1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* SCTP kernel implementation
3 * (C) Copyright Red Hat Inc. 2017
4 *
5 * This file is part of the SCTP kernel implementation
6 *
7 * These functions implement sctp diag support.
8 *
9 * Please send any bug reports or fixes you make to the
10 * email addresched(es):
11 * lksctp developers <linux-sctp@vger.kernel.org>
12 *
13 * Written or modified by:
14 * Xin Long <lucien.xin@gmail.com>
15 */
16
17 #include <linux/module.h>
18 #include <linux/inet_diag.h>
19 #include <linux/sock_diag.h>
20 #include <net/sctp/sctp.h>
21
22 static void sctp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
23 void *info);
24
25 /* define some functions to make asoc/ep fill look clean */
26 static void inet_diag_msg_sctpasoc_fill(struct inet_diag_msg *r,
27 struct sock *sk,
28 struct sctp_association *asoc)
29 {
30 union sctp_addr laddr, paddr;
31 struct dst_entry *dst;
32 struct timer_list *t3_rtx = &asoc->peer.primary_path->T3_rtx_timer;
33
34 laddr = list_entry(asoc->base.bind_addr.address_list.next,
35 struct sctp_sockaddr_entry, list)->a;
36 paddr = asoc->peer.primary_path->ipaddr;
37 dst = asoc->peer.primary_path->dst;
38
39 r->idiag_family = sk->sk_family;
40 r->id.idiag_sport = htons(asoc->base.bind_addr.port);
41 r->id.idiag_dport = htons(asoc->peer.port);
42 r->id.idiag_if = dst ? dst->dev->ifindex : 0;
43 sock_diag_save_cookie(sk, r->id.idiag_cookie);
44
45 #if IS_ENABLED(CONFIG_IPV6)
46 if (sk->sk_family == AF_INET6) {
47 *(struct in6_addr *)r->id.idiag_src = laddr.v6.sin6_addr;
48 *(struct in6_addr *)r->id.idiag_dst = paddr.v6.sin6_addr;
49 } else
50 #endif
51 {
52 memset(&r->id.idiag_src, 0, sizeof(r->id.idiag_src));
53 memset(&r->id.idiag_dst, 0, sizeof(r->id.idiag_dst));
54
55 r->id.idiag_src[0] = laddr.v4.sin_addr.s_addr;
56 r->id.idiag_dst[0] = paddr.v4.sin_addr.s_addr;
57 }
58
59 r->idiag_state = asoc->state;
60 if (timer_pending(t3_rtx)) {
61 r->idiag_timer = SCTP_EVENT_TIMEOUT_T3_RTX;
62 r->idiag_retrans = asoc->rtx_data_chunks;
63 r->idiag_expires = jiffies_to_msecs(t3_rtx->expires - jiffies);
64 }
65 }
66
67 static int inet_diag_msg_sctpladdrs_fill(struct sk_buff *skb,
68 struct list_head *address_list)
69 {
70 struct sctp_sockaddr_entry *laddr;
71 int addrlen = sizeof(struct sockaddr_storage);
72 int addrcnt = 0;
73 struct nlattr *attr;
74 void *info = NULL;
75
76 list_for_each_entry_rcu(laddr, address_list, list)
77 addrcnt++;
78
79 attr = nla_reserve(skb, INET_DIAG_LOCALS, addrlen * addrcnt);
80 if (!attr)
81 return -EMSGSIZE;
82
83 info = nla_data(attr);
84 list_for_each_entry_rcu(laddr, address_list, list) {
85 memcpy(info, &laddr->a, sizeof(laddr->a));
86 memset(info + sizeof(laddr->a), 0, addrlen - sizeof(laddr->a));
87 info += addrlen;
88 }
89
90 return 0;
91 }
92
93 static int inet_diag_msg_sctpaddrs_fill(struct sk_buff *skb,
94 struct sctp_association *asoc)
95 {
96 int addrlen = sizeof(struct sockaddr_storage);
97 struct sctp_transport *from;
98 struct nlattr *attr;
99 void *info = NULL;
100
