xref: /openbmc/linux/net/ipv4/inet_diag.c (revision bc5aa3a0)
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 	u32 ifindex;
48 };
49 
50 static DEFINE_MUTEX(inet_diag_table_mutex);
51 
52 static const struct inet_diag_handler *inet_diag_lock_handler(int proto)
53 {
54 	if (!inet_diag_table[proto])
55 		request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
56 			       NETLINK_SOCK_DIAG, AF_INET, proto);
57 
58 	mutex_lock(&inet_diag_table_mutex);
59 	if (!inet_diag_table[proto])
60 		return ERR_PTR(-ENOENT);
61 
62 	return inet_diag_table[proto];
63 }
64 
65 static void inet_diag_unlock_handler(const struct inet_diag_handler *handler)
66 {
67 	mutex_unlock(&inet_diag_table_mutex);
68 }
69 
70 void inet_diag_msg_common_fill(struct inet_diag_msg *r, struct sock *sk)
71 {
72 	r->idiag_family = sk->sk_family;
73 
74 	r->id.idiag_sport = htons(sk->sk_num);
75 	r->id.idiag_dport = sk->sk_dport;
76 	r->id.idiag_if = sk->sk_bound_dev_if;
77 	sock_diag_save_cookie(sk, r->id.idiag_cookie);
78 
79 #if IS_ENABLED(CONFIG_IPV6)
80 	if (sk->sk_family == AF_INET6) {
81 		*(struct in6_addr *)r->id.idiag_src = sk->sk_v6_rcv_saddr;
82 		*(struct in6_addr *)r->id.idiag_dst = sk->sk_v6_daddr;
83 	} else
84 #endif
85 	{
86 	memset(&r->id.idiag_src, 0, sizeof(r->id.idiag_src));
87 	memset(&r->id.idiag_dst, 0, sizeof(r->id.idiag_dst));
88 
89 	r->id.idiag_src[0] = sk->sk_rcv_saddr;
90 	r->id.idiag_dst[0] = sk->sk_daddr;
91 	}
92 }
93 EXPORT_SYMBOL_GPL(inet_diag_msg_common_fill);
94 
95 static size_t inet_sk_attr_size(void)
96 {
97 	return	  nla_total_size(sizeof(struct tcp_info))
98 		+ nla_total_size(1) /* INET_DIAG_SHUTDOWN */
99 		+ nla_total_size(1) /* INET_DIAG_TOS */
100 		+ nla_total_size(1) /* INET_DIAG_TCLASS */
101 		+ nla_total_size(sizeof(struct inet_diag_meminfo))
102 		+ nla_total_size(sizeof(struct inet_diag_msg))
103 		+ nla_total_size(SK_MEMINFO_VARS * sizeof(u32))
104 		+ nla_total_size(TCP_CA_NAME_MAX)
105 		+ nla_total_size(sizeof(struct tcpvegas_info))
106 		+ 64;
107 }
108 
109 int inet_diag_msg_attrs_fill(struct sock *sk, struct sk_buff *skb,
110 			     struct inet_diag_msg *r, int ext,
111 			     struct user_namespace *user_ns)
112 {
113 	const struct inet_sock *inet = inet_sk(sk);
114 
115 	if (nla_put_u8(skb, INET_DIAG_SHUTDOWN, sk->sk_shutdown))
116 		goto errout;
117 
118 	/* IPv6 dual-stack sockets use inet->tos for IPv4 connections,
119 	 * hence this needs to be included regardless of socket family.
120 	 */
121 	if (ext & (1 << (INET_DIAG_TOS - 1)))
122 		if (nla_put_u8(skb, INET_DIAG_TOS, inet->tos) < 0)
123 			goto errout;
124 
125 #if IS_ENABLED(CONFIG_IPV6)
126 	if (r->idiag_family == AF_INET6) {
127 		if (ext & (1 << (INET_DIAG_TCLASS - 1)))
128 			if (nla_put_u8(skb, INET_DIAG_TCLASS,
129 				       inet6_sk(sk)->tclass) < 0)
130 				goto errout;
131 
132 		if (((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) &&
133 		    nla_put_u8(skb, INET_DIAG_SKV6ONLY, ipv6_only_sock(sk)))
134 			goto errout;
135 	}
136 #endif
137 
138 	r->idiag_uid = from_kuid_munged(user_ns, sock_i_uid(sk));
139 	r->idiag_inode = sock_i_ino(sk);
140 
141 	return 0;
142 errout:
143 	return 1;
144 }
145 EXPORT_SYMBOL_GPL(inet_diag_msg_attrs_fill);
146 
147 int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk,
148 		      struct sk_buff *skb, const struct inet_diag_req_v2 *req,
149 		      struct user_namespace *user_ns,
150 		      u32 portid, u32 seq, u16 nlmsg_flags,
151 		      const struct nlmsghdr *unlh)
152 {
153 	const struct tcp_congestion_ops *ca_ops;
154 	const struct inet_diag_handler *handler;
155 	int ext = req->idiag_ext;
156 	struct inet_diag_msg *r;
157 	struct nlmsghdr  *nlh;
158 	struct nlattr *attr;
159 	void *info = NULL;
160 
161 	handler = inet_diag_table[req->sdiag_protocol];
162 	BUG_ON(!handler);
163 
164 	nlh = nlmsg_put(skb, portid, seq, unlh->nlmsg_type, sizeof(*r),
165 			nlmsg_flags);
166 	if (!nlh)
167 		return -EMSGSIZE;
168 
169 	r = nlmsg_data(nlh);
