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;
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         for (i = 0; i < group_info->ngroups; i++) {
274                 kgid_t gid = group_info->gid[i];
275 
276                 if (gid_lte(low, gid) && gid_lte(gid, high))
277                         goto out_release_group;
278         }
279 
280         ret = -EACCES;
281 
282 out_release_group:
283         put_group_info(group_info);
284         return ret;
285 }
286 EXPORT_SYMBOL_GPL(ping_init_sock);
287 
288 void ping_close(struct sock *sk, long timeout)
289 {
290         pr_debug("ping_close(sk=%p,sk->num=%u)\n",
291                  inet_sk(sk), inet_sk(sk)->inet_num);
292         pr_debug("isk->refcnt = %d\n", sk->sk_refcnt.counter);
293 
294         sk_common_release(sk);
295 }
296 EXPORT_SYMBOL_GPL(ping_close);
297 
298 /* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */
299 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
300                                 struct sockaddr *uaddr, int addr_len) {
301         struct net *net = sock_net(sk);
302         if (sk->sk_family == AF_INET) {
303                 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
304                 int chk_addr_ret;
305 
306                 if (addr_len < sizeof(*addr))
307                         return -EINVAL;
308 
309                 if (addr->sin_family != AF_INET &&
310                     !(addr->sin_family == AF_UNSPEC &&
311                       addr->sin_addr.s_addr == htonl(INADDR_ANY)))
312                         return -EAFNOSUPPORT;
313 
314                 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",
315                          sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
316 
317                 chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
318 
319                 if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
320                         chk_addr_ret = RTN_LOCAL;
321 
322                 if ((net->ipv4.sysctl_ip_nonlocal_bind == 0 &&
323                     isk->freebind == 0 && isk->transparent == 0 &&
324                      chk_addr_ret != RTN_LOCAL) ||
325                     chk_addr_ret == RTN_MULTICAST ||
326                     chk_addr_ret == RTN_BROADCAST)
327                         return -EADDRNOTAVAIL;
328 
329 #if IS_ENABLED(CONFIG_IPV6)
330         } else if (sk->sk_family == AF_INET6) {
331                 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
332                 int addr_type, scoped, has_addr;
333                 struct net_device *dev = NULL;
334 
335                 if (addr_len < sizeof(*addr))
336                         return -EINVAL;
337 
338                 if (addr->sin6_family != AF_INET6)
339                         return -EAFNOSUPPORT;
340 
341                 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n",
342                          sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port));
343 
344                 addr_type = ipv6_addr_type(&addr->sin6_addr);
345                 scoped = __ipv6_addr_needs_scope_id(addr_type);
346                 if ((addr_type != IPV6_ADDR_ANY &&
347                      !(addr_type & IPV6_ADDR_UNICAST)) ||
348                     (scoped && !addr->sin6_scope_id))
349                         return -EINVAL;
350 
351                 rcu_read_lock();
352                 if (addr->sin6_scope_id) {
353                         dev = dev_get_by_index_rcu(net, addr->sin6_scope_id);
354                         if (!dev) {
355                                 rcu_read_unlock();
356                                 return -ENODEV;
357                         }
358                 }
359                 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev,
360                                                     scoped);
361                 rcu_read_unlock();
362 
363                 if (!(net->ipv6.sysctl.ip_nonlocal_bind ||
364                       isk->freebind || isk->transparent || has_addr ||
365                       addr_type == IPV6_ADDR_ANY))
366                         return -EADDRNOTAVAIL;
367 
368                 if (scoped)
369                         sk->sk_bound_dev_if = addr->sin6_scope_id;
370 #endif
371         } else {
372                 return -EAFNOSUPPORT;
373         }
374         return 0;
375 }
376 
377 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr)
378 {
379         if (saddr->sa_family == AF_INET) {
380                 struct inet_sock *isk = inet_sk(sk);
381                 struct sockaddr_in *addr = (struct sockaddr_in *) saddr;
382                 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
383 #if IS_ENABLED(CONFIG_IPV6)
384         } else if (saddr->sa_family == AF_INET6) {
385                 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr;
386                 struct ipv6_pinfo *np = inet6_sk(sk);
387                 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr;
388 #endif
389         }
390 }
391 
392 static void ping_clear_saddr(struct sock *sk, int dif)
393 {
394         sk->sk_bound_dev_if = dif;
395         if (sk->sk_family == AF_INET) {
396                 struct inet_sock *isk = inet_sk(sk);
397                 isk->inet_rcv_saddr = isk->inet_saddr = 0;
398 #if IS_ENABLED(CONFIG_IPV6)
399         } else if (sk->sk_family == AF_INET6) {
400                 struct ipv6_pinfo *np = inet6_sk(sk);
401                 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
402                 memset(&np->saddr, 0, sizeof(np->saddr));
403 #endif
404         }
405 }
406 /*
407  * We need our own bind because there are no privileged id's == local ports.
