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 */
inet_diag_msg_sctpasoc_fill(struct inet_diag_msg * r,struct sock * sk,struct sctp_association * asoc)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
inet_diag_msg_sctpladdrs_fill(struct sk_buff * skb,struct list_head * address_list)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 rcu_read_lock();
77 list_for_each_entry_rcu(laddr, address_list, list)
78 addrcnt++;
79 rcu_read_unlock();
80
81 attr = nla_reserve(skb, INET_DIAG_LOCALS, addrlen * addrcnt);
82 if (!attr)
83 return -EMSGSIZE;
84
85 info = nla_data(attr);
86 rcu_read_lock();
87 list_for_each_entry_rcu(laddr, address_list, list) {
88 memcpy(info, &laddr->a, sizeof(laddr->a));
89 memset(info + sizeof(laddr->a), 0, addrlen - sizeof(laddr->a));
90 info += addrlen;
91
92 if (!--addrcnt)
93 break;
94 }
95 rcu_read_unlock();
96
97 return 0;
98 }
99
inet_diag_msg_sctpaddrs_fill(struct sk_buff * skb,struct sctp_association * asoc)100 static int inet_diag_msg_sctpaddrs_fill(struct sk_buff *skb,
101 struct sctp_association *asoc)
102 {
103 int addrlen = sizeof(struct sockaddr_storage);
104 struct sctp_transport *from;
105 struct nlattr *attr;
106 void *info = NULL;
107
108 attr = nla_reserve(skb, INET_DIAG_PEERS,
109 addrlen * asoc->peer.transport_count);
110 if (!attr)
111 return -EMSGSIZE;
112
113 info = nla_data(attr);
114 list_for_each_entry(from, &asoc->peer.transport_addr_list,
115 transports) {
116 memcpy(info, &from->ipaddr, sizeof(from->ipaddr));
117 memset(info + sizeof(from->ipaddr), 0,
118 addrlen - sizeof(from->ipaddr));
119 info += addrlen;
120 }
121
122 return 0;
123 }
124
125 /* sctp asoc/ep fill*/
inet_sctp_diag_fill(struct sock * sk,struct sctp_association * asoc,struct sk_buff * skb,const struct inet_diag_req_v2 * req,struct user_namespace * user_ns,int portid,u32 seq,u16 nlmsg_flags,const struct nlmsghdr * unlh,bool net_admin)126 static int inet_sctp_diag_fill(struct sock *sk, struct sctp_association *asoc,
127 struct sk_buff *skb,
128 const struct inet_diag_req_v2 *req,
129 struct user_namespace *user_ns,
130 int portid, u32 seq, u16 nlmsg_flags,
131 const struct nlmsghdr *unlh,
132 bool net_admin)
133 {
134 struct sctp_endpoint *ep = sctp_sk(sk)->ep;
135 struct list_head *addr_list;
136 struct inet_diag_msg *r;
137 struct nlmsghdr *nlh;
138 int ext = req->idiag_ext;
139 struct sctp_infox infox;
140 void *info = NULL;
141
142 nlh = nlmsg_put(skb, portid, seq, unlh->nlmsg_type, sizeof(*r),
143 nlmsg_flags);
144 if (!nlh)
145 return -EMSGSIZE;
146
147 r = nlmsg_data(nlh);
148 BUG_ON(!sk_fullsock(sk));
149
150 r->idiag_timer = 0;
151 r->idiag_retrans = 0;
152 r->idiag_expires = 0;
153 if (asoc) {
154 inet_diag_msg_sctpasoc_fill(r, sk, asoc);
155 } else {
156 inet_diag_msg_common_fill(r, sk);
157 r->idiag_state = sk->sk_state;
158 }
159
160 if (inet_diag_msg_attrs_fill(sk, skb, r, ext, user_ns, net_admin))
161 goto errout;
162
163 if (ext & (1 << (INET_DIAG_SKMEMINFO - 1))) {
164 u32 mem[SK_MEMINFO_VARS];
165 int amt;
166
167 if (asoc && asoc->ep->sndbuf_policy)
168 amt = asoc->sndbuf_used;
169 else
170 amt = sk_wmem_alloc_get(sk);
171 mem[SK_MEMINFO_WMEM_ALLOC] = amt;
172 if (asoc && asoc->ep->rcvbuf_policy)
173 amt = atomic_read(&asoc->rmem_alloc);
174 else
175 amt = sk_rmem_alloc_get(sk);
176 mem[SK_MEMINFO_RMEM_ALLOC] = amt;
177 mem[SK_MEMINFO_RCVBUF] = sk->sk_rcvbuf;
178 mem[SK_MEMINFO_SNDBUF] = sk->sk_sndbuf;
179 mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
180 mem[SK_MEMINFO_WMEM_QUEUED] = sk->sk_wmem_queued;
181 mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
