2 * NET3: Implementation of the ICMP protocol layer.
4 * Alan Cox, <alan@redhat.com>
6 * Version: $Id: icmp.c,v 1.85 2002/02/01 22:01:03 davem Exp $
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.
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.
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
26 * Alan Cox : Added 216,128 byte paths to the MTU
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
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
44 * Thomas Quinot : ICMP Dest Unreach codes up to 15 are
46 * Andi Kleen : Check all packet lengths properly
47 * and moved all kfree_skb() up to
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
57 * Tristan Greaves : Added sysctl option to ignore bogus
58 * broadcast responses from broken routers.
62 * - Should use skb_pull() instead of all the manual checking.
63 * This would also greatly simply some upper layer error handlers. --AK
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>
75 #include <linux/inet.h>
76 #include <linux/inetdevice.h>
77 #include <linux/netdevice.h>
78 #include <linux/string.h>
79 #include <linux/netfilter_ipv4.h>
82 #include <net/route.h>
83 #include <net/protocol.h>
88 #include <linux/skbuff.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>
98 * Build xmit assembly blocks
107 struct icmphdr icmph;
111 struct ip_options replyopts;
112 unsigned char optbuf[40];
118 DEFINE_SNMP_STAT(struct icmp_mib, icmp_statistics) __read_mostly;
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'. */
123 struct icmp_err icmp_err_convert[] = {
125 .errno = ENETUNREACH, /* ICMP_NET_UNREACH */
129 .errno = EHOSTUNREACH, /* ICMP_HOST_UNREACH */
133 .errno = ENOPROTOOPT /* ICMP_PROT_UNREACH */,
137 .errno = ECONNREFUSED, /* ICMP_PORT_UNREACH */
141 .errno = EMSGSIZE, /* ICMP_FRAG_NEEDED */
145 .errno = EOPNOTSUPP, /* ICMP_SR_FAILED */
149 .errno = ENETUNREACH, /* ICMP_NET_UNKNOWN */
153 .errno = EHOSTDOWN, /* ICMP_HOST_UNKNOWN */
157 .errno = ENONET, /* ICMP_HOST_ISOLATED */
161 .errno = ENETUNREACH, /* ICMP_NET_ANO */
165 .errno = EHOSTUNREACH, /* ICMP_HOST_ANO */
169 .errno = ENETUNREACH, /* ICMP_NET_UNR_TOS */
173 .errno = EHOSTUNREACH, /* ICMP_HOST_UNR_TOS */
177 .errno = EHOSTUNREACH, /* ICMP_PKT_FILTERED */
181 .errno = EHOSTUNREACH, /* ICMP_PREC_VIOLATION */
185 .errno = EHOSTUNREACH, /* ICMP_PREC_CUTOFF */
190 /* Control parameters for ECHO replies. */
191 int sysctl_icmp_echo_ignore_all;
192 int sysctl_icmp_echo_ignore_broadcasts = 1;
194 /* Control parameter - ignore bogus broadcast responses? */
195 int sysctl_icmp_ignore_bogus_error_responses = 1;
198 * Configurable global rate limit.
200 * ratelimit defines tokens/packet consumed for dst->rate_token bucket
201 * ratemask defines which icmp types are ratelimited by setting
205 * dest unreachable (3), source quench (4),
206 * time exceeded (11), parameter problem (12)
209 int sysctl_icmp_ratelimit = 1 * HZ;
210 int sysctl_icmp_ratemask = 0x1818;
211 int sysctl_icmp_errors_use_inbound_ifaddr;
214 * ICMP control array. This specifies what to do with each ICMP.
217 struct 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 */
224 static const struct icmp_control icmp_pointers[NR_ICMP_TYPES+1];
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.
231 * On SMP we have one ICMP socket per-cpu.
233 static DEFINE_PER_CPU(struct socket *, __icmp_socket) = NULL;
234 #define icmp_socket __get_cpu_var(__icmp_socket)
236 static __inline__ int icmp_xmit_lock(void)
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.
250 static void icmp_xmit_unlock(void)
252 spin_unlock_bh(&icmp_socket->sk->sk_lock.slock);
256 * Send an ICMP frame.
