1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * "Ping" sockets
8 *
9 * Based on ipv4/udp.c code.
10 *
11 * Authors: Vasiliy Kulikov / Openwall (for Linux 2.6),
12 * Pavel Kankovsky (for Linux 2.4.32)
13 *
14 * Pavel gave all rights to bugs to Vasiliy,
15 * none of the bugs are Pavel's now.
16 */
17
18 #include <linux/uaccess.h>
19 #include <linux/types.h>
20 #include <linux/fcntl.h>
21 #include <linux/socket.h>
22 #include <linux/sockios.h>
23 #include <linux/in.h>
24 #include <linux/errno.h>
25 #include <linux/timer.h>
26 #include <linux/mm.h>
27 #include <linux/inet.h>
28 #include <linux/netdevice.h>
29 #include <net/snmp.h>
30 #include <net/ip.h>
31 #include <net/icmp.h>
32 #include <net/protocol.h>
33 #include <linux/skbuff.h>
34 #include <linux/proc_fs.h>
35 #include <linux/export.h>
36 #include <linux/bpf-cgroup.h>
37 #include <net/sock.h>
38 #include <net/ping.h>
39 #include <net/udp.h>
40 #include <net/route.h>
41 #include <net/inet_common.h>
42 #include <net/checksum.h>
43
44 #if IS_ENABLED(CONFIG_IPV6)
45 #include <linux/in6.h>
46 #include <linux/icmpv6.h>
47 #include <net/addrconf.h>
48 #include <net/ipv6.h>
49 #include <net/transp_v6.h>
50 #endif
51
52 #define ping_portaddr_for_each_entry(__sk, node, list) \
53 hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
54 #define ping_portaddr_for_each_entry_rcu(__sk, node, list) \
55 hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
56
57 struct ping_table {
58 struct hlist_nulls_head hash[PING_HTABLE_SIZE];
59 spinlock_t lock;
60 };
61
62 static struct ping_table ping_table;
63 struct pingv6_ops pingv6_ops;
64 EXPORT_SYMBOL_GPL(pingv6_ops);
65
66 static u16 ping_port_rover;
67
ping_hashfn(const struct net * net,u32 num,u32 mask)68 static inline u32 ping_hashfn(const struct net *net, u32 num, u32 mask)
69 {
70 u32 res = (num + net_hash_mix(net)) & mask;
71
72 pr_debug("hash(%u) = %u\n", num, res);
73 return res;
74 }
75 EXPORT_SYMBOL_GPL(ping_hash);
76
ping_hashslot(struct ping_table * table,struct net * net,unsigned int num)77 static inline struct hlist_nulls_head *ping_hashslot(struct ping_table *table,
78 struct net *net, unsigned int num)
79 {
80 return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)];
81 }
82
ping_get_port(struct sock * sk,unsigned short ident)83 int ping_get_port(struct sock *sk, unsigned short ident)
84 {
85 struct hlist_nulls_node *node;
86 struct hlist_nulls_head *hlist;
87 struct inet_sock *isk, *isk2;
88 struct sock *sk2 = NULL;
89
90 isk = inet_sk(sk);
91 spin_lock(&ping_table.lock);
92 if (ident == 0) {
93 u32 i;
94 u16 result = ping_port_rover + 1;
95
96 for (i = 0; i < (1L << 16); i++, result++) {
97 if (!result)
98 result++; /* avoid zero */
99 hlist = ping_hashslot(&ping_table, sock_net(sk),
100 result);
101 ping_portaddr_for_each_entry(sk2, node, hlist) {
102 isk2 = inet_sk(sk2);
103
104 if (isk2->inet_num == result)
105 goto next_port;
106 }
107
108 /* found */
109 ping_port_rover = ident = result;
110 break;
111 next_port:
112 ;
113 }
114 if (i >= (1L << 16))
115 goto fail;
116 } else {
117 hlist = ping_hashslot(&ping_table, sock_net(sk), ident);
118 ping_portaddr_for_each_entry(sk2, node, hlist) {
119 isk2 = inet_sk(sk2);
120
121 /* BUG? Why is this reuse and not reuseaddr? ping.c
122 * doesn't turn off SO_REUSEADDR, and it doesn't expect
123 * that other ping processes can steal its packets.
