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64
65#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
66
67#include <linux/module.h>
68#include <linux/types.h>
69#include <linux/jiffies.h>
70#include <linux/kernel.h>
71#include <linux/fcntl.h>
72#include <linux/socket.h>
73#include <linux/in.h>
74#include <linux/inet.h>
75#include <linux/inetdevice.h>
76#include <linux/netdevice.h>
77#include <linux/string.h>
78#include <linux/netfilter_ipv4.h>
79#include <linux/slab.h>
80#include <net/snmp.h>
81#include <net/ip.h>
82#include <net/route.h>
83#include <net/protocol.h>
84#include <net/icmp.h>
85#include <net/tcp.h>
86#include <net/udp.h>
87#include <net/raw.h>
88#include <net/ping.h>
89#include <linux/skbuff.h>
90#include <net/sock.h>
91#include <linux/errno.h>
92#include <linux/timer.h>
93#include <linux/init.h>
94#include <asm/uaccess.h>
95#include <net/checksum.h>
96#include <net/xfrm.h>
97#include <net/inet_common.h>
98#include <net/ip_fib.h>
99
100
101
102
103
104struct icmp_bxm {
105 struct sk_buff *skb;
106 int offset;
107 int data_len;
108
109 struct {
110 struct icmphdr icmph;
111 __be32 times[3];
112 } data;
113 int head_len;
114 struct ip_options_data replyopts;
115};
116
117
118
119
120const struct icmp_err icmp_err_convert[] = {
121 {
122 .errno = ENETUNREACH,
123 .fatal = 0,
124 },
125 {
126 .errno = EHOSTUNREACH,
127 .fatal = 0,
128 },
129 {
130 .errno = ENOPROTOOPT ,
131 .fatal = 1,
132 },
133 {
134 .errno = ECONNREFUSED,
135 .fatal = 1,
136 },
137 {
138 .errno = EMSGSIZE,
139 .fatal = 0,
140 },
141 {
142 .errno = EOPNOTSUPP,
143 .fatal = 0,
144 },
145 {
146 .errno = ENETUNREACH,
147 .fatal = 1,
148 },
149 {
150 .errno = EHOSTDOWN,
151 .fatal = 1,
152 },
153 {
154 .errno = ENONET,
155 .fatal = 1,
156 },
157 {
158 .errno = ENETUNREACH,
159 .fatal = 1,
160 },
161 {
162 .errno = EHOSTUNREACH,
163 .fatal = 1,
164 },
165 {
166 .errno = ENETUNREACH,
167 .fatal = 0,
168 },
169 {
170 .errno = EHOSTUNREACH,
171 .fatal = 0,
172 },
173 {
174 .errno = EHOSTUNREACH,
175 .fatal = 1,
176 },
177 {
178 .errno = EHOSTUNREACH,
179 .fatal = 1,
180 },
181 {
182 .errno = EHOSTUNREACH,
183 .fatal = 1,
184 },
185};
186EXPORT_SYMBOL(icmp_err_convert);
187
188
189
190
191
192struct icmp_control {
193 void (*handler)(struct sk_buff *skb);
194 short error;
195};
196
197static const struct icmp_control icmp_pointers[NR_ICMP_TYPES+1];
198
199
200
201
202
203
204
205
206static struct sock *icmp_sk(struct net *net)
207{
208 return net->ipv4.icmp_sk[smp_processor_id()];
209}
210
211static inline struct sock *icmp_xmit_lock(struct net *net)
212{
213 struct sock *sk;
214
215 local_bh_disable();
216
217 sk = icmp_sk(net);
218
219 if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
220
221
222
223 local_bh_enable();
224 return NULL;
225 }
226 return sk;
227}
228
229static inline void icmp_xmit_unlock(struct sock *sk)
230{
231 spin_unlock_bh(&sk->sk_lock.slock);
232}
233
234
235
236
237
238static inline bool icmpv4_xrlim_allow(struct net *net, struct rtable *rt,
239 struct flowi4 *fl4, int type, int code)
240{
241 struct dst_entry *dst = &rt->dst;
242 bool rc = true;
243
244 if (type > NR_ICMP_TYPES)
245 goto out;
246
247
248 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)
249 goto out;
250
251
252 if (dst->dev && (dst->dev->flags&IFF_LOOPBACK))
253 goto out;
254
255
256 if ((1 << type) & net->ipv4.sysctl_icmp_ratemask) {
257 struct inet_peer *peer = inet_getpeer_v4(net->ipv4.peers, fl4->daddr, 1);
258 rc = inet_peer_xrlim_allow(peer,