408  * Moreover, we don't allow binding to multi- and broadcast addresses.
409  */
410 
411 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
412 {
413         struct inet_sock *isk = inet_sk(sk);
414         unsigned short snum;
415         int err;
416         int dif = sk->sk_bound_dev_if;
417 
418         err = ping_check_bind_addr(sk, isk, uaddr, addr_len);
419         if (err)
420                 return err;
421 
422         lock_sock(sk);
423 
424         err = -EINVAL;
425         if (isk->inet_num != 0)
426                 goto out;
427 
428         err = -EADDRINUSE;
429         ping_set_saddr(sk, uaddr);
430         snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port);
431         if (ping_get_port(sk, snum) != 0) {
432                 ping_clear_saddr(sk, dif);
433                 goto out;
434         }
435 
436         pr_debug("after bind(): num = %d, dif = %d\n",
437                  (int)isk->inet_num,
438                  (int)sk->sk_bound_dev_if);
439 
440         err = 0;
441         if (sk->sk_family == AF_INET && isk->inet_rcv_saddr)
442                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
443 #if IS_ENABLED(CONFIG_IPV6)
444         if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr))
445                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
446 #endif
447 
448         if (snum)
449                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
450         isk->inet_sport = htons(isk->inet_num);
451         isk->inet_daddr = 0;
452         isk->inet_dport = 0;
453 
454 #if IS_ENABLED(CONFIG_IPV6)
455         if (sk->sk_family == AF_INET6)
456                 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr));
457 #endif
458 
459         sk_dst_reset(sk);
460 out:
461         release_sock(sk);
462         pr_debug("ping_v4_bind -> %d\n", err);
463         return err;
464 }
465 EXPORT_SYMBOL_GPL(ping_bind);
466 
467 /*
468  * Is this a supported type of ICMP message?
469  */
470 
471 static inline int ping_supported(int family, int type, int code)
472 {
473         return (family == AF_INET && type == ICMP_ECHO && code == 0) ||
474                (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0);
475 }
476 
477 /*
478  * This routine is called by the ICMP module when it gets some
479  * sort of error condition.
480  */
481 
482 void ping_err(struct sk_buff *skb, int offset, u32 info)
483 {
484         int family;
485         struct icmphdr *icmph;
486         struct inet_sock *inet_sock;
487         int type;
488         int code;
489         struct net *net = dev_net(skb->dev);
490         struct sock *sk;
491         int harderr;
492         int err;
493 
494         if (skb->protocol == htons(ETH_P_IP)) {
495                 family = AF_INET;
496                 type = icmp_hdr(skb)->type;
497                 code = icmp_hdr(skb)->code;
498                 icmph = (struct icmphdr *)(skb->data + offset);
499         } else if (skb->protocol == htons(ETH_P_IPV6)) {
500                 family = AF_INET6;
501                 type = icmp6_hdr(skb)->icmp6_type;
502                 code = icmp6_hdr(skb)->icmp6_code;
503                 icmph = (struct icmphdr *) (skb->data + offset);
504         } else {
505                 BUG();
506         }
507 
508         /* We assume the packet has already been checked by icmp_unreach */
509 
510         if (!ping_supported(family, icmph->type, icmph->code))
511                 return;
512 
513         pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n",
514                  skb->protocol, type, code, ntohs(icmph->un.echo.id),
515                  ntohs(icmph->un.echo.sequence));
516 
517         sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
518         if (!sk) {
519                 pr_debug("no socket, dropping\n");
520                 return; /* No socket for error */
521         }
522         pr_debug("err on socket %p\n", sk);
523 
524         err = 0;
525         harderr = 0;
526         inet_sock = inet_sk(sk);
527 
528         if (skb->protocol == htons(ETH_P_IP)) {
529                 switch (type) {
530                 default:
531                 case ICMP_TIME_EXCEEDED:
532                         err = EHOSTUNREACH;
533                         break;
534                 case ICMP_SOURCE_QUENCH:
535                         /* This is not a real error but ping wants to see it.
