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 int ping_hashfn(struct net *net, unsigned int num, unsigned int mask)
 68 {
 69         int res = (num + net_hash_mix(net)) & mask;
 70 
 71         pr_debug("hash(%d) = %d\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                 sock_put(sk);
162                 isk->inet_num = 0;
163                 isk->inet_sport = 0;
164                 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
165                 write_unlock_bh(&ping_table.lock);
166         }
167 }
168 EXPORT_SYMBOL_GPL(ping_unhash);
169 
170 static struct sock *ping_lookup(struct net *net, struct sk_buff *skb, u16 ident)
171 {
172         struct hlist_nulls_head *hslot = ping_hashslot(&ping_table, net, ident);
173         struct sock *sk = NULL;
174         struct inet_sock *isk;
175         struct hlist_nulls_node *hnode;
176         int dif = skb->dev->ifindex;
177 
178         if (skb->protocol == htons(ETH_P_IP)) {
179                 pr_debug("try to find: num = %d, daddr = %pI4, dif = %d\n",
180                          (int)ident, &ip_hdr(skb)->daddr, dif);
181 #if IS_ENABLED(CONFIG_IPV6)
182         } else if (skb->protocol == htons(ETH_P_IPV6)) {
183                 pr_debug("try to find: num = %d, daddr = %pI6c, dif = %d\n",
184                          (int)ident, &ipv6_hdr(skb)->daddr, dif);
185 #endif
186         }
187 
188         read_lock_bh(&ping_table.lock);
189 
190         ping_portaddr_for_each_entry(sk, hnode, hslot) {
191                 isk = inet_sk(sk);
192 
193                 pr_debug("iterate\n");
194                 if (isk->inet_num != ident)
195                         continue;
196 
197                 if (skb->protocol == htons(ETH_P_IP) &&
198                     sk->sk_family == AF_INET) {
199                         pr_debug("found: %p: num=%d, daddr=%pI4, dif=%d\n", sk,
200                                  (int) isk->inet_num, &isk->inet_rcv_saddr,
201                                  sk->sk_bound_dev_if);
202 
203                         if (isk->inet_rcv_saddr &&
204                             isk->inet_rcv_saddr != ip_hdr(skb)->daddr)
205                                 continue;
206 #if IS_ENABLED(CONFIG_IPV6)
207                 } else if (skb->protocol == htons(ETH_P_IPV6) &&
208                            sk->sk_family == AF_INET6) {
209 
210                         pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk,
211                                  (int) isk->inet_num,
212                                  &sk->sk_v6_rcv_saddr,
213                                  sk->sk_bound_dev_if);
214 
215                         if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
216                             !ipv6_addr_equal(&sk->sk_v6_rcv_saddr,
217                                              &ipv6_hdr(skb)->daddr))
218                                 continue;
219 #endif
220                 }
221 
222                 if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)
223                         continue;
224 
225                 sock_hold(sk);
226                 goto exit;
227         }
228 
229         sk = NULL;
230 exit:
231         read_unlock_bh(&ping_table.lock);
232 
233         return sk;
234 }
235 
236 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low,
237                                           kgid_t *high)
238 {
239         kgid_t *data = net->ipv4.sysctl_ping_group_range;
240         unsigned int seq;
241 
242         do {
243                 seq = read_seqbegin(&net->ipv4.sysctl_local_ports.lock);
244 
245                 *low = data[0];
246                 *high = data[1];
247         } while (read_seqretry(&net->ipv4.sysctl_local_ports.lock, seq));
248 }
249 
250 
251 int ping_init_sock(struct sock *sk)
252 {
253         struct net *net = sock_net(sk);
254         kgid_t group = current_egid();
255         struct group_info *group_info = get_current_groups();
256         int i, j, count = group_info->ngroups;
257         kgid_t low, high;
258 
259         inet_get_ping_group_range_net(net, &low, &high);
260         if (gid_lte(low, group) && gid_lte(group, high))
261                 return 0;
262 
263         for (i = 0; i < group_info->nblocks; i++) {
264                 int cp_count = min_t(int, NGROUPS_PER_BLOCK, count);
265                 for (j = 0; j < cp_count; j++) {
266                         kgid_t gid = group_info->blocks[i][j];
267                         if (gid_lte(low, gid) && gid_lte(gid, high))
268                                 return 0;
269                 }
270 
271                 count -= cp_count;
272         }
273 
274         return -EACCES;
275 }
276 EXPORT_SYMBOL_GPL(ping_init_sock);
277 
278 void ping_close(struct sock *sk, long timeout)
279 {
280         pr_debug("ping_close(sk=%p,sk->num=%u)\n",
