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                 }
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 
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.ping_group_range.range;
240         unsigned int seq;
241 
242         do {
243                 seq = read_seqbegin(&net->ipv4.ping_group_range.lock);
244 
245                 *low = data[0];
246                 *high = data[1];
247         } while (read_seqretry(&net->ipv4.ping_group_range.lock, seq));
248 }
249 
250 
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         inet_get_ping_group_range_net(net, &low, &high);
261         if (gid_lte(low, group) && gid_lte(group, high))
262                 return 0;
263 
264         group_info = get_current_groups();
265         count = group_info->ngroups;
266         for (i = 0; i < group_info->nblocks; i++) {
267                 int cp_count = min_t(int, NGROUPS_PER_BLOCK, count);
268                 for (j = 0; j < cp_count; j++) {
269                         kgid_t gid = group_info->blocks[i][j];
270                         if (gid_lte(low, gid) && gid_lte(gid, high))
271                                 goto out_release_group;
272                 }
273 
274                 count -= cp_count;
275         }
276 
277         ret = -EACCES;
278 
279 out_release_group:
280         put_group_info(group_info);
281         return ret;
282 }
283 EXPORT_SYMBOL_GPL(ping_init_sock);
284 
285 void ping_close(struct sock *sk, long timeout)
286 {
287         pr_debug("ping_close(sk=%p,sk->num=%u)\n",
288                  inet_sk(sk), inet_sk(sk)->inet_num);
289         pr_debug("isk->refcnt = %d\n", sk->sk_refcnt.counter);
290 
291         sk_common_release(sk);
292 }
293 EXPORT_SYMBOL_GPL(ping_close);
294 
295 /* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */
296 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
297                                 struct sockaddr *uaddr, int addr_len) {
298         struct net *net = sock_net(sk);
299         if (sk->sk_family == AF_INET) {
300                 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
301                 int chk_addr_ret;
302 
303                 if (addr_len < sizeof(*addr))
304                         return -EINVAL;
305 
306                 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",
307                          sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
308 
309                 chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
310 
311                 if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
312                         chk_addr_ret = RTN_LOCAL;
313 
314                 if ((sysctl_ip_nonlocal_bind == 0 &&
315                     isk->freebind == 0 && isk->transparent == 0 &&
316                      chk_addr_ret != RTN_LOCAL) ||
317                     chk_addr_ret == RTN_MULTICAST ||
318                     chk_addr_ret == RTN_BROADCAST)
319                         return -EADDRNOTAVAIL;
320 
321 #if IS_ENABLED(CONFIG_IPV6)
322         } else if (sk->sk_family == AF_INET6) {
323                 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
324                 int addr_type, scoped, has_addr;
325                 struct net_device *dev = NULL;
326 
327                 if (addr_len < sizeof(*addr))
328                         return -EINVAL;
329 
330                 if (addr->sin6_family != AF_INET6)
331                         return -EINVAL;
332 
333                 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n",
334                          sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port));
335 
336                 addr_type = ipv6_addr_type(&addr->sin6_addr);
337                 scoped = __ipv6_addr_needs_scope_id(addr_type);
338                 if ((addr_type != IPV6_ADDR_ANY &&
339                      !(addr_type & IPV6_ADDR_UNICAST)) ||
340                     (scoped && !addr->sin6_scope_id))
341                         return -EINVAL;
342 
343                 rcu_read_lock();
344                 if (addr->sin6_scope_id) {
345                         dev = dev_get_by_index_rcu(net, addr->sin6_scope_id);
346                         if (!dev) {
347                                 rcu_read_unlock();
348                                 return -ENODEV;