101 attr = nla_reserve(skb, INET_DIAG_PEERS,
102 addrlen * asoc->peer.transport_count);
103 if (!attr)
104 return -EMSGSIZE;
105
106 info = nla_data(attr);
107 list_for_each_entry(from, &asoc->peer.transport_addr_list,
108 transports) {
109 memcpy(info, &from->ipaddr, sizeof(from->ipaddr));
110 memset(info + sizeof(from->ipaddr), 0,
111 addrlen - sizeof(from->ipaddr));
112 info += addrlen;
113 }
114
115 return 0;
116 }
117
118 /* sctp asoc/ep fill*/
119 static int inet_sctp_diag_fill(struct sock *sk, struct sctp_association *asoc,
120 struct sk_buff *skb,
121 const struct inet_diag_req_v2 *req,
122 struct user_namespace *user_ns,
123 int portid, u32 seq, u16 nlmsg_flags,
124 const struct nlmsghdr *unlh,
125 bool net_admin)
126 {
127 struct sctp_endpoint *ep = sctp_sk(sk)->ep;
128 struct list_head *addr_list;
129 struct inet_diag_msg *r;
130 struct nlmsghdr *nlh;
131 int ext = req->idiag_ext;
132 struct sctp_infox infox;
133 void *info = NULL;
134
135 nlh = nlmsg_put(skb, portid, seq, unlh->nlmsg_type, sizeof(*r),
136 nlmsg_flags);
137 if (!nlh)
138 return -EMSGSIZE;
139
140 r = nlmsg_data(nlh);
141 BUG_ON(!sk_fullsock(sk));
142
143 r->idiag_timer = 0;
144 r->idiag_retrans = 0;
145 r->idiag_expires = 0;
146 if (asoc) {
147 inet_diag_msg_sctpasoc_fill(r, sk, asoc);
148 } else {
149 inet_diag_msg_common_fill(r, sk);
150 r->idiag_state = sk->sk_state;
151 }
152
153 if (inet_diag_msg_attrs_fill(sk, skb, r, ext, user_ns, net_admin))
154 goto errout;
155
156 if (ext & (1 << (INET_DIAG_SKMEMINFO - 1))) {
157 u32 mem[SK_MEMINFO_VARS];
158 int amt;
159
160 if (asoc && asoc->ep->sndbuf_policy)
161 amt = asoc->sndbuf_used;
162 else
163 amt = sk_wmem_alloc_get(sk);
164 mem[SK_MEMINFO_WMEM_ALLOC] = amt;
165 if (asoc && asoc->ep->rcvbuf_policy)
166 amt = atomic_read(&asoc->rmem_alloc);
167 else
168 amt = sk_rmem_alloc_get(sk);
169 mem[SK_MEMINFO_RMEM_ALLOC] = amt;
170 mem[SK_MEMINFO_RCVBUF] = sk->sk_rcvbuf;
171 mem[SK_MEMINFO_SNDBUF] = sk->sk_sndbuf;
172 mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
173 mem[SK_MEMINFO_WMEM_QUEUED] = sk->sk_wmem_queued;
174 mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
175 mem[SK_MEMINFO_BACKLOG] = READ_ONCE(sk->sk_backlog.len);
176 mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
177
178 if (nla_put(skb, INET_DIAG_SKMEMINFO, sizeof(mem), &mem) < 0)
179 goto errout;
180 }
181
182 if (ext & (1 << (INET_DIAG_INFO - 1))) {
183 struct nlattr *attr;
184
185 attr = nla_reserve_64bit(skb, INET_DIAG_INFO,
186 sizeof(struct sctp_info),
187 INET_DIAG_PAD);
188 if (!attr)
189 goto errout;
190
191 info = nla_data(attr);
192 }
193 infox.sctpinfo = (struct sctp_info *)info;
194 infox.asoc = asoc;
195 sctp_diag_get_info(sk, r, &infox);
196
197 addr_list = asoc ? &asoc->base.bind_addr.address_list
198 : &ep->base.bind_addr.address_list;
199 if (inet_diag_msg_sctpladdrs_fill(skb, addr_list))
200 goto errout;
201
202 if (asoc && (ext & (1 << (INET_DIAG_CONG - 1))))
203 if (nla_put_string(skb, INET_DIAG_CONG, "reno") < 0)
204 goto errout;
205
206 if (asoc && inet_diag_msg_sctpaddrs_fill(skb, asoc))
207 goto errout;
208
209 nlmsg_end(skb, nlh);
210 return 0;
211
212 errout:
213 nlmsg_cancel(skb, nlh);
214 return -EMSGSIZE;
215 }
216
217 /* callback and param */
218 struct sctp_comm_param {
219 struct sk_buff *skb;
220 struct netlink_callback *cb;
221 const struct inet_diag_req_v2 *r;
222 const struct nlmsghdr *nlh;
223 bool net_admin;
224 };
225
226 static size_t inet_assoc_attr_size(struct sctp_association *asoc)
227 {
228 int addrlen = sizeof(struct sockaddr_storage);
229 int addrcnt = 0;
230 struct sctp_sockaddr_entry *laddr;
231
232 list_for_each_entry_rcu(laddr, &asoc->base.bind_addr.address_list,
233 list)
234 addrcnt++;
235
236 return nla_total_size(sizeof(struct sctp_info))
237 + nla_total_size(addrlen * asoc->peer.transport_count)
238 + nla_total_size(addrlen * addrcnt)
239 + nla_total_size(sizeof(struct inet_diag_msg))
240 + inet_diag_msg_attrs_size()
241 + nla_total_size(sizeof(struct inet_diag_meminfo))
242 + 64;
243 }
244
245 static int sctp_sock_dump_one(struct sctp_endpoint *ep, struct sctp_transport *tsp, void *p)
246 {
247 struct sctp_association *assoc = tsp->asoc;
248 struct sctp_comm_param *commp = p;
249 struct sock *sk = ep->base.sk;
250 const struct inet_diag_req_v2 *req = commp->r;
251 struct sk_buff *skb = commp->skb;
252 struct sk_buff *rep;
253 int err;
254
255 err = sock_diag_check_cookie(sk, req->id.idiag_cookie);
256 if (err)
257 return err;
258
259 rep = nlmsg_new(inet_assoc_attr_size(assoc), GFP_KERNEL);
260 if (!rep)
261 return -ENOMEM;
262
263 lock_sock(sk);
264 if (ep != assoc->ep) {
265 err = -EAGAIN;
266 goto out;
267 }
268
269 err = inet_sctp_diag_fill(sk, assoc, rep, req, sk_user_ns(NETLINK_CB(skb).sk),
270 NETLINK_CB(skb).portid, commp->nlh->nlmsg_seq, 0,
271 commp->nlh, commp->net_admin);
272 if (err < 0) {
273 WARN_ON(err == -EMSGSIZE);
274 goto out;
275 }
276 release_sock(sk);
277
278 return nlmsg_unicast(sock_net(skb->sk)->diag_nlsk, rep, NETLINK_CB(skb).portid);
279
280 out:
281 release_sock(sk);
282 kfree_skb(rep);
283 return err;
284 }
285
286 static int sctp_sock_dump(struct sctp_endpoint *ep, struct sctp_transport *tsp, void *p)
287 {
288 struct sctp_comm_param *commp = p;
289 struct sock *sk = ep->base.sk;
290 struct sk_buff *skb = commp->skb;
291 struct netlink_callback *cb = commp->cb;
292 const struct inet_diag_req_v2 *r = commp->r;
293 struct sctp_association *assoc;
294 int err = 0;
295
296 lock_sock(sk);
297 if (ep != tsp->asoc->ep)
298 goto release;
299 list_for_each_entry(assoc, &ep->asocs, asocs) {
300 if (cb->args[4] < cb->args[1])
301 goto next;
302
303 if (r->id.idiag_sport != htons(assoc->base.bind_addr.port) &&
304 r->id.idiag_sport)
305 goto next;
306 if (r->id.idiag_dport != htons(assoc->peer.port) &&
307 r->id.idiag_dport)
308 goto next;
309
310 if (!cb->args[3] &&
311 inet_sctp_diag_fill(sk, NULL, skb, r,
312 sk_user_ns(NETLINK_CB(cb->skb).sk),
313 NETLINK_CB(cb->skb).portid,
314 cb->nlh->nlmsg_seq,
315 NLM_F_MULTI, cb->nlh,
316 commp->net_admin) < 0) {
317 err = 1;
318 goto release;
319 }
