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 <linux/bpf-cgroup.h>
37#include <net/sock.h>
38#include <net/ping.h>
39#include <net/udp.h>
40#include <net/route.h>
41#include <net/inet_common.h>
42#include <net/checksum.h>
43
44#if IS_ENABLED(CONFIG_IPV6)
45#include <linux/in6.h>
46#include <linux/icmpv6.h>
47#include <net/addrconf.h>
48#include <net/ipv6.h>
49#include <net/transp_v6.h>
50#endif
51
52struct ping_table {
53 struct hlist_head hash[PING_HTABLE_SIZE];
54 spinlock_t lock;
55};
56
57static struct ping_table ping_table;
58struct pingv6_ops pingv6_ops;
59EXPORT_SYMBOL_GPL(pingv6_ops);
60
61static u16 ping_port_rover;
62
63static inline u32 ping_hashfn(const struct net *net, u32 num, u32 mask)
64{
65 u32 res = (num + net_hash_mix(net)) & mask;
66
67 pr_debug("hash(%u) = %u\n", num, res);
68 return res;
69}
70EXPORT_SYMBOL_GPL(ping_hash);
71
72static inline struct hlist_head *ping_hashslot(struct ping_table *table,
73 struct net *net, unsigned int num)
74{
75 return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)];
76}
77
78int ping_get_port(struct sock *sk, unsigned short ident)
79{
80 struct inet_sock *isk, *isk2;
81 struct hlist_head *hlist;
82 struct sock *sk2 = NULL;
83
84 isk = inet_sk(sk);
85 spin_lock(lock: &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(table: &ping_table, net: sock_net(sk),
94 num: result);
95 sk_for_each(sk2, 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;
105next_port:
106 ;
107 }
108 if (i >= (1L << 16))
109 goto fail;
110 } else {
111 hlist = ping_hashslot(table: &ping_table, net: sock_net(sk), num: ident);
112 sk_for_each(sk2, 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 sk_add_node_rcu(sk, list: hlist);
131 sock_set_flag(sk, flag: SOCK_RCU_FREE);
132 sock_prot_inuse_add(net: sock_net(sk), prot: sk->sk_prot, val: 1);
133 }
134 spin_unlock(lock: &ping_table.lock);
135 return 0;
136
137fail:
138 spin_unlock(lock: &ping_table.lock);
139 return -EADDRINUSE;
140}
141EXPORT_SYMBOL_GPL(ping_get_port);
142
143int 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
151void 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 spin_lock(lock: &ping_table.lock);
157 if (sk_del_node_init_rcu(sk)) {
158 isk->inet_num = 0;
159 isk->inet_sport = 0;
160 sock_prot_inuse_add(net: sock_net(sk), prot: sk->sk_prot, val: -1);
161 }
162 spin_unlock(lock: &ping_table.lock);
163}
164EXPORT_SYMBOL_GPL(ping_unhash);
165
166/* Called under rcu_read_lock() */
167static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
168{
169 struct hlist_head *hslot = ping_hashslot(table: &ping_table, net, num: ident);
170 struct sock *sk = NULL;
171 struct inet_sock *isk;
172 int dif, sdif;
173
174 if (skb->protocol == htons(ETH_P_IP)) {
175 dif = inet_iif(skb);
176 sdif = inet_sdif(skb);
177 pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n",
178 (int)ident, &ip_hdr(skb)->daddr, dif);
179#if IS_ENABLED(CONFIG_IPV6)
180 } else if (skb->protocol == htons(ETH_P_IPV6)) {
181 dif = inet6_iif(skb);
182 sdif = inet6_sdif(skb);
183 pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n",
184 (int)ident, &ipv6_hdr(skb)->daddr, dif);
185#endif
186 } else {
187 return NULL;
188 }
189
190 sk_for_each_rcu(sk, 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(a: &sk->sk_v6_rcv_saddr) &&
216 !ipv6_addr_equal(a1: &sk->sk_v6_rcv_saddr,
217 a2: &ipv6_hdr(skb)->daddr))
218 continue;
219#endif
220 } else {
221 continue;
222 }
223
224 if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif &&
225 sk->sk_bound_dev_if != sdif)
226 continue;
227
228 goto exit;
229 }
230
231 sk = NULL;
232exit:
233
234 return sk;
235}
236
237static void inet_get_ping_group_range_net(struct net *net, kgid_t *low,
238 kgid_t *high)
239{
240 kgid_t *data = net->ipv4.ping_group_range.range;
241 unsigned int seq;
242
243 do {
244 seq = read_seqbegin(sl: &net->ipv4.ping_group_range.lock);
245
246 *low = data[0];
247 *high = data[1];
248 } while (read_seqretry(sl: &net->ipv4.ping_group_range.lock, start: seq));
249}
250
251
252int ping_init_sock(struct sock *sk)
253{
254 struct net *net = sock_net(sk);
255 kgid_t group = current_egid();
256 struct group_info *group_info;
257 int i;
258 kgid_t low, high;
259 int ret = 0;
260
261 if (sk->sk_family == AF_INET6)
262 sk->sk_ipv6only = 1;
263
264 inet_get_ping_group_range_net(net, low: &low, high: &high);
265 if (gid_lte(left: low, right: group) && gid_lte(left: group, right: high))
