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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 <linux/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#include <net/l3mdev.h>
100
101
102
103
104
105struct icmp_bxm {
106 struct sk_buff *skb;
107 int offset;
108 int data_len;
109
110 struct {
111 struct icmphdr icmph;
112 __be32 times[3];
113 } data;
114 int head_len;
115 struct ip_options_data replyopts;
116};
117
118
119
120
121const struct icmp_err icmp_err_convert[] = {
122 {
123 .errno = ENETUNREACH,
124 .fatal = 0,
125 },
126 {
127 .errno = EHOSTUNREACH,
128 .fatal = 0,
129 },
130 {
131 .errno = ENOPROTOOPT ,
132 .fatal = 1,
133 },
134 {
135 .errno = ECONNREFUSED,
136 .fatal = 1,
137 },
138 {
139 .errno = EMSGSIZE,
140 .fatal = 0,
141 },
142 {
143 .errno = EOPNOTSUPP,
144 .fatal = 0,
145 },
146 {
147 .errno = ENETUNREACH,
148 .fatal = 1,
149 },
150 {
151 .errno = EHOSTDOWN,
152 .fatal = 1,
153 },
154 {
155 .errno = ENONET,
156 .fatal = 1,
157 },
158 {
159 .errno = ENETUNREACH,
160 .fatal = 1,
161 },
162 {
163 .errno = EHOSTUNREACH,
164 .fatal = 1,
165 },
166 {
167 .errno = ENETUNREACH,
168 .fatal = 0,
169 },
170 {
171 .errno = EHOSTUNREACH,
172 .fatal = 0,
173 },
174 {
175 .errno = EHOSTUNREACH,
176 .fatal = 1,
177 },
178 {
179 .errno = EHOSTUNREACH,
180 .fatal = 1,
181 },
182 {
183 .errno = EHOSTUNREACH,
184 .fatal = 1,
185 },
186};
187EXPORT_SYMBOL(icmp_err_convert);
188
189
190
191
192
193struct icmp_control {
194 bool (*handler)(struct sk_buff *skb);
195 short error;
196};
197
198static const struct icmp_control icmp_pointers[NR_ICMP_TYPES+1];
199
200
201
202
203
204
205
206
207static struct sock *icmp_sk(struct net *net)
208{
209 return *this_cpu_ptr(net->ipv4.icmp_sk);
210}
211
212
213static inline struct sock *icmp_xmit_lock(struct net *net)
214{
215 struct sock *sk;
216
217 sk = icmp_sk(net);
218
219 if (unlikely(!spin_trylock(&sk->sk_lock.slock))) {
220
221
222
223 return NULL;
224 }
225 return sk;
226}
227
228static inline void icmp_xmit_unlock(struct sock *sk)
229{
230 spin_unlock(&sk->sk_lock.slock);
231}
232
233int sysctl_icmp_msgs_per_sec __read_mostly = 1000;
234int sysctl_icmp_msgs_burst __read_mostly = 50;
235
236static struct {
237 spinlock_t lock;
238 u32 credit;
239 u32 stamp;
240} icmp_global = {
241 .lock = __SPIN_LOCK_UNLOCKED(icmp_global.lock),
242};
243
244
245
246
247
248
249
250
251bool icmp_global_allow(void)
252{
253 u32 credit, delta, incr = 0, now = (u32)jiffies;
254 bool rc = false;
255
256
257
258
259 if (!icmp_global.credit) {
260 delta = min_t(u32, now - icmp_global.stamp, HZ);
261 if (delta < HZ / 50)
262 return false;
263 }
264
265 spin_lock(&icmp_global.lock);
266 delta = min_t(u32, now - icmp_global.stamp, HZ);
267 if (delta >= HZ / 50) {
268 incr = sysctl_icmp_msgs_per_sec * delta / HZ ;
269 if (incr)
270 icmp_global.stamp = now;
271 }
272 credit = min_t(u32, icmp_global.credit + incr, sysctl_icmp_msgs_burst);
273 if (credit) {
274 credit--;
275 rc = true;
276 }
277 icmp_global.credit = credit;
