xref: /openbmc/linux/net/ipv4/ping.c (revision ae3473231e77a3f1909d48cd144cebe5e1d049b3)
1 /*
2  * INET		An implementation of the TCP/IP protocol suite for the LINUX
3  *		operating system.  INET is implemented using the  BSD Socket
4  *		interface as the means of communication with the user level.
5  *
6  *		"Ping" sockets
7  *
8  *		This program is free software; you can redistribute it and/or
9  *		modify it under the terms of the GNU General Public License
10  *		as published by the Free Software Foundation; either version
11  *		2 of the License, or (at your option) any later version.
12  *
13  * Based on ipv4/udp.c code.
14  *
15  * Authors:	Vasiliy Kulikov / Openwall (for Linux 2.6),
16  *		Pavel Kankovsky (for Linux 2.4.32)
17  *
18  * Pavel gave all rights to bugs to Vasiliy,
19  * none of the bugs are Pavel's now.
20  *
21  */
22 
23 #include <linux/uaccess.h>
24 #include <linux/types.h>
25 #include <linux/fcntl.h>
26 #include <linux/socket.h>
27 #include <linux/sockios.h>
28 #include <linux/in.h>
29 #include <linux/errno.h>
30 #include <linux/timer.h>
31 #include <linux/mm.h>
32 #include <linux/inet.h>
33 #include <linux/netdevice.h>
34 #include <net/snmp.h>
35 #include <net/ip.h>
36 #include <net/icmp.h>
37 #include <net/protocol.h>
38 #include <linux/skbuff.h>
39 #include <linux/proc_fs.h>
40 #include <linux/export.h>
41 #include <net/sock.h>
42 #include <net/ping.h>
43 #include <net/udp.h>
44 #include <net/route.h>
45 #include <net/inet_common.h>
46 #include <net/checksum.h>
47 
48 #if IS_ENABLED(CONFIG_IPV6)
49 #include <linux/in6.h>
50 #include <linux/icmpv6.h>
51 #include <net/addrconf.h>
52 #include <net/ipv6.h>
53 #include <net/transp_v6.h>
54 #endif
55 
56 struct ping_table {
57 	struct hlist_nulls_head	hash[PING_HTABLE_SIZE];
58 	rwlock_t		lock;
59 };
60 
61 static struct ping_table ping_table;
62 struct pingv6_ops pingv6_ops;
63 EXPORT_SYMBOL_GPL(pingv6_ops);
64 
65 static u16 ping_port_rover;
66 
67 static inline u32 ping_hashfn(const struct net *net, u32 num, u32 mask)
68 {
69 	u32 res = (num + net_hash_mix(net)) & mask;
70 
71 	pr_debug("hash(%u) = %u\n", num, res);
72 	return res;
73 }
74 EXPORT_SYMBOL_GPL(ping_hash);
75 
76 static inline struct hlist_nulls_head *ping_hashslot(struct ping_table *table,
77 					     struct net *net, unsigned int num)
78 {
79 	return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)];
80 }
81 
82 int ping_get_port(struct sock *sk, unsigned short ident)
83 {
84 	struct hlist_nulls_node *node;
85 	struct hlist_nulls_head *hlist;
86 	struct inet_sock *isk, *isk2;
87 	struct sock *sk2 = NULL;
88 
89 	isk = inet_sk(sk);
90 	write_lock_bh(&ping_table.lock);
91 	if (ident == 0) {
92 		u32 i;
93 		u16 result = ping_port_rover + 1;
94 
95 		for (i = 0; i < (1L << 16); i++, result++) {
96 			if (!result)
97 				result++; /* avoid zero */
98 			hlist = ping_hashslot(&ping_table, sock_net(sk),
99 					    result);
100 			ping_portaddr_for_each_entry(sk2, node, hlist) {
101 				isk2 = inet_sk(sk2);
102 
103 				if (isk2->inet_num == result)
104 					goto next_port;
105 			}
106 
107 			/* found */
108 			ping_port_rover = ident = result;
109 			break;
110 next_port:
111 			;
112 		}
113 		if (i >= (1L << 16))
114 			goto fail;
115 	} else {
116 		hlist = ping_hashslot(&ping_table, sock_net(sk), ident);
117 		ping_portaddr_for_each_entry(sk2, node, hlist) {
118 			isk2 = inet_sk(sk2);
119 
120 			/* BUG? Why is this reuse and not reuseaddr? ping.c
121 			 * doesn't turn off SO_REUSEADDR, and it doesn't expect
122 			 * that other ping processes can steal its packets.