170 	BUG_ON(!sk_fullsock(sk));
171 
172 	inet_diag_msg_common_fill(r, sk);
173 	r->idiag_state = sk->sk_state;
174 	r->idiag_timer = 0;
175 	r->idiag_retrans = 0;
176 
177 	if (inet_diag_msg_attrs_fill(sk, skb, r, ext, user_ns))
178 		goto errout;
179 
180 	if (ext & (1 << (INET_DIAG_MEMINFO - 1))) {
181 		struct inet_diag_meminfo minfo = {
182 			.idiag_rmem = sk_rmem_alloc_get(sk),
183 			.idiag_wmem = sk->sk_wmem_queued,
184 			.idiag_fmem = sk->sk_forward_alloc,
185 			.idiag_tmem = sk_wmem_alloc_get(sk),
186 		};
187 
188 		if (nla_put(skb, INET_DIAG_MEMINFO, sizeof(minfo), &minfo) < 0)
189 			goto errout;
190 	}
191 
192 	if (ext & (1 << (INET_DIAG_SKMEMINFO - 1)))
193 		if (sock_diag_put_meminfo(sk, skb, INET_DIAG_SKMEMINFO))
194 			goto errout;
195 
196 	if (!icsk) {
197 		handler->idiag_get_info(sk, r, NULL);
198 		goto out;
199 	}
200 
201 	if (icsk->icsk_pending == ICSK_TIME_RETRANS ||
202 	    icsk->icsk_pending == ICSK_TIME_EARLY_RETRANS ||
203 	    icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) {
204 		r->idiag_timer = 1;
205 		r->idiag_retrans = icsk->icsk_retransmits;
206 		r->idiag_expires =
207 			jiffies_to_msecs(icsk->icsk_timeout - jiffies);
208 	} else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
209 		r->idiag_timer = 4;
210 		r->idiag_retrans = icsk->icsk_probes_out;
211 		r->idiag_expires =
212 			jiffies_to_msecs(icsk->icsk_timeout - jiffies);
213 	} else if (timer_pending(&sk->sk_timer)) {
214 		r->idiag_timer = 2;
215 		r->idiag_retrans = icsk->icsk_probes_out;
216 		r->idiag_expires =
217 			jiffies_to_msecs(sk->sk_timer.expires - jiffies);
218 	} else {
219 		r->idiag_timer = 0;
220 		r->idiag_expires = 0;
221 	}
222 
223 	if ((ext & (1 << (INET_DIAG_INFO - 1))) && handler->idiag_info_size) {
224 		attr = nla_reserve_64bit(skb, INET_DIAG_INFO,
225 					 handler->idiag_info_size,
226 					 INET_DIAG_PAD);
227 		if (!attr)
228 			goto errout;
229 
230 		info = nla_data(attr);
231 	}
232 
233 	if (ext & (1 << (INET_DIAG_CONG - 1))) {
234 		int err = 0;
235 
236 		rcu_read_lock();
237 		ca_ops = READ_ONCE(icsk->icsk_ca_ops);
238 		if (ca_ops)
239 			err = nla_put_string(skb, INET_DIAG_CONG, ca_ops->name);
240 		rcu_read_unlock();
241 		if (err < 0)
242 			goto errout;
243 	}
244 
245 	handler->idiag_get_info(sk, r, info);
246 
247 	if (sk->sk_state < TCP_TIME_WAIT) {
248 		union tcp_cc_info info;
249 		size_t sz = 0;
250 		int attr;
251 
252 		rcu_read_lock();
253 		ca_ops = READ_ONCE(icsk->icsk_ca_ops);
254 		if (ca_ops && ca_ops->get_info)
255 			sz = ca_ops->get_info(sk, ext, &attr, &info);
256 		rcu_read_unlock();
257 		if (sz && nla_put(skb, attr, sz, &info) < 0)
258 			goto errout;
259 	}
260 
261 out:
262 	nlmsg_end(skb, nlh);
263 	return 0;
264 
265 errout:
266 	nlmsg_cancel(skb, nlh);
267 	return -EMSGSIZE;
268 }
269 EXPORT_SYMBOL_GPL(inet_sk_diag_fill);
270 
271 static int inet_csk_diag_fill(struct sock *sk,
272 			      struct sk_buff *skb,
273 			      const struct inet_diag_req_v2 *req,
274 			      struct user_namespace *user_ns,
275 			      u32 portid, u32 seq, u16 nlmsg_flags,
276 			      const struct nlmsghdr *unlh)
277 {
278 	return inet_sk_diag_fill(sk, inet_csk(sk), skb, req,
279 				 user_ns, portid, seq, nlmsg_flags, unlh);
280 }
281 
282 static int inet_twsk_diag_fill(struct sock *sk,
283 			       struct sk_buff *skb,
284 			       u32 portid, u32 seq, u16 nlmsg_flags,
285 			       const struct nlmsghdr *unlh)
286 {
287 	struct inet_timewait_sock *tw = inet_twsk(sk);
288 	struct inet_diag_msg *r;
289 	struct nlmsghdr *nlh;
290 	long tmo;
291 
292 	nlh = nlmsg_put(skb, portid, seq, unlh->nlmsg_type, sizeof(*r),
293 			nlmsg_flags);
294 	if (!nlh)
295 		return -EMSGSIZE;
296 
297 	r = nlmsg_data(nlh);
298 	BUG_ON(tw->tw_state != TCP_TIME_WAIT);
299 
300 	tmo = tw->tw_timer.expires - jiffies;
301 	if (tmo < 0)
302 		tmo = 0;
303 
304 	inet_diag_msg_common_fill(r, sk);
305 	r->idiag_retrans      = 0;
306 
307 	r->idiag_state	      = tw->tw_substate;
