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 u32 ping_hashfn(const struct net *net, u32 num, u32 mask)
 68 {
 69         u32 res = (num + net_hash_mix(net)) & mask;
 70 
 71         pr_debug("hash(%u) = %u\n", num, res);
 72         return res;
 73 }
 74 EXPORT_SYMBOL_GPL(ping_hash);
 75 
 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 int ping_hash(struct sock *sk)
149 {
150         pr_debug("ping_hash(sk->port=%u)\n", inet_sk(sk)->inet_num);
151         BUG(); /* "Please do not press this button again." */
152 
153         return 0;
154 }
155 
156 void ping_unhash(struct sock *sk)
157 {
158         struct inet_sock *isk = inet_sk(sk);
159         pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);
160         if (sk_hashed(sk)) {
161                 write_lock_bh(&ping_table.lock);
162                 hlist_nulls_del(&sk->sk_nulls_node);
163                 sk_nulls_node_init(&sk->sk_nulls_node);
164                 sock_put(sk);
165                 isk->inet_num = 0;
166                 isk->inet_sport = 0;
167                 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
168                 write_unlock_bh(&ping_table.lock);
169         }
170 }
171 EXPORT_SYMBOL_GPL(ping_unhash);
172 
173 static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
174 {
175         struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident);
176         struct sock *sk = NULL;
177         struct inet_sock *isk;
178         struct hlist_nulls_node *hnode;
179         int dif = skb->dev->ifindex;
180 
181         if (skb->protocol == htons(ETH_P_IP)) {
182                 pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n",
183                          (int)ident, &ip_hdr(skb)->daddr, dif);
184 #if IS_ENABLED(CONFIG_IPV6)
185         } else if (skb->protocol == htons(ETH_P_IPV6)) {
186                 pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n",
187                          (int)ident, &ipv6_hdr(skb)->daddr, dif);
188 #endif
189         }
190 
191         read_lock_bh(&ping_table.lock);
192 
193         ping_portaddr_for_each_entry(sk, hnode, hslot) {
194                 isk = inet_sk(sk);
195 
196                 pr_debug("iterate\n");
197                 if (isk->inet_num != ident)
198                         continue;
199 
200                 if (skb->protocol == htons(ETH_P_IP) &&
201                     sk->sk_family == AF_INET) {
202                         pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk,
203                                  (int) isk->inet_num, &isk->inet_rcv_saddr,
204                                  sk->sk_bound_dev_if);
205 
206                         if (isk->inet_rcv_saddr &&
207                             isk->inet_rcv_saddr != ip_hdr(skb)->daddr)
208                                 continue;
209 #if IS_ENABLED(CONFIG_IPV6)
210                 } else if (skb->protocol == htons(ETH_P_IPV6) &&
211                            sk->sk_family == AF_INET6) {
212 
213                         pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk,
214                                  (int) isk->inet_num,
215                                  &sk->sk_v6_rcv_saddr,
216                                  sk->sk_bound_dev_if);
217 
218                         if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
219                             !ipv6_addr_equal(&sk->sk_v6_rcv_saddr,
220                                              &ipv6_hdr(skb)->daddr))
221                                 continue;
222 #endif
223                 } else {
224                         continue;
225                 }
226 
227                 if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)
228                         continue;
229 
230                 sock_hold(sk);
231                 goto exit;
232         }
233 
234         sk = NULL;
235 exit:
236         read_unlock_bh(&ping_table.lock);
237 
238         return sk;
239 }
240 
241 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low,
242                                           kgid_t *high)
243 {
244         kgid_t *data = net->ipv4.ping_group_range.range;
245         unsigned int seq;
246 
247         do {
248                 seq = read_seqbegin(&net->ipv4.ping_group_range.lock);
249 
250                 *low = data[0];
251                 *high = data[1];
252         } while (read_seqretry(&net->ipv4.ping_group_range.lock, seq));
253 }
254 
255 
256 int ping_init_sock(struct sock *sk)
257 {
258         struct net *net = sock_net(sk);
259         kgid_t group = current_egid();
260         struct group_info *group_info;
261         int i, j, count;
262         kgid_t low, high;
263         int ret = 0;
264 
265         if (sk->sk_family == AF_INET6)
266                 sk->sk_ipv6only = 1;
267 
268         inet_get_ping_group_range_net(net, &low, &high);
269         if (gid_lte(low, group) && gid_lte(group, high))
270                 return 0;
271 
272         group_info = get_current_groups();
273         count = group_info->ngroups;
274         for (i = 0; i < group_info->nblocks; i++) {
275                 int cp_count = min_t(int, NGROUPS_PER_BLOCK, count);
276                 for (j = 0; j < cp_count; j++) {
277                         kgid_t gid = group_info->blocks[i][j];
278                         if (gid_lte(low, gid) && gid_lte(gid, high))
279                                 goto out_release_group;
