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 (!(isk->freebind || isk->transparent || has_addr ||
367                       addr_type == IPV6_ADDR_ANY))
368                         return -EADDRNOTAVAIL;
369 
370                 if (scoped)
371                         sk->sk_bound_dev_if = addr->sin6_scope_id;
372 #endif
373         } else {
374                 return -EAFNOSUPPORT;
375         }
376         return 0;
377 }
378 
379 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr)
380 {
381         if (saddr->sa_family == AF_INET) {
382                 struct inet_sock *isk = inet_sk(sk);
383                 struct sockaddr_in *addr = (struct sockaddr_in *) saddr;
384                 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
385 #if IS_ENABLED(CONFIG_IPV6)
386         } else if (saddr->sa_family == AF_INET6) {
387                 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr;
388                 struct ipv6_pinfo *np = inet6_sk(sk);
389                 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr;
390 #endif
391         }
392 }
393 
394 static void ping_clear_saddr(struct sock *sk, int dif)
395 {
396         sk->sk_bound_dev_if = dif;
397         if (sk->sk_family == AF_INET) {
398                 struct inet_sock *isk = inet_sk(sk);
399                 isk->inet_rcv_saddr = isk->inet_saddr = 0;
400 #if IS_ENABLED(CONFIG_IPV6)
401         } else if (sk->sk_family == AF_INET6) {
402                 struct ipv6_pinfo *np = inet6_sk(sk);
403                 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
404                 memset(&np->saddr, 0, sizeof(np->saddr));
405 #endif
406         }
407 }
408 /*
409  * We need our own bind because there are no privileged id's == local ports.
410  * Moreover, we don't allow binding to multi- and broadcast addresses.
411  */
412 
413 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
414 {
415         struct inet_sock *isk = inet_sk(sk);
416         unsigned short snum;
417         int err;
418         int dif = sk->sk_bound_dev_if;
419 
420         err = ping_check_bind_addr(sk, isk, uaddr, addr_len);
421         if (err)
422                 return err;
423 
424         lock_sock(sk);
425 
426         err = -EINVAL;
427         if (isk->inet_num != 0)
428                 goto out;
429 
430         err = -EADDRINUSE;
431         ping_set_saddr(sk, uaddr);
432         snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port);
433         if (ping_get_port(sk, snum) != 0) {
434                 ping_clear_saddr(sk, dif);
435                 goto out;
436         }
437 
438         pr_debug("after bind(): num = %d, dif = %d\n",
439                  (int)isk->inet_num,
440                  (int)sk->sk_bound_dev_if);
441 
442         err = 0;
443         if (sk->sk_family == AF_INET && isk->inet_rcv_saddr)
444                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
445 #if IS_ENABLED(CONFIG_IPV6)
446         if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr))
447                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
448 #endif
449 
450         if (snum)
451                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
452         isk->inet_sport = htons(isk->inet_num);
453         isk->inet_daddr = 0;
454         isk->inet_dport = 0;
455 
456 #if IS_ENABLED(CONFIG_IPV6)
457         if (sk->sk_family == AF_INET6)
458                 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr));
459 #endif
460 
461         sk_dst_reset(sk);
462 out:
463         release_sock(sk);
464         pr_debug("ping_v4_bind -> %d\n", err);
465         return err;
466 }
467 EXPORT_SYMBOL_GPL(ping_bind);
468 
469 /*
470  * Is this a supported type of ICMP message?
471  */
472 
473 static inline int ping_supported(int family, int type, int code)
474 {
475         return (family == AF_INET && type == ICMP_ECHO && code == 0) ||
476                (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0);
477 }
478 
479 /*
480  * This routine is called by the ICMP module when it gets some
481  * sort of error condition.
