1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * "Ping" sockets
8 *
9 * Based on ipv4/udp.c code.
10 *
11 * Authors: Vasiliy Kulikov / Openwall (for Linux 2.6),
12 * Pavel Kankovsky (for Linux 2.4.32)
13 *
14 * Pavel gave all rights to bugs to Vasiliy,
15 * none of the bugs are Pavel's now.
16 */
17
18 #include <linux/uaccess.h>
19 #include <linux/types.h>
20 #include <linux/fcntl.h>
21 #include <linux/socket.h>
22 #include <linux/sockios.h>
23 #include <linux/in.h>
24 #include <linux/errno.h>
25 #include <linux/timer.h>
26 #include <linux/mm.h>
27 #include <linux/inet.h>
28 #include <linux/netdevice.h>
29 #include <net/snmp.h>
30 #include <net/ip.h>
31 #include <net/icmp.h>
32 #include <net/protocol.h>
33 #include <linux/skbuff.h>
34 #include <linux/proc_fs.h>
35 #include <linux/export.h>
36 #include <net/sock.h>
37 #include <net/ping.h>
38 #include <net/udp.h>
39 #include <net/route.h>
40 #include <net/inet_common.h>
41 #include <net/checksum.h>
42
43 #if IS_ENABLED(CONFIG_IPV6)
44 #include <linux/in6.h>
45 #include <linux/icmpv6.h>
46 #include <net/addrconf.h>
47 #include <net/ipv6.h>
48 #include <net/transp_v6.h>
49 #endif
50
51 struct ping_table {
52 struct hlist_nulls_head hash[PING_HTABLE_SIZE];
53 rwlock_t lock;
54 };
55
56 static struct ping_table ping_table;
57 struct pingv6_ops pingv6_ops;
58 EXPORT_SYMBOL_GPL(pingv6_ops);
59
60 static u16 ping_port_rover;
61
ping_hashfn(const struct net * net,u32 num,u32 mask)62 static inline u32 ping_hashfn(const struct net *net, u32 num, u32 mask)
63 {
64 u32 res = (num + net_hash_mix(net)) & mask;
65
66 pr_debug("hash(%u) = %u\n", num, res);
67 return res;
68 }
69 EXPORT_SYMBOL_GPL(ping_hash);
70
ping_hashslot(struct ping_table * table,struct net * net,unsigned int num)71 static inline struct hlist_nulls_head *ping_hashslot(struct ping_table *table,
72 struct net *net, unsigned int num)
73 {
74 return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)];
75 }
76
ping_get_port(struct sock * sk,unsigned short ident)77 int ping_get_port(struct sock *sk, unsigned short ident)
78 {
79 struct hlist_nulls_node *node;
80 struct hlist_nulls_head *hlist;
81 struct inet_sock *isk, *isk2;
82 struct sock *sk2 = NULL;
83
84 isk = inet_sk(sk);
85 write_lock_bh(&ping_table.lock);
86 if (ident == 0) {
87 u32 i;
88 u16 result = ping_port_rover + 1;
89
90 for (i = 0; i < (1L << 16); i++, result++) {
91 if (!result)
92 result++; /* avoid zero */
93 hlist = ping_hashslot(&ping_table, sock_net(sk),
94 result);
95 ping_portaddr_for_each_entry(sk2, node, hlist) {
96 isk2 = inet_sk(sk2);
97
98 if (isk2->inet_num == result)
99 goto next_port;
100 }
101
102 /* found */
103 ping_port_rover = ident = result;
104 break;
105 next_port:
106 ;
107 }
108 if (i >= (1L << 16))
109 goto fail;
110 } else {
111 hlist = ping_hashslot(&ping_table, sock_net(sk), ident);
112 ping_portaddr_for_each_entry(sk2, node, hlist) {
113 isk2 = inet_sk(sk2);
114
115 /* BUG? Why is this reuse and not reuseaddr? ping.c
116 * doesn't turn off SO_REUSEADDR, and it doesn't expect
117 * that other ping processes can steal its packets.
