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[PATCH] x86_64: IOMMU printk cleanup
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / ipv4 / icmp.c
CommitLineData
1da177e4
LT		 1/*
2 * NET3: Implementation of the ICMP protocol layer.
3 *
4 * Alan Cox, <alan@redhat.com>
5 *
6 * Version: $Id: icmp.c,v 1.85 2002/02/01 22:01:03 davem Exp $
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 * Some of the function names and the icmp unreach table for this
14 * module were derived from [icmp.c 1.0.11 06/02/93] by
15 * Ross Biro, Fred N. van Kempen, Mark Evans, Alan Cox, Gerhard Koerting.
16 * Other than that this module is a complete rewrite.
17 *
18 * Fixes:
19 * Clemens Fruhwirth : introduce global icmp rate limiting
20 * with icmp type masking ability instead
21 * of broken per type icmp timeouts.
22 * Mike Shaver : RFC1122 checks.
23 * Alan Cox : Multicast ping reply as self.
24 * Alan Cox : Fix atomicity lockup in ip_build_xmit
25 * call.
26 * Alan Cox : Added 216,128 byte paths to the MTU
27 * code.
28 * Martin Mares : RFC1812 checks.
29 * Martin Mares : Can be configured to follow redirects
30 * if acting as a router _without_ a
31 * routing protocol (RFC 1812).
32 * Martin Mares : Echo requests may be configured to
33 * be ignored (RFC 1812).
34 * Martin Mares : Limitation of ICMP error message
35 * transmit rate (RFC 1812).
36 * Martin Mares : TOS and Precedence set correctly
37 * (RFC 1812).
38 * Martin Mares : Now copying as much data from the
39 * original packet as we can without
40 * exceeding 576 bytes (RFC 1812).
41 * Willy Konynenberg : Transparent proxying support.
42 * Keith Owens : RFC1191 correction for 4.2BSD based
43 * path MTU bug.
44 * Thomas Quinot : ICMP Dest Unreach codes up to 15 are
45 * valid (RFC 1812).
46 * Andi Kleen : Check all packet lengths properly
47 * and moved all kfree_skb() up to
48 * icmp_rcv.
49 * Andi Kleen : Move the rate limit bookkeeping
50 * into the dest entry and use a token
51 * bucket filter (thanks to ANK). Make
52 * the rates sysctl configurable.
53 * Yu Tianli : Fixed two ugly bugs in icmp_send
54 * - IP option length was accounted wrongly
55 * - ICMP header length was not accounted
56 * at all.
57 * Tristan Greaves : Added sysctl option to ignore bogus
58 * broadcast responses from broken routers.
59 *
60 * To Fix:
61 *
62 * - Should use skb_pull() instead of all the manual checking.
63 * This would also greatly simply some upper layer error handlers. --AK
64 *
65 */
66
67#include <linux/config.h>
68#include <linux/module.h>
69#include <linux/types.h>
70#include <linux/jiffies.h>
71#include <linux/kernel.h>
72#include <linux/fcntl.h>
73#include <linux/socket.h>
74#include <linux/in.h>
75#include <linux/inet.h>
14c85021 76#include <linux/inetdevice.h>
1da177e4
LT		 77#include <linux/netdevice.h>
78#include <linux/string.h>
79#include <linux/netfilter_ipv4.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 <linux/skbuff.h>
89#include <net/sock.h>
90#include <linux/errno.h>
91#include <linux/timer.h>
92#include <linux/init.h>
93#include <asm/system.h>
94#include <asm/uaccess.h>
95#include <net/checksum.h>
96
97/*
98 * Build xmit assembly blocks
99 */
100
101struct icmp_bxm {
102 struct sk_buff *skb;
103 int offset;
104 int data_len;
105
106 struct {
107 struct icmphdr icmph;
108 __u32 times[3];
109 } data;
110 int head_len;
111 struct ip_options replyopts;
112 unsigned char optbuf[40];
113};
114
115/*
116 * Statistics
117 */
ba89966c 118DEFINE_SNMP_STAT(struct icmp_mib, icmp_statistics) __read_mostly;
1da177e4
LT		 119
120/* An array of errno for error messages from dest unreach. */
121/* RFC 1122: 3.2.2.1 States that NET_UNREACH, HOST_UNREACH and SR_FAILED MUST be considered 'transient errs'. */
122
123struct icmp_err icmp_err_convert[] = {
124 {
125 .errno = ENETUNREACH, /* ICMP_NET_UNREACH */
126 .fatal = 0,
127 },
128 {
129 .errno = EHOSTUNREACH, /* ICMP_HOST_UNREACH */
130 .fatal = 0,
131 },