280                 }
281 
282                 count -= cp_count;
283         }
284 
285         ret = -EACCES;
286 
287 out_release_group:
288         put_group_info(group_info);
289         return ret;
290 }
291 EXPORT_SYMBOL_GPL(ping_init_sock);
292 
293 void ping_close(struct sock *sk, long timeout)
294 {
295         pr_debug("ping_close(sk=%p,sk->num=%u)\n",
296                  inet_sk(sk), inet_sk(sk)->inet_num);
297         pr_debug("isk->refcnt = %d\n", sk->sk_refcnt.counter);
298 
299         sk_common_release(sk);
300 }
301 EXPORT_SYMBOL_GPL(ping_close);
302 
303 /* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */
304 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
305                                 struct sockaddr *uaddr, int addr_len) {
306         struct net *net = sock_net(sk);
307         if (sk->sk_family == AF_INET) {
308                 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
309                 int chk_addr_ret;
310 
311                 if (addr_len < sizeof(*addr))
312                         return -EINVAL;
313 
314                 if (addr->sin_family != AF_INET &&
315                     !(addr->sin_family == AF_UNSPEC &&
316                       addr->sin_addr.s_addr == htonl(INADDR_ANY)))
317                         return -EAFNOSUPPORT;
318 
319                 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",
320                          sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
321 
322                 chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
323 
324                 if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
325                         chk_addr_ret = RTN_LOCAL;
326 
327                 if ((net->ipv4.sysctl_ip_nonlocal_bind == 0 &&
328                     isk->freebind == 0 && isk->transparent == 0 &&
329                      chk_addr_ret != RTN_LOCAL) ||
330                     chk_addr_ret == RTN_MULTICAST ||
331                     chk_addr_ret == RTN_BROADCAST)
332                         return -EADDRNOTAVAIL;
333 
334 #if IS_ENABLED(CONFIG_IPV6)
335         } else if (sk->sk_family == AF_INET6) {
336                 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
337                 int addr_type, scoped, has_addr;
338                 struct net_device *dev = NULL;
339 
340                 if (addr_len < sizeof(*addr))
341                         return -EINVAL;
342 
343                 if (addr->sin6_family != AF_INET6)
344                         return -EAFNOSUPPORT;
345 
346                 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n",
347                          sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port));
348 
349                 addr_type = ipv6_addr_type(&addr->sin6_addr);
350                 scoped = __ipv6_addr_needs_scope_id(addr_type);
351                 if ((addr_type != IPV6_ADDR_ANY &&
352                      !(addr_type & IPV6_ADDR_UNICAST)) ||
353                     (scoped && !addr->sin6_scope_id))
354                         return -EINVAL;
355 
356                 rcu_read_lock();
357                 if (addr->sin6_scope_id) {
358                         dev = dev_get_by_index_rcu(net, addr->sin6_scope_id);
359                         if (!dev) {
360                                 rcu_read_unlock();
361                                 return -ENODEV;
362                         }
363                 }
364                 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev,
365                                                     scoped);
366                 rcu_read_unlock();
367 
368                 if (!(net->ipv6.sysctl.ip_nonlocal_bind ||
369                       isk->freebind || isk->transparent || has_addr ||
370                       addr_type == IPV6_ADDR_ANY))
371                         return -EADDRNOTAVAIL;
372 
373                 if (scoped)
374                         sk->sk_bound_dev_if = addr->sin6_scope_id;
375 #endif
376         } else {
377                 return -EAFNOSUPPORT;
378         }
379         return 0;
380 }
381 
382 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr)
383 {
384         if (saddr->sa_family == AF_INET) {
385                 struct inet_sock *isk = inet_sk(sk);
386                 struct sockaddr_in *addr = (struct sockaddr_in *) saddr;
387                 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
388 #if IS_ENABLED(CONFIG_IPV6)
389         } else if (saddr->sa_family == AF_INET6) {
390                 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr;
391                 struct ipv6_pinfo *np = inet6_sk(sk);
392                 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr;
393 #endif
394         }
395 }
396 
397 static void ping_clear_saddr(struct sock *sk, int dif)
398 {
399         sk->sk_bound_dev_if = dif;
400         if (sk->sk_family == AF_INET) {
401                 struct inet_sock *isk = inet_sk(sk);
402                 isk->inet_rcv_saddr = isk->inet_saddr = 0;
403 #if IS_ENABLED(CONFIG_IPV6)
404         } else if (sk->sk_family == AF_INET6) {
405                 struct ipv6_pinfo *np = inet6_sk(sk);
406                 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
407                 memset(&np->saddr, 0, sizeof(np->saddr));
408 #endif
409         }
410 }
411 /*
412  * We need our own bind because there are no privileged id's == local ports.