118 */
119 if ((isk2->inet_num == ident) &&
120 (sk2 != sk) &&
121 (!sk2->sk_reuse || !sk->sk_reuse))
122 goto fail;
123 }
124 }
125
126 pr_debug("found port/ident = %d\n", ident);
127 isk->inet_num = ident;
128 if (sk_unhashed(sk)) {
129 pr_debug("was not hashed\n");
130 sock_hold(sk);
131 hlist_nulls_add_head(&sk->sk_nulls_node, hlist);
132 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
133 }
134 write_unlock_bh(&ping_table.lock);
135 return 0;
136
137 fail:
138 write_unlock_bh(&ping_table.lock);
139 return 1;
140 }
141 EXPORT_SYMBOL_GPL(ping_get_port);
142
ping_hash(struct sock * sk)143 int ping_hash(struct sock *sk)
144 {
145 pr_debug("ping_hash(sk->port=%u)\n", inet_sk(sk)->inet_num);
146 BUG(); /* "Please do not press this button again." */
147
148 return 0;
149 }
150
ping_unhash(struct sock * sk)151 void ping_unhash(struct sock *sk)
152 {
153 struct inet_sock *isk = inet_sk(sk);
154
155 pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);
156 write_lock_bh(&ping_table.lock);
157 if (sk_hashed(sk)) {
158 hlist_nulls_del(&sk->sk_nulls_node);
159 sk_nulls_node_init(&sk->sk_nulls_node);
160 sock_put(sk);
161 isk->inet_num = 0;
162 isk->inet_sport = 0;
163 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
164 }
165 write_unlock_bh(&ping_table.lock);
166 }
167 EXPORT_SYMBOL_GPL(ping_unhash);
168
ping_lookup(struct net * net,struct sk_buff * skb,u16 ident)169 static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
170 {
171 struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident);
172 struct sock *sk = NULL;
173 struct inet_sock *isk;
174 struct hlist_nulls_node *hnode;
175 int dif, sdif;
176
177 if (skb->protocol == htons(ETH_P_IP)) {
178 dif = inet_iif(skb);
179 sdif = inet_sdif(skb);
180 pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n",
181 (int)ident, &ip_hdr(skb)->daddr, dif);
182 #if IS_ENABLED(CONFIG_IPV6)
183 } else if (skb->protocol == htons(ETH_P_IPV6)) {
184 dif = inet6_iif(skb);
185 sdif = inet6_sdif(skb);
186 pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n",
187 (int)ident, &ipv6_hdr(skb)->daddr, dif);
188 #endif
189 } else {
190 return NULL;
191 }
192
193 read_lock_bh(&ping_table.lock);
194
195 ping_portaddr_for_each_entry(sk, hnode, hslot) {
196 isk = inet_sk(sk);
197
198 pr_debug("iterate\n");
199 if (isk->inet_num != ident)
200 continue;
201
202 if (skb->protocol == htons(ETH_P_IP) &&
203 sk->sk_family == AF_INET) {
204 pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk,
205 (int) isk->inet_num, &isk->inet_rcv_saddr,
206 sk->sk_bound_dev_if);
207
208 if (isk->inet_rcv_saddr &&
209 isk->inet_rcv_saddr != ip_hdr(skb)->daddr)
210 continue;
211 #if IS_ENABLED(CONFIG_IPV6)
212 } else if (skb->protocol == htons(ETH_P_IPV6) &&
213 sk->sk_family == AF_INET6) {
214
215 pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk,
216 (int) isk->inet_num,
217 &sk->sk_v6_rcv_saddr,
218 sk->sk_bound_dev_if);
219
220 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
221 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr,
222 &ipv6_hdr(skb)->daddr))
223 continue;
224 #endif
225 } else {
226 continue;
227 }
228
229 if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif &&
230 sk->sk_bound_dev_if != sdif)
231 continue;
232
233 sock_hold(sk);
234 goto exit;
235 }
236
237 sk = NULL;
238 exit:
239 read_unlock_bh(&ping_table.lock);
240
241 return sk;
242 }
243
inet_get_ping_group_range_net(struct net * net,kgid_t * low,kgid_t * high)244 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low,
245 kgid_t *high)
246 {
247 kgid_t *data = net->ipv4.ping_group_range.range;
248 unsigned int seq;
249
250 do {
