Version:  2.0.40 2.2.26 2.4.37 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10

Linux/net/ipv4/ping.c

  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 
 67 static inline int ping_hashfn(struct net *net, unsigned int num, unsigned int mask)
 68 {
 69         int res = (num + net_hash_mix(net)) & mask;
 70 
 71         pr_debug("hash(%d) = %d\n", num, res);
 72         return res;
 73 }
 74 EXPORT_SYMBOL_GPL(ping_hash);
 75 
 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 
 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 
148 void 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 
154 void ping_unhash(struct sock *sk)
155 {
156         struct inet_sock *isk = inet_sk(sk);
157         pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);
158         if (sk_hashed(sk)) {
159                 write_lock_bh(&ping_table.lock);
160                 hlist_nulls_del(&sk->sk_nulls_node);
161                 sock_put(sk);
162                 isk->inet_num = 0;
163                 isk->inet_sport = 0;
164                 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
165                 write_unlock_bh(&ping_table.lock);
166         }
167 }
168 EXPORT_SYMBOL_GPL(ping_unhash);
169 
170 static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
171 {
172         struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident);
173         struct sock *sk = NULL;
174         struct inet_sock *isk;
175         struct hlist_nulls_node *hnode;
176         int dif = skb->dev->ifindex;
177 
178         if (skb->protocol == htons(ETH_P_IP)) {
179                 pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n",
180                          (int)ident, &ip_hdr(skb)->daddr, dif);
181 #if IS_ENABLED(CONFIG_IPV6)
182         } else if (skb->protocol == htons(ETH_P_IPV6)) {
183                 pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n",
184                          (int)ident, &ipv6_hdr(skb)->daddr, dif);
185 #endif
186         }
187 
188         read_lock_bh(&ping_table.lock);
189 
190         ping_portaddr_for_each_entry(sk, hnode, hslot) {
191                 isk = inet_sk(sk);
192 
193                 pr_debug("iterate\n");
194                 if (isk->inet_num != ident)
195                         continue;
196 
197                 if (skb->protocol == htons(ETH_P_IP) &&
198                     sk->sk_family == AF_INET) {
199                         pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk,
200                                  (int) isk->inet_num, &isk->inet_rcv_saddr,
201                                  sk->sk_bound_dev_if);
202 
203                         if (isk->inet_rcv_saddr &&
204                             isk->inet_rcv_saddr != ip_hdr(skb)->daddr)
205                                 continue;
206 #if IS_ENABLED(CONFIG_IPV6)
207                 } else if (skb->protocol == htons(ETH_P_IPV6) &&
208                            sk->sk_family == AF_INET6) {
209 
210                         pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk,
211                                  (int) isk->inet_num,
212                                  &sk->sk_v6_rcv_saddr,
213                                  sk->sk_bound_dev_if);
214 
215                         if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
216                             !ipv6_addr_equal(&sk->sk_v6_rcv_saddr,
217                                              &ipv6_hdr(skb)->daddr))
218                                 continue;
219 #endif
220                 } else {
221                         continue;
222                 }
223 
224                 if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)
225                         continue;
226 
227                 sock_hold(sk);
228                 goto exit;
229         }
230 
231         sk = NULL;
232 exit:
233         read_unlock_bh(&ping_table.lock);
234 
235         return sk;
236 }
237 
238 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low,
239                                           kgid_t *high)
240 {
241         kgid_t *data = net->ipv4.ping_group_range.range;
242         unsigned int seq;
243 
244         do {
245                 seq = read_seqbegin(&net->ipv4.ping_group_range.lock);
246 
247                 *low = data[0];
248                 *high = data[1];
249         } while (read_seqretry(&net->ipv4.ping_group_range.lock, seq));
250 }
251 
252 
253 int ping_init_sock(struct sock *sk)
254 {
255         struct net *net = sock_net(sk);
256         kgid_t group = current_egid();
257         struct group_info *group_info;
258         int i, j, count;
259         kgid_t low, high;
260         int ret = 0;
261 
262         inet_get_ping_group_range_net(net, &low, &high);
263         if (gid_lte(low, group) && gid_lte(group, high))
264                 return 0;
265 
266         group_info = get_current_groups();
267         count = group_info->ngroups;
268         for (i = 0; i < group_info->nblocks; i++) {
269                 int cp_count = min_t(int, NGROUPS_PER_BLOCK, count);
270                 for (j = 0; j < cp_count; j++) {
271                         kgid_t gid = group_info->blocks[i][j];
272                         if (gid_lte(low, gid) && gid_lte(gid, high))