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.
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.
271 * RFC 1812: 4.3.2.8 SHOULD be able to limit error message rate
272 * SHOULD allow setting of rate limits
274 * Shared between ICMPv4 and ICMPv6.
276 #define XRLIM_BURST_FACTOR 6
277 int xrlim_allow(struct dst_entry *dst, int timeout)
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;
294 static inline int icmpv4_xrlim_allow(struct rtable *rt, int type, int code)
296 struct dst_entry *dst = &rt->u.dst;
299 if (type > NR_ICMP_TYPES)
302 /* Don't limit PMTU discovery. */
303 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)
306 /* No rate limit on loopback */
307 if (dst->dev && (dst->dev->flags&IFF_LOOPBACK))
310 /* Limit if icmp type is enabled in ratemask. */
311 if ((1 << type) & sysctl_icmp_ratemask)
312 rc = xrlim_allow(dst, sysctl_icmp_ratelimit);
318 * Maintain the counters used in the SNMP statistics for outgoing ICMP
320 static void icmp_out_count(int type)
322 if (type <= NR_ICMP_TYPES) {
323 ICMP_INC_STATS(icmp_pointers[type].output_entry);
324 ICMP_INC_STATS(ICMP_MIB_OUTMSGS);
329 * Checksum each fragment, and on the first include the headers and final
332 static int icmp_glue_bits(void *from, char *to, int offset, int len, int odd,
335 struct icmp_bxm *icmp_param = (struct icmp_bxm *)from;
338 csum = skb_copy_and_csum_bits(icmp_param->skb,
339 icmp_param->offset + offset,
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);
348 static void icmp_push_reply(struct icmp_bxm *icmp_param,
349 struct ipcm_cookie *ipc, struct rtable *rt)
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) {
359 struct icmphdr *icmph = skb->h.icmph;
360 unsigned int csum = 0;
361 struct sk_buff *skb1;
363 skb_queue_walk(&icmp_socket->sk->sk_write_queue, skb1) {
364 csum = csum_add(csum, skb1->csum);
366 csum = csum_partial_copy_nocheck((void *)&icmp_param->data,
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);
376 * Driving logic for building and sending ICMP messages.
379 static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
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;
387 if (ip_options_echo(&icmp_param->replyopts, skb))
390 if (icmp_xmit_lock())
393 icmp_param->data.icmph.checksum = 0;
394 icmp_out_count(icmp_param->data.icmph.type);
396 inet->tos = skb->nh.iph->tos;
397 daddr = ipc.addr = rt->rt_src;
399 if (icmp_param->replyopts.optlen) {
400 ipc.opt = &icmp_param->replyopts;
402 daddr = icmp_param->replyopts.faddr;
405 struct flowi fl = { .nl_u = { .ip4_u =
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))
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);
423 * Send an ICMP message in response to a situation
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.
433 void icmp_send(struct sk_buff *skb_in, int type, int code, u32 info)
437 struct icmp_bxm icmp_param;
438 struct rtable *rt = (struct rtable *)skb_in->dst;
439 struct ipcm_cookie ipc;
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
451 iph = skb_in->nh.iph;
453 if ((u8 *)iph < skb_in->head || (u8 *)(iph + 1) > skb_in->tail)
457 * No replies to physical multicast/broadcast
459 if (skb_in->pkt_type != PACKET_HOST)
463 * Now check at the protocol level
465 if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
469 * Only reply to fragment 0. We byte re-order the constant
470 * mask for efficiency.
472 if (iph->frag_off & htons(IP_OFFSET))
476 * If we send an ICMP error to an ICMP error a mess would result..
478 if (icmp_pointers[type].error) {
480 * We are an error, check if we are replying to an
483 if (iph->protocol == IPPROTO_ICMP) {
484 u8 _inner_type, *itp;
486 itp = skb_header_pointer(skb_in,
489 offsetof(struct icmphdr,
498 * Assume any unknown ICMP type is an error. This
499 * isn't specified by the RFC, but think about it..
