xref: /linux/net/ipv4/inet_diag.c (revision 3eee9ac24cef892e6883b3669544c6101b70c91e)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * inet_diag.c	Module for monitoring INET transport protocols sockets.
4  *
5  * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
6  */
7 
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/types.h>
11 #include <linux/fcntl.h>
12 #include <linux/random.h>
13 #include <linux/slab.h>
14 #include <linux/cache.h>
15 #include <linux/init.h>
16 #include <linux/time.h>
17 
18 #include <net/icmp.h>
19 #include <net/tcp.h>
20 #include <net/ipv6.h>
21 #include <net/inet_common.h>
22 #include <net/inet_connection_sock.h>
23 #include <net/inet_hashtables.h>
24 #include <net/inet_timewait_sock.h>
25 #include <net/inet6_hashtables.h>
26 #include <net/bpf_sk_storage.h>
27 #include <net/netlink.h>
28 
29 #include <linux/inet.h>
30 #include <linux/stddef.h>
31 
32 #include <linux/inet_diag.h>
33 #include <linux/sock_diag.h>
34 
35 static const struct inet_diag_handler __rcu **inet_diag_table;
36 
37 struct inet_diag_entry {
38 	const __be32 *saddr;
39 	const __be32 *daddr;
40 	u16 sport;
41 	u16 dport;
42 	u16 family;
43 	u16 userlocks;
44 	u32 ifindex;
45 	u32 mark;
46 #ifdef CONFIG_SOCK_CGROUP_DATA
47 	u64 cgroup_id;
48 #endif
49 };
50 
51 static const struct inet_diag_handler *inet_diag_lock_handler(int proto)
52 {
53 	const struct inet_diag_handler *handler;
54 
55 	if (proto < 0 || proto >= IPPROTO_MAX)
56 		return NULL;
57 
58 	if (!READ_ONCE(inet_diag_table[proto]))
59 		sock_load_diag_module(AF_INET, proto);
60 
61 	rcu_read_lock();
62 	handler = rcu_dereference(inet_diag_table[proto]);
63 	if (handler && !try_module_get(handler->owner))
64 		handler = NULL;
65 	rcu_read_unlock();
66 
67 	return handler;
68 }
69 
70 static void inet_diag_unlock_handler(const struct inet_diag_handler *handler)
71 {
72 	module_put(handler->owner);
73 }
74 
75 void inet_diag_msg_common_fill(struct inet_diag_msg *r, struct sock *sk)
76 {
77 	r->idiag_family = sk->sk_family;
78 
79 	r->id.idiag_sport = htons(sk->sk_num);
80 	r->id.idiag_dport = sk->sk_dport;
81 	r->id.idiag_if = sk->sk_bound_dev_if;
82 	sock_diag_save_cookie(sk, r->id.idiag_cookie);
83 
84 #if IS_ENABLED(CONFIG_IPV6)
85 	if (sk->sk_family == AF_INET6) {
86 		*(struct in6_addr *)r->id.idiag_src = sk->sk_v6_rcv_saddr;
87 		*(struct in6_addr *)r->id.idiag_dst = sk->sk_v6_daddr;
88 	} else
89 #endif
90 	{
91 	memset(&r->id.idiag_src, 0, sizeof(r->id.idiag_src));
92 	memset(&r->id.idiag_dst, 0, sizeof(r->id.idiag_dst));
93 
94 	r->id.idiag_src[0] = sk->sk_rcv_saddr;
95 	r->id.idiag_dst[0] = sk->sk_daddr;
96 	}
97 }
98 EXPORT_SYMBOL_GPL(inet_diag_msg_common_fill);
99 
100 static size_t inet_sk_attr_size(struct sock *sk,
101 				const struct inet_diag_req_v2 *req,
102 				bool net_admin)
103 {
104 	const struct inet_diag_handler *handler;
105 	size_t aux = 0;
106 
107 	rcu_read_lock();
108 	handler = rcu_dereference(inet_diag_table[req->sdiag_protocol]);
109 	DEBUG_NET_WARN_ON_ONCE(!handler);
110 	if (handler && handler->idiag_get_aux_size)
111 		aux = handler->idiag_get_aux_size(sk, net_admin);
112 	rcu_read_unlock();
113 
114 	return	  nla_total_size(sizeof(struct tcp_info))
115 		+ nla_total_size(sizeof(struct inet_diag_msg))
116 		+ inet_diag_msg_attrs_size()
117 		+ nla_total_size(sizeof(struct inet_diag_meminfo))
118 		+ nla_total_size(SK_MEMINFO_VARS * sizeof(u32))
119 		+ nla_total_size(TCP_CA_NAME_MAX)
120 		+ nla_total_size(sizeof(struct tcpvegas_info))
121 		+ aux
122 		+ 64;
123 }
124 
125 int inet_diag_msg_attrs_fill(struct sock *sk, struct sk_buff *skb,
126 			     struct inet_diag_msg *r, int ext,
127 			     struct user_namespace *user_ns,
128 			     bool net_admin)
129 {
130 	const struct inet_sock *inet = inet_sk(sk);
131 	struct inet_diag_sockopt inet_sockopt;
132 
133 	if (nla_put_u8(skb, INET_DIAG_SHUTDOWN, sk->sk_shutdown))
134 		goto errout;
135 
136 	/* IPv6 dual-stack sockets use inet->tos for IPv4 connections,
137 	 * hence this needs to be included regardless of socket family.
138 	 */
139 	if (ext & (1 << (INET_DIAG_TOS - 1)))
140 		if (nla_put_u8(skb, INET_DIAG_TOS, READ_ONCE(inet->tos)) < 0)
141 			goto errout;
142 
143 #if IS_ENABLED(CONFIG_IPV6)
144 	if (r->idiag_family == AF_INET6) {
145 		if (ext & (1 << (INET_DIAG_TCLASS - 1)))
146 			if (nla_put_u8(skb, INET_DIAG_TCLASS,
147 				       inet6_sk(sk)->tclass) < 0)
148 				goto errout;
149 
150 		if (((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) &&
151 		    nla_put_u8(skb, INET_DIAG_SKV6ONLY, ipv6_only_sock(sk)))
152 			goto errout;
153 	}
154 #endif
155 
156 	if (net_admin && nla_put_u32(skb, INET_DIAG_MARK, READ_ONCE(sk->sk_mark)))
157 		goto errout;
158 
159 	if (ext & (1 << (INET_DIAG_CLASS_ID - 1)) ||
160 	    ext & (1 << (INET_DIAG_TCLASS - 1))) {
161 		u32 classid = 0;
162 
163 #ifdef CONFIG_SOCK_CGROUP_DATA
164 		classid = sock_cgroup_classid(&sk->sk_cgrp_data);
165 #endif
166 		/* Fallback to socket priority if class id isn't set.
167 		 * Classful qdiscs use it as direct reference to class.
168 		 * For cgroup2 classid is always zero.
