1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * "Ping" sockets
8 *
9 * Based on ipv4/udp.c code.
10 *
11 * Authors: Vasiliy Kulikov / Openwall (for Linux 2.6),
12 * Pavel Kankovsky (for Linux 2.4.32)
13 *
14 * Pavel gave all rights to bugs to Vasiliy,
15 * none of the bugs are Pavel's now.
16 */
17
18 #include <linux/uaccess.h>
19 #include <linux/types.h>
20 #include <linux/fcntl.h>
21 #include <linux/socket.h>
22 #include <linux/sockios.h>
23 #include <linux/in.h>
24 #include <linux/errno.h>
25 #include <linux/timer.h>
26 #include <linux/mm.h>
27 #include <linux/inet.h>
28 #include <linux/netdevice.h>
29 #include <net/snmp.h>
30 #include <net/ip.h>
31 #include <net/icmp.h>
32 #include <net/protocol.h>
33 #include <linux/skbuff.h>
34 #include <linux/proc_fs.h>
35 #include <linux/export.h>
36 #include <net/sock.h>
37 #include <net/ping.h>
38 #include <net/udp.h>
39 #include <net/route.h>
40 #include <net/inet_common.h>
41 #include <net/checksum.h>
42
43 #if IS_ENABLED(CONFIG_IPV6)
44 #include <linux/in6.h>
45 #include <linux/icmpv6.h>
46 #include <net/addrconf.h>
47 #include <net/ipv6.h>
48 #include <net/transp_v6.h>
49 #endif
50
51 struct ping_table {
52 struct hlist_nulls_head hash[PING_HTABLE_SIZE];
53 rwlock_t lock;
54 };
55
56 static struct ping_table ping_table;
57 struct pingv6_ops pingv6_ops;
58 EXPORT_SYMBOL_GPL(pingv6_ops);
59
60 static u16 ping_port_rover;
61
ping_hashfn(const struct net * net,u32 num,u32 mask)62 static inline u32 ping_hashfn(const struct net *net, u32 num, u32 mask)
63 {
64 u32 res = (num + net_hash_mix(net)) & mask;
65
66 pr_debug("hash(%u) = %u\n", num, res);
67 return res;
68 }
69 EXPORT_SYMBOL_GPL(ping_hash);
70
ping_hashslot(struct ping_table * table,struct net * net,unsigned int num)71 static inline struct hlist_nulls_head *ping_hashslot(struct ping_table *table,
72 struct net *net, unsigned int num)
73 {
74 return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)];
75 }
76
ping_get_port(struct sock * sk,unsigned short ident)77 int ping_get_port(struct sock *sk, unsigned short ident)
78 {
79 struct hlist_nulls_node *node;
80 struct hlist_nulls_head *hlist;
81 struct inet_sock *isk, *isk2;
82 struct sock *sk2 = NULL;
83
84 isk = inet_sk(sk);
85 write_lock_bh(&ping_table.lock);
86 if (ident == 0) {
87 u32 i;
88 u16 result = ping_port_rover + 1;
89
90 for (i = 0; i < (1L << 16); i++, result++) {
91 if (!result)
92 result++; /* avoid zero */
93 hlist = ping_hashslot(&ping_table, sock_net(sk),
94 result);
95 ping_portaddr_for_each_entry(sk2, node, hlist) {
96 isk2 = inet_sk(sk2);
97
98 if (isk2->inet_num == result)
99 goto next_port;
100 }
101
102 /* found */
103 ping_port_rover = ident = result;
104 break;
105 next_port:
106 ;
107 }
108 if (i >= (1L << 16))
109 goto fail;
110 } else {
111 hlist = ping_hashslot(&ping_table, sock_net(sk), ident);
112 ping_portaddr_for_each_entry(sk2, node, hlist) {
113 isk2 = inet_sk(sk2);
114
115 /* BUG? Why is this reuse and not reuseaddr? ping.c
116 * doesn't turn off SO_REUSEADDR, and it doesn't expect
117 * that other ping processes can steal its packets.