308 	r->idiag_timer	      = 3;
309 	r->idiag_expires      = jiffies_to_msecs(tmo);
310 	r->idiag_rqueue	      = 0;
311 	r->idiag_wqueue	      = 0;
312 	r->idiag_uid	      = 0;
313 	r->idiag_inode	      = 0;
314 
315 	nlmsg_end(skb, nlh);
316 	return 0;
317 }
318 
319 static int inet_req_diag_fill(struct sock *sk, struct sk_buff *skb,
320 			      u32 portid, u32 seq, u16 nlmsg_flags,
321 			      const struct nlmsghdr *unlh)
322 {
323 	struct inet_diag_msg *r;
324 	struct nlmsghdr *nlh;
325 	long tmo;
326 
327 	nlh = nlmsg_put(skb, portid, seq, unlh->nlmsg_type, sizeof(*r),
328 			nlmsg_flags);
329 	if (!nlh)
330 		return -EMSGSIZE;
331 
332 	r = nlmsg_data(nlh);
333 	inet_diag_msg_common_fill(r, sk);
334 	r->idiag_state = TCP_SYN_RECV;
335 	r->idiag_timer = 1;
336 	r->idiag_retrans = inet_reqsk(sk)->num_retrans;
337 
338 	BUILD_BUG_ON(offsetof(struct inet_request_sock, ir_cookie) !=
339 		     offsetof(struct sock, sk_cookie));
340 
341 	tmo = inet_reqsk(sk)->rsk_timer.expires - jiffies;
342 	r->idiag_expires = (tmo >= 0) ? jiffies_to_msecs(tmo) : 0;
343 	r->idiag_rqueue	= 0;
344 	r->idiag_wqueue	= 0;
345 	r->idiag_uid	= 0;
346 	r->idiag_inode	= 0;
347 
348 	nlmsg_end(skb, nlh);
349 	return 0;
350 }
351 
352 static int sk_diag_fill(struct sock *sk, struct sk_buff *skb,
353 			const struct inet_diag_req_v2 *r,
354 			struct user_namespace *user_ns,
355 			u32 portid, u32 seq, u16 nlmsg_flags,
356 			const struct nlmsghdr *unlh)
357 {
358 	if (sk->sk_state == TCP_TIME_WAIT)
359 		return inet_twsk_diag_fill(sk, skb, portid, seq,
360 					   nlmsg_flags, unlh);
361 
362 	if (sk->sk_state == TCP_NEW_SYN_RECV)
363 		return inet_req_diag_fill(sk, skb, portid, seq,
364 					  nlmsg_flags, unlh);
365 
366 	return inet_csk_diag_fill(sk, skb, r, user_ns, portid, seq,
367 				  nlmsg_flags, unlh);
368 }
369 
370 struct sock *inet_diag_find_one_icsk(struct net *net,
371 				     struct inet_hashinfo *hashinfo,
372 				     const struct inet_diag_req_v2 *req)
373 {
374 	struct sock *sk;
375 
376 	rcu_read_lock();
377 	if (req->sdiag_family == AF_INET)
378 		sk = inet_lookup(net, hashinfo, NULL, 0, req->id.idiag_dst[0],
379 				 req->id.idiag_dport, req->id.idiag_src[0],
380 				 req->id.idiag_sport, req->id.idiag_if);
381 #if IS_ENABLED(CONFIG_IPV6)
382 	else if (req->sdiag_family == AF_INET6) {
383 		if (ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_dst) &&
384 		    ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_src))
385 			sk = inet_lookup(net, hashinfo, NULL, 0, req->id.idiag_dst[3],
386 					 req->id.idiag_dport, req->id.idiag_src[3],
387 					 req->id.idiag_sport, req->id.idiag_if);
388 		else
389 			sk = inet6_lookup(net, hashinfo, NULL, 0,
390 					  (struct in6_addr *)req->id.idiag_dst,
391 					  req->id.idiag_dport,
392 					  (struct in6_addr *)req->id.idiag_src,
393 					  req->id.idiag_sport,
394 					  req->id.idiag_if);
395 	}
396 #endif
397 	else {
398 		rcu_read_unlock();
399 		return ERR_PTR(-EINVAL);
400 	}
401 	rcu_read_unlock();
402 	if (!sk)
403 		return ERR_PTR(-ENOENT);
404 
405 	if (sock_diag_check_cookie(sk, req->id.idiag_cookie)) {
406 		sock_gen_put(sk);
407 		return ERR_PTR(-ENOENT);
408 	}
409 
410 	return sk;
411 }
412 EXPORT_SYMBOL_GPL(inet_diag_find_one_icsk);
413 
414 int inet_diag_dump_one_icsk(struct inet_hashinfo *hashinfo,
415 			    struct sk_buff *in_skb,
416 			    const struct nlmsghdr *nlh,
417 			    const struct inet_diag_req_v2 *req)
418 {
419 	struct net *net = sock_net(in_skb->sk);
420 	struct sk_buff *rep;
421 	struct sock *sk;
422 	int err;
423 
424 	sk = inet_diag_find_one_icsk(net, hashinfo, req);
425 	if (IS_ERR(sk))
426 		return PTR_ERR(sk);
427 
428 	rep = nlmsg_new(inet_sk_attr_size(), GFP_KERNEL);
429 	if (!rep) {
430 		err = -ENOMEM;
431 		goto out;
432 	}
433 
434 	err = sk_diag_fill(sk, rep, req,
435 			   sk_user_ns(NETLINK_CB(in_skb).sk),
436 			   NETLINK_CB(in_skb).portid,
437 			   nlh->nlmsg_seq, 0, nlh);
438 	if (err < 0) {
439 		WARN_ON(err == -EMSGSIZE);