536                          * Report it with some fake errno.
537                          */
538                         err = EREMOTEIO;
539                         break;
540                 case ICMP_PARAMETERPROB:
541                         err = EPROTO;
542                         harderr = 1;
543                         break;
544                 case ICMP_DEST_UNREACH:
545                         if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
546                                 ipv4_sk_update_pmtu(skb, sk, info);
547                                 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) {
548                                         err = EMSGSIZE;
549                                         harderr = 1;
550                                         break;
551                                 }
552                                 goto out;
553                         }
554                         err = EHOSTUNREACH;
555                         if (code <= NR_ICMP_UNREACH) {
556                                 harderr = icmp_err_convert[code].fatal;
557                                 err = icmp_err_convert[code].errno;
558                         }
559                         break;
560                 case ICMP_REDIRECT:
561                         /* See ICMP_SOURCE_QUENCH */
562                         ipv4_sk_redirect(skb, sk);
563                         err = EREMOTEIO;
564                         break;
565                 }
566 #if IS_ENABLED(CONFIG_IPV6)
567         } else if (skb->protocol == htons(ETH_P_IPV6)) {
568                 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err);
569 #endif
570         }
571 
572         /*
573          *      RFC1122: OK.  Passes ICMP errors back to application, as per
574          *      4.1.3.3.
575          */
576         if ((family == AF_INET && !inet_sock->recverr) ||
577             (family == AF_INET6 && !inet6_sk(sk)->recverr)) {
578                 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
579                         goto out;
580         } else {
581                 if (family == AF_INET) {
582                         ip_icmp_error(sk, skb, err, 0 /* no remote port */,
583                                       info, (u8 *)icmph);
584 #if IS_ENABLED(CONFIG_IPV6)
585                 } else if (family == AF_INET6) {
586                         pingv6_ops.ipv6_icmp_error(sk, skb, err, 0,
587                                                    info, (u8 *)icmph);
588 #endif
589                 }
590         }
591         sk->sk_err = err;
592         sk->sk_error_report(sk);
593 out:
594         sock_put(sk);
595 }
596 EXPORT_SYMBOL_GPL(ping_err);
597 
598 /*
599  *      Copy and checksum an ICMP Echo packet from user space into a buffer
600  *      starting from the payload.
601  */
602 
603 int ping_getfrag(void *from, char *to,
604                  int offset, int fraglen, int odd, struct sk_buff *skb)
605 {
606         struct pingfakehdr *pfh = (struct pingfakehdr *)from;
607 
608         if (offset == 0) {
609                 fraglen -= sizeof(struct icmphdr);
610                 if (fraglen < 0)
611                         BUG();
612                 if (!csum_and_copy_from_iter_full(to + sizeof(struct icmphdr),
613                             fraglen, &pfh->wcheck,
614                             &pfh->msg->msg_iter))
615                         return -EFAULT;
616         } else if (offset < sizeof(struct icmphdr)) {
617                         BUG();
618         } else {
619                 if (!csum_and_copy_from_iter_full(to, fraglen, &pfh->wcheck,
620                                             &pfh->msg->msg_iter))
621                         return -EFAULT;
622         }
623 
624 #if IS_ENABLED(CONFIG_IPV6)
625         /* For IPv6, checksum each skb as we go along, as expected by
626          * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in
627          * wcheck, it will be finalized in ping_v4_push_pending_frames.
