This is a note to let you know that I've just added the patch titled
mptcp: listen diag dump support
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mptcp-listen-diag-dump-support.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit c22fba7e0f7e1bc8702bb0c3b4d956076344dc14
Author: Florian Westphal <fw@xxxxxxxxx>
Date: Fri Apr 8 12:46:00 2022 -0700
mptcp: listen diag dump support
[ Upstream commit 4fa39b701ce9be7ec2169f7fba4f8dc1a3b92aac ]
makes 'ss -Ml' show mptcp listen sockets.
Iterate over the tcp listen sockets and pick those that have mptcp ulp
info attached.
mptcp_diag_get_info() is modified to prefer msk->first for mptcp sockets
in listen state. This reports accurate number for recv and send queue
(pending / max connection backlog counters).
Sample output:
ss -Mil
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN 0 20 127.0.0.1:12000 0.0.0.0:*
subflows_max:2
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: Mat Martineau <mathew.j.martineau@xxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Stable-dep-of: 871019b22d1b ("net: set SOCK_RCU_FREE before inserting socket into hashtable")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/mptcp/mptcp_diag.c b/net/mptcp/mptcp_diag.c
index fb98b438b2c90..4d8625d0b179a 100644
--- a/net/mptcp/mptcp_diag.c
+++ b/net/mptcp/mptcp_diag.c
@@ -69,8 +69,83 @@ static int mptcp_diag_dump_one(struct netlink_callback *cb,
struct mptcp_diag_ctx {
long s_slot;
long s_num;
+ unsigned int l_slot;
+ unsigned int l_num;
};
+static void mptcp_diag_dump_listeners(struct sk_buff *skb, struct netlink_callback *cb,
+ const struct inet_diag_req_v2 *r,
+ bool net_admin)
+{
+ struct inet_diag_dump_data *cb_data = cb->data;
+ struct mptcp_diag_ctx *diag_ctx = (void *)cb->ctx;
+ struct nlattr *bc = cb_data->inet_diag_nla_bc;
+ struct net *net = sock_net(skb->sk);
+ int i;
+
+ for (i = diag_ctx->l_slot; i < INET_LHTABLE_SIZE; i++) {
+ struct inet_listen_hashbucket *ilb;
+ struct hlist_nulls_node *node;
+ struct sock *sk;
+ int num = 0;
+
+ ilb = &tcp_hashinfo.listening_hash[i];
+
+ rcu_read_lock();
+ spin_lock(&ilb->lock);
+ sk_nulls_for_each(sk, node, &ilb->nulls_head) {
+ const struct mptcp_subflow_context *ctx = mptcp_subflow_ctx(sk);
+ struct inet_sock *inet = inet_sk(sk);
+ int ret;
+
+ if (num < diag_ctx->l_num)
+ goto next_listen;
+
+ if (!ctx || strcmp(inet_csk(sk)->icsk_ulp_ops->name, "mptcp"))
+ goto next_listen;
+
+ sk = ctx->conn;
+ if (!sk || !net_eq(sock_net(sk), net))
+ goto next_listen;
+
+ if (r->sdiag_family != AF_UNSPEC &&
+ sk->sk_family != r->sdiag_family)
+ goto next_listen;
+
+ if (r->id.idiag_sport != inet->inet_sport &&
+ r->id.idiag_sport)
+ goto next_listen;
+
+ if (!refcount_inc_not_zero(&sk->sk_refcnt))
+ goto next_listen;
+
+ ret = sk_diag_dump(sk, skb, cb, r, bc, net_admin);
+
+ sock_put(sk);
+
+ if (ret < 0) {
+ spin_unlock(&ilb->lock);
+ rcu_read_unlock();
+ diag_ctx->l_slot = i;
+ diag_ctx->l_num = num;
+ return;
+ }
+ diag_ctx->l_num = num + 1;
+ num = 0;
+next_listen:
+ ++num;
+ }
+ spin_unlock(&ilb->lock);
+ rcu_read_unlock();
+
+ cond_resched();
+ diag_ctx->l_num = 0;
+ }
+
+ diag_ctx->l_num = 0;
+ diag_ctx->l_slot = i;
+}
+
static void mptcp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
const struct inet_diag_req_v2 *r)
{
@@ -114,6 +189,9 @@ static void mptcp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
}
cond_resched();
}
+
+ if ((r->idiag_states & TCPF_LISTEN) && r->id.idiag_dport == 0)
+ mptcp_diag_dump_listeners(skb, cb, r, net_admin);
}
static void mptcp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
@@ -127,6 +205,19 @@ static void mptcp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
r->idiag_rqueue = sk_rmem_alloc_get(sk);
r->idiag_wqueue = sk_wmem_alloc_get(sk);
+
+ if (inet_sk_state_load(sk) == TCP_LISTEN) {
+ struct sock *lsk = READ_ONCE(msk->first);
+
+ if (lsk) {
+ /* override with settings from tcp listener,
+ * so Send-Q will show accept queue.
+ */
+ r->idiag_rqueue = READ_ONCE(lsk->sk_ack_backlog);
+ r->idiag_wqueue = READ_ONCE(lsk->sk_max_ack_backlog);
+ }
+ }
+
if (!info)
return;