501 if (*itp > NR_ICMP_TYPES ||
502 icmp_pointers[*itp].error)
507 if (icmp_xmit_lock())
511 * Construct source address and options.
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);
522 tos = icmp_pointers[type].error ? ((iph->tos & IPTOS_TOS_MASK) |
523 IPTOS_PREC_INTERNETCONTROL) :
526 if (ip_options_echo(&icmp_param.replyopts, skb_in))
531 * Prepare data for ICMP header.
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;
549 .daddr = icmp_param.replyopts.srr ?
550 icmp_param.replyopts.faddr :
556 .proto = IPPROTO_ICMP,
564 if (ip_route_output_key(&rt, &fl))
568 if (!icmpv4_xrlim_allow(rt, type, code))
571 /* RFC says return as much as we can without exceeding 576 bytes. */
573 room = dst_mtu(&rt->u.dst);
576 room -= sizeof(struct iphdr) + icmp_param.replyopts.optlen;
577 room -= sizeof(struct icmphdr);
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);
584 icmp_push_reply(&icmp_param, &ipc, rt);
594 * Handle ICMP_DEST_UNREACH, ICMP_TIME_EXCEED, and ICMP_QUENCH.
597 static void icmp_unreach(struct sk_buff *skb)
600 struct icmphdr *icmph;
602 struct net_protocol *ipprot;
607 * Incomplete header ?
608 * Only checks for the IP header, there should be an
609 * additional check for longer headers in upper levels.
612 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
615 icmph = skb->h.icmph;
616 iph = (struct iphdr *)skb->data;
618 if (iph->ihl < 5) /* Mangled header, drop. */
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:
628 case ICMP_FRAG_NEEDED:
629 if (ipv4_config.no_pmtu_disc) {
630 LIMIT_NETDEBUG(KERN_INFO "ICMP: %u.%u.%u.%u: "
631 "fragmentation needed "
633 NIPQUAD(iph->daddr));
635 info = ip_rt_frag_needed(iph,
636 ntohs(icmph->un.frag.mtu));
642 LIMIT_NETDEBUG(KERN_INFO "ICMP: %u.%u.%u.%u: Source "
644 NIPQUAD(iph->daddr));
649 if (icmph->code > NR_ICMP_UNREACH)
651 } else if (icmph->type == ICMP_PARAMETERPROB)
652 info = ntohl(icmph->un.gateway) >> 24;
655 * Throw it at our lower layers
657 * RFC 1122: 3.2.2 MUST extract the protocol ID from the passed
659 * RFC 1122: 3.2.2.1 MUST pass ICMP unreach messages to the
661 * RFC 1122: 3.2.2.2 MUST pass ICMP time expired messages to
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.
672 if (!sysctl_icmp_ignore_bogus_error_responses &&
673 inet_addr_type(iph->daddr) == RTN_BROADCAST) {
675 printk(KERN_WARNING "%u.%u.%u.%u sent an invalid ICMP "
677 "error to a broadcast: %u.%u.%u.%u on %s\n",
678 NIPQUAD(skb->nh.iph->saddr),
679 icmph->type, icmph->code,
685 /* Checkin full IP header plus 8 bytes of protocol to
686 * avoid additional coding at protocol handlers.
688 if (!pskb_may_pull(skb, iph->ihl * 4 + 8))
691 iph = (struct iphdr *)skb->data;
692 protocol = iph->protocol;
695 * Deliver ICMP message to raw sockets. Pretty useless feature?
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,
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;
710 read_unlock(&raw_v4_lock);
713 ipprot = rcu_dereference(inet_protos[hash]);
714 if (ipprot && ipprot->err_handler)
715 ipprot->err_handler(skb, info);
721 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
727 * Handle ICMP_REDIRECT.
730 static void icmp_redirect(struct sk_buff *skb)
735 if (skb->len < sizeof(struct iphdr))
739 * Get the copied header of the packet that caused the redirect
741 if (!pskb_may_pull(skb, sizeof(struct iphdr)))
744 iph = (struct iphdr *)skb->data;
747 switch (skb->h.icmph->code & 7) {
749 case ICMP_REDIR_NETTOS:
751 * As per RFC recommendations now handle it as a host redirect.