124 */
125 if ((isk2->inet_num == ident) &&
126 (sk2 != sk) &&
127 (!sk2->sk_reuse || !sk->sk_reuse))
128 goto fail;
129 }
130 }
131
132 pr_debug("found port/ident = %d\n", ident);
133 isk->inet_num = ident;
134 if (sk_unhashed(sk)) {
135 pr_debug("was not hashed\n");
136 sock_hold(sk);
137 sock_set_flag(sk, SOCK_RCU_FREE);
138 hlist_nulls_add_head_rcu(&sk->sk_nulls_node, hlist);
139 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
140 }
141 spin_unlock(&ping_table.lock);
142 return 0;
143
144 fail:
145 spin_unlock(&ping_table.lock);
146 return -EADDRINUSE;
147 }
148 EXPORT_SYMBOL_GPL(ping_get_port);
149
ping_hash(struct sock * sk)150 int ping_hash(struct sock *sk)
151 {
152 pr_debug("ping_hash(sk->port=%u)\n", inet_sk(sk)->inet_num);
153 BUG(); /* "Please do not press this button again." */
154
155 return 0;
156 }
157
ping_unhash(struct sock * sk)158 void ping_unhash(struct sock *sk)
159 {
160 struct inet_sock *isk = inet_sk(sk);
161
162 pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);
163 spin_lock(&ping_table.lock);
164 if (sk_hashed(sk)) {
165 hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
166 sock_put(sk);
167 isk->inet_num = 0;
168 isk->inet_sport = 0;
169 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
170 }
171 spin_unlock(&ping_table.lock);
172 }
173 EXPORT_SYMBOL_GPL(ping_unhash);
174
175 /* Called under rcu_read_lock() */
ping_lookup(struct net * net,struct sk_buff * skb,u16 ident)176 static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
177 {
178 struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident);
179 struct sock *sk = NULL;
180 struct inet_sock *isk;
181 struct hlist_nulls_node *hnode;
182 int dif, sdif;
183
184 if (skb->protocol == htons(ETH_P_IP)) {
185 dif = inet_iif(skb);
186 sdif = inet_sdif(skb);
187 pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n",
188 (int)ident, &ip_hdr(skb)->daddr, dif);
189 #if IS_ENABLED(CONFIG_IPV6)
190 } else if (skb->protocol == htons(ETH_P_IPV6)) {
191 dif = inet6_iif(skb);
192 sdif = inet6_sdif(skb);
193 pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n",
194 (int)ident, &ipv6_hdr(skb)->daddr, dif);
195 #endif
196 } else {
197 return NULL;
198 }
199
200 ping_portaddr_for_each_entry_rcu(sk, hnode, hslot) {
201 isk = inet_sk(sk);
202
203 pr_debug("iterate\n");
204 if (isk->inet_num != ident)
205 continue;
206
207 if (skb->protocol == htons(ETH_P_IP) &&
208 sk->sk_family == AF_INET) {
209 pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk,
210 (int) isk->inet_num, &isk->inet_rcv_saddr,
211 sk->sk_bound_dev_if);
212
213 if (isk->inet_rcv_saddr &&
214 isk->inet_rcv_saddr != ip_hdr(skb)->daddr)
215 continue;
216 #if IS_ENABLED(CONFIG_IPV6)
217 } else if (skb->protocol == htons(ETH_P_IPV6) &&
218 sk->sk_family == AF_INET6) {
219
220 pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk,
221 (int) isk->inet_num,
222 &sk->sk_v6_rcv_saddr,
223 sk->sk_bound_dev_if);
224
225 if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
226 !ipv6_addr_equal(&sk->sk_v6_rcv_saddr,
227 &ipv6_hdr(skb)->daddr))
228 continue;
229 #endif
230 } else {
231 continue;
232 }
233
234 if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif &&
235 sk->sk_bound_dev_if != sdif)
236 continue;
237
238 goto exit;
239 }
240
241 sk = NULL;
242 exit:
243
244 return sk;
245 }
246
inet_get_ping_group_range_net(struct net * net,kgid_t * low,kgid_t * high)247 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low,
248 kgid_t *high)
249 {
250 kgid_t *data = net->ipv4.ping_group_range.range;
251 unsigned int seq;
252
253 do {
254 seq = read_seqbegin(&net->ipv4.ping_group_range.lock);
255
256 *low = data[0];
257 *high = data[1];
258 } while (read_seqretry(&net->ipv4.ping_group_range.lock, seq));
259 }
260
261
ping_init_sock(struct sock * sk)262 int ping_init_sock(struct sock *sk)
263 {
264 struct net *net = sock_net(sk);
265 kgid_t group = current_egid();
266 struct group_info *group_info;
267 int i;
268 kgid_t low, high;
269 int ret = 0;
270
271 if (sk->sk_family == AF_INET6)
272 sk->sk_ipv6only = 1;
273
274 inet_get_ping_group_range_net(net, &low, &high);
275 if (gid_lte(low, group) && gid_lte(group, high))
276 return 0;
277
278 group_info = get_current_groups();
279 for (i = 0; i < group_info->ngroups; i++) {
280 kgid_t gid = group_info->gid[i];
281
282 if (gid_lte(low, gid) && gid_lte(gid, high))
283 goto out_release_group;
284 }
285
286 ret = -EACCES;
287
288 out_release_group:
289 put_group_info(group_info);
290 return ret;
291 }
292 EXPORT_SYMBOL_GPL(ping_init_sock);
293
ping_close(struct sock * sk,long timeout)294 void ping_close(struct sock *sk, long timeout)
295 {
296 pr_debug("ping_close(sk=%p,sk->num=%u)\n",
297 inet_sk(sk), inet_sk(sk)->inet_num);
298 pr_debug("isk->refcnt = %d\n", refcount_read(&sk->sk_refcnt));
299
300 sk_common_release(sk);
301 }
302 EXPORT_SYMBOL_GPL(ping_close);
303
ping_pre_connect(struct sock * sk,struct sockaddr * uaddr,int addr_len)304 static int ping_pre_connect(struct sock *sk, struct sockaddr *uaddr,
305 int addr_len)
306 {
307 /* This check is replicated from __ip4_datagram_connect() and
308 * intended to prevent BPF program called below from accessing bytes
309 * that are out of the bound specified by user in addr_len.
