Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 1143 insertions, 0 deletions

diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
new file mode 100644
index 00000000000..85bf0d3e294
--- /dev/null
+++ b/net/ipv4/icmp.c
@@ -0,0 +1,1143 @@
+/*
+ *	NET3:	Implementation of the ICMP protocol layer.
+ *
+ *		Alan Cox, <alan@redhat.com>
+ *
+ *	Version: $Id: icmp.c,v 1.85 2002/02/01 22:01:03 davem Exp $
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ *
+ *	Some of the function names and the icmp unreach table for this
+ *	module were derived from [icmp.c 1.0.11 06/02/93] by
+ *	Ross Biro, Fred N. van Kempen, Mark Evans, Alan Cox, Gerhard Koerting.
+ *	Other than that this module is a complete rewrite.
+ *
+ *	Fixes:
+ *	Clemens Fruhwirth	:	introduce global icmp rate limiting
+ *					with icmp type masking ability instead
+ *					of broken per type icmp timeouts.
+ *		Mike Shaver	:	RFC1122 checks.
+ *		Alan Cox	:	Multicast ping reply as self.
+ *		Alan Cox	:	Fix atomicity lockup in ip_build_xmit
+ *					call.
+ *		Alan Cox	:	Added 216,128 byte paths to the MTU
+ *					code.
+ *		Martin Mares	:	RFC1812 checks.
+ *		Martin Mares	:	Can be configured to follow redirects
+ *					if acting as a router _without_ a
+ *					routing protocol (RFC 1812).
+ *		Martin Mares	:	Echo requests may be configured to
+ *					be ignored (RFC 1812).
+ *		Martin Mares	:	Limitation of ICMP error message
+ *					transmit rate (RFC 1812).
+ *		Martin Mares	:	TOS and Precedence set correctly
+ *					(RFC 1812).
+ *		Martin Mares	:	Now copying as much data from the
+ *					original packet as we can without
+ *					exceeding 576 bytes (RFC 1812).
+ *	Willy Konynenberg	:	Transparent proxying support.
+ *		Keith Owens	:	RFC1191 correction for 4.2BSD based
+ *					path MTU bug.
+ *		Thomas Quinot	:	ICMP Dest Unreach codes up to 15 are
+ *					valid (RFC 1812).
+ *		Andi Kleen	:	Check all packet lengths properly
+ *					and moved all kfree_skb() up to
+ *					icmp_rcv.
+ *		Andi Kleen	:	Move the rate limit bookkeeping
+ *					into the dest entry and use a token
+ *					bucket filter (thanks to ANK). Make
+ *					the rates sysctl configurable.
+ *		Yu Tianli	:	Fixed two ugly bugs in icmp_send
+ *					- IP option length was accounted wrongly
+ *					- ICMP header length was not accounted
+ *					  at all.
+ *              Tristan Greaves :       Added sysctl option to ignore bogus
+ *              			broadcast responses from broken routers.
+ *
+ * To Fix:
+ *
+ *	- Should use skb_pull() instead of all the manual checking.