320 cb->args[3] = 1;
321
322 if (inet_sctp_diag_fill(sk, assoc, skb, r,
323 sk_user_ns(NETLINK_CB(cb->skb).sk),
324 NETLINK_CB(cb->skb).portid,
325 cb->nlh->nlmsg_seq, 0, cb->nlh,
326 commp->net_admin) < 0) {
327 err = 1;
328 goto release;
329 }
330 next:
331 cb->args[4]++;
332 }
333 cb->args[1] = 0;
334 cb->args[3] = 0;
335 cb->args[4] = 0;
336 release:
337 release_sock(sk);
338 return err;
339 }
340
341 static int sctp_sock_filter(struct sctp_endpoint *ep, struct sctp_transport *tsp, void *p)
342 {
343 struct sctp_comm_param *commp = p;
344 struct sock *sk = ep->base.sk;
345 const struct inet_diag_req_v2 *r = commp->r;
346
347 /* find the ep only once through the transports by this condition */
348 if (!list_is_first(&tsp->asoc->asocs, &ep->asocs))
349 return 0;
350
351 if (r->sdiag_family != AF_UNSPEC && sk->sk_family != r->sdiag_family)
352 return 0;
353
354 return 1;
355 }
356
357 static int sctp_ep_dump(struct sctp_endpoint *ep, void *p)
358 {
359 struct sctp_comm_param *commp = p;
360 struct sock *sk = ep->base.sk;
361 struct sk_buff *skb = commp->skb;
362 struct netlink_callback *cb = commp->cb;
363 const struct inet_diag_req_v2 *r = commp->r;
364 struct net *net = sock_net(skb->sk);
365 struct inet_sock *inet = inet_sk(sk);
366 int err = 0;
367
368 if (!net_eq(sock_net(sk), net))
369 goto out;
370
371 if (cb->args[4] < cb->args[1])
372 goto next;
373
374 if (!(r->idiag_states & TCPF_LISTEN) && !list_empty(&ep->asocs))
375 goto next;
376
377 if (r->sdiag_family != AF_UNSPEC &&
378 sk->sk_family != r->sdiag_family)
379 goto next;
380
381 if (r->id.idiag_sport != inet->inet_sport &&
382 r->id.idiag_sport)
383 goto next;
384
385 if (r->id.idiag_dport != inet->inet_dport &&
386 r->id.idiag_dport)
387 goto next;
388
389 if (inet_sctp_diag_fill(sk, NULL, skb, r,
390 sk_user_ns(NETLINK_CB(cb->skb).sk),
391 NETLINK_CB(cb->skb).portid,
392 cb->nlh->nlmsg_seq, NLM_F_MULTI,
393 cb->nlh, commp->net_admin) < 0) {
394 err = 2;
395 goto out;
396 }
397 next:
398 cb->args[4]++;
399 out:
400 return err;
401 }
402
403 /* define the functions for sctp_diag_handler*/
404 static void sctp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
405 void *info)
406 {
407 struct sctp_infox *infox = (struct sctp_infox *)info;
408
409 if (infox->asoc) {
410 r->idiag_rqueue = atomic_read(&infox->asoc->rmem_alloc);
411 r->idiag_wqueue = infox->asoc->sndbuf_used;
412 } else {
413 r->idiag_rqueue = READ_ONCE(sk->sk_ack_backlog);
414 r->idiag_wqueue = READ_ONCE(sk->sk_max_ack_backlog);
415 }
416 if (infox->sctpinfo)
417 sctp_get_sctp_info(sk, infox->asoc, infox->sctpinfo);
418 }
419
420 static int sctp_diag_dump_one(struct netlink_callback *cb,
421 const struct inet_diag_req_v2 *req)
422 {
423 struct sk_buff *skb = cb->skb;
424 struct net *net = sock_net(skb->sk);
425 const struct nlmsghdr *nlh = cb->nlh;
426 union sctp_addr laddr, paddr;
427 int dif = req->id.idiag_if;
428 struct sctp_comm_param commp = {
429 .skb = skb,
430 .r = req,
431 .nlh = nlh,
432 .net_admin = netlink_net_capable(skb, CAP_NET_ADMIN),
