xref: /openbmc/linux/net/ipv4/inet_diag.c (revision a06c488d)
1 /*
2  * inet_diag.c	Module for monitoring INET transport protocols sockets.
3  *
4  * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
5  *
6  *	This program is free software; you can redistribute it and/or
7  *      modify it under the terms of the GNU General Public License
8  *      as published by the Free Software Foundation; either version
9  *      2 of the License, or (at your option) any later version.
10  */
11 
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/types.h>
15 #include <linux/fcntl.h>
16 #include <linux/random.h>
17 #include <linux/slab.h>
18 #include <linux/cache.h>
19 #include <linux/init.h>
20 #include <linux/time.h>
21 
22 #include <net/icmp.h>
23 #include <net/tcp.h>
24 #include <net/ipv6.h>
25 #include <net/inet_common.h>
26 #include <net/inet_connection_sock.h>
27 #include <net/inet_hashtables.h>
28 #include <net/inet_timewait_sock.h>
29 #include <net/inet6_hashtables.h>
30 #include <net/netlink.h>
31 
32 #include <linux/inet.h>
33 #include <linux/stddef.h>
34 
35 #include <linux/inet_diag.h>
36 #include <linux/sock_diag.h>
37 
38 static const struct inet_diag_handler **inet_diag_table;
39 
40 struct inet_diag_entry {
41 	const __be32 *saddr;
42 	const __be32 *daddr;
43 	u16 sport;
44 	u16 dport;
45 	u16 family;
46 	u16 userlocks;
47 };
48 
49 static DEFINE_MUTEX(inet_diag_table_mutex);
50 
51 static const struct inet_diag_handler *inet_diag_lock_handler(int proto)
52 {
53 	if (!inet_diag_table[proto])
54 		request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
55 			       NETLINK_SOCK_DIAG, AF_INET, proto);
56 
57 	mutex_lock(&inet_diag_table_mutex);
58 	if (!inet_diag_table[proto])
59 		return ERR_PTR(-ENOENT);
60 
61 	return inet_diag_table[proto];
62 }
63 
64 static void inet_diag_unlock_handler(const struct inet_diag_handler *handler)
65 {
66 	mutex_unlock(&inet_diag_table_mutex);
67 }
68 
69 static void inet_diag_msg_common_fill(struct inet_diag_msg *r, struct sock *sk)
70 {
71 	r->idiag_family = sk->sk_family;
72 
73 	r->id.idiag_sport = htons(sk->sk_num);
74 	r->id.idiag_dport = sk->sk_dport;
75 	r->id.idiag_if = sk->sk_bound_dev_if;
76 	sock_diag_save_cookie(sk, r->id.idiag_cookie);
77 
78 #if IS_ENABLED(CONFIG_IPV6)
79 	if (sk->sk_family == AF_INET6) {
80 		*(struct in6_addr *)r->id.idiag_src = sk->sk_v6_rcv_saddr;
81 		*(struct in6_addr *)r->id.idiag_dst = sk->sk_v6_daddr;
82 	} else
83 #endif
84 	{
85 	memset(&r->id.idiag_src, 0, sizeof(r->id.idiag_src));
86 	memset(&r->id.idiag_dst, 0, sizeof(r->id.idiag_dst));
87 
88 	r->id.idiag_src[0] = sk->sk_rcv_saddr;
89 	r->id.idiag_dst[0] = sk->sk_daddr;
90 	}
91 }
92 
93 static size_t inet_sk_attr_size(void)
94 {
95 	return	  nla_total_size(sizeof(struct tcp_info))
96 		+ nla_total_size(1) /* INET_DIAG_SHUTDOWN */
97 		+ nla_total_size(1) /* INET_DIAG_TOS */
98 		+ nla_total_size(1) /* INET_DIAG_TCLASS */
99 		+ nla_total_size(sizeof(struct inet_diag_meminfo))
100 		+ nla_total_size(sizeof(struct inet_diag_msg))
101 		+ nla_total_size(SK_MEMINFO_VARS * sizeof(u32))
102 		+ nla_total_size(TCP_CA_NAME_MAX)
103 		+ nla_total_size(sizeof(struct tcpvegas_info))
104 		+ 64;
105 }
106 
107 int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk,
108 		      struct sk_buff *skb, const struct inet_diag_req_v2 *req,
109 		      struct user_namespace *user_ns,
110 		      u32 portid, u32 seq, u16 nlmsg_flags,
111 		      const struct nlmsghdr *unlh)
112 {
113 	const struct inet_sock *inet = inet_sk(sk);
114 	const struct tcp_congestion_ops *ca_ops;
115 	const struct inet_diag_handler *handler;
116 	int ext = req->idiag_ext;
117 	struct inet_diag_msg *r;
118 	struct nlmsghdr  *nlh;
119 	struct nlattr *attr;
120 	void *info = NULL;
121 
122 	handler = inet_diag_table[req->sdiag_protocol];
123 	BUG_ON(!handler);
124 
125 	nlh = nlmsg_put(skb, portid, seq, unlh->nlmsg_type, sizeof(*r),
126 			nlmsg_flags);
127 	if (!nlh)
128 		return -EMSGSIZE;
129 
130 	r = nlmsg_data(nlh);
131 	BUG_ON(!sk_fullsock(sk));
132 
133 	inet_diag_msg_common_fill(r, sk);
134 	r->idiag_state = sk->sk_state;
135 	r->idiag_timer = 0;
136 	r->idiag_retrans = 0;
137 
138 	if (nla_put_u8(skb, INET_DIAG_SHUTDOWN, sk->sk_shutdown))
139 		goto errout;
140 
141 	/* IPv6 dual-stack sockets use inet->tos for IPv4 connections,
142 	 * hence this needs to be included regardless of socket family.
