linux/net/mptcp/mptcp_diag.c
Paolo Abeni ac3b45f609 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: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-09 12:38:41 -07:00

170 lines
4.4 KiB
C

// 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 */);