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
ping_hashfn(const struct net * net,u32 num,u32 mask)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
ping_hashslot(struct ping_table * table,struct net * net,unsigned int num)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
ping_get_port(struct sock * sk,unsigned short ident)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
ping_hash(struct sock * sk)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
ping_unhash(struct sock * sk)156 void ping_unhash(struct sock *sk)
157 {
158 struct inet_sock *isk = inet_sk(sk);
159
160 pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);
161 write_lock_bh(&ping_table.lock);
162 if (sk_hashed(sk)) {
163 hlist_nulls_del(&sk->sk_nulls_node);
164 sk_nulls_node_init(&sk->sk_nulls_node);
165 sock_put(sk);
166 isk->inet_num = 0;
167 isk->inet_sport = 0;
168 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
169 }
170 write_unlock_bh(&ping_table.lock);
171 }
172 EXPORT_SYMBOL_GPL(ping_unhash);
173
ping_lookup(struct net * net,struct sk_buff * skb,u16 ident)174 static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
175 {
176 struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident);
177 struct sock *sk = NULL;
178 struct inet_sock *isk;
179 struct hlist_nulls_node *hnode;
180 int dif = skb->dev->ifindex;
181
182 if (skb->protocol == htons(ETH_P_IP)) {
183 pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n",
184 (int)ident, &ip_hdr(skb)->daddr, dif);
185 #if IS_ENABLED(CONFIG_IPV6)
186 } else if (skb->protocol == htons(ETH_P_IPV6)) {
187 pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n",
188 (int)ident, &ipv6_hdr(skb)->daddr, dif);
189 #endif
190 }
191
192 read_lock_bh(&ping_table.lock);
193
194 ping_portaddr_for_each_entry(sk, hnode, hslot) {
195 isk = inet_sk(sk);
196
197 pr_debug("iterate\n");
198 if (isk->inet_num != ident)
199 continue;
200
201 if (skb->protocol == htons(ETH_P_IP) &&
202 sk->sk_family == AF_INET) {
203 pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk,
204 (int) isk->inet_num, &isk->inet_rcv_saddr,
205 sk->sk_bound_dev_if);
206
207 if (isk->inet_rcv_saddr &&
208 isk->inet_rcv_saddr != ip_hdr(skb)->daddr)
209 continue;
210 #if IS_ENABLED(CONFIG_IPV6)
211 } else if (skb->protocol == htons(ETH_P_IPV6) &&
212 sk->sk_family == AF_INET6) {
213
214 pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk,
215 (int) isk->inet_num,
216 &sk->sk_v6_rcv_saddr,
217 sk->sk_bound_dev_if);
218
219 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
220 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr,
221 &ipv6_hdr(skb)->daddr))
222 continue;
223 #endif
224 } else {
225 continue;
226 }
227
228 if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)
229 continue;
230
231 sock_hold(sk);
232 goto exit;
233 }
234
235 sk = NULL;
236 exit:
237 read_unlock_bh(&ping_table.lock);
238
239 return sk;
240 }
241
inet_get_ping_group_range_net(struct net * net,kgid_t * low,kgid_t * high)242 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low,
243 kgid_t *high)
244 {
245 kgid_t *data = net->ipv4.ping_group_range.range;
246 unsigned int seq;
247
248 do {
249 seq = read_seqbegin(&net->ipv4.ping_group_range.lock);
250
251 *low = data[0];
252 *high = data[1];
253 } while (read_seqretry(&net->ipv4.ping_group_range.lock, seq));
254 }
255
256
ping_init_sock(struct sock * sk)257 int ping_init_sock(struct sock *sk)
258 {
259 struct net *net = sock_net(sk);