281                  inet_sk(sk), inet_sk(sk)->inet_num);
282         pr_debug("isk->refcnt = %d\n", sk->sk_refcnt.counter);
283 
284         sk_common_release(sk);
285 }
286 EXPORT_SYMBOL_GPL(ping_close);
287 
288 /* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */
289 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
290                                 struct sockaddr *uaddr, int addr_len) {
291         struct net *net = sock_net(sk);
292         if (sk->sk_family == AF_INET) {
293                 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
294                 int chk_addr_ret;
295 
296                 if (addr_len < sizeof(*addr))
297                         return -EINVAL;
298 
299                 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",
300                          sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
301 
302                 chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
303 
304                 if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
305                         chk_addr_ret = RTN_LOCAL;
306 
307                 if ((sysctl_ip_nonlocal_bind == 0 &&
308                     isk->freebind == 0 && isk->transparent == 0 &&
309                      chk_addr_ret != RTN_LOCAL) ||
310                     chk_addr_ret == RTN_MULTICAST ||
311                     chk_addr_ret == RTN_BROADCAST)
312                         return -EADDRNOTAVAIL;
313 
314 #if IS_ENABLED(CONFIG_IPV6)
315         } else if (sk->sk_family == AF_INET6) {
316                 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
317                 int addr_type, scoped, has_addr;
318                 struct net_device *dev = NULL;
319 
320                 if (addr_len < sizeof(*addr))
321                         return -EINVAL;
322 
323                 if (addr->sin6_family != AF_INET6)
324                         return -EINVAL;
325 
326                 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n",
327                          sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port));
328 
329                 addr_type = ipv6_addr_type(&addr->sin6_addr);
330                 scoped = __ipv6_addr_needs_scope_id(addr_type);
331                 if ((addr_type != IPV6_ADDR_ANY &&
332                      !(addr_type & IPV6_ADDR_UNICAST)) ||
333                     (scoped && !addr->sin6_scope_id))
334                         return -EINVAL;
335 
336                 rcu_read_lock();
337                 if (addr->sin6_scope_id) {
338                         dev = dev_get_by_index_rcu(net, addr->sin6_scope_id);
339                         if (!dev) {
340                                 rcu_read_unlock();
341                                 return -ENODEV;
342                         }
343                 }
344                 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev,
345                                                     scoped);
346                 rcu_read_unlock();
347 
348                 if (!(isk->freebind || isk->transparent || has_addr ||
349                       addr_type == IPV6_ADDR_ANY))
350                         return -EADDRNOTAVAIL;
351 
352                 if (scoped)
353                         sk->sk_bound_dev_if = addr->sin6_scope_id;
354 #endif
355         } else {
356                 return -EAFNOSUPPORT;
357         }
358         return 0;
359 }
360 
361 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr)
362 {
363         if (saddr->sa_family == AF_INET) {
364                 struct inet_sock *isk = inet_sk(sk);
365                 struct sockaddr_in *addr = (struct sockaddr_in *) saddr;
366                 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
367 #if IS_ENABLED(CONFIG_IPV6)
368         } else if (saddr->sa_family == AF_INET6) {
369                 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr;
370                 struct ipv6_pinfo *np = inet6_sk(sk);
371                 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr;
372 #endif
373         }
374 }
375 
376 static void ping_clear_saddr(struct sock *sk, int dif)
377 {
378         sk->sk_bound_dev_if = dif;
379         if (sk->sk_family == AF_INET) {
380                 struct inet_sock *isk = inet_sk(sk);
381                 isk->inet_rcv_saddr = isk->inet_saddr = 0;
382 #if IS_ENABLED(CONFIG_IPV6)
383         } else if (sk->sk_family == AF_INET6) {
384                 struct ipv6_pinfo *np = inet6_sk(sk);
385                 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
386                 memset(&np->saddr, 0, sizeof(np->saddr));
387 #endif
388         }
389 }
390 /*
391  * We need our own bind because there are no privileged id's == local ports.
392  * Moreover, we don't allow binding to multi- and broadcast addresses.