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, skb->dev);
762 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
767 * Handle ICMP_ECHO ("ping") requests.
769 * RFC 1122: 3.2.2.6 MUST have an echo server that answers ICMP echo
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.
778 static void icmp_echo(struct sk_buff *skb)
780 if (!sysctl_icmp_echo_ignore_all) {
781 struct icmp_bxm icmp_param;
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);
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.
800 static void icmp_timestamp(struct sk_buff *skb)
803 struct icmp_bxm icmp_param;
811 * Fill in the current time as ms since midnight UT:
813 do_gettimeofday(&tv);
814 icmp_param.data.times[1] = htonl((tv.tv_sec % 86400) * 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))
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);
830 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
836 * Handle ICMP_ADDRESS_MASK requests. (RFC950)
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(),
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.
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
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
864 * Furthermore you can do it with a usermode address agent program
868 static void icmp_address(struct sk_buff *skb)
872 printk(KERN_DEBUG "a guy asks for address mask. Who is it?\n");
877 * RFC1812 (4.3.3.9). A router SHOULD listen all replies, and complain
878 * loudly if an inconsistency is found.
881 static void icmp_address_reply(struct sk_buff *skb)
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;
888 if (skb->len < 4 || !(rt->rt_flags&RTCF_DIRECTSRC))
891 in_dev = in_dev_get(dev);
895 if (in_dev->ifa_list &&
896 IN_DEV_LOG_MARTIANS(in_dev) &&
897 IN_DEV_FORWARD(in_dev)) {
900 mp = skb_header_pointer(skb, 0, sizeof(_mask), &_mask);
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))
907 if (!ifa && net_ratelimit()) {
908 printk(KERN_INFO "Wrong address mask %u.%u.%u.%u from "
910 NIPQUAD(*mp), dev->name, NIPQUAD(rt->rt_src));
918 #ifdef CONFIG_ICMP_IPOD
919 #include <linux/reboot.h>
921 int sysctl_icmp_ipod_version = 2;
922 int sysctl_icmp_ipod_enabled = 0;
923 u32 sysctl_icmp_ipod_host = 0xffffffff;
924 u32 sysctl_icmp_ipod_mask = 0xffffffff;
925 char sysctl_icmp_ipod_key[32+1] = { "SETMETOSOMETHINGTHIRTYTWOBYTES!!" };
926 #define IPOD_CHECK_KEY \
927 (sysctl_icmp_ipod_key[0] != 0)
928 #define IPOD_VALID_KEY(d) \
929 (strncmp(sysctl_icmp_ipod_key, (char *)(d), strlen(sysctl_icmp_ipod_key)) == 0)
931 static void icmp_ping_of_death(struct sk_buff *skb)
933 struct icmphdr *icmph = skb->h.icmph;
934 struct iphdr *iph = skb->nh.iph;
938 printk(KERN_INFO "IPOD: got type=6, code=%d, host=%u.%u.%u.%u\n", icmph->code, ntohs(iph->tot_len), NIPQUAD(iph->saddr));
942 * If IPOD not enabled or wrong ICMP code, ignore.
944 if (!sysctl_icmp_ipod_enabled || icmph->code != 6)
948 * First check the source address info.
949 * If host not set, ignore.
951 if (sysctl_icmp_ipod_host != 0xffffffff &&
952 (ntohl(iph->saddr) & sysctl_icmp_ipod_mask) == sysctl_icmp_ipod_host) {
954 * Now check the key if enabled.
955 * If packet doesn't contain enough data or key
956 * is otherwise invalid, ignore.
958 if (IPOD_CHECK_KEY) {
959 if (pskb_may_pull(skb, sizeof(sysctl_icmp_ipod_key)-1) &&
960 IPOD_VALID_KEY(skb->data))
968 sysctl_icmp_ipod_enabled = 0;
969 printk(KERN_CRIT "IPOD: reboot forced by %u.%u.%u.%u...\n",
970 NIPQUAD(iph->saddr));
971 machine_restart(NULL);
973 printk(KERN_WARNING "IPOD: from %u.%u.%u.%u rejected\n",
974 NIPQUAD(iph->saddr));
979 static void icmp_discard(struct sk_buff *skb)
984 * Deal with incoming ICMP packets.