259 net->ipv4.sysctl_icmp_ratelimit);
260 if (peer)
261 inet_putpeer(peer);
262 }
263out:
264 return rc;
265}
266
267
268
269
270void icmp_out_count(struct net *net, unsigned char type)
271{
272 ICMPMSGOUT_INC_STATS(net, type);
273 ICMP_INC_STATS(net, ICMP_MIB_OUTMSGS);
274}
275
276
277
278
279
280static int icmp_glue_bits(void *from, char *to, int offset, int len, int odd,
281 struct sk_buff *skb)
282{
283 struct icmp_bxm *icmp_param = (struct icmp_bxm *)from;
284 __wsum csum;
285
286 csum = skb_copy_and_csum_bits(icmp_param->skb,
287 icmp_param->offset + offset,
288 to, len, 0);
289
290 skb->csum = csum_block_add(skb->csum, csum, odd);
291 if (icmp_pointers[icmp_param->data.icmph.type].error)
292 nf_ct_attach(skb, icmp_param->skb);
293 return 0;
294}
295
296static void icmp_push_reply(struct icmp_bxm *icmp_param,
297 struct flowi4 *fl4,
298 struct ipcm_cookie *ipc, struct rtable **rt)
299{
300 struct sock *sk;
301 struct sk_buff *skb;
302
303 sk = icmp_sk(dev_net((*rt)->dst.dev));
304 if (ip_append_data(sk, fl4, icmp_glue_bits, icmp_param,
305 icmp_param->data_len+icmp_param->head_len,
306 icmp_param->head_len,
307 ipc, rt, MSG_DONTWAIT) < 0) {
308 ICMP_INC_STATS_BH(sock_net(sk), ICMP_MIB_OUTERRORS);
309 ip_flush_pending_frames(sk);
310 } else if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) {
311 struct icmphdr *icmph = icmp_hdr(skb);
312 __wsum csum = 0;
313 struct sk_buff *skb1;
314
315 skb_queue_walk(&sk->sk_write_queue, skb1) {
316 csum = csum_add(csum, skb1->csum);
317 }
318 csum = csum_partial_copy_nocheck((void *)&icmp_param->data,
319 (char *)icmph,
320 icmp_param->head_len, csum);
321 icmph->checksum = csum_fold(csum);
322 skb->ip_summed = CHECKSUM_NONE;
323 ip_push_pending_frames(sk, fl4);
324 }
325}
326
327
328
329
330
331static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
332{
333 struct ipcm_cookie ipc;
334 struct rtable *rt = skb_rtable(skb);
335 struct net *net = dev_net(rt->dst.dev);
336 struct flowi4 fl4;
337 struct sock *sk;
338 struct inet_sock *inet;
339 __be32 daddr, saddr;
340
341 if (ip_options_echo(&icmp_param->replyopts.opt.opt, skb))
342 return;
343
344 sk = icmp_xmit_lock(net);
345 if (sk == NULL)
346 return;
347 inet = inet_sk(sk);
348
349 icmp_param->data.icmph.checksum = 0;
350
351 inet->tos = ip_hdr(skb)->tos;
352 daddr = ipc.addr = ip_hdr(skb)->saddr;
353 saddr = fib_compute_spec_dst(skb);
354 ipc.opt = NULL;
355 ipc.tx_flags = 0;
356 if (icmp_param->replyopts.opt.opt.optlen) {
357 ipc.opt = &icmp_param->replyopts.opt;
358 if (ipc.opt->opt.srr)
359 daddr = icmp_param->replyopts.opt.opt.faddr;
360 }
361 memset(&fl4, 0, sizeof(fl4));
362 fl4.daddr = daddr;
363 fl4.saddr = saddr;
364 fl4.flowi4_tos = RT_TOS(ip_hdr(skb)->tos);
365 fl4.flowi4_proto = IPPROTO_ICMP;
366 security_skb_classify_flow(skb, flowi4_to_flowi(&fl4));
367 rt = ip_route_output_key(net, &fl4);
368 if (IS_ERR(rt))
369 goto out_unlock;
370 if (icmpv4_xrlim_allow(net, rt, &fl4, icmp_param->data.icmph.type,
371 icmp_param->data.icmph.code))
372 icmp_push_reply(icmp_param, &fl4, &ipc, &rt);
373 ip_rt_put(rt);
374out_unlock:
375 icmp_xmit_unlock(sk);
376}
377
378static struct rtable *icmp_route_lookup(struct net *net,
379 struct flowi4 *fl4,
380 struct sk_buff *skb_in,
381 const struct iphdr *iph,
382 __be32 saddr, u8 tos,
383 int type, int code,
384 struct icmp_bxm *param)
385{
386 struct rtable *rt, *rt2;
387 struct flowi4 fl4_dec;
388 int err;
389
390 memset(fl4, 0, sizeof(*fl4));
391 fl4->daddr = (param->replyopts.opt.opt.srr ?
