1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * "Ping" sockets
8 *
9 * Based on ipv4/udp.c code.
10 *
11 * Authors: Vasiliy Kulikov / Openwall (for Linux 2.6),
12 * Pavel Kankovsky (for Linux 2.4.32)
13 *
14 * Pavel gave all rights to bugs to Vasiliy,
15 * none of the bugs are Pavel's now.
16 */
17
18 #include <linux/uaccess.h>
19 #include <linux/types.h>
20 #include <linux/fcntl.h>
21 #include <linux/socket.h>
22 #include <linux/sockios.h>
23 #include <linux/in.h>
24 #include <linux/errno.h>
25 #include <linux/timer.h>
26 #include <linux/mm.h>
27 #include <linux/inet.h>
28 #include <linux/netdevice.h>
29 #include <net/snmp.h>
30 #include <net/ip.h>
31 #include <net/icmp.h>
32 #include <net/protocol.h>
33 #include <linux/skbuff.h>
34 #include <linux/proc_fs.h>
35 #include <linux/export.h>
36 #include <net/sock.h>
37 #include <net/ping.h>
38 #include <net/udp.h>
39 #include <net/route.h>
40 #include <net/inet_common.h>
41 #include <net/checksum.h>
42
43 #if IS_ENABLED(CONFIG_IPV6)
44 #include <linux/in6.h>
45 #include <linux/icmpv6.h>
46 #include <net/addrconf.h>
47 #include <net/ipv6.h>
48 #include <net/transp_v6.h>
49 #endif
50
51 struct ping_table {
52 struct hlist_nulls_head hash[PING_HTABLE_SIZE];
53 spinlock_t lock;
54 };
55
56 static struct ping_table ping_table;
57 struct pingv6_ops pingv6_ops;
58 EXPORT_SYMBOL_GPL(pingv6_ops);
59
60 static u16 ping_port_rover;
61
ping_hashfn(const struct net * net,u32 num,u32 mask)62 static inline u32 ping_hashfn(const struct net *net, u32 num, u32 mask)
63 {
64 u32 res = (num + net_hash_mix(net)) & mask;
65
66 pr_debug("hash(%u) = %u\n", num, res);
67 return res;
68 }
69 EXPORT_SYMBOL_GPL(ping_hash);
70
ping_hashslot(struct ping_table * table,struct net * net,unsigned int num)71 static inline struct hlist_nulls_head *ping_hashslot(struct ping_table *table,
72 struct net *net, unsigned int num)
73 {
74 return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)];
75 }
76
ping_get_port(struct sock * sk,unsigned short ident)77 int ping_get_port(struct sock *sk, unsigned short ident)
78 {
79 struct hlist_nulls_node *node;
80 struct hlist_nulls_head *hlist;
81 struct inet_sock *isk, *isk2;
82 struct sock *sk2 = NULL;
83
84 isk = inet_sk(sk);
85 spin_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(&ping_table, sock_net(sk),
94 result);
95 ping_portaddr_for_each_entry(sk2, node, hlist) {
96 isk2 = inet_sk(sk2);
97
98 if (isk2->inet_num == result)
99 goto next_port;
100 }
101
102 /* found */
103 ping_port_rover = ident = result;
104 break;
105 next_port:
106 ;
107 }
108 if (i >= (1L << 16))
109 goto fail;
110 } else {
111 hlist = ping_hashslot(&ping_table, sock_net(sk), ident);
112 ping_portaddr_for_each_entry(sk2, node, hlist) {
113 isk2 = inet_sk(sk2);
114
115 /* BUG? Why is this reuse and not reuseaddr? ping.c
116 * doesn't turn off SO_REUSEADDR, and it doesn't expect
117 * that other ping processes can steal its packets.