273                                 goto out_release_group;
274                 }
275 
276                 count -= cp_count;
277         }
278 
279         ret = -EACCES;
280 
281 out_release_group:
282         put_group_info(group_info);
283         return ret;
284 }
285 EXPORT_SYMBOL_GPL(ping_init_sock);
286 
287 void ping_close(struct sock *sk, long timeout)
288 {
289         pr_debug("ping_close(sk=%p,sk->num=%u)\n",
290                  inet_sk(sk), inet_sk(sk)->inet_num);
291         pr_debug("isk->refcnt = %d\n", sk->sk_refcnt.counter);
292 
293         sk_common_release(sk);
294 }
295 EXPORT_SYMBOL_GPL(ping_close);
296 
297 /* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */
298 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
299                                 struct sockaddr *uaddr, int addr_len) {
300         struct net *net = sock_net(sk);
301         if (sk->sk_family == AF_INET) {
302                 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
303                 int chk_addr_ret;
304 
305                 if (addr_len < sizeof(*addr))
306                         return -EINVAL;
307 
308                 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",
309                          sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
310 
311                 chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
312 
313                 if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
314                         chk_addr_ret = RTN_LOCAL;
315 
316                 if ((net->ipv4.sysctl_ip_nonlocal_bind == 0 &&
317                     isk->freebind == 0 && isk->transparent == 0 &&
318                      chk_addr_ret != RTN_LOCAL) ||
319                     chk_addr_ret == RTN_MULTICAST ||
320                     chk_addr_ret == RTN_BROADCAST)
321                         return -EADDRNOTAVAIL;
322 
323 #if IS_ENABLED(CONFIG_IPV6)
324         } else if (sk->sk_family == AF_INET6) {
325                 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
326                 int addr_type, scoped, has_addr;
327                 struct net_device *dev = NULL;
328 
329                 if (addr_len < sizeof(*addr))
330                         return -EINVAL;
331 
332                 if (addr->sin6_family != AF_INET6)
333                         return -EINVAL;
334 
335                 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n",
336                          sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port));
337 
338                 addr_type = ipv6_addr_type(&addr->sin6_addr);
339                 scoped = __ipv6_addr_needs_scope_id(addr_type);
340                 if ((addr_type != IPV6_ADDR_ANY &&
341                      !(addr_type & IPV6_ADDR_UNICAST)) ||
342                     (scoped && !addr->sin6_scope_id))
343                         return -EINVAL;
344 
345                 rcu_read_lock();
346                 if (addr->sin6_scope_id) {
347                         dev = dev_get_by_index_rcu(net, addr->sin6_scope_id);
348                         if (!dev) {
349                                 rcu_read_unlock();
350                                 return -ENODEV;
351                         }
352                 }
353                 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev,
354                                                     scoped);
355                 rcu_read_unlock();
356 
357                 if (!(isk->freebind || isk->transparent || has_addr ||
358                       addr_type == IPV6_ADDR_ANY))
359                         return -EADDRNOTAVAIL;
360 
361                 if (scoped)
362                         sk->sk_bound_dev_if = addr->sin6_scope_id;
363 #endif
364         } else {
365                 return -EAFNOSUPPORT;
366         }
367         return 0;
368 }
369 
370 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr)
371 {
372         if (saddr->sa_family == AF_INET) {
373                 struct inet_sock *isk = inet_sk(sk);
374                 struct sockaddr_in *addr = (struct sockaddr_in *) saddr;
375                 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
376 #if IS_ENABLED(CONFIG_IPV6)
377         } else if (saddr->sa_family == AF_INET6) {
378                 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr;
379                 struct ipv6_pinfo *np = inet6_sk(sk);
380                 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr;
381 #endif
382         }
383 }
384 
385 static void ping_clear_saddr(struct sock *sk, int dif)
386 {
387         sk->sk_bound_dev_if = dif;
388         if (sk->sk_family == AF_INET) {
389                 struct inet_sock *isk = inet_sk(sk);
390                 isk->inet_rcv_saddr = isk->inet_saddr = 0;
391 #if IS_ENABLED(CONFIG_IPV6)
392         } else if (sk->sk_family == AF_INET6) {
393                 struct ipv6_pinfo *np = inet6_sk(sk);
394                 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
395                 memset(&np->saddr, 0, sizeof(np->saddr));
396 #endif
397         }
398 }
399 /*
400  * We need our own bind because there are no privileged id's == local ports.
401  * Moreover, we don't allow binding to multi- and broadcast addresses.
