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 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                 sk_nulls_node_init(&sk->sk_nulls_node);
162                 sock_put(sk);
163                 isk->inet_num = 0;
164                 isk->inet_sport = 0;
165                 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
166                 write_unlock_bh(&ping_table.lock);
167         }
168 }
169 EXPORT_SYMBOL_GPL(ping_unhash);
170 
171 static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
172 {
173         struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident);
174         struct sock *sk = NULL;
175         struct inet_sock *isk;
176         struct hlist_nulls_node *hnode;
177         int dif = skb->dev->ifindex;
178 
179         if (skb->protocol == htons(ETH_P_IP)) {
180                 pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n",
181                          (int)ident, &ip_hdr(skb)->daddr, dif);
182 #if IS_ENABLED(CONFIG_IPV6)
183         } else if (skb->protocol == htons(ETH_P_IPV6)) {
184                 pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n",
185                          (int)ident, &ipv6_hdr(skb)->daddr, dif);
186 #endif
187         }
188 
189         read_lock_bh(&ping_table.lock);
190 
191         ping_portaddr_for_each_entry(sk, hnode, hslot) {
192                 isk = inet_sk(sk);
193 
194                 pr_debug("iterate\n");
195                 if (isk->inet_num != ident)
196                         continue;
197 
198                 if (skb->protocol == htons(ETH_P_IP) &&
199                     sk->sk_family == AF_INET) {
200                         pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk,
201                                  (int) isk->inet_num, &isk->inet_rcv_saddr,
202                                  sk->sk_bound_dev_if);
203 
204                         if (isk->inet_rcv_saddr &&
205                             isk->inet_rcv_saddr != ip_hdr(skb)->daddr)
206                                 continue;
207 #if IS_ENABLED(CONFIG_IPV6)
208                 } else if (skb->protocol == htons(ETH_P_IPV6) &&
209                            sk->sk_family == AF_INET6) {
210 
211                         pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk,
212                                  (int) isk->inet_num,
213                                  &sk->sk_v6_rcv_saddr,
214                                  sk->sk_bound_dev_if);
215 
216                         if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
217                             !ipv6_addr_equal(&sk->sk_v6_rcv_saddr,
218                                              &ipv6_hdr(skb)->daddr))
219                                 continue;
220 #endif
221                 } else {
222                         continue;
223                 }
224 
225                 if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)
226                         continue;
227 
228                 sock_hold(sk);
229                 goto exit;
230         }
231 
232         sk = NULL;
233 exit:
234         read_unlock_bh(&ping_table.lock);
235 
236         return sk;
237 }
238 
239 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low,
240                                           kgid_t *high)
241 {
242         kgid_t *data = net->ipv4.ping_group_range.range;
243         unsigned int seq;
244 
245         do {
246                 seq = read_seqbegin(&net->ipv4.ping_group_range.lock);
247 
248                 *low = data[0];
249                 *high = data[1];
250         } while (read_seqretry(&net->ipv4.ping_group_range.lock, seq));
251 }
252 
253 
254 int ping_init_sock(struct sock *sk)
255 {
256         struct net *net = sock_net(sk);
257         kgid_t group = current_egid();
258         struct group_info *group_info;
259         int i, j, count;
260         kgid_t low, high;
261         int ret = 0;
262 
263         if (sk->sk_family == AF_INET6)
264                 sk->sk_ipv6only = 1;
265 
266         inet_get_ping_group_range_net(net, &low, &high);
267         if (gid_lte(low, group) && gid_lte(group, high))
268                 return 0;
269 
270         group_info = get_current_groups();
271         count = group_info->ngroups;
272         for (i = 0; i < group_info->nblocks; i++) {
273                 int cp_count = min_t(int, NGROUPS_PER_BLOCK, count);
274                 for (j = 0; j < cp_count; j++) {
275                         kgid_t gid = group_info->blocks[i][j];
276                         if (gid_lte(low, gid) && gid_lte(gid, high))
277                                 goto out_release_group;
278                 }
279 
280                 count -= cp_count;
281         }
282 
283         ret = -EACCES;
284 
285 out_release_group:
286         put_group_info(group_info);
287         return ret;
288 }
289 EXPORT_SYMBOL_GPL(ping_init_sock);
290 
291 void ping_close(struct sock *sk, long timeout)
292 {
293         pr_debug("ping_close(sk=%p,sk->num=%u)\n",
294                  inet_sk(sk), inet_sk(sk)->inet_num);
