diff options
Diffstat (limited to 'net/mptcp/subflow.c')
-rw-r--r-- | net/mptcp/subflow.c | 143 |
1 files changed, 97 insertions, 46 deletions
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index dadaf85db720..ba065b66551a 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -408,9 +408,8 @@ void mptcp_subflow_reset(struct sock *ssk) tcp_send_active_reset(ssk, GFP_ATOMIC); tcp_done(ssk); - if (!test_and_set_bit(MPTCP_WORK_CLOSE_SUBFLOW, &mptcp_sk(sk)->flags) && - schedule_work(&mptcp_sk(sk)->work)) - return; /* worker will put sk for us */ + if (!test_and_set_bit(MPTCP_WORK_CLOSE_SUBFLOW, &mptcp_sk(sk)->flags)) + mptcp_schedule_work(sk); sock_put(sk); } @@ -696,14 +695,6 @@ static bool subflow_hmac_valid(const struct request_sock *req, return !crypto_memneq(hmac, mp_opt->hmac, MPTCPOPT_HMAC_LEN); } -static void mptcp_force_close(struct sock *sk) -{ - /* the msk is not yet exposed to user-space, and refcount is 2 */ - inet_sk_state_store(sk, TCP_CLOSE); - sk_common_release(sk); - sock_put(sk); -} - static void subflow_ulp_fallback(struct sock *sk, struct mptcp_subflow_context *old_ctx) { @@ -724,9 +715,12 @@ void mptcp_subflow_drop_ctx(struct sock *ssk) if (!ctx) return; - subflow_ulp_fallback(ssk, ctx); - if (ctx->conn) - sock_put(ctx->conn); + list_del(&mptcp_subflow_ctx(ssk)->node); + if (inet_csk(ssk)->icsk_ulp_ops) { + subflow_ulp_fallback(ssk, ctx); + if (ctx->conn) + sock_put(ctx->conn); + } kfree_rcu(ctx, rcu); } @@ -755,7 +749,6 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk, struct mptcp_subflow_request_sock *subflow_req; struct mptcp_options_received mp_opt; bool fallback, fallback_is_fatal; - struct sock *new_msk = NULL; struct mptcp_sock *owner; struct sock *child; @@ -784,14 +777,9 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk, * options. */ mptcp_get_options(skb, &mp_opt); - if (!(mp_opt.suboptions & OPTIONS_MPTCP_MPC)) { + if (!(mp_opt.suboptions & OPTIONS_MPTCP_MPC)) fallback = true; - goto create_child; - } - new_msk = mptcp_sk_clone(listener->conn, &mp_opt, req); - if (!new_msk) - fallback = true; } else if (subflow_req->mp_join) { mptcp_get_options(skb, &mp_opt); if (!(mp_opt.suboptions & OPTIONS_MPTCP_MPJ) || @@ -820,23 +808,23 @@ create_child: subflow_add_reset_reason(skb, MPTCP_RST_EMPTCP); goto dispose_child; } - - if (new_msk) - mptcp_copy_inaddrs(new_msk, child); - mptcp_subflow_drop_ctx(child); - goto out; + goto fallback; } /* ssk inherits options of listener sk */ ctx->setsockopt_seq = listener->setsockopt_seq; if (ctx->mp_capable) { - owner = mptcp_sk(new_msk); + ctx->conn = mptcp_sk_clone(listener->conn, &mp_opt, req); + if (!ctx->conn) + goto fallback; + + owner = mptcp_sk(ctx->conn); /* this can't race with mptcp_close(), as the msk is * not yet exposted to user-space */ - inet_sk_state_store((void *)new_msk, TCP_ESTABLISHED); + inet_sk_state_store(ctx->conn, TCP_ESTABLISHED); /* record the newly created socket as the first msk * subflow, but don't link it yet into conn_list @@ -846,11 +834,9 @@ create_child: /* new mpc subflow takes ownership of the newly * created mptcp socket */ - mptcp_sk(new_msk)->setsockopt_seq = ctx->setsockopt_seq; + owner->setsockopt_seq = ctx->setsockopt_seq; mptcp_pm_new_connection(owner, child, 1); mptcp_token_accept(subflow_req, owner); - ctx->conn = new_msk; - new_msk = NULL; /* set msk addresses early to ensure mptcp_pm_get_local_id() * uses the correct data @@ -867,7 +853,7 @@ create_child: */ if (mp_opt.suboptions & OPTION_MPTCP_MPC_ACK) { mptcp_subflow_fully_established(ctx, &mp_opt); - mptcp_pm_fully_established(owner, child, GFP_ATOMIC); + mptcp_pm_fully_established(owner, child); ctx->pm_notified = 