1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * "Ping" sockets
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
12 *
13 * Based on ipv4/udp.c code.
14 *
15 * Authors: Vasiliy Kulikov / Openwall (for Linux 2.6),
16 * Pavel Kankovsky (for Linux 2.4.32)
17 *
18 * Pavel gave all rights to bugs to Vasiliy,
19 * none of the bugs are Pavel's now.
20 *
21 */
22
23 #include <linux/uaccess.h>
24 #include <linux/types.h>
25 #include <linux/fcntl.h>
26 #include <linux/socket.h>
27 #include <linux/sockios.h>
28 #include <linux/in.h>
29 #include <linux/errno.h>
30 #include <linux/timer.h>
31 #include <linux/mm.h>
32 #include <linux/inet.h>
33 #include <linux/netdevice.h>
34 #include <net/snmp.h>
35 #include <net/ip.h>
36 #include <net/icmp.h>
37 #include <net/protocol.h>
38 #include <linux/skbuff.h>
39 #include <linux/proc_fs.h>
40 #include <linux/export.h>
41 #include <net/sock.h>
42 #include <net/ping.h>
43 #include <net/udp.h>
44 #include <net/route.h>
45 #include <net/inet_common.h>
46 #include <net/checksum.h>
47
48 #if IS_ENABLED(CONFIG_IPV6)
49 #include <linux/in6.h>
50 #include <linux/icmpv6.h>
51 #include <net/addrconf.h>
52 #include <net/ipv6.h>
53 #include <net/transp_v6.h>
54 #endif
55
56 struct ping_table {
57 struct hlist_nulls_head hash[PING_HTABLE_SIZE];
58 rwlock_t lock;
59 };
60
61 static struct ping_table ping_table;
62 struct pingv6_ops pingv6_ops;
63 EXPORT_SYMBOL_GPL(pingv6_ops);
64
65 static u16 ping_port_rover;
66
ping_hashfn(const struct net * net,u32 num,u32 mask)67 static inline u32 ping_hashfn(const struct net *net, u32 num, u32 mask)
68 {
69 u32 res = (num + net_hash_mix(net)) & mask;
70
71 pr_debug("hash(%u) = %u\n", num, res);
72 return res;
73 }
74 EXPORT_SYMBOL_GPL(ping_hash);
75
ping_hashslot(struct ping_table * table,struct net * net,unsigned int num)76 static inline struct hlist_nulls_head *ping_hashslot(struct ping_table *table,
77 struct net *net, unsigned int num)
78 {
79 return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)];
80 }
81
ping_get_port(struct sock * sk,unsigned short ident)82 int ping_get_port(struct sock *sk, unsigned short ident)
83 {
84 struct hlist_nulls_node *node;
85 struct hlist_nulls_head *hlist;
86 struct inet_sock *isk, *isk2;
87 struct sock *sk2 = NULL;
88
89 isk = inet_sk(sk);
90 write_lock_bh(&ping_table.lock);
91 if (ident == 0) {
92 u32 i;
93 u16 result = ping_port_rover + 1;
94
95 for (i = 0; i < (1L << 16); i++, result++) {
96 if (!result)
97 result++; /* avoid zero */
98 hlist = ping_hashslot(&ping_table, sock_net(sk),
99 result);
100 ping_portaddr_for_each_entry(sk2, node, hlist) {
101 isk2 = inet_sk(sk2);
102
103 if (isk2->inet_num == result)
104 goto next_port;
105 }
106
107 /* found */
108 ping_port_rover = ident = result;
109 break;
110 next_port:
111 ;
112 }
113 if (i >= (1L << 16))
114 goto fail;
115 } else {
116 hlist = ping_hashslot(&ping_table, sock_net(sk), ident);
117 ping_portaddr_for_each_entry(sk2, node, hlist) {
118 isk2 = inet_sk(sk2);
119
120 /* BUG? Why is this reuse and not reuseaddr? ping.c
121 * doesn't turn off SO_REUSEADDR, and it doesn't expect
122 * that other ping processes can steal its packets.
