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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;
59
60static inline u32 ping_hashfn(const struct net *net, u32 num, u32 mask)
61{
62 u32 res = (num + net_hash_mix(net)) & mask;
63
64 pr_debug("hash(%u) = %u\n", num, res);
65 return res;
66}
67
68static inline struct hlist_head *ping_hashslot(struct ping_table *table,
69 struct net *net, unsigned int num)
70{
71 return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)];
72}
73
74int ping_get_port(struct sock *sk, unsigned short ident)
75{
76 struct net *net = sock_net(sk);
77 struct inet_sock *isk, *isk2;
78 struct hlist_head *hlist;
79 struct sock *sk2 = NULL;
80
81 isk = inet_sk(sk);
82 spin_lock(&ping_table.lock);
83 if (ident == 0) {
84 u16 result = net->ipv4.ping_port_rover + 1;
85 u32 i;
86
87 for (i = 0; i < (1L << 16); i++, result++) {
88 if (!result)
89 continue; /* avoid zero */
90 hlist = ping_hashslot(&ping_table, net, result);
91 sk_for_each(sk2, hlist) {
92 if (!net_eq(sock_net(sk2), net))
93 continue;
94 isk2 = inet_sk(sk2);
95
96 if (isk2->inet_num == result)
97 goto next_port;
98 }
99
100 /* found */
101 net->ipv4.ping_port_rover = ident = result;
102 break;
103next_port:
104 ;
105 }
106 if (i >= (1L << 16))
107 goto fail;
108 } else {
109 hlist = ping_hashslot(&ping_table, net, ident);
110 sk_for_each(sk2, hlist) {
111 if (!net_eq(sock_net(sk2), net))
112 continue;
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, hlist);
131 sock_set_flag(sk, SOCK_RCU_FREE);
132 sock_prot_inuse_add(net, sk->sk_prot, 1);
133 }
134 spin_unlock(&ping_table.lock);
135 return 0;
136
137fail:
138 spin_unlock(&ping_table.lock);
139 return -EADDRINUSE;
140}
141
142void ping_unhash(struct sock *sk)
143{
144 struct inet_sock *isk = inet_sk(sk);
145
146 pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);
147 spin_lock(&ping_table.lock);
148 if (sk_del_node_init_rcu(sk)) {
149 WRITE_ONCE(isk->inet_num, 0);
150 isk->inet_sport = 0;
151 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
152 }
153 spin_unlock(&ping_table.lock);
154}
155
156/* Called under rcu_read_lock() */
157static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
158{
159 struct hlist_head *hslot = ping_hashslot(&ping_table, net, ident);
160 struct sock *sk = NULL;
161 struct inet_sock *isk;
162 int dif, sdif;
163
164 if (skb->protocol == htons(ETH_P_IP)) {
165 dif = inet_iif(skb);
166 sdif = inet_sdif(skb);
167 pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n",
168 (int)ident, &ip_hdr(skb)->daddr, dif);
169#if IS_ENABLED(CONFIG_IPV6)
170 } else if (skb->protocol == htons(ETH_P_IPV6)) {
171 dif = inet6_iif(skb);
172 sdif = inet6_sdif(skb);
173 pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n",
174 (int)ident, &ipv6_hdr(skb)->daddr, dif);
175#endif
176 } else {
177 return NULL;
178 }
179
180 sk_for_each_rcu(sk, hslot) {
181 int bound_dev_if;
182
183 if (!net_eq(sock_net(sk), net))
184 continue;
185 isk = inet_sk(sk);
186
187 pr_debug("iterate\n");
188 if (READ_ONCE(isk->inet_num) != ident)
189 continue;
190
191 bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
192 if (skb->protocol == htons(ETH_P_IP) &&
193 sk->sk_family == AF_INET) {
194 __be32 rcv_saddr = READ_ONCE(isk->inet_rcv_saddr);
195
196 pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk,
197 ident, &rcv_saddr,
198 bound_dev_if);
199
200 if (rcv_saddr && rcv_saddr != ip_hdr(skb)->daddr)
201 continue;
202#if IS_ENABLED(CONFIG_IPV6)
203 } else if (skb->protocol == htons(ETH_P_IPV6) &&
204 sk->sk_family == AF_INET6) {
205
206 pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk,
207 ident,
208 &sk->sk_v6_rcv_saddr,
209 bound_dev_if);
210
211 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
212 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr,