132 {
133 .errno = ENOPROTOOPT /* ICMP_PROT_UNREACH */,
134 .fatal = 1,
135 },
136 {
137 .errno = ECONNREFUSED, /* ICMP_PORT_UNREACH */
138 .fatal = 1,
139 },
140 {
141 .errno = EMSGSIZE, /* ICMP_FRAG_NEEDED */
142 .fatal = 0,
143 },
144 {
145 .errno = EOPNOTSUPP, /* ICMP_SR_FAILED */
146 .fatal = 0,
147 },
148 {
149 .errno = ENETUNREACH, /* ICMP_NET_UNKNOWN */
150 .fatal = 1,
151 },
152 {
153 .errno = EHOSTDOWN, /* ICMP_HOST_UNKNOWN */
154 .fatal = 1,
155 },
156 {
157 .errno = ENONET, /* ICMP_HOST_ISOLATED */
158 .fatal = 1,
159 },
160 {
161 .errno = ENETUNREACH, /* ICMP_NET_ANO */
162 .fatal = 1,
163 },
164 {
165 .errno = EHOSTUNREACH, /* ICMP_HOST_ANO */
166 .fatal = 1,
167 },
168 {
169 .errno = ENETUNREACH, /* ICMP_NET_UNR_TOS */
170 .fatal = 0,
171 },
172 {
173 .errno = EHOSTUNREACH, /* ICMP_HOST_UNR_TOS */
174 .fatal = 0,
175 },
176 {
177 .errno = EHOSTUNREACH, /* ICMP_PKT_FILTERED */
178 .fatal = 1,
179 },
180 {
181 .errno = EHOSTUNREACH, /* ICMP_PREC_VIOLATION */
182 .fatal = 1,
183 },
184 {
185 .errno = EHOSTUNREACH, /* ICMP_PREC_CUTOFF */
186 .fatal = 1,
187 },
188};
189
190/* Control parameters for ECHO replies. */
191int sysctl_icmp_echo_ignore_all;
7ce31246 192int sysctl_icmp_echo_ignore_broadcasts = 1;
1da177e4
LT		 193
194/* Control parameter - ignore bogus broadcast responses? */
195int sysctl_icmp_ignore_bogus_error_responses;
196
197/*
198 * Configurable global rate limit.
199 *
200 * ratelimit defines tokens/packet consumed for dst->rate_token bucket
201 * ratemask defines which icmp types are ratelimited by setting
202 * it's bit position.
203 *
204 * default:
205 * dest unreachable (3), source quench (4),
206 * time exceeded (11), parameter problem (12)
207 */
208
209int sysctl_icmp_ratelimit = 1 * HZ;
210int sysctl_icmp_ratemask = 0x1818;
1c2fb7f9 211int sysctl_icmp_errors_use_inbound_ifaddr;
1da177e4
LT		 212
213/*
214 * ICMP control array. This specifies what to do with each ICMP.
215 */
216
217struct icmp_control {
218 int output_entry; /* Field for increment on output */
219 int input_entry; /* Field for increment on input */
220 void (*handler)(struct sk_buff *skb);
221 short error; /* This ICMP is classed as an error message */
222};
223
9b5b5cff 224static const struct icmp_control icmp_pointers[NR_ICMP_TYPES+1];
1da177e4
LT		 225
226/*
227 * The ICMP socket(s). This is the most convenient way to flow control
228 * our ICMP output as well as maintain a clean interface throughout
229 * all layers. All Socketless IP sends will soon be gone.
230 *
231 * On SMP we have one ICMP socket per-cpu.
232 */
233static DEFINE_PER_CPU(struct socket *, __icmp_socket) = NULL;
234#define icmp_socket __get_cpu_var(__icmp_socket)
235
236static __inline__ int icmp_xmit_lock(void)
237{
238 local_bh_disable();
239
240 if (unlikely(!spin_trylock(&icmp_socket->sk->sk_lock.slock))) {
241 /* This can happen if the output path signals a
242 * dst_link_failure() for an outgoing ICMP packet.
243 */
244 local_bh_enable();
245 return 1;
246 }
247 return 0;
248}
249
250static void icmp_xmit_unlock(void)
251{
252 spin_unlock_bh(&icmp_socket->sk->sk_lock.slock);
253}
254
255/*
256 * Send an ICMP frame.
257 */
258
259/*
260 * Check transmit rate limitation for given message.
261 * The rate information is held in the destination cache now.
262 * This function is generic and could be used for other purposes
263 * too. It uses a Token bucket filter as suggested by Alexey Kuznetsov.
264 *
265 * Note that the same dst_entry fields are modified by functions in
266 * route.c too, but these work for packet destinations while xrlim_allow
267 * works for icmp destinations. This means the rate limiting information
268 * for one "ip object" is shared - and these ICMPs are twice limited:
269 * by source and by destination.
270 *
271 * RFC 1812: 4.3.2.8 SHOULD be able to limit error message rate
272 * SHOULD allow setting of rate limits
273 *
274 * Shared between ICMPv4 and ICMPv6.