278 spin_unlock(&icmp_global.lock);
279 return rc;
280}
281EXPORT_SYMBOL(icmp_global_allow);
282
283static bool icmpv4_mask_allow(struct net *net, int type, int code)
284{
285 if (type > NR_ICMP_TYPES)
286 return true;
287
288
289 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)
290 return true;
291
292
293 if (!((1 << type) & net->ipv4.sysctl_icmp_ratemask))
294 return true;
295
296 return false;
297}
298
299static bool icmpv4_global_allow(struct net *net, int type, int code)
300{
301 if (icmpv4_mask_allow(net, type, code))
302 return true;
303
304 if (icmp_global_allow())
305 return true;
306
307 return false;
308}
309
310
311
312
313
314static bool icmpv4_xrlim_allow(struct net *net, struct rtable *rt,
315 struct flowi4 *fl4, int type, int code)
316{
317 struct dst_entry *dst = &rt->dst;
318 struct inet_peer *peer;
319 bool rc = true;
320 int vif;
321
322 if (icmpv4_mask_allow(net, type, code))
323 goto out;
324
325
326 if (dst->dev && (dst->dev->flags&IFF_LOOPBACK))
327 goto out;
328
329 vif = l3mdev_master_ifindex(dst->dev);
330 peer = inet_getpeer_v4(net->ipv4.peers, fl4->daddr, vif, 1);
331 rc = inet_peer_xrlim_allow(peer, net->ipv4.sysctl_icmp_ratelimit);
332 if (peer)
333 inet_putpeer(peer);
334out:
335 return rc;
336}
337
338
339
340
341void icmp_out_count(struct net *net, unsigned char type)
342{
343 ICMPMSGOUT_INC_STATS(net, type);
344 ICMP_INC_STATS(net, ICMP_MIB_OUTMSGS);
345}
346
347
348
349
350
351static int icmp_glue_bits(void *from, char *to, int offset, int len, int odd,
352 struct sk_buff *skb)
353{
354 struct icmp_bxm *icmp_param = (struct icmp_bxm *)from;
355 __wsum csum;
356
357 csum = skb_copy_and_csum_bits(icmp_param->skb,
358 icmp_param->offset + offset,
359 to, len, 0);
360
361 skb->csum = csum_block_add(skb->csum, csum, odd);
362 if (icmp_pointers[icmp_param->data.icmph.type].error)
363 nf_ct_attach(skb, icmp_param->skb);
364 return 0;
365}
366
367static void icmp_push_reply(struct icmp_bxm *icmp_param,
368 struct flowi4 *fl4,
369 struct ipcm_cookie *ipc, struct rtable **rt)
370{
371 struct sock *sk;
372 struct sk_buff *skb;
373
374 sk = icmp_sk(dev_net((*rt)->dst.dev));
375 if (ip_append_data(sk, fl4, icmp_glue_bits, icmp_param,
376 icmp_param->data_len+icmp_param->head_len,
377 icmp_param->head_len,
378 ipc, rt, MSG_DONTWAIT) < 0) {
379 __ICMP_INC_STATS(sock_net(sk), ICMP_MIB_OUTERRORS);
380 ip_flush_pending_frames(sk);
381 } else if ((skb = skb_peek(&sk->sk_write_queue)) != NULL) {
382 struct icmphdr *icmph = icmp_hdr(skb);
383 __wsum csum = 0;
384 struct sk_buff *skb1;
385
386 skb_queue_walk(&sk->sk_write_queue, skb1) {
387 csum = csum_add(csum, skb1->csum);
388 }
389 csum = csum_partial_copy_nocheck((void *)&icmp_param->data,
390 (char *)icmph,
391 icmp_param->head_len, csum);
392 icmph->checksum = csum_fold(csum);
393 skb->ip_summed = CHECKSUM_NONE;
394 ip_push_pending_frames(sk, fl4);
395 }
396}
397
398
399
400
401
402static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
403{
404 struct ipcm_cookie ipc;