118 */
119 if ((isk2->inet_num == ident) &&
120 (sk2 != sk) &&
121 (!sk2->sk_reuse || !sk->sk_reuse))
122 goto fail;
123 }
124 }
125
126 pr_debug("found port/ident = %d\n", ident);
127 isk->inet_num = ident;
128 if (sk_unhashed(sk)) {
129 pr_debug("was not hashed\n");
130 sock_hold(sk);
131 hlist_nulls_add_head(&sk->sk_nulls_node, hlist);
132 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
133 }
134 write_unlock_bh(&ping_table.lock);
135 return 0;
136
137 fail:
138 write_unlock_bh(&ping_table.lock);
139 return 1;
140 }
141 EXPORT_SYMBOL_GPL(ping_get_port);
142
ping_hash(struct sock * sk)143 int ping_hash(struct sock *sk)
144 {
145 pr_debug("ping_hash(sk->port=%u)\n", inet_sk(sk)->inet_num);
146 BUG(); /* "Please do not press this button again." */
147
148 return 0;
149 }
150
ping_unhash(struct sock * sk)151 void ping_unhash(struct sock *sk)
152 {
153 struct inet_sock *isk = inet_sk(sk);
154
155 pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);
156 write_lock_bh(&ping_table.lock);
157 if (sk_hashed(sk)) {
158 hlist_nulls_del(&sk->sk_nulls_node);
159 sk_nulls_node_init(&sk->sk_nulls_node);
160 sock_put(sk);
161 isk->inet_num = 0;
162 isk->inet_sport = 0;
163 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
164 }
165 write_unlock_bh(&ping_table.lock);
166 }
167 EXPORT_SYMBOL_GPL(ping_unhash);
168
ping_lookup(struct net * net,struct sk_buff * skb,u16 ident)169 static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
170 {
171 struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident);
172 struct sock *sk = NULL;
173 struct inet_sock *isk;
174 struct hlist_nulls_node *hnode;
175 int dif = skb->dev->ifindex;
176
177 if (skb->protocol == htons(ETH_P_IP)) {
178 pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n",
179 (int)ident, &ip_hdr(skb)->daddr, dif);
180 #if IS_ENABLED(CONFIG_IPV6)
181 } else if (skb->protocol == htons(ETH_P_IPV6)) {
182 pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n",
183 (int)ident, &ipv6_hdr(skb)->daddr, dif);
184 #endif
185 }
186
187 read_lock_bh(&ping_table.lock);
188
189 ping_portaddr_for_each_entry(sk, hnode, hslot) {
190 isk = inet_sk(sk);
191
192 pr_debug("iterate\n");
193 if (isk->inet_num != ident)
194 continue;
195
196 if (skb->protocol == htons(ETH_P_IP) &&
197 sk->sk_family == AF_INET) {
198 pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk,
199 (int) isk->inet_num, &isk->inet_rcv_saddr,
200 sk->sk_bound_dev_if);
201
202 if (isk->inet_rcv_saddr &&
203 isk->inet_rcv_saddr != ip_hdr(skb)->daddr)
204 continue;
205 #if IS_ENABLED(CONFIG_IPV6)
206 } else if (skb->protocol == htons(ETH_P_IPV6) &&
207 sk->sk_family == AF_INET6) {
208
209 pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk,
210 (int) isk->inet_num,
211 &sk->sk_v6_rcv_saddr,
212 sk->sk_bound_dev_if);
213
214 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
215 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr,
216 &ipv6_hdr(skb)->daddr))
217 continue;
218 #endif
219 } else {
220 continue;
221 }
222
223 if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)
224 continue;
225
226 sock_hold(sk);
227 goto exit;
228 }
229
230 sk = NULL;
231 exit:
232 read_unlock_bh(&ping_table.lock);
233
234 return sk;
235 }
236
inet_get_ping_group_range_net(struct net * net,kgid_t * low,kgid_t * high)237 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low,
238 kgid_t *high)
239 {
240 kgid_t *data = net->ipv4.ping_group_range.range;
241 unsigned int seq;
242
243 do {
244 seq = read_seqbegin(&net->ipv4.ping_group_range.lock);
245
246 *low = data[0];
247 *high = data[1];
248 } while (read_seqretry(&net->ipv4.ping_group_range.lock, seq));
249 }
250
251
ping_init_sock(struct sock * sk)252 int ping_init_sock(struct sock *sk)
253 {
254 struct net *net = sock_net(sk);
255 kgid_t group = current_egid();
256 struct group_info *group_info;
257 int i;
258 kgid_t low, high;
259 int ret = 0;
260
261 if (sk->sk_family == AF_INET6)
262 sk->sk_ipv6only = 1;
263
264 inet_get_ping_group_range_net(net, &low, &high);
265 if (gid_lte(low, group) && gid_lte(group, high))
266 return 0;
267
268 group_info = get_current_groups();
269 for (i = 0; i < group_info->ngroups; i++) {
270 kgid_t gid = group_info->gid[i];
271
272 if (gid_lte(low, gid) && gid_lte(gid, high))
273 goto out_release_group;
274 }
275
276 ret = -EACCES;
277
278 out_release_group:
279 put_group_info(group_info);
280 return ret;
281 }
282 EXPORT_SYMBOL_GPL(ping_init_sock);
283
ping_close(struct sock * sk,long timeout)284 void ping_close(struct sock *sk, long timeout)
285 {
286 pr_debug("ping_close(sk=%p,sk->num=%u)\n",
287 inet_sk(sk), inet_sk(sk)->inet_num);
288 pr_debug("isk->refcnt = %d\n", refcount_read(&sk->sk_refcnt));
289
290 sk_common_release(sk);
291 }
292 EXPORT_SYMBOL_GPL(ping_close);
293