143 	 */
144 	if (ext & (1 << (INET_DIAG_TOS - 1)))
145 		if (nla_put_u8(skb, INET_DIAG_TOS, inet->tos) < 0)
146 			goto errout;
147 
148 #if IS_ENABLED(CONFIG_IPV6)
149 	if (r->idiag_family == AF_INET6) {
150 		if (ext & (1 << (INET_DIAG_TCLASS - 1)))
151 			if (nla_put_u8(skb, INET_DIAG_TCLASS,
152 				       inet6_sk(sk)->tclass) < 0)
153 				goto errout;
154 
155 		if (((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) &&
156 		    nla_put_u8(skb, INET_DIAG_SKV6ONLY, ipv6_only_sock(sk)))
157 			goto errout;
158 	}
159 #endif
160 
161 	r->idiag_uid = from_kuid_munged(user_ns, sock_i_uid(sk));
162 	r->idiag_inode = sock_i_ino(sk);
163 
164 	if (ext & (1 << (INET_DIAG_MEMINFO - 1))) {
165 		struct inet_diag_meminfo minfo = {
166 			.idiag_rmem = sk_rmem_alloc_get(sk),
167 			.idiag_wmem = sk->sk_wmem_queued,
168 			.idiag_fmem = sk->sk_forward_alloc,
169 			.idiag_tmem = sk_wmem_alloc_get(sk),
170 		};
171 
172 		if (nla_put(skb, INET_DIAG_MEMINFO, sizeof(minfo), &minfo) < 0)
173 			goto errout;
174 	}
175 
176 	if (ext & (1 << (INET_DIAG_SKMEMINFO - 1)))
177 		if (sock_diag_put_meminfo(sk, skb, INET_DIAG_SKMEMINFO))
178 			goto errout;
179 
180 	if (!icsk) {
181 		handler->idiag_get_info(sk, r, NULL);
182 		goto out;
183 	}
184 
185 #define EXPIRES_IN_MS(tmo)  DIV_ROUND_UP((tmo - jiffies) * 1000, HZ)
186 
187 	if (icsk->icsk_pending == ICSK_TIME_RETRANS ||
188 	    icsk->icsk_pending == ICSK_TIME_EARLY_RETRANS ||
189 	    icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) {
190 		r->idiag_timer = 1;
191 		r->idiag_retrans = icsk->icsk_retransmits;
192 		r->idiag_expires = EXPIRES_IN_MS(icsk->icsk_timeout);
193 	} else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
194 		r->idiag_timer = 4;
195 		r->idiag_retrans = icsk->icsk_probes_out;
196 		r->idiag_expires = EXPIRES_IN_MS(icsk->icsk_timeout);
197 	} else if (timer_pending(&sk->sk_timer)) {
198 		r->idiag_timer = 2;
199 		r->idiag_retrans = icsk->icsk_probes_out;
200 		r->idiag_expires = EXPIRES_IN_MS(sk->sk_timer.expires);
201 	} else {
202 		r->idiag_timer = 0;
203 		r->idiag_expires = 0;
204 	}
205 #undef EXPIRES_IN_MS
206 
207 	if ((ext & (1 << (INET_DIAG_INFO - 1))) && handler->idiag_info_size) {
208 		attr = nla_reserve(skb, INET_DIAG_INFO,
209 				   handler->idiag_info_size);
210 		if (!attr)
211 			goto errout;
212 
213 		info = nla_data(attr);
214 	}
215 
216 	if (ext & (1 << (INET_DIAG_CONG - 1))) {
217 		int err = 0;
218 
219 		rcu_read_lock();
220 		ca_ops = READ_ONCE(icsk->icsk_ca_ops);
221 		if (ca_ops)
222 			err = nla_put_string(skb, INET_DIAG_CONG, ca_ops->name);
223 		rcu_read_unlock();
224 		if (err < 0)
225 			goto errout;
226 	}
227 
228 	handler->idiag_get_info(sk, r, info);
229 
230 	if (sk->sk_state < TCP_TIME_WAIT) {
231 		union tcp_cc_info info;
232 		size_t sz = 0;
233 		int attr;
234 
235 		rcu_read_lock();
236 		ca_ops = READ_ONCE(icsk->icsk_ca_ops);
237 		if (ca_ops && ca_ops->get_info)
238 			sz = ca_ops->get_info(sk, ext, &attr, &info);
239 		rcu_read_unlock();
240 		if (sz && nla_put(skb, attr, sz, &info) < 0)
241 			goto errout;
242 	}
243 
244 out:
245 	nlmsg_end(skb, nlh);
246 	return 0;
247 
248 errout:
249 	nlmsg_cancel(skb, nlh);
250 	return -EMSGSIZE;
251 }
252 EXPORT_SYMBOL_GPL(inet_sk_diag_fill);
253 
254 static int inet_csk_diag_fill(struct sock *sk,
255 			      struct sk_buff *skb,
256 			      const struct inet_diag_req_v2 *req,
257 			      struct user_namespace *user_ns,
258 			      u32 portid, u32 seq, u16 nlmsg_flags,