405 struct rtable *rt = skb_rtable(skb);
406 struct net *net = dev_net(rt->dst.dev);
407 struct flowi4 fl4;
408 struct sock *sk;
409 struct inet_sock *inet;
410 __be32 daddr, saddr;
411 u32 mark = IP4_REPLY_MARK(net, skb->mark);
412 int type = icmp_param->data.icmph.type;
413 int code = icmp_param->data.icmph.code;
414
415 if (ip_options_echo(net, &icmp_param->replyopts.opt.opt, skb))
416 return;
417
418
419 local_bh_disable();
420
421
422 if (!icmpv4_global_allow(net, type, code))
423 goto out_bh_enable;
424
425 sk = icmp_xmit_lock(net);
426 if (!sk)
427 goto out_bh_enable;
428 inet = inet_sk(sk);
429
430 icmp_param->data.icmph.checksum = 0;
431
432 inet->tos = ip_hdr(skb)->tos;
433 sk->sk_mark = mark;
434 daddr = ipc.addr = ip_hdr(skb)->saddr;
435 saddr = fib_compute_spec_dst(skb);
436 ipc.opt = NULL;
437 ipc.tx_flags = 0;
438 ipc.ttl = 0;
439 ipc.tos = -1;
440
441 if (icmp_param->replyopts.opt.opt.optlen) {
442 ipc.opt = &icmp_param->replyopts.opt;
443 if (ipc.opt->opt.srr)
444 daddr = icmp_param->replyopts.opt.opt.faddr;
445 }
446 memset(&fl4, 0, sizeof(fl4));
447 fl4.daddr = daddr;
448 fl4.saddr = saddr;
449 fl4.flowi4_mark = mark;
450 fl4.flowi4_uid = sock_net_uid(net, NULL);
451 fl4.flowi4_tos = RT_TOS(ip_hdr(skb)->tos);
452 fl4.flowi4_proto = IPPROTO_ICMP;
453 fl4.flowi4_oif = l3mdev_master_ifindex(skb->dev);
454 security_skb_classify_flow(skb, flowi4_to_flowi(&fl4));
455 rt = ip_route_output_key(net, &fl4);
456 if (IS_ERR(rt))
457 goto out_unlock;
458 if (icmpv4_xrlim_allow(net, rt, &fl4, type, code))
459 icmp_push_reply(icmp_param, &fl4, &ipc, &rt);
460 ip_rt_put(rt);
461out_unlock:
462 icmp_xmit_unlock(sk);
463out_bh_enable:
464 local_bh_enable();
465}
466
467static struct rtable *icmp_route_lookup(struct net *net,
468 struct flowi4 *fl4,
469 struct sk_buff *skb_in,
470 const struct iphdr *iph,
471 __be32 saddr, u8 tos, u32 mark,
472 int type, int code,
473 struct icmp_bxm *param)
474{
475 struct rtable *rt, *rt2;
476 struct flowi4 fl4_dec;
477 int err;
478
479 memset(fl4, 0, sizeof(*fl4));
480 fl4->daddr = (param->replyopts.opt.opt.srr ?
481 param->replyopts.opt.opt.faddr : iph->saddr);
482 fl4->saddr = saddr;
483 fl4->flowi4_mark = mark;
484 fl4->flowi4_uid = sock_net_uid(net, NULL);
485 fl4->flowi4_tos = RT_TOS(tos);
486 fl4->flowi4_proto = IPPROTO_ICMP;
487 fl4->fl4_icmp_type = type;
488 fl4->fl4_icmp_code = code;
489 fl4->flowi4_oif = l3mdev_master_ifindex(skb_dst(skb_in)->dev);
490
491 security_skb_classify_flow(skb_in, flowi4_to_flowi(fl4));
492 rt = ip_route_output_key_hash(net, fl4, skb_in);
493 if (IS_ERR(rt))
494 return rt;
495
496
497 rt2 = rt;
498
499 rt = (struct rtable *) xfrm_lookup(net, &rt->dst,
500 flowi4_to_flowi(fl4), NULL, 0);
501 if (!IS_ERR(rt)) {
502 if (rt != rt2)
503 return rt;
504 } else if (PTR_ERR(rt) == -EPERM) {
505 rt = NULL;
506 } else
507 return rt;
508
509 err = xfrm_decode_session_reverse(skb_in, flowi4_to_flowi(&fl4_dec), AF_INET);
510 if (err)
511 goto relookup_failed;
512