440 		nlmsg_free(rep);
441 		goto out;
442 	}
443 	err = netlink_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid,
444 			      MSG_DONTWAIT);
445 	if (err > 0)
446 		err = 0;
447 
448 out:
449 	if (sk)
450 		sock_gen_put(sk);
451 
452 	return err;
453 }
454 EXPORT_SYMBOL_GPL(inet_diag_dump_one_icsk);
455 
456 static int inet_diag_cmd_exact(int cmd, struct sk_buff *in_skb,
457 			       const struct nlmsghdr *nlh,
458 			       const struct inet_diag_req_v2 *req)
459 {
460 	const struct inet_diag_handler *handler;
461 	int err;
462 
463 	handler = inet_diag_lock_handler(req->sdiag_protocol);
464 	if (IS_ERR(handler))
465 		err = PTR_ERR(handler);
466 	else if (cmd == SOCK_DIAG_BY_FAMILY)
467 		err = handler->dump_one(in_skb, nlh, req);
468 	else if (cmd == SOCK_DESTROY && handler->destroy)
469 		err = handler->destroy(in_skb, req);
470 	else
471 		err = -EOPNOTSUPP;
472 	inet_diag_unlock_handler(handler);
473 
474 	return err;
475 }
476 
477 static int bitstring_match(const __be32 *a1, const __be32 *a2, int bits)
478 {
479 	int words = bits >> 5;
480 
481 	bits &= 0x1f;
482 
483 	if (words) {
484 		if (memcmp(a1, a2, words << 2))
485 			return 0;
486 	}
487 	if (bits) {
488 		__be32 w1, w2;
489 		__be32 mask;
490 
491 		w1 = a1[words];
492 		w2 = a2[words];
493 
494 		mask = htonl((0xffffffff) << (32 - bits));
495 
496 		if ((w1 ^ w2) & mask)
497 			return 0;
498 	}
499 
500 	return 1;
501 }
502 
503 static int inet_diag_bc_run(const struct nlattr *_bc,
504 			    const struct inet_diag_entry *entry)
505 {
506 	const void *bc = nla_data(_bc);
507 	int len = nla_len(_bc);
508 
509 	while (len > 0) {
510 		int yes = 1;
511 		const struct inet_diag_bc_op *op = bc;
512 
513 		switch (op->code) {
514 		case INET_DIAG_BC_NOP:
515 			break;
516 		case INET_DIAG_BC_JMP:
517 			yes = 0;
518 			break;
519 		case INET_DIAG_BC_S_GE:
520 			yes = entry->sport >= op[1].no;
521 			break;
522 		case INET_DIAG_BC_S_LE:
523 			yes = entry->sport <= op[1].no;
524 			break;
525 		case INET_DIAG_BC_D_GE:
526 			yes = entry->dport >= op[1].no;
527 			break;
528 		case INET_DIAG_BC_D_LE:
529 			yes = entry->dport <= op[1].no;
530 			break;
531 		case INET_DIAG_BC_AUTO:
532 			yes = !(entry->userlocks & SOCK_BINDPORT_LOCK);
533 			break;
534 		case INET_DIAG_BC_S_COND:
535 		case INET_DIAG_BC_D_COND: {
536 			const struct inet_diag_hostcond *cond;
537 			const __be32 *addr;
538 
539 			cond = (const struct inet_diag_hostcond *)(op + 1);
540 			if (cond->port != -1 &&
541 			    cond->port != (op->code == INET_DIAG_BC_S_COND ?
542 					     entry->sport : entry->dport)) {
543 				yes = 0;
544 				break;
545 			}
546 
547 			if (op->code == INET_DIAG_BC_S_COND)
548 				addr = entry->saddr;
549 			else
550 				addr = entry->daddr;
551 
552 			if (cond->family != AF_UNSPEC &&
553 			    cond->family != entry->family) {
554 				if (entry->family == AF_INET6 &&
555 				    cond->family == AF_INET) {
556 					if (addr[0] == 0 && addr[1] == 0 &&
557 					    addr[2] == htonl(0xffff) &&
558 					    bitstring_match(addr + 3,
559 							    cond->addr,
560 							    cond->prefix_len))
561 						break;
562 				}
563 				yes = 0;
564 				break;
565 			}
566 
567 			if (cond->prefix_len == 0)
568 				break;
569 			if (bitstring_match(addr, cond->addr,
570 					    cond->prefix_len))
571 				break;
572 			yes = 0;
573 			break;
574 		}
575 		case INET_DIAG_BC_DEV_COND: {
576 			u32 ifindex;
577 
578 			ifindex = *((const u32 *)(op + 1));
579 			if (ifindex != entry->ifindex)
580 				yes = 0;
581 			break;
582 		}
583 		}
584 
585 		if (yes) {
586 			len -= op->yes;
587 			bc += op->yes;
588 		} else {
589 			len -= op->no;
590 			bc += op->no;
591 		}
592 	}
593 	return len == 0;
594 }
595 
596 /* This helper is available for all sockets (ESTABLISH, TIMEWAIT, SYN_RECV)
597  */
598 static void entry_fill_addrs(struct inet_diag_entry *entry,
599 			     const struct sock *sk)
600 {
601 #if IS_ENABLED(CONFIG_IPV6)