169 		 */
170 		if (!classid)
171 			classid = READ_ONCE(sk->sk_priority);
172 
173 		if (nla_put_u32(skb, INET_DIAG_CLASS_ID, classid))
174 			goto errout;
175 	}
176 
177 #ifdef CONFIG_SOCK_CGROUP_DATA
178 	if (nla_put_u64_64bit(skb, INET_DIAG_CGROUP_ID,
179 			      cgroup_id(sock_cgroup_ptr(&sk->sk_cgrp_data)),
180 			      INET_DIAG_PAD))
181 		goto errout;
182 #endif
183 
184 	r->idiag_uid = from_kuid_munged(user_ns, sock_i_uid(sk));
185 	r->idiag_inode = sock_i_ino(sk);
186 
187 	memset(&inet_sockopt, 0, sizeof(inet_sockopt));
188 	inet_sockopt.recverr	= inet_test_bit(RECVERR, sk);
189 	inet_sockopt.is_icsk	= inet_test_bit(IS_ICSK, sk);
190 	inet_sockopt.freebind	= inet_test_bit(FREEBIND, sk);
191 	inet_sockopt.hdrincl	= inet_test_bit(HDRINCL, sk);
192 	inet_sockopt.mc_loop	= inet_test_bit(MC_LOOP, sk);
193 	inet_sockopt.transparent = inet_test_bit(TRANSPARENT, sk);
194 	inet_sockopt.mc_all	= inet_test_bit(MC_ALL, sk);
195 	inet_sockopt.nodefrag	= inet_test_bit(NODEFRAG, sk);
196 	inet_sockopt.bind_address_no_port = inet_test_bit(BIND_ADDRESS_NO_PORT, sk);
197 	inet_sockopt.recverr_rfc4884 = inet_test_bit(RECVERR_RFC4884, sk);
198 	inet_sockopt.defer_connect = inet_test_bit(DEFER_CONNECT, sk);
199 	if (nla_put(skb, INET_DIAG_SOCKOPT, sizeof(inet_sockopt),
200 		    &inet_sockopt))
201 		goto errout;
202 
203 	return 0;
204 errout:
205 	return 1;
206 }
207 EXPORT_SYMBOL_GPL(inet_diag_msg_attrs_fill);
208 
209 static int inet_diag_parse_attrs(const struct nlmsghdr *nlh, int hdrlen,
210 				 struct nlattr **req_nlas)
211 {
212 	struct nlattr *nla;
213 	int remaining;
214 
215 	nlmsg_for_each_attr(nla, nlh, hdrlen, remaining) {
216 		int type = nla_type(nla);
217 
218 		if (type == INET_DIAG_REQ_PROTOCOL && nla_len(nla) != sizeof(u32))
219 			return -EINVAL;
220 
221 		if (type < __INET_DIAG_REQ_MAX)
222 			req_nlas[type] = nla;
223 	}
224 	return 0;
225 }
226 
227 static int inet_diag_get_protocol(const struct inet_diag_req_v2 *req,
228 				  const struct inet_diag_dump_data *data)
229 {
230 	if (data->req_nlas[INET_DIAG_REQ_PROTOCOL])
231 		return nla_get_u32(data->req_nlas[INET_DIAG_REQ_PROTOCOL]);
232 	return req->sdiag_protocol;
233 }
234 
235 #define MAX_DUMP_ALLOC_SIZE (KMALLOC_MAX_SIZE - SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
236 
237 int inet_sk_diag_fill(struct sock *sk, struct inet_connection_sock *icsk,
238 		      struct sk_buff *skb, struct netlink_callback *cb,
239 		      const struct inet_diag_req_v2 *req,
240 		      u16 nlmsg_flags, bool net_admin)
241 {
242 	const struct tcp_congestion_ops *ca_ops;
243 	const struct inet_diag_handler *handler;
244 	struct inet_diag_dump_data *cb_data;
245 	int ext = req->idiag_ext;
246 	struct inet_diag_msg *r;
247 	struct nlmsghdr  *nlh;
248 	struct nlattr *attr;
249 	void *info = NULL;
250 	int protocol;
251 
252 	cb_data = cb->data;
253 	protocol = inet_diag_get_protocol(req, cb_data);
254 
255 	/* inet_diag_lock_handler() made sure inet_diag_table[] is stable. */
256 	handler = rcu_dereference_protected(inet_diag_table[protocol], 1);
257 	DEBUG_NET_WARN_ON_ONCE(!handler);
258 	if (!handler)
259 		return -ENXIO;
260 
261 	nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
262 			cb->nlh->nlmsg_type, sizeof(*r), nlmsg_flags);
263 	if (!nlh)
264 		return -EMSGSIZE;
265 
266 	r = nlmsg_data(nlh);
267 	BUG_ON(!sk_fullsock(sk));
268 
269 	inet_diag_msg_common_fill(r, sk);
270 	r->idiag_state = sk->sk_state;
271 	r->idiag_timer = 0;
272 	r->idiag_retrans = 0;
273 	r->idiag_expires = 0;
274 
275 	if (inet_diag_msg_attrs_fill(sk, skb, r, ext,
276 				     sk_user_ns(NETLINK_CB(cb->skb).sk),
277 				     net_admin))
278 		goto errout;
279 
280 	if (ext & (1 << (INET_DIAG_MEMINFO - 1))) {
281 		struct inet_diag_meminfo minfo = {
282 			.idiag_rmem = sk_rmem_alloc_get(sk),
283 			.idiag_wmem = READ_ONCE(sk->sk_wmem_queued),
284 			.idiag_fmem = sk_forward_alloc_get(sk),
285 			.idiag_tmem = sk_wmem_alloc_get(sk),
286 		};
287 
288 		if (nla_put(skb, INET_DIAG_MEMINFO, sizeof(minfo), &minfo) < 0)
289 			goto errout;
290 	}
291 
292 	if (ext & (1 << (INET_DIAG_SKMEMINFO - 1)))
293 		if (sock_diag_put_meminfo(sk, skb, INET_DIAG_SKMEMINFO))
294 			goto errout;
295 
296 	/*
297 	 * RAW sockets might have user-defined protocols assigned,
298 	 * so report the one supplied on socket creation.
299 	 */
300 	if (sk->sk_type == SOCK_RAW) {
301 		if (nla_put_u8(skb, INET_DIAG_PROTOCOL, sk->sk_protocol))
302 			goto errout;
303 	}
304 
305 	if (!icsk) {
306 		handler->idiag_get_info(sk, r, NULL);
307 		goto out;
308 	}
309 
310 	if (icsk->icsk_pending == ICSK_TIME_RETRANS ||
311 	    icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT ||
312 	    icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) {
313 		r->idiag_timer = 1;
314 		r->idiag_retrans = icsk->icsk_retransmits;
315 		r->idiag_expires =
316 			jiffies_delta_to_msecs(icsk->icsk_timeout - jiffies);
317 	} else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
318 		r->idiag_timer = 4;
319 		r->idiag_retrans = icsk->icsk_probes_out;
320 		r->idiag_expires =
321 			jiffies_delta_to_msecs(icsk->icsk_timeout - jiffies);
322 	} else if (timer_pending(&sk->sk_timer)) {
323 		r->idiag_timer = 2;
324 		r->idiag_retrans = icsk->icsk_probes_out;
325 		r->idiag_expires =
326 			jiffies_delta_to_msecs(sk->sk_timer.expires - jiffies);
327 	}
328 
329 	if ((ext & (1 << (INET_DIAG_INFO - 1))) && handler->idiag_info_size) {
330 		attr = nla_reserve_64bit(skb, INET_DIAG_INFO,
331 					 handler->idiag_info_size,
332 					 INET_DIAG_PAD);
333 		if (!attr)
334 			goto errout;
335 
336 		info = nla_data(attr);
337 	}
338 
339 	if (ext & (1 << (INET_DIAG_CONG - 1))) {
340 		int err = 0;
341 
342 		rcu_read_lock();
343 		ca_ops = READ_ONCE(icsk->icsk_ca_ops);
344 		if (ca_ops)
345 			err = nla_put_string(skb, INET_DIAG_CONG, ca_ops->name);
346 		rcu_read_unlock();
347 		if (err < 0)
348 			goto errout;
349 	}
350 
351 	handler->idiag_get_info(sk, r, info);
352 
353 	if (ext & (1 << (INET_DIAG_INFO - 1)) && handler->idiag_get_aux)
354 		if (handler->idiag_get_aux(sk, net_admin, skb) < 0)
355 			goto errout;
356 
357 	if (sk->sk_state < TCP_TIME_WAIT) {
358 		union tcp_cc_info info;
359 		size_t sz = 0;
360 		int attr;
361 
362 		rcu_read_lock();
363 		ca_ops = READ_ONCE(icsk->icsk_ca_ops);
364 		if (ca_ops && ca_ops->get_info)
365 			sz = ca_ops->get_info(sk, ext, &attr, &info);
366 		rcu_read_unlock();
367 		if (sz && nla_put(skb, attr, sz, &info) < 0)
368 			goto errout;
369 	}
370 
371 	/* Keep it at the end for potential retry with a larger skb,
372 	 * or else do best-effort fitting, which is only done for the
373 	 * first_nlmsg.
