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net: add build-time checks for msg->msg_name size
[deliverable/linux.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 int ping_hashfn(struct net *net, unsigned int num, unsigned int mask)
68 {
69 int res = (num + net_hash_mix(net)) & mask;
70
71 pr_debug("hash(%d) = %d\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 void 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
154 void ping_unhash(struct sock *sk)
155 {
156 struct inet_sock *isk = inet_sk(sk);
157 pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);
158 if (sk_hashed(sk)) {
159 write_lock_bh(&ping_table.lock);
160 hlist_nulls_del(&sk->sk_nulls_node);
161 sock_put(sk);
162 isk->inet_num = 0;
163 isk->inet_sport = 0;
164 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
165 write_unlock_bh(&ping_table.lock);
166 }
167 }
168 EXPORT_SYMBOL_GPL(ping_unhash);
169
170 static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
171 {
172 struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident);
173 struct sock *sk = NULL;
174 struct inet_sock *isk;
175 struct hlist_nulls_node *hnode;
176 int dif = skb->dev->ifindex;
177
178 if (skb->protocol == htons(ETH_P_IP)) {
179 pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n",
180 (int)ident, &ip_hdr(skb)->daddr, dif);
181 #if IS_ENABLED(CONFIG_IPV6)
182 } else if (skb->protocol == htons(ETH_P_IPV6)) {
183 pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n",
184 (int)ident, &ipv6_hdr(skb)->daddr, dif);
185 #endif
186 }
187
188 read_lock_bh(&ping_table.lock);
189
190 ping_portaddr_for_each_entry(sk, hnode, hslot) {
191 isk = inet_sk(sk);
192
193 pr_debug("iterate\n");
194 if (isk->inet_num != ident)
195 continue;
196
197 if (skb->protocol == htons(ETH_P_IP) &&
198 sk->sk_family == AF_INET) {
199 pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk,
200 (int) isk->inet_num, &isk->inet_rcv_saddr,
201 sk->sk_bound_dev_if);
202
203 if (isk->inet_rcv_saddr &&
204 isk->inet_rcv_saddr != ip_hdr(skb)->daddr)
205 continue;
206 #if IS_ENABLED(CONFIG_IPV6)
207 } else if (skb->protocol == htons(ETH_P_IPV6) &&
208 sk->sk_family == AF_INET6) {
209
210 pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk,
211 (int) isk->inet_num,
212 &sk->sk_v6_rcv_saddr,
213 sk->sk_bound_dev_if);
214
215 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
216 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr,
217 &ipv6_hdr(skb)->daddr))
218 continue;
219 #endif
220 }
221
222 if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)
223 continue;
224
225 sock_hold(sk);
226 goto exit;
227 }
228
229 sk = NULL;
230 exit:
231 read_unlock_bh(&ping_table.lock);
232
233 return sk;
234 }
235
236 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low,
237 kgid_t *high)
238 {
239 kgid_t *data = net->ipv4.sysctl_ping_group_range;
240 unsigned int seq;
241
242 do {
243 seq = read_seqbegin(&net->ipv4.sysctl_local_ports.lock);
244
245 *low = data[0];
246 *high = data[1];
247 } while (read_seqretry(&net->ipv4.sysctl_local_ports.lock, seq));
248 }
249
250
251 int ping_init_sock(struct sock *sk)
252 {
253 struct net *net = sock_net(sk);
254 kgid_t group = current_egid();
255 struct group_info *group_info = get_current_groups();
256 int i, j, count = group_info->ngroups;
257 kgid_t low, high;
258
259 inet_get_ping_group_range_net(net, &low, &high);
260 if (gid_lte(low, group) && gid_lte(group, high))
261 return 0;
262
263 for (i = 0; i < group_info->nblocks; i++) {
264 int cp_count = min_t(int, NGROUPS_PER_BLOCK, count);
265 for (j = 0; j < cp_count; j++) {
266 kgid_t gid = group_info->blocks[i][j];
267 if (gid_lte(low, gid) && gid_lte(gid, high))
268 return 0;
269 }
270
271 count -= cp_count;
272 }
273
274 return -EACCES;
275 }
276 EXPORT_SYMBOL_GPL(ping_init_sock);
277
278 void ping_close(struct sock *sk, long timeout)
279 {
280 pr_debug("ping_close(sk=%p,sk->num=%u)\n",
281 inet_sk(sk), inet_sk(sk)->inet_num);
282 pr_debug("isk->refcnt = %d\n", sk->sk_refcnt.counter);
283
284 sk_common_release(sk);
285 }
286 EXPORT_SYMBOL_GPL(ping_close);
287
288 /* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */
289 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
