xref: /openbmc/linux/net/sctp/diag.c (revision f9a82c48)
1 /* SCTP kernel implementation
2  * (C) Copyright Red Hat Inc. 2017
3  *
4  * This file is part of the SCTP kernel implementation
5  *
6  * These functions implement sctp diag support.
7  *
8  * This SCTP implementation is free software;
9  * you can redistribute it and/or modify it under the terms of
10  * the GNU General Public License as published by
11  * the Free Software Foundation; either version 2, or (at your option)
12  * any later version.
13  *
14  * This SCTP implementation is distributed in the hope that it
15  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
16  *                 ************************
17  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
18  * See the GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with GNU CC; see the file COPYING.  If not, see
22  * <http://www.gnu.org/licenses/>.
23  *
24  * Please send any bug reports or fixes you make to the
25  * email addresched(es):
26  *    lksctp developers <linux-sctp@vger.kernel.org>
27  *
28  * Written or modified by:
29  *    Xin Long <lucien.xin@gmail.com>
30  */
31 
32 #include <linux/module.h>
33 #include <linux/inet_diag.h>
34 #include <linux/sock_diag.h>
35 #include <net/sctp/sctp.h>
36 
37 static void sctp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
38 			       void *info);
39 
40 /* define some functions to make asoc/ep fill look clean */
41 static void inet_diag_msg_sctpasoc_fill(struct inet_diag_msg *r,
42 					struct sock *sk,
43 					struct sctp_association *asoc)
44 {
45 	union sctp_addr laddr, paddr;
46 	struct dst_entry *dst;
47 	struct timer_list *t3_rtx = &asoc->peer.primary_path->T3_rtx_timer;
48 
49 	laddr = list_entry(asoc->base.bind_addr.address_list.next,
50 			   struct sctp_sockaddr_entry, list)->a;
51 	paddr = asoc->peer.primary_path->ipaddr;
52 	dst = asoc->peer.primary_path->dst;
53 
54 	r->idiag_family = sk->sk_family;
55 	r->id.idiag_sport = htons(asoc->base.bind_addr.port);
56 	r->id.idiag_dport = htons(asoc->peer.port);
57 	r->id.idiag_if = dst ? dst->dev->ifindex : 0;
58 	sock_diag_save_cookie(sk, r->id.idiag_cookie);
59 
60 #if IS_ENABLED(CONFIG_IPV6)
61 	if (sk->sk_family == AF_INET6) {
62 		*(struct in6_addr *)r->id.idiag_src = laddr.v6.sin6_addr;
63 		*(struct in6_addr *)r->id.idiag_dst = paddr.v6.sin6_addr;
64 	} else
65 #endif
66 	{
67 		memset(&r->id.idiag_src, 0, sizeof(r->id.idiag_src));
68 		memset(&r->id.idiag_dst, 0, sizeof(r->id.idiag_dst));
69 
70 		r->id.idiag_src[0] = laddr.v4.sin_addr.s_addr;
71 		r->id.idiag_dst[0] = paddr.v4.sin_addr.s_addr;
72 	}
73 
74 	r->idiag_state = asoc->state;
75 	if (timer_pending(t3_rtx)) {
76 		r->idiag_timer = SCTP_EVENT_TIMEOUT_T3_RTX;
77 		r->idiag_retrans = asoc->rtx_data_chunks;
78 		r->idiag_expires = jiffies_to_msecs(t3_rtx->expires - jiffies);
79 	} else {
80 		r->idiag_timer = 0;
81 		r->idiag_retrans = 0;
82 		r->idiag_expires = 0;
83 	}
84 }
85 
86 static int inet_diag_msg_sctpladdrs_fill(struct sk_buff *skb,
87 					 struct list_head *address_list)
88 {
89 	struct sctp_sockaddr_entry *laddr;
90 	int addrlen = sizeof(struct sockaddr_storage);
91 	int addrcnt = 0;
92 	struct nlattr *attr;
93 	void *info = NULL;
94 
95 	list_for_each_entry_rcu(laddr, address_list, list)
96 		addrcnt++;
97 
98 	attr = nla_reserve(skb, INET_DIAG_LOCALS, addrlen * addrcnt);
99 	if (!attr)
100 		return -EMSGSIZE;