349                         }
350                 }
351                 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev,
352                                                     scoped);
353                 rcu_read_unlock();
354 
355                 if (!(isk->freebind || isk->transparent || has_addr ||
356                       addr_type == IPV6_ADDR_ANY))
357                         return -EADDRNOTAVAIL;
358 
359                 if (scoped)
360                         sk->sk_bound_dev_if = addr->sin6_scope_id;
361 #endif
362         } else {
363                 return -EAFNOSUPPORT;
364         }
365         return 0;
366 }
367 
368 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr)
369 {
370         if (saddr->sa_family == AF_INET) {
371                 struct inet_sock *isk = inet_sk(sk);
372                 struct sockaddr_in *addr = (struct sockaddr_in *) saddr;
373                 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
374 #if IS_ENABLED(CONFIG_IPV6)
375         } else if (saddr->sa_family == AF_INET6) {
376                 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr;
377                 struct ipv6_pinfo *np = inet6_sk(sk);
378                 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr;
379 #endif
380         }
381 }
382 
383 static void ping_clear_saddr(struct sock *sk, int dif)
384 {
385         sk->sk_bound_dev_if = dif;
386         if (sk->sk_family == AF_INET) {
387                 struct inet_sock *isk = inet_sk(sk);
388                 isk->inet_rcv_saddr = isk->inet_saddr = 0;
389 #if IS_ENABLED(CONFIG_IPV6)
390         } else if (sk->sk_family == AF_INET6) {
391                 struct ipv6_pinfo *np = inet6_sk(sk);
392                 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
393                 memset(&np->saddr, 0, sizeof(np->saddr));
394 #endif
395         }
396 }
397 /*
398  * We need our own bind because there are no privileged id's == local ports.
399  * Moreover, we don't allow binding to multi- and broadcast addresses.
400  */
401 
402 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
403 {
404         struct inet_sock *isk = inet_sk(sk);
405         unsigned short snum;
406         int err;
407         int dif = sk->sk_bound_dev_if;
408 
409         err = ping_check_bind_addr(sk, isk, uaddr, addr_len);
410         if (err)
411                 return err;
412 
413         lock_sock(sk);
414 
415         err = -EINVAL;
416         if (isk->inet_num != 0)
417                 goto out;
418 
419         err = -EADDRINUSE;
420         ping_set_saddr(sk, uaddr);
421         snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port);
422         if (ping_get_port(sk, snum) != 0) {
423                 ping_clear_saddr(sk, dif);
424                 goto out;
425         }
426 
427         pr_debug("after bind(): num = %d, dif = %d\n",
428                  (int)isk->inet_num,
429                  (int)sk->sk_bound_dev_if);
430 
431         err = 0;
432         if (sk->sk_family == AF_INET && isk->inet_rcv_saddr)
433                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
434 #if IS_ENABLED(CONFIG_IPV6)
435         if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr))
436                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
437 #endif
438 
439         if (snum)
440                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
441         isk->inet_sport = htons(isk->inet_num);
442         isk->inet_daddr = 0;
443         isk->inet_dport = 0;
444 
445 #if IS_ENABLED(CONFIG_IPV6)
446         if (sk->sk_family == AF_INET6)
447                 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr));
448 #endif
449 
450         sk_dst_reset(sk);
451 out:
452         release_sock(sk);
453         pr_debug("ping_v4_bind -> %d\n", err);
454         return err;
455 }
456 EXPORT_SYMBOL_GPL(ping_bind);
457 
458 /*
459  * Is this a supported type of ICMP message?
460  */
461 
462 static inline int ping_supported(int family, int type, int code)
463 {
464         return (family == AF_INET && type == ICMP_ECHO && code == 0) ||
465                (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0);
466 }
467 
468 /*
469  * This routine is called by the ICMP module when it gets some
470  * sort of error condition.
