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 
 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 
206                         pr_debug("found: %p: num=%d, daddr=%pI6c, dif=%d\n", sk,
207                                  (int) isk->inet_num,
208                                  &sk->sk_v6_rcv_saddr,
209                                  sk->sk_bound_dev_if);
210 
211                         if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr) &&
212                             !ipv6_addr_equal(&sk->sk_v6_rcv_saddr,
213                                              &ipv6_hdr(skb)->daddr))
214                                 continue;
215 #endif
216                 }
217 
218                 if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)
219                         continue;
220 
221                 sock_hold(sk);
222                 goto exit;
223         }
224 
225         sk = NULL;
226 exit:
227         read_unlock_bh(&ping_table.lock);
228 
229         return sk;
230 }
231 
232 static void inet_get_ping_group_range_net(struct net *net, kgid_t *low,
233                                           kgid_t *high)
234 {
235         kgid_t *data = net->ipv4.sysctl_ping_group_range;
236         unsigned int seq;
237 
238         do {
239                 seq = read_seqbegin(&net->ipv4.sysctl_local_ports.lock);
240 
241                 *low = data[0];
242                 *high = data[1];
243         } while (read_seqretry(&net->ipv4.sysctl_local_ports.lock, seq));
244 }
245 
246 
247 int ping_init_sock(struct sock *sk)
248 {
249         struct net *net = sock_net(sk);
250         kgid_t group = current_egid();
251         struct group_info *group_info = get_current_groups();
252         int i, j, count = group_info->ngroups;
253         kgid_t low, high;
254 
255         inet_get_ping_group_range_net(net, &low, &high);
256         if (gid_lte(low, group) && gid_lte(group, high))
257                 return 0;
258 
259         for (i = 0; i < group_info->nblocks; i++) {
260                 int cp_count = min_t(int, NGROUPS_PER_BLOCK, count);
261                 for (j = 0; j < cp_count; j++) {
262                         kgid_t gid = group_info->blocks[i][j];
263                         if (gid_lte(low, gid) && gid_lte(gid, high))
264                                 return 0;
265                 }
266 
267                 count -= cp_count;
268         }
269 
270         return -EACCES;
271 }
272 EXPORT_SYMBOL_GPL(ping_init_sock);
273 
274 void ping_close(struct sock *sk, long timeout)
275 {
276         pr_debug("ping_close(sk=%p,sk->num=%u)\n",
277                  inet_sk(sk), inet_sk(sk)->inet_num);
278         pr_debug("isk->refcnt = %d\n", sk->sk_refcnt.counter);
279 
280         sk_common_release(sk);
281 }
282 EXPORT_SYMBOL_GPL(ping_close);
283 
284 /* Checks the bind address and possibly modifies sk->sk_bound_dev_if. */
285 static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk,
286                                 struct sockaddr *uaddr, int addr_len) {
287         struct net *net = sock_net(sk);
288         if (sk->sk_family == AF_INET) {
289                 struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;
290                 int chk_addr_ret;
291 
292                 if (addr_len < sizeof(*addr))
293                         return -EINVAL;
294 
295                 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",
296                          sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));
297 
298                 chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
299 
300                 if (addr->sin_addr.s_addr == htonl(INADDR_ANY))
301                         chk_addr_ret = RTN_LOCAL;
302 
303                 if ((sysctl_ip_nonlocal_bind == 0 &&
304                     isk->freebind == 0 && isk->transparent == 0 &&
305                      chk_addr_ret != RTN_LOCAL) ||
306                     chk_addr_ret == RTN_MULTICAST ||
307                     chk_addr_ret == RTN_BROADCAST)
308                         return -EADDRNOTAVAIL;
309 
310 #if IS_ENABLED(CONFIG_IPV6)
311         } else if (sk->sk_family == AF_INET6) {
312                 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) uaddr;
313                 int addr_type, scoped, has_addr;
314                 struct net_device *dev = NULL;
315 
316                 if (addr_len < sizeof(*addr))
317                         return -EINVAL;
318 
319                 pr_debug("ping_check_bind_addr(sk=%p,addr=%pI6c,port=%d)\n",
320                          sk, addr->sin6_addr.s6_addr, ntohs(addr->sin6_port));
321 
322                 addr_type = ipv6_addr_type(&addr->sin6_addr);
323                 scoped = __ipv6_addr_needs_scope_id(addr_type);
324                 if ((addr_type != IPV6_ADDR_ANY &&