294 /* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */
ping_check_bind_addr(struct sock * sk,struct inet_sock * isk,struct sockaddr * uaddr,int addr_len)295 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
296 struct sockaddr *uaddr, int addr_len)
297 {
298 struct net *net = sock_net(sk);
299 if (sk->sk_family == AF_INET) {
300 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
301 int chk_addr_ret;
302
303 if (addr_len < sizeof(*addr))
304 return -EINVAL;
305
306 if (addr->sin_family != AF_INET &&
307 !(addr->sin_family == AF_UNSPEC &&
308 addr->sin_addr.s_addr == htonl(INADDR_ANY)))
309 return -EAFNOSUPPORT;
310
311 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",
312 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
313
314 if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
315 chk_addr_ret = RTN_LOCAL;
316 else
317 chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
318
319 if ((!inet_can_nonlocal_bind(net, isk) &&
320 chk_addr_ret != RTN_LOCAL) ||
321 chk_addr_ret == RTN_MULTICAST ||
322 chk_addr_ret == RTN_BROADCAST)
323 return -EADDRNOTAVAIL;
324
325 #if IS_ENABLED(CONFIG_IPV6)
326 } else if (sk->sk_family == AF_INET6) {
327 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
328 int addr_type, scoped, has_addr;
329 struct net_device *dev = NULL;
330
331 if (addr_len < sizeof(*addr))
332 return -EINVAL;
333
334 if (addr->sin6_family != AF_INET6)
335 return -EAFNOSUPPORT;
336
337 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n",
338 sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port));
339
340 addr_type = ipv6_addr_type(&addr->sin6_addr);
341 scoped = __ipv6_addr_needs_scope_id(addr_type);
342 if ((addr_type != IPV6_ADDR_ANY &&
343 !(addr_type & IPV6_ADDR_UNICAST)) ||
344 (scoped && !addr->sin6_scope_id))
345 return -EINVAL;
346
347 rcu_read_lock();
348 if (addr->sin6_scope_id) {
349 dev = dev_get_by_index_rcu(net, addr->sin6_scope_id);
350 if (!dev) {
351 rcu_read_unlock();
352 return -ENODEV;
353 }
354 }
355 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev,
356 scoped);
357 rcu_read_unlock();
358
359 if (!(ipv6_can_nonlocal_bind(net, isk) || has_addr ||
360 addr_type == IPV6_ADDR_ANY))
361 return -EADDRNOTAVAIL;
362
363 if (scoped)
364 sk->sk_bound_dev_if = addr->sin6_scope_id;
365 #endif
366 } else {
367 return -EAFNOSUPPORT;
368 }
369 return 0;
370 }
371
ping_set_saddr(struct sock * sk,struct sockaddr * saddr)372 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr)
373 {
374 if (saddr->sa_family == AF_INET) {
375 struct inet_sock *isk = inet_sk(sk);
376 struct sockaddr_in *addr = (struct sockaddr_in *) saddr;
377 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
378 #if IS_ENABLED(CONFIG_IPV6)
379 } else if (saddr->sa_family == AF_INET6) {
380 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr;
381 struct ipv6_pinfo *np = inet6_sk(sk);
382 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr;
383 #endif
384 }
385 }
386
387 /*
388 * We need our own bind because there are no privileged id's == local ports.
389 * Moreover, we don't allow binding to multi- and broadcast addresses.
390 */
391
ping_bind(struct sock * sk,struct sockaddr * uaddr,int addr_len)392 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
393 {
394 struct inet_sock *isk = inet_sk(sk);
395 unsigned short snum;
396 int err;
397 int dif = sk->sk_bound_dev_if;
398
399 err = ping_check_bind_addr(sk, isk, uaddr, addr_len);
400 if (err)
401 return err;
402
403 lock_sock(sk);
404
405 err = -EINVAL;
406 if (isk->inet_num != 0)
407 goto out;
408
409 err = -EADDRINUSE;
410 snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port);
411 if (ping_get_port(sk, snum) != 0) {
412 /* Restore possibly modified sk->sk_bound_dev_if by ping_check_bind_addr(). */
413 sk->sk_bound_dev_if = dif;
414 goto out;
415 }
416 ping_set_saddr(sk, uaddr);
417
418 pr_debug("after bind(): num = %hu, dif = %d\n",
419 isk->inet_num,
420 sk->sk_bound_dev_if);
421
422 err = 0;
423 if (sk->sk_family == AF_INET && isk->inet_rcv_saddr)
424 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
425 #if IS_ENABLED(CONFIG_IPV6)
426 if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr))
427 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
428 #endif
429
430 if (snum)
431 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
432 isk->inet_sport = htons(isk->inet_num);
433 isk->inet_daddr = 0;
434 isk->inet_dport = 0;
435
436 #if IS_ENABLED(CONFIG_IPV6)
437 if (sk->sk_family == AF_INET6)
438 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr));
439 #endif
440
441 sk_dst_reset(sk);
442 out:
443 release_sock(sk);
444 pr_debug("ping_v4_bind -> %d\n", err);
445 return err;
446 }
447 EXPORT_SYMBOL_GPL(ping_bind);
448
449 /*
450 * Is this a supported type of ICMP message?
