mptcp: consolidate synack processing.

Currently the MPTCP code uses 2 hooks to process syn-ack
packets, mptcp_rcv_synsent() and the sk_rx_dst_set()
callback.

We can drop the first, moving the relevant code into the
latter, reducing the hooking into the TCP code. This is
also needed by the next patch.

v1 -> v2:
 - use local tcp sock ptr instead of casting the sk variable
   several times - DaveM

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/mptcp.h b/include/net/mptcp.h
index 0e7c5471010bda14c7a17f096036cdf425b63fc3..4ecfa7d5e0c7546754e6cb44c13271f5ba2fb7e0 100644 (file)
--- a/include/net/mptcp.h
+++ b/include/net/mptcp.h
@@ -72,7 +72,6 @@ void mptcp_parse_option(const struct sk_buff *skb, const unsigned char *ptr,
                        int opsize, struct tcp_options_received *opt_rx);
 bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
                       unsigned int *size, struct mptcp_out_options *opts);
-void mptcp_rcv_synsent(struct sock *sk);
 bool mptcp_synack_options(const struct request_sock *req, unsigned int *size,
                          struct mptcp_out_options *opts);
 bool mptcp_established_options(struct sock *sk, struct sk_buff *skb,

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index bf4ced9273e8e84b95204db9bfe86867c0a3ee13..81425542da4499706f893ae9c4e9efc302834f2f 100644 (file)
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -5990,9 +5990,6 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
                tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);
                tcp_initialize_rcv_mss(sk);
 
-               if (sk_is_mptcp(sk))
-                       mptcp_rcv_synsent(sk);
-
                /* Remember, tcp_poll() does not lock socket!
                 * Change state from SYN-SENT only after copied_seq
                 * is initialized. */

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index 4a7c467b99db460387cb8f88e8a33a277229b49d..8fea686a55624182d583e038c1452e2bfa9e5e15 100644 (file)
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -344,28 +344,6 @@ bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
        return false;
 }
 
-void mptcp_rcv_synsent(struct sock *sk)
-{
-       struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
-       struct tcp_sock *tp = tcp_sk(sk);
-
-       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;
-               pr_debug("subflow=%p, remote_key=%llu", subflow,
-                        subflow->remote_key);
-       } else if (subflow->request_join && tp->rx_opt.mptcp.mp_join) {
-               subflow->mp_join = 1;
-               subflow->thmac = tp->rx_opt.mptcp.thmac;
-               subflow->remote_nonce = tp->rx_opt.mptcp.nonce;
-               pr_debug("subflow=%p, thmac=%llu, remote_nonce=%u", subflow,
-                        subflow->thmac, subflow->remote_nonce);
-       } else if (subflow->request_mptcp) {
-               tcp_sk(sk)->is_mptcp = 0;
-       }
-}
-
 /* MP_JOIN client subflow must wait for 4th ack before sending any data:
  * TCP can't schedule delack timer before the subflow is fully established.
  * MPTCP uses the delack timer to do 3rd ack retransmissions

diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 71256f03707fe6063c99220cc11fc29b6cb7354d..84f6408594c95eb27ca19605f1a77e739ae4913d 100644 (file)
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -222,6 +222,7 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
 {
        struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
        struct sock *parent = subflow->conn;
+       struct tcp_sock *tp = tcp_sk(sk);
 
        subflow->icsk_af_ops->sk_rx_dst_set(sk, skb);
 
@@ -230,14 +231,35 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
                parent->sk_state_change(parent);
        }
 
-       if (subflow->conn_finished || !tcp_sk(sk)->is_mptcp)
+       /* be sure no special action on any packet other than syn-ack */
+       if (subflow->conn_finished)
+               return;
+
+       subflow->conn_finished = 1;
+
+       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;
+               pr_debug("subflow=%p, remote_key=%llu", subflow,
+                        subflow->remote_key);
+       } else if (subflow->request_join && tp->rx_opt.mptcp.mp_join) {
+               subflow->mp_join = 1;
+               subflow->thmac = tp->rx_opt.mptcp.thmac;
+               subflow->remote_nonce = tp->rx_opt.mptcp.nonce;
+               pr_debug("subflow=%p, thmac=%llu, remote_nonce=%u", subflow,
+                        subflow->thmac, subflow->remote_nonce);
+       } else if (subflow->request_mptcp) {
+               tp->is_mptcp = 0;
+       }
+
+       if (!tp->is_mptcp)
                return;
 
        if (subflow->mp_capable) {
                pr_debug("subflow=%p, remote_key=%llu", mptcp_subflow_ctx(sk),
                         subflow->remote_key);
                mptcp_finish_connect(sk);
-               subflow->conn_finished = 1;
 
                if (skb) {
                        pr_debug("synack seq=%u", TCP_SKB_CB(skb)->seq);
@@ -264,7 +286,6 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
                if (!mptcp_finish_join(sk))
                        goto do_reset;
 
-               subflow->conn_finished = 1;
                MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINSYNACKRX);
        } else {
 do_reset: