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TOMOYO Linux Cross Reference
Linux/net/ipv4/ping.c

Version: ~ [ linux-5.3-rc4 ] ~ [ linux-5.2.8 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.66 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.138 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.189 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.189 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.71 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
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  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 
 57 struct ping_table ping_table;
 58 struct pingv6_ops pingv6_ops;
 59 EXPORT_SYMBOL_GPL(pingv6_ops);
 60 
 61 static u16 ping_port_rover;
 62 
 63 static inline int ping_hashfn(struct net *net, unsigned int num, unsigned int mask)
 64 {
 65         int res = (num + net_hash_mix(net)) & mask;
 66 
 67         pr_debug("hash(%d) = %d\n", num, res);
 68         return res;
 69 }
 70 EXPORT_SYMBOL_GPL(ping_hash);
 71 
 72 static inline struct hlist_nulls_head *ping_hashslot(struct ping_table *table,
 73                                              struct net *net, unsigned int num)
 74 {
 75         return &table->hash[ping_hashfn(net, num, PING_HTABLE_MASK)];
 76 }
 77 
 78 int ping_get_port(struct sock *sk, unsigned short ident)
 79 {
 80         struct hlist_nulls_node *node;
 81         struct hlist_nulls_head *hlist;
 82         struct inet_sock *isk, *isk2;
 83         struct sock *sk2 = NULL;
 84 
 85         isk = inet_sk(sk);
 86         write_lock_bh(&ping_table.lock);
 87         if (ident == 0) {
 88                 u32 i;
 89                 u16 result = ping_port_rover + 1;
 90 
 91                 for (i = 0; i < (1L << 16); i++, result++) {
 92                         if (!result)
 93                                 result++; /* avoid zero */
 94                         hlist = ping_hashslot(&ping_table, sock_net(sk),
 95                                             result);
 96                         ping_portaddr_for_each_entry(sk2, node, hlist) {
 97                                 isk2 = inet_sk(sk2);
 98 
 99                                 if (isk2->inet_num == result)
100                                         goto next_port;
101                         }
102 
103                         /* found */
104                         ping_port_rover = ident = result;
105                         break;
106 next_port:
107                         ;
108                 }
109                 if (i >= (1L << 16))
110                         goto fail;
111         } else {
112                 hlist = ping_hashslot(&ping_table, sock_net(sk), ident);
113                 ping_portaddr_for_each_entry(sk2, node, hlist) {
114                         isk2 = inet_sk(sk2);
115 
116                         /* BUG? Why is this reuse and not reuseaddr? ping.c
117                          * doesn't turn off SO_REUSEADDR, and it doesn't expect
118                          * that other ping processes can steal its packets.
119                          */
120                         if ((isk2->inet_num == ident) &&
121                             (sk2 != sk) &&
122                             (!sk2->sk_reuse || !sk->sk_reuse))
123                                 goto fail;
124                 }
125         }
126 
127         pr_debug("found port/ident = %d\n", ident);
128         isk->inet_num = ident;
129         if (sk_unhashed(sk)) {
130                 pr_debug("was not hashed\n");
131                 sock_hold(sk);
132                 hlist_nulls_add_head(&sk->sk_nulls_node, hlist);
133                 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
134         }
135         write_unlock_bh(&ping_table.lock);
136         return 0;
137 
138 fail:
139         write_unlock_bh(&ping_table.lock);
140         return 1;
141 }
142 EXPORT_SYMBOL_GPL(ping_get_port);
143 
144 void ping_hash(struct sock *sk)
145 {
146         pr_debug("ping_hash(sk->port=%u)\n", inet_sk(sk)->inet_num);
147         BUG(); /* "Please do not press this button again." */
148 }
149 
150 void ping_unhash(struct sock *sk)
151 {
152         struct inet_sock *isk = inet_sk(sk);
153         pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);
154         if (sk_hashed(sk)) {
155                 write_lock_bh(&ping_table.lock);
156                 hlist_nulls_del(&sk->sk_nulls_node);
157                 sock_put(sk);
158                 isk->inet_num = 0;
159                 isk->inet_sport = 0;
160                 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
161                 write_unlock_bh(&ping_table.lock);
162         }
163 }
164 EXPORT_SYMBOL_GPL(ping_unhash);
165 
166 static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
167 {
168         struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident);
169         struct sock *sk = NULL;
170         struct inet_sock *isk;
171         struct hlist_nulls_node *hnode;
172         int dif = skb->dev->ifindex;
173 
174         if (skb->protocol == htons(ETH_P_IP)) {
175                 pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n",
176                          (int)ident, &ip_hdr(skb)->daddr, dif);
177 #if IS_ENABLED(CONFIG_IPV6)
178         } else if (skb->protocol == htons(ETH_P_IPV6)) {
179                 pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n",
180                          (int)ident, &ipv6_hdr(skb)->daddr, dif);
181 #endif
182         }
183 
184         read_lock_bh(&ping_table.lock);
185 
186         ping_portaddr_for_each_entry(sk, hnode, hslot) {
187                 isk = inet_sk(sk);
188 
189                 pr_debug("iterate\n");
190                 if (isk->inet_num != ident)
191                         continue;
192 
193                 if (skb->protocol == htons(ETH_P_IP) &&
194                     sk->sk_family == AF_INET) {
195                         pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk,
196                                  (int) isk->inet_num, &isk->inet_rcv_saddr,
197                                  sk->sk_bound_dev_if);
198 
199                         if (isk->inet_rcv_saddr &&
200                             isk->inet_rcv_saddr != ip_hdr(skb)->daddr)
201                                 continue;
202 #if IS_ENABLED(CONFIG_IPV6)
203                 } else if (skb->protocol == htons(ETH_P_IPV6) &&
204                            sk->sk_family == AF_INET6) {
205                         struct ipv6_pinfo *np = inet6_sk(sk);
206 
207                         pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk,
208                                  (int) isk->inet_num,
209                                  &inet6_sk(sk)->rcv_saddr,
210                                  sk->sk_bound_dev_if);
211 
212                         if (!ipv6_addr_any(&np->rcv_saddr) &&
213                             !ipv6_addr_equal(&np->rcv_saddr,
214                                              &ipv6_hdr(skb)->daddr))
215                                 continue;
216 #endif
217                 }
218 
219                 if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)
220                         continue;
221 
222                 sock_hold(sk);
223                 goto exit;
224         }
225 
226         sk = NULL;
227 exit:
228         read_unlock_bh(&ping_table.lock);
229 
230         return sk;
231 }
232 
233 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low,
234                                           kgid_t *high)
235 {
236         kgid_t *data = net->ipv4.sysctl_ping_group_range;
237         unsigned int seq;
238 
239         do {
240                 seq = read_seqbegin(&sysctl_local_ports.lock);
241 
242                 *low = data[0];
243                 *high = data[1];
244         } while (read_seqretry(&sysctl_local_ports.lock, seq));
245 }
246 
247 
248 int ping_init_sock(struct sock *sk)
249 {
250         struct net *net = sock_net(sk);
251         kgid_t group = current_egid();
252         struct group_info *group_info = get_current_groups();
253         int i, j, count = group_info->ngroups;
254         kgid_t low, high;
255 
256         inet_get_ping_group_range_net(net, &low, &high);
257         if (gid_lte(low, group) && gid_lte(group, high))
258                 return 0;
259 
260         for (i = 0; i < group_info->nblocks; i++) {
261                 int cp_count = min_t(int, NGROUPS_PER_BLOCK, count);
262                 for (j = 0; j < cp_count; j++) {
263                         kgid_t gid = group_info->blocks[i][j];
264                         if (gid_lte(low, gid) && gid_lte(gid, high))
265                                 return 0;
266                 }
267 
268                 count -= cp_count;
269         }
270 
271         return -EACCES;
272 }
273 EXPORT_SYMBOL_GPL(ping_init_sock);
274 
275 void ping_close(struct sock *sk, long timeout)
276 {
277         pr_debug("ping_close(sk=%p,sk->num=%u)\n",
278                  inet_sk(sk), inet_sk(sk)->inet_num);
279         pr_debug("isk->refcnt = %d\n", sk->sk_refcnt.counter);
280 
281         sk_common_release(sk);
282 }
283 EXPORT_SYMBOL_GPL(ping_close);
284 
285 /* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */
286 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
287                                 struct sockaddr *uaddr, int addr_len) {
288         struct net *net = sock_net(sk);
289         if (sk->sk_family == AF_INET) {
290                 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
291                 int chk_addr_ret;
292 
293                 if (addr_len < sizeof(*addr))
294                         return -EINVAL;
295 
296                 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",
297                          sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
298 
299                 chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
300 
301                 if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
302                         chk_addr_ret = RTN_LOCAL;
303 
304                 if ((sysctl_ip_nonlocal_bind == 0 &&
305                     isk->freebind == 0 && isk->transparent == 0 &&
306                      chk_addr_ret != RTN_LOCAL) ||
307                     chk_addr_ret == RTN_MULTICAST ||
308                     chk_addr_ret == RTN_BROADCAST)
309                         return -EADDRNOTAVAIL;
310 
311 #if IS_ENABLED(CONFIG_IPV6)
312         } else if (sk->sk_family == AF_INET6) {
313                 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
314                 int addr_type, scoped, has_addr;
315                 struct net_device *dev = NULL;
316 
317                 if (addr_len < sizeof(*addr))
318                         return -EINVAL;
319 
320                 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n",
321                          sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port));
322 
323                 addr_type = ipv6_addr_type(&addr->sin6_addr);
324                 scoped = __ipv6_addr_needs_scope_id(addr_type);
325                 if ((addr_type != IPV6_ADDR_ANY &&
326                      !(addr_type & IPV6_ADDR_UNICAST)) ||
327                     (scoped && !addr->sin6_scope_id))
328                         return -EINVAL;
329 
330                 rcu_read_lock();
331                 if (addr->sin6_scope_id) {
332                         dev = dev_get_by_index_rcu(net, addr->sin6_scope_id);
333                         if (!dev) {
334                                 rcu_read_unlock();
335                                 return -ENODEV;
336                         }
337                 }
338                 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev,
339                                                     scoped);
340                 rcu_read_unlock();
341 
342                 if (!(isk->freebind || isk->transparent || has_addr ||
343                       addr_type == IPV6_ADDR_ANY))
344                         return -EADDRNOTAVAIL;
345 
346                 if (scoped)
347                         sk->sk_bound_dev_if = addr->sin6_scope_id;
348 #endif
349         } else {
350                 return -EAFNOSUPPORT;
351         }
352         return 0;
353 }
354 
355 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr)
356 {
357         if (saddr->sa_family == AF_INET) {
358                 struct inet_sock *isk = inet_sk(sk);
359                 struct sockaddr_in *addr = (struct sockaddr_in *) saddr;
360                 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
361 #if IS_ENABLED(CONFIG_IPV6)
362         } else if (saddr->sa_family == AF_INET6) {
363                 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr;
364                 struct ipv6_pinfo *np = inet6_sk(sk);
365                 np->rcv_saddr = np->saddr = addr->sin6_addr;
366 #endif
367         }
368 }
369 
370 static void ping_clear_saddr(struct sock *sk, int dif)
371 {
372         sk->sk_bound_dev_if = dif;
373         if (sk->sk_family == AF_INET) {
374                 struct inet_sock *isk = inet_sk(sk);
375                 isk->inet_rcv_saddr = isk->inet_saddr = 0;
376 #if IS_ENABLED(CONFIG_IPV6)
377         } else if (sk->sk_family == AF_INET6) {
378                 struct ipv6_pinfo *np = inet6_sk(sk);
379                 memset(&np->rcv_saddr, 0, sizeof(np->rcv_saddr));
380                 memset(&np->saddr, 0, sizeof(np->saddr));
381 #endif
382         }
383 }
384 /*
385  * We need our own bind because there are no privileged id's == local ports.
386  * Moreover, we don't allow binding to multi- and broadcast addresses.
387  */
388 
389 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
390 {
391         struct inet_sock *isk = inet_sk(sk);
392         unsigned short snum;
393         int err;
394         int dif = sk->sk_bound_dev_if;
395 
396         err = ping_check_bind_addr(sk, isk, uaddr, addr_len);
397         if (err)
398                 return err;
399 
400         lock_sock(sk);
401 
402         err = -EINVAL;
403         if (isk->inet_num != 0)
404                 goto out;
405 
406         err = -EADDRINUSE;
407         ping_set_saddr(sk, uaddr);
408         snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port);
409         if (ping_get_port(sk, snum) != 0) {
410                 ping_clear_saddr(sk, dif);
411                 goto out;
412         }
413 
414         pr_debug("after bind(): num = %d, dif = %d\n",
415                  (int)isk->inet_num,
416                  (int)sk->sk_bound_dev_if);
417 
418         err = 0;
419         if ((sk->sk_family == AF_INET && isk->inet_rcv_saddr) ||
420             (sk->sk_family == AF_INET6 &&
421              !ipv6_addr_any(&inet6_sk(sk)->rcv_saddr)))
422                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
423 
424         if (snum)
425                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
426         isk->inet_sport = htons(isk->inet_num);
427         isk->inet_daddr = 0;
428         isk->inet_dport = 0;
429 
430 #if IS_ENABLED(CONFIG_IPV6)
431         if (sk->sk_family == AF_INET6)
432                 memset(&inet6_sk(sk)->daddr, 0, sizeof(inet6_sk(sk)->daddr));
433 #endif
434 
435         sk_dst_reset(sk);
436 out:
437         release_sock(sk);
438         pr_debug("ping_v4_bind -> %d\n", err);
439         return err;
440 }
441 EXPORT_SYMBOL_GPL(ping_bind);
442 
443 /*
444  * Is this a supported type of ICMP message?
445  */
446 
447 static inline int ping_supported(int family, int type, int code)
448 {
449         return (family == AF_INET && type == ICMP_ECHO && code == 0) ||
450                (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0);
451 }
452 
453 /*
454  * This routine is called by the ICMP module when it gets some
455  * sort of error condition.
456  */
457 
458 void ping_err(struct sk_buff *skb, int offset, u32 info)
459 {
460         int family;
461         struct icmphdr *icmph;
462         struct inet_sock *inet_sock;
463         int type;
464         int code;
465         struct net *net = dev_net(skb->dev);
466         struct sock *sk;
467         int harderr;
468         int err;
469 
470         if (skb->protocol == htons(ETH_P_IP)) {
471                 family = AF_INET;
472                 type = icmp_hdr(skb)->type;
473                 code = icmp_hdr(skb)->code;
474                 icmph = (struct icmphdr *)(skb->data + offset);
475         } else if (skb->protocol == htons(ETH_P_IPV6)) {
476                 family = AF_INET6;
477                 type = icmp6_hdr(skb)->icmp6_type;
478                 code = icmp6_hdr(skb)->icmp6_code;
479                 icmph = (struct icmphdr *) (skb->data + offset);
480         } else {
481                 BUG();
482         }
483 
484         /* We assume the packet has already been checked by icmp_unreach */
485 
486         if (!ping_supported(family, icmph->type, icmph->code))
487                 return;
488 
489         pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n",
490                  skb->protocol, type, code, ntohs(icmph->un.echo.id),
491                  ntohs(icmph->un.echo.sequence));
492 
493         sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
494         if (sk == NULL) {
495                 pr_debug("no socket, dropping\n");
496                 return; /* No socket for error */
497         }
498         pr_debug("err on socket %p\n", sk);
499 
500         err = 0;
501         harderr = 0;
502         inet_sock = inet_sk(sk);
503 
504         if (skb->protocol == htons(ETH_P_IP)) {
505                 switch (type) {
506                 default:
507                 case ICMP_TIME_EXCEEDED:
508                         err = EHOSTUNREACH;
509                         break;
510                 case ICMP_SOURCE_QUENCH:
511                         /* This is not a real error but ping wants to see it.
512                          * Report it with some fake errno.
513                          */
514                         err = EREMOTEIO;
515                         break;
516                 case ICMP_PARAMETERPROB:
517                         err = EPROTO;
518                         harderr = 1;
519                         break;
520                 case ICMP_DEST_UNREACH:
521                         if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
522                                 ipv4_sk_update_pmtu(skb, sk, info);
523                                 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) {
524                                         err = EMSGSIZE;
525                                         harderr = 1;
526                                         break;
527                                 }
528                                 goto out;
529                         }
530                         err = EHOSTUNREACH;
531                         if (code <= NR_ICMP_UNREACH) {
532                                 harderr = icmp_err_convert[code].fatal;
533                                 err = icmp_err_convert[code].errno;
534                         }
535                         break;
536                 case ICMP_REDIRECT:
537                         /* See ICMP_SOURCE_QUENCH */
538                         ipv4_sk_redirect(skb, sk);
539                         err = EREMOTEIO;
540                         break;
541                 }
542 #if IS_ENABLED(CONFIG_IPV6)
543         } else if (skb->protocol == htons(ETH_P_IPV6)) {
544                 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err);
545 #endif
546         }
547 
548         /*
549          *      RFC1122: OK.  Passes ICMP errors back to application, as per
550          *      4.1.3.3.
551          */
552         if ((family == AF_INET && !inet_sock->recverr) ||
553             (family == AF_INET6 && !inet6_sk(sk)->recverr)) {
554                 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
555                         goto out;
556         } else {
557                 if (family == AF_INET) {
558                         ip_icmp_error(sk, skb, err, 0 /* no remote port */,
559                                       info, (u8 *)icmph);
560 #if IS_ENABLED(CONFIG_IPV6)
561                 } else if (family == AF_INET6) {
562                         pingv6_ops.ipv6_icmp_error(sk, skb, err, 0,
563                                                    info, (u8 *)icmph);
564 #endif
565                 }
566         }
567         sk->sk_err = err;
568         sk->sk_error_report(sk);
569 out:
570         sock_put(sk);
571 }
572 EXPORT_SYMBOL_GPL(ping_err);
573 
574 /*
575  *      Copy and checksum an ICMP Echo packet from user space into a buffer
576  *      starting from the payload.
577  */
578 
579 int ping_getfrag(void *from, char *to,
580                  int offset, int fraglen, int odd, struct sk_buff *skb)
581 {
582         struct pingfakehdr *pfh = (struct pingfakehdr *)from;
583 
584         if (offset == 0) {
585                 if (fraglen < sizeof(struct icmphdr))
586                         BUG();
587                 if (csum_partial_copy_fromiovecend(to + sizeof(struct icmphdr),
588                             pfh->iov, 0, fraglen - sizeof(struct icmphdr),
589                             &pfh->wcheck))
590                         return -EFAULT;
591         } else if (offset < sizeof(struct icmphdr)) {
592                         BUG();
593         } else {
594                 if (csum_partial_copy_fromiovecend
595                                 (to, pfh->iov, offset - sizeof(struct icmphdr),
596                                  fraglen, &pfh->wcheck))
597                         return -EFAULT;
598         }
599 
600 #if IS_ENABLED(CONFIG_IPV6)
601         /* For IPv6, checksum each skb as we go along, as expected by
602          * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in
603          * wcheck, it will be finalized in ping_v4_push_pending_frames.