259 			      const struct nlmsghdr *unlh)
260 {
261 	return inet_sk_diag_fill(sk, inet_csk(sk), skb, req,
262 				 user_ns, portid, seq, nlmsg_flags, unlh);
263 }
264 
265 static int inet_twsk_diag_fill(struct sock *sk,
266 			       struct sk_buff *skb,
267 			       u32 portid, u32 seq, u16 nlmsg_flags,
268 			       const struct nlmsghdr *unlh)
269 {
270 	struct inet_timewait_sock *tw = inet_twsk(sk);
271 	struct inet_diag_msg *r;
272 	struct nlmsghdr *nlh;
273 	long tmo;
274 
275 	nlh = nlmsg_put(skb, portid, seq, unlh->nlmsg_type, sizeof(*r),
276 			nlmsg_flags);
277 	if (!nlh)
278 		return -EMSGSIZE;
279 
280 	r = nlmsg_data(nlh);
281 	BUG_ON(tw->tw_state != TCP_TIME_WAIT);
282 
283 	tmo = tw->tw_timer.expires - jiffies;
284 	if (tmo < 0)
285 		tmo = 0;
286 
287 	inet_diag_msg_common_fill(r, sk);
288 	r->idiag_retrans      = 0;
289 
290 	r->idiag_state	      = tw->tw_substate;
291 	r->idiag_timer	      = 3;
292 	r->idiag_expires      = jiffies_to_msecs(tmo);
293 	r->idiag_rqueue	      = 0;
294 	r->idiag_wqueue	      = 0;
295 	r->idiag_uid	      = 0;
296 	r->idiag_inode	      = 0;
297 
298 	nlmsg_end(skb, nlh);
299 	return 0;
300 }
301 
302 static int inet_req_diag_fill(struct sock *sk, struct sk_buff *skb,
303 			      u32 portid, u32 seq, u16 nlmsg_flags,
304 			      const struct nlmsghdr *unlh)
305 {
306 	struct inet_diag_msg *r;
307 	struct nlmsghdr *nlh;
308 	long tmo;
309 
310 	nlh = nlmsg_put(skb, portid, seq, unlh->nlmsg_type, sizeof(*r),
311 			nlmsg_flags);
312 	if (!nlh)
313 		return -EMSGSIZE;
314 
315 	r = nlmsg_data(nlh);
316 	inet_diag_msg_common_fill(r, sk);
317 	r->idiag_state = TCP_SYN_RECV;
318 	r->idiag_timer = 1;
319 	r->idiag_retrans = inet_reqsk(sk)->num_retrans;
320 
321 	BUILD_BUG_ON(offsetof(struct inet_request_sock, ir_cookie) !=
322 		     offsetof(struct sock, sk_cookie));
323 
324 	tmo = inet_reqsk(sk)->rsk_timer.expires - jiffies;
325 	r->idiag_expires = (tmo >= 0) ? jiffies_to_msecs(tmo) : 0;
326 	r->idiag_rqueue	= 0;
327 	r->idiag_wqueue	= 0;
328 	r->idiag_uid	= 0;
329 	r->idiag_inode	= 0;
330 
331 	nlmsg_end(skb, nlh);
332 	return 0;
333 }
334 
335 static int sk_diag_fill(struct sock *sk, struct sk_buff *skb,
336 			const struct inet_diag_req_v2 *r,
337 			struct user_namespace *user_ns,
338 			u32 portid, u32 seq, u16 nlmsg_flags,
339 			const struct nlmsghdr *unlh)
340 {
341 	if (sk->sk_state == TCP_TIME_WAIT)
342 		return inet_twsk_diag_fill(sk, skb, portid, seq,
343 					   nlmsg_flags, unlh);
344 
345 	if (sk->sk_state == TCP_NEW_SYN_RECV)
346 		return inet_req_diag_fill(sk, skb, portid, seq,
347 					  nlmsg_flags, unlh);
348 
349 	return inet_csk_diag_fill(sk, skb, r, user_ns, portid, seq,
350 				  nlmsg_flags, unlh);
351 }
352 
353 struct sock *inet_diag_find_one_icsk(struct net *net,
354 				     struct inet_hashinfo *hashinfo,
355 				     const struct inet_diag_req_v2 *req)
356 {
357 	struct sock *sk;
358 
359 	if (req->sdiag_family == AF_INET)
360 		sk = inet_lookup(net, hashinfo, req->id.idiag_dst[0],
361 				 req->id.idiag_dport, req->id.idiag_src[0],
362 				 req->id.idiag_sport, req->id.idiag_if);
363 #if IS_ENABLED(CONFIG_IPV6)
364 	else if (req->sdiag_family == AF_INET6)
365 		sk = inet6_lookup(net, hashinfo,
366 				  (struct in6_addr *)req->id.idiag_dst,
367 				  req->id.idiag_dport,
368 				  (struct in6_addr *)req->id.idiag_src,
369 				  req->id.idiag_sport,
370 				  req->id.idiag_if);
371 #endif
372 	else
373 		return ERR_PTR(-EINVAL);
374 
375 	if (!sk)
376 		return ERR_PTR(-ENOENT);