260 kgid_t group = current_egid();
261 struct group_info *group_info;
262 int i;
263 kgid_t low, high;
264 int ret = 0;
265
266 if (sk->sk_family == AF_INET6)
267 sk->sk_ipv6only = 1;
268
269 inet_get_ping_group_range_net(net, &low, &high);
270 if (gid_lte(low, group) && gid_lte(group, high))
271 return 0;
272
273 group_info = get_current_groups();
274 for (i = 0; i < group_info->ngroups; i++) {
275 kgid_t gid = group_info->gid[i];
276
277 if (gid_lte(low, gid) && gid_lte(gid, high))
278 goto out_release_group;
279 }
280
281 ret = -EACCES;
282
283 out_release_group:
284 put_group_info(group_info);
285 return ret;
286 }
287 EXPORT_SYMBOL_GPL(ping_init_sock);
288
ping_close(struct sock * sk,long timeout)289 void ping_close(struct sock *sk, long timeout)
290 {
291 pr_debug("ping_close(sk=%p,sk->num=%u)\n",
292 inet_sk(sk), inet_sk(sk)->inet_num);
293 pr_debug("isk->refcnt = %d\n", refcount_read(&sk->sk_refcnt));
294
295 sk_common_release(sk);
296 }
297 EXPORT_SYMBOL_GPL(ping_close);
298
299 /* 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)300 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
301 struct sockaddr *uaddr, int addr_len) {
302 struct net *net = sock_net(sk);
303 if (sk->sk_family == AF_INET) {
304 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
305 int chk_addr_ret;
306
307 if (addr_len < sizeof(*addr))
308 return -EINVAL;
309
310 if (addr->sin_family != AF_INET &&
311 !(addr->sin_family == AF_UNSPEC &&
312 addr->sin_addr.s_addr == htonl(INADDR_ANY)))
313 return -EAFNOSUPPORT;
314
315 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",
316 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
317
318 chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
319
320 if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
321 chk_addr_ret = RTN_LOCAL;
322
323 if ((!inet_can_nonlocal_bind(net, isk) &&
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 (!(ipv6_can_nonlocal_bind(net, isk) || has_addr ||
364 addr_type == IPV6_ADDR_ANY))
365 return -EADDRNOTAVAIL;
366
367 if (scoped)
368 sk->sk_bound_dev_if = addr->sin6_scope_id;
369 #endif
370 } else {
371 return -EAFNOSUPPORT;
372 }
373 return 0;
374 }
375
ping_set_saddr(struct sock * sk,struct sockaddr * saddr)376 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr)
377 {
378 if (saddr->sa_family == AF_INET) {
379 struct inet_sock *isk = inet_sk(sk);
380 struct sockaddr_in *addr = (struct sockaddr_in *) saddr;
381 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
382 #if IS_ENABLED(CONFIG_IPV6)
383 } else if (saddr->sa_family == AF_INET6) {
384 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr;
385 struct ipv6_pinfo *np = inet6_sk(sk);
386 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr;
387 #endif
388 }
389 }
390
ping_clear_saddr(struct sock * sk,int dif)391 static void ping_clear_saddr(struct sock *sk, int dif)
392 {
393 sk->sk_bound_dev_if = dif;
394 if (sk->sk_family == AF_INET) {
395 struct inet_sock *isk = inet_sk(sk);
396 isk->inet_rcv_saddr = isk->inet_saddr = 0;
397 #if IS_ENABLED(CONFIG_IPV6)
398 } else if (sk->sk_family == AF_INET6) {
399 struct ipv6_pinfo *np = inet6_sk(sk);
400 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
401 memset(&np->saddr, 0, sizeof(np->saddr));
402 #endif
403 }
404 }
405 /*
406 * We need our own bind because there are no privileged id's == local ports.
407 * Moreover, we don't allow binding to multi- and broadcast addresses.