251 seq = read_seqbegin(&net->ipv4.ping_group_range.lock);
252
253 *low = data[0];
254 *high = data[1];
255 } while (read_seqretry(&net->ipv4.ping_group_range.lock, seq));
256 }
257
258
ping_init_sock(struct sock * sk)259 int ping_init_sock(struct sock *sk)
260 {
261 struct net *net = sock_net(sk);
262 kgid_t group = current_egid();
263 struct group_info *group_info;
264 int i;
265 kgid_t low, high;
266 int ret = 0;
267
268 if (sk->sk_family == AF_INET6)
269 sk->sk_ipv6only = 1;
270
271 inet_get_ping_group_range_net(net, &low, &high);
272 if (gid_lte(low, group) && gid_lte(group, high))
273 return 0;
274
275 group_info = get_current_groups();
276 for (i = 0; i < group_info->ngroups; i++) {
277 kgid_t gid = group_info->gid[i];
278
279 if (gid_lte(low, gid) && gid_lte(gid, high))
280 goto out_release_group;
281 }
282
283 ret = -EACCES;
284
285 out_release_group:
286 put_group_info(group_info);
287 return ret;
288 }
289 EXPORT_SYMBOL_GPL(ping_init_sock);
290
ping_close(struct sock * sk,long timeout)291 void ping_close(struct sock *sk, long timeout)
292 {
293 pr_debug("ping_close(sk=%p,sk->num=%u)\n",
294 inet_sk(sk), inet_sk(sk)->inet_num);
295 pr_debug("isk->refcnt = %d\n", refcount_read(&sk->sk_refcnt));
296
297 sk_common_release(sk);
298 }
299 EXPORT_SYMBOL_GPL(ping_close);
300
301 /* 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)302 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
303 struct sockaddr *uaddr, int addr_len)
304 {
305 struct net *net = sock_net(sk);
306 if (sk->sk_family == AF_INET) {
307 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
308 u32 tb_id = RT_TABLE_LOCAL;
309 int chk_addr_ret;
310
311 if (addr_len < sizeof(*addr))
312 return -EINVAL;
313
314 if (addr->sin_family != AF_INET &&
315 !(addr->sin_family == AF_UNSPEC &&
316 addr->sin_addr.s_addr == htonl(INADDR_ANY)))
317 return -EAFNOSUPPORT;
318
319 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",
320 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
321
322 if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
323 chk_addr_ret = RTN_LOCAL;
324 else {
325 tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id;
326 chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
327 }
328
329 if ((!inet_can_nonlocal_bind(net, isk) &&
330 chk_addr_ret != RTN_LOCAL) ||
331 chk_addr_ret == RTN_MULTICAST ||
332 chk_addr_ret == RTN_BROADCAST)
333 return -EADDRNOTAVAIL;
334
335 #if IS_ENABLED(CONFIG_IPV6)
336 } else if (sk->sk_family == AF_INET6) {
337 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
338 int addr_type, scoped, has_addr;
339 struct net_device *dev = NULL;
340
341 if (addr_len < sizeof(*addr))
342 return -EINVAL;
343
344 if (addr->sin6_family != AF_INET6)
345 return -EAFNOSUPPORT;
346
347 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n",
348 sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port));
349
350 addr_type = ipv6_addr_type(&addr->sin6_addr);
351 scoped = __ipv6_addr_needs_scope_id(addr_type);
352 if ((addr_type != IPV6_ADDR_ANY &&
353 !(addr_type & IPV6_ADDR_UNICAST)) ||
354 (scoped && !addr->sin6_scope_id))
355 return -EINVAL;
356
357 rcu_read_lock();
358 if (addr->sin6_scope_id) {
359 dev = dev_get_by_index_rcu(net, addr->sin6_scope_id);
360 if (!dev) {
361 rcu_read_unlock();
362 return -ENODEV;
363 }
364 }
365
366 if (!dev && sk->sk_bound_dev_if) {
367 dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if);
368 if (!dev) {
369 rcu_read_unlock();
370 return -ENODEV;
371 }
372 }
373 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev,
374 scoped);
375 rcu_read_unlock();
376
377 if (!(ipv6_can_nonlocal_bind(net, isk) || has_addr ||
378 addr_type == IPV6_ADDR_ANY))
379 return -EADDRNOTAVAIL;
380
381 if (scoped)
382 sk->sk_bound_dev_if = addr->sin6_scope_id;
383 #endif
384 } else {
385 return -EAFNOSUPPORT;
386 }
387 return 0;
388 }
389
ping_set_saddr(struct sock * sk,struct sockaddr * saddr)390 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr)
391 {
392 if (saddr->sa_family == AF_INET) {
393 struct inet_sock *isk = inet_sk(sk);
394 struct sockaddr_in *addr = (struct sockaddr_in *) saddr;
395 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
396 #if IS_ENABLED(CONFIG_IPV6)
397 } else if (saddr->sa_family == AF_INET6) {
398 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr;
399 struct ipv6_pinfo *np = inet6_sk(sk);
400 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr;
401 #endif
402 }
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 snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port);
429 if (ping_get_port(sk, snum) != 0) {
430 /* Restore possibly modified sk->sk_bound_dev_if by ping_check_bind_addr(). */
431 sk->sk_bound_dev_if = dif;
432 goto out;
433 }
434 ping_set_saddr(sk, uaddr);
435
436 pr_debug("after bind(): num = %hu, dif = %d\n",
437 isk->inet_num,
438 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
ping_supported(int family,int type,int code)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
ping_err(struct sk_buff * skb,int offset,u32 info)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
ping_getfrag(void * from,char * to,int offset,int fraglen,int odd,struct sk_buff * skb)603 int ping_getfrag(void *from, char *to,
604 int offset, int fraglen, int odd, struct sk_buff *skb)
605 {
606 struct pingfakehdr *pfh = (struct pingfakehdr *)from;
607
608 if (offset == 0) {
609 fraglen -= sizeof(struct icmphdr);
610 if (fraglen < 0)
611 BUG();
612 if (!csum_and_copy_from_iter_full(to + sizeof(struct icmphdr),
613 fraglen, &pfh->wcheck,
614 &pfh->msg->msg_iter))
615 return -EFAULT;
616 } else if (offset < sizeof(struct icmphdr)) {
617 BUG();
618 } else {
619 if (!csum_and_copy_from_iter_full(to, fraglen, &pfh->wcheck,
620 &pfh->msg->msg_iter))
621 return -EFAULT;
622 }
623
624 #if IS_ENABLED(CONFIG_IPV6)
625 /* For IPv6, checksum each skb as we go along, as expected by
626 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in
627 * wcheck, it will be finalized in ping_v4_push_pending_frames.
628 */
629 if (pfh->family == AF_INET6) {
630 skb->csum = pfh->wcheck;
631 skb->ip_summed = CHECKSUM_NONE;
632 pfh->wcheck = 0;
633 }
634 #endif
635
636 return 0;
637 }
638 EXPORT_SYMBOL_GPL(ping_getfrag);
639
ping_v4_push_pending_frames(struct sock * sk,struct pingfakehdr * pfh,struct flowi4 * fl4)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 if (!skb)
646 return 0;
647 pfh->wcheck = csum_partial((char *)&pfh->icmph,
648 sizeof(struct icmphdr), pfh->wcheck);
649 pfh->icmph.checksum = csum_fold(pfh->wcheck);
650 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
651 skb->ip_summed = CHECKSUM_NONE;
652 return ip_push_pending_frames(sk, fl4);
653 }
654
ping_common_sendmsg(int family,struct msghdr * msg,size_t len,void * user_icmph,size_t icmph_len)655 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
656 void *user_icmph, size_t icmph_len)
657 {
658 u8 type, code;
659
660 if (len > 0xFFFF)
661 return -EMSGSIZE;
662
663 /* Must have at least a full ICMP header. */
664 if (len < icmph_len)
665 return -EINVAL;
666
667 /*
668 * Check the flags.
669 */
670
671 /* Mirror BSD error message compatibility */
672 if (msg->msg_flags & MSG_OOB)
673 return -EOPNOTSUPP;
674
675 /*
676 * Fetch the ICMP header provided by the userland.
677 * iovec is modified! The ICMP header is consumed.