266 return 0;
267
268 group_info = get_current_groups();
269 for (i = 0; i < group_info->ngroups; i++) {
270 kgid_t gid = group_info->gid[i];
271
272 if (gid_lte(left: low, right: gid) && gid_lte(left: gid, right: high))
273 goto out_release_group;
274 }
275
276 ret = -EACCES;
277
278out_release_group:
279 put_group_info(group_info);
280 return ret;
281}
282EXPORT_SYMBOL_GPL(ping_init_sock);
283
284void ping_close(struct sock *sk, long timeout)
285{
286 pr_debug("ping_close(sk=%p,sk->num=%u)\n",
287 inet_sk(sk), inet_sk(sk)->inet_num);
288 pr_debug("isk->refcnt = %d\n", refcount_read(&sk->sk_refcnt));
289
290 sk_common_release(sk);
291}
292EXPORT_SYMBOL_GPL(ping_close);
293
294static int ping_pre_connect(struct sock *sk, struct sockaddr *uaddr,
295 int addr_len)
296{
297 /* This check is replicated from __ip4_datagram_connect() and
298 * intended to prevent BPF program called below from accessing bytes
299 * that are out of the bound specified by user in addr_len.
300 */
301 if (addr_len < sizeof(struct sockaddr_in))
302 return -EINVAL;
303
304 return BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr, &addr_len);
305}
306
307/* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */
308static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
309 struct sockaddr *uaddr, int addr_len)
310{
311 struct net *net = sock_net(sk);
312 if (sk->sk_family == AF_INET) {
313 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
314 u32 tb_id = RT_TABLE_LOCAL;
315 int chk_addr_ret;
316
317 if (addr_len < sizeof(*addr))
318 return -EINVAL;
319
320 if (addr->sin_family != AF_INET &&
321 !(addr->sin_family == AF_UNSPEC &&
322 addr->sin_addr.s_addr == htonl(INADDR_ANY)))
323 return -EAFNOSUPPORT;
324
325 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",
326 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
327
328 if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
329 return 0;
330
331 tb_id = l3mdev_fib_table_by_index(net, ifindex: sk->sk_bound_dev_if) ? : tb_id;
332 chk_addr_ret = inet_addr_type_table(net, addr: addr->sin_addr.s_addr, tb_id);
333
334 if (chk_addr_ret == RTN_MULTICAST ||
335 chk_addr_ret == RTN_BROADCAST ||
336 (chk_addr_ret != RTN_LOCAL &&
337 !inet_can_nonlocal_bind(net, inet: isk)))
338 return -EADDRNOTAVAIL;
339
340#if IS_ENABLED(CONFIG_IPV6)
341 } else if (sk->sk_family == AF_INET6) {
342 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
343 int addr_type, scoped, has_addr;
344 struct net_device *dev = NULL;
345
346 if (addr_len < sizeof(*addr))
347 return -EINVAL;
348
349 if (addr->sin6_family != AF_INET6)
350 return -EAFNOSUPPORT;
351
352 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n",
353 sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port));
354
355 addr_type = ipv6_addr_type(addr: &addr->sin6_addr);
356 scoped = __ipv6_addr_needs_scope_id(type: addr_type);
357 if ((addr_type != IPV6_ADDR_ANY &&
358 !(addr_type & IPV6_ADDR_UNICAST)) ||
359 (scoped && !addr->sin6_scope_id))
360 return -EINVAL;
361
362 rcu_read_lock();
363 if (addr->sin6_scope_id) {
364 dev = dev_get_by_index_rcu(net, ifindex: addr->sin6_scope_id);
365 if (!dev) {
366 rcu_read_unlock();
367 return -ENODEV;
368 }
369 }
370
371 if (!dev && sk->sk_bound_dev_if) {
372 dev = dev_get_by_index_rcu(net, ifindex: sk->sk_bound_dev_if);
373 if (!dev) {
374 rcu_read_unlock();
375 return -ENODEV;
376 }
377 }
378 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev,
379 scoped);
380 rcu_read_unlock();
381
382 if (!(ipv6_can_nonlocal_bind(net, inet: isk) || has_addr ||
383 addr_type == IPV6_ADDR_ANY))
384 return -EADDRNOTAVAIL;
385
386 if (scoped)
387 sk->sk_bound_dev_if = addr->sin6_scope_id;
388#endif
389 } else {
390 return -EAFNOSUPPORT;
391 }
392 return 0;
393}
394
395static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr)
396{
397 if (saddr->sa_family == AF_INET) {
398 struct inet_sock *isk = inet_sk(sk);
399 struct sockaddr_in *addr = (struct sockaddr_in *) saddr;
400 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
401#if IS_ENABLED(CONFIG_IPV6)
402 } else if (saddr->sa_family == AF_INET6) {
403 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr;
404 struct ipv6_pinfo *np = inet6_sk(sk: sk);
405 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr;
406#endif
407 }
408}
409
410/*
411 * We need our own bind because there are no privileged id's == local ports.