118 */
119 if ((isk2->inet_num == ident) &&
120 (sk2 != sk) &&
121 (!sk2->sk_reuse || !sk->sk_reuse))
122 goto fail;
123 }
124 }
125
126 pr_debug("found port/ident = %d\n", ident);
127 isk->inet_num = ident;
128 if (sk_unhashed(sk)) {
129 pr_debug("was not hashed\n");
130 sock_hold(sk);
131 sock_set_flag(sk, SOCK_RCU_FREE);
132 hlist_nulls_add_head_rcu(&sk->sk_nulls_node, hlist);
133 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
134 }
135 spin_unlock(&ping_table.lock);
136 return 0;
137
138 fail:
139 spin_unlock(&ping_table.lock);
140 return 1;
141 }
142 EXPORT_SYMBOL_GPL(ping_get_port);
143
ping_hash(struct sock * sk)144 int ping_hash(struct sock *sk)
145 {
146 pr_debug("ping_hash(sk->port=%u)\n", inet_sk(sk)->inet_num);
147 BUG(); /* "Please do not press this button again." */
148
149 return 0;
150 }
151
ping_unhash(struct sock * sk)152 void ping_unhash(struct sock *sk)
153 {
154 struct inet_sock *isk = inet_sk(sk);
155
156 pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);
157 spin_lock(&ping_table.lock);
158 if (sk_hashed(sk)) {
159 hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
160 sock_put(sk);
161 isk->inet_num = 0;
162 isk->inet_sport = 0;
163 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
164 }
165 spin_unlock(&ping_table.lock);
166 }
167 EXPORT_SYMBOL_GPL(ping_unhash);
168
169 /* Called under rcu_read_lock() */
ping_lookup(struct net * net,struct sk_buff * skb,u16 ident)170 static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
171 {
172 struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident);
173 struct sock *sk = NULL;
174 struct inet_sock *isk;
175 struct hlist_nulls_node *hnode;
176 int dif, sdif;
177
178 if (skb->protocol == htons(ETH_P_IP)) {
179 dif = inet_iif(skb);
180 sdif = inet_sdif(skb);
181 pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n",
182 (int)ident, &ip_hdr(skb)->daddr, dif);
183 #if IS_ENABLED(CONFIG_IPV6)
184 } else if (skb->protocol == htons(ETH_P_IPV6)) {
185 dif = inet6_iif(skb);
186 sdif = inet6_sdif(skb);
187 pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n",
188 (int)ident, &ipv6_hdr(skb)->daddr, dif);
189 #endif
190 } else {
191 return NULL;
192 }
193
194 ping_portaddr_for_each_entry(sk, hnode, hslot) {
195 isk = inet_sk(sk);
196
197 pr_debug("iterate\n");
198 if (isk->inet_num != ident)
199 continue;
200
201 if (skb->protocol == htons(ETH_P_IP) &&
202 sk->sk_family == AF_INET) {
203 pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk,
204 (int) isk->inet_num, &isk->inet_rcv_saddr,
205 sk->sk_bound_dev_if);
206
207 if (isk->inet_rcv_saddr &&
208 isk->inet_rcv_saddr != ip_hdr(skb)->daddr)
209 continue;
210 #if IS_ENABLED(CONFIG_IPV6)
211 } else if (skb->protocol == htons(ETH_P_IPV6) &&
212 sk->sk_family == AF_INET6) {
213
214 pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk,
215 (int) isk->inet_num,
216 &sk->sk_v6_rcv_saddr,
217 sk->sk_bound_dev_if);
218
219 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
220 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr,
221 &ipv6_hdr(skb)->daddr))
222 continue;
223 #endif
224 } else {
225 continue;
226 }
227
228 if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif &&
229 sk->sk_bound_dev_if != sdif)
230 continue;
231
232 goto exit;
233 }
234
235 sk = NULL;
236 exit:
237
238 return sk;
239 }
240
inet_get_ping_group_range_net(struct net * net,kgid_t * low,kgid_t * high)241 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low,
242 kgid_t *high)
243 {
244 kgid_t *data = net->ipv4.ping_group_range.range;
245 unsigned int seq;
246
247 do {
248 seq = read_seqbegin(&net->ipv4.ping_group_range.lock);
249
250 *low = data[0];
251 *high = data[1];
252 } while (read_seqretry(&net->ipv4.ping_group_range.lock, seq));
253 }
254
255
ping_init_sock(struct sock * sk)256 int ping_init_sock(struct sock *sk)
257 {
258 struct net *net = sock_net(sk);
259 kgid_t group = current_egid();
260 struct group_info *group_info;
261 int i;
262 kgid_t low, high;
263 int ret = 0;
264
265 if (sk->sk_family == AF_INET6)
266 sk->sk_ipv6only = 1;
267
268 inet_get_ping_group_range_net(net, &low, &high);
269 if (gid_lte(low, group) && gid_lte(group, high))
270 return 0;
271
272 group_info = get_current_groups();
273 for (i = 0; i < group_info->ngroups; i++) {
274 kgid_t gid = group_info->gid[i];
275
276 if (gid_lte(low, gid) && gid_lte(gid, high))
277 goto out_release_group;
278 }
279
280 ret = -EACCES;
281
282 out_release_group:
283 put_group_info(group_info);
284 return ret;
285 }
286 EXPORT_SYMBOL_GPL(ping_init_sock);
287
ping_close(struct sock * sk,long timeout)288 void ping_close(struct sock *sk, long timeout)
289 {
290 pr_debug("ping_close(sk=%p,sk->num=%u)\n",
291 inet_sk(sk), inet_sk(sk)->inet_num);
292 pr_debug("isk->refcnt = %d\n", refcount_read(&sk->sk_refcnt));
293
294 sk_common_release(sk);
295 }
296 EXPORT_SYMBOL_GPL(ping_close);
297
298 /* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */
ping_check_bind_addr(struct sock * sk,struct inet_sock * isk,struct sockaddr * uaddr,int addr_len)299 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
300 struct sockaddr *uaddr, int addr_len)
301 {
302 struct net *net = sock_net(sk);
303 if (sk->sk_family == AF_INET) {
304 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
305 u32 tb_id = RT_TABLE_LOCAL;
306 int chk_addr_ret;
307
308 if (addr_len < sizeof(*addr))
309 return -EINVAL;
310
311 if (addr->sin_family != AF_INET &&
312 !(addr->sin_family == AF_UNSPEC &&
313 addr->sin_addr.s_addr == htonl(INADDR_ANY)))
314 return -EAFNOSUPPORT;
315
316 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",
317 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
318
319 if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
320 return 0;
321
322 tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id;
323 chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
324
325 if (chk_addr_ret == RTN_MULTICAST ||
326 chk_addr_ret == RTN_BROADCAST ||
327 (chk_addr_ret != RTN_LOCAL &&
328 !inet_can_nonlocal_bind(net, isk)))
329 return -EADDRNOTAVAIL;
330
331 #if IS_ENABLED(CONFIG_IPV6)
332 } else if (sk->sk_family == AF_INET6) {
333 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
334 int addr_type, scoped, has_addr;
335 struct net_device *dev = NULL;
336
337 if (addr_len < sizeof(*addr))
338 return -EINVAL;
339
340 if (addr->sin6_family != AF_INET6)
341 return -EAFNOSUPPORT;
342
343 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n",
344 sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port));
345
346 addr_type = ipv6_addr_type(&addr->sin6_addr);
347 scoped = __ipv6_addr_needs_scope_id(addr_type);
348 if ((addr_type != IPV6_ADDR_ANY &&
349 !(addr_type & IPV6_ADDR_UNICAST)) ||
350 (scoped && !addr->sin6_scope_id))
351 return -EINVAL;
352
353 rcu_read_lock();
354 if (addr->sin6_scope_id) {
355 dev = dev_get_by_index_rcu(net, addr->sin6_scope_id);
356 if (!dev) {
357 rcu_read_unlock();
358 return -ENODEV;
359 }
360 }
361
362 if (!dev && sk->sk_bound_dev_if) {
363 dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if);
364 if (!dev) {
365 rcu_read_unlock();
366 return -ENODEV;
367 }
368 }
369 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev,
370 scoped);
371 rcu_read_unlock();
372
373 if (!(ipv6_can_nonlocal_bind(net, isk) || has_addr ||
374 addr_type == IPV6_ADDR_ANY))
375 return -EADDRNOTAVAIL;
376
377 if (scoped)
378 sk->sk_bound_dev_if = addr->sin6_scope_id;
379 #endif
380 } else {
381 return -EAFNOSUPPORT;
382 }
383 return 0;
384 }
385
ping_set_saddr(struct sock * sk,struct sockaddr * saddr)386 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr)
387 {
388 if (saddr->sa_family == AF_INET) {
389 struct inet_sock *isk = inet_sk(sk);
390 struct sockaddr_in *addr = (struct sockaddr_in *) saddr;
391 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
392 #if IS_ENABLED(CONFIG_IPV6)
393 } else if (saddr->sa_family == AF_INET6) {
394 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr;
395 struct ipv6_pinfo *np = inet6_sk(sk);
396 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr;
397 #endif
398 }
399 }
400
401 /*
402 * We need our own bind because there are no privileged id's == local ports.
403 * Moreover, we don't allow binding to multi- and broadcast addresses.
404 */
405
ping_bind(struct sock * sk,struct sockaddr * uaddr,int addr_len)406 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
407 {
408 struct inet_sock *isk = inet_sk(sk);
409 unsigned short snum;
410 int err;
411 int dif = sk->sk_bound_dev_if;
412
413 err = ping_check_bind_addr(sk, isk, uaddr, addr_len);
414 if (err)
415 return err;
416
417 lock_sock(sk);
418
419 err = -EINVAL;
420 if (isk->inet_num != 0)
421 goto out;
422
423 err = -EADDRINUSE;
424 snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port);
425 if (ping_get_port(sk, snum) != 0) {
426 /* Restore possibly modified sk->sk_bound_dev_if by ping_check_bind_addr(). */
427 sk->sk_bound_dev_if = dif;
428 goto out;
429 }
430 ping_set_saddr(sk, uaddr);
431
432 pr_debug("after bind(): num = %hu, dif = %d\n",
433 isk->inet_num,
434 sk->sk_bound_dev_if);
435
436 err = 0;
437 if (sk->sk_family == AF_INET && isk->inet_rcv_saddr)
438 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
439 #if IS_ENABLED(CONFIG_IPV6)
440 if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr))
441 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
442 #endif
443
444 if (snum)
445 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
446 isk->inet_sport = htons(isk->inet_num);
447 isk->inet_daddr = 0;
448 isk->inet_dport = 0;
449
450 #if IS_ENABLED(CONFIG_IPV6)
451 if (sk->sk_family == AF_INET6)
452 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr));
453 #endif
454
455 sk_dst_reset(sk);
456 out:
457 release_sock(sk);
458 pr_debug("ping_v4_bind -> %d\n", err);
459 return err;
460 }
461 EXPORT_SYMBOL_GPL(ping_bind);
462
463 /*
464 * Is this a supported type of ICMP message?