325                      !(addr_type & IPV6_ADDR_UNICAST)) ||
326                     (scoped && !addr->sin6_scope_id))
327                         return -EINVAL;
328 
329                 rcu_read_lock();
330                 if (addr->sin6_scope_id) {
331                         dev = dev_get_by_index_rcu(net, addr->sin6_scope_id);
332                         if (!dev) {
333                                 rcu_read_unlock();
334                                 return -ENODEV;
335                         }
336                 }
337                 has_addr = pingv6_ops.ipv6_chk_addr(net, &addr->sin6_addr, dev,
338                                                     scoped);
339                 rcu_read_unlock();
340 
341                 if (!(isk->freebind || isk->transparent || has_addr ||
342                       addr_type == IPV6_ADDR_ANY))
343                         return -EADDRNOTAVAIL;
344 
345                 if (scoped)
346                         sk->sk_bound_dev_if = addr->sin6_scope_id;
347 #endif
348         } else {
349                 return -EAFNOSUPPORT;
350         }
351         return 0;
352 }
353 
354 static void ping_set_saddr(struct sock *sk, struct sockaddr *saddr)
355 {
356         if (saddr->sa_family == AF_INET) {
357                 struct inet_sock *isk = inet_sk(sk);
358                 struct sockaddr_in *addr = (struct sockaddr_in *) saddr;
359                 isk->inet_rcv_saddr = isk->inet_saddr = addr->sin_addr.s_addr;
360 #if IS_ENABLED(CONFIG_IPV6)
361         } else if (saddr->sa_family == AF_INET6) {
362                 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) saddr;
363                 struct ipv6_pinfo *np = inet6_sk(sk);
364                 sk->sk_v6_rcv_saddr = np->saddr = addr->sin6_addr;
365 #endif
366         }
367 }
368 
369 static void ping_clear_saddr(struct sock *sk, int dif)
370 {
371         sk->sk_bound_dev_if = dif;
372         if (sk->sk_family == AF_INET) {
373                 struct inet_sock *isk = inet_sk(sk);
374                 isk->inet_rcv_saddr = isk->inet_saddr = 0;
375 #if IS_ENABLED(CONFIG_IPV6)
376         } else if (sk->sk_family == AF_INET6) {
377                 struct ipv6_pinfo *np = inet6_sk(sk);
378                 memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
379                 memset(&np->saddr, 0, sizeof(np->saddr));
380 #endif
381         }
382 }
383 /*
384  * We need our own bind because there are no privileged id's == local ports.
385  * Moreover, we don't allow binding to multi- and broadcast addresses.
386  */
387 
388 int ping_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
389 {
390         struct inet_sock *isk = inet_sk(sk);
391         unsigned short snum;
392         int err;
393         int dif = sk->sk_bound_dev_if;
394 
395         err = ping_check_bind_addr(sk, isk, uaddr, addr_len);
396         if (err)
397                 return err;
398 
399         lock_sock(sk);
400 
401         err = -EINVAL;
402         if (isk->inet_num != 0)
403                 goto out;
404 
405         err = -EADDRINUSE;
406         ping_set_saddr(sk, uaddr);
407         snum = ntohs(((struct sockaddr_in *)uaddr)->sin_port);
408         if (ping_get_port(sk, snum) != 0) {
409                 ping_clear_saddr(sk, dif);
410                 goto out;
411         }
412 
413         pr_debug("after bind(): num = %d, dif = %d\n",
414                  (int)isk->inet_num,
415                  (int)sk->sk_bound_dev_if);
416 
417         err = 0;
418         if (sk->sk_family == AF_INET && isk->inet_rcv_saddr)
419                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
420 #if IS_ENABLED(CONFIG_IPV6)
421         if (sk->sk_family == AF_INET6 && !ipv6_addr_any(&sk->sk_v6_rcv_saddr))
422                 sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
423 #endif
424 
425         if (snum)
426                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
427         isk->inet_sport = htons(isk->inet_num);
428         isk->inet_daddr = 0;
429         isk->inet_dport = 0;
430 
431 #if IS_ENABLED(CONFIG_IPV6)
432         if (sk->sk_family == AF_INET6)
433                 memset(&sk->sk_v6_daddr, 0, sizeof(sk->sk_v6_daddr));
434 #endif
435 
436         sk_dst_reset(sk);
437 out:
438         release_sock(sk);
439         pr_debug("ping_v4_bind -> %d\n", err);
440         return err;
441 }
442 EXPORT_SYMBOL_GPL(ping_bind);
443 
444 /*
445  * Is this a supported type of ICMP message?
446  */
447 
448 static inline int ping_supported(int family, int type, int code)
449 {
450         return (family == AF_INET && type == ICMP_ECHO && code == 0) ||
451                (family == AF_INET6 && type == ICMPV6_ECHO_REQUEST && code == 0);
452 }
453 
454 /*
455  * This routine is called by the ICMP module when it gets some
456  * sort of error condition.