123 */
124 if ((isk2->inet_num == ident) &&
125 (sk2 != sk) &&
126 (!sk2->sk_reuse || !sk->sk_reuse))
127 goto fail;
128 }
129 }
130
131 pr_debug("found port/ident = %d\n", ident);
132 isk->inet_num = ident;
133 if (sk_unhashed(sk)) {
134 pr_debug("was not hashed\n");
135 sock_hold(sk);
136 hlist_nulls_add_head(&sk->sk_nulls_node, hlist);
137 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
138 }
139 write_unlock_bh(&ping_table.lock);
140 return 0;
141
142 fail:
143 write_unlock_bh(&ping_table.lock);
144 return 1;
145 }
146 EXPORT_SYMBOL_GPL(ping_get_port);
147
ping_hash(struct sock * sk)148 int ping_hash(struct sock *sk)
149 {
150 pr_debug("ping_hash(sk->port=%u)\n", inet_sk(sk)->inet_num);
151 BUG(); /* "Please do not press this button again." */
152
153 return 0;
154 }
155
ping_unhash(struct sock * sk)156 void ping_unhash(struct sock *sk)
157 {
158 struct inet_sock *isk = inet_sk(sk);
159
160 pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);
161 write_lock_bh(&ping_table.lock);
162 if (sk_hashed(sk)) {
163 hlist_nulls_del(&sk->sk_nulls_node);
164 sk_nulls_node_init(&sk->sk_nulls_node);
165 sock_put(sk);
166 isk->inet_num = 0;
167 isk->inet_sport = 0;
168 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
169 }
170 write_unlock_bh(&ping_table.lock);
171 }
172 EXPORT_SYMBOL_GPL(ping_unhash);
173
ping_lookup(struct net * net,struct sk_buff * skb,u16 ident)174 static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
175 {
176 struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident);
177 struct sock *sk = NULL;
178 struct inet_sock *isk;
179 struct hlist_nulls_node *hnode;
180 int dif = skb->dev->ifindex;
181
182 if (skb->protocol == htons(ETH_P_IP)) {
183 pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n",
184 (int)ident, &ip_hdr(skb)->daddr, dif);
185 #if IS_ENABLED(CONFIG_IPV6)
186 } else if (skb->protocol == htons(ETH_P_IPV6)) {
187 pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n",
188 (int)ident, &ipv6_hdr(skb)->daddr, dif);
189 #endif
190 }
191
192 read_lock_bh(&ping_table.lock);
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 continue;
230
231 sock_hold(sk);
232 goto exit;
233 }
234
235 sk = NULL;
236 exit:
237 read_unlock_bh(&ping_table.lock);
238
239 return sk;
240 }
241
inet_get_ping_group_range_net(struct net * net,kgid_t * low,kgid_t * high)242 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low,
243 kgid_t *high)
244 {
245 kgid_t *data = net->ipv4.ping_group_range.range;
246 unsigned int seq;
247
248 do {
249 seq = read_seqbegin(&net->ipv4.ping_group_range.lock);
250
251 *low = data[0];
252 *high = data[1];
253 } while (read_seqretry(&net->ipv4.ping_group_range.lock, seq));
254 }
255
256
ping_init_sock(struct sock * sk)257 int ping_init_sock(struct sock *sk)
258 {
259 struct net *net = sock_net(sk);
260 kgid_t group = current_egid();
261 struct group_info *group_info;
262 int i;
263 kgid_t low, high;
264 int ret = 0;
265
266 if (sk->sk_family == AF_INET6)
267 sk->sk_ipv6only = 1;
268
269 inet_get_ping_group_range_net(net, &low, &high);
270 if (gid_lte(low, group) && gid_lte(group, high))
271 return 0;
272
273 group_info = get_current_groups();
274 for (i = 0; i < group_info->ngroups; i++) {
275 kgid_t gid = group_info->gid[i];
276
277 if (gid_lte(low, gid) && gid_lte(gid, high))
278 goto out_release_group;
279 }
280
281 ret = -EACCES;
282
283 out_release_group:
284 put_group_info(group_info);
285 return ret;
286 }
287 EXPORT_SYMBOL_GPL(ping_init_sock);
288
ping_close(struct sock * sk,long timeout)289 void ping_close(struct sock *sk, long timeout)
290 {
291 pr_debug("ping_close(sk=%p,sk->num=%u)\n",
292 inet_sk(sk), inet_sk(sk)->inet_num);
293 pr_debug("isk->refcnt = %d\n", sk->sk_refcnt.counter);
294
295 sk_common_release(sk);
296 }
297 EXPORT_SYMBOL_GPL(ping_close);
298
299 /* 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)300 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
301 struct sockaddr *uaddr, int addr_len) {
302 struct net *net = sock_net(sk);
303 if (sk->sk_family == AF_INET) {
304 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
305 int chk_addr_ret;
306
307 if (addr_len < sizeof(*addr))
308 return -EINVAL;
309
310 if (addr->sin_family != AF_INET &&
311 !(addr->sin_family == AF_UNSPEC &&
312 addr->sin_addr.s_addr == htonl(INADDR_ANY)))
313 return -EAFNOSUPPORT;
314
315 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",