123 			 */
124 			if ((isk2->inet_num == ident) &&
125 			    (sk2 != sk) &&
126 			    (!sk2->sk_reuse || !sk->sk_reuse))
127 				goto fail;
128 		}
129 	}
130 
131 	pr_debug("found port/ident = %d\n", ident);
132 	isk->inet_num = ident;
133 	if (sk_unhashed(sk)) {
134 		pr_debug("was not hashed\n");
135 		sock_hold(sk);
136 		hlist_nulls_add_head(&sk->sk_nulls_node, hlist);
137 		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
138 	}
139 	write_unlock_bh(&ping_table.lock);
140 	return 0;
141 
142 fail:
143 	write_unlock_bh(&ping_table.lock);
144 	return 1;
145 }
146 EXPORT_SYMBOL_GPL(ping_get_port);
147 
148 int ping_hash(struct sock *sk)
149 {
150 	pr_debug("ping_hash(sk->port=%u)\n", inet_sk(sk)->inet_num);
151 	BUG(); /* "Please do not press this button again." */
152 
153 	return 0;
154 }
155 
156 void ping_unhash(struct sock *sk)
157 {
158 	struct inet_sock *isk = inet_sk(sk);
159 	pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);
160 	if (sk_hashed(sk)) {
161 		write_lock_bh(&ping_table.lock);
162 		hlist_nulls_del(&sk->sk_nulls_node);
163 		sk_nulls_node_init(&sk->sk_nulls_node);
164 		sock_put(sk);
165 		isk->inet_num = 0;
166 		isk->inet_sport = 0;
167 		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
168 		write_unlock_bh(&ping_table.lock);
169 	}
170 }
171 EXPORT_SYMBOL_GPL(ping_unhash);
172 
173 static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
174 {
175 	struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident);
176 	struct sock *sk = NULL;
177 	struct inet_sock *isk;
178 	struct hlist_nulls_node *hnode;
179 	int dif = skb->dev->ifindex;
180 
181 	if (skb->protocol == htons(ETH_P_IP)) {
182 		pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n",
183 			 (int)ident, &ip_hdr(skb)->daddr, dif);
184 #if IS_ENABLED(CONFIG_IPV6)
185 	} else if (skb->protocol == htons(ETH_P_IPV6)) {
186 		pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n",
187 			 (int)ident, &ipv6_hdr(skb)->daddr, dif);
188 #endif
189 	}
190 
191 	read_lock_bh(&ping_table.lock);
192 
193 	ping_portaddr_for_each_entry(sk, hnode, hslot) {
194 		isk = inet_sk(sk);
195 
196 		pr_debug("iterate\n");
197 		if (isk->inet_num != ident)
198 			continue;
199 
200 		if (skb->protocol == htons(ETH_P_IP) &&
201 		    sk->sk_family == AF_INET) {
202 			pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk,
203 				 (int) isk->inet_num, &isk->inet_rcv_saddr,
204 				 sk->sk_bound_dev_if);
205 
206 			if (isk->inet_rcv_saddr &&
207 			    isk->inet_rcv_saddr != ip_hdr(skb)->daddr)
208 				continue;
209 #if IS_ENABLED(CONFIG_IPV6)
210 		} else if (skb->protocol == htons(ETH_P_IPV6) &&
211 			   sk->sk_family == AF_INET6) {
212 
213 			pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk,
214 				 (int) isk->inet_num,
215 				 &sk->sk_v6_rcv_saddr,
216 				 sk->sk_bound_dev_if);
217 
218 			if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
219 			    !ipv6_addr_equal(&sk->sk_v6_rcv_saddr,
220 					     &ipv6_hdr(skb)->daddr))
221 				continue;
222 #endif
223 		} else {
224 			continue;
225 		}
226 
227 		if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)
228 			continue;
229 
230 		sock_hold(sk);
231 		goto exit;
232 	}
233 
234 	sk = NULL;
235 exit:
236 	read_unlock_bh(&ping_table.lock);
237 
238 	return sk;
239 }
240 
241 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low,
242 					  kgid_t *high)
243 {
244 	kgid_t *data = net->ipv4.ping_group_range.range;
245 	unsigned int seq;
246 
247 	do {
248 		seq = read_seqbegin(&net->ipv4.ping_group_range.lock);
249 
250 		*low = data[0];
251 		*high = data[1];
252 	} while (read_seqretry(&net->ipv4.ping_group_range.lock, seq));
253 }
254 
255 
256 int ping_init_sock(struct sock *sk)
257 {
258 	struct net *net = sock_net(sk);
259 	kgid_t group = current_egid();
260 	struct group_info *group_info;
261 	int i;
262 	kgid_t low, high;
263 	int ret = 0;
264 
265 	if (sk->sk_family == AF_INET6)
266 		sk->sk_ipv6only = 1;
267 
268 	inet_get_ping_group_range_net(net, &low, &high);
269 	if (gid_lte(low, group) && gid_lte(group, high))
270 		return 0;
271 
272 	group_info = get_current_groups();
273 	for (i = 0; i < group_info->ngroups; i++) {
274 		kgid_t gid = group_info->gid[i];
275 
276 		if (gid_lte(low, gid) && gid_lte(gid, high))
277 			goto out_release_group;
278 	}
279 
280 	ret = -EACCES;
281 
282 out_release_group:
283 	put_group_info(group_info);
284 	return ret;
285 }
286 EXPORT_SYMBOL_GPL(ping_init_sock);
287 
288 void ping_close(struct sock *sk, long timeout)
289 {
290 	pr_debug("ping_close(sk=%p,sk->num=%u)\n",
291 		 inet_sk(sk), inet_sk(sk)->inet_num);
292 	pr_debug("isk->refcnt = %d\n", sk->sk_refcnt.counter);
293 
294 	sk_common_release(sk);
295 }
296 EXPORT_SYMBOL_GPL(ping_close);
297 
298 /* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */
299 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
300 				struct sockaddr *uaddr, int addr_len) {
301 	struct net *net = sock_net(sk);
302 	if (sk->sk_family == AF_INET) {
303 		struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
