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