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
57 struct ping_table ping_table;
58 struct pingv6_ops pingv6_ops;
59 EXPORT_SYMBOL_GPL(pingv6_ops);
60
61 static u16 ping_port_rover;
62
ping_hashfn(struct net * net,unsigned int num,unsigned int mask)63 static inline int ping_hashfn(struct net *net, unsigned int num, unsigned int mask)
64 {
65 int res = (num + net_hash_mix(net)) & mask;
66
67 pr_debug("hash(%d) = %d\n", num, res);
68 return res;
69 }
70 EXPORT_SYMBOL_GPL(ping_hash);
71
ping_hashslot(struct ping_table * table,struct net * net,unsigned int num)72 static inline struct hlist_nulls_head *ping_hashslot(struct ping_table *table,
73 struct net *net, unsigned int num)
74 {
75 return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)];
76 }
77
ping_get_port(struct sock * sk,unsigned short ident)78 int ping_get_port(struct sock *sk, unsigned short ident)
79 {
80 struct hlist_nulls_node *node;
81 struct hlist_nulls_head *hlist;
82 struct inet_sock *isk, *isk2;
83 struct sock *sk2 = NULL;
84
85 isk = inet_sk(sk);
86 write_lock_bh(&ping_table.lock);
87 if (ident == 0) {
88 u32 i;
89 u16 result = ping_port_rover + 1;
90
91 for (i = 0; i < (1L << 16); i++, result++) {
92 if (!result)
93 result++; /* avoid zero */
94 hlist = ping_hashslot(&ping_table, sock_net(sk),
95 result);
96 ping_portaddr_for_each_entry(sk2, node, hlist) {
97 isk2 = inet_sk(sk2);
98
99 if (isk2->inet_num == result)
100 goto next_port;
101 }
102
103 /* found */
104 ping_port_rover = ident = result;
105 break;
106 next_port:
107 ;
108 }
109 if (i >= (1L << 16))
110 goto fail;
111 } else {
112 hlist = ping_hashslot(&ping_table, sock_net(sk), ident);
113 ping_portaddr_for_each_entry(sk2, node, hlist) {
114 isk2 = inet_sk(sk2);
115
116 /* BUG? Why is this reuse and not reuseaddr? ping.c
117 * doesn't turn off SO_REUSEADDR, and it doesn't expect
118 * that other ping processes can steal its packets.
119 */
120 if ((isk2->inet_num == ident) &&
121 (sk2 != sk) &&
122 (!sk2->sk_reuse || !sk->sk_reuse))
123 goto fail;
124 }
125 }
126
127 pr_debug("found port/ident = %d\n", ident);
128 isk->inet_num = ident;
129 if (sk_unhashed(sk)) {
130 pr_debug("was not hashed\n");
131 sock_hold(sk);
132 hlist_nulls_add_head(&sk->sk_nulls_node, hlist);
133 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
134 }
135 write_unlock_bh(&ping_table.lock);
136 return 0;
137
138 fail:
139 write_unlock_bh(&ping_table.lock);
140 return 1;
141 }
142 EXPORT_SYMBOL_GPL(ping_get_port);
143
ping_hash(struct sock * sk)144 void 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
ping_unhash(struct sock * sk)150 void ping_unhash(struct sock *sk)
151 {
152 struct inet_sock *isk = inet_sk(sk);
153 pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);
154 if (sk_hashed(sk)) {
155 write_lock_bh(&ping_table.lock);
156 hlist_nulls_del(&sk->sk_nulls_node);
157 sk_nulls_node_init(&sk->sk_nulls_node);
158 sock_put(sk);
159 isk->inet_num = 0;
160 isk->inet_sport = 0;
161 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
162 write_unlock_bh(&ping_table.lock);
163 }
164 }
165 EXPORT_SYMBOL_GPL(ping_unhash);
166
ping_lookup(struct net * net,struct sk_buff * skb,u16 ident)167 static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
168 {
169 struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident);
170 struct sock *sk = NULL;
171 struct inet_sock *isk;
172 struct hlist_nulls_node *hnode;
173 int dif = skb->dev->ifindex;
174
175 if (skb->protocol == htons(ETH_P_IP)) {
176 pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n",
177 (int)ident, &ip_hdr(skb)->daddr, dif);
178 #if IS_ENABLED(CONFIG_IPV6)
179 } else if (skb->protocol == htons(ETH_P_IPV6)) {
180 pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n",
181 (int)ident, &ipv6_hdr(skb)->daddr, dif);
182 #endif
183 }
184
185 read_lock_bh(&ping_table.lock);
186
187 ping_portaddr_for_each_entry(sk, hnode, hslot) {
188 isk = inet_sk(sk);
