]> git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - net/core/sock_diag.c
net: fix ifindex collision during namespace removal
[mirror_ubuntu-bionic-kernel.git] / net / core / sock_diag.c
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
18 static const struct sock_diag_handler *sock_diag_handlers[AF_MAX];
19 static int (*inet_rcv_compat)(struct sk_buff *skb, struct nlmsghdr *nlh);
20 static DEFINE_MUTEX(sock_diag_table_mutex);
21 static struct workqueue_struct *broadcast_wq;
22
23 u64 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
35 int 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 }
48 EXPORT_SYMBOL_GPL(sock_diag_check_cookie);
49
50 void 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 }
57 EXPORT_SYMBOL_GPL(sock_diag_save_cookie);
58
59 int 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 }
67 EXPORT_SYMBOL_GPL(sock_diag_put_meminfo);
68
69 int 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);
101 out:
102 rcu_read_unlock();
103 return err;
104 }
105 EXPORT_SYMBOL(sock_diag_put_filterinfo);
106
107 struct broadcast_sk {
108 struct sock *sk;
109 struct work_struct work;
110 };
111
112 static 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
119 static 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);
146 out:
147 sk_destruct(sk);
148 kfree(bsk);
149 }
150
151 void 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
163 void 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 }
169 EXPORT_SYMBOL_GPL(sock_diag_register_inet_compat);
170
171 void 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 }
177 EXPORT_SYMBOL_GPL(sock_diag_unregister_inet_compat);
178
179 int 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 }
195 EXPORT_SYMBOL_GPL(sock_diag_register);
196
197 void 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 }
209 EXPORT_SYMBOL_GPL(sock_diag_unregister);
210
211 static 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 request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
226 NETLINK_SOCK_DIAG, req->sdiag_family);
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
243 static 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 request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
253 NETLINK_SOCK_DIAG, AF_INET);
254
255 mutex_lock(&sock_diag_table_mutex);
256 if (inet_rcv_compat != NULL)
257 ret = inet_rcv_compat(skb, nlh);
258 else
259 ret = -EOPNOTSUPP;
260 mutex_unlock(&sock_diag_table_mutex);
261
262 return ret;
263 case SOCK_DIAG_BY_FAMILY:
264 case SOCK_DESTROY:
265 return __sock_diag_cmd(skb, nlh);
266 default:
267 return -EINVAL;
268 }
269 }
270
271 static DEFINE_MUTEX(sock_diag_mutex);
272
273 static void sock_diag_rcv(struct sk_buff *skb)
274 {
275 mutex_lock(&sock_diag_mutex);
276 netlink_rcv_skb(skb, &sock_diag_rcv_msg);
277 mutex_unlock(&sock_diag_mutex);
278 }
279
280 static int sock_diag_bind(struct net *net, int group)
281 {
282 switch (group) {
283 case SKNLGRP_INET_TCP_DESTROY:
284 case SKNLGRP_INET_UDP_DESTROY:
285 if (!sock_diag_handlers[AF_INET])
286 request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
287 NETLINK_SOCK_DIAG, AF_INET);
288 break;
289 case SKNLGRP_INET6_TCP_DESTROY:
290 case SKNLGRP_INET6_UDP_DESTROY:
291 if (!sock_diag_handlers[AF_INET6])
292 request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
293 NETLINK_SOCK_DIAG, AF_INET6);
294 break;
295 }
296 return 0;
297 }
298
299 int sock_diag_destroy(struct sock *sk, int err)
300 {
301 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
302 return -EPERM;
303
304 if (!sk->sk_prot->diag_destroy)
305 return -EOPNOTSUPP;
306
307 return sk->sk_prot->diag_destroy(sk, err);
308 }
309 EXPORT_SYMBOL_GPL(sock_diag_destroy);
310
311 static int __net_init diag_net_init(struct net *net)
312 {
313 struct netlink_kernel_cfg cfg = {
314 .groups = SKNLGRP_MAX,
315 .input = sock_diag_rcv,
316 .bind = sock_diag_bind,
317 .flags = NL_CFG_F_NONROOT_RECV,
318 };
319
320 net->diag_nlsk = netlink_kernel_create(net, NETLINK_SOCK_DIAG, &cfg);
321 return net->diag_nlsk == NULL ? -ENOMEM : 0;
322 }
323
324 static void __net_exit diag_net_exit(struct net *net)
325 {
326 netlink_kernel_release(net->diag_nlsk);
327 net->diag_nlsk = NULL;
328 }
329
330 static struct pernet_operations diag_net_ops = {
331 .init = diag_net_init,
332 .exit = diag_net_exit,
333 };
334
335 static int __init sock_diag_init(void)
336 {
337 broadcast_wq = alloc_workqueue("sock_diag_events", 0, 0);
338 BUG_ON(!broadcast_wq);
339 return register_pernet_subsys(&diag_net_ops);
340 }
341 device_initcall(sock_diag_init);