451 */
452
ping_supported(int family,int type,int code)453 static inline int ping_supported(int family, int type, int code)
454 {
455 return (family == AF_INET && type == ICMP_ECHO && code == 0) ||
456 (family == AF_INET && type == ICMP_EXT_ECHO && code == 0) ||
457 (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0) ||
458 (family == AF_INET6 && type == ICMPV6_EXT_ECHO_REQUEST && code == 0);
459 }
460
461 /*
462 * This routine is called by the ICMP module when it gets some
463 * sort of error condition.
464 */
465
ping_err(struct sk_buff * skb,int offset,u32 info)466 void ping_err(struct sk_buff *skb, int offset, u32 info)
467 {
468 int family;
469 struct icmphdr *icmph;
470 struct inet_sock *inet_sock;
471 int type;
472 int code;
473 struct net *net = dev_net(skb->dev);
474 struct sock *sk;
475 int harderr;
476 int err;
477
478 if (skb->protocol == htons(ETH_P_IP)) {
479 family = AF_INET;
480 type = icmp_hdr(skb)->type;
481 code = icmp_hdr(skb)->code;
482 icmph = (struct icmphdr *)(skb->data + offset);
483 } else if (skb->protocol == htons(ETH_P_IPV6)) {
484 family = AF_INET6;
485 type = icmp6_hdr(skb)->icmp6_type;
486 code = icmp6_hdr(skb)->icmp6_code;
487 icmph = (struct icmphdr *) (skb->data + offset);
488 } else {
489 BUG();
490 }
491
492 /* We assume the packet has already been checked by icmp_unreach */
493
494 if (!ping_supported(family, icmph->type, icmph->code))
495 return;
496
497 pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n",
498 skb->protocol, type, code, ntohs(icmph->un.echo.id),
499 ntohs(icmph->un.echo.sequence));
500
501 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
502 if (!sk) {
503 pr_debug("no socket, dropping\n");
504 return; /* No socket for error */
505 }
506 pr_debug("err on socket %p\n", sk);
507
508 err = 0;
509 harderr = 0;
510 inet_sock = inet_sk(sk);
511
512 if (skb->protocol == htons(ETH_P_IP)) {
513 switch (type) {
514 default:
515 case ICMP_TIME_EXCEEDED:
516 err = EHOSTUNREACH;
517 break;
518 case ICMP_SOURCE_QUENCH:
519 /* This is not a real error but ping wants to see it.
520 * Report it with some fake errno.
521 */
522 err = EREMOTEIO;
523 break;
524 case ICMP_PARAMETERPROB:
525 err = EPROTO;
526 harderr = 1;
527 break;
528 case ICMP_DEST_UNREACH:
529 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
530 ipv4_sk_update_pmtu(skb, sk, info);
531 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) {
532 err = EMSGSIZE;
533 harderr = 1;
534 break;
535 }
536 goto out;
537 }
538 err = EHOSTUNREACH;
539 if (code <= NR_ICMP_UNREACH) {
540 harderr = icmp_err_convert[code].fatal;
541 err = icmp_err_convert[code].errno;
542 }
543 break;
544 case ICMP_REDIRECT:
545 /* See ICMP_SOURCE_QUENCH */
546 ipv4_sk_redirect(skb, sk);
547 err = EREMOTEIO;
548 break;
549 }
550 #if IS_ENABLED(CONFIG_IPV6)
551 } else if (skb->protocol == htons(ETH_P_IPV6)) {
552 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err);
553 #endif
554 }
555
556 /*
557 * RFC1122: OK. Passes ICMP errors back to application, as per
558 * 4.1.3.3.
559 */
560 if ((family == AF_INET && !inet_sock->recverr) ||
561 (family == AF_INET6 && !inet6_sk(sk)->recverr)) {
562 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
563 goto out;
564 } else {
565 if (family == AF_INET) {
566 ip_icmp_error(sk, skb, err, 0 /* no remote port */,
567 info, (u8 *)icmph);
568 #if IS_ENABLED(CONFIG_IPV6)
569 } else if (family == AF_INET6) {
570 pingv6_ops.ipv6_icmp_error(sk, skb, err, 0,
571 info, (u8 *)icmph);
572 #endif
573 }
574 }
575 sk->sk_err = err;
576 sk->sk_error_report(sk);
577 out:
578 sock_put(sk);
579 }
580 EXPORT_SYMBOL_GPL(ping_err);
581
582 /*
583 * Copy and checksum an ICMP Echo packet from user space into a buffer
584 * starting from the payload.
