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 struct net *net = sock_net(sk);
305 if (sk->sk_family == AF_INET) {
306 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
307 u32 tb_id = RT_TABLE_LOCAL;
308 int chk_addr_ret;
309
310 if (addr_len < sizeof(*addr))
311 return -EINVAL;
312
313 if (addr->sin_family != AF_INET &&
314 !(addr->sin_family == AF_UNSPEC &&
315 addr->sin_addr.s_addr == htonl(INADDR_ANY)))
316 return -EAFNOSUPPORT;
317
318 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",
319 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
320
321 tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id;
322 chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
323
324 if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
325 chk_addr_ret = RTN_LOCAL;
326
327 if ((!inet_can_nonlocal_bind(net, isk) &&
328 chk_addr_ret != RTN_LOCAL) ||
329 chk_addr_ret == RTN_MULTICAST ||
330 chk_addr_ret == RTN_BROADCAST)
331 return -EADDRNOTAVAIL;
332
333 #if IS_ENABLED(CONFIG_IPV6)
334 } else if (sk->sk_family == AF_INET6) {
335 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
336 int addr_type, scoped, has_addr;
337 struct net_device *dev = NULL;
338
339 if (addr_len < sizeof(*addr))
340 return -EINVAL;
341
342 if (addr->sin6_family != AF_INET6)
343 return -EAFNOSUPPORT;
344
345 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n",
346 sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port));
347
348 addr_type = ipv6_addr_type(&addr->sin6_addr);
349 scoped = __ipv6_addr_needs_scope_id(addr_type);
350 if ((addr_type != IPV6_ADDR_ANY &&
351 !(addr_type & IPV6_ADDR_UNICAST)) ||
352 (scoped && !addr->sin6_scope_id))
353 return -EINVAL;
354
355 rcu_read_lock();
356 if (addr->sin6_scope_id) {
357 dev = dev_get_by_index_rcu(net, addr->sin6_scope_id);
358 if (!dev) {
359 rcu_read_unlock();
360 return -ENODEV;
361 }
362 }
363
364 if (!dev && sk->sk_bound_dev_if) {
365 dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if);
366 if (!dev) {
367 rcu_read_unlock();
368 return -ENODEV;
369 }
370 }
371 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev,
372 scoped);
373 rcu_read_unlock();
374
375 if (!(ipv6_can_nonlocal_bind(net, isk) || has_addr ||
376 addr_type == IPV6_ADDR_ANY))
377 return -EADDRNOTAVAIL;
378
379 if (scoped)
380 sk->sk_bound_dev_if = addr->sin6_scope_id;
381 #endif
382 } else {
383 return -EAFNOSUPPORT;
384 }
385 return 0;
386 }
387
ping_set_saddr(struct sock * sk,struct sockaddr * saddr)388 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr)
389 {
390 if (saddr->sa_family == AF_INET) {
391 struct inet_sock *isk = inet_sk(sk);
392 struct sockaddr_in *addr = (struct sockaddr_in *) saddr;
393 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
394 #if IS_ENABLED(CONFIG_IPV6)
395 } else if (saddr->sa_family == AF_INET6) {
396 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr;
397 struct ipv6_pinfo *np = inet6_sk(sk);
398 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr;
399 #endif
400 }
401 }
402
ping_clear_saddr(struct sock * sk,int dif)403 static void ping_clear_saddr(struct sock *sk, int dif)
404 {
405 sk->sk_bound_dev_if = dif;
406 if (sk->sk_family == AF_INET) {
407 struct inet_sock *isk = inet_sk(sk);
408 isk->inet_rcv_saddr = isk->inet_saddr = 0;
409 #if IS_ENABLED(CONFIG_IPV6)
410 } else if (sk->sk_family == AF_INET6) {
411 struct ipv6_pinfo *np = inet6_sk(sk);
412 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
413 memset(&np->saddr, 0, sizeof(np->saddr));
414 #endif
415 }
416 }
417 /*
418 * We need our own bind because there are no privileged id's == local ports.
419 * Moreover, we don't allow binding to multi- and broadcast addresses.