482  */
483 
484 void ping_err(struct sk_buff *skb, int offset, u32 info)
485 {
486         int family;
487         struct icmphdr *icmph;
488         struct inet_sock *inet_sock;
489         int type;
490         int code;
491         struct net *net = dev_net(skb->dev);
492         struct sock *sk;
493         int harderr;
494         int err;
495 
496         if (skb->protocol == htons(ETH_P_IP)) {
497                 family = AF_INET;
498                 type = icmp_hdr(skb)->type;
499                 code = icmp_hdr(skb)->code;
500                 icmph = (struct icmphdr *)(skb->data + offset);
501         } else if (skb->protocol == htons(ETH_P_IPV6)) {
502                 family = AF_INET6;
503                 type = icmp6_hdr(skb)->icmp6_type;
504                 code = icmp6_hdr(skb)->icmp6_code;
505                 icmph = (struct icmphdr *) (skb->data + offset);
506         } else {
507                 BUG();
508         }
509 
510         /* We assume the packet has already been checked by icmp_unreach */
511 
512         if (!ping_supported(family, icmph->type, icmph->code))
513                 return;
514 
515         pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n",
516                  skb->protocol, type, code, ntohs(icmph->un.echo.id),
517                  ntohs(icmph->un.echo.sequence));
518 
519         sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
520         if (!sk) {
521                 pr_debug("no socket, dropping\n");
522                 return; /* No socket for error */
523         }
524         pr_debug("err on socket %p\n", sk);
525 
526         err = 0;
527         harderr = 0;
528         inet_sock = inet_sk(sk);
529 
530         if (skb->protocol == htons(ETH_P_IP)) {
531                 switch (type) {
532                 default:
533                 case ICMP_TIME_EXCEEDED:
534                         err = EHOSTUNREACH;
535                         break;
536                 case ICMP_SOURCE_QUENCH:
537                         /* This is not a real error but ping wants to see it.
538                          * Report it with some fake errno.
539                          */
540                         err = EREMOTEIO;
541                         break;
542                 case ICMP_PARAMETERPROB:
543                         err = EPROTO;
544                         harderr = 1;
545                         break;
546                 case ICMP_DEST_UNREACH:
547                         if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
548                                 ipv4_sk_update_pmtu(skb, sk, info);
549                                 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) {
550                                         err = EMSGSIZE;
551                                         harderr = 1;
552                                         break;
553                                 }
554                                 goto out;
555                         }
556                         err = EHOSTUNREACH;
557                         if (code <= NR_ICMP_UNREACH) {
558                                 harderr = icmp_err_convert[code].fatal;
559                                 err = icmp_err_convert[code].errno;
560                         }
561                         break;
562                 case ICMP_REDIRECT:
563                         /* See ICMP_SOURCE_QUENCH */
564                         ipv4_sk_redirect(skb, sk);
565                         err = EREMOTEIO;
566                         break;
567                 }
568 #if IS_ENABLED(CONFIG_IPV6)
569         } else if (skb->protocol == htons(ETH_P_IPV6)) {
570                 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err);
571 #endif
572         }
573 
574         /*
575          *      RFC1122: OK.  Passes ICMP errors back to application, as per
576          *      4.1.3.3.
577          */
578         if ((family == AF_INET && !inet_sock->recverr) ||
579             (family == AF_INET6 && !inet6_sk(sk)->recverr)) {
580                 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
581                         goto out;
582         } else {
583                 if (family == AF_INET) {
584                         ip_icmp_error(sk, skb, err, 0 /* no remote port */,
585                                       info, (u8 *)icmph);
586 #if IS_ENABLED(CONFIG_IPV6)
587                 } else if (family == AF_INET6) {
588                         pingv6_ops.ipv6_icmp_error(sk, skb, err, 0,
589                                                    info, (u8 *)icmph);
590 #endif
591                 }
592         }
593         sk->sk_err = err;
594         sk->sk_error_report(sk);
595 out:
596         sock_put(sk);
597 }
598 EXPORT_SYMBOL_GPL(ping_err);
599 
600 /*
601  *      Copy and checksum an ICMP Echo packet from user space into a buffer
602  *      starting from the payload.
603  */
604 
605 int ping_getfrag(void *from, char *to,
606                  int offset, int fraglen, int odd, struct sk_buff *skb)
607 {
608         struct pingfakehdr *pfh = (struct pingfakehdr *)from;
609 
610         if (offset == 0) {
611                 fraglen -= sizeof(struct icmphdr);
612                 if (fraglen < 0)
613                         BUG();
614                 if (csum_and_copy_from_iter(to + sizeof(struct icmphdr),
615                             fraglen, &pfh->wcheck,
616                             &pfh->msg->msg_iter) != fraglen)
617                         return -EFAULT;
618         } else if (offset < sizeof(struct icmphdr)) {
619                         BUG();
620         } else {
621                 if (csum_and_copy_from_iter(to, fraglen, &pfh->wcheck,
622                                             &pfh->msg->msg_iter) != fraglen)
623                         return -EFAULT;
624         }
625 
626 #if IS_ENABLED(CONFIG_IPV6)
627         /* For IPv6, checksum each skb as we go along, as expected by
628          * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in
629          * wcheck, it will be finalized in ping_v4_push_pending_frames.