604          */
605         if (pfh->family == AF_INET6) {
606                 skb->csum = pfh->wcheck;
607                 skb->ip_summed = CHECKSUM_NONE;
608                 pfh->wcheck = 0;
609         }
610 #endif
611 
612         return 0;
613 }
614 EXPORT_SYMBOL_GPL(ping_getfrag);
615 
616 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
617                                        struct flowi4 *fl4)
618 {
619         struct sk_buff *skb = skb_peek(&sk->sk_write_queue);
620 
621         pfh->wcheck = csum_partial((char *)&pfh->icmph,
622                 sizeof(struct icmphdr), pfh->wcheck);
623         pfh->icmph.checksum = csum_fold(pfh->wcheck);
624         memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
625         skb->ip_summed = CHECKSUM_NONE;
626         return ip_push_pending_frames(sk, fl4);
627 }
628 
629 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
630                         void *user_icmph, size_t icmph_len) {
631         u8 type, code;
632 
633         if (len > 0xFFFF)
634                 return -EMSGSIZE;
635 
636         /*
637          *      Check the flags.
638          */
639 
640         /* Mirror BSD error message compatibility */
641         if (msg->msg_flags & MSG_OOB)
642                 return -EOPNOTSUPP;
643 
644         /*
645          *      Fetch the ICMP header provided by the userland.
646          *      iovec is modified! The ICMP header is consumed.
647          */
648         if (memcpy_fromiovec(user_icmph, msg->msg_iov, icmph_len))
649                 return -EFAULT;
650 
651         if (family == AF_INET) {
652                 type = ((struct icmphdr *) user_icmph)->type;
653                 code = ((struct icmphdr *) user_icmph)->code;
654 #if IS_ENABLED(CONFIG_IPV6)
655         } else if (family == AF_INET6) {
656                 type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
657                 code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
658 #endif
659         } else {
660                 BUG();
661         }
662 
663         if (!ping_supported(family, type, code))
664                 return -EINVAL;
665 
666         return 0;
667 }
668 EXPORT_SYMBOL_GPL(ping_common_sendmsg);
669 
670 int ping_v4_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
671                     size_t len)
672 {
673         struct net *net = sock_net(sk);
674         struct flowi4 fl4;
675         struct inet_sock *inet = inet_sk(sk);
676         struct ipcm_cookie ipc;
677         struct icmphdr user_icmph;
678         struct pingfakehdr pfh;
679         struct rtable *rt = NULL;
680         struct ip_options_data opt_copy;
681         int free = 0;
682         __be32 saddr, daddr, faddr;
683         u8  tos;
684         int err;
685 
686         pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
687 
688         err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
689                                   sizeof(user_icmph));
690         if (err)
691                 return err;
692 
693         /*
694          *      Get and verify the address.
695          */
696 
697         if (msg->msg_name) {
698                 struct sockaddr_in *usin = (struct sockaddr_in *)msg->msg_name;
699                 if (msg->msg_namelen < sizeof(*usin))
700                         return -EINVAL;
701                 if (usin->sin_family != AF_INET)
702                         return -EINVAL;
703                 daddr = usin->sin_addr.s_addr;
704                 /* no remote port */
705         } else {
706                 if (sk->sk_state != TCP_ESTABLISHED)
707                         return -EDESTADDRREQ;
708                 daddr = inet->inet_daddr;
709                 /* no remote port */
710         }
711 
712         ipc.addr = inet->inet_saddr;
713         ipc.opt = NULL;
714         ipc.oif = sk->sk_bound_dev_if;
715         ipc.tx_flags = 0;
716 
717         sock_tx_timestamp(sk, &ipc.tx_flags);
718 
719         if (msg->msg_controllen) {
720                 err = ip_cmsg_send(sock_net(sk), msg, &ipc);
721                 if (err)
722                         return err;
723                 if (ipc.opt)
724                         free = 1;
725         }
726         if (!ipc.opt) {
727                 struct ip_options_rcu *inet_opt;
728 
729                 rcu_read_lock();
730                 inet_opt = rcu_dereference(inet->inet_opt);
731                 if (inet_opt) {
732                         memcpy(&opt_copy, inet_opt,
733                                sizeof(*inet_opt) + inet_opt->opt.optlen);
734                         ipc.opt = &opt_copy.opt;
735                 }
736                 rcu_read_unlock();
737         }
738 
739         saddr = ipc.addr;
740         ipc.addr = faddr = daddr;
741 
742         if (ipc.opt && ipc.opt->opt.srr) {
743                 if (!daddr)
744                         return -EINVAL;
745                 faddr = ipc.opt->opt.faddr;
746         }
747         tos = RT_TOS(inet->tos);
748         if (sock_flag(sk, SOCK_LOCALROUTE) ||
749             (msg->msg_flags & MSG_DONTROUTE) ||
750             (ipc.opt && ipc.opt->opt.is_strictroute)) {
751                 tos |= RTO_ONLINK;
752         }
753 
754         if (ipv4_is_multicast(daddr)) {
755                 if (!ipc.oif)
756                         ipc.oif = inet->mc_index;
757                 if (!saddr)
758                         saddr = inet->mc_addr;
759         } else if (!ipc.oif)
760                 ipc.oif = inet->uc_index;
761 
762         flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
763                            RT_SCOPE_UNIVERSE, sk->sk_protocol,
764                            inet_sk_flowi_flags(sk), faddr, saddr, 0, 0);
765 
766         security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