189
190 pr_debug("iterate\n");
191 if (isk->inet_num != ident)
192 continue;
193
194 if (skb->protocol == htons(ETH_P_IP) &&
195 sk->sk_family == AF_INET) {
196 pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk,
197 (int) isk->inet_num, &isk->inet_rcv_saddr,
198 sk->sk_bound_dev_if);
199
200 if (isk->inet_rcv_saddr &&
201 isk->inet_rcv_saddr != ip_hdr(skb)->daddr)
202 continue;
203 #if IS_ENABLED(CONFIG_IPV6)
204 } else if (skb->protocol == htons(ETH_P_IPV6) &&
205 sk->sk_family == AF_INET6) {
206 struct ipv6_pinfo *np = inet6_sk(sk);
207
208 pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk,
209 (int) isk->inet_num,
210 &inet6_sk(sk)->rcv_saddr,
211 sk->sk_bound_dev_if);
212
213 if (!ipv6_addr_any(&np->rcv_saddr) &&
214 !ipv6_addr_equal(&np->rcv_saddr,
215 &ipv6_hdr(skb)->daddr))
216 continue;
217 #endif
218 } else {
219 continue;
220 }
221
222 if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)
223 continue;
224
225 sock_hold(sk);
226 goto exit;
227 }
228
229 sk = NULL;
230 exit:
231 read_unlock_bh(&ping_table.lock);
232
233 return sk;
234 }
235
inet_get_ping_group_range_net(struct net * net,kgid_t * low,kgid_t * high)236 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low,
237 kgid_t *high)
238 {
239 kgid_t *data = net->ipv4.sysctl_ping_group_range;
240 unsigned int seq;
241
242 do {
243 seq = read_seqbegin(&sysctl_local_ports.lock);
244
245 *low = data[0];
246 *high = data[1];
247 } while (read_seqretry(&sysctl_local_ports.lock, seq));
248 }
249
250
ping_init_sock(struct sock * sk)251 int ping_init_sock(struct sock *sk)
252 {
253 struct net *net = sock_net(sk);
254 kgid_t group = current_egid();
255 struct group_info *group_info;
256 int i, j, count;
257 kgid_t low, high;
258 int ret = 0;
259
260 if (sk->sk_family == AF_INET6)
261 inet6_sk(sk)->ipv6only = 1;
262
263 inet_get_ping_group_range_net(net, &low, &high);
264 if (gid_lte(low, group) && gid_lte(group, high))
265 return 0;
266
267 group_info = get_current_groups();
268 count = group_info->ngroups;
269 for (i = 0; i < group_info->nblocks; i++) {
270 int cp_count = min_t(int, NGROUPS_PER_BLOCK, count);
271 for (j = 0; j < cp_count; j++) {
272 kgid_t gid = group_info->blocks[i][j];
273 if (gid_lte(low, gid) && gid_lte(gid, high))
274 goto out_release_group;
275 }
276
277 count -= cp_count;
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", sk->sk_refcnt.counter);
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 int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
300 struct sockaddr *uaddr, int addr_len) {
301 struct net *net = sock_net(sk);
302 if (sk->sk_family == AF_INET) {
303 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
304 int chk_addr_ret;
305
306 if (addr_len < sizeof(*addr))
307 return -EINVAL;
308
309 if (addr->sin_family != AF_INET &&
310 !(addr->sin_family == AF_UNSPEC &&
311 addr->sin_addr.s_addr == htonl(INADDR_ANY)))
312 return -EAFNOSUPPORT;
313
314 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",
315 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
316
317 chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
318
319 if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
320 chk_addr_ret = RTN_LOCAL;
321
322 if ((sysctl_ip_nonlocal_bind == 0 &&
323 isk->freebind == 0 && isk->transparent == 0 &&
324 chk_addr_ret != RTN_LOCAL) ||
325 chk_addr_ret == RTN_MULTICAST ||
326 chk_addr_ret == RTN_BROADCAST)
327 return -EADDRNOTAVAIL;
328
329 #if IS_ENABLED(CONFIG_IPV6)
330 } else if (sk->sk_family == AF_INET6) {
331 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
332 int addr_type, scoped, has_addr;
333 struct net_device *dev = NULL;
334
335 if (addr_len < sizeof(*addr))
336 return -EINVAL;
337
338 if (addr->sin6_family != AF_INET6)
339 return -EAFNOSUPPORT;
340
341 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n",
342 sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port));
343