101 
102 	info = nla_data(attr);
103 	list_for_each_entry_rcu(laddr, address_list, list) {
104 		memcpy(info, &laddr->a, sizeof(laddr->a));
105 		memset(info + sizeof(laddr->a), 0, addrlen - sizeof(laddr->a));
106 		info += addrlen;
107 	}
108 
109 	return 0;
110 }
111 
112 static int inet_diag_msg_sctpaddrs_fill(struct sk_buff *skb,
113 					struct sctp_association *asoc)
114 {
115 	int addrlen = sizeof(struct sockaddr_storage);
116 	struct sctp_transport *from;
117 	struct nlattr *attr;
118 	void *info = NULL;
119 
120 	attr = nla_reserve(skb, INET_DIAG_PEERS,
121 			   addrlen * asoc->peer.transport_count);
122 	if (!attr)
123 		return -EMSGSIZE;
124 
125 	info = nla_data(attr);
126 	list_for_each_entry(from, &asoc->peer.transport_addr_list,
127 			    transports) {
128 		memcpy(info, &from->ipaddr, sizeof(from->ipaddr));
129 		memset(info + sizeof(from->ipaddr), 0,
130 		       addrlen - sizeof(from->ipaddr));
131 		info += addrlen;
132 	}
133 
134 	return 0;
135 }
136 
137 /* sctp asoc/ep fill*/
138 static int inet_sctp_diag_fill(struct sock *sk, struct sctp_association *asoc,
139 			       struct sk_buff *skb,
140 			       const struct inet_diag_req_v2 *req,
141 			       struct user_namespace *user_ns,
142 			       int portid, u32 seq, u16 nlmsg_flags,
143 			       const struct nlmsghdr *unlh,
144 			       bool net_admin)
145 {
146 	struct sctp_endpoint *ep = sctp_sk(sk)->ep;
147 	struct list_head *addr_list;
148 	struct inet_diag_msg *r;
149 	struct nlmsghdr  *nlh;
150 	int ext = req->idiag_ext;
151 	struct sctp_infox infox;
152 	void *info = NULL;
153 
154 	nlh = nlmsg_put(skb, portid, seq, unlh->nlmsg_type, sizeof(*r),
155 			nlmsg_flags);
156 	if (!nlh)
157 		return -EMSGSIZE;
158 
159 	r = nlmsg_data(nlh);
160 	BUG_ON(!sk_fullsock(sk));
161 
162 	if (asoc) {
163 		inet_diag_msg_sctpasoc_fill(r, sk, asoc);
164 	} else {
165 		inet_diag_msg_common_fill(r, sk);
166 		r->idiag_state = sk->sk_state;
167 		r->idiag_timer = 0;
168 		r->idiag_retrans = 0;
169 	}
170 
171 	if (inet_diag_msg_attrs_fill(sk, skb, r, ext, user_ns, net_admin))
172 		goto errout;
173 
174 	if (ext & (1 << (INET_DIAG_SKMEMINFO - 1))) {
175 		u32 mem[SK_MEMINFO_VARS];
176 		int amt;
177 
178 		if (asoc && asoc->ep->sndbuf_policy)
179 			amt = asoc->sndbuf_used;
180 		else
181 			amt = sk_wmem_alloc_get(sk);
182 		mem[SK_MEMINFO_WMEM_ALLOC] = amt;
183 		if (asoc && asoc->ep->rcvbuf_policy)
184 			amt = atomic_read(&asoc->rmem_alloc);
185 		else
186 			amt = sk_rmem_alloc_get(sk);
187 		mem[SK_MEMINFO_RMEM_ALLOC] = amt;
188 		mem[SK_MEMINFO_RCVBUF] = sk->sk_rcvbuf;
189 		mem[SK_MEMINFO_SNDBUF] = sk->sk_sndbuf;
190 		mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
191 		mem[SK_MEMINFO_WMEM_QUEUED] = sk->sk_wmem_queued;
192 		mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
193 		mem[SK_MEMINFO_BACKLOG] = sk->sk_backlog.len;
194 		mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
195 
196 		if (nla_put(skb, INET_DIAG_SKMEMINFO, sizeof(mem), &mem) < 0)
197 			goto errout;
198 	}
199 
200 	if (ext & (1 << (INET_DIAG_INFO - 1))) {
201 		struct nlattr *attr;
202 
203 		attr = nla_reserve_64bit(skb, INET_DIAG_INFO,
204 					 sizeof(struct sctp_info),
205 					 INET_DIAG_PAD);
206 		if (!attr)
207 			goto errout;
208 
209 		info = nla_data(attr);
210 	}
211 	infox.sctpinfo = (struct sctp_info *)info;
212 	infox.asoc = asoc;
213 	sctp_diag_get_info(sk, r, &infox);