374 	 */
375 	if (cb_data->bpf_stg_diag) {
376 		bool first_nlmsg = ((unsigned char *)nlh == skb->data);
377 		unsigned int prev_min_dump_alloc;
378 		unsigned int total_nla_size = 0;
379 		unsigned int msg_len;
380 		int err;
381 
382 		msg_len = skb_tail_pointer(skb) - (unsigned char *)nlh;
383 		err = bpf_sk_storage_diag_put(cb_data->bpf_stg_diag, sk, skb,
384 					      INET_DIAG_SK_BPF_STORAGES,
385 					      &total_nla_size);
386 
387 		if (!err)
388 			goto out;
389 
390 		total_nla_size += msg_len;
391 		prev_min_dump_alloc = cb->min_dump_alloc;
392 		if (total_nla_size > prev_min_dump_alloc)
393 			cb->min_dump_alloc = min_t(u32, total_nla_size,
394 						   MAX_DUMP_ALLOC_SIZE);
395 
396 		if (!first_nlmsg)
397 			goto errout;
398 
399 		if (cb->min_dump_alloc > prev_min_dump_alloc)
400 			/* Retry with pskb_expand_head() with
401 			 * __GFP_DIRECT_RECLAIM
402 			 */
403 			goto errout;
404 
405 		WARN_ON_ONCE(total_nla_size <= prev_min_dump_alloc);
406 
407 		/* Send what we have for this sk
408 		 * and move on to the next sk in the following
409 		 * dump()
410 		 */
411 	}
412 
413 out:
414 	nlmsg_end(skb, nlh);
415 	return 0;
416 
417 errout:
418 	nlmsg_cancel(skb, nlh);
419 	return -EMSGSIZE;
420 }
421 EXPORT_SYMBOL_GPL(inet_sk_diag_fill);
422 
423 static int inet_twsk_diag_fill(struct sock *sk,
424 			       struct sk_buff *skb,
425 			       struct netlink_callback *cb,
426 			       u16 nlmsg_flags, bool net_admin)
427 {
428 	struct inet_timewait_sock *tw = inet_twsk(sk);
429 	struct inet_diag_msg *r;
430 	struct nlmsghdr *nlh;
431 	long tmo;
432 
433 	nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid,
434 			cb->nlh->nlmsg_seq, cb->nlh->nlmsg_type,
435 			sizeof(*r), nlmsg_flags);
436 	if (!nlh)
437 		return -EMSGSIZE;
438 
439 	r = nlmsg_data(nlh);
440 	BUG_ON(tw->tw_state != TCP_TIME_WAIT);
441 
442 	inet_diag_msg_common_fill(r, sk);
443 	r->idiag_retrans      = 0;
444 
445 	r->idiag_state	      = tw->tw_substate;
446 	r->idiag_timer	      = 3;
447 	tmo = tw->tw_timer.expires - jiffies;
448 	r->idiag_expires      = jiffies_delta_to_msecs(tmo);
449 	r->idiag_rqueue	      = 0;
450 	r->idiag_wqueue	      = 0;
451 	r->idiag_uid	      = 0;
452 	r->idiag_inode	      = 0;
453 
454 	if (net_admin && nla_put_u32(skb, INET_DIAG_MARK,
455 				     tw->tw_mark)) {
456 		nlmsg_cancel(skb, nlh);
457 		return -EMSGSIZE;
458 	}
459 
460 	nlmsg_end(skb, nlh);
461 	return 0;
462 }
463 
464 static int inet_req_diag_fill(struct sock *sk, struct sk_buff *skb,
465 			      struct netlink_callback *cb,
466 			      u16 nlmsg_flags, bool net_admin)
467 {
468 	struct request_sock *reqsk = inet_reqsk(sk);
469 	struct inet_diag_msg *r;
470 	struct nlmsghdr *nlh;
471 	long tmo;
472 
473 	nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
474 			cb->nlh->nlmsg_type, sizeof(*r), nlmsg_flags);
475 	if (!nlh)
476 		return -EMSGSIZE;
477 
478 	r = nlmsg_data(nlh);
479 	inet_diag_msg_common_fill(r, sk);
480 	r->idiag_state = TCP_SYN_RECV;
481 	r->idiag_timer = 1;
482 	r->idiag_retrans = reqsk->num_retrans;
483 
484 	BUILD_BUG_ON(offsetof(struct inet_request_sock, ir_cookie) !=
485 		     offsetof(struct sock, sk_cookie));
486 
487 	tmo = inet_reqsk(sk)->rsk_timer.expires - jiffies;
488 	r->idiag_expires = jiffies_delta_to_msecs(tmo);
489 	r->idiag_rqueue	= 0;
490 	r->idiag_wqueue	= 0;
491 	r->idiag_uid	= 0;
492 	r->idiag_inode	= 0;
493 
494 	if (net_admin && nla_put_u32(skb, INET_DIAG_MARK,
495 				     inet_rsk(reqsk)->ir_mark)) {
496 		nlmsg_cancel(skb, nlh);
497 		return -EMSGSIZE;
498 	}
499 
500 	nlmsg_end(skb, nlh);
501 	return 0;
502 }
503 
504 static int sk_diag_fill(struct sock *sk, struct sk_buff *skb,
505 			struct netlink_callback *cb,
506 			const struct inet_diag_req_v2 *r,
507 			u16 nlmsg_flags, bool net_admin)
508 {
509 	if (sk->sk_state == TCP_TIME_WAIT)
510 		return inet_twsk_diag_fill(sk, skb, cb, nlmsg_flags, net_admin);
511 
512 	if (sk->sk_state == TCP_NEW_SYN_RECV)
513 		return inet_req_diag_fill(sk, skb, cb, nlmsg_flags, net_admin);
514 
515 	return inet_sk_diag_fill(sk, inet_csk(sk), skb, cb, r, nlmsg_flags,
516 				 net_admin);
517 }
518 
519 struct sock *inet_diag_find_one_icsk(struct net *net,
520 				     struct inet_hashinfo *hashinfo,
521 				     const struct inet_diag_req_v2 *req)
522 {
523 	struct sock *sk;
524 
525 	rcu_read_lock();
526 	if (req->sdiag_family == AF_INET)
527 		sk = inet_lookup(net, hashinfo, NULL, 0, req->id.idiag_dst[0],
528 				 req->id.idiag_dport, req->id.idiag_src[0],
529 				 req->id.idiag_sport, req->id.idiag_if);
530 #if IS_ENABLED(CONFIG_IPV6)
531 	else if (req->sdiag_family == AF_INET6) {
532 		if (ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_dst) &&