1; } } else if (ctx->mp_join) { @@ -900,11 +886,6 @@ create_child: } } -out: - /* dispose of the left over mptcp master, if any */ - if (unlikely(new_msk)) - mptcp_force_close(new_msk); - /* check for expected invariant - should never trigger, just help * catching eariler subtle bugs */ @@ -922,6 +903,10 @@ dispose_child: /* The last child reference will be released by the caller */ return child; + +fallback: + mptcp_subflow_drop_ctx(child); + return child; } static struct inet_connection_sock_af_ops subflow_specific __ro_after_init; @@ -1118,8 +1103,8 @@ static enum mapping_status get_mapping_status(struct sock *ssk, skb_ext_del(skb, SKB_EXT_MPTCP); return MAPPING_OK; } else { - if (updated && schedule_work(&msk->work)) - sock_hold((struct sock *)msk); + if (updated) + mptcp_schedule_work((struct sock *)msk); return MAPPING_DATA_FIN; } @@ -1222,17 +1207,12 @@ static void mptcp_subflow_discard_data(struct sock *ssk, struct sk_buff *skb, /* sched mptcp worker to remove the subflow if no more data is pending */ static void subflow_sched_work_if_closed(struct mptcp_sock *msk, struct sock *ssk) { - struct sock *sk = (struct sock *)msk; - if (likely(ssk->sk_state != TCP_CLOSE)) return; if (skb_queue_empty(&ssk->sk_receive_queue) && - !test_and_set_bit(MPTCP_WORK_CLOSE_SUBFLOW, &msk->flags)) { - sock_hold(sk); - if (!schedule_work(&msk->work)) - sock_put(sk); - } + !test_and_set_bit(MPTCP_WORK_CLOSE_SUBFLOW, &msk->flags)) + mptcp_schedule_work((struct sock *)msk); } static bool subflow_can_fallback(struct mptcp_subflow_context *subflow) @@ -1825,6 +1805,77 @@ static void subflow_state_change(struct sock *sk) } } +void mptcp_subflow_queue_clean(struct sock *listener_sk, struct sock *listener_ssk) +{ + struct request_sock_queue *queue = &inet_csk(listener_ssk)->icsk_accept_queue; + struct mptcp_sock *msk, *next, *head = NULL; + struct request_sock *req; + struct sock *sk; + + /* build a list of all unaccepted mptcp sockets */ + spin_lock_bh(&queue->rskq_lock); + for (req = queue->rskq_accept_head; req; req = req->dl_next) { + struct mptcp_subflow_context *subflow; + struct sock *ssk = req->sk; + + if (!sk_is_mptcp(ssk)) + continue; + + subflow = mptcp_subflow_ctx(ssk); + if (!subflow || !subflow->conn) + continue; + + /* skip if already in list */ + sk = subflow->conn; + msk = mptcp_sk(sk); + if (msk->dl_next || msk == head) + continue; + + sock_hold(sk); + msk->dl_next = head; + head = msk; + } + spin_unlock_bh(&queue->rskq_lock); + if (!head) + return; + + /* can't acquire the msk socket lock under the subflow one, + * or will cause ABBA deadlock + */ + release_sock(listener_ssk); + + for (msk = head; msk; msk = next) { + sk = (struct sock *)msk; + + lock_sock_nested(sk, SINGLE_DEPTH_NESTING); + next = msk->dl_next; + msk->dl_next = NULL; + + __mptcp_unaccepted_force_close(sk); + release_sock(sk); + + /* lockdep will report a false positive ABBA deadlock + * between cancel_work_sync and the listener socket. + * The involved locks belong to different sockets WRT + * the existing AB chain. + * Using a per socket key is problematic as key + * deregistration requires process context and must be + * performed at socket disposal time, in atomic + * context. + * Just tell lockdep to consider the listener socket + * released here. + */ + mutex_release(&listener_sk->sk_lock.dep_map, _RET_IP_); + mptcp_cancel_work(sk); + mutex_acquire(&listener_sk->sk_lock.dep_map, 0, 0, _RET_IP_); + + sock_put(sk); + } + + /* we are still under the listener msk socket lock */ + lock_sock_nested(listener_ssk, SINGLE_DEPTH_NESTING); +} + static int subflow_ulp_init(struct sock *sk) { struct inet_connection_sock *icsk = inet_csk(sk); |