630          */
631         if (pfh->family == AF_INET6) {
632                 skb->csum = pfh->wcheck;
633                 skb->ip_summed = CHECKSUM_NONE;
634                 pfh->wcheck = 0;
635         }
636 #endif
637 
638         return 0;
639 }
640 EXPORT_SYMBOL_GPL(ping_getfrag);
641 
642 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
643                                        struct flowi4 *fl4)
644 {
645         struct sk_buff *skb = skb_peek(&sk->sk_write_queue);
646 
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         /*
663          *      Check the flags.
664          */
665 
666         /* Mirror BSD error message compatibility */
667         if (msg->msg_flags & MSG_OOB)
668                 return -EOPNOTSUPP;
669 
670         /*
671          *      Fetch the ICMP header provided by the userland.
672          *      iovec is modified! The ICMP header is consumed.
673          */
674         if (memcpy_from_msg(user_icmph, msg, icmph_len))
675                 return -EFAULT;
676 
677         if (family == AF_INET) {
678                 type = ((struct icmphdr *) user_icmph)->type;
679                 code = ((struct icmphdr *) user_icmph)->code;
680 #if IS_ENABLED(CONFIG_IPV6)
681         } else if (family == AF_INET6) {
682                 type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
683                 code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
684 #endif
685         } else {
686                 BUG();
687         }
688 
689         if (!ping_supported(family, type, code))
690                 return -EINVAL;
691 
692         return 0;
693 }
694 EXPORT_SYMBOL_GPL(ping_common_sendmsg);
695 
696 static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
697 {
698         struct net *net = sock_net(sk);
699         struct flowi4 fl4;
700         struct inet_sock *inet = inet_sk(sk);
701         struct ipcm_cookie ipc;
702         struct icmphdr user_icmph;
703         struct pingfakehdr pfh;
704         struct rtable *rt = NULL;
705         struct ip_options_data opt_copy;
706         int free = 0;
707         __be32 saddr, daddr, faddr;
708         u8  tos;
709         int err;
710 
711         pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
712 
713         err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
714                                   sizeof(user_icmph));
715         if (err)
716                 return err;
717 
718         /*
719          *      Get and verify the address.
720          */
721 
722         if (msg->msg_name) {
723                 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
724                 if (msg->msg_namelen < sizeof(*usin))
725                         return -EINVAL;
726                 if (usin->sin_family != AF_INET)
727                         return -EAFNOSUPPORT;
728                 daddr = usin->sin_addr.s_addr;
729                 /* no remote port */
730         } else {
731                 if (sk->sk_state != TCP_ESTABLISHED)
732                         return -EDESTADDRREQ;
733                 daddr = inet->inet_daddr;
734                 /* no remote port */
735         }
736 
737         ipc.addr = inet->inet_saddr;
738         ipc.opt = NULL;
739         ipc.oif = sk->sk_bound_dev_if;
740         ipc.tx_flags = 0;
741         ipc.ttl = 0;
742         ipc.tos = -1;
743 
744         sock_tx_timestamp(sk, &ipc.tx_flags);
745 
746         if (msg->msg_controllen) {
747                 err = ip_cmsg_send(sock_net(sk), msg, &ipc, false);
748                 if (err)
749                         return err;
750                 if (ipc.opt)
751                         free = 1;
752         }
753         if (!ipc.opt) {
754                 struct ip_options_rcu *inet_opt;
755 
756                 rcu_read_lock();
757                 inet_opt = rcu_dereference(inet->inet_opt);
758                 if (inet_opt) {
759                         memcpy(&opt_copy, inet_opt,
760                                sizeof(*inet_opt) + inet_opt->opt.optlen);
761                         ipc.opt = &opt_copy.opt;
762                 }
763                 rcu_read_unlock();
764         }
765 
766         saddr = ipc.addr;
767         ipc.addr = faddr = daddr;
768 
769         if (ipc.opt && ipc.opt->opt.srr) {
770                 if (!daddr)
771                         return -EINVAL;
772                 faddr = ipc.opt->opt.faddr;