290 struct sockaddr *uaddr, int addr_len) {
291 struct net *net = sock_net(sk);
292 if (sk->sk_family == AF_INET) {
293 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
294 int chk_addr_ret;
295
296 if (addr_len < sizeof(*addr))
297 return -EINVAL;
298
299 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",
300 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
301
302 chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
303
304 if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
305 chk_addr_ret = RTN_LOCAL;
306
307 if ((sysctl_ip_nonlocal_bind == 0 &&
308 isk->freebind == 0 && isk->transparent == 0 &&
309 chk_addr_ret != RTN_LOCAL) ||
310 chk_addr_ret == RTN_MULTICAST ||
311 chk_addr_ret == RTN_BROADCAST)
312 return -EADDRNOTAVAIL;
313
314 #if IS_ENABLED(CONFIG_IPV6)
315 } else if (sk->sk_family == AF_INET6) {
316 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
317 int addr_type, scoped, has_addr;
318 struct net_device *dev = NULL;
319
320 if (addr_len < sizeof(*addr))
321 return -EINVAL;
322
323 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n",
324 sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port));
325
326 addr_type = ipv6_addr_type(&addr->sin6_addr);
327 scoped = __ipv6_addr_needs_scope_id(addr_type);
328 if ((addr_type != IPV6_ADDR_ANY &&
329 !(addr_type & IPV6_ADDR_UNICAST)) ||
330 (scoped && !addr->sin6_scope_id))
331 return -EINVAL;
332
333 rcu_read_lock();
334 if (addr->sin6_scope_id) {
335 dev = dev_get_by_index_rcu(net, addr->sin6_scope_id);
336 if (!dev) {
337 rcu_read_unlock();
338 return -ENODEV;
339 }
340 }
341 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev,
342 scoped);
343 rcu_read_unlock();
344
345 if (!(isk->freebind || isk->transparent || has_addr ||
346 addr_type == IPV6_ADDR_ANY))
347 return -EADDRNOTAVAIL;
348
349 if (scoped)
350 sk->sk_bound_dev_if = addr->sin6_scope_id;
351 #endif
352 } else {
353 return -EAFNOSUPPORT;
354 }
355 return 0;
356 }
357
358 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr)
359 {
360 if (saddr->sa_family == AF_INET) {
361 struct inet_sock *isk = inet_sk(sk);
362 struct sockaddr_in *addr = (struct sockaddr_in *) saddr;
363 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
364 #if IS_ENABLED(CONFIG_IPV6)
365 } else if (saddr->sa_family == AF_INET6) {
366 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr;
367 struct ipv6_pinfo *np = inet6_sk(sk);
368 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr;
369 #endif
370 }
371 }
372
373 static void ping_clear_saddr(struct sock *sk, int dif)
374 {
375 sk->sk_bound_dev_if = dif;
376 if (sk->sk_family == AF_INET) {
377 struct inet_sock *isk = inet_sk(sk);
378 isk->inet_rcv_saddr = isk->inet_saddr = 0;
379 #if IS_ENABLED(CONFIG_IPV6)
380 } else if (sk->sk_family == AF_INET6) {
381 struct ipv6_pinfo *np = inet6_sk(sk);
382 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
383 memset(&np->saddr, 0, sizeof(np->saddr));
384 #endif
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
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 ping_set_saddr(sk, uaddr);
411 snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port);
412 if (ping_get_port(sk, snum) != 0) {
413 ping_clear_saddr(sk, dif);
414 goto out;
415 }
416
417 pr_debug("after bind(): num = %d, dif = %d\n",
418 (int)isk->inet_num,
419 (int)sk->sk_bound_dev_if);
420
421 err = 0;
422 if (sk->sk_family == AF_INET && isk->inet_rcv_saddr)
423 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
424 #if IS_ENABLED(CONFIG_IPV6)
425 if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr))
426 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
427 #endif
428
429 if (snum)
430 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
431 isk->inet_sport = htons(isk->inet_num);
432 isk->inet_daddr = 0;
433 isk->inet_dport = 0;
434
435 #if IS_ENABLED(CONFIG_IPV6)
436 if (sk->sk_family == AF_INET6)
437 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr));
438 #endif
439
440 sk_dst_reset(sk);
441 out:
442 release_sock(sk);
443 pr_debug("ping_v4_bind -> %d\n", err);
444 return err;
445 }
446 EXPORT_SYMBOL_GPL(ping_bind);
447
448 /*
449 * Is this a supported type of ICMP message?