275 */
276#define XRLIM_BURST_FACTOR 6
277int xrlim_allow(struct dst_entry *dst, int timeout)
278{
279 unsigned long now;
280 int rc = 0;
281
282 now = jiffies;
283 dst->rate_tokens += now - dst->rate_last;
284 dst->rate_last = now;
285 if (dst->rate_tokens > XRLIM_BURST_FACTOR * timeout)
286 dst->rate_tokens = XRLIM_BURST_FACTOR * timeout;
287 if (dst->rate_tokens >= timeout) {
288 dst->rate_tokens -= timeout;
289 rc = 1;
290 }
291 return rc;
292}
293
294static inline int icmpv4_xrlim_allow(struct rtable *rt, int type, int code)
295{
296 struct dst_entry *dst = &rt->u.dst;
297 int rc = 1;
298
299 if (type > NR_ICMP_TYPES)
300 goto out;
301
302 /* Don't limit PMTU discovery. */
303 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)
304 goto out;
305
306 /* No rate limit on loopback */
307 if (dst->dev && (dst->dev->flags&IFF_LOOPBACK))
308 goto out;
309
310 /* Limit if icmp type is enabled in ratemask. */
311 if ((1 << type) & sysctl_icmp_ratemask)
312 rc = xrlim_allow(dst, sysctl_icmp_ratelimit);
313out:
314 return rc;
315}
316
317/*
318 * Maintain the counters used in the SNMP statistics for outgoing ICMP
319 */
320static void icmp_out_count(int type)
321{
322 if (type <= NR_ICMP_TYPES) {
323 ICMP_INC_STATS(icmp_pointers[type].output_entry);
324 ICMP_INC_STATS(ICMP_MIB_OUTMSGS);
325 }
326}
327
328/*
329 * Checksum each fragment, and on the first include the headers and final
330 * checksum.
331 */
332static int icmp_glue_bits(void *from, char *to, int offset, int len, int odd,
333 struct sk_buff *skb)
334{
335 struct icmp_bxm *icmp_param = (struct icmp_bxm *)from;
336 unsigned int csum;
337
338 csum = skb_copy_and_csum_bits(icmp_param->skb,
339 icmp_param->offset + offset,
340 to, len, 0);
341
342 skb->csum = csum_block_add(skb->csum, csum, odd);
343 if (icmp_pointers[icmp_param->data.icmph.type].error)
344 nf_ct_attach(skb, icmp_param->skb);
345 return 0;
346}
347
348static void icmp_push_reply(struct icmp_bxm *icmp_param,
349 struct ipcm_cookie *ipc, struct rtable *rt)
350{
351 struct sk_buff *skb;
352
cb94c62c
PM		 353 if (ip_append_data(icmp_socket->sk, icmp_glue_bits, icmp_param,
354 icmp_param->data_len+icmp_param->head_len,
355 icmp_param->head_len,
356 ipc, rt, MSG_DONTWAIT) < 0)
357 ip_flush_pending_frames(icmp_socket->sk);
358 else if ((skb = skb_peek(&icmp_socket->sk->sk_write_queue)) != NULL) {
1da177e4
LT		 359 struct icmphdr *icmph = skb->h.icmph;
360 unsigned int csum = 0;
361 struct sk_buff *skb1;
362
363 skb_queue_walk(&icmp_socket->sk->sk_write_queue, skb1) {
364 csum = csum_add(csum, skb1->csum);
365 }
366 csum = csum_partial_copy_nocheck((void *)&icmp_param->data,
367 (char *)icmph,
368 icmp_param->head_len, csum);
369 icmph->checksum = csum_fold(csum);
370 skb->ip_summed = CHECKSUM_NONE;
371 ip_push_pending_frames(icmp_socket->sk);
372 }
373}
374
375/*
376 * Driving logic for building and sending ICMP messages.
377 */
378
379static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
380{
381 struct sock *sk = icmp_socket->sk;
382 struct inet_sock *inet = inet_sk(sk);
383 struct ipcm_cookie ipc;
384 struct rtable *rt = (struct rtable *)skb->dst;
385 u32 daddr;
386
387 if (ip_options_echo(&icmp_param->replyopts, skb))
f00c401b 388 return;
1da177e4
LT		 389
390 if (icmp_xmit_lock())
391 return;
392
393 icmp_param->data.icmph.checksum = 0;
394 icmp_out_count(icmp_param->data.icmph.type);
395
396 inet->tos = skb->nh.iph->tos;
397 daddr = ipc.addr = rt->rt_src;
398 ipc.opt = NULL;
399 if (icmp_param->replyopts.optlen) {
400 ipc.opt = &icmp_param->replyopts;
401 if (ipc.opt->srr)
402 daddr = icmp_param->replyopts.faddr;
403 }
404 {
405 struct flowi fl = { .nl_u = { .ip4_u =
406 { .daddr = daddr,
407 .saddr = rt->rt_spec_dst,
408 .tos = RT_TOS(skb->nh.iph->tos) } },
409 .proto = IPPROTO_ICMP };
410 if (ip_route_output_key(&rt, &fl))
411 goto out_unlock;
412 }
413 if (icmpv4_xrlim_allow(rt, icmp_param->data.icmph.type,
414 icmp_param->data.icmph.code))
415 icmp_push_reply(icmp_param, &ipc, rt);
416 ip_rt_put(rt);
417out_unlock:
418 icmp_xmit_unlock();
1da177e4
LT		 419}
420
421
422/*
423 * Send an ICMP message in response to a situation
424 *
425 * RFC 1122: 3.2.2 MUST send at least the IP header and 8 bytes of header.
426 * MAY send more (we do).
427 * MUST NOT change this header information.
428 * MUST NOT reply to a multicast/broadcast IP address.
429 * MUST NOT reply to a multicast/broadcast MAC address.
430 * MUST reply to only the first fragment.