214 
215 	addr_list = asoc ? &asoc->base.bind_addr.address_list
216 			 : &ep->base.bind_addr.address_list;
217 	if (inet_diag_msg_sctpladdrs_fill(skb, addr_list))
218 		goto errout;
219 
220 	if (asoc && (ext & (1 << (INET_DIAG_CONG - 1))))
221 		if (nla_put_string(skb, INET_DIAG_CONG, "reno") < 0)
222 			goto errout;
223 
224 	if (asoc && inet_diag_msg_sctpaddrs_fill(skb, asoc))
225 		goto errout;
226 
227 	nlmsg_end(skb, nlh);
228 	return 0;
229 
230 errout:
231 	nlmsg_cancel(skb, nlh);
232 	return -EMSGSIZE;
233 }
234 
235 /* callback and param */
236 struct sctp_comm_param {
237 	struct sk_buff *skb;
238 	struct netlink_callback *cb;
239 	const struct inet_diag_req_v2 *r;
240 	const struct nlmsghdr *nlh;
241 	bool net_admin;
242 };
243 
244 static size_t inet_assoc_attr_size(struct sctp_association *asoc)
245 {
246 	int addrlen = sizeof(struct sockaddr_storage);
247 	int addrcnt = 0;
248 	struct sctp_sockaddr_entry *laddr;
249 
250 	list_for_each_entry_rcu(laddr, &asoc->base.bind_addr.address_list,
251 				list)
252 		addrcnt++;
253 
254 	return	  nla_total_size(sizeof(struct sctp_info))
255 		+ nla_total_size(1) /* INET_DIAG_SHUTDOWN */
256 		+ nla_total_size(1) /* INET_DIAG_TOS */
257 		+ nla_total_size(1) /* INET_DIAG_TCLASS */
258 		+ nla_total_size(4) /* INET_DIAG_MARK */
259 		+ nla_total_size(4) /* INET_DIAG_CLASS_ID */
260 		+ nla_total_size(addrlen * asoc->peer.transport_count)
261 		+ nla_total_size(addrlen * addrcnt)
262 		+ nla_total_size(sizeof(struct inet_diag_meminfo))
263 		+ nla_total_size(sizeof(struct inet_diag_msg))
264 		+ 64;
265 }
266 
267 static int sctp_tsp_dump_one(struct sctp_transport *tsp, void *p)
268 {
269 	struct sctp_association *assoc = tsp->asoc;
270 	struct sock *sk = tsp->asoc->base.sk;
271 	struct sctp_comm_param *commp = p;
272 	struct sk_buff *in_skb = commp->skb;
273 	const struct inet_diag_req_v2 *req = commp->r;
274 	const struct nlmsghdr *nlh = commp->nlh;
275 	struct net *net = sock_net(in_skb->sk);
276 	struct sk_buff *rep;
277 	int err;
278 
279 	err = sock_diag_check_cookie(sk, req->id.idiag_cookie);
280 	if (err)
281 		goto out;
282 
283 	err = -ENOMEM;
284 	rep = nlmsg_new(inet_assoc_attr_size(assoc), GFP_KERNEL);
285 	if (!rep)
286 		goto out;
287 
288 	lock_sock(sk);
289 	if (sk != assoc->base.sk) {
290 		release_sock(sk);
291 		sk = assoc->base.sk;
292 		lock_sock(sk);
293 	}
294 	err = inet_sctp_diag_fill(sk, assoc, rep, req,
295 				  sk_user_ns(NETLINK_CB(in_skb).sk),
296 				  NETLINK_CB(in_skb).portid,
297 				  nlh->nlmsg_seq, 0, nlh,
298 				  commp->net_admin);
299 	release_sock(sk);
300 	if (err < 0) {
301 		WARN_ON(err == -EMSGSIZE);
302 		kfree_skb(rep);
303 		goto out;
304 	}
305 
306 	err = netlink_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid,
307 			      MSG_DONTWAIT);
308 	if (err > 0)
309 		err = 0;
310 out:
311 	return err;
312 }
313 
314 static int sctp_sock_dump(struct sctp_transport *tsp, void *p)
315 {
316 	struct sctp_endpoint *ep = tsp->asoc->ep;
317 	struct sctp_comm_param *commp = p;
318 	struct sock *sk = ep->base.sk;
319 	struct sk_buff *skb = commp->skb;
320 	struct netlink_callback *cb = commp->cb;
321 	const struct inet_diag_req_v2 *r = commp->r;
322 	struct sctp_association *assoc;
323 	int err = 0;
324 
325 	lock_sock(sk);
326 	list_for_each_entry(assoc, &ep->asocs, asocs) {
327 		if (cb->args[4] < cb->args[1])
328 			goto next;