295         pr_debug("isk->refcnt = %d\n", sk->sk_refcnt.counter);
296 
297         sk_common_release(sk);
298 }
299 EXPORT_SYMBOL_GPL(ping_close);
300 
301 /* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */
302 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
303                                 struct sockaddr *uaddr, int addr_len) {
304         struct net *net = sock_net(sk);
305         if (sk->sk_family == AF_INET) {
306                 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
307                 int chk_addr_ret;
308 
309                 if (addr_len < sizeof(*addr))
310                         return -EINVAL;
311 
312                 if (addr->sin_family != AF_INET &&
313                     !(addr->sin_family == AF_UNSPEC &&
314                       addr->sin_addr.s_addr == htonl(INADDR_ANY)))
315                         return -EAFNOSUPPORT;
316 
317                 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",
318                          sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
319 
320                 chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
321 
322                 if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
323                         chk_addr_ret = RTN_LOCAL;
324 
325                 if ((net->ipv4.sysctl_ip_nonlocal_bind == 0 &&
326                     isk->freebind == 0 && isk->transparent == 0 &&
327                      chk_addr_ret != RTN_LOCAL) ||
328                     chk_addr_ret == RTN_MULTICAST ||
329                     chk_addr_ret == RTN_BROADCAST)
330                         return -EADDRNOTAVAIL;
331 
332 #if IS_ENABLED(CONFIG_IPV6)
333         } else if (sk->sk_family == AF_INET6) {
334                 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
335                 int addr_type, scoped, has_addr;
336                 struct net_device *dev = NULL;
337 
338                 if (addr_len < sizeof(*addr))
339                         return -EINVAL;
340 
341                 if (addr->sin6_family != AF_INET6)
342                         return -EAFNOSUPPORT;
343 
344                 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n",
345                          sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port));
346 
347                 addr_type = ipv6_addr_type(&addr->sin6_addr);
348                 scoped = __ipv6_addr_needs_scope_id(addr_type);
349                 if ((addr_type != IPV6_ADDR_ANY &&
350                      !(addr_type & IPV6_ADDR_UNICAST)) ||
351                     (scoped && !addr->sin6_scope_id))
352                         return -EINVAL;
353 
354                 rcu_read_lock();
355                 if (addr->sin6_scope_id) {
356                         dev = dev_get_by_index_rcu(net, addr->sin6_scope_id);
357                         if (!dev) {
358                                 rcu_read_unlock();
359                                 return -ENODEV;
360                         }
361                 }
362                 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev,
363                                                     scoped);
364                 rcu_read_unlock();
365 
366                 if (!(net->ipv6.sysctl.ip_nonlocal_bind ||
367                       isk->freebind || isk->transparent || has_addr ||
368                       addr_type == IPV6_ADDR_ANY))
369                         return -EADDRNOTAVAIL;
370 
371                 if (scoped)
372                         sk->sk_bound_dev_if = addr->sin6_scope_id;
373 #endif
374         } else {
375                 return -EAFNOSUPPORT;
376         }
377         return 0;
378 }
379 
380 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr)
381 {
382         if (saddr->sa_family == AF_INET) {
383                 struct inet_sock *isk = inet_sk(sk);
384                 struct sockaddr_in *addr = (struct sockaddr_in *) saddr;
385                 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
386 #if IS_ENABLED(CONFIG_IPV6)
387         } else if (saddr->sa_family == AF_INET6) {
388                 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr;
389                 struct ipv6_pinfo *np = inet6_sk(sk);
390                 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr;
391 #endif
392         }
393 }
394 
395 static void ping_clear_saddr(struct sock *sk, int dif)
396 {
397         sk->sk_bound_dev_if = dif;
398         if (sk->sk_family == AF_INET) {
399                 struct inet_sock *isk = inet_sk(sk);
400                 isk->inet_rcv_saddr = isk->inet_saddr = 0;
401 #if IS_ENABLED(CONFIG_IPV6)
402         } else if (sk->sk_family == AF_INET6) {
403                 struct ipv6_pinfo *np = inet6_sk(sk);
404                 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
405                 memset(&np->saddr, 0, sizeof(np->saddr));
406 #endif
407         }
408 }
409 /*
410  * We need our own bind because there are no privileged id's == local ports.
411  * Moreover, we don't allow binding to multi- and broadcast addresses.