412 * Moreover, we don't allow binding to multi- and broadcast addresses.
413 */
414
415int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
416{
417 struct inet_sock *isk = inet_sk(sk);
418 unsigned short snum;
419 int err;
420 int dif = sk->sk_bound_dev_if;
421
422 err = ping_check_bind_addr(sk, isk, uaddr, addr_len);
423 if (err)
424 return err;
425
426 lock_sock(sk);
427
428 err = -EINVAL;
429 if (isk->inet_num != 0)
430 goto out;
431
432 err = -EADDRINUSE;
433 snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port);
434 if (ping_get_port(sk, snum) != 0) {
435 /* Restore possibly modified sk->sk_bound_dev_if by ping_check_bind_addr(). */
436 sk->sk_bound_dev_if = dif;
437 goto out;
438 }
439 ping_set_saddr(sk, saddr: uaddr);
440
441 pr_debug("after bind(): num = %hu, dif = %d\n",
442 isk->inet_num,
443 sk->sk_bound_dev_if);
444
445 err = 0;
446 if (sk->sk_family == AF_INET && isk->inet_rcv_saddr)
447 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
448#if IS_ENABLED(CONFIG_IPV6)
449 if (sk->sk_family == AF_INET6 && !ipv6_addr_any(a: &sk->sk_v6_rcv_saddr))
450 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
451#endif
452
453 if (snum)
454 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
455 isk->inet_sport = htons(isk->inet_num);
456 isk->inet_daddr = 0;
457 isk->inet_dport = 0;
458
459#if IS_ENABLED(CONFIG_IPV6)
460 if (sk->sk_family == AF_INET6)
461 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr));
462#endif
463
464 sk_dst_reset(sk);
465out:
466 release_sock(sk);
467 pr_debug("ping_v4_bind -> %d\n", err);
468 return err;
469}
470EXPORT_SYMBOL_GPL(ping_bind);
471
472/*
473 * Is this a supported type of ICMP message?
474 */
475
476static inline int ping_supported(int family, int type, int code)
477{
478 return (family == AF_INET && type == ICMP_ECHO && code == 0) ||
479 (family == AF_INET && type == ICMP_EXT_ECHO && code == 0) ||
480 (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0) ||
481 (family == AF_INET6 && type == ICMPV6_EXT_ECHO_REQUEST && code == 0);
482}
483
484/*
485 * This routine is called by the ICMP module when it gets some
486 * sort of error condition.
487 */
488
489void ping_err(struct sk_buff *skb, int offset, u32 info)
490{
491 int family;
492 struct icmphdr *icmph;
493 struct inet_sock *inet_sock;
494 int type;
495 int code;
496 struct net *net = dev_net(dev: skb->dev);
497 struct sock *sk;
498 int harderr;
499 int err;
500
501 if (skb->protocol == htons(ETH_P_IP)) {
502 family = AF_INET;
503 type = icmp_hdr(skb)->type;
504 code = icmp_hdr(skb)->code;
505 icmph = (struct icmphdr *)(skb->data + offset);
506 } else if (skb->protocol == htons(ETH_P_IPV6)) {
507 family = AF_INET6;
508 type = icmp6_hdr(skb)->icmp6_type;
509 code = icmp6_hdr(skb)->icmp6_code;
510 icmph = (struct icmphdr *) (skb->data + offset);
511 } else {
512 BUG();
513 }
514
515 /* We assume the packet has already been checked by icmp_unreach */
516
517 if (!ping_supported(family, type: icmph->type, code: icmph->code))
518 return;
519
520 pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n",
521 skb->protocol, type, code, ntohs(icmph->un.echo.id),
522 ntohs(icmph->un.echo.sequence));
523
524 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
525 if (!sk) {
526 pr_debug("no socket, dropping\n");
527 return; /* No socket for error */
528 }
529 pr_debug("err on socket %p\n", sk);
530
531 err = 0;
532 harderr = 0;
533 inet_sock = inet_sk(sk);
534
535 if (skb->protocol == htons(ETH_P_IP)) {
536 switch (type) {
537 default:
538 case ICMP_TIME_EXCEEDED:
539 err = EHOSTUNREACH;
540 break;
541 case ICMP_SOURCE_QUENCH:
542 /* This is not a real error but ping wants to see it.