377 
378 	if (sock_diag_check_cookie(sk, req->id.idiag_cookie)) {
379 		sock_gen_put(sk);
380 		return ERR_PTR(-ENOENT);
381 	}
382 
383 	return sk;
384 }
385 EXPORT_SYMBOL_GPL(inet_diag_find_one_icsk);
386 
387 int inet_diag_dump_one_icsk(struct inet_hashinfo *hashinfo,
388 			    struct sk_buff *in_skb,
389 			    const struct nlmsghdr *nlh,
390 			    const struct inet_diag_req_v2 *req)
391 {
392 	struct net *net = sock_net(in_skb->sk);
393 	struct sk_buff *rep;
394 	struct sock *sk;
395 	int err;
396 
397 	sk = inet_diag_find_one_icsk(net, hashinfo, req);
398 	if (IS_ERR(sk))
399 		return PTR_ERR(sk);
400 
401 	rep = nlmsg_new(inet_sk_attr_size(), GFP_KERNEL);
402 	if (!rep) {
403 		err = -ENOMEM;
404 		goto out;
405 	}
406 
407 	err = sk_diag_fill(sk, rep, req,
408 			   sk_user_ns(NETLINK_CB(in_skb).sk),
409 			   NETLINK_CB(in_skb).portid,
410 			   nlh->nlmsg_seq, 0, nlh);
411 	if (err < 0) {
412 		WARN_ON(err == -EMSGSIZE);
413 		nlmsg_free(rep);
414 		goto out;
415 	}
416 	err = netlink_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid,
417 			      MSG_DONTWAIT);
418 	if (err > 0)
419 		err = 0;
420 
421 out:
422 	if (sk)
423 		sock_gen_put(sk);
424 
425 	return err;
426 }
427 EXPORT_SYMBOL_GPL(inet_diag_dump_one_icsk);
428 
429 static int inet_diag_cmd_exact(int cmd, struct sk_buff *in_skb,
430 			       const struct nlmsghdr *nlh,
431 			       const struct inet_diag_req_v2 *req)
432 {
433 	const struct inet_diag_handler *handler;
434 	int err;
435 
436 	handler = inet_diag_lock_handler(req->sdiag_protocol);
437 	if (IS_ERR(handler))
438 		err = PTR_ERR(handler);
439 	else if (cmd == SOCK_DIAG_BY_FAMILY)
440 		err = handler->dump_one(in_skb, nlh, req);
441 	else if (cmd == SOCK_DESTROY && handler->destroy)
442 		err = handler->destroy(in_skb, req);
443 	else
444 		err = -EOPNOTSUPP;
445 	inet_diag_unlock_handler(handler);
446 
447 	return err;
448 }
449 
450 static int bitstring_match(const __be32 *a1, const __be32 *a2, int bits)
451 {
452 	int words = bits >> 5;
453 
454 	bits &= 0x1f;
455 
456 	if (words) {
457 		if (memcmp(a1, a2, words << 2))
458 			return 0;
459 	}
460 	if (bits) {
461 		__be32 w1, w2;
462 		__be32 mask;
463 
464 		w1 = a1[words];
465 		w2 = a2[words];
466 
467 		mask = htonl((0xffffffff) << (32 - bits));
468 
469 		if ((w1 ^ w2) & mask)
470 			return 0;
471 	}
472 
473 	return 1;
474 }
475 
476 static int inet_diag_bc_run(const struct nlattr *_bc,
477 			    const struct inet_diag_entry *entry)
478 {
479 	const void *bc = nla_data(_bc);
480 	int len = nla_len(_bc);
481 
482 	while (len > 0) {
483 		int yes = 1;
484 		const struct inet_diag_bc_op *op = bc;
485 
486 		switch (op->code) {
487 		case INET_DIAG_BC_NOP:
488 			break;
489 		case INET_DIAG_BC_JMP:
490 			yes = 0;
491 			break;
492 		case INET_DIAG_BC_S_GE:
493 			yes = entry->sport >= op[1].no;
494 			break;
495 		case INET_DIAG_BC_S_LE:
496 			yes = entry->sport <= op[1].no;
497 			break;
498 		case INET_DIAG_BC_D_GE:
499 			yes = entry->dport >= op[1].no;
500 			break;
501 		case INET_DIAG_BC_D_LE:
502 			yes = entry->dport <= op[1].no;
503 			break;
504 		case INET_DIAG_BC_AUTO:
505 			yes = !(entry->userlocks & SOCK_BINDPORT_LOCK);
506 			break;
507 		case INET_DIAG_BC_S_COND:
508 		case INET_DIAG_BC_D_COND: {
509 			const struct inet_diag_hostcond *cond;
510 			const __be32 *addr;
511 
512 			cond = (const struct inet_diag_hostcond *)(op + 1);
513 			if (cond->port != -1 &&
514 			    cond->port != (op->code == INET_DIAG_BC_S_COND ?
