diff options
| -rw-r--r-- | net/mptcp/options.c | 56 | ||||
| -rw-r--r-- | net/mptcp/protocol.c | 16 | ||||
| -rw-r--r-- | net/mptcp/protocol.h | 10 | ||||
| -rw-r--r-- | net/mptcp/subflow.c | 40 |
4 files changed, 95 insertions, 27 deletions
diff --git a/net/mptcp/options.c b/net/mptcp/options.c index 8f82ff9a5a8e..45acd877bef3 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -243,6 +243,7 @@ void mptcp_rcv_synsent(struct sock *sk) pr_debug("subflow=%p", subflow); if (subflow->request_mptcp && tp->rx_opt.mptcp.mp_capable) { subflow->mp_capable = 1; + subflow->can_ack = 1; subflow->remote_key = tp->rx_opt.mptcp.sndr_key; } else { tcp_sk(sk)->is_mptcp = 0; @@ -332,6 +333,7 @@ static bool mptcp_established_options_dss(struct sock *sk, struct sk_buff *skb, struct mptcp_ext *mpext; struct mptcp_sock *msk; unsigned int ack_size; + bool ret = false; u8 tcp_fin; if (skb) { @@ -355,6 +357,14 @@ static bool mptcp_established_options_dss(struct sock *sk, struct sk_buff *skb, if (skb && tcp_fin && subflow->conn->sk_state != TCP_ESTABLISHED) mptcp_write_data_fin(subflow, &opts->ext_copy); + ret = true; + } + + opts->ext_copy.use_ack = 0; + msk = mptcp_sk(subflow->conn); + if (!msk || !READ_ONCE(msk->can_ack)) { + *size = ALIGN(dss_size, 4); + return ret; } ack_size = TCPOLEN_MPTCP_DSS_ACK64; @@ -365,15 +375,7 @@ static bool mptcp_established_options_dss(struct sock *sk, struct sk_buff *skb, dss_size += ack_size; - msk = mptcp_sk(mptcp_subflow_ctx(sk)->conn); - if (msk) { - opts->ext_copy.data_ack = msk->ack_seq; - } else { - mptcp_crypto_key_sha(mptcp_subflow_ctx(sk)->remote_key, - NULL, &opts->ext_copy.data_ack); - opts->ext_copy.data_ack++; - } - + opts->ext_copy.data_ack = msk->ack_seq; opts->ext_copy.ack64 = 1; opts->ext_copy.use_ack = 1; @@ -422,13 +424,46 @@ bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, return false; } +static bool check_fourth_ack(struct mptcp_subflow_context *subflow, + struct sk_buff *skb, + struct mptcp_options_received *mp_opt) +{ + /* here we can process OoO, in-window pkts, only in-sequence 4th ack + * are relevant + */ + if (likely(subflow->fourth_ack || + TCP_SKB_CB(skb)->seq != subflow->ssn_offset + 1)) + return true; + + if (mp_opt->use_ack) + subflow->fourth_ack = 1; + + if (subflow->can_ack) + return true; + + /* If the first established packet does not contain MP_CAPABLE + data + * then fallback to TCP + */ + if (!mp_opt->mp_capable) { + subflow->mp_capable = 0; + tcp_sk(mptcp_subflow_tcp_sock(subflow))->is_mptcp = 0; + return false; + } + subflow->remote_key = mp_opt->sndr_key; + subflow->can_ack = 1; + return true; +} + void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb, struct tcp_options_received *opt_rx) { + struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); struct mptcp_options_received *mp_opt; struct mptcp_ext *mpext; mp_opt = &opt_rx->mptcp; + if (!check_fourth_ack(subflow, skb, mp_opt)) + return; if (!mp_opt->dss) return; @@ -441,9 +476,6 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb, if (mp_opt->use_map) { if (mp_opt->mpc_map) { - struct mptcp_subflow_context *subflow = - mptcp_subflow_ctx(sk); - /* this is an MP_CAPABLE carrying MPTCP data * we know this map the first chunk of data */ diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 45e482864a19..1b64dfaa5f63 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -30,7 +30,7 @@ */ static struct socket *__mptcp_nmpc_socket(const struct mptcp_sock *msk) { - if (!msk->subflow || mptcp_subflow_ctx(msk->subflow->sk)->fourth_ack) + if (!msk->subflow || READ_ONCE(msk->can_ack)) return NULL; return msk->subflow; @@ -651,17 +651,20 @@ static struct sock *mptcp_accept(struct sock *sk, int flags, int *err, __mptcp_init_sock(new_mptcp_sock); msk = mptcp_sk(new_mptcp_sock); - msk->remote_key = subflow->remote_key; msk->local_key = subflow->local_key; msk->token = subflow->token; msk->subflow = NULL; mptcp_token_update_accept(newsk, new_mptcp_sock); - mptcp_crypto_key_sha(msk->remote_key, NULL, &ack_seq); msk->write_seq = subflow->idsn + 1; - ack_seq++; - msk->ack_seq = ack_seq; + if (subflow->can_ack) { + msk->can_ack = true; + msk->remote_key = subflow->remote_key; + mptcp_crypto_key_sha(msk->remote_key, NULL, &ack_seq); + ack_seq++; + msk->ack_seq = ack_seq; + } newsk = new_mptcp_sock; mptcp_copy_inaddrs(newsk, ssk); list_add(&subflow->node, &msk->conn_list); @@ -678,8 +681,6 @@ static struct sock *mptcp_accept(struct sock *sk, int flags, int *err, * the receive path and process the pending ones */ lock_sock(ssk); - subflow->map_seq = ack_seq; - subflow->map_subflow_seq = 1; subflow->rel_write_seq = 1; subflow->tcp_sock = ssk; subflow->conn = new_mptcp_sock; @@ -795,6 +796,7 @@ void mptcp_finish_connect(struct sock *ssk) WRITE_ONCE(msk->token, subflow->token); WRITE_ONCE(msk->write_seq, subflow->idsn + 1); WRITE_ONCE(msk->ack_seq, ack_seq); + WRITE_ONCE(msk->can_ack, 1); } static void mptcp_sock_graft(struct sock *sk, struct socket *parent) diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 36b90024d34d..10eaa7c7381b 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -69,6 +69,7 @@ struct mptcp_sock { u64 ack_seq; u32 token; unsigned long flags; + bool can_ack; struct list_head conn_list; struct skb_ext *cached_ext; /* for the next sendmsg */ struct socket *subflow; /* outgoing connect/listener/!mp_capable */ @@ -84,9 +85,10 @@ static inline struct mptcp_sock *mptcp_sk(const struct sock *sk) struct mptcp_subflow_request_sock { struct tcp_request_sock sk; - u8 mp_capable : 1, + u16 mp_capable : 1, mp_join : 1, - backup : 1; + backup : 1, + remote_key_valid : 1; u64 local_key; u64 remote_key; u64 idsn; @@ -118,8 +120,10 @@ struct mptcp_subflow_context { fourth_ack : 1, /* send initial DSS */ conn_finished : 1, map_valid : 1, + mpc_map : 1, data_avail : 1, - rx_eof : 1; + rx_eof : 1, + can_ack : 1; /* only after processing the remote a key */ struct sock *tcp_sock; /* tcp sk backpointer */ struct sock *conn; /* parent mptcp_sock */ diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 8892855f4f52..8cfa1d29d59c 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -61,6 +61,7 @@ static void subflow_init_req(struct request_sock *req, mptcp_get_options(skb, &rx_opt); subflow_req->mp_capable = 0; + subflow_req->remote_key_valid = 0; #ifdef CONFIG_TCP_MD5SIG /* no MPTCP if MD5SIG is enabled on this socket or we may run out of @@ -185,17 +186,28 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk, pr_debug("listener=%p, req=%p, conn=%p", listener, req, listener->conn); - /* if the sk is MP_CAPABLE, we need to fetch the client key */ + /* if the sk is MP_CAPABLE, we try to fetch the client key */ subflow_req = mptcp_subflow_rsk(req); if (subflow_req->mp_capable) { + if (TCP_SKB_CB(skb)->seq != subflow_req->ssn_offset + 1) { + /* here we can receive and accept an in-window, + * out-of-order pkt, which will not carry the MP_CAPABLE + * opt even on mptcp enabled paths + */ + goto create_child; + } + opt_rx.mptcp.mp_capable = 0; mptcp_get_options(skb, &opt_rx); - if (!opt_rx.mptcp.mp_capable) - subflow_req->mp_capable = 0; - else + if (opt_rx.mptcp.mp_capable) { subflow_req->remote_key = opt_rx.mptcp.sndr_key; + subflow_req->remote_key_valid = 1; + } else { + subflow_req->mp_capable = 0; + } } +create_child: child = listener->icsk_af_ops->syn_recv_sock(sk, skb, req, dst, req_unhash, own_req); @@ -377,6 +389,7 @@ static enum mapping_status get_mapping_status(struct sock *ssk) subflow->map_subflow_seq = mpext->subflow_seq; subflow->map_data_len = data_len; subflow->map_valid = 1; + subflow->mpc_map = mpext->mpc_map; pr_debug("new map seq=%llu subflow_seq=%u data_len=%u", subflow->map_seq, subflow->map_subflow_seq, subflow->map_data_len); @@ -428,6 +441,19 @@ static bool subflow_check_data_avail(struct sock *ssk) if (WARN_ON_ONCE(!skb)) return false; + /* if msk lacks the remote key, this subflow must provide an + * MP_CAPABLE-based mapping + */ + if (unlikely(!READ_ONCE(msk->can_ack))) { + if (!subflow->mpc_map) { + ssk->sk_err = EBADMSG; + goto fatal; + } + WRITE_ONCE(msk->remote_key, subflow->remote_key); + WRITE_ONCE(msk->ack_seq, subflow->map_seq); + WRITE_ONCE(msk->can_ack, true); + } + old_ack = READ_ONCE(msk->ack_seq); ack_seq = mptcp_subflow_get_mapped_dsn(subflow); pr_debug("msk ack_seq=%llx subflow ack_seq=%llx", old_ack, @@ -752,13 +778,17 @@ static void subflow_ulp_clone(const struct request_sock *req, return; } + /* see comments in subflow_syn_recv_sock(), MPTCP connection is fully + * established only after we receive the remote key + */ new_ctx->conn_finished = 1; new_ctx->icsk_af_ops = old_ctx->icsk_af_ops; new_ctx->tcp_data_ready = old_ctx->tcp_data_ready; new_ctx->tcp_state_change = old_ctx->tcp_state_change; new_ctx->tcp_write_space = old_ctx->tcp_write_space; new_ctx->mp_capable = 1; - new_ctx->fourth_ack = 1; + new_ctx->fourth_ack = subflow_req->remote_key_valid; + new_ctx->can_ack = subflow_req->remote_key_valid; new_ctx->remote_key = subflow_req->remote_key; new_ctx->local_key = subflow_req->local_key; new_ctx->token = subflow_req->token; |