471  */
472 
473 void ping_err(struct sk_buff *skb, int offset, u32 info)
474 {
475         int family;
476         struct icmphdr *icmph;
477         struct inet_sock *inet_sock;
478         int type;
479         int code;
480         struct net *net = dev_net(skb->dev);
481         struct sock *sk;
482         int harderr;
483         int err;
484 
485         if (skb->protocol == htons(ETH_P_IP)) {
486                 family = AF_INET;
487                 type = icmp_hdr(skb)->type;
488                 code = icmp_hdr(skb)->code;
489                 icmph = (struct icmphdr *)(skb->data + offset);
490         } else if (skb->protocol == htons(ETH_P_IPV6)) {
491                 family = AF_INET6;
492                 type = icmp6_hdr(skb)->icmp6_type;
493                 code = icmp6_hdr(skb)->icmp6_code;
494                 icmph = (struct icmphdr *) (skb->data + offset);
495         } else {
496                 BUG();
497         }
498 
499         /* We assume the packet has already been checked by icmp_unreach */
500 
501         if (!ping_supported(family, icmph->type, icmph->code))
502                 return;
503 
504         pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n",
505                  skb->protocol, type, code, ntohs(icmph->un.echo.id),
506                  ntohs(icmph->un.echo.sequence));
507 
508         sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
509         if (sk == NULL) {
510                 pr_debug("no socket, dropping\n");
511                 return; /* No socket for error */
512         }
513         pr_debug("err on socket %p\n", sk);
514 
515         err = 0;
516         harderr = 0;
517         inet_sock = inet_sk(sk);
518 
519         if (skb->protocol == htons(ETH_P_IP)) {
520                 switch (type) {
521                 default:
522                 case ICMP_TIME_EXCEEDED:
523                         err = EHOSTUNREACH;
524                         break;
525                 case ICMP_SOURCE_QUENCH:
526                         /* This is not a real error but ping wants to see it.
527                          * Report it with some fake errno.
528                          */
529                         err = EREMOTEIO;
530                         break;
531                 case ICMP_PARAMETERPROB:
532                         err = EPROTO;
533                         harderr = 1;
534                         break;
535                 case ICMP_DEST_UNREACH:
536                         if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
537                                 ipv4_sk_update_pmtu(skb, sk, info);
538                                 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) {
539                                         err = EMSGSIZE;
540                                         harderr = 1;
541                                         break;
542                                 }
543                                 goto out;
544                         }
545                         err = EHOSTUNREACH;
546                         if (code <= NR_ICMP_UNREACH) {
547                                 harderr = icmp_err_convert[code].fatal;
548                                 err = icmp_err_convert[code].errno;
549                         }
550                         break;
551                 case ICMP_REDIRECT:
552                         /* See ICMP_SOURCE_QUENCH */
553                         ipv4_sk_redirect(skb, sk);
554                         err = EREMOTEIO;
555                         break;
556                 }
557 #if IS_ENABLED(CONFIG_IPV6)
558         } else if (skb->protocol == htons(ETH_P_IPV6)) {
559                 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err);
560 #endif
561         }
562 
563         /*
564          *      RFC1122: OK.  Passes ICMP errors back to application, as per
565          *      4.1.3.3.
566          */
567         if ((family == AF_INET && !inet_sock->recverr) ||
568             (family == AF_INET6 && !inet6_sk(sk)->recverr)) {
569                 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
570                         goto out;
571         } else {
572                 if (family == AF_INET) {
573                         ip_icmp_error(sk, skb, err, 0 /* no remote port */,
574                                       info, (u8 *)icmph);
575 #if IS_ENABLED(CONFIG_IPV6)
576                 } else if (family == AF_INET6) {
577                         pingv6_ops.ipv6_icmp_error(sk, skb, err, 0,
578                                                    info, (u8 *)icmph);
579 #endif
580                 }
581         }
582         sk->sk_err = err;
583         sk->sk_error_report(sk);
584 out:
585         sock_put(sk);
586 }
587 EXPORT_SYMBOL_GPL(ping_err);
588 
589 /*
590  *      Copy and checksum an ICMP Echo packet from user space into a buffer
591  *      starting from the payload.