450 */
451
452 static inline int ping_supported(int family, int type, int code)
453 {
454 return (family == AF_INET && type == ICMP_ECHO && code == 0) ||
455 (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0);
456 }
457
458 /*
459 * This routine is called by the ICMP module when it gets some
460 * sort of error condition.
461 */
462
463 void ping_err(struct sk_buff *skb, int offset, u32 info)
464 {
465 int family;
466 struct icmphdr *icmph;
467 struct inet_sock *inet_sock;
468 int type;
469 int code;
470 struct net *net = dev_net(skb->dev);
471 struct sock *sk;
472 int harderr;
473 int err;
474
475 if (skb->protocol == htons(ETH_P_IP)) {
476 family = AF_INET;
477 type = icmp_hdr(skb)->type;
478 code = icmp_hdr(skb)->code;
479 icmph = (struct icmphdr *)(skb->data + offset);
480 } else if (skb->protocol == htons(ETH_P_IPV6)) {
481 family = AF_INET6;
482 type = icmp6_hdr(skb)->icmp6_type;
483 code = icmp6_hdr(skb)->icmp6_code;
484 icmph = (struct icmphdr *) (skb->data + offset);
485 } else {
486 BUG();
487 }
488
489 /* We assume the packet has already been checked by icmp_unreach */
490
491 if (!ping_supported(family, icmph->type, icmph->code))
492 return;
493
494 pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n",
495 skb->protocol, type, code, ntohs(icmph->un.echo.id),
496 ntohs(icmph->un.echo.sequence));
497
498 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
499 if (sk == NULL) {
500 pr_debug("no socket, dropping\n");
501 return; /* No socket for error */
502 }
503 pr_debug("err on socket %p\n", sk);
504
505 err = 0;
506 harderr = 0;
507 inet_sock = inet_sk(sk);
508
509 if (skb->protocol == htons(ETH_P_IP)) {
510 switch (type) {
511 default:
512 case ICMP_TIME_EXCEEDED:
513 err = EHOSTUNREACH;
514 break;
515 case ICMP_SOURCE_QUENCH:
516 /* This is not a real error but ping wants to see it.
517 * Report it with some fake errno.
518 */
519 err = EREMOTEIO;
520 break;
521 case ICMP_PARAMETERPROB:
522 err = EPROTO;
523 harderr = 1;
524 break;
525 case ICMP_DEST_UNREACH:
526 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
527 ipv4_sk_update_pmtu(skb, sk, info);
528 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) {
529 err = EMSGSIZE;
530 harderr = 1;
531 break;
532 }
533 goto out;
534 }
535 err = EHOSTUNREACH;
536 if (code <= NR_ICMP_UNREACH) {
537 harderr = icmp_err_convert[code].fatal;
538 err = icmp_err_convert[code].errno;
539 }
540 break;
541 case ICMP_REDIRECT:
542 /* See ICMP_SOURCE_QUENCH */
543 ipv4_sk_redirect(skb, sk);
544 err = EREMOTEIO;
545 break;
546 }
547 #if IS_ENABLED(CONFIG_IPV6)
548 } else if (skb->protocol == htons(ETH_P_IPV6)) {
549 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err);
550 #endif
551 }
552
553 /*
554 * RFC1122: OK. Passes ICMP errors back to application, as per
555 * 4.1.3.3.
