From 49fa1919d6bcdcf3cf3d080c1943f537f6ed5e70 Mon Sep 17 00:00:00 2001 From: Geliang Tang Date: Tue, 26 Apr 2022 14:57:15 -0700 Subject: [PATCH] mptcp: reset subflow when MP_FAIL doesn't respond This patch adds a new msk->flags bit MPTCP_FAIL_NO_RESPONSE, then reuses sk_timer to trigger a check if we have not received a response from the peer after sending MP_FAIL. If the peer doesn't respond properly, reset the subflow. Signed-off-by: Geliang Tang Signed-off-by: Mat Martineau Signed-off-by: David S. Miller --- net/mptcp/pm.c | 8 ++++++++ net/mptcp/protocol.c | 48 ++++++++++++++++++++++++++++++++++++++++++++ net/mptcp/protocol.h | 1 + net/mptcp/subflow.c | 11 ++++++++++ 4 files changed, 68 insertions(+) diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c index 971e843a304c..14f448d82bb2 100644 --- a/net/mptcp/pm.c +++ b/net/mptcp/pm.c @@ -287,6 +287,7 @@ void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq) { struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); struct mptcp_sock *msk = mptcp_sk(subflow->conn); + struct sock *s = (struct sock *)msk; pr_debug("fail_seq=%llu", fail_seq); @@ -299,6 +300,13 @@ void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq) subflow->send_mp_fail = 1; MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPFAILTX); subflow->send_infinite_map = 1; + } else if (s && inet_sk_state_load(s) != TCP_CLOSE) { + pr_debug("MP_FAIL response received"); + + mptcp_data_lock(s); + if (inet_sk_state_load(s) != TCP_CLOSE) + sk_stop_timer(s, &s->sk_timer); + mptcp_data_unlock(s); } } diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index ea74122065f1..a5d466e6b538 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -2169,10 +2169,38 @@ static void mptcp_retransmit_timer(struct timer_list *t) sock_put(sk); } +static struct mptcp_subflow_context * +mp_fail_response_expect_subflow(struct mptcp_sock *msk) +{ + struct mptcp_subflow_context *subflow, *ret = NULL; + + mptcp_for_each_subflow(msk, subflow) { + if (READ_ONCE(subflow->mp_fail_response_expect)) { + ret = subflow; + break; + } + } + + return ret; +} + +static void mptcp_check_mp_fail_response(struct mptcp_sock *msk) +{ + struct mptcp_subflow_context *subflow; + struct sock *sk = (struct sock *)msk; + + bh_lock_sock(sk); + subflow = mp_fail_response_expect_subflow(msk); + if (subflow) + __set_bit(MPTCP_FAIL_NO_RESPONSE, &msk->flags); + bh_unlock_sock(sk); +} + static void mptcp_timeout_timer(struct timer_list *t) { struct sock *sk = from_timer(sk, t, sk_timer); + mptcp_check_mp_fail_response(mptcp_sk(sk)); mptcp_schedule_work(sk); sock_put(sk); } @@ -2499,6 +2527,23 @@ reset_timer: mptcp_data_unlock(sk); } +static void mptcp_mp_fail_no_response(struct mptcp_sock *msk) +{ + struct mptcp_subflow_context *subflow; + struct sock *ssk; + bool slow; + + subflow = mp_fail_response_expect_subflow(msk); + if (subflow) { + pr_debug("MP_FAIL doesn't respond, reset the subflow"); + + ssk = mptcp_subflow_tcp_sock(subflow); + slow = lock_sock_fast(ssk); + mptcp_subflow_reset(ssk); + unlock_sock_fast(ssk, slow); + } +} + static void mptcp_worker(struct work_struct *work) { struct mptcp_sock *msk = container_of(work, struct mptcp_sock, work); @@ -2539,6 +2584,9 @@ static void mptcp_worker(struct work_struct *work) if (test_and_clear_bit(MPTCP_WORK_RTX, &msk->flags)) __mptcp_retrans(sk); + if (test_and_clear_bit(MPTCP_FAIL_NO_RESPONSE, &msk->flags)) + mptcp_mp_fail_no_response(msk); + unlock: release_sock(sk); sock_put(sk); diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index cc66c81a8fab..3a8740fef918 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -116,6 +116,7 @@ #define MPTCP_WORK_EOF 3 #define MPTCP_FALLBACK_DONE 4 #define MPTCP_WORK_CLOSE_SUBFLOW 5 +#define MPTCP_FAIL_NO_RESPONSE 6 /* MPTCP socket release cb flags */ #define MPTCP_PUSH_PENDING 1 diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index ca2352ad20d4..75c824b67ca9 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -968,6 +968,7 @@ static enum mapping_status get_mapping_status(struct sock *ssk, { struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); bool csum_reqd = READ_ONCE(msk->csum_enabled); + struct sock *sk = (struct sock *)msk; struct mptcp_ext *mpext; struct sk_buff *skb; u16 data_len; @@ -1009,6 +1010,12 @@ static enum mapping_status get_mapping_status(struct sock *ssk, pr_debug("infinite mapping received"); MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_INFINITEMAPRX); subflow->map_data_len = 0; + if (sk && inet_sk_state_load(sk) != TCP_CLOSE) { + mptcp_data_lock(sk); + if (inet_sk_state_load(sk) != TCP_CLOSE) + sk_stop_timer(sk, &sk->sk_timer); + mptcp_data_unlock(sk); + } return MAPPING_INVALID; } @@ -1219,6 +1226,10 @@ fallback: sk_eat_skb(ssk, skb); } else { WRITE_ONCE(subflow->mp_fail_response_expect, true); + /* The data lock is acquired in __mptcp_move_skbs() */ + sk_reset_timer((struct sock *)msk, + &((struct sock *)msk)->sk_timer, + jiffies + TCP_RTO_MAX); } WRITE_ONCE(subflow->data_avail, MPTCP_SUBFLOW_NODATA); return true; -- 2.25.1