585 */
586
ping_getfrag(void * from,char * to,int offset,int fraglen,int odd,struct sk_buff * skb)587 int ping_getfrag(void *from, char *to,
588 int offset, int fraglen, int odd, struct sk_buff *skb)
589 {
590 struct pingfakehdr *pfh = (struct pingfakehdr *)from;
591
592 if (offset == 0) {
593 fraglen -= sizeof(struct icmphdr);
594 if (fraglen < 0)
595 BUG();
596 if (!csum_and_copy_from_iter_full(to + sizeof(struct icmphdr),
597 fraglen, &pfh->wcheck,
598 &pfh->msg->msg_iter))
599 return -EFAULT;
600 } else if (offset < sizeof(struct icmphdr)) {
601 BUG();
602 } else {
603 if (!csum_and_copy_from_iter_full(to, fraglen, &pfh->wcheck,
604 &pfh->msg->msg_iter))
605 return -EFAULT;
606 }
607
608 #if IS_ENABLED(CONFIG_IPV6)
609 /* For IPv6, checksum each skb as we go along, as expected by
610 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in
611 * wcheck, it will be finalized in ping_v4_push_pending_frames.
612 */
613 if (pfh->family == AF_INET6) {
614 skb->csum = pfh->wcheck;
615 skb->ip_summed = CHECKSUM_NONE;
616 pfh->wcheck = 0;
617 }
618 #endif
619
620 return 0;
621 }
622 EXPORT_SYMBOL_GPL(ping_getfrag);
623
ping_v4_push_pending_frames(struct sock * sk,struct pingfakehdr * pfh,struct flowi4 * fl4)624 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
625 struct flowi4 *fl4)
626 {
627 struct sk_buff *skb = skb_peek(&sk->sk_write_queue);
628
629 if (!skb)
630 return 0;
631 pfh->wcheck = csum_partial((char *)&pfh->icmph,
632 sizeof(struct icmphdr), pfh->wcheck);
633 pfh->icmph.checksum = csum_fold(pfh->wcheck);
634 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
635 skb->ip_summed = CHECKSUM_NONE;
636 return ip_push_pending_frames(sk, fl4);
637 }
638
ping_common_sendmsg(int family,struct msghdr * msg,size_t len,void * user_icmph,size_t icmph_len)639 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
640 void *user_icmph, size_t icmph_len)
641 {
642 u8 type, code;
643
644 if (len > 0xFFFF)
645 return -EMSGSIZE;
646
647 /* Must have at least a full ICMP header. */
648 if (len < icmph_len)
649 return -EINVAL;
650
651 /*
652 * Check the flags.
653 */
654
655 /* Mirror BSD error message compatibility */
656 if (msg->msg_flags & MSG_OOB)
657 return -EOPNOTSUPP;
658
659 /*
660 * Fetch the ICMP header provided by the userland.
661 * iovec is modified! The ICMP header is consumed.
662 */
663 if (memcpy_from_msg(user_icmph, msg, icmph_len))
664 return -EFAULT;
665
666 if (family == AF_INET) {
667 type = ((struct icmphdr *) user_icmph)->type;
668 code = ((struct icmphdr *) user_icmph)->code;
669 #if IS_ENABLED(CONFIG_IPV6)
670 } else if (family == AF_INET6) {
671 type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
672 code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
673 #endif
674 } else {
675 BUG();
676 }
677
678 if (!ping_supported(family, type, code))
679 return -EINVAL;
680
681 return 0;
682 }
683 EXPORT_SYMBOL_GPL(ping_common_sendmsg);
684
ping_v4_sendmsg(struct sock * sk,struct msghdr * msg,size_t len)685 static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
686 {
687 struct net *net = sock_net(sk);
688 struct flowi4 fl4;
689 struct inet_sock *inet = inet_sk(sk);
690 struct ipcm_cookie ipc;
691 struct icmphdr user_icmph;
692 struct pingfakehdr pfh;
693 struct rtable *rt = NULL;
694 struct ip_options_data opt_copy;
695 int free = 0;
696 __be32 saddr, daddr, faddr;
697 u8 tos;
698 int err;
699
700 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
701
702 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
703 sizeof(user_icmph));
704 if (err)
705 return err;
706
707 /*
708 * Get and verify the address.