433 };
434
435 if (req->sdiag_family == AF_INET) {
436 laddr.v4.sin_port = req->id.idiag_sport;
437 laddr.v4.sin_addr.s_addr = req->id.idiag_src[0];
438 laddr.v4.sin_family = AF_INET;
439
440 paddr.v4.sin_port = req->id.idiag_dport;
441 paddr.v4.sin_addr.s_addr = req->id.idiag_dst[0];
442 paddr.v4.sin_family = AF_INET;
443 } else {
444 laddr.v6.sin6_port = req->id.idiag_sport;
445 memcpy(&laddr.v6.sin6_addr, req->id.idiag_src,
446 sizeof(laddr.v6.sin6_addr));
447 laddr.v6.sin6_family = AF_INET6;
448
449 paddr.v6.sin6_port = req->id.idiag_dport;
450 memcpy(&paddr.v6.sin6_addr, req->id.idiag_dst,
451 sizeof(paddr.v6.sin6_addr));
452 paddr.v6.sin6_family = AF_INET6;
453 }
454
455 return sctp_transport_lookup_process(sctp_sock_dump_one,
456 net, &laddr, &paddr, &commp, dif);
457 }
458
459 static void sctp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
460 const struct inet_diag_req_v2 *r)
461 {
462 u32 idiag_states = r->idiag_states;
463 struct net *net = sock_net(skb->sk);
464 struct sctp_comm_param commp = {
465 .skb = skb,
466 .cb = cb,
467 .r = r,
468 .net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN),
469 };
470 int pos = cb->args[2];
471
472 /* eps hashtable dumps
473 * args:
474 * 0 : if it will traversal listen sock
475 * 1 : to record the sock pos of this time's traversal
476 * 4 : to work as a temporary variable to traversal list
477 */
478 if (cb->args[0] == 0) {
479 if (!(idiag_states & TCPF_LISTEN))
480 goto skip;
481 if (sctp_for_each_endpoint(sctp_ep_dump, &commp))
482 goto done;
483 skip:
484 cb->args[0] = 1;
485 cb->args[1] = 0;
486 cb->args[4] = 0;
487 }
488
489 /* asocs by transport hashtable dump
490 * args:
491 * 1 : to record the assoc pos of this time's traversal
492 * 2 : to record the transport pos of this time's traversal
493 * 3 : to mark if we have dumped the ep info of the current asoc
494 * 4 : to work as a temporary variable to traversal list
495 * 5 : to save the sk we get from travelsing the tsp list.
496 */
497 if (!(idiag_states & ~(TCPF_LISTEN | TCPF_CLOSE)))
498 goto done;
499
500 sctp_transport_traverse_process(sctp_sock_filter, sctp_sock_dump,
501 net, &pos, &commp);
502 cb->args[2] = pos;
503
504 done:
505 cb->args[1] = cb->args[4];
506 cb->args[4] = 0;
507 }
508
509 static const struct inet_diag_handler sctp_diag_handler = {
510 .owner = THIS_MODULE,
511 .dump = sctp_diag_dump,
512 .dump_one = sctp_diag_dump_one,
513 .idiag_get_info = sctp_diag_get_info,
514 .idiag_type = IPPROTO_SCTP,
515 .idiag_info_size = sizeof(struct sctp_info),
516 };
517
518 static int __init sctp_diag_init(void)
519 {
520 return inet_diag_register(&sctp_diag_handler);
521 }
522
523 static void __exit sctp_diag_exit(void)
524 {
525 inet_diag_unregister(&sctp_diag_handler);
526 }
527
528 module_init(sctp_diag_init);
529 module_exit(sctp_diag_exit);
530 MODULE_LICENSE("GPL");
531 MODULE_DESCRIPTION("SCTP socket monitoring via SOCK_DIAG");
532 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-132);
533
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