628          */
629         if (pfh->family == AF_INET6) {
630                 skb->csum = pfh->wcheck;
631                 skb->ip_summed = CHECKSUM_NONE;
632                 pfh->wcheck = 0;
633         }
634 #endif
635 
636         return 0;
637 }
638 EXPORT_SYMBOL_GPL(ping_getfrag);
639 
640 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
641                                        struct flowi4 *fl4)
642 {
643         struct sk_buff *skb = skb_peek(&sk->sk_write_queue);
644 
645         if (!skb)
646                 return 0;
647         pfh->wcheck = csum_partial((char *)&pfh->icmph,
648                 sizeof(struct icmphdr), pfh->wcheck);
649         pfh->icmph.checksum = csum_fold(pfh->wcheck);
650         memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
651         skb->ip_summed = CHECKSUM_NONE;
652         return ip_push_pending_frames(sk, fl4);
653 }
654 
655 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
656                         void *user_icmph, size_t icmph_len) {
657         u8 type, code;
658 
659         if (len > 0xFFFF)
660                 return -EMSGSIZE;
661 
662         /* Must have at least a full ICMP header. */
663         if (len < icmph_len)
664                 return -EINVAL;
665 
666         /*
667          *      Check the flags.
668          */
669 
670         /* Mirror BSD error message compatibility */
671         if (msg->msg_flags & MSG_OOB)
672                 return -EOPNOTSUPP;
673 
674         /*
675          *      Fetch the ICMP header provided by the userland.
676          *      iovec is modified! The ICMP header is consumed.
677          */
678         if (memcpy_from_msg(user_icmph, msg, icmph_len))
679                 return -EFAULT;
680 
681         if (family == AF_INET) {
682                 type = ((struct icmphdr *) user_icmph)->type;
683                 code = ((struct icmphdr *) user_icmph)->code;
684 #if IS_ENABLED(CONFIG_IPV6)
685         } else if (family == AF_INET6) {
686                 type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
687                 code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
688 #endif
689         } else {
690                 BUG();
691         }
692 
693         if (!ping_supported(family, type, code))
694                 return -EINVAL;
695 
696         return 0;
697 }
698 EXPORT_SYMBOL_GPL(ping_common_sendmsg);
699 
700 static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
701 {
702         struct net *net = sock_net(sk);
703         struct flowi4 fl4;
704         struct inet_sock *inet = inet_sk(sk);
705         struct ipcm_cookie ipc;
706         struct icmphdr user_icmph;
707         struct pingfakehdr pfh;
708         struct rtable *rt = NULL;
709         struct ip_options_data opt_copy;
710         int free = 0;
711         __be32 saddr, daddr, faddr;
712         u8  tos;
713         int err;
714 
715         pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
716 
717         err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
718                                   sizeof(user_icmph));
719         if (err)
720                 return err;
721 
722         /*
723          *      Get and verify the address.
