1 | /* License: GPL */ |
2 | |
3 | #include <linux/filter.h> |
4 | #include <linux/mutex.h> |
5 | #include <linux/socket.h> |
6 | #include <linux/skbuff.h> |
7 | #include <net/netlink.h> |
8 | #include <net/net_namespace.h> |
9 | #include <linux/module.h> |
10 | #include <net/sock.h> |
11 | #include <linux/kernel.h> |
12 | #include <linux/tcp.h> |
13 | #include <linux/workqueue.h> |
14 | #include <linux/nospec.h> |
15 | #include <linux/cookie.h> |
16 | #include <linux/inet_diag.h> |
17 | #include <linux/sock_diag.h> |
18 | |
19 | static const struct sock_diag_handler *sock_diag_handlers[AF_MAX]; |
20 | static int (*inet_rcv_compat)(struct sk_buff *skb, struct nlmsghdr *nlh); |
21 | static DEFINE_MUTEX(sock_diag_table_mutex); |
22 | static struct workqueue_struct *broadcast_wq; |
23 | |
24 | DEFINE_COOKIE(sock_cookie); |
25 | |
26 | u64 __sock_gen_cookie(struct sock *sk) |
27 | { |
28 | u64 res = atomic64_read(v: &sk->sk_cookie); |
29 | |
30 | if (!res) { |
31 | u64 new = gen_cookie_next(gc: &sock_cookie); |
32 | |
33 | atomic64_cmpxchg(v: &sk->sk_cookie, old: res, new); |
34 | |
35 | /* Another thread might have changed sk_cookie before us. */ |
36 | res = atomic64_read(v: &sk->sk_cookie); |
37 | } |
38 | return res; |
39 | } |
40 | |
41 | int sock_diag_check_cookie(struct sock *sk, const __u32 *cookie) |
42 | { |
43 | u64 res; |
44 | |
45 | if (cookie[0] == INET_DIAG_NOCOOKIE && cookie[1] == INET_DIAG_NOCOOKIE) |
46 | return 0; |
47 | |
48 | res = sock_gen_cookie(sk); |
49 | if ((u32)res != cookie[0] || (u32)(res >> 32) != cookie[1]) |
50 | return -ESTALE; |
51 | |
52 | return 0; |
53 | } |
54 | EXPORT_SYMBOL_GPL(sock_diag_check_cookie); |
55 | |
56 | void sock_diag_save_cookie(struct sock *sk, __u32 *cookie) |
57 | { |
58 | u64 res = sock_gen_cookie(sk); |
59 | |
60 | cookie[0] = (u32)res; |
61 | cookie[1] = (u32)(res >> 32); |
62 | } |
63 | EXPORT_SYMBOL_GPL(sock_diag_save_cookie); |
64 | |
65 | int sock_diag_put_meminfo(struct sock *sk, struct sk_buff *skb, int attrtype) |
66 | { |
67 | u32 mem[SK_MEMINFO_VARS]; |
68 | |
69 | sk_get_meminfo(sk, meminfo: mem); |
70 | |
71 | return nla_put(skb, attrtype, attrlen: sizeof(mem), data: &mem); |
72 | } |
73 | EXPORT_SYMBOL_GPL(sock_diag_put_meminfo); |
74 | |
75 | int sock_diag_put_filterinfo(bool may_report_filterinfo, struct sock *sk, |
76 | struct sk_buff *skb, int attrtype) |
77 | { |
78 | struct sock_fprog_kern *fprog; |
79 | struct sk_filter *filter; |
80 | struct nlattr *attr; |
81 | unsigned int flen; |
82 | int err = 0; |
83 | |
84 | if (!may_report_filterinfo) { |
85 | nla_reserve(skb, attrtype, attrlen: 0); |
86 | return 0; |
87 | } |
88 | |
89 | rcu_read_lock(); |
90 | filter = rcu_dereference(sk->sk_filter); |
91 | if (!filter) |
92 | goto out; |
93 | |
94 | fprog = filter->prog->orig_prog; |
95 | if (!fprog) |
96 | goto out; |
97 | |
98 | flen = bpf_classic_proglen(fprog); |
99 | |
100 | attr = nla_reserve(skb, attrtype, attrlen: flen); |
101 | if (attr == NULL) { |
102 | err = -EMSGSIZE; |
103 | goto out; |
104 | } |
105 | |
106 | memcpy(nla_data(attr), fprog->filter, flen); |
107 | out: |
108 | rcu_read_unlock(); |
109 | return err; |
110 | } |
111 | EXPORT_SYMBOL(sock_diag_put_filterinfo); |
112 | |
113 | struct broadcast_sk { |
114 | struct sock *sk; |
115 | struct work_struct work; |
116 | }; |
117 | |
118 | static size_t sock_diag_nlmsg_size(void) |
119 | { |
120 | return NLMSG_ALIGN(sizeof(struct inet_diag_msg) |
121 | + nla_total_size(sizeof(u8)) /* INET_DIAG_PROTOCOL */ |
