The user-space need to preperly 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 identifed 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.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
---
v2 -> v3:
- fix msk subflow_id init (Matttbe)
v1 -> v2:
- properly set subflow_id for the first passive subflow and active subflows, too
- drop the tcpi_fackets overload
---
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 28da6a9fe8fd..9998b2dd150e 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;
@@ -845,6 +846,7 @@ 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;
@@ -2775,6 +2777,7 @@ 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);
@@ -3206,6 +3209,9 @@ struct sock *mptcp_sk_clone_init(const struct sock *sk,
msk->setsockopt_seq = mptcp_sk(sk)->setsockopt_seq;
mptcp_init_sched(msk, mptcp_sk(sk)->sched);
+ /* 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 de94c01746dc..f9180ecce5e4 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -319,7 +319,8 @@ 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;
};
@@ -501,6 +502,8 @@ 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 63ac4dc621d4..c7001a23550a 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);
--
2.40.1