556 */
557 if ((family == AF_INET && !inet_sock->recverr) ||
558 (family == AF_INET6 && !inet6_sk(sk)->recverr)) {
559 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
560 goto out;
561 } else {
562 if (family == AF_INET) {
563 ip_icmp_error(sk, skb, err, 0 /* no remote port */,
564 info, (u8 *)icmph);
565 #if IS_ENABLED(CONFIG_IPV6)
566 } else if (family == AF_INET6) {
567 pingv6_ops.ipv6_icmp_error(sk, skb, err, 0,
568 info, (u8 *)icmph);
569 #endif
570 }
571 }
572 sk->sk_err = err;
573 sk->sk_error_report(sk);
574 out:
575 sock_put(sk);
576 }
577 EXPORT_SYMBOL_GPL(ping_err);
578
579 /*
580 * Copy and checksum an ICMP Echo packet from user space into a buffer
581 * starting from the payload.
582 */
583
584 int ping_getfrag(void *from, char *to,
585 int offset, int fraglen, int odd, struct sk_buff *skb)
586 {
587 struct pingfakehdr *pfh = (struct pingfakehdr *)from;
588
589 if (offset == 0) {
590 if (fraglen < sizeof(struct icmphdr))
591 BUG();
592 if (csum_partial_copy_fromiovecend(to + sizeof(struct icmphdr),
593 pfh->iov, 0, fraglen - sizeof(struct icmphdr),
594 &pfh->wcheck))
595 return -EFAULT;
596 } else if (offset < sizeof(struct icmphdr)) {
597 BUG();
598 } else {
599 if (csum_partial_copy_fromiovecend
600 (to, pfh->iov, offset - sizeof(struct icmphdr),
601 fraglen, &pfh->wcheck))
602 return -EFAULT;
603 }
604
605 #if IS_ENABLED(CONFIG_IPV6)
606 /* For IPv6, checksum each skb as we go along, as expected by
607 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in
608 * wcheck, it will be finalized in ping_v4_push_pending_frames.
609 */
610 if (pfh->family == AF_INET6) {
611 skb->csum = pfh->wcheck;
612 skb->ip_summed = CHECKSUM_NONE;
613 pfh->wcheck = 0;
614 }
615 #endif
616
617 return 0;
618 }
619 EXPORT_SYMBOL_GPL(ping_getfrag);
620
621 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
622 struct flowi4 *fl4)
623 {
624 struct sk_buff *skb = skb_peek(&sk->sk_write_queue);
625
626 pfh->wcheck = csum_partial((char *)&pfh->icmph,
627 sizeof(struct icmphdr), pfh->wcheck);
628 pfh->icmph.checksum = csum_fold(pfh->wcheck);
629 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
630 skb->ip_summed = CHECKSUM_NONE;
631 return ip_push_pending_frames(sk, fl4);
632 }
633
634 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
635 void *user_icmph, size_t icmph_len) {
636 u8 type, code;
637
638 if (len > 0xFFFF)
639 return -EMSGSIZE;
640
641 /*
642 * Check the flags.
643 */
644
645 /* Mirror BSD error message compatibility */
646 if (msg->msg_flags & MSG_OOB)
647 return -EOPNOTSUPP;
648
649 /*
650 * Fetch the ICMP header provided by the userland.
651 * iovec is modified! The ICMP header is consumed.
652 */
653 if (memcpy_fromiovec(user_icmph, msg->msg_iov, icmph_len))
654 return -EFAULT;
655
656 if (family == AF_INET) {
657 type = ((struct icmphdr *) user_icmph)->type;
658 code = ((struct icmphdr *) user_icmph)->code;
659 #if IS_ENABLED(CONFIG_IPV6)
660 } else if (family == AF_INET6) {
661 type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
662 code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
663 #endif
664 } else {
665 BUG();
666 }
667
668 if (!ping_supported(family, type, code))
669 return -EINVAL;
670
671 return 0;
672 }
673 EXPORT_SYMBOL_GPL(ping_common_sendmsg);
674
675 static int ping_v4_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
676 size_t len)
677 {
678 struct net *net = sock_net(sk);
679 struct flowi4 fl4;
680 struct inet_sock *inet = inet_sk(sk);
681 struct ipcm_cookie ipc;
682 struct icmphdr user_icmph;
683 struct pingfakehdr pfh;
684 struct rtable *rt = NULL;
685 struct ip_options_data opt_copy;
686 int free = 0;
687 __be32 saddr, daddr, faddr;
688 u8 tos;
689 int err;
690
691 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
692
693 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
694 sizeof(user_icmph));
695 if (err)
696 return err;
697
698 /*
699 * Get and verify the address.