709 */
710
711 if (msg->msg_name) {
712 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
713 if (msg->msg_namelen < sizeof(*usin))
714 return -EINVAL;
715 if (usin->sin_family != AF_INET)
716 return -EAFNOSUPPORT;
717 daddr = usin->sin_addr.s_addr;
718 /* no remote port */
719 } else {
720 if (sk->sk_state != TCP_ESTABLISHED)
721 return -EDESTADDRREQ;
722 daddr = inet->inet_daddr;
723 /* no remote port */
724 }
725
726 ipcm_init_sk(&ipc, inet);
727
728 if (msg->msg_controllen) {
729 err = ip_cmsg_send(sk, msg, &ipc, false);
730 if (unlikely(err)) {
731 kfree(ipc.opt);
732 return err;
733 }
734 if (ipc.opt)
735 free = 1;
736 }
737 if (!ipc.opt) {
738 struct ip_options_rcu *inet_opt;
739
740 rcu_read_lock();
741 inet_opt = rcu_dereference(inet->inet_opt);
742 if (inet_opt) {
743 memcpy(&opt_copy, inet_opt,
744 sizeof(*inet_opt) + inet_opt->opt.optlen);
745 ipc.opt = &opt_copy.opt;
746 }
747 rcu_read_unlock();
748 }
749
750 saddr = ipc.addr;
751 ipc.addr = faddr = daddr;
752
753 if (ipc.opt && ipc.opt->opt.srr) {
754 if (!daddr) {
755 err = -EINVAL;
756 goto out_free;
757 }
758 faddr = ipc.opt->opt.faddr;
759 }
760 tos = get_rttos(&ipc, inet);
761 if (sock_flag(sk, SOCK_LOCALROUTE) ||
762 (msg->msg_flags & MSG_DONTROUTE) ||
763 (ipc.opt && ipc.opt->opt.is_strictroute)) {
764 tos |= RTO_ONLINK;
765 }
766
767 if (ipv4_is_multicast(daddr)) {
768 if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif))
769 ipc.oif = inet->mc_index;
770 if (!saddr)
771 saddr = inet->mc_addr;
772 } else if (!ipc.oif)
773 ipc.oif = inet->uc_index;
774
775 flowi4_init_output(&fl4, ipc.oif, ipc.sockc.mark, tos,
776 RT_SCOPE_UNIVERSE, sk->sk_protocol,
777 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0,
778 sk->sk_uid);
779
780 fl4.fl4_icmp_type = user_icmph.type;
781 fl4.fl4_icmp_code = user_icmph.code;
782
783 security_sk_classify_flow(sk, flowi4_to_flowi_common(&fl4));
784 rt = ip_route_output_flow(net, &fl4, sk);
785 if (IS_ERR(rt)) {
786 err = PTR_ERR(rt);
787 rt = NULL;
788 if (err == -ENETUNREACH)
789 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
790 goto out;
791 }
792
793 err = -EACCES;
794 if ((rt->rt_flags & RTCF_BROADCAST) &&
795 !sock_flag(sk, SOCK_BROADCAST))
796 goto out;
797
798 if (msg->msg_flags & MSG_CONFIRM)
799 goto do_confirm;
800 back_from_confirm:
801
802 if (!ipc.addr)
803 ipc.addr = fl4.daddr;
804
805 lock_sock(sk);
806
807 pfh.icmph.type = user_icmph.type; /* already checked */
808 pfh.icmph.code = user_icmph.code; /* ditto */
809 pfh.icmph.checksum = 0;
810 pfh.icmph.un.echo.id = inet->inet_sport;
811 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
812 pfh.msg = msg;
813 pfh.wcheck = 0;
814 pfh.family = AF_INET;
815
816 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
817 0, &ipc, &rt, msg->msg_flags);
818 if (err)
819 ip_flush_pending_frames(sk);
820 else
821 err = ping_v4_push_pending_frames(sk, &pfh, &fl4);
822 release_sock(sk);
823
824 out:
825 ip_rt_put(rt);
826 out_free:
827 if (free)
828 kfree(ipc.opt);
829 if (!err) {
830 icmp_out_count(sock_net(sk), user_icmph.type);
831 return len;
832 }
833 return err;
834
835 do_confirm:
836 if (msg->msg_flags & MSG_PROBE)
837 dst_confirm_neigh(&rt->dst, &fl4.daddr);
838 if (!(msg->msg_flags & MSG_PROBE) || len)
839 goto back_from_confirm;
840 err = 0;
841 goto out;
842 }
843
ping_recvmsg(struct sock * sk,struct msghdr * msg,size_t len,int noblock,int flags,int * addr_len)844 int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock,
845 int flags, int *addr_len)
846 {
847 struct inet_sock *isk = inet_sk(sk);
848 int family = sk->sk_family;
849 struct sk_buff *skb;
850 int copied, err;
851
852 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
853
854 err = -EOPNOTSUPP;
855 if (flags & MSG_OOB)
856 goto out;
857
858 if (flags & MSG_ERRQUEUE)
859 return inet_recv_error(sk, msg, len, addr_len);
860
861 skb = skb_recv_datagram(sk, flags, noblock, &err);
862 if (!skb)
863 goto out;
864
865 copied = skb->len;
866 if (copied > len) {
867 msg->msg_flags |= MSG_TRUNC;
868 copied = len;
869 }
870
871 /* Don't bother checking the checksum */
872 err = skb_copy_datagram_msg(skb, 0, msg, copied);
873 if (err)
874 goto done;
875
876 sock_recv_timestamp(msg, sk, skb);
877
878 /* Copy the address and add cmsg data. */
879 if (family == AF_INET) {