393  */
394 
395 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
396 {
397         struct inet_sock *isk = inet_sk(sk);
398         unsigned short snum;
399         int err;
400         int dif = sk->sk_bound_dev_if;
401 
402         err = ping_check_bind_addr(sk, isk, uaddr, addr_len);
403         if (err)
404                 return err;
405 
406         lock_sock(sk);
407 
408         err = -EINVAL;
409         if (isk->inet_num != 0)
410                 goto out;
411 
412         err = -EADDRINUSE;
413         ping_set_saddr(sk, uaddr);
414         snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port);
415         if (ping_get_port(sk, snum) != 0) {
416                 ping_clear_saddr(sk, dif);
417                 goto out;
418         }
419 
420         pr_debug("after bind(): num = %d, dif = %d\n",
421                  (int)isk->inet_num,
422                  (int)sk->sk_bound_dev_if);
423 
424         err = 0;
425         if (sk->sk_family == AF_INET && isk->inet_rcv_saddr)
426                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
427 #if IS_ENABLED(CONFIG_IPV6)
428         if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr))
429                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
430 #endif
431 
432         if (snum)
433                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
434         isk->inet_sport = htons(isk->inet_num);
435         isk->inet_daddr = 0;
436         isk->inet_dport = 0;
437 
438 #if IS_ENABLED(CONFIG_IPV6)
439         if (sk->sk_family == AF_INET6)
440                 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr));
441 #endif
442 
443         sk_dst_reset(sk);
444 out:
445         release_sock(sk);
446         pr_debug("ping_v4_bind -> %d\n", err);
447         return err;
448 }
449 EXPORT_SYMBOL_GPL(ping_bind);
450 
451 /*
452  * Is this a supported type of ICMP message?
453  */
454 
455 static inline int ping_supported(int family, int type, int code)
456 {
457         return (family == AF_INET && type == ICMP_ECHO && code == 0) ||
458                (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0);
459 }
460 
461 /*
462  * This routine is called by the ICMP module when it gets some
463  * sort of error condition.
464  */
465 
466 void ping_err(struct sk_buff *skb, int offset, u32 info)
467 {
468         int family;
469         struct icmphdr *icmph;
470         struct inet_sock *inet_sock;
471         int type;
472         int code;
473         struct net *net = dev_net(skb->dev);
474         struct sock *sk;
475         int harderr;
476         int err;
477 
478         if (skb->protocol == htons(ETH_P_IP)) {
479                 family = AF_INET;
480                 type = icmp_hdr(skb)->type;
481                 code = icmp_hdr(skb)->code;
482                 icmph = (struct icmphdr *)(skb->data + offset);
483         } else if (skb->protocol == htons(ETH_P_IPV6)) {
484                 family = AF_INET6;
485                 type = icmp6_hdr(skb)->icmp6_type;
486                 code = icmp6_hdr(skb)->icmp6_code;
487                 icmph = (struct icmphdr *) (skb->data + offset);
488         } else {
489                 BUG();
490         }
491 
492         /* We assume the packet has already been checked by icmp_unreach */
493 
494         if (!ping_supported(family, icmph->type, icmph->code))
495                 return;
496 
497         pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n",
498                  skb->protocol, type, code, ntohs(icmph->un.echo.id),
499                  ntohs(icmph->un.echo.sequence));
500 
501         sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
502         if (sk == NULL) {
503                 pr_debug("no socket, dropping\n");
504                 return; /* No socket for error */
505         }
506         pr_debug("err on socket %p\n", sk);
507 
508         err = 0;
509         harderr = 0;
510         inet_sock = inet_sk(sk);
511 
512         if (skb->protocol == htons(ETH_P_IP)) {
513                 switch (type) {
514                 default:
515                 case ICMP_TIME_EXCEEDED:
516                         err = EHOSTUNREACH;
517                         break;
518                 case ICMP_SOURCE_QUENCH:
519                         /* This is not a real error but ping wants to see it.
520                          * Report it with some fake errno.
521                          */
522                         err = EREMOTEIO;
523                         break;
524                 case ICMP_PARAMETERPROB:
525                         err = EPROTO;
526                         harderr = 1;
527                         break;
528                 case ICMP_DEST_UNREACH:
529                         if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
530                                 ipv4_sk_update_pmtu(skb, sk, info);
531                                 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) {
532                                         err = EMSGSIZE;
533                                         harderr = 1;
534                                         break;
535                                 }
536                                 goto out;
537                         }
538                         err = EHOSTUNREACH;
539                         if (code <= NR_ICMP_UNREACH) {
540                                 harderr = icmp_err_convert[code].fatal;
541                                 err = icmp_err_convert[code].errno;
542                         }
543                         break;
544                 case ICMP_REDIRECT:
545                         /* See ICMP_SOURCE_QUENCH */
546                         ipv4_sk_redirect(skb, sk);
547                         err = EREMOTEIO;
548                         break;
549                 }
550 #if IS_ENABLED(CONFIG_IPV6)
551         } else if (skb->protocol == htons(ETH_P_IPV6)) {
552                 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err);
553 #endif
554         }
555 
556         /*
557          *      RFC1122: OK.  Passes ICMP errors back to application, as per
558          *      4.1.3.3.