420 */
421
ping_bind(struct sock * sk,struct sockaddr * uaddr,int addr_len)422 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
423 {
424 struct inet_sock *isk = inet_sk(sk);
425 unsigned short snum;
426 int err;
427 int dif = sk->sk_bound_dev_if;
428
429 err = ping_check_bind_addr(sk, isk, uaddr, addr_len);
430 if (err)
431 return err;
432
433 lock_sock(sk);
434
435 err = -EINVAL;
436 if (isk->inet_num != 0)
437 goto out;
438
439 err = -EADDRINUSE;
440 ping_set_saddr(sk, uaddr);
441 snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port);
442 if (ping_get_port(sk, snum) != 0) {
443 ping_clear_saddr(sk, dif);
444 goto out;
445 }
446
447 pr_debug("after bind(): num = %hu, dif = %d\n",
448 isk->inet_num,
449 sk->sk_bound_dev_if);
450
451 err = 0;
452 if (sk->sk_family == AF_INET && isk->inet_rcv_saddr)
453 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
454 #if IS_ENABLED(CONFIG_IPV6)
455 if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr))
456 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
457 #endif
458
459 if (snum)
460 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
461 isk->inet_sport = htons(isk->inet_num);
462 isk->inet_daddr = 0;
463 isk->inet_dport = 0;
464
465 #if IS_ENABLED(CONFIG_IPV6)
466 if (sk->sk_family == AF_INET6)
467 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr));
468 #endif
469
470 sk_dst_reset(sk);
471 out:
472 release_sock(sk);
473 pr_debug("ping_v4_bind -> %d\n", err);
474 return err;
475 }
476 EXPORT_SYMBOL_GPL(ping_bind);
477
478 /*
479 * Is this a supported type of ICMP message?
480 */
481
ping_supported(int family,int type,int code)482 static inline int ping_supported(int family, int type, int code)
483 {
484 return (family == AF_INET && type == ICMP_ECHO && code == 0) ||
485 (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0);
486 }
487
488 /*
489 * This routine is called by the ICMP module when it gets some
490 * sort of error condition.
491 */
492
ping_err(struct sk_buff * skb,int offset,u32 info)493 void ping_err(struct sk_buff *skb, int offset, u32 info)
494 {
495 int family;
496 struct icmphdr *icmph;
497 struct inet_sock *inet_sock;
498 int type;
499 int code;
500 struct net *net = dev_net(skb->dev);
501 struct sock *sk;
502 int harderr;
503 int err;
504
505 if (skb->protocol == htons(ETH_P_IP)) {
506 family = AF_INET;
507 type = icmp_hdr(skb)->type;
508 code = icmp_hdr(skb)->code;
509 icmph = (struct icmphdr *)(skb->data + offset);
510 } else if (skb->protocol == htons(ETH_P_IPV6)) {
511 family = AF_INET6;
512 type = icmp6_hdr(skb)->icmp6_type;
513 code = icmp6_hdr(skb)->icmp6_code;
514 icmph = (struct icmphdr *) (skb->data + offset);
515 } else {
516 BUG();
517 }
518
519 /* We assume the packet has already been checked by icmp_unreach */
520
521 if (!ping_supported(family, icmph->type, icmph->code))
522 return;
523
524 pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n",
525 skb->protocol, type, code, ntohs(icmph->un.echo.id),
526 ntohs(icmph->un.echo.sequence));
527
528 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
529 if (!sk) {
530 pr_debug("no socket, dropping\n");
531 return; /* No socket for error */
532 }
533 pr_debug("err on socket %p\n", sk);
534
535 err = 0;
536 harderr = 0;
537 inet_sock = inet_sk(sk);
538
539 if (skb->protocol == htons(ETH_P_IP)) {
540 switch (type) {
541 default:
542 case ICMP_TIME_EXCEEDED:
543 err = EHOSTUNREACH;
544 break;
545 case ICMP_SOURCE_QUENCH:
546 /* This is not a real error but ping wants to see it.
547 * Report it with some fake errno.