316 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
317
318 chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
319
320 if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
321 chk_addr_ret = RTN_LOCAL;
322
323 if ((net->ipv4.sysctl_ip_nonlocal_bind == 0 &&
324 isk->freebind == 0 && isk->transparent == 0 &&
325 chk_addr_ret != RTN_LOCAL) ||
326 chk_addr_ret == RTN_MULTICAST ||
327 chk_addr_ret == RTN_BROADCAST)
328 return -EADDRNOTAVAIL;
329
330 #if IS_ENABLED(CONFIG_IPV6)
331 } else if (sk->sk_family == AF_INET6) {
332 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
333 int addr_type, scoped, has_addr;
334 struct net_device *dev = NULL;
335
336 if (addr_len < sizeof(*addr))
337 return -EINVAL;
338
339 if (addr->sin6_family != AF_INET6)
340 return -EAFNOSUPPORT;
341
342 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n",
343 sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port));
344
345 addr_type = ipv6_addr_type(&addr->sin6_addr);
346 scoped = __ipv6_addr_needs_scope_id(addr_type);
347 if ((addr_type != IPV6_ADDR_ANY &&
348 !(addr_type & IPV6_ADDR_UNICAST)) ||
349 (scoped && !addr->sin6_scope_id))
350 return -EINVAL;
351
352 rcu_read_lock();
353 if (addr->sin6_scope_id) {
354 dev = dev_get_by_index_rcu(net, addr->sin6_scope_id);
355 if (!dev) {
356 rcu_read_unlock();
357 return -ENODEV;
358 }
359 }
360 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev,
361 scoped);
362 rcu_read_unlock();
363
364 if (!(net->ipv6.sysctl.ip_nonlocal_bind ||
365 isk->freebind || isk->transparent || has_addr ||
366 addr_type == IPV6_ADDR_ANY))
367 return -EADDRNOTAVAIL;
368
369 if (scoped)
370 sk->sk_bound_dev_if = addr->sin6_scope_id;
371 #endif
372 } else {
373 return -EAFNOSUPPORT;
374 }
375 return 0;
376 }
377
ping_set_saddr(struct sock * sk,struct sockaddr * saddr)378 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr)
379 {
380 if (saddr->sa_family == AF_INET) {
381 struct inet_sock *isk = inet_sk(sk);
382 struct sockaddr_in *addr = (struct sockaddr_in *) saddr;
383 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
384 #if IS_ENABLED(CONFIG_IPV6)
385 } else if (saddr->sa_family == AF_INET6) {
386 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr;
387 struct ipv6_pinfo *np = inet6_sk(sk);
388 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr;
389 #endif
390 }
391 }
392
ping_clear_saddr(struct sock * sk,int dif)393 static void ping_clear_saddr(struct sock *sk, int dif)
394 {
395 sk->sk_bound_dev_if = dif;
396 if (sk->sk_family == AF_INET) {
397 struct inet_sock *isk = inet_sk(sk);
398 isk->inet_rcv_saddr = isk->inet_saddr = 0;
399 #if IS_ENABLED(CONFIG_IPV6)
400 } else if (sk->sk_family == AF_INET6) {
401 struct ipv6_pinfo *np = inet6_sk(sk);
402 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
403 memset(&np->saddr, 0, sizeof(np->saddr));
404 #endif
405 }
406 }
407 /*
408 * We need our own bind because there are no privileged id's == local ports.
409 * Moreover, we don't allow binding to multi- and broadcast addresses.
410 */
411
ping_bind(struct sock * sk,struct sockaddr * uaddr,int addr_len)412 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
413 {
414 struct inet_sock *isk = inet_sk(sk);
415 unsigned short snum;
416 int err;
417 int dif = sk->sk_bound_dev_if;
418
419 err = ping_check_bind_addr(sk, isk, uaddr, addr_len);
420 if (err)
421 return err;
422
423 lock_sock(sk);
424
425 err = -EINVAL;
426 if (isk->inet_num != 0)
427 goto out;
428
429 err = -EADDRINUSE;
430 ping_set_saddr(sk, uaddr);
431 snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port);
432 if (ping_get_port(sk, snum) != 0) {
433 ping_clear_saddr(sk, dif);
434 goto out;
435 }
436
437 pr_debug("after bind(): num = %d, dif = %d\n",
438 (int)isk->inet_num,
439 (int)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);
461 out:
462 release_sock(sk);
463 pr_debug("ping_v4_bind -> %d\n", err);
464 return err;
465 }
466 EXPORT_SYMBOL_GPL(ping_bind);
467
468 /*
469 * Is this a supported type of ICMP message?
470 */
471
ping_supported(int family,int type,int code)472 static inline int ping_supported(int family, int type, int code)
473 {
474 return (family == AF_INET && type == ICMP_ECHO && code == 0) ||
475 (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0);
476 }
477
478 /*
479 * This routine is called by the ICMP module when it gets some
480 * sort of error condition.
