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_IPV6_MOD_GPL(pingv6_ops);
60
61static inline u32 ping_hashfn(const struct net *net, u32 num, u32 mask)
62{
63 u32 res = (num + net_hash_mix(net)) & mask;
64
65 pr_debug("hash(%u) = %u\n", num, res);
66 return res;
67}
68
69static inline struct hlist_head *ping_hashslot(struct ping_table *table,
70 struct net *net, unsigned int num)
71{
72 return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)];
73}
74
75int ping_get_port(struct sock *sk, unsigned short ident)
76{
77 struct net *net = sock_net(sk);
78 struct inet_sock *isk, *isk2;
79 struct hlist_head *hlist;
80 struct sock *sk2 = NULL;
81
82 isk = inet_sk(sk);
83 spin_lock(lock: &ping_table.lock);
84 if (ident == 0) {
85 u16 result = net->ipv4.ping_port_rover + 1;
86 u32 i;
87
88 for (i = 0; i < (1L << 16); i++, result++) {
89 if (!result)
90 continue; /* avoid zero */
91 hlist = ping_hashslot(table: &ping_table, net, num: result);
92 sk_for_each(sk2, hlist) {
93 if (!net_eq(net1: sock_net(sk: sk2), net2: net))
94 continue;
95 isk2 = inet_sk(sk2);
96
97 if (isk2->inet_num == result)
98 goto next_port;
99 }
100
101 /* found */
102 net->ipv4.ping_port_rover = ident = result;
103 break;
104next_port:
105 ;
106 }
107 if (i >= (1L << 16))
108 goto fail;
109 } else {
110 hlist = ping_hashslot(table: &ping_table, net, num: ident);
111 sk_for_each(sk2, hlist) {
112 if (!net_eq(net1: sock_net(sk: sk2), net2: net))
113 continue;
114 isk2 = inet_sk(sk2);
115
116 /* BUG? Why is this reuse and not reuseaddr? ping.c
117 * doesn't turn off SO_REUSEADDR, and it doesn't expect
118 * that other ping processes can steal its packets.
119 */
120 if ((isk2->inet_num == ident) &&
121 (sk2 != sk) &&
122 (!sk2->sk_reuse || !sk->sk_reuse))
123 goto fail;
124 }
125 }
126
127 pr_debug("found port/ident = %d\n", ident);
128 isk->inet_num = ident;
129 if (sk_unhashed(sk)) {
130 pr_debug("was not hashed\n");
131 sk_add_node_rcu(sk, list: hlist);
132 sock_set_flag(sk, flag: SOCK_RCU_FREE);
133 sock_prot_inuse_add(net, prot: sk->sk_prot, val: 1);
134 }
135 spin_unlock(lock: &ping_table.lock);
136 return 0;
137
138fail:
139 spin_unlock(lock: &ping_table.lock);
140 return -EADDRINUSE;
141}
142EXPORT_IPV6_MOD_GPL(ping_get_port);
143
144void ping_unhash(struct sock *sk)
145{
146 struct inet_sock *isk = inet_sk(sk);
147
148 pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);
149 spin_lock(lock: &ping_table.lock);
150 if (sk_del_node_init_rcu(sk)) {
151 isk->inet_num = 0;
152 isk->inet_sport = 0;
153 sock_prot_inuse_add(net: sock_net(sk), prot: sk->sk_prot, val: -1);
154 }
155 spin_unlock(lock: &ping_table.lock);
156}
157EXPORT_IPV6_MOD_GPL(ping_unhash);
158
159/* Called under rcu_read_lock() */
160static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
161{
162 struct hlist_head *hslot = ping_hashslot(table: &ping_table, net, num: ident);
163 struct sock *sk = NULL;
164 struct inet_sock *isk;
165 int dif, sdif;
166
167 if (skb->protocol == htons(ETH_P_IP)) {
168 dif = inet_iif(skb);
169 sdif = inet_sdif(skb);
170 pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n",
171 (int)ident, &ip_hdr(skb)->daddr, dif);
172#if IS_ENABLED(CONFIG_IPV6)