465 */
466
ping_supported(int family,int type,int code)467 static inline int ping_supported(int family, int type, int code)
468 {
469 return (family == AF_INET && type == ICMP_ECHO && code == 0) ||
470 (family == AF_INET && type == ICMP_EXT_ECHO && code == 0) ||
471 (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0) ||
472 (family == AF_INET6 && type == ICMPV6_EXT_ECHO_REQUEST && code == 0);
473 }
474
475 /*
476 * This routine is called by the ICMP module when it gets some
477 * sort of error condition.
478 */
479
ping_err(struct sk_buff * skb,int offset,u32 info)480 void ping_err(struct sk_buff *skb, int offset, u32 info)
481 {
482 int family;
483 struct icmphdr *icmph;
484 struct inet_sock *inet_sock;
485 int type;
486 int code;
487 struct net *net = dev_net(skb->dev);
488 struct sock *sk;
489 int harderr;
490 int err;
491
492 if (skb->protocol == htons(ETH_P_IP)) {
493 family = AF_INET;
494 type = icmp_hdr(skb)->type;
495 code = icmp_hdr(skb)->code;
496 icmph = (struct icmphdr *)(skb->data + offset);
497 } else if (skb->protocol == htons(ETH_P_IPV6)) {
498 family = AF_INET6;
499 type = icmp6_hdr(skb)->icmp6_type;
500 code = icmp6_hdr(skb)->icmp6_code;
501 icmph = (struct icmphdr *) (skb->data + offset);
502 } else {
503 BUG();
504 }
505
506 /* We assume the packet has already been checked by icmp_unreach */
507
508 if (!ping_supported(family, icmph->type, icmph->code))
509 return;
510
511 pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n",
512 skb->protocol, type, code, ntohs(icmph->un.echo.id),
513 ntohs(icmph->un.echo.sequence));
514
515 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
516 if (!sk) {
517 pr_debug("no socket, dropping\n");
518 return; /* No socket for error */
519 }
520 pr_debug("err on socket %p\n", sk);
521
522 err = 0;
523 harderr = 0;
524 inet_sock = inet_sk(sk);
525
526 if (skb->protocol == htons(ETH_P_IP)) {
527 switch (type) {
528 default:
529 case ICMP_TIME_EXCEEDED:
530 err = EHOSTUNREACH;
531 break;
532 case ICMP_SOURCE_QUENCH:
533 /* This is not a real error but ping wants to see it.
534 * Report it with some fake errno.
535 */
536 err = EREMOTEIO;
537 break;
538 case ICMP_PARAMETERPROB:
539 err = EPROTO;
540 harderr = 1;
541 break;
542 case ICMP_DEST_UNREACH:
543 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
544 ipv4_sk_update_pmtu(skb, sk, info);
545 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) {
546 err = EMSGSIZE;
547 harderr = 1;
548 break;
549 }
550 goto out;
551 }
552 err = EHOSTUNREACH;
553 if (code <= NR_ICMP_UNREACH) {
554 harderr = icmp_err_convert[code].fatal;
555 err = icmp_err_convert[code].errno;
556 }
557 break;
558 case ICMP_REDIRECT:
559 /* See ICMP_SOURCE_QUENCH */
560 ipv4_sk_redirect(skb, sk);
561 err = EREMOTEIO;
562 break;
563 }
564 #if IS_ENABLED(CONFIG_IPV6)
565 } else if (skb->protocol == htons(ETH_P_IPV6)) {
566 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err);
567 #endif
568 }
569
570 /*
571 * RFC1122: OK. Passes ICMP errors back to application, as per
572 * 4.1.3.3.
573 */
574 if ((family == AF_INET && !inet_sock->recverr) ||
575 (family == AF_INET6 && !inet6_sk(sk)->recverr)) {
576 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
577 goto out;
578 } else {
579 if (family == AF_INET) {
580 ip_icmp_error(sk, skb, err, 0 /* no remote port */,
581 info, (u8 *)icmph);
582 #if IS_ENABLED(CONFIG_IPV6)
583 } else if (family == AF_INET6) {
584 pingv6_ops.ipv6_icmp_error(sk, skb, err, 0,
585 info, (u8 *)icmph);
586 #endif
587 }
588 }
589 sk->sk_err = err;
590 sk_error_report(sk);
591 out:
592 return;
593 }
594 EXPORT_SYMBOL_GPL(ping_err);
595
596 /*
597 * Copy and checksum an ICMP Echo packet from user space into a buffer
598 * starting from the payload.
599 */
600
ping_getfrag(void * from,char * to,int offset,int fraglen,int odd,struct sk_buff * skb)601 int ping_getfrag(void *from, char *to,
602 int offset, int fraglen, int odd, struct sk_buff *skb)
603 {
604 struct pingfakehdr *pfh = from;
605
606 if (offset == 0) {
607 fraglen -= sizeof(struct icmphdr);
608 if (fraglen < 0)
609 BUG();
610 if (!csum_and_copy_from_iter_full(to + sizeof(struct icmphdr),
611 fraglen, &pfh->wcheck,
612 &pfh->msg->msg_iter))
613 return -EFAULT;
614 } else if (offset < sizeof(struct icmphdr)) {
615 BUG();
616 } else {
617 if (!csum_and_copy_from_iter_full(to, fraglen, &pfh->wcheck,
618 &pfh->msg->msg_iter))
619 return -EFAULT;
620 }
621
622 #if IS_ENABLED(CONFIG_IPV6)
623 /* For IPv6, checksum each skb as we go along, as expected by
624 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in
625 * wcheck, it will be finalized in ping_v4_push_pending_frames.