213 &ipv6_hdr(skb)->daddr))
214 continue;
215#endif
216 } else {
217 continue;
218 }
219
220 if (bound_dev_if && bound_dev_if != dif &&
221 bound_dev_if != sdif)
222 continue;
223
224 goto exit;
225 }
226
227 sk = NULL;
228exit:
229
230 return sk;
231}
232
233static void inet_get_ping_group_range_net(struct net *net, kgid_t *low,
234 kgid_t *high)
235{
236 kgid_t *data = net->ipv4.ping_group_range.range;
237 unsigned int seq;
238
239 do {
240 seq = read_seqbegin(&net->ipv4.ping_group_range.lock);
241
242 *low = data[0];
243 *high = data[1];
244 } while (read_seqretry(&net->ipv4.ping_group_range.lock, seq));
245}
246
247
248int ping_init_sock(struct sock *sk)
249{
250 struct net *net = sock_net(sk);
251 kgid_t group = current_egid();
252 struct group_info *group_info;
253 int i;
254 kgid_t low, high;
255 int ret = 0;
256
257 if (sk->sk_family == AF_INET6)
258 sk->sk_ipv6only = 1;
259
260 inet_get_ping_group_range_net(net, &low, &high);
261 if (gid_lte(low, group) && gid_lte(group, high))
262 return 0;
263
264 group_info = get_current_groups();
265 for (i = 0; i < group_info->ngroups; i++) {
266 kgid_t gid = group_info->gid[i];
267
268 if (gid_lte(low, gid) && gid_lte(gid, high))
269 goto out_release_group;
270 }
271
272 ret = -EACCES;
273
274out_release_group:
275 put_group_info(group_info);
276 return ret;
277}
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}
287
288static int ping_pre_connect(struct sock *sk, struct sockaddr_unsized *uaddr,
289 int addr_len)
290{
291 /* This check is replicated from __ip4_datagram_connect() and
292 * intended to prevent BPF program called below from accessing bytes
293 * that are out of the bound specified by user in addr_len.
294 */
295 if (addr_len < sizeof(struct sockaddr_in))
296 return -EINVAL;
297
298 return BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr, &addr_len);
299}
300
301/* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */
302static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
303 struct sockaddr_unsized *uaddr, int addr_len)
304{
305 struct net *net = sock_net(sk);
306 if (sk->sk_family == AF_INET) {
307 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
308 u32 tb_id = RT_TABLE_LOCAL;
309 int chk_addr_ret;
310
311 if (addr_len < sizeof(*addr))
312 return -EINVAL;
313
314 if (addr->sin_family != AF_INET &&
315 !(addr->sin_family == AF_UNSPEC &&
316 addr->sin_addr.s_addr == htonl(INADDR_ANY)))
317 return -EAFNOSUPPORT;
318
319 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",
320 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
321
322 if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
323 return 0;
324
325 tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id;
326 chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
327
328 if (chk_addr_ret == RTN_MULTICAST ||
329 chk_addr_ret == RTN_BROADCAST ||
330 (chk_addr_ret != RTN_LOCAL &&
331 !inet_can_nonlocal_bind(net, isk)))
332 return -EADDRNOTAVAIL;
333
334#if IS_ENABLED(CONFIG_IPV6)
335 } else if (sk->sk_family == AF_INET6) {
336 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
337 int addr_type, scoped, has_addr;
338 struct net_device *dev = NULL;
339
340 if (addr_len < sizeof(*addr))
341 return -EINVAL;
342
343 if (addr->sin6_family != AF_INET6)
344 return -EAFNOSUPPORT;
345
346 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n",
347 sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port));
348
349 addr_type = ipv6_addr_type(&addr->sin6_addr);
350 scoped = __ipv6_addr_needs_scope_id(addr_type);
351 if ((addr_type != IPV6_ADDR_ANY &&
352 !(addr_type & IPV6_ADDR_UNICAST)) ||
353 (scoped && !addr->sin6_scope_id))
354 return -EINVAL;
355
356 rcu_read_lock();
357 if (addr->sin6_scope_id) {
358 dev = dev_get_by_index_rcu(net, addr->sin6_scope_id);
359 if (!dev) {
