1 // SPDX-License-Identifier: GPL-2.0
2 /* MPTCP socket monitoring support
3 *
4 * Copyright (c) 2020 Red Hat
5 *
6 * Author: Paolo Abeni <pabeni@redhat.com>
7 */
8
9 #include <linux/kernel.h>
10 #include <linux/net.h>
11 #include <linux/inet_diag.h>
12 #include <net/netlink.h>
13 #include <uapi/linux/mptcp.h>
14 #include "protocol.h"
15
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)16 static int sk_diag_dump(struct sock *sk, struct sk_buff *skb,
17 struct netlink_callback *cb,
18 const struct inet_diag_req_v2 *req,
19 struct nlattr *bc, bool net_admin)
20 {
21 if (!inet_diag_bc_sk(bc, sk))
22 return 0;
23
24 return inet_sk_diag_fill(sk, inet_csk(sk), skb, cb, req, NLM_F_MULTI,
25 net_admin);
26 }
27
mptcp_diag_dump_one(struct netlink_callback * cb,const struct inet_diag_req_v2 * req)28 static int mptcp_diag_dump_one(struct netlink_callback *cb,
29 const struct inet_diag_req_v2 *req)
30 {
31 struct sk_buff *in_skb = cb->skb;
32 struct mptcp_sock *msk = NULL;
33 struct sk_buff *rep;
34 int err = -ENOENT;
35 struct net *net;
36 struct sock *sk;
37
38 net = sock_net(in_skb->sk);
39 msk = mptcp_token_get_sock(net, req->id.idiag_cookie[0]);
40 if (!msk)
41 goto out_nosk;
42
43 err = -ENOMEM;
44 sk = (struct sock *)msk;
45 rep = nlmsg_new(nla_total_size(sizeof(struct inet_diag_msg)) +
46 inet_diag_msg_attrs_size() +
47 nla_total_size(sizeof(struct mptcp_info)) +
48 nla_total_size(sizeof(struct inet_diag_meminfo)) + 64,
49 GFP_KERNEL);
50 if (!rep)
51 goto out;
52
53 err = inet_sk_diag_fill(sk, inet_csk(sk), rep, cb, req, 0,
54 netlink_net_capable(in_skb, CAP_NET_ADMIN));
55 if (err < 0) {
56 WARN_ON(err == -EMSGSIZE);
57 kfree_skb(rep);
58 goto out;
59 }
60 err = nlmsg_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid);
61
62 out:
63 sock_put(sk);
64
65 out_nosk:
66 return err;
67 }
68
mptcp_diag_dump(struct sk_buff * skb,struct netlink_callback * cb,const struct inet_diag_req_v2 * r)69 static void mptcp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
70 const struct inet_diag_req_v2 *r)
71 {
72 bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN);
73 struct net *net = sock_net(skb->sk);
74 struct inet_diag_dump_data *cb_data;
75 struct mptcp_sock *msk;
76 struct nlattr *bc;
77
78 cb_data = cb->data;
79 bc = cb_data->inet_diag_nla_bc;
80
81 while ((msk = mptcp_token_iter_next(net, &cb->args[0], &cb->args[1])) !=
82 NULL) {
83 struct inet_sock *inet = (struct inet_sock *)msk;
84 struct sock *sk = (struct sock *)msk;
85 int ret = 0;
86
87 if (!(r->idiag_states & (1 << sk->sk_state)))
88 goto next;
89 if (r->sdiag_family != AF_UNSPEC &&
90 sk->sk_family != r->sdiag_family)
91 goto next;
92 if (r->id.idiag_sport != inet->inet_sport &&
93 r->id.idiag_sport)
94 goto next;
95 if (r->id.idiag_dport != inet->inet_dport &&
96 r->id.idiag_dport)
97 goto next;
98
99 ret = sk_diag_dump(sk, skb, cb, r, bc, net_admin);
100 next:
101 sock_put(sk);
102 if (ret < 0) {
103 /* will retry on the same position */
104 cb->args[1]--;
105 break;
106 }
107 cond_resched();
108 }
109 }
110
mptcp_diag_get_info(struct sock * sk,struct inet_diag_msg * r,void * _info)111 static void mptcp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
112 void *_info)
113 {
114 struct mptcp_sock *msk = mptcp_sk(sk);
115 struct mptcp_info *info = _info;
116
117 r->idiag_rqueue = sk_rmem_alloc_get(sk);
118 r->idiag_wqueue = sk_wmem_alloc_get(sk);
119 if (!info)
120 return;
121
122 mptcp_diag_fill_info(msk, info);
123 }
124
125 static const struct inet_diag_handler mptcp_diag_handler = {
126 .dump = mptcp_diag_dump,
127 .dump_one = mptcp_diag_dump_one,
128 .idiag_get_info = mptcp_diag_get_info,
129 .idiag_type = IPPROTO_MPTCP,
130 .idiag_info_size = sizeof(struct mptcp_info),
131 };
132
mptcp_diag_init(void)133 static int __init mptcp_diag_init(void)
134 {
135 return inet_diag_register(&mptcp_diag_handler);
136 }
137
mptcp_diag_exit(void)138 static void __exit mptcp_diag_exit(void)
139 {
140 inet_diag_unregister(&mptcp_diag_handler);
141 }
142
143 module_init(mptcp_diag_init);
144 module_exit(mptcp_diag_exit);
145 MODULE_LICENSE("GPL");
146 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-262 /* AF_INET - IPPROTO_MPTCP */);
147