457  */
458 
459 void ping_err(struct sk_buff *skb, int offset, u32 info)
460 {
461         int family;
462         struct icmphdr *icmph;
463         struct inet_sock *inet_sock;
464         int type;
465         int code;
466         struct net *net = dev_net(skb->dev);
467         struct sock *sk;
468         int harderr;
469         int err;
470 
471         if (skb->protocol == htons(ETH_P_IP)) {
472                 family = AF_INET;
473                 type = icmp_hdr(skb)->type;
474                 code = icmp_hdr(skb)->code;
475                 icmph = (struct icmphdr *)(skb->data + offset);
476         } else if (skb->protocol == htons(ETH_P_IPV6)) {
477                 family = AF_INET6;
478                 type = icmp6_hdr(skb)->icmp6_type;
479                 code = icmp6_hdr(skb)->icmp6_code;
480                 icmph = (struct icmphdr *) (skb->data + offset);
481         } else {
482                 BUG();
483         }
484 
485         /* We assume the packet has already been checked by icmp_unreach */
486 
487         if (!ping_supported(family, icmph->type, icmph->code))
488                 return;
489 
490         pr_debug("ping_err(proto=0x%x,type=%d,code=%d,id=%04x,seq=%04x)\n",
491                  skb->protocol, type, code, ntohs(icmph->un.echo.id),
492                  ntohs(icmph->un.echo.sequence));
493 
494         sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
495         if (sk == NULL) {
496                 pr_debug("no socket, dropping\n");
497                 return; /* No socket for error */
498         }
499         pr_debug("err on socket %p\n", sk);
500 
501         err = 0;
502         harderr = 0;
503         inet_sock = inet_sk(sk);
504 
505         if (skb->protocol == htons(ETH_P_IP)) {
506                 switch (type) {
507                 default:
508                 case ICMP_TIME_EXCEEDED:
509                         err = EHOSTUNREACH;
510                         break;
511                 case ICMP_SOURCE_QUENCH:
512                         /* This is not a real error but ping wants to see it.
513                          * Report it with some fake errno.
514                          */
515                         err = EREMOTEIO;
516                         break;
517                 case ICMP_PARAMETERPROB:
518                         err = EPROTO;
519                         harderr = 1;
520                         break;
521                 case ICMP_DEST_UNREACH:
522                         if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
523                                 ipv4_sk_update_pmtu(skb, sk, info);
524                                 if (inet_sock->pmtudisc != IP_PMTUDISC_DONT) {
525                                         err = EMSGSIZE;
526                                         harderr = 1;
527                                         break;
528                                 }
529                                 goto out;
530                         }
531                         err = EHOSTUNREACH;
532                         if (code <= NR_ICMP_UNREACH) {
533                                 harderr = icmp_err_convert[code].fatal;
534                                 err = icmp_err_convert[code].errno;
535                         }
536                         break;
537                 case ICMP_REDIRECT:
538                         /* See ICMP_SOURCE_QUENCH */
539                         ipv4_sk_redirect(skb, sk);
540                         err = EREMOTEIO;
541                         break;
542                 }
543 #if IS_ENABLED(CONFIG_IPV6)
544         } else if (skb->protocol == htons(ETH_P_IPV6)) {
545                 harderr = pingv6_ops.icmpv6_err_convert(type, code, &err);
546 #endif
547         }
548 
549         /*
550          *      RFC1122: OK.  Passes ICMP errors back to application, as per
551          *      4.1.3.3.
552          */
553         if ((family == AF_INET && !inet_sock->recverr) ||
554             (family == AF_INET6 && !inet6_sk(sk)->recverr)) {
555                 if (!harderr || sk->sk_state != TCP_ESTABLISHED)
556                         goto out;
557         } else {
558                 if (family == AF_INET) {
559                         ip_icmp_error(sk, skb, err, 0 /* no remote port */,
560                                       info, (u8 *)icmph);
561 #if IS_ENABLED(CONFIG_IPV6)
562                 } else if (family == AF_INET6) {
563                         pingv6_ops.ipv6_icmp_error(sk, skb, err, 0,
564                                                    info, (u8 *)icmph);
565 #endif
566                 }
567         }
568         sk->sk_err = err;
569         sk->sk_error_report(sk);
570 out:
571         sock_put(sk);
572 }
573 EXPORT_SYMBOL_GPL(ping_err);
574 
575 /*
576  *      Copy and checksum an ICMP Echo packet from user space into a buffer
577  *      starting from the payload.