548 */
549 err = EREMOTEIO;
550 break;
551 case ICMP_PARAMETERPROB:
552 err = EPROTO;
553 harderr = 1;
554 break;
555 case ICMP_DEST_UNREACH:
556 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
557 ipv4_sk_update_pmtu(skb, sk, info);
558 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) {
559 err = EMSGSIZE;
560 harderr = 1;
561 break;
562 }
563 goto out;
564 }
565 err = EHOSTUNREACH;
566 if (code <= NR_ICMP_UNREACH) {
567 harderr = icmp_err_convert[code].fatal;
568 err = icmp_err_convert[code].errno;
569 }
570 break;
571 case ICMP_REDIRECT:
572 /* See ICMP_SOURCE_QUENCH */
573 ipv4_sk_redirect(skb, sk);
574 err = EREMOTEIO;
575 break;
576 }
577 #if IS_ENABLED(CONFIG_IPV6)
578 } else if (skb->protocol == htons(ETH_P_IPV6)) {
579 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err);
580 #endif
581 }
582
583 /*
584 * RFC1122: OK. Passes ICMP errors back to application, as per
585 * 4.1.3.3.
586 */
587 if ((family == AF_INET && !inet_sock->recverr) ||
588 (family == AF_INET6 && !inet6_sk(sk)->recverr)) {
589 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
590 goto out;
591 } else {
592 if (family == AF_INET) {
593 ip_icmp_error(sk, skb, err, 0 /* no remote port */,
594 info, (u8 *)icmph);
595 #if IS_ENABLED(CONFIG_IPV6)
596 } else if (family == AF_INET6) {
597 pingv6_ops.ipv6_icmp_error(sk, skb, err, 0,
598 info, (u8 *)icmph);
599 #endif
600 }
601 }
602 sk->sk_err = err;
603 sk->sk_error_report(sk);
604 out:
605 sock_put(sk);
606 }
607 EXPORT_SYMBOL_GPL(ping_err);
608
609 /*
610 * Copy and checksum an ICMP Echo packet from user space into a buffer
611 * starting from the payload.
612 */
613
ping_getfrag(void * from,char * to,int offset,int fraglen,int odd,struct sk_buff * skb)614 int ping_getfrag(void *from, char *to,
615 int offset, int fraglen, int odd, struct sk_buff *skb)
616 {
617 struct pingfakehdr *pfh = (struct pingfakehdr *)from;
618
619 if (offset == 0) {
620 fraglen -= sizeof(struct icmphdr);
621 if (fraglen < 0)
622 BUG();
623 if (!csum_and_copy_from_iter_full(to + sizeof(struct icmphdr),
624 fraglen, &pfh->wcheck,
625 &pfh->msg->msg_iter))
626 return -EFAULT;
627 } else if (offset < sizeof(struct icmphdr)) {
628 BUG();
629 } else {
630 if (!csum_and_copy_from_iter_full(to, fraglen, &pfh->wcheck,
631 &pfh->msg->msg_iter))
632 return -EFAULT;
633 }
634
635 #if IS_ENABLED(CONFIG_IPV6)
636 /* For IPv6, checksum each skb as we go along, as expected by
637 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in
638 * wcheck, it will be finalized in ping_v4_push_pending_frames.
639 */
640 if (pfh->family == AF_INET6) {
641 skb->csum = pfh->wcheck;
642 skb->ip_summed = CHECKSUM_NONE;
643 pfh->wcheck = 0;
644 }
645 #endif
646
647 return 0;
648 }
649 EXPORT_SYMBOL_GPL(ping_getfrag);
650
ping_v4_push_pending_frames(struct sock * sk,struct pingfakehdr * pfh,struct flowi4 * fl4)651 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
652 struct flowi4 *fl4)
653 {
654 struct sk_buff *skb = skb_peek(&sk->sk_write_queue);
655
656 if (!skb)
657 return 0;
658 pfh->wcheck = csum_partial((char *)&pfh->icmph,
659 sizeof(struct icmphdr), pfh->wcheck);
660 pfh->icmph.checksum = csum_fold(pfh->wcheck);
661 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
662 skb->ip_summed = CHECKSUM_NONE;
663 return ip_push_pending_frames(sk, fl4);
664 }
665
ping_common_sendmsg(int family,struct msghdr * msg,size_t len,void * user_icmph,size_t icmph_len)666 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
667 void *user_icmph, size_t icmph_len) {
668 u8 type, code;
669
670 if (len > 0xFFFF)
671 return -EMSGSIZE;
672
673 /* Must have at least a full ICMP header. */
674 if (len < icmph_len)
675 return -EINVAL;
676
677 /*
678 * Check the flags.
679 */
680
681 /* Mirror BSD error message compatibility */
682 if (msg->msg_flags & MSG_OOB)
683 return -EOPNOTSUPP;
684
685 /*
686 * Fetch the ICMP header provided by the userland.