344 addr_type = ipv6_addr_type(&addr->sin6_addr);
345 scoped = __ipv6_addr_needs_scope_id(addr_type);
346 if ((addr_type != IPV6_ADDR_ANY &&
347 !(addr_type & IPV6_ADDR_UNICAST)) ||
348 (scoped && !addr->sin6_scope_id))
349 return -EINVAL;
350
351 rcu_read_lock();
352 if (addr->sin6_scope_id) {
353 dev = dev_get_by_index_rcu(net, addr->sin6_scope_id);
354 if (!dev) {
355 rcu_read_unlock();
356 return -ENODEV;
357 }
358 }
359 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev,
360 scoped);
361 rcu_read_unlock();
362
363 if (!(isk->freebind || isk->transparent || has_addr ||
364 addr_type == IPV6_ADDR_ANY))
365 return -EADDRNOTAVAIL;
366
367 if (scoped)
368 sk->sk_bound_dev_if = addr->sin6_scope_id;
369 #endif
370 } else {
371 return -EAFNOSUPPORT;
372 }
373 return 0;
374 }
375
ping_set_saddr(struct sock * sk,struct sockaddr * saddr)376 void ping_set_saddr(struct sock *sk, struct sockaddr *saddr)
377 {
378 if (saddr->sa_family == AF_INET) {
379 struct inet_sock *isk = inet_sk(sk);
380 struct sockaddr_in *addr = (struct sockaddr_in *) saddr;
381 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
382 #if IS_ENABLED(CONFIG_IPV6)
383 } else if (saddr->sa_family == AF_INET6) {
384 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr;
385 struct ipv6_pinfo *np = inet6_sk(sk);
386 np->rcv_saddr = np->saddr = addr->sin6_addr;
387 #endif
388 }
389 }
390
ping_clear_saddr(struct sock * sk,int dif)391 void ping_clear_saddr(struct sock *sk, int dif)
392 {
393 sk->sk_bound_dev_if = dif;
394 if (sk->sk_family == AF_INET) {
395 struct inet_sock *isk = inet_sk(sk);
396 isk->inet_rcv_saddr = isk->inet_saddr = 0;
397 #if IS_ENABLED(CONFIG_IPV6)
398 } else if (sk->sk_family == AF_INET6) {
399 struct ipv6_pinfo *np = inet6_sk(sk);
400 memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr));
401 memset(&np->saddr, 0, sizeof(np->saddr));
402 #endif
403 }
404 }
405 /*
406 * We need our own bind because there are no privileged id's == local ports.
407 * Moreover, we don't allow binding to multi- and broadcast addresses.
408 */
409
ping_bind(struct sock * sk,struct sockaddr * uaddr,int addr_len)410 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
411 {
412 struct inet_sock *isk = inet_sk(sk);
413 unsigned short snum;
414 int err;
415 int dif = sk->sk_bound_dev_if;
416
417 err = ping_check_bind_addr(sk, isk, uaddr, addr_len);
418 if (err)
419 return err;
420
421 lock_sock(sk);
422
423 err = -EINVAL;
424 if (isk->inet_num != 0)
425 goto out;
426
427 err = -EADDRINUSE;
428 ping_set_saddr(sk, uaddr);
429 snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port);
430 if (ping_get_port(sk, snum) != 0) {
431 ping_clear_saddr(sk, dif);
432 goto out;
433 }
434
435 pr_debug("after bind(): num = %d, dif = %d\n",
436 (int)isk->inet_num,
437 (int)sk->sk_bound_dev_if);
438
439 err = 0;
440 if ((sk->sk_family == AF_INET && isk->inet_rcv_saddr) ||
441 (sk->sk_family == AF_INET6 &&
442 !ipv6_addr_any(&inet6_sk(sk)->rcv_saddr)))
443 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
444
445 if (snum)
446 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
447 isk->inet_sport = htons(isk->inet_num);
448 isk->inet_daddr = 0;
449 isk->inet_dport = 0;
450
451 #if IS_ENABLED(CONFIG_IPV6)
452 if (sk->sk_family == AF_INET6)
453 memset(&inet6_sk(sk)->daddr, 0, sizeof(inet6_sk(sk)->daddr));
454 #endif
455
456 sk_dst_reset(sk);
457 out:
458 release_sock(sk);
459 pr_debug("ping_v4_bind -> %d\n", err);
460 return err;
461 }
462 EXPORT_SYMBOL_GPL(ping_bind);
463
464 /*
465 * Is this a supported type of ICMP message?
466 */
467
ping_supported(int family,int type,int code)468 static inline int ping_supported(int family, int type, int code)
469 {
470 return (family == AF_INET && type == ICMP_ECHO && code == 0) ||
471 (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0);
472 }
473
474 /*
475 * This routine is called by the ICMP module when it gets some
476 * sort of error condition.