559          */
560         if ((family == AF_INET && !inet_sock->recverr) ||
561             (family == AF_INET6 && !inet6_sk(sk)->recverr)) {
562                 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
563                         goto out;
564         } else {
565                 if (family == AF_INET) {
566                         ip_icmp_error(sk, skb, err, 0 /* no remote port */,
567                                       info, (u8 *)icmph);
568 #if IS_ENABLED(CONFIG_IPV6)
569                 } else if (family == AF_INET6) {
570                         pingv6_ops.ipv6_icmp_error(sk, skb, err, 0,
571                                                    info, (u8 *)icmph);
572 #endif
573                 }
574         }
575         sk->sk_err = err;
576         sk->sk_error_report(sk);
577 out:
578         sock_put(sk);
579 }
580 EXPORT_SYMBOL_GPL(ping_err);
581 
582 /*
583  *      Copy and checksum an ICMP Echo packet from user space into a buffer
584  *      starting from the payload.
585  */
586 
587 int ping_getfrag(void *from, char *to,
588                  int offset, int fraglen, int odd, struct sk_buff *skb)
589 {
590         struct pingfakehdr *pfh = (struct pingfakehdr *)from;
591 
592         if (offset == 0) {
593                 if (fraglen < sizeof(struct icmphdr))
594                         BUG();
595                 if (csum_partial_copy_fromiovecend(to + sizeof(struct icmphdr),
596                             pfh->iov, 0, fraglen - sizeof(struct icmphdr),
597                             &pfh->wcheck))
598                         return -EFAULT;
599         } else if (offset < sizeof(struct icmphdr)) {
600                         BUG();
601         } else {
602                 if (csum_partial_copy_fromiovecend
603                                 (to, pfh->iov, offset - sizeof(struct icmphdr),
604                                  fraglen, &pfh->wcheck))
605                         return -EFAULT;
606         }
607 
608 #if IS_ENABLED(CONFIG_IPV6)
609         /* For IPv6, checksum each skb as we go along, as expected by
610          * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in
611          * wcheck, it will be finalized in ping_v4_push_pending_frames.
612          */
613         if (pfh->family == AF_INET6) {
614                 skb->csum = pfh->wcheck;
615                 skb->ip_summed = CHECKSUM_NONE;
616                 pfh->wcheck = 0;
617         }
618 #endif
619 
620         return 0;
621 }
622 EXPORT_SYMBOL_GPL(ping_getfrag);
623 
624 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
625                                        struct flowi4 *fl4)
626 {
627         struct sk_buff *skb = skb_peek(&sk->sk_write_queue);
628 
629         pfh->wcheck = csum_partial((char *)&pfh->icmph,
630                 sizeof(struct icmphdr), pfh->wcheck);
631         pfh->icmph.checksum = csum_fold(pfh->wcheck);
632         memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
633         skb->ip_summed = CHECKSUM_NONE;
634         return ip_push_pending_frames(sk, fl4);
635 }
636 
637 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
638                         void *user_icmph, size_t icmph_len) {
639         u8 type, code;
640 
641         if (len > 0xFFFF)
642                 return -EMSGSIZE;
643 
644         /*
645          *      Check the flags.
646          */
647 
648         /* Mirror BSD error message compatibility */
649         if (msg->msg_flags & MSG_OOB)
650                 return -EOPNOTSUPP;
651 
652         /*
653          *      Fetch the ICMP header provided by the userland.
654          *      iovec is modified! The ICMP header is consumed.
655          */
656         if (memcpy_fromiovec(user_icmph, msg->msg_iov, icmph_len))
657                 return -EFAULT;
658 
659         if (family == AF_INET) {
660                 type = ((struct icmphdr *) user_icmph)->type;
661                 code = ((struct icmphdr *) user_icmph)->code;
662 #if IS_ENABLED(CONFIG_IPV6)
663         } else if (family == AF_INET6) {
664                 type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
665                 code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
666 #endif
667         } else {
668                 BUG();
669         }
670 
671         if (!ping_supported(family, type, code))
672                 return -EINVAL;
673 
674         return 0;
675 }
676 EXPORT_SYMBOL_GPL(ping_common_sendmsg);
677 
678 static int ping_v4_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
679                            size_t len)
680 {
681         struct net *net = sock_net(sk);
682         struct flowi4 fl4;
683         struct inet_sock *inet = inet_sk(sk);
684         struct ipcm_cookie ipc;
685         struct icmphdr user_icmph;
686         struct pingfakehdr pfh;
687         struct rtable *rt = NULL;
688         struct ip_options_data opt_copy;
689         int free = 0;
690         __be32 saddr, daddr, faddr;
691         u8  tos;
692         int err;
693 
694         pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
695 
696         err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
697                                   sizeof(user_icmph));
698         if (err)
699                 return err;
700 
701         /*
702          *      Get and verify the address.