402  */
403 
404 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
405 {
406         struct inet_sock *isk = inet_sk(sk);
407         unsigned short snum;
408         int err;
409         int dif = sk->sk_bound_dev_if;
410 
411         err = ping_check_bind_addr(sk, isk, uaddr, addr_len);
412         if (err)
413                 return err;
414 
415         lock_sock(sk);
416 
417         err = -EINVAL;
418         if (isk->inet_num != 0)
419                 goto out;
420 
421         err = -EADDRINUSE;
422         ping_set_saddr(sk, uaddr);
423         snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port);
424         if (ping_get_port(sk, snum) != 0) {
425                 ping_clear_saddr(sk, dif);
426                 goto out;
427         }
428 
429         pr_debug("after bind(): num = %d, dif = %d\n",
430                  (int)isk->inet_num,
431                  (int)sk->sk_bound_dev_if);
432 
433         err = 0;
434         if (sk->sk_family == AF_INET && isk->inet_rcv_saddr)
435                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
436 #if IS_ENABLED(CONFIG_IPV6)
437         if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr))
438                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
439 #endif
440 
441         if (snum)
442                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
443         isk->inet_sport = htons(isk->inet_num);
444         isk->inet_daddr = 0;
445         isk->inet_dport = 0;
446 
447 #if IS_ENABLED(CONFIG_IPV6)
448         if (sk->sk_family == AF_INET6)
449                 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr));
450 #endif
451 
452         sk_dst_reset(sk);
453 out:
454         release_sock(sk);
455         pr_debug("ping_v4_bind -> %d\n", err);
456         return err;
457 }
458 EXPORT_SYMBOL_GPL(ping_bind);
459 
460 /*
461  * Is this a supported type of ICMP message?
462  */
463 
464 static inline int ping_supported(int family, int type, int code)
465 {
466         return (family == AF_INET && type == ICMP_ECHO && code == 0) ||
467                (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0);
468 }
469 
470 /*
471  * This routine is called by the ICMP module when it gets some
472  * sort of error condition.
473  */
474 
475 void ping_err(struct sk_buff *skb, int offset, u32 info)
476 {
477         int family;
478         struct icmphdr *icmph;
479         struct inet_sock *inet_sock;
480         int type;
481         int code;
482         struct net *net = dev_net(skb->dev);
483         struct sock *sk;
484         int harderr;
485         int err;
486 
487         if (skb->protocol == htons(ETH_P_IP)) {
488                 family = AF_INET;
489                 type = icmp_hdr(skb)->type;
490                 code = icmp_hdr(skb)->code;
491                 icmph = (struct icmphdr *)(skb->data + offset);
492         } else if (skb->protocol == htons(ETH_P_IPV6)) {
493                 family = AF_INET6;
494                 type = icmp6_hdr(skb)->icmp6_type;
495                 code = icmp6_hdr(skb)->icmp6_code;
496                 icmph = (struct icmphdr *) (skb->data + offset);
497         } else {
498                 BUG();
499         }
500 
501         /* We assume the packet has already been checked by icmp_unreach */
502 
503         if (!ping_supported(family, icmph->type, icmph->code))
504                 return;
505 
506         pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n",
507                  skb->protocol, type, code, ntohs(icmph->un.echo.id),
508                  ntohs(icmph->un.echo.sequence));
509 
510         sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
511         if (sk == NULL) {
512                 pr_debug("no socket, dropping\n");
513                 return; /* No socket for error */
514         }
515         pr_debug("err on socket %p\n", sk);
516 
517         err = 0;
518         harderr = 0;
519         inet_sock = inet_sk(sk);
520 
521         if (skb->protocol == htons(ETH_P_IP)) {
522                 switch (type) {
523                 default:
524                 case ICMP_TIME_EXCEEDED:
525                         err = EHOSTUNREACH;
526                         break;
527                 case ICMP_SOURCE_QUENCH:
528                         /* This is not a real error but ping wants to see it.
529                          * Report it with some fake errno.