515 					     entry->sport : entry->dport)) {
516 				yes = 0;
517 				break;
518 			}
519 
520 			if (op->code == INET_DIAG_BC_S_COND)
521 				addr = entry->saddr;
522 			else
523 				addr = entry->daddr;
524 
525 			if (cond->family != AF_UNSPEC &&
526 			    cond->family != entry->family) {
527 				if (entry->family == AF_INET6 &&
528 				    cond->family == AF_INET) {
529 					if (addr[0] == 0 && addr[1] == 0 &&
530 					    addr[2] == htonl(0xffff) &&
531 					    bitstring_match(addr + 3,
532 							    cond->addr,
533 							    cond->prefix_len))
534 						break;
535 				}
536 				yes = 0;
537 				break;
538 			}
539 
540 			if (cond->prefix_len == 0)
541 				break;
542 			if (bitstring_match(addr, cond->addr,
543 					    cond->prefix_len))
544 				break;
545 			yes = 0;
546 			break;
547 		}
548 		}
549 
550 		if (yes) {
551 			len -= op->yes;
552 			bc += op->yes;
553 		} else {
554 			len -= op->no;
555 			bc += op->no;
556 		}
557 	}
558 	return len == 0;
559 }
560 
561 /* This helper is available for all sockets (ESTABLISH, TIMEWAIT, SYN_RECV)
562  */
563 static void entry_fill_addrs(struct inet_diag_entry *entry,
564 			     const struct sock *sk)
565 {
566 #if IS_ENABLED(CONFIG_IPV6)
567 	if (sk->sk_family == AF_INET6) {
568 		entry->saddr = sk->sk_v6_rcv_saddr.s6_addr32;
569 		entry->daddr = sk->sk_v6_daddr.s6_addr32;
570 	} else
571 #endif
572 	{
573 		entry->saddr = &sk->sk_rcv_saddr;
574 		entry->daddr = &sk->sk_daddr;
575 	}
576 }
577 
578 int inet_diag_bc_sk(const struct nlattr *bc, struct sock *sk)
579 {
580 	struct inet_sock *inet = inet_sk(sk);
581 	struct inet_diag_entry entry;
582 
583 	if (!bc)
584 		return 1;
585 
586 	entry.family = sk->sk_family;
587 	entry_fill_addrs(&entry, sk);
588 	entry.sport = inet->inet_num;
589 	entry.dport = ntohs(inet->inet_dport);
590 	entry.userlocks = sk_fullsock(sk) ? sk->sk_userlocks : 0;
591 
592 	return inet_diag_bc_run(bc, &entry);
593 }
594 EXPORT_SYMBOL_GPL(inet_diag_bc_sk);
595 
596 static int valid_cc(const void *bc, int len, int cc)
597 {
598 	while (len >= 0) {
599 		const struct inet_diag_bc_op *op = bc;
600 
601 		if (cc > len)
602 			return 0;
603 		if (cc == len)
604 			return 1;
605 		if (op->yes < 4 || op->yes & 3)
606 			return 0;
607 		len -= op->yes;
608 		bc  += op->yes;
609 	}
610 	return 0;
611 }
612 
613 /* Validate an inet_diag_hostcond. */
614 static bool valid_hostcond(const struct inet_diag_bc_op *op, int len,
615 			   int *min_len)
616 {
617 	struct inet_diag_hostcond *cond;
618 	int addr_len;
619 
620 	/* Check hostcond space. */
621 	*min_len += sizeof(struct inet_diag_hostcond);
622 	if (len < *min_len)
623 		return false;
624 	cond = (struct inet_diag_hostcond *)(op + 1);
625 
626 	/* Check address family and address length. */
627 	switch (cond->family) {
628 	case AF_UNSPEC:
629 		addr_len = 0;
630 		break;
631 	case AF_INET:
632 		addr_len = sizeof(struct in_addr);
633 		break;
634 	case AF_INET6:
635 		addr_len = sizeof(struct in6_addr);
636 		break;
637 	default:
638 		return false;
639 	}
640 	*min_len += addr_len;
641 	if (len < *min_len)
642 		return false;
643 
644 	/* Check prefix length (in bits) vs address length (in bytes). */
645 	if (cond->prefix_len > 8 * addr_len)
646 		return false;
647 
648 	return true;
649 }
650 
651 /* Validate a port comparison operator. */
652 static bool valid_port_comparison(const struct inet_diag_bc_op *op,
653 				  int len, int *min_len)
654 {
655 	/* Port comparisons put the port in a follow-on inet_diag_bc_op. */
656 	*min_len += sizeof(struct inet_diag_bc_op);
657 	if (len < *min_len)
658 		return false;
659 	return true;
660 }
661 
662 static int inet_diag_bc_audit(const void *bytecode, int bytecode_len)
663 {
664 	const void *bc = bytecode;
665 	int  len = bytecode_len;
666 
667 	while (len > 0) {
668 		int min_len = sizeof(struct inet_diag_bc_op);
669 		const struct inet_diag_bc_op *op = bc;
670 
671 		switch (op->code) {
672 		case INET_DIAG_BC_S_COND:
673 		case INET_DIAG_BC_D_COND:
674 			if (!valid_hostcond(bc, len, &min_len))
675 				return -EINVAL;
676 			break;
677 		case INET_DIAG_BC_S_GE:
678 		case INET_DIAG_BC_S_LE:
679 		case INET_DIAG_BC_D_GE:
680 		case INET_DIAG_BC_D_LE:
681 			if (!valid_port_comparison(bc, len, &min_len))
682 				return -EINVAL;
683 			break;
684 		case INET_DIAG_BC_AUTO:
685 		case INET_DIAG_BC_JMP:
686 		case INET_DIAG_BC_NOP:
687 			break;
688 		default:
689 			return -EINVAL;
690 		}
691 
692 		if (op->code != INET_DIAG_BC_NOP) {
693 			if (op->no < min_len || op->no > len + 4 || op->no & 3)
694 				return -EINVAL;
695 			if (op->no < len &&
696 			    !valid_cc(bytecode, bytecode_len, len - op->no))
697 				return -EINVAL;
698 		}
699 
700 		if (op->yes < min_len || op->yes > len + 4 || op->yes & 3)
701 			return -EINVAL;
702 		bc  += op->yes;
703 		len -= op->yes;
704 	}
705 	return len == 0 ? 0 : -EINVAL;
706 }
707 
708 static int inet_csk_diag_dump(struct sock *sk,
709 			      struct sk_buff *skb,
710 			      struct netlink_callback *cb,
711 			      const struct inet_diag_req_v2 *r,
712 			      const struct nlattr *bc)
713 {
714 	if (!inet_diag_bc_sk(bc, sk))
715 		return 0;
716 
717 	return inet_csk_diag_fill(sk, skb, r,
718 				  sk_user_ns(NETLINK_CB(cb->skb).sk),
719 				  NETLINK_CB(cb->skb).portid,
720 				  cb->nlh->nlmsg_seq, NLM_F_MULTI, cb->nlh);
721 }
722 
723 static void twsk_build_assert(void)
724 {
725 	BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_family) !=
726 		     offsetof(struct sock, sk_family));
727 
728 	BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_num) !=
729 		     offsetof(struct inet_sock, inet_num));
730 
731 	BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_dport) !=
732 		     offsetof(struct inet_sock, inet_dport));
733 
734 	BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_rcv_saddr) !=
735 		     offsetof(struct inet_sock, inet_rcv_saddr));
736 
737 	BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_daddr) !=
738 		     offsetof(struct inet_sock, inet_daddr));
739 
740 #if IS_ENABLED(CONFIG_IPV6)
741 	BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_v6_rcv_saddr) !=
742 		     offsetof(struct sock, sk_v6_rcv_saddr));
743 
744 	BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_v6_daddr) !=
745 		     offsetof(struct sock, sk_v6_daddr));
746 #endif
747 }
748 
749 void inet_diag_dump_icsk(struct inet_hashinfo *hashinfo, struct sk_buff *skb,
750 			 struct netlink_callback *cb,
751 			 const struct inet_diag_req_v2 *r, struct nlattr *bc)
752 {
753 	struct net *net = sock_net(skb->sk);
754 	int i, num, s_i, s_num;
755 	u32 idiag_states = r->idiag_states;
756 
757 	if (idiag_states & TCPF_SYN_RECV)
758 		idiag_states |= TCPF_NEW_SYN_RECV;
759 	s_i = cb->args[1];
760 	s_num = num = cb->args[2];
761 
762 	if (cb->args[0] == 0) {
763 		if (!(idiag_states & TCPF_LISTEN))
764 			goto skip_listen_ht;
765 
766 		for (i = s_i; i < INET_LHTABLE_SIZE; i++) {
767 			struct inet_listen_hashbucket *ilb;
768 			struct hlist_nulls_node *node;
769 			struct sock *sk;
770 
771 			num = 0;
772 			ilb = &hashinfo->listening_hash[i];
773 			spin_lock_bh(&ilb->lock);
774 			sk_nulls_for_each(sk, node, &ilb->head) {
775 				struct inet_sock *inet = inet_sk(sk);
776 
777 				if (!net_eq(sock_net(sk), net))
778 					continue;
779 
780 				if (num < s_num) {
781 					num++;
782 					continue;
783 				}
784 
785 				if (r->sdiag_family != AF_UNSPEC &&
786 				    sk->sk_family != r->sdiag_family)
787 					goto next_listen;
788 
789 				if (r->id.idiag_sport != inet->inet_sport &&
790 				    r->id.idiag_sport)
791 					goto next_listen;
792 
793 				if (r->id.idiag_dport ||
794 				    cb->args[3] > 0)
795 					goto next_listen;
796 
797 				if (inet_csk_diag_dump(sk, skb, cb, r, bc) < 0) {
798 					spin_unlock_bh(&ilb->lock);
799 					goto done;
800 				}
801 
802 next_listen:
803 				cb->args[3] = 0;
804 				cb->args[4] = 0;
805 				++num;
806 			}
807 			spin_unlock_bh(&ilb->lock);
808 
809 			s_num = 0;
810 			cb->args[3] = 0;
811 			cb->args[4] = 0;
812 		}
813 skip_listen_ht:
814 		cb->args[0] = 1;
815 		s_i = num = s_num = 0;
816 	}
817 
818 	if (!(idiag_states & ~TCPF_LISTEN))
819 		goto out;
820 
821 	for (i = s_i; i <= hashinfo->ehash_mask; i++) {
822 		struct inet_ehash_bucket *head = &hashinfo->ehash[i];
823 		spinlock_t *lock = inet_ehash_lockp(hashinfo, i);
824 		struct hlist_nulls_node *node;
825 		struct sock *sk;
826 
827 		num = 0;
828 
829 		if (hlist_nulls_empty(&head->chain))
830 			continue;
831 
832 		if (i > s_i)
833 			s_num = 0;
834 
835 		spin_lock_bh(lock);
836 		sk_nulls_for_each(sk, node, &head->chain) {
837 			int state, res;
838 
839 			if (!net_eq(sock_net(sk), net))
840 				continue;
841 			if (num < s_num)
842 				goto next_normal;
843 			state = (sk->sk_state == TCP_TIME_WAIT) ?