431 */
432
433void icmp_send(struct sk_buff *skb_in, int type, int code, u32 info)
434{
435 struct iphdr *iph;
436 int room;
437 struct icmp_bxm icmp_param;
438 struct rtable *rt = (struct rtable *)skb_in->dst;
439 struct ipcm_cookie ipc;
440 u32 saddr;
441 u8 tos;
442
443 if (!rt)
444 goto out;
445
446 /*
447 * Find the original header. It is expected to be valid, of course.
448 * Check this, icmp_send is called from the most obscure devices
449 * sometimes.
450 */
451 iph = skb_in->nh.iph;
452
453 if ((u8 *)iph < skb_in->head || (u8 *)(iph + 1) > skb_in->tail)
454 goto out;
455
456 /*
457 * No replies to physical multicast/broadcast
458 */
459 if (skb_in->pkt_type != PACKET_HOST)
460 goto out;
461
462 /*
463 * Now check at the protocol level
464 */
465 if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
466 goto out;
467
468 /*
469 * Only reply to fragment 0. We byte re-order the constant
470 * mask for efficiency.
471 */
472 if (iph->frag_off & htons(IP_OFFSET))
473 goto out;
474
475 /*
476 * If we send an ICMP error to an ICMP error a mess would result..
477 */
478 if (icmp_pointers[type].error) {
479 /*
480 * We are an error, check if we are replying to an
481 * ICMP error
482 */
483 if (iph->protocol == IPPROTO_ICMP) {
484 u8 _inner_type, *itp;
485
486 itp = skb_header_pointer(skb_in,
487 skb_in->nh.raw +
488 (iph->ihl << 2) +
489 offsetof(struct icmphdr,
490 type) -
491 skb_in->data,
492 sizeof(_inner_type),
493 &_inner_type);
494 if (itp == NULL)
495 goto out;
496
497 /*
498 * Assume any unknown ICMP type is an error. This
499 * isn't specified by the RFC, but think about it..
500 */
501 if (*itp > NR_ICMP_TYPES ||
502 icmp_pointers[*itp].error)
503 goto out;
504 }
505 }
506
507 if (icmp_xmit_lock())
508 return;
509
510 /*
511 * Construct source address and options.
512 */
513
514 saddr = iph->daddr;
1c2fb7f9
S		 515 if (!(rt->rt_flags & RTCF_LOCAL)) {
516 if (sysctl_icmp_errors_use_inbound_ifaddr)
517 saddr = inet_select_addr(skb_in->dev, 0, RT_SCOPE_LINK);
518 else
519 saddr = 0;
520 }
1da177e4
LT		 521
522 tos = icmp_pointers[type].error ? ((iph->tos & IPTOS_TOS_MASK) |
523 IPTOS_PREC_INTERNETCONTROL) :
524 iph->tos;
525
526 if (ip_options_echo(&icmp_param.replyopts, skb_in))
527 goto ende;
528
529
530 /*
531 * Prepare data for ICMP header.
532 */
533
534 icmp_param.data.icmph.type = type;
535 icmp_param.data.icmph.code = code;
536 icmp_param.data.icmph.un.gateway = info;
537 icmp_param.data.icmph.checksum = 0;
538 icmp_param.skb = skb_in;
539 icmp_param.offset = skb_in->nh.raw - skb_in->data;
540 icmp_out_count(icmp_param.data.icmph.type);
541 inet_sk(icmp_socket->sk)->tos = tos;
542 ipc.addr = iph->saddr;
543 ipc.opt = &icmp_param.replyopts;
544
545 {
546 struct flowi fl = {
547 .nl_u = {
548 .ip4_u = {
549 .daddr = icmp_param.replyopts.srr ?
550 icmp_param.replyopts.faddr :
551 iph->saddr,
552 .saddr = saddr,
553 .tos = RT_TOS(tos)
554 }
555 },
556 .proto = IPPROTO_ICMP,
557 .uli_u = {
558 .icmpt = {
559 .type = type,
560 .code = code
561 }
562 }
563 };
564 if (ip_route_output_key(&rt, &fl))
565 goto out_unlock;
566 }
567
568 if (!icmpv4_xrlim_allow(rt, type, code))
569 goto ende;
570
571 /* RFC says return as much as we can without exceeding 576 bytes. */
572
573 room = dst_mtu(&rt->u.dst);
574 if (room > 576)
575 room = 576;
576 room -= sizeof(struct iphdr) + icmp_param.replyopts.optlen;
577 room -= sizeof(struct icmphdr);
578
579 icmp_param.data_len = skb_in->len - icmp_param.offset;
580 if (icmp_param.data_len > room)
581 icmp_param.data_len = room;
582 icmp_param.head_len = sizeof(struct icmphdr);
583
584 icmp_push_reply(&icmp_param, &ipc, rt);
585ende:
586 ip_rt_put(rt);
587out_unlock:
588 icmp_xmit_unlock();
589out:;
590}
591
592
593/*
594 * Handle ICMP_DEST_UNREACH, ICMP_TIME_EXCEED, and ICMP_QUENCH.
595 */
596
597static void icmp_unreach(struct sk_buff *skb)
598{
599 struct iphdr *iph;
600 struct icmphdr *icmph;
601 int hash, protocol;
602 struct net_protocol *ipprot;
603 struct sock *raw_sk;
604 u32 info = 0;
605
606 /*
607 * Incomplete header ?