530                          */
531                         err = EREMOTEIO;
532                         break;
533                 case ICMP_PARAMETERPROB:
534                         err = EPROTO;
535                         harderr = 1;
536                         break;
537                 case ICMP_DEST_UNREACH:
538                         if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
539                                 ipv4_sk_update_pmtu(skb, sk, info);
540                                 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) {
541                                         err = EMSGSIZE;
542                                         harderr = 1;
543                                         break;
544                                 }
545                                 goto out;
546                         }
547                         err = EHOSTUNREACH;
548                         if (code <= NR_ICMP_UNREACH) {
549                                 harderr = icmp_err_convert[code].fatal;
550                                 err = icmp_err_convert[code].errno;
551                         }
552                         break;
553                 case ICMP_REDIRECT:
554                         /* See ICMP_SOURCE_QUENCH */
555                         ipv4_sk_redirect(skb, sk);
556                         err = EREMOTEIO;
557                         break;
558                 }
559 #if IS_ENABLED(CONFIG_IPV6)
560         } else if (skb->protocol == htons(ETH_P_IPV6)) {
561                 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err);
562 #endif
563         }
564 
565         /*
566          *      RFC1122: OK.  Passes ICMP errors back to application, as per
567          *      4.1.3.3.
568          */
569         if ((family == AF_INET && !inet_sock->recverr) ||
570             (family == AF_INET6 && !inet6_sk(sk)->recverr)) {
571                 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
572                         goto out;
573         } else {
574                 if (family == AF_INET) {
575                         ip_icmp_error(sk, skb, err, 0 /* no remote port */,
576                                       info, (u8 *)icmph);
577 #if IS_ENABLED(CONFIG_IPV6)
578                 } else if (family == AF_INET6) {
579                         pingv6_ops.ipv6_icmp_error(sk, skb, err, 0,
580                                                    info, (u8 *)icmph);
581 #endif
582                 }
583         }
584         sk->sk_err = err;
585         sk->sk_error_report(sk);
586 out:
587         sock_put(sk);
588 }
589 EXPORT_SYMBOL_GPL(ping_err);
590 
591 /*
592  *      Copy and checksum an ICMP Echo packet from user space into a buffer
593  *      starting from the payload.
594  */
595 
596 int ping_getfrag(void *from, char *to,
597                  int offset, int fraglen, int odd, struct sk_buff *skb)
598 {
599         struct pingfakehdr *pfh = (struct pingfakehdr *)from;
600 
601         if (offset == 0) {
602                 if (fraglen < sizeof(struct icmphdr))
603                         BUG();
604                 if (csum_partial_copy_fromiovecend(to + sizeof(struct icmphdr),
605                             pfh->iov, 0, fraglen - sizeof(struct icmphdr),
606                             &pfh->wcheck))
607                         return -EFAULT;
608         } else if (offset < sizeof(struct icmphdr)) {
609                         BUG();
610         } else {
611                 if (csum_partial_copy_fromiovecend
612                                 (to, pfh->iov, offset - sizeof(struct icmphdr),
613                                  fraglen, &pfh->wcheck))
614                         return -EFAULT;
615         }
616 
617 #if IS_ENABLED(CONFIG_IPV6)
618         /* For IPv6, checksum each skb as we go along, as expected by
619          * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in
620          * wcheck, it will be finalized in ping_v4_push_pending_frames.
621          */
622         if (pfh->family == AF_INET6) {
623                 skb->csum = pfh->wcheck;
624                 skb->ip_summed = CHECKSUM_NONE;
625                 pfh->wcheck = 0;
626         }
627 #endif
628 
629         return 0;
630 }
631 EXPORT_SYMBOL_GPL(ping_getfrag);
632 
633 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
634                                        struct flowi4 *fl4)
635 {
636         struct sk_buff *skb = skb_peek(&sk->sk_write_queue);
637 
638         pfh->wcheck = csum_partial((char *)&pfh->icmph,
639                 sizeof(struct icmphdr), pfh->wcheck);
640         pfh->icmph.checksum = csum_fold(pfh->wcheck);
641         memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
642         skb->ip_summed = CHECKSUM_NONE;
643         return ip_push_pending_frames(sk, fl4);
644 }
645 
646 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
647                         void *user_icmph, size_t icmph_len) {
648         u8 type, code;
649 
650         if (len > 0xFFFF)
651                 return -EMSGSIZE;
652 
653         /*
654          *      Check the flags.
655          */
656 
657         /* Mirror BSD error message compatibility */
658         if (msg->msg_flags & MSG_OOB)
659                 return -EOPNOTSUPP;
660 
661         /*
662          *      Fetch the ICMP header provided by the userland.
663          *      iovec is modified! The ICMP header is consumed.