678 */
679 if (memcpy_from_msg(user_icmph, msg, icmph_len))
680 return -EFAULT;
681
682 if (family == AF_INET) {
683 type = ((struct icmphdr *) user_icmph)->type;
684 code = ((struct icmphdr *) user_icmph)->code;
685 #if IS_ENABLED(CONFIG_IPV6)
686 } else if (family == AF_INET6) {
687 type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
688 code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
689 #endif
690 } else {
691 BUG();
692 }
693
694 if (!ping_supported(family, type, code))
695 return -EINVAL;
696
697 return 0;
698 }
699 EXPORT_SYMBOL_GPL(ping_common_sendmsg);
700
ping_v4_sendmsg(struct sock * sk,struct msghdr * msg,size_t len)701 static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
702 {
703 struct net *net = sock_net(sk);
704 struct flowi4 fl4;
705 struct inet_sock *inet = inet_sk(sk);
706 struct ipcm_cookie ipc;
707 struct icmphdr user_icmph;
708 struct pingfakehdr pfh;
709 struct rtable *rt = NULL;
710 struct ip_options_data opt_copy;
711 int free = 0;
712 __be32 saddr, daddr, faddr;
713 u8 tos;
714 int err;
715
716 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
717
718 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
719 sizeof(user_icmph));
720 if (err)
721 return err;
722
723 /*
724 * Get and verify the address.
725 */
726
727 if (msg->msg_name) {
728 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
729 if (msg->msg_namelen < sizeof(*usin))
730 return -EINVAL;
731 if (usin->sin_family != AF_INET)
732 return -EAFNOSUPPORT;
733 daddr = usin->sin_addr.s_addr;
734 /* no remote port */
735 } else {
736 if (sk->sk_state != TCP_ESTABLISHED)
737 return -EDESTADDRREQ;
738 daddr = inet->inet_daddr;
739 /* no remote port */
740 }
741
742 ipcm_init_sk(&ipc, inet);
743
744 if (msg->msg_controllen) {
745 err = ip_cmsg_send(sk, msg, &ipc, false);
746 if (unlikely(err)) {
747 kfree(ipc.opt);
748 return err;
749 }
750 if (ipc.opt)
751 free = 1;
752 }
753 if (!ipc.opt) {
754 struct ip_options_rcu *inet_opt;
755
756 rcu_read_lock();
757 inet_opt = rcu_dereference(inet->inet_opt);
758 if (inet_opt) {
759 memcpy(&opt_copy, inet_opt,
760 sizeof(*inet_opt) + inet_opt->opt.optlen);
761 ipc.opt = &opt_copy.opt;
762 }
763 rcu_read_unlock();
764 }
765
766 saddr = ipc.addr;
767 ipc.addr = faddr = daddr;
768
769 if (ipc.opt && ipc.opt->opt.srr) {
770 if (!daddr) {
771 err = -EINVAL;
772 goto out_free;
773 }
774 faddr = ipc.opt->opt.faddr;
775 }
776 tos = get_rttos(&ipc, inet);
777 if (sock_flag(sk, SOCK_LOCALROUTE) ||
778 (msg->msg_flags & MSG_DONTROUTE) ||
779 (ipc.opt && ipc.opt->opt.is_strictroute)) {
780 tos |= RTO_ONLINK;
781 }
782
783 if (ipv4_is_multicast(daddr)) {
784 if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif))
785 ipc.oif = inet->mc_index;
786 if (!saddr)
787 saddr = inet->mc_addr;
788 } else if (!ipc.oif)
789 ipc.oif = inet->uc_index;
790
791 flowi4_init_output(&fl4, ipc.oif, ipc.sockc.mark, tos,
792 RT_SCOPE_UNIVERSE, sk->sk_protocol,
793 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0,
794 sk->sk_uid);
795
796 fl4.fl4_icmp_type = user_icmph.type;
797 fl4.fl4_icmp_code = user_icmph.code;
798
799 security_sk_classify_flow(sk, flowi4_to_flowi_common(&fl4));
800 rt = ip_route_output_flow(net, &fl4, sk);
801 if (IS_ERR(rt)) {
802 err = PTR_ERR(rt);
803 rt = NULL;
804 if (err == -ENETUNREACH)
805 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
806 goto out;
807 }
808
809 err = -EACCES;
810 if ((rt->rt_flags & RTCF_BROADCAST) &&
811 !sock_flag(sk, SOCK_BROADCAST))
812 goto out;
813
814 if (msg->msg_flags & MSG_CONFIRM)
815 goto do_confirm;
816 back_from_confirm:
817
818 if (!ipc.addr)
819 ipc.addr = fl4.daddr;
820
821 lock_sock(sk);
822
823 pfh.icmph.type = user_icmph.type; /* already checked */
824 pfh.icmph.code = user_icmph.code; /* ditto */