360 rcu_read_unlock();
361 return -ENODEV;
362 }
363 }
364
365 if (!dev && sk->sk_bound_dev_if) {
366 dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if);
367 if (!dev) {
368 rcu_read_unlock();
369 return -ENODEV;
370 }
371 }
372 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev,
373 scoped);
374 rcu_read_unlock();
375
376 if (!(ipv6_can_nonlocal_bind(net, isk) || has_addr ||
377 addr_type == IPV6_ADDR_ANY))
378 return -EADDRNOTAVAIL;
379
380 if (scoped)
381 sk->sk_bound_dev_if = addr->sin6_scope_id;
382#endif
383 } else {
384 return -EAFNOSUPPORT;
385 }
386 return 0;
387}
388
389static void ping_set_saddr(struct sock *sk, struct sockaddr_unsized *saddr)
390{
391 if (saddr->sa_family == AF_INET) {
392 struct inet_sock *isk = inet_sk(sk);
393 struct sockaddr_in *addr = (struct sockaddr_in *) saddr;
394
395 isk->inet_saddr = addr->sin_addr.s_addr;
396 WRITE_ONCE(isk->inet_rcv_saddr, addr->sin_addr.s_addr);
397#if IS_ENABLED(CONFIG_IPV6)
398 } else if (saddr->sa_family == AF_INET6) {
399 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr;
400 struct ipv6_pinfo *np = inet6_sk(sk);
401 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr;
402#endif
403 }
404}
405
406/*
407 * We need our own bind because there are no privileged id's == local ports.
408 * Moreover, we don't allow binding to multi- and broadcast addresses.
409 */
410
411int ping_bind(struct sock *sk, struct sockaddr_unsized *uaddr, int addr_len)
412{
413 struct inet_sock *isk = inet_sk(sk);
414 unsigned short snum;
415 int err;
416 int dif = sk->sk_bound_dev_if;
417
418 err = ping_check_bind_addr(sk, isk, uaddr, addr_len);
419 if (err)
420 return err;
421
422 lock_sock(sk);
423
424 err = -EINVAL;
425 if (isk->inet_num != 0)
426 goto out;
427
428 err = -EADDRINUSE;
429 snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port);
430 if (ping_get_port(sk, snum) != 0) {
431 /* Restore possibly modified sk->sk_bound_dev_if by ping_check_bind_addr(). */
432 sk->sk_bound_dev_if = dif;
433 goto out;
434 }
435 ping_set_saddr(sk, uaddr);
436
437 pr_debug("after bind(): num = %hu, dif = %d\n",
438 isk->inet_num,
439 sk->sk_bound_dev_if);
440
441 err = 0;
442 if (sk->sk_family == AF_INET && isk->inet_rcv_saddr)
443 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
444#if IS_ENABLED(CONFIG_IPV6)
445 if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr))
446 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
447#endif
448
449 if (snum)
450 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
451 isk->inet_sport = htons(isk->inet_num);
452 isk->inet_daddr = 0;
453 isk->inet_dport = 0;
454
455#if IS_ENABLED(CONFIG_IPV6)
456 if (sk->sk_family == AF_INET6)
457 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr));
458#endif
459
460 sk_dst_reset(sk);
461out:
462 release_sock(sk);
463 pr_debug("ping_v4_bind -> %d\n", err);
464 return err;
465}
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(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, icmph->type, 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, 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, 0 /* no remote port */,
585 info, (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}
598
599/*
600 * Copy and checksum an ICMP Echo packet from user space into a buffer
601 * starting from the payload.
602 */
603
604int ping_getfrag(void *from, char *to,
605 int offset, int fraglen, int odd, struct sk_buff *skb)
606{
607 struct pingfakehdr *pfh = from;
608
609 if (!csum_and_copy_from_iter_full(to, fraglen, &pfh->wcheck,
610 &pfh->msg->msg_iter))
611 return -EFAULT;
612
613#if IS_ENABLED(CONFIG_IPV6)
614 /* For IPv6, checksum each skb as we go along, as expected by
615 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in
616 * wcheck, it will be finalized in ping_v4_push_pending_frames.