592  */
593 
594 int ping_getfrag(void *from, char *to,
595                  int offset, int fraglen, int odd, struct sk_buff *skb)
596 {
597         struct pingfakehdr *pfh = (struct pingfakehdr *)from;
598 
599         if (offset == 0) {
600                 if (fraglen < sizeof(struct icmphdr))
601                         BUG();
602                 if (csum_partial_copy_fromiovecend(to + sizeof(struct icmphdr),
603                             pfh->iov, 0, fraglen - sizeof(struct icmphdr),
604                             &pfh->wcheck))
605                         return -EFAULT;
606         } else if (offset < sizeof(struct icmphdr)) {
607                         BUG();
608         } else {
609                 if (csum_partial_copy_fromiovecend
610                                 (to, pfh->iov, offset - sizeof(struct icmphdr),
611                                  fraglen, &pfh->wcheck))
612                         return -EFAULT;
613         }
614 
615 #if IS_ENABLED(CONFIG_IPV6)
616         /* For IPv6, checksum each skb as we go along, as expected by
617          * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in
618          * wcheck, it will be finalized in ping_v4_push_pending_frames.
619          */
620         if (pfh->family == AF_INET6) {
621                 skb->csum = pfh->wcheck;
622                 skb->ip_summed = CHECKSUM_NONE;
623                 pfh->wcheck = 0;
624         }
625 #endif
626 
627         return 0;
628 }
629 EXPORT_SYMBOL_GPL(ping_getfrag);
630 
631 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
632                                        struct flowi4 *fl4)
633 {
634         struct sk_buff *skb = skb_peek(&sk->sk_write_queue);
635 
636         pfh->wcheck = csum_partial((char *)&pfh->icmph,
637                 sizeof(struct icmphdr), pfh->wcheck);
638         pfh->icmph.checksum = csum_fold(pfh->wcheck);
639         memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
640         skb->ip_summed = CHECKSUM_NONE;
641         return ip_push_pending_frames(sk, fl4);
642 }
643 
644 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
645                         void *user_icmph, size_t icmph_len) {
646         u8 type, code;
647 
648         if (len > 0xFFFF)
649                 return -EMSGSIZE;
650 
651         /*
652          *      Check the flags.
653          */
654 
655         /* Mirror BSD error message compatibility */
656         if (msg->msg_flags & MSG_OOB)
657                 return -EOPNOTSUPP;
658 
659         /*
660          *      Fetch the ICMP header provided by the userland.
661          *      iovec is modified! The ICMP header is consumed.
662          */
663         if (memcpy_fromiovec(user_icmph, msg->msg_iov, icmph_len))
664                 return -EFAULT;
665 
666         if (family == AF_INET) {
667                 type = ((struct icmphdr *) user_icmph)->type;
668                 code = ((struct icmphdr *) user_icmph)->code;
669 #if IS_ENABLED(CONFIG_IPV6)
670         } else if (family == AF_INET6) {
671                 type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
672                 code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
673 #endif
674         } else {
675                 BUG();
676         }
677 
678         if (!ping_supported(family, type, code))
679                 return -EINVAL;
680 
681         return 0;
682 }
683 EXPORT_SYMBOL_GPL(ping_common_sendmsg);
684 
685 static int ping_v4_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
686                            size_t len)
687 {
688         struct net *net = sock_net(sk);
689         struct flowi4 fl4;
690         struct inet_sock *inet = inet_sk(sk);
691         struct ipcm_cookie ipc;
692         struct icmphdr user_icmph;
693         struct pingfakehdr pfh;
694         struct rtable *rt = NULL;
695         struct ip_options_data opt_copy;
696         int free = 0;
697         __be32 saddr, daddr, faddr;
698         u8  tos;
699         int err;
700 
701         pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
702 
703         err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
704                                   sizeof(user_icmph));
705         if (err)
706                 return err;
707 
708         /*
709          *      Get and verify the address.
