Commit ac3b45f6 authored by Paolo Abeni's avatar Paolo Abeni Committed by David S. Miller
Browse files

mptcp: add MPTCP socket diag interface 



exposes basic inet socket attribute, plus some MPTCP socket
fields comprising PM status and MPTCP-level sequence numbers.

Reviewed-by: default avatarMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 96d890da

include/uapi/linux/mptcp.h

+17 −0
Original line number Diff line number Diff line
@@ -86,4 +86,21 @@ enum { 
	__MPTCP_PM_CMD_AFTER_LAST

};



#define MPTCP_INFO_FLAG_FALLBACK		_BITUL(0)

#define MPTCP_INFO_FLAG_REMOTE_KEY_RECEIVED	_BITUL(1)



struct mptcp_info {

	__u8	mptcpi_subflows;

	__u8	mptcpi_add_addr_signal;

	__u8	mptcpi_add_addr_accepted;

	__u8	mptcpi_subflows_max;

	__u8	mptcpi_add_addr_signal_max;

	__u8	mptcpi_add_addr_accepted_max;

	__u32	mptcpi_flags;

	__u32	mptcpi_token;

	__u64	mptcpi_write_seq;

	__u64	mptcpi_snd_una;

	__u64	mptcpi_rcv_nxt;

};



#endif /* _UAPI_MPTCP_H */

net/mptcp/Kconfig

+4 −0
Original line number Diff line number Diff line
@@ -13,6 +13,10 @@ config MPTCP 


if MPTCP



config INET_MPTCP_DIAG

	depends on INET_DIAG

	def_tristate INET_DIAG



config MPTCP_IPV6

	bool "MPTCP: IPv6 support for Multipath TCP"

	select IPV6

net/mptcp/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -4,6 +4,8 @@ obj-$(CONFIG_MPTCP) += mptcp.o 
mptcp-y := protocol.o subflow.o options.o token.o crypto.o ctrl.o pm.o diag.o \

	   mib.o pm_netlink.o



obj-$(CONFIG_INET_MPTCP_DIAG) += mptcp_diag.o



mptcp_crypto_test-objs := crypto_test.o

mptcp_token_test-objs := token_test.o

obj-$(CONFIG_MPTCP_KUNIT_TESTS) += mptcp_crypto_test.o mptcp_token_test.o

net/mptcp/mptcp_diag.c

0 → 100644
+169 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/* MPTCP socket monitoring support

 *

 * Copyright (c) 2020 Red Hat

 *

 * Author: Paolo Abeni <pabeni@redhat.com>

 */



#include <linux/kernel.h>

#include <linux/net.h>

#include <linux/inet_diag.h>

#include <net/netlink.h>

#include <uapi/linux/mptcp.h>

#include "protocol.h"



static int sk_diag_dump(struct sock *sk, struct sk_buff *skb,

			struct netlink_callback *cb,

			const struct inet_diag_req_v2 *req,

			struct nlattr *bc, bool net_admin)

{

	if (!inet_diag_bc_sk(bc, sk))

		return 0;



	return inet_sk_diag_fill(sk, inet_csk(sk), skb, cb, req, NLM_F_MULTI,

				 net_admin);

}



static int mptcp_diag_dump_one(struct netlink_callback *cb,

			       const struct inet_diag_req_v2 *req)

{

	struct sk_buff *in_skb = cb->skb;

	struct mptcp_sock *msk = NULL;

	struct sk_buff *rep;

	int err = -ENOENT;

	struct net *net;

	struct sock *sk;



	net = sock_net(in_skb->sk);

	msk = mptcp_token_get_sock(req->id.idiag_cookie[0]);

	if (!msk)

		goto out_nosk;



	err = -ENOMEM;

	sk = (struct sock *)msk;

	rep = nlmsg_new(nla_total_size(sizeof(struct inet_diag_msg)) +

			inet_diag_msg_attrs_size() +

			nla_total_size(sizeof(struct mptcp_info)) +

			nla_total_size(sizeof(struct inet_diag_meminfo)) + 64,

			GFP_KERNEL);

	if (!rep)

		goto out;



	err = inet_sk_diag_fill(sk, inet_csk(sk), rep, cb, req, 0,

				netlink_net_capable(in_skb, CAP_NET_ADMIN));

	if (err < 0) {

		WARN_ON(err == -EMSGSIZE);

		kfree_skb(rep);

		goto out;