617 */
618 if (pfh->family == AF_INET6) {
619 skb->csum = csum_block_add(skb->csum, pfh->wcheck, odd);
620 skb->ip_summed = CHECKSUM_NONE;
621 pfh->wcheck = 0;
622 }
623#endif
624
625 return 0;
626}
627
628static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
629 struct flowi4 *fl4)
630{
631 struct sk_buff *skb = skb_peek(&sk->sk_write_queue);
632
633 if (!skb)
634 return 0;
635 pfh->wcheck = csum_partial((char *)&pfh->icmph,
636 sizeof(struct icmphdr), pfh->wcheck);
637 pfh->icmph.checksum = csum_fold(pfh->wcheck);
638 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
639 skb->ip_summed = CHECKSUM_NONE;
640 return ip_push_pending_frames(sk, fl4);
641}
642
643int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
644 void *user_icmph, size_t icmph_len)
645{
646 u8 type, code;
647
648 if (len > 0xFFFF)
649 return -EMSGSIZE;
650
651 /* Must have at least a full ICMP header. */
652 if (len < icmph_len)
653 return -EINVAL;
654
655 /*
656 * Check the flags.
657 */
658
659 /* Mirror BSD error message compatibility */
660 if (msg->msg_flags & MSG_OOB)
661 return -EOPNOTSUPP;
662
663 /*
664 * Fetch the ICMP header provided by the userland.
665 * iovec is modified! The ICMP header is consumed.
666 */
667 if (memcpy_from_msg(user_icmph, msg, icmph_len))
668 return -EFAULT;
669
670 if (family == AF_INET) {
671 type = ((struct icmphdr *) user_icmph)->type;
672 code = ((struct icmphdr *) user_icmph)->code;
673#if IS_ENABLED(CONFIG_IPV6)
674 } else if (family == AF_INET6) {
675 type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
676 code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
677#endif
678 } else {
679 BUG();
680 }
681
682 if (!ping_supported(family, type, code))
683 return -EINVAL;
684
685 return 0;
686}
687
688static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
689{
690 DEFINE_RAW_FLEX(struct ip_options_rcu, opt_copy, opt.__data,
691 IP_OPTIONS_DATA_FIXED_SIZE);
692 struct net *net = sock_net(sk);
693 struct flowi4 fl4;
694 struct inet_sock *inet = inet_sk(sk);
695 struct ipcm_cookie ipc;
696 struct icmphdr user_icmph;
697 struct pingfakehdr pfh;
698 struct rtable *rt = NULL;
699 int free = 0;
700 __be32 saddr, daddr, faddr;
701 u8 scope;
702 int err;
703
704 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
705
706 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
707 sizeof(user_icmph));
708 if (err)
709 return err;
710
711 /*
712 * Get and verify the address.
713 */
714
715 if (msg->msg_name) {
716 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
717 if (msg->msg_namelen < sizeof(*usin))
718 return -EINVAL;
719 if (usin->sin_family != AF_INET)
720 return -EAFNOSUPPORT;
721 daddr = usin->sin_addr.s_addr;
722 /* no remote port */
723 } else {
724 if (sk->sk_state != TCP_ESTABLISHED)
725 return -EDESTADDRREQ;
726 daddr = inet->inet_daddr;
727 /* no remote port */
728 }
729
730 ipcm_init_sk(&ipc, inet);
731
732 if (msg->msg_controllen) {
733 err = ip_cmsg_send(sk, msg, &ipc, false);
734 if (unlikely(err)) {
735 kfree(ipc.opt);
736 return err;
737 }
738 if (ipc.opt)
739 free = 1;
740 }
741 if (!ipc.opt) {
742 struct ip_options_rcu *inet_opt;
743
744 rcu_read_lock();
745 inet_opt = rcu_dereference(inet->inet_opt);
746 if (inet_opt) {
747 memcpy(opt_copy, inet_opt,
748 sizeof(*inet_opt) + inet_opt->opt.optlen);
749 ipc.opt = opt_copy;
750 }
751 rcu_read_unlock();
752 }
753
754 saddr = ipc.addr;
755 ipc.addr = faddr = daddr;
756
757 if (ipc.opt && ipc.opt->opt.srr) {
758 if (!daddr) {
759 err = -EINVAL;
760 goto out_free;
761 }
762 faddr = ipc.opt->opt.faddr;