173 } else if (skb->protocol == htons(ETH_P_IPV6)) {
174 dif = inet6_iif(skb);
175 sdif = inet6_sdif(skb);
176 pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n",
177 (int)ident, &ipv6_hdr(skb)->daddr, dif);
178#endif
179 } else {
180 return NULL;
181 }
182
183 sk_for_each_rcu(sk, hslot) {
184 if (!net_eq(net1: sock_net(sk), net2: net))
185 continue;
186 isk = inet_sk(sk);
187
188 pr_debug("iterate\n");
189 if (isk->inet_num != ident)
190 continue;
191
192 if (skb->protocol == htons(ETH_P_IP) &&
193 sk->sk_family == AF_INET) {
194 pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk,
195 (int) isk->inet_num, &isk->inet_rcv_saddr,
196 sk->sk_bound_dev_if);
197
198 if (isk->inet_rcv_saddr &&
199 isk->inet_rcv_saddr != ip_hdr(skb)->daddr)
200 continue;
201#if IS_ENABLED(CONFIG_IPV6)
202 } else if (skb->protocol == htons(ETH_P_IPV6) &&
203 sk->sk_family == AF_INET6) {
204
205 pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk,
206 (int) isk->inet_num,
207 &sk->sk_v6_rcv_saddr,
208 sk->sk_bound_dev_if);
209
210 if (!ipv6_addr_any(a: &sk->sk_v6_rcv_saddr) &&
211 !ipv6_addr_equal(a1: &sk->sk_v6_rcv_saddr,
212 a2: &ipv6_hdr(skb)->daddr))
213 continue;
214#endif
215 } else {
216 continue;
217 }
218
219 if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif &&
220 sk->sk_bound_dev_if != sdif)
221 continue;
222
223 goto exit;
224 }
225
226 sk = NULL;
227exit:
228
229 return sk;
230}
231
232static void inet_get_ping_group_range_net(struct net *net, kgid_t *low,
233 kgid_t *high)
234{
235 kgid_t *data = net->ipv4.ping_group_range.range;
236 unsigned int seq;
237
238 do {
239 seq = read_seqbegin(sl: &net->ipv4.ping_group_range.lock);
240
241 *low = data[0];
242 *high = data[1];
243 } while (read_seqretry(sl: &net->ipv4.ping_group_range.lock, start: seq));
244}
245
246
247int ping_init_sock(struct sock *sk)
248{
249 struct net *net = sock_net(sk);
250 kgid_t group = current_egid();
251 struct group_info *group_info;
252 int i;
253 kgid_t low, high;
254 int ret = 0;
255
256 if (sk->sk_family == AF_INET6)
257 sk->sk_ipv6only = 1;
258
259 inet_get_ping_group_range_net(net, low: &low, high: &high);
260 if (gid_lte(left: low, right: group) && gid_lte(left: group, right: high))
261 return 0;
262
263 group_info = get_current_groups();
264 for (i = 0; i < group_info->ngroups; i++) {
265 kgid_t gid = group_info->gid[i];
266
267 if (gid_lte(left: low, right: gid) && gid_lte(left: gid, right: high))
268 goto out_release_group;
269 }
270
271 ret = -EACCES;
272
273out_release_group:
274 put_group_info(group_info);
275 return ret;
276}
277EXPORT_IPV6_MOD_GPL(ping_init_sock);
278
279void ping_close(struct sock *sk, long timeout)
280{
281 pr_debug("ping_close(sk=%p,sk->num=%u)\n",
282 inet_sk(sk), inet_sk(sk)->inet_num);
283 pr_debug("isk->refcnt = %d\n", refcount_read(&sk->sk_refcnt));
284
285 sk_common_release(sk);
286}
287EXPORT_IPV6_MOD_GPL(ping_close);
288
289static int ping_pre_connect(struct sock *sk, struct sockaddr *uaddr,
290 int addr_len)
291{
292 /* This check is replicated from __ip4_datagram_connect() and
293 * intended to prevent BPF program called below from accessing bytes
294 * that are out of the bound specified by user in addr_len.