481 */
482
ping_err(struct sk_buff * skb,int offset,u32 info)483 void ping_err(struct sk_buff *skb, int offset, u32 info)
484 {
485 int family;
486 struct icmphdr *icmph;
487 struct inet_sock *inet_sock;
488 int type;
489 int code;
490 struct net *net = dev_net(skb->dev);
491 struct sock *sk;
492 int harderr;
493 int err;
494
495 if (skb->protocol == htons(ETH_P_IP)) {
496 family = AF_INET;
497 type = icmp_hdr(skb)->type;
498 code = icmp_hdr(skb)->code;
499 icmph = (struct icmphdr *)(skb->data + offset);
500 } else if (skb->protocol == htons(ETH_P_IPV6)) {
501 family = AF_INET6;
502 type = icmp6_hdr(skb)->icmp6_type;
503 code = icmp6_hdr(skb)->icmp6_code;
504 icmph = (struct icmphdr *) (skb->data + offset);
505 } else {
506 BUG();
507 }
508
509 /* We assume the packet has already been checked by icmp_unreach */
510
511 if (!ping_supported(family, icmph->type, icmph->code))
512 return;
513
514 pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n",
515 skb->protocol, type, code, ntohs(icmph->un.echo.id),
516 ntohs(icmph->un.echo.sequence));
517
518 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
519 if (!sk) {
520 pr_debug("no socket, dropping\n");
521 return; /* No socket for error */
522 }
523 pr_debug("err on socket %p\n", sk);
524
525 err = 0;
526 harderr = 0;
527 inet_sock = inet_sk(sk);
528
529 if (skb->protocol == htons(ETH_P_IP)) {
530 switch (type) {
531 default:
532 case ICMP_TIME_EXCEEDED:
533 err = EHOSTUNREACH;
534 break;
535 case ICMP_SOURCE_QUENCH:
536 /* This is not a real error but ping wants to see it.
537 * Report it with some fake errno.
538 */
539 err = EREMOTEIO;
540 break;
541 case ICMP_PARAMETERPROB:
542 err = EPROTO;
543 harderr = 1;
544 break;
545 case ICMP_DEST_UNREACH:
546 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
547 ipv4_sk_update_pmtu(skb, sk, info);
548 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) {
549 err = EMSGSIZE;
550 harderr = 1;
551 break;
552 }
553 goto out;
554 }
555 err = EHOSTUNREACH;
556 if (code <= NR_ICMP_UNREACH) {
557 harderr = icmp_err_convert[code].fatal;
558 err = icmp_err_convert[code].errno;
559 }
560 break;
561 case ICMP_REDIRECT:
562 /* See ICMP_SOURCE_QUENCH */
563 ipv4_sk_redirect(skb, sk);
564 err = EREMOTEIO;
565 break;
566 }
567 #if IS_ENABLED(CONFIG_IPV6)
568 } else if (skb->protocol == htons(ETH_P_IPV6)) {
569 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err);
570 #endif
571 }
572
573 /*
574 * RFC1122: OK. Passes ICMP errors back to application, as per
575 * 4.1.3.3.
576 */
577 if ((family == AF_INET && !inet_sock->recverr) ||
578 (family == AF_INET6 && !inet6_sk(sk)->recverr)) {
579 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
580 goto out;
581 } else {
582 if (family == AF_INET) {
583 ip_icmp_error(sk, skb, err, 0 /* no remote port */,
584 info, (u8 *)icmph);
585 #if IS_ENABLED(CONFIG_IPV6)
586 } else if (family == AF_INET6) {
587 pingv6_ops.ipv6_icmp_error(sk, skb, err, 0,
588 info, (u8 *)icmph);
589 #endif
590 }
591 }
592 sk->sk_err = err;
593 sk->sk_error_report(sk);
594 out:
595 sock_put(sk);
596 }
597 EXPORT_SYMBOL_GPL(ping_err);
598
599 /*
600 * Copy and checksum an ICMP Echo packet from user space into a buffer
601 * starting from the payload.
602 */
603
ping_getfrag(void * from,char * to,int offset,int fraglen,int odd,struct sk_buff * skb)604 int ping_getfrag(void *from, char *to,
605 int offset, int fraglen, int odd, struct sk_buff *skb)
606 {
607 struct pingfakehdr *pfh = (struct pingfakehdr *)from;
608
609 if (offset == 0) {
610 fraglen -= sizeof(struct icmphdr);
611 if (fraglen < 0)
612 BUG();
613 if (csum_and_copy_from_iter(to + sizeof(struct icmphdr),
614 fraglen, &pfh->wcheck,
615 &pfh->msg->msg_iter) != fraglen)
616 return -EFAULT;
617 } else if (offset < sizeof(struct icmphdr)) {
618 BUG();
619 } else {
620 if (csum_and_copy_from_iter(to, fraglen, &pfh->wcheck,
621 &pfh->msg->msg_iter) != fraglen)
622 return -EFAULT;
623 }
624
625 #if IS_ENABLED(CONFIG_IPV6)
626 /* For IPv6, checksum each skb as we go along, as expected by
627 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in
628 * wcheck, it will be finalized in ping_v4_push_pending_frames.