513 if (inet_addr_type_dev_table(net, skb_dst(skb_in)->dev,
514 fl4_dec.saddr) == RTN_LOCAL) {
515 rt2 = __ip_route_output_key(net, &fl4_dec);
516 if (IS_ERR(rt2))
517 err = PTR_ERR(rt2);
518 } else {
519 struct flowi4 fl4_2 = {};
520 unsigned long orefdst;
521
522 fl4_2.daddr = fl4_dec.saddr;
523 rt2 = ip_route_output_key(net, &fl4_2);
524 if (IS_ERR(rt2)) {
525 err = PTR_ERR(rt2);
526 goto relookup_failed;
527 }
528
529 orefdst = skb_in->_skb_refdst;
530 skb_dst_set(skb_in, NULL);
531 err = ip_route_input(skb_in, fl4_dec.daddr, fl4_dec.saddr,
532 RT_TOS(tos), rt2->dst.dev);
533
534 dst_release(&rt2->dst);
535 rt2 = skb_rtable(skb_in);
536 skb_in->_skb_refdst = orefdst;
537 }
538
539 if (err)
540 goto relookup_failed;
541
542 rt2 = (struct rtable *) xfrm_lookup(net, &rt2->dst,
543 flowi4_to_flowi(&fl4_dec), NULL,
544 XFRM_LOOKUP_ICMP);
545 if (!IS_ERR(rt2)) {
546 dst_release(&rt->dst);
547 memcpy(fl4, &fl4_dec, sizeof(*fl4));
548 rt = rt2;
549 } else if (PTR_ERR(rt2) == -EPERM) {
550 if (rt)
551 dst_release(&rt->dst);
552 return rt2;
553 } else {
554 err = PTR_ERR(rt2);
555 goto relookup_failed;
556 }
557 return rt;
558
559relookup_failed:
560 if (rt)
561 return rt;
562 return ERR_PTR(err);
563}
564
565
566
567
568
569
570
571
572
573
574
575
576void icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info)
577{
578 struct iphdr *iph;
579 int room;
580 struct icmp_bxm icmp_param;
581 struct rtable *rt = skb_rtable(skb_in);
582 struct ipcm_cookie ipc;
583 struct flowi4 fl4;
584 __be32 saddr;
585 u8 tos;
586 u32 mark;
587 struct net *net;
588 struct sock *sk;
589
590 if (!rt)
591 goto out;
592 net = dev_net(rt->dst.dev);
593
594
595
596
597
598
599 iph = ip_hdr(skb_in);
600
601 if ((u8 *)iph < skb_in->head ||
602 (skb_network_header(skb_in) + sizeof(*iph)) >
603 skb_tail_pointer(skb_in))
604 goto out;
605
606
607
608
609 if (skb_in->pkt_type != PACKET_HOST)
610 goto out;
611
612
613
614
615 if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
616 goto out;
617
618
619
620
621
622 if (iph->frag_off & htons(IP_OFFSET))
623 goto out;
624
625
626
627
628 if (icmp_pointers[type].error) {
629
630
631
632
633 if (iph->protocol == IPPROTO_ICMP) {
634 u8 _inner_type, *itp;
635
636 itp = skb_header_pointer(skb_in,
637 skb_network_header(skb_in) +
638 (iph->ihl << 2) +
639 offsetof(struct icmphdr,
640 type) -
641 skb_in->data,
642 sizeof(_inner_type),
643 &_inner_type);
644 if (!itp)
645 goto out;
646
647
648
649
650
651 if (*itp > NR_ICMP_TYPES ||
652 icmp_pointers[*itp].error)
653 goto out;
654 }
655 }
656
657
658 local_bh_disable();
659
660
661
662
663
664 if (!(skb_in->dev && (skb_in->dev->flags&IFF_LOOPBACK)) &&
665 !icmpv4_global_allow(net, type, code))
666 goto out_bh_enable;
667
668 sk = icmp_xmit_lock(net);
669 if (!sk)
670 goto out_bh_enable;
671
672
673
674
675
676 saddr = iph->daddr;
677 if (!(rt->rt_flags & RTCF_LOCAL)) {
678 struct net_device *dev = NULL;
679
680 rcu_read_lock();
681 if (rt_is_input_route(rt) &&
682 net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr)