477 */
478
ping_err(struct sk_buff * skb,int offset,u32 info)479 void ping_err(struct sk_buff *skb, int offset, u32 info)
480 {
481 int family;
482 struct icmphdr *icmph;
483 struct inet_sock *inet_sock;
484 int type;
485 int code;
486 struct net *net = dev_net(skb->dev);
487 struct sock *sk;
488 int harderr;
489 int err;
490
491 if (skb->protocol == htons(ETH_P_IP)) {
492 family = AF_INET;
493 type = icmp_hdr(skb)->type;
494 code = icmp_hdr(skb)->code;
495 icmph = (struct icmphdr *)(skb->data + offset);
496 } else if (skb->protocol == htons(ETH_P_IPV6)) {
497 family = AF_INET6;
498 type = icmp6_hdr(skb)->icmp6_type;
499 code = icmp6_hdr(skb)->icmp6_code;
500 icmph = (struct icmphdr *) (skb->data + offset);
501 } else {
502 BUG();
503 }
504
505 /* We assume the packet has already been checked by icmp_unreach */
506
507 if (!ping_supported(family, icmph->type, icmph->code))
508 return;
509
510 pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n",
511 skb->protocol, type, code, ntohs(icmph->un.echo.id),
512 ntohs(icmph->un.echo.sequence));
513
514 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
515 if (sk == NULL) {
516 pr_debug("no socket, dropping\n");
517 return; /* No socket for error */
518 }
519 pr_debug("err on socket %p\n", sk);
520
521 err = 0;
522 harderr = 0;
523 inet_sock = inet_sk(sk);
524
525 if (skb->protocol == htons(ETH_P_IP)) {
526 switch (type) {
527 default:
528 case ICMP_TIME_EXCEEDED:
529 err = EHOSTUNREACH;
530 break;
531 case ICMP_SOURCE_QUENCH:
532 /* This is not a real error but ping wants to see it.
533 * Report it with some fake errno.
534 */
535 err = EREMOTEIO;
536 break;
537 case ICMP_PARAMETERPROB:
538 err = EPROTO;
539 harderr = 1;
540 break;
541 case ICMP_DEST_UNREACH:
542 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
543 ipv4_sk_update_pmtu(skb, sk, info);
544 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) {
545 err = EMSGSIZE;
546 harderr = 1;
547 break;
548 }
549 goto out;
550 }
551 err = EHOSTUNREACH;
552 if (code <= NR_ICMP_UNREACH) {
553 harderr = icmp_err_convert[code].fatal;
554 err = icmp_err_convert[code].errno;
555 }
556 break;
557 case ICMP_REDIRECT:
558 /* See ICMP_SOURCE_QUENCH */
559 ipv4_sk_redirect(skb, sk);
560 err = EREMOTEIO;
561 break;
562 }
563 #if IS_ENABLED(CONFIG_IPV6)
564 } else if (skb->protocol == htons(ETH_P_IPV6)) {
565 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err);
566 #endif
567 }
568
569 /*
570 * RFC1122: OK. Passes ICMP errors back to application, as per
571 * 4.1.3.3.
572 */
573 if ((family == AF_INET && !inet_sock->recverr) ||
574 (family == AF_INET6 && !inet6_sk(sk)->recverr)) {
575 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
576 goto out;
577 } else {
578 if (family == AF_INET) {
579 ip_icmp_error(sk, skb, err, 0 /* no remote port */,
580 info, (u8 *)icmph);
581 #if IS_ENABLED(CONFIG_IPV6)
582 } else if (family == AF_INET6) {
583 pingv6_ops.ipv6_icmp_error(sk, skb, err, 0,
584 info, (u8 *)icmph);
585 #endif
586 }
587 }
588 sk->sk_err = err;
589 sk->sk_error_report(sk);
590 out:
591 sock_put(sk);
592 }
593 EXPORT_SYMBOL_GPL(ping_err);
594
595 /*
596 * Copy and checksum an ICMP Echo packet from user space into a buffer
597 * starting from the payload.
598 */
599
ping_getfrag(void * from,char * to,int offset,int fraglen,int odd,struct sk_buff * skb)600 int ping_getfrag(void *from, char *to,
601 int offset, int fraglen, int odd, struct sk_buff *skb)
602 {
603 struct pingfakehdr *pfh = (struct pingfakehdr *)from;
604
605 if (offset == 0) {
606 if (fraglen < sizeof(struct icmphdr))
607 BUG();
608 if (csum_partial_copy_fromiovecend(to + sizeof(struct icmphdr),
609 pfh->iov, 0, fraglen - sizeof(struct icmphdr),
610 &pfh->wcheck))
611 return -EFAULT;
612 } else if (offset < sizeof(struct icmphdr)) {
613 BUG();
614 } else {
615 if (csum_partial_copy_fromiovecend
616 (to, pfh->iov, offset - sizeof(struct icmphdr),
617 fraglen, &pfh->wcheck))
618 return -EFAULT;
619 }
620
621 #if IS_ENABLED(CONFIG_IPV6)
622 /* For IPv6, checksum each skb as we go along, as expected by
623 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in
624 * wcheck, it will be finalized in ping_v4_push_pending_frames.
