xref: /openbmc/linux/net/sctp/diag.c (revision e29dc460)
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(addrlen * asoc->peer.transport_count)
260 		+ nla_total_size(addrlen * addrcnt)
261 		+ nla_total_size(sizeof(struct inet_diag_meminfo))
262 		+ nla_total_size(sizeof(struct inet_diag_msg))
263 		+ 64;
264 }
265 
266 static int sctp_tsp_dump_one(struct sctp_transport *tsp, void *p)
267 {
268 	struct sctp_association *assoc = tsp->asoc;
269 	struct sock *sk = tsp->asoc->base.sk;
270 	struct sctp_comm_param *commp = p;
271 	struct sk_buff *in_skb = commp->skb;
272 	const struct inet_diag_req_v2 *req = commp->r;
273 	const struct nlmsghdr *nlh = commp->nlh;
274 	struct net *net = sock_net(in_skb->sk);
275 	struct sk_buff *rep;
276 	int err;
277 
278 	err = sock_diag_check_cookie(sk, req->id.idiag_cookie);
279 	if (err)
280 		goto out;
281 
282 	err = -ENOMEM;
283 	rep = nlmsg_new(inet_assoc_attr_size(assoc), GFP_KERNEL);
284 	if (!rep)
285 		goto out;
286 
287 	lock_sock(sk);
288 	if (sk != assoc->base.sk) {
289 		release_sock(sk);
290 		sk = assoc->base.sk;
291 		lock_sock(sk);
292 	}
293 	err = inet_sctp_diag_fill(sk, assoc, rep, req,
294 				  sk_user_ns(NETLINK_CB(in_skb).sk),
295 				  NETLINK_CB(in_skb).portid,
296 				  nlh->nlmsg_seq, 0, nlh,
297 				  commp->net_admin);
298 	release_sock(sk);
299 	if (err < 0) {
300 		WARN_ON(err == -EMSGSIZE);
301 		kfree_skb(rep);
302 		goto out;
303 	}
304 
305 	err = netlink_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid,
306 			      MSG_DONTWAIT);
307 	if (err > 0)
308 		err = 0;
309 out:
310 	return err;
311 }
312 
313 static int sctp_sock_dump(struct sctp_transport *tsp, void *p)
314 {
315 	struct sctp_endpoint *ep = tsp->asoc->ep;
316 	struct sctp_comm_param *commp = p;
317 	struct sock *sk = ep->base.sk;
318 	struct sk_buff *skb = commp->skb;
319 	struct netlink_callback *cb = commp->cb;
320 	const struct inet_diag_req_v2 *r = commp->r;
321 	struct sctp_association *assoc;
322 	int err = 0;
323 
324 	lock_sock(sk);
325 	list_for_each_entry(assoc, &ep->asocs, asocs) {
326 		if (cb->args[4] < cb->args[1])
327 			goto next;
328 
329 		if (r->id.idiag_sport != htons(assoc->base.bind_addr.port) &&
330 		    r->id.idiag_sport)
331 			goto next;
332 		if (r->id.idiag_dport != htons(assoc->peer.port) &&
333 		    r->id.idiag_dport)
334 			goto next;
335 
336 		if (!cb->args[3] &&
337 		    inet_sctp_diag_fill(sk, NULL, skb, r,
338 					sk_user_ns(NETLINK_CB(cb->skb).sk),
339 					NETLINK_CB(cb->skb).portid,
340 					cb->nlh->nlmsg_seq,
341 					NLM_F_MULTI, cb->nlh,
342 					commp->net_admin) < 0) {
343 			err = 1;
344 			goto release;
345 		}
346 		cb->args[3] = 1;
347 
348 		if (inet_sctp_diag_fill(sk, assoc, skb, r,
349 					sk_user_ns(NETLINK_CB(cb->skb).sk),
350 					NETLINK_CB(cb->skb).portid,
351 					cb->nlh->nlmsg_seq, 0, cb->nlh,
352 					commp->net_admin) < 0) {
353 			err = 1;
354 			goto release;
355 		}
356 next:
357 		cb->args[4]++;
358 	}