413  * Moreover, we don't allow binding to multi- and broadcast addresses.
414  */
415 
416 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
417 {
418         struct inet_sock *isk = inet_sk(sk);
419         unsigned short snum;
420         int err;
421         int dif = sk->sk_bound_dev_if;
422 
423         err = ping_check_bind_addr(sk, isk, uaddr, addr_len);
424         if (err)
425                 return err;
426 
427         lock_sock(sk);
428 
429         err = -EINVAL;
430         if (isk->inet_num != 0)
431                 goto out;
432 
433         err = -EADDRINUSE;
434         ping_set_saddr(sk, uaddr);
435         snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port);
436         if (ping_get_port(sk, snum) != 0) {
437                 ping_clear_saddr(sk, dif);
438                 goto out;
439         }
440 
441         pr_debug("after bind(): num = %d, dif = %d\n",
442                  (int)isk->inet_num,
443                  (int)sk->sk_bound_dev_if);
444 
445         err = 0;
446         if (sk->sk_family == AF_INET && isk->inet_rcv_saddr)
447                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
448 #if IS_ENABLED(CONFIG_IPV6)
449         if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr))
450                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
451 #endif
452 
453         if (snum)
454                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
455         isk->inet_sport = htons(isk->inet_num);
456         isk->inet_daddr = 0;
457         isk->inet_dport = 0;
458 
459 #if IS_ENABLED(CONFIG_IPV6)
460         if (sk->sk_family == AF_INET6)
461                 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr));
462 #endif
463 
464         sk_dst_reset(sk);
465 out:
466         release_sock(sk);
467         pr_debug("ping_v4_bind -> %d\n", err);
468         return err;
469 }
470 EXPORT_SYMBOL_GPL(ping_bind);
471 
472 /*
473  * Is this a supported type of ICMP message?
474  */
475 
476 static inline int ping_supported(int family, int type, int code)
477 {
478         return (family == AF_INET && type == ICMP_ECHO && code == 0) ||
479                (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0);
480 }
481 
482 /*
483  * This routine is called by the ICMP module when it gets some
484  * sort of error condition.
485  */
486 
487 void ping_err(struct sk_buff *skb, int offset, u32 info)
488 {
489         int family;
490         struct icmphdr *icmph;
491         struct inet_sock *inet_sock;
492         int type;
493         int code;
494         struct net *net = dev_net(skb->dev);
495         struct sock *sk;
496         int harderr;
497         int err;
498 
499         if (skb->protocol == htons(ETH_P_IP)) {
500                 family = AF_INET;
501                 type = icmp_hdr(skb)->type;
502                 code = icmp_hdr(skb)->code;
503                 icmph = (struct icmphdr *)(skb->data + offset);
504         } else if (skb->protocol == htons(ETH_P_IPV6)) {
505                 family = AF_INET6;
506                 type = icmp6_hdr(skb)->icmp6_type;
507                 code = icmp6_hdr(skb)->icmp6_code;
508                 icmph = (struct icmphdr *) (skb->data + offset);
509         } else {
510                 BUG();
511         }
512 
513         /* We assume the packet has already been checked by icmp_unreach */
514 
515         if (!ping_supported(family, icmph->type, icmph->code))
516                 return;
517 
518         pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n",
519                  skb->protocol, type, code, ntohs(icmph->un.echo.id),
520                  ntohs(icmph->un.echo.sequence));
521 
522         sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
523         if (!sk) {
524                 pr_debug("no socket, dropping\n");
525                 return; /* No socket for error */
526         }
527         pr_debug("err on socket %p\n", sk);
528 
529         err = 0;
530         harderr = 0;
531         inet_sock = inet_sk(sk);
532 
533         if (skb->protocol == htons(ETH_P_IP)) {
534                 switch (type) {
535                 default:
536                 case ICMP_TIME_EXCEEDED:
537                         err = EHOSTUNREACH;
538                         break;
539                 case ICMP_SOURCE_QUENCH:
540                         /* This is not a real error but ping wants to see it.
