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 | 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 | |
242 | static 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 | |
269 | static DEFINE_MUTEX(sock_diag_mutex); |
270 | |
271 | static 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 | |
278 | static 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 | |
295 | int 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 | } |
305 | EXPORT_SYMBOL_GPL(sock_diag_destroy); |
306 | |
307 | static 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 | |
320 | static void __net_exit diag_net_exit(struct net *net) |
321 | { |
322 | netlink_kernel_release(net->diag_nlsk); |
323 | net->diag_nlsk = NULL; |
324 | } |
325 | |
326 | static struct pernet_operations diag_net_ops = { |
327 | .init = diag_net_init, |
328 | .exit = diag_net_exit, |
329 | }; |
330 | |
331 | static 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 | } |
337 | device_initcall(sock_diag_init); |
338 | |