880 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
881
882 if (sin) {
883 sin->sin_family = AF_INET;
884 sin->sin_port = 0 /* skb->h.uh->source */;
885 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
886 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
887 *addr_len = sizeof(*sin);
888 }
889
890 if (isk->cmsg_flags)
891 ip_cmsg_recv(msg, skb);
892
893 #if IS_ENABLED(CONFIG_IPV6)
894 } else if (family == AF_INET6) {
895 struct ipv6_pinfo *np = inet6_sk(sk);
896 struct ipv6hdr *ip6 = ipv6_hdr(skb);
897 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
898
899 if (sin6) {
900 sin6->sin6_family = AF_INET6;
901 sin6->sin6_port = 0;
902 sin6->sin6_addr = ip6->saddr;
903 sin6->sin6_flowinfo = 0;
904 if (np->sndflow)
905 sin6->sin6_flowinfo = ip6_flowinfo(ip6);
906 sin6->sin6_scope_id =
907 ipv6_iface_scope_id(&sin6->sin6_addr,
908 inet6_iif(skb));
909 *addr_len = sizeof(*sin6);
910 }
911
912 if (inet6_sk(sk)->rxopt.all)
913 pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb);
914 if (skb->protocol == htons(ETH_P_IPV6) &&
915 inet6_sk(sk)->rxopt.all)
916 pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb);
917 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags)
918 ip_cmsg_recv(msg, skb);
919 #endif
920 } else {
921 BUG();
922 }
923
924 err = copied;
925
926 done:
927 skb_free_datagram(sk, skb);
928 out:
929 pr_debug("ping_recvmsg -> %d\n", err);
930 return err;
931 }
932 EXPORT_SYMBOL_GPL(ping_recvmsg);
933
ping_queue_rcv_skb(struct sock * sk,struct sk_buff * skb)934 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
935 {
936 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
937 inet_sk(sk), inet_sk(sk)->inet_num, skb);
938 if (sock_queue_rcv_skb(sk, skb) < 0) {
939 kfree_skb(skb);
940 pr_debug("ping_queue_rcv_skb -> failed\n");
941 return -1;
942 }
943 return 0;
944 }
945 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
946
947
948 /*
949 * All we need to do is get the socket.
950 */
951
ping_rcv(struct sk_buff * skb)952 bool ping_rcv(struct sk_buff *skb)
953 {
954 struct sock *sk;
955 struct net *net = dev_net(skb->dev);
956 struct icmphdr *icmph = icmp_hdr(skb);
957
958 /* We assume the packet has already been checked by icmp_rcv */
959
960 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
961 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
962
963 /* Push ICMP header back */
964 skb_push(skb, skb->data - (u8 *)icmph);
965
966 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
967 if (sk) {
968 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
969
970 pr_debug("rcv on socket %p\n", sk);
971 if (skb2)
972 ping_queue_rcv_skb(sk, skb2);
973 sock_put(sk);
974 return true;
975 }
976 pr_debug("no socket, dropping\n");
977
978 return false;
979 }
980 EXPORT_SYMBOL_GPL(ping_rcv);
981
982 struct proto ping_prot = {
983 .name = "PING",
984 .owner = THIS_MODULE,
985 .init = ping_init_sock,
986 .close = ping_close,
987 .connect = ip4_datagram_connect,
988 .disconnect = __udp_disconnect,
989 .setsockopt = ip_setsockopt,
990 .getsockopt = ip_getsockopt,
991 .sendmsg = ping_v4_sendmsg,
992 .recvmsg = ping_recvmsg,
993 .bind = ping_bind,
994 .backlog_rcv = ping_queue_rcv_skb,
995 .release_cb = ip4_datagram_release_cb,
996 .hash = ping_hash,
997 .unhash = ping_unhash,
998 .get_port = ping_get_port,
999 .obj_size = sizeof(struct inet_sock),
1000 };
1001 EXPORT_SYMBOL(ping_prot);
1002
1003 #ifdef CONFIG_PROC_FS
1004
ping_get_first(struct seq_file * seq,int start)1005 static struct sock *ping_get_first(struct seq_file *seq, int start)
1006 {
1007 struct sock *sk;
1008 struct ping_iter_state *state = seq->private;
1009 struct net *net = seq_file_net(seq);
1010
1011 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
1012 ++state->bucket) {
1013 struct hlist_nulls_node *node;
1014 struct hlist_nulls_head *hslot;
1015
1016 hslot = &ping_table.hash[state->bucket];
1017
1018 if (hlist_nulls_empty(hslot))
1019 continue;
1020
1021 sk_nulls_for_each(sk, node, hslot) {
1022 if (net_eq(sock_net(sk), net) &&
1023 sk->sk_family == state->family)
1024 goto found;
1025 }
1026 }
1027 sk = NULL;
1028 found:
1029 return sk;
1030 }
1031
ping_get_next(struct seq_file * seq,struct sock * sk)1032 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
1033 {