541                          * Report it with some fake errno.
542                          */
543                         err = EREMOTEIO;
544                         break;
545                 case ICMP_PARAMETERPROB:
546                         err = EPROTO;
547                         harderr = 1;
548                         break;
549                 case ICMP_DEST_UNREACH:
550                         if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
551                                 ipv4_sk_update_pmtu(skb, sk, info);
552                                 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) {
553                                         err = EMSGSIZE;
554                                         harderr = 1;
555                                         break;
556                                 }
557                                 goto out;
558                         }
559                         err = EHOSTUNREACH;
560                         if (code <= NR_ICMP_UNREACH) {
561                                 harderr = icmp_err_convert[code].fatal;
562                                 err = icmp_err_convert[code].errno;
563                         }
564                         break;
565                 case ICMP_REDIRECT:
566                         /* See ICMP_SOURCE_QUENCH */
567                         ipv4_sk_redirect(skb, sk);
568                         err = EREMOTEIO;
569                         break;
570                 }
571 #if IS_ENABLED(CONFIG_IPV6)
572         } else if (skb->protocol == htons(ETH_P_IPV6)) {
573                 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err);
574 #endif
575         }
576 
577         /*
578          *      RFC1122: OK.  Passes ICMP errors back to application, as per
579          *      4.1.3.3.
580          */
581         if ((family == AF_INET && !inet_sock->recverr) ||
582             (family == AF_INET6 && !inet6_sk(sk)->recverr)) {
583                 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
584                         goto out;
585         } else {
586                 if (family == AF_INET) {
587                         ip_icmp_error(sk, skb, err, 0 /* no remote port */,
588                                       info, (u8 *)icmph);
589 #if IS_ENABLED(CONFIG_IPV6)
590                 } else if (family == AF_INET6) {
591                         pingv6_ops.ipv6_icmp_error(sk, skb, err, 0,
592                                                    info, (u8 *)icmph);
593 #endif
594                 }
595         }
596         sk->sk_err = err;
597         sk->sk_error_report(sk);
598 out:
599         sock_put(sk);
600 }
601 EXPORT_SYMBOL_GPL(ping_err);
602 
603 /*
604  *      Copy and checksum an ICMP Echo packet from user space into a buffer
605  *      starting from the payload.
606  */
607 
608 int ping_getfrag(void *from, char *to,
609                  int offset, int fraglen, int odd, struct sk_buff *skb)
610 {
611         struct pingfakehdr *pfh = (struct pingfakehdr *)from;
612 
613         if (offset == 0) {
614                 fraglen -= sizeof(struct icmphdr);
615                 if (fraglen < 0)
616                         BUG();
617                 if (csum_and_copy_from_iter(to + sizeof(struct icmphdr),
618                             fraglen, &pfh->wcheck,
619                             &pfh->msg->msg_iter) != fraglen)
620                         return -EFAULT;
621         } else if (offset < sizeof(struct icmphdr)) {
622                         BUG();
623         } else {
624                 if (csum_and_copy_from_iter(to, fraglen, &pfh->wcheck,
625                                             &pfh->msg->msg_iter) != fraglen)
626                         return -EFAULT;
627         }
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 = pfh->wcheck;
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 
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         pfh->wcheck = csum_partial((char *)&pfh->icmph,
651                 sizeof(struct icmphdr), pfh->wcheck);
652         pfh->icmph.checksum = csum_fold(pfh->wcheck);
653         memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
654         skb->ip_summed = CHECKSUM_NONE;
655         return ip_push_pending_frames(sk, fl4);
656 }
657 
658 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
659                         void *user_icmph, size_t icmph_len) {
660         u8 type, code;
661 
662         if (len > 0xFFFF)
663                 return -EMSGSIZE;
664 
665         /*
666          *      Check the flags.
667          */
668 
669         /* Mirror BSD error message compatibility */
670         if (msg->msg_flags & MSG_OOB)
671                 return -EOPNOTSUPP;
672 
673         /*
674          *      Fetch the ICMP header provided by the userland.