763 }
764 scope = ip_sendmsg_scope(inet, &ipc, msg);
765
766 if (ipv4_is_multicast(daddr)) {
767 if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif))
768 ipc.oif = READ_ONCE(inet->mc_index);
769 if (!saddr)
770 saddr = READ_ONCE(inet->mc_addr);
771 } else if (!ipc.oif)
772 ipc.oif = READ_ONCE(inet->uc_index);
773
774 flowi4_init_output(&fl4, ipc.oif, ipc.sockc.mark,
775 ipc.tos & INET_DSCP_MASK, scope,
776 sk->sk_protocol, inet_sk_flowi_flags(sk), faddr,
777 saddr, 0, 0, sk_uid(sk));
778
779 fl4.fl4_icmp_type = user_icmph.type;
780 fl4.fl4_icmp_code = user_icmph.code;
781
782 security_sk_classify_flow(sk, flowi4_to_flowi_common(&fl4));
783 rt = ip_route_output_flow(net, &fl4, sk);
784 if (IS_ERR(rt)) {
785 err = PTR_ERR(rt);
786 rt = NULL;
787 if (err == -ENETUNREACH)
788 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
789 goto out;
790 }
791
792 err = -EACCES;
793 if ((rt->rt_flags & RTCF_BROADCAST) &&
794 !sock_flag(sk, SOCK_BROADCAST))
795 goto out;
796
797 if (msg->msg_flags & MSG_CONFIRM)
798 goto do_confirm;
799back_from_confirm:
800
801 if (!ipc.addr)
802 ipc.addr = fl4.daddr;
803
804 lock_sock(sk);
805
806 pfh.icmph.type = user_icmph.type; /* already checked */
807 pfh.icmph.code = user_icmph.code; /* ditto */
808 pfh.icmph.checksum = 0;
809 pfh.icmph.un.echo.id = inet->inet_sport;
810 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
811 pfh.msg = msg;
812 pfh.wcheck = 0;
813 pfh.family = AF_INET;
814
815 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
816 sizeof(struct icmphdr), &ipc, &rt,
817 msg->msg_flags);
818 if (err)
819 ip_flush_pending_frames(sk);
820 else
821 err = ping_v4_push_pending_frames(sk, &pfh, &fl4);
822 release_sock(sk);
823
824out:
825 ip_rt_put(rt);
826out_free:
827 if (free)
828 kfree(ipc.opt);
829 if (!err)
830 return len;
831 return err;
832
833do_confirm:
834 if (msg->msg_flags & MSG_PROBE)
835 dst_confirm_neigh(&rt->dst, &fl4.daddr);
836 if (!(msg->msg_flags & MSG_PROBE) || len)
837 goto back_from_confirm;
838 err = 0;
839 goto out;
840}
841
842int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags)
843{
844 struct inet_sock *isk = inet_sk(sk);
845 int family = sk->sk_family;
846 struct sk_buff *skb;
847 int copied, err;
848
849 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk,
850 READ_ONCE(isk->inet_num));
851
852 err = -EOPNOTSUPP;
853 if (flags & MSG_OOB)
854 goto out;
855
856 if (flags & MSG_ERRQUEUE)
857 return inet_recv_error(sk, msg, len);
858
859 skb = skb_recv_datagram(sk, flags, &err);
860 if (!skb)
861 goto out;
862
863 copied = skb->len;
864 if (copied > len) {
865 msg->msg_flags |= MSG_TRUNC;
866 copied = len;
867 }
868
869 /* Don't bother checking the checksum */
870 err = skb_copy_datagram_msg(skb, 0, msg, copied);
871 if (err)
872 goto done;
873
874 sock_recv_timestamp(msg, sk, skb);
875
876 /* Copy the address and add cmsg data. */
877 if (family == AF_INET) {
878 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
879
880 if (sin) {
881 sin->sin_family = AF_INET;
882 sin->sin_port = 0 /* skb->h.uh->source */;
883 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
884 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
885 msg->msg_namelen = sizeof(*sin);
886 }
887
888 if (inet_cmsg_flags(isk))
889 ip_cmsg_recv(msg, skb);
890
891#if IS_ENABLED(CONFIG_IPV6)
892 } else if (family == AF_INET6) {
893 struct ipv6hdr *ip6 = ipv6_hdr(skb);
894 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
895
896 if (sin6) {
897 sin6->sin6_family = AF_INET6;
898 sin6->sin6_port = 0;