543 * Report it with some fake errno.
544 */
545 err = EREMOTEIO;
546 break;
547 case ICMP_PARAMETERPROB:
548 err = EPROTO;
549 harderr = 1;
550 break;
551 case ICMP_DEST_UNREACH:
552 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
553 ipv4_sk_update_pmtu(skb, sk, mtu: info);
554 if (READ_ONCE(inet_sock->pmtudisc) != IP_PMTUDISC_DONT) {
555 err = EMSGSIZE;
556 harderr = 1;
557 break;
558 }
559 goto out;
560 }
561 err = EHOSTUNREACH;
562 if (code <= NR_ICMP_UNREACH) {
563 harderr = icmp_err_convert[code].fatal;
564 err = icmp_err_convert[code].errno;
565 }
566 break;
567 case ICMP_REDIRECT:
568 /* See ICMP_SOURCE_QUENCH */
569 ipv4_sk_redirect(skb, sk);
570 err = EREMOTEIO;
571 break;
572 }
573#if IS_ENABLED(CONFIG_IPV6)
574 } else if (skb->protocol == htons(ETH_P_IPV6)) {
575 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err);
576#endif
577 }
578
579 /*
580 * RFC1122: OK. Passes ICMP errors back to application, as per
581 * 4.1.3.3.
582 */
583 if ((family == AF_INET && !inet_test_bit(RECVERR, sk)) ||
584 (family == AF_INET6 && !inet6_test_bit(RECVERR6, sk))) {
585 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
586 goto out;
587 } else {
588 if (family == AF_INET) {
589 ip_icmp_error(sk, skb, err, port: 0 /* no remote port */,
590 info, payload: (u8 *)icmph);
591#if IS_ENABLED(CONFIG_IPV6)
592 } else if (family == AF_INET6) {
593 pingv6_ops.ipv6_icmp_error(sk, skb, err, 0,
594 info, (u8 *)icmph);
595#endif
596 }
597 }
598 sk->sk_err = err;
599 sk_error_report(sk);
600out:
601 return;
602}
603EXPORT_SYMBOL_GPL(ping_err);
604
605/*
606 * Copy and checksum an ICMP Echo packet from user space into a buffer
607 * starting from the payload.
608 */
609
610int ping_getfrag(void *from, char *to,
611 int offset, int fraglen, int odd, struct sk_buff *skb)
612{
613 struct pingfakehdr *pfh = from;
614
615 if (!csum_and_copy_from_iter_full(addr: to, bytes: fraglen, csum: &pfh->wcheck,
616 i: &pfh->msg->msg_iter))
617 return -EFAULT;
618
619#if IS_ENABLED(CONFIG_IPV6)
620 /* For IPv6, checksum each skb as we go along, as expected by
621 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in
622 * wcheck, it will be finalized in ping_v4_push_pending_frames.
623 */
624 if (pfh->family == AF_INET6) {
625 skb->csum = csum_block_add(csum: skb->csum, csum2: pfh->wcheck, offset: odd);
626 skb->ip_summed = CHECKSUM_NONE;
627 pfh->wcheck = 0;
628 }
629#endif
630
631 return 0;
632}
633EXPORT_SYMBOL_GPL(ping_getfrag);
634
635static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
636 struct flowi4 *fl4)
637{
638 struct sk_buff *skb = skb_peek(list_: &sk->sk_write_queue);
639
640 if (!skb)
641 return 0;
642 pfh->wcheck = csum_partial(buff: (char *)&pfh->icmph,
643 len: sizeof(struct icmphdr), sum: pfh->wcheck);
644 pfh->icmph.checksum = csum_fold(sum: pfh->wcheck);
645 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
646 skb->ip_summed = CHECKSUM_NONE;
647 return ip_push_pending_frames(sk, fl4);
648}
649
650int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
651 void *user_icmph, size_t icmph_len)
652{
653 u8 type, code;
654
655 if (len > 0xFFFF)
656 return -EMSGSIZE;
657
658 /* Must have at least a full ICMP header. */
659 if (len < icmph_len)
660 return -EINVAL;
661
662 /*
663 * Check the flags.