578  */
579 
580 int ping_getfrag(void *from, char *to,
581                  int offset, int fraglen, int odd, struct sk_buff *skb)
582 {
583         struct pingfakehdr *pfh = (struct pingfakehdr *)from;
584 
585         if (offset == 0) {
586                 if (fraglen < sizeof(struct icmphdr))
587                         BUG();
588                 if (csum_partial_copy_fromiovecend(to + sizeof(struct icmphdr),
589                             pfh->iov, 0, fraglen - sizeof(struct icmphdr),
590                             &pfh->wcheck))
591                         return -EFAULT;
592         } else if (offset < sizeof(struct icmphdr)) {
593                         BUG();
594         } else {
595                 if (csum_partial_copy_fromiovecend
596                                 (to, pfh->iov, offset - sizeof(struct icmphdr),
597                                  fraglen, &pfh->wcheck))
598                         return -EFAULT;
599         }
600 
601 #if IS_ENABLED(CONFIG_IPV6)
602         /* For IPv6, checksum each skb as we go along, as expected by
603          * icmpv6_push_pending_frames. For IPv4, accumulate the checksum in
604          * wcheck, it will be finalized in ping_v4_push_pending_frames.
605          */
606         if (pfh->family == AF_INET6) {
607                 skb->csum = pfh->wcheck;
608                 skb->ip_summed = CHECKSUM_NONE;
609                 pfh->wcheck = 0;
610         }
611 #endif
612 
613         return 0;
614 }
615 EXPORT_SYMBOL_GPL(ping_getfrag);
616 
617 static int ping_v4_push_pending_frames(struct sock *sk, struct pingfakehdr *pfh,
618                                        struct flowi4 *fl4)
619 {
620         struct sk_buff *skb = skb_peek(&sk->sk_write_queue);
621 
622         pfh->wcheck = csum_partial((char *)&pfh->icmph,
623                 sizeof(struct icmphdr), pfh->wcheck);
624         pfh->icmph.checksum = csum_fold(pfh->wcheck);
625         memcpy(icmp_hdr(skb), &pfh->icmph, sizeof(struct icmphdr));
626         skb->ip_summed = CHECKSUM_NONE;
627         return ip_push_pending_frames(sk, fl4);
628 }
629 
630 int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
631                         void *user_icmph, size_t icmph_len) {
632         u8 type, code;
633 
634         if (len > 0xFFFF)
635                 return -EMSGSIZE;
636 
637         /*
638          *      Check the flags.
639          */
640 
641         /* Mirror BSD error message compatibility */
642         if (msg->msg_flags & MSG_OOB)
643                 return -EOPNOTSUPP;
644 
645         /*
646          *      Fetch the ICMP header provided by the userland.
647          *      iovec is modified! The ICMP header is consumed.
648          */
649         if (memcpy_fromiovec(user_icmph, msg->msg_iov, icmph_len))
650                 return -EFAULT;
651 
652         if (family == AF_INET) {
653                 type = ((struct icmphdr *) user_icmph)->type;
654                 code = ((struct icmphdr *) user_icmph)->code;
655 #if IS_ENABLED(CONFIG_IPV6)
656         } else if (family == AF_INET6) {
657                 type = ((struct icmp6hdr *) user_icmph)->icmp6_type;
658                 code = ((struct icmp6hdr *) user_icmph)->icmp6_code;
659 #endif
660         } else {
661                 BUG();
662         }
663 
664         if (!ping_supported(family, type, code))
665                 return -EINVAL;
666 
667         return 0;
668 }
669 EXPORT_SYMBOL_GPL(ping_common_sendmsg);
670 
671 int ping_v4_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
672                     size_t len)
673 {
674         struct net *net = sock_net(sk);
675         struct flowi4 fl4;
676         struct inet_sock *inet = inet_sk(sk);
677         struct ipcm_cookie ipc;
678         struct icmphdr user_icmph;
679         struct pingfakehdr pfh;
680         struct rtable *rt = NULL;
681         struct ip_options_data opt_copy;
682         int free = 0;
683         __be32 saddr, daddr, faddr;
684         u8  tos;
685         int err;
686 
687         pr_debug("ping_v4_sendmsg(sk=%p,sk->num=%u)\n", inet, inet->inet_num);
688 
689         err = ping_common_sendmsg(AF_INET, msg, len, &user_icmph,
690                                   sizeof(user_icmph));
691         if (err)
692                 return err;
693 
694         /*
695          *      Get and verify the address.