295 */
296 if (addr_len < sizeof(struct sockaddr_in))
297 return -EINVAL;
298
299 return BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr, &addr_len);
300}
301
302/* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */
303static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
304 struct sockaddr *uaddr, int addr_len)
305{
306 struct net *net = sock_net(sk);
307 if (sk->sk_family == AF_INET) {
308 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
309 u32 tb_id = RT_TABLE_LOCAL;
310 int chk_addr_ret;
311
312 if (addr_len < sizeof(*addr))
313 return -EINVAL;
314
315 if (addr->sin_family != AF_INET &&
316 !(addr->sin_family == AF_UNSPEC &&
317 addr->sin_addr.s_addr == htonl(INADDR_ANY)))
318 return -EAFNOSUPPORT;
319
320 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",
321 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
322
323 if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
324 return 0;
325
326 tb_id = l3mdev_fib_table_by_index(net, ifindex: sk->sk_bound_dev_if) ? : tb_id;
327 chk_addr_ret = inet_addr_type_table(net, addr: addr->sin_addr.s_addr, tb_id);
328
329 if (chk_addr_ret == RTN_MULTICAST ||
330 chk_addr_ret == RTN_BROADCAST ||
331 (chk_addr_ret != RTN_LOCAL &&
332 !inet_can_nonlocal_bind(net, inet: isk)))
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: &addr->sin6_addr);
351 scoped = __ipv6_addr_needs_scope_id(type: 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, ifindex: 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, ifindex: 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, inet: 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
390static 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: 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
410int 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, ident: 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, saddr: 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(a: &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(s: &sk->sk_v6_daddr, c: 0, n: sizeof(sk->sk_v6_daddr));
457#endif
458
459 sk_dst_reset(sk);
460out:
461 release_sock(sk);
462 pr_debug("ping_v4_bind -> %d\n", err);
463 return err;
464}
465EXPORT_IPV6_MOD_GPL(ping_bind);
466
467/*
468 * Is this a supported type of ICMP message?
469 */
470
471static inline int ping_supported(int family, int type, int code)
472{
473 return (family == AF_INET && type == ICMP_ECHO && code == 0) ||
474 (family == AF_INET && type == ICMP_EXT_ECHO && code == 0) ||
475 (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0) ||
476 (family == AF_INET6 && type == ICMPV6_EXT_ECHO_REQUEST && code == 0);
477}
478
479/*
480 * This routine is called by the ICMP module when it gets some
481 * sort of error condition.
482 */
483
484void ping_err(struct sk_buff *skb, int offset, u32 info)
485{
486 int family;
487 struct icmphdr *icmph;
488 struct inet_sock *inet_sock;
489 int type;
490 int code;
491 struct net *net = dev_net(dev: skb->dev);
492 struct sock *sk;
493 int harderr;
494 int err;
495
496 if (skb->protocol == htons(ETH_P_IP)) {
497 family = AF_INET;
498 type = icmp_hdr(skb)->type;
499 code = icmp_hdr(skb)->code;
500 icmph = (struct icmphdr *)(skb->data + offset);
501 } else if (skb->protocol == htons(ETH_P_IPV6)) {
502 family = AF_INET6;
503 type = icmp6_hdr(skb)->icmp6_type;
504 code = icmp6_hdr(skb)->icmp6_code;
505 icmph = (struct icmphdr *) (skb->data + offset);
506 } else {
507 BUG();
508 }
509
510 /* We assume the packet has already been checked by icmp_unreach */
511
512 if (!ping_supported(family, type: icmph->type, code: icmph->code))
513 return;
514
515 pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n",
516 skb->protocol, type, code, ntohs(icmph->un.echo.id),
517 ntohs(icmph->un.echo.sequence));
518
519 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
520 if (!sk) {
521 pr_debug("no socket, dropping\n");
522 return; /* No socket for error */
523 }
524 pr_debug("err on socket %p\n", sk);
525
526 err = 0;
527 harderr = 0;
528 inet_sock = inet_sk(sk);
529
530 if (skb->protocol == htons(ETH_P_IP)) {
531 switch (type) {
532 default:
533 case ICMP_TIME_EXCEEDED:
534 err = EHOSTUNREACH;
535 break;
536 case ICMP_SOURCE_QUENCH:
537 /* This is not a real error but ping wants to see it.
538 * Report it with some fake errno.
