1/* License: GPL */
2
3#include <linux/mutex.h>
4#include <linux/socket.h>
5#include <linux/skbuff.h>
6#include <net/netlink.h>
7#include <net/net_namespace.h>
8#include <linux/module.h>
9#include <net/sock.h>
10#include <linux/kernel.h>
11#include <linux/tcp.h>
12#include <linux/workqueue.h>
13#include <linux/nospec.h>
14
15#include <linux/inet_diag.h>
16#include <linux/sock_diag.h>
17
18static const struct sock_diag_handler *sock_diag_handlers[AF_MAX];
19static int (*inet_rcv_compat)(struct sk_buff *skb, struct nlmsghdr *nlh);
20static DEFINE_MUTEX(sock_diag_table_mutex);
21static struct workqueue_struct *broadcast_wq;
22
23u64 sock_gen_cookie(struct sock *sk)
24{
25 while (1) {
26 u64 res = atomic64_read(&sk->sk_cookie);
27
28 if (res)
29 return res;
30 res = atomic64_inc_return(&sock_net(sk)->cookie_gen);
31 atomic64_cmpxchg(&sk->sk_cookie, 0, res);
32 }
33}
34
35int sock_diag_check_cookie(struct sock *sk, const __u32 *cookie)
36{
37 u64 res;
38
39 if (cookie[0] == INET_DIAG_NOCOOKIE && cookie[1] == INET_DIAG_NOCOOKIE)
40 return 0;
41
42 res = sock_gen_cookie(sk);
43 if ((u32)res != cookie[0] || (u32)(res >> 32) != cookie[1])
44 return -ESTALE;
45
46 return 0;
47}
48EXPORT_SYMBOL_GPL(sock_diag_check_cookie);
49
50void sock_diag_save_cookie(struct sock *sk, __u32 *cookie)
51{
52 u64 res = sock_gen_cookie(sk);
53
54 cookie[0] = (u32)res;
55 cookie[1] = (u32)(res >> 32);
56}
57EXPORT_SYMBOL_GPL(sock_diag_save_cookie);
58
59int sock_diag_put_meminfo(struct sock *sk, struct sk_buff *skb, int attrtype)
60{
61 u32 mem[SK_MEMINFO_VARS];
62
63 sk_get_meminfo(sk, mem);
64
65 return nla_put(skb, attrtype, sizeof(mem), &mem);
66}
67EXPORT_SYMBOL_GPL(sock_diag_put_meminfo);
68
69int sock_diag_put_filterinfo(bool may_report_filterinfo, struct sock *sk,
70 struct sk_buff *skb, int attrtype)
71{
72 struct sock_fprog_kern *fprog;
73 struct sk_filter *filter;
74 struct nlattr *attr;
75 unsigned int flen;
76 int err = 0;
77
78 if (!may_report_filterinfo) {
79 nla_reserve(skb, attrtype, 0);
80 return 0;
81 }
82
83 rcu_read_lock();
84 filter = rcu_dereference(sk->sk_filter);
85 if (!filter)
86 goto out;
87
88 fprog = filter->prog->orig_prog;
89 if (!fprog)
90 goto out;
91
92 flen = bpf_classic_proglen(fprog);
93
94 attr = nla_reserve(skb, attrtype, flen);
95 if (attr == NULL) {
96 err = -EMSGSIZE;
97 goto out;
98 }
99
100 memcpy(nla_data(attr), fprog->filter, flen);
101out:
102 rcu_read_unlock();
103 return err;
104}
105EXPORT_SYMBOL(sock_diag_put_filterinfo);
106
107struct broadcast_sk {
108 struct sock *sk;
109 struct work_struct work;
110};
111
112static size_t sock_diag_nlmsg_size(void)
113{
114 return NLMSG_ALIGN(sizeof(struct inet_diag_msg)
115 + nla_total_size(sizeof(u8)) /* INET_DIAG_PROTOCOL */
116 + nla_total_size_64bit(sizeof(struct tcp_info))); /* INET_DIAG_INFO */
117}
118
119static void sock_diag_broadcast_destroy_work(struct work_struct *work)
120{
