1
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;
22static atomic64_t cookie_gen;
23
24u64 sock_gen_cookie(struct sock *sk)
25{
26 while (1) {
27 u64 res = atomic64_read(&sk->sk_cookie);
28
29 if (res)
30 return res;
31 res = atomic64_inc_return(&cookie_gen);
32 atomic64_cmpxchg(&sk->sk_cookie, 0, res);
33 }
34}
35
36int sock_diag_check_cookie(struct sock *sk, const __u32 *cookie)
37{
38 u64 res;
39
40 if (cookie[0] == INET_DIAG_NOCOOKIE && cookie[1] == INET_DIAG_NOCOOKIE)
41 return 0;
42
43 res = sock_gen_cookie(sk);
44 if ((u32)res != cookie[0] || (u32)(res >> 32) != cookie[1])
45 return -ESTALE;
46
47 return 0;
48}
49EXPORT_SYMBOL_GPL(sock_diag_check_cookie);
50
51void sock_diag_save_cookie(struct sock *sk, __u32 *cookie)
52{
53 u64 res = sock_gen_cookie(sk);
54
55 cookie[0] = (u32)res;
56 cookie[1] = (u32)(res >> 32);
57}
58EXPORT_SYMBOL_GPL(sock_diag_save_cookie);
59
60int sock_diag_put_meminfo(struct sock *sk, struct sk_buff *skb, int attrtype)
61{
62 u32 mem[SK_MEMINFO_VARS];
63
64 sk_get_meminfo(sk, mem);
65
66 return nla_put(skb, attrtype, sizeof(mem), &mem);
67}
68EXPORT_SYMBOL_GPL(sock_diag_put_meminfo);
69
70int sock_diag_put_filterinfo(bool may_report_filterinfo, struct sock *sk,
71 struct sk_buff *skb, int attrtype)
72{
73 struct sock_fprog_kern *fprog;
74 struct sk_filter *filter;
75 struct nlattr *attr;
76 unsigned int flen;
77 int err = 0;
78
79 if (!may_report_filterinfo) {
80 nla_reserve(skb, attrtype, 0);
81 return 0;
82 }
83
84 rcu_read_lock();
85 filter = rcu_dereference(sk->sk_filter);
86 if (!filter)
87 goto out;
88
89 fprog = filter->prog->orig_prog;
90 if (!fprog)
91 goto out;
92
93 flen = bpf_classic_proglen(fprog);
94
95 attr = nla_reserve(skb, attrtype, flen);
96 if (attr == NULL) {
97 err = -EMSGSIZE;
98 goto out;
99 }
100
101 memcpy(nla_data(attr), fprog->filter, flen);
102out:
103 rcu_read_unlock();
104 return err;
105}
106EXPORT_SYMBOL(sock_diag_put_filterinfo);
107
108struct broadcast_sk {
109 struct sock *sk;
110 struct work_struct work;
111};
112
113static size_t sock_diag_nlmsg_size(void)
114{
115 return NLMSG_ALIGN(sizeof(struct inet_diag_msg)
116 + nla_total_size(sizeof(u8))
117 + nla_total_size_64bit(sizeof(struct tcp_info)));
118}
119
120static void sock_diag_broadcast_destroy_work(struct work_struct *work)
121{
122 struct broadcast_sk *bsk =
123 container_of(work, struct broadcast_sk, work);
124 struct sock *sk = bsk->sk;
125 const struct sock_diag_handler *hndl;
126 struct sk_buff *skb;
127 const enum sknetlink_groups group = sock_diag_destroy_group(sk);
128 int err = -1;
129
130 WARN_ON(group == SKNLGRP_NONE);
131
132 skb = nlmsg_new(sock_diag_nlmsg_size(), GFP_KERNEL);
133 if (!skb)
134 goto out;
135
136 mutex_lock(&sock_diag_table_mutex);
137 hndl = sock_diag_handlers[sk->sk_family];
138 if (hndl && hndl->get_info)
139 err = hndl->get_info(skb, sk);
140 mutex_unlock(&sock_diag_table_mutex);
141
142 if (!err)
143 nlmsg_multicast(sock_net(sk)->diag_nlsk, skb, 0, group,
144 GFP_KERNEL);
145 else
146 kfree_skb(skb);
147out:
148 sk_destruct(sk);
149 kfree(bsk);
150}
151
152void sock_diag_broadcast_destroy(struct sock *sk)
153{
154
155 struct broadcast_sk *bsk =
156 kmalloc(sizeof(struct broadcast_sk), GFP_ATOMIC);
157 if (!bsk)
158 return sk_destruct(sk);
159 bsk->sk = sk;
160 INIT_WORK(&bsk->work, sock_diag_broadcast_destroy_work);
161 queue_work(broadcast_wq, &bsk->work);
162}
163
164void sock_diag_register_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh))
165{
166 mutex_lock(&sock_diag_table_mutex);
167 inet_rcv_compat = fn;
168 mutex_unlock(&sock_diag_table_mutex);
169}
170EXPORT_SYMBOL_GPL(sock_diag_register_inet_compat);
171
172void sock_diag_unregister_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh))
173{
174 mutex_lock(&sock_diag_table_mutex);
175 inet_rcv_compat = NULL;
176 mutex_unlock(&sock_diag_table_mutex);
177}
178EXPORT_SYMBOL_GPL(sock_diag_unregister_inet_compat);
179
180int sock_diag_register(const struct sock_diag_handler *hndl)
181{
182 int err = 0;
183