696          */
697 
698         if (msg->msg_name) {
699                 struct sockaddr_in *usin = (struct sockaddr_in *)msg->msg_name;
700                 if (msg->msg_namelen < sizeof(*usin))
701                         return -EINVAL;
702                 if (usin->sin_family != AF_INET)
703                         return -EINVAL;
704                 daddr = usin->sin_addr.s_addr;
705                 /* no remote port */
706         } else {
707                 if (sk->sk_state != TCP_ESTABLISHED)
708                         return -EDESTADDRREQ;
709                 daddr = inet->inet_daddr;
710                 /* no remote port */
711         }
712 
713         ipc.addr = inet->inet_saddr;
714         ipc.opt = NULL;
715         ipc.oif = sk->sk_bound_dev_if;
716         ipc.tx_flags = 0;
717         ipc.ttl = 0;
718         ipc.tos = -1;
719 
720         sock_tx_timestamp(sk, &ipc.tx_flags);
721 
722         if (msg->msg_controllen) {
723                 err = ip_cmsg_send(sock_net(sk), msg, &ipc);
724                 if (err)
725                         return err;
726                 if (ipc.opt)
727                         free = 1;
728         }
729         if (!ipc.opt) {
730                 struct ip_options_rcu *inet_opt;
731 
732                 rcu_read_lock();
733                 inet_opt = rcu_dereference(inet->inet_opt);
734                 if (inet_opt) {
735                         memcpy(&opt_copy, inet_opt,
736                                sizeof(*inet_opt) + inet_opt->opt.optlen);
737                         ipc.opt = &opt_copy.opt;
738                 }
739                 rcu_read_unlock();
740         }
741 
742         saddr = ipc.addr;
743         ipc.addr = faddr = daddr;
744 
745         if (ipc.opt && ipc.opt->opt.srr) {
746                 if (!daddr)
747                         return -EINVAL;
748                 faddr = ipc.opt->opt.faddr;
749         }
750         tos = get_rttos(&ipc, inet);
751         if (sock_flag(sk, SOCK_LOCALROUTE) ||
752             (msg->msg_flags & MSG_DONTROUTE) ||
753             (ipc.opt && ipc.opt->opt.is_strictroute)) {
754                 tos |= RTO_ONLINK;
755         }
756 
757         if (ipv4_is_multicast(daddr)) {
758                 if (!ipc.oif)
759                         ipc.oif = inet->mc_index;
760                 if (!saddr)
761                         saddr = inet->mc_addr;
762         } else if (!ipc.oif)
763                 ipc.oif = inet->uc_index;
764 
765         flowi4_init_output(&fl4, ipc.oif, sk->sk_mark, tos,
766                            RT_SCOPE_UNIVERSE, sk->sk_protocol,
767                            inet_sk_flowi_flags(sk), faddr, saddr, 0, 0);
768 
769         security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
770         rt = ip_route_output_flow(net, &fl4, sk);
771         if (IS_ERR(rt)) {
772                 err = PTR_ERR(rt);
773                 rt = NULL;
774                 if (err == -ENETUNREACH)
775                         IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
776                 goto out;
777         }
778 
779         err = -EACCES;
780         if ((rt->rt_flags & RTCF_BROADCAST) &&
781             !sock_flag(sk, SOCK_BROADCAST))
782                 goto out;
783 
784         if (msg->msg_flags & MSG_CONFIRM)
785                 goto do_confirm;
786 back_from_confirm:
787 
788         if (!ipc.addr)
789                 ipc.addr = fl4.daddr;
790 
791         lock_sock(sk);
792 
793         pfh.icmph.type = user_icmph.type; /* already checked */
794         pfh.icmph.code = user_icmph.code; /* ditto */
795         pfh.icmph.checksum = 0;
796         pfh.icmph.un.echo.id = inet->inet_sport;
797         pfh.icmph.un.echo.sequence = user_icmph.un.echo.sequence;
798         pfh.iov = msg->msg_iov;
799         pfh.wcheck = 0;
800         pfh.family = AF_INET;
801 
802         err = ip_append_data(sk, &fl4, ping_getfrag, &pfh, len,
803                         0, &ipc, &rt, msg->msg_flags);
804         if (err)
805                 ip_flush_pending_frames(sk);
806         else
807                 err = ping_v4_push_pending_frames(sk, &pfh, &fl4);
808         release_sock(sk);
809 
810 out:
811         ip_rt_put(rt);
812         if (free)
813                 kfree(ipc.opt);
814         if (!err) {