683 dev = dev_get_by_index_rcu(net, inet_iif(skb_in));
684
685 if (dev)
686 saddr = inet_select_addr(dev, 0, RT_SCOPE_LINK);
687 else
688 saddr = 0;
689 rcu_read_unlock();
690 }
691
692 tos = icmp_pointers[type].error ? ((iph->tos & IPTOS_TOS_MASK) |
693 IPTOS_PREC_INTERNETCONTROL) :
694 iph->tos;
695 mark = IP4_REPLY_MARK(net, skb_in->mark);
696
697 if (ip_options_echo(net, &icmp_param.replyopts.opt.opt, skb_in))
698 goto out_unlock;
699
700
701
702
703
704
705 icmp_param.data.icmph.type = type;
706 icmp_param.data.icmph.code = code;
707 icmp_param.data.icmph.un.gateway = info;
708 icmp_param.data.icmph.checksum = 0;
709 icmp_param.skb = skb_in;
710 icmp_param.offset = skb_network_offset(skb_in);
711 inet_sk(sk)->tos = tos;
712 sk->sk_mark = mark;
713 ipc.addr = iph->saddr;
714 ipc.opt = &icmp_param.replyopts.opt;
715 ipc.tx_flags = 0;
716 ipc.ttl = 0;
717 ipc.tos = -1;
718
719 rt = icmp_route_lookup(net, &fl4, skb_in, iph, saddr, tos, mark,
720 type, code, &icmp_param);
721 if (IS_ERR(rt))
722 goto out_unlock;
723
724
725 if (!icmpv4_xrlim_allow(net, rt, &fl4, type, code))
726 goto ende;
727
728
729
730 room = dst_mtu(&rt->dst);
731 if (room > 576)
732 room = 576;
733 room -= sizeof(struct iphdr) + icmp_param.replyopts.opt.opt.optlen;
734 room -= sizeof(struct icmphdr);
735
736 icmp_param.data_len = skb_in->len - icmp_param.offset;
737 if (icmp_param.data_len > room)
738 icmp_param.data_len = room;
739 icmp_param.head_len = sizeof(struct icmphdr);
740
741 icmp_push_reply(&icmp_param, &fl4, &ipc, &rt);
742ende:
743 ip_rt_put(rt);
744out_unlock:
745 icmp_xmit_unlock(sk);
746out_bh_enable:
747 local_bh_enable();
748out:;
749}
750EXPORT_SYMBOL(icmp_send);
751
752
753static void icmp_socket_deliver(struct sk_buff *skb, u32 info)
754{
755 const struct iphdr *iph = (const struct iphdr *) skb->data;
756 const struct net_protocol *ipprot;
757 int protocol = iph->protocol;
758
759
760
761
762 if (!pskb_may_pull(skb, iph->ihl * 4 + 8)) {
763 __ICMP_INC_STATS(dev_net(skb->dev), ICMP_MIB_INERRORS);
764 return;
765 }
766
767 raw_icmp_error(skb, protocol, info);
768
769 ipprot = rcu_dereference(inet_protos[protocol]);
770 if (ipprot && ipprot->err_handler)
771 ipprot->err_handler(skb, info);
772}
773
774static bool icmp_tag_validation(int proto)
775{
776 bool ok;
777
778 rcu_read_lock();
779 ok = rcu_dereference(inet_protos[proto])->icmp_strict_tag_validation;
780 rcu_read_unlock();
781 return ok;
782}
783
784
785
786
787
788
789static bool icmp_unreach(struct sk_buff *skb)
790{
791 const struct iphdr *iph;
792 struct icmphdr *icmph;
793 struct net *net;
794 u32 info = 0;
795
796 net = dev_net(skb_dst(skb)->dev);
797
798
799
800
801
802
803
804 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
805 goto out_err;
806
807 icmph = icmp_hdr(skb);
808 iph = (const struct iphdr *)skb->data;
809
810 if (iph->ihl < 5)
811 goto out_err;
812
813 switch (icmph->type) {
814 case ICMP_DEST_UNREACH:
815 switch (icmph->code & 15) {
816 case ICMP_NET_UNREACH:
817 case ICMP_HOST_UNREACH:
818 case ICMP_PROT_UNREACH:
819 case ICMP_PORT_UNREACH:
820 break;
821 case ICMP_FRAG_NEEDED:
822
823
824
825
826 switch (net->ipv4.sysctl_ip_no_pmtu_disc) {
827 default:
828 net_dbg_ratelimited("%pI4: fragmentation needed and DF set\n",
829 &iph->daddr);
830 break;
831 case 2:
832 goto out;
833 case 3:
834 if (!icmp_tag_validation(iph->protocol))
835 goto out;
836
837 case 0:
838 info = ntohs(icmph->un.frag.mtu);
839 }
840 break;
841 case ICMP_SR_FAILED:
842 net_dbg_ratelimited("%pI4: Source Route Failed\n",
843 &iph->daddr);
844 break;
845 default:
846 break;
847 }
848 if (icmph->code > NR_ICMP_UNREACH)
849 goto out;
850 break;
851 case ICMP_PARAMETERPROB:
852 info = ntohl(icmph->un.gateway) >> 24;
853 break;
854 case ICMP_TIME_EXCEEDED:
855 __ICMP_INC_STATS(net, ICMP_MIB_INTIMEEXCDS);
856 if (icmph->code == ICMP_EXC_FRAGTIME)
857 goto out;
858 break;
859 }
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879 if (!net->ipv4.sysctl_icmp_ignore_bogus_error_responses &&
880 inet_addr_type_dev_table(net, skb->dev, iph->daddr) == RTN_BROADCAST) {
881 net_warn_ratelimited("%pI4 sent an invalid ICMP type %u, code %u error to a broadcast: %pI4 on %s\n",
882 &ip_hdr(skb)->saddr,
883 icmph->type, icmph->code,
884 &iph->daddr, skb->dev->name);
885 goto out;
886 }
887
888 icmp_socket_deliver(skb, info);
889
890out:
891 return true;
892out_err:
893 __ICMP_INC_STATS(net, ICMP_MIB_INERRORS);
894 return false;
895}
896
897
898
899
900
901
902static bool icmp_redirect(struct sk_buff *skb)
903{
904 if (skb->len < sizeof(struct iphdr)) {
905 __ICMP_INC_STATS(dev_net(skb->dev), ICMP_MIB_INERRORS);
906 return false;
907 }
908
909 if (!pskb_may_pull(skb, sizeof(struct iphdr))) {
910
911 return false;
912 }
913
914 icmp_socket_deliver(skb, icmp_hdr(skb)->un.gateway);
915 return true;
916}
917
918
919
920
921
922
923
924
925
926
927
928
929
930static bool icmp_echo(struct sk_buff *skb)
931{
932 struct net *net;
933
934 net = dev_net(skb_dst(skb)->dev);
935 if (!net->ipv4.sysctl_icmp_echo_ignore_all) {
936 struct icmp_bxm icmp_param;
937
938 icmp_param.data.icmph = *icmp_hdr(skb);
939 icmp_param.data.icmph.type = ICMP_ECHOREPLY;
940 icmp_param.skb = skb;
941 icmp_param.offset = 0;
942 icmp_param.data_len = skb->len;
943 icmp_param.head_len = sizeof(struct icmphdr);
944 icmp_reply(&icmp_param, skb);
945 }
946
947 return true;
948}
949
950
951
952
953
954
955
956
957static bool icmp_timestamp(struct sk_buff *skb)
958{
959 struct icmp_bxm icmp_param;
960
961
962
963 if (skb->len < 4)
964 goto out_err;
965
966
967
968
969 icmp_param.data.times[1] = inet_current_timestamp();
970 icmp_param.data.times[2] = icmp_param.data.times[1];
971
972 BUG_ON(skb_copy_bits(skb, 0, &icmp_param.data.times[0], 4));
973
974 icmp_param.data.icmph = *icmp_hdr(skb);
975 icmp_param.data.icmph.type = ICMP_TIMESTAMPREPLY;
976 icmp_param.data.icmph.code = 0;
977 icmp_param.skb = skb;
978 icmp_param.offset = 0;
979 icmp_param.data_len = 0;