767         rt = ip_route_output_flow(net, &fl4, sk);
768         if (IS_ERR(rt)) {
769                 err = PTR_ERR(rt);
770                 rt = NULL;
771                 if (err == -ENETUNREACH)
772                         IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
773                 goto out;
774         }
775 
776         err = -EACCES;
777         if ((rt->rt_flags & RTCF_BROADCAST) &&
778             !sock_flag(sk, SOCK_BROADCAST))
779                 goto out;
780 
781         if (msg->msg_flags & MSG_CONFIRM)
782                 goto do_confirm;
783 back_from_confirm:
784 
785         if (!ipc.addr)
786                 ipc.addr = fl4.daddr;
787 
788         lock_sock(sk);
789 
790         pfh.icmph.type = user_icmph.type; /* already checked */
791         pfh.icmph.code = user_icmph.code; /* ditto */
792         pfh.icmph.checksum = 0;
793         pfh.icmph.un.echo.id = inet->inet_sport;
794         pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
795         pfh.iov = msg->msg_iov;
796         pfh.wcheck = 0;
797         pfh.family = AF_INET;
798 
799         err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
800                         0, &ipc, &rt, msg->msg_flags);
801         if (err)
802                 ip_flush_pending_frames(sk);
803         else
804                 err = ping_v4_push_pending_frames(sk, &pfh, &fl4);
805         release_sock(sk);
806 
807 out:
808         ip_rt_put(rt);
809         if (free)
810                 kfree(ipc.opt);
811         if (!err) {
812                 icmp_out_count(sock_net(sk), user_icmph.type);
813                 return len;
814         }
815         return err;
816 
817 do_confirm:
818         dst_confirm(&rt->dst);
819         if (!(msg->msg_flags & MSG_PROBE) || len)
820                 goto back_from_confirm;
821         err = 0;
822         goto out;
823 }
824 
825 int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
826                  size_t len, int noblock, int flags, int *addr_len)
827 {
828         struct inet_sock *isk = inet_sk(sk);
829         int family = sk->sk_family;
830         struct sockaddr_in *sin;
831         struct sockaddr_in6 *sin6;
832         struct sk_buff *skb;
833         int copied, err;
834 
835         pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
836 
837         err = -EOPNOTSUPP;
838         if (flags & MSG_OOB)
839                 goto out;
840 
841         if (addr_len) {
842                 if (family == AF_INET)
843                         *addr_len = sizeof(*sin);
844                 else if (family == AF_INET6 && addr_len)
845                         *addr_len = sizeof(*sin6);
846         }
847 
848         if (flags & MSG_ERRQUEUE) {
849                 if (family == AF_INET) {
850                         return ip_recv_error(sk, msg, len);
851 #if IS_ENABLED(CONFIG_IPV6)
852                 } else if (family == AF_INET6) {
853                         return pingv6_ops.ipv6_recv_error(sk, msg, len);
854 #endif
855                 }
856         }
857 
858         skb = skb_recv_datagram(sk, flags, noblock, &err);
859         if (!skb)
860                 goto out;
861 
862         copied = skb->len;
863         if (copied > len) {
864                 msg->msg_flags |= MSG_TRUNC;
865                 copied = len;
866         }
867 
868         /* Don't bother checking the checksum */
869         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
870         if (err)
871                 goto done;
872 
873         sock_recv_timestamp(msg, sk, skb);
874 
875         /* Copy the address and add cmsg data. */
876         if (family == AF_INET) {
877                 sin = (struct sockaddr_in *) msg->msg_name;
878                 sin->sin_family = AF_INET;
879                 sin->sin_port = 0 /* skb->h.uh->source */;
880                 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
881                 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
882 
883                 if (isk->cmsg_flags)
884                         ip_cmsg_recv(msg, skb);
885 
886 #if IS_ENABLED(CONFIG_IPV6)
887         } else if (family == AF_INET6) {
888                 struct ipv6_pinfo *np = inet6_sk(sk);
889                 struct ipv6hdr *ip6 = ipv6_hdr(skb);
890                 sin6 = (struct sockaddr_in6 *) msg->msg_name;
891                 sin6->sin6_family = AF_INET6;
892                 sin6->sin6_port = 0;
893                 sin6->sin6_addr = ip6->saddr;
894 
895                 sin6->sin6_flowinfo = 0;
896                 if (np->sndflow)
897                         sin6->sin6_flowinfo = ip6_flowinfo(ip6);
898 
899                 sin6->sin6_scope_id = ipv6_iface_scope_id(&sin6->sin6_addr,
900                                                           IP6CB(skb)->iif);
901 
902                 if (inet6_sk(sk)->rxopt.all)
903                         pingv6_ops.ip6_datagram_recv_ctl(sk, msg, skb);
904 #endif
905         } else {
906                 BUG();
907         }
908 
909         err = copied;
910 
911 done:
912         skb_free_datagram(sk, skb);
913 out:
914         pr_debug("ping_recvmsg -> %d\n", err);
915         return err;
916 }
917 EXPORT_SYMBOL_GPL(ping_recvmsg);
918 
919 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
920 {
921         pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
922                  inet_sk(sk), inet_sk(sk)->inet_num, skb);
923         if (sock_queue_rcv_skb(sk, skb) < 0) {
924                 kfree_skb(skb);
925                 pr_debug("ping_queue_rcv_skb -> failed\n");
926                 return -1;
927         }
928         return 0;
929 }
930 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
931 
932 
933 /*
934  *      All we need to do is get the socket.