626 */
627 if (pfh->family == AF_INET6) {
628 skb->csum = pfh->wcheck;
629 skb->ip_summed = CHECKSUM_NONE;
630 pfh->wcheck = 0;
631 }
632 #endif
633
634 return 0;
635 }
636 EXPORT_SYMBOL_GPL(ping_getfrag);
637
ping_v4_push_pending_frames(struct sock * sk,struct pingfakehdr * pfh,struct flowi4 * fl4)638 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
639 struct flowi4 *fl4)
640 {
641 struct sk_buff *skb = skb_peek(&sk->sk_write_queue);
642
643 if (!skb)
644 return 0;
645 pfh->wcheck = csum_partial((char *)&pfh->icmph,
646 sizeof(struct icmphdr), pfh->wcheck);
647 pfh->icmph.checksum = csum_fold(pfh->wcheck);
648 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
649 skb->ip_summed = CHECKSUM_NONE;
650 return ip_push_pending_frames(sk, fl4);
651 }
652
ping_common_sendmsg(int family,struct msghdr * msg,size_t len,void * user_icmph,size_t icmph_len)653 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
654 void *user_icmph, size_t icmph_len)
655 {
656 u8 type, code;
657
658 if (len > 0xFFFF)
659 return -EMSGSIZE;
660
661 /* Must have at least a full ICMP header. */
662 if (len < icmph_len)
663 return -EINVAL;
664
665 /*
666 * Check the flags.
667 */
668
669 /* Mirror BSD error message compatibility */
670 if (msg->msg_flags & MSG_OOB)
671 return -EOPNOTSUPP;
672
673 /*
674 * Fetch the ICMP header provided by the userland.
675 * iovec is modified! The ICMP header is consumed.
676 */
677 if (memcpy_from_msg(user_icmph, msg, icmph_len))
678 return -EFAULT;
679
680 if (family == AF_INET) {
681 type = ((struct icmphdr *) user_icmph)->type;
682 code = ((struct icmphdr *) user_icmph)->code;
683 #if IS_ENABLED(CONFIG_IPV6)
684 } else if (family == AF_INET6) {
685 type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
686 code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
687 #endif
688 } else {
689 BUG();
690 }
691
692 if (!ping_supported(family, type, code))
693 return -EINVAL;
694
695 return 0;
696 }
697 EXPORT_SYMBOL_GPL(ping_common_sendmsg);
698
ping_v4_sendmsg(struct sock * sk,struct msghdr * msg,size_t len)699 static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
700 {
701 struct net *net = sock_net(sk);
702 struct flowi4 fl4;
703 struct inet_sock *inet = inet_sk(sk);
704 struct ipcm_cookie ipc;
705 struct icmphdr user_icmph;
706 struct pingfakehdr pfh;
707 struct rtable *rt = NULL;
708 struct ip_options_data opt_copy;
709 int free = 0;
710 __be32 saddr, daddr, faddr;
711 u8 tos;
712 int err;
713
714 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
715
716 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
717 sizeof(user_icmph));
718 if (err)
719 return err;
720
721 /*
722 * Get and verify the address.