703          */
704 
705         if (msg->msg_name) {
706                 DECLARE_SOCKADDR(struct sockaddr_in *, usin, msg->msg_name);
707                 if (msg->msg_namelen < sizeof(*usin))
708                         return -EINVAL;
709                 if (usin->sin_family != AF_INET)
710                         return -EINVAL;
711                 daddr = usin->sin_addr.s_addr;
712                 /* no remote port */
713         } else {
714                 if (sk->sk_state != TCP_ESTABLISHED)
715                         return -EDESTADDRREQ;
716                 daddr = inet->inet_daddr;
717                 /* no remote port */
718         }
719 
720         ipc.addr = inet->inet_saddr;
721         ipc.opt = NULL;
722         ipc.oif = sk->sk_bound_dev_if;
723         ipc.tx_flags = 0;
724         ipc.ttl = 0;
725         ipc.tos = -1;
726 
727         sock_tx_timestamp(sk, &ipc.tx_flags);
728 
729         if (msg->msg_controllen) {
730                 err = ip_cmsg_send(sock_net(sk), msg, &ipc);
731                 if (err)
732                         return err;
733                 if (ipc.opt)
734                         free = 1;
735         }
736         if (!ipc.opt) {
737                 struct ip_options_rcu *inet_opt;
738 
739                 rcu_read_lock();
740                 inet_opt = rcu_dereference(inet->inet_opt);
741                 if (inet_opt) {
742                         memcpy(&opt_copy, inet_opt,
743                                sizeof(*inet_opt) + inet_opt->opt.optlen);
744                         ipc.opt = &opt_copy.opt;
745                 }
746                 rcu_read_unlock();
747         }
748 
749         saddr = ipc.addr;
750         ipc.addr = faddr = daddr;
751 
752         if (ipc.opt && ipc.opt->opt.srr) {
753                 if (!daddr)
754                         return -EINVAL;
755                 faddr = ipc.opt->opt.faddr;
756         }
757         tos = get_rttos(&ipc, inet);
758         if (sock_flag(sk, SOCK_LOCALROUTE) ||
759             (msg->msg_flags & MSG_DONTROUTE) ||
760             (ipc.opt && ipc.opt->opt.is_strictroute)) {
761                 tos |= RTO_ONLINK;
762         }
763 
764         if (ipv4_is_multicast(daddr)) {
765                 if (!ipc.oif)
766                         ipc.oif = inet->mc_index;
767                 if (!saddr)
768                         saddr = inet->mc_addr;
769         } else if (!ipc.oif)
770                 ipc.oif = inet->uc_index;
771 
772         flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
773                            RT_SCOPE_UNIVERSE, sk->sk_protocol,
774                            inet_sk_flowi_flags(sk), faddr, saddr, 0, 0);
775 
776         security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
777         rt = ip_route_output_flow(net, &fl4, sk);
778         if (IS_ERR(rt)) {
779                 err = PTR_ERR(rt);
780                 rt = NULL;
781                 if (err == -ENETUNREACH)
782                         IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
783                 goto out;
784         }
785 
786         err = -EACCES;
787         if ((rt->rt_flags & RTCF_BROADCAST) &&
788             !sock_flag(sk, SOCK_BROADCAST))
789                 goto out;
790 
791         if (msg->msg_flags & MSG_CONFIRM)
792                 goto do_confirm;
793 back_from_confirm:
794 
795         if (!ipc.addr)
796                 ipc.addr = fl4.daddr;
797 
798         lock_sock(sk);
799 
800         pfh.icmph.type = user_icmph.type; /* already checked */
801         pfh.icmph.code = user_icmph.code; /* ditto */
802         pfh.icmph.checksum = 0;
803         pfh.icmph.un.echo.id = inet->inet_sport;
804         pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
805         pfh.iov = msg->msg_iov;
806         pfh.wcheck = 0;
807         pfh.family = AF_INET;
808 
809         err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
810                         0, &ipc, &rt, msg->msg_flags);
811         if (err)
812                 ip_flush_pending_frames(sk);
813         else
814                 err = ping_v4_push_pending_frames(sk, &pfh, &fl4);
815         release_sock(sk);
816 
817 out:
818         ip_rt_put(rt);
819         if (free)
820                 kfree(ipc.opt);
821         if (!err) {
822                 icmp_out_count(sock_net(sk), user_icmph.type);
823                 return len;
824         }
825         return err;
826 
827 do_confirm:
828         dst_confirm(&rt->dst);