412  */
413 
414 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
415 {
416         struct inet_sock *isk = inet_sk(sk);
417         unsigned short snum;
418         int err;
419         int dif = sk->sk_bound_dev_if;
420 
421         err = ping_check_bind_addr(sk, isk, uaddr, addr_len);
422         if (err)
423                 return err;
424 
425         lock_sock(sk);
426 
427         err = -EINVAL;
428         if (isk->inet_num != 0)
429                 goto out;
430 
431         err = -EADDRINUSE;
432         ping_set_saddr(sk, uaddr);
433         snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port);
434         if (ping_get_port(sk, snum) != 0) {
435                 ping_clear_saddr(sk, dif);
436                 goto out;
437         }
438 
439         pr_debug("after bind(): num = %d, dif = %d\n",
440                  (int)isk->inet_num,
441                  (int)sk->sk_bound_dev_if);
442 
443         err = 0;
444         if (sk->sk_family == AF_INET && isk->inet_rcv_saddr)
445                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
446 #if IS_ENABLED(CONFIG_IPV6)
447         if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr))
448                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
449 #endif
450 
451         if (snum)
452                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
453         isk->inet_sport = htons(isk->inet_num);
454         isk->inet_daddr = 0;
455         isk->inet_dport = 0;
456 
457 #if IS_ENABLED(CONFIG_IPV6)
458         if (sk->sk_family == AF_INET6)
459                 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr));
460 #endif
461 
462         sk_dst_reset(sk);
463 out:
464         release_sock(sk);
465         pr_debug("ping_v4_bind -> %d\n", err);
466         return err;
467 }
468 EXPORT_SYMBOL_GPL(ping_bind);
469 
470 /*
471  * Is this a supported type of ICMP message?
472  */
473 
474 static inline int ping_supported(int family, int type, int code)
475 {
476         return (family == AF_INET && type == ICMP_ECHO && code == 0) ||
477                (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0);
478 }
479 
480 /*
481  * This routine is called by the ICMP module when it gets some
482  * sort of error condition.
483  */
484 
485 void ping_err(struct sk_buff *skb, int offset, u32 info)
486 {
487         int family;
488         struct icmphdr *icmph;
489         struct inet_sock *inet_sock;
490         int type;
491         int code;
492         struct net *net = dev_net(skb->dev);
493         struct sock *sk;
494         int harderr;
495         int err;
496 
497         if (skb->protocol == htons(ETH_P_IP)) {
498                 family = AF_INET;
499                 type = icmp_hdr(skb)->type;
500                 code = icmp_hdr(skb)->code;
501                 icmph = (struct icmphdr *)(skb->data + offset);
502         } else if (skb->protocol == htons(ETH_P_IPV6)) {
503                 family = AF_INET6;
504                 type = icmp6_hdr(skb)->icmp6_type;
505                 code = icmp6_hdr(skb)->icmp6_code;
506                 icmph = (struct icmphdr *) (skb->data + offset);
507         } else {
508                 BUG();
509         }
510 
511         /* We assume the packet has already been checked by icmp_unreach */
512 
513         if (!ping_supported(family, icmph->type, icmph->code))
514                 return;
515 
516         pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n",
517                  skb->protocol, type, code, ntohs(icmph->un.echo.id),
518                  ntohs(icmph->un.echo.sequence));
519 
520         sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
521         if (!sk) {
522                 pr_debug("no socket, dropping\n");
523                 return; /* No socket for error */
524         }
525         pr_debug("err on socket %p\n", sk);
526 
527         err = 0;
528         harderr = 0;
529         inet_sock = inet_sk(sk);
530 
531         if (skb->protocol == htons(ETH_P_IP)) {
532                 switch (type) {
533                 default:
534                 case ICMP_TIME_EXCEEDED:
535                         err = EHOSTUNREACH;
536                         break;
537                 case ICMP_SOURCE_QUENCH:
538                         /* This is not a real error but ping wants to see it.
539                          * Report it with some fake errno.
540                          */
541                         err = EREMOTEIO;
542                         break;
543                 case ICMP_PARAMETERPROB:
544                         err = EPROTO;
545                         harderr = 1;
546                         break;
547                 case ICMP_DEST_UNREACH:
548                         if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
549                                 ipv4_sk_update_pmtu(skb, sk, info);
550                                 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) {
551                                         err = EMSGSIZE;
552                                         harderr = 1;
553                                         break;
554                                 }
555                                 goto out;
556                         }
557                         err = EHOSTUNREACH;
558                         if (code <= NR_ICMP_UNREACH) {
559                                 harderr = icmp_err_convert[code].fatal;
560                                 err = icmp_err_convert[code].errno;
561                         }
562                         break;
563                 case ICMP_REDIRECT:
564                         /* See ICMP_SOURCE_QUENCH */
565                         ipv4_sk_redirect(skb, sk);
566                         err = EREMOTEIO;
567                         break;
568                 }
569 #if IS_ENABLED(CONFIG_IPV6)
570         } else if (skb->protocol == htons(ETH_P_IPV6)) {
571                 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err);
572 #endif
573         }
574 
575         /*
576          *      RFC1122: OK.  Passes ICMP errors back to application, as per
577          *      4.1.3.3.