608 * Only checks for the IP header, there should be an
609 * additional check for longer headers in upper levels.
610 */
611
612 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
613 goto out_err;
614
615 icmph = skb->h.icmph;
616 iph = (struct iphdr *)skb->data;
617
618 if (iph->ihl < 5) /* Mangled header, drop. */
619 goto out_err;
620
621 if (icmph->type == ICMP_DEST_UNREACH) {
622 switch (icmph->code & 15) {
623 case ICMP_NET_UNREACH:
624 case ICMP_HOST_UNREACH:
625 case ICMP_PROT_UNREACH:
626 case ICMP_PORT_UNREACH:
627 break;
628 case ICMP_FRAG_NEEDED:
629 if (ipv4_config.no_pmtu_disc) {
64ce2073 630 LIMIT_NETDEBUG(KERN_INFO "ICMP: %u.%u.%u.%u: "
1da177e4
LT		 631 "fragmentation needed "
632 "and DF set.\n",
64ce2073 633 NIPQUAD(iph->daddr));
1da177e4
LT		 634 } else {
635 info = ip_rt_frag_needed(iph,
636 ntohs(icmph->un.frag.mtu));
637 if (!info)
638 goto out;
639 }
640 break;
641 case ICMP_SR_FAILED:
64ce2073 642 LIMIT_NETDEBUG(KERN_INFO "ICMP: %u.%u.%u.%u: Source "
1da177e4 643 "Route Failed.\n",
64ce2073 644 NIPQUAD(iph->daddr));
1da177e4
LT		 645 break;
646 default:
647 break;
648 }
649 if (icmph->code > NR_ICMP_UNREACH)
650 goto out;
651 } else if (icmph->type == ICMP_PARAMETERPROB)
652 info = ntohl(icmph->un.gateway) >> 24;
653
654 /*
655 * Throw it at our lower layers
656 *
657 * RFC 1122: 3.2.2 MUST extract the protocol ID from the passed
658 * header.
659 * RFC 1122: 3.2.2.1 MUST pass ICMP unreach messages to the
660 * transport layer.
661 * RFC 1122: 3.2.2.2 MUST pass ICMP time expired messages to
662 * transport layer.
663 */
664
665 /*
666 * Check the other end isnt violating RFC 1122. Some routers send
667 * bogus responses to broadcast frames. If you see this message
668 * first check your netmask matches at both ends, if it does then
669 * get the other vendor to fix their kit.
670 */
671
672 if (!sysctl_icmp_ignore_bogus_error_responses &&
673 inet_addr_type(iph->daddr) == RTN_BROADCAST) {
674 if (net_ratelimit())
675 printk(KERN_WARNING "%u.%u.%u.%u sent an invalid ICMP "
676 "type %u, code %u "
677 "error to a broadcast: %u.%u.%u.%u on %s\n",
678 NIPQUAD(skb->nh.iph->saddr),
679 icmph->type, icmph->code,
680 NIPQUAD(iph->daddr),
681 skb->dev->name);
682 goto out;
683 }
684
685 /* Checkin full IP header plus 8 bytes of protocol to
686 * avoid additional coding at protocol handlers.
687 */
688 if (!pskb_may_pull(skb, iph->ihl * 4 + 8))
689 goto out;
690
691 iph = (struct iphdr *)skb->data;
692 protocol = iph->protocol;
693
694 /*
695 * Deliver ICMP message to raw sockets. Pretty useless feature?
696 */
697
698 /* Note: See raw.c and net/raw.h, RAWV4_HTABLE_SIZE==MAX_INET_PROTOS */
699 hash = protocol & (MAX_INET_PROTOS - 1);
700 read_lock(&raw_v4_lock);
701 if ((raw_sk = sk_head(&raw_v4_htable[hash])) != NULL) {
702 while ((raw_sk = __raw_v4_lookup(raw_sk, protocol, iph->daddr,
703 iph->saddr,
704 skb->dev->ifindex)) != NULL) {
705 raw_err(raw_sk, skb, info);
706 raw_sk = sk_next(raw_sk);
707 iph = (struct iphdr *)skb->data;
708 }
709 }
710 read_unlock(&raw_v4_lock);
711
712 rcu_read_lock();
713 ipprot = rcu_dereference(inet_protos[hash]);
714 if (ipprot && ipprot->err_handler)
715 ipprot->err_handler(skb, info);
716 rcu_read_unlock();
717
718out:
719 return;
720out_err:
721 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
722 goto out;
723}
724
725
726/*
727 * Handle ICMP_REDIRECT.
728 */
729
730static void icmp_redirect(struct sk_buff *skb)
731{
732 struct iphdr *iph;
733 unsigned long ip;
734
735 if (skb->len < sizeof(struct iphdr))
736 goto out_err;
737
738 /*
739 * Get the copied header of the packet that caused the redirect
740 */
741 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
742 goto out;
743
744 iph = (struct iphdr *)skb->data;
745 ip = iph->daddr;
746
747 switch (skb->h.icmph->code & 7) {
748 case ICMP_REDIR_NET:
749 case ICMP_REDIR_NETTOS:
750 /*
751 * As per RFC recommendations now handle it as a host redirect.