723 */
724
725 if (msg->msg_name) {
726 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
727 if (msg->msg_namelen < sizeof(*usin))
728 return -EINVAL;
729 if (usin->sin_family != AF_INET)
730 return -EAFNOSUPPORT;
731 daddr = usin->sin_addr.s_addr;
732 /* no remote port */
733 } else {
734 if (sk->sk_state != TCP_ESTABLISHED)
735 return -EDESTADDRREQ;
736 daddr = inet->inet_daddr;
737 /* no remote port */
738 }
739
740 ipcm_init_sk(&ipc, inet);
741
742 if (msg->msg_controllen) {
743 err = ip_cmsg_send(sk, msg, &ipc, false);
744 if (unlikely(err)) {
745 kfree(ipc.opt);
746 return err;
747 }
748 if (ipc.opt)
749 free = 1;
750 }
751 if (!ipc.opt) {
752 struct ip_options_rcu *inet_opt;
753
754 rcu_read_lock();
755 inet_opt = rcu_dereference(inet->inet_opt);
756 if (inet_opt) {
757 memcpy(&opt_copy, inet_opt,
758 sizeof(*inet_opt) + inet_opt->opt.optlen);
759 ipc.opt = &opt_copy.opt;
760 }
761 rcu_read_unlock();
762 }
763
764 saddr = ipc.addr;
765 ipc.addr = faddr = daddr;
766
767 if (ipc.opt && ipc.opt->opt.srr) {
768 if (!daddr) {
769 err = -EINVAL;
770 goto out_free;
771 }
772 faddr = ipc.opt->opt.faddr;
773 }
774 tos = get_rttos(&ipc, inet);
775 if (sock_flag(sk, SOCK_LOCALROUTE) ||
776 (msg->msg_flags & MSG_DONTROUTE) ||
777 (ipc.opt && ipc.opt->opt.is_strictroute)) {
778 tos |= RTO_ONLINK;
779 }
780
781 if (ipv4_is_multicast(daddr)) {
782 if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif))
783 ipc.oif = inet->mc_index;
784 if (!saddr)
785 saddr = inet->mc_addr;
786 } else if (!ipc.oif)
787 ipc.oif = inet->uc_index;
788
789 flowi4_init_output(&fl4, ipc.oif, ipc.sockc.mark, tos,
790 RT_SCOPE_UNIVERSE, sk->sk_protocol,
791 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0,
792 sk->sk_uid);
793
794 fl4.fl4_icmp_type = user_icmph.type;
795 fl4.fl4_icmp_code = user_icmph.code;
796
797 security_sk_classify_flow(sk, flowi4_to_flowi_common(&fl4));
798 rt = ip_route_output_flow(net, &fl4, sk);
799 if (IS_ERR(rt)) {
800 err = PTR_ERR(rt);
801 rt = NULL;
802 if (err == -ENETUNREACH)
803 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
804 goto out;
805 }
806
807 err = -EACCES;
808 if ((rt->rt_flags & RTCF_BROADCAST) &&
809 !sock_flag(sk, SOCK_BROADCAST))
810 goto out;
811
812 if (msg->msg_flags & MSG_CONFIRM)
813 goto do_confirm;
814 back_from_confirm:
815
816 if (!ipc.addr)
817 ipc.addr = fl4.daddr;
818
819 lock_sock(sk);
820
821 pfh.icmph.type = user_icmph.type; /* already checked */
822 pfh.icmph.code = user_icmph.code; /* ditto */
823 pfh.icmph.checksum = 0;
824 pfh.icmph.un.echo.id = inet->inet_sport;
825 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
826 pfh.msg = msg;
827 pfh.wcheck = 0;
828 pfh.family = AF_INET;
829
830 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
831 0, &ipc, &rt, msg->msg_flags);
832 if (err)
833 ip_flush_pending_frames(sk);
834 else
835 err = ping_v4_push_pending_frames(sk, &pfh, &fl4);
836 release_sock(sk);
837
838 out:
839 ip_rt_put(rt);
840 out_free:
841 if (free)
842 kfree(ipc.opt);
843 if (!err) {
844 icmp_out_count(sock_net(sk), user_icmph.type);
845 return len;
846 }
847 return err;
848
849 do_confirm:
850 if (msg->msg_flags & MSG_PROBE)
851 dst_confirm_neigh(&rt->dst, &fl4.daddr);
852 if (!(msg->msg_flags & MSG_PROBE) || len)
853 goto back_from_confirm;
854 err = 0;
855 goto out;
856 }
857
ping_recvmsg(struct sock * sk,struct msghdr * msg,size_t len,int flags,int * addr_len)858 int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags,
859 int *addr_len)
860 {
861 struct inet_sock *isk = inet_sk(sk);
862 int family = sk->sk_family;
863 struct sk_buff *skb;
864 int copied, err;
865
866 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
867
868 err = -EOPNOTSUPP;
869 if (flags & MSG_OOB)
870 goto out;
871
872 if (flags & MSG_ERRQUEUE)
873 return inet_recv_error(sk, msg, len, addr_len);
874
875 skb = skb_recv_datagram(sk, flags, &err);
876 if (!skb)
877 goto out;
878
879 copied = skb->len;
880 if (copied > len) {
881 msg->msg_flags |= MSG_TRUNC;
882 copied = len;
883 }
884
885 /* Don't bother checking the checksum */
886 err = skb_copy_datagram_msg(skb, 0, msg, copied);
887 if (err)
888 goto done;
889
890 sock_recv_timestamp(msg, sk, skb);
891
892 /* Copy the address and add cmsg data. */
893 if (family == AF_INET) {
894 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
895
896 if (sin) {
897 sin->sin_family = AF_INET;
898 sin->sin_port = 0 /* skb->h.uh->source */;