625 */
626 if (pfh->family == AF_INET6) {
627 skb->csum = pfh->wcheck;
628 skb->ip_summed = CHECKSUM_NONE;
629 pfh->wcheck = 0;
630 }
631 #endif
632
633 return 0;
634 }
635 EXPORT_SYMBOL_GPL(ping_getfrag);
636
ping_v4_push_pending_frames(struct sock * sk,struct pingfakehdr * pfh,struct flowi4 * fl4)637 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
638 struct flowi4 *fl4)
639 {
640 struct sk_buff *skb = skb_peek(&sk->sk_write_queue);
641
642 pfh->wcheck = csum_partial((char *)&pfh->icmph,
643 sizeof(struct icmphdr), pfh->wcheck);
644 pfh->icmph.checksum = csum_fold(pfh->wcheck);
645 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
646 skb->ip_summed = CHECKSUM_NONE;
647 return ip_push_pending_frames(sk, fl4);
648 }
649
ping_common_sendmsg(int family,struct msghdr * msg,size_t len,void * user_icmph,size_t icmph_len)650 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
651 void *user_icmph, size_t icmph_len) {
652 u8 type, code;
653
654 if (len > 0xFFFF)
655 return -EMSGSIZE;
656
657 /*
658 * Check the flags.
659 */
660
661 /* Mirror BSD error message compatibility */
662 if (msg->msg_flags & MSG_OOB)
663 return -EOPNOTSUPP;
664
665 /*
666 * Fetch the ICMP header provided by the userland.
667 * iovec is modified! The ICMP header is consumed.
668 */
669 if (memcpy_fromiovec(user_icmph, msg->msg_iov, icmph_len))
670 return -EFAULT;
671
672 if (family == AF_INET) {
673 type = ((struct icmphdr *) user_icmph)->type;
674 code = ((struct icmphdr *) user_icmph)->code;
675 #if IS_ENABLED(CONFIG_IPV6)
676 } else if (family == AF_INET6) {
677 type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
678 code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
679 #endif
680 } else {
681 BUG();
682 }
683
684 if (!ping_supported(family, type, code))
685 return -EINVAL;
686
687 return 0;
688 }
689 EXPORT_SYMBOL_GPL(ping_common_sendmsg);
690
ping_v4_sendmsg(struct kiocb * iocb,struct sock * sk,struct msghdr * msg,size_t len)691 int ping_v4_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
692 size_t len)
693 {
694 struct net *net = sock_net(sk);
695 struct flowi4 fl4;
696 struct inet_sock *inet = inet_sk(sk);
697 struct ipcm_cookie ipc;
698 struct icmphdr user_icmph;
699 struct pingfakehdr pfh;
700 struct rtable *rt = NULL;
701 struct ip_options_data opt_copy;
702 int free = 0;
703 __be32 saddr, daddr, faddr;
704 u8 tos;
705 int err;
706
707 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
708
709 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
710 sizeof(user_icmph));
711 if (err)
712 return err;
713
714 /*
715 * Get and verify the address.
716 */
717
718 if (msg->msg_name) {
719 struct sockaddr_in *usin = (struct sockaddr_in *)msg->msg_name;
720 if (msg->msg_namelen < sizeof(*usin))
721 return -EINVAL;
722 if (usin->sin_family != AF_INET)
723 return -EAFNOSUPPORT;
724 daddr = usin->sin_addr.s_addr;
725 /* no remote port */
726 } else {
727 if (sk->sk_state != TCP_ESTABLISHED)
728 return -EDESTADDRREQ;
729 daddr = inet->inet_daddr;
730 /* no remote port */
731 }
732
733 ipc.addr = inet->inet_saddr;
734 ipc.opt = NULL;
735 ipc.oif = sk->sk_bound_dev_if;
736 ipc.tx_flags = 0;
737
738 sock_tx_timestamp(sk, &ipc.tx_flags);
739
740 if (msg->msg_controllen) {
741 err = ip_cmsg_send(sock_net(sk), msg, &ipc);
742 if (err)
743 return err;
744 if (ipc.opt)
745 free = 1;
746 }
747 if (!ipc.opt) {
748 struct ip_options_rcu *inet_opt;
749
750 rcu_read_lock();
751 inet_opt = rcu_dereference(inet->inet_opt);
752 if (inet_opt) {
753 memcpy(&opt_copy, inet_opt,
754 sizeof(*inet_opt) + inet_opt->opt.optlen);
755 ipc.opt = &opt_copy.opt;
756 }
757 rcu_read_unlock();
758 }
759
760 saddr = ipc.addr;
761 ipc.addr = faddr = daddr;
762
763 if (ipc.opt && ipc.opt->opt.srr) {
764 if (!daddr)
765 return -EINVAL;
766 faddr = ipc.opt->opt.faddr;
767 }
768 tos = RT_TOS(inet->tos);
769 if (sock_flag(sk, SOCK_LOCALROUTE) ||
770 (msg->msg_flags & MSG_DONTROUTE) ||
771 (ipc.opt && ipc.opt->opt.is_strictroute)) {
772 tos |= RTO_ONLINK;
773 }
774
775 if (ipv4_is_multicast(daddr)) {
776 if (!ipc.oif)
777 ipc.oif = inet->mc_index;
778 if (!saddr)
779 saddr = inet->mc_addr;
780 } else if (!ipc.oif)
781 ipc.oif = inet->uc_index;
782
783 flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
784 RT_SCOPE_UNIVERSE, sk->sk_protocol,
785 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0,
786 sk->sk_uid);
787
