From: Paolo Abeni pabeni@redhat.com
The user-space need to properly account the data received/sent by individual subflows. When additional subflows are created and/or closed during the MPTCP socket lifetime, the information currently exposed via MPTCP_TCPINFO are not enough: subflows are identified only by the sequential position inside the info dumps, and that will change with the above mentioned events.
To solve the above problem, this patch introduces a new subflow identifier that is unique inside the given MPTCP socket scope.
The initial subflow get the id 1 and the other subflows get incremental values at join time.
Link: https://github.com/multipath-tcp/mptcp_net-next/issues/388 Signed-off-by: Paolo Abeni pabeni@redhat.com Reviewed-by: Matthieu Baerts matthieu.baerts@tessares.net Signed-off-by: Matthieu Baerts matthieu.baerts@tessares.net --- net/mptcp/protocol.c | 6 ++++++ net/mptcp/protocol.h | 5 ++++- net/mptcp/subflow.c | 2 ++ 3 files changed, 12 insertions(+), 1 deletion(-)
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index d5b8e488bce1..4ebd6e9aa949 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -96,6 +96,7 @@ static int __mptcp_socket_create(struct mptcp_sock *msk) list_add(&subflow->node, &msk->conn_list); sock_hold(ssock->sk); subflow->request_mptcp = 1; + subflow->subflow_id = msk->subflow_id++;
/* This is the first subflow, always with id 0 */ subflow->local_id_valid = 1; @@ -847,6 +848,7 @@ static bool __mptcp_finish_join(struct mptcp_sock *msk, struct sock *ssk) if (sk->sk_socket && !ssk->sk_socket) mptcp_sock_graft(ssk, sk->sk_socket);
+ mptcp_subflow_ctx(ssk)->subflow_id = msk->subflow_id++; mptcp_sockopt_sync_locked(msk, ssk); mptcp_subflow_joined(msk, ssk); return true; @@ -2732,6 +2734,7 @@ static int __mptcp_init_sock(struct sock *sk) WRITE_ONCE(msk->csum_enabled, mptcp_is_checksum_enabled(sock_net(sk))); WRITE_ONCE(msk->allow_infinite_fallback, true); msk->recovery = false; + msk->subflow_id = 1;
mptcp_pm_data_init(msk);
@@ -3160,6 +3163,9 @@ struct sock *mptcp_sk_clone_init(const struct sock *sk, msk->wnd_end = msk->snd_nxt + req->rsk_rcv_wnd; msk->setsockopt_seq = mptcp_sk(sk)->setsockopt_seq;
+ /* passive msk is created after the first/MPC subflow */ + msk->subflow_id = 2; + sock_reset_flag(nsk, SOCK_RCU_FREE); security_inet_csk_clone(nsk, req);
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 27adfcc5aaa2..bb4cacd92778 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -323,7 +323,8 @@ struct mptcp_sock { u64 rtt_us; /* last maximum rtt of subflows */ } rcvq_space;
- u32 setsockopt_seq; + u32 subflow_id; + u32 setsockopt_seq; char ca_name[TCP_CA_NAME_MAX]; struct mptcp_sock *dl_next; }; @@ -504,6 +505,8 @@ struct mptcp_subflow_context { u8 reset_reason:4; u8 stale_count;
+ u32 subflow_id; + long delegated_status; unsigned long fail_tout;
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 4688daa6b38b..222dfcdadf2e 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -819,6 +819,7 @@ static struct sock *subflow_syn_recv_sock(const struct sock *sk, if (!ctx->conn) goto fallback;
+ ctx->subflow_id = 1; owner = mptcp_sk(ctx->conn); mptcp_pm_new_connection(owner, child, 1);
@@ -1574,6 +1575,7 @@ int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc, subflow->remote_id = remote_id; subflow->request_join = 1; subflow->request_bkup = !!(flags & MPTCP_PM_ADDR_FLAG_BACKUP); + subflow->subflow_id = msk->subflow_id++; mptcp_info2sockaddr(remote, &addr, ssk->sk_family);
sock_hold(ssk);