diff options
Diffstat (limited to 'net/mptcp/protocol.c')
| -rw-r--r-- | net/mptcp/protocol.c | 95 |
1 files changed, 68 insertions, 27 deletions
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 9936e33ac351..34dd0e278a82 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -954,7 +954,8 @@ fallback: pr_debug("block timeout %ld", timeo); mptcp_wait_data(sk, &timeo); - if (unlikely(__mptcp_tcp_fallback(msk))) + ssock = __mptcp_tcp_fallback(msk); + if (unlikely(ssock)) goto fallback; } @@ -1262,11 +1263,14 @@ static void mptcp_close(struct sock *sk, long timeout) lock_sock(sk); - mptcp_token_destroy(msk->token); inet_sk_state_store(sk, TCP_CLOSE); - __mptcp_flush_join_list(msk); - + /* be sure to always acquire the join list lock, to sync vs + * mptcp_finish_join(). + */ + spin_lock_bh(&msk->join_list_lock); + list_splice_tail_init(&msk->join_list, &msk->conn_list); + spin_unlock_bh(&msk->join_list_lock); list_splice_init(&msk->conn_list, &conn_list); data_fin_tx_seq = msk->write_seq; @@ -1316,11 +1320,12 @@ static void mptcp_copy_inaddrs(struct sock *msk, const struct sock *ssk) 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); + /* Should never be called. + * inet_stream_connect() calls ->disconnect, but that + * refers to the subflow socket, not the mptcp one. + */ + WARN_ON_ONCE(1); + return 0; } #if IS_ENABLED(CONFIG_MPTCP_IPV6) @@ -1332,7 +1337,9 @@ static struct ipv6_pinfo *mptcp_inet6_sk(const struct sock *sk) } #endif -struct sock *mptcp_sk_clone(const struct sock *sk, struct request_sock *req) +struct sock *mptcp_sk_clone(const struct sock *sk, + const struct mptcp_options_received *mp_opt, + struct request_sock *req) { struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); struct sock *nsk = sk_clone_lock(sk, GFP_ATOMIC); @@ -1355,26 +1362,30 @@ struct sock *mptcp_sk_clone(const struct sock *sk, struct request_sock *req) msk->subflow = NULL; if (unlikely(mptcp_token_new_accept(subflow_req->token, nsk))) { + nsk->sk_state = TCP_CLOSE; bh_unlock_sock(nsk); /* we can't call into mptcp_close() here - possible BH context - * free the sock directly + * free the sock directly. + * sk_clone_lock() sets nsk refcnt to two, hence call sk_free() + * too. */ - nsk->sk_prot->destroy(nsk); + sk_common_release(nsk); sk_free(nsk); return NULL; } msk->write_seq = subflow_req->idsn + 1; atomic64_set(&msk->snd_una, msk->write_seq); - if (subflow_req->remote_key_valid) { + if (mp_opt->mp_capable) { msk->can_ack = true; - msk->remote_key = subflow_req->remote_key; + msk->remote_key = mp_opt->sndr_key; mptcp_crypto_key_sha(msk->remote_key, NULL, &ack_seq); ack_seq++; msk->ack_seq = ack_seq; } + sock_reset_flag(nsk, SOCK_RCU_FREE); /* will be fully established after successful MPC subflow creation */ inet_sk_state_store(nsk, TCP_SYN_RECV); bh_unlock_sock(nsk); @@ -1431,6 +1442,7 @@ static struct sock *mptcp_accept(struct sock *sk, int flags, int *err, newsk = new_mptcp_sock; mptcp_copy_inaddrs(newsk, ssk); list_add(&subflow->node, &msk->conn_list); + inet_sk_state_store(newsk, TCP_ESTABLISHED); bh_unlock_sock(new_mptcp_sock); @@ -1448,6 +1460,7 @@ static void mptcp_destroy(struct sock *sk) { struct mptcp_sock *msk = mptcp_sk(sk); + mptcp_token_destroy(msk->token); if (msk->cached_ext) __skb_ext_put(msk->cached_ext); @@ -1614,20 +1627,30 @@ bool mptcp_finish_join(struct sock *sk) if (!msk->pm.server_side) return true; - /* passive connection, attach to msk socket */ + if (!mptcp_pm_allow_new_subflow(msk)) + return false; + + /* active connections are already on conn_list, and we can't acquire + * msk lock here. + * use the join list lock as synchronization point and double-check + * msk status to avoid racing with mptcp_close() + */ + spin_lock_bh(&msk->join_list_lock); + ret = inet_sk_state_load(parent) == TCP_ESTABLISHED; + if (ret && !WARN_ON_ONCE(!list_empty(&subflow->node))) + list_add_tail(&subflow->node, &msk->join_list); + spin_unlock_bh(&msk->join_list_lock); + if (!ret) + return false; + + /* attach to msk socket only after we are sure he will deal with us + * at close time + */ parent_sock = READ_ONCE(parent->sk_socket); if (parent_sock && !sk->sk_socket) mptcp_sock_graft(sk, parent_sock); - - ret = mptcp_pm_allow_new_subflow(msk); - if (ret) { - /* active connections are already on conn_list */ - spin_lock_bh(&msk->join_list_lock); - if (!WARN_ON_ONCE(!list_empty(&subflow->node))) - list_add_tail(&subflow->node, &msk->join_list); - spin_unlock_bh(&msk->join_list_lock); - } - return ret; + subflow->map_seq = msk->ack_seq; + return true; } bool mptcp_sk_is_subflow(const struct sock *sk) @@ -1701,6 +1724,14 @@ static int mptcp_stream_connect(struct socket *sock, struct sockaddr *uaddr, int err; lock_sock(sock->sk); + if (sock->state != SS_UNCONNECTED && msk->subflow) { + /* pending connection or invalid state, let existing subflow + * cope with that + */ + ssock = msk->subflow; + goto do_connect; + } + ssock = __mptcp_socket_create(msk, TCP_SYN_SENT); if (IS_ERR(ssock)) { err = PTR_ERR(ssock); @@ -1715,9 +1746,17 @@ static int mptcp_stream_connect(struct socket *sock, struct sockaddr *uaddr, mptcp_subflow_ctx(ssock->sk)->request_mptcp = 0; #endif +do_connect: err = ssock->ops->connect(ssock, uaddr, addr_len, flags); - inet_sk_state_store(sock->sk, inet_sk_state_load(ssock->sk)); - mptcp_copy_inaddrs(sock->sk, ssock->sk); + sock->state = ssock->state; + + /* on successful connect, the msk state will be moved to established by + * subflow_finish_connect() + */ + if (!err || err == EINPROGRESS) + mptcp_copy_inaddrs(sock->sk, ssock->sk); + else + inet_sk_state_store(sock->sk, inet_sk_state_load(ssock->sk)); unlock: release_sock(sock->sk); @@ -1775,6 +1814,8 @@ static int mptcp_listen(struct socket *sock, int backlog) goto unlock; } + sock_set_flag(sock->sk, SOCK_RCU_FREE); + err = ssock->ops->listen(ssock, backlog); inet_sk_state_store(sock->sk, inet_sk_state_load(ssock->sk)); if (!err) |