724          */
725 
726         if (msg->msg_name) {
727                 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
728                 if (msg->msg_namelen < sizeof(*usin))
729                         return -EINVAL;
730                 if (usin->sin_family != AF_INET)
731                         return -EAFNOSUPPORT;
732                 daddr = usin->sin_addr.s_addr;
733                 /* no remote port */
734         } else {
735                 if (sk->sk_state != TCP_ESTABLISHED)
736                         return -EDESTADDRREQ;
737                 daddr = inet->inet_daddr;
738                 /* no remote port */
739         }
740 
741         ipc.sockc.tsflags = sk->sk_tsflags;
742         ipc.addr = inet->inet_saddr;
743         ipc.opt = NULL;
744         ipc.oif = sk->sk_bound_dev_if;
745         ipc.tx_flags = 0;
746         ipc.ttl = 0;
747         ipc.tos = -1;
748 
749         if (msg->msg_controllen) {
750                 err = ip_cmsg_send(sk, msg, &ipc, false);
751                 if (unlikely(err)) {
752                         kfree(ipc.opt);
753                         return err;
754                 }
755                 if (ipc.opt)
756                         free = 1;
757         }
758         if (!ipc.opt) {
759                 struct ip_options_rcu *inet_opt;
760 
761                 rcu_read_lock();
762                 inet_opt = rcu_dereference(inet->inet_opt);
763                 if (inet_opt) {
764                         memcpy(&opt_copy, inet_opt,
765                                sizeof(*inet_opt) + inet_opt->opt.optlen);
766                         ipc.opt = &opt_copy.opt;
767                 }
768                 rcu_read_unlock();
769         }
770 
771         sock_tx_timestamp(sk, ipc.sockc.tsflags, &ipc.tx_flags);
772 
773         saddr = ipc.addr;
774         ipc.addr = faddr = daddr;
775 
776         if (ipc.opt && ipc.opt->opt.srr) {
777                 if (!daddr)
778                         return -EINVAL;
779                 faddr = ipc.opt->opt.faddr;
780         }
781         tos = get_rttos(&ipc, inet);
782         if (sock_flag(sk, SOCK_LOCALROUTE) ||
783             (msg->msg_flags & MSG_DONTROUTE) ||
784             (ipc.opt && ipc.opt->opt.is_strictroute)) {
785                 tos |= RTO_ONLINK;
786         }
787 
788         if (ipv4_is_multicast(daddr)) {
789                 if (!ipc.oif)
790                         ipc.oif = inet->mc_index;
791                 if (!saddr)
792                         saddr = inet->mc_addr;
793         } else if (!ipc.oif)
794                 ipc.oif = inet->uc_index;
795 
796         flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
797                            RT_SCOPE_UNIVERSE, sk->sk_protocol,
798                            inet_sk_flowi_flags(sk), faddr, saddr, 0, 0,
799                            sk->sk_uid);
800 
801         security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
802         rt = ip_route_output_flow(net, &fl4, sk);
803         if (IS_ERR(rt)) {
804                 err = PTR_ERR(rt);
805                 rt = NULL;
806                 if (err == -ENETUNREACH)
807                         IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
808                 goto out;
809         }
810 
811         err = -EACCES;
812         if ((rt->rt_flags & RTCF_BROADCAST) &&
813             !sock_flag(sk, SOCK_BROADCAST))
814                 goto out;
815 
816         if (msg->msg_flags & MSG_CONFIRM)
817                 goto do_confirm;
818 back_from_confirm:
819 
820         if (!ipc.addr)
821                 ipc.addr = fl4.daddr;
822 
823         lock_sock(sk);
824 
825         pfh.icmph.type = user_icmph.type; /* already checked */
826         pfh.icmph.code = user_icmph.code; /* ditto */
827         pfh.icmph.checksum = 0;
828         pfh.icmph.un.echo.id = inet->inet_sport;
829         pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
830         pfh.msg = msg;
831         pfh.wcheck = 0;
832         pfh.family = AF_INET;
833 
834         err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
835                         0, &ipc, &rt, msg->msg_flags);
836         if (err)
837                 ip_flush_pending_frames(sk);
838         else
839                 err = ping_v4_push_pending_frames(sk, &pfh, &fl4);
840         release_sock(sk);
841 
842 out:
843         ip_rt_put(rt);
