struct sock *sk, int flags) lock_sock(sk); __mptcp_clear_xmit(sk); release_sock(sk); + mptcp_cancel_work(sk); return tcp_disconnect(sk, flags); } diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index f855c954a8ff..e9d4a852c7f1 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -88,6 +88,7 @@ /* MPTCP socket flags */ #define MPTCP_DATA_READY 0 #define MPTCP_SEND_SPACE 1 +#define MPTCP_WORK_RTX 2 static inline __be32 mptcp_option(u8 subopt, u8 len, u8 nib, u8 field) { |