752 */
753 case ICMP_REDIR_HOST:
754 case ICMP_REDIR_HOSTTOS:
755 ip_rt_redirect(skb->nh.iph->saddr, ip, skb->h.icmph->un.gateway,
756 iph->saddr, iph->tos, skb->dev);
757 break;
758 }
759out:
760 return;
761out_err:
762 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
763 goto out;
764}
765
766/*
767 * Handle ICMP_ECHO ("ping") requests.
768 *
769 * RFC 1122: 3.2.2.6 MUST have an echo server that answers ICMP echo
770 * requests.
771 * RFC 1122: 3.2.2.6 Data received in the ICMP_ECHO request MUST be
772 * included in the reply.
773 * RFC 1812: 4.3.3.6 SHOULD have a config option for silently ignoring
774 * echo requests, MUST have default=NOT.
775 * See also WRT handling of options once they are done and working.
776 */
777
778static void icmp_echo(struct sk_buff *skb)
779{
780 if (!sysctl_icmp_echo_ignore_all) {
781 struct icmp_bxm icmp_param;
782
783 icmp_param.data.icmph = *skb->h.icmph;
784 icmp_param.data.icmph.type = ICMP_ECHOREPLY;
785 icmp_param.skb = skb;
786 icmp_param.offset = 0;
787 icmp_param.data_len = skb->len;
788 icmp_param.head_len = sizeof(struct icmphdr);
789 icmp_reply(&icmp_param, skb);
790 }
791}
792
793/*
794 * Handle ICMP Timestamp requests.
795 * RFC 1122: 3.2.2.8 MAY implement ICMP timestamp requests.
796 * SHOULD be in the kernel for minimum random latency.
797 * MUST be accurate to a few minutes.
798 * MUST be updated at least at 15Hz.
799 */
800static void icmp_timestamp(struct sk_buff *skb)
801{
802 struct timeval tv;
803 struct icmp_bxm icmp_param;
804 /*
805 * Too short.
806 */
807 if (skb->len < 4)
808 goto out_err;
809
810 /*
811 * Fill in the current time as ms since midnight UT:
812 */
813 do_gettimeofday(&tv);
814 icmp_param.data.times[1] = htonl((tv.tv_sec % 86400) * 1000 +
815 tv.tv_usec / 1000);
816 icmp_param.data.times[2] = icmp_param.data.times[1];
817 if (skb_copy_bits(skb, 0, &icmp_param.data.times[0], 4))
818 BUG();
819 icmp_param.data.icmph = *skb->h.icmph;
820 icmp_param.data.icmph.type = ICMP_TIMESTAMPREPLY;
821 icmp_param.data.icmph.code = 0;
822 icmp_param.skb = skb;
823 icmp_param.offset = 0;
824 icmp_param.data_len = 0;
825 icmp_param.head_len = sizeof(struct icmphdr) + 12;
826 icmp_reply(&icmp_param, skb);
827out:
828 return;
829out_err:
830 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
831 goto out;
832}
833
834
835/*
836 * Handle ICMP_ADDRESS_MASK requests. (RFC950)
837 *
838 * RFC1122 (3.2.2.9). A host MUST only send replies to
839 * ADDRESS_MASK requests if it's been configured as an address mask
840 * agent. Receiving a request doesn't constitute implicit permission to
841 * act as one. Of course, implementing this correctly requires (SHOULD)
842 * a way to turn the functionality on and off. Another one for sysctl(),
843 * I guess. -- MS
844 *
845 * RFC1812 (4.3.3.9). A router MUST implement it.
846 * A router SHOULD have switch turning it on/off.
847 * This switch MUST be ON by default.
848 *
849 * Gratuitous replies, zero-source replies are not implemented,
850 * that complies with RFC. DO NOT implement them!!! All the idea
851 * of broadcast addrmask replies as specified in RFC950 is broken.
852 * The problem is that it is not uncommon to have several prefixes
853 * on one physical interface. Moreover, addrmask agent can even be
854 * not aware of existing another prefixes.
855 * If source is zero, addrmask agent cannot choose correct prefix.
856 * Gratuitous mask announcements suffer from the same problem.
857 * RFC1812 explains it, but still allows to use ADDRMASK,
858 * that is pretty silly. --ANK
859 *
860 * All these rules are so bizarre, that I removed kernel addrmask
861 * support at all. It is wrong, it is obsolete, nobody uses it in
862 * any case. --ANK
863 *
864 * Furthermore you can do it with a usermode address agent program
865 * anyway...
866 */
867
868static void icmp_address(struct sk_buff *skb)
869{
870#if 0
871 if (net_ratelimit())
872 printk(KERN_DEBUG "a guy asks for address mask. Who is it?\n");
873#endif
874}
875
876/*
877 * RFC1812 (4.3.3.9). A router SHOULD listen all replies, and complain
878 * loudly if an inconsistency is found.