664          */
665         if (memcpy_from_msg(user_icmph, msg, icmph_len))
666                 return -EFAULT;
667 
668         if (family == AF_INET) {
669                 type = ((struct icmphdr *) user_icmph)->type;
670                 code = ((struct icmphdr *) user_icmph)->code;
671 #if IS_ENABLED(CONFIG_IPV6)
672         } else if (family == AF_INET6) {
673                 type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
674                 code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
675 #endif
676         } else {
677                 BUG();
678         }
679 
680         if (!ping_supported(family, type, code))
681                 return -EINVAL;
682 
683         return 0;
684 }
685 EXPORT_SYMBOL_GPL(ping_common_sendmsg);
686 
687 static int ping_v4_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
688                            size_t len)
689 {
690         struct net *net = sock_net(sk);
691         struct flowi4 fl4;
692         struct inet_sock *inet = inet_sk(sk);
693         struct ipcm_cookie ipc;
694         struct icmphdr user_icmph;
695         struct pingfakehdr pfh;
696         struct rtable *rt = NULL;
697         struct ip_options_data opt_copy;
698         int free = 0;
699         __be32 saddr, daddr, faddr;
700         u8  tos;
701         int err;
702 
703         pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
704 
705         err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
706                                   sizeof(user_icmph));
707         if (err)
708                 return err;
709 
710         /*
711          *      Get and verify the address.
712          */
713 
714         if (msg->msg_name) {
715                 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
716                 if (msg->msg_namelen < sizeof(*usin))
717                         return -EINVAL;
718                 if (usin->sin_family != AF_INET)
719                         return -EINVAL;
720                 daddr = usin->sin_addr.s_addr;
721                 /* no remote port */
722         } else {
723                 if (sk->sk_state != TCP_ESTABLISHED)
724                         return -EDESTADDRREQ;
725                 daddr = inet->inet_daddr;
726                 /* no remote port */
727         }
728 
729         ipc.addr = inet->inet_saddr;
730         ipc.opt = NULL;
731         ipc.oif = sk->sk_bound_dev_if;
732         ipc.tx_flags = 0;
733         ipc.ttl = 0;
734         ipc.tos = -1;
735 
736         sock_tx_timestamp(sk, &ipc.tx_flags);
737 
738         if (msg->msg_controllen) {
739                 err = ip_cmsg_send(sock_net(sk), msg, &ipc, false);
740                 if (err)
741                         return err;
742                 if (ipc.opt)
743                         free = 1;
744         }
745         if (!ipc.opt) {
746                 struct ip_options_rcu *inet_opt;
747 
748                 rcu_read_lock();
749                 inet_opt = rcu_dereference(inet->inet_opt);
750                 if (inet_opt) {
751                         memcpy(&opt_copy, inet_opt,
752                                sizeof(*inet_opt) + inet_opt->opt.optlen);
753                         ipc.opt = &opt_copy.opt;
754                 }
755                 rcu_read_unlock();
756         }
757 
758         saddr = ipc.addr;
759         ipc.addr = faddr = daddr;
760 
761         if (ipc.opt && ipc.opt->opt.srr) {
762                 if (!daddr)
763                         return -EINVAL;
764                 faddr = ipc.opt->opt.faddr;
765         }
766         tos = get_rttos(&ipc, inet);
767         if (sock_flag(sk, SOCK_LOCALROUTE) ||
768             (msg->msg_flags & MSG_DONTROUTE) ||
769             (ipc.opt && ipc.opt->opt.is_strictroute)) {
770                 tos |= RTO_ONLINK;
771         }
772 
773         if (ipv4_is_multicast(daddr)) {
774                 if (!ipc.oif)
775                         ipc.oif = inet->mc_index;
776                 if (!saddr)
777                         saddr = inet->mc_addr;
778         } else if (!ipc.oif)
779                 ipc.oif = inet->uc_index;
780 
781         flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
782                            RT_SCOPE_UNIVERSE, sk->sk_protocol,
783                            inet_sk_flowi_flags(sk), faddr, saddr, 0, 0);
784 
785         security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
786         rt = ip_route_output_flow(net, &fl4, sk);
787         if (IS_ERR(rt)) {
788                 err = PTR_ERR(rt);
789                 rt = NULL;
790                 if (err == -ENETUNREACH)
791                         IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
792                 goto out;
793         }
794 
795         err = -EACCES;
796         if ((rt->rt_flags & RTCF_BROADCAST) &&
797             !sock_flag(sk, SOCK_BROADCAST))
798                 goto out;
799 
800         if (msg->msg_flags & MSG_CONFIRM)
801                 goto do_confirm;
802 back_from_confirm:
803 
804         if (!ipc.addr)
805                 ipc.addr = fl4.daddr;
806 
807         lock_sock(sk);
808 
809         pfh.icmph.type = user_icmph.type; /* already checked */
