diag.c

  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
 22static 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 */
 26static 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
 67static 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
100static 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*/
126static 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
219errout:
220	nlmsg_cancel(skb, nlh);
221	return -EMSGSIZE;
222}
223
224/* callback and param */
225struct 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
233static 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
253static 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
291out:
292	release_sock(sk);
293	kfree_skb(rep);
294	return err;
295}
296
297static 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		}
341next:
342		cb->args[4]++;
343	}
344	cb->args[1] = 0;
345	cb->args[3] = 0;
346	cb->args[4] = 0;
347release:
348	release_sock(sk);
349	return err;
350}
351
352static 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
368static 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	}
408next:
409	cb->args[4]++;
410out:
411	return err;
412}
413
414/* define the functions for sctp_diag_handler*/
415static 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
431static 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
470static 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;
494skip:
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
515done:
516	cb->args[1] = cb->args[4];
517	cb->args[4] = 0;
518}
519
520static 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
529static int __init sctp_diag_init(void)
530{
531	return inet_diag_register(&sctp_diag_handler);
532}
533
534static void __exit sctp_diag_exit(void)
535{
536	inet_diag_unregister(&sctp_diag_handler);
537}
538
539module_init(sctp_diag_init);
540module_exit(sctp_diag_exit);
541MODULE_LICENSE("GPL");
542MODULE_DESCRIPTION("SCTP socket monitoring via SOCK_DIAG");
543MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-132);