675          *      iovec is modified! The ICMP header is consumed.
676          */
677         if (memcpy_from_msg(user_icmph, msg, icmph_len))
678                 return -EFAULT;
679 
680         if (family == AF_INET) {
681                 type = ((struct icmphdr *) user_icmph)->type;
682                 code = ((struct icmphdr *) user_icmph)->code;
683 #if IS_ENABLED(CONFIG_IPV6)
684         } else if (family == AF_INET6) {
685                 type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
686                 code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
687 #endif
688         } else {
689                 BUG();
690         }
691 
692         if (!ping_supported(family, type, code))
693                 return -EINVAL;
694 
695         return 0;
696 }
697 EXPORT_SYMBOL_GPL(ping_common_sendmsg);
698 
699 static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
700 {
701         struct net *net = sock_net(sk);
702         struct flowi4 fl4;
703         struct inet_sock *inet = inet_sk(sk);
704         struct ipcm_cookie ipc;
705         struct icmphdr user_icmph;
706         struct pingfakehdr pfh;
707         struct rtable *rt = NULL;
708         struct ip_options_data opt_copy;
709         int free = 0;
710         __be32 saddr, daddr, faddr;
711         u8  tos;
712         int err;
713 
714         pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
715 
716         err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
717                                   sizeof(user_icmph));
718         if (err)
719                 return err;
720 
721         /*
722          *      Get and verify the address.
723          */
724 
725         if (msg->msg_name) {
726                 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
727                 if (msg->msg_namelen < sizeof(*usin))
728                         return -EINVAL;
729                 if (usin->sin_family != AF_INET)
730                         return -EAFNOSUPPORT;
731                 daddr = usin->sin_addr.s_addr;
732                 /* no remote port */
733         } else {
734                 if (sk->sk_state != TCP_ESTABLISHED)
735                         return -EDESTADDRREQ;
736                 daddr = inet->inet_daddr;
737                 /* no remote port */
738         }
739 
740         ipc.addr = inet->inet_saddr;
741         ipc.opt = NULL;
742         ipc.oif = sk->sk_bound_dev_if;
743         ipc.tx_flags = 0;
744         ipc.ttl = 0;
745         ipc.tos = -1;
746 
747         sock_tx_timestamp(sk, &ipc.tx_flags);
748 
749         if (msg->msg_controllen) {
750                 err = ip_cmsg_send(sock_net(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                         return -EINVAL;
777                 faddr = ipc.opt->opt.faddr;
778         }
779         tos = get_rttos(&ipc, inet);
780         if (sock_flag(sk, SOCK_LOCALROUTE) ||
781             (msg->msg_flags & MSG_DONTROUTE) ||
782             (ipc.opt && ipc.opt->opt.is_strictroute)) {
783                 tos |= RTO_ONLINK;
784         }
785 
786         if (ipv4_is_multicast(daddr)) {
787                 if (!ipc.oif)
788                         ipc.oif = inet->mc_index;
789                 if (!saddr)
790                         saddr = inet->mc_addr;
791         } else if (!ipc.oif)
792                 ipc.oif = inet->uc_index;
793 
794         flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
795                            RT_SCOPE_UNIVERSE, sk->sk_protocol,
796                            inet_sk_flowi_flags(sk), faddr, saddr, 0, 0);
797 
798         security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
799         rt = ip_route_output_flow(net, &fl4, sk);
800         if (IS_ERR(rt)) {
801                 err = PTR_ERR(rt);
802                 rt = NULL;
803                 if (err == -ENETUNREACH)
804                         IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
805                 goto out;
806         }
807 
808         err = -EACCES;
809         if ((rt->rt_flags & RTCF_BROADCAST) &&
810             !sock_flag(sk, SOCK_BROADCAST))
811                 goto out;
812 
813         if (msg->msg_flags & MSG_CONFIRM)
814                 goto do_confirm;
815 back_from_confirm:
816 
817         if (!ipc.addr)
818                 ipc.addr = fl4.daddr;
819 
820         lock_sock(sk);
821 
822         pfh.icmph.type = user_icmph.type; /* already checked */
823         pfh.icmph.code = user_icmph.code; /* ditto */
824         pfh.icmph.checksum = 0;
825         pfh.icmph.un.echo.id = inet->inet_sport;
826         pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
827         pfh.msg = msg;
828         pfh.wcheck = 0;
829         pfh.family = AF_INET;