935  */
936 
937 void ping_rcv(struct sk_buff *skb)
938 {
939         struct sock *sk;
940         struct net *net = dev_net(skb->dev);
941         struct icmphdr *icmph = icmp_hdr(skb);
942 
943         /* We assume the packet has already been checked by icmp_rcv */
944 
945         pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
946                  skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
947 
948         /* Push ICMP header back */
949         skb_push(skb, skb->data - (u8 *)icmph);
950 
951         sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
952         if (sk != NULL) {
953                 pr_debug("rcv on socket %p\n", sk);
954                 ping_queue_rcv_skb(sk, skb_get(skb));
955                 sock_put(sk);
956                 return;
957         }
958         pr_debug("no socket, dropping\n");
959 
960         /* We're called from icmp_rcv(). kfree_skb() is done there. */
961 }
962 EXPORT_SYMBOL_GPL(ping_rcv);
963 
964 struct proto ping_prot = {
965         .name =         "PING",
966         .owner =        THIS_MODULE,
967         .init =         ping_init_sock,
968         .close =        ping_close,
969         .connect =      ip4_datagram_connect,
970         .disconnect =   udp_disconnect,
971         .setsockopt =   ip_setsockopt,
972         .getsockopt =   ip_getsockopt,
973         .sendmsg =      ping_v4_sendmsg,
974         .recvmsg =      ping_recvmsg,
975         .bind =         ping_bind,
976         .backlog_rcv =  ping_queue_rcv_skb,
977         .release_cb =   ip4_datagram_release_cb,
978         .hash =         ping_hash,
979         .unhash =       ping_unhash,
980         .get_port =     ping_get_port,
981         .obj_size =     sizeof(struct inet_sock),
982 };
983 EXPORT_SYMBOL(ping_prot);
984 
985 #ifdef CONFIG_PROC_FS
986 
987 static struct sock *ping_get_first(struct seq_file *seq, int start)
988 {
989         struct sock *sk;
990         struct ping_iter_state *state = seq->private;
991         struct net *net = seq_file_net(seq);
992 
993         for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
994              ++state->bucket) {
995                 struct hlist_nulls_node *node;
996                 struct hlist_nulls_head *hslot;
997 
998                 hslot = &ping_table.hash[state->bucket];
999 
1000                 if (hlist_nulls_empty(hslot))
1001                         continue;
1002 
1003                 sk_nulls_for_each(sk, node, hslot) {
1004                         if (net_eq(sock_net(sk), net) &&
1005                             sk->sk_family == state->family)
1006                                 goto found;
1007                 }
1008         }
1009         sk = NULL;
1010 found:
1011         return sk;
1012 }
1013 
1014 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
1015 {
1016         struct ping_iter_state *state = seq->private;
1017         struct net *net = seq_file_net(seq);
1018 
1019         do {
1020                 sk = sk_nulls_next(sk);
1021         } while (sk && (!net_eq(sock_net(sk), net)));
1022 
1023         if (!sk)
1024                 return ping_get_first(seq, state->bucket + 1);
1025         return sk;
1026 }
1027 
1028 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
1029 {
1030         struct sock *sk = ping_get_first(seq, 0);
1031 
1032         if (sk)
1033                 while (pos && (sk = ping_get_next(seq, sk)) != NULL)
1034                         --pos;
1035         return pos ? NULL : sk;
1036 }
1037 
1038 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
1039 {
1040         struct ping_iter_state *state = seq->private;
1041         state->bucket = 0;
1042         state->family = family;
1043 
1044         read_lock_bh(&ping_table.lock);
1045 
1046         return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1047 }
1048 EXPORT_SYMBOL_GPL(ping_seq_start);
1049 
1050 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos)
1051 {
1052         return ping_seq_start(seq, pos, AF_INET);
1053 }
1054 
1055 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1056 {
1057         struct sock *sk;
1058 
1059         if (v == SEQ_START_TOKEN)
1060                 sk = ping_get_idx(seq, 0);
1061         else
1062                 sk = ping_get_next(seq, v);
1063 
1064         ++*pos;
1065         return sk;
1066 }
1067 EXPORT_SYMBOL_GPL(ping_seq_next);
1068 
1069 void ping_seq_stop(struct seq_file *seq, void *v)
1070 {
1071         read_unlock_bh(&ping_table.lock);
1072 }
1073 EXPORT_SYMBOL_GPL(ping_seq_stop);
