Commit 4fa39b70 authored by Florian Westphal's avatar Florian Westphal Committed by David S. Miller
Browse files

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: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e8887b71

net/mptcp/mptcp_diag.c

+91 −0
Original line number Diff line number Diff line
@@ -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,
@@ -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;