182 mem[SK_MEMINFO_BACKLOG] = READ_ONCE(sk->sk_backlog.len);
183 mem[SK_MEMINFO_DROPS] = sk_drops_read(sk);
184
185 if (nla_put(skb, INET_DIAG_SKMEMINFO, sizeof(mem), &mem) < 0)
186 goto errout;
187 }
188
189 if (ext & (1 << (INET_DIAG_INFO - 1))) {
190 struct nlattr *attr;
191
192 attr = nla_reserve_64bit(skb, INET_DIAG_INFO,
193 sizeof(struct sctp_info),
194 INET_DIAG_PAD);
195 if (!attr)
196 goto errout;
197
198 info = nla_data(attr);
199 }
200 infox.sctpinfo = (struct sctp_info *)info;
201 infox.asoc = asoc;
202 sctp_diag_get_info(sk, r, &infox);
203
204 addr_list = asoc ? &asoc->base.bind_addr.address_list
205 : &ep->base.bind_addr.address_list;
206 if (inet_diag_msg_sctpladdrs_fill(skb, addr_list))
207 goto errout;
208
209 if (asoc && (ext & (1 << (INET_DIAG_CONG - 1))))
210 if (nla_put_string(skb, INET_DIAG_CONG, "reno") < 0)
211 goto errout;
212
213 if (asoc && inet_diag_msg_sctpaddrs_fill(skb, asoc))
214 goto errout;
215
216 nlmsg_end(skb, nlh);
217 return 0;
218
219 errout:
220 nlmsg_cancel(skb, nlh);
221 return -EMSGSIZE;
222 }
223
224 /* callback and param */
225 struct sctp_comm_param {
226 struct sk_buff *skb;
227 struct netlink_callback *cb;
228 const struct inet_diag_req_v2 *r;
229 const struct nlmsghdr *nlh;
230 bool net_admin;
231 };
232
inet_assoc_attr_size(struct sock * sk,struct sctp_association * asoc)233 static size_t inet_assoc_attr_size(struct sock *sk,
234 struct sctp_association *asoc)
235 {
236 int addrlen = sizeof(struct sockaddr_storage);
237 int addrcnt = 0;
238 struct sctp_sockaddr_entry *laddr;
239
240 list_for_each_entry_rcu(laddr, &asoc->base.bind_addr.address_list,
241 list, lockdep_sock_is_held(sk))
242 addrcnt++;
243
244 return nla_total_size(sizeof(struct sctp_info))
245 + nla_total_size(addrlen * asoc->peer.transport_count)
246 + nla_total_size(addrlen * addrcnt)
247 + nla_total_size(sizeof(struct inet_diag_msg))
248 + inet_diag_msg_attrs_size()
249 + nla_total_size(sizeof(struct inet_diag_meminfo))
250 + 64;
251 }
252
sctp_sock_dump_one(struct sctp_endpoint * ep,struct sctp_transport * tsp,void * p)253 static int sctp_sock_dump_one(struct sctp_endpoint *ep, struct sctp_transport *tsp, void *p)
254 {
255 struct sctp_association *assoc = tsp->asoc;
256 struct sctp_comm_param *commp = p;
257 struct sock *sk = ep->base.sk;
258 const struct inet_diag_req_v2 *req = commp->r;
259 struct sk_buff *skb = commp->skb;
260 struct sk_buff *rep;
261 int err;
262
263 err = sock_diag_check_cookie(sk, req->id.idiag_cookie);
264 if (err)
265 return err;
266
267 lock_sock(sk);
268
269 rep = nlmsg_new(inet_assoc_attr_size(sk, assoc), GFP_KERNEL);
270 if (!rep) {
271 release_sock(sk);
272 return -ENOMEM;
273 }
274
275 if (ep != assoc->ep) {
276 err = -EAGAIN;
277 goto out;
278 }
279
280 err = inet_sctp_diag_fill(sk, assoc, rep, req, sk_user_ns(NETLINK_CB(skb).sk),
281 NETLINK_CB(skb).portid, commp->nlh->nlmsg_seq, 0,
282 commp->nlh, commp->net_admin);
283 if (err < 0) {
284 WARN_ON(err == -EMSGSIZE);
285 goto out;
286 }
287 release_sock(sk);
288
289 return nlmsg_unicast(sock_net(skb->sk)->diag_nlsk, rep, NETLINK_CB(skb).portid);
290
291 out:
292 release_sock(sk);
293 kfree_skb(rep);
294 return err;
295 }
296
sctp_sock_dump(struct sctp_endpoint * ep,struct sctp_transport * tsp,void * p)297 static int sctp_sock_dump(struct sctp_endpoint *ep, struct sctp_transport *tsp, void *p)
298 {
299 struct sctp_comm_param *commp = p;
300 struct sock *sk = ep->base.sk;
301 struct sk_buff *skb = commp->skb;
302 struct netlink_callback *cb = commp->cb;
303 const struct inet_diag_req_v2 *r = commp->r;