304 		int chk_addr_ret;
305 
306 		if (addr_len < sizeof(*addr))
307 			return -EINVAL;
308 
309 		if (addr->sin_family != AF_INET &&
310 		    !(addr->sin_family == AF_UNSPEC &&
311 		      addr->sin_addr.s_addr == htonl(INADDR_ANY)))
312 			return -EAFNOSUPPORT;
313 
314 		pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",
315 			 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
316 
317 		chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
318 
319 		if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
320 			chk_addr_ret = RTN_LOCAL;
321 
322 		if ((net->ipv4.sysctl_ip_nonlocal_bind == 0 &&
323 		    isk->freebind == 0 && isk->transparent == 0 &&
324 		     chk_addr_ret != RTN_LOCAL) ||
325 		    chk_addr_ret == RTN_MULTICAST ||
326 		    chk_addr_ret == RTN_BROADCAST)
327 			return -EADDRNOTAVAIL;
328 
329 #if IS_ENABLED(CONFIG_IPV6)
330 	} else if (sk->sk_family == AF_INET6) {
331 		struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
332 		int addr_type, scoped, has_addr;
333 		struct net_device *dev = NULL;
334 
335 		if (addr_len < sizeof(*addr))
336 			return -EINVAL;
337 
338 		if (addr->sin6_family != AF_INET6)
339 			return -EAFNOSUPPORT;
340 
341 		pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n",
342 			 sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port));
343 
344 		addr_type = ipv6_addr_type(&addr->sin6_addr);
345 		scoped = __ipv6_addr_needs_scope_id(addr_type);
346 		if ((addr_type != IPV6_ADDR_ANY &&
347 		     !(addr_type & IPV6_ADDR_UNICAST)) ||
348 		    (scoped && !addr->sin6_scope_id))
349 			return -EINVAL;
350 
351 		rcu_read_lock();
352 		if (addr->sin6_scope_id) {
353 			dev = dev_get_by_index_rcu(net, addr->sin6_scope_id);
354 			if (!dev) {
355 				rcu_read_unlock();
356 				return -ENODEV;
357 			}
358 		}
359 		has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev,
360 						    scoped);
361 		rcu_read_unlock();
362 
363 		if (!(net->ipv6.sysctl.ip_nonlocal_bind ||
364 		      isk->freebind || isk->transparent || has_addr ||
365 		      addr_type == IPV6_ADDR_ANY))
366 			return -EADDRNOTAVAIL;
367 
368 		if (scoped)
369 			sk->sk_bound_dev_if = addr->sin6_scope_id;
370 #endif
371 	} else {
372 		return -EAFNOSUPPORT;
373 	}
374 	return 0;
375 }
376 
377 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr)
378 {
379 	if (saddr->sa_family == AF_INET) {
380 		struct inet_sock *isk = inet_sk(sk);
381 		struct sockaddr_in *addr = (struct sockaddr_in *) saddr;
382 		isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
383 #if IS_ENABLED(CONFIG_IPV6)
384 	} else if (saddr->sa_family == AF_INET6) {
385 		struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr;
386 		struct ipv6_pinfo *np = inet6_sk(sk);
387 		sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr;
388 #endif
389 	}
390 }
391 
392 static void ping_clear_saddr(struct sock *sk, int dif)
393 {
394 	sk->sk_bound_dev_if = dif;
395 	if (sk->sk_family == AF_INET) {
396 		struct inet_sock *isk = inet_sk(sk);
397 		isk->inet_rcv_saddr = isk->inet_saddr = 0;
398 #if IS_ENABLED(CONFIG_IPV6)
399 	} else if (sk->sk_family == AF_INET6) {
400 		struct ipv6_pinfo *np = inet6_sk(sk);
401 		memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
402 		memset(&np->saddr, 0, sizeof(np->saddr));
403 #endif
404 	}
405 }
406 /*
407  * We need our own bind because there are no privileged id's == local ports.
408  * Moreover, we don't allow binding to multi- and broadcast addresses.
409  */
410 
411 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
412 {
413 	struct inet_sock *isk = inet_sk(sk);
414 	unsigned short snum;
415 	int err;
416 	int dif = sk->sk_bound_dev_if;
417 
418 	err = ping_check_bind_addr(sk, isk, uaddr, addr_len);
419 	if (err)
420 		return err;
421 
422 	lock_sock(sk);
423 
424 	err = -EINVAL;
425 	if (isk->inet_num != 0)
426 		goto out;
427 
428 	err = -EADDRINUSE;
429 	ping_set_saddr(sk, uaddr);
430 	snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port);
431 	if (ping_get_port(sk, snum) != 0) {
432 		ping_clear_saddr(sk, dif);
433 		goto out;
434 	}
435 
436 	pr_debug("after bind(): num = %d, dif = %d\n",
437 		 (int)isk->inet_num,
438 		 (int)sk->sk_bound_dev_if);
439 
440 	err = 0;
441 	if (sk->sk_family == AF_INET && isk->inet_rcv_saddr)
442 		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
443 #if IS_ENABLED(CONFIG_IPV6)
444 	if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr))
445 		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
446 #endif
447 
448 	if (snum)
449 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
450 	isk->inet_sport = htons(isk->inet_num);
451 	isk->inet_daddr = 0;
452 	isk->inet_dport = 0;
453 
454 #if IS_ENABLED(CONFIG_IPV6)
455 	if (sk->sk_family == AF_INET6)
456 		memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr));
457 #endif
458 
459 	sk_dst_reset(sk);
460 out:
461 	release_sock(sk);
462 	pr_debug("ping_v4_bind -> %d\n", err);
463 	return err;
464 }
465 EXPORT_SYMBOL_GPL(ping_bind);
466 
467 /*
468  * Is this a supported type of ICMP message?