539 */
540 err = EREMOTEIO;
541 break;
542 case ICMP_PARAMETERPROB:
543 err = EPROTO;
544 harderr = 1;
545 break;
546 case ICMP_DEST_UNREACH:
547 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
548 ipv4_sk_update_pmtu(skb, sk, mtu: info);
549 if (READ_ONCE(inet_sock->pmtudisc) != IP_PMTUDISC_DONT) {
550 err = EMSGSIZE;
551 harderr = 1;
552 break;
553 }
554 goto out;
555 }
556 err = EHOSTUNREACH;
557 if (code <= NR_ICMP_UNREACH) {
558 harderr = icmp_err_convert[code].fatal;
559 err = icmp_err_convert[code].errno;
560 }
561 break;
562 case ICMP_REDIRECT:
563 /* See ICMP_SOURCE_QUENCH */
564 ipv4_sk_redirect(skb, sk);
565 err = EREMOTEIO;
566 break;
567 }
568#if IS_ENABLED(CONFIG_IPV6)
569 } else if (skb->protocol == htons(ETH_P_IPV6)) {
570 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err);
571#endif
572 }
573
574 /*
575 * RFC1122: OK. Passes ICMP errors back to application, as per
576 * 4.1.3.3.
577 */
578 if ((family == AF_INET && !inet_test_bit(RECVERR, sk)) ||
579 (family == AF_INET6 && !inet6_test_bit(RECVERR6, sk))) {
580 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
581 goto out;
582 } else {
583 if (family == AF_INET) {
584 ip_icmp_error(sk, skb, err, port: 0 /* no remote port */,
585 info, payload: (u8 *)icmph);
586#if IS_ENABLED(CONFIG_IPV6)
587 } else if (family == AF_INET6) {
588 pingv6_ops.ipv6_icmp_error(sk, skb, err, 0,
589 info, (u8 *)icmph);
590#endif
591 }
592 }
593 sk->sk_err = err;
594 sk_error_report(sk);
595out:
596 return;
597}
598EXPORT_IPV6_MOD_GPL(ping_err);
599
600/*
601 * Copy and checksum an ICMP Echo packet from user space into a buffer
602 * starting from the payload.
603 */
604
605int ping_getfrag(void *from, char *to,
606 int offset, int fraglen, int odd, struct sk_buff *skb)
607{
608 struct pingfakehdr *pfh = from;
609
610 if (!csum_and_copy_from_iter_full(addr: to, bytes: fraglen, csum: &pfh->wcheck,
611 i: &pfh->msg->msg_iter))
612 return -EFAULT;
613
614#if IS_ENABLED(CONFIG_IPV6)
615 /* For IPv6, checksum each skb as we go along, as expected by
616 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in
617 * wcheck, it will be finalized in ping_v4_push_pending_frames.
618 */
619 if (pfh->family == AF_INET6) {
620 skb->csum = csum_block_add(csum: skb->csum, csum2: pfh->wcheck, offset: odd);
621 skb->ip_summed = CHECKSUM_NONE;
622 pfh->wcheck = 0;
623 }
624#endif
625
626 return 0;
627}
628EXPORT_IPV6_MOD_GPL(ping_getfrag);
629
630static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
631 struct flowi4 *fl4)
632{
633 struct sk_buff *skb = skb_peek(list_: &sk->sk_write_queue);
634
635 if (!skb)
636 return 0;
637 pfh->wcheck = csum_partial(buff: (char *)&pfh->icmph,
638 len: sizeof(struct icmphdr), sum: pfh->wcheck);
639 pfh->icmph.checksum = csum_fold(sum: pfh->wcheck);
640 memcpy(to: icmp_hdr(skb), from: &pfh->icmph, len: sizeof(struct icmphdr));
641 skb->ip_summed = CHECKSUM_NONE;
642 return ip_push_pending_frames(sk, fl4);
643}
644
645int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
646 void *user_icmph, size_t icmph_len)
647{
648 u8 type, code;
649
650 if (len > 0xFFFF)
651 return -EMSGSIZE;
652
653 /* Must have at least a full ICMP header. */
654 if (len < icmph_len)
655 return -EINVAL;
656
657 /*
658 * Check the flags.
659 */
660
661 /* Mirror BSD error message compatibility */
662 if (msg->msg_flags & MSG_OOB)
663 return -EOPNOTSUPP;
664
665 /*
666 * Fetch the ICMP header provided by the userland.
667 * iovec is modified! The ICMP header is consumed.