310 */
311 if (addr_len < sizeof(struct sockaddr_in))
312 return -EINVAL;
313
314 return BPF_CGROUP_RUN_PROG_INET4_CONNECT_LOCK(sk, uaddr);
315 }
316
317 /* 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)318 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
319 struct sockaddr *uaddr, int addr_len)
320 {
321 struct net *net = sock_net(sk);
322 if (sk->sk_family == AF_INET) {
323 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
324 u32 tb_id = RT_TABLE_LOCAL;
325 int chk_addr_ret;
326
327 if (addr_len < sizeof(*addr))
328 return -EINVAL;
329
330 if (addr->sin_family != AF_INET &&
331 !(addr->sin_family == AF_UNSPEC &&
332 addr->sin_addr.s_addr == htonl(INADDR_ANY)))
333 return -EAFNOSUPPORT;
334
335 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",
336 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
337
338 if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
339 return 0;
340
341 tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id;
342 chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
343
344 if (chk_addr_ret == RTN_MULTICAST ||
345 chk_addr_ret == RTN_BROADCAST ||
346 (chk_addr_ret != RTN_LOCAL &&
347 !inet_can_nonlocal_bind(net, isk)))
348 return -EADDRNOTAVAIL;
349
350 #if IS_ENABLED(CONFIG_IPV6)
351 } else if (sk->sk_family == AF_INET6) {
352 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
353 int addr_type, scoped, has_addr;
354 struct net_device *dev = NULL;
355
356 if (addr_len < sizeof(*addr))
357 return -EINVAL;
358
359 if (addr->sin6_family != AF_INET6)
360 return -EAFNOSUPPORT;
361
362 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n",
363 sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port));
364
365 addr_type = ipv6_addr_type(&addr->sin6_addr);
366 scoped = __ipv6_addr_needs_scope_id(addr_type);
367 if ((addr_type != IPV6_ADDR_ANY &&
368 !(addr_type & IPV6_ADDR_UNICAST)) ||
369 (scoped && !addr->sin6_scope_id))
370 return -EINVAL;
371
372 rcu_read_lock();
373 if (addr->sin6_scope_id) {
374 dev = dev_get_by_index_rcu(net, addr->sin6_scope_id);
375 if (!dev) {
376 rcu_read_unlock();
377 return -ENODEV;
378 }
379 }
380
381 if (!dev && sk->sk_bound_dev_if) {
382 dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if);
383 if (!dev) {
384 rcu_read_unlock();
385 return -ENODEV;
386 }
387 }
388 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev,
389 scoped);
390 rcu_read_unlock();
391
392 if (!(ipv6_can_nonlocal_bind(net, isk) || has_addr ||
393 addr_type == IPV6_ADDR_ANY))
394 return -EADDRNOTAVAIL;
395
396 if (scoped)
397 sk->sk_bound_dev_if = addr->sin6_scope_id;
398 #endif
399 } else {
400 return -EAFNOSUPPORT;
401 }
402 return 0;
403 }
404
ping_set_saddr(struct sock * sk,struct sockaddr * saddr)405 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr)
406 {
407 if (saddr->sa_family == AF_INET) {
408 struct inet_sock *isk = inet_sk(sk);
409 struct sockaddr_in *addr = (struct sockaddr_in *) saddr;
410 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
411 #if IS_ENABLED(CONFIG_IPV6)
412 } else if (saddr->sa_family == AF_INET6) {
413 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr;
414 struct ipv6_pinfo *np = inet6_sk(sk);
415 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr;
416 #endif
417 }
418 }
419
420 /*
421 * We need our own bind because there are no privileged id's == local ports.
422 * Moreover, we don't allow binding to multi- and broadcast addresses.
423 */
424
ping_bind(struct sock * sk,struct sockaddr * uaddr,int addr_len)425 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
426 {
427 struct inet_sock *isk = inet_sk(sk);
428 unsigned short snum;
429 int err;
430 int dif = sk->sk_bound_dev_if;
431
432 err = ping_check_bind_addr(sk, isk, uaddr, addr_len);
433 if (err)
434 return err;
435
436 lock_sock(sk);
437
438 err = -EINVAL;
439 if (isk->inet_num != 0)
440 goto out;
441
442 err = -EADDRINUSE;
443 snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port);
444 if (ping_get_port(sk, snum) != 0) {
445 /* Restore possibly modified sk->sk_bound_dev_if by ping_check_bind_addr(). */
446 sk->sk_bound_dev_if = dif;
447 goto out;
448 }
449 ping_set_saddr(sk, uaddr);
450
451 pr_debug("after bind(): num = %hu, dif = %d\n",
452 isk->inet_num,
453 sk->sk_bound_dev_if);
454
455 err = 0;
456 if (sk->sk_family == AF_INET && isk->inet_rcv_saddr)
457 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
458 #if IS_ENABLED(CONFIG_IPV6)
459 if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr))
460 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
461 #endif
462
463 if (snum)
464 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
465 isk->inet_sport = htons(isk->inet_num);
466 isk->inet_daddr = 0;
467 isk->inet_dport = 0;
468
469 #if IS_ENABLED(CONFIG_IPV6)
470 if (sk->sk_family == AF_INET6)
471 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr));
472 #endif
473
474 sk_dst_reset(sk);
475 out:
476 release_sock(sk);
477 pr_debug("ping_v4_bind -> %d\n", err);
478 return err;
479 }
480 EXPORT_SYMBOL_GPL(ping_bind);
481
482 /*
483 * Is this a supported type of ICMP message?