469  */
470 
471 static inline int ping_supported(int family, int type, int code)
472 {
473 	return (family == AF_INET && type == ICMP_ECHO && code == 0) ||
474 	       (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0);
475 }
476 
477 /*
478  * This routine is called by the ICMP module when it gets some
479  * sort of error condition.
480  */
481 
482 void ping_err(struct sk_buff *skb, int offset, u32 info)
483 {
484 	int family;
485 	struct icmphdr *icmph;
486 	struct inet_sock *inet_sock;
487 	int type;
488 	int code;
489 	struct net *net = dev_net(skb->dev);
490 	struct sock *sk;
491 	int harderr;
492 	int err;
493 
494 	if (skb->protocol == htons(ETH_P_IP)) {
495 		family = AF_INET;
496 		type = icmp_hdr(skb)->type;
497 		code = icmp_hdr(skb)->code;
498 		icmph = (struct icmphdr *)(skb->data + offset);
499 	} else if (skb->protocol == htons(ETH_P_IPV6)) {
500 		family = AF_INET6;
501 		type = icmp6_hdr(skb)->icmp6_type;
502 		code = icmp6_hdr(skb)->icmp6_code;
503 		icmph = (struct icmphdr *) (skb->data + offset);
504 	} else {
505 		BUG();
506 	}
507 
508 	/* We assume the packet has already been checked by icmp_unreach */
509 
510 	if (!ping_supported(family, icmph->type, icmph->code))
511 		return;
512 
513 	pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n",
514 		 skb->protocol, type, code, ntohs(icmph->un.echo.id),
515 		 ntohs(icmph->un.echo.sequence));
516 
517 	sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
518 	if (!sk) {
519 		pr_debug("no socket, dropping\n");
520 		return;	/* No socket for error */
521 	}
522 	pr_debug("err on socket %p\n", sk);
523 
524 	err = 0;
525 	harderr = 0;
526 	inet_sock = inet_sk(sk);
527 
528 	if (skb->protocol == htons(ETH_P_IP)) {
529 		switch (type) {
530 		default:
531 		case ICMP_TIME_EXCEEDED:
532 			err = EHOSTUNREACH;
533 			break;
534 		case ICMP_SOURCE_QUENCH:
535 			/* This is not a real error but ping wants to see it.
536 			 * Report it with some fake errno.
537 			 */
538 			err = EREMOTEIO;
539 			break;
540 		case ICMP_PARAMETERPROB:
541 			err = EPROTO;
542 			harderr = 1;
543 			break;
544 		case ICMP_DEST_UNREACH:
545 			if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
546 				ipv4_sk_update_pmtu(skb, sk, info);
547 				if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) {
548 					err = EMSGSIZE;
549 					harderr = 1;
550 					break;
551 				}
552 				goto out;
553 			}
554 			err = EHOSTUNREACH;
555 			if (code <= NR_ICMP_UNREACH) {
556 				harderr = icmp_err_convert[code].fatal;
557 				err = icmp_err_convert[code].errno;
558 			}
559 			break;
560 		case ICMP_REDIRECT:
561 			/* See ICMP_SOURCE_QUENCH */
562 			ipv4_sk_redirect(skb, sk);
563 			err = EREMOTEIO;
564 			break;
565 		}
566 #if IS_ENABLED(CONFIG_IPV6)
567 	} else if (skb->protocol == htons(ETH_P_IPV6)) {
568 		harderr = pingv6_ops.icmpv6_err_convert(type, code, &err);
569 #endif
570 	}
571 
572 	/*
573 	 *      RFC1122: OK.  Passes ICMP errors back to application, as per
574 	 *	4.1.3.3.
575 	 */
576 	if ((family == AF_INET && !inet_sock->recverr) ||
577 	    (family == AF_INET6 && !inet6_sk(sk)->recverr)) {
578 		if (!harderr || sk->sk_state != TCP_ESTABLISHED)
579 			goto out;
580 	} else {
581 		if (family == AF_INET) {
582 			ip_icmp_error(sk, skb, err, 0 /* no remote port */,
583 				      info, (u8 *)icmph);
584 #if IS_ENABLED(CONFIG_IPV6)
585 		} else if (family == AF_INET6) {
586 			pingv6_ops.ipv6_icmp_error(sk, skb, err, 0,
587 						   info, (u8 *)icmph);
588 #endif
589 		}
590 	}
591 	sk->sk_err = err;
592 	sk->sk_error_report(sk);
593 out:
594 	sock_put(sk);
595 }
596 EXPORT_SYMBOL_GPL(ping_err);
597 
598 /*
599  *	Copy and checksum an ICMP Echo packet from user space into a buffer
600  *	starting from the payload.