664 */
665
666 /* Mirror BSD error message compatibility */
667 if (msg->msg_flags & MSG_OOB)
668 return -EOPNOTSUPP;
669
670 /*
671 * Fetch the ICMP header provided by the userland.
672 * iovec is modified! The ICMP header is consumed.
673 */
674 if (memcpy_from_msg(data: user_icmph, msg, len: icmph_len))
675 return -EFAULT;
676
677 if (family == AF_INET) {
678 type = ((struct icmphdr *) user_icmph)->type;
679 code = ((struct icmphdr *) user_icmph)->code;
680#if IS_ENABLED(CONFIG_IPV6)
681 } else if (family == AF_INET6) {
682 type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
683 code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
684#endif
685 } else {
686 BUG();
687 }
688
689 if (!ping_supported(family, type, code))
690 return -EINVAL;
691
692 return 0;
693}
694EXPORT_SYMBOL_GPL(ping_common_sendmsg);
695
696static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
697{
698 struct net *net = sock_net(sk);
699 struct flowi4 fl4;
700 struct inet_sock *inet = inet_sk(sk);
701 struct ipcm_cookie ipc;
702 struct icmphdr user_icmph;
703 struct pingfakehdr pfh;
704 struct rtable *rt = NULL;
705 struct ip_options_data opt_copy;
706 int free = 0;
707 __be32 saddr, daddr, faddr;
708 u8 tos, scope;
709 int err;
710
711 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
712
713 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
714 sizeof(user_icmph));
715 if (err)
716 return err;
717
718 /*
719 * Get and verify the address.
720 */
721
722 if (msg->msg_name) {
723 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
724 if (msg->msg_namelen < sizeof(*usin))
725 return -EINVAL;
726 if (usin->sin_family != AF_INET)
727 return -EAFNOSUPPORT;
728 daddr = usin->sin_addr.s_addr;
729 /* no remote port */
730 } else {
731 if (sk->sk_state != TCP_ESTABLISHED)
732 return -EDESTADDRREQ;
733 daddr = inet->inet_daddr;
734 /* no remote port */
735 }
736
737 ipcm_init_sk(ipcm: &ipc, inet);
738
739 if (msg->msg_controllen) {
740 err = ip_cmsg_send(sk, msg, ipc: &ipc, allow_ipv6: false);
741 if (unlikely(err)) {
742 kfree(objp: ipc.opt);
743 return err;
744 }
745 if (ipc.opt)
746 free = 1;
747 }
748 if (!ipc.opt) {
749 struct ip_options_rcu *inet_opt;
750
751 rcu_read_lock();
752 inet_opt = rcu_dereference(inet->inet_opt);
753 if (inet_opt) {
754 memcpy(&opt_copy, inet_opt,
755 sizeof(*inet_opt) + inet_opt->opt.optlen);
756 ipc.opt = &opt_copy.opt;
757 }
758 rcu_read_unlock();
759 }
760
761 saddr = ipc.addr;
762 ipc.addr = faddr = daddr;
763
764 if (ipc.opt && ipc.opt->opt.srr) {
765 if (!daddr) {
766 err = -EINVAL;
767 goto out_free;
768 }
769 faddr = ipc.opt->opt.faddr;
770 }
771 tos = get_rttos(ipc: &ipc, inet);
772 scope = ip_sendmsg_scope(inet, ipc: &ipc, msg);
773
774 if (ipv4_is_multicast(addr: daddr)) {
775 if (!ipc.oif || netif_index_is_l3_master(net: sock_net(sk), ifindex: ipc.oif))
776 ipc.oif = READ_ONCE(inet->mc_index);
777 if (!saddr)
778 saddr = READ_ONCE(inet->mc_addr);
779 } else if (!ipc.oif)
780 ipc.oif = READ_ONCE(inet->uc_index);
781
782 flowi4_init_output(fl4: &fl4, oif: ipc.oif, mark: ipc.sockc.mark, tos, scope,
783 proto: sk->sk_protocol, flags: inet_sk_flowi_flags(sk), daddr: faddr,
784 saddr, dport: 0, sport: 0, uid: sk->sk_uid);
785
786 fl4.fl4_icmp_type = user_icmph.type;
787 fl4.fl4_icmp_code = user_icmph.code;
788
789 security_sk_classify_flow(sk, flic: flowi4_to_flowi_common(fl4: &fl4));
790 rt = ip_route_output_flow(net, flp: &fl4, sk);
791 if (IS_ERR(ptr: rt)) {
792 err = PTR_ERR(ptr: rt);
793 rt = NULL;
794 if (err == -ENETUNREACH)
795 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
796 goto out;
797 }
798
799 err = -EACCES;
800 if ((rt->rt_flags & RTCF_BROADCAST) &&
801 !sock_flag(sk, flag: SOCK_BROADCAST))
802 goto out;
803
804 if (msg->msg_flags & MSG_CONFIRM)
805 goto do_confirm;
806back_from_confirm:
807
808 if (!ipc.addr)
809 ipc.addr = fl4.daddr;
810
811 lock_sock(sk);
812
813 pfh.icmph.type = user_icmph.type; /* already checked */
814 pfh.icmph.code = user_icmph.code; /* ditto */
