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Message-Id: <20191002233655.24323-41-mathew.j.martineau@linux.intel.com>
Date: Wed, 2 Oct 2019 16:36:50 -0700
From: Mat Martineau <mathew.j.martineau@...ux.intel.com>
To: netdev@...r.kernel.org, edumazet@...gle.com
Cc: Paolo Abeni <pabeni@...hat.com>, cpaasch@...le.com, fw@...len.de,
peter.krystad@...ux.intel.com, dcaratti@...hat.com,
matthieu.baerts@...sares.net
Subject: [RFC PATCH v2 40/45] mptcp: implement and use MPTCP-level retransmission
From: Paolo Abeni <pabeni@...hat.com>
On timeout event, schedule a work queue to do the retransmission.
Retransmission code resemple closely 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@...hat.com>
---
net/mptcp/protocol.c | 81 ++++++++++++++++++++++++++++++++++++++++++--
net/mptcp/protocol.h | 11 ++++++
2 files changed, 89 insertions(+), 3 deletions(-)
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 6366dfd65aa8..b54fecf528b9 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -759,10 +759,12 @@ 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 {
+ if (schedule_work(&msk->rtx_work))
+ sock_hold(sk);
+ }
}
static void mptcp_retransmit_timer(struct timer_list *t)
@@ -784,6 +786,66 @@ static void mptcp_retransmit_timer(struct timer_list *t)
sock_put(sk);
}
+static void mptcp_retransmit(struct work_struct *work)
+{
+ int orig_len, orig_offset, ret, mss_now = 0, size_goal = 0;
+ struct mptcp_data_frag *dfrag;
+ struct sock *ssk, *sk;
+ struct mptcp_sock *msk;
+ u64 orig_write_seq;
+ size_t copied = 0;
+ struct msghdr msg;
+ long timeo = 0;
+
+ msk = container_of(work, struct mptcp_sock, rtx_work);
+ sk = &msk->sk.icsk_inet.sk;
+
+ lock_sock(sk);
+ mptcp_clean_una(sk);
+ dfrag = mptcp_rtx_head(sk);
+ if (!dfrag)
+ goto unlock;
+
+ ssk = mptcp_subflow_get_ref(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;
+ }
+ 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);
+ sock_put(ssk);
+
+reset_unlock:
+ if (!mptcp_timer_pending(sk))
+ mptcp_reset_timer(sk);
+
+unlock:
+ release_sock(sk);
+ sock_put(sk);
+}
+
static int __mptcp_init_sock(struct sock *sk)
{
struct mptcp_sock *msk = mptcp_sk(sk);
@@ -791,6 +853,8 @@ static int __mptcp_init_sock(struct sock *sk)
INIT_LIST_HEAD(&msk->conn_list);
INIT_LIST_HEAD(&msk->rtx_queue);
+ INIT_WORK(&msk->rtx_work, mptcp_retransmit);
+
/* re-use the csk retrans timer for MPTCP-level retrans */
timer_setup(&msk->sk.icsk_retransmit_timer, mptcp_retransmit_timer, 0);
@@ -823,6 +887,14 @@ static void __mptcp_clear_xmit(struct sock *sk)
dfrag_clear(sk, dfrag);
}
+static void mptcp_cancel_rtx_work(struct sock *sk)
+{
+ struct mptcp_sock *msk = mptcp_sk(sk);
+
+ if (cancel_work_sync(&msk->rtx_work))
+ sock_put(sk);
+}
+
static void mptcp_close(struct sock *sk, long timeout)
{
struct mptcp_subflow_context *subflow, *tmp;
@@ -852,6 +924,8 @@ static void mptcp_close(struct sock *sk, long timeout)
__mptcp_clear_xmit(sk);
release_sock(sk);
+ mptcp_cancel_rtx_work(sk);
+
sk_common_release(sk);
}
@@ -860,6 +934,7 @@ static int mptcp_disconnect(struct sock *sk, int flags)
lock_sock(sk);
__mptcp_clear_xmit(sk);
release_sock(sk);
+ mptcp_cancel_rtx_work(sk);
return tcp_disconnect(sk, flags);
}
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index ef35d0aa8eb7..0c6bc8617cf4 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -133,6 +133,7 @@ struct mptcp_sock {
u32 token;
unsigned long flags;
u16 dport;
+ struct work_struct rtx_work;
struct list_head conn_list;
struct list_head rtx_queue;
struct socket *subflow; /* outgoing connect/listener/!mp_capable */
@@ -158,6 +159,16 @@ static inline struct mptcp_data_frag *mptcp_rtx_tail(const struct sock *sk)
return list_last_entry(&msk->rtx_queue, struct mptcp_data_frag, list);
}
+static inline struct mptcp_data_frag *mptcp_rtx_head(const struct sock *sk)
+{
+ struct mptcp_sock *msk = mptcp_sk(sk);
+
+ if (list_empty(&msk->rtx_queue))
+ return NULL;
+
+ return list_first_entry(&msk->rtx_queue, struct mptcp_data_frag, list);
+}
+
struct mptcp_subflow_request_sock {
struct tcp_request_sock sk;
u8 mp_capable : 1,
--
2.23.0
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