980 icmp_param.head_len = sizeof(struct icmphdr) + 12;
981 icmp_reply(&icmp_param, skb);
982 return true;
983
984out_err:
985 __ICMP_INC_STATS(dev_net(skb_dst(skb)->dev), ICMP_MIB_INERRORS);
986 return false;
987}
988
989static bool icmp_discard(struct sk_buff *skb)
990{
991
992 return true;
993}
994
995
996
997
998int icmp_rcv(struct sk_buff *skb)
999{
1000 struct icmphdr *icmph;
1001 struct rtable *rt = skb_rtable(skb);
1002 struct net *net = dev_net(rt->dst.dev);
1003 bool success;
1004
1005 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1006 struct sec_path *sp = skb_sec_path(skb);
1007 int nh;
1008
1009 if (!(sp && sp->xvec[sp->len - 1]->props.flags &
1010 XFRM_STATE_ICMP))
1011 goto drop;
1012
1013 if (!pskb_may_pull(skb, sizeof(*icmph) + sizeof(struct iphdr)))
1014 goto drop;
1015
1016 nh = skb_network_offset(skb);
1017 skb_set_network_header(skb, sizeof(*icmph));
1018
1019 if (!xfrm4_policy_check_reverse(NULL, XFRM_POLICY_IN, skb))
1020 goto drop;
1021
1022 skb_set_network_header(skb, nh);
1023 }
1024
1025 __ICMP_INC_STATS(net, ICMP_MIB_INMSGS);
1026
1027 if (skb_checksum_simple_validate(skb))
1028 goto csum_error;
1029
1030 if (!pskb_pull(skb, sizeof(*icmph)))
1031 goto error;
1032
1033 icmph = icmp_hdr(skb);
1034
1035 ICMPMSGIN_INC_STATS(net, icmph->type);
1036
1037
1038
1039
1040
1041
1042 if (icmph->type > NR_ICMP_TYPES)
1043 goto error;
1044
1045
1046
1047
1048
1049
1050 if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
1051
1052
1053
1054
1055
1056
1057 if ((icmph->type == ICMP_ECHO ||
1058 icmph->type == ICMP_TIMESTAMP) &&
1059 net->ipv4.sysctl_icmp_echo_ignore_broadcasts) {
1060 goto error;
1061 }
1062 if (icmph->type != ICMP_ECHO &&
1063 icmph->type != ICMP_TIMESTAMP &&
1064 icmph->type != ICMP_ADDRESS &&
1065 icmph->type != ICMP_ADDRESSREPLY) {
1066 goto error;
1067 }
1068 }
1069
1070 success = icmp_pointers[icmph->type].handler(skb);
1071
1072 if (success) {
1073 consume_skb(skb);
1074 return NET_RX_SUCCESS;
1075 }
1076
1077drop:
1078 kfree_skb(skb);
1079 return NET_RX_DROP;
1080csum_error:
1081 __ICMP_INC_STATS(net, ICMP_MIB_CSUMERRORS);
1082error:
1083 __ICMP_INC_STATS(net, ICMP_MIB_INERRORS);
1084 goto drop;
1085}
1086
1087void icmp_err(struct sk_buff *skb, u32 info)
1088{
1089 struct iphdr *iph = (struct iphdr *)skb->data;
1090 int offset = iph->ihl<<2;
1091 struct icmphdr *icmph = (struct icmphdr *)(skb->data + offset);
1092 int type = icmp_hdr(skb)->type;
1093 int code = icmp_hdr(skb)->code;
1094 struct net *net = dev_net(skb->dev);
1095
1096
1097
1098
1099
1100 if (icmph->type != ICMP_ECHOREPLY) {
1101 ping_err(skb, offset, info);
1102 return;
1103 }
1104
1105 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)
1106 ipv4_update_pmtu(skb, net, info, 0, 0, IPPROTO_ICMP, 0);
1107 else if (type == ICMP_REDIRECT)
1108 ipv4_redirect(skb, net, 0, 0, IPPROTO_ICMP, 0);
1109}
1110
1111
1112
1113
1114static const struct icmp_control icmp_pointers[NR_ICMP_TYPES + 1] = {
1115 [ICMP_ECHOREPLY] = {
1116 .handler = ping_rcv,
1117 },