+ *	  This would also greatly simply some upper layer error handlers. --AK
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/fcntl.h>
+#include <linux/socket.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/string.h>
+#include <linux/netfilter_ipv4.h>
+#include <net/snmp.h>
+#include <net/ip.h>
+#include <net/route.h>
+#include <net/protocol.h>
+#include <net/icmp.h>
+#include <net/tcp.h>
+#include <net/udp.h>
+#include <net/raw.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <linux/errno.h>
+#include <linux/timer.h>
+#include <linux/init.h>
+#include <asm/system.h>
+#include <asm/uaccess.h>
+#include <net/checksum.h>
+
+/*
+ *	Build xmit assembly blocks
+ */
+
+struct icmp_bxm {
+	struct sk_buff *skb;
+	int offset;
+	int data_len;
+
+	struct {
+		struct icmphdr icmph;
+		__u32	       times[3];
+	} data;
+	int head_len;
+	struct ip_options replyopts;
+	unsigned char  optbuf[40];
+};
+
+/*
+ *	Statistics
+ */
+DEFINE_SNMP_STAT(struct icmp_mib, icmp_statistics);
+
+/* An array of errno for error messages from dest unreach. */
+/* RFC 1122: 3.2.2.1 States that NET_UNREACH, HOST_UNREACH and SR_FAILED MUST be considered 'transient errs'. */
+
+struct icmp_err icmp_err_convert[] = {
+	{
+		.errno = ENETUNREACH,	/* ICMP_NET_UNREACH */
+		.fatal = 0,
+	},
+	{
+		.errno = EHOSTUNREACH,	/* ICMP_HOST_UNREACH */
+		.fatal = 0,
+	},
+	{
+		.errno = ENOPROTOOPT	/* ICMP_PROT_UNREACH */,
+		.fatal = 1,
+	},
+	{
+		.errno = ECONNREFUSED,	/* ICMP_PORT_UNREACH */
+		.fatal = 1,
+	},
+	{
+		.errno = EMSGSIZE,	/* ICMP_FRAG_NEEDED */
+		.fatal = 0,
+	},
+	{
+		.errno = EOPNOTSUPP,	/* ICMP_SR_FAILED */
+		.fatal = 0,
+	},
+	{
+		.errno = ENETUNREACH,	/* ICMP_NET_UNKNOWN */
+		.fatal = 1,
+	},
+	{
+		.errno = EHOSTDOWN,	/* ICMP_HOST_UNKNOWN */
+		.fatal = 1,
+	},
+	{
+		.errno = ENONET,	/* ICMP_HOST_ISOLATED */
+		.fatal = 1,
+	},
+	{
+		.errno = ENETUNREACH,	/* ICMP_NET_ANO	*/
+		.fatal = 1,
+	},
+	{
+		.errno = EHOSTUNREACH,	/* ICMP_HOST_ANO */
+		.fatal = 1,
+	},
+	{
+		.errno = ENETUNREACH,	/* ICMP_NET_UNR_TOS */
+		.fatal = 0,
+	},
+	{
+		.errno = EHOSTUNREACH,	/* ICMP_HOST_UNR_TOS */
+		.fatal = 0,
+	},
+	{
+		.errno = EHOSTUNREACH,	/* ICMP_PKT_FILTERED */
+		.fatal = 1,
+	},
+	{
+		.errno = EHOSTUNREACH,	/* ICMP_PREC_VIOLATION */
+		.fatal = 1,
+	},
+	{
+		.errno = EHOSTUNREACH,	/* ICMP_PREC_CUTOFF */
+		.fatal = 1,
+	},
+};
+
+/* Control parameters for ECHO replies. */
+int sysctl_icmp_echo_ignore_all;
+int sysctl_icmp_echo_ignore_broadcasts;
+
+/* Control parameter - ignore bogus broadcast responses? */
+int sysctl_icmp_ignore_bogus_error_responses;
+
+/*
+ * 	Configurable global rate limit.
+ *
+ *	ratelimit defines tokens/packet consumed for dst->rate_token bucket
+ *	ratemask defines which icmp types are ratelimited by setting
+ * 	it's bit position.
+ *
+ *	default:
+ *	dest unreachable (3), source quench (4),
+ *	time exceeded (11), parameter problem (12)
+ */
+
+int sysctl_icmp_ratelimit = 1 * HZ;
+int sysctl_icmp_ratemask = 0x1818;
+
+/*
+ *	ICMP control array. This specifies what to do with each ICMP.
+ */
+
+struct icmp_control {
+	int output_entry;	/* Field for increment on output */
+	int input_entry;	/* Field for increment on input */
+	void (*handler)(struct sk_buff *skb);
+	short   error;		/* This ICMP is classed as an error message */
+};
+
+static struct icmp_control icmp_pointers[NR_ICMP_TYPES+1];
+
+/*
+ *	The ICMP socket(s). This is the most convenient way to flow control
+ *	our ICMP output as well as maintain a clean interface throughout
+ *	all layers. All Socketless IP sends will soon be gone.
+ *
+ *	On SMP we have one ICMP socket per-cpu.
+ */
+static DEFINE_PER_CPU(struct socket *, __icmp_socket) = NULL;
+#define icmp_socket	__get_cpu_var(__icmp_socket)
+
+static __inline__ int icmp_xmit_lock(void)
+{
+	local_bh_disable();
+
+	if (unlikely(!spin_trylock(&icmp_socket->sk->sk_lock.slock))) {
+		/* This can happen if the output path signals a
+		 * dst_link_failure() for an outgoing ICMP packet.
