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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi...
[mirror_ubuntu-artful-kernel.git] / net / ipv4 / ping.c
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(to + sizeof(struct icmphdr),
613 fraglen, &pfh->wcheck,
614 &pfh->msg->msg_iter) != fraglen)
615 return -EFAULT;
616 } else if (offset < sizeof(struct icmphdr)) {
617 BUG();
618 } else {
619 if (csum_and_copy_from_iter(to, fraglen, &pfh->wcheck,
620 &pfh->msg->msg_iter) != fraglen)
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 /*
661 * Check the flags.
662 */
663
664 /* Mirror BSD error message compatibility */
665 if (msg->msg_flags & MSG_OOB)
666 return -EOPNOTSUPP;
667
668 /*
669 * Fetch the ICMP header provided by the userland.
670 * iovec is modified! The ICMP header is consumed.
671 */
672 if (memcpy_from_msg(user_icmph, msg, icmph_len))
673 return -EFAULT;
674
675 if (family == AF_INET) {
676 type = ((struct icmphdr *) user_icmph)->type;
677 code = ((struct icmphdr *) user_icmph)->code;
678 #if IS_ENABLED(CONFIG_IPV6)
679 } else if (family == AF_INET6) {
680 type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
681 code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
682 #endif
683 } else {
684 BUG();
685 }
686
687 if (!ping_supported(family, type, code))
688 return -EINVAL;
689
690 return 0;
691 }
692 EXPORT_SYMBOL_GPL(ping_common_sendmsg);
693
694 static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
695 {
696 struct net *net = sock_net(sk);
697 struct flowi4 fl4;
698 struct inet_sock *inet = inet_sk(sk);
699 struct ipcm_cookie ipc;
700 struct icmphdr user_icmph;
701 struct pingfakehdr pfh;
702 struct rtable *rt = NULL;
703 struct ip_options_data opt_copy;
704 int free = 0;
705 __be32 saddr, daddr, faddr;
706 u8 tos;
707 int err;
708
709 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
710
711 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
712 sizeof(user_icmph));
713 if (err)
714 return err;
715
716 /*
717 * Get and verify the address.
718 */
719
720 if (msg->msg_name) {
721 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
722 if (msg->msg_namelen < sizeof(*usin))
723 return -EINVAL;
724 if (usin->sin_family != AF_INET)
725 return -EAFNOSUPPORT;
726 daddr = usin->sin_addr.s_addr;
727 /* no remote port */
728 } else {
729 if (sk->sk_state != TCP_ESTABLISHED)
730 return -EDESTADDRREQ;
731 daddr = inet->inet_daddr;
732 /* no remote port */
733 }
734
735 ipc.sockc.tsflags = sk->sk_tsflags;
736 ipc.addr = inet->inet_saddr;
737 ipc.opt = NULL;
738 ipc.oif = sk->sk_bound_dev_if;
739 ipc.tx_flags = 0;
740 ipc.ttl = 0;
741 ipc.tos = -1;
742
743 if (msg->msg_controllen) {
744 err = ip_cmsg_send(sk, msg, &ipc, false);
745 if (unlikely(err)) {
746 kfree(ipc.opt);
747 return err;
748 }
749 if (ipc.opt)
750 free = 1;
751 }
752 if (!ipc.opt) {
753 struct ip_options_rcu *inet_opt;
754
755 rcu_read_lock();
756 inet_opt = rcu_dereference(inet->inet_opt);
757 if (inet_opt) {
758 memcpy(&opt_copy, inet_opt,
759 sizeof(*inet_opt) + inet_opt->opt.optlen);
760 ipc.opt = &opt_copy.opt;
761 }
762 rcu_read_unlock();
763 }
764
765 sock_tx_timestamp(sk, ipc.sockc.tsflags, &ipc.tx_flags);
766
767 saddr = ipc.addr;
768 ipc.addr = faddr = daddr;
769
770 if (ipc.opt && ipc.opt->opt.srr) {
771 if (!daddr)
772 return -EINVAL;
773 faddr = ipc.opt->opt.faddr;
774 }
775 tos = get_rttos(&ipc, inet);
776 if (sock_flag(sk, SOCK_LOCALROUTE) ||
777 (msg->msg_flags & MSG_DONTROUTE) ||
778 (ipc.opt && ipc.opt->opt.is_strictroute)) {