829         if (!(msg->msg_flags & MSG_PROBE) || len)
830                 goto back_from_confirm;
831         err = 0;
832         goto out;
833 }
834 
835 int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
836                  size_t len, int noblock, int flags, int *addr_len)
837 {
838         struct inet_sock *isk = inet_sk(sk);
839         int family = sk->sk_family;
840         struct sk_buff *skb;
841         int copied, err;
842 
843         pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
844 
845         err = -EOPNOTSUPP;
846         if (flags & MSG_OOB)
847                 goto out;
848 
849         if (flags & MSG_ERRQUEUE) {
850                 if (family == AF_INET) {
851                         return ip_recv_error(sk, msg, len, addr_len);
852 #if IS_ENABLED(CONFIG_IPV6)
853                 } else if (family == AF_INET6) {
854                         return pingv6_ops.ipv6_recv_error(sk, msg, len,
855                                                           addr_len);
856 #endif
857                 }
858         }
859 
860         skb = skb_recv_datagram(sk, flags, noblock, &err);
861         if (!skb)
862                 goto out;
863 
864         copied = skb->len;
865         if (copied > len) {
866                 msg->msg_flags |= MSG_TRUNC;
867                 copied = len;
868         }
869 
870         /* Don't bother checking the checksum */
871         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
872         if (err)
873                 goto done;
874 
875         sock_recv_timestamp(msg, sk, skb);
876 
877         /* Copy the address and add cmsg data. */
878         if (family == AF_INET) {
879                 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
880 
881                 if (sin) {
882                         sin->sin_family = AF_INET;
883                         sin->sin_port = 0 /* skb->h.uh->source */;
884                         sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
885                         memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
886                         *addr_len = sizeof(*sin);
887                 }
888 
889                 if (isk->cmsg_flags)
890                         ip_cmsg_recv(msg, skb);
891 
892 #if IS_ENABLED(CONFIG_IPV6)
893         } else if (family == AF_INET6) {
894                 struct ipv6_pinfo *np = inet6_sk(sk);
895                 struct ipv6hdr *ip6 = ipv6_hdr(skb);
896                 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
897 
898                 if (sin6) {
899                         sin6->sin6_family = AF_INET6;
900                         sin6->sin6_port = 0;
901                         sin6->sin6_addr = ip6->saddr;
902                         sin6->sin6_flowinfo = 0;
903                         if (np->sndflow)
904                                 sin6->sin6_flowinfo = ip6_flowinfo(ip6);
905                         sin6->sin6_scope_id =
906                                 ipv6_iface_scope_id(&sin6->sin6_addr,
907                                                     IP6CB(skb)->iif);
908                         *addr_len = sizeof(*sin6);
909                 }
910 
911                 if (inet6_sk(sk)->rxopt.all)
912                         pingv6_ops.ip6_datagram_recv_common_ctl(sk, msg, skb);
913                 if (skb->protocol == htons(ETH_P_IPV6) &&
914                     inet6_sk(sk)->rxopt.all)
915                         pingv6_ops.ip6_datagram_recv_specific_ctl(sk, msg, skb);
916                 else if (skb->protocol == htons(ETH_P_IP) && isk->cmsg_flags)
917                         ip_cmsg_recv(msg, skb);
918 #endif
919         } else {
920                 BUG();
921         }
922 
923         err = copied;
924 
925 done:
926         skb_free_datagram(sk, skb);
927 out:
928         pr_debug("ping_recvmsg -> %d\n", err);
929         return err;
930 }
931 EXPORT_SYMBOL_GPL(ping_recvmsg);
932 
933 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
934 {
935         pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
936                  inet_sk(sk), inet_sk(sk)->inet_num, skb);
937         if (sock_queue_rcv_skb(sk, skb) < 0) {
938                 kfree_skb(skb);
939                 pr_debug("ping_queue_rcv_skb -> failed\n");
940                 return -1;
941         }
942         return 0;
943 }
944 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
945 
946 
947 /*
948  *      All we need to do is get the socket.