899 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
900 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
901 *addr_len = sizeof(*sin);
902 }
903
904 if (isk->cmsg_flags)
905 ip_cmsg_recv(msg, skb);
906
907 #if IS_ENABLED(CONFIG_IPV6)
908 } else if (family == AF_INET6) {
909 struct ipv6_pinfo *np = inet6_sk(sk);
910 struct ipv6hdr *ip6 = ipv6_hdr(skb);
911 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
912
913 if (sin6) {
914 sin6->sin6_family = AF_INET6;
915 sin6->sin6_port = 0;
916 sin6->sin6_addr = ip6->saddr;
917 sin6->sin6_flowinfo = 0;
918 if (np->sndflow)
919 sin6->sin6_flowinfo = ip6_flowinfo(ip6);
920 sin6->sin6_scope_id =
921 ipv6_iface_scope_id(&sin6->sin6_addr,
922 inet6_iif(skb));
923 *addr_len = sizeof(*sin6);
924 }
925
926 if (inet6_sk(sk)->rxopt.all)
927 pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb);
928 if (skb->protocol == htons(ETH_P_IPV6) &&
929 inet6_sk(sk)->rxopt.all)
930 pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb);
931 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags)
932 ip_cmsg_recv(msg, skb);
933 #endif
934 } else {
935 BUG();
936 }
937
938 err = copied;
939
940 done:
941 skb_free_datagram(sk, skb);
942 out:
943 pr_debug("ping_recvmsg -> %d\n", err);
944 return err;
945 }
946 EXPORT_SYMBOL_GPL(ping_recvmsg);
947
__ping_queue_rcv_skb(struct sock * sk,struct sk_buff * skb)948 static enum skb_drop_reason __ping_queue_rcv_skb(struct sock *sk,
949 struct sk_buff *skb)
950 {
951 enum skb_drop_reason reason;
952
953 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
954 inet_sk(sk), inet_sk(sk)->inet_num, skb);
955 if (sock_queue_rcv_skb_reason(sk, skb, &reason) < 0) {
956 kfree_skb_reason(skb, reason);
957 pr_debug("ping_queue_rcv_skb -> failed\n");
958 return reason;
959 }
960 return SKB_NOT_DROPPED_YET;
961 }
962
ping_queue_rcv_skb(struct sock * sk,struct sk_buff * skb)963 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
964 {
965 return __ping_queue_rcv_skb(sk, skb) ? -1 : 0;
966 }
967 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
968
969
970 /*
971 * All we need to do is get the socket.
972 */
973
ping_rcv(struct sk_buff * skb)974 enum skb_drop_reason ping_rcv(struct sk_buff *skb)
975 {
976 enum skb_drop_reason reason = SKB_DROP_REASON_NO_SOCKET;
977 struct sock *sk;
978 struct net *net = dev_net(skb->dev);
979 struct icmphdr *icmph = icmp_hdr(skb);
980
981 /* We assume the packet has already been checked by icmp_rcv */
982
983 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
984 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
985
986 /* Push ICMP header back */
987 skb_push(skb, skb->data - (u8 *)icmph);
988
989 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
990 if (sk) {
991 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
992
993 pr_debug("rcv on socket %p\n", sk);
994 if (skb2)
995 reason = __ping_queue_rcv_skb(sk, skb2);
996 else
997 reason = SKB_DROP_REASON_NOMEM;
998 }
999
1000 if (reason)
1001 pr_debug("no socket, dropping\n");
1002
1003 return reason;
1004 }
1005 EXPORT_SYMBOL_GPL(ping_rcv);
1006
1007 struct proto ping_prot = {
1008 .name = "PING",
1009 .owner = THIS_MODULE,
1010 .init = ping_init_sock,
1011 .close = ping_close,
1012 .connect = ip4_datagram_connect,
1013 .disconnect = __udp_disconnect,
1014 .setsockopt = ip_setsockopt,
1015 .getsockopt = ip_getsockopt,
1016 .sendmsg = ping_v4_sendmsg,
1017 .recvmsg = ping_recvmsg,
1018 .bind = ping_bind,
1019 .backlog_rcv = ping_queue_rcv_skb,
1020 .release_cb = ip4_datagram_release_cb,
1021 .hash = ping_hash,
1022 .unhash = ping_unhash,
1023 .get_port = ping_get_port,
1024 .put_port = ping_unhash,
1025 .obj_size = sizeof(struct inet_sock),
1026 };
1027 EXPORT_SYMBOL(ping_prot);
1028
1029 #ifdef CONFIG_PROC_FS
1030
ping_get_first(struct seq_file * seq,int start)1031 static struct sock *ping_get_first(struct seq_file *seq, int start)
1032 {
1033 struct sock *sk;
1034 struct ping_iter_state *state = seq->private;
1035 struct net *net = seq_file_net(seq);
1036
1037 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
1038 ++state->bucket) {
1039 struct hlist_nulls_node *node;
1040 struct hlist_nulls_head *hslot;
1041
1042 hslot = &ping_table.hash[state->bucket];
1043
1044 if (hlist_nulls_empty(hslot))
1045 continue;
1046
1047 sk_nulls_for_each(sk, node, hslot) {
1048 if (net_eq(sock_net(sk), net) &&
1049 sk->sk_family == state->family)
1050 goto found;
1051 }
1052 }
1053 sk = NULL;