329 
330 		if (r->id.idiag_sport != htons(assoc->base.bind_addr.port) &&
331 		    r->id.idiag_sport)
332 			goto next;
333 		if (r->id.idiag_dport != htons(assoc->peer.port) &&
334 		    r->id.idiag_dport)
335 			goto next;
336 
337 		if (!cb->args[3] &&
338 		    inet_sctp_diag_fill(sk, NULL, skb, r,
339 					sk_user_ns(NETLINK_CB(cb->skb).sk),
340 					NETLINK_CB(cb->skb).portid,
341 					cb->nlh->nlmsg_seq,
342 					NLM_F_MULTI, cb->nlh,
343 					commp->net_admin) < 0) {
344 			err = 1;
345 			goto release;
346 		}
347 		cb->args[3] = 1;
348 
349 		if (inet_sctp_diag_fill(sk, assoc, skb, r,
350 					sk_user_ns(NETLINK_CB(cb->skb).sk),
351 					NETLINK_CB(cb->skb).portid,
352 					cb->nlh->nlmsg_seq, 0, cb->nlh,
353 					commp->net_admin) < 0) {
354 			err = 1;
355 			goto release;
356 		}
357 next:
358 		cb->args[4]++;
359 	}
360 	cb->args[1] = 0;
361 	cb->args[3] = 0;
362 	cb->args[4] = 0;
363 release:
364 	release_sock(sk);
365 	return err;
366 }
367 
368 static int sctp_sock_filter(struct sctp_transport *tsp, void *p)
369 {
370 	struct sctp_endpoint *ep = tsp->asoc->ep;
371 	struct sctp_comm_param *commp = p;
372 	struct sock *sk = ep->base.sk;
373 	const struct inet_diag_req_v2 *r = commp->r;
374 	struct sctp_association *assoc =
375 		list_entry(ep->asocs.next, struct sctp_association, asocs);
376 
377 	/* find the ep only once through the transports by this condition */
378 	if (tsp->asoc != assoc)
379 		return 0;
380 
381 	if (r->sdiag_family != AF_UNSPEC && sk->sk_family != r->sdiag_family)
382 		return 0;
383 
384 	return 1;
385 }
386 
387 static int sctp_ep_dump(struct sctp_endpoint *ep, void *p)
388 {
389 	struct sctp_comm_param *commp = p;
390 	struct sock *sk = ep->base.sk;
391 	struct sk_buff *skb = commp->skb;
392 	struct netlink_callback *cb = commp->cb;
393 	const struct inet_diag_req_v2 *r = commp->r;
394 	struct net *net = sock_net(skb->sk);
395 	struct inet_sock *inet = inet_sk(sk);
396 	int err = 0;
397 
398 	if (!net_eq(sock_net(sk), net))
399 		goto out;
400 
401 	if (cb->args[4] < cb->args[1])
402 		goto next;
403 
404 	if (!(r->idiag_states & TCPF_LISTEN) && !list_empty(&ep->asocs))
405 		goto next;
406 
407 	if (r->sdiag_family != AF_UNSPEC &&
408 	    sk->sk_family != r->sdiag_family)
409 		goto next;
410 
411 	if (r->id.idiag_sport != inet->inet_sport &&
412 	    r->id.idiag_sport)
413 		goto next;
414 
415 	if (r->id.idiag_dport != inet->inet_dport &&
416 	    r->id.idiag_dport)
417 		goto next;
418 
419 	if (inet_sctp_diag_fill(sk, NULL, skb, r,
420 				sk_user_ns(NETLINK_CB(cb->skb).sk),
421 				NETLINK_CB(cb->skb).portid,
422 				cb->nlh->nlmsg_seq, NLM_F_MULTI,
423 				cb->nlh, commp->net_admin) < 0) {
424 		err = 2;
425 		goto out;
426 	}
427 next:
428 	cb->args[4]++;
429 out:
430 	return err;
431 }
432 
433 /* define the functions for sctp_diag_handler*/
434 static void sctp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
435 			       void *info)
436 {
437 	struct sctp_infox *infox = (struct sctp_infox *)info;
438 
439 	if (infox->asoc) {
440 		r->idiag_rqueue = atomic_read(&infox->asoc->rmem_alloc);
441 		r->idiag_wqueue = infox->asoc->sndbuf_used;
442 	} else {
443 		r->idiag_rqueue = sk->sk_ack_backlog;
444 		r->idiag_wqueue = sk->sk_max_ack_backlog;
445 	}
446 	if (infox->sctpinfo)
447 		sctp_get_sctp_info(sk, infox->asoc, infox->sctpinfo);
448 }
449 
450 static int sctp_diag_dump_one(struct sk_buff *in_skb,