392 param->replyopts.opt.opt.faddr : iph->saddr);
393 fl4->saddr = saddr;
394 fl4->flowi4_tos = RT_TOS(tos);
395 fl4->flowi4_proto = IPPROTO_ICMP;
396 fl4->fl4_icmp_type = type;
397 fl4->fl4_icmp_code = code;
398 security_skb_classify_flow(skb_in, flowi4_to_flowi(fl4));
399 rt = __ip_route_output_key(net, fl4);
400 if (IS_ERR(rt))
401 return rt;
402
403
404 rt2 = rt;
405
406 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
407 flowi4_to_flowi(fl4), NULL, 0);
408 if (!IS_ERR(rt)) {
409 if (rt != rt2)
410 return rt;
411 } else if (PTR_ERR(rt) == -EPERM) {
412 rt = NULL;
413 } else
414 return rt;
415
416 err = xfrm_decode_session_reverse(skb_in, flowi4_to_flowi(&fl4_dec), AF_INET);
417 if (err)
418 goto relookup_failed;
419
420 if (inet_addr_type(net, fl4_dec.saddr) == RTN_LOCAL) {
421 rt2 = __ip_route_output_key(net, &fl4_dec);
422 if (IS_ERR(rt2))
423 err = PTR_ERR(rt2);
424 } else {
425 struct flowi4 fl4_2 = {};
426 unsigned long orefdst;
427
428 fl4_2.daddr = fl4_dec.saddr;
429 rt2 = ip_route_output_key(net, &fl4_2);
430 if (IS_ERR(rt2)) {
431 err = PTR_ERR(rt2);
432 goto relookup_failed;
433 }
434
435 orefdst = skb_in->_skb_refdst;
436 err = ip_route_input(skb_in, fl4_dec.daddr, fl4_dec.saddr,
437 RT_TOS(tos), rt2->dst.dev);
438
439 dst_release(&rt2->dst);
440 rt2 = skb_rtable(skb_in);
441 skb_in->_skb_refdst = orefdst;
442 }
443
444 if (err)
445 goto relookup_failed;
446
447 rt2 = (struct rtable *) xfrm_lookup(net, &rt2->dst,
448 flowi4_to_flowi(&fl4_dec), NULL,
449 XFRM_LOOKUP_ICMP);
450 if (!IS_ERR(rt2)) {
451 dst_release(&rt->dst);
452 memcpy(fl4, &fl4_dec, sizeof(*fl4));
453 rt = rt2;
454 } else if (PTR_ERR(rt2) == -EPERM) {
455 if (rt)
456 dst_release(&rt->dst);
457 return rt2;
458 } else {
459 err = PTR_ERR(rt2);
460 goto relookup_failed;
461 }
462 return rt;
463
464relookup_failed:
465 if (rt)
466 return rt;
467 return ERR_PTR(err);
468}
469
470
471
472
473
474
475
476
477
478
479
480
481void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
482{
483 struct iphdr *iph;
484 int room;
485 struct icmp_bxm *icmp_param;
486 struct rtable *rt = skb_rtable(skb_in);
487 struct ipcm_cookie ipc;
488 struct flowi4 fl4;
489 __be32 saddr;
490 u8 tos;
491 struct net *net;
492 struct sock *sk;
493
494 if (!rt)
495 goto out;
496 net = dev_net(rt->dst.dev);
497
498
499
500
501
502
503 iph = ip_hdr(skb_in);
504
505 if ((u8 *)iph < skb_in->head ||
506 (skb_network_header(skb_in) + sizeof(*iph)) >
507 skb_tail_pointer(skb_in))
508 goto out;
509
510
511
512
513 if (skb_in->pkt_type != PACKET_HOST)
514 goto out;
515
516
517
518
519 if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
520 goto out;
521
522
523
524
525
526 if (iph->frag_off & htons(IP_OFFSET))
527 goto out;
528
529
530
531
532 if (icmp_pointers[type].error) {
533
534
535
536
537 if (iph->protocol == IPPROTO_ICMP) {
538 u8 _inner_type, *itp;
539
540 itp = skb_header_pointer(skb_in,
541 skb_network_header(skb_in) +
542 (iph->ihl << 2) +
543 offsetof(struct icmphdr,