629 */
630 if (pfh->family == AF_INET6) {
631 skb->csum = pfh->wcheck;
632 skb->ip_summed = CHECKSUM_NONE;
633 pfh->wcheck = 0;
634 }
635 #endif
636
637 return 0;
638 }
639 EXPORT_SYMBOL_GPL(ping_getfrag);
640
ping_v4_push_pending_frames(struct sock * sk,struct pingfakehdr * pfh,struct flowi4 * fl4)641 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
642 struct flowi4 *fl4)
643 {
644 struct sk_buff *skb = skb_peek(&sk->sk_write_queue);
645
646 if (!skb)
647 return 0;
648 pfh->wcheck = csum_partial((char *)&pfh->icmph,
649 sizeof(struct icmphdr), pfh->wcheck);
650 pfh->icmph.checksum = csum_fold(pfh->wcheck);
651 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
652 skb->ip_summed = CHECKSUM_NONE;
653 return ip_push_pending_frames(sk, fl4);
654 }
655
ping_common_sendmsg(int family,struct msghdr * msg,size_t len,void * user_icmph,size_t icmph_len)656 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
657 void *user_icmph, size_t icmph_len) {
658 u8 type, code;
659
660 if (len > 0xFFFF)
661 return -EMSGSIZE;
662
663 /* Must have at least a full ICMP header. */
664 if (len < icmph_len)
665 return -EINVAL;
666
667 /*
668 * Check the flags.
669 */
670
671 /* Mirror BSD error message compatibility */
672 if (msg->msg_flags & MSG_OOB)
673 return -EOPNOTSUPP;
674
675 /*
676 * Fetch the ICMP header provided by the userland.
677 * iovec is modified! The ICMP header is consumed.
678 */
679 if (memcpy_from_msg(user_icmph, msg, icmph_len))
680 return -EFAULT;
681
682 if (family == AF_INET) {
683 type = ((struct icmphdr *) user_icmph)->type;
684 code = ((struct icmphdr *) user_icmph)->code;
685 #if IS_ENABLED(CONFIG_IPV6)
686 } else if (family == AF_INET6) {
687 type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
688 code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
689 #endif
690 } else {
691 BUG();
692 }
693
694 if (!ping_supported(family, type, code))
695 return -EINVAL;
696
697 return 0;
698 }
699 EXPORT_SYMBOL_GPL(ping_common_sendmsg);
700
ping_v4_sendmsg(struct sock * sk,struct msghdr * msg,size_t len)701 static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
702 {
703 struct net *net = sock_net(sk);
704 struct flowi4 fl4;
705 struct inet_sock *inet = inet_sk(sk);
706 struct ipcm_cookie ipc;
707 struct icmphdr user_icmph;
708 struct pingfakehdr pfh;
709 struct rtable *rt = NULL;
710 struct ip_options_data opt_copy;
711 int free = 0;
712 __be32 saddr, daddr, faddr;
713 u8 tos;
714 int err;
715
716 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
717
718 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
719 sizeof(user_icmph));
720 if (err)
721 return err;
722
723 /*
724 * Get and verify the address.
725 */
726
727 if (msg->msg_name) {
728 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
729 if (msg->msg_namelen < sizeof(*usin))
730 return -EINVAL;
731 if (usin->sin_family != AF_INET)
732 return -EAFNOSUPPORT;
733 daddr = usin->sin_addr.s_addr;
734 /* no remote port */
735 } else {
736 if (sk->sk_state != TCP_ESTABLISHED)
737 return -EDESTADDRREQ;
738 daddr = inet->inet_daddr;
739 /* no remote port */
740 }
741
742 ipc.sockc.tsflags = sk->sk_tsflags;
743 ipc.addr = inet->inet_saddr;
744 ipc.opt = NULL;
745 ipc.oif = sk->sk_bound_dev_if;
746 ipc.tx_flags = 0;
747 ipc.ttl = 0;
748 ipc.tos = -1;
749
750 if (msg->msg_controllen) {
751 err = ip_cmsg_send(sk, msg, &ipc, false);
752 if (unlikely(err)) {
753 kfree(ipc.opt);
754 return err;
755 }
756 if (ipc.opt)
757 free = 1;
758 }
759 if (!ipc.opt) {
760 struct ip_options_rcu *inet_opt;
761
762 rcu_read_lock();
763 inet_opt = rcu_dereference(inet->inet_opt);
764 if (inet_opt) {
765 memcpy(&opt_copy, inet_opt,
766 sizeof(*inet_opt) + inet_opt->opt.optlen);
767 ipc.opt = &opt_copy.opt;
768 }
769 rcu_read_unlock();
770 }
771
772 sock_tx_timestamp(sk, ipc.sockc.tsflags, &ipc.tx_flags);
773
774 saddr = ipc.addr;
775 ipc.addr = faddr = daddr;
776
777 if (ipc.opt && ipc.opt->opt.srr) {
778 if (!daddr)
779 return -EINVAL;
780 faddr = ipc.opt->opt.faddr;
781 }
782 tos = get_rttos(&ipc, inet);
783 if (sock_flag(sk, SOCK_LOCALROUTE) ||
784 (msg->msg_flags & MSG_DONTROUTE) ||
785 (ipc.opt && ipc.opt->opt.is_strictroute)) {
786 tos |= RTO_ONLINK;
787 }
788
789 if (ipv4_is_multicast(daddr)) {
790 if (!ipc.oif)
791 ipc.oif = inet->mc_index;
792 if (!saddr)
793 saddr = inet->mc_addr;
794 } else if (!ipc.oif)
795 ipc.oif = inet->uc_index;
796
797 flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