1054 found:
1055 return sk;
1056 }
1057
ping_get_next(struct seq_file * seq,struct sock * sk)1058 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
1059 {
1060 struct ping_iter_state *state = seq->private;
1061 struct net *net = seq_file_net(seq);
1062
1063 do {
1064 sk = sk_nulls_next(sk);
1065 } while (sk && (!net_eq(sock_net(sk), net)));
1066
1067 if (!sk)
1068 return ping_get_first(seq, state->bucket + 1);
1069 return sk;
1070 }
1071
ping_get_idx(struct seq_file * seq,loff_t pos)1072 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
1073 {
1074 struct sock *sk = ping_get_first(seq, 0);
1075
1076 if (sk)
1077 while (pos && (sk = ping_get_next(seq, sk)) != NULL)
1078 --pos;
1079 return pos ? NULL : sk;
1080 }
1081
ping_seq_start(struct seq_file * seq,loff_t * pos,sa_family_t family)1082 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
1083 __acquires(RCU)
1084 {
1085 struct ping_iter_state *state = seq->private;
1086 state->bucket = 0;
1087 state->family = family;
1088
1089 rcu_read_lock();
1090
1091 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1092 }
1093 EXPORT_SYMBOL_GPL(ping_seq_start);
1094
ping_v4_seq_start(struct seq_file * seq,loff_t * pos)1095 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos)
1096 {
1097 return ping_seq_start(seq, pos, AF_INET);
1098 }
1099
ping_seq_next(struct seq_file * seq,void * v,loff_t * pos)1100 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1101 {
1102 struct sock *sk;
1103
1104 if (v == SEQ_START_TOKEN)
1105 sk = ping_get_idx(seq, 0);
1106 else
1107 sk = ping_get_next(seq, v);
1108
1109 ++*pos;
1110 return sk;
1111 }
1112 EXPORT_SYMBOL_GPL(ping_seq_next);
1113
ping_seq_stop(struct seq_file * seq,void * v)1114 void ping_seq_stop(struct seq_file *seq, void *v)
1115 __releases(RCU)
1116 {
1117 rcu_read_unlock();
1118 }
1119 EXPORT_SYMBOL_GPL(ping_seq_stop);
1120
ping_v4_format_sock(struct sock * sp,struct seq_file * f,int bucket)1121 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f,
1122 int bucket)
1123 {
1124 struct inet_sock *inet = inet_sk(sp);
1125 __be32 dest = inet->inet_daddr;
1126 __be32 src = inet->inet_rcv_saddr;
1127 __u16 destp = ntohs(inet->inet_dport);
1128 __u16 srcp = ntohs(inet->inet_sport);
1129
1130 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
1131 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u",
1132 bucket, src, srcp, dest, destp, sp->sk_state,
1133 sk_wmem_alloc_get(sp),
1134 sk_rmem_alloc_get(sp),
1135 0, 0L, 0,
1136 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
1137 0, sock_i_ino(sp),
1138 refcount_read(&sp->sk_refcnt), sp,
1139 atomic_read(&sp->sk_drops));
1140 }
1141
ping_v4_seq_show(struct seq_file * seq,void * v)1142 static int ping_v4_seq_show(struct seq_file *seq, void *v)
1143 {
1144 seq_setwidth(seq, 127);
1145 if (v == SEQ_START_TOKEN)
1146 seq_puts(seq, " sl local_address rem_address st tx_queue "
1147 "rx_queue tr tm->when retrnsmt uid timeout "
1148 "inode ref pointer drops");
1149 else {
1150 struct ping_iter_state *state = seq->private;
1151
1152 ping_v4_format_sock(v, seq, state->bucket);
1153 }
1154 seq_pad(seq, '\n');
1155 return 0;
1156 }
1157
1158 static const struct seq_operations ping_v4_seq_ops = {
1159 .start = ping_v4_seq_start,
1160 .show = ping_v4_seq_show,
1161 .next = ping_seq_next,
1162 .stop = ping_seq_stop,
1163 };
1164
ping_v4_proc_init_net(struct net * net)1165 static int __net_init ping_v4_proc_init_net(struct net *net)
1166 {
1167 if (!proc_create_net("icmp", 0444, net->proc_net, &ping_v4_seq_ops,
1168 sizeof(struct ping_iter_state)))
1169 return -ENOMEM;
1170 return 0;
1171 }
1172
ping_v4_proc_exit_net(struct net * net)1173 static void __net_exit ping_v4_proc_exit_net(struct net *net)
1174 {
1175 remove_proc_entry("icmp", net->proc_net);
1176 }
1177
1178 static struct pernet_operations ping_v4_net_ops = {
1179 .init = ping_v4_proc_init_net,
1180 .exit = ping_v4_proc_exit_net,
1181 };
1182
ping_proc_init(void)1183 int __init ping_proc_init(void)
1184 {
1185 return register_pernet_subsys(&ping_v4_net_ops);
1186 }
1187
ping_proc_exit(void)1188 void ping_proc_exit(void)
1189 {
1190 unregister_pernet_subsys(&ping_v4_net_ops);
1191 }
1192
1193 #endif
1194
ping_init(void)1195 void __init ping_init(void)
1196 {
1197 int i;
1198
1199 for (i = 0; i < PING_HTABLE_SIZE; i++)
1200 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i);
1201 spin_lock_init(&ping_table.lock);
1202 }
1203