From 4fa39b701ce9be7ec2169f7fba4f8dc1a3b92aac Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Fri, 8 Apr 2022 12:46:00 -0700 Subject: [PATCH] mptcp: listen diag dump support 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 Signed-off-by: Mat Martineau Signed-off-by: David S. Miller --- net/mptcp/mptcp_diag.c | 91 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 91 insertions(+) diff --git a/net/mptcp/mptcp_diag.c b/net/mptcp/mptcp_diag.c index c4992eeb67d8..dbb6d876a203 100644 --- a/net/mptcp/mptcp_diag.c +++ b/net/mptcp/mptcp_diag.c @@ -69,8 +69,83 @@ out_nosk: 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 @@ next: } 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, @@ -124,6 +202,19 @@ 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;