788 security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
789 rt = ip_route_output_flow(net, &fl4, sk);
790 if (IS_ERR(rt)) {
791 err = PTR_ERR(rt);
792 rt = NULL;
793 if (err == -ENETUNREACH)
794 IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
795 goto out;
796 }
797
798 err = -EACCES;
799 if ((rt->rt_flags & RTCF_BROADCAST) &&
800 !sock_flag(sk, SOCK_BROADCAST))
801 goto out;
802
803 if (msg->msg_flags & MSG_CONFIRM)
804 goto do_confirm;
805 back_from_confirm:
806
807 if (!ipc.addr)
808 ipc.addr = fl4.daddr;
809
810 lock_sock(sk);
811
812 pfh.icmph.type = user_icmph.type; /* already checked */
813 pfh.icmph.code = user_icmph.code; /* ditto */
814 pfh.icmph.checksum = 0;
815 pfh.icmph.un.echo.id = inet->inet_sport;
816 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
817 pfh.iov = msg->msg_iov;
818 pfh.wcheck = 0;
819 pfh.family = AF_INET;
820
821 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
822 0, &ipc, &rt, msg->msg_flags);
823 if (err)
824 ip_flush_pending_frames(sk);
825 else
826 err = ping_v4_push_pending_frames(sk, &pfh, &fl4);
827 release_sock(sk);
828
829 out:
830 ip_rt_put(rt);
831 if (free)
832 kfree(ipc.opt);
833 if (!err) {
834 icmp_out_count(sock_net(sk), user_icmph.type);
835 return len;
836 }
837 return err;
838
839 do_confirm:
840 dst_confirm(&rt->dst);
841 if (!(msg->msg_flags & MSG_PROBE) || len)
842 goto back_from_confirm;
843 err = 0;
844 goto out;
845 }
846
ping_recvmsg(struct kiocb * iocb,struct sock * sk,struct msghdr * msg,size_t len,int noblock,int flags,int * addr_len)847 int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
848 size_t len, int noblock, int flags, int *addr_len)
849 {
850 struct inet_sock *isk = inet_sk(sk);
851 int family = sk->sk_family;
852 struct sk_buff *skb;
853 int copied, err;
854
855 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
856
857 err = -EOPNOTSUPP;
858 if (flags & MSG_OOB)
859 goto out;
860
861 if (flags & MSG_ERRQUEUE) {
862 if (family == AF_INET) {
863 return ip_recv_error(sk, msg, len, addr_len);
864 #if IS_ENABLED(CONFIG_IPV6)
865 } else if (family == AF_INET6) {
866 return pingv6_ops.ipv6_recv_error(sk, msg, len,
867 addr_len);
868 #endif
869 }
870 }
871
872 skb = skb_recv_datagram(sk, flags, noblock, &err);
873 if (!skb)
874 goto out;
875
876 copied = skb->len;
877 if (copied > len) {
878 msg->msg_flags |= MSG_TRUNC;
879 copied = len;
880 }
881
882 /* Don't bother checking the checksum */
883 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
884 if (err)
885 goto done;
886
887 sock_recv_timestamp(msg, sk, skb);
888
889 /* Copy the address and add cmsg data. */
890 if (family == AF_INET) {
891 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
892
893 if (sin) {
894 sin->sin_family = AF_INET;
895 sin->sin_port = 0 /* skb->h.uh->source */;
896 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
897 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
898 *addr_len = sizeof(*sin);
899 }
900
901 if (isk->cmsg_flags)
902 ip_cmsg_recv(msg, skb);
903
904 #if IS_ENABLED(CONFIG_IPV6)
905 } else if (family == AF_INET6) {
906 struct ipv6_pinfo *np = inet6_sk(sk);
907 struct ipv6hdr *ip6 = ipv6_hdr(skb);
908 struct sockaddr_in6 *sin6 =
909 (struct sockaddr_in6 *)msg->msg_name;
910
911 if (sin6) {
912 sin6->sin6_family = AF_INET6;
913 sin6->sin6_port = 0;
914 sin6->sin6_addr = ip6->saddr;
915 sin6->sin6_flowinfo = 0;
916 if (np->sndflow)
917 sin6->sin6_flowinfo = ip6_flowinfo(ip6);
918 sin6->sin6_scope_id =
919 ipv6_iface_scope_id(&sin6->sin6_addr,
920 IP6CB(skb)->iif);
921 *addr_len = sizeof(*sin6);
922 }
923
924 if (inet6_sk(sk)->rxopt.all)
925 pingv6_ops.ip6_datagram_recv_ctl(sk, msg, skb);
926 #endif
927 } else {
928 BUG();
929 }
930
931 err = copied;
932
933 done:
934 skb_free_datagram(sk, skb);
935 out:
936 pr_debug("ping_recvmsg -> %d\n", err);
937 return err;
938 }
939 EXPORT_SYMBOL_GPL(ping_recvmsg);
940
ping_queue_rcv_skb(struct sock * sk,struct sk_buff * skb)941 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
942 {
943 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
944 inet_sk(sk), inet_sk(sk)->inet_num, skb);
945 if (sock_queue_rcv_skb(sk, skb) < 0) {
946 kfree_skb(skb);
947 pr_debug("ping_queue_rcv_skb -> failed\n");
948 return -1;
949 }
950 return 0;
951 }
952 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
953
954
955 /*
956 * All we need to do is get the socket.