710          */
711 
712         if (msg->msg_name) {
713                 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
714                 if (msg->msg_namelen < sizeof(*usin))
715                         return -EINVAL;
716                 if (usin->sin_family != AF_INET)
717                         return -EINVAL;
718                 daddr = usin->sin_addr.s_addr;
719                 /* no remote port */
720         } else {
721                 if (sk->sk_state != TCP_ESTABLISHED)
722                         return -EDESTADDRREQ;
723                 daddr = inet->inet_daddr;
724                 /* no remote port */
725         }
726 
727         ipc.addr = inet->inet_saddr;
728         ipc.opt = NULL;
729         ipc.oif = sk->sk_bound_dev_if;
730         ipc.tx_flags = 0;
731         ipc.ttl = 0;
732         ipc.tos = -1;
733 
734         sock_tx_timestamp(sk, &ipc.tx_flags);
735 
736         if (msg->msg_controllen) {
737                 err = ip_cmsg_send(sock_net(sk), msg, &ipc, false);
738                 if (err)
739                         return err;
740                 if (ipc.opt)
741                         free = 1;
742         }
743         if (!ipc.opt) {
744                 struct ip_options_rcu *inet_opt;
745 
746                 rcu_read_lock();
747                 inet_opt = rcu_dereference(inet->inet_opt);
748                 if (inet_opt) {
749                         memcpy(&opt_copy, inet_opt,
750                                sizeof(*inet_opt) + inet_opt->opt.optlen);
751                         ipc.opt = &opt_copy.opt;
752                 }
753                 rcu_read_unlock();
754         }
755 
756         saddr = ipc.addr;
757         ipc.addr = faddr = daddr;
758 
759         if (ipc.opt && ipc.opt->opt.srr) {
760                 if (!daddr)
761                         return -EINVAL;
762                 faddr = ipc.opt->opt.faddr;
763         }
764         tos = get_rttos(&ipc, inet);
765         if (sock_flag(sk, SOCK_LOCALROUTE) ||
766             (msg->msg_flags & MSG_DONTROUTE) ||
767             (ipc.opt && ipc.opt->opt.is_strictroute)) {
768                 tos |= RTO_ONLINK;
769         }
770 
771         if (ipv4_is_multicast(daddr)) {
772                 if (!ipc.oif)
773                         ipc.oif = inet->mc_index;
774                 if (!saddr)
775                         saddr = inet->mc_addr;
776         } else if (!ipc.oif)
777                 ipc.oif = inet->uc_index;
778 
779         flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
780                            RT_SCOPE_UNIVERSE, sk->sk_protocol,
781                            inet_sk_flowi_flags(sk), faddr, saddr, 0, 0);
782 
783         security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
784         rt = ip_route_output_flow(net, &fl4, sk);
785         if (IS_ERR(rt)) {
786                 err = PTR_ERR(rt);
787                 rt = NULL;
788                 if (err == -ENETUNREACH)
789                         IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
790                 goto out;
791         }
792 
793         err = -EACCES;
794         if ((rt->rt_flags & RTCF_BROADCAST) &&
795             !sock_flag(sk, SOCK_BROADCAST))
796                 goto out;
797 
798         if (msg->msg_flags & MSG_CONFIRM)
799                 goto do_confirm;
800 back_from_confirm:
801 
802         if (!ipc.addr)
803                 ipc.addr = fl4.daddr;
804 
805         lock_sock(sk);
806 
807         pfh.icmph.type = user_icmph.type; /* already checked */
808         pfh.icmph.code = user_icmph.code; /* ditto */
809         pfh.icmph.checksum = 0;
810         pfh.icmph.un.echo.id = inet->inet_sport;
811         pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
812         pfh.iov = msg->msg_iov;
813         pfh.wcheck = 0;
814         pfh.family = AF_INET;
815 
816         err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
817                         0, &ipc, &rt, msg->msg_flags);
818         if (err)
819                 ip_flush_pending_frames(sk);
820         else
821                 err = ping_v4_push_pending_frames(sk, &pfh, &fl4);
822         release_sock(sk);
823 
824 out:
825         ip_rt_put(rt);
826         if (free)
827                 kfree(ipc.opt);
828         if (!err) {
829                 icmp_out_count(sock_net(sk), user_icmph.type);
830                 return len;
831         }
832         return err;
833 
834 do_confirm:
835         dst_confirm(&rt->dst);