578          */
579         if ((family == AF_INET && !inet_sock->recverr) ||
580             (family == AF_INET6 && !inet6_sk(sk)->recverr)) {
581                 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
582                         goto out;
583         } else {
584                 if (family == AF_INET) {
585                         ip_icmp_error(sk, skb, err, 0 /* no remote port */,
586                                       info, (u8 *)icmph);
587 #if IS_ENABLED(CONFIG_IPV6)
588                 } else if (family == AF_INET6) {
589                         pingv6_ops.ipv6_icmp_error(sk, skb, err, 0,
590                                                    info, (u8 *)icmph);
591 #endif
592                 }
593         }
594         sk->sk_err = err;
595         sk->sk_error_report(sk);
596 out:
597         sock_put(sk);
598 }
599 EXPORT_SYMBOL_GPL(ping_err);
600 
601 /*
602  *      Copy and checksum an ICMP Echo packet from user space into a buffer
603  *      starting from the payload.
604  */
605 
606 int ping_getfrag(void *from, char *to,
607                  int offset, int fraglen, int odd, struct sk_buff *skb)
608 {
609         struct pingfakehdr *pfh = (struct pingfakehdr *)from;
610 
611         if (offset == 0) {
612                 fraglen -= sizeof(struct icmphdr);
613                 if (fraglen < 0)
614                         BUG();
615                 if (csum_and_copy_from_iter(to + sizeof(struct icmphdr),
616                             fraglen, &pfh->wcheck,
617                             &pfh->msg->msg_iter) != fraglen)
618                         return -EFAULT;
619         } else if (offset < sizeof(struct icmphdr)) {
620                         BUG();
621         } else {
622                 if (csum_and_copy_from_iter(to, fraglen, &pfh->wcheck,
623                                             &pfh->msg->msg_iter) != fraglen)
624                         return -EFAULT;
625         }
626 
627 #if IS_ENABLED(CONFIG_IPV6)
628         /* For IPv6, checksum each skb as we go along, as expected by
629          * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in
630          * wcheck, it will be finalized in ping_v4_push_pending_frames.
631          */
632         if (pfh->family == AF_INET6) {
633                 skb->csum = pfh->wcheck;
634                 skb->ip_summed = CHECKSUM_NONE;
635                 pfh->wcheck = 0;
636         }
637 #endif
638 
639         return 0;
640 }
641 EXPORT_SYMBOL_GPL(ping_getfrag);
642 
643 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
644                                        struct flowi4 *fl4)
645 {
646         struct sk_buff *skb = skb_peek(&sk->sk_write_queue);
647 
648         pfh->wcheck = csum_partial((char *)&pfh->icmph,
649                 sizeof(struct icmphdr), pfh->wcheck);
650         pfh->icmph.checksum = csum_fold(pfh->wcheck);
651         memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
652         skb->ip_summed = CHECKSUM_NONE;
653         return ip_push_pending_frames(sk, fl4);
654 }
655 
656 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
657                         void *user_icmph, size_t icmph_len) {
658         u8 type, code;
659 
660         if (len > 0xFFFF)
661                 return -EMSGSIZE;
662 
663         /*
664          *      Check the flags.
665          */
666 
667         /* Mirror BSD error message compatibility */
668         if (msg->msg_flags & MSG_OOB)
669                 return -EOPNOTSUPP;
670 
671         /*
672          *      Fetch the ICMP header provided by the userland.
673          *      iovec is modified! The ICMP header is consumed.