844 				inet_twsk(sk)->tw_substate : sk->sk_state;
845 			if (!(idiag_states & (1 << state)))
846 				goto next_normal;
847 			if (r->sdiag_family != AF_UNSPEC &&
848 			    sk->sk_family != r->sdiag_family)
849 				goto next_normal;
850 			if (r->id.idiag_sport != htons(sk->sk_num) &&
851 			    r->id.idiag_sport)
852 				goto next_normal;
853 			if (r->id.idiag_dport != sk->sk_dport &&
854 			    r->id.idiag_dport)
855 				goto next_normal;
856 			twsk_build_assert();
857 
858 			if (!inet_diag_bc_sk(bc, sk))
859 				goto next_normal;
860 
861 			res = sk_diag_fill(sk, skb, r,
862 					   sk_user_ns(NETLINK_CB(cb->skb).sk),
863 					   NETLINK_CB(cb->skb).portid,
864 					   cb->nlh->nlmsg_seq, NLM_F_MULTI,
865 					   cb->nlh);
866 			if (res < 0) {
867 				spin_unlock_bh(lock);
868 				goto done;
869 			}
870 next_normal:
871 			++num;
872 		}
873 
874 		spin_unlock_bh(lock);
875 	}
876 
877 done:
878 	cb->args[1] = i;
879 	cb->args[2] = num;
880 out:
881 	;
882 }
883 EXPORT_SYMBOL_GPL(inet_diag_dump_icsk);
884 
885 static int __inet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
886 			    const struct inet_diag_req_v2 *r,
887 			    struct nlattr *bc)
888 {
889 	const struct inet_diag_handler *handler;
890 	int err = 0;
891 
892 	handler = inet_diag_lock_handler(r->sdiag_protocol);
893 	if (!IS_ERR(handler))
894 		handler->dump(skb, cb, r, bc);
895 	else
896 		err = PTR_ERR(handler);
897 	inet_diag_unlock_handler(handler);
898 
899 	return err ? : skb->len;
900 }
901 
902 static int inet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
903 {
904 	int hdrlen = sizeof(struct inet_diag_req_v2);
905 	struct nlattr *bc = NULL;
906 
907 	if (nlmsg_attrlen(cb->nlh, hdrlen))
908 		bc = nlmsg_find_attr(cb->nlh, hdrlen, INET_DIAG_REQ_BYTECODE);
909 
910 	return __inet_diag_dump(skb, cb, nlmsg_data(cb->nlh), bc);
911 }
912 
913 static int inet_diag_type2proto(int type)
914 {
915 	switch (type) {
916 	case TCPDIAG_GETSOCK:
917 		return IPPROTO_TCP;
918 	case DCCPDIAG_GETSOCK:
919 		return IPPROTO_DCCP;
920 	default:
921 		return 0;
922 	}
923 }
924 
925 static int inet_diag_dump_compat(struct sk_buff *skb,
926 				 struct netlink_callback *cb)
927 {
928 	struct inet_diag_req *rc = nlmsg_data(cb->nlh);
929 	int hdrlen = sizeof(struct inet_diag_req);
930 	struct inet_diag_req_v2 req;
931 	struct nlattr *bc = NULL;
932 
933 	req.sdiag_family = AF_UNSPEC; /* compatibility */
934 	req.sdiag_protocol = inet_diag_type2proto(cb->nlh->nlmsg_type);
935 	req.idiag_ext = rc->idiag_ext;
936 	req.idiag_states = rc->idiag_states;
937 	req.id = rc->id;
938 
939 	if (nlmsg_attrlen(cb->nlh, hdrlen))
940 		bc = nlmsg_find_attr(cb->nlh, hdrlen, INET_DIAG_REQ_BYTECODE);
941 
942 	return __inet_diag_dump(skb, cb, &req, bc);
943 }
944 
945 static int inet_diag_get_exact_compat(struct sk_buff *in_skb,
946 				      const struct nlmsghdr *nlh)
947 {
948 	struct inet_diag_req *rc = nlmsg_data(nlh);
949 	struct inet_diag_req_v2 req;
950 
951 	req.sdiag_family = rc->idiag_family;
952 	req.sdiag_protocol = inet_diag_type2proto(nlh->nlmsg_type);
953 	req.idiag_ext = rc->idiag_ext;
954 	req.idiag_states = rc->idiag_states;
955 	req.id = rc->id;
956 
957 	return inet_diag_cmd_exact(SOCK_DIAG_BY_FAMILY, in_skb, nlh, &req);
958 }
959 
960 static int inet_diag_rcv_msg_compat(struct sk_buff *skb, struct nlmsghdr *nlh)
961 {
962 	int hdrlen = sizeof(struct inet_diag_req);
963 	struct net *net = sock_net(skb->sk);
964 
965 	if (nlh->nlmsg_type >= INET_DIAG_GETSOCK_MAX ||
966 	    nlmsg_len(nlh) < hdrlen)
967 		return -EINVAL;
968 
969 	if (nlh->nlmsg_flags & NLM_F_DUMP) {
970 		if (nlmsg_attrlen(nlh, hdrlen)) {
971 			struct nlattr *attr;
972 
973 			attr = nlmsg_find_attr(nlh, hdrlen,
974 					       INET_DIAG_REQ_BYTECODE);
975 			if (!attr ||
976 			    nla_len(attr) < sizeof(struct inet_diag_bc_op) ||
977 			    inet_diag_bc_audit(nla_data(attr), nla_len(attr)))
978 				return -EINVAL;
979 		}
980 		{
981 			struct netlink_dump_control c = {
982 				.dump = inet_diag_dump_compat,
983 			};
984 			return netlink_dump_start(net->diag_nlsk, skb, nlh, &c);
985 		}
986 	}
987 
988 	return inet_diag_get_exact_compat(skb, nlh);
989 }
990 
991 static int inet_diag_handler_cmd(struct sk_buff *skb, struct nlmsghdr *h)
992 {
993 	int hdrlen = sizeof(struct inet_diag_req_v2);
994 	struct net *net = sock_net(skb->sk);
995 
996 	if (nlmsg_len(h) < hdrlen)
997 		return -EINVAL;
998 
999 	if (h->nlmsg_type == SOCK_DIAG_BY_FAMILY &&