798 RT_SCOPE_UNIVERSE, sk->sk_protocol,
799 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0,
800 sk->sk_uid);
801
802 security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
803 rt = ip_route_output_flow(net, &fl4, sk);
804 if (IS_ERR(rt)) {
805 err = PTR_ERR(rt);
806 rt = NULL;
807 if (err == -ENETUNREACH)
808 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
809 goto out;
810 }
811
812 err = -EACCES;
813 if ((rt->rt_flags & RTCF_BROADCAST) &&
814 !sock_flag(sk, SOCK_BROADCAST))
815 goto out;
816
817 if (msg->msg_flags & MSG_CONFIRM)
818 goto do_confirm;
819 back_from_confirm:
820
821 if (!ipc.addr)
822 ipc.addr = fl4.daddr;
823
824 lock_sock(sk);
825
826 pfh.icmph.type = user_icmph.type; /* already checked */
827 pfh.icmph.code = user_icmph.code; /* ditto */
828 pfh.icmph.checksum = 0;
829 pfh.icmph.un.echo.id = inet->inet_sport;
830 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
831 pfh.msg = msg;
832 pfh.wcheck = 0;
833 pfh.family = AF_INET;
834
835 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
836 0, &ipc, &rt, msg->msg_flags);
837 if (err)
838 ip_flush_pending_frames(sk);
839 else
840 err = ping_v4_push_pending_frames(sk, &pfh, &fl4);
841 release_sock(sk);
842
843 out:
844 ip_rt_put(rt);
845 if (free)
846 kfree(ipc.opt);
847 if (!err) {
848 icmp_out_count(sock_net(sk), user_icmph.type);
849 return len;
850 }
851 return err;
852
853 do_confirm:
854 dst_confirm(&rt->dst);
855 if (!(msg->msg_flags & MSG_PROBE) || len)
856 goto back_from_confirm;
857 err = 0;
858 goto out;
859 }
860
ping_recvmsg(struct sock * sk,struct msghdr * msg,size_t len,int noblock,int flags,int * addr_len)861 int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock,
862 int flags, int *addr_len)
863 {
864 struct inet_sock *isk = inet_sk(sk);
865 int family = sk->sk_family;
866 struct sk_buff *skb;
867 int copied, err;
868
869 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
870
871 err = -EOPNOTSUPP;
872 if (flags & MSG_OOB)
873 goto out;
874
875 if (flags & MSG_ERRQUEUE)
876 return inet_recv_error(sk, msg, len, addr_len);
877
878 skb = skb_recv_datagram(sk, flags, noblock, &err);
879 if (!skb)
880 goto out;
881
882 copied = skb->len;
883 if (copied > len) {
884 msg->msg_flags |= MSG_TRUNC;
885 copied = len;
886 }
887
888 /* Don't bother checking the checksum */
889 err = skb_copy_datagram_msg(skb, 0, msg, copied);
890 if (err)
891 goto done;
892
893 sock_recv_timestamp(msg, sk, skb);
894
895 /* Copy the address and add cmsg data. */
896 if (family == AF_INET) {
897 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
898
899 if (sin) {
900 sin->sin_family = AF_INET;
901 sin->sin_port = 0 /* skb->h.uh->source */;
902 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
903 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
904 *addr_len = sizeof(*sin);
905 }
906
907 if (isk->cmsg_flags)
908 ip_cmsg_recv(msg, skb);
909
910 #if IS_ENABLED(CONFIG_IPV6)
911 } else if (family == AF_INET6) {
912 struct ipv6_pinfo *np = inet6_sk(sk);
913 struct ipv6hdr *ip6 = ipv6_hdr(skb);
914 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
915
916 if (sin6) {
917 sin6->sin6_family = AF_INET6;
918 sin6->sin6_port = 0;
919 sin6->sin6_addr = ip6->saddr;
920 sin6->sin6_flowinfo = 0;
921 if (np->sndflow)
922 sin6->sin6_flowinfo = ip6_flowinfo(ip6);
923 sin6->sin6_scope_id =
924 ipv6_iface_scope_id(&sin6->sin6_addr,
925 inet6_iif(skb));
926 *addr_len = sizeof(*sin6);
927 }
928
929 if (inet6_sk(sk)->rxopt.all)
930 pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb);
931 if (skb->protocol == htons(ETH_P_IPV6) &&
932 inet6_sk(sk)->rxopt.all)
933 pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb);
934 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags)
935 ip_cmsg_recv(msg, skb);
936 #endif
937 } else {
938 BUG();
939 }
940
941 err = copied;
942
943 done:
944 skb_free_datagram(sk, skb);
945 out:
946 pr_debug("ping_recvmsg -> %d\n", err);
947 return err;
948 }
949 EXPORT_SYMBOL_GPL(ping_recvmsg);
950
ping_queue_rcv_skb(struct sock * sk,struct sk_buff * skb)951 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
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(sk, skb) < 0) {
956 kfree_skb(skb);
957 pr_debug("ping_queue_rcv_skb -> failed\n");
958 return -1;
959 }
960 return 0;
961 }
962 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
963
964
965 /*
966 * All we need to do is get the socket.