1074 
1075 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f,
1076                 int bucket, int *len)
1077 {
1078         struct inet_sock *inet = inet_sk(sp);
1079         __be32 dest = inet->inet_daddr;
1080         __be32 src = inet->inet_rcv_saddr;
1081         __u16 destp = ntohs(inet->inet_dport);
1082         __u16 srcp = ntohs(inet->inet_sport);
1083 
1084         seq_printf(f, "%5d: %08X:%04X %08X:%04X"
1085                 " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %pK %d%n",
1086                 bucket, src, srcp, dest, destp, sp->sk_state,
1087                 sk_wmem_alloc_get(sp),
1088                 sk_rmem_alloc_get(sp),
1089                 0, 0L, 0,
1090                 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
1091                 0, sock_i_ino(sp),
1092                 atomic_read(&sp->sk_refcnt), sp,
1093                 atomic_read(&sp->sk_drops), len);
1094 }
1095 
1096 static int ping_v4_seq_show(struct seq_file *seq, void *v)
1097 {
1098         if (v == SEQ_START_TOKEN)
1099                 seq_printf(seq, "%-127s\n",
1100                            "  sl  local_address rem_address   st tx_queue "
1101                            "rx_queue tr tm->when retrnsmt   uid  timeout "
1102                            "inode ref pointer drops");
1103         else {
1104                 struct ping_iter_state *state = seq->private;
1105                 int len;
1106 
1107                 ping_v4_format_sock(v, seq, state->bucket, &len);
1108                 seq_printf(seq, "%*s\n", 127 - len, "");
1109         }
1110         return 0;
1111 }
1112 
1113 static const struct seq_operations ping_v4_seq_ops = {
1114         .show           = ping_v4_seq_show,
1115         .start          = ping_v4_seq_start,
1116         .next           = ping_seq_next,
1117         .stop           = ping_seq_stop,
1118 };
1119 
1120 static int ping_seq_open(struct inode *inode, struct file *file)
1121 {
1122         struct ping_seq_afinfo *afinfo = PDE_DATA(inode);
1123         return seq_open_net(inode, file, &afinfo->seq_ops,
1124                            sizeof(struct ping_iter_state));
1125 }
1126 
1127 const struct file_operations ping_seq_fops = {
1128         .open           = ping_seq_open,
1129         .read           = seq_read,
1130         .llseek         = seq_lseek,
1131         .release        = seq_release_net,
1132 };
1133 EXPORT_SYMBOL_GPL(ping_seq_fops);
1134 
1135 static struct ping_seq_afinfo ping_v4_seq_afinfo = {
1136         .name           = "icmp",
1137         .family         = AF_INET,
1138         .seq_fops       = &ping_seq_fops,
1139         .seq_ops        = {
1140                 .start          = ping_v4_seq_start,
1141                 .show           = ping_v4_seq_show,
1142                 .next           = ping_seq_next,
1143                 .stop           = ping_seq_stop,
1144         },
1145 };
1146 
1147 int ping_proc_register(struct net *net, struct ping_seq_afinfo *afinfo)
1148 {
1149         struct proc_dir_entry *p;
1150         p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
1151                              afinfo->seq_fops, afinfo);
1152         if (!p)
1153                 return -ENOMEM;
1154         return 0;
1155 }
1156 EXPORT_SYMBOL_GPL(ping_proc_register);
1157 
1158 void ping_proc_unregister(struct net *net, struct ping_seq_afinfo *afinfo)
1159 {
1160         remove_proc_entry(afinfo->name, net->proc_net);
1161 }
1162 EXPORT_SYMBOL_GPL(ping_proc_unregister);
1163 
1164 static int __net_init ping_v4_proc_init_net(struct net *net)
1165 {
1166         return ping_proc_register(net, &ping_v4_seq_afinfo);
1167 }
1168 
1169 static void __net_exit ping_v4_proc_exit_net(struct net *net)
1170 {
1171         ping_proc_unregister(net, &ping_v4_seq_afinfo);
1172 }
1173 
1174 static struct pernet_operations ping_v4_net_ops = {
1175         .init = ping_v4_proc_init_net,
1176         .exit = ping_v4_proc_exit_net,
1177 };
1178 
1179 int __init ping_proc_init(void)
1180 {
1181         return register_pernet_subsys(&ping_v4_net_ops);
1182 }
1183 
1184 void ping_proc_exit(void)
1185 {
1186         unregister_pernet_subsys(&ping_v4_net_ops);
1187 }
1188 
1189 #endif
1190 
1191 void __init ping_init(void)
1192 {
1193         int i;
1194 
1195         for (i = 0; i < PING_HTABLE_SIZE; i++)
1196                 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i);
1197         rwlock_init(&ping_table.lock);
1198 }
1199 

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