484 */
485
ping_supported(int family,int type,int code)486 static inline int ping_supported(int family, int type, int code)
487 {
488 return (family == AF_INET && type == ICMP_ECHO && code == 0) ||
489 (family == AF_INET && type == ICMP_EXT_ECHO && code == 0) ||
490 (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0) ||
491 (family == AF_INET6 && type == ICMPV6_EXT_ECHO_REQUEST && code == 0);
492 }
493
494 /*
495 * This routine is called by the ICMP module when it gets some
496 * sort of error condition.
497 */
498
ping_err(struct sk_buff * skb,int offset,u32 info)499 void ping_err(struct sk_buff *skb, int offset, u32 info)
500 {
501 int family;
502 struct icmphdr *icmph;
503 struct inet_sock *inet_sock;
504 int type;
505 int code;
506 struct net *net = dev_net(skb->dev);
507 struct sock *sk;
508 int harderr;
509 int err;
510
511 if (skb->protocol == htons(ETH_P_IP)) {
512 family = AF_INET;
513 type = icmp_hdr(skb)->type;
514 code = icmp_hdr(skb)->code;
515 icmph = (struct icmphdr *)(skb->data + offset);
516 } else if (skb->protocol == htons(ETH_P_IPV6)) {
517 family = AF_INET6;
518 type = icmp6_hdr(skb)->icmp6_type;
519 code = icmp6_hdr(skb)->icmp6_code;
520 icmph = (struct icmphdr *) (skb->data + offset);
521 } else {
522 BUG();
523 }
524
525 /* We assume the packet has already been checked by icmp_unreach */
526
527 if (!ping_supported(family, icmph->type, icmph->code))
528 return;
529
530 pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n",
531 skb->protocol, type, code, ntohs(icmph->un.echo.id),
532 ntohs(icmph->un.echo.sequence));
533
534 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
535 if (!sk) {
536 pr_debug("no socket, dropping\n");
537 return; /* No socket for error */
538 }
539 pr_debug("err on socket %p\n", sk);
540
541 err = 0;
542 harderr = 0;
543 inet_sock = inet_sk(sk);
544
545 if (skb->protocol == htons(ETH_P_IP)) {
546 switch (type) {
547 default:
548 case ICMP_TIME_EXCEEDED:
549 err = EHOSTUNREACH;
550 break;
551 case ICMP_SOURCE_QUENCH:
552 /* This is not a real error but ping wants to see it.
553 * Report it with some fake errno.
554 */
555 err = EREMOTEIO;
556 break;
557 case ICMP_PARAMETERPROB:
558 err = EPROTO;
559 harderr = 1;
560 break;
561 case ICMP_DEST_UNREACH:
562 if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
563 ipv4_sk_update_pmtu(skb, sk, info);
564 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) {
565 err = EMSGSIZE;
566 harderr = 1;
567 break;
568 }
569 goto out;
570 }
571 err = EHOSTUNREACH;
572 if (code <= NR_ICMP_UNREACH) {
573 harderr = icmp_err_convert[code].fatal;
574 err = icmp_err_convert[code].errno;
575 }
576 break;
577 case ICMP_REDIRECT:
578 /* See ICMP_SOURCE_QUENCH */
579 ipv4_sk_redirect(skb, sk);
580 err = EREMOTEIO;
581 break;
582 }
583 #if IS_ENABLED(CONFIG_IPV6)
584 } else if (skb->protocol == htons(ETH_P_IPV6)) {
585 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err);
586 #endif
587 }
588
589 /*
590 * RFC1122: OK. Passes ICMP errors back to application, as per
591 * 4.1.3.3.
592 */
593 if ((family == AF_INET && !inet_sock->recverr) ||
594 (family == AF_INET6 && !inet6_sk(sk)->recverr)) {
595 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
596 goto out;
597 } else {
598 if (family == AF_INET) {
599 ip_icmp_error(sk, skb, err, 0 /* no remote port */,
600 info, (u8 *)icmph);
601 #if IS_ENABLED(CONFIG_IPV6)
602 } else if (family == AF_INET6) {
603 pingv6_ops.ipv6_icmp_error(sk, skb, err, 0,
604 info, (u8 *)icmph);
605 #endif
606 }
607 }
608 sk->sk_err = err;
609 sk_error_report(sk);
610 out:
611 return;
612 }
613 EXPORT_SYMBOL_GPL(ping_err);
614
615 /*
616 * Copy and checksum an ICMP Echo packet from user space into a buffer
617 * starting from the payload.