844         if (free)
845                 kfree(ipc.opt);
846         if (!err) {
847                 icmp_out_count(sock_net(sk), user_icmph.type);
848                 return len;
849         }
850         return err;
851 
852 do_confirm:
853         dst_confirm(&rt->dst);
854         if (!(msg->msg_flags & MSG_PROBE) || len)
855                 goto back_from_confirm;
856         err = 0;
857         goto out;
858 }
859 
860 int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock,
861                  int flags, int *addr_len)
862 {
863         struct inet_sock *isk = inet_sk(sk);
864         int family = sk->sk_family;
865         struct sk_buff *skb;
866         int copied, err;
867 
868         pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
869 
870         err = -EOPNOTSUPP;
871         if (flags & MSG_OOB)
872                 goto out;
873 
874         if (flags & MSG_ERRQUEUE)
875                 return inet_recv_error(sk, msg, len, addr_len);
876 
877         skb = skb_recv_datagram(sk, flags, noblock, &err);
878         if (!skb)
879                 goto out;
880 
881         copied = skb->len;
882         if (copied > len) {
883                 msg->msg_flags |= MSG_TRUNC;
884                 copied = len;
885         }
886 
887         /* Don't bother checking the checksum */
888         err = skb_copy_datagram_msg(skb, 0, msg, copied);
889         if (err)
890                 goto done;
891 
892         sock_recv_timestamp(msg, sk, skb);
893 
894         /* Copy the address and add cmsg data. */
895         if (family == AF_INET) {
896                 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
897 
898                 if (sin) {
899                         sin->sin_family = AF_INET;
900                         sin->sin_port = 0 /* skb->h.uh->source */;
901                         sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
902                         memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
903                         *addr_len = sizeof(*sin);
904                 }
905 
906                 if (isk->cmsg_flags)
907                         ip_cmsg_recv(msg, skb);
908 
909 #if IS_ENABLED(CONFIG_IPV6)
910         } else if (family == AF_INET6) {
911                 struct ipv6_pinfo *np = inet6_sk(sk);
912                 struct ipv6hdr *ip6 = ipv6_hdr(skb);
913                 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
914 
915                 if (sin6) {
916                         sin6->sin6_family = AF_INET6;
917                         sin6->sin6_port = 0;
918                         sin6->sin6_addr = ip6->saddr;
919                         sin6->sin6_flowinfo = 0;
920                         if (np->sndflow)
921                                 sin6->sin6_flowinfo = ip6_flowinfo(ip6);
922                         sin6->sin6_scope_id =
923                                 ipv6_iface_scope_id(&sin6->sin6_addr,
924                                                     inet6_iif(skb));
925                         *addr_len = sizeof(*sin6);
926                 }
927 
928                 if (inet6_sk(sk)->rxopt.all)
929                         pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb);
930                 if (skb->protocol == htons(ETH_P_IPV6) &&
931                     inet6_sk(sk)->rxopt.all)
932                         pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb);
933                 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags)
934                         ip_cmsg_recv(msg, skb);
935 #endif
936         } else {
937                 BUG();
938         }
939 
940         err = copied;
941 
942 done:
943         skb_free_datagram(sk, skb);
944 out:
945         pr_debug("ping_recvmsg -> %d\n", err);
946         return err;
947 }
948 EXPORT_SYMBOL_GPL(ping_recvmsg);
949 
950 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
951 {
952         pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
953                  inet_sk(sk), inet_sk(sk)->inet_num, skb);
954         if (sock_queue_rcv_skb(sk, skb) < 0) {
955                 kfree_skb(skb);
956                 pr_debug("ping_queue_rcv_skb -> failed\n");
957                 return -1;
958         }
959         return 0;
960 }
961 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
962 
963 
964 /*
965  *      All we need to do is get the socket.