602 	if (sk->sk_family == AF_INET6) {
603 		entry->saddr = sk->sk_v6_rcv_saddr.s6_addr32;
604 		entry->daddr = sk->sk_v6_daddr.s6_addr32;
605 	} else
606 #endif
607 	{
608 		entry->saddr = &sk->sk_rcv_saddr;
609 		entry->daddr = &sk->sk_daddr;
610 	}
611 }
612 
613 int inet_diag_bc_sk(const struct nlattr *bc, struct sock *sk)
614 {
615 	struct inet_sock *inet = inet_sk(sk);
616 	struct inet_diag_entry entry;
617 
618 	if (!bc)
619 		return 1;
620 
621 	entry.family = sk->sk_family;
622 	entry_fill_addrs(&entry, sk);
623 	entry.sport = inet->inet_num;
624 	entry.dport = ntohs(inet->inet_dport);
625 	entry.ifindex = sk->sk_bound_dev_if;
626 	entry.userlocks = sk_fullsock(sk) ? sk->sk_userlocks : 0;
627 
628 	return inet_diag_bc_run(bc, &entry);
629 }
630 EXPORT_SYMBOL_GPL(inet_diag_bc_sk);
631 
632 static int valid_cc(const void *bc, int len, int cc)
633 {
634 	while (len >= 0) {
635 		const struct inet_diag_bc_op *op = bc;
636 
637 		if (cc > len)
638 			return 0;
639 		if (cc == len)
640 			return 1;
641 		if (op->yes < 4 || op->yes & 3)
642 			return 0;
643 		len -= op->yes;
644 		bc  += op->yes;
645 	}
646 	return 0;
647 }
648 
649 /* data is u32 ifindex */
650 static bool valid_devcond(const struct inet_diag_bc_op *op, int len,
651 			  int *min_len)
652 {
653 	/* Check ifindex space. */
654 	*min_len += sizeof(u32);
655 	if (len < *min_len)
656 		return false;
657 
658 	return true;
659 }
660 /* Validate an inet_diag_hostcond. */
661 static bool valid_hostcond(const struct inet_diag_bc_op *op, int len,
662 			   int *min_len)
663 {
664 	struct inet_diag_hostcond *cond;
665 	int addr_len;
666 
667 	/* Check hostcond space. */
668 	*min_len += sizeof(struct inet_diag_hostcond);
669 	if (len < *min_len)
670 		return false;
671 	cond = (struct inet_diag_hostcond *)(op + 1);
672 
673 	/* Check address family and address length. */
674 	switch (cond->family) {
675 	case AF_UNSPEC:
676 		addr_len = 0;
677 		break;
678 	case AF_INET:
679 		addr_len = sizeof(struct in_addr);
680 		break;
681 	case AF_INET6:
682 		addr_len = sizeof(struct in6_addr);
683 		break;
684 	default:
685 		return false;
686 	}
687 	*min_len += addr_len;
688 	if (len < *min_len)
689 		return false;
690 
691 	/* Check prefix length (in bits) vs address length (in bytes). */
692 	if (cond->prefix_len > 8 * addr_len)
693 		return false;
694 
695 	return true;
696 }
697 
698 /* Validate a port comparison operator. */
699 static bool valid_port_comparison(const struct inet_diag_bc_op *op,
700 				  int len, int *min_len)
701 {
702 	/* Port comparisons put the port in a follow-on inet_diag_bc_op. */
703 	*min_len += sizeof(struct inet_diag_bc_op);
704 	if (len < *min_len)
705 		return false;
706 	return true;
707 }
708 
709 static int inet_diag_bc_audit(const void *bytecode, int bytecode_len)
710 {
711 	const void *bc = bytecode;
712 	int  len = bytecode_len;
713 
714 	while (len > 0) {
715 		int min_len = sizeof(struct inet_diag_bc_op);
716 		const struct inet_diag_bc_op *op = bc;
717 
718 		switch (op->code) {
719 		case INET_DIAG_BC_S_COND:
720 		case INET_DIAG_BC_D_COND:
721 			if (!valid_hostcond(bc, len, &min_len))
722 				return -EINVAL;
723 			break;
724 		case INET_DIAG_BC_DEV_COND:
725 			if (!valid_devcond(bc, len, &min_len))
726 				return -EINVAL;
727 			break;
728 		case INET_DIAG_BC_S_GE:
729 		case INET_DIAG_BC_S_LE:
730 		case INET_DIAG_BC_D_GE:
731 		case INET_DIAG_BC_D_LE:
732 			if (!valid_port_comparison(bc, len, &min_len))
733 				return -EINVAL;
734 			break;
735 		case INET_DIAG_BC_AUTO:
736 		case INET_DIAG_BC_JMP:
737 		case INET_DIAG_BC_NOP:
738 			break;
739 		default:
740 			return -EINVAL;
741 		}
742 
743 		if (op->code != INET_DIAG_BC_NOP) {
744 			if (op->no < min_len || op->no > len + 4 || op->no & 3)
745 				return -EINVAL;
746 			if (op->no < len &&
747 			    !valid_cc(bytecode, bytecode_len, len - op->no))
748 				return -EINVAL;
749 		}
750 
751 		if (op->yes < min_len || op->yes > len + 4 || op->yes & 3)
752 			return -EINVAL;