668 */
669 if (memcpy_from_msg(data: user_icmph, msg, len: icmph_len))
670 return -EFAULT;
671
672 if (family == AF_INET) {
673 type = ((struct icmphdr *) user_icmph)->type;
674 code = ((struct icmphdr *) user_icmph)->code;
675#if IS_ENABLED(CONFIG_IPV6)
676 } else if (family == AF_INET6) {
677 type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
678 code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
679#endif
680 } else {
681 BUG();
682 }
683
684 if (!ping_supported(family, type, code))
685 return -EINVAL;
686
687 return 0;
688}
689EXPORT_IPV6_MOD_GPL(ping_common_sendmsg);
690
691static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
692{
693 struct net *net = sock_net(sk);
694 struct flowi4 fl4;
695 struct inet_sock *inet = inet_sk(sk);
696 struct ipcm_cookie ipc;
697 struct icmphdr user_icmph;
698 struct pingfakehdr pfh;
699 struct rtable *rt = NULL;
700 struct ip_options_data opt_copy;
701 int free = 0;
702 __be32 saddr, daddr, faddr;
703 u8 scope;
704 int err;
705
706 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
707
708 err = ping_common_sendmsg(AF_INET, msg, len, user_icmph: &user_icmph,
709 icmph_len: sizeof(user_icmph));
710 if (err)
711 return err;
712
713 /*
714 * Get and verify the address.
715 */
716
717 if (msg->msg_name) {
718 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
719 if (msg->msg_namelen < sizeof(*usin))
720 return -EINVAL;
721 if (usin->sin_family != AF_INET)
722 return -EAFNOSUPPORT;
723 daddr = usin->sin_addr.s_addr;
724 /* no remote port */
725 } else {
726 if (sk->sk_state != TCP_ESTABLISHED)
727 return -EDESTADDRREQ;
728 daddr = inet->inet_daddr;
729 /* no remote port */
730 }
731
732 ipcm_init_sk(ipcm: &ipc, inet);
733
734 if (msg->msg_controllen) {
735 err = ip_cmsg_send(sk, msg, ipc: &ipc, allow_ipv6: false);
736 if (unlikely(err)) {
737 kfree(objp: ipc.opt);
738 return err;
739 }
740 if (ipc.opt)
741 free = 1;
742 }
743 if (!ipc.opt) {
744 struct ip_options_rcu *inet_opt;
745
746 rcu_read_lock();
747 inet_opt = rcu_dereference(inet->inet_opt);
748 if (inet_opt) {
749 memcpy(to: &opt_copy, from: inet_opt,
750 len: sizeof(*inet_opt) + inet_opt->opt.optlen);
751 ipc.opt = &opt_copy.opt;
752 }
753 rcu_read_unlock();
754 }
755
756 saddr = ipc.addr;
757 ipc.addr = faddr = daddr;
758
759 if (ipc.opt && ipc.opt->opt.srr) {
760 if (!daddr) {
761 err = -EINVAL;
762 goto out_free;
763 }
764 faddr = ipc.opt->opt.faddr;
765 }
766 scope = ip_sendmsg_scope(inet, ipc: &ipc, msg);
767
768 if (ipv4_is_multicast(addr: daddr)) {
769 if (!ipc.oif || netif_index_is_l3_master(net: sock_net(sk), ifindex: ipc.oif))
770 ipc.oif = READ_ONCE(inet->mc_index);
771 if (!saddr)
772 saddr = READ_ONCE(inet->mc_addr);
773 } else if (!ipc.oif)
774 ipc.oif = READ_ONCE(inet->uc_index);
775
776 flowi4_init_output(fl4: &fl4, oif: ipc.oif, mark: ipc.sockc.mark,
777 tos: ipc.tos & INET_DSCP_MASK, scope,
778 proto: sk->sk_protocol, flags: inet_sk_flowi_flags(sk), daddr: faddr,
779 saddr, dport: 0, sport: 0, uid: sk_uid(sk));
780
781 fl4.fl4_icmp_type = user_icmph.type;
782 fl4.fl4_icmp_code = user_icmph.code;
783
784 security_sk_classify_flow(sk, flic: flowi4_to_flowi_common(fl4: &fl4));
785 rt = ip_route_output_flow(net, flp: &fl4, sk);
786 if (IS_ERR(ptr: rt)) {
787 err = PTR_ERR(ptr: rt);
788 rt = NULL;
789 if (err == -ENETUNREACH)
790 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
791 goto out;
792 }
793
794 err = -EACCES;
795 if ((rt->rt_flags & RTCF_BROADCAST) &&
796 !sock_flag(sk, flag: SOCK_BROADCAST))
797 goto out;
798
799 if (msg->msg_flags & MSG_CONFIRM)
800 goto do_confirm;
801back_from_confirm:
802
803 if (!ipc.addr)
804 ipc.addr = fl4.daddr;
805
806 lock_sock(sk);
807
808 pfh.icmph.type = user_icmph.type; /* already checked */
809 pfh.icmph.code = user_icmph.code; /* ditto */
810 pfh.icmph.checksum = 0;
811 pfh.icmph.un.echo.id = inet->inet_sport;