451 			      const struct nlmsghdr *nlh,
452 			      const struct inet_diag_req_v2 *req)
453 {
454 	struct net *net = sock_net(in_skb->sk);
455 	union sctp_addr laddr, paddr;
456 	struct sctp_comm_param commp = {
457 		.skb = in_skb,
458 		.r = req,
459 		.nlh = nlh,
460 		.net_admin = netlink_net_capable(in_skb, CAP_NET_ADMIN),
461 	};
462 
463 	if (req->sdiag_family == AF_INET) {
464 		laddr.v4.sin_port = req->id.idiag_sport;
465 		laddr.v4.sin_addr.s_addr = req->id.idiag_src[0];
466 		laddr.v4.sin_family = AF_INET;
467 
468 		paddr.v4.sin_port = req->id.idiag_dport;
469 		paddr.v4.sin_addr.s_addr = req->id.idiag_dst[0];
470 		paddr.v4.sin_family = AF_INET;
471 	} else {
472 		laddr.v6.sin6_port = req->id.idiag_sport;
473 		memcpy(&laddr.v6.sin6_addr, req->id.idiag_src,
474 		       sizeof(laddr.v6.sin6_addr));
475 		laddr.v6.sin6_family = AF_INET6;
476 
477 		paddr.v6.sin6_port = req->id.idiag_dport;
478 		memcpy(&paddr.v6.sin6_addr, req->id.idiag_dst,
479 		       sizeof(paddr.v6.sin6_addr));
480 		paddr.v6.sin6_family = AF_INET6;
481 	}
482 
483 	return sctp_transport_lookup_process(sctp_tsp_dump_one,
484 					     net, &laddr, &paddr, &commp);
485 }
486 
487 static void sctp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
488 			   const struct inet_diag_req_v2 *r, struct nlattr *bc)
489 {
490 	u32 idiag_states = r->idiag_states;
491 	struct net *net = sock_net(skb->sk);
492 	struct sctp_comm_param commp = {
493 		.skb = skb,
494 		.cb = cb,
495 		.r = r,
496 		.net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN),
497 	};
498 	int pos = cb->args[2];
499 
500 	/* eps hashtable dumps
501 	 * args:
502 	 * 0 : if it will traversal listen sock
503 	 * 1 : to record the sock pos of this time's traversal
504 	 * 4 : to work as a temporary variable to traversal list
505 	 */
506 	if (cb->args[0] == 0) {
507 		if (!(idiag_states & TCPF_LISTEN))
508 			goto skip;
509 		if (sctp_for_each_endpoint(sctp_ep_dump, &commp))
510 			goto done;
511 skip:
512 		cb->args[0] = 1;
513 		cb->args[1] = 0;
514 		cb->args[4] = 0;
515 	}
516 
517 	/* asocs by transport hashtable dump
518 	 * args:
519 	 * 1 : to record the assoc pos of this time's traversal
520 	 * 2 : to record the transport pos of this time's traversal
521 	 * 3 : to mark if we have dumped the ep info of the current asoc
522 	 * 4 : to work as a temporary variable to traversal list
523 	 * 5 : to save the sk we get from travelsing the tsp list.
524 	 */
525 	if (!(idiag_states & ~(TCPF_LISTEN | TCPF_CLOSE)))
526 		goto done;
527 
528 	sctp_for_each_transport(sctp_sock_filter, sctp_sock_dump,
529 				net, &pos, &commp);
530 	cb->args[2] = pos;
531 
532 done:
533 	cb->args[1] = cb->args[4];
534 	cb->args[4] = 0;
535 }
536 
537 static const struct inet_diag_handler sctp_diag_handler = {
538 	.dump		 = sctp_diag_dump,
539 	.dump_one	 = sctp_diag_dump_one,
540 	.idiag_get_info  = sctp_diag_get_info,
541 	.idiag_type	 = IPPROTO_SCTP,
542 	.idiag_info_size = sizeof(struct sctp_info),
543 };
544 
545 static int __init sctp_diag_init(void)
546 {
547 	return inet_diag_register(&sctp_diag_handler);
548 }
549 
550 static void __exit sctp_diag_exit(void)
551 {
552 	inet_diag_unregister(&sctp_diag_handler);
553 }
554 
555 module_init(sctp_diag_init);
556 module_exit(sctp_diag_exit);
557 MODULE_LICENSE("GPL");
558 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-132);
559