601  */
602 
603 int ping_getfrag(void *from, char *to,
604 		 int offset, int fraglen, int odd, struct sk_buff *skb)
605 {
606 	struct pingfakehdr *pfh = (struct pingfakehdr *)from;
607 
608 	if (offset == 0) {
609 		fraglen -= sizeof(struct icmphdr);
610 		if (fraglen < 0)
611 			BUG();
612 		if (!csum_and_copy_from_iter_full(to + sizeof(struct icmphdr),
613 			    fraglen, &pfh->wcheck,
614 			    &pfh->msg->msg_iter))
615 			return -EFAULT;
616 	} else if (offset < sizeof(struct icmphdr)) {
617 			BUG();
618 	} else {
619 		if (!csum_and_copy_from_iter_full(to, fraglen, &pfh->wcheck,
620 					    &pfh->msg->msg_iter))
621 			return -EFAULT;
622 	}
623 
624 #if IS_ENABLED(CONFIG_IPV6)
625 	/* For IPv6, checksum each skb as we go along, as expected by
626 	 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in
627 	 * wcheck, it will be finalized in ping_v4_push_pending_frames.
628 	 */
629 	if (pfh->family == AF_INET6) {
630 		skb->csum = pfh->wcheck;
631 		skb->ip_summed = CHECKSUM_NONE;
632 		pfh->wcheck = 0;
633 	}
634 #endif
635 
636 	return 0;
637 }
638 EXPORT_SYMBOL_GPL(ping_getfrag);
639 
640 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
641 				       struct flowi4 *fl4)
642 {
643 	struct sk_buff *skb = skb_peek(&sk->sk_write_queue);
644 
645 	pfh->wcheck = csum_partial((char *)&pfh->icmph,
646 		sizeof(struct icmphdr), pfh->wcheck);
647 	pfh->icmph.checksum = csum_fold(pfh->wcheck);
648 	memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
649 	skb->ip_summed = CHECKSUM_NONE;
650 	return ip_push_pending_frames(sk, fl4);
651 }
652 
653 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
654 			void *user_icmph, size_t icmph_len) {
655 	u8 type, code;
656 
657 	if (len > 0xFFFF)
658 		return -EMSGSIZE;
659 
660 	/* Must have at least a full ICMP header. */
661 	if (len < icmph_len)
662 		return -EINVAL;
663 
664 	/*
665 	 *	Check the flags.
666 	 */
667 
668 	/* Mirror BSD error message compatibility */
669 	if (msg->msg_flags & MSG_OOB)
670 		return -EOPNOTSUPP;
671 
672 	/*
673 	 *	Fetch the ICMP header provided by the userland.
674 	 *	iovec is modified! The ICMP header is consumed.
675 	 */
676 	if (memcpy_from_msg(user_icmph, msg, icmph_len))
677 		return -EFAULT;
678 
679 	if (family == AF_INET) {
680 		type = ((struct icmphdr *) user_icmph)->type;
681 		code = ((struct icmphdr *) user_icmph)->code;
682 #if IS_ENABLED(CONFIG_IPV6)
683 	} else if (family == AF_INET6) {
684 		type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
685 		code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
686 #endif
687 	} else {
688 		BUG();
689 	}
690 
691 	if (!ping_supported(family, type, code))
692 		return -EINVAL;
693 
694 	return 0;
695 }
696 EXPORT_SYMBOL_GPL(ping_common_sendmsg);
697 
698 static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
699 {
700 	struct net *net = sock_net(sk);
701 	struct flowi4 fl4;
702 	struct inet_sock *inet = inet_sk(sk);
703 	struct ipcm_cookie ipc;
704 	struct icmphdr user_icmph;
705 	struct pingfakehdr pfh;
706 	struct rtable *rt = NULL;
707 	struct ip_options_data opt_copy;
708 	int free = 0;
709 	__be32 saddr, daddr, faddr;
710 	u8  tos;
711 	int err;
712 
713 	pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
714 
715 	err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
716 				  sizeof(user_icmph));
717 	if (err)
718 		return err;
719 
720 	/*
721 	 *	Get and verify the address.
