diff options
| -rw-r--r-- | net/mptcp/options.c | 3 | ||||
| -rw-r--r-- | net/mptcp/protocol.c | 40 | ||||
| -rw-r--r-- | net/mptcp/protocol.h | 26 | ||||
| -rw-r--r-- | net/mptcp/subflow.c | 11 |
4 files changed, 61 insertions, 19 deletions
diff --git a/net/mptcp/options.c b/net/mptcp/options.c index 421ced031289..1f898888b223 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -978,8 +978,9 @@ static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk, if (subflow->mp_join) goto reset; subflow->mp_capable = 0; + if (!mptcp_try_fallback(ssk)) + goto reset; pr_fallback(msk); - mptcp_do_fallback(ssk); return false; } diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index edf14c2c2062..b08a42fcbb65 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -560,10 +560,9 @@ static bool mptcp_check_data_fin(struct sock *sk) static void mptcp_dss_corruption(struct mptcp_sock *msk, struct sock *ssk) { - if (READ_ONCE(msk->allow_infinite_fallback)) { + if (mptcp_try_fallback(ssk)) { MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DSSCORRUPTIONFALLBACK); - mptcp_do_fallback(ssk); } else { MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_DSSCORRUPTIONRESET); mptcp_subflow_reset(ssk); @@ -803,6 +802,14 @@ static bool __mptcp_finish_join(struct mptcp_sock *msk, struct sock *ssk) if (sk->sk_state != TCP_ESTABLISHED) return false; + spin_lock_bh(&msk->fallback_lock); + if (__mptcp_check_fallback(msk)) { + spin_unlock_bh(&msk->fallback_lock); + return false; + } + mptcp_subflow_joined(msk, ssk); + spin_unlock_bh(&msk->fallback_lock); + /* attach to msk socket only after we are sure we will deal with it * at close time */ @@ -811,7 +818,6 @@ static bool __mptcp_finish_join(struct mptcp_sock *msk, struct sock *ssk) mptcp_subflow_ctx(ssk)->subflow_id = msk->subflow_id++; mptcp_sockopt_sync_locked(msk, ssk); - mptcp_subflow_joined(msk, ssk); mptcp_stop_tout_timer(sk); __mptcp_propagate_sndbuf(sk, ssk); return true; @@ -1136,10 +1142,14 @@ static void mptcp_update_infinite_map(struct mptcp_sock *msk, mpext->infinite_map = 1; mpext->data_len = 0; + if (!mptcp_try_fallback(ssk)) { + mptcp_subflow_reset(ssk); + return; + } + MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_INFINITEMAPTX); mptcp_subflow_ctx(ssk)->send_infinite_map = 0; pr_fallback(msk); - mptcp_do_fallback(ssk); } #define MPTCP_MAX_GSO_SIZE (GSO_LEGACY_MAX_SIZE - (MAX_TCP_HEADER + 1)) @@ -2543,9 +2553,9 @@ static void mptcp_check_fastclose(struct mptcp_sock *msk) static void __mptcp_retrans(struct sock *sk) { + struct mptcp_sendmsg_info info = { .data_lock_held = true, }; struct mptcp_sock *msk = mptcp_sk(sk); struct mptcp_subflow_context *subflow; - struct mptcp_sendmsg_info info = {}; struct mptcp_data_frag *dfrag; struct sock *ssk; int ret, err; @@ -2590,6 +2600,18 @@ static void __mptcp_retrans(struct sock *sk) info.sent = 0; info.limit = READ_ONCE(msk->csum_enabled) ? dfrag->data_len : dfrag->already_sent; + + /* + * make the whole retrans decision, xmit, disallow + * fallback atomic + */ + spin_lock_bh(&msk->fallback_lock); + if (__mptcp_check_fallback(msk)) { + spin_unlock_bh(&msk->fallback_lock); + release_sock(ssk); + return; + } + while (info.sent < info.limit) { ret = mptcp_sendmsg_frag(sk, ssk, dfrag, &info); if (ret <= 0) @@ -2605,6 +2627,7 @@ static void __mptcp_retrans(struct sock *sk) info.size_goal); WRITE_ONCE(msk->allow_infinite_fallback, false); } + spin_unlock_bh(&msk->fallback_lock); release_sock(ssk); } @@ -2738,6 +2761,7 @@ static void __mptcp_init_sock(struct sock *sk) msk->last_ack_recv = tcp_jiffies32; mptcp_pm_data_init(msk); + spin_lock_init(&msk->fallback_lock); /* re-use the csk retrans timer for MPTCP-level retrans */ timer_setup(&msk->sk.icsk_retransmit_timer, mptcp_retransmit_timer, 0); @@ -3524,7 +3548,13 @@ bool mptcp_finish_join(struct sock *ssk) /* active subflow, already present inside the conn_list */ if (!list_empty(&subflow->node)) { + spin_lock_bh(&msk->fallback_lock); + if (__mptcp_check_fallback(msk)) { + spin_unlock_bh(&msk->fallback_lock); + return false; + } mptcp_subflow_joined(msk, ssk); + spin_unlock_bh(&msk->fallback_lock); mptcp_propagate_sndbuf(parent, ssk); return true; } diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 3dd11dd3ba16..2a60c3c71651 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -350,6 +350,10 @@ struct mptcp_sock { u32 subflow_id; u32 setsockopt_seq; char ca_name[TCP_CA_NAME_MAX]; + + spinlock_t fallback_lock; /* protects fallback and + * allow_infinite_fallback + */ }; #define mptcp_data_lock(sk) spin_lock_bh(&(sk)->sk_lock.slock) @@ -1216,15 +1220,21 @@ static inline bool mptcp_check_fallback(const struct sock *sk) return __mptcp_check_fallback(msk); } -static inline void __mptcp_do_fallback(struct mptcp_sock *msk) +static inline bool __mptcp_try_fallback(struct mptcp_sock *msk) { if (__mptcp_check_fallback(msk)) { pr_debug("TCP fallback already done (msk=%p)\n", msk); - return; + return true; } - if (WARN_ON_ONCE(!READ_ONCE(msk->allow_infinite_fallback))) - return; + spin_lock_bh(&msk->fallback_lock); + if (!msk->allow_infinite_fallback) { + spin_unlock_bh(&msk->fallback_lock); + return false; + } + set_bit(MPTCP_FALLBACK_DONE, &msk->flags); + spin_unlock_bh(&msk->fallback_lock); + return true; } static inline bool __mptcp_has_initial_subflow(const struct mptcp_sock *msk) @@ -1236,14 +1246,15 @@ static inline bool __mptcp_has_initial_subflow(const struct mptcp_sock *msk) TCPF_SYN_RECV | TCPF_LISTEN)); } -static inline void mptcp_do_fallback(struct sock *ssk) +static inline bool mptcp_try_fallback(struct sock *ssk) { struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); struct sock *sk = subflow->conn; struct mptcp_sock *msk; msk = mptcp_sk(sk); - __mptcp_do_fallback(msk); + if (!__mptcp_try_fallback(msk)) + return false; if (READ_ONCE(msk->snd_data_fin_enable) && !(ssk->sk_shutdown & SEND_SHUTDOWN)) { gfp_t saved_allocation = ssk->sk_allocation; @@ -1255,6 +1266,7 @@ static inline void mptcp_do_fallback(struct sock *ssk) tcp_shutdown(ssk, SEND_SHUTDOWN); ssk->sk_allocation = saved_allocation; } + return true; } #define pr_fallback(a) pr_debug("%s:fallback to TCP (msk=%p)\n", __func__, a) @@ -1264,7 +1276,7 @@ static inline void mptcp_subflow_early_fallback(struct mptcp_sock *msk, { pr_fallback(msk); subflow->request_mptcp = 0; - __mptcp_do_fallback(msk); + WARN_ON_ONCE(!__mptcp_try_fallback(msk)); } static inline bool mptcp_check_infinite_map(struct sk_buff *skb) diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 15613d691bfe..a6a35985e551 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -544,9 +544,11 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb) mptcp_get_options(skb, &mp_opt); if (subflow->request_mptcp) { if (!(mp_opt.suboptions & OPTION_MPTCP_MPC_SYNACK)) { + if (!mptcp_try_fallback(sk)) + goto do_reset; + MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPCAPABLEACTIVEFALLBACK); - mptcp_do_fallback(sk); pr_fallback(msk); goto fallback; } @@ -1395,7 +1397,7 @@ fallback: return true; } - if (!READ_ONCE(msk->allow_infinite_fallback)) { + if (!mptcp_try_fallback(ssk)) { /* fatal protocol error, close the socket. * subflow_error_report() will introduce the appropriate barriers */ @@ -1413,8 +1415,6 @@ reset: WRITE_ONCE(subflow->data_avail, false); return false; } - - mptcp_do_fallback(ssk); } skb = skb_peek(&ssk->sk_receive_queue); @@ -1679,7 +1679,6 @@ int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_pm_local *local, /* discard the subflow socket */ mptcp_sock_graft(ssk, sk->sk_socket); iput(SOCK_INODE(sf)); - WRITE_ONCE(msk->allow_infinite_fallback, false); mptcp_stop_tout_timer(sk); return 0; @@ -1851,7 +1850,7 @@ static void subflow_state_change(struct sock *sk) msk = mptcp_sk(parent); if (subflow_simultaneous_connect(sk)) { - mptcp_do_fallback(sk); + WARN_ON_ONCE(!mptcp_try_fallback(sk)); pr_fallback(msk); subflow->conn_finished = 1; mptcp_propagate_state(parent, sk, subflow, NULL); |