899 sin6->sin6_addr = ip6->saddr;
900 sin6->sin6_flowinfo = 0;
901 if (inet6_test_bit(SNDFLOW, sk))
902 sin6->sin6_flowinfo = ip6_flowinfo(ip6);
903 sin6->sin6_scope_id =
904 ipv6_iface_scope_id(&sin6->sin6_addr,
905 inet6_iif(skb));
906 msg->msg_namelen = sizeof(*sin6);
907 }
908
909 if (inet6_sk(sk)->rxopt.all)
910 pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb);
911 if (skb->protocol == htons(ETH_P_IPV6) &&
912 inet6_sk(sk)->rxopt.all)
913 pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb);
914 else if (skb->protocol == htons(ETH_P_IP) &&
915 inet_cmsg_flags(isk))
916 ip_cmsg_recv(msg, skb);
917#endif
918 } else {
919 BUG();
920 }
921
922 err = copied;
923
924done:
925 skb_free_datagram(sk, skb);
926out:
927 pr_debug("ping_recvmsg -> %d\n", err);
928 return err;
929}
930
931static enum skb_drop_reason __ping_queue_rcv_skb(struct sock *sk,
932 struct sk_buff *skb)
933{
934 enum skb_drop_reason reason;
935
936 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
937 inet_sk(sk), inet_sk(sk)->inet_num, skb);
938 reason = sock_queue_rcv_skb_reason(sk, skb);
939 if (reason) {
940 sk_skb_reason_drop(sk, skb, reason);
941 pr_debug("ping_queue_rcv_skb -> failed\n");
942 return reason;
943 }
944 return SKB_NOT_DROPPED_YET;
945}
946
947int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
948{
949 return __ping_queue_rcv_skb(sk, skb) ? -1 : 0;
950}
951
952
953/*
954 * All we need to do is get the socket.
955 */
956
957enum skb_drop_reason ping_rcv(struct sk_buff *skb)
958{
959 struct net *net = dev_net(skb->dev);
960 struct icmphdr *icmph = icmp_hdr(skb);
961 struct sock *sk;
962
963 /* We assume the packet has already been checked by icmp_rcv */
964
965 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
966 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
967
968 /* Push ICMP header back */
969 skb_push(skb, skb->data - (u8 *)icmph);
970
971 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
972 if (sk)
973 return __ping_queue_rcv_skb(sk, skb);
974
975 kfree_skb_reason(skb, SKB_DROP_REASON_NO_SOCKET);
976 return SKB_DROP_REASON_NO_SOCKET;
977}
978
979struct proto ping_prot = {
980 .name = "PING",
981 .owner = THIS_MODULE,
982 .init = ping_init_sock,
983 .close = ping_close,
984 .pre_connect = ping_pre_connect,
985 .connect = ip4_datagram_connect,
986 .disconnect = __udp_disconnect,
987 .setsockopt = ip_setsockopt,
988 .getsockopt = ip_getsockopt,
989 .sendmsg = ping_v4_sendmsg,
990 .recvmsg = ping_recvmsg,
991 .bind = ping_bind,
992 .backlog_rcv = ping_queue_rcv_skb,
993 .release_cb = ip4_datagram_release_cb,
994 .unhash = ping_unhash,
995 .get_port = ping_get_port,
996 .put_port = ping_unhash,
997 .obj_size = sizeof(struct inet_sock),
998};
999
1000#ifdef CONFIG_PROC_FS
1001
1002static struct sock *ping_get_first(struct seq_file *seq, int start)
1003{
1004 struct sock *sk;
1005 struct ping_iter_state *state = seq->private;
1006 struct net *net = seq_file_net(seq);
1007
1008 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
1009 ++state->bucket) {
1010 struct hlist_head *hslot;
1011
1012 hslot = &ping_table.hash[state->bucket];
1013
1014 if (hlist_empty(hslot))
1015 continue;
1016
1017 sk_for_each(sk, hslot) {
1018 if (net_eq(sock_net(sk), net) &&
1019 sk->sk_family == state->family)
1020 goto found;
1021 }
1022 }
1023 sk = NULL;
1024found:
1025 return sk;
1026}
1027
1028static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
1029{
1030 struct ping_iter_state *state = seq->private;
1031 struct net *net = seq_file_net(seq);
1032
1033 do {
1034 sk = sk_next(sk);