815 pfh.icmph.checksum = 0;
816 pfh.icmph.un.echo.id = inet->inet_sport;
817 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
818 pfh.msg = msg;
819 pfh.wcheck = 0;
820 pfh.family = AF_INET;
821
822 err = ip_append_data(sk, fl4: &fl4, getfrag: ping_getfrag, from: &pfh, len,
823 protolen: sizeof(struct icmphdr), ipc: &ipc, rt: &rt,
824 flags: msg->msg_flags);
825 if (err)
826 ip_flush_pending_frames(sk);
827 else
828 err = ping_v4_push_pending_frames(sk, pfh: &pfh, fl4: &fl4);
829 release_sock(sk);
830
831out:
832 ip_rt_put(rt);
833out_free:
834 if (free)
835 kfree(objp: ipc.opt);
836 if (!err) {
837 icmp_out_count(net: sock_net(sk), type: user_icmph.type);
838 return len;
839 }
840 return err;
841
842do_confirm:
843 if (msg->msg_flags & MSG_PROBE)
844 dst_confirm_neigh(dst: &rt->dst, daddr: &fl4.daddr);
845 if (!(msg->msg_flags & MSG_PROBE) || len)
846 goto back_from_confirm;
847 err = 0;
848 goto out;
849}
850
851int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags,
852 int *addr_len)
853{
854 struct inet_sock *isk = inet_sk(sk);
855 int family = sk->sk_family;
856 struct sk_buff *skb;
857 int copied, err;
858
859 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
860
861 err = -EOPNOTSUPP;
862 if (flags & MSG_OOB)
863 goto out;
864
865 if (flags & MSG_ERRQUEUE)
866 return inet_recv_error(sk, msg, len, addr_len);
867
868 skb = skb_recv_datagram(sk, flags, err: &err);
869 if (!skb)
870 goto out;
871
872 copied = skb->len;
873 if (copied > len) {
874 msg->msg_flags |= MSG_TRUNC;
875 copied = len;
876 }
877
878 /* Don't bother checking the checksum */
879 err = skb_copy_datagram_msg(from: skb, offset: 0, msg, size: copied);
880 if (err)
881 goto done;
882
883 sock_recv_timestamp(msg, sk, skb);
884
885 /* Copy the address and add cmsg data. */
886 if (family == AF_INET) {
887 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
888
889 if (sin) {
890 sin->sin_family = AF_INET;
891 sin->sin_port = 0 /* skb->h.uh->source */;
892 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
893 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
894 *addr_len = sizeof(*sin);
895 }
896
897 if (inet_cmsg_flags(inet: isk))
898 ip_cmsg_recv(msg, skb);
899
900#if IS_ENABLED(CONFIG_IPV6)
901 } else if (family == AF_INET6) {
902 struct ipv6hdr *ip6 = ipv6_hdr(skb);
903 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
904
905 if (sin6) {
906 sin6->sin6_family = AF_INET6;
907 sin6->sin6_port = 0;
908 sin6->sin6_addr = ip6->saddr;
909 sin6->sin6_flowinfo = 0;
910 if (inet6_test_bit(SNDFLOW, sk))
911 sin6->sin6_flowinfo = ip6_flowinfo(hdr: ip6);
912 sin6->sin6_scope_id =
913 ipv6_iface_scope_id(addr: &sin6->sin6_addr,
914 iface: inet6_iif(skb));
915 *addr_len = sizeof(*sin6);
916 }
917
918 if (inet6_sk(sk: sk)->rxopt.all)
919 pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb);
920 if (skb->protocol == htons(ETH_P_IPV6) &&
921 inet6_sk(sk: sk)->rxopt.all)
922 pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb);
923 else if (skb->protocol == htons(ETH_P_IP) &&
924 inet_cmsg_flags(inet: isk))
925 ip_cmsg_recv(msg, skb);
926#endif
927 } else {
928 BUG();
929 }
930
931 err = copied;
932
933done:
934 skb_free_datagram(sk, skb);
935out:
936 pr_debug("ping_recvmsg -> %d\n", err);
937 return err;
938}
939EXPORT_SYMBOL_GPL(ping_recvmsg);
940
941static enum skb_drop_reason __ping_queue_rcv_skb(struct sock *sk,
942 struct sk_buff *skb)
943{
944 enum skb_drop_reason reason;
945
946 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
947 inet_sk(sk), inet_sk(sk)->inet_num, skb);
948 if (sock_queue_rcv_skb_reason(sk, skb, reason: &reason) < 0) {
949 kfree_skb_reason(skb, reason);
950 pr_debug("ping_queue_rcv_skb -> failed\n");
951 return reason;
952 }
953 return SKB_NOT_DROPPED_YET;
954}
955
956int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
957{
958 return __ping_queue_rcv_skb(sk, skb) ? -1 : 0;
959}
960EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
961
962
963/*
964 * All we need to do is get the socket.