815                 icmp_out_count(sock_net(sk), user_icmph.type);
816                 return len;
817         }
818         return err;
819 
820 do_confirm:
821         dst_confirm(&rt->dst);
822         if (!(msg->msg_flags & MSG_PROBE) || len)
823                 goto back_from_confirm;
824         err = 0;
825         goto out;
826 }
827 
828 int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
829                  size_t len, int noblock, int flags, int *addr_len)
830 {
831         struct inet_sock *isk = inet_sk(sk);
832         int family = sk->sk_family;
833         struct sk_buff *skb;
834         int copied, err;
835 
836         pr_debug("ping_recvmsg(sk=%p,sk->num=%u)\n", isk, isk->inet_num);
837 
838         err = -EOPNOTSUPP;
839         if (flags & MSG_OOB)
840                 goto out;
841 
842         if (flags & MSG_ERRQUEUE) {
843                 if (family == AF_INET) {
844                         return ip_recv_error(sk, msg, len, addr_len);
845 #if IS_ENABLED(CONFIG_IPV6)
846                 } else if (family == AF_INET6) {
847                         return pingv6_ops.ipv6_recv_error(sk, msg, len,
848                                                           addr_len);
849 #endif
850                 }
851         }
852 
853         skb = skb_recv_datagram(sk, flags, noblock, &err);
854         if (!skb)
855                 goto out;
856 
857         copied = skb->len;
858         if (copied > len) {
859                 msg->msg_flags |= MSG_TRUNC;
860                 copied = len;
861         }
862 
863         /* Don't bother checking the checksum */
864         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
865         if (err)
866                 goto done;
867 
868         sock_recv_timestamp(msg, sk, skb);
869 
870         /* Copy the address and add cmsg data. */
871         if (family == AF_INET) {
872                 struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
873 
874                 if (sin) {
875                         sin->sin_family = AF_INET;
876                         sin->sin_port = 0 /* skb->h.uh->source */;
877                         sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
878                         memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
879                         *addr_len = sizeof(*sin);
880                 }
881 
882                 if (isk->cmsg_flags)
883                         ip_cmsg_recv(msg, skb);
884 
885 #if IS_ENABLED(CONFIG_IPV6)
886         } else if (family == AF_INET6) {
887                 struct ipv6_pinfo *np = inet6_sk(sk);
888                 struct ipv6hdr *ip6 = ipv6_hdr(skb);
889                 struct sockaddr_in6 *sin6 =
890                         (struct sockaddr_in6 *)msg->msg_name;
891 
892                 if (sin6) {
893                         sin6->sin6_family = AF_INET6;
894                         sin6->sin6_port = 0;
895                         sin6->sin6_addr = ip6->saddr;
896                         sin6->sin6_flowinfo = 0;
897                         if (np->sndflow)
898                                 sin6->sin6_flowinfo = ip6_flowinfo(ip6);
899                         sin6->sin6_scope_id =
900                                 ipv6_iface_scope_id(&sin6->sin6_addr,
901                                                     IP6CB(skb)->iif);
902                         *addr_len = sizeof(*sin6);
903                 }
904 
905                 if (inet6_sk(sk)->rxopt.all)
906                         pingv6_ops.ip6_datagram_recv_ctl(sk, msg, skb);
907 #endif
908         } else {
909                 BUG();
910         }
911 
912         err = copied;
913 
914 done:
915         skb_free_datagram(sk, skb);
916 out:
917         pr_debug("ping_recvmsg -> %d\n", err);
918         return err;
919 }
920 EXPORT_SYMBOL_GPL(ping_recvmsg);
921 
922 int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
923 {
924         pr_debug("ping_queue_rcv_skb(sk=%p,sk->num=%d,skb=%p)\n",
925                  inet_sk(sk), inet_sk(sk)->inet_num, skb);
926         if (sock_queue_rcv_skb(sk, skb) < 0) {
927                 kfree_skb(skb);
928                 pr_debug("ping_queue_rcv_skb -> failed\n");
929                 return -1;
930         }
931         return 0;
932 }
933 EXPORT_SYMBOL_GPL(ping_queue_rcv_skb);
934 
935 
936 /*
937  *      All we need to do is get the socket.