967 */
968
ping_rcv(struct sk_buff * skb)969 bool ping_rcv(struct sk_buff *skb)
970 {
971 struct sock *sk;
972 struct net *net = dev_net(skb->dev);
973 struct icmphdr *icmph = icmp_hdr(skb);
974
975 /* We assume the packet has already been checked by icmp_rcv */
976
977 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
978 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
979
980 /* Push ICMP header back */
981 skb_push(skb, skb->data - (u8 *)icmph);
982
983 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
984 if (sk) {
985 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
986
987 pr_debug("rcv on socket %p\n", sk);
988 if (skb2)
989 ping_queue_rcv_skb(sk, skb2);
990 sock_put(sk);
991 return true;
992 }
993 pr_debug("no socket, dropping\n");
994
995 return false;
996 }
997 EXPORT_SYMBOL_GPL(ping_rcv);
998
999 struct proto ping_prot = {
1000 .name = "PING",
1001 .owner = THIS_MODULE,
1002 .init = ping_init_sock,
1003 .close = ping_close,
1004 .connect = ip4_datagram_connect,
1005 .disconnect = __udp_disconnect,
1006 .setsockopt = ip_setsockopt,
1007 .getsockopt = ip_getsockopt,
1008 .sendmsg = ping_v4_sendmsg,
1009 .recvmsg = ping_recvmsg,
1010 .bind = ping_bind,
1011 .backlog_rcv = ping_queue_rcv_skb,
1012 .release_cb = ip4_datagram_release_cb,
1013 .hash = ping_hash,
1014 .unhash = ping_unhash,
1015 .get_port = ping_get_port,
1016 .obj_size = sizeof(struct inet_sock),
1017 };
1018 EXPORT_SYMBOL(ping_prot);
1019
1020 #ifdef CONFIG_PROC_FS
1021
ping_get_first(struct seq_file * seq,int start)1022 static struct sock *ping_get_first(struct seq_file *seq, int start)
1023 {
1024 struct sock *sk;
1025 struct ping_iter_state *state = seq->private;
1026 struct net *net = seq_file_net(seq);
1027
1028 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
1029 ++state->bucket) {
1030 struct hlist_nulls_node *node;
1031 struct hlist_nulls_head *hslot;
1032
1033 hslot = &ping_table.hash[state->bucket];
1034
1035 if (hlist_nulls_empty(hslot))
1036 continue;
1037
1038 sk_nulls_for_each(sk, node, hslot) {
1039 if (net_eq(sock_net(sk), net) &&
1040 sk->sk_family == state->family)
1041 goto found;
1042 }
1043 }
1044 sk = NULL;
1045 found:
1046 return sk;
1047 }
1048
ping_get_next(struct seq_file * seq,struct sock * sk)1049 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
1050 {
1051 struct ping_iter_state *state = seq->private;
1052 struct net *net = seq_file_net(seq);
1053
1054 do {
1055 sk = sk_nulls_next(sk);
1056 } while (sk && (!net_eq(sock_net(sk), net)));
1057
1058 if (!sk)
1059 return ping_get_first(seq, state->bucket + 1);
1060 return sk;
1061 }
1062
ping_get_idx(struct seq_file * seq,loff_t pos)1063 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
1064 {
1065 struct sock *sk = ping_get_first(seq, 0);
1066
1067 if (sk)
1068 while (pos && (sk = ping_get_next(seq, sk)) != NULL)
1069 --pos;
1070 return pos ? NULL : sk;
1071 }
1072
ping_seq_start(struct seq_file * seq,loff_t * pos,sa_family_t family)1073 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
1074 __acquires(ping_table.lock)
1075 {
1076 struct ping_iter_state *state = seq->private;
1077 state->bucket = 0;
1078 state->family = family;
1079
1080 read_lock_bh(&ping_table.lock);
1081
1082 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1083 }
1084 EXPORT_SYMBOL_GPL(ping_seq_start);
1085
ping_v4_seq_start(struct seq_file * seq,loff_t * pos)1086 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos)
1087 {
1088 return ping_seq_start(seq, pos, AF_INET);
1089 }
1090
ping_seq_next(struct seq_file * seq,void * v,loff_t * pos)1091 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1092 {
1093 struct sock *sk;
1094
1095 if (v == SEQ_START_TOKEN)
1096 sk = ping_get_idx(seq, 0);
1097 else
1098 sk = ping_get_next(seq, v);
1099
1100 ++*pos;
1101 return sk;
1102 }
1103 EXPORT_SYMBOL_GPL(ping_seq_next);
1104
ping_seq_stop(struct seq_file * seq,void * v)1105 void ping_seq_stop(struct seq_file *seq, void *v)