533 		    ipv6_addr_v4mapped((struct in6_addr *)req->id.idiag_src))
534 			sk = inet_lookup(net, hashinfo, NULL, 0, req->id.idiag_dst[3],
535 					 req->id.idiag_dport, req->id.idiag_src[3],
536 					 req->id.idiag_sport, req->id.idiag_if);
537 		else
538 			sk = inet6_lookup(net, hashinfo, NULL, 0,
539 					  (struct in6_addr *)req->id.idiag_dst,
540 					  req->id.idiag_dport,
541 					  (struct in6_addr *)req->id.idiag_src,
542 					  req->id.idiag_sport,
543 					  req->id.idiag_if);
544 	}
545 #endif
546 	else {
547 		rcu_read_unlock();
548 		return ERR_PTR(-EINVAL);
549 	}
550 	rcu_read_unlock();
551 	if (!sk)
552 		return ERR_PTR(-ENOENT);
553 
554 	if (sock_diag_check_cookie(sk, req->id.idiag_cookie)) {
555 		sock_gen_put(sk);
556 		return ERR_PTR(-ENOENT);
557 	}
558 
559 	return sk;
560 }
561 EXPORT_SYMBOL_GPL(inet_diag_find_one_icsk);
562 
563 int inet_diag_dump_one_icsk(struct inet_hashinfo *hashinfo,
564 			    struct netlink_callback *cb,
565 			    const struct inet_diag_req_v2 *req)
566 {
567 	struct sk_buff *in_skb = cb->skb;
568 	bool net_admin = netlink_net_capable(in_skb, CAP_NET_ADMIN);
569 	struct net *net = sock_net(in_skb->sk);
570 	struct sk_buff *rep;
571 	struct sock *sk;
572 	int err;
573 
574 	sk = inet_diag_find_one_icsk(net, hashinfo, req);
575 	if (IS_ERR(sk))
576 		return PTR_ERR(sk);
577 
578 	rep = nlmsg_new(inet_sk_attr_size(sk, req, net_admin), GFP_KERNEL);
579 	if (!rep) {
580 		err = -ENOMEM;
581 		goto out;
582 	}
583 
584 	err = sk_diag_fill(sk, rep, cb, req, 0, net_admin);
585 	if (err < 0) {
586 		WARN_ON(err == -EMSGSIZE);
587 		nlmsg_free(rep);
588 		goto out;
589 	}
590 	err = nlmsg_unicast(net->diag_nlsk, rep, NETLINK_CB(in_skb).portid);
591 
592 out:
593 	if (sk)
594 		sock_gen_put(sk);
595 
596 	return err;
597 }
598 EXPORT_SYMBOL_GPL(inet_diag_dump_one_icsk);
599 
600 static int inet_diag_cmd_exact(int cmd, struct sk_buff *in_skb,
601 			       const struct nlmsghdr *nlh,
602 			       int hdrlen,
603 			       const struct inet_diag_req_v2 *req)
604 {
605 	const struct inet_diag_handler *handler;
606 	struct inet_diag_dump_data dump_data;
607 	int err, protocol;
608 
609 	memset(&dump_data, 0, sizeof(dump_data));
610 	err = inet_diag_parse_attrs(nlh, hdrlen, dump_data.req_nlas);
611 	if (err)
612 		return err;
613 
614 	protocol = inet_diag_get_protocol(req, &dump_data);
615 
616 	handler = inet_diag_lock_handler(protocol);
617 	if (!handler)
618 		return -ENOENT;
619 
620 	if (cmd == SOCK_DIAG_BY_FAMILY) {
621 		struct netlink_callback cb = {
622 			.nlh = nlh,
623 			.skb = in_skb,
624 			.data = &dump_data,
625 		};
626 		err = handler->dump_one(&cb, req);
627 	} else if (cmd == SOCK_DESTROY && handler->destroy) {
628 		err = handler->destroy(in_skb, req);
629 	} else {
630 		err = -EOPNOTSUPP;
631 	}
632 	inet_diag_unlock_handler(handler);
633 
634 	return err;
635 }
636 
637 static int bitstring_match(const __be32 *a1, const __be32 *a2, int bits)
638 {
639 	int words = bits >> 5;
640 
641 	bits &= 0x1f;
642 
643 	if (words) {
644 		if (memcmp(a1, a2, words << 2))
645 			return 0;
646 	}
647 	if (bits) {
648 		__be32 w1, w2;
649 		__be32 mask;
650 
651 		w1 = a1[words];
652 		w2 = a2[words];
653 
654 		mask = htonl((0xffffffff) << (32 - bits));
655 
656 		if ((w1 ^ w2) & mask)
657 			return 0;
658 	}
659 
660 	return 1;
661 }
662 
663 static int inet_diag_bc_run(const struct nlattr *_bc,
664 			    const struct inet_diag_entry *entry)
665 {
666 	const void *bc = nla_data(_bc);
667 	int len = nla_len(_bc);
668 
669 	while (len > 0) {
670 		int yes = 1;
671 		const struct inet_diag_bc_op *op = bc;
672 
673 		switch (op->code) {
674 		case INET_DIAG_BC_NOP:
675 			break;
676 		case INET_DIAG_BC_JMP:
677 			yes = 0;
678 			break;
679 		case INET_DIAG_BC_S_EQ:
680 			yes = entry->sport == op[1].no;
681 			break;
682 		case INET_DIAG_BC_S_GE:
683 			yes = entry->sport >= op[1].no;
684 			break;
685 		case INET_DIAG_BC_S_LE:
686 			yes = entry->sport <= op[1].no;
687 			break;
688 		case INET_DIAG_BC_D_EQ:
689 			yes = entry->dport == op[1].no;
690 			break;
691 		case INET_DIAG_BC_D_GE:
692 			yes = entry->dport >= op[1].no;
693 			break;
694 		case INET_DIAG_BC_D_LE:
695 			yes = entry->dport <= op[1].no;
696 			break;
697 		case INET_DIAG_BC_AUTO:
698 			yes = !(entry->userlocks & SOCK_BINDPORT_LOCK);
699 			break;
700 		case INET_DIAG_BC_S_COND:
701 		case INET_DIAG_BC_D_COND: {
702 			const struct inet_diag_hostcond *cond;
703 			const __be32 *addr;
704 
705 			cond = (const struct inet_diag_hostcond *)(op + 1);
706 			if (cond->port != -1 &&
707 			    cond->port != (op->code == INET_DIAG_BC_S_COND ?