544 type) -
545 skb_in->data,
546 sizeof(_inner_type),
547 &_inner_type);
548 if (itp == NULL)
549 goto out;
550
551
552
553
554
555 if (*itp > NR_ICMP_TYPES ||
556 icmp_pointers[*itp].error)
557 goto out;
558 }
559 }
560
561 icmp_param = kmalloc(sizeof(*icmp_param), GFP_ATOMIC);
562 if (!icmp_param)
563 return;
564
565 sk = icmp_xmit_lock(net);
566 if (sk == NULL)
567 goto out_free;
568
569
570
571
572
573 saddr = iph->daddr;
574 if (!(rt->rt_flags & RTCF_LOCAL)) {
575 struct net_device *dev = NULL;
576
577 rcu_read_lock();
578 if (rt_is_input_route(rt) &&
579 net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr)
580 dev = dev_get_by_index_rcu(net, inet_iif(skb_in));
581
582 if (dev)
583 saddr = inet_select_addr(dev, 0, RT_SCOPE_LINK);
584 else
585 saddr = 0;
586 rcu_read_unlock();
587 }
588
589 tos = icmp_pointers[type].error ? ((iph->tos & IPTOS_TOS_MASK) |
590 IPTOS_PREC_INTERNETCONTROL) :
591 iph->tos;
592
593 if (ip_options_echo(&icmp_param->replyopts.opt.opt, skb_in))
594 goto out_unlock;
595
596
597
598
599
600
601 icmp_param->data.icmph.type = type;
602 icmp_param->data.icmph.code = code;
603 icmp_param->data.icmph.un.gateway = info;
604 icmp_param->data.icmph.checksum = 0;
605 icmp_param->skb = skb_in;
606 icmp_param->offset = skb_network_offset(skb_in);
607 inet_sk(sk)->tos = tos;
608 ipc.addr = iph->saddr;
609 ipc.opt = &icmp_param->replyopts.opt;
610 ipc.tx_flags = 0;
611
612 rt = icmp_route_lookup(net, &fl4, skb_in, iph, saddr, tos,
613 type, code, icmp_param);
614 if (IS_ERR(rt))
615 goto out_unlock;
616
617 if (!icmpv4_xrlim_allow(net, rt, &fl4, type, code))
618 goto ende;
619
620
621
622 room = dst_mtu(&rt->dst);
623 if (room > 576)
624 room = 576;
625 room -= sizeof(struct iphdr) + icmp_param->replyopts.opt.opt.optlen;
626 room -= sizeof(struct icmphdr);
627
628 icmp_param->data_len = skb_in->len - icmp_param->offset;
629 if (icmp_param->data_len > room)
630 icmp_param->data_len = room;
631 icmp_param->head_len = sizeof(struct icmphdr);
632
633 icmp_push_reply(icmp_param, &fl4, &ipc, &rt);
634ende:
635 ip_rt_put(rt);
636out_unlock:
637 icmp_xmit_unlock(sk);
638out_free:
639 kfree(icmp_param);
640out:;
641}
642EXPORT_SYMBOL(icmp_send);
643
644
645static void icmp_socket_deliver(struct sk_buff *skb, u32 info)
646{
647 const struct iphdr *iph = (const struct iphdr *) skb->data;
648 const struct net_protocol *ipprot;
649 int protocol = iph->protocol;
650
651
652
653
654 if (!pskb_may_pull(skb, iph->ihl * 4 + 8))
655 return;
656
657 raw_icmp_error(skb, protocol, info);
658
659 rcu_read_lock();
660 ipprot = rcu_dereference(inet_protos[protocol]);
661 if (ipprot && ipprot->err_handler)
662 ipprot->err_handler(skb, info);
663 rcu_read_unlock();
664}
665
666
667
668
669
670
671static void icmp_unreach(struct sk_buff *skb)
672{
673 const struct iphdr *iph;
674 struct icmphdr *icmph;
675 struct net *net;
676 u32 info = 0;
677
678 net = dev_net(skb_dst(skb)->dev);
679
680
681
682
683
684
685