986 int icmp_rcv(struct sk_buff *skb)
988 struct icmphdr *icmph;
989 struct rtable *rt = (struct rtable *)skb->dst;
991 ICMP_INC_STATS_BH(ICMP_MIB_INMSGS);
993 switch (skb->ip_summed) {
995 if (!(u16)csum_fold(skb->csum))
1000 if (__skb_checksum_complete(skb))
1004 if (!pskb_pull(skb, sizeof(struct icmphdr)))
1007 icmph = skb->h.icmph;
1010 * 18 is the highest 'known' ICMP type. Anything else is a mystery
1012 * RFC 1122: 3.2.2 Unknown ICMP messages types MUST be silently
1015 if (icmph->type > NR_ICMP_TYPES)
1020 * Parse the ICMP message
1023 if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
1025 * RFC 1122: 3.2.2.6 An ICMP_ECHO to broadcast MAY be
1026 * silently ignored (we let user decide with a sysctl).
1027 * RFC 1122: 3.2.2.8 An ICMP_TIMESTAMP MAY be silently
1028 * discarded if to broadcast/multicast.
1030 if ((icmph->type == ICMP_ECHO ||
1031 icmph->type == ICMP_TIMESTAMP) &&
1032 sysctl_icmp_echo_ignore_broadcasts) {
1035 if (icmph->type != ICMP_ECHO &&
1036 icmph->type != ICMP_TIMESTAMP &&
1037 icmph->type != ICMP_ADDRESS &&
1038 icmph->type != ICMP_ADDRESSREPLY) {
1043 #if defined(CONFIG_VNET) || defined(CONFIG_VNET_MODULE)
1044 /* VNET: Bypass stack if the echo ID was bound to a (presumably raw) socket */
1045 if (vnet_active && skb->sk) {
1046 switch (icmph->type) {
1047 case ICMP_ECHOREPLY:
1049 case ICMP_TIMESTAMP:
1050 case ICMP_TIMESTAMPREPLY:
1051 case ICMP_INFO_REQUEST:
1052 case ICMP_INFO_REPLY:
1054 case ICMP_ADDRESSREPLY:
1060 ICMP_INC_STATS_BH(icmp_pointers[icmph->type].input_entry);
1061 icmp_pointers[icmph->type].handler(skb);
1067 ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
1072 * This table is the definition of how we handle ICMP.
1074 static const struct icmp_control icmp_pointers[NR_ICMP_TYPES + 1] = {
1075 [ICMP_ECHOREPLY] = {
1076 .output_entry = ICMP_MIB_OUTECHOREPS,
1077 .input_entry = ICMP_MIB_INECHOREPS,
1078 .handler = icmp_discard,
1081 .output_entry = ICMP_MIB_DUMMY,
1082 .input_entry = ICMP_MIB_INERRORS,
1083 .handler = icmp_discard,
1087 .output_entry = ICMP_MIB_DUMMY,
1088 .input_entry = ICMP_MIB_INERRORS,
1089 .handler = icmp_discard,
1092 [ICMP_DEST_UNREACH] = {
1093 .output_entry = ICMP_MIB_OUTDESTUNREACHS,
1094 .input_entry = ICMP_MIB_INDESTUNREACHS,
1095 .handler = icmp_unreach,
1098 [ICMP_SOURCE_QUENCH] = {
1099 .output_entry = ICMP_MIB_OUTSRCQUENCHS,
1100 .input_entry = ICMP_MIB_INSRCQUENCHS,
1101 .handler = icmp_unreach,
1105 .output_entry = ICMP_MIB_OUTREDIRECTS,
1106 .input_entry = ICMP_MIB_INREDIRECTS,
1107 .handler = icmp_redirect,
1110 #ifdef CONFIG_ICMP_IPOD
1112 .output_entry = ICMP_MIB_DUMMY,
1113 .input_entry = ICMP_MIB_DUMMY,