812 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
813 pfh.msg = msg;
814 pfh.wcheck = 0;
815 pfh.family = AF_INET;
816
817 err = ip_append_data(sk, fl4: &fl4, getfrag: ping_getfrag, from: &pfh, len,
818 protolen: sizeof(struct icmphdr), ipc: &ipc, rt: &rt,
819 flags: msg->msg_flags);
820 if (err)
821 ip_flush_pending_frames(sk);
822 else
823 err = ping_v4_push_pending_frames(sk, pfh: &pfh, fl4: &fl4);
824 release_sock(sk);
825
826out:
827 ip_rt_put(rt);
828out_free:
829 if (free)
830 kfree(objp: ipc.opt);
831 if (!err) {
832 icmp_out_count(net: sock_net(sk), type: user_icmph.type);
833 return len;
834 }
835 return err;
836
837do_confirm:
838 if (msg->msg_flags & MSG_PROBE)
839 dst_confirm_neigh(dst: &rt->dst, daddr: &fl4.daddr);
840 if (!(msg->msg_flags & MSG_PROBE) || len)
841 goto back_from_confirm;
842 err = 0;
843 goto out;
844}
845
846int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags,
847 int *addr_len)
848{
849 struct inet_sock *isk = inet_sk(sk);
850 int family = sk->sk_family;
851 struct sk_buff *skb;
852 int copied, err;
853
854 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
855
856 err = -EOPNOTSUPP;
857 if (flags & MSG_OOB)
858 goto out;
859
860 if (flags & MSG_ERRQUEUE)
861 return inet_recv_error(sk, msg, len, addr_len);
862
863 skb = skb_recv_datagram(sk, flags, err: &err);
864 if (!skb)
865 goto out;
866
867 copied = skb->len;
868 if (copied > len) {
869 msg->msg_flags |= MSG_TRUNC;
870 copied = len;
871 }
872
873 /* Don't bother checking the checksum */
874 err = skb_copy_datagram_msg(from: skb, offset: 0, msg, size: copied);
875 if (err)
876 goto done;
877
878 sock_recv_timestamp(msg, sk, skb);
879
880 /* Copy the address and add cmsg data. */
881 if (family == AF_INET) {
882 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
883
884 if (sin) {
885 sin->sin_family = AF_INET;
886 sin->sin_port = 0 /* skb->h.uh->source */;
887 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
888 memset(s: sin->sin_zero, c: 0, n: sizeof(sin->sin_zero));
889 *addr_len = sizeof(*sin);
890 }
891
892 if (inet_cmsg_flags(inet: isk))
893 ip_cmsg_recv(msg, skb);
894
895#if IS_ENABLED(CONFIG_IPV6)
896 } else if (family == AF_INET6) {
897 struct ipv6hdr *ip6 = ipv6_hdr(skb);
898 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
899
900 if (sin6) {
901 sin6->sin6_family = AF_INET6;
902 sin6->sin6_port = 0;
903 sin6->sin6_addr = ip6->saddr;
904 sin6->sin6_flowinfo = 0;
905 if (inet6_test_bit(SNDFLOW, sk))
906 sin6->sin6_flowinfo = ip6_flowinfo(hdr: ip6);
907 sin6->sin6_scope_id =
908 ipv6_iface_scope_id(addr: &sin6->sin6_addr,
909 iface: inet6_iif(skb));
910 *addr_len = sizeof(*sin6);
911 }
912
913 if (inet6_sk(sk: sk)->rxopt.all)
914 pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb);
915 if (skb->protocol == htons(ETH_P_IPV6) &&
916 inet6_sk(sk: sk)->rxopt.all)
917 pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb);
918 else if (skb->protocol == htons(ETH_P_IP) &&
919 inet_cmsg_flags(inet: isk))
920 ip_cmsg_recv(msg, skb);
921#endif
922 } else {
923 BUG();
924 }
925
926 err = copied;
927
928done:
929 skb_free_datagram(sk, skb);
930out:
931 pr_debug("ping_recvmsg -> %d\n", err);
932 return err;
933}
934EXPORT_IPV6_MOD_GPL(ping_recvmsg);
935
936static enum skb_drop_reason __ping_queue_rcv_skb(struct sock *sk,
937 struct sk_buff *skb)
938{
939 enum skb_drop_reason reason;
940
941 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
942 inet_sk(sk), inet_sk(sk)->inet_num, skb);
943 if (sock_queue_rcv_skb_reason(sk, skb, reason: &reason) < 0) {
944 sk_skb_reason_drop(sk, skb, reason);
945 pr_debug("ping_queue_rcv_skb -> failed\n");
946 return reason;
947 }
948 return SKB_NOT_DROPPED_YET;
949}
950
951int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
952{
953 return __ping_queue_rcv_skb(sk, skb) ? -1 : 0;
954}
955EXPORT_IPV6_MOD_GPL(ping_queue_rcv_skb);
956
957
958/*
959 * All we need to do is get the socket.