674          */
675         if (memcpy_from_msg(user_icmph, msg, icmph_len))
676                 return -EFAULT;
677 
678         if (family == AF_INET) {
679                 type = ((struct icmphdr *) user_icmph)->type;
680                 code = ((struct icmphdr *) user_icmph)->code;
681 #if IS_ENABLED(CONFIG_IPV6)
682         } else if (family == AF_INET6) {
683                 type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
684                 code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
685 #endif
686         } else {
687                 BUG();
688         }
689 
690         if (!ping_supported(family, type, code))
691                 return -EINVAL;
692 
693         return 0;
694 }
695 EXPORT_SYMBOL_GPL(ping_common_sendmsg);
696 
697 static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
698 {
699         struct net *net = sock_net(sk);
700         struct flowi4 fl4;
701         struct inet_sock *inet = inet_sk(sk);
702         struct ipcm_cookie ipc;
703         struct icmphdr user_icmph;
704         struct pingfakehdr pfh;
705         struct rtable *rt = NULL;
706         struct ip_options_data opt_copy;
707         int free = 0;
708         __be32 saddr, daddr, faddr;
709         u8  tos;
710         int err;
711 
712         pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
713 
714         err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
715                                   sizeof(user_icmph));
716         if (err)
717                 return err;
718 
719         /*
720          *      Get and verify the address.
721          */
722 
723         if (msg->msg_name) {
724                 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
725                 if (msg->msg_namelen < sizeof(*usin))
726                         return -EINVAL;
727                 if (usin->sin_family != AF_INET)
728                         return -EAFNOSUPPORT;
729                 daddr = usin->sin_addr.s_addr;
730                 /* no remote port */
731         } else {
732                 if (sk->sk_state != TCP_ESTABLISHED)
733                         return -EDESTADDRREQ;
734                 daddr = inet->inet_daddr;
735                 /* no remote port */
736         }
737 
738         ipc.addr = inet->inet_saddr;
739         ipc.opt = NULL;
740         ipc.oif = sk->sk_bound_dev_if;
741         ipc.tx_flags = 0;
742         ipc.ttl = 0;
743         ipc.tos = -1;
744 
745         sock_tx_timestamp(sk, &ipc.tx_flags);
746 
747         if (msg->msg_controllen) {
748                 err = ip_cmsg_send(sock_net(sk), msg, &ipc, false);
749                 if (unlikely(err)) {
750                         kfree(ipc.opt);
751                         return err;
752                 }
753                 if (ipc.opt)
754                         free = 1;
755         }
756         if (!ipc.opt) {
757                 struct ip_options_rcu *inet_opt;
758 
759                 rcu_read_lock();
760                 inet_opt = rcu_dereference(inet->inet_opt);
761                 if (inet_opt) {
762                         memcpy(&opt_copy, inet_opt,
763                                sizeof(*inet_opt) + inet_opt->opt.optlen);
764                         ipc.opt = &opt_copy.opt;
765                 }
766                 rcu_read_unlock();
767         }
768 
769         saddr = ipc.addr;
770         ipc.addr = faddr = daddr;
771 
772         if (ipc.opt && ipc.opt->opt.srr) {
773                 if (!daddr)
774                         return -EINVAL;
775                 faddr = ipc.opt->opt.faddr;
776         }
777         tos = get_rttos(&ipc, inet);
778         if (sock_flag(sk, SOCK_LOCALROUTE) ||
779             (msg->msg_flags & MSG_DONTROUTE) ||
780             (ipc.opt && ipc.opt->opt.is_strictroute)) {
781                 tos |= RTO_ONLINK;
782         }
783 
784         if (ipv4_is_multicast(daddr)) {
785                 if (!ipc.oif)
786                         ipc.oif = inet->mc_index;
787                 if (!saddr)
788                         saddr = inet->mc_addr;
789         } else if (!ipc.oif)
790                 ipc.oif = inet->uc_index;
791 
792         flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
793                            RT_SCOPE_UNIVERSE, sk->sk_protocol,
794                            inet_sk_flowi_flags(sk), faddr, saddr, 0, 0);
795 
796         security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
797         rt = ip_route_output_flow(net, &fl4, sk);
798         if (IS_ERR(rt)) {
799                 err = PTR_ERR(rt);
800                 rt = NULL;
801                 if (err == -ENETUNREACH)
802                         IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
803                 goto out;
804         }
805 
806         err = -EACCES;
807         if ((rt->rt_flags & RTCF_BROADCAST) &&
808             !sock_flag(sk, SOCK_BROADCAST))
809                 goto out;
810 
811         if (msg->msg_flags & MSG_CONFIRM)
812                 goto do_confirm;
813 back_from_confirm:
814 
815         if (!ipc.addr)
816                 ipc.addr = fl4.daddr;
817 