1034 struct ping_iter_state *state = seq->private;
1035 struct net *net = seq_file_net(seq);
1036
1037 do {
1038 sk = sk_nulls_next(sk);
1039 } while (sk && (!net_eq(sock_net(sk), net)));
1040
1041 if (!sk)
1042 return ping_get_first(seq, state->bucket + 1);
1043 return sk;
1044 }
1045
ping_get_idx(struct seq_file * seq,loff_t pos)1046 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
1047 {
1048 struct sock *sk = ping_get_first(seq, 0);
1049
1050 if (sk)
1051 while (pos && (sk = ping_get_next(seq, sk)) != NULL)
1052 --pos;
1053 return pos ? NULL : sk;
1054 }
1055
ping_seq_start(struct seq_file * seq,loff_t * pos,sa_family_t family)1056 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
1057 __acquires(ping_table.lock)
1058 {
1059 struct ping_iter_state *state = seq->private;
1060 state->bucket = 0;
1061 state->family = family;
1062
1063 read_lock_bh(&ping_table.lock);
1064
1065 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1066 }
1067 EXPORT_SYMBOL_GPL(ping_seq_start);
1068
ping_v4_seq_start(struct seq_file * seq,loff_t * pos)1069 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos)
1070 {
1071 return ping_seq_start(seq, pos, AF_INET);
1072 }
1073
ping_seq_next(struct seq_file * seq,void * v,loff_t * pos)1074 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1075 {
1076 struct sock *sk;
1077
1078 if (v == SEQ_START_TOKEN)
1079 sk = ping_get_idx(seq, 0);
1080 else
1081 sk = ping_get_next(seq, v);
1082
1083 ++*pos;
1084 return sk;
1085 }
1086 EXPORT_SYMBOL_GPL(ping_seq_next);
1087
ping_seq_stop(struct seq_file * seq,void * v)1088 void ping_seq_stop(struct seq_file *seq, void *v)
1089 __releases(ping_table.lock)
1090 {
1091 read_unlock_bh(&ping_table.lock);
1092 }
1093 EXPORT_SYMBOL_GPL(ping_seq_stop);
1094
ping_v4_format_sock(struct sock * sp,struct seq_file * f,int bucket)1095 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f,
1096 int bucket)
1097 {
1098 struct inet_sock *inet = inet_sk(sp);
1099 __be32 dest = inet->inet_daddr;
1100 __be32 src = inet->inet_rcv_saddr;
1101 __u16 destp = ntohs(inet->inet_dport);
1102 __u16 srcp = ntohs(inet->inet_sport);
1103
1104 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
1105 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u",
1106 bucket, src, srcp, dest, destp, sp->sk_state,
1107 sk_wmem_alloc_get(sp),
1108 sk_rmem_alloc_get(sp),
1109 0, 0L, 0,
1110 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
1111 0, sock_i_ino(sp),
1112 refcount_read(&sp->sk_refcnt), sp,
1113 atomic_read(&sp->sk_drops));
1114 }
1115
ping_v4_seq_show(struct seq_file * seq,void * v)1116 static int ping_v4_seq_show(struct seq_file *seq, void *v)
1117 {
1118 seq_setwidth(seq, 127);
1119 if (v == SEQ_START_TOKEN)
1120 seq_puts(seq, " sl local_address rem_address st tx_queue "
1121 "rx_queue tr tm->when retrnsmt uid timeout "
1122 "inode ref pointer drops");
1123 else {
1124 struct ping_iter_state *state = seq->private;
1125
1126 ping_v4_format_sock(v, seq, state->bucket);
1127 }
1128 seq_pad(seq, '\n');
1129 return 0;
1130 }
1131
1132 static const struct seq_operations ping_v4_seq_ops = {
1133 .start = ping_v4_seq_start,
1134 .show = ping_v4_seq_show,
1135 .next = ping_seq_next,
1136 .stop = ping_seq_stop,
1137 };
1138
ping_v4_proc_init_net(struct net * net)1139 static int __net_init ping_v4_proc_init_net(struct net *net)
1140 {
1141 if (!proc_create_net("icmp", 0444, net->proc_net, &ping_v4_seq_ops,
1142 sizeof(struct ping_iter_state)))
1143 return -ENOMEM;
1144 return 0;
1145 }
1146
ping_v4_proc_exit_net(struct net * net)1147 static void __net_exit ping_v4_proc_exit_net(struct net *net)
1148 {
1149 remove_proc_entry("icmp", net->proc_net);
1150 }
1151
1152 static struct pernet_operations ping_v4_net_ops = {
1153 .init = ping_v4_proc_init_net,
1154 .exit = ping_v4_proc_exit_net,
1155 };
1156
ping_proc_init(void)1157 int __init ping_proc_init(void)
1158 {
1159 return register_pernet_subsys(&ping_v4_net_ops);
1160 }
1161
ping_proc_exit(void)1162 void ping_proc_exit(void)
1163 {
1164 unregister_pernet_subsys(&ping_v4_net_ops);
1165 }
1166
1167 #endif
1168
ping_init(void)1169 void __init ping_init(void)
1170 {
1171 int i;
1172
1173 for (i = 0; i < PING_HTABLE_SIZE; i++)
1174 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i);
1175 rwlock_init(&ping_table.lock);
1176 }
1177