779 tos |= RTO_ONLINK;
780 }
781
782 if (ipv4_is_multicast(daddr)) {
783 if (!ipc.oif)
784 ipc.oif = inet->mc_index;
785 if (!saddr)
786 saddr = inet->mc_addr;
787 } else if (!ipc.oif)
788 ipc.oif = inet->uc_index;
789
790 flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
791 RT_SCOPE_UNIVERSE, sk->sk_protocol,
792 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0);
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 if (free)
838 kfree(ipc.opt);
839 if (!err) {
840 icmp_out_count(sock_net(sk), user_icmph.type);
841 return len;
842 }
843 return err;
844
845 do_confirm:
846 dst_confirm(&rt->dst);
847 if (!(msg->msg_flags & MSG_PROBE) || len)
848 goto back_from_confirm;
849 err = 0;
850 goto out;
851 }
852
853 int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock,
854 int flags, int *addr_len)
855 {
856 struct inet_sock *isk = inet_sk(sk);
857 int family = sk->sk_family;
858 struct sk_buff *skb;
859 int copied, err;
860
861 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
862
863 err = -EOPNOTSUPP;
864 if (flags & MSG_OOB)
865 goto out;
866
867 if (flags & MSG_ERRQUEUE)
868 return inet_recv_error(sk, msg, len, addr_len);
869
870 skb = skb_recv_datagram(sk, flags, noblock, &err);
871 if (!skb)
872 goto out;
873
874 copied = skb->len;
875 if (copied > len) {
876 msg->msg_flags |= MSG_TRUNC;
877 copied = len;
878 }
879
880 /* Don't bother checking the checksum */
881 err = skb_copy_datagram_msg(skb, 0, msg, copied);
882 if (err)
883 goto done;
884
885 sock_recv_timestamp(msg, sk, skb);
886
887 /* Copy the address and add cmsg data. */
888 if (family == AF_INET) {
889 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
890
891 if (sin) {
892 sin->sin_family = AF_INET;
893 sin->sin_port = 0 /* skb->h.uh->source */;
894 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
895 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
896 *addr_len = sizeof(*sin);
897 }
898
899 if (isk->cmsg_flags)
900 ip_cmsg_recv(msg, skb);
901
902 #if IS_ENABLED(CONFIG_IPV6)
903 } else if (family == AF_INET6) {
904 struct ipv6_pinfo *np = inet6_sk(sk);
905 struct ipv6hdr *ip6 = ipv6_hdr(skb);
906 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
907
908 if (sin6) {
909 sin6->sin6_family = AF_INET6;
910 sin6->sin6_port = 0;
911 sin6->sin6_addr = ip6->saddr;
912 sin6->sin6_flowinfo = 0;
913 if (np->sndflow)
914 sin6->sin6_flowinfo = ip6_flowinfo(ip6);
915 sin6->sin6_scope_id =
916 ipv6_iface_scope_id(&sin6->sin6_addr,
917 inet6_iif(skb));
918 *addr_len = sizeof(*sin6);
919 }
920
921 if (inet6_sk(sk)->rxopt.all)
922 pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb);
923 if (skb->protocol == htons(ETH_P_IPV6) &&
924 inet6_sk(sk)->rxopt.all)
925 pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb);
926 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags)
927 ip_cmsg_recv(msg, skb);
928 #endif
929 } else {
930 BUG();
931 }
932
933 err = copied;
934
935 done:
936 skb_free_datagram(sk, skb);
937 out:
938 pr_debug("ping_recvmsg -> %d\n", err);
939 return err;
940 }
941 EXPORT_SYMBOL_GPL(ping_recvmsg);
942
943 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
944 {
945 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
946 inet_sk(sk), inet_sk(sk)->inet_num, skb);
947 if (sock_queue_rcv_skb(sk, skb) < 0) {
948 kfree_skb(skb);
949 pr_debug("ping_queue_rcv_skb -> failed\n");
950 return -1;
951 }
952 return 0;
953 }
954 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
955
956
957 /*
958 * All we need to do is get the socket.