700 */
701
702 if (msg->msg_name) {
703 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
704 if (msg->msg_namelen < sizeof(*usin))
705 return -EINVAL;
706 if (usin->sin_family != AF_INET)
707 return -EINVAL;
708 daddr = usin->sin_addr.s_addr;
709 /* no remote port */
710 } else {
711 if (sk->sk_state != TCP_ESTABLISHED)
712 return -EDESTADDRREQ;
713 daddr = inet->inet_daddr;
714 /* no remote port */
715 }
716
717 ipc.addr = inet->inet_saddr;
718 ipc.opt = NULL;
719 ipc.oif = sk->sk_bound_dev_if;
720 ipc.tx_flags = 0;
721 ipc.ttl = 0;
722 ipc.tos = -1;
723
724 sock_tx_timestamp(sk, &ipc.tx_flags);
725
726 if (msg->msg_controllen) {
727 err = ip_cmsg_send(sock_net(sk), msg, &ipc);
728 if (err)
729 return err;
730 if (ipc.opt)
731 free = 1;
732 }
733 if (!ipc.opt) {
734 struct ip_options_rcu *inet_opt;
735
736 rcu_read_lock();
737 inet_opt = rcu_dereference(inet->inet_opt);
738 if (inet_opt) {
739 memcpy(&opt_copy, inet_opt,
740 sizeof(*inet_opt) + inet_opt->opt.optlen);
741 ipc.opt = &opt_copy.opt;
742 }
743 rcu_read_unlock();
744 }
745
746 saddr = ipc.addr;
747 ipc.addr = faddr = daddr;
748
749 if (ipc.opt && ipc.opt->opt.srr) {
750 if (!daddr)
751 return -EINVAL;
752 faddr = ipc.opt->opt.faddr;
753 }
754 tos = get_rttos(&ipc, inet);
755 if (sock_flag(sk, SOCK_LOCALROUTE) ||
756 (msg->msg_flags & MSG_DONTROUTE) ||
757 (ipc.opt && ipc.opt->opt.is_strictroute)) {
758 tos |= RTO_ONLINK;
759 }
760
761 if (ipv4_is_multicast(daddr)) {
762 if (!ipc.oif)
763 ipc.oif = inet->mc_index;
764 if (!saddr)
765 saddr = inet->mc_addr;
766 } else if (!ipc.oif)
767 ipc.oif = inet->uc_index;
768
769 flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
770 RT_SCOPE_UNIVERSE, sk->sk_protocol,
771 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0);
772
773 security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
774 rt = ip_route_output_flow(net, &fl4, sk);
775 if (IS_ERR(rt)) {
776 err = PTR_ERR(rt);
777 rt = NULL;
778 if (err == -ENETUNREACH)
779 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
780 goto out;
781 }
782
783 err = -EACCES;
784 if ((rt->rt_flags & RTCF_BROADCAST) &&
785 !sock_flag(sk, SOCK_BROADCAST))
786 goto out;
787
788 if (msg->msg_flags & MSG_CONFIRM)
789 goto do_confirm;
790 back_from_confirm:
791
792 if (!ipc.addr)
793 ipc.addr = fl4.daddr;
794
795 lock_sock(sk);
796
797 pfh.icmph.type = user_icmph.type; /* already checked */
798 pfh.icmph.code = user_icmph.code; /* ditto */
799 pfh.icmph.checksum = 0;
800 pfh.icmph.un.echo.id = inet->inet_sport;
801 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
802 pfh.iov = msg->msg_iov;
803 pfh.wcheck = 0;
804 pfh.family = AF_INET;
805
806 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
807 0, &ipc, &rt, msg->msg_flags);
808 if (err)
809 ip_flush_pending_frames(sk);
810 else
811 err = ping_v4_push_pending_frames(sk, &pfh, &fl4);
812 release_sock(sk);
813
814 out:
815 ip_rt_put(rt);
816 if (free)
817 kfree(ipc.opt);
818 if (!err) {