687 * iovec is modified! The ICMP header is consumed.
688 */
689 if (memcpy_from_msg(user_icmph, msg, icmph_len))
690 return -EFAULT;
691
692 if (family == AF_INET) {
693 type = ((struct icmphdr *) user_icmph)->type;
694 code = ((struct icmphdr *) user_icmph)->code;
695 #if IS_ENABLED(CONFIG_IPV6)
696 } else if (family == AF_INET6) {
697 type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
698 code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
699 #endif
700 } else {
701 BUG();
702 }
703
704 if (!ping_supported(family, type, code))
705 return -EINVAL;
706
707 return 0;
708 }
709 EXPORT_SYMBOL_GPL(ping_common_sendmsg);
710
ping_v4_sendmsg(struct sock * sk,struct msghdr * msg,size_t len)711 static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
712 {
713 struct net *net = sock_net(sk);
714 struct flowi4 fl4;
715 struct inet_sock *inet = inet_sk(sk);
716 struct ipcm_cookie ipc;
717 struct icmphdr user_icmph;
718 struct pingfakehdr pfh;
719 struct rtable *rt = NULL;
720 struct ip_options_data opt_copy;
721 int free = 0;
722 __be32 saddr, daddr, faddr;
723 u8 tos;
724 int err;
725
726 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
727
728 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
729 sizeof(user_icmph));
730 if (err)
731 return err;
732
733 /*
734 * Get and verify the address.
735 */
736
737 if (msg->msg_name) {
738 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
739 if (msg->msg_namelen < sizeof(*usin))
740 return -EINVAL;
741 if (usin->sin_family != AF_INET)
742 return -EAFNOSUPPORT;
743 daddr = usin->sin_addr.s_addr;
744 /* no remote port */
745 } else {
746 if (sk->sk_state != TCP_ESTABLISHED)
747 return -EDESTADDRREQ;
748 daddr = inet->inet_daddr;
749 /* no remote port */
750 }
751
752 ipcm_init_sk(&ipc, inet);
753
754 if (msg->msg_controllen) {
755 err = ip_cmsg_send(sk, msg, &ipc, false);
756 if (unlikely(err)) {
757 kfree(ipc.opt);
758 return err;
759 }
760 if (ipc.opt)
761 free = 1;
762 }
763 if (!ipc.opt) {
764 struct ip_options_rcu *inet_opt;
765
766 rcu_read_lock();
767 inet_opt = rcu_dereference(inet->inet_opt);
768 if (inet_opt) {
769 memcpy(&opt_copy, inet_opt,
770 sizeof(*inet_opt) + inet_opt->opt.optlen);
771 ipc.opt = &opt_copy.opt;
772 }
773 rcu_read_unlock();
774 }
775
776 saddr = ipc.addr;
777 ipc.addr = faddr = daddr;
778
779 if (ipc.opt && ipc.opt->opt.srr) {
780 if (!daddr) {
781 err = -EINVAL;
782 goto out_free;
783 }
784 faddr = ipc.opt->opt.faddr;
785 }
786 tos = get_rttos(&ipc, inet);
787 if (sock_flag(sk, SOCK_LOCALROUTE) ||
788 (msg->msg_flags & MSG_DONTROUTE) ||
789 (ipc.opt && ipc.opt->opt.is_strictroute)) {
790 tos |= RTO_ONLINK;
791 }
792
793 if (ipv4_is_multicast(daddr)) {
794 if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif))
795 ipc.oif = inet->mc_index;
796 if (!saddr)
797 saddr = inet->mc_addr;
798 } else if (!ipc.oif)
799 ipc.oif = inet->uc_index;
800
801 flowi4_init_output(&fl4, ipc.oif, ipc.sockc.mark, tos,
802 RT_SCOPE_UNIVERSE, sk->sk_protocol,
803 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0,
804 sk->sk_uid);
805
806 fl4.fl4_icmp_type = user_icmph.type;
807 fl4.fl4_icmp_code = user_icmph.code;
808
809 security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
810 rt = ip_route_output_flow(net, &fl4, sk);
811 if (IS_ERR(rt)) {
812 err = PTR_ERR(rt);
813 rt = NULL;
814 if (err == -ENETUNREACH)
815 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
816 goto out;
817 }
818
819 err = -EACCES;
820 if ((rt->rt_flags & RTCF_BROADCAST) &&
821 !sock_flag(sk, SOCK_BROADCAST))
822 goto out;
823
824 if (msg->msg_flags & MSG_CONFIRM)
825 goto do_confirm;
826 back_from_confirm:
827
828 if (!ipc.addr)
829 ipc.addr = fl4.daddr;
830
831 lock_sock(sk);
832
833 pfh.icmph.type = user_icmph.type; /* already checked */