818         lock_sock(sk);
819 
820         pfh.icmph.type = user_icmph.type; /* already checked */
821         pfh.icmph.code = user_icmph.code; /* ditto */
822         pfh.icmph.checksum = 0;
823         pfh.icmph.un.echo.id = inet->inet_sport;
824         pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
825         pfh.msg = msg;
826         pfh.wcheck = 0;
827         pfh.family = AF_INET;
828 
829         err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
830                         0, &ipc, &rt, msg->msg_flags);
831         if (err)
832                 ip_flush_pending_frames(sk);
833         else
834                 err = ping_v4_push_pending_frames(sk, &pfh, &fl4);
835         release_sock(sk);
836 
837 out:
838         ip_rt_put(rt);
839         if (free)
840                 kfree(ipc.opt);
841         if (!err) {
842                 icmp_out_count(sock_net(sk), user_icmph.type);
843                 return len;
844         }
845         return err;
846 
847 do_confirm:
848         dst_confirm(&rt->dst);
849         if (!(msg->msg_flags & MSG_PROBE) || len)
850                 goto back_from_confirm;
851         err = 0;
852         goto out;
853 }
854 
855 int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock,
856                  int flags, int *addr_len)
857 {
858         struct inet_sock *isk = inet_sk(sk);
859         int family = sk->sk_family;
860         struct sk_buff *skb;
861         int copied, err;
862 
863         pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
864 
865         err = -EOPNOTSUPP;
866         if (flags & MSG_OOB)
867                 goto out;
868 
869         if (flags & MSG_ERRQUEUE)
870                 return inet_recv_error(sk, msg, len, addr_len);
871 
872         skb = skb_recv_datagram(sk, flags, noblock, &err);
873         if (!skb)
874                 goto out;
875 
876         copied = skb->len;
877         if (copied > len) {
878                 msg->msg_flags |= MSG_TRUNC;
879                 copied = len;
880         }
881 
882         /* Don't bother checking the checksum */
883         err = skb_copy_datagram_msg(skb, 0, msg, copied);
884         if (err)
885                 goto done;
886 
887         sock_recv_timestamp(msg, sk, skb);
888 
889         /* Copy the address and add cmsg data. */
890         if (family == AF_INET) {
891                 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
892 
893                 if (sin) {
894                         sin->sin_family = AF_INET;
895                         sin->sin_port = 0 /* skb->h.uh->source */;
896                         sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
897                         memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
898                         *addr_len = sizeof(*sin);
899                 }
900 
901                 if (isk->cmsg_flags)
902                         ip_cmsg_recv(msg, skb);
903 
904 #if IS_ENABLED(CONFIG_IPV6)
905         } else if (family == AF_INET6) {
906                 struct ipv6_pinfo *np = inet6_sk(sk);
907                 struct ipv6hdr *ip6 = ipv6_hdr(skb);
908                 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
909 
910                 if (sin6) {
911                         sin6->sin6_family = AF_INET6;
912                         sin6->sin6_port = 0;
913                         sin6->sin6_addr = ip6->saddr;
914                         sin6->sin6_flowinfo = 0;
915                         if (np->sndflow)
916                                 sin6->sin6_flowinfo = ip6_flowinfo(ip6);
917                         sin6->sin6_scope_id =
918                                 ipv6_iface_scope_id(&sin6->sin6_addr,
919                                                     inet6_iif(skb));
920                         *addr_len = sizeof(*sin6);
921                 }
922 
923                 if (inet6_sk(sk)->rxopt.all)
924                         pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb);
925                 if (skb->protocol == htons(ETH_P_IPV6) &&
926                     inet6_sk(sk)->rxopt.all)
927                         pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb);
928                 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags)
929                         ip_cmsg_recv(msg, skb);
930 #endif
931         } else {
932                 BUG();
933         }
934 
935         err = copied;
936 
937 done:
938         skb_free_datagram(sk, skb);
939 out:
940         pr_debug("ping_recvmsg -> %d\n", err);
941         return err;
942 }
943 EXPORT_SYMBOL_GPL(ping_recvmsg);
944 
945 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
946 {
947         pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
948                  inet_sk(sk), inet_sk(sk)->inet_num, skb);
949         if (sock_queue_rcv_skb(sk, skb) < 0) {
950                 kfree_skb(skb);
951                 pr_debug("ping_queue_rcv_skb -> failed\n");
952                 return -1;
953         }
954         return 0;
955 }
956 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
957 
958 
959 /*
960  *      All we need to do is get the socket.