819 icmp_out_count(sock_net(sk), user_icmph.type);
820 return len;
821 }
822 return err;
823
824 do_confirm:
825 dst_confirm(&rt->dst);
826 if (!(msg->msg_flags & MSG_PROBE) || len)
827 goto back_from_confirm;
828 err = 0;
829 goto out;
830 }
831
832 int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
833 size_t len, int noblock, int flags, int *addr_len)
834 {
835 struct inet_sock *isk = inet_sk(sk);
836 int family = sk->sk_family;
837 struct sk_buff *skb;
838 int copied, err;
839
840 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
841
842 err = -EOPNOTSUPP;
843 if (flags & MSG_OOB)
844 goto out;
845
846 if (flags & MSG_ERRQUEUE) {
847 if (family == AF_INET) {
848 return ip_recv_error(sk, msg, len, addr_len);
849 #if IS_ENABLED(CONFIG_IPV6)
850 } else if (family == AF_INET6) {
851 return pingv6_ops.ipv6_recv_error(sk, msg, len,
852 addr_len);
853 #endif
854 }
855 }
856
857 skb = skb_recv_datagram(sk, flags, noblock, &err);
858 if (!skb)
859 goto out;
860
861 copied = skb->len;
862 if (copied > len) {
863 msg->msg_flags |= MSG_TRUNC;
864 copied = len;
865 }
866
867 /* Don't bother checking the checksum */
868 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
869 if (err)
870 goto done;
871
872 sock_recv_timestamp(msg, sk, skb);
873
874 /* Copy the address and add cmsg data. */
875 if (family == AF_INET) {
876 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
877
878 if (sin) {
879 sin->sin_family = AF_INET;
880 sin->sin_port = 0 /* skb->h.uh->source */;
881 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
882 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
883 *addr_len = sizeof(*sin);
884 }
885
886 if (isk->cmsg_flags)
887 ip_cmsg_recv(msg, skb);
888
889 #if IS_ENABLED(CONFIG_IPV6)
890 } else if (family == AF_INET6) {
891 struct ipv6_pinfo *np = inet6_sk(sk);
892 struct ipv6hdr *ip6 = ipv6_hdr(skb);
893 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
894
895 if (sin6) {
896 sin6->sin6_family = AF_INET6;
897 sin6->sin6_port = 0;
898 sin6->sin6_addr = ip6->saddr;
899 sin6->sin6_flowinfo = 0;
900 if (np->sndflow)
901 sin6->sin6_flowinfo = ip6_flowinfo(ip6);
902 sin6->sin6_scope_id =
903 ipv6_iface_scope_id(&sin6->sin6_addr,
904 IP6CB(skb)->iif);
905 *addr_len = sizeof(*sin6);
906 }
907
908 if (inet6_sk(sk)->rxopt.all)
909 pingv6_ops.ip6_datagram_recv_ctl(sk, msg, skb);
910 #endif
911 } else {
912 BUG();
913 }
914
915 err = copied;
916
917 done:
918 skb_free_datagram(sk, skb);
919 out:
920 pr_debug("ping_recvmsg -> %d\n", err);
921 return err;
922 }
923 EXPORT_SYMBOL_GPL(ping_recvmsg);
924
925 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
926 {
927 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
928 inet_sk(sk), inet_sk(sk)->inet_num, skb);
929 if (sock_queue_rcv_skb(sk, skb) < 0) {
930 kfree_skb(skb);
931 pr_debug("ping_queue_rcv_skb -> failed\n");
932 return -1;
933 }
934 return 0;
935 }
936 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
937
938
939 /*
940 * All we need to do is get the socket.