408 */
409
ping_bind(struct sock * sk,struct sockaddr * uaddr,int addr_len)410 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
411 {
412 struct inet_sock *isk = inet_sk(sk);
413 unsigned short snum;
414 int err;
415 int dif = sk->sk_bound_dev_if;
416
417 err = ping_check_bind_addr(sk, isk, uaddr, addr_len);
418 if (err)
419 return err;
420
421 lock_sock(sk);
422
423 err = -EINVAL;
424 if (isk->inet_num != 0)
425 goto out;
426
427 err = -EADDRINUSE;
428 ping_set_saddr(sk, uaddr);
429 snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port);
430 if (ping_get_port(sk, snum) != 0) {
431 ping_clear_saddr(sk, dif);
432 goto out;
433 }
434
435 pr_debug("after bind(): num = %hu, dif = %d\n",
436 isk->inet_num,
437 sk->sk_bound_dev_if);
438
439 err = 0;
440 if (sk->sk_family == AF_INET && isk->inet_rcv_saddr)
441 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
442 #if IS_ENABLED(CONFIG_IPV6)
443 if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr))
444 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
445 #endif
446
447 if (snum)
448 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
449 isk->inet_sport = htons(isk->inet_num);
450 isk->inet_daddr = 0;
451 isk->inet_dport = 0;
452
453 #if IS_ENABLED(CONFIG_IPV6)
454 if (sk->sk_family == AF_INET6)
455 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr));
456 #endif
457
458 sk_dst_reset(sk);
459 out:
460 release_sock(sk);
461 pr_debug("ping_v4_bind -> %d\n", err);
462 return err;
463 }
464 EXPORT_SYMBOL_GPL(ping_bind);
465
466 /*
467 * Is this a supported type of ICMP message?
468 */
469
ping_supported(int family,int type,int code)470 static inline int ping_supported(int family, int type, int code)
471 {
472 return (family == AF_INET && type == ICMP_ECHO && code == 0) ||
473 (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0);
474 }
475
476 /*
477 * This routine is called by the ICMP module when it gets some
478 * sort of error condition.
479 */
480
ping_err(struct sk_buff * skb,int offset,u32 info)481 void ping_err(struct sk_buff *skb, int offset, u32 info)
482 {
483 int family;
484 struct icmphdr *icmph;
485 struct inet_sock *inet_sock;
486 int type;
487 int code;
488 struct net *net = dev_net(skb->dev);
489 struct sock *sk;
490 int harderr;
491 int err;
492
493 if (skb->protocol == htons(ETH_P_IP)) {
494 family = AF_INET;
495 type = icmp_hdr(skb)->type;
496 code = icmp_hdr(skb)->code;
497 icmph = (struct icmphdr *)(skb->data + offset);
498 } else if (skb->protocol == htons(ETH_P_IPV6)) {
499 family = AF_INET6;
500 type = icmp6_hdr(skb)->icmp6_type;
501 code = icmp6_hdr(skb)->icmp6_code;
502 icmph = (struct icmphdr *) (skb->data + offset);
503 } else {
504 BUG();
505 }
506
507 /* We assume the packet has already been checked by icmp_unreach */
508
509 if (!ping_supported(family, icmph->type, icmph->code))
510 return;
511
512 pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n",
513 skb->protocol, type, code, ntohs(icmph->un.echo.id),
514 ntohs(icmph->un.echo.sequence));
515
516 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
517 if (!sk) {
518 pr_debug("no socket, dropping\n");
519 return; /* No socket for error */
520 }
521 pr_debug("err on socket %p\n", sk);
522
523 err = 0;
524 harderr = 0;
525 inet_sock = inet_sk(sk);
526
527 if (skb->protocol == htons(ETH_P_IP)) {
528 switch (type) {
529 default:
530 case ICMP_TIME_EXCEEDED:
531 err = EHOSTUNREACH;
532 break;
533 case ICMP_SOURCE_QUENCH:
534 /* This is not a real error but ping wants to see it.
535 * Report it with some fake errno.
536 */
537 err = EREMOTEIO;
538 break;
539 case ICMP_PARAMETERPROB:
540 err = EPROTO;
541 harderr = 1;
542 break;
543 case ICMP_DEST_UNREACH:
544 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
545 ipv4_sk_update_pmtu(skb, sk, info);
546 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) {
547 err = EMSGSIZE;
548 harderr = 1;
549 break;
550 }
551 goto out;
552 }
553 err = EHOSTUNREACH;
554 if (code <= NR_ICMP_UNREACH) {
555 harderr = icmp_err_convert[code].fatal;
556 err = icmp_err_convert[code].errno;
557 }
558 break;
559 case ICMP_REDIRECT:
560 /* See ICMP_SOURCE_QUENCH */
561 ipv4_sk_redirect(skb, sk);
562 err = EREMOTEIO;
563 break;
564 }
565 #if IS_ENABLED(CONFIG_IPV6)
566 } else if (skb->protocol == htons(ETH_P_IPV6)) {
567 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err);
568 #endif
569 }
570
571 /*
572 * RFC1122: OK. Passes ICMP errors back to application, as per
573 * 4.1.3.3.