722 	 */
723 
724 	if (msg->msg_name) {
725 		DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
726 		if (msg->msg_namelen < sizeof(*usin))
727 			return -EINVAL;
728 		if (usin->sin_family != AF_INET)
729 			return -EAFNOSUPPORT;
730 		daddr = usin->sin_addr.s_addr;
731 		/* no remote port */
732 	} else {
733 		if (sk->sk_state != TCP_ESTABLISHED)
734 			return -EDESTADDRREQ;
735 		daddr = inet->inet_daddr;
736 		/* no remote port */
737 	}
738 
739 	ipc.sockc.tsflags = sk->sk_tsflags;
740 	ipc.addr = inet->inet_saddr;
741 	ipc.opt = NULL;
742 	ipc.oif = sk->sk_bound_dev_if;
743 	ipc.tx_flags = 0;
744 	ipc.ttl = 0;
745 	ipc.tos = -1;
746 
747 	if (msg->msg_controllen) {
748 		err = ip_cmsg_send(sk, msg, &ipc, false);
749 		if (unlikely(err)) {
750 			kfree(ipc.opt);
751 			return err;
752 		}
753 		if (ipc.opt)
754 			free = 1;
755 	}
756 	if (!ipc.opt) {
757 		struct ip_options_rcu *inet_opt;
758 
759 		rcu_read_lock();
760 		inet_opt = rcu_dereference(inet->inet_opt);
761 		if (inet_opt) {
762 			memcpy(&opt_copy, inet_opt,
763 			       sizeof(*inet_opt) + inet_opt->opt.optlen);
764 			ipc.opt = &opt_copy.opt;
765 		}
766 		rcu_read_unlock();
767 	}
768 
769 	sock_tx_timestamp(sk, ipc.sockc.tsflags, &ipc.tx_flags);
770 
771 	saddr = ipc.addr;
772 	ipc.addr = faddr = daddr;
773 
774 	if (ipc.opt && ipc.opt->opt.srr) {
775 		if (!daddr)
776 			return -EINVAL;
777 		faddr = ipc.opt->opt.faddr;
778 	}
779 	tos = get_rttos(&ipc, inet);
780 	if (sock_flag(sk, SOCK_LOCALROUTE) ||
781 	    (msg->msg_flags & MSG_DONTROUTE) ||
782 	    (ipc.opt && ipc.opt->opt.is_strictroute)) {
783 		tos |= RTO_ONLINK;
784 	}
785 
786 	if (ipv4_is_multicast(daddr)) {
787 		if (!ipc.oif)
788 			ipc.oif = inet->mc_index;
789 		if (!saddr)
790 			saddr = inet->mc_addr;
791 	} else if (!ipc.oif)
792 		ipc.oif = inet->uc_index;
793 
794 	flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
795 			   RT_SCOPE_UNIVERSE, sk->sk_protocol,
796 			   inet_sk_flowi_flags(sk), faddr, saddr, 0, 0,
797 			   sk->sk_uid);
798 
799 	security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
800 	rt = ip_route_output_flow(net, &fl4, sk);
801 	if (IS_ERR(rt)) {
802 		err = PTR_ERR(rt);
803 		rt = NULL;
804 		if (err == -ENETUNREACH)
805 			IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
806 		goto out;
807 	}
808 
809 	err = -EACCES;
810 	if ((rt->rt_flags & RTCF_BROADCAST) &&
811 	    !sock_flag(sk, SOCK_BROADCAST))
812 		goto out;
813 
814 	if (msg->msg_flags & MSG_CONFIRM)
815 		goto do_confirm;
816 back_from_confirm:
817 
818 	if (!ipc.addr)
819 		ipc.addr = fl4.daddr;
820 
821 	lock_sock(sk);
822 
823 	pfh.icmph.type = user_icmph.type; /* already checked */
824 	pfh.icmph.code = user_icmph.code; /* ditto */
825 	pfh.icmph.checksum = 0;
826 	pfh.icmph.un.echo.id = inet->inet_sport;
827 	pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
828 	pfh.msg = msg;
829 	pfh.wcheck = 0;
830 	pfh.family = AF_INET;
831 
832 	err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
833 			0, &ipc, &rt, msg->msg_flags);
834 	if (err)
835 		ip_flush_pending_frames(sk);
836 	else
837 		err = ping_v4_push_pending_frames(sk, &pfh, &fl4);
838 	release_sock(sk);
839 
840 out:
841 	ip_rt_put(rt);
842 	if (free)
843 		kfree(ipc.opt);
844 	if (!err) {
845 		icmp_out_count(sock_net(sk), user_icmph.type);
846 		return len;
847 	}
848 	return err;
849 
850 do_confirm:
851 	dst_confirm(&rt->dst);
852 	if (!(msg->msg_flags & MSG_PROBE) || len)
853 		goto back_from_confirm;
854 	err = 0;
855 	goto out;
856 }
857 
858 int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock,
859 		 int flags, int *addr_len)
860 {
861 	struct inet_sock *isk = inet_sk(sk);
862 	int family = sk->sk_family;
863 	struct sk_buff *skb;
864 	int copied, err;
865 
866 	pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
867 
868 	err = -EOPNOTSUPP;
869 	if (flags & MSG_OOB)
870 		goto out;
871 
872 	if (flags & MSG_ERRQUEUE)
873 		return inet_recv_error(sk, msg, len, addr_len);
874 
875 	skb = skb_recv_datagram(sk, flags, noblock, &err);
876 	if (!skb)
877 		goto out;
878 
879 	copied = skb->len;
880 	if (copied > len) {
881 		msg->msg_flags |= MSG_TRUNC;
882 		copied = len;
883 	}
884 
885 	/* Don't bother checking the checksum */
886 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
887 	if (err)
888 		goto done;
889 
890 	sock_recv_timestamp(msg, sk, skb);
891 
892 	/* Copy the address and add cmsg data. */
893 	if (family == AF_INET) {
894 		DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
895 
896 		if (sin) {
897 			sin->sin_family = AF_INET;
898 			sin->sin_port = 0 /* skb->h.uh->source */;
899 			sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
900 			memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
901 			*addr_len = sizeof(*sin);
902 		}
903 
904 		if (isk->cmsg_flags)
905 			ip_cmsg_recv(msg, skb);
906 
907 #if IS_ENABLED(CONFIG_IPV6)
908 	} else if (family == AF_INET6) {
909 		struct ipv6_pinfo *np = inet6_sk(sk);
910 		struct ipv6hdr *ip6 = ipv6_hdr(skb);
911 		DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
912 
913 		if (sin6) {
914 			sin6->sin6_family = AF_INET6;
915 			sin6->sin6_port = 0;
916 			sin6->sin6_addr = ip6->saddr;
917 			sin6->sin6_flowinfo = 0;
918 			if (np->sndflow)
919 				sin6->sin6_flowinfo = ip6_flowinfo(ip6);
920 			sin6->sin6_scope_id =
921 				ipv6_iface_scope_id(&sin6->sin6_addr,
922 						    inet6_iif(skb));
923 			*addr_len = sizeof(*sin6);
924 		}
925 
926 		if (inet6_sk(sk)->rxopt.all)
927 			pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb);
928 		if (skb->protocol == htons(ETH_P_IPV6) &&
929 		    inet6_sk(sk)->rxopt.all)
930 			pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb);
931 		else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags)
932 			ip_cmsg_recv(msg, skb);
933 #endif
934 	} else {
935 		BUG();
936 	}
937 
938 	err = copied;
939 
940 done:
941 	skb_free_datagram(sk, skb);
942 out:
943 	pr_debug("ping_recvmsg -> %d\n", err);
944 	return err;
945 }
946 EXPORT_SYMBOL_GPL(ping_recvmsg);
947 
948 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
949 {
950 	pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
951 		 inet_sk(sk), inet_sk(sk)->inet_num, skb);
952 	if (sock_queue_rcv_skb(sk, skb) < 0) {
953 		kfree_skb(skb);
954 		pr_debug("ping_queue_rcv_skb -> failed\n");
955 		return -1;
956 	}
957 	return 0;
958 }
959 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
960 
961 
962 /*
963  *	All we need to do is get the socket.