830 
831         err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
832                         0, &ipc, &rt, msg->msg_flags);
833         if (err)
834                 ip_flush_pending_frames(sk);
835         else
836                 err = ping_v4_push_pending_frames(sk, &pfh, &fl4);
837         release_sock(sk);
838 
839 out:
840         ip_rt_put(rt);
841         if (free)
842                 kfree(ipc.opt);
843         if (!err) {
844                 icmp_out_count(sock_net(sk), user_icmph.type);
845                 return len;
846         }
847         return err;
848 
849 do_confirm:
850         dst_confirm(&rt->dst);
851         if (!(msg->msg_flags & MSG_PROBE) || len)
852                 goto back_from_confirm;
853         err = 0;
854         goto out;
855 }
856 
857 int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock,
858                  int flags, int *addr_len)
859 {
860         struct inet_sock *isk = inet_sk(sk);
861         int family = sk->sk_family;
862         struct sk_buff *skb;
863         int copied, err;
864 
865         pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
866 
867         err = -EOPNOTSUPP;
868         if (flags & MSG_OOB)
869                 goto out;
870 
871         if (flags & MSG_ERRQUEUE)
872                 return inet_recv_error(sk, msg, len, addr_len);
873 
874         skb = skb_recv_datagram(sk, flags, noblock, &err);
875         if (!skb)
876                 goto out;
877 
878         copied = skb->len;
879         if (copied > len) {
880                 msg->msg_flags |= MSG_TRUNC;
881                 copied = len;
882         }
883 
884         /* Don't bother checking the checksum */
885         err = skb_copy_datagram_msg(skb, 0, msg, copied);
886         if (err)
887                 goto done;
888 
889         sock_recv_timestamp(msg, sk, skb);
890 
891         /* Copy the address and add cmsg data. */
892         if (family == AF_INET) {
893                 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
894 
895                 if (sin) {
896                         sin->sin_family = AF_INET;
897                         sin->sin_port = 0 /* skb->h.uh->source */;
898                         sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
899                         memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
900                         *addr_len = sizeof(*sin);
901                 }
902 
903                 if (isk->cmsg_flags)
904                         ip_cmsg_recv(msg, skb);
905 
906 #if IS_ENABLED(CONFIG_IPV6)
907         } else if (family == AF_INET6) {
908                 struct ipv6_pinfo *np = inet6_sk(sk);
909                 struct ipv6hdr *ip6 = ipv6_hdr(skb);
910                 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
911 
912                 if (sin6) {
913                         sin6->sin6_family = AF_INET6;
914                         sin6->sin6_port = 0;
915                         sin6->sin6_addr = ip6->saddr;
916                         sin6->sin6_flowinfo = 0;
917                         if (np->sndflow)
918                                 sin6->sin6_flowinfo = ip6_flowinfo(ip6);
919                         sin6->sin6_scope_id =
920                                 ipv6_iface_scope_id(&sin6->sin6_addr,
921                                                     inet6_iif(skb));
922                         *addr_len = sizeof(*sin6);
923                 }
924 
925                 if (inet6_sk(sk)->rxopt.all)
926                         pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb);
927                 if (skb->protocol == htons(ETH_P_IPV6) &&
928                     inet6_sk(sk)->rxopt.all)
929                         pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb);
930                 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags)
931                         ip_cmsg_recv(msg, skb);
932 #endif
933         } else {
934                 BUG();
935         }
936 
937         err = copied;
938 
939 done:
940         skb_free_datagram(sk, skb);
941 out:
942         pr_debug("ping_recvmsg -> %d\n", err);
943         return err;
944 }
945 EXPORT_SYMBOL_GPL(ping_recvmsg);
946 
947 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
948 {
949         pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
950                  inet_sk(sk), inet_sk(sk)->inet_num, skb);
951         if (sock_queue_rcv_skb(sk, skb) < 0) {
952                 kfree_skb(skb);
953                 pr_debug("ping_queue_rcv_skb -> failed\n");
954                 return -1;
955         }
956         return 0;
957 }
958 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
959 
960 
961 /*
962  *      All we need to do is get the socket.