359 	cb->args[1] = 0;
360 	cb->args[3] = 0;
361 	cb->args[4] = 0;
362 release:
363 	release_sock(sk);
364 	return err;
365 }
366 
367 static int sctp_sock_filter(struct sctp_transport *tsp, void *p)
368 {
369 	struct sctp_endpoint *ep = tsp->asoc->ep;
370 	struct sctp_comm_param *commp = p;
371 	struct sock *sk = ep->base.sk;
372 	const struct inet_diag_req_v2 *r = commp->r;
373 	struct sctp_association *assoc =
374 		list_entry(ep->asocs.next, struct sctp_association, asocs);
375 
376 	/* find the ep only once through the transports by this condition */
377 	if (tsp->asoc != assoc)
378 		return 0;
379 
380 	if (r->sdiag_family != AF_UNSPEC && sk->sk_family != r->sdiag_family)
381 		return 0;
382 
383 	return 1;
384 }
385 
386 static int sctp_ep_dump(struct sctp_endpoint *ep, void *p)
387 {
388 	struct sctp_comm_param *commp = p;
389 	struct sock *sk = ep->base.sk;
390 	struct sk_buff *skb = commp->skb;
391 	struct netlink_callback *cb = commp->cb;
392 	const struct inet_diag_req_v2 *r = commp->r;
393 	struct net *net = sock_net(skb->sk);
394 	struct inet_sock *inet = inet_sk(sk);
395 	int err = 0;
396 
397 	if (!net_eq(sock_net(sk), net))
398 		goto out;
399 
400 	if (cb->args[4] < cb->args[1])
401 		goto next;
402 
403 	if (!(r->idiag_states & TCPF_LISTEN) && !list_empty(&ep->asocs))
404 		goto next;
405 
406 	if (r->sdiag_family != AF_UNSPEC &&
407 	    sk->sk_family != r->sdiag_family)
408 		goto next;
409 
410 	if (r->id.idiag_sport != inet->inet_sport &&
411 	    r->id.idiag_sport)
412 		goto next;
413 
414 	if (r->id.idiag_dport != inet->inet_dport &&
415 	    r->id.idiag_dport)
416 		goto next;
417 
418 	if (inet_sctp_diag_fill(sk, NULL, skb, r,
419 				sk_user_ns(NETLINK_CB(cb->skb).sk),
420 				NETLINK_CB(cb->skb).portid,
421 				cb->nlh->nlmsg_seq, NLM_F_MULTI,
422 				cb->nlh, commp->net_admin) < 0) {
423 		err = 2;
424 		goto out;
425 	}
426 next:
427 	cb->args[4]++;
428 out:
429 	return err;
430 }
431 
432 /* define the functions for sctp_diag_handler*/
433 static void sctp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
434 			       void *info)
435 {
436 	struct sctp_infox *infox = (struct sctp_infox *)info;
437 
438 	if (infox->asoc) {
439 		r->idiag_rqueue = atomic_read(&infox->asoc->rmem_alloc);
440 		r->idiag_wqueue = infox->asoc->sndbuf_used;
441 	} else {
442 		r->idiag_rqueue = sk->sk_ack_backlog;
443 		r->idiag_wqueue = sk->sk_max_ack_backlog;
444 	}
445 	if (infox->sctpinfo)
446 		sctp_get_sctp_info(sk, infox->asoc, infox->sctpinfo);
447 }
448 
449 static int sctp_diag_dump_one(struct sk_buff *in_skb,
450 			      const struct nlmsghdr *nlh,
451 			      const struct inet_diag_req_v2 *req)
452 {
453 	struct net *net = sock_net(in_skb->sk);
454 	union sctp_addr laddr, paddr;
455 	struct sctp_comm_param commp = {
456 		.skb = in_skb,
457 		.r = req,
458 		.nlh = nlh,
459 		.net_admin = netlink_net_capable(in_skb, CAP_NET_ADMIN),
460 	};
461 
462 	if (req->sdiag_family == AF_INET) {