964  */
965 
966 bool ping_rcv(struct sk_buff *skb)
967 {
968 	struct sock *sk;
969 	struct net *net = dev_net(skb->dev);
970 	struct icmphdr *icmph = icmp_hdr(skb);
971 
972 	/* We assume the packet has already been checked by icmp_rcv */
973 
974 	pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
975 		 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
976 
977 	/* Push ICMP header back */
978 	skb_push(skb, skb->data - (u8 *)icmph);
979 
980 	sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
981 	if (sk) {
982 		struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
983 
984 		pr_debug("rcv on socket %p\n", sk);
985 		if (skb2)
986 			ping_queue_rcv_skb(sk, skb2);
987 		sock_put(sk);
988 		return true;
989 	}
990 	pr_debug("no socket, dropping\n");
991 
992 	return false;
993 }
994 EXPORT_SYMBOL_GPL(ping_rcv);
995 
996 struct proto ping_prot = {
997 	.name =		"PING",
998 	.owner =	THIS_MODULE,
999 	.init =		ping_init_sock,
1000 	.close =	ping_close,
1001 	.connect =	ip4_datagram_connect,
1002 	.disconnect =	__udp_disconnect,
1003 	.setsockopt =	ip_setsockopt,
1004 	.getsockopt =	ip_getsockopt,
1005 	.sendmsg =	ping_v4_sendmsg,
1006 	.recvmsg =	ping_recvmsg,
1007 	.bind =		ping_bind,
1008 	.backlog_rcv =	ping_queue_rcv_skb,
1009 	.release_cb =	ip4_datagram_release_cb,
1010 	.hash =		ping_hash,
1011 	.unhash =	ping_unhash,
1012 	.get_port =	ping_get_port,
1013 	.obj_size =	sizeof(struct inet_sock),
1014 };
1015 EXPORT_SYMBOL(ping_prot);
1016 
1017 #ifdef CONFIG_PROC_FS
1018 
1019 static struct sock *ping_get_first(struct seq_file *seq, int start)
1020 {
1021 	struct sock *sk;
1022 	struct ping_iter_state *state = seq->private;
1023 	struct net *net = seq_file_net(seq);
1024 
1025 	for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
1026 	     ++state->bucket) {
1027 		struct hlist_nulls_node *node;
1028 		struct hlist_nulls_head *hslot;
1029 
1030 		hslot = &ping_table.hash[state->bucket];
1031 
1032 		if (hlist_nulls_empty(hslot))
1033 			continue;
1034 
1035 		sk_nulls_for_each(sk, node, hslot) {
1036 			if (net_eq(sock_net(sk), net) &&
1037 			    sk->sk_family == state->family)
1038 				goto found;
1039 		}
1040 	}
1041 	sk = NULL;
1042 found:
1043 	return sk;
1044 }
1045 
1046 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
1047 {
1048 	struct ping_iter_state *state = seq->private;
1049 	struct net *net = seq_file_net(seq);
1050 
1051 	do {
1052 		sk = sk_nulls_next(sk);
1053 	} while (sk && (!net_eq(sock_net(sk), net)));
1054 
1055 	if (!sk)
1056 		return ping_get_first(seq, state->bucket + 1);
1057 	return sk;
1058 }
1059 
1060 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
1061 {
1062 	struct sock *sk = ping_get_first(seq, 0);
1063 
1064 	if (sk)
1065 		while (pos && (sk = ping_get_next(seq, sk)) != NULL)
1066 			--pos;
1067 	return pos ? NULL : sk;
1068 }
1069 
1070 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
1071 	__acquires(ping_table.lock)
1072 {
1073 	struct ping_iter_state *state = seq->private;
1074 	state->bucket = 0;
1075 	state->family = family;
1076 
1077 	read_lock_bh(&ping_table.lock);
1078 
1079 	return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1080 }
1081 EXPORT_SYMBOL_GPL(ping_seq_start);
1082 
1083 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos)
1084 {
1085 	return ping_seq_start(seq, pos, AF_INET);
1086 }
1087 
1088 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1089 {
1090 	struct sock *sk;
1091 
1092 	if (v == SEQ_START_TOKEN)
1093 		sk = ping_get_idx(seq, 0);
1094 	else
1095 		sk = ping_get_next(seq, v);
1096 
1097 	++*pos;
1098 	return sk;
1099 }