1118 [1] = {
1119 .handler = icmp_discard,
1120 .error = 1,
1121 },
1122 [2] = {
1123 .handler = icmp_discard,
1124 .error = 1,
1125 },
1126 [ICMP_DEST_UNREACH] = {
1127 .handler = icmp_unreach,
1128 .error = 1,
1129 },
1130 [ICMP_SOURCE_QUENCH] = {
1131 .handler = icmp_unreach,
1132 .error = 1,
1133 },
1134 [ICMP_REDIRECT] = {
1135 .handler = icmp_redirect,
1136 .error = 1,
1137 },
1138 [6] = {
1139 .handler = icmp_discard,
1140 .error = 1,
1141 },
1142 [7] = {
1143 .handler = icmp_discard,
1144 .error = 1,
1145 },
1146 [ICMP_ECHO] = {
1147 .handler = icmp_echo,
1148 },
1149 [9] = {
1150 .handler = icmp_discard,
1151 .error = 1,
1152 },
1153 [10] = {
1154 .handler = icmp_discard,
1155 .error = 1,
1156 },
1157 [ICMP_TIME_EXCEEDED] = {
1158 .handler = icmp_unreach,
1159 .error = 1,
1160 },
1161 [ICMP_PARAMETERPROB] = {
1162 .handler = icmp_unreach,
1163 .error = 1,
1164 },
1165 [ICMP_TIMESTAMP] = {
1166 .handler = icmp_timestamp,
1167 },
1168 [ICMP_TIMESTAMPREPLY] = {
1169 .handler = icmp_discard,
1170 },
1171 [ICMP_INFO_REQUEST] = {
1172 .handler = icmp_discard,
1173 },
1174 [ICMP_INFO_REPLY] = {
1175 .handler = icmp_discard,
1176 },
1177 [ICMP_ADDRESS] = {
1178 .handler = icmp_discard,
1179 },
1180 [ICMP_ADDRESSREPLY] = {
1181 .handler = icmp_discard,
1182 },
1183};
1184
1185static void __net_exit icmp_sk_exit(struct net *net)
1186{
1187 int i;
1188
1189 for_each_possible_cpu(i)
1190 inet_ctl_sock_destroy(*per_cpu_ptr(net->ipv4.icmp_sk, i));
1191 free_percpu(net->ipv4.icmp_sk);
1192 net->ipv4.icmp_sk = NULL;
1193}
1194
1195static int __net_init icmp_sk_init(struct net *net)
1196{
1197 int i, err;
1198
1199 net->ipv4.icmp_sk = alloc_percpu(struct sock *);
1200 if (!net->ipv4.icmp_sk)
1201 return -ENOMEM;
1202
1203 for_each_possible_cpu(i) {
1204 struct sock *sk;
1205
1206 err = inet_ctl_sock_create(&sk, PF_INET,
1207 SOCK_RAW, IPPROTO_ICMP, net);
1208 if (err < 0)
1209 goto fail;
1210
1211 *per_cpu_ptr(net->ipv4.icmp_sk, i) = sk;
1212
1213
1214
1215
1216 sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024);
1217
1218
1219
1220
1221 sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
1222 inet_sk(sk)->pmtudisc = IP_PMTUDISC_DONT;
1223 }
1224
1225
1226 net->ipv4.sysctl_icmp_echo_ignore_all = 0;
1227 net->ipv4.sysctl_icmp_echo_ignore_broadcasts = 1;
1228
1229
1230 net->ipv4.sysctl_icmp_ignore_bogus_error_responses = 1;
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244 net->ipv4.sysctl_icmp_ratelimit = 1 * HZ;
1245 net->ipv4.sysctl_icmp_ratemask = 0x1818;
1246 net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr = 0;
1247
1248 return 0;
1249
1250fail:
1251 for_each_possible_cpu(i)
1252 inet_ctl_sock_destroy(*per_cpu_ptr(net->ipv4.icmp_sk, i));
1253 free_percpu(net->ipv4.icmp_sk);
1254 return err;
1255}
1256
1257static struct pernet_operations __net_initdata icmp_sk_ops = {
1258 .init = icmp_sk_init,
1259 .exit = icmp_sk_exit,
1260};
1261
1262int __init icmp_init(void)
1263{
1264 return register_pernet_subsys(&icmp_sk_ops);
1265}
1266