879 */
880
881static void icmp_address_reply(struct sk_buff *skb)
882{
883 struct rtable *rt = (struct rtable *)skb->dst;
884 struct net_device *dev = skb->dev;
885 struct in_device *in_dev;
886 struct in_ifaddr *ifa;
887
888 if (skb->len < 4 || !(rt->rt_flags&RTCF_DIRECTSRC))
889 goto out;
890
891 in_dev = in_dev_get(dev);
892 if (!in_dev)
893 goto out;
894 rcu_read_lock();
895 if (in_dev->ifa_list &&
896 IN_DEV_LOG_MARTIANS(in_dev) &&
897 IN_DEV_FORWARD(in_dev)) {
898 u32 _mask, *mp;
899
900 mp = skb_header_pointer(skb, 0, sizeof(_mask), &_mask);
09a62660 901 BUG_ON(mp == NULL);
1da177e4
LT		 902 for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) {
903 if (*mp == ifa->ifa_mask &&
904 inet_ifa_match(rt->rt_src, ifa))
905 break;
906 }
907 if (!ifa && net_ratelimit()) {
908 printk(KERN_INFO "Wrong address mask %u.%u.%u.%u from "
909 "%s/%u.%u.%u.%u\n",
910 NIPQUAD(*mp), dev->name, NIPQUAD(rt->rt_src));
911 }
912 }
913 rcu_read_unlock();
914 in_dev_put(in_dev);
915out:;
916}
917
918static void icmp_discard(struct sk_buff *skb)
919{
920}
921
922/*
923 * Deal with incoming ICMP packets.
924 */
925int icmp_rcv(struct sk_buff *skb)
926{
927 struct icmphdr *icmph;
928 struct rtable *rt = (struct rtable *)skb->dst;
929
930 ICMP_INC_STATS_BH(ICMP_MIB_INMSGS);
931
932 switch (skb->ip_summed) {
933 case CHECKSUM_HW:
934 if (!(u16)csum_fold(skb->csum))
935 break;
fb286bb2 936 /* fall through */
1da177e4 937 case CHECKSUM_NONE:
fb286bb2
HX		 938 skb->csum = 0;
939 if (__skb_checksum_complete(skb))
1da177e4 940 goto error;
1da177e4
LT		 941 }
942
943 if (!pskb_pull(skb, sizeof(struct icmphdr)))
944 goto error;
945
946 icmph = skb->h.icmph;
947
948 /*
949 * 18 is the highest 'known' ICMP type. Anything else is a mystery
950 *
951 * RFC 1122: 3.2.2 Unknown ICMP messages types MUST be silently
952 * discarded.
953 */
954 if (icmph->type > NR_ICMP_TYPES)
955 goto error;
956
957
958 /*
959 * Parse the ICMP message
960 */
961
962 if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
963 /*
964 * RFC 1122: 3.2.2.6 An ICMP_ECHO to broadcast MAY be
965 * silently ignored (we let user decide with a sysctl).
966 * RFC 1122: 3.2.2.8 An ICMP_TIMESTAMP MAY be silently
967 * discarded if to broadcast/multicast.
968 */
4c866aa7
AK		 969 if ((icmph->type == ICMP_ECHO ||
970 icmph->type == ICMP_TIMESTAMP) &&
1da177e4
LT		 971 sysctl_icmp_echo_ignore_broadcasts) {
972 goto error;
973 }
974 if (icmph->type != ICMP_ECHO &&
975 icmph->type != ICMP_TIMESTAMP &&
976 icmph->type != ICMP_ADDRESS &&
977 icmph->type != ICMP_ADDRESSREPLY) {
978 goto error;
979 }
980 }
981
982 ICMP_INC_STATS_BH(icmp_pointers[icmph->type].input_entry);
983 icmp_pointers[icmph->type].handler(skb);
984
985drop:
986 kfree_skb(skb);
987 return 0;
988error:
989 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
990 goto drop;
991}
992
993/*
994 * This table is the definition of how we handle ICMP.