825 pfh.icmph.checksum = 0;
826 pfh.icmph.un.echo.id = inet->inet_sport;
827 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
828 pfh.msg = msg;
829 pfh.wcheck = 0;
830 pfh.family = AF_INET;
831
832 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
833 0, &ipc, &rt, msg->msg_flags);
834 if (err)
835 ip_flush_pending_frames(sk);
836 else
837 err = ping_v4_push_pending_frames(sk, &pfh, &fl4);
838 release_sock(sk);
839
840 out:
841 ip_rt_put(rt);
842 out_free:
843 if (free)
844 kfree(ipc.opt);
845 if (!err) {
846 icmp_out_count(sock_net(sk), user_icmph.type);
847 return len;
848 }
849 return err;
850
851 do_confirm:
852 if (msg->msg_flags & MSG_PROBE)
853 dst_confirm_neigh(&rt->dst, &fl4.daddr);
854 if (!(msg->msg_flags & MSG_PROBE) || len)
855 goto back_from_confirm;
856 err = 0;
857 goto out;
858 }
859
ping_recvmsg(struct sock * sk,struct msghdr * msg,size_t len,int noblock,int flags,int * addr_len)860 int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock,
861 int flags, int *addr_len)
862 {
863 struct inet_sock *isk = inet_sk(sk);
864 int family = sk->sk_family;
865 struct sk_buff *skb;
866 int copied, err;
867
868 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
869
870 err = -EOPNOTSUPP;
871 if (flags & MSG_OOB)
872 goto out;
873
874 if (flags & MSG_ERRQUEUE)
875 return inet_recv_error(sk, msg, len, addr_len);
876
877 skb = skb_recv_datagram(sk, flags, noblock, &err);
878 if (!skb)
879 goto out;
880
881 copied = skb->len;
882 if (copied > len) {
883 msg->msg_flags |= MSG_TRUNC;
884 copied = len;
885 }
886
887 /* Don't bother checking the checksum */
888 err = skb_copy_datagram_msg(skb, 0, msg, copied);
889 if (err)
890 goto done;
891
892 sock_recv_timestamp(msg, sk, skb);
893
894 /* Copy the address and add cmsg data. */
895 if (family == AF_INET) {
896 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
897
898 if (sin) {
899 sin->sin_family = AF_INET;
900 sin->sin_port = 0 /* skb->h.uh->source */;
901 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
902 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
903 *addr_len = sizeof(*sin);
904 }
905
906 if (isk->cmsg_flags)
907 ip_cmsg_recv(msg, skb);
908
909 #if IS_ENABLED(CONFIG_IPV6)
910 } else if (family == AF_INET6) {
911 struct ipv6_pinfo *np = inet6_sk(sk);
912 struct ipv6hdr *ip6 = ipv6_hdr(skb);
913 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
914
915 if (sin6) {
916 sin6->sin6_family = AF_INET6;
917 sin6->sin6_port = 0;
918 sin6->sin6_addr = ip6->saddr;
919 sin6->sin6_flowinfo = 0;
920 if (np->sndflow)
921 sin6->sin6_flowinfo = ip6_flowinfo(ip6);
922 sin6->sin6_scope_id =
923 ipv6_iface_scope_id(&sin6->sin6_addr,
924 inet6_iif(skb));
925 *addr_len = sizeof(*sin6);
926 }
927
928 if (inet6_sk(sk)->rxopt.all)
929 pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb);
930 if (skb->protocol == htons(ETH_P_IPV6) &&
931 inet6_sk(sk)->rxopt.all)
932 pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb);
933 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags)
934 ip_cmsg_recv(msg, skb);
935 #endif
936 } else {
937 BUG();
938 }
939
940 err = copied;
941
942 done:
943 skb_free_datagram(sk, skb);
944 out:
945 pr_debug("ping_recvmsg -> %d\n", err);
946 return err;
947 }
948 EXPORT_SYMBOL_GPL(ping_recvmsg);
949
ping_queue_rcv_skb(struct sock * sk,struct sk_buff * skb)950 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
951 {
952 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
953 inet_sk(sk), inet_sk(sk)->inet_num, skb);
954 if (sock_queue_rcv_skb(sk, skb) < 0) {
955 kfree_skb(skb);
956 pr_debug("ping_queue_rcv_skb -> failed\n");
957 return -1;
958 }
959 return 0;
960 }
961 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
962
963
964 /*
965 * All we need to do is get the socket.