834 pfh.icmph.code = user_icmph.code; /* ditto */
835 pfh.icmph.checksum = 0;
836 pfh.icmph.un.echo.id = inet->inet_sport;
837 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
838 pfh.msg = msg;
839 pfh.wcheck = 0;
840 pfh.family = AF_INET;
841
842 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
843 0, &ipc, &rt, msg->msg_flags);
844 if (err)
845 ip_flush_pending_frames(sk);
846 else
847 err = ping_v4_push_pending_frames(sk, &pfh, &fl4);
848 release_sock(sk);
849
850 out:
851 ip_rt_put(rt);
852 out_free:
853 if (free)
854 kfree(ipc.opt);
855 if (!err) {
856 icmp_out_count(sock_net(sk), user_icmph.type);
857 return len;
858 }
859 return err;
860
861 do_confirm:
862 if (msg->msg_flags & MSG_PROBE)
863 dst_confirm_neigh(&rt->dst, &fl4.daddr);
864 if (!(msg->msg_flags & MSG_PROBE) || len)
865 goto back_from_confirm;
866 err = 0;
867 goto out;
868 }
869
ping_recvmsg(struct sock * sk,struct msghdr * msg,size_t len,int noblock,int flags,int * addr_len)870 int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock,
871 int flags, int *addr_len)
872 {
873 struct inet_sock *isk = inet_sk(sk);
874 int family = sk->sk_family;
875 struct sk_buff *skb;
876 int copied, err;
877
878 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
879
880 err = -EOPNOTSUPP;
881 if (flags & MSG_OOB)
882 goto out;
883
884 if (flags & MSG_ERRQUEUE)
885 return inet_recv_error(sk, msg, len, addr_len);
886
887 skb = skb_recv_datagram(sk, flags, noblock, &err);
888 if (!skb)
889 goto out;
890
891 copied = skb->len;
892 if (copied > len) {
893 msg->msg_flags |= MSG_TRUNC;
894 copied = len;
895 }
896
897 /* Don't bother checking the checksum */
898 err = skb_copy_datagram_msg(skb, 0, msg, copied);
899 if (err)
900 goto done;
901
902 sock_recv_timestamp(msg, sk, skb);
903
904 /* Copy the address and add cmsg data. */
905 if (family == AF_INET) {
906 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
907
908 if (sin) {
909 sin->sin_family = AF_INET;
910 sin->sin_port = 0 /* skb->h.uh->source */;
911 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
912 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
913 *addr_len = sizeof(*sin);
914 }
915
916 if (isk->cmsg_flags)
917 ip_cmsg_recv(msg, skb);
918
919 #if IS_ENABLED(CONFIG_IPV6)
920 } else if (family == AF_INET6) {
921 struct ipv6_pinfo *np = inet6_sk(sk);
922 struct ipv6hdr *ip6 = ipv6_hdr(skb);
923 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
924
925 if (sin6) {
926 sin6->sin6_family = AF_INET6;
927 sin6->sin6_port = 0;
928 sin6->sin6_addr = ip6->saddr;
929 sin6->sin6_flowinfo = 0;
930 if (np->sndflow)
931 sin6->sin6_flowinfo = ip6_flowinfo(ip6);
932 sin6->sin6_scope_id =
933 ipv6_iface_scope_id(&sin6->sin6_addr,
934 inet6_iif(skb));
935 *addr_len = sizeof(*sin6);
936 }
937
938 if (inet6_sk(sk)->rxopt.all)
939 pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb);
940 if (skb->protocol == htons(ETH_P_IPV6) &&
941 inet6_sk(sk)->rxopt.all)
942 pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb);
943 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags)
944 ip_cmsg_recv(msg, skb);
945 #endif
946 } else {
947 BUG();
948 }
949
950 err = copied;
951
952 done:
953 skb_free_datagram(sk, skb);
954 out:
955 pr_debug("ping_recvmsg -> %d\n", err);
956 return err;
957 }
958 EXPORT_SYMBOL_GPL(ping_recvmsg);
959
ping_queue_rcv_skb(struct sock * sk,struct sk_buff * skb)960 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
961 {
962 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
963 inet_sk(sk), inet_sk(sk)->inet_num, skb);
964 if (sock_queue_rcv_skb(sk, skb) < 0) {
965 kfree_skb(skb);
966 pr_debug("ping_queue_rcv_skb -> failed\n");
967 return -1;
968 }
969 return 0;
970 }
971 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
972
973
974 /*
975 * All we need to do is get the socket.