963  */
964 
965 bool ping_rcv(struct sk_buff *skb)
966 {
967         struct sock *sk;
968         struct net *net = dev_net(skb->dev);
969         struct icmphdr *icmph = icmp_hdr(skb);
970 
971         /* We assume the packet has already been checked by icmp_rcv */
972 
973         pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
974                  skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
975 
976         /* Push ICMP header back */
977         skb_push(skb, skb->data - (u8 *)icmph);
978 
979         sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
980         if (sk) {
981                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
982 
983                 pr_debug("rcv on socket %p\n", sk);
984                 if (skb2)
985                         ping_queue_rcv_skb(sk, skb2);
986                 sock_put(sk);
987                 return true;
988         }
989         pr_debug("no socket, dropping\n");
990 
991         return false;
992 }
993 EXPORT_SYMBOL_GPL(ping_rcv);
994 
995 struct proto ping_prot = {
996         .name =         "PING",
997         .owner =        THIS_MODULE,
998         .init =         ping_init_sock,
999         .close =        ping_close,
1000         .connect =      ip4_datagram_connect,
1001         .disconnect =   udp_disconnect,
1002         .setsockopt =   ip_setsockopt,
1003         .getsockopt =   ip_getsockopt,
1004         .sendmsg =      ping_v4_sendmsg,
1005         .recvmsg =      ping_recvmsg,
1006         .bind =         ping_bind,
1007         .backlog_rcv =  ping_queue_rcv_skb,
1008         .release_cb =   ip4_datagram_release_cb,
1009         .hash =         ping_hash,
1010         .unhash =       ping_unhash,
1011         .get_port =     ping_get_port,
1012         .obj_size =     sizeof(struct inet_sock),
1013 };
1014 EXPORT_SYMBOL(ping_prot);
1015 
1016 #ifdef CONFIG_PROC_FS
1017 
1018 static struct sock *ping_get_first(struct seq_file *seq, int start)
1019 {
1020         struct sock *sk;
1021         struct ping_iter_state *state = seq->private;
1022         struct net *net = seq_file_net(seq);
1023 
1024         for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
1025              ++state->bucket) {
1026                 struct hlist_nulls_node *node;
1027                 struct hlist_nulls_head *hslot;
1028 
1029                 hslot = &ping_table.hash[state->bucket];
1030 
1031                 if (hlist_nulls_empty(hslot))
1032                         continue;
1033 
1034                 sk_nulls_for_each(sk, node, hslot) {
1035                         if (net_eq(sock_net(sk), net) &&
1036                             sk->sk_family == state->family)
1037                                 goto found;
1038                 }
1039         }
1040         sk = NULL;
1041 found:
1042         return sk;
1043 }
1044 
1045 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
1046 {
1047         struct ping_iter_state *state = seq->private;
1048         struct net *net = seq_file_net(seq);
1049 
1050         do {
1051                 sk = sk_nulls_next(sk);
1052         } while (sk && (!net_eq(sock_net(sk), net)));
1053 
1054         if (!sk)
1055                 return ping_get_first(seq, state->bucket + 1);
1056         return sk;
1057 }
1058 
1059 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
1060 {
1061         struct sock *sk = ping_get_first(seq, 0);
1062 
1063         if (sk)
1064                 while (pos && (sk = ping_get_next(seq, sk)) != NULL)
1065                         --pos;
1066         return pos ? NULL : sk;
1067 }
1068 
1069 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
1070         __acquires(ping_table.lock)
1071 {
1072         struct ping_iter_state *state = seq->private;
1073         state->bucket = 0;
1074         state->family = family;
1075 
1076         read_lock_bh(&ping_table.lock);
1077 
1078         return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1079 }
1080 EXPORT_SYMBOL_GPL(ping_seq_start);
1081 
1082 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos)
1083 {
1084         return ping_seq_start(seq, pos, AF_INET);
1085 }
1086 
1087 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1088 {
1089         struct sock *sk;
1090 
1091         if (v == SEQ_START_TOKEN)
1092                 sk = ping_get_idx(seq, 0);
1093         else
1094                 sk = ping_get_next(seq, v);
1095 
1096         ++*pos;