708 					     entry->sport : entry->dport)) {
709 				yes = 0;
710 				break;
711 			}
712 
713 			if (op->code == INET_DIAG_BC_S_COND)
714 				addr = entry->saddr;
715 			else
716 				addr = entry->daddr;
717 
718 			if (cond->family != AF_UNSPEC &&
719 			    cond->family != entry->family) {
720 				if (entry->family == AF_INET6 &&
721 				    cond->family == AF_INET) {
722 					if (addr[0] == 0 && addr[1] == 0 &&
723 					    addr[2] == htonl(0xffff) &&
724 					    bitstring_match(addr + 3,
725 							    cond->addr,
726 							    cond->prefix_len))
727 						break;
728 				}
729 				yes = 0;
730 				break;
731 			}
732 
733 			if (cond->prefix_len == 0)
734 				break;
735 			if (bitstring_match(addr, cond->addr,
736 					    cond->prefix_len))
737 				break;
738 			yes = 0;
739 			break;
740 		}
741 		case INET_DIAG_BC_DEV_COND: {
742 			u32 ifindex;
743 
744 			ifindex = *((const u32 *)(op + 1));
745 			if (ifindex != entry->ifindex)
746 				yes = 0;
747 			break;
748 		}
749 		case INET_DIAG_BC_MARK_COND: {
750 			struct inet_diag_markcond *cond;
751 
752 			cond = (struct inet_diag_markcond *)(op + 1);
753 			if ((entry->mark & cond->mask) != cond->mark)
754 				yes = 0;
755 			break;
756 		}
757 #ifdef CONFIG_SOCK_CGROUP_DATA
758 		case INET_DIAG_BC_CGROUP_COND: {
759 			u64 cgroup_id;
760 
761 			cgroup_id = get_unaligned((const u64 *)(op + 1));
762 			if (cgroup_id != entry->cgroup_id)
763 				yes = 0;
764 			break;
765 		}
766 #endif
767 		}
768 
769 		if (yes) {
770 			len -= op->yes;
771 			bc += op->yes;
772 		} else {
773 			len -= op->no;
774 			bc += op->no;
775 		}
776 	}
777 	return len == 0;
778 }
779 
780 /* This helper is available for all sockets (ESTABLISH, TIMEWAIT, SYN_RECV)
781  */
782 static void entry_fill_addrs(struct inet_diag_entry *entry,
783 			     const struct sock *sk)
784 {
785 #if IS_ENABLED(CONFIG_IPV6)
786 	if (sk->sk_family == AF_INET6) {
787 		entry->saddr = sk->sk_v6_rcv_saddr.s6_addr32;
788 		entry->daddr = sk->sk_v6_daddr.s6_addr32;
789 	} else
790 #endif
791 	{
792 		entry->saddr = &sk->sk_rcv_saddr;
793 		entry->daddr = &sk->sk_daddr;
794 	}
795 }
796 
797 int inet_diag_bc_sk(const struct nlattr *bc, struct sock *sk)
798 {
799 	struct inet_sock *inet = inet_sk(sk);
800 	struct inet_diag_entry entry;
801 
802 	if (!bc)
803 		return 1;
804 
805 	entry.family = sk->sk_family;
806 	entry_fill_addrs(&entry, sk);
807 	entry.sport = inet->inet_num;
808 	entry.dport = ntohs(inet->inet_dport);
809 	entry.ifindex = sk->sk_bound_dev_if;
810 	entry.userlocks = sk_fullsock(sk) ? sk->sk_userlocks : 0;
811 	if (sk_fullsock(sk))
812 		entry.mark = READ_ONCE(sk->sk_mark);
813 	else if (sk->sk_state == TCP_NEW_SYN_RECV)
814 		entry.mark = inet_rsk(inet_reqsk(sk))->ir_mark;
815 	else if (sk->sk_state == TCP_TIME_WAIT)
816 		entry.mark = inet_twsk(sk)->tw_mark;
817 	else
818 		entry.mark = 0;
819 #ifdef CONFIG_SOCK_CGROUP_DATA
820 	entry.cgroup_id = sk_fullsock(sk) ?
821 		cgroup_id(sock_cgroup_ptr(&sk->sk_cgrp_data)) : 0;
822 #endif
823 
824 	return inet_diag_bc_run(bc, &entry);
825 }
826 EXPORT_SYMBOL_GPL(inet_diag_bc_sk);
827 
828 static int valid_cc(const void *bc, int len, int cc)
829 {
830 	while (len >= 0) {
831 		const struct inet_diag_bc_op *op = bc;
832 
833 		if (cc > len)
834 			return 0;
835 		if (cc == len)
836 			return 1;
837 		if (op->yes < 4 || op->yes & 3)
838 			return 0;
839 		len -= op->yes;
840 		bc  += op->yes;
841 	}
842 	return 0;
843 }
844 
845 /* data is u32 ifindex */
846 static bool valid_devcond(const struct inet_diag_bc_op *op, int len,
847 			  int *min_len)
848 {
849 	/* Check ifindex space. */
850 	*min_len += sizeof(u32);
851 	if (len < *min_len)
852 		return false;
853 
854 	return true;
855 }
856 /* Validate an inet_diag_hostcond. */
857 static bool valid_hostcond(const struct inet_diag_bc_op *op, int len,
858 			   int *min_len)
859 {
860 	struct inet_diag_hostcond *cond;
861 	int addr_len;
862 
863 	/* Check hostcond space. */
864 	*min_len += sizeof(struct inet_diag_hostcond);
865 	if (len < *min_len)
866 		return false;
867 	cond = (struct inet_diag_hostcond *)(op + 1);
868 
869 	/* Check address family and address length. */
870 	switch (cond->family) {
871 	case AF_UNSPEC:
872 		addr_len = 0;
873 		break;
874 	case AF_INET:
875 		addr_len = sizeof(struct in_addr);
876 		break;
877 	case AF_INET6:
878 		addr_len = sizeof(struct in6_addr);
879 		break;
880 	default:
881 		return false;
882 	}
883 	*min_len += addr_len;
884 	if (len < *min_len)
885 		return false;
886 
887 	/* Check prefix length (in bits) vs address length (in bytes). */
888 	if (cond->prefix_len > 8 * addr_len)
889 		return false;
890 
891 	return true;
892 }
893 
894 /* Validate a port comparison operator. */
895 static bool valid_port_comparison(const struct inet_diag_bc_op *op,
896 				  int len, int *min_len)
897 {
898 	/* Port comparisons put the port in a follow-on inet_diag_bc_op. */
899 	*min_len += sizeof(struct inet_diag_bc_op);
900 	if (len < *min_len)
901 		return false;
902 	return true;
903 }
904 
905 static bool valid_markcond(const struct inet_diag_bc_op *op, int len,
906 			   int *min_len)
907 {
908 	*min_len += sizeof(struct inet_diag_markcond);
909 	return len >= *min_len;
910 }
911 
912 #ifdef CONFIG_SOCK_CGROUP_DATA
913 static bool valid_cgroupcond(const struct inet_diag_bc_op *op, int len,
914 			     int *min_len)
915 {
916 	*min_len += sizeof(u64);
917 	return len >= *min_len;
918 }
919 #endif
920 
921 static int inet_diag_bc_audit(const struct nlattr *attr,
922 			      const struct sk_buff *skb)
923 {
924 	bool net_admin = netlink_net_capable(skb, CAP_NET_ADMIN);
925 	const void *bytecode, *bc;
926 	int bytecode_len, len;
927 
928 	if (!attr || nla_len(attr) < sizeof(struct inet_diag_bc_op))
929 		return -EINVAL;
930 
931 	bytecode = bc = nla_data(attr);
932 	len = bytecode_len = nla_len(attr);
933 
934 	while (len > 0) {
935 		int min_len = sizeof(struct inet_diag_bc_op);
936 		const struct inet_diag_bc_op *op = bc;
937 
938 		switch (op->code) {
939 		case INET_DIAG_BC_S_COND:
940 		case INET_DIAG_BC_D_COND:
941 			if (!valid_hostcond(bc, len, &min_len))
942 				return -EINVAL;
943 			break;
944 		case INET_DIAG_BC_DEV_COND:
945 			if (!valid_devcond(bc, len, &min_len))
946 				return -EINVAL;
947 			break;
948 		case INET_DIAG_BC_S_EQ:
949 		case INET_DIAG_BC_S_GE:
950 		case INET_DIAG_BC_S_LE:
951 		case INET_DIAG_BC_D_EQ:
952 		case INET_DIAG_BC_D_GE:
953 		case INET_DIAG_BC_D_LE:
954 			if (!valid_port_comparison(bc, len, &min_len))
955 				return -EINVAL;
956 			break;
957 		case INET_DIAG_BC_MARK_COND:
958 			if (!net_admin)
959 				return -EPERM;
960 			if (!valid_markcond(bc, len, &min_len))
961 				return -EINVAL;
962 			break;
963 #ifdef CONFIG_SOCK_CGROUP_DATA
964 		case INET_DIAG_BC_CGROUP_COND:
965 			if (!valid_cgroupcond(bc, len, &min_len))