957 */
958
ping_rcv(struct sk_buff * skb)959 void ping_rcv(struct sk_buff *skb)
960 {
961 struct sock *sk;
962 struct net *net = dev_net(skb->dev);
963 struct icmphdr *icmph = icmp_hdr(skb);
964
965 /* We assume the packet has already been checked by icmp_rcv */
966
967 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
968 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
969
970 /* Push ICMP header back */
971 skb_push(skb, skb->data - (u8 *)icmph);
972
973 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
974 if (sk != NULL) {
975 pr_debug("rcv on socket %p\n", sk);
976 ping_queue_rcv_skb(sk, skb_get(skb));
977 sock_put(sk);
978 return;
979 }
980 pr_debug("no socket, dropping\n");
981
982 /* We're called from icmp_rcv(). kfree_skb() is done there. */
983 }
984 EXPORT_SYMBOL_GPL(ping_rcv);
985
986 struct proto ping_prot = {
987 .name = "PING",
988 .owner = THIS_MODULE,
989 .init = ping_init_sock,
990 .close = ping_close,
991 .connect = ip4_datagram_connect,
992 .disconnect = udp_disconnect,
993 .setsockopt = ip_setsockopt,
994 .getsockopt = ip_getsockopt,
995 .sendmsg = ping_v4_sendmsg,
996 .recvmsg = ping_recvmsg,
997 .bind = ping_bind,
998 .backlog_rcv = ping_queue_rcv_skb,
999 .release_cb = ip4_datagram_release_cb,
1000 .hash = ping_hash,
1001 .unhash = ping_unhash,
1002 .get_port = ping_get_port,
1003 .obj_size = sizeof(struct inet_sock),
1004 };
1005 EXPORT_SYMBOL(ping_prot);
1006
1007 #ifdef CONFIG_PROC_FS
1008
ping_get_first(struct seq_file * seq,int start)1009 static struct sock *ping_get_first(struct seq_file *seq, int start)
1010 {
1011 struct sock *sk;
1012 struct ping_iter_state *state = seq->private;
1013 struct net *net = seq_file_net(seq);
1014
1015 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
1016 ++state->bucket) {
1017 struct hlist_nulls_node *node;
1018 struct hlist_nulls_head *hslot;
1019
1020 hslot = &ping_table.hash[state->bucket];
1021
1022 if (hlist_nulls_empty(hslot))
1023 continue;
1024
1025 sk_nulls_for_each(sk, node, hslot) {
1026 if (net_eq(sock_net(sk), net))
1027 goto found;
1028 }
1029 }
1030 sk = NULL;
1031 found:
1032 return sk;
1033 }
1034
ping_get_next(struct seq_file * seq,struct sock * sk)1035 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
1036 {
1037 struct ping_iter_state *state = seq->private;
1038 struct net *net = seq_file_net(seq);
1039
1040 do {
1041 sk = sk_nulls_next(sk);
1042 } while (sk && (!net_eq(sock_net(sk), net)));
1043
1044 if (!sk)
1045 return ping_get_first(seq, state->bucket + 1);
1046 return sk;
1047 }
1048
ping_get_idx(struct seq_file * seq,loff_t pos)1049 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
1050 {
1051 struct sock *sk = ping_get_first(seq, 0);
1052
1053 if (sk)
1054 while (pos && (sk = ping_get_next(seq, sk)) != NULL)
1055 --pos;
1056 return pos ? NULL : sk;
1057 }
1058
ping_seq_start(struct seq_file * seq,loff_t * pos)1059 static void *ping_seq_start(struct seq_file *seq, loff_t *pos)
1060 {
1061 struct ping_iter_state *state = seq->private;
1062 state->bucket = 0;
1063
1064 read_lock_bh(&ping_table.lock);
1065
1066 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1067 }
1068
ping_seq_next(struct seq_file * seq,void * v,loff_t * pos)1069 static void *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
ping_seq_stop(struct seq_file * seq,void * v)1082 static void ping_seq_stop(struct seq_file *seq, void *v)