976 */
977
ping_rcv(struct sk_buff * skb)978 bool ping_rcv(struct sk_buff *skb)
979 {
980 struct sock *sk;
981 struct net *net = dev_net(skb->dev);
982 struct icmphdr *icmph = icmp_hdr(skb);
983 bool rc = false;
984
985 /* We assume the packet has already been checked by icmp_rcv */
986
987 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
988 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
989
990 /* Push ICMP header back */
991 skb_push(skb, skb->data - (u8 *)icmph);
992
993 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
994 if (sk) {
995 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
996
997 pr_debug("rcv on socket %p\n", sk);
998 if (skb2 && !ping_queue_rcv_skb(sk, skb2))
999 rc = true;
1000 sock_put(sk);
1001 }
1002
1003 if (!rc)
1004 pr_debug("no socket, dropping\n");
1005
1006 return rc;
1007 }
1008 EXPORT_SYMBOL_GPL(ping_rcv);
1009
1010 struct proto ping_prot = {
1011 .name = "PING",
1012 .owner = THIS_MODULE,
1013 .init = ping_init_sock,
1014 .close = ping_close,
1015 .connect = ip4_datagram_connect,
1016 .disconnect = __udp_disconnect,
1017 .setsockopt = ip_setsockopt,
1018 .getsockopt = ip_getsockopt,
1019 .sendmsg = ping_v4_sendmsg,
1020 .recvmsg = ping_recvmsg,
1021 .bind = ping_bind,
1022 .backlog_rcv = ping_queue_rcv_skb,
1023 .release_cb = ip4_datagram_release_cb,
1024 .hash = ping_hash,
1025 .unhash = ping_unhash,
1026 .get_port = ping_get_port,
1027 .obj_size = sizeof(struct inet_sock),
1028 };
1029 EXPORT_SYMBOL(ping_prot);
1030
1031 #ifdef CONFIG_PROC_FS
1032
ping_get_first(struct seq_file * seq,int start)1033 static struct sock *ping_get_first(struct seq_file *seq, int start)
1034 {
1035 struct sock *sk;
1036 struct ping_iter_state *state = seq->private;
1037 struct net *net = seq_file_net(seq);
1038
1039 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
1040 ++state->bucket) {
1041 struct hlist_nulls_node *node;
1042 struct hlist_nulls_head *hslot;
1043
1044 hslot = &ping_table.hash[state->bucket];
1045
1046 if (hlist_nulls_empty(hslot))
1047 continue;
1048
1049 sk_nulls_for_each(sk, node, hslot) {
1050 if (net_eq(sock_net(sk), net) &&
1051 sk->sk_family == state->family)
1052 goto found;
1053 }
1054 }
1055 sk = NULL;
1056 found:
1057 return sk;
1058 }
1059
ping_get_next(struct seq_file * seq,struct sock * sk)1060 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
1061 {
1062 struct ping_iter_state *state = seq->private;
1063 struct net *net = seq_file_net(seq);
1064
1065 do {
1066 sk = sk_nulls_next(sk);
1067 } while (sk && (!net_eq(sock_net(sk), net)));
1068
1069 if (!sk)
1070 return ping_get_first(seq, state->bucket + 1);
1071 return sk;
1072 }
1073
ping_get_idx(struct seq_file * seq,loff_t pos)1074 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
1075 {
1076 struct sock *sk = ping_get_first(seq, 0);
1077
1078 if (sk)
1079 while (pos && (sk = ping_get_next(seq, sk)) != NULL)
1080 --pos;
1081 return pos ? NULL : sk;
1082 }
1083
ping_seq_start(struct seq_file * seq,loff_t * pos,sa_family_t family)1084 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
1085 __acquires(ping_table.lock)
1086 {
1087 struct ping_iter_state *state = seq->private;
1088 state->bucket = 0;
1089 state->family = family;
1090
1091 read_lock_bh(&ping_table.lock);
1092