941 */
942
943 void ping_rcv(struct sk_buff *skb)
944 {
945 struct sock *sk;
946 struct net *net = dev_net(skb->dev);
947 struct icmphdr *icmph = icmp_hdr(skb);
948
949 /* We assume the packet has already been checked by icmp_rcv */
950
951 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
952 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
953
954 /* Push ICMP header back */
955 skb_push(skb, skb->data - (u8 *)icmph);
956
957 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
958 if (sk != NULL) {
959 pr_debug("rcv on socket %p\n", sk);
960 ping_queue_rcv_skb(sk, skb_get(skb));
961 sock_put(sk);
962 return;
963 }
964 pr_debug("no socket, dropping\n");
965
966 /* We're called from icmp_rcv(). kfree_skb() is done there. */
967 }
968 EXPORT_SYMBOL_GPL(ping_rcv);
969
970 struct proto ping_prot = {
971 .name = "PING",
972 .owner = THIS_MODULE,
973 .init = ping_init_sock,
974 .close = ping_close,
975 .connect = ip4_datagram_connect,
976 .disconnect = udp_disconnect,
977 .setsockopt = ip_setsockopt,
978 .getsockopt = ip_getsockopt,
979 .sendmsg = ping_v4_sendmsg,
980 .recvmsg = ping_recvmsg,
981 .bind = ping_bind,
982 .backlog_rcv = ping_queue_rcv_skb,
983 .release_cb = ip4_datagram_release_cb,
984 .hash = ping_hash,
985 .unhash = ping_unhash,
986 .get_port = ping_get_port,
987 .obj_size = sizeof(struct inet_sock),
988 };
989 EXPORT_SYMBOL(ping_prot);
990
991 #ifdef CONFIG_PROC_FS
992
993 static struct sock *ping_get_first(struct seq_file *seq, int start)
994 {
995 struct sock *sk;
996 struct ping_iter_state *state = seq->private;
997 struct net *net = seq_file_net(seq);
998
999 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
1000 ++state->bucket) {
1001 struct hlist_nulls_node *node;
1002 struct hlist_nulls_head *hslot;
1003
1004 hslot = &ping_table.hash[state->bucket];
1005
1006 if (hlist_nulls_empty(hslot))
1007 continue;
1008
1009 sk_nulls_for_each(sk, node, hslot) {
1010 if (net_eq(sock_net(sk), net) &&
1011 sk->sk_family == state->family)
1012 goto found;
1013 }
1014 }
1015 sk = NULL;
1016 found:
1017 return sk;
1018 }
1019
1020 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
1021 {
1022 struct ping_iter_state *state = seq->private;
1023 struct net *net = seq_file_net(seq);
1024
1025 do {
1026 sk = sk_nulls_next(sk);
1027 } while (sk && (!net_eq(sock_net(sk), net)));
1028
1029 if (!sk)
1030 return ping_get_first(seq, state->bucket + 1);
1031 return sk;
1032 }
1033
1034 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
1035 {
1036 struct sock *sk = ping_get_first(seq, 0);
1037
1038 if (sk)
1039 while (pos && (sk = ping_get_next(seq, sk)) != NULL)
1040 --pos;
1041 return pos ? NULL : sk;
1042 }
1043
1044 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
1045 {
1046 struct ping_iter_state *state = seq->private;
1047 state->bucket = 0;
1048 state->family = family;
1049
1050 read_lock_bh(&ping_table.lock);
1051
1052 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1053 }
1054 EXPORT_SYMBOL_GPL(ping_seq_start);
1055
1056 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos)
1057 {
1058 return ping_seq_start(seq, pos, AF_INET);
1059 }
1060
1061 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1062 {
1063 struct sock *sk;
1064
1065 if (v == SEQ_START_TOKEN)
1066 sk = ping_get_idx(seq, 0);
1067 else
1068 sk = ping_get_next(seq, v);
1069
1070 ++*pos;
1071 return sk;
1072 }
1073 EXPORT_SYMBOL_GPL(ping_seq_next);
1074
1075 void ping_seq_stop(struct seq_file *seq, void *v)
1076 {
1077 read_unlock_bh(&ping_table.lock);
1078 }
1079 EXPORT_SYMBOL_GPL(ping_seq_stop);