574 */
575 if ((family == AF_INET && !inet_sock->recverr) ||
576 (family == AF_INET6 && !inet6_sk(sk)->recverr)) {
577 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
578 goto out;
579 } else {
580 if (family == AF_INET) {
581 ip_icmp_error(sk, skb, err, 0 /* no remote port */,
582 info, (u8 *)icmph);
583 #if IS_ENABLED(CONFIG_IPV6)
584 } else if (family == AF_INET6) {
585 pingv6_ops.ipv6_icmp_error(sk, skb, err, 0,
586 info, (u8 *)icmph);
587 #endif
588 }
589 }
590 sk->sk_err = err;
591 sk->sk_error_report(sk);
592 out:
593 sock_put(sk);
594 }
595 EXPORT_SYMBOL_GPL(ping_err);
596
597 /*
598 * Copy and checksum an ICMP Echo packet from user space into a buffer
599 * starting from the payload.
600 */
601
ping_getfrag(void * from,char * to,int offset,int fraglen,int odd,struct sk_buff * skb)602 int ping_getfrag(void *from, char *to,
603 int offset, int fraglen, int odd, struct sk_buff *skb)
604 {
605 struct pingfakehdr *pfh = (struct pingfakehdr *)from;
606
607 if (offset == 0) {
608 fraglen -= sizeof(struct icmphdr);
609 if (fraglen < 0)
610 BUG();
611 if (!csum_and_copy_from_iter_full(to + sizeof(struct icmphdr),
612 fraglen, &pfh->wcheck,
613 &pfh->msg->msg_iter))
614 return -EFAULT;
615 } else if (offset < sizeof(struct icmphdr)) {
616 BUG();
617 } else {
618 if (!csum_and_copy_from_iter_full(to, fraglen, &pfh->wcheck,
619 &pfh->msg->msg_iter))
620 return -EFAULT;
621 }
622
623 #if IS_ENABLED(CONFIG_IPV6)
624 /* For IPv6, checksum each skb as we go along, as expected by
625 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in
626 * wcheck, it will be finalized in ping_v4_push_pending_frames.
627 */
628 if (pfh->family == AF_INET6) {
629 skb->csum = pfh->wcheck;
630 skb->ip_summed = CHECKSUM_NONE;
631 pfh->wcheck = 0;
632 }
633 #endif
634
635 return 0;
636 }
637 EXPORT_SYMBOL_GPL(ping_getfrag);
638
ping_v4_push_pending_frames(struct sock * sk,struct pingfakehdr * pfh,struct flowi4 * fl4)639 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
640 struct flowi4 *fl4)
641 {
642 struct sk_buff *skb = skb_peek(&sk->sk_write_queue);
643
644 if (!skb)
645 return 0;
646 pfh->wcheck = csum_partial((char *)&pfh->icmph,
647 sizeof(struct icmphdr), pfh->wcheck);
648 pfh->icmph.checksum = csum_fold(pfh->wcheck);
649 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
650 skb->ip_summed = CHECKSUM_NONE;
651 return ip_push_pending_frames(sk, fl4);
652 }
653
ping_common_sendmsg(int family,struct msghdr * msg,size_t len,void * user_icmph,size_t icmph_len)654 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
655 void *user_icmph, size_t icmph_len) {
656 u8 type, code;
657
658 if (len > 0xFFFF)
659 return -EMSGSIZE;
660
661 /* Must have at least a full ICMP header. */
662 if (len < icmph_len)
663 return -EINVAL;
664
665 /*
666 * Check the flags.
667 */
668
669 /* Mirror BSD error message compatibility */
670 if (msg->msg_flags & MSG_OOB)
671 return -EOPNOTSUPP;
672
673 /*
674 * Fetch the ICMP header provided by the userland.
675 * iovec is modified! The ICMP header is consumed.