686 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
687 goto out_err;
688
689 icmph = icmp_hdr(skb);
690 iph = (const struct iphdr *)skb->data;
691
692 if (iph->ihl < 5)
693 goto out_err;
694
695 if (icmph->type == ICMP_DEST_UNREACH) {
696 switch (icmph->code & 15) {
697 case ICMP_NET_UNREACH:
698 case ICMP_HOST_UNREACH:
699 case ICMP_PROT_UNREACH:
700 case ICMP_PORT_UNREACH:
701 break;
702 case ICMP_FRAG_NEEDED:
703 if (ipv4_config.no_pmtu_disc) {
704 LIMIT_NETDEBUG(KERN_INFO pr_fmt("%pI4: fragmentation needed and DF set\n"),
705 &iph->daddr);
706 } else {
707 info = ntohs(icmph->un.frag.mtu);
708 if (!info)
709 goto out;
710 }
711 break;
712 case ICMP_SR_FAILED:
713 LIMIT_NETDEBUG(KERN_INFO pr_fmt("%pI4: Source Route Failed\n"),
714 &iph->daddr);
715 break;
716 default:
717 break;
718 }
719 if (icmph->code > NR_ICMP_UNREACH)
720 goto out;
721 } else if (icmph->type == ICMP_PARAMETERPROB)
722 info = ntohl(icmph->un.gateway) >> 24;
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742 if (!net->ipv4.sysctl_icmp_ignore_bogus_error_responses &&
743 inet_addr_type(net, iph->daddr) == RTN_BROADCAST) {
744 net_warn_ratelimited("%pI4 sent an invalid ICMP type %u, code %u error to a broadcast: %pI4 on %s\n",
745 &ip_hdr(skb)->saddr,
746 icmph->type, icmph->code,
747 &iph->daddr, skb->dev->name);
748 goto out;
749 }
750
751 icmp_socket_deliver(skb, info);
752
753out:
754 return;
755out_err:
756 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
757 goto out;
758}
759
760
761
762
763
764
765static void icmp_redirect(struct sk_buff *skb)
766{
767 if (skb->len < sizeof(struct iphdr)) {
768 ICMP_INC_STATS_BH(dev_net(skb->dev), ICMP_MIB_INERRORS);
769 return;
770 }
771
772 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
773 return;
774
775 icmp_socket_deliver(skb, icmp_hdr(skb)->un.gateway);
776}
777
778
779
780
781
782
783
784
785
786
787
788
789
790static void icmp_echo(struct sk_buff *skb)
791{
792 struct net *net;
793
794 net = dev_net(skb_dst(skb)->dev);
795 if (!net->ipv4.sysctl_icmp_echo_ignore_all) {
796 struct icmp_bxm icmp_param;
797
798 icmp_param.data.icmph = *icmp_hdr(skb);
799 icmp_param.data.icmph.type = ICMP_ECHOREPLY;
800 icmp_param.skb = skb;
801 icmp_param.offset = 0;
802 icmp_param.data_len = skb->len;
803 icmp_param.head_len = sizeof(struct icmphdr);
804 icmp_reply(&icmp_param, skb);
805 }
806}
807
808
809
810
811
812
813
814
815static void icmp_timestamp(struct sk_buff *skb)
816{
817 struct timespec tv;
818 struct icmp_bxm icmp_param;
819
820
821
822 if (skb->len < 4)
823 goto out_err;
824
825
826
827
828 getnstimeofday(&tv);
829 icmp_param.data.times[1] = htonl((tv.tv_sec % 86400) * MSEC_PER_SEC +
830 tv.tv_nsec / NSEC_PER_MSEC);
831 icmp_param.data.times[2] = icmp_param.data.times[1];
832 if (skb_copy_bits(skb, 0, &icmp_param.data.times[0], 4))
833 BUG();
834 icmp_param.data.icmph = *icmp_hdr(skb);
835 icmp_param.data.icmph.type = ICMP_TIMESTAMPREPLY;
836 icmp_param.data.icmph.code = 0;
837 icmp_param.skb = skb;