1093 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1094 }
1095 EXPORT_SYMBOL_GPL(ping_seq_start);
1096
ping_v4_seq_start(struct seq_file * seq,loff_t * pos)1097 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos)
1098 {
1099 return ping_seq_start(seq, pos, AF_INET);
1100 }
1101
ping_seq_next(struct seq_file * seq,void * v,loff_t * pos)1102 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1103 {
1104 struct sock *sk;
1105
1106 if (v == SEQ_START_TOKEN)
1107 sk = ping_get_idx(seq, 0);
1108 else
1109 sk = ping_get_next(seq, v);
1110
1111 ++*pos;
1112 return sk;
1113 }
1114 EXPORT_SYMBOL_GPL(ping_seq_next);
1115
ping_seq_stop(struct seq_file * seq,void * v)1116 void ping_seq_stop(struct seq_file *seq, void *v)
1117 __releases(ping_table.lock)
1118 {
1119 read_unlock_bh(&ping_table.lock);
1120 }
1121 EXPORT_SYMBOL_GPL(ping_seq_stop);
1122
ping_v4_format_sock(struct sock * sp,struct seq_file * f,int bucket)1123 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f,
1124 int bucket)
1125 {
1126 struct inet_sock *inet = inet_sk(sp);
1127 __be32 dest = inet->inet_daddr;
1128 __be32 src = inet->inet_rcv_saddr;
1129 __u16 destp = ntohs(inet->inet_dport);
1130 __u16 srcp = ntohs(inet->inet_sport);
1131
1132 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
1133 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u",
1134 bucket, src, srcp, dest, destp, sp->sk_state,
1135 sk_wmem_alloc_get(sp),
1136 sk_rmem_alloc_get(sp),
1137 0, 0L, 0,
1138 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
1139 0, sock_i_ino(sp),
1140 refcount_read(&sp->sk_refcnt), sp,
1141 atomic_read(&sp->sk_drops));
1142 }
1143
ping_v4_seq_show(struct seq_file * seq,void * v)1144 static int ping_v4_seq_show(struct seq_file *seq, void *v)
1145 {
1146 seq_setwidth(seq, 127);
1147 if (v == SEQ_START_TOKEN)
1148 seq_puts(seq, " sl local_address rem_address st tx_queue "
1149 "rx_queue tr tm->when retrnsmt uid timeout "
1150 "inode ref pointer drops");
1151 else {
1152 struct ping_iter_state *state = seq->private;
1153
1154 ping_v4_format_sock(v, seq, state->bucket);
1155 }
1156 seq_pad(seq, '\n');
1157 return 0;
1158 }
1159
1160 static const struct seq_operations ping_v4_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
ping_v4_proc_init_net(struct net * net)1167 static int __net_init ping_v4_proc_init_net(struct net *net)
1168 {
1169 if (!proc_create_net("icmp", 0444, net->proc_net, &ping_v4_seq_ops,
1170 sizeof(struct ping_iter_state)))
1171 return -ENOMEM;
1172 return 0;
1173 }
1174
ping_v4_proc_exit_net(struct net * net)1175 static void __net_exit ping_v4_proc_exit_net(struct net *net)
1176 {
1177 remove_proc_entry("icmp", net->proc_net);
1178 }
1179
1180 static struct pernet_operations ping_v4_net_ops = {
1181 .init = ping_v4_proc_init_net,
1182 .exit = ping_v4_proc_exit_net,
1183 };
1184
ping_proc_init(void)1185 int __init ping_proc_init(void)
1186 {
1187 return register_pernet_subsys(&ping_v4_net_ops);
1188 }
1189
ping_proc_exit(void)1190 void ping_proc_exit(void)
1191 {
1192 unregister_pernet_subsys(&ping_v4_net_ops);
1193 }
1194
1195 #endif
1196
ping_init(void)1197 void __init ping_init(void)
1198 {
1199 int i;
1200
1201 for (i = 0; i < PING_HTABLE_SIZE; i++)
1202 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i);
1203 rwlock_init(&ping_table.lock);
1204 }
1205