122 | + nla_total_size_64bit(sizeof(struct tcp_info))); /* INET_DIAG_INFO */ |
123 | } |
124 | |
125 | static void sock_diag_broadcast_destroy_work(struct work_struct *work) |
126 | { |
127 | struct broadcast_sk *bsk = |
128 | container_of(work, struct broadcast_sk, work); |
129 | struct sock *sk = bsk->sk; |
130 | const struct sock_diag_handler *hndl; |
131 | struct sk_buff *skb; |
132 | const enum sknetlink_groups group = sock_diag_destroy_group(sk); |
133 | int err = -1; |
134 | |
135 | WARN_ON(group == SKNLGRP_NONE); |
136 | |
137 | skb = nlmsg_new(payload: sock_diag_nlmsg_size(), GFP_KERNEL); |
138 | if (!skb) |
139 | goto out; |
140 | |
141 | mutex_lock(&sock_diag_table_mutex); |
142 | hndl = sock_diag_handlers[sk->sk_family]; |
143 | if (hndl && hndl->get_info) |
144 | err = hndl->get_info(skb, sk); |
145 | mutex_unlock(lock: &sock_diag_table_mutex); |
146 | |
147 | if (!err) |
148 | nlmsg_multicast(sk: sock_net(sk)->diag_nlsk, skb, portid: 0, group, |
149 | GFP_KERNEL); |
150 | else |
151 | kfree_skb(skb); |
152 | out: |
153 | sk_destruct(sk); |
154 | kfree(objp: bsk); |
155 | } |
156 | |
157 | void sock_diag_broadcast_destroy(struct sock *sk) |
158 | { |
159 | /* Note, this function is often called from an interrupt context. */ |
160 | struct broadcast_sk *bsk = |
161 | kmalloc(size: sizeof(struct broadcast_sk), GFP_ATOMIC); |
162 | if (!bsk) |
163 | return sk_destruct(sk); |
164 | bsk->sk = sk; |
165 | INIT_WORK(&bsk->work, sock_diag_broadcast_destroy_work); |
166 | queue_work(wq: broadcast_wq, work: &bsk->work); |
167 | } |
168 | |
169 | void sock_diag_register_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh)) |
170 | { |
171 | mutex_lock(&sock_diag_table_mutex); |
172 | inet_rcv_compat = fn; |
173 | mutex_unlock(lock: &sock_diag_table_mutex); |
174 | } |
175 | EXPORT_SYMBOL_GPL(sock_diag_register_inet_compat); |
176 | |
177 | void sock_diag_unregister_inet_compat(int (*fn)(struct sk_buff *skb, struct nlmsghdr *nlh)) |
178 | { |
179 | mutex_lock(&sock_diag_table_mutex); |
180 | inet_rcv_compat = NULL; |
181 | mutex_unlock(lock: &sock_diag_table_mutex); |
182 | } |
183 | EXPORT_SYMBOL_GPL(sock_diag_unregister_inet_compat); |
184 | |
185 | int sock_diag_register(const struct sock_diag_handler *hndl) |
186 | { |
187 | int err = 0; |
188 | |
189 | if (hndl->family >= AF_MAX) |
190 | return -EINVAL; |
191 | |
192 | mutex_lock(&sock_diag_table_mutex); |
193 | if (sock_diag_handlers[hndl->family]) |
194 | err = -EBUSY; |
195 | else |
196 | sock_diag_handlers[hndl->family] = hndl; |
197 | mutex_unlock(lock: &sock_diag_table_mutex); |
198 | |
199 | return err; |
200 | } |
201 | EXPORT_SYMBOL_GPL(sock_diag_register); |
202 | |
203 | void sock_diag_unregister(const struct sock_diag_handler *hnld) |
204 | { |
205 | int family = hnld->family; |
206 | |
207 | if (family >= AF_MAX) |
208 | return; |
209 | |
210 | mutex_lock(&sock_diag_table_mutex); |
211 | BUG_ON(sock_diag_handlers[family] != hnld); |
212 | sock_diag_handlers[family] = NULL; |
213 | mutex_unlock(lock: &sock_diag_table_mutex); |
214 | } |
215 | EXPORT_SYMBOL_GPL(sock_diag_unregister); |
216 | |
217 | static int __sock_diag_cmd(struct sk_buff *skb, struct nlmsghdr *nlh) |
218 | { |
219 | int err; |
220 | struct sock_diag_req *req = nlmsg_data(nlh); |
221 | const struct sock_diag_handler *hndl; |
222 | |
223 | if (nlmsg_len(nlh) < sizeof(*req)) |
224 | return -EINVAL; |
225 | |
226 | if (req->sdiag_family >= AF_MAX) |
227 | return -EINVAL; |
228 | req->sdiag_family = array_index_nospec(req->sdiag_family, AF_MAX); |
229 | |