810         pfh.icmph.code = user_icmph.code; /* ditto */
811         pfh.icmph.checksum = 0;
812         pfh.icmph.un.echo.id = inet->inet_sport;
813         pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
814         /* XXX: stripping const */
815         pfh.iov = (struct iovec *)msg->msg_iter.iov;
816         pfh.wcheck = 0;
817         pfh.family = AF_INET;
818 
819         err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
820                         0, &ipc, &rt, msg->msg_flags);
821         if (err)
822                 ip_flush_pending_frames(sk);
823         else
824                 err = ping_v4_push_pending_frames(sk, &pfh, &fl4);
825         release_sock(sk);
826 
827 out:
828         ip_rt_put(rt);
829         if (free)
830                 kfree(ipc.opt);
831         if (!err) {
832                 icmp_out_count(sock_net(sk), user_icmph.type);
833                 return len;
834         }
835         return err;
836 
837 do_confirm:
838         dst_confirm(&rt->dst);
839         if (!(msg->msg_flags & MSG_PROBE) || len)
840                 goto back_from_confirm;
841         err = 0;
842         goto out;
843 }
844 
845 int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
846                  size_t len, int noblock, int flags, int *addr_len)
847 {
848         struct inet_sock *isk = inet_sk(sk);
849         int family = sk->sk_family;
850         struct sk_buff *skb;
851         int copied, err;
852 
853         pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
854 
855         err = -EOPNOTSUPP;
856         if (flags & MSG_OOB)
857                 goto out;
858 
859         if (flags & MSG_ERRQUEUE)
860                 return inet_recv_error(sk, msg, len, addr_len);
861 
862         skb = skb_recv_datagram(sk, flags, noblock, &err);
863         if (!skb)
864                 goto out;
865 
866         copied = skb->len;
867         if (copied > len) {
868                 msg->msg_flags |= MSG_TRUNC;
869                 copied = len;
870         }
871 
872         /* Don't bother checking the checksum */
873         err = skb_copy_datagram_msg(skb, 0, msg, copied);
874         if (err)
875                 goto done;
876 
877         sock_recv_timestamp(msg, sk, skb);
878 
879         /* Copy the address and add cmsg data. */
880         if (family == AF_INET) {
881                 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
882 
883                 if (sin) {
884                         sin->sin_family = AF_INET;
885                         sin->sin_port = 0 /* skb->h.uh->source */;
886                         sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
887                         memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
888                         *addr_len = sizeof(*sin);
889                 }
890 
891                 if (isk->cmsg_flags)
892                         ip_cmsg_recv(msg, skb);
893 
894 #if IS_ENABLED(CONFIG_IPV6)
895         } else if (family == AF_INET6) {
896                 struct ipv6_pinfo *np = inet6_sk(sk);
897                 struct ipv6hdr *ip6 = ipv6_hdr(skb);
898                 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
899 
900                 if (sin6) {
901                         sin6->sin6_family = AF_INET6;
902                         sin6->sin6_port = 0;
903                         sin6->sin6_addr = ip6->saddr;
904                         sin6->sin6_flowinfo = 0;
905                         if (np->sndflow)
906                                 sin6->sin6_flowinfo = ip6_flowinfo(ip6);
907                         sin6->sin6_scope_id =
908                                 ipv6_iface_scope_id(&sin6->sin6_addr,
909                                                     inet6_iif(skb));
910                         *addr_len = sizeof(*sin6);
911                 }
912 
913                 if (inet6_sk(sk)->rxopt.all)
914                         pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb);
915                 if (skb->protocol == htons(ETH_P_IPV6) &&
916                     inet6_sk(sk)->rxopt.all)
917                         pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb);
918                 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags)
919                         ip_cmsg_recv(msg, skb);
920 #endif
921         } else {
922                 BUG();
923         }
924 
925         err = copied;
926 
927 done:
928         skb_free_datagram(sk, skb);
929 out:
930         pr_debug("ping_recvmsg -> %d\n", err);
931         return err;
932 }
933 EXPORT_SYMBOL_GPL(ping_recvmsg);
934 
935 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
936 {
937         pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
938                  inet_sk(sk), inet_sk(sk)->inet_num, skb);
939         if (sock_queue_rcv_skb(sk, skb) < 0) {
940                 kfree_skb(skb);
941                 pr_debug("ping_queue_rcv_skb -> failed\n");
942                 return -1;
943         }
944         return 0;
945 }
946 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
947 
948 
949 /*
950  *      All we need to do is get the socket.