1097         return sk;
1098 }
1099 EXPORT_SYMBOL_GPL(ping_seq_next);
1100 
1101 void ping_seq_stop(struct seq_file *seq, void *v)
1102         __releases(ping_table.lock)
1103 {
1104         read_unlock_bh(&ping_table.lock);
1105 }
1106 EXPORT_SYMBOL_GPL(ping_seq_stop);
1107 
1108 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f,
1109                 int bucket)
1110 {
1111         struct inet_sock *inet = inet_sk(sp);
1112         __be32 dest = inet->inet_daddr;
1113         __be32 src = inet->inet_rcv_saddr;
1114         __u16 destp = ntohs(inet->inet_dport);
1115         __u16 srcp = ntohs(inet->inet_sport);
1116 
1117         seq_printf(f, "%5d: %08X:%04X %08X:%04X"
1118                 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d",
1119                 bucket, src, srcp, dest, destp, sp->sk_state,
1120                 sk_wmem_alloc_get(sp),
1121                 sk_rmem_alloc_get(sp),
1122                 0, 0L, 0,
1123                 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
1124                 0, sock_i_ino(sp),
1125                 atomic_read(&sp->sk_refcnt), sp,
1126                 atomic_read(&sp->sk_drops));
1127 }
1128 
1129 static int ping_v4_seq_show(struct seq_file *seq, void *v)
1130 {
1131         seq_setwidth(seq, 127);
1132         if (v == SEQ_START_TOKEN)
1133                 seq_puts(seq, "  sl  local_address rem_address   st tx_queue "
1134                            "rx_queue tr tm->when retrnsmt   uid  timeout "
1135                            "inode ref pointer drops");
1136         else {
1137                 struct ping_iter_state *state = seq->private;
1138 
1139                 ping_v4_format_sock(v, seq, state->bucket);
1140         }
1141         seq_pad(seq, '\n');
1142         return 0;
1143 }
1144 
1145 static int ping_seq_open(struct inode *inode, struct file *file)
1146 {
1147         struct ping_seq_afinfo *afinfo = PDE_DATA(inode);
1148         return seq_open_net(inode, file, &afinfo->seq_ops,
1149                            sizeof(struct ping_iter_state));
1150 }
1151 
1152 const struct file_operations ping_seq_fops = {
1153         .open           = ping_seq_open,
1154         .read           = seq_read,
1155         .llseek         = seq_lseek,
1156         .release        = seq_release_net,
1157 };
1158 EXPORT_SYMBOL_GPL(ping_seq_fops);
1159 
1160 static struct ping_seq_afinfo ping_v4_seq_afinfo = {
1161         .name           = "icmp",
1162         .family         = AF_INET,
1163         .seq_fops       = &ping_seq_fops,
1164         .seq_ops        = {
1165                 .start          = ping_v4_seq_start,
1166                 .show           = ping_v4_seq_show,
1167                 .next           = ping_seq_next,
1168                 .stop           = ping_seq_stop,
1169         },
1170 };
1171 
1172 int ping_proc_register(struct net *net, struct ping_seq_afinfo *afinfo)
1173 {
1174         struct proc_dir_entry *p;
1175         p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
1176                              afinfo->seq_fops, afinfo);
1177         if (!p)
1178                 return -ENOMEM;
1179         return 0;
1180 }
1181 EXPORT_SYMBOL_GPL(ping_proc_register);
1182 
1183 void ping_proc_unregister(struct net *net, struct ping_seq_afinfo *afinfo)
1184 {
1185         remove_proc_entry(afinfo->name, net->proc_net);
1186 }
1187 EXPORT_SYMBOL_GPL(ping_proc_unregister);
1188 
1189 static int __net_init ping_v4_proc_init_net(struct net *net)
1190 {
1191         return ping_proc_register(net, &ping_v4_seq_afinfo);
1192 }
1193 
1194 static void __net_exit ping_v4_proc_exit_net(struct net *net)
1195 {
1196         ping_proc_unregister(net, &ping_v4_seq_afinfo);
1197 }
1198 
1199 static struct pernet_operations ping_v4_net_ops = {
1200         .init = ping_v4_proc_init_net,
1201         .exit = ping_v4_proc_exit_net,
1202 };
1203 
1204 int __init ping_proc_init(void)
1205 {
1206         return register_pernet_subsys(&ping_v4_net_ops);
1207 }
1208 
1209 void ping_proc_exit(void)
1210 {
1211         unregister_pernet_subsys(&ping_v4_net_ops);
1212 }
1213 
1214 #endif
1215 
1216 void __init ping_init(void)
1217 {
1218         int i;
1219 
1220         for (i = 0; i < PING_HTABLE_SIZE; i++)
1221                 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i);
1222         rwlock_init(&ping_table.lock);
1223 }
1224 

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