1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/module.h>
3
4 #include <net/sock.h>
5 #include <linux/netlink.h>
6 #include <linux/sock_diag.h>
7 #include <linux/netlink_diag.h>
8 #include <linux/rhashtable.h>
9
10 #include "af_netlink.h"
11
sk_diag_dump_groups(struct sock * sk,struct sk_buff * nlskb)12 static int sk_diag_dump_groups(struct sock *sk, struct sk_buff *nlskb)
13 {
14 struct netlink_sock *nlk = nlk_sk(sk);
15
16 if (nlk->groups == NULL)
17 return 0;
18
19 return nla_put(nlskb, NETLINK_DIAG_GROUPS, NLGRPSZ(nlk->ngroups),
20 nlk->groups);
21 }
22
sk_diag_put_flags(struct sock * sk,struct sk_buff * skb)23 static int sk_diag_put_flags(struct sock *sk, struct sk_buff *skb)
24 {
25 struct netlink_sock *nlk = nlk_sk(sk);
26 u32 flags = 0;
27
28 if (nlk->cb_running)
29 flags |= NDIAG_FLAG_CB_RUNNING;
30 if (nlk->flags & NETLINK_F_RECV_PKTINFO)
31 flags |= NDIAG_FLAG_PKTINFO;
32 if (nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR)
33 flags |= NDIAG_FLAG_BROADCAST_ERROR;
34 if (nlk->flags & NETLINK_F_RECV_NO_ENOBUFS)
35 flags |= NDIAG_FLAG_NO_ENOBUFS;
36 if (nlk->flags & NETLINK_F_LISTEN_ALL_NSID)
37 flags |= NDIAG_FLAG_LISTEN_ALL_NSID;
38 if (nlk->flags & NETLINK_F_CAP_ACK)
39 flags |= NDIAG_FLAG_CAP_ACK;
40
41 return nla_put_u32(skb, NETLINK_DIAG_FLAGS, flags);
42 }
43
sk_diag_fill(struct sock * sk,struct sk_buff * skb,struct netlink_diag_req * req,u32 portid,u32 seq,u32 flags,int sk_ino)44 static int sk_diag_fill(struct sock *sk, struct sk_buff *skb,
45 struct netlink_diag_req *req,
46 u32 portid, u32 seq, u32 flags, int sk_ino)
47 {
48 struct nlmsghdr *nlh;
49 struct netlink_diag_msg *rep;
50 struct netlink_sock *nlk = nlk_sk(sk);
51
52 nlh = nlmsg_put(skb, portid, seq, SOCK_DIAG_BY_FAMILY, sizeof(*rep),
53 flags);
54 if (!nlh)
55 return -EMSGSIZE;
56
57 rep = nlmsg_data(nlh);
58 rep->ndiag_family = AF_NETLINK;
59 rep->ndiag_type = sk->sk_type;
60 rep->ndiag_protocol = sk->sk_protocol;
61 rep->ndiag_state = sk->sk_state;
62
63 rep->ndiag_ino = sk_ino;
64 rep->ndiag_portid = nlk->portid;
65 rep->ndiag_dst_portid = nlk->dst_portid;
66 rep->ndiag_dst_group = nlk->dst_group;
67 sock_diag_save_cookie(sk, rep->ndiag_cookie);
68
69 if ((req->ndiag_show & NDIAG_SHOW_GROUPS) &&
70 sk_diag_dump_groups(sk, skb))
71 goto out_nlmsg_trim;
72
73 if ((req->ndiag_show & NDIAG_SHOW_MEMINFO) &&
74 sock_diag_put_meminfo(sk, skb, NETLINK_DIAG_MEMINFO))
75 goto out_nlmsg_trim;
76
77 if ((req->ndiag_show & NDIAG_SHOW_FLAGS) &&
78 sk_diag_put_flags(sk, skb))
79 goto out_nlmsg_trim;
80
81 nlmsg_end(skb, nlh);
82 return 0;
83
84 out_nlmsg_trim:
85 nlmsg_cancel(skb, nlh);
86 return -EMSGSIZE;
87 }
88
__netlink_diag_dump(struct sk_buff * skb,struct netlink_callback * cb,int protocol,int s_num)89 static int __netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
90 int protocol, int s_num)
91 {
92 struct rhashtable_iter *hti = (void *)cb->args[2];
93 struct netlink_table *tbl = &nl_table[protocol];
94 struct net *net = sock_net(skb->sk);
95 struct netlink_diag_req *req;
96 struct netlink_sock *nlsk;
97 struct sock *sk;
98 int num = 2;
99 int ret = 0;
100
101 req = nlmsg_data(cb->nlh);
102
103 if (s_num > 1)
104 goto mc_list;
105
106 num--;
107
108 if (!hti) {
109 hti = kmalloc(sizeof(*hti), GFP_KERNEL);
110 if (!hti)
111 return -ENOMEM;
112
113 cb->args[2] = (long)hti;