1100 EXPORT_SYMBOL_GPL(ping_seq_next);
1101 
1102 void ping_seq_stop(struct seq_file *seq, void *v)
1103 	__releases(ping_table.lock)
1104 {
1105 	read_unlock_bh(&ping_table.lock);
1106 }
1107 EXPORT_SYMBOL_GPL(ping_seq_stop);
1108 
1109 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f,
1110 		int bucket)
1111 {
1112 	struct inet_sock *inet = inet_sk(sp);
1113 	__be32 dest = inet->inet_daddr;
1114 	__be32 src = inet->inet_rcv_saddr;
1115 	__u16 destp = ntohs(inet->inet_dport);
1116 	__u16 srcp = ntohs(inet->inet_sport);
1117 
1118 	seq_printf(f, "%5d: %08X:%04X %08X:%04X"
1119 		" %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d",
1120 		bucket, src, srcp, dest, destp, sp->sk_state,
1121 		sk_wmem_alloc_get(sp),
1122 		sk_rmem_alloc_get(sp),
1123 		0, 0L, 0,
1124 		from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
1125 		0, sock_i_ino(sp),
1126 		atomic_read(&sp->sk_refcnt), sp,
1127 		atomic_read(&sp->sk_drops));
1128 }
1129 
1130 static int ping_v4_seq_show(struct seq_file *seq, void *v)
1131 {
1132 	seq_setwidth(seq, 127);
1133 	if (v == SEQ_START_TOKEN)
1134 		seq_puts(seq, "  sl  local_address rem_address   st tx_queue "
1135 			   "rx_queue tr tm->when retrnsmt   uid  timeout "
1136 			   "inode ref pointer drops");
1137 	else {
1138 		struct ping_iter_state *state = seq->private;
1139 
1140 		ping_v4_format_sock(v, seq, state->bucket);
1141 	}
1142 	seq_pad(seq, '\n');
1143 	return 0;
1144 }
1145 
1146 static int ping_seq_open(struct inode *inode, struct file *file)
1147 {
1148 	struct ping_seq_afinfo *afinfo = PDE_DATA(inode);
1149 	return seq_open_net(inode, file, &afinfo->seq_ops,
1150 			   sizeof(struct ping_iter_state));
1151 }
1152 
1153 const struct file_operations ping_seq_fops = {
1154 	.open		= ping_seq_open,
1155 	.read		= seq_read,
1156 	.llseek		= seq_lseek,
1157 	.release	= seq_release_net,
1158 };
1159 EXPORT_SYMBOL_GPL(ping_seq_fops);
1160 
1161 static struct ping_seq_afinfo ping_v4_seq_afinfo = {
1162 	.name		= "icmp",
1163 	.family		= AF_INET,
1164 	.seq_fops	= &ping_seq_fops,
1165 	.seq_ops	= {
1166 		.start		= ping_v4_seq_start,
1167 		.show		= ping_v4_seq_show,
1168 		.next		= ping_seq_next,
1169 		.stop		= ping_seq_stop,
1170 	},
1171 };
1172 
1173 int ping_proc_register(struct net *net, struct ping_seq_afinfo *afinfo)
1174 {
1175 	struct proc_dir_entry *p;
1176 	p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
1177 			     afinfo->seq_fops, afinfo);
1178 	if (!p)
1179 		return -ENOMEM;
1180 	return 0;
1181 }
1182 EXPORT_SYMBOL_GPL(ping_proc_register);
1183 
1184 void ping_proc_unregister(struct net *net, struct ping_seq_afinfo *afinfo)
1185 {
1186 	remove_proc_entry(afinfo->name, net->proc_net);
1187 }
1188 EXPORT_SYMBOL_GPL(ping_proc_unregister);
1189 
1190 static int __net_init ping_v4_proc_init_net(struct net *net)
1191 {
1192 	return ping_proc_register(net, &ping_v4_seq_afinfo);
1193 }
1194 
1195 static void __net_exit ping_v4_proc_exit_net(struct net *net)
1196 {
1197 	ping_proc_unregister(net, &ping_v4_seq_afinfo);
1198 }
1199 
1200 static struct pernet_operations ping_v4_net_ops = {
1201 	.init = ping_v4_proc_init_net,
1202 	.exit = ping_v4_proc_exit_net,
1203 };
1204 
1205 int __init ping_proc_init(void)
1206 {
1207 	return register_pernet_subsys(&ping_v4_net_ops);
1208 }
1209 
1210 void ping_proc_exit(void)
1211 {
1212 	unregister_pernet_subsys(&ping_v4_net_ops);
1213 }
1214 
1215 #endif
1216 
1217 void __init ping_init(void)
1218 {
1219 	int i;
1220 
1221 	for (i = 0; i < PING_HTABLE_SIZE; i++)
1222 		INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i);
1223 	rwlock_init(&ping_table.lock);
1224 }
1225