773         }
774         tos = get_rttos(&ipc, inet);
775         if (sock_flag(sk, SOCK_LOCALROUTE) ||
776             (msg->msg_flags & MSG_DONTROUTE) ||
777             (ipc.opt && ipc.opt->opt.is_strictroute)) {
778                 tos |= RTO_ONLINK;
779         }
780 
781         if (ipv4_is_multicast(daddr)) {
782                 if (!ipc.oif)
783                         ipc.oif = inet->mc_index;
784                 if (!saddr)
785                         saddr = inet->mc_addr;
786         } else if (!ipc.oif)
787                 ipc.oif = inet->uc_index;
788 
789         flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
790                            RT_SCOPE_UNIVERSE, sk->sk_protocol,
791                            inet_sk_flowi_flags(sk), faddr, saddr, 0, 0);
792 
793         security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
794         rt = ip_route_output_flow(net, &fl4, sk);
795         if (IS_ERR(rt)) {
796                 err = PTR_ERR(rt);
797                 rt = NULL;
798                 if (err == -ENETUNREACH)
799                         IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
800                 goto out;
801         }
802 
803         err = -EACCES;
804         if ((rt->rt_flags & RTCF_BROADCAST) &&
805             !sock_flag(sk, SOCK_BROADCAST))
806                 goto out;
807 
808         if (msg->msg_flags & MSG_CONFIRM)
809                 goto do_confirm;
810 back_from_confirm:
811 
812         if (!ipc.addr)
813                 ipc.addr = fl4.daddr;
814 
815         lock_sock(sk);
816 
817         pfh.icmph.type = user_icmph.type; /* already checked */
818         pfh.icmph.code = user_icmph.code; /* ditto */
819         pfh.icmph.checksum = 0;
820         pfh.icmph.un.echo.id = inet->inet_sport;
821         pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
822         pfh.msg = msg;
823         pfh.wcheck = 0;
824         pfh.family = AF_INET;
825 
826         err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
827                         0, &ipc, &rt, msg->msg_flags);
828         if (err)
829                 ip_flush_pending_frames(sk);
830         else
831                 err = ping_v4_push_pending_frames(sk, &pfh, &fl4);
832         release_sock(sk);
833 
834 out:
835         ip_rt_put(rt);
836         if (free)
837                 kfree(ipc.opt);
838         if (!err) {
839                 icmp_out_count(sock_net(sk), user_icmph.type);
840                 return len;
841         }
842         return err;
843 
844 do_confirm:
845         dst_confirm(&rt->dst);
846         if (!(msg->msg_flags & MSG_PROBE) || len)
847                 goto back_from_confirm;
848         err = 0;
849         goto out;
850 }
851 
852 int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock,
853                  int flags, int *addr_len)
854 {
855         struct inet_sock *isk = inet_sk(sk);
856         int family = sk->sk_family;
857         struct sk_buff *skb;
858         int copied, err;
859 
860         pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
861 
862         err = -EOPNOTSUPP;
863         if (flags & MSG_OOB)
864                 goto out;
865 
866         if (flags & MSG_ERRQUEUE)
867                 return inet_recv_error(sk, msg, len, addr_len);
868 
869         skb = skb_recv_datagram(sk, flags, noblock, &err);
870         if (!skb)
871                 goto out;
872 
873         copied = skb->len;
874         if (copied > len) {
875                 msg->msg_flags |= MSG_TRUNC;
876                 copied = len;
877         }
878 
879         /* Don't bother checking the checksum */
880         err = skb_copy_datagram_msg(skb, 0, msg, copied);
881         if (err)
882                 goto done;
883 
884         sock_recv_timestamp(msg, sk, skb);
885 
886         /* Copy the address and add cmsg data. */
887         if (family == AF_INET) {
888                 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
889 
890                 if (sin) {
891                         sin->sin_family = AF_INET;
892                         sin->sin_port = 0 /* skb->h.uh->source */;
893                         sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
894                         memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
895                         *addr_len = sizeof(*sin);
896                 }
897 