304 struct sctp_association *assoc;
305 int err = 0;
306
307 lock_sock(sk);
308 if (ep != tsp->asoc->ep)
309 goto release;
310 list_for_each_entry(assoc, &ep->asocs, asocs) {
311 if (cb->args[4] < cb->args[1])
312 goto next;
313
314 if (r->id.idiag_sport != htons(assoc->base.bind_addr.port) &&
315 r->id.idiag_sport)
316 goto next;
317 if (r->id.idiag_dport != htons(assoc->peer.port) &&
318 r->id.idiag_dport)
319 goto next;
320
321 if (!cb->args[3] &&
322 inet_sctp_diag_fill(sk, NULL, skb, r,
323 sk_user_ns(NETLINK_CB(cb->skb).sk),
324 NETLINK_CB(cb->skb).portid,
325 cb->nlh->nlmsg_seq,
326 NLM_F_MULTI, cb->nlh,
327 commp->net_admin) < 0) {
328 err = 1;
329 goto release;
330 }
331 cb->args[3] = 1;
332
333 if (inet_sctp_diag_fill(sk, assoc, skb, r,
334 sk_user_ns(NETLINK_CB(cb->skb).sk),
335 NETLINK_CB(cb->skb).portid,
336 cb->nlh->nlmsg_seq, 0, cb->nlh,
337 commp->net_admin) < 0) {
338 err = 1;
339 goto release;
340 }
341 next:
342 cb->args[4]++;
343 }
344 cb->args[1] = 0;
345 cb->args[3] = 0;
346 cb->args[4] = 0;
347 release:
348 release_sock(sk);
349 return err;
350 }
351
sctp_sock_filter(struct sctp_endpoint * ep,struct sctp_transport * tsp,void * p)352 static int sctp_sock_filter(struct sctp_endpoint *ep, struct sctp_transport *tsp, void *p)
353 {
354 struct sctp_comm_param *commp = p;
355 struct sock *sk = ep->base.sk;
356 const struct inet_diag_req_v2 *r = commp->r;
357
358 /* find the ep only once through the transports by this condition */
359 if (!list_is_first(&tsp->asoc->asocs, &ep->asocs))
360 return 0;
361
362 if (r->sdiag_family != AF_UNSPEC && sk->sk_family != r->sdiag_family)
363 return 0;
364
365 return 1;
366 }
367
sctp_ep_dump(struct sctp_endpoint * ep,void * p)368 static int sctp_ep_dump(struct sctp_endpoint *ep, void *p)
369 {
370 struct sctp_comm_param *commp = p;
371 struct sock *sk = ep->base.sk;
372 struct sk_buff *skb = commp->skb;
373 struct netlink_callback *cb = commp->cb;
374 const struct inet_diag_req_v2 *r = commp->r;
375 struct net *net = sock_net(skb->sk);
376 struct inet_sock *inet = inet_sk(sk);
377 int err = 0;
378
379 if (!net_eq(sock_net(sk), net))
380 goto out;
381
382 if (cb->args[4] < cb->args[1])
383 goto next;
384
385 if (!(r->idiag_states & TCPF_LISTEN) && !list_empty(&ep->asocs))
386 goto next;
387
388 if (r->sdiag_family != AF_UNSPEC &&
389 sk->sk_family != r->sdiag_family)
390 goto next;
391
392 if (r->id.idiag_sport != inet->inet_sport &&
393 r->id.idiag_sport)
394 goto next;
395
396 if (r->id.idiag_dport != inet->inet_dport &&
397 r->id.idiag_dport)
398 goto next;
399
400 if (inet_sctp_diag_fill(sk, NULL, skb, r,
401 sk_user_ns(NETLINK_CB(cb->skb).sk),
402 NETLINK_CB(cb->skb).portid,
403 cb->nlh->nlmsg_seq, NLM_F_MULTI,
404 cb->nlh, commp->net_admin) < 0) {
405 err = 2;
406 goto out;
407 }
408 next:
409 cb->args[4]++;
410 out:
411 return err;
412 }
413
414 /* define the functions for sctp_diag_handler*/
sctp_diag_get_info(struct sock * sk,struct inet_diag_msg * r,void * info)415 static void sctp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
416 void *info)
417 {
418 struct sctp_infox *infox = (struct sctp_infox *)info;
419
420 if (infox->asoc) {
421 r->idiag_rqueue = atomic_read(&infox->asoc->rmem_alloc);
422 r->idiag_wqueue = infox->asoc->sndbuf_used;
423 } else {
424 r->idiag_rqueue = READ_ONCE(sk->sk_ack_backlog);
425 r->idiag_wqueue = READ_ONCE(sk->sk_max_ack_backlog);
426 }
427 if (infox->sctpinfo)
428 sctp_get_sctp_info(sk, infox->asoc, infox->sctpinfo);
429 }
430