836         if (!(msg->msg_flags & MSG_PROBE) || len)
837                 goto back_from_confirm;
838         err = 0;
839         goto out;
840 }
841 
842 int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
843                  size_t len, int noblock, int flags, int *addr_len)
844 {
845         struct inet_sock *isk = inet_sk(sk);
846         int family = sk->sk_family;
847         struct sk_buff *skb;
848         int copied, err;
849 
850         pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
851 
852         err = -EOPNOTSUPP;
853         if (flags & MSG_OOB)
854                 goto out;
855 
856         if (flags & MSG_ERRQUEUE) {
857                 if (family == AF_INET) {
858                         return ip_recv_error(sk, msg, len, addr_len);
859 #if IS_ENABLED(CONFIG_IPV6)
860                 } else if (family == AF_INET6) {
861                         return pingv6_ops.ipv6_recv_error(sk, msg, len,
862                                                           addr_len);
863 #endif
864                 }
865         }
866 
867         skb = skb_recv_datagram(sk, flags, noblock, &err);
868         if (!skb)
869                 goto out;
870 
871         copied = skb->len;
872         if (copied > len) {
873                 msg->msg_flags |= MSG_TRUNC;
874                 copied = len;
875         }
876 
877         /* Don't bother checking the checksum */
878         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
879         if (err)
880                 goto done;
881 
882         sock_recv_timestamp(msg, sk, skb);
883 
884         /* Copy the address and add cmsg data. */
885         if (family == AF_INET) {
886                 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
887 
888                 if (sin) {
889                         sin->sin_family = AF_INET;
890                         sin->sin_port = 0 /* skb->h.uh->source */;
891                         sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
892                         memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
893                         *addr_len = sizeof(*sin);
894                 }
895 
896                 if (isk->cmsg_flags)
897                         ip_cmsg_recv(msg, skb);
898 
899 #if IS_ENABLED(CONFIG_IPV6)
900         } else if (family == AF_INET6) {
901                 struct ipv6_pinfo *np = inet6_sk(sk);
902                 struct ipv6hdr *ip6 = ipv6_hdr(skb);
903                 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
904 
905                 if (sin6) {
906                         sin6->sin6_family = AF_INET6;
907                         sin6->sin6_port = 0;
908                         sin6->sin6_addr = ip6->saddr;
909                         sin6->sin6_flowinfo = 0;
910                         if (np->sndflow)
911                                 sin6->sin6_flowinfo = ip6_flowinfo(ip6);
912                         sin6->sin6_scope_id =
913                                 ipv6_iface_scope_id(&sin6->sin6_addr,
914                                                     inet6_iif(skb));
915                         *addr_len = sizeof(*sin6);
916                 }
917 
918                 if (inet6_sk(sk)->rxopt.all)
919                         pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb);
920                 if (skb->protocol == htons(ETH_P_IPV6) &&
921                     inet6_sk(sk)->rxopt.all)
922                         pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb);
923                 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags)
924                         ip_cmsg_recv(msg, skb);
925 #endif
926         } else {
927                 BUG();
928         }
929 
930         err = copied;
931 
932 done:
933         skb_free_datagram(sk, skb);
934 out:
935         pr_debug("ping_recvmsg -> %d\n", err);
936         return err;
937 }
938 EXPORT_SYMBOL_GPL(ping_recvmsg);
939 
940 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
941 {
942         pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
943                  inet_sk(sk), inet_sk(sk)->inet_num, skb);
944         if (sock_queue_rcv_skb(sk, skb) < 0) {
945                 kfree_skb(skb);
946                 pr_debug("ping_queue_rcv_skb -> failed\n");
947                 return -1;
948         }
949         return 0;
950 }
951 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
952 
953 
954 /*
955  *      All we need to do is get the socket.