676 */
677 if (memcpy_from_msg(user_icmph, msg, icmph_len))
678 return -EFAULT;
679
680 if (family == AF_INET) {
681 type = ((struct icmphdr *) user_icmph)->type;
682 code = ((struct icmphdr *) user_icmph)->code;
683 #if IS_ENABLED(CONFIG_IPV6)
684 } else if (family == AF_INET6) {
685 type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
686 code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
687 #endif
688 } else {
689 BUG();
690 }
691
692 if (!ping_supported(family, type, code))
693 return -EINVAL;
694
695 return 0;
696 }
697 EXPORT_SYMBOL_GPL(ping_common_sendmsg);
698
ping_v4_sendmsg(struct sock * sk,struct msghdr * msg,size_t len)699 static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
700 {
701 struct net *net = sock_net(sk);
702 struct flowi4 fl4;
703 struct inet_sock *inet = inet_sk(sk);
704 struct ipcm_cookie ipc;
705 struct icmphdr user_icmph;
706 struct pingfakehdr pfh;
707 struct rtable *rt = NULL;
708 struct ip_options_data opt_copy;
709 int free = 0;
710 __be32 saddr, daddr, faddr;
711 u8 tos;
712 int err;
713
714 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
715
716 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
717 sizeof(user_icmph));
718 if (err)
719 return err;
720
721 /*
722 * Get and verify the address.
723 */
724
725 if (msg->msg_name) {
726 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
727 if (msg->msg_namelen < sizeof(*usin))
728 return -EINVAL;
729 if (usin->sin_family != AF_INET)
730 return -EAFNOSUPPORT;
731 daddr = usin->sin_addr.s_addr;
732 /* no remote port */
733 } else {
734 if (sk->sk_state != TCP_ESTABLISHED)
735 return -EDESTADDRREQ;
736 daddr = inet->inet_daddr;
737 /* no remote port */
738 }
739
740 ipcm_init_sk(&ipc, inet);
741
742 if (msg->msg_controllen) {
743 err = ip_cmsg_send(sk, msg, &ipc, false);
744 if (unlikely(err)) {
745 kfree(ipc.opt);
746 return err;
747 }
748 if (ipc.opt)
749 free = 1;
750 }
751 if (!ipc.opt) {
752 struct ip_options_rcu *inet_opt;
753
754 rcu_read_lock();
755 inet_opt = rcu_dereference(inet->inet_opt);
756 if (inet_opt) {
757 memcpy(&opt_copy, inet_opt,
758 sizeof(*inet_opt) + inet_opt->opt.optlen);
759 ipc.opt = &opt_copy.opt;
760 }
761 rcu_read_unlock();
762 }
763
764 saddr = ipc.addr;
765 ipc.addr = faddr = daddr;
766
767 if (ipc.opt && ipc.opt->opt.srr) {
768 if (!daddr) {
769 err = -EINVAL;
770 goto out_free;
771 }
772 faddr = ipc.opt->opt.faddr;
773 }
774 tos = get_rttos(&ipc, inet);
775 if (sock_flag(sk, SOCK_LOCALROUTE) ||
776 (msg->msg_flags & MSG_DONTROUTE) ||
777 (ipc.opt && ipc.opt->opt.is_strictroute)) {
778 tos |= RTO_ONLINK;
779 }
780
781 if (ipv4_is_multicast(daddr)) {
782 if (!ipc.oif)
783 ipc.oif = inet->mc_index;
784 if (!saddr)
785 saddr = inet->mc_addr;
786 } else if (!ipc.oif)
787 ipc.oif = inet->uc_index;
788
789 flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
790 RT_SCOPE_UNIVERSE, sk->sk_protocol,
791 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0,
792 sk->sk_uid);
793
794 security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
795 rt = ip_route_output_flow(net, &fl4, sk);
796 if (IS_ERR(rt)) {
797 err = PTR_ERR(rt);
798 rt = NULL;
799 if (err == -ENETUNREACH)
800 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
801 goto out;
802 }
803
804 err = -EACCES;
805 if ((rt->rt_flags & RTCF_BROADCAST) &&
806 !sock_flag(sk, SOCK_BROADCAST))
807 goto out;
808
809 if (msg->msg_flags & MSG_CONFIRM)
810 goto do_confirm;
811 back_from_confirm:
812
813 if (!ipc.addr)
814 ipc.addr = fl4.daddr;
815
816 lock_sock(sk);
817
818 pfh.icmph.type = user_icmph.type; /* already checked */
819 pfh.icmph.code = user_icmph.code; /* ditto */
820 pfh.icmph.checksum = 0;
821 pfh.icmph.un.echo.id = inet->inet_sport;