949  */
950 
951 void ping_rcv(struct sk_buff *skb)
952 {
953         struct sock *sk;
954         struct net *net = dev_net(skb->dev);
955         struct icmphdr *icmph = icmp_hdr(skb);
956 
957         /* We assume the packet has already been checked by icmp_rcv */
958 
959         pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
960                  skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
961 
962         /* Push ICMP header back */
963         skb_push(skb, skb->data - (u8 *)icmph);
964 
965         sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
966         if (sk != NULL) {
967                 pr_debug("rcv on socket %p\n", sk);
968                 ping_queue_rcv_skb(sk, skb_get(skb));
969                 sock_put(sk);
970                 return;
971         }
972         pr_debug("no socket, dropping\n");
973 
974         /* We're called from icmp_rcv(). kfree_skb() is done there. */
975 }
976 EXPORT_SYMBOL_GPL(ping_rcv);
977 
978 struct proto ping_prot = {
979         .name =         "PING",
980         .owner =        THIS_MODULE,
981         .init =         ping_init_sock,
982         .close =        ping_close,
983         .connect =      ip4_datagram_connect,
984         .disconnect =   udp_disconnect,
985         .setsockopt =   ip_setsockopt,
986         .getsockopt =   ip_getsockopt,
987         .sendmsg =      ping_v4_sendmsg,
988         .recvmsg =      ping_recvmsg,
989         .bind =         ping_bind,
990         .backlog_rcv =  ping_queue_rcv_skb,
991         .release_cb =   ip4_datagram_release_cb,
992         .hash =         ping_hash,
993         .unhash =       ping_unhash,
994         .get_port =     ping_get_port,
995         .obj_size =     sizeof(struct inet_sock),
996 };
997 EXPORT_SYMBOL(ping_prot);
998 
999 #ifdef CONFIG_PROC_FS
1000 
1001 static struct sock *ping_get_first(struct seq_file *seq, int start)
1002 {
1003         struct sock *sk;
1004         struct ping_iter_state *state = seq->private;
1005         struct net *net = seq_file_net(seq);
1006 
1007         for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
1008              ++state->bucket) {
1009                 struct hlist_nulls_node *node;
1010                 struct hlist_nulls_head *hslot;
1011 
1012                 hslot = &ping_table.hash[state->bucket];
1013 
1014                 if (hlist_nulls_empty(hslot))
1015                         continue;
1016 
1017                 sk_nulls_for_each(sk, node, hslot) {
1018                         if (net_eq(sock_net(sk), net) &&
1019                             sk->sk_family == state->family)
1020                                 goto found;
1021                 }
1022         }
1023         sk = NULL;
1024 found:
1025         return sk;
1026 }
1027 
1028 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
1029 {
1030         struct ping_iter_state *state = seq->private;
1031         struct net *net = seq_file_net(seq);
1032 
1033         do {
1034                 sk = sk_nulls_next(sk);
1035         } while (sk && (!net_eq(sock_net(sk), net)));
1036 
1037         if (!sk)
1038                 return ping_get_first(seq, state->bucket + 1);
1039         return sk;
1040 }
1041 
1042 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
1043 {
1044         struct sock *sk = ping_get_first(seq, 0);
1045 
1046         if (sk)
1047                 while (pos && (sk = ping_get_next(seq, sk)) != NULL)
1048                         --pos;
1049         return pos ? NULL : sk;
1050 }
1051 
1052 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
1053 {
1054         struct ping_iter_state *state = seq->private;
1055         state->bucket = 0;
1056         state->family = family;
1057 
1058         read_lock_bh(&ping_table.lock);
1059 
1060         return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1061 }
1062 EXPORT_SYMBOL_GPL(ping_seq_start);
1063 
1064 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos)
1065 {
1066         return ping_seq_start(seq, pos, AF_INET);
1067 }
1068 
1069 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1070 {
1071         struct sock *sk;
1072 
1073         if (v == SEQ_START_TOKEN)
1074                 sk = ping_get_idx(seq, 0);
1075         else
1076                 sk = ping_get_next(seq, v);
1077 
1078         ++*pos;
1079         return sk;
1080 }
1081 EXPORT_SYMBOL_GPL(ping_seq_next);
1082 
1083 void ping_seq_stop(struct seq_file *seq, void *v)
1084 {
1085         read_unlock_bh(&ping_table.lock);