121 struct broadcast_sk *bsk =
122 container_of(work, struct broadcast_sk, work);
123 struct sock *sk = bsk->sk;
124 const struct sock_diag_handler *hndl;
125 struct sk_buff *skb;
126 const enum sknetlink_groups group = sock_diag_destroy_group(sk);
127 int err = -1;
128
129 WARN_ON(group == SKNLGRP_NONE);
130
131 skb = nlmsg_new(sock_diag_nlmsg_size(), GFP_KERNEL);
132 if (!skb)
133 goto out;
134
135 mutex_lock(&sock_diag_table_mutex);
136 hndl = sock_diag_handlers[sk->sk_family];
137 if (hndl && hndl->get_info)
138 err = hndl->get_info(skb, sk);
139 mutex_unlock(&sock_diag_table_mutex);
140
141 if (!err)
142 nlmsg_multicast(sock_net(sk)->diag_nlsk, skb, 0, group,
143 GFP_KERNEL);
144 else
145 kfree_skb(skb);
146out:
147 sk_destruct(sk);
148 kfree(bsk);
149}
150
151void sock_diag_broadcast_destroy(struct sock *sk)
152{
153 /* Note, this function is often called from an interrupt context. */
154 struct broadcast_sk *bsk =
155 kmalloc(sizeof(struct broadcast_sk), GFP_ATOMIC);
156 if (!bsk)
157 return sk_destruct(sk);
158 bsk->sk = sk;
159 INIT_WORK(&bsk->work, sock_diag_broadcast_destroy_work);
160 queue_work(broadcast_wq, &bsk->work);
161}
162
163void sock_diag_register_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh))
164{
165 mutex_lock(&sock_diag_table_mutex);
166 inet_rcv_compat = fn;
167 mutex_unlock(&sock_diag_table_mutex);
168}
169EXPORT_SYMBOL_GPL(sock_diag_register_inet_compat);
170
171void sock_diag_unregister_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh))
172{
173 mutex_lock(&sock_diag_table_mutex);
174 inet_rcv_compat = NULL;
175 mutex_unlock(&sock_diag_table_mutex);
176}
177EXPORT_SYMBOL_GPL(sock_diag_unregister_inet_compat);
178
179int sock_diag_register(const struct sock_diag_handler *hndl)
180{
181 int err = 0;
182
183 if (hndl->family >= AF_MAX)
184 return -EINVAL;
185
186 mutex_lock(&sock_diag_table_mutex);
187 if (sock_diag_handlers[hndl->family])
188 err = -EBUSY;
189 else
190 sock_diag_handlers[hndl->family] = hndl;
191 mutex_unlock(&sock_diag_table_mutex);
192
193 return err;
194}
195EXPORT_SYMBOL_GPL(sock_diag_register);
196
197void sock_diag_unregister(const struct sock_diag_handler *hnld)
198{
199 int family = hnld->family;
200
201 if (family >= AF_MAX)
202 return;
203
204 mutex_lock(&sock_diag_table_mutex);
205 BUG_ON(sock_diag_handlers[family] != hnld);
206 sock_diag_handlers[family] = NULL;
207 mutex_unlock(&sock_diag_table_mutex);
208}
209EXPORT_SYMBOL_GPL(sock_diag_unregister);
210
211static int __sock_diag_cmd(struct sk_buff *skb, struct nlmsghdr *nlh)
212{
213 int err;
214 struct sock_diag_req *req = nlmsg_data(nlh);
215 const struct sock_diag_handler *hndl;
216
217 if (nlmsg_len(nlh) < sizeof(*req))
218 return -EINVAL;
219
220 if (req->sdiag_family >= AF_MAX)
221 return -EINVAL;
222 req->sdiag_family = array_index_nospec(req->sdiag_family, AF_MAX);
223
224 if (sock_diag_handlers[req->sdiag_family] == NULL)