1114 .handler = icmp_ping_of_death,
1119 .output_entry = ICMP_MIB_DUMMY,
1120 .input_entry = ICMP_MIB_INERRORS,
1121 .handler = icmp_discard,
1126 .output_entry = ICMP_MIB_DUMMY,
1127 .input_entry = ICMP_MIB_INERRORS,
1128 .handler = icmp_discard,
1132 .output_entry = ICMP_MIB_OUTECHOS,
1133 .input_entry = ICMP_MIB_INECHOS,
1134 .handler = icmp_echo,
1137 .output_entry = ICMP_MIB_DUMMY,
1138 .input_entry = ICMP_MIB_INERRORS,
1139 .handler = icmp_discard,
1143 .output_entry = ICMP_MIB_DUMMY,
1144 .input_entry = ICMP_MIB_INERRORS,
1145 .handler = icmp_discard,
1148 [ICMP_TIME_EXCEEDED] = {
1149 .output_entry = ICMP_MIB_OUTTIMEEXCDS,
1150 .input_entry = ICMP_MIB_INTIMEEXCDS,
1151 .handler = icmp_unreach,
1154 [ICMP_PARAMETERPROB] = {
1155 .output_entry = ICMP_MIB_OUTPARMPROBS,
1156 .input_entry = ICMP_MIB_INPARMPROBS,
1157 .handler = icmp_unreach,
1160 [ICMP_TIMESTAMP] = {
1161 .output_entry = ICMP_MIB_OUTTIMESTAMPS,
1162 .input_entry = ICMP_MIB_INTIMESTAMPS,
1163 .handler = icmp_timestamp,
1165 [ICMP_TIMESTAMPREPLY] = {
1166 .output_entry = ICMP_MIB_OUTTIMESTAMPREPS,
1167 .input_entry = ICMP_MIB_INTIMESTAMPREPS,
1168 .handler = icmp_discard,
1170 [ICMP_INFO_REQUEST] = {
1171 .output_entry = ICMP_MIB_DUMMY,
1172 .input_entry = ICMP_MIB_DUMMY,
1173 .handler = icmp_discard,
1175 [ICMP_INFO_REPLY] = {
1176 .output_entry = ICMP_MIB_DUMMY,
1177 .input_entry = ICMP_MIB_DUMMY,
1178 .handler = icmp_discard,
1181 .output_entry = ICMP_MIB_OUTADDRMASKS,
1182 .input_entry = ICMP_MIB_INADDRMASKS,
1183 .handler = icmp_address,
1185 [ICMP_ADDRESSREPLY] = {
1186 .output_entry = ICMP_MIB_OUTADDRMASKREPS,
1187 .input_entry = ICMP_MIB_INADDRMASKREPS,
1188 .handler = icmp_address_reply,
1192 void __init icmp_init(struct net_proto_family *ops)
1194 struct inet_sock *inet;
1197 for_each_possible_cpu(i) {
1200 err = sock_create_kern(PF_INET, SOCK_RAW, IPPROTO_ICMP,
1201 &per_cpu(__icmp_socket, i));
1204 panic("Failed to create the ICMP control socket.\n");
1206 per_cpu(__icmp_socket, i)->sk->sk_allocation = GFP_ATOMIC;
1208 /* Enough space for 2 64K ICMP packets, including
1209 * sk_buff struct overhead.
1211 per_cpu(__icmp_socket, i)->sk->sk_sndbuf =
1212 (2 * ((64 * 1024) + sizeof(struct sk_buff)));
1214 inet = inet_sk(per_cpu(__icmp_socket, i)->sk);
1216 inet->pmtudisc = IP_PMTUDISC_DONT;
1218 /* Unhash it so that IP input processing does not even
1219 * see it, we do not wish this socket to see incoming
1222 per_cpu(__icmp_socket, i)->sk->sk_prot->unhash(per_cpu(__icmp_socket, i)->sk);
1226 EXPORT_SYMBOL(icmp_err_convert);
1227 EXPORT_SYMBOL(icmp_send);
1228 EXPORT_SYMBOL(icmp_statistics);
1229 EXPORT_SYMBOL(xrlim_allow);