898                 if (isk->cmsg_flags)
899                         ip_cmsg_recv(msg, skb);
900 
901 #if IS_ENABLED(CONFIG_IPV6)
902         } else if (family == AF_INET6) {
903                 struct ipv6_pinfo *np = inet6_sk(sk);
904                 struct ipv6hdr *ip6 = ipv6_hdr(skb);
905                 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
906 
907                 if (sin6) {
908                         sin6->sin6_family = AF_INET6;
909                         sin6->sin6_port = 0;
910                         sin6->sin6_addr = ip6->saddr;
911                         sin6->sin6_flowinfo = 0;
912                         if (np->sndflow)
913                                 sin6->sin6_flowinfo = ip6_flowinfo(ip6);
914                         sin6->sin6_scope_id =
915                                 ipv6_iface_scope_id(&sin6->sin6_addr,
916                                                     inet6_iif(skb));
917                         *addr_len = sizeof(*sin6);
918                 }
919 
920                 if (inet6_sk(sk)->rxopt.all)
921                         pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb);
922                 if (skb->protocol == htons(ETH_P_IPV6) &&
923                     inet6_sk(sk)->rxopt.all)
924                         pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb);
925                 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags)
926                         ip_cmsg_recv(msg, skb);
927 #endif
928         } else {
929                 BUG();
930         }
931 
932         err = copied;
933 
934 done:
935         skb_free_datagram(sk, skb);
936 out:
937         pr_debug("ping_recvmsg -> %d\n", err);
938         return err;
939 }
940 EXPORT_SYMBOL_GPL(ping_recvmsg);
941 
942 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
943 {
944         pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
945                  inet_sk(sk), inet_sk(sk)->inet_num, skb);
946         if (sock_queue_rcv_skb(sk, skb) < 0) {
947                 kfree_skb(skb);
948                 pr_debug("ping_queue_rcv_skb -> failed\n");
949                 return -1;
950         }
951         return 0;
952 }
953 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
954 
955 
956 /*
957  *      All we need to do is get the socket.
958  */
959 
960 bool ping_rcv(struct sk_buff *skb)
961 {
962         struct sock *sk;
963         struct net *net = dev_net(skb->dev);
964         struct icmphdr *icmph = icmp_hdr(skb);
965 
966         /* We assume the packet has already been checked by icmp_rcv */
967 
968         pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
969                  skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
970 
971         /* Push ICMP header back */
972         skb_push(skb, skb->data - (u8 *)icmph);
973 
974         sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
975         if (sk) {
976                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
977 
978                 pr_debug("rcv on socket %p\n", sk);
979                 if (skb2)
980                         ping_queue_rcv_skb(sk, skb2);
981                 sock_put(sk);
982                 return true;
983         }
984         pr_debug("no socket, dropping\n");
985 
986         return false;
987 }
988 EXPORT_SYMBOL_GPL(ping_rcv);
989 
990 struct proto ping_prot = {
991         .name =         "PING",
992         .owner =        THIS_MODULE,
993         .init =         ping_init_sock,
994         .close =        ping_close,
995         .connect =      ip4_datagram_connect,
996         .disconnect =   udp_disconnect,
997         .setsockopt =   ip_setsockopt,
998         .getsockopt =   ip_getsockopt,
999         .sendmsg =      ping_v4_sendmsg,
1000         .recvmsg =      ping_recvmsg,
1001         .bind =         ping_bind,
1002         .backlog_rcv =  ping_queue_rcv_skb,
1003         .release_cb =   ip4_datagram_release_cb,
1004         .hash =         ping_hash,
1005         .unhash =       ping_unhash,
1006         .get_port =     ping_get_port,
1007         .obj_size =     sizeof(struct inet_sock),
1008 };
1009 EXPORT_SYMBOL(ping_prot);
1010 
1011 #ifdef CONFIG_PROC_FS
1012 
1013 static struct sock *ping_get_first(struct seq_file *seq, int start)
1014 {
1015         struct sock *sk;
1016         struct ping_iter_state *state = seq->private;
1017         struct net *net = seq_file_net(seq);