753 		bc  += op->yes;
754 		len -= op->yes;
755 	}
756 	return len == 0 ? 0 : -EINVAL;
757 }
758 
759 static int inet_csk_diag_dump(struct sock *sk,
760 			      struct sk_buff *skb,
761 			      struct netlink_callback *cb,
762 			      const struct inet_diag_req_v2 *r,
763 			      const struct nlattr *bc)
764 {
765 	if (!inet_diag_bc_sk(bc, sk))
766 		return 0;
767 
768 	return inet_csk_diag_fill(sk, skb, r,
769 				  sk_user_ns(NETLINK_CB(cb->skb).sk),
770 				  NETLINK_CB(cb->skb).portid,
771 				  cb->nlh->nlmsg_seq, NLM_F_MULTI, cb->nlh);
772 }
773 
774 static void twsk_build_assert(void)
775 {
776 	BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_family) !=
777 		     offsetof(struct sock, sk_family));
778 
779 	BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_num) !=
780 		     offsetof(struct inet_sock, inet_num));
781 
782 	BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_dport) !=
783 		     offsetof(struct inet_sock, inet_dport));
784 
785 	BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_rcv_saddr) !=
786 		     offsetof(struct inet_sock, inet_rcv_saddr));
787 
788 	BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_daddr) !=
789 		     offsetof(struct inet_sock, inet_daddr));
790 
791 #if IS_ENABLED(CONFIG_IPV6)
792 	BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_v6_rcv_saddr) !=
793 		     offsetof(struct sock, sk_v6_rcv_saddr));
794 
795 	BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_v6_daddr) !=
796 		     offsetof(struct sock, sk_v6_daddr));
797 #endif
798 }
799 
800 void inet_diag_dump_icsk(struct inet_hashinfo *hashinfo, struct sk_buff *skb,
801 			 struct netlink_callback *cb,
802 			 const struct inet_diag_req_v2 *r, struct nlattr *bc)
803 {
804 	struct net *net = sock_net(skb->sk);
805 	int i, num, s_i, s_num;
806 	u32 idiag_states = r->idiag_states;
807 
808 	if (idiag_states & TCPF_SYN_RECV)
809 		idiag_states |= TCPF_NEW_SYN_RECV;
810 	s_i = cb->args[1];
811 	s_num = num = cb->args[2];
812 
813 	if (cb->args[0] == 0) {
814 		if (!(idiag_states & TCPF_LISTEN))
815 			goto skip_listen_ht;
816 
817 		for (i = s_i; i < INET_LHTABLE_SIZE; i++) {
818 			struct inet_listen_hashbucket *ilb;
819 			struct sock *sk;
820 
821 			num = 0;
822 			ilb = &hashinfo->listening_hash[i];
823 			spin_lock_bh(&ilb->lock);
824 			sk_for_each(sk, &ilb->head) {
825 				struct inet_sock *inet = inet_sk(sk);
826 
827 				if (!net_eq(sock_net(sk), net))
828 					continue;
829 
830 				if (num < s_num) {
831 					num++;
832 					continue;
833 				}
834 
835 				if (r->sdiag_family != AF_UNSPEC &&
836 				    sk->sk_family != r->sdiag_family)
837 					goto next_listen;
838 
839 				if (r->id.idiag_sport != inet->inet_sport &&
840 				    r->id.idiag_sport)
841 					goto next_listen;
842 
843 				if (r->id.idiag_dport ||
844 				    cb->args[3] > 0)
845 					goto next_listen;
846 
847 				if (inet_csk_diag_dump(sk, skb, cb, r, bc) < 0) {
848 					spin_unlock_bh(&ilb->lock);
849 					goto done;
850 				}
851 
852 next_listen:
853 				cb->args[3] = 0;
854 				cb->args[4] = 0;
855 				++num;
856 			}
857 			spin_unlock_bh(&ilb->lock);
858 
859 			s_num = 0;
860 			cb->args[3] = 0;
861 			cb->args[4] = 0;
862 		}
863 skip_listen_ht:
864 		cb->args[0] = 1;
865 		s_i = num = s_num = 0;
866 	}
867 
868 	if (!(idiag_states & ~TCPF_LISTEN))
869 		goto out;
870 
871 	for (i = s_i; i <= hashinfo->ehash_mask; i++) {
872 		struct inet_ehash_bucket *head = &hashinfo->ehash[i];
873 		spinlock_t *lock = inet_ehash_lockp(hashinfo, i);
874 		struct hlist_nulls_node *node;
875 		struct sock *sk;
876 
877 		num = 0;
878 
879 		if (hlist_nulls_empty(&head->chain))
880 			continue;
881 
882 		if (i > s_i)
883 			s_num = 0;
884 
885 		spin_lock_bh(lock);
886 		sk_nulls_for_each(sk, node, &head->chain) {
887 			int state, res;
888 
889 			if (!net_eq(sock_net(sk), net))
890 				continue;
891 			if (num < s_num)
892 				goto next_normal;
893 			state = (sk->sk_state == TCP_TIME_WAIT) ?