	}

	err = netlink_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid,

			      MSG_DONTWAIT);

	if (err > 0)

		err = 0;

out:

	sock_put(sk);



out_nosk:

	return err;

}



static void mptcp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,

			    const struct inet_diag_req_v2 *r)

{

	bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN);

	struct net *net = sock_net(skb->sk);

	struct inet_diag_dump_data *cb_data;

	struct mptcp_sock *msk;

	struct nlattr *bc;



	cb_data = cb->data;

	bc = cb_data->inet_diag_nla_bc;



	while ((msk = mptcp_token_iter_next(net, &cb->args[0], &cb->args[1])) !=

	       NULL) {

		struct inet_sock *inet = (struct inet_sock *)msk;

		struct sock *sk = (struct sock *)msk;

		int ret = 0;



		if (!(r->idiag_states & (1 << sk->sk_state)))

			goto next;

		if (r->sdiag_family != AF_UNSPEC &&

		    sk->sk_family != r->sdiag_family)

			goto next;

		if (r->id.idiag_sport != inet->inet_sport &&

		    r->id.idiag_sport)

			goto next;

		if (r->id.idiag_dport != inet->inet_dport &&

		    r->id.idiag_dport)

			goto next;



		ret = sk_diag_dump(sk, skb, cb, r, bc, net_admin);

next:

		sock_put(sk);

		if (ret < 0) {

			/* will retry on the same position */

			cb->args[1]--;

			break;

		}

		cond_resched();

	}

}



static void mptcp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,

				void *_info)

{

	struct mptcp_sock *msk = mptcp_sk(sk);

	struct mptcp_info *info = _info;

	u32 flags = 0;

	bool slow;

	u8 val;



	r->idiag_rqueue = sk_rmem_alloc_get(sk);

	r->idiag_wqueue = sk_wmem_alloc_get(sk);

	if (!info)

		return;



	slow = lock_sock_fast(sk);

	info->mptcpi_subflows = READ_ONCE(msk->pm.subflows);

	info->mptcpi_add_addr_signal = READ_ONCE(msk->pm.add_addr_signaled);

	info->mptcpi_add_addr_accepted = READ_ONCE(msk->pm.add_addr_accepted);

	info->mptcpi_subflows_max = READ_ONCE(msk->pm.subflows_max);

	val = READ_ONCE(msk->pm.add_addr_signal_max);

	info->mptcpi_add_addr_signal_max = val;

	val = READ_ONCE(msk->pm.add_addr_accept_max);

	info->mptcpi_add_addr_accepted_max = val;

	if (test_bit(MPTCP_FALLBACK_DONE, &msk->flags))

		flags |= MPTCP_INFO_FLAG_FALLBACK;

	if (READ_ONCE(msk->can_ack))

		flags |= MPTCP_INFO_FLAG_REMOTE_KEY_RECEIVED;

	info->mptcpi_flags = flags;

	info->mptcpi_token = READ_ONCE(msk->token);

	info->mptcpi_write_seq = READ_ONCE(msk->write_seq);

	info->mptcpi_snd_una = atomic64_read(&msk->snd_una);

	info->mptcpi_rcv_nxt = READ_ONCE(msk->ack_seq);

	unlock_sock_fast(sk, slow);

}



static const struct inet_diag_handler mptcp_diag_handler = {

	.dump		 = mptcp_diag_dump,

	.dump_one	 = mptcp_diag_dump_one,

	.idiag_get_info  = mptcp_diag_get_info,

	.idiag_type	 = IPPROTO_MPTCP,

	.idiag_info_size = sizeof(struct mptcp_info),

};



static int __init mptcp_diag_init(void)

{

	return inet_diag_register(&mptcp_diag_handler);

}



static void __exit mptcp_diag_exit(void)

{

	inet_diag_unregister(&mptcp_diag_handler);

}



module_init(mptcp_diag_init);

module_exit(mptcp_diag_exit);

MODULE_LICENSE("GPL");

MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-262 /* AF_INET - IPPROTO_MPTCP */);