838 icmp_param.offset = 0;
839 icmp_param.data_len = 0;
840 icmp_param.head_len = sizeof(struct icmphdr) + 12;
841 icmp_reply(&icmp_param, skb);
842out:
843 return;
844out_err:
845 ICMP_INC_STATS_BH(dev_net(skb_dst(skb)->dev), ICMP_MIB_INERRORS);
846 goto out;
847}
848
849static void icmp_discard(struct sk_buff *skb)
850{
851}
852
853
854
855
856int icmp_rcv(struct sk_buff *skb)
857{
858 struct icmphdr *icmph;
859 struct rtable *rt = skb_rtable(skb);
860 struct net *net = dev_net(rt->dst.dev);
861
862 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
863 struct sec_path *sp = skb_sec_path(skb);
864 int nh;
865
866 if (!(sp && sp->xvec[sp->len - 1]->props.flags &
867 XFRM_STATE_ICMP))
868 goto drop;
869
870 if (!pskb_may_pull(skb, sizeof(*icmph) + sizeof(struct iphdr)))
871 goto drop;
872
873 nh = skb_network_offset(skb);
874 skb_set_network_header(skb, sizeof(*icmph));
875
876 if (!xfrm4_policy_check_reverse(NULL, XFRM_POLICY_IN, skb))
877 goto drop;
878
879 skb_set_network_header(skb, nh);
880 }
881
882 ICMP_INC_STATS_BH(net, ICMP_MIB_INMSGS);
883
884 switch (skb->ip_summed) {
885 case CHECKSUM_COMPLETE:
886 if (!csum_fold(skb->csum))
887 break;
888
889 case CHECKSUM_NONE:
890 skb->csum = 0;
891 if (__skb_checksum_complete(skb))
892 goto csum_error;
893 }
894
895 if (!pskb_pull(skb, sizeof(*icmph)))
896 goto error;
897
898 icmph = icmp_hdr(skb);
899
900 ICMPMSGIN_INC_STATS_BH(net, icmph->type);
901
902
903
904
905
906
907 if (icmph->type > NR_ICMP_TYPES)
908 goto error;
909
910
911
912
913
914
915 if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
916
917
918
919
920
921
922 if ((icmph->type == ICMP_ECHO ||
923 icmph->type == ICMP_TIMESTAMP) &&
924 net->ipv4.sysctl_icmp_echo_ignore_broadcasts) {
925 goto error;
926 }
927 if (icmph->type != ICMP_ECHO &&
928 icmph->type != ICMP_TIMESTAMP &&
929 icmph->type != ICMP_ADDRESS &&
930 icmph->type != ICMP_ADDRESSREPLY) {
931 goto error;
932 }
933 }
934
935 icmp_pointers[icmph->type].handler(skb);
936
937drop:
938 kfree_skb(skb);
939 return 0;
940csum_error:
941 ICMP_INC_STATS_BH(net, ICMP_MIB_CSUMERRORS);
942error:
943 ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
944 goto drop;
945}
946
947void icmp_err(struct sk_buff *skb, u32 info)
948{
949 struct iphdr *iph = (struct iphdr *)skb->data;
950 int offset = iph->ihl<<2;
951 struct icmphdr *icmph = (struct icmphdr *)(skb->data + offset);
952 int type = icmp_hdr(skb)->type;
953 int code = icmp_hdr(skb)->code;
954 struct net *net = dev_net(skb->dev);
955
956
957
958
959
960 if (icmph->type != ICMP_ECHOREPLY) {
961 ping_err(skb, offset, info);
962 return;
963 }
964
965 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)
966 ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_ICMP, 0);
967 else if (type == ICMP_REDIRECT)
968 ipv4_redirect(skb, net, 0, 0, IPPROTO_ICMP, 0);
969}
970
971
972
973
974static const struct icmp_control icmp_pointers[NR_ICMP_TYPES + 1] = {
975 [ICMP_ECHOREPLY] = {
976 .handler = ping_rcv,