951  */
952 
953 bool ping_rcv(struct sk_buff *skb)
954 {
955         struct sock *sk;
956         struct net *net = dev_net(skb->dev);
957         struct icmphdr *icmph = icmp_hdr(skb);
958 
959         /* We assume the packet has already been checked by icmp_rcv */
960 
961         pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
962                  skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
963 
964         /* Push ICMP header back */
965         skb_push(skb, skb->data - (u8 *)icmph);
966 
967         sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
968         if (sk != NULL) {
969                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
970 
971                 pr_debug("rcv on socket %p\n", sk);
972                 if (skb2)
973                         ping_queue_rcv_skb(sk, skb2);
974                 sock_put(sk);
975                 return true;
976         }
977         pr_debug("no socket, dropping\n");
978 
979         return false;
980 }
981 EXPORT_SYMBOL_GPL(ping_rcv);
982 
983 struct proto ping_prot = {
984         .name =         "PING",
985         .owner =        THIS_MODULE,
986         .init =         ping_init_sock,
987         .close =        ping_close,
988         .connect =      ip4_datagram_connect,
989         .disconnect =   udp_disconnect,
990         .setsockopt =   ip_setsockopt,
991         .getsockopt =   ip_getsockopt,
992         .sendmsg =      ping_v4_sendmsg,
993         .recvmsg =      ping_recvmsg,
994         .bind =         ping_bind,
995         .backlog_rcv =  ping_queue_rcv_skb,
996         .release_cb =   ip4_datagram_release_cb,
997         .hash =         ping_hash,
998         .unhash =       ping_unhash,
999         .get_port =     ping_get_port,
1000         .obj_size =     sizeof(struct inet_sock),
1001 };
1002 EXPORT_SYMBOL(ping_prot);
1003 
1004 #ifdef CONFIG_PROC_FS
1005 
1006 static struct sock *ping_get_first(struct seq_file *seq, int start)
1007 {
1008         struct sock *sk;
1009         struct ping_iter_state *state = seq->private;
1010         struct net *net = seq_file_net(seq);
1011 
1012         for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
1013              ++state->bucket) {
1014                 struct hlist_nulls_node *node;
1015                 struct hlist_nulls_head *hslot;
1016 
1017                 hslot = &ping_table.hash[state->bucket];
1018 
1019                 if (hlist_nulls_empty(hslot))
1020                         continue;
1021 
1022                 sk_nulls_for_each(sk, node, hslot) {
1023                         if (net_eq(sock_net(sk), net) &&
1024                             sk->sk_family == state->family)
1025                                 goto found;
1026                 }
1027         }
1028         sk = NULL;
1029 found:
1030         return sk;
1031 }
1032 
1033 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
1034 {
1035         struct ping_iter_state *state = seq->private;
1036         struct net *net = seq_file_net(seq);
1037 
1038         do {
1039                 sk = sk_nulls_next(sk);
1040         } while (sk && (!net_eq(sock_net(sk), net)));
1041 
1042         if (!sk)
1043                 return ping_get_first(seq, state->bucket + 1);
1044         return sk;
1045 }
1046 
1047 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
1048 {
1049         struct sock *sk = ping_get_first(seq, 0);
1050 
1051         if (sk)
1052                 while (pos && (sk = ping_get_next(seq, sk)) != NULL)
1053                         --pos;
1054         return pos ? NULL : sk;
1055 }
1056 
1057 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
1058 {
1059         struct ping_iter_state *state = seq->private;
1060         state->bucket = 0;
1061         state->family = family;
1062 
1063         read_lock_bh(&ping_table.lock);
1064 
1065         return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1066 }
1067 EXPORT_SYMBOL_GPL(ping_seq_start);
1068 
1069 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos)
1070 {
1071         return ping_seq_start(seq, pos, AF_INET);
1072 }
1073 
1074 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1075 {
1076         struct sock *sk;
1077 
1078         if (v == SEQ_START_TOKEN)
1079                 sk = ping_get_idx(seq, 0);
1080         else
1081                 sk = ping_get_next(seq, v);
1082 
1083         ++*pos;
1084         return sk;
1085 }
1086 EXPORT_SYMBOL_GPL(ping_seq_next);
1087 
1088 void ping_seq_stop(struct seq_file *seq, void *v)
1089 {