960 */
961
962enum skb_drop_reason ping_rcv(struct sk_buff *skb)
963{
964 struct net *net = dev_net(dev: skb->dev);
965 struct icmphdr *icmph = icmp_hdr(skb);
966 struct sock *sk;
967
968 /* We assume the packet has already been checked by icmp_rcv */
969
970 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
971 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
972
973 /* Push ICMP header back */
974 skb_push(skb, len: skb->data - (u8 *)icmph);
975
976 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
977 if (sk)
978 return __ping_queue_rcv_skb(sk, skb);
979
980 kfree_skb_reason(skb, reason: SKB_DROP_REASON_NO_SOCKET);
981 return SKB_DROP_REASON_NO_SOCKET;
982}
983EXPORT_IPV6_MOD_GPL(ping_rcv);
984
985struct proto ping_prot = {
986 .name = "PING",
987 .owner = THIS_MODULE,
988 .init = ping_init_sock,
989 .close = ping_close,
990 .pre_connect = ping_pre_connect,
991 .connect = ip4_datagram_connect,
992 .disconnect = __udp_disconnect,
993 .setsockopt = ip_setsockopt,
994 .getsockopt = ip_getsockopt,
995 .sendmsg = ping_v4_sendmsg,
996 .recvmsg = ping_recvmsg,
997 .bind = ping_bind,
998 .backlog_rcv = ping_queue_rcv_skb,
999 .release_cb = ip4_datagram_release_cb,
1000 .unhash = ping_unhash,
1001 .get_port = ping_get_port,
1002 .put_port = ping_unhash,
1003 .obj_size = sizeof(struct inet_sock),
1004};
1005EXPORT_IPV6_MOD(ping_prot);
1006
1007#ifdef CONFIG_PROC_FS
1008
1009static struct sock *ping_get_first(struct seq_file *seq, int start)
1010{
1011 struct sock *sk;
1012 struct ping_iter_state *state = seq->private;
1013 struct net *net = seq_file_net(seq);
1014
1015 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
1016 ++state->bucket) {
1017 struct hlist_head *hslot;
1018
1019 hslot = &ping_table.hash[state->bucket];
1020
1021 if (hlist_empty(h: hslot))
1022 continue;
1023
1024 sk_for_each(sk, hslot) {
1025 if (net_eq(net1: sock_net(sk), net2: net) &&
1026 sk->sk_family == state->family)
1027 goto found;
1028 }
1029 }
1030 sk = NULL;
1031found:
1032 return sk;
1033}
1034
1035static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
1036{
1037 struct ping_iter_state *state = seq->private;
1038 struct net *net = seq_file_net(seq);
1039
1040 do {
1041 sk = sk_next(sk);
1042 } while (sk && (!net_eq(net1: sock_net(sk), net2: net)));
1043
1044 if (!sk)
1045 return ping_get_first(seq, start: state->bucket + 1);
1046 return sk;
1047}
1048
1049static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
1050{
1051 struct sock *sk = ping_get_first(seq, start: 0);
1052
1053 if (sk)
1054 while (pos && (sk = ping_get_next(seq, sk)) != NULL)
1055 --pos;
1056 return pos ? NULL : sk;
1057}
1058
1059void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
1060 __acquires(ping_table.lock)
1061{
1062 struct ping_iter_state *state = seq->private;
1063 state->bucket = 0;
1064 state->family = family;
1065
1066 spin_lock(lock: &ping_table.lock);
1067
1068 return *pos ? ping_get_idx(seq, pos: *pos-1) : SEQ_START_TOKEN;
1069}
1070EXPORT_IPV6_MOD_GPL(ping_seq_start);