1035 } while (sk && (!net_eq(sock_net(sk), net)));
1036
1037 if (!sk)
1038 return ping_get_first(seq, state->bucket + 1);
1039 return sk;
1040}
1041
1042static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
1043{
1044 struct sock *sk = ping_get_first(seq, 0);
1045
1046 if (sk)
1047 while (pos && (sk = ping_get_next(seq, sk)) != NULL)
1048 --pos;
1049 return pos ? NULL : sk;
1050}
1051
1052void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
1053 __acquires(ping_table.lock)
1054{
1055 struct ping_iter_state *state = seq->private;
1056 state->bucket = 0;
1057 state->family = family;
1058
1059 spin_lock(&ping_table.lock);
1060
1061 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1062}
1063
1064static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos)
1065{
1066 return ping_seq_start(seq, pos, AF_INET);
1067}
1068
1069void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1070{
1071 struct sock *sk;
1072
1073 if (v == SEQ_START_TOKEN)
1074 sk = ping_get_idx(seq, 0);
1075 else
1076 sk = ping_get_next(seq, v);
1077
1078 ++*pos;
1079 return sk;
1080}
1081
1082void ping_seq_stop(struct seq_file *seq, void *v)
1083 __releases(ping_table.lock)
1084{
1085 spin_unlock(&ping_table.lock);
1086}
1087
1088static void ping_v4_format_sock(struct sock *sp, struct seq_file *f,
1089 int bucket)
1090{
1091 struct inet_sock *inet = inet_sk(sp);
1092 __be32 dest = inet->inet_daddr;
1093 __be32 src = inet->inet_rcv_saddr;
1094 __u16 destp = ntohs(inet->inet_dport);
1095 __u16 srcp = ntohs(inet->inet_sport);
1096
1097 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
1098 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %llu %d %pK %u",
1099 bucket, src, srcp, dest, destp, sp->sk_state,
1100 sk_wmem_alloc_get(sp),
1101 sk_rmem_alloc_get(sp),
1102 0, 0L, 0,
1103 from_kuid_munged(seq_user_ns(f), sk_uid(sp)),
1104 0, sock_i_ino(sp),
1105 refcount_read(&sp->sk_refcnt), sp,
1106 sk_drops_read(sp));
1107}
1108
1109static int ping_v4_seq_show(struct seq_file *seq, void *v)
1110{
1111 seq_setwidth(seq, 127);
1112 if (v == SEQ_START_TOKEN)
1113 seq_puts(seq, " sl local_address rem_address st tx_queue "
1114 "rx_queue tr tm->when retrnsmt uid timeout "
1115 "inode ref pointer drops");
1116 else {
1117 struct ping_iter_state *state = seq->private;
1118
1119 ping_v4_format_sock(v, seq, state->bucket);
1120 }
1121 seq_pad(seq, '\n');
1122 return 0;
1123}
1124
1125static const struct seq_operations ping_v4_seq_ops = {
1126 .start = ping_v4_seq_start,
1127 .show = ping_v4_seq_show,
1128 .next = ping_seq_next,
1129 .stop = ping_seq_stop,
1130};
1131
1132static int __net_init ping_v4_proc_init_net(struct net *net)
1133{
1134 if (!proc_create_net("icmp", 0444, net->proc_net, &ping_v4_seq_ops,
1135 sizeof(struct ping_iter_state)))
1136 return -ENOMEM;
1137
1138 net->ipv4.ping_port_rover = get_random_u16();
1139 return 0;
1140}
1141
1142static void __net_exit ping_v4_proc_exit_net(struct net *net)
1143{
1144 remove_proc_entry("icmp", net->proc_net);
1145}
1146
1147static struct pernet_operations ping_v4_net_ops = {
1148 .init = ping_v4_proc_init_net,
1149 .exit = ping_v4_proc_exit_net,
1150};
1151
1152int __init ping_proc_init(void)
1153{
1154 return register_pernet_subsys(&ping_v4_net_ops);
1155}
1156
1157void ping_proc_exit(void)
1158{
1159 unregister_pernet_subsys(&ping_v4_net_ops);
1160}
1161
1162#endif
1163
1164void __init ping_init(void)
1165{
1166 int i;
1167
1168 for (i = 0; i < PING_HTABLE_SIZE; i++)
1169 INIT_HLIST_HEAD(&ping_table.hash[i]);
1170 spin_lock_init(&ping_table.lock);
1171}