956  */
957 
958 void ping_rcv(struct sk_buff *skb)
959 {
960         struct sock *sk;
961         struct net *net = dev_net(skb->dev);
962         struct icmphdr *icmph = icmp_hdr(skb);
963 
964         /* We assume the packet has already been checked by icmp_rcv */
965 
966         pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
967                  skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
968 
969         /* Push ICMP header back */
970         skb_push(skb, skb->data - (u8 *)icmph);
971 
972         sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
973         if (sk != NULL) {
974                 pr_debug("rcv on socket %p\n", sk);
975                 ping_queue_rcv_skb(sk, skb_get(skb));
976                 sock_put(sk);
977                 return;
978         }
979         pr_debug("no socket, dropping\n");
980 
981         /* We're called from icmp_rcv(). kfree_skb() is done there. */
982 }
983 EXPORT_SYMBOL_GPL(ping_rcv);
984 
985 struct proto ping_prot = {
986         .name =         "PING",
987         .owner =        THIS_MODULE,
988         .init =         ping_init_sock,
989         .close =        ping_close,
990         .connect =      ip4_datagram_connect,
991         .disconnect =   udp_disconnect,
992         .setsockopt =   ip_setsockopt,
993         .getsockopt =   ip_getsockopt,
994         .sendmsg =      ping_v4_sendmsg,
995         .recvmsg =      ping_recvmsg,
996         .bind =         ping_bind,
997         .backlog_rcv =  ping_queue_rcv_skb,
998         .release_cb =   ip4_datagram_release_cb,
999         .hash =         ping_hash,
1000         .unhash =       ping_unhash,
1001         .get_port =     ping_get_port,
1002         .obj_size =     sizeof(struct inet_sock),
1003 };
1004 EXPORT_SYMBOL(ping_prot);
1005 
1006 #ifdef CONFIG_PROC_FS
1007 
1008 static struct sock *ping_get_first(struct seq_file *seq, int start)
1009 {
1010         struct sock *sk;
1011         struct ping_iter_state *state = seq->private;
1012         struct net *net = seq_file_net(seq);
1013 
1014         for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
1015              ++state->bucket) {
1016                 struct hlist_nulls_node *node;
1017                 struct hlist_nulls_head *hslot;
1018 
1019                 hslot = &ping_table.hash[state->bucket];
1020 
1021                 if (hlist_nulls_empty(hslot))
1022                         continue;
1023 
1024                 sk_nulls_for_each(sk, node, hslot) {
1025                         if (net_eq(sock_net(sk), net) &&
1026                             sk->sk_family == state->family)
1027                                 goto found;
1028                 }
1029         }
1030         sk = NULL;
1031 found:
1032         return sk;
1033 }
1034 
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 
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 
1059 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
1060 {
1061         struct ping_iter_state *state = seq->private;
1062         state->bucket = 0;
1063         state->family = family;
1064 
1065         read_lock_bh(&ping_table.lock);
1066 
1067         return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1068 }
1069 EXPORT_SYMBOL_GPL(ping_seq_start);
1070 
1071 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos)
1072 {
1073         return ping_seq_start(seq, pos, AF_INET);
1074 }
1075 
1076 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1077 {
1078         struct sock *sk;
1079 
1080         if (v == SEQ_START_TOKEN)
1081                 sk = ping_get_idx(seq, 0);
1082         else
1083                 sk = ping_get_next(seq, v);
1084 
1085         ++*pos;
1086         return sk;
1087 }
1088 EXPORT_SYMBOL_GPL(ping_seq_next);
1089 
1090 void ping_seq_stop(struct seq_file *seq, void *v)
1091 {
1092         read_unlock_bh(&ping_table.lock);
1093 }
1094 EXPORT_SYMBOL_GPL(ping_seq_stop);
1095 
1096 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f,
1097                 int bucket)
1098 {
1099         struct inet_sock *inet = inet_sk(sp);
1100         __be32 dest = inet->inet_daddr;
1101         __be32 src = inet->inet_rcv_saddr;