1083 {
1084 read_unlock_bh(&ping_table.lock);
1085 }
1086
ping_format_sock(struct sock * sp,struct seq_file * f,int bucket,int * len)1087 static void ping_format_sock(struct sock *sp, struct seq_file *f,
1088 int bucket, int *len)
1089 {
1090 struct inet_sock *inet = inet_sk(sp);
1091 __be32 dest = inet->inet_daddr;
1092 __be32 src = inet->inet_rcv_saddr;
1093 __u16 destp = ntohs(inet->inet_dport);
1094 __u16 srcp = ntohs(inet->inet_sport);
1095
1096 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
1097 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %d%n",
1098 bucket, src, srcp, dest, destp, sp->sk_state,
1099 sk_wmem_alloc_get(sp),
1100 sk_rmem_alloc_get(sp),
1101 0, 0L, 0,
1102 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
1103 0, sock_i_ino(sp),
1104 atomic_read(&sp->sk_refcnt), sp,
1105 atomic_read(&sp->sk_drops), len);
1106 }
1107
ping_seq_show(struct seq_file * seq,void * v)1108 static int ping_seq_show(struct seq_file *seq, void *v)
1109 {
1110 if (v == SEQ_START_TOKEN)
1111 seq_printf(seq, "%-127s\n",
1112 " sl local_address rem_address st tx_queue "
1113 "rx_queue tr tm->when retrnsmt uid timeout "
1114 "inode ref pointer drops");
1115 else {
1116 struct ping_iter_state *state = seq->private;
1117 int len;
1118
1119 ping_format_sock(v, seq, state->bucket, &len);
1120 seq_printf(seq, "%*s\n", 127 - len, "");
1121 }
1122 return 0;
1123 }
1124
1125 static const struct seq_operations ping_seq_ops = {
1126 .show = ping_seq_show,
1127 .start = ping_seq_start,
1128 .next = ping_seq_next,
1129 .stop = ping_seq_stop,
1130 };
1131
ping_seq_open(struct inode * inode,struct file * file)1132 static int ping_seq_open(struct inode *inode, struct file *file)
1133 {
1134 return seq_open_net(inode, file, &ping_seq_ops,
1135 sizeof(struct ping_iter_state));
1136 }
1137
1138 static const struct file_operations ping_seq_fops = {
1139 .open = ping_seq_open,
1140 .read = seq_read,
1141 .llseek = seq_lseek,
1142 .release = seq_release_net,
1143 };
1144
ping_proc_register(struct net * net)1145 static int ping_proc_register(struct net *net)
1146 {
1147 struct proc_dir_entry *p;
1148 int rc = 0;
1149
1150 p = proc_create("icmp", S_IRUGO, net->proc_net, &ping_seq_fops);
1151 if (!p)
1152 rc = -ENOMEM;
1153 return rc;
1154 }
1155
ping_proc_unregister(struct net * net)1156 static void ping_proc_unregister(struct net *net)
1157 {
1158 remove_proc_entry("icmp", net->proc_net);
1159 }
1160
1161
ping_proc_init_net(struct net * net)1162 static int __net_init ping_proc_init_net(struct net *net)
1163 {
1164 return ping_proc_register(net);
1165 }
1166
ping_proc_exit_net(struct net * net)1167 static void __net_exit ping_proc_exit_net(struct net *net)
1168 {
1169 ping_proc_unregister(net);
1170 }
1171
1172 static struct pernet_operations ping_net_ops = {
1173 .init = ping_proc_init_net,
1174 .exit = ping_proc_exit_net,
1175 };
1176
ping_proc_init(void)1177 int __init ping_proc_init(void)
1178 {
1179 return register_pernet_subsys(&ping_net_ops);
1180 }
1181
ping_proc_exit(void)1182 void ping_proc_exit(void)
1183 {
1184 unregister_pernet_subsys(&ping_net_ops);
1185 }
1186
1187 #endif
1188
ping_init(void)1189 void __init ping_init(void)
1190 {
1191 int i;
1192
1193 for (i = 0; i < PING_HTABLE_SIZE; i++)
1194 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i);
1195 rwlock_init(&ping_table.lock);
1196 }
1197