822 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
823 pfh.msg = msg;
824 pfh.wcheck = 0;
825 pfh.family = AF_INET;
826
827 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
828 0, &ipc, &rt, msg->msg_flags);
829 if (err)
830 ip_flush_pending_frames(sk);
831 else
832 err = ping_v4_push_pending_frames(sk, &pfh, &fl4);
833 release_sock(sk);
834
835 out:
836 ip_rt_put(rt);
837 out_free:
838 if (free)
839 kfree(ipc.opt);
840 if (!err) {
841 icmp_out_count(sock_net(sk), user_icmph.type);
842 return len;
843 }
844 return err;
845
846 do_confirm:
847 if (msg->msg_flags & MSG_PROBE)
848 dst_confirm_neigh(&rt->dst, &fl4.daddr);
849 if (!(msg->msg_flags & MSG_PROBE) || len)
850 goto back_from_confirm;
851 err = 0;
852 goto out;
853 }
854
ping_recvmsg(struct sock * sk,struct msghdr * msg,size_t len,int noblock,int flags,int * addr_len)855 int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock,
856 int flags, int *addr_len)
857 {
858 struct inet_sock *isk = inet_sk(sk);
859 int family = sk->sk_family;
860 struct sk_buff *skb;
861 int copied, err;
862
863 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
864
865 err = -EOPNOTSUPP;
866 if (flags & MSG_OOB)
867 goto out;
868
869 if (flags & MSG_ERRQUEUE)
870 return inet_recv_error(sk, msg, len, addr_len);
871
872 skb = skb_recv_datagram(sk, flags, noblock, &err);
873 if (!skb)
874 goto out;
875
876 copied = skb->len;
877 if (copied > len) {
878 msg->msg_flags |= MSG_TRUNC;
879 copied = len;
880 }
881
882 /* Don't bother checking the checksum */
883 err = skb_copy_datagram_msg(skb, 0, msg, copied);
884 if (err)
885 goto done;
886
887 sock_recv_timestamp(msg, sk, skb);
888
889 /* Copy the address and add cmsg data. */
890 if (family == AF_INET) {
891 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
892
893 if (sin) {
894 sin->sin_family = AF_INET;
895 sin->sin_port = 0 /* skb->h.uh->source */;
896 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
897 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
898 *addr_len = sizeof(*sin);
899 }
900
901 if (isk->cmsg_flags)
902 ip_cmsg_recv(msg, skb);
903
904 #if IS_ENABLED(CONFIG_IPV6)
905 } else if (family == AF_INET6) {
906 struct ipv6_pinfo *np = inet6_sk(sk);
907 struct ipv6hdr *ip6 = ipv6_hdr(skb);
908 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
909
910 if (sin6) {
911 sin6->sin6_family = AF_INET6;
912 sin6->sin6_port = 0;
913 sin6->sin6_addr = ip6->saddr;
914 sin6->sin6_flowinfo = 0;
915 if (np->sndflow)
916 sin6->sin6_flowinfo = ip6_flowinfo(ip6);
917 sin6->sin6_scope_id =
918 ipv6_iface_scope_id(&sin6->sin6_addr,
919 inet6_iif(skb));
920 *addr_len = sizeof(*sin6);
921 }
922
923 if (inet6_sk(sk)->rxopt.all)
924 pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb);
925 if (skb->protocol == htons(ETH_P_IPV6) &&
926 inet6_sk(sk)->rxopt.all)
927 pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb);
928 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags)
929 ip_cmsg_recv(msg, skb);
930 #endif
931 } else {
932 BUG();
933 }
934
935 err = copied;
936
937 done:
938 skb_free_datagram(sk, skb);
939 out:
940 pr_debug("ping_recvmsg -> %d\n", err);
941 return err;
942 }
943 EXPORT_SYMBOL_GPL(ping_recvmsg);
944
ping_queue_rcv_skb(struct sock * sk,struct sk_buff * skb)945 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
946 {
947 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
948 inet_sk(sk), inet_sk(sk)->inet_num, skb);
949 if (sock_queue_rcv_skb(sk, skb) < 0) {
950 kfree_skb(skb);
951 pr_debug("ping_queue_rcv_skb -> failed\n");
952 return -1;
953 }
954 return 0;
955 }
956 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
957
958
959 /*
960 * All we need to do is get the socket.