114 }
115
116 if (!s_num)
117 rhashtable_walk_enter(&tbl->hash, hti);
118
119 rhashtable_walk_start(hti);
120
121 while ((nlsk = rhashtable_walk_next(hti))) {
122 if (IS_ERR(nlsk)) {
123 ret = PTR_ERR(nlsk);
124 if (ret == -EAGAIN) {
125 ret = 0;
126 continue;
127 }
128 break;
129 }
130
131 sk = (struct sock *)nlsk;
132
133 if (!net_eq(sock_net(sk), net))
134 continue;
135
136 if (sk_diag_fill(sk, skb, req,
137 NETLINK_CB(cb->skb).portid,
138 cb->nlh->nlmsg_seq,
139 NLM_F_MULTI,
140 sock_i_ino(sk)) < 0) {
141 ret = 1;
142 break;
143 }
144 }
145
146 rhashtable_walk_stop(hti);
147
148 if (ret)
149 goto done;
150
151 rhashtable_walk_exit(hti);
152 num++;
153
154 mc_list:
155 read_lock(&nl_table_lock);
156 sk_for_each_bound(sk, &tbl->mc_list) {
157 if (sk_hashed(sk))
158 continue;
159 if (!net_eq(sock_net(sk), net))
160 continue;
161 if (num < s_num) {
162 num++;
163 continue;
164 }
165
166 if (sk_diag_fill(sk, skb, req,
167 NETLINK_CB(cb->skb).portid,
168 cb->nlh->nlmsg_seq,
169 NLM_F_MULTI,
170 sock_i_ino(sk)) < 0) {
171 ret = 1;
172 break;
173 }
174 num++;
175 }
176 read_unlock(&nl_table_lock);
177
178 done:
179 cb->args[0] = num;
180
181 return ret;
182 }
183
netlink_diag_dump(struct sk_buff * skb,struct netlink_callback * cb)184 static int netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
185 {
186 struct netlink_diag_req *req;
187 int s_num = cb->args[0];
188 int err = 0;
189
190 req = nlmsg_data(cb->nlh);
191
192 if (req->sdiag_protocol == NDIAG_PROTO_ALL) {
193 int i;
194
195 for (i = cb->args[1]; i < MAX_LINKS; i++) {
196 err = __netlink_diag_dump(skb, cb, i, s_num);
197 if (err)
198 break;
199 s_num = 0;
200 }
201 cb->args[1] = i;
202 } else {
203 if (req->sdiag_protocol >= MAX_LINKS)
204 return -ENOENT;
205
206 err = __netlink_diag_dump(skb, cb, req->sdiag_protocol, s_num);
207 }
208
209 return err < 0 ? err : skb->len;
210 }
211
netlink_diag_dump_done(struct netlink_callback * cb)212 static int netlink_diag_dump_done(struct netlink_callback *cb)
213 {
214 struct rhashtable_iter *hti = (void *)cb->args[2];
215
216 if (cb->args[0] == 1)
217 rhashtable_walk_exit(hti);
218
219 kfree(hti);
220
221 return 0;
222 }
223
netlink_diag_handler_dump(struct sk_buff * skb,struct nlmsghdr * h)224 static int netlink_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h)
225 {
226 int hdrlen = sizeof(struct netlink_diag_req);
227 struct net *net = sock_net(skb->sk);
228
229 if (nlmsg_len(h) < hdrlen)
230 return -EINVAL;
231
232 if (h->nlmsg_flags & NLM_F_DUMP) {
233 struct netlink_dump_control c = {
234 .dump = netlink_diag_dump,
235 .done = netlink_diag_dump_done,
236 };
237 return netlink_dump_start(net->diag_nlsk, skb, h, &c);
238 } else
239 return -EOPNOTSUPP;
240 }
241
242 static const struct sock_diag_handler netlink_diag_handler = {
243 .family = AF_NETLINK,
244 .dump = netlink_diag_handler_dump,
245 };
246
netlink_diag_init(void)247 static int __init netlink_diag_init(void)
248 {
249 return sock_diag_register(&netlink_diag_handler);
250 }
251
netlink_diag_exit(void)252 static void __exit netlink_diag_exit(void)
253 {
254 sock_diag_unregister(&netlink_diag_handler);
255 }
256
257 module_init(netlink_diag_init);
258 module_exit(netlink_diag_exit);
259 MODULE_LICENSE("GPL");
260 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 16 /* AF_NETLINK */);
261