+		 */
+		local_bh_enable();
+		return 1;
+	}
+	return 0;
+}
+
+static void icmp_xmit_unlock(void)
+{
+	spin_unlock_bh(&icmp_socket->sk->sk_lock.slock);
+}
+
+/*
+ *	Send an ICMP frame.
+ */
+
+/*
+ *	Check transmit rate limitation for given message.
+ *	The rate information is held in the destination cache now.
+ *	This function is generic and could be used for other purposes
+ *	too. It uses a Token bucket filter as suggested by Alexey Kuznetsov.
+ *
+ *	Note that the same dst_entry fields are modified by functions in
+ *	route.c too, but these work for packet destinations while xrlim_allow
+ *	works for icmp destinations. This means the rate limiting information
+ *	for one "ip object" is shared - and these ICMPs are twice limited:
+ *	by source and by destination.
+ *
+ *	RFC 1812: 4.3.2.8 SHOULD be able to limit error message rate
+ *			  SHOULD allow setting of rate limits
+ *
+ * 	Shared between ICMPv4 and ICMPv6.
+ */
+#define XRLIM_BURST_FACTOR 6
+int xrlim_allow(struct dst_entry *dst, int timeout)
+{
+	unsigned long now;
+	int rc = 0;
+
+	now = jiffies;
+	dst->rate_tokens += now - dst->rate_last;
+	dst->rate_last = now;
+	if (dst->rate_tokens > XRLIM_BURST_FACTOR * timeout)
+		dst->rate_tokens = XRLIM_BURST_FACTOR * timeout;
+	if (dst->rate_tokens >= timeout) {
+		dst->rate_tokens -= timeout;
+		rc = 1;
+	}
+	return rc;
+}
+
+static inline int icmpv4_xrlim_allow(struct rtable *rt, int type, int code)
+{
+	struct dst_entry *dst = &rt->u.dst;
+	int rc = 1;
+
+	if (type > NR_ICMP_TYPES)
+		goto out;
+
+	/* Don't limit PMTU discovery. */
+	if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)
+		goto out;
+
+	/* No rate limit on loopback */
+	if (dst->dev && (dst->dev->flags&IFF_LOOPBACK))
+ 		goto out;
+
+	/* Limit if icmp type is enabled in ratemask. */
+	if ((1 << type) & sysctl_icmp_ratemask)
+		rc = xrlim_allow(dst, sysctl_icmp_ratelimit);
+out:
+	return rc;
+}
+
+/*
+ *	Maintain the counters used in the SNMP statistics for outgoing ICMP
+ */
+static void icmp_out_count(int type)
+{
+	if (type <= NR_ICMP_TYPES) {
+		ICMP_INC_STATS(icmp_pointers[type].output_entry);
+		ICMP_INC_STATS(ICMP_MIB_OUTMSGS);
+	}
+}
+
+/*
+ *	Checksum each fragment, and on the first include the headers and final
+ *	checksum.
+ */
+static int icmp_glue_bits(void *from, char *to, int offset, int len, int odd,
+			  struct sk_buff *skb)
+{
+	struct icmp_bxm *icmp_param = (struct icmp_bxm *)from;
+	unsigned int csum;
+
+	csum = skb_copy_and_csum_bits(icmp_param->skb,
+				      icmp_param->offset + offset,
+				      to, len, 0);
+
+	skb->csum = csum_block_add(skb->csum, csum, odd);
+	if (icmp_pointers[icmp_param->data.icmph.type].error)
+		nf_ct_attach(skb, icmp_param->skb);
+	return 0;
+}
+
+static void icmp_push_reply(struct icmp_bxm *icmp_param,
+			    struct ipcm_cookie *ipc, struct rtable *rt)
+{
+	struct sk_buff *skb;
+
+	ip_append_data(icmp_socket->sk, icmp_glue_bits, icmp_param,
+		       icmp_param->data_len+icmp_param->head_len,
+		       icmp_param->head_len,
+		       ipc, rt, MSG_DONTWAIT);
+
+	if ((skb = skb_peek(&icmp_socket->sk->sk_write_queue)) != NULL) {
+		struct icmphdr *icmph = skb->h.icmph;
+		unsigned int csum = 0;
+		struct sk_buff *skb1;
+
+		skb_queue_walk(&icmp_socket->sk->sk_write_queue, skb1) {
+			csum = csum_add(csum, skb1->csum);
+		}
+		csum = csum_partial_copy_nocheck((void *)&icmp_param->data,
+						 (char *)icmph,
+						 icmp_param->head_len, csum);
+		icmph->checksum = csum_fold(csum);
+		skb->ip_summed = CHECKSUM_NONE;
+		ip_push_pending_frames(icmp_socket->sk);
+	}
+}
+
+/*
+ *	Driving logic for building and sending ICMP messages.