966 */
967
ping_rcv(struct sk_buff * skb)968 bool ping_rcv(struct sk_buff *skb)
969 {
970 struct sock *sk;
971 struct net *net = dev_net(skb->dev);
972 struct icmphdr *icmph = icmp_hdr(skb);
973 bool rc = false;
974
975 /* We assume the packet has already been checked by icmp_rcv */
976
977 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
978 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
979
980 /* Push ICMP header back */
981 skb_push(skb, skb->data - (u8 *)icmph);
982
983 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
984 if (sk) {
985 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
986
987 pr_debug("rcv on socket %p\n", sk);
988 if (skb2 && !ping_queue_rcv_skb(sk, skb2))
989 rc = true;
990 sock_put(sk);
991 }
992
993 if (!rc)
994 pr_debug("no socket, dropping\n");
995
996 return rc;
997 }
998 EXPORT_SYMBOL_GPL(ping_rcv);
999
1000 struct proto ping_prot = {
1001 .name = "PING",
1002 .owner = THIS_MODULE,
1003 .init = ping_init_sock,
1004 .close = ping_close,
1005 .connect = ip4_datagram_connect,
1006 .disconnect = __udp_disconnect,
1007 .setsockopt = ip_setsockopt,
1008 .getsockopt = ip_getsockopt,
1009 .sendmsg = ping_v4_sendmsg,
1010 .recvmsg = ping_recvmsg,
1011 .bind = ping_bind,
1012 .backlog_rcv = ping_queue_rcv_skb,
1013 .release_cb = ip4_datagram_release_cb,
1014 .hash = ping_hash,
1015 .unhash = ping_unhash,
1016 .get_port = ping_get_port,
1017 .obj_size = sizeof(struct inet_sock),
1018 };
1019 EXPORT_SYMBOL(ping_prot);
1020
1021 #ifdef CONFIG_PROC_FS
1022
ping_get_first(struct seq_file * seq,int start)1023 static struct sock *ping_get_first(struct seq_file *seq, int start)
1024 {
1025 struct sock *sk;
1026 struct ping_iter_state *state = seq->private;
1027 struct net *net = seq_file_net(seq);
1028
1029 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
1030 ++state->bucket) {
1031 struct hlist_nulls_node *node;
1032 struct hlist_nulls_head *hslot;
1033
1034 hslot = &ping_table.hash[state->bucket];
1035
1036 if (hlist_nulls_empty(hslot))
1037 continue;
1038
1039 sk_nulls_for_each(sk, node, hslot) {
1040 if (net_eq(sock_net(sk), net) &&
1041 sk->sk_family == state->family)
1042 goto found;
1043 }
1044 }
1045 sk = NULL;
1046 found:
1047 return sk;
1048 }
1049
ping_get_next(struct seq_file * seq,struct sock * sk)1050 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
1051 {
1052 struct ping_iter_state *state = seq->private;
1053 struct net *net = seq_file_net(seq);
1054
1055 do {
1056 sk = sk_nulls_next(sk);
1057 } while (sk && (!net_eq(sock_net(sk), net)));
1058
1059 if (!sk)
1060 return ping_get_first(seq, state->bucket + 1);
1061 return sk;
1062 }
1063
ping_get_idx(struct seq_file * seq,loff_t pos)1064 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
1065 {
1066 struct sock *sk = ping_get_first(seq, 0);
1067
1068 if (sk)
1069 while (pos && (sk = ping_get_next(seq, sk)) != NULL)
1070 --pos;
1071 return pos ? NULL : sk;
1072 }
1073
ping_seq_start(struct seq_file * seq,loff_t * pos,sa_family_t family)1074 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
1075 __acquires(ping_table.lock)
1076 {
1077 struct ping_iter_state *state = seq->private;
1078 state->bucket = 0;
1079 state->family = family;
1080
1081 read_lock_bh(&ping_table.lock);
1082
1083 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1084 }