938  */
939 
940 void ping_rcv(struct sk_buff *skb)
941 {
942         struct sock *sk;
943         struct net *net = dev_net(skb->dev);
944         struct icmphdr *icmph = icmp_hdr(skb);
945 
946         /* We assume the packet has already been checked by icmp_rcv */
947 
948         pr_debug("ping_rcv(skb=%p,id=%04x,seq=%04x)\n",
949                  skb, ntohs(icmph->un.echo.id), ntohs(icmph->un.echo.sequence));
950 
951         /* Push ICMP header back */
952         skb_push(skb, skb->data - (u8 *)icmph);
953 
954         sk = ping_lookup(net, skb, ntohs(icmph->un.echo.id));
955         if (sk != NULL) {
956                 pr_debug("rcv on socket %p\n", sk);
957                 ping_queue_rcv_skb(sk, skb_get(skb));
958                 sock_put(sk);
959                 return;
960         }
961         pr_debug("no socket, dropping\n");
962 
963         /* We're called from icmp_rcv(). kfree_skb() is done there. */
964 }
965 EXPORT_SYMBOL_GPL(ping_rcv);
966 
967 struct proto ping_prot = {
968         .name =         "PING",
969         .owner =        THIS_MODULE,
970         .init =         ping_init_sock,
971         .close =        ping_close,
972         .connect =      ip4_datagram_connect,
973         .disconnect =   udp_disconnect,
974         .setsockopt =   ip_setsockopt,
975         .getsockopt =   ip_getsockopt,
976         .sendmsg =      ping_v4_sendmsg,
977         .recvmsg =      ping_recvmsg,
978         .bind =         ping_bind,
979         .backlog_rcv =  ping_queue_rcv_skb,
980         .release_cb =   ip4_datagram_release_cb,
981         .hash =         ping_hash,
982         .unhash =       ping_unhash,
983         .get_port =     ping_get_port,
984         .obj_size =     sizeof(struct inet_sock),
985 };
986 EXPORT_SYMBOL(ping_prot);
987 
988 #ifdef CONFIG_PROC_FS
989 
990 static struct sock *ping_get_first(struct seq_file *seq, int start)
991 {
992         struct sock *sk;
993         struct ping_iter_state *state = seq->private;
994         struct net *net = seq_file_net(seq);
995 
996         for (state->bucket = start; state->bucket < PING_HTABLE_SIZE;
997              ++state->bucket) {
998                 struct hlist_nulls_node *node;
999                 struct hlist_nulls_head *hslot;
1000 
1001                 hslot = &ping_table.hash[state->bucket];
1002 
1003                 if (hlist_nulls_empty(hslot))
1004                         continue;
1005 
1006                 sk_nulls_for_each(sk, node, hslot) {
1007                         if (net_eq(sock_net(sk), net) &&
1008                             sk->sk_family == state->family)
1009                                 goto found;
1010                 }
1011         }
1012         sk = NULL;
1013 found:
1014         return sk;
1015 }
1016 
1017 static struct sock *ping_get_next(struct seq_file *seq, struct sock *sk)
1018 {
1019         struct ping_iter_state *state = seq->private;
1020         struct net *net = seq_file_net(seq);
1021 
1022         do {
1023                 sk = sk_nulls_next(sk);
1024         } while (sk && (!net_eq(sock_net(sk), net)));
1025 
1026         if (!sk)
1027                 return ping_get_first(seq, state->bucket + 1);
1028         return sk;
1029 }
1030 
1031 static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
1032 {
1033         struct sock *sk = ping_get_first(seq, 0);
1034 
1035         if (sk)
1036                 while (pos && (sk = ping_get_next(seq, sk)) != NULL)
1037                         --pos;
1038         return pos ? NULL : sk;
1039 }
1040 
1041 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
1042 {
1043         struct ping_iter_state *state = seq->private;
1044         state->bucket = 0;
1045         state->family = family;
1046 
1047         read_lock_bh(&ping_table.lock);
1048 
1049         return *pos ? ping_get_idx(seq, *pos-1) : SEQ_START_TOKEN;
1050 }
1051 EXPORT_SYMBOL_GPL(ping_seq_start);
1052 
1053 static void *ping_v4_seq_start(struct seq_file *seq, loff_t *pos)
1054 {
1055         return ping_seq_start(seq, pos, AF_INET);
1056 }
1057 
1058 void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1059 {
1060         struct sock *sk;
1061 
1062         if (v == SEQ_START_TOKEN)
1063                 sk = ping_get_idx(seq, 0);
1064         else
1065                 sk = ping_get_next(seq, v);
1066 
1067         ++*pos;
1068         return sk;
1069 }
1070 EXPORT_SYMBOL_GPL(ping_seq_next);
1071 
1072 void ping_seq_stop(struct seq_file *seq, void *v)
1073 {