894 				inet_twsk(sk)->tw_substate : sk->sk_state;
895 			if (!(idiag_states & (1 << state)))
896 				goto next_normal;
897 			if (r->sdiag_family != AF_UNSPEC &&
898 			    sk->sk_family != r->sdiag_family)
899 				goto next_normal;
900 			if (r->id.idiag_sport != htons(sk->sk_num) &&
901 			    r->id.idiag_sport)
902 				goto next_normal;
903 			if (r->id.idiag_dport != sk->sk_dport &&
904 			    r->id.idiag_dport)
905 				goto next_normal;
906 			twsk_build_assert();
907 
908 			if (!inet_diag_bc_sk(bc, sk))
909 				goto next_normal;
910 
911 			res = sk_diag_fill(sk, skb, r,
912 					   sk_user_ns(NETLINK_CB(cb->skb).sk),
913 					   NETLINK_CB(cb->skb).portid,
914 					   cb->nlh->nlmsg_seq, NLM_F_MULTI,
915 					   cb->nlh);
916 			if (res < 0) {
917 				spin_unlock_bh(lock);
918 				goto done;
919 			}
920 next_normal:
921 			++num;
922 		}
923 
924 		spin_unlock_bh(lock);
925 		cond_resched();
926 	}
927 
928 done:
929 	cb->args[1] = i;
930 	cb->args[2] = num;
931 out:
932 	;
933 }
934 EXPORT_SYMBOL_GPL(inet_diag_dump_icsk);
935 
936 static int __inet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
937 			    const struct inet_diag_req_v2 *r,
938 			    struct nlattr *bc)
939 {
940 	const struct inet_diag_handler *handler;
941 	int err = 0;
942 
943 	handler = inet_diag_lock_handler(r->sdiag_protocol);
944 	if (!IS_ERR(handler))
945 		handler->dump(skb, cb, r, bc);
946 	else
947 		err = PTR_ERR(handler);
948 	inet_diag_unlock_handler(handler);
949 
950 	return err ? : skb->len;
951 }
952 
953 static int inet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
954 {
955 	int hdrlen = sizeof(struct inet_diag_req_v2);
956 	struct nlattr *bc = NULL;
957 
958 	if (nlmsg_attrlen(cb->nlh, hdrlen))
959 		bc = nlmsg_find_attr(cb->nlh, hdrlen, INET_DIAG_REQ_BYTECODE);
960 
961 	return __inet_diag_dump(skb, cb, nlmsg_data(cb->nlh), bc);
962 }
963 
964 static int inet_diag_type2proto(int type)
965 {
966 	switch (type) {
967 	case TCPDIAG_GETSOCK:
968 		return IPPROTO_TCP;
969 	case DCCPDIAG_GETSOCK:
970 		return IPPROTO_DCCP;
971 	default:
972 		return 0;
973 	}
974 }
975 
976 static int inet_diag_dump_compat(struct sk_buff *skb,
977 				 struct netlink_callback *cb)
978 {
979 	struct inet_diag_req *rc = nlmsg_data(cb->nlh);
980 	int hdrlen = sizeof(struct inet_diag_req);
981 	struct inet_diag_req_v2 req;
982 	struct nlattr *bc = NULL;
983 
984 	req.sdiag_family = AF_UNSPEC; /* compatibility */
985 	req.sdiag_protocol = inet_diag_type2proto(cb->nlh->nlmsg_type);
986 	req.idiag_ext = rc->idiag_ext;
987 	req.idiag_states = rc->idiag_states;
988 	req.id = rc->id;
989 
990 	if (nlmsg_attrlen(cb->nlh, hdrlen))
991 		bc = nlmsg_find_attr(cb->nlh, hdrlen, INET_DIAG_REQ_BYTECODE);
992 
993 	return __inet_diag_dump(skb, cb, &req, bc);
994 }
995 
996 static int inet_diag_get_exact_compat(struct sk_buff *in_skb,
997 				      const struct nlmsghdr *nlh)
998 {
999 	struct inet_diag_req *rc = nlmsg_data(nlh);
1000 	struct inet_diag_req_v2 req;
1001 
1002 	req.sdiag_family = rc->idiag_family;
1003 	req.sdiag_protocol = inet_diag_type2proto(nlh->nlmsg_type);
1004 	req.idiag_ext = rc->idiag_ext;
1005 	req.idiag_states = rc->idiag_states;
1006 	req.id = rc->id;
1007 
1008 	return inet_diag_cmd_exact(SOCK_DIAG_BY_FAMILY, in_skb, nlh, &req);
1009 }
1010 
1011 static int inet_diag_rcv_msg_compat(struct sk_buff *skb, struct nlmsghdr *nlh)
1012 {
1013 	int hdrlen = sizeof(struct inet_diag_req);
1014 	struct net *net = sock_net(skb->sk);
1015 
1016 	if (nlh->nlmsg_type >= INET_DIAG_GETSOCK_MAX ||
1017 	    nlmsg_len(nlh) < hdrlen)
1018 		return -EINVAL;
1019 
1020 	if (nlh->nlmsg_flags & NLM_F_DUMP) {
1021 		if (nlmsg_attrlen(nlh, hdrlen)) {
1022 			struct nlattr *attr;
1023 
1024 			attr = nlmsg_find_attr(nlh, hdrlen,
1025 					       INET_DIAG_REQ_BYTECODE);
1026 			if (!attr ||
1027 			    nla_len(attr) < sizeof(struct inet_diag_bc_op) ||
1028 			    inet_diag_bc_audit(nla_data(attr), nla_len(attr)))
1029 				return -EINVAL;
1030 		}
1031 		{
1032 			struct netlink_dump_control c = {
1033 				.dump = inet_diag_dump_compat,
1034 			};
1035 			return netlink_dump_start(net->diag_nlsk, skb, nlh, &c);
1036 		}
1037 	}
1038 
1039 	return inet_diag_get_exact_compat(skb, nlh);
1040 }
1041 
1042 static int inet_diag_handler_cmd(struct sk_buff *skb, struct nlmsghdr *h)
1043 {
1044 	int hdrlen = sizeof(struct inet_diag_req_v2);
1045 	struct net *net = sock_net(skb->sk);
1046 
1047 	if (nlmsg_len(h) < hdrlen)
1048 		return -EINVAL;
1049 
1050 	if (h->nlmsg_type == SOCK_DIAG_BY_FAMILY &&