1085 EXPORT_SYMBOL_GPL(ping_seq_start);
1086
ping_v4_seq_start(struct seq_file * seq,loff_t * pos)1087 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos)
1088 {
1089 return ping_seq_start(seq, pos, AF_INET);
1090 }
1091
ping_seq_next(struct seq_file * seq,void * v,loff_t * pos)1092 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1093 {
1094 struct sock *sk;
1095
1096 if (v == SEQ_START_TOKEN)
1097 sk = ping_get_idx(seq, 0);
1098 else
1099 sk = ping_get_next(seq, v);
1100
1101 ++*pos;
1102 return sk;
1103 }
1104 EXPORT_SYMBOL_GPL(ping_seq_next);
1105
ping_seq_stop(struct seq_file * seq,void * v)1106 void ping_seq_stop(struct seq_file *seq, void *v)
1107 __releases(ping_table.lock)
1108 {
1109 read_unlock_bh(&ping_table.lock);
1110 }
1111 EXPORT_SYMBOL_GPL(ping_seq_stop);
1112
ping_v4_format_sock(struct sock * sp,struct seq_file * f,int bucket)1113 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f,
1114 int bucket)
1115 {
1116 struct inet_sock *inet = inet_sk(sp);
1117 __be32 dest = inet->inet_daddr;
1118 __be32 src = inet->inet_rcv_saddr;
1119 __u16 destp = ntohs(inet->inet_dport);
1120 __u16 srcp = ntohs(inet->inet_sport);
1121
1122 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
1123 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u",
1124 bucket, src, srcp, dest, destp, sp->sk_state,
1125 sk_wmem_alloc_get(sp),
1126 sk_rmem_alloc_get(sp),
1127 0, 0L, 0,
1128 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
1129 0, sock_i_ino(sp),
1130 refcount_read(&sp->sk_refcnt), sp,
1131 atomic_read(&sp->sk_drops));
1132 }
1133
ping_v4_seq_show(struct seq_file * seq,void * v)1134 static int ping_v4_seq_show(struct seq_file *seq, void *v)
1135 {
1136 seq_setwidth(seq, 127);
1137 if (v == SEQ_START_TOKEN)
1138 seq_puts(seq, " sl local_address rem_address st tx_queue "
1139 "rx_queue tr tm->when retrnsmt uid timeout "
1140 "inode ref pointer drops");
1141 else {
1142 struct ping_iter_state *state = seq->private;
1143
1144 ping_v4_format_sock(v, seq, state->bucket);
1145 }
1146 seq_pad(seq, '\n');
1147 return 0;
1148 }
1149
1150 static const struct seq_operations ping_v4_seq_ops = {
1151 .start = ping_v4_seq_start,
1152 .show = ping_v4_seq_show,
1153 .next = ping_seq_next,
1154 .stop = ping_seq_stop,
1155 };
1156
ping_v4_proc_init_net(struct net * net)1157 static int __net_init ping_v4_proc_init_net(struct net *net)
1158 {
1159 if (!proc_create_net("icmp", 0444, net->proc_net, &ping_v4_seq_ops,
1160 sizeof(struct ping_iter_state)))
1161 return -ENOMEM;
1162 return 0;
1163 }
1164
ping_v4_proc_exit_net(struct net * net)1165 static void __net_exit ping_v4_proc_exit_net(struct net *net)
1166 {
1167 remove_proc_entry("icmp", net->proc_net);
1168 }
1169
1170 static struct pernet_operations ping_v4_net_ops = {
1171 .init = ping_v4_proc_init_net,
1172 .exit = ping_v4_proc_exit_net,
1173 };
1174
ping_proc_init(void)1175 int __init ping_proc_init(void)
1176 {
1177 return register_pernet_subsys(&ping_v4_net_ops);
1178 }
1179
ping_proc_exit(void)1180 void ping_proc_exit(void)
1181 {
1182 unregister_pernet_subsys(&ping_v4_net_ops);
1183 }
1184
1185 #endif
1186
ping_init(void)1187 void __init ping_init(void)
1188 {
1189 int i;
1190
1191 for (i = 0; i < PING_HTABLE_SIZE; i++)
1192 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i);
1193 rwlock_init(&ping_table.lock);
1194 }
1195