1071
1072static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos)
1073{
1074 return ping_seq_start(seq, pos, AF_INET);
1075}
1076
1077void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1078{
1079 struct sock *sk;
1080
1081 if (v == SEQ_START_TOKEN)
1082 sk = ping_get_idx(seq, pos: 0);
1083 else
1084 sk = ping_get_next(seq, sk: v);
1085
1086 ++*pos;
1087 return sk;
1088}
1089EXPORT_IPV6_MOD_GPL(ping_seq_next);
1090
1091void ping_seq_stop(struct seq_file *seq, void *v)
1092 __releases(ping_table.lock)
1093{
1094 spin_unlock(lock: &ping_table.lock);
1095}
1096EXPORT_IPV6_MOD_GPL(ping_seq_stop);
1097
1098static void ping_v4_format_sock(struct sock *sp, struct seq_file *f,
1099 int bucket)
1100{
1101 struct inet_sock *inet = inet_sk(sp);
1102 __be32 dest = inet->inet_daddr;
1103 __be32 src = inet->inet_rcv_saddr;
1104 __u16 destp = ntohs(inet->inet_dport);
1105 __u16 srcp = ntohs(inet->inet_sport);
1106
1107 seq_printf(m: f, fmt: "%5d: %08X:%04X %08X:%04X"
1108 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u",
1109 bucket, src, srcp, dest, destp, sp->sk_state,
1110 sk_wmem_alloc_get(sk: sp),
1111 sk_rmem_alloc_get(sk: sp),
1112 0, 0L, 0,
1113 from_kuid_munged(to: seq_user_ns(seq: f), kuid: sk_uid(sk: sp)),
1114 0, sock_i_ino(sk: sp),
1115 refcount_read(r: &sp->sk_refcnt), sp,
1116 sk_drops_read(sk: sp));
1117}
1118
1119static int ping_v4_seq_show(struct seq_file *seq, void *v)
1120{
1121 seq_setwidth(m: seq, size: 127);
1122 if (v == SEQ_START_TOKEN)
1123 seq_puts(m: seq, s: " sl local_address rem_address st tx_queue "
1124 "rx_queue tr tm->when retrnsmt uid timeout "
1125 "inode ref pointer drops");
1126 else {
1127 struct ping_iter_state *state = seq->private;
1128
1129 ping_v4_format_sock(sp: v, f: seq, bucket: state->bucket);
1130 }
1131 seq_pad(m: seq, c: '\n');
1132 return 0;
1133}
1134
1135static const struct seq_operations ping_v4_seq_ops = {
1136 .start = ping_v4_seq_start,
1137 .show = ping_v4_seq_show,
1138 .next = ping_seq_next,
1139 .stop = ping_seq_stop,
1140};
1141
1142static int __net_init ping_v4_proc_init_net(struct net *net)
1143{
1144 if (!proc_create_net("icmp", 0444, net->proc_net, &ping_v4_seq_ops,
1145 sizeof(struct ping_iter_state)))
1146 return -ENOMEM;
1147
1148 net->ipv4.ping_port_rover = get_random_u16();
1149 return 0;
1150}
1151
1152static void __net_exit ping_v4_proc_exit_net(struct net *net)
1153{
1154 remove_proc_entry("icmp", net->proc_net);
1155}
1156
1157static struct pernet_operations ping_v4_net_ops = {
1158 .init = ping_v4_proc_init_net,
1159 .exit = ping_v4_proc_exit_net,
1160};
1161
1162int __init ping_proc_init(void)
1163{
1164 return register_pernet_subsys(&ping_v4_net_ops);
1165}
1166
1167void ping_proc_exit(void)
1168{
1169 unregister_pernet_subsys(&ping_v4_net_ops);
1170}
1171
1172#endif
1173
1174void __init ping_init(void)
1175{
1176 int i;
1177
1178 for (i = 0; i < PING_HTABLE_SIZE; i++)
1179 INIT_HLIST_HEAD(&ping_table.hash[i]);
1180 spin_lock_init(&ping_table.lock);
1181}
1182