959 */
960
961 bool ping_rcv(struct sk_buff *skb)
962 {
963 struct sock *sk;
964 struct net *net = dev_net(skb->dev);
965 struct icmphdr *icmph = icmp_hdr(skb);
966
967 /* We assume the packet has already been checked by icmp_rcv */
968
969 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
970 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
971
972 /* Push ICMP header back */
973 skb_push(skb, skb->data - (u8 *)icmph);
974
975 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
976 if (sk) {
977 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
978
979 pr_debug("rcv on socket %p\n", sk);
980 if (skb2)
981 ping_queue_rcv_skb(sk, skb2);
982 sock_put(sk);
983 return true;
984 }
985 pr_debug("no socket, dropping\n");
986
987 return false;
988 }
989 EXPORT_SYMBOL_GPL(ping_rcv);
990
991 struct proto ping_prot = {
992 .name = "PING",
993 .owner = THIS_MODULE,
994 .init = ping_init_sock,
995 .close = ping_close,
996 .connect = ip4_datagram_connect,
997 .disconnect = __udp_disconnect,
998 .setsockopt = ip_setsockopt,
999 .getsockopt = ip_getsockopt,
1000 .sendmsg = ping_v4_sendmsg,
1001 .recvmsg = ping_recvmsg,
1002 .bind = ping_bind,
1003 .backlog_rcv = ping_queue_rcv_skb,
1004 .release_cb = ip4_datagram_release_cb,
1005 .hash = ping_hash,
1006 .unhash = ping_unhash,
1007 .get_port = ping_get_port,
1008 .obj_size = sizeof(struct inet_sock),
1009 };
1010 EXPORT_SYMBOL(ping_prot);
1011
1012 #ifdef CONFIG_PROC_FS
1013
1014 static struct sock *ping_get_first(struct seq_file *seq, int start)
1015 {
1016 struct sock *sk;
1017 struct ping_iter_state *state = seq->private;
1018 struct net *net = seq_file_net(seq);
1019
1020 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
1021 ++state->bucket) {
1022 struct hlist_nulls_node *node;
1023 struct hlist_nulls_head *hslot;
1024
1025 hslot = &ping_table.hash[state->bucket];
1026
1027 if (hlist_nulls_empty(hslot))
1028 continue;
1029
1030 sk_nulls_for_each(sk, node, hslot) {
1031 if (net_eq(sock_net(sk), net) &&
1032 sk->sk_family == state->family)
1033 goto found;
1034 }
1035 }
1036 sk = NULL;
1037 found:
1038 return sk;
1039 }
1040
1041 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
1042 {
1043 struct ping_iter_state *state = seq->private;
1044 struct net *net = seq_file_net(seq);
1045
1046 do {
1047 sk = sk_nulls_next(sk);
1048 } while (sk && (!net_eq(sock_net(sk), net)));
1049
1050 if (!sk)
1051 return ping_get_first(seq, state->bucket + 1);
1052 return sk;
1053 }
1054
1055 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
1056 {
1057 struct sock *sk = ping_get_first(seq, 0);
1058
1059 if (sk)
1060 while (pos && (sk = ping_get_next(seq, sk)) != NULL)
1061 --pos;
1062 return pos ? NULL : sk;
1063 }
1064
1065 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
1066 __acquires(ping_table.lock)
1067 {
1068 struct ping_iter_state *state = seq->private;
1069 state->bucket = 0;
1070 state->family = family;
1071
1072 read_lock_bh(&ping_table.lock);
1073
1074 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1075 }
1076 EXPORT_SYMBOL_GPL(ping_seq_start);
1077
1078 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos)
1079 {
1080 return ping_seq_start(seq, pos, AF_INET);
1081 }
1082
1083 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1084 {
1085 struct sock *sk;
1086
1087 if (v == SEQ_START_TOKEN)
1088 sk = ping_get_idx(seq, 0);
1089 else
1090 sk = ping_get_next(seq, v);
1091
1092 ++*pos;
1093 return sk;
1094 }
1095 EXPORT_SYMBOL_GPL(ping_seq_next);
1096