618 */
619
ping_getfrag(void * from,char * to,int offset,int fraglen,int odd,struct sk_buff * skb)620 int ping_getfrag(void *from, char *to,
621 int offset, int fraglen, int odd, struct sk_buff *skb)
622 {
623 struct pingfakehdr *pfh = from;
624
625 if (!csum_and_copy_from_iter_full(to, fraglen, &pfh->wcheck,
626 &pfh->msg->msg_iter))
627 return -EFAULT;
628
629 #if IS_ENABLED(CONFIG_IPV6)
630 /* For IPv6, checksum each skb as we go along, as expected by
631 * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in
632 * wcheck, it will be finalized in ping_v4_push_pending_frames.
633 */
634 if (pfh->family == AF_INET6) {
635 skb->csum = csum_block_add(skb->csum, pfh->wcheck, odd);
636 skb->ip_summed = CHECKSUM_NONE;
637 pfh->wcheck = 0;
638 }
639 #endif
640
641 return 0;
642 }
643 EXPORT_SYMBOL_GPL(ping_getfrag);
644
ping_v4_push_pending_frames(struct sock * sk,struct pingfakehdr * pfh,struct flowi4 * fl4)645 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
646 struct flowi4 *fl4)
647 {
648 struct sk_buff *skb = skb_peek(&sk->sk_write_queue);
649
650 if (!skb)
651 return 0;
652 pfh->wcheck = csum_partial((char *)&pfh->icmph,
653 sizeof(struct icmphdr), pfh->wcheck);
654 pfh->icmph.checksum = csum_fold(pfh->wcheck);
655 memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
656 skb->ip_summed = CHECKSUM_NONE;
657 return ip_push_pending_frames(sk, fl4);
658 }
659
ping_common_sendmsg(int family,struct msghdr * msg,size_t len,void * user_icmph,size_t icmph_len)660 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
661 void *user_icmph, size_t icmph_len)
662 {
663 u8 type, code;
664
665 if (len > 0xFFFF)
666 return -EMSGSIZE;
667
668 /* Must have at least a full ICMP header. */
669 if (len < icmph_len)
670 return -EINVAL;
671
672 /*
673 * Check the flags.
674 */
675
676 /* Mirror BSD error message compatibility */
677 if (msg->msg_flags & MSG_OOB)
678 return -EOPNOTSUPP;
679
680 /*
681 * Fetch the ICMP header provided by the userland.
682 * iovec is modified! The ICMP header is consumed.
683 */
684 if (memcpy_from_msg(user_icmph, msg, icmph_len))
685 return -EFAULT;
686
687 if (family == AF_INET) {
688 type = ((struct icmphdr *) user_icmph)->type;
689 code = ((struct icmphdr *) user_icmph)->code;
690 #if IS_ENABLED(CONFIG_IPV6)
691 } else if (family == AF_INET6) {
692 type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
693 code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
694 #endif
695 } else {
696 BUG();
697 }
698
699 if (!ping_supported(family, type, code))
700 return -EINVAL;
701
702 return 0;
703 }
704 EXPORT_SYMBOL_GPL(ping_common_sendmsg);
705
ping_v4_sendmsg(struct sock * sk,struct msghdr * msg,size_t len)706 static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
707 {
708 struct net *net = sock_net(sk);
709 struct flowi4 fl4;
710 struct inet_sock *inet = inet_sk(sk);
711 struct ipcm_cookie ipc;
712 struct icmphdr user_icmph;
713 struct pingfakehdr pfh;
714 struct rtable *rt = NULL;
715 struct ip_options_data opt_copy;
716 int free = 0;
717 __be32 saddr, daddr, faddr;
718 u8 tos;
719 int err;
720
721 pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
722
723 err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
724 sizeof(user_icmph));
725 if (err)
726 return err;
727
728 /*
729 * Get and verify the address.