230 | if (sock_diag_handlers[req->sdiag_family] == NULL) |
231 | sock_load_diag_module(family: req->sdiag_family, protocol: 0); |
232 | |
233 | mutex_lock(&sock_diag_table_mutex); |
234 | hndl = sock_diag_handlers[req->sdiag_family]; |
235 | if (hndl == NULL) |
236 | err = -ENOENT; |
237 | else if (nlh->nlmsg_type == SOCK_DIAG_BY_FAMILY) |
238 | err = hndl->dump(skb, nlh); |
239 | else if (nlh->nlmsg_type == SOCK_DESTROY && hndl->destroy) |
240 | err = hndl->destroy(skb, nlh); |
241 | else |
242 | err = -EOPNOTSUPP; |
243 | mutex_unlock(lock: &sock_diag_table_mutex); |
244 | |
245 | return err; |
246 | } |
247 | |
248 | static int sock_diag_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, |
249 | struct netlink_ext_ack *extack) |
250 | { |
251 | int ret; |
252 | |
253 | switch (nlh->nlmsg_type) { |
254 | case TCPDIAG_GETSOCK: |
255 | case DCCPDIAG_GETSOCK: |
256 | if (inet_rcv_compat == NULL) |
257 | sock_load_diag_module(AF_INET, protocol: 0); |
258 | |
259 | mutex_lock(&sock_diag_table_mutex); |
260 | if (inet_rcv_compat != NULL) |
261 | ret = inet_rcv_compat(skb, nlh); |
262 | else |
263 | ret = -EOPNOTSUPP; |
264 | mutex_unlock(lock: &sock_diag_table_mutex); |
265 | |
266 | return ret; |
267 | case SOCK_DIAG_BY_FAMILY: |
268 | case SOCK_DESTROY: |
269 | return __sock_diag_cmd(skb, nlh); |
270 | default: |
271 | return -EINVAL; |
272 | } |
273 | } |
274 | |
275 | static DEFINE_MUTEX(sock_diag_mutex); |
276 | |
277 | static void sock_diag_rcv(struct sk_buff *skb) |
278 | { |
279 | mutex_lock(&sock_diag_mutex); |
280 | netlink_rcv_skb(skb, cb: &sock_diag_rcv_msg); |
281 | mutex_unlock(lock: &sock_diag_mutex); |
282 | } |
283 | |
284 | static int sock_diag_bind(struct net *net, int group) |
285 | { |
286 | switch (group) { |
287 | case SKNLGRP_INET_TCP_DESTROY: |
288 | case SKNLGRP_INET_UDP_DESTROY: |
289 | if (!sock_diag_handlers[AF_INET]) |
290 | sock_load_diag_module(AF_INET, protocol: 0); |
291 | break; |
292 | case SKNLGRP_INET6_TCP_DESTROY: |
293 | case SKNLGRP_INET6_UDP_DESTROY: |
294 | if (!sock_diag_handlers[AF_INET6]) |
295 | sock_load_diag_module(AF_INET6, protocol: 0); |
296 | break; |
297 | } |
298 | return 0; |
299 | } |
300 | |
301 | int sock_diag_destroy(struct sock *sk, int err) |
302 | { |
303 | if (!ns_capable(ns: sock_net(sk)->user_ns, CAP_NET_ADMIN)) |
304 | return -EPERM; |
305 | |
306 | if (!sk->sk_prot->diag_destroy) |
307 | return -EOPNOTSUPP; |
308 | |
309 | return sk->sk_prot->diag_destroy(sk, err); |
310 | } |
311 | EXPORT_SYMBOL_GPL(sock_diag_destroy); |
312 | |
313 | static int __net_init diag_net_init(struct net *net) |
314 | { |
315 | struct netlink_kernel_cfg cfg = { |
316 | .groups = SKNLGRP_MAX, |
317 | .input = sock_diag_rcv, |
318 | .bind = sock_diag_bind, |
319 | .flags = NL_CFG_F_NONROOT_RECV, |
320 | }; |
321 | |
322 | net->diag_nlsk = netlink_kernel_create(net, NETLINK_SOCK_DIAG, cfg: &cfg); |
323 | return net->diag_nlsk == NULL ? -ENOMEM : 0; |
324 | } |
325 | |
326 | static void __net_exit diag_net_exit(struct net *net) |
327 | { |
328 | netlink_kernel_release(sk: net->diag_nlsk); |
329 | net->diag_nlsk = NULL; |
330 | } |
331 | |
332 | static struct pernet_operations diag_net_ops = { |
333 | .init = diag_net_init, |
334 | .exit = diag_net_exit, |
335 | }; |
336 | |
337 | static int __init sock_diag_init(void) |
338 | { |
339 | broadcast_wq = alloc_workqueue(fmt: "sock_diag_events" , flags: 0, max_active: 0); |
340 | BUG_ON(!broadcast_wq); |
341 | return register_pernet_subsys(&diag_net_ops); |
342 | } |
343 | device_initcall(sock_diag_init); |
344 | |