463 		laddr.v4.sin_port = req->id.idiag_sport;
464 		laddr.v4.sin_addr.s_addr = req->id.idiag_src[0];
465 		laddr.v4.sin_family = AF_INET;
466 
467 		paddr.v4.sin_port = req->id.idiag_dport;
468 		paddr.v4.sin_addr.s_addr = req->id.idiag_dst[0];
469 		paddr.v4.sin_family = AF_INET;
470 	} else {
471 		laddr.v6.sin6_port = req->id.idiag_sport;
472 		memcpy(&laddr.v6.sin6_addr, req->id.idiag_src,
473 		       sizeof(laddr.v6.sin6_addr));
474 		laddr.v6.sin6_family = AF_INET6;
475 
476 		paddr.v6.sin6_port = req->id.idiag_dport;
477 		memcpy(&paddr.v6.sin6_addr, req->id.idiag_dst,
478 		       sizeof(paddr.v6.sin6_addr));
479 		paddr.v6.sin6_family = AF_INET6;
480 	}
481 
482 	return sctp_transport_lookup_process(sctp_tsp_dump_one,
483 					     net, &laddr, &paddr, &commp);
484 }
485 
486 static void sctp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
487 			   const struct inet_diag_req_v2 *r, struct nlattr *bc)
488 {
489 	u32 idiag_states = r->idiag_states;
490 	struct net *net = sock_net(skb->sk);
491 	struct sctp_comm_param commp = {
492 		.skb = skb,
493 		.cb = cb,
494 		.r = r,
495 		.net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN),
496 	};
497 	int pos = cb->args[2];
498 
499 	/* eps hashtable dumps
500 	 * args:
501 	 * 0 : if it will traversal listen sock
502 	 * 1 : to record the sock pos of this time's traversal
503 	 * 4 : to work as a temporary variable to traversal list
504 	 */
505 	if (cb->args[0] == 0) {
506 		if (!(idiag_states & TCPF_LISTEN))
507 			goto skip;
508 		if (sctp_for_each_endpoint(sctp_ep_dump, &commp))
509 			goto done;
510 skip:
511 		cb->args[0] = 1;
512 		cb->args[1] = 0;
513 		cb->args[4] = 0;
514 	}
515 
516 	/* asocs by transport hashtable dump
517 	 * args:
518 	 * 1 : to record the assoc pos of this time's traversal
519 	 * 2 : to record the transport pos of this time's traversal
520 	 * 3 : to mark if we have dumped the ep info of the current asoc
521 	 * 4 : to work as a temporary variable to traversal list
522 	 * 5 : to save the sk we get from travelsing the tsp list.
523 	 */
524 	if (!(idiag_states & ~(TCPF_LISTEN | TCPF_CLOSE)))
525 		goto done;
526 
527 	sctp_for_each_transport(sctp_sock_filter, sctp_sock_dump,
528 				net, &pos, &commp);
529 	cb->args[2] = pos;
530 
531 done:
532 	cb->args[1] = cb->args[4];
533 	cb->args[4] = 0;
534 }
535 
536 static const struct inet_diag_handler sctp_diag_handler = {
537 	.dump		 = sctp_diag_dump,
538 	.dump_one	 = sctp_diag_dump_one,
539 	.idiag_get_info  = sctp_diag_get_info,
540 	.idiag_type	 = IPPROTO_SCTP,
541 	.idiag_info_size = sizeof(struct sctp_info),
542 };
543 
544 static int __init sctp_diag_init(void)
545 {
546 	return inet_diag_register(&sctp_diag_handler);
547 }
548 
549 static void __exit sctp_diag_exit(void)
550 {
551 	inet_diag_unregister(&sctp_diag_handler);
552 }
553 
554 module_init(sctp_diag_init);
555 module_exit(sctp_diag_exit);
556 MODULE_LICENSE("GPL");
557 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-132);
558