sctp_diag_dump_one(struct netlink_callback * cb,const struct inet_diag_req_v2 * req)431 static int sctp_diag_dump_one(struct netlink_callback *cb,
432 const struct inet_diag_req_v2 *req)
433 {
434 struct sk_buff *skb = cb->skb;
435 struct net *net = sock_net(skb->sk);
436 const struct nlmsghdr *nlh = cb->nlh;
437 union sctp_addr laddr, paddr;
438 int dif = req->id.idiag_if;
439 struct sctp_comm_param commp = {
440 .skb = skb,
441 .r = req,
442 .nlh = nlh,
443 .net_admin = netlink_net_capable(skb, CAP_NET_ADMIN),
444 };
445
446 if (req->sdiag_family == AF_INET) {
447 laddr.v4.sin_port = req->id.idiag_sport;
448 laddr.v4.sin_addr.s_addr = req->id.idiag_src[0];
449 laddr.v4.sin_family = AF_INET;
450
451 paddr.v4.sin_port = req->id.idiag_dport;
452 paddr.v4.sin_addr.s_addr = req->id.idiag_dst[0];
453 paddr.v4.sin_family = AF_INET;
454 } else {
455 laddr.v6.sin6_port = req->id.idiag_sport;
456 memcpy(&laddr.v6.sin6_addr, req->id.idiag_src,
457 sizeof(laddr.v6.sin6_addr));
458 laddr.v6.sin6_family = AF_INET6;
459
460 paddr.v6.sin6_port = req->id.idiag_dport;
461 memcpy(&paddr.v6.sin6_addr, req->id.idiag_dst,
462 sizeof(paddr.v6.sin6_addr));
463 paddr.v6.sin6_family = AF_INET6;
464 }
465
466 return sctp_transport_lookup_process(sctp_sock_dump_one,
467 net, &laddr, &paddr, &commp, dif);
468 }
469
sctp_diag_dump(struct sk_buff * skb,struct netlink_callback * cb,const struct inet_diag_req_v2 * r)470 static void sctp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
471 const struct inet_diag_req_v2 *r)
472 {
473 u32 idiag_states = r->idiag_states;
474 struct net *net = sock_net(skb->sk);
475 struct sctp_comm_param commp = {
476 .skb = skb,
477 .cb = cb,
478 .r = r,
479 .net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN),
480 };
481 int pos = cb->args[2];
482
483 /* eps hashtable dumps
484 * args:
485 * 0 : if it will traversal listen sock
486 * 1 : to record the sock pos of this time's traversal
487 * 4 : to work as a temporary variable to traversal list
488 */
489 if (cb->args[0] == 0) {
490 if (!(idiag_states & TCPF_LISTEN))
491 goto skip;
492 if (sctp_for_each_endpoint(sctp_ep_dump, &commp))
493 goto done;
494 skip:
495 cb->args[0] = 1;
496 cb->args[1] = 0;
497 cb->args[4] = 0;
498 }
499
500 /* asocs by transport hashtable dump
501 * args:
502 * 1 : to record the assoc pos of this time's traversal
503 * 2 : to record the transport pos of this time's traversal
504 * 3 : to mark if we have dumped the ep info of the current asoc
505 * 4 : to work as a temporary variable to traversal list
506 * 5 : to save the sk we get from travelsing the tsp list.
507 */
508 if (!(idiag_states & ~(TCPF_LISTEN | TCPF_CLOSE)))
509 goto done;
510
511 sctp_transport_traverse_process(sctp_sock_filter, sctp_sock_dump,
512 net, &pos, &commp);
513 cb->args[2] = pos;
514
515 done:
516 cb->args[1] = cb->args[4];
517 cb->args[4] = 0;
518 }
519
520 static const struct inet_diag_handler sctp_diag_handler = {
521 .owner = THIS_MODULE,
522 .dump = sctp_diag_dump,
523 .dump_one = sctp_diag_dump_one,
524 .idiag_get_info = sctp_diag_get_info,
525 .idiag_type = IPPROTO_SCTP,
526 .idiag_info_size = sizeof(struct sctp_info),
527 };
528
sctp_diag_init(void)529 static int __init sctp_diag_init(void)
530 {
531 return inet_diag_register(&sctp_diag_handler);
532 }
533
sctp_diag_exit(void)534 static void __exit sctp_diag_exit(void)
535 {
536 inet_diag_unregister(&sctp_diag_handler);
537 }
538
539 module_init(sctp_diag_init);
540 module_exit(sctp_diag_exit);
541 MODULE_LICENSE("GPL");
542 MODULE_DESCRIPTION("SCTP socket monitoring via SOCK_DIAG");
543 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-132);
544