961  */
962 
963 bool ping_rcv(struct sk_buff *skb)
964 {
965         struct sock *sk;
966         struct net *net = dev_net(skb->dev);
967         struct icmphdr *icmph = icmp_hdr(skb);
968 
969         /* We assume the packet has already been checked by icmp_rcv */
970 
971         pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
972                  skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
973 
974         /* Push ICMP header back */
975         skb_push(skb, skb->data - (u8 *)icmph);
976 
977         sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
978         if (sk) {
979                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
980 
981                 pr_debug("rcv on socket %p\n", sk);
982                 if (skb2)
983                         ping_queue_rcv_skb(sk, skb2);
984                 sock_put(sk);
985                 return true;
986         }
987         pr_debug("no socket, dropping\n");
988 
989         return false;
990 }
991 EXPORT_SYMBOL_GPL(ping_rcv);
992 
993 struct proto ping_prot = {
994         .name =         "PING",
995         .owner =        THIS_MODULE,
996         .init =         ping_init_sock,
997         .close =        ping_close,
998         .connect =      ip4_datagram_connect,
999         .disconnect =   udp_disconnect,
1000         .setsockopt =   ip_setsockopt,
1001         .getsockopt =   ip_getsockopt,
1002         .sendmsg =      ping_v4_sendmsg,
1003         .recvmsg =      ping_recvmsg,
1004         .bind =         ping_bind,
1005         .backlog_rcv =  ping_queue_rcv_skb,
1006         .release_cb =   ip4_datagram_release_cb,
1007         .hash =         ping_hash,
1008         .unhash =       ping_unhash,
1009         .get_port =     ping_get_port,
1010         .obj_size =     sizeof(struct inet_sock),
1011 };
1012 EXPORT_SYMBOL(ping_prot);
1013 
1014 #ifdef CONFIG_PROC_FS
1015 
1016 static struct sock *ping_get_first(struct seq_file *seq, int start)
1017 {
1018         struct sock *sk;
1019         struct ping_iter_state *state = seq->private;
1020         struct net *net = seq_file_net(seq);
1021 
1022         for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
1023              ++state->bucket) {
1024                 struct hlist_nulls_node *node;
1025                 struct hlist_nulls_head *hslot;
1026 
1027                 hslot = &ping_table.hash[state->bucket];
1028 
1029                 if (hlist_nulls_empty(hslot))
1030                         continue;
1031 
1032                 sk_nulls_for_each(sk, node, hslot) {
1033                         if (net_eq(sock_net(sk), net) &&
1034                             sk->sk_family == state->family)
1035                                 goto found;
1036                 }
1037         }
1038         sk = NULL;
1039 found:
1040         return sk;
1041 }
1042 
1043 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
1044 {
1045         struct ping_iter_state *state = seq->private;
1046         struct net *net = seq_file_net(seq);
1047 
1048         do {
1049                 sk = sk_nulls_next(sk);
1050         } while (sk && (!net_eq(sock_net(sk), net)));
1051 
1052         if (!sk)
1053                 return ping_get_first(seq, state->bucket + 1);
1054         return sk;
1055 }
1056 
1057 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
1058 {
1059         struct sock *sk = ping_get_first(seq, 0);
1060 
1061         if (sk)
1062                 while (pos && (sk = ping_get_next(seq, sk)) != NULL)
1063                         --pos;
1064         return pos ? NULL : sk;
1065 }
1066 
1067 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
1068         __acquires(ping_table.lock)
1069 {
1070         struct ping_iter_state *state = seq->private;
1071         state->bucket = 0;
1072         state->family = family;
1073 
1074         read_lock_bh(&ping_table.lock);
1075 
1076         return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1077 }
1078 EXPORT_SYMBOL_GPL(ping_seq_start);
1079 
1080 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos)
1081 {
1082         return ping_seq_start(seq, pos, AF_INET);
1083 }
1084 
1085 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1086 {
1087         struct sock *sk;
1088 
1089         if (v == SEQ_START_TOKEN)
1090                 sk = ping_get_idx(seq, 0);
1091         else
1092                 sk = ping_get_next(seq, v);
1093 
1094         ++*pos;
1095         return sk;
1096 }
1097 EXPORT_SYMBOL_GPL(ping_seq_next);
1098 
1099 void ping_seq_stop(struct seq_file *seq, void *v)