961 */
962
ping_rcv(struct sk_buff * skb)963 bool ping_rcv(struct sk_buff *skb)
964 {
965 struct sock *sk;
966 struct net *net = dev_net(skb->dev);
967 struct icmphdr *icmph = icmp_hdr(skb);
968
969 /* We assume the packet has already been checked by icmp_rcv */
970
971 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
972 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
973
974 /* Push ICMP header back */
975 skb_push(skb, skb->data - (u8 *)icmph);
976
977 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
978 if (sk) {
979 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
980
981 pr_debug("rcv on socket %p\n", sk);
982 if (skb2)
983 ping_queue_rcv_skb(sk, skb2);
984 sock_put(sk);
985 return true;
986 }
987 pr_debug("no socket, dropping\n");
988
989 return false;
990 }
991 EXPORT_SYMBOL_GPL(ping_rcv);
992
993 struct proto ping_prot = {
994 .name = "PING",
995 .owner = THIS_MODULE,
996 .init = ping_init_sock,
997 .close = ping_close,
998 .connect = ip4_datagram_connect,
999 .disconnect = __udp_disconnect,
1000 .setsockopt = ip_setsockopt,
1001 .getsockopt = ip_getsockopt,
1002 .sendmsg = ping_v4_sendmsg,
1003 .recvmsg = ping_recvmsg,
1004 .bind = ping_bind,
1005 .backlog_rcv = ping_queue_rcv_skb,
1006 .release_cb = ip4_datagram_release_cb,
1007 .hash = ping_hash,
1008 .unhash = ping_unhash,
1009 .get_port = ping_get_port,
1010 .obj_size = sizeof(struct inet_sock),
1011 };
1012 EXPORT_SYMBOL(ping_prot);
1013
1014 #ifdef CONFIG_PROC_FS
1015
ping_get_first(struct seq_file * seq,int start)1016 static struct sock *ping_get_first(struct seq_file *seq, int start)
1017 {
1018 struct sock *sk;
1019 struct ping_iter_state *state = seq->private;
1020 struct net *net = seq_file_net(seq);
1021
1022 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
1023 ++state->bucket) {
1024 struct hlist_nulls_node *node;
1025 struct hlist_nulls_head *hslot;
1026
1027 hslot = &ping_table.hash[state->bucket];
1028
1029 if (hlist_nulls_empty(hslot))
1030 continue;
1031
1032 sk_nulls_for_each(sk, node, hslot) {
1033 if (net_eq(sock_net(sk), net) &&
1034 sk->sk_family == state->family)
1035 goto found;
1036 }
1037 }
1038 sk = NULL;
1039 found:
1040 return sk;
1041 }
1042
ping_get_next(struct seq_file * seq,struct sock * sk)1043 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
1044 {
1045 struct ping_iter_state *state = seq->private;
1046 struct net *net = seq_file_net(seq);
1047
1048 do {
1049 sk = sk_nulls_next(sk);
1050 } while (sk && (!net_eq(sock_net(sk), net)));
1051
1052 if (!sk)
1053 return ping_get_first(seq, state->bucket + 1);
1054 return sk;
1055 }
1056
ping_get_idx(struct seq_file * seq,loff_t pos)1057 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
1058 {
1059 struct sock *sk = ping_get_first(seq, 0);
1060
1061 if (sk)
1062 while (pos && (sk = ping_get_next(seq, sk)) != NULL)
1063 --pos;
1064 return pos ? NULL : sk;
1065 }
1066
ping_seq_start(struct seq_file * seq,loff_t * pos,sa_family_t family)1067 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
1068 __acquires(ping_table.lock)
1069 {
1070 struct ping_iter_state *state = seq->private;
1071 state->bucket = 0;
1072 state->family = family;
1073
1074 read_lock_bh(&ping_table.lock);
1075
1076 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1077 }
1078 EXPORT_SYMBOL_GPL(ping_seq_start);