965 */
966
967enum skb_drop_reason ping_rcv(struct sk_buff *skb)
968{
969 enum skb_drop_reason reason = SKB_DROP_REASON_NO_SOCKET;
970 struct sock *sk;
971 struct net *net = dev_net(dev: skb->dev);
972 struct icmphdr *icmph = icmp_hdr(skb);
973
974 /* We assume the packet has already been checked by icmp_rcv */
975
976 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
977 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
978
979 /* Push ICMP header back */
980 skb_push(skb, len: skb->data - (u8 *)icmph);
981
982 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
983 if (sk) {
984 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
985
986 pr_debug("rcv on socket %p\n", sk);
987 if (skb2)
988 reason = __ping_queue_rcv_skb(sk, skb: skb2);
989 else
990 reason = SKB_DROP_REASON_NOMEM;
991 }
992
993 if (reason)
994 pr_debug("no socket, dropping\n");
995
996 return reason;
997}
998EXPORT_SYMBOL_GPL(ping_rcv);
999
1000struct proto ping_prot = {
1001 .name = "PING",
1002 .owner = THIS_MODULE,
1003 .init = ping_init_sock,
1004 .close = ping_close,
1005 .pre_connect = ping_pre_connect,
1006 .connect = ip4_datagram_connect,
1007 .disconnect = __udp_disconnect,
1008 .setsockopt = ip_setsockopt,
1009 .getsockopt = ip_getsockopt,
1010 .sendmsg = ping_v4_sendmsg,
1011 .recvmsg = ping_recvmsg,
1012 .bind = ping_bind,
1013 .backlog_rcv = ping_queue_rcv_skb,
1014 .release_cb = ip4_datagram_release_cb,
1015 .hash = ping_hash,
1016 .unhash = ping_unhash,
1017 .get_port = ping_get_port,
1018 .put_port = ping_unhash,
1019 .obj_size = sizeof(struct inet_sock),
1020};
1021EXPORT_SYMBOL(ping_prot);
1022
1023#ifdef CONFIG_PROC_FS
1024
1025static struct sock *ping_get_first(struct seq_file *seq, int start)
1026{
1027 struct sock *sk;
1028 struct ping_iter_state *state = seq->private;
1029 struct net *net = seq_file_net(seq);
1030
1031 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
1032 ++state->bucket) {
1033 struct hlist_head *hslot;
1034
1035 hslot = &ping_table.hash[state->bucket];
1036
1037 if (hlist_empty(h: hslot))
1038 continue;
1039
1040 sk_for_each(sk, hslot) {
1041 if (net_eq(net1: sock_net(sk), net2: net) &&
1042 sk->sk_family == state->family)
1043 goto found;
1044 }
1045 }
1046 sk = NULL;
1047found:
1048 return sk;
1049}
1050
1051static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
1052{
1053 struct ping_iter_state *state = seq->private;
1054 struct net *net = seq_file_net(seq);
1055
1056 do {
1057 sk = sk_next(sk);
1058 } while (sk && (!net_eq(net1: sock_net(sk), net2: net)));
1059
1060 if (!sk)
1061 return ping_get_first(seq, start: state->bucket + 1);
1062 return sk;
1063}
1064
1065static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
1066{
1067 struct sock *sk = ping_get_first(seq, start: 0);
1068
1069 if (sk)
1070 while (pos && (sk = ping_get_next(seq, sk)) != NULL)
1071 --pos;
1072 return pos ? NULL : sk;
1073}
1074
1075void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
1076 __acquires(ping_table.lock)
1077{
1078 struct ping_iter_state *state = seq->private;
1079 state->bucket = 0;
1080 state->family = family;
1081
1082 spin_lock(lock: &ping_table.lock);
1083