+ */
+
+static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
+{
+	struct sock *sk = icmp_socket->sk;
+	struct inet_sock *inet = inet_sk(sk);
+	struct ipcm_cookie ipc;
+	struct rtable *rt = (struct rtable *)skb->dst;
+	u32 daddr;
+
+	if (ip_options_echo(&icmp_param->replyopts, skb))
+		goto out;
+
+	if (icmp_xmit_lock())
+		return;
+
+	icmp_param->data.icmph.checksum = 0;
+	icmp_out_count(icmp_param->data.icmph.type);
+
+	inet->tos = skb->nh.iph->tos;
+	daddr = ipc.addr = rt->rt_src;
+	ipc.opt = NULL;
+	if (icmp_param->replyopts.optlen) {
+		ipc.opt = &icmp_param->replyopts;
+		if (ipc.opt->srr)
+			daddr = icmp_param->replyopts.faddr;
+	}
+	{
+		struct flowi fl = { .nl_u = { .ip4_u =
+					      { .daddr = daddr,
+						.saddr = rt->rt_spec_dst,
+						.tos = RT_TOS(skb->nh.iph->tos) } },
+				    .proto = IPPROTO_ICMP };
+		if (ip_route_output_key(&rt, &fl))
+			goto out_unlock;
+	}
+	if (icmpv4_xrlim_allow(rt, icmp_param->data.icmph.type,
+			       icmp_param->data.icmph.code))
+		icmp_push_reply(icmp_param, &ipc, rt);
+	ip_rt_put(rt);
+out_unlock:
+	icmp_xmit_unlock();
+out:;
+}
+
+
+/*
+ *	Send an ICMP message in response to a situation
+ *
+ *	RFC 1122: 3.2.2	MUST send at least the IP header and 8 bytes of header.
+ *		  MAY send more (we do).
+ *			MUST NOT change this header information.
+ *			MUST NOT reply to a multicast/broadcast IP address.
+ *			MUST NOT reply to a multicast/broadcast MAC address.
+ *			MUST reply to only the first fragment.
+ */
+
+void icmp_send(struct sk_buff *skb_in, int type, int code, u32 info)
+{
+	struct iphdr *iph;
+	int room;
+	struct icmp_bxm icmp_param;
+	struct rtable *rt = (struct rtable *)skb_in->dst;
+	struct ipcm_cookie ipc;
+	u32 saddr;
+	u8  tos;
+
+	if (!rt)
+		goto out;
+
+	/*
+	 *	Find the original header. It is expected to be valid, of course.
+	 *	Check this, icmp_send is called from the most obscure devices
+	 *	sometimes.
+	 */
+	iph = skb_in->nh.iph;
+
+	if ((u8 *)iph < skb_in->head || (u8 *)(iph + 1) > skb_in->tail)
+		goto out;
+
+	/*
+	 *	No replies to physical multicast/broadcast
+	 */
+	if (skb_in->pkt_type != PACKET_HOST)
+		goto out;
+
+	/*
+	 *	Now check at the protocol level
+	 */
+	if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
+		goto out;
+
+	/*
+	 *	Only reply to fragment 0. We byte re-order the constant
+	 *	mask for efficiency.
+	 */
+	if (iph->frag_off & htons(IP_OFFSET))
+		goto out;
+
+	/*
+	 *	If we send an ICMP error to an ICMP error a mess would result..