995 */
9b5b5cff 996static const struct icmp_control icmp_pointers[NR_ICMP_TYPES + 1] = {
1da177e4
LT		 997 [ICMP_ECHOREPLY] = {
998 .output_entry = ICMP_MIB_OUTECHOREPS,
999 .input_entry = ICMP_MIB_INECHOREPS,
1000 .handler = icmp_discard,
1001 },
1002 [1] = {
1003 .output_entry = ICMP_MIB_DUMMY,
1004 .input_entry = ICMP_MIB_INERRORS,
1005 .handler = icmp_discard,
1006 .error = 1,
1007 },
1008 [2] = {
1009 .output_entry = ICMP_MIB_DUMMY,
1010 .input_entry = ICMP_MIB_INERRORS,
1011 .handler = icmp_discard,
1012 .error = 1,
1013 },
1014 [ICMP_DEST_UNREACH] = {
1015 .output_entry = ICMP_MIB_OUTDESTUNREACHS,
1016 .input_entry = ICMP_MIB_INDESTUNREACHS,
1017 .handler = icmp_unreach,
1018 .error = 1,
1019 },
1020 [ICMP_SOURCE_QUENCH] = {
1021 .output_entry = ICMP_MIB_OUTSRCQUENCHS,
1022 .input_entry = ICMP_MIB_INSRCQUENCHS,
1023 .handler = icmp_unreach,
1024 .error = 1,
1025 },
1026 [ICMP_REDIRECT] = {
1027 .output_entry = ICMP_MIB_OUTREDIRECTS,
1028 .input_entry = ICMP_MIB_INREDIRECTS,
1029 .handler = icmp_redirect,
1030 .error = 1,
1031 },
1032 [6] = {
1033 .output_entry = ICMP_MIB_DUMMY,
1034 .input_entry = ICMP_MIB_INERRORS,
1035 .handler = icmp_discard,
1036 .error = 1,
1037 },
1038 [7] = {
1039 .output_entry = ICMP_MIB_DUMMY,
1040 .input_entry = ICMP_MIB_INERRORS,
1041 .handler = icmp_discard,
1042 .error = 1,
1043 },
1044 [ICMP_ECHO] = {
1045 .output_entry = ICMP_MIB_OUTECHOS,
1046 .input_entry = ICMP_MIB_INECHOS,
1047 .handler = icmp_echo,
1048 },
1049 [9] = {
1050 .output_entry = ICMP_MIB_DUMMY,
1051 .input_entry = ICMP_MIB_INERRORS,
1052 .handler = icmp_discard,
1053 .error = 1,
1054 },
1055 [10] = {
1056 .output_entry = ICMP_MIB_DUMMY,
1057 .input_entry = ICMP_MIB_INERRORS,
1058 .handler = icmp_discard,
1059 .error = 1,
1060 },
1061 [ICMP_TIME_EXCEEDED] = {
1062 .output_entry = ICMP_MIB_OUTTIMEEXCDS,
1063 .input_entry = ICMP_MIB_INTIMEEXCDS,
1064 .handler = icmp_unreach,
1065 .error = 1,
1066 },
1067 [ICMP_PARAMETERPROB] = {
1068 .output_entry = ICMP_MIB_OUTPARMPROBS,
1069 .input_entry = ICMP_MIB_INPARMPROBS,
1070 .handler = icmp_unreach,
1071 .error = 1,
1072 },
1073 [ICMP_TIMESTAMP] = {
1074 .output_entry = ICMP_MIB_OUTTIMESTAMPS,
1075 .input_entry = ICMP_MIB_INTIMESTAMPS,
1076 .handler = icmp_timestamp,
1077 },
1078 [ICMP_TIMESTAMPREPLY] = {
1079 .output_entry = ICMP_MIB_OUTTIMESTAMPREPS,
1080 .input_entry = ICMP_MIB_INTIMESTAMPREPS,
1081 .handler = icmp_discard,
1082 },
1083 [ICMP_INFO_REQUEST] = {
1084 .output_entry = ICMP_MIB_DUMMY,
1085 .input_entry = ICMP_MIB_DUMMY,
1086 .handler = icmp_discard,
1087 },
1088 [ICMP_INFO_REPLY] = {
1089 .output_entry = ICMP_MIB_DUMMY,
1090 .input_entry = ICMP_MIB_DUMMY,
1091 .handler = icmp_discard,
1092 },
1093 [ICMP_ADDRESS] = {
1094 .output_entry = ICMP_MIB_OUTADDRMASKS,
1095 .input_entry = ICMP_MIB_INADDRMASKS,
1096 .handler = icmp_address,
1097 },
1098 [ICMP_ADDRESSREPLY] = {
1099 .output_entry = ICMP_MIB_OUTADDRMASKREPS,
1100 .input_entry = ICMP_MIB_INADDRMASKREPS,
1101 .handler = icmp_address_reply,
1102 },
1103};
1104
1105void __init icmp_init(struct net_proto_family *ops)
1106{
1107 struct inet_sock *inet;
1108 int i;
1109
670c02c2 1110 for_each_cpu(i) {
1da177e4
LT		 1111 int err;
1112
1da177e4
LT		 1113 err = sock_create_kern(PF_INET, SOCK_RAW, IPPROTO_ICMP,
1114 &per_cpu(__icmp_socket, i));
1115
1116 if (err < 0)
1117 panic("Failed to create the ICMP control socket.\n");
1118
1119 per_cpu(__icmp_socket, i)->sk->sk_allocation = GFP_ATOMIC;
1120
1121 /* Enough space for 2 64K ICMP packets, including
1122 * sk_buff struct overhead.
1123 */
1124 per_cpu(__icmp_socket, i)->sk->sk_sndbuf =
1125 (2 * ((64 * 1024) + sizeof(struct sk_buff)));
1126
1127 inet = inet_sk(per_cpu(__icmp_socket, i)->sk);
1128 inet->uc_ttl = -1;
1129 inet->pmtudisc = IP_PMTUDISC_DONT;
1130
1131 /* Unhash it so that IP input processing does not even
1132 * see it, we do not wish this socket to see incoming
1133 * packets.
1134 */
1135 per_cpu(__icmp_socket, i)->sk->sk_prot->unhash(per_cpu(__icmp_socket, i)->sk);
1136 }
1137}
1138
1139EXPORT_SYMBOL(icmp_err_convert);
1140EXPORT_SYMBOL(icmp_send);
1141EXPORT_SYMBOL(icmp_statistics);
1142EXPORT_SYMBOL(xrlim_allow);
kernel source for telekom puls (alcatel/mediatek)