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(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 = netlink_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid,
61 MSG_DONTWAIT);
62 if (err > 0)
63 err = 0;
64 out:
65 sock_put(sk);
66
67 out_nosk:
68 return err;
69 }
70
mptcp_diag_dump(struct sk_buff * skb,struct netlink_callback * cb,const struct inet_diag_req_v2 * r)71 static void mptcp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
72 const struct inet_diag_req_v2 *r)
73 {
74 bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN);
75 struct net *net = sock_net(skb->sk);
76 struct inet_diag_dump_data *cb_data;
77 struct mptcp_sock *msk;
78 struct nlattr *bc;
79
80 cb_data = cb->data;
81 bc = cb_data->inet_diag_nla_bc;
82
83 while ((msk = mptcp_token_iter_next(net, &cb->args[0], &cb->args[1])) !=
84 NULL) {
85 struct inet_sock *inet = (struct inet_sock *)msk;
86 struct sock *sk = (struct sock *)msk;
87 int ret = 0;
88
89 if (!(r->idiag_states & (1 << sk->sk_state)))
90 goto next;
91 if (r->sdiag_family != AF_UNSPEC &&
92 sk->sk_family != r->sdiag_family)
93 goto next;
94 if (r->id.idiag_sport != inet->inet_sport &&
95 r->id.idiag_sport)
96 goto next;
97 if (r->id.idiag_dport != inet->inet_dport &&
98 r->id.idiag_dport)
99 goto next;
100
101 ret = sk_diag_dump(sk, skb, cb, r, bc, net_admin);
102 next:
103 sock_put(sk);
104 if (ret < 0) {
105 /* will retry on the same position */
106 cb->args[1]--;
107 break;
108 }
109 cond_resched();
110 }
111 }
112
mptcp_diag_get_info(struct sock * sk,struct inet_diag_msg * r,void * _info)113 static void mptcp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
114 void *_info)
115 {
116 struct mptcp_sock *msk = mptcp_sk(sk);
117 struct mptcp_info *info = _info;
118 u32 flags = 0;
119 bool slow;
120 u8 val;
121
122 r->idiag_rqueue = sk_rmem_alloc_get(sk);
123 r->idiag_wqueue = sk_wmem_alloc_get(sk);
124 if (!info)
125 return;
126
127 slow = lock_sock_fast(sk);
128 info->mptcpi_subflows = READ_ONCE(msk->pm.subflows);
129 info->mptcpi_add_addr_signal = READ_ONCE(msk->pm.add_addr_signaled);
130 info->mptcpi_add_addr_accepted = READ_ONCE(msk->pm.add_addr_accepted);
131 info->mptcpi_local_addr_used = READ_ONCE(msk->pm.local_addr_used);
132 info->mptcpi_subflows_max = mptcp_pm_get_subflows_max(msk);
133 val = mptcp_pm_get_add_addr_signal_max(msk);
134 info->mptcpi_add_addr_signal_max = val;
135 val = mptcp_pm_get_add_addr_accept_max(msk);
136 info->mptcpi_add_addr_accepted_max = val;
137 info->mptcpi_local_addr_max = mptcp_pm_get_local_addr_max(msk);
138 if (test_bit(MPTCP_FALLBACK_DONE, &msk->flags))
139 flags |= MPTCP_INFO_FLAG_FALLBACK;
140 if (READ_ONCE(msk->can_ack))
141 flags |= MPTCP_INFO_FLAG_REMOTE_KEY_RECEIVED;
142 info->mptcpi_flags = flags;
143 info->mptcpi_token = READ_ONCE(msk->token);
144 info->mptcpi_write_seq = READ_ONCE(msk->write_seq);
145 info->mptcpi_snd_una = READ_ONCE(msk->snd_una);
146 info->mptcpi_rcv_nxt = READ_ONCE(msk->ack_seq);
147 unlock_sock_fast(sk, slow);
148 }
149
150 static const struct inet_diag_handler mptcp_diag_handler = {
151 .dump = mptcp_diag_dump,
152 .dump_one = mptcp_diag_dump_one,
153 .idiag_get_info = mptcp_diag_get_info,
154 .idiag_type = IPPROTO_MPTCP,
155 .idiag_info_size = sizeof(struct mptcp_info),
156 };
157
mptcp_diag_init(void)158 static int __init mptcp_diag_init(void)
159 {
160 return inet_diag_register(&mptcp_diag_handler);
161 }
162
mptcp_diag_exit(void)163 static void __exit mptcp_diag_exit(void)
164 {
165 inet_diag_unregister(&mptcp_diag_handler);
166 }
167
168 module_init(mptcp_diag_init);
169 module_exit(mptcp_diag_exit);
170 MODULE_LICENSE("GPL");
171 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-262 /* AF_INET - IPPROTO_MPTCP */);
172