1102         __u16 destp = ntohs(inet->inet_dport);
1103         __u16 srcp = ntohs(inet->inet_sport);
1104 
1105         seq_printf(f, "%5d: %08X:%04X %08X:%04X"
1106                 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d",
1107                 bucket, src, srcp, dest, destp, sp->sk_state,
1108                 sk_wmem_alloc_get(sp),
1109                 sk_rmem_alloc_get(sp),
1110                 0, 0L, 0,
1111                 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
1112                 0, sock_i_ino(sp),
1113                 atomic_read(&sp->sk_refcnt), sp,
1114                 atomic_read(&sp->sk_drops));
1115 }
1116 
1117 static int ping_v4_seq_show(struct seq_file *seq, void *v)
1118 {
1119         seq_setwidth(seq, 127);
1120         if (v == SEQ_START_TOKEN)
1121                 seq_puts(seq, "  sl  local_address rem_address   st tx_queue "
1122                            "rx_queue tr tm->when retrnsmt   uid  timeout "
1123                            "inode ref pointer drops");
1124         else {
1125                 struct ping_iter_state *state = seq->private;
1126 
1127                 ping_v4_format_sock(v, seq, state->bucket);
1128         }
1129         seq_pad(seq, '\n');
1130         return 0;
1131 }
1132 
1133 static const struct seq_operations ping_v4_seq_ops = {
1134         .show           = ping_v4_seq_show,
1135         .start          = ping_v4_seq_start,
1136         .next           = ping_seq_next,
1137         .stop           = ping_seq_stop,
1138 };
1139 
1140 static int ping_seq_open(struct inode *inode, struct file *file)
1141 {
1142         struct ping_seq_afinfo *afinfo = PDE_DATA(inode);
1143         return seq_open_net(inode, file, &afinfo->seq_ops,
1144                            sizeof(struct ping_iter_state));
1145 }
1146 
1147 const struct file_operations ping_seq_fops = {
1148         .open           = ping_seq_open,
1149         .read           = seq_read,
1150         .llseek         = seq_lseek,
1151         .release        = seq_release_net,
1152 };
1153 EXPORT_SYMBOL_GPL(ping_seq_fops);
1154 
1155 static struct ping_seq_afinfo ping_v4_seq_afinfo = {
1156         .name           = "icmp",
1157         .family         = AF_INET,
1158         .seq_fops       = &ping_seq_fops,
1159         .seq_ops        = {
1160                 .start          = ping_v4_seq_start,
1161                 .show           = ping_v4_seq_show,
1162                 .next           = ping_seq_next,
1163                 .stop           = ping_seq_stop,
1164         },
1165 };
1166 
1167 int ping_proc_register(struct net *net, struct ping_seq_afinfo *afinfo)
1168 {
1169         struct proc_dir_entry *p;
1170         p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
1171                              afinfo->seq_fops, afinfo);
1172         if (!p)
1173                 return -ENOMEM;
1174         return 0;
1175 }
1176 EXPORT_SYMBOL_GPL(ping_proc_register);
1177 
1178 void ping_proc_unregister(struct net *net, struct ping_seq_afinfo *afinfo)
1179 {
1180         remove_proc_entry(afinfo->name, net->proc_net);
1181 }
1182 EXPORT_SYMBOL_GPL(ping_proc_unregister);
1183 
1184 static int __net_init ping_v4_proc_init_net(struct net *net)
1185 {
1186         return ping_proc_register(net, &ping_v4_seq_afinfo);
1187 }
1188 
1189 static void __net_exit ping_v4_proc_exit_net(struct net *net)
1190 {
1191         ping_proc_unregister(net, &ping_v4_seq_afinfo);
1192 }
1193 
1194 static struct pernet_operations ping_v4_net_ops = {
1195         .init = ping_v4_proc_init_net,
1196         .exit = ping_v4_proc_exit_net,
1197 };
1198 
1199 int __init ping_proc_init(void)
1200 {
1201         return register_pernet_subsys(&ping_v4_net_ops);
1202 }
1203 
1204 void ping_proc_exit(void)
1205 {
1206         unregister_pernet_subsys(&ping_v4_net_ops);
1207 }
1208 
1209 #endif
1210 
1211 void __init ping_init(void)
1212 {
1213         int i;
1214 
1215         for (i = 0; i < PING_HTABLE_SIZE; i++)
1216                 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i);
1217         rwlock_init(&ping_table.lock);
1218 }
1219 

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