1079
ping_v4_seq_start(struct seq_file * seq,loff_t * pos)1080 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos)
1081 {
1082 return ping_seq_start(seq, pos, AF_INET);
1083 }
1084
ping_seq_next(struct seq_file * seq,void * v,loff_t * pos)1085 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1086 {
1087 struct sock *sk;
1088
1089 if (v == SEQ_START_TOKEN)
1090 sk = ping_get_idx(seq, 0);
1091 else
1092 sk = ping_get_next(seq, v);
1093
1094 ++*pos;
1095 return sk;
1096 }
1097 EXPORT_SYMBOL_GPL(ping_seq_next);
1098
ping_seq_stop(struct seq_file * seq,void * v)1099 void ping_seq_stop(struct seq_file *seq, void *v)
1100 __releases(ping_table.lock)
1101 {
1102 read_unlock_bh(&ping_table.lock);
1103 }
1104 EXPORT_SYMBOL_GPL(ping_seq_stop);
1105
ping_v4_format_sock(struct sock * sp,struct seq_file * f,int bucket)1106 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f,
1107 int bucket)
1108 {
1109 struct inet_sock *inet = inet_sk(sp);
1110 __be32 dest = inet->inet_daddr;
1111 __be32 src = inet->inet_rcv_saddr;
1112 __u16 destp = ntohs(inet->inet_dport);
1113 __u16 srcp = ntohs(inet->inet_sport);
1114
1115 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
1116 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d",
1117 bucket, src, srcp, dest, destp, sp->sk_state,
1118 sk_wmem_alloc_get(sp),
1119 sk_rmem_alloc_get(sp),
1120 0, 0L, 0,
1121 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
1122 0, sock_i_ino(sp),
1123 refcount_read(&sp->sk_refcnt), sp,
1124 atomic_read(&sp->sk_drops));
1125 }
1126
ping_v4_seq_show(struct seq_file * seq,void * v)1127 static int ping_v4_seq_show(struct seq_file *seq, void *v)
1128 {
1129 seq_setwidth(seq, 127);
1130 if (v == SEQ_START_TOKEN)
1131 seq_puts(seq, " sl local_address rem_address st tx_queue "
1132 "rx_queue tr tm->when retrnsmt uid timeout "
1133 "inode ref pointer drops");
1134 else {
1135 struct ping_iter_state *state = seq->private;
1136
1137 ping_v4_format_sock(v, seq, state->bucket);
1138 }
1139 seq_pad(seq, '\n');
1140 return 0;
1141 }
1142
1143 static const struct seq_operations ping_v4_seq_ops = {
1144 .start = ping_v4_seq_start,
1145 .show = ping_v4_seq_show,
1146 .next = ping_seq_next,
1147 .stop = ping_seq_stop,
1148 };
1149
ping_v4_proc_init_net(struct net * net)1150 static int __net_init ping_v4_proc_init_net(struct net *net)
1151 {
1152 if (!proc_create_net("icmp", 0444, net->proc_net, &ping_v4_seq_ops,
1153 sizeof(struct ping_iter_state)))
1154 return -ENOMEM;
1155 return 0;
1156 }
1157
ping_v4_proc_exit_net(struct net * net)1158 static void __net_exit ping_v4_proc_exit_net(struct net *net)
1159 {
1160 remove_proc_entry("icmp", net->proc_net);
1161 }
1162
1163 static struct pernet_operations ping_v4_net_ops = {
1164 .init = ping_v4_proc_init_net,
1165 .exit = ping_v4_proc_exit_net,
1166 };
1167
ping_proc_init(void)1168 int __init ping_proc_init(void)
1169 {
1170 return register_pernet_subsys(&ping_v4_net_ops);
1171 }
1172
ping_proc_exit(void)1173 void ping_proc_exit(void)
1174 {
1175 unregister_pernet_subsys(&ping_v4_net_ops);
1176 }
1177
1178 #endif
1179
ping_init(void)1180 void __init ping_init(void)
1181 {
1182 int i;
1183
1184 for (i = 0; i < PING_HTABLE_SIZE; i++)
1185 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i);
1186 rwlock_init(&ping_table.lock);
1187 }
1188