966  */
967 
968 bool ping_rcv(struct sk_buff *skb)
969 {
970         struct sock *sk;
971         struct net *net = dev_net(skb->dev);
972         struct icmphdr *icmph = icmp_hdr(skb);
973 
974         /* We assume the packet has already been checked by icmp_rcv */
975 
976         pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
977                  skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
978 
979         /* Push ICMP header back */
980         skb_push(skb, skb->data - (u8 *)icmph);
981 
982         sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
983         if (sk) {
984                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
985 
986                 pr_debug("rcv on socket %p\n", sk);
987                 if (skb2)
988                         ping_queue_rcv_skb(sk, skb2);
989                 sock_put(sk);
990                 return true;
991         }
992         pr_debug("no socket, dropping\n");
993 
994         return false;
995 }
996 EXPORT_SYMBOL_GPL(ping_rcv);
997 
998 struct proto ping_prot = {
999         .name =         "PING",
1000         .owner =        THIS_MODULE,
1001         .init =         ping_init_sock,
1002         .close =        ping_close,
1003         .connect =      ip4_datagram_connect,
1004         .disconnect =   __udp_disconnect,
1005         .setsockopt =   ip_setsockopt,
1006         .getsockopt =   ip_getsockopt,
1007         .sendmsg =      ping_v4_sendmsg,
1008         .recvmsg =      ping_recvmsg,
1009         .bind =         ping_bind,
1010         .backlog_rcv =  ping_queue_rcv_skb,
1011         .release_cb =   ip4_datagram_release_cb,
1012         .hash =         ping_hash,
1013         .unhash =       ping_unhash,
1014         .get_port =     ping_get_port,
1015         .obj_size =     sizeof(struct inet_sock),
1016 };
1017 EXPORT_SYMBOL(ping_prot);
1018 
1019 #ifdef CONFIG_PROC_FS
1020 
1021 static struct sock *ping_get_first(struct seq_file *seq, int start)
1022 {
1023         struct sock *sk;
1024         struct ping_iter_state *state = seq->private;
1025         struct net *net = seq_file_net(seq);
1026 
1027         for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
1028              ++state->bucket) {
1029                 struct hlist_nulls_node *node;
1030                 struct hlist_nulls_head *hslot;
1031 
1032                 hslot = &ping_table.hash[state->bucket];
1033 
1034                 if (hlist_nulls_empty(hslot))
1035                         continue;
1036 
1037                 sk_nulls_for_each(sk, node, hslot) {
1038                         if (net_eq(sock_net(sk), net) &&
1039                             sk->sk_family == state->family)
1040                                 goto found;
1041                 }
1042         }
1043         sk = NULL;
1044 found:
1045         return sk;
1046 }
1047 
1048 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
1049 {
1050         struct ping_iter_state *state = seq->private;
1051         struct net *net = seq_file_net(seq);
1052 
1053         do {
1054                 sk = sk_nulls_next(sk);
1055         } while (sk && (!net_eq(sock_net(sk), net)));
1056 
1057         if (!sk)
1058                 return ping_get_first(seq, state->bucket + 1);
1059         return sk;
1060 }
1061 
1062 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
1063 {
1064         struct sock *sk = ping_get_first(seq, 0);
1065 
1066         if (sk)
1067                 while (pos && (sk = ping_get_next(seq, sk)) != NULL)
1068                         --pos;
1069         return pos ? NULL : sk;
1070 }
1071 
1072 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
1073         __acquires(ping_table.lock)
1074 {
1075         struct ping_iter_state *state = seq->private;
1076         state->bucket = 0;
1077         state->family = family;
1078 
1079         read_lock_bh(&ping_table.lock);
1080 
1081         return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1082 }
1083 EXPORT_SYMBOL_GPL(ping_seq_start);
1084 
1085 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos)
1086 {
1087         return ping_seq_start(seq, pos, AF_INET);
1088 }
1089 
1090 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1091 {
1092         struct sock *sk;
1093 
1094         if (v == SEQ_START_TOKEN)
1095                 sk = ping_get_idx(seq, 0);
1096         else
1097                 sk = ping_get_next(seq, v);
1098 
1099         ++*pos;