730 */
731
732 if (msg->msg_name) {
733 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
734 if (msg->msg_namelen < sizeof(*usin))
735 return -EINVAL;
736 if (usin->sin_family != AF_INET)
737 return -EAFNOSUPPORT;
738 daddr = usin->sin_addr.s_addr;
739 /* no remote port */
740 } else {
741 if (sk->sk_state != TCP_ESTABLISHED)
742 return -EDESTADDRREQ;
743 daddr = inet->inet_daddr;
744 /* no remote port */
745 }
746
747 ipcm_init_sk(&ipc, inet);
748
749 if (msg->msg_controllen) {
750 err = ip_cmsg_send(sk, msg, &ipc, false);
751 if (unlikely(err)) {
752 kfree(ipc.opt);
753 return err;
754 }
755 if (ipc.opt)
756 free = 1;
757 }
758 if (!ipc.opt) {
759 struct ip_options_rcu *inet_opt;
760
761 rcu_read_lock();
762 inet_opt = rcu_dereference(inet->inet_opt);
763 if (inet_opt) {
764 memcpy(&opt_copy, inet_opt,
765 sizeof(*inet_opt) + inet_opt->opt.optlen);
766 ipc.opt = &opt_copy.opt;
767 }
768 rcu_read_unlock();
769 }
770
771 saddr = ipc.addr;
772 ipc.addr = faddr = daddr;
773
774 if (ipc.opt && ipc.opt->opt.srr) {
775 if (!daddr) {
776 err = -EINVAL;
777 goto out_free;
778 }
779 faddr = ipc.opt->opt.faddr;
780 }
781 tos = get_rttos(&ipc, inet);
782 if (sock_flag(sk, SOCK_LOCALROUTE) ||
783 (msg->msg_flags & MSG_DONTROUTE) ||
784 (ipc.opt && ipc.opt->opt.is_strictroute)) {
785 tos |= RTO_ONLINK;
786 }
787
788 if (ipv4_is_multicast(daddr)) {
789 if (!ipc.oif || netif_index_is_l3_master(sock_net(sk), ipc.oif))
790 ipc.oif = inet->mc_index;
791 if (!saddr)
792 saddr = inet->mc_addr;
793 } else if (!ipc.oif)
794 ipc.oif = inet->uc_index;
795
796 flowi4_init_output(&fl4, ipc.oif, ipc.sockc.mark, tos,
797 RT_SCOPE_UNIVERSE, sk->sk_protocol,
798 inet_sk_flowi_flags(sk), faddr, saddr, 0, 0,
799 sk->sk_uid);
800
801 fl4.fl4_icmp_type = user_icmph.type;
802 fl4.fl4_icmp_code = user_icmph.code;
803
804 security_sk_classify_flow(sk, flowi4_to_flowi_common(&fl4));
805 rt = ip_route_output_flow(net, &fl4, sk);
806 if (IS_ERR(rt)) {
807 err = PTR_ERR(rt);
808 rt = NULL;
809 if (err == -ENETUNREACH)
810 IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
811 goto out;
812 }
813
814 err = -EACCES;
815 if ((rt->rt_flags & RTCF_BROADCAST) &&
816 !sock_flag(sk, SOCK_BROADCAST))
817 goto out;
818
819 if (msg->msg_flags & MSG_CONFIRM)
820 goto do_confirm;
821 back_from_confirm:
822
823 if (!ipc.addr)
824 ipc.addr = fl4.daddr;
825
826 lock_sock(sk);
827
828 pfh.icmph.type = user_icmph.type; /* already checked */
829 pfh.icmph.code = user_icmph.code; /* ditto */
830 pfh.icmph.checksum = 0;
831 pfh.icmph.un.echo.id = inet->inet_sport;
832 pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
833 pfh.msg = msg;
834 pfh.wcheck = 0;
835 pfh.family = AF_INET;
836
837 err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
838 sizeof(struct icmphdr), &ipc, &rt,
839 msg->msg_flags);
840 if (err)
841 ip_flush_pending_frames(sk);
842 else
843 err = ping_v4_push_pending_frames(sk, &pfh, &fl4);
844 release_sock(sk);
845
846 out:
847 ip_rt_put(rt);
848 out_free:
849 if (free)
850 kfree(ipc.opt);
851 if (!err) {
852 icmp_out_count(sock_net(sk), user_icmph.type);
853 return len;
854 }
855 return err;
856
857 do_confirm:
858 if (msg->msg_flags & MSG_PROBE)
859 dst_confirm_neigh(&rt->dst, &fl4.daddr);
860 if (!(msg->msg_flags & MSG_PROBE) || len)
861 goto back_from_confirm;
862 err = 0;
863 goto out;
864 }
865
ping_recvmsg(struct sock * sk,struct msghdr * msg,size_t len,int flags,int * addr_len)866 int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags,
867 int *addr_len)
868 {
869 struct inet_sock *isk = inet_sk(sk);
870 int family = sk->sk_family;
871 struct sk_buff *skb;
872 int copied, err;
873
874 pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
875
876 err = -EOPNOTSUPP;
877 if (flags & MSG_OOB)
878 goto out;
879
880 if (flags & MSG_ERRQUEUE)
881 return inet_recv_error(sk, msg, len, addr_len);
882
883 skb = skb_recv_datagram(sk, flags, &err);
884 if (!skb)
885 goto out;
886
887 copied = skb->len;
888 if (copied > len) {
889 msg->msg_flags |= MSG_TRUNC;
890 copied = len;
891 }
892
893 /* Don't bother checking the checksum */
894 err = skb_copy_datagram_msg(skb, 0, msg, copied);
895 if (err)
896 goto done;
897
898 sock_recv_timestamp(msg, sk, skb);
899
900 /* Copy the address and add cmsg data. */
901 if (family == AF_INET) {
902 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
903
904 if (sin) {
905 sin->sin_family = AF_INET;
906 sin->sin_port = 0 /* skb->h.uh->source */;