1097 void ping_seq_stop(struct seq_file *seq, void *v)
1098 __releases(ping_table.lock)
1099 {
1100 read_unlock_bh(&ping_table.lock);
1101 }
1102 EXPORT_SYMBOL_GPL(ping_seq_stop);
1103
1104 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f,
1105 int bucket)
1106 {
1107 struct inet_sock *inet = inet_sk(sp);
1108 __be32 dest = inet->inet_daddr;
1109 __be32 src = inet->inet_rcv_saddr;
1110 __u16 destp = ntohs(inet->inet_dport);
1111 __u16 srcp = ntohs(inet->inet_sport);
1112
1113 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
1114 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d",
1115 bucket, src, srcp, dest, destp, sp->sk_state,
1116 sk_wmem_alloc_get(sp),
1117 sk_rmem_alloc_get(sp),
1118 0, 0L, 0,
1119 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
1120 0, sock_i_ino(sp),
1121 atomic_read(&sp->sk_refcnt), sp,
1122 atomic_read(&sp->sk_drops));
1123 }
1124
1125 static int ping_v4_seq_show(struct seq_file *seq, void *v)
1126 {
1127 seq_setwidth(seq, 127);
1128 if (v == SEQ_START_TOKEN)
1129 seq_puts(seq, " sl local_address rem_address st tx_queue "
1130 "rx_queue tr tm->when retrnsmt uid timeout "
1131 "inode ref pointer drops");
1132 else {
1133 struct ping_iter_state *state = seq->private;
1134
1135 ping_v4_format_sock(v, seq, state->bucket);
1136 }
1137 seq_pad(seq, '\n');
1138 return 0;
1139 }
1140
1141 static int ping_seq_open(struct inode *inode, struct file *file)
1142 {
1143 struct ping_seq_afinfo *afinfo = PDE_DATA(inode);
1144 return seq_open_net(inode, file, &afinfo->seq_ops,
1145 sizeof(struct ping_iter_state));
1146 }
1147
1148 const struct file_operations ping_seq_fops = {
1149 .open = ping_seq_open,
1150 .read = seq_read,
1151 .llseek = seq_lseek,
1152 .release = seq_release_net,
1153 };
1154 EXPORT_SYMBOL_GPL(ping_seq_fops);
1155
1156 static struct ping_seq_afinfo ping_v4_seq_afinfo = {
1157 .name = "icmp",
1158 .family = AF_INET,
1159 .seq_fops = &ping_seq_fops,
1160 .seq_ops = {
1161 .start = ping_v4_seq_start,
1162 .show = ping_v4_seq_show,
1163 .next = ping_seq_next,
1164 .stop = ping_seq_stop,
1165 },
1166 };
1167
1168 int ping_proc_register(struct net *net, struct ping_seq_afinfo *afinfo)
1169 {
1170 struct proc_dir_entry *p;
1171 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
1172 afinfo->seq_fops, afinfo);
1173 if (!p)
1174 return -ENOMEM;
1175 return 0;
1176 }
1177 EXPORT_SYMBOL_GPL(ping_proc_register);
1178
1179 void ping_proc_unregister(struct net *net, struct ping_seq_afinfo *afinfo)
1180 {
1181 remove_proc_entry(afinfo->name, net->proc_net);
1182 }
1183 EXPORT_SYMBOL_GPL(ping_proc_unregister);
1184
1185 static int __net_init ping_v4_proc_init_net(struct net *net)
1186 {
1187 return ping_proc_register(net, &ping_v4_seq_afinfo);
1188 }
1189
1190 static void __net_exit ping_v4_proc_exit_net(struct net *net)
1191 {
1192 ping_proc_unregister(net, &ping_v4_seq_afinfo);
1193 }
1194
1195 static struct pernet_operations ping_v4_net_ops = {
1196 .init = ping_v4_proc_init_net,
1197 .exit = ping_v4_proc_exit_net,
1198 };
1199
1200 int __init ping_proc_init(void)
1201 {
1202 return register_pernet_subsys(&ping_v4_net_ops);
1203 }
1204
1205 void ping_proc_exit(void)
1206 {
1207 unregister_pernet_subsys(&ping_v4_net_ops);
1208 }
1209
1210 #endif
1211
1212 void __init ping_init(void)
1213 {
1214 int i;
1215
1216 for (i = 0; i < PING_HTABLE_SIZE; i++)
1217 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i);
1218 rwlock_init(&ping_table.lock);
1219 }
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