1000 	    h->nlmsg_flags & NLM_F_DUMP) {
1001 		if (nlmsg_attrlen(h, hdrlen)) {
1002 			struct nlattr *attr;
1003 
1004 			attr = nlmsg_find_attr(h, hdrlen,
1005 					       INET_DIAG_REQ_BYTECODE);
1006 			if (!attr ||
1007 			    nla_len(attr) < sizeof(struct inet_diag_bc_op) ||
1008 			    inet_diag_bc_audit(nla_data(attr), nla_len(attr)))
1009 				return -EINVAL;
1010 		}
1011 		{
1012 			struct netlink_dump_control c = {
1013 				.dump = inet_diag_dump,
1014 			};
1015 			return netlink_dump_start(net->diag_nlsk, skb, h, &c);
1016 		}
1017 	}
1018 
1019 	return inet_diag_cmd_exact(h->nlmsg_type, skb, h, nlmsg_data(h));
1020 }
1021 
1022 static
1023 int inet_diag_handler_get_info(struct sk_buff *skb, struct sock *sk)
1024 {
1025 	const struct inet_diag_handler *handler;
1026 	struct nlmsghdr *nlh;
1027 	struct nlattr *attr;
1028 	struct inet_diag_msg *r;
1029 	void *info = NULL;
1030 	int err = 0;
1031 
1032 	nlh = nlmsg_put(skb, 0, 0, SOCK_DIAG_BY_FAMILY, sizeof(*r), 0);
1033 	if (!nlh)
1034 		return -ENOMEM;
1035 
1036 	r = nlmsg_data(nlh);
1037 	memset(r, 0, sizeof(*r));
1038 	inet_diag_msg_common_fill(r, sk);
1039 	if (sk->sk_type == SOCK_DGRAM || sk->sk_type == SOCK_STREAM)
1040 		r->id.idiag_sport = inet_sk(sk)->inet_sport;
1041 	r->idiag_state = sk->sk_state;
1042 
1043 	if ((err = nla_put_u8(skb, INET_DIAG_PROTOCOL, sk->sk_protocol))) {
1044 		nlmsg_cancel(skb, nlh);
1045 		return err;
1046 	}
1047 
1048 	handler = inet_diag_lock_handler(sk->sk_protocol);
1049 	if (IS_ERR(handler)) {
1050 		inet_diag_unlock_handler(handler);
1051 		nlmsg_cancel(skb, nlh);
1052 		return PTR_ERR(handler);
1053 	}
1054 
1055 	attr = handler->idiag_info_size
1056 		? nla_reserve(skb, INET_DIAG_INFO, handler->idiag_info_size)
1057 		: NULL;
1058 	if (attr)
1059 		info = nla_data(attr);
1060 
1061 	handler->idiag_get_info(sk, r, info);
1062 	inet_diag_unlock_handler(handler);
1063 
1064 	nlmsg_end(skb, nlh);
1065 	return 0;
1066 }
1067 
1068 static const struct sock_diag_handler inet_diag_handler = {
1069 	.family = AF_INET,
1070 	.dump = inet_diag_handler_cmd,
1071 	.get_info = inet_diag_handler_get_info,
1072 	.destroy = inet_diag_handler_cmd,
1073 };
1074 
1075 static const struct sock_diag_handler inet6_diag_handler = {
1076 	.family = AF_INET6,
1077 	.dump = inet_diag_handler_cmd,
1078 	.get_info = inet_diag_handler_get_info,
1079 	.destroy = inet_diag_handler_cmd,
1080 };
1081 
1082 int inet_diag_register(const struct inet_diag_handler *h)
1083 {
1084 	const __u16 type = h->idiag_type;
1085 	int err = -EINVAL;
1086 
1087 	if (type >= IPPROTO_MAX)
1088 		goto out;
1089 
1090 	mutex_lock(&inet_diag_table_mutex);
1091 	err = -EEXIST;
1092 	if (!inet_diag_table[type]) {
1093 		inet_diag_table[type] = h;
1094 		err = 0;
1095 	}
1096 	mutex_unlock(&inet_diag_table_mutex);
1097 out:
1098 	return err;
1099 }
1100 EXPORT_SYMBOL_GPL(inet_diag_register);
1101 
1102 void inet_diag_unregister(const struct inet_diag_handler *h)
1103 {
1104 	const __u16 type = h->idiag_type;
1105 
1106 	if (type >= IPPROTO_MAX)
1107 		return;
1108 
1109 	mutex_lock(&inet_diag_table_mutex);
1110 	inet_diag_table[type] = NULL;
1111 	mutex_unlock(&inet_diag_table_mutex);
1112 }
1113 EXPORT_SYMBOL_GPL(inet_diag_unregister);
1114 
1115 static int __init inet_diag_init(void)
1116 {
1117 	const int inet_diag_table_size = (IPPROTO_MAX *
1118 					  sizeof(struct inet_diag_handler *));
1119 	int err = -ENOMEM;
1120 
1121 	inet_diag_table = kzalloc(inet_diag_table_size, GFP_KERNEL);
1122 	if (!inet_diag_table)
1123 		goto out;
1124 
1125 	err = sock_diag_register(&inet_diag_handler);
1126 	if (err)
1127 		goto out_free_nl;
1128 
1129 	err = sock_diag_register(&inet6_diag_handler);
1130 	if (err)
1131 		goto out_free_inet;
1132 
1133 	sock_diag_register_inet_compat(inet_diag_rcv_msg_compat);
1134 out:
1135 	return err;
1136 
1137 out_free_inet:
1138 	sock_diag_unregister(&inet_diag_handler);
1139 out_free_nl:
1140 	kfree(inet_diag_table);
1141 	goto out;
1142 }
1143 
1144 static void __exit inet_diag_exit(void)
1145 {
1146 	sock_diag_unregister(&inet6_diag_handler);
1147 	sock_diag_unregister(&inet_diag_handler);
1148 	sock_diag_unregister_inet_compat(inet_diag_rcv_msg_compat);
1149 	kfree(inet_diag_table);
1150 }
1151 
1152 module_init(inet_diag_init);
1153 module_exit(inet_diag_exit);
1154 MODULE_LICENSE("GPL");
1155 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2 /* AF_INET */);
1156 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 10 /* AF_INET6 */);
1157