225 sock_load_diag_module(req->sdiag_family, 0);
226
227 mutex_lock(&sock_diag_table_mutex);
228 hndl = sock_diag_handlers[req->sdiag_family];
229 if (hndl == NULL)
230 err = -ENOENT;
231 else if (nlh->nlmsg_type == SOCK_DIAG_BY_FAMILY)
232 err = hndl->dump(skb, nlh);
233 else if (nlh->nlmsg_type == SOCK_DESTROY && hndl->destroy)
234 err = hndl->destroy(skb, nlh);
235 else
236 err = -EOPNOTSUPP;
237 mutex_unlock(&sock_diag_table_mutex);
238
239 return err;
240}
241
242static int sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
243 struct netlink_ext_ack *extack)
244{
245 int ret;
246
247 switch (nlh->nlmsg_type) {
248 case TCPDIAG_GETSOCK:
249 case DCCPDIAG_GETSOCK:
250 if (inet_rcv_compat == NULL)
251 sock_load_diag_module(AF_INET, 0);
252
253 mutex_lock(&sock_diag_table_mutex);
254 if (inet_rcv_compat != NULL)
255 ret = inet_rcv_compat(skb, nlh);
256 else
257 ret = -EOPNOTSUPP;
258 mutex_unlock(&sock_diag_table_mutex);
259
260 return ret;
261 case SOCK_DIAG_BY_FAMILY:
262 case SOCK_DESTROY:
263 return __sock_diag_cmd(skb, nlh);
264 default:
265 return -EINVAL;
266 }
267}
268
269static DEFINE_MUTEX(sock_diag_mutex);
270
271static void sock_diag_rcv(struct sk_buff *skb)
272{
273 mutex_lock(&sock_diag_mutex);
274 netlink_rcv_skb(skb, &sock_diag_rcv_msg);
275 mutex_unlock(&sock_diag_mutex);
276}
277
278static int sock_diag_bind(struct net *net, int group)
279{
280 switch (group) {
281 case SKNLGRP_INET_TCP_DESTROY:
282 case SKNLGRP_INET_UDP_DESTROY:
283 if (!sock_diag_handlers[AF_INET])
284 sock_load_diag_module(AF_INET, 0);
285 break;
286 case SKNLGRP_INET6_TCP_DESTROY:
287 case SKNLGRP_INET6_UDP_DESTROY:
288 if (!sock_diag_handlers[AF_INET6])
289 sock_load_diag_module(AF_INET6, 0);
290 break;
291 }
292 return 0;
293}
294
295int sock_diag_destroy(struct sock *sk, int err)
296{
297 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
298 return -EPERM;
299
300 if (!sk->sk_prot->diag_destroy)
301 return -EOPNOTSUPP;
302
303 return sk->sk_prot->diag_destroy(sk, err);
304}
305EXPORT_SYMBOL_GPL(sock_diag_destroy);
306
307static int __net_init diag_net_init(struct net *net)
308{
309 struct netlink_kernel_cfg cfg = {
310 .groups = SKNLGRP_MAX,
311 .input = sock_diag_rcv,
312 .bind = sock_diag_bind,
313 .flags = NL_CFG_F_NONROOT_RECV,
314 };
315
316 net->diag_nlsk = netlink_kernel_create(net, NETLINK_SOCK_DIAG, &cfg);
317 return net->diag_nlsk == NULL ? -ENOMEM : 0;
318}
319
320static void __net_exit diag_net_exit(struct net *net)
321{
322 netlink_kernel_release(net->diag_nlsk);
323 net->diag_nlsk = NULL;
324}
325
326static struct pernet_operations diag_net_ops = {
327 .init = diag_net_init,
328 .exit = diag_net_exit,
329};
330
331static int __init sock_diag_init(void)
332{
333 broadcast_wq = alloc_workqueue("sock_diag_events", 0, 0);
334 BUG_ON(!broadcast_wq);
335 return register_pernet_subsys(&diag_net_ops);
336}
337device_initcall(sock_diag_init);
338