1100         return sk;
1101 }
1102 EXPORT_SYMBOL_GPL(ping_seq_next);
1103 
1104 void ping_seq_stop(struct seq_file *seq, void *v)
1105         __releases(ping_table.lock)
1106 {
1107         read_unlock_bh(&ping_table.lock);
1108 }
1109 EXPORT_SYMBOL_GPL(ping_seq_stop);
1110 
1111 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f,
1112                 int bucket)
1113 {
1114         struct inet_sock *inet = inet_sk(sp);
1115         __be32 dest = inet->inet_daddr;
1116         __be32 src = inet->inet_rcv_saddr;
1117         __u16 destp = ntohs(inet->inet_dport);
1118         __u16 srcp = ntohs(inet->inet_sport);
1119 
1120         seq_printf(f, "%5d: %08X:%04X %08X:%04X"
1121                 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d",
1122                 bucket, src, srcp, dest, destp, sp->sk_state,
1123                 sk_wmem_alloc_get(sp),
1124                 sk_rmem_alloc_get(sp),
1125                 0, 0L, 0,
1126                 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
1127                 0, sock_i_ino(sp),
1128                 atomic_read(&sp->sk_refcnt), sp,
1129                 atomic_read(&sp->sk_drops));
1130 }
1131 
1132 static int ping_v4_seq_show(struct seq_file *seq, void *v)
1133 {
1134         seq_setwidth(seq, 127);
1135         if (v == SEQ_START_TOKEN)
1136                 seq_puts(seq, "  sl  local_address rem_address   st tx_queue "
1137                            "rx_queue tr tm->when retrnsmt   uid  timeout "
1138                            "inode ref pointer drops");
1139         else {
1140                 struct ping_iter_state *state = seq->private;
1141 
1142                 ping_v4_format_sock(v, seq, state->bucket);
1143         }
1144         seq_pad(seq, '\n');
1145         return 0;
1146 }
1147 
1148 static int ping_seq_open(struct inode *inode, struct file *file)
1149 {
1150         struct ping_seq_afinfo *afinfo = PDE_DATA(inode);
1151         return seq_open_net(inode, file, &afinfo->seq_ops,
1152                            sizeof(struct ping_iter_state));
1153 }
1154 
1155 const struct file_operations ping_seq_fops = {
1156         .open           = ping_seq_open,
1157         .read           = seq_read,
1158         .llseek         = seq_lseek,
1159         .release        = seq_release_net,
1160 };
1161 EXPORT_SYMBOL_GPL(ping_seq_fops);
1162 
1163 static struct ping_seq_afinfo ping_v4_seq_afinfo = {
1164         .name           = "icmp",
1165         .family         = AF_INET,
1166         .seq_fops       = &ping_seq_fops,
1167         .seq_ops        = {
1168                 .start          = ping_v4_seq_start,
1169                 .show           = ping_v4_seq_show,
1170                 .next           = ping_seq_next,
1171                 .stop           = ping_seq_stop,
1172         },
1173 };
1174 
1175 int ping_proc_register(struct net *net, struct ping_seq_afinfo *afinfo)
1176 {
1177         struct proc_dir_entry *p;
1178         p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
1179                              afinfo->seq_fops, afinfo);
1180         if (!p)
1181                 return -ENOMEM;
1182         return 0;
1183 }
1184 EXPORT_SYMBOL_GPL(ping_proc_register);
1185 
1186 void ping_proc_unregister(struct net *net, struct ping_seq_afinfo *afinfo)
1187 {
1188         remove_proc_entry(afinfo->name, net->proc_net);
1189 }
1190 EXPORT_SYMBOL_GPL(ping_proc_unregister);
1191 
1192 static int __net_init ping_v4_proc_init_net(struct net *net)
1193 {
1194         return ping_proc_register(net, &ping_v4_seq_afinfo);
1195 }
1196 
1197 static void __net_exit ping_v4_proc_exit_net(struct net *net)
1198 {
1199         ping_proc_unregister(net, &ping_v4_seq_afinfo);
1200 }
1201 
1202 static struct pernet_operations ping_v4_net_ops = {
1203         .init = ping_v4_proc_init_net,
1204         .exit = ping_v4_proc_exit_net,
1205 };
1206 
1207 int __init ping_proc_init(void)
1208 {
1209         return register_pernet_subsys(&ping_v4_net_ops);
1210 }
1211 
1212 void ping_proc_exit(void)
1213 {
1214         unregister_pernet_subsys(&ping_v4_net_ops);
1215 }
1216 
1217 #endif
1218 
1219 void __init ping_init(void)
1220 {
1221         int i;
1222 
1223         for (i = 0; i < PING_HTABLE_SIZE; i++)
1224                 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i);
1225         rwlock_init(&ping_table.lock);
1226 }
1227 

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