1100         __releases(ping_table.lock)
1101 {
1102         read_unlock_bh(&ping_table.lock);
1103 }
1104 EXPORT_SYMBOL_GPL(ping_seq_stop);
1105 
1106 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f,
1107                 int bucket)
1108 {
1109         struct inet_sock *inet = inet_sk(sp);
1110         __be32 dest = inet->inet_daddr;
1111         __be32 src = inet->inet_rcv_saddr;
1112         __u16 destp = ntohs(inet->inet_dport);
1113         __u16 srcp = ntohs(inet->inet_sport);
1114 
1115         seq_printf(f, "%5d: %08X:%04X %08X:%04X"
1116                 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d",
1117                 bucket, src, srcp, dest, destp, sp->sk_state,
1118                 sk_wmem_alloc_get(sp),
1119                 sk_rmem_alloc_get(sp),
1120                 0, 0L, 0,
1121                 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
1122                 0, sock_i_ino(sp),
1123                 atomic_read(&sp->sk_refcnt), sp,
1124                 atomic_read(&sp->sk_drops));
1125 }
1126 
1127 static int ping_v4_seq_show(struct seq_file *seq, void *v)
1128 {
1129         seq_setwidth(seq, 127);
1130         if (v == SEQ_START_TOKEN)
1131                 seq_puts(seq, "  sl  local_address rem_address   st tx_queue "
1132                            "rx_queue tr tm->when retrnsmt   uid  timeout "
1133                            "inode ref pointer drops");
1134         else {
1135                 struct ping_iter_state *state = seq->private;
1136 
1137                 ping_v4_format_sock(v, seq, state->bucket);
1138         }
1139         seq_pad(seq, '\n');
1140         return 0;
1141 }
1142 
1143 static const struct seq_operations ping_v4_seq_ops = {
1144         .show           = ping_v4_seq_show,
1145         .start          = ping_v4_seq_start,
1146         .next           = ping_seq_next,
1147         .stop           = ping_seq_stop,
1148 };
1149 
1150 static int ping_seq_open(struct inode *inode, struct file *file)
1151 {
1152         struct ping_seq_afinfo *afinfo = PDE_DATA(inode);
1153         return seq_open_net(inode, file, &afinfo->seq_ops,
1154                            sizeof(struct ping_iter_state));
1155 }
1156 
1157 const struct file_operations ping_seq_fops = {
1158         .open           = ping_seq_open,
1159         .read           = seq_read,
1160         .llseek         = seq_lseek,
1161         .release        = seq_release_net,
1162 };
1163 EXPORT_SYMBOL_GPL(ping_seq_fops);
1164 
1165 static struct ping_seq_afinfo ping_v4_seq_afinfo = {
1166         .name           = "icmp",
1167         .family         = AF_INET,
1168         .seq_fops       = &ping_seq_fops,
1169         .seq_ops        = {
1170                 .start          = ping_v4_seq_start,
1171                 .show           = ping_v4_seq_show,
1172                 .next           = ping_seq_next,
1173                 .stop           = ping_seq_stop,
1174         },
1175 };
1176 
1177 int ping_proc_register(struct net *net, struct ping_seq_afinfo *afinfo)
1178 {
1179         struct proc_dir_entry *p;
1180         p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
1181                              afinfo->seq_fops, afinfo);
1182         if (!p)
1183                 return -ENOMEM;
1184         return 0;
1185 }
1186 EXPORT_SYMBOL_GPL(ping_proc_register);
1187 
1188 void ping_proc_unregister(struct net *net, struct ping_seq_afinfo *afinfo)
1189 {
1190         remove_proc_entry(afinfo->name, net->proc_net);
1191 }
1192 EXPORT_SYMBOL_GPL(ping_proc_unregister);
1193 
1194 static int __net_init ping_v4_proc_init_net(struct net *net)
1195 {
1196         return ping_proc_register(net, &ping_v4_seq_afinfo);
1197 }
1198 
1199 static void __net_exit ping_v4_proc_exit_net(struct net *net)
1200 {
1201         ping_proc_unregister(net, &ping_v4_seq_afinfo);
1202 }
1203 
1204 static struct pernet_operations ping_v4_net_ops = {
1205         .init = ping_v4_proc_init_net,
1206         .exit = ping_v4_proc_exit_net,
1207 };
1208 
1209 int __init ping_proc_init(void)
1210 {
1211         return register_pernet_subsys(&ping_v4_net_ops);
1212 }
1213 
1214 void ping_proc_exit(void)
1215 {
1216         unregister_pernet_subsys(&ping_v4_net_ops);
1217 }
1218 
1219 #endif
1220 
1221 void __init ping_init(void)
1222 {
1223         int i;
1224 
1225         for (i = 0; i < PING_HTABLE_SIZE; i++)
1226                 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i);
1227         rwlock_init(&ping_table.lock);
1228 }
1229 

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