1106 __releases(ping_table.lock)
1107 {
1108 read_unlock_bh(&ping_table.lock);
1109 }
1110 EXPORT_SYMBOL_GPL(ping_seq_stop);
1111
ping_v4_format_sock(struct sock * sp,struct seq_file * f,int bucket)1112 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f,
1113 int bucket)
1114 {
1115 struct inet_sock *inet = inet_sk(sp);
1116 __be32 dest = inet->inet_daddr;
1117 __be32 src = inet->inet_rcv_saddr;
1118 __u16 destp = ntohs(inet->inet_dport);
1119 __u16 srcp = ntohs(inet->inet_sport);
1120
1121 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
1122 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d",
1123 bucket, src, srcp, dest, destp, sp->sk_state,
1124 sk_wmem_alloc_get(sp),
1125 sk_rmem_alloc_get(sp),
1126 0, 0L, 0,
1127 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
1128 0, sock_i_ino(sp),
1129 atomic_read(&sp->sk_refcnt), sp,
1130 atomic_read(&sp->sk_drops));
1131 }
1132
ping_v4_seq_show(struct seq_file * seq,void * v)1133 static int ping_v4_seq_show(struct seq_file *seq, void *v)
1134 {
1135 seq_setwidth(seq, 127);
1136 if (v == SEQ_START_TOKEN)
1137 seq_puts(seq, " sl local_address rem_address st tx_queue "
1138 "rx_queue tr tm->when retrnsmt uid timeout "
1139 "inode ref pointer drops");
1140 else {
1141 struct ping_iter_state *state = seq->private;
1142
1143 ping_v4_format_sock(v, seq, state->bucket);
1144 }
1145 seq_pad(seq, '\n');
1146 return 0;
1147 }
1148
ping_seq_open(struct inode * inode,struct file * file)1149 static int ping_seq_open(struct inode *inode, struct file *file)
1150 {
1151 struct ping_seq_afinfo *afinfo = PDE_DATA(inode);
1152 return seq_open_net(inode, file, &afinfo->seq_ops,
1153 sizeof(struct ping_iter_state));
1154 }
1155
1156 const struct file_operations ping_seq_fops = {
1157 .open = ping_seq_open,
1158 .read = seq_read,
1159 .llseek = seq_lseek,
1160 .release = seq_release_net,
1161 };
1162 EXPORT_SYMBOL_GPL(ping_seq_fops);
1163
1164 static struct ping_seq_afinfo ping_v4_seq_afinfo = {
1165 .name = "icmp",
1166 .family = AF_INET,
1167 .seq_fops = &ping_seq_fops,
1168 .seq_ops = {
1169 .start = ping_v4_seq_start,
1170 .show = ping_v4_seq_show,
1171 .next = ping_seq_next,
1172 .stop = ping_seq_stop,
1173 },
1174 };
1175
ping_proc_register(struct net * net,struct ping_seq_afinfo * afinfo)1176 int ping_proc_register(struct net *net, struct ping_seq_afinfo *afinfo)
1177 {
1178 struct proc_dir_entry *p;
1179 p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
1180 afinfo->seq_fops, afinfo);
1181 if (!p)
1182 return -ENOMEM;
1183 return 0;
1184 }
1185 EXPORT_SYMBOL_GPL(ping_proc_register);
1186
ping_proc_unregister(struct net * net,struct ping_seq_afinfo * afinfo)1187 void ping_proc_unregister(struct net *net, struct ping_seq_afinfo *afinfo)
1188 {
1189 remove_proc_entry(afinfo->name, net->proc_net);
1190 }
1191 EXPORT_SYMBOL_GPL(ping_proc_unregister);
1192
ping_v4_proc_init_net(struct net * net)1193 static int __net_init ping_v4_proc_init_net(struct net *net)
1194 {
1195 return ping_proc_register(net, &ping_v4_seq_afinfo);
1196 }
1197
ping_v4_proc_exit_net(struct net * net)1198 static void __net_exit ping_v4_proc_exit_net(struct net *net)
1199 {
1200 ping_proc_unregister(net, &ping_v4_seq_afinfo);
1201 }
1202
1203 static struct pernet_operations ping_v4_net_ops = {
1204 .init = ping_v4_proc_init_net,
1205 .exit = ping_v4_proc_exit_net,
1206 };
1207
ping_proc_init(void)1208 int __init ping_proc_init(void)
1209 {
1210 return register_pernet_subsys(&ping_v4_net_ops);
1211 }
1212
ping_proc_exit(void)1213 void ping_proc_exit(void)
1214 {
1215 unregister_pernet_subsys(&ping_v4_net_ops);
1216 }
1217
1218 #endif
1219
ping_init(void)1220 void __init ping_init(void)
1221 {
1222 int i;
1223
1224 for (i = 0; i < PING_HTABLE_SIZE; i++)
1225 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i);
1226 rwlock_init(&ping_table.lock);
1227 }
1228