1086 }
1087 EXPORT_SYMBOL_GPL(ping_seq_stop);
1088 
1089 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f,
1090                 int bucket)
1091 {
1092         struct inet_sock *inet = inet_sk(sp);
1093         __be32 dest = inet->inet_daddr;
1094         __be32 src = inet->inet_rcv_saddr;
1095         __u16 destp = ntohs(inet->inet_dport);
1096         __u16 srcp = ntohs(inet->inet_sport);
1097 
1098         seq_printf(f, "%5d: %08X:%04X %08X:%04X"
1099                 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d",
1100                 bucket, src, srcp, dest, destp, sp->sk_state,
1101                 sk_wmem_alloc_get(sp),
1102                 sk_rmem_alloc_get(sp),
1103                 0, 0L, 0,
1104                 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
1105                 0, sock_i_ino(sp),
1106                 atomic_read(&sp->sk_refcnt), sp,
1107                 atomic_read(&sp->sk_drops));
1108 }
1109 
1110 static int ping_v4_seq_show(struct seq_file *seq, void *v)
1111 {
1112         seq_setwidth(seq, 127);
1113         if (v == SEQ_START_TOKEN)
1114                 seq_puts(seq, "  sl  local_address rem_address   st tx_queue "
1115                            "rx_queue tr tm->when retrnsmt   uid  timeout "
1116                            "inode ref pointer drops");
1117         else {
1118                 struct ping_iter_state *state = seq->private;
1119 
1120                 ping_v4_format_sock(v, seq, state->bucket);
1121         }
1122         seq_pad(seq, '\n');
1123         return 0;
1124 }
1125 
1126 static const struct seq_operations ping_v4_seq_ops = {
1127         .show           = ping_v4_seq_show,
1128         .start          = ping_v4_seq_start,
1129         .next           = ping_seq_next,
1130         .stop           = ping_seq_stop,
1131 };
1132 
1133 static int ping_seq_open(struct inode *inode, struct file *file)
1134 {
1135         struct ping_seq_afinfo *afinfo = PDE_DATA(inode);
1136         return seq_open_net(inode, file, &afinfo->seq_ops,
1137                            sizeof(struct ping_iter_state));
1138 }
1139 
1140 const struct file_operations ping_seq_fops = {
1141         .open           = ping_seq_open,
1142         .read           = seq_read,
1143         .llseek         = seq_lseek,
1144         .release        = seq_release_net,
1145 };
1146 EXPORT_SYMBOL_GPL(ping_seq_fops);
1147 
1148 static struct ping_seq_afinfo ping_v4_seq_afinfo = {
1149         .name           = "icmp",
1150         .family         = AF_INET,
1151         .seq_fops       = &ping_seq_fops,
1152         .seq_ops        = {
1153                 .start          = ping_v4_seq_start,
1154                 .show           = ping_v4_seq_show,
1155                 .next           = ping_seq_next,
1156                 .stop           = ping_seq_stop,
1157         },
1158 };
1159 
1160 int ping_proc_register(struct net *net, struct ping_seq_afinfo *afinfo)
1161 {
1162         struct proc_dir_entry *p;
1163         p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
1164                              afinfo->seq_fops, afinfo);
1165         if (!p)
1166                 return -ENOMEM;
1167         return 0;
1168 }
1169 EXPORT_SYMBOL_GPL(ping_proc_register);
1170 
1171 void ping_proc_unregister(struct net *net, struct ping_seq_afinfo *afinfo)
1172 {
1173         remove_proc_entry(afinfo->name, net->proc_net);
1174 }
1175 EXPORT_SYMBOL_GPL(ping_proc_unregister);
1176 
1177 static int __net_init ping_v4_proc_init_net(struct net *net)
1178 {
1179         return ping_proc_register(net, &ping_v4_seq_afinfo);
1180 }
1181 
1182 static void __net_exit ping_v4_proc_exit_net(struct net *net)
1183 {
1184         ping_proc_unregister(net, &ping_v4_seq_afinfo);
1185 }
1186 
1187 static struct pernet_operations ping_v4_net_ops = {
1188         .init = ping_v4_proc_init_net,
1189         .exit = ping_v4_proc_exit_net,
1190 };
1191 
1192 int __init ping_proc_init(void)
1193 {
1194         return register_pernet_subsys(&ping_v4_net_ops);
1195 }
1196 
1197 void ping_proc_exit(void)
1198 {
1199         unregister_pernet_subsys(&ping_v4_net_ops);
1200 }
1201 
1202 #endif
1203 
1204 void __init ping_init(void)
1205 {
1206         int i;
1207 
1208         for (i = 0; i < PING_HTABLE_SIZE; i++)
1209                 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i);
1210         rwlock_init(&ping_table.lock);
1211 }
1212 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us