1018 
1019         for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
1020              ++state->bucket) {
1021                 struct hlist_nulls_node *node;
1022                 struct hlist_nulls_head *hslot;
1023 
1024                 hslot = &ping_table.hash[state->bucket];
1025 
1026                 if (hlist_nulls_empty(hslot))
1027                         continue;
1028 
1029                 sk_nulls_for_each(sk, node, hslot) {
1030                         if (net_eq(sock_net(sk), net) &&
1031                             sk->sk_family == state->family)
1032                                 goto found;
1033                 }
1034         }
1035         sk = NULL;
1036 found:
1037         return sk;
1038 }
1039 
1040 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
1041 {
1042         struct ping_iter_state *state = seq->private;
1043         struct net *net = seq_file_net(seq);
1044 
1045         do {
1046                 sk = sk_nulls_next(sk);
1047         } while (sk && (!net_eq(sock_net(sk), net)));
1048 
1049         if (!sk)
1050                 return ping_get_first(seq, state->bucket + 1);
1051         return sk;
1052 }
1053 
1054 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
1055 {
1056         struct sock *sk = ping_get_first(seq, 0);
1057 
1058         if (sk)
1059                 while (pos && (sk = ping_get_next(seq, sk)) != NULL)
1060                         --pos;
1061         return pos ? NULL : sk;
1062 }
1063 
1064 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
1065 {
1066         struct ping_iter_state *state = seq->private;
1067         state->bucket = 0;
1068         state->family = family;
1069 
1070         read_lock_bh(&ping_table.lock);
1071 
1072         return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1073 }
1074 EXPORT_SYMBOL_GPL(ping_seq_start);
1075 
1076 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos)
1077 {
1078         return ping_seq_start(seq, pos, AF_INET);
1079 }
1080 
1081 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1082 {
1083         struct sock *sk;
1084 
1085         if (v == SEQ_START_TOKEN)
1086                 sk = ping_get_idx(seq, 0);
1087         else
1088                 sk = ping_get_next(seq, v);
1089 
1090         ++*pos;
1091         return sk;
1092 }
1093 EXPORT_SYMBOL_GPL(ping_seq_next);
1094 
1095 void ping_seq_stop(struct seq_file *seq, void *v)
1096 {
1097         read_unlock_bh(&ping_table.lock);
1098 }
1099 EXPORT_SYMBOL_GPL(ping_seq_stop);
1100 
1101 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f,
1102                 int bucket)
1103 {
1104         struct inet_sock *inet = inet_sk(sp);
1105         __be32 dest = inet->inet_daddr;
1106         __be32 src = inet->inet_rcv_saddr;
1107         __u16 destp = ntohs(inet->inet_dport);
1108         __u16 srcp = ntohs(inet->inet_sport);
1109 
1110         seq_printf(f, "%5d: %08X:%04X %08X:%04X"
1111                 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d",
1112                 bucket, src, srcp, dest, destp, sp->sk_state,
1113                 sk_wmem_alloc_get(sp),
1114                 sk_rmem_alloc_get(sp),
1115                 0, 0L, 0,
1116                 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
1117                 0, sock_i_ino(sp),
1118                 atomic_read(&sp->sk_refcnt), sp,
1119                 atomic_read(&sp->sk_drops));
1120 }
1121 
1122 static int ping_v4_seq_show(struct seq_file *seq, void *v)
1123 {
1124         seq_setwidth(seq, 127);
1125         if (v == SEQ_START_TOKEN)
1126                 seq_puts(seq, "  sl  local_address rem_address   st tx_queue "
1127                            "rx_queue tr tm->when retrnsmt   uid  timeout "
1128                            "inode ref pointer drops");
1129         else {
1130                 struct ping_iter_state *state = seq->private;
1131 
1132                 ping_v4_format_sock(v, seq, state->bucket);
1133         }
1134         seq_pad(seq, '\n');
1135         return 0;
1136 }
1137 
1138 static const struct seq_operations ping_v4_seq_ops = {
1139         .show           = ping_v4_seq_show,
1140         .start          = ping_v4_seq_start,
1141         .next           = ping_seq_next,
1142         .stop           = ping_seq_stop,
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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