907 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
908 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
909 *addr_len = sizeof(*sin);
910 }
911
912 if (isk->cmsg_flags)
913 ip_cmsg_recv(msg, skb);
914
915 #if IS_ENABLED(CONFIG_IPV6)
916 } else if (family == AF_INET6) {
917 struct ipv6_pinfo *np = inet6_sk(sk);
918 struct ipv6hdr *ip6 = ipv6_hdr(skb);
919 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
920
921 if (sin6) {
922 sin6->sin6_family = AF_INET6;
923 sin6->sin6_port = 0;
924 sin6->sin6_addr = ip6->saddr;
925 sin6->sin6_flowinfo = 0;
926 if (np->sndflow)
927 sin6->sin6_flowinfo = ip6_flowinfo(ip6);
928 sin6->sin6_scope_id =
929 ipv6_iface_scope_id(&sin6->sin6_addr,
930 inet6_iif(skb));
931 *addr_len = sizeof(*sin6);
932 }
933
934 if (inet6_sk(sk)->rxopt.all)
935 pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb);
936 if (skb->protocol == htons(ETH_P_IPV6) &&
937 inet6_sk(sk)->rxopt.all)
938 pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb);
939 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags)
940 ip_cmsg_recv(msg, skb);
941 #endif
942 } else {
943 BUG();
944 }
945
946 err = copied;
947
948 done:
949 skb_free_datagram(sk, skb);
950 out:
951 pr_debug("ping_recvmsg -> %d\n", err);
952 return err;
953 }
954 EXPORT_SYMBOL_GPL(ping_recvmsg);
955
__ping_queue_rcv_skb(struct sock * sk,struct sk_buff * skb)956 static enum skb_drop_reason __ping_queue_rcv_skb(struct sock *sk,
957 struct sk_buff *skb)
958 {
959 enum skb_drop_reason reason;
960
961 pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
962 inet_sk(sk), inet_sk(sk)->inet_num, skb);
963 if (sock_queue_rcv_skb_reason(sk, skb, &reason) < 0) {
964 kfree_skb_reason(skb, reason);
965 pr_debug("ping_queue_rcv_skb -> failed\n");
966 return reason;
967 }
968 return SKB_NOT_DROPPED_YET;
969 }
970
ping_queue_rcv_skb(struct sock * sk,struct sk_buff * skb)971 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
972 {
973 return __ping_queue_rcv_skb(sk, skb) ? -1 : 0;
974 }
975 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
976
977
978 /*
979 * All we need to do is get the socket.
980 */
981
ping_rcv(struct sk_buff * skb)982 enum skb_drop_reason ping_rcv(struct sk_buff *skb)
983 {
984 enum skb_drop_reason reason = SKB_DROP_REASON_NO_SOCKET;
985 struct sock *sk;
986 struct net *net = dev_net(skb->dev);
987 struct icmphdr *icmph = icmp_hdr(skb);
988
989 /* We assume the packet has already been checked by icmp_rcv */
990
991 pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
992 skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
993
994 /* Push ICMP header back */
995 skb_push(skb, skb->data - (u8 *)icmph);
996
997 sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
998 if (sk) {
999 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
1000
1001 pr_debug("rcv on socket %p\n", sk);
1002 if (skb2)
1003 reason = __ping_queue_rcv_skb(sk, skb2);
1004 else
1005 reason = SKB_DROP_REASON_NOMEM;
1006 }
1007
1008 if (reason)
1009 pr_debug("no socket, dropping\n");
1010
1011 return reason;
1012 }
1013 EXPORT_SYMBOL_GPL(ping_rcv);
1014
1015 struct proto ping_prot = {
1016 .name = "PING",
1017 .owner = THIS_MODULE,
1018 .init = ping_init_sock,
1019 .close = ping_close,
1020 .pre_connect = ping_pre_connect,
1021 .connect = ip4_datagram_connect,
1022 .disconnect = __udp_disconnect,
1023 .setsockopt = ip_setsockopt,
1024 .getsockopt = ip_getsockopt,
1025 .sendmsg = ping_v4_sendmsg,
1026 .recvmsg = ping_recvmsg,
1027 .bind = ping_bind,
1028 .backlog_rcv = ping_queue_rcv_skb,
1029 .release_cb = ip4_datagram_release_cb,
1030 .hash = ping_hash,
1031 .unhash = ping_unhash,
1032 .get_port = ping_get_port,
1033 .put_port = ping_unhash,
1034 .obj_size = sizeof(struct inet_sock),
1035 };
1036 EXPORT_SYMBOL(ping_prot);
1037
1038 #ifdef CONFIG_PROC_FS
1039
ping_get_first(struct seq_file * seq,int start)1040 static struct sock *ping_get_first(struct seq_file *seq, int start)
1041 {
1042 struct sock *sk;
1043 struct ping_iter_state *state = seq->private;
1044 struct net *net = seq_file_net(seq);
1045
1046 for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
1047 ++state->bucket) {
1048 struct hlist_nulls_node *node;
1049 struct hlist_nulls_head *hslot;
1050
1051 hslot = &ping_table.hash[state->bucket];
1052
1053 if (hlist_nulls_empty(hslot))
1054 continue;
1055
1056 sk_nulls_for_each(sk, node, hslot) {
1057 if (net_eq(sock_net(sk), net) &&
1058 sk->sk_family == state->family)
1059 goto found;
1060 }
1061 }
1062 sk = NULL;