1080
1081 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f,
1082 int bucket)
1083 {
1084 struct inet_sock *inet = inet_sk(sp);
1085 __be32 dest = inet->inet_daddr;
1086 __be32 src = inet->inet_rcv_saddr;
1087 __u16 destp = ntohs(inet->inet_dport);
1088 __u16 srcp = ntohs(inet->inet_sport);
1089
1090 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
1091 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d",
1092 bucket, src, srcp, dest, destp, sp->sk_state,
1093 sk_wmem_alloc_get(sp),
1094 sk_rmem_alloc_get(sp),
1095 0, 0L, 0,
1096 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
1097 0, sock_i_ino(sp),
1098 atomic_read(&sp->sk_refcnt), sp,
1099 atomic_read(&sp->sk_drops));
1100 }
1101
1102 static int ping_v4_seq_show(struct seq_file *seq, void *v)
1103 {
1104 seq_setwidth(seq, 127);
1105 if (v == SEQ_START_TOKEN)
1106 seq_puts(seq, " sl local_address rem_address st tx_queue "
1107 "rx_queue tr tm->when retrnsmt uid timeout "
1108 "inode ref pointer drops");
1109 else {
1110 struct ping_iter_state *state = seq->private;
1111
1112 ping_v4_format_sock(v, seq, state->bucket);
1113 }
1114 seq_pad(seq, '\n');
1115 return 0;
1116 }
1117
1118 static const struct seq_operations ping_v4_seq_ops = {
1119 .show = ping_v4_seq_show,
1120 .start = ping_v4_seq_start,
1121 .next = ping_seq_next,
1122 .stop = ping_seq_stop,
1123 };
1124
1125 static int ping_seq_open(struct inode *inode, struct file *file)
1126 {
1127 struct ping_seq_afinfo *afinfo = PDE_DATA(inode);
1128 return seq_open_net(inode, file, &afinfo->seq_ops,
1129 sizeof(struct ping_iter_state));
1130 }
1131
1132 const struct file_operations ping_seq_fops = {
1133 .open = ping_seq_open,
1134 .read = seq_read,
1135 .llseek = seq_lseek,
1136 .release = seq_release_net,
1137 };
1138 EXPORT_SYMBOL_GPL(ping_seq_fops);
1139
1140 static struct ping_seq_afinfo ping_v4_seq_afinfo = {
1141 .name = "icmp",
1142 .family = AF_INET,
1143 .seq_fops = &ping_seq_fops,
1144 .seq_ops = {
1145 .start = ping_v4_seq_start,
1146 .show = ping_v4_seq_show,
1147 .next = ping_seq_next,
1148 .stop = ping_seq_stop,
1149 },
1150 };
1151
1152 int ping_proc_register(struct net *net, struct ping_seq_afinfo *afinfo)
1153 {
1154 struct proc_dir_entry *p;
1155 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
1156 afinfo->seq_fops, afinfo);
1157 if (!p)
1158 return -ENOMEM;
1159 return 0;
1160 }
1161 EXPORT_SYMBOL_GPL(ping_proc_register);
1162
1163 void ping_proc_unregister(struct net *net, struct ping_seq_afinfo *afinfo)
1164 {
1165 remove_proc_entry(afinfo->name, net->proc_net);
1166 }
1167 EXPORT_SYMBOL_GPL(ping_proc_unregister);
1168
1169 static int __net_init ping_v4_proc_init_net(struct net *net)
1170 {
1171 return ping_proc_register(net, &ping_v4_seq_afinfo);
1172 }
1173
1174 static void __net_exit ping_v4_proc_exit_net(struct net *net)
1175 {
1176 ping_proc_unregister(net, &ping_v4_seq_afinfo);
1177 }
1178
1179 static struct pernet_operations ping_v4_net_ops = {
1180 .init = ping_v4_proc_init_net,
1181 .exit = ping_v4_proc_exit_net,
1182 };
1183
1184 int __init ping_proc_init(void)
1185 {
1186 return register_pernet_subsys(&ping_v4_net_ops);
1187 }
1188
1189 void ping_proc_exit(void)
1190 {
1191 unregister_pernet_subsys(&ping_v4_net_ops);
1192 }
1193
1194 #endif
1195
1196 void __init ping_init(void)
1197 {
1198 int i;
1199
1200 for (i = 0; i < PING_HTABLE_SIZE; i++)
1201 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i);
1202 rwlock_init(&ping_table.lock);
1203 }
Linux kernel - Deliverables
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