966 				return -EINVAL;
967 			break;
968 #endif
969 		case INET_DIAG_BC_AUTO:
970 		case INET_DIAG_BC_JMP:
971 		case INET_DIAG_BC_NOP:
972 			break;
973 		default:
974 			return -EINVAL;
975 		}
976 
977 		if (op->code != INET_DIAG_BC_NOP) {
978 			if (op->no < min_len || op->no > len + 4 || op->no & 3)
979 				return -EINVAL;
980 			if (op->no < len &&
981 			    !valid_cc(bytecode, bytecode_len, len - op->no))
982 				return -EINVAL;
983 		}
984 
985 		if (op->yes < min_len || op->yes > len + 4 || op->yes & 3)
986 			return -EINVAL;
987 		bc  += op->yes;
988 		len -= op->yes;
989 	}
990 	return len == 0 ? 0 : -EINVAL;
991 }
992 
993 static void twsk_build_assert(void)
994 {
995 	BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_family) !=
996 		     offsetof(struct sock, sk_family));
997 
998 	BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_num) !=
999 		     offsetof(struct inet_sock, inet_num));
1000 
1001 	BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_dport) !=
1002 		     offsetof(struct inet_sock, inet_dport));
1003 
1004 	BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_rcv_saddr) !=
1005 		     offsetof(struct inet_sock, inet_rcv_saddr));
1006 
1007 	BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_daddr) !=
1008 		     offsetof(struct inet_sock, inet_daddr));
1009 
1010 #if IS_ENABLED(CONFIG_IPV6)
1011 	BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_v6_rcv_saddr) !=
1012 		     offsetof(struct sock, sk_v6_rcv_saddr));
1013 
1014 	BUILD_BUG_ON(offsetof(struct inet_timewait_sock, tw_v6_daddr) !=
1015 		     offsetof(struct sock, sk_v6_daddr));
1016 #endif
1017 }
1018 
1019 void inet_diag_dump_icsk(struct inet_hashinfo *hashinfo, struct sk_buff *skb,
1020 			 struct netlink_callback *cb,
1021 			 const struct inet_diag_req_v2 *r)
1022 {
1023 	bool net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN);
1024 	struct inet_diag_dump_data *cb_data = cb->data;
1025 	struct net *net = sock_net(skb->sk);
1026 	u32 idiag_states = r->idiag_states;
1027 	int i, num, s_i, s_num;
1028 	struct nlattr *bc;
1029 	struct sock *sk;
1030 
1031 	bc = cb_data->inet_diag_nla_bc;
1032 	if (idiag_states & TCPF_SYN_RECV)
1033 		idiag_states |= TCPF_NEW_SYN_RECV;
1034 	s_i = cb->args[1];
1035 	s_num = num = cb->args[2];
1036 
1037 	if (cb->args[0] == 0) {
1038 		if (!(idiag_states & TCPF_LISTEN) || r->id.idiag_dport)
1039 			goto skip_listen_ht;
1040 
1041 		for (i = s_i; i <= hashinfo->lhash2_mask; i++) {
1042 			struct inet_listen_hashbucket *ilb;
1043 			struct hlist_nulls_node *node;
1044 
1045 			num = 0;
1046 			ilb = &hashinfo->lhash2[i];
1047 
1048 			if (hlist_nulls_empty(&ilb->nulls_head)) {
1049 				s_num = 0;
1050 				continue;
1051 			}
1052 			spin_lock(&ilb->lock);
1053 			sk_nulls_for_each(sk, node, &ilb->nulls_head) {
1054 				struct inet_sock *inet = inet_sk(sk);
1055 
1056 				if (!net_eq(sock_net(sk), net))
1057 					continue;
1058 
1059 				if (num < s_num) {
1060 					num++;
1061 					continue;
1062 				}
1063 
1064 				if (r->sdiag_family != AF_UNSPEC &&
1065 				    sk->sk_family != r->sdiag_family)
1066 					goto next_listen;
1067 
1068 				if (r->id.idiag_sport != inet->inet_sport &&
1069 				    r->id.idiag_sport)
1070 					goto next_listen;
1071 
1072 				if (!inet_diag_bc_sk(bc, sk))
1073 					goto next_listen;
1074 
1075 				if (inet_sk_diag_fill(sk, inet_csk(sk), skb,
1076 						      cb, r, NLM_F_MULTI,
1077 						      net_admin) < 0) {
1078 					spin_unlock(&ilb->lock);
1079 					goto done;
1080 				}
1081 
1082 next_listen:
1083 				++num;
1084 			}
1085 			spin_unlock(&ilb->lock);
1086 
1087 			s_num = 0;
1088 		}
1089 skip_listen_ht:
1090 		cb->args[0] = 1;
1091 		s_i = num = s_num = 0;
1092 	}
1093 
1094 /* Process a maximum of SKARR_SZ sockets at a time when walking hash buckets
1095  * with bh disabled.
1096  */
1097 #define SKARR_SZ 16
1098 
1099 	/* Dump bound but inactive (not listening, connecting, etc.) sockets */
1100 	if (cb->args[0] == 1) {
1101 		if (!(idiag_states & TCPF_BOUND_INACTIVE))
1102 			goto skip_bind_ht;
1103 
1104 		for (i = s_i; i < hashinfo->bhash_size; i++) {
1105 			struct inet_bind_hashbucket *ibb;
1106 			struct inet_bind2_bucket *tb2;
1107 			struct sock *sk_arr[SKARR_SZ];
1108 			int num_arr[SKARR_SZ];
1109 			int idx, accum, res;
1110 
1111 resume_bind_walk:
1112 			num = 0;
1113 			accum = 0;
1114 			ibb = &hashinfo->bhash2[i];
1115 
1116 			if (hlist_empty(&ibb->chain)) {
1117 				s_num = 0;
1118 				continue;
1119 			}
1120 			spin_lock_bh(&ibb->lock);
1121 			inet_bind_bucket_for_each(tb2, &ibb->chain) {
1122 				if (!net_eq(ib2_net(tb2), net))
1123 					continue;
1124 
1125 				sk_for_each_bound(sk, &tb2->owners) {
1126 					struct inet_sock *inet = inet_sk(sk);
1127 
1128 					if (num < s_num)
1129 						goto next_bind;
1130 
1131 					if (sk->sk_state != TCP_CLOSE ||
1132 					    !inet->inet_num)
1133 						goto next_bind;
1134 
1135 					if (r->sdiag_family != AF_UNSPEC &&
1136 					    r->sdiag_family != sk->sk_family)
1137 						goto next_bind;
1138 
1139 					if (!inet_diag_bc_sk(bc, sk))
1140 						goto next_bind;
1141 
1142 					sock_hold(sk);
1143 					num_arr[accum] = num;
1144 					sk_arr[accum] = sk;
1145 					if (++accum == SKARR_SZ)
1146 						goto pause_bind_walk;
1147 next_bind:
1148 					num++;
1149 				}
1150 			}
1151 pause_bind_walk:
1152 			spin_unlock_bh(&ibb->lock);
1153 
1154 			res = 0;
1155 			for (idx = 0; idx < accum; idx++) {
1156 				if (res >= 0) {
1157 					res = inet_sk_diag_fill(sk_arr[idx],
1158 								NULL, skb, cb,
1159 								r, NLM_F_MULTI,
1160 								net_admin);
1161 					if (res < 0)
1162 						num = num_arr[idx];
1163 				}
1164 				sock_put(sk_arr[idx]);
1165 			}
1166 			if (res < 0)
1167 				goto done;
1168 
1169 			cond_resched();
1170 
1171 			if (accum == SKARR_SZ) {
1172 				s_num = num + 1;
1173 				goto resume_bind_walk;
1174 			}
1175 
1176 			s_num = 0;
1177 		}
1178 skip_bind_ht:
1179 		cb->args[0] = 2;
1180 		s_i = num = s_num = 0;
1181 	}
1182 
1183 	if (!(idiag_states & ~TCPF_LISTEN))
1184 		goto out;
1185 
1186 	for (i = s_i; i <= hashinfo->ehash_mask; i++) {
1187 		struct inet_ehash_bucket *head = &hashinfo->ehash[i];
1188 		spinlock_t *lock = inet_ehash_lockp(hashinfo, i);
1189 		struct hlist_nulls_node *node;
1190 		struct sock *sk_arr[SKARR_SZ];
1191 		int num_arr[SKARR_SZ];
1192 		int idx, accum, res;
1193 
1194 		if (hlist_nulls_empty(&head->chain))
1195 			continue;
1196 
1197 		if (i > s_i)
1198 			s_num = 0;
1199 
1200 next_chunk:
1201 		num = 0;
1202 		accum = 0;
1203 		spin_lock_bh(lock);
1204 		sk_nulls_for_each(sk, node, &head->chain) {
1205 			int state;
1206 
1207 			if (!net_eq(sock_net(sk), net))
1208 				continue;
1209 			if (num < s_num)
1210 				goto next_normal;
1211 			state = (sk->sk_state == TCP_TIME_WAIT) ?