1051 	    h->nlmsg_flags & NLM_F_DUMP) {
1052 		if (nlmsg_attrlen(h, hdrlen)) {
1053 			struct nlattr *attr;
1054 
1055 			attr = nlmsg_find_attr(h, hdrlen,
1056 					       INET_DIAG_REQ_BYTECODE);
1057 			if (!attr ||
1058 			    nla_len(attr) < sizeof(struct inet_diag_bc_op) ||
1059 			    inet_diag_bc_audit(nla_data(attr), nla_len(attr)))
1060 				return -EINVAL;
1061 		}
1062 		{
1063 			struct netlink_dump_control c = {
1064 				.dump = inet_diag_dump,
1065 			};
1066 			return netlink_dump_start(net->diag_nlsk, skb, h, &c);
1067 		}
1068 	}
1069 
1070 	return inet_diag_cmd_exact(h->nlmsg_type, skb, h, nlmsg_data(h));
1071 }
1072 
1073 static
1074 int inet_diag_handler_get_info(struct sk_buff *skb, struct sock *sk)
1075 {
1076 	const struct inet_diag_handler *handler;
1077 	struct nlmsghdr *nlh;
1078 	struct nlattr *attr;
1079 	struct inet_diag_msg *r;
1080 	void *info = NULL;
1081 	int err = 0;
1082 
1083 	nlh = nlmsg_put(skb, 0, 0, SOCK_DIAG_BY_FAMILY, sizeof(*r), 0);
1084 	if (!nlh)
1085 		return -ENOMEM;
1086 
1087 	r = nlmsg_data(nlh);
1088 	memset(r, 0, sizeof(*r));
1089 	inet_diag_msg_common_fill(r, sk);
1090 	if (sk->sk_type == SOCK_DGRAM || sk->sk_type == SOCK_STREAM)
1091 		r->id.idiag_sport = inet_sk(sk)->inet_sport;
1092 	r->idiag_state = sk->sk_state;
1093 
1094 	if ((err = nla_put_u8(skb, INET_DIAG_PROTOCOL, sk->sk_protocol))) {
1095 		nlmsg_cancel(skb, nlh);
1096 		return err;
1097 	}
1098 
1099 	handler = inet_diag_lock_handler(sk->sk_protocol);
1100 	if (IS_ERR(handler)) {
1101 		inet_diag_unlock_handler(handler);
1102 		nlmsg_cancel(skb, nlh);
1103 		return PTR_ERR(handler);
1104 	}
1105 
1106 	attr = handler->idiag_info_size
1107 		? nla_reserve_64bit(skb, INET_DIAG_INFO,
1108 				    handler->idiag_info_size,
1109 				    INET_DIAG_PAD)
1110 		: NULL;
1111 	if (attr)
1112 		info = nla_data(attr);
1113 
1114 	handler->idiag_get_info(sk, r, info);
1115 	inet_diag_unlock_handler(handler);
1116 
1117 	nlmsg_end(skb, nlh);
1118 	return 0;
1119 }
1120 
1121 static const struct sock_diag_handler inet_diag_handler = {
1122 	.family = AF_INET,
1123 	.dump = inet_diag_handler_cmd,
1124 	.get_info = inet_diag_handler_get_info,
1125 	.destroy = inet_diag_handler_cmd,
1126 };
1127 
1128 static const struct sock_diag_handler inet6_diag_handler = {
1129 	.family = AF_INET6,
1130 	.dump = inet_diag_handler_cmd,
1131 	.get_info = inet_diag_handler_get_info,
1132 	.destroy = inet_diag_handler_cmd,
1133 };
1134 
1135 int inet_diag_register(const struct inet_diag_handler *h)
1136 {
1137 	const __u16 type = h->idiag_type;
1138 	int err = -EINVAL;
1139 
1140 	if (type >= IPPROTO_MAX)
1141 		goto out;
1142 
1143 	mutex_lock(&inet_diag_table_mutex);
1144 	err = -EEXIST;
1145 	if (!inet_diag_table[type]) {
1146 		inet_diag_table[type] = h;
1147 		err = 0;
1148 	}
1149 	mutex_unlock(&inet_diag_table_mutex);
1150 out:
1151 	return err;
1152 }
1153 EXPORT_SYMBOL_GPL(inet_diag_register);
1154 
1155 void inet_diag_unregister(const struct inet_diag_handler *h)
1156 {
1157 	const __u16 type = h->idiag_type;
1158 
1159 	if (type >= IPPROTO_MAX)
1160 		return;
1161 
1162 	mutex_lock(&inet_diag_table_mutex);
1163 	inet_diag_table[type] = NULL;
1164 	mutex_unlock(&inet_diag_table_mutex);
1165 }
1166 EXPORT_SYMBOL_GPL(inet_diag_unregister);
1167 
1168 static int __init inet_diag_init(void)
1169 {
1170 	const int inet_diag_table_size = (IPPROTO_MAX *
1171 					  sizeof(struct inet_diag_handler *));
1172 	int err = -ENOMEM;
1173 
1174 	inet_diag_table = kzalloc(inet_diag_table_size, GFP_KERNEL);
1175 	if (!inet_diag_table)
1176 		goto out;
1177 
1178 	err = sock_diag_register(&inet_diag_handler);
1179 	if (err)
1180 		goto out_free_nl;
1181 
1182 	err = sock_diag_register(&inet6_diag_handler);
1183 	if (err)
1184 		goto out_free_inet;
1185 
1186 	sock_diag_register_inet_compat(inet_diag_rcv_msg_compat);
1187 out:
1188 	return err;
1189 
1190 out_free_inet:
1191 	sock_diag_unregister(&inet_diag_handler);
1192 out_free_nl:
1193 	kfree(inet_diag_table);
1194 	goto out;
1195 }
1196 
1197 static void __exit inet_diag_exit(void)
1198 {
1199 	sock_diag_unregister(&inet6_diag_handler);
1200 	sock_diag_unregister(&inet_diag_handler);
1201 	sock_diag_unregister_inet_compat(inet_diag_rcv_msg_compat);
1202 	kfree(inet_diag_table);
1203 }
1204 
1205 module_init(inet_diag_init);
1206 module_exit(inet_diag_exit);
1207 MODULE_LICENSE("GPL");
1208 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2 /* AF_INET */);
1209 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 10 /* AF_INET6 */);
1210