1074         read_unlock_bh(&ping_table.lock);
1075 }
1076 EXPORT_SYMBOL_GPL(ping_seq_stop);
1077 
1078 static void ping_v4_format_sock(struct sock *sp, struct seq_file *f,
1079                 int bucket)
1080 {
1081         struct inet_sock *inet = inet_sk(sp);
1082         __be32 dest = inet->inet_daddr;
1083         __be32 src = inet->inet_rcv_saddr;
1084         __u16 destp = ntohs(inet->inet_dport);
1085         __u16 srcp = ntohs(inet->inet_sport);
1086 
1087         seq_printf(f, "%5d: %08X:%04X %08X:%04X"
1088                 " %02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d",
1089                 bucket, src, srcp, dest, destp, sp->sk_state,
1090                 sk_wmem_alloc_get(sp),
1091                 sk_rmem_alloc_get(sp),
1092                 0, 0L, 0,
1093                 from_kuid_munged(seq_user_ns(f), sock_i_uid(sp)),
1094                 0, sock_i_ino(sp),
1095                 atomic_read(&sp->sk_refcnt), sp,
1096                 atomic_read(&sp->sk_drops));
1097 }
1098 
1099 static int ping_v4_seq_show(struct seq_file *seq, void *v)
1100 {
1101         seq_setwidth(seq, 127);
1102         if (v == SEQ_START_TOKEN)
1103                 seq_puts(seq, "  sl  local_address rem_address   st tx_queue "
1104                            "rx_queue tr tm->when retrnsmt   uid  timeout "
1105                            "inode ref pointer drops");
1106         else {
1107                 struct ping_iter_state *state = seq->private;
1108 
1109                 ping_v4_format_sock(v, seq, state->bucket);
1110         }
1111         seq_pad(seq, '\n');
1112         return 0;
1113 }
1114 
1115 static const struct seq_operations ping_v4_seq_ops = {
1116         .show           = ping_v4_seq_show,
1117         .start          = ping_v4_seq_start,
1118         .next           = ping_seq_next,
1119         .stop           = ping_seq_stop,
1120 };
1121 
1122 static int ping_seq_open(struct inode *inode, struct file *file)
1123 {
1124         struct ping_seq_afinfo *afinfo = PDE_DATA(inode);
1125         return seq_open_net(inode, file, &afinfo->seq_ops,
1126                            sizeof(struct ping_iter_state));
1127 }
1128 
1129 const struct file_operations ping_seq_fops = {
1130         .open           = ping_seq_open,
1131         .read           = seq_read,
1132         .llseek         = seq_lseek,
1133         .release        = seq_release_net,
1134 };
1135 EXPORT_SYMBOL_GPL(ping_seq_fops);
1136 
1137 static struct ping_seq_afinfo ping_v4_seq_afinfo = {
1138         .name           = "icmp",
1139         .family         = AF_INET,
1140         .seq_fops       = &ping_seq_fops,
1141         .seq_ops        = {
1142                 .start          = ping_v4_seq_start,
1143                 .show           = ping_v4_seq_show,
1144                 .next           = ping_seq_next,
1145                 .stop           = ping_seq_stop,
1146         },
1147 };
1148 
1149 int ping_proc_register(struct net *net, struct ping_seq_afinfo *afinfo)
1150 {
1151         struct proc_dir_entry *p;
1152         p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
1153                              afinfo->seq_fops, afinfo);
1154         if (!p)
1155                 return -ENOMEM;
1156         return 0;
1157 }
1158 EXPORT_SYMBOL_GPL(ping_proc_register);
1159 
1160 void ping_proc_unregister(struct net *net, struct ping_seq_afinfo *afinfo)
1161 {
1162         remove_proc_entry(afinfo->name, net->proc_net);
1163 }
1164 EXPORT_SYMBOL_GPL(ping_proc_unregister);
1165 
1166 static int __net_init ping_v4_proc_init_net(struct net *net)
1167 {
1168         return ping_proc_register(net, &ping_v4_seq_afinfo);
1169 }
1170 
1171 static void __net_exit ping_v4_proc_exit_net(struct net *net)
1172 {
1173         ping_proc_unregister(net, &ping_v4_seq_afinfo);
1174 }
1175 
1176 static struct pernet_operations ping_v4_net_ops = {
1177         .init = ping_v4_proc_init_net,
1178         .exit = ping_v4_proc_exit_net,
1179 };
1180 
1181 int __init ping_proc_init(void)
1182 {
1183         return register_pernet_subsys(&ping_v4_net_ops);
1184 }
1185 
1186 void ping_proc_exit(void)
1187 {
1188         unregister_pernet_subsys(&ping_v4_net_ops);
1189 }
1190 
1191 #endif
1192 
1193 void __init ping_init(void)
1194 {
1195         int i;
1196 
1197         for (i = 0; i < PING_HTABLE_SIZE; i++)
1198                 INIT_HLIST_NULLS_HEAD(&ping_table.hash[i], i);
1199         rwlock_init(&ping_table.lock);
1200 }
1201 

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