1090         read_unlock_bh(&ping_table.lock);
1091 }
1092 EXPORT_SYMBOL_GPL(ping_seq_stop);
1093 
1094 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f,
1095                 int bucket)
1096 {
1097         struct inet_sock *inet = inet_sk(sp);
1098         __be32 dest = inet->inet_daddr;
1099         __be32 src = inet->inet_rcv_saddr;
1100         __u16 destp = ntohs(inet->inet_dport);
1101         __u16 srcp = ntohs(inet->inet_sport);
1102 
1103         seq_printf(f, "%5d: %08X:%04X %08X:%04X"
1104                 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d",
1105                 bucket, src, srcp, dest, destp, sp->sk_state,
1106                 sk_wmem_alloc_get(sp),
1107                 sk_rmem_alloc_get(sp),
1108                 0, 0L, 0,
1109                 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
1110                 0, sock_i_ino(sp),
1111                 atomic_read(&sp->sk_refcnt), sp,
1112                 atomic_read(&sp->sk_drops));
1113 }
1114 
1115 static int ping_v4_seq_show(struct seq_file *seq, void *v)
1116 {
1117         seq_setwidth(seq, 127);
1118         if (v == SEQ_START_TOKEN)
1119                 seq_puts(seq, "  sl  local_address rem_address   st tx_queue "
1120                            "rx_queue tr tm->when retrnsmt   uid  timeout "
1121                            "inode ref pointer drops");
1122         else {
1123                 struct ping_iter_state *state = seq->private;
1124 
1125                 ping_v4_format_sock(v, seq, state->bucket);
1126         }
1127         seq_pad(seq, '\n');
1128         return 0;
1129 }
1130 
1131 static const struct seq_operations ping_v4_seq_ops = {
1132         .show           = ping_v4_seq_show,
1133         .start          = ping_v4_seq_start,
1134         .next           = ping_seq_next,
1135         .stop           = ping_seq_stop,
1136 };
1137 
1138 static int ping_seq_open(struct inode *inode, struct file *file)
1139 {
1140         struct ping_seq_afinfo *afinfo = PDE_DATA(inode);
1141         return seq_open_net(inode, file, &afinfo->seq_ops,
1142                            sizeof(struct ping_iter_state));
1143 }
1144 
1145 const struct file_operations ping_seq_fops = {
1146         .open           = ping_seq_open,
1147         .read           = seq_read,
1148         .llseek         = seq_lseek,
1149         .release        = seq_release_net,
1150 };
1151 EXPORT_SYMBOL_GPL(ping_seq_fops);
1152 
1153 static struct ping_seq_afinfo ping_v4_seq_afinfo = {
1154         .name           = "icmp",
1155         .family         = AF_INET,
1156         .seq_fops       = &ping_seq_fops,
1157         .seq_ops        = {
1158                 .start          = ping_v4_seq_start,
1159                 .show           = ping_v4_seq_show,
1160                 .next           = ping_seq_next,
1161                 .stop           = ping_seq_stop,
1162         },
1163 };
1164 
1165 int ping_proc_register(struct net *net, struct ping_seq_afinfo *afinfo)
1166 {
1167         struct proc_dir_entry *p;
1168         p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
1169                              afinfo->seq_fops, afinfo);
1170         if (!p)
1171                 return -ENOMEM;
1172         return 0;
1173 }
1174 EXPORT_SYMBOL_GPL(ping_proc_register);
1175 
1176 void ping_proc_unregister(struct net *net, struct ping_seq_afinfo *afinfo)
1177 {
1178         remove_proc_entry(afinfo->name, net->proc_net);
1179 }
1180 EXPORT_SYMBOL_GPL(ping_proc_unregister);
1181 
1182 static int __net_init ping_v4_proc_init_net(struct net *net)
1183 {
1184         return ping_proc_register(net, &ping_v4_seq_afinfo);
1185 }
1186 
1187 static void __net_exit ping_v4_proc_exit_net(struct net *net)
1188 {
1189         ping_proc_unregister(net, &ping_v4_seq_afinfo);
1190 }
1191 
1192 static struct pernet_operations ping_v4_net_ops = {
1193         .init = ping_v4_proc_init_net,
1194         .exit = ping_v4_proc_exit_net,
1195 };
1196 
1197 int __init ping_proc_init(void)
1198 {
1199         return register_pernet_subsys(&ping_v4_net_ops);
1200 }
1201 
1202 void ping_proc_exit(void)
1203 {
1204         unregister_pernet_subsys(&ping_v4_net_ops);
1205 }
1206 
1207 #endif
1208 
1209 void __init ping_init(void)
1210 {
1211         int i;
1212 
1213         for (i = 0; i < PING_HTABLE_SIZE; i++)
1214                 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i);
1215         rwlock_init(&ping_table.lock);
1216 }
1217 

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