1063 found:
1064 return sk;
1065 }
1066
ping_get_next(struct seq_file * seq,struct sock * sk)1067 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
1068 {
1069 struct ping_iter_state *state = seq->private;
1070 struct net *net = seq_file_net(seq);
1071
1072 do {
1073 sk = sk_nulls_next(sk);
1074 } while (sk && (!net_eq(sock_net(sk), net)));
1075
1076 if (!sk)
1077 return ping_get_first(seq, state->bucket + 1);
1078 return sk;
1079 }
1080
ping_get_idx(struct seq_file * seq,loff_t pos)1081 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
1082 {
1083 struct sock *sk = ping_get_first(seq, 0);
1084
1085 if (sk)
1086 while (pos && (sk = ping_get_next(seq, sk)) != NULL)
1087 --pos;
1088 return pos ? NULL : sk;
1089 }
1090
ping_seq_start(struct seq_file * seq,loff_t * pos,sa_family_t family)1091 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
1092 __acquires(ping_table.lock)
1093 {
1094 struct ping_iter_state *state = seq->private;
1095 state->bucket = 0;
1096 state->family = family;
1097
1098 spin_lock(&ping_table.lock);
1099
1100 return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1101 }
1102 EXPORT_SYMBOL_GPL(ping_seq_start);
1103
ping_v4_seq_start(struct seq_file * seq,loff_t * pos)1104 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos)
1105 {
1106 return ping_seq_start(seq, pos, AF_INET);
1107 }
1108
ping_seq_next(struct seq_file * seq,void * v,loff_t * pos)1109 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1110 {
1111 struct sock *sk;
1112
1113 if (v == SEQ_START_TOKEN)
1114 sk = ping_get_idx(seq, 0);
1115 else
1116 sk = ping_get_next(seq, v);
1117
1118 ++*pos;
1119 return sk;
1120 }
1121 EXPORT_SYMBOL_GPL(ping_seq_next);
1122
ping_seq_stop(struct seq_file * seq,void * v)1123 void ping_seq_stop(struct seq_file *seq, void *v)
1124 __releases(ping_table.lock)
1125 {
1126 spin_unlock(&ping_table.lock);
1127 }
1128 EXPORT_SYMBOL_GPL(ping_seq_stop);
1129
ping_v4_format_sock(struct sock * sp,struct seq_file * f,int bucket)1130 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f,
1131 int bucket)
1132 {
1133 struct inet_sock *inet = inet_sk(sp);
1134 __be32 dest = inet->inet_daddr;
1135 __be32 src = inet->inet_rcv_saddr;
1136 __u16 destp = ntohs(inet->inet_dport);
1137 __u16 srcp = ntohs(inet->inet_sport);
1138
1139 seq_printf(f, "%5d: %08X:%04X %08X:%04X"
1140 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u",
1141 bucket, src, srcp, dest, destp, sp->sk_state,
1142 sk_wmem_alloc_get(sp),
1143 sk_rmem_alloc_get(sp),
1144 0, 0L, 0,
1145 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
1146 0, sock_i_ino(sp),
1147 refcount_read(&sp->sk_refcnt), sp,
1148 atomic_read(&sp->sk_drops));
1149 }
1150
ping_v4_seq_show(struct seq_file * seq,void * v)1151 static int ping_v4_seq_show(struct seq_file *seq, void *v)
1152 {
1153 seq_setwidth(seq, 127);
1154 if (v == SEQ_START_TOKEN)
1155 seq_puts(seq, " sl local_address rem_address st tx_queue "
1156 "rx_queue tr tm->when retrnsmt uid timeout "
1157 "inode ref pointer drops");
1158 else {
1159 struct ping_iter_state *state = seq->private;
1160
1161 ping_v4_format_sock(v, seq, state->bucket);
1162 }
1163 seq_pad(seq, '\n');
1164 return 0;
1165 }
1166
1167 static const struct seq_operations ping_v4_seq_ops = {
1168 .start = ping_v4_seq_start,
1169 .show = ping_v4_seq_show,
1170 .next = ping_seq_next,
1171 .stop = ping_seq_stop,
1172 };
1173
ping_v4_proc_init_net(struct net * net)1174 static int __net_init ping_v4_proc_init_net(struct net *net)
1175 {
1176 if (!proc_create_net("icmp", 0444, net->proc_net, &ping_v4_seq_ops,
1177 sizeof(struct ping_iter_state)))
1178 return -ENOMEM;
1179 return 0;
1180 }
1181
ping_v4_proc_exit_net(struct net * net)1182 static void __net_exit ping_v4_proc_exit_net(struct net *net)
1183 {
1184 remove_proc_entry("icmp", net->proc_net);
1185 }
1186
1187 static struct pernet_operations ping_v4_net_ops = {
1188 .init = ping_v4_proc_init_net,
1189 .exit = ping_v4_proc_exit_net,
1190 };
1191
ping_proc_init(void)1192 int __init ping_proc_init(void)
1193 {
1194 return register_pernet_subsys(&ping_v4_net_ops);
1195 }
1196
ping_proc_exit(void)1197 void ping_proc_exit(void)
1198 {
1199 unregister_pernet_subsys(&ping_v4_net_ops);
1200 }
1201
1202 #endif
1203
ping_init(void)1204 void __init ping_init(void)
1205 {
1206 int i;
1207
1208 for (i = 0; i < PING_HTABLE_SIZE; i++)
1209 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i);
1210 spin_lock_init(&ping_table.lock);
1211 }
1212