1084 return *pos ? ping_get_idx(seq, pos: *pos-1) : SEQ_START_TOKEN;
1085}
1086EXPORT_SYMBOL_GPL(ping_seq_start);
1087
1088static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos)
1089{
1090 return ping_seq_start(seq, pos, AF_INET);
1091}
1092
1093void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1094{
1095 struct sock *sk;
1096
1097 if (v == SEQ_START_TOKEN)
1098 sk = ping_get_idx(seq, pos: 0);
1099 else
1100 sk = ping_get_next(seq, sk: v);
1101
1102 ++*pos;
1103 return sk;
1104}
1105EXPORT_SYMBOL_GPL(ping_seq_next);
1106
1107void ping_seq_stop(struct seq_file *seq, void *v)
1108 __releases(ping_table.lock)
1109{
1110 spin_unlock(lock: &ping_table.lock);
1111}
1112EXPORT_SYMBOL_GPL(ping_seq_stop);
1113
1114static void ping_v4_format_sock(struct sock *sp, struct seq_file *f,
1115 int bucket)
1116{
1117 struct inet_sock *inet = inet_sk(sp);
1118 __be32 dest = inet->inet_daddr;
1119 __be32 src = inet->inet_rcv_saddr;
1120 __u16 destp = ntohs(inet->inet_dport);
1121 __u16 srcp = ntohs(inet->inet_sport);
1122
1123 seq_printf(m: f, fmt: "%5d: %08X:%04X %08X:%04X"
1124 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u",
1125 bucket, src, srcp, dest, destp, sp->sk_state,
1126 sk_wmem_alloc_get(sk: sp),
1127 sk_rmem_alloc_get(sk: sp),
1128 0, 0L, 0,
1129 from_kuid_munged(to: seq_user_ns(seq: f), uid: sock_i_uid(sk: sp)),
1130 0, sock_i_ino(sk: sp),
1131 refcount_read(r: &sp->sk_refcnt), sp,
1132 atomic_read(v: &sp->sk_drops));
1133}
1134
1135static int ping_v4_seq_show(struct seq_file *seq, void *v)
1136{
1137 seq_setwidth(m: seq, size: 127);
1138 if (v == SEQ_START_TOKEN)
1139 seq_puts(m: seq, s: " sl local_address rem_address st tx_queue "
1140 "rx_queue tr tm->when retrnsmt uid timeout "
1141 "inode ref pointer drops");
1142 else {
1143 struct ping_iter_state *state = seq->private;
1144
1145 ping_v4_format_sock(sp: v, f: seq, bucket: state->bucket);
1146 }
1147 seq_pad(m: seq, c: '\n');
1148 return 0;
1149}
1150
1151static const struct seq_operations ping_v4_seq_ops = {
1152 .start = ping_v4_seq_start,
1153 .show = ping_v4_seq_show,
1154 .next = ping_seq_next,
1155 .stop = ping_seq_stop,
1156};
1157
1158static int __net_init ping_v4_proc_init_net(struct net *net)
1159{
1160 if (!proc_create_net("icmp", 0444, net->proc_net, &ping_v4_seq_ops,
1161 sizeof(struct ping_iter_state)))
1162 return -ENOMEM;
1163 return 0;
1164}
1165
1166static void __net_exit ping_v4_proc_exit_net(struct net *net)
1167{
1168 remove_proc_entry("icmp", net->proc_net);
1169}
1170
1171static struct pernet_operations ping_v4_net_ops = {
1172 .init = ping_v4_proc_init_net,
1173 .exit = ping_v4_proc_exit_net,
1174};
1175
1176int __init ping_proc_init(void)
1177{
1178 return register_pernet_subsys(&ping_v4_net_ops);
1179}
1180
1181void ping_proc_exit(void)
1182{
1183 unregister_pernet_subsys(&ping_v4_net_ops);
1184}
1185
1186#endif
1187
1188void __init ping_init(void)
1189{
1190 int i;
1191
1192 for (i = 0; i < PING_HTABLE_SIZE; i++)
1193 INIT_HLIST_HEAD(&ping_table.hash[i]);
1194 spin_lock_init(&ping_table.lock);
1195}
1196

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source code of linux/net/ipv4/ping.c