184 if (hndl->family >= AF_MAX)
185 return -EINVAL;
186
187 mutex_lock(&sock_diag_table_mutex);
188 if (sock_diag_handlers[hndl->family])
189 err = -EBUSY;
190 else
191 sock_diag_handlers[hndl->family] = hndl;
192 mutex_unlock(&sock_diag_table_mutex);
193
194 return err;
195}
196EXPORT_SYMBOL_GPL(sock_diag_register);
197
198void sock_diag_unregister(const struct sock_diag_handler *hnld)
199{
200 int family = hnld->family;
201
202 if (family >= AF_MAX)
203 return;
204
205 mutex_lock(&sock_diag_table_mutex);
206 BUG_ON(sock_diag_handlers[family] != hnld);
207 sock_diag_handlers[family] = NULL;
208 mutex_unlock(&sock_diag_table_mutex);
209}
210EXPORT_SYMBOL_GPL(sock_diag_unregister);
211
212static int __sock_diag_cmd(struct sk_buff *skb, struct nlmsghdr *nlh)
213{
214 int err;
215 struct sock_diag_req *req = nlmsg_data(nlh);
216 const struct sock_diag_handler *hndl;
217
218 if (nlmsg_len(nlh) < sizeof(*req))
219 return -EINVAL;
220
221 if (req->sdiag_family >= AF_MAX)
222 return -EINVAL;
223 req->sdiag_family = array_index_nospec(req->sdiag_family, AF_MAX);
224
225 if (sock_diag_handlers[req->sdiag_family] == NULL)
226 sock_load_diag_module(req->sdiag_family, 0);
227
228 mutex_lock(&sock_diag_table_mutex);
229 hndl = sock_diag_handlers[req->sdiag_family];
230 if (hndl == NULL)
231 err = -ENOENT;
232 else if (nlh->nlmsg_type == SOCK_DIAG_BY_FAMILY)
233 err = hndl->dump(skb, nlh);
234 else if (nlh->nlmsg_type == SOCK_DESTROY && hndl->destroy)
235 err = hndl->destroy(skb, nlh);
236 else
237 err = -EOPNOTSUPP;
238 mutex_unlock(&sock_diag_table_mutex);
239
240 return err;
241}
242
243static int sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
244 struct netlink_ext_ack *extack)
245{
246 int ret;
247
248 switch (nlh->nlmsg_type) {
249 case TCPDIAG_GETSOCK:
250 case DCCPDIAG_GETSOCK:
251 if (inet_rcv_compat == NULL)
252 sock_load_diag_module(AF_INET, 0);
253
254 mutex_lock(&sock_diag_table_mutex);
255 if (inet_rcv_compat != NULL)
256 ret = inet_rcv_compat(skb, nlh);
257 else
258 ret = -EOPNOTSUPP;
259 mutex_unlock(&sock_diag_table_mutex);
260
261 return ret;
262 case SOCK_DIAG_BY_FAMILY:
263 case SOCK_DESTROY:
264 return __sock_diag_cmd(skb, nlh);
265 default:
266 return -EINVAL;
267 }
268}
269
270static DEFINE_MUTEX(sock_diag_mutex);
271
272static void sock_diag_rcv(struct sk_buff *skb)
273{
274 mutex_lock(&sock_diag_mutex);
275 netlink_rcv_skb(skb, &sock_diag_rcv_msg);
276 mutex_unlock(&sock_diag_mutex);
277}
278
279static int sock_diag_bind(struct net *net, int group)
280{
281 switch (group) {
282 case SKNLGRP_INET_TCP_DESTROY:
283 case SKNLGRP_INET_UDP_DESTROY:
284 if (!sock_diag_handlers[AF_INET])
285 sock_load_diag_module(AF_INET, 0);
286 break;
287 case SKNLGRP_INET6_TCP_DESTROY:
288 case SKNLGRP_INET6_UDP_DESTROY:
289 if (!sock_diag_handlers[AF_INET6])
290 sock_load_diag_module(AF_INET6, 0);
291 break;
292 }
293 return 0;
294}
295
296int sock_diag_destroy(struct sock *sk, int err)
297{
298 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
299 return -EPERM;
300
301 if (!sk->sk_prot->diag_destroy)
302 return -EOPNOTSUPP;
303
304 return sk->sk_prot->diag_destroy(sk, err);
305}
306EXPORT_SYMBOL_GPL(sock_diag_destroy);
307
308static int __net_init diag_net_init(struct net *net)
309{
310 struct netlink_kernel_cfg cfg = {
311 .groups = SKNLGRP_MAX,
312 .input = sock_diag_rcv,
313 .bind = sock_diag_bind,
314 .flags = NL_CFG_F_NONROOT_RECV,
315 };
316
317 net->diag_nlsk = netlink_kernel_create(net, NETLINK_SOCK_DIAG, &cfg);
318 return net->diag_nlsk == NULL ? -ENOMEM : 0;
319}
320
321static void __net_exit diag_net_exit(struct net *net)
322{
323 netlink_kernel_release(net->diag_nlsk);
324 net->diag_nlsk = NULL;
325}
326
327static struct pernet_operations diag_net_ops = {
328 .init = diag_net_init,
329 .exit = diag_net_exit,
330};
331
332static int __init sock_diag_init(void)
333{
334 broadcast_wq = alloc_workqueue("sock_diag_events", 0, 0);
335 BUG_ON(!broadcast_wq);
336 return register_pernet_subsys(&diag_net_ops);
337}
338device_initcall(sock_diag_init);
339