977 },
978 [1] = {
979 .handler = icmp_discard,
980 .error = 1,
981 },
982 [2] = {
983 .handler = icmp_discard,
984 .error = 1,
985 },
986 [ICMP_DEST_UNREACH] = {
987 .handler = icmp_unreach,
988 .error = 1,
989 },
990 [ICMP_SOURCE_QUENCH] = {
991 .handler = icmp_unreach,
992 .error = 1,
993 },
994 [ICMP_REDIRECT] = {
995 .handler = icmp_redirect,
996 .error = 1,
997 },
998 [6] = {
999 .handler = icmp_discard,
1000 .error = 1,
1001 },
1002 [7] = {
1003 .handler = icmp_discard,
1004 .error = 1,
1005 },
1006 [ICMP_ECHO] = {
1007 .handler = icmp_echo,
1008 },
1009 [9] = {
1010 .handler = icmp_discard,
1011 .error = 1,
1012 },
1013 [10] = {
1014 .handler = icmp_discard,
1015 .error = 1,
1016 },
1017 [ICMP_TIME_EXCEEDED] = {
1018 .handler = icmp_unreach,
1019 .error = 1,
1020 },
1021 [ICMP_PARAMETERPROB] = {
1022 .handler = icmp_unreach,
1023 .error = 1,
1024 },
1025 [ICMP_TIMESTAMP] = {
1026 .handler = icmp_timestamp,
1027 },
1028 [ICMP_TIMESTAMPREPLY] = {
1029 .handler = icmp_discard,
1030 },
1031 [ICMP_INFO_REQUEST] = {
1032 .handler = icmp_discard,
1033 },
1034 [ICMP_INFO_REPLY] = {
1035 .handler = icmp_discard,
1036 },
1037 [ICMP_ADDRESS] = {
1038 .handler = icmp_discard,
1039 },
1040 [ICMP_ADDRESSREPLY] = {
1041 .handler = icmp_discard,
1042 },
1043};
1044
1045static void __net_exit icmp_sk_exit(struct net *net)
1046{
1047 int i;
1048
1049 for_each_possible_cpu(i)
1050 inet_ctl_sock_destroy(net->ipv4.icmp_sk[i]);
1051 kfree(net->ipv4.icmp_sk);
1052 net->ipv4.icmp_sk = NULL;
1053}
1054
1055static int __net_init icmp_sk_init(struct net *net)
1056{
1057 int i, err;
1058
1059 net->ipv4.icmp_sk =
1060 kzalloc(nr_cpu_ids * sizeof(struct sock *), GFP_KERNEL);
1061 if (net->ipv4.icmp_sk == NULL)
1062 return -ENOMEM;
1063
1064 for_each_possible_cpu(i) {
1065 struct sock *sk;
1066
1067 err = inet_ctl_sock_create(&sk, PF_INET,
1068 SOCK_RAW, IPPROTO_ICMP, net);
1069 if (err < 0)
1070 goto fail;
1071
1072 net->ipv4.icmp_sk[i] = sk;
1073
1074
1075
1076
1077 sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024);
1078
1079
1080
1081
1082 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
1083 inet_sk(sk)->pmtudisc = IP_PMTUDISC_DONT;
1084 }
1085
1086
1087 net->ipv4.sysctl_icmp_echo_ignore_all = 0;
1088 net->ipv4.sysctl_icmp_echo_ignore_broadcasts = 1;
1089
1090
1091 net->ipv4.sysctl_icmp_ignore_bogus_error_responses = 1;
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105 net->ipv4.sysctl_icmp_ratelimit = 1 * HZ;
1106 net->ipv4.sysctl_icmp_ratemask = 0x1818;
1107 net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr = 0;
1108
1109 return 0;
1110
1111fail:
1112 for_each_possible_cpu(i)
1113 inet_ctl_sock_destroy(net->ipv4.icmp_sk[i]);
1114 kfree(net->ipv4.icmp_sk);
1115 return err;
1116}
1117
1118static struct pernet_operations __net_initdata icmp_sk_ops = {
1119 .init = icmp_sk_init,
1120 .exit = icmp_sk_exit,
1121};
1122
1123int __init icmp_init(void)
1124{
1125 return register_pernet_subsys(&icmp_sk_ops);
1126}
1127