1212 				inet_twsk(sk)->tw_substate : sk->sk_state;
1213 			if (!(idiag_states & (1 << state)))
1214 				goto next_normal;
1215 			if (r->sdiag_family != AF_UNSPEC &&
1216 			    sk->sk_family != r->sdiag_family)
1217 				goto next_normal;
1218 			if (r->id.idiag_sport != htons(sk->sk_num) &&
1219 			    r->id.idiag_sport)
1220 				goto next_normal;
1221 			if (r->id.idiag_dport != sk->sk_dport &&
1222 			    r->id.idiag_dport)
1223 				goto next_normal;
1224 			twsk_build_assert();
1225 
1226 			if (!inet_diag_bc_sk(bc, sk))
1227 				goto next_normal;
1228 
1229 			if (!refcount_inc_not_zero(&sk->sk_refcnt))
1230 				goto next_normal;
1231 
1232 			num_arr[accum] = num;
1233 			sk_arr[accum] = sk;
1234 			if (++accum == SKARR_SZ)
1235 				break;
1236 next_normal:
1237 			++num;
1238 		}
1239 		spin_unlock_bh(lock);
1240 		res = 0;
1241 		for (idx = 0; idx < accum; idx++) {
1242 			if (res >= 0) {
1243 				res = sk_diag_fill(sk_arr[idx], skb, cb, r,
1244 						   NLM_F_MULTI, net_admin);
1245 				if (res < 0)
1246 					num = num_arr[idx];
1247 			}
1248 			sock_gen_put(sk_arr[idx]);
1249 		}
1250 		if (res < 0)
1251 			break;
1252 		cond_resched();
1253 		if (accum == SKARR_SZ) {
1254 			s_num = num + 1;
1255 			goto next_chunk;
1256 		}
1257 	}
1258 
1259 done:
1260 	cb->args[1] = i;
1261 	cb->args[2] = num;
1262 out:
1263 	;
1264 }
1265 EXPORT_SYMBOL_GPL(inet_diag_dump_icsk);
1266 
1267 static int __inet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
1268 			    const struct inet_diag_req_v2 *r)
1269 {
1270 	struct inet_diag_dump_data *cb_data = cb->data;
1271 	const struct inet_diag_handler *handler;
1272 	u32 prev_min_dump_alloc;
1273 	int protocol, err = 0;
1274 
1275 	protocol = inet_diag_get_protocol(r, cb_data);
1276 
1277 again:
1278 	prev_min_dump_alloc = cb->min_dump_alloc;
1279 	handler = inet_diag_lock_handler(protocol);
1280 	if (handler) {
1281 		handler->dump(skb, cb, r);
1282 		inet_diag_unlock_handler(handler);
1283 	} else {
1284 		err = -ENOENT;
1285 	}
1286 	/* The skb is not large enough to fit one sk info and
1287 	 * inet_sk_diag_fill() has requested for a larger skb.
1288 	 */
1289 	if (!skb->len && cb->min_dump_alloc > prev_min_dump_alloc) {
1290 		err = pskb_expand_head(skb, 0, cb->min_dump_alloc, GFP_KERNEL);
1291 		if (!err)
1292 			goto again;
1293 	}
1294 
1295 	return err ? : skb->len;
1296 }
1297 
1298 static int inet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
1299 {
1300 	return __inet_diag_dump(skb, cb, nlmsg_data(cb->nlh));
1301 }
1302 
1303 static int __inet_diag_dump_start(struct netlink_callback *cb, int hdrlen)
1304 {
1305 	const struct nlmsghdr *nlh = cb->nlh;
1306 	struct inet_diag_dump_data *cb_data;
1307 	struct sk_buff *skb = cb->skb;
1308 	struct nlattr *nla;
1309 	int err;
1310 
1311 	cb_data = kzalloc(sizeof(*cb_data), GFP_KERNEL);
1312 	if (!cb_data)
1313 		return -ENOMEM;
1314 
1315 	err = inet_diag_parse_attrs(nlh, hdrlen, cb_data->req_nlas);
1316 	if (err) {
1317 		kfree(cb_data);
1318 		return err;
1319 	}
1320 	nla = cb_data->inet_diag_nla_bc;
1321 	if (nla) {
1322 		err = inet_diag_bc_audit(nla, skb);
1323 		if (err) {
1324 			kfree(cb_data);
1325 			return err;
1326 		}
1327 	}
1328 
1329 	nla = cb_data->inet_diag_nla_bpf_stgs;
1330 	if (nla) {
1331 		struct bpf_sk_storage_diag *bpf_stg_diag;
1332 
1333 		bpf_stg_diag = bpf_sk_storage_diag_alloc(nla);
1334 		if (IS_ERR(bpf_stg_diag)) {
1335 			kfree(cb_data);
1336 			return PTR_ERR(bpf_stg_diag);
1337 		}
1338 		cb_data->bpf_stg_diag = bpf_stg_diag;
1339 	}
1340 
1341 	cb->data = cb_data;
1342 	return 0;
1343 }
1344 
1345 static int inet_diag_dump_start(struct netlink_callback *cb)
1346 {
1347 	return __inet_diag_dump_start(cb, sizeof(struct inet_diag_req_v2));
1348 }
1349 
1350 static int inet_diag_dump_start_compat(struct netlink_callback *cb)
1351 {
1352 	return __inet_diag_dump_start(cb, sizeof(struct inet_diag_req));
1353 }
1354 
1355 static int inet_diag_dump_done(struct netlink_callback *cb)
1356 {
1357 	struct inet_diag_dump_data *cb_data = cb->data;
1358 
1359 	bpf_sk_storage_diag_free(cb_data->bpf_stg_diag);
1360 	kfree(cb->data);
1361 
1362 	return 0;
1363 }
1364 
1365 static int inet_diag_type2proto(int type)
1366 {
1367 	switch (type) {
1368 	case TCPDIAG_GETSOCK:
1369 		return IPPROTO_TCP;
1370 	case DCCPDIAG_GETSOCK:
1371 		return IPPROTO_DCCP;
1372 	default:
1373 		return 0;
1374 	}
1375 }
1376 
1377 static int inet_diag_dump_compat(struct sk_buff *skb,
1378 				 struct netlink_callback *cb)
1379 {
1380 	struct inet_diag_req *rc = nlmsg_data(cb->nlh);
1381 	struct inet_diag_req_v2 req;
1382 
1383 	req.sdiag_family = AF_UNSPEC; /* compatibility */
1384 	req.sdiag_protocol = inet_diag_type2proto(cb->nlh->nlmsg_type);
1385 	req.idiag_ext = rc->idiag_ext;
1386 	req.idiag_states = rc->idiag_states;
1387 	req.id = rc->id;
1388 
1389 	return __inet_diag_dump(skb, cb, &req);
1390 }
1391 
1392 static int inet_diag_get_exact_compat(struct sk_buff *in_skb,
1393 				      const struct nlmsghdr *nlh)
1394 {
1395 	struct inet_diag_req *rc = nlmsg_data(nlh);
1396 	struct inet_diag_req_v2 req;
1397 
1398 	req.sdiag_family = rc->idiag_family;
1399 	req.sdiag_protocol = inet_diag_type2proto(nlh->nlmsg_type);
1400 	req.idiag_ext = rc->idiag_ext;
1401 	req.idiag_states = rc->idiag_states;
1402 	req.id = rc->id;
1403 
1404 	return inet_diag_cmd_exact(SOCK_DIAG_BY_FAMILY, in_skb, nlh,
