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