1405 				   sizeof(struct inet_diag_req), &req);
1406 }
1407 
1408 static int inet_diag_rcv_msg_compat(struct sk_buff *skb, struct nlmsghdr *nlh)
1409 {
1410 	int hdrlen = sizeof(struct inet_diag_req);
1411 	struct net *net = sock_net(skb->sk);
1412 
1413 	if (nlh->nlmsg_type >= INET_DIAG_GETSOCK_MAX ||
1414 	    nlmsg_len(nlh) < hdrlen)
1415 		return -EINVAL;
1416 
1417 	if (nlh->nlmsg_flags & NLM_F_DUMP) {
1418 		struct netlink_dump_control c = {
1419 			.start = inet_diag_dump_start_compat,
1420 			.done = inet_diag_dump_done,
1421 			.dump = inet_diag_dump_compat,
1422 		};
1423 		return netlink_dump_start(net->diag_nlsk, skb, nlh, &c);
1424 	}
1425 
1426 	return inet_diag_get_exact_compat(skb, nlh);
1427 }
1428 
1429 static int inet_diag_handler_cmd(struct sk_buff *skb, struct nlmsghdr *h)
1430 {
1431 	int hdrlen = sizeof(struct inet_diag_req_v2);
1432 	struct net *net = sock_net(skb->sk);
1433 
1434 	if (nlmsg_len(h) < hdrlen)
1435 		return -EINVAL;
1436 
1437 	if (h->nlmsg_type == SOCK_DIAG_BY_FAMILY &&
1438 	    h->nlmsg_flags & NLM_F_DUMP) {
1439 		struct netlink_dump_control c = {
1440 			.start = inet_diag_dump_start,
1441 			.done = inet_diag_dump_done,
1442 			.dump = inet_diag_dump,
1443 		};
1444 		return netlink_dump_start(net->diag_nlsk, skb, h, &c);
1445 	}
1446 
1447 	return inet_diag_cmd_exact(h->nlmsg_type, skb, h, hdrlen,
1448 				   nlmsg_data(h));
1449 }
1450 
1451 static
1452 int inet_diag_handler_get_info(struct sk_buff *skb, struct sock *sk)
1453 {
1454 	const struct inet_diag_handler *handler;
1455 	struct nlmsghdr *nlh;
1456 	struct nlattr *attr;
1457 	struct inet_diag_msg *r;
1458 	void *info = NULL;
1459 	int err = 0;
1460 
1461 	nlh = nlmsg_put(skb, 0, 0, SOCK_DIAG_BY_FAMILY, sizeof(*r), 0);
1462 	if (!nlh)
1463 		return -ENOMEM;
1464 
1465 	r = nlmsg_data(nlh);
1466 	memset(r, 0, sizeof(*r));
1467 	inet_diag_msg_common_fill(r, sk);
1468 	if (sk->sk_type == SOCK_DGRAM || sk->sk_type == SOCK_STREAM)
1469 		r->id.idiag_sport = inet_sk(sk)->inet_sport;
1470 	r->idiag_state = sk->sk_state;
1471 
1472 	if ((err = nla_put_u8(skb, INET_DIAG_PROTOCOL, sk->sk_protocol))) {
1473 		nlmsg_cancel(skb, nlh);
1474 		return err;
1475 	}
1476 
1477 	handler = inet_diag_lock_handler(sk->sk_protocol);
1478 	if (!handler) {
1479 		nlmsg_cancel(skb, nlh);
1480 		return -ENOENT;
1481 	}
1482 
1483 	attr = handler->idiag_info_size
1484 		? nla_reserve_64bit(skb, INET_DIAG_INFO,
1485 				    handler->idiag_info_size,
1486 				    INET_DIAG_PAD)
1487 		: NULL;
1488 	if (attr)
1489 		info = nla_data(attr);
1490 
1491 	handler->idiag_get_info(sk, r, info);
1492 	inet_diag_unlock_handler(handler);
1493 
1494 	nlmsg_end(skb, nlh);
1495 	return 0;
1496 }
1497 
1498 static const struct sock_diag_handler inet_diag_handler = {
1499 	.owner = THIS_MODULE,
1500 	.family = AF_INET,
1501 	.dump = inet_diag_handler_cmd,
1502 	.get_info = inet_diag_handler_get_info,
1503 	.destroy = inet_diag_handler_cmd,
1504 };
1505 
1506 static const struct sock_diag_handler inet6_diag_handler = {
1507 	.owner = THIS_MODULE,
1508 	.family = AF_INET6,
1509 	.dump = inet_diag_handler_cmd,
1510 	.get_info = inet_diag_handler_get_info,
1511 	.destroy = inet_diag_handler_cmd,
1512 };
1513 
1514 int inet_diag_register(const struct inet_diag_handler *h)
1515 {
1516 	const __u16 type = h->idiag_type;
1517 
1518 	if (type >= IPPROTO_MAX)
1519 		return -EINVAL;
1520 
1521 	return !cmpxchg((const struct inet_diag_handler **)&inet_diag_table[type],
1522 			NULL, h) ? 0 : -EEXIST;
1523 }
1524 EXPORT_SYMBOL_GPL(inet_diag_register);
1525 
1526 void inet_diag_unregister(const struct inet_diag_handler *h)
1527 {
1528 	const __u16 type = h->idiag_type;
1529 
1530 	if (type >= IPPROTO_MAX)
1531 		return;
1532 
1533 	xchg((const struct inet_diag_handler **)&inet_diag_table[type],
1534 	     NULL);
1535 }
1536 EXPORT_SYMBOL_GPL(inet_diag_unregister);
1537 
1538 static const struct sock_diag_inet_compat inet_diag_compat = {
1539 	.owner	= THIS_MODULE,
1540 	.fn	= inet_diag_rcv_msg_compat,
1541 };
1542 
1543 static int __init inet_diag_init(void)
1544 {
1545 	const int inet_diag_table_size = (IPPROTO_MAX *
1546 					  sizeof(struct inet_diag_handler *));
1547 	int err = -ENOMEM;
1548 
1549 	inet_diag_table = kzalloc(inet_diag_table_size, GFP_KERNEL);
1550 	if (!inet_diag_table)
1551 		goto out;
1552 
1553 	err = sock_diag_register(&inet_diag_handler);
1554 	if (err)
1555 		goto out_free_nl;
1556 
1557 	err = sock_diag_register(&inet6_diag_handler);
1558 	if (err)
1559 		goto out_free_inet;
1560 
1561 	sock_diag_register_inet_compat(&inet_diag_compat);
1562 out:
1563 	return err;
1564 
1565 out_free_inet:
1566 	sock_diag_unregister(&inet_diag_handler);
1567 out_free_nl:
1568 	kfree(inet_diag_table);
1569 	goto out;
1570 }
1571 
1572 static void __exit inet_diag_exit(void)
1573 {
1574 	sock_diag_unregister(&inet6_diag_handler);
1575 	sock_diag_unregister(&inet_diag_handler);
1576 	sock_diag_unregister_inet_compat(&inet_diag_compat);
1577 	kfree(inet_diag_table);
1578 }
1579 
1580 module_init(inet_diag_init);
1581 module_exit(inet_diag_exit);
1582 MODULE_LICENSE("GPL");
1583 MODULE_DESCRIPTION("INET/INET6: socket monitoring via SOCK_DIAG");
1584 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2 /* AF_INET */);
1585 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 10 /* AF_INET6 */);
1586