+	 */
+	if (icmp_pointers[type].error) {
+		/*
+		 *	We are an error, check if we are replying to an
+		 *	ICMP error
+		 */
+		if (iph->protocol == IPPROTO_ICMP) {
+			u8 _inner_type, *itp;
+
+			itp = skb_header_pointer(skb_in,
+						 skb_in->nh.raw +
+						 (iph->ihl << 2) +
+						 offsetof(struct icmphdr,
+							  type) -
+						 skb_in->data,
+						 sizeof(_inner_type),
+						 &_inner_type);
+			if (itp == NULL)
+				goto out;
+
+			/*
+			 *	Assume any unknown ICMP type is an error. This
+			 *	isn't specified by the RFC, but think about it..
+			 */
+			if (*itp > NR_ICMP_TYPES ||
+			    icmp_pointers[*itp].error)
+				goto out;
+		}
+	}
+
+	if (icmp_xmit_lock())
+		return;
+
+	/*
+	 *	Construct source address and options.
+	 */
+
+	saddr = iph->daddr;
+	if (!(rt->rt_flags & RTCF_LOCAL))
+		saddr = 0;
+
+	tos = icmp_pointers[type].error ? ((iph->tos & IPTOS_TOS_MASK) |
+					   IPTOS_PREC_INTERNETCONTROL) :
+					  iph->tos;
+
+	if (ip_options_echo(&icmp_param.replyopts, skb_in))
+		goto ende;
+
+
+	/*
+	 *	Prepare data for ICMP header.
+	 */
+
+	icmp_param.data.icmph.type	 = type;
+	icmp_param.data.icmph.code	 = code;
+	icmp_param.data.icmph.un.gateway = info;
+	icmp_param.data.icmph.checksum	 = 0;
+	icmp_param.skb	  = skb_in;
+	icmp_param.offset = skb_in->nh.raw - skb_in->data;
+	icmp_out_count(icmp_param.data.icmph.type);
+	inet_sk(icmp_socket->sk)->tos = tos;
+	ipc.addr = iph->saddr;
+	ipc.opt = &icmp_param.replyopts;
+
+	{
+		struct flowi fl = {
+			.nl_u = {
+				.ip4_u = {
+					.daddr = icmp_param.replyopts.srr ?
+						icmp_param.replyopts.faddr :
+						iph->saddr,
+					.saddr = saddr,
+					.tos = RT_TOS(tos)
+				}
+			},
+			.proto = IPPROTO_ICMP,
+			.uli_u = {
+				.icmpt = {
+					.type = type,
+					.code = code
+				}
+			}
+		};
+		if (ip_route_output_key(&rt, &fl))
+			goto out_unlock;
+	}
+
+	if (!icmpv4_xrlim_allow(rt, type, code))
+		goto ende;
+
+	/* RFC says return as much as we can without exceeding 576 bytes. */
+
+	room = dst_mtu(&rt->u.dst);
+	if (room > 576)
+		room = 576;
+	room -= sizeof(struct iphdr) + icmp_param.replyopts.optlen;
+	room -= sizeof(struct icmphdr);
+
+	icmp_param.data_len = skb_in->len - icmp_param.offset;
+	if (icmp_param.data_len > room)
+		icmp_param.data_len = room;
+	icmp_param.head_len = sizeof(struct icmphdr);
+
+	icmp_push_reply(&icmp_param, &ipc, rt);
+ende:
+	ip_rt_put(rt);
+out_unlock:
+	icmp_xmit_unlock();
+out:;
+}
+
+
+/*
+ *	Handle ICMP_DEST_UNREACH, ICMP_TIME_EXCEED, and ICMP_QUENCH.
+ */
+
+static void icmp_unreach(struct sk_buff *skb)
+{
+	struct iphdr *iph;
+	struct icmphdr *icmph;
+	int hash, protocol;
+	struct net_protocol *ipprot;
+	struct sock *raw_sk;
+	u32 info = 0;
+
+	/*
+	 *	Incomplete header ?
+	 * 	Only checks for the IP header, there should be an
+	 *	additional check for longer headers in upper levels.
+	 */
+
+	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
+		goto out_err;
+
+	icmph = skb->h.icmph;
+	iph   = (struct iphdr *)skb->data;
+
+	if (iph->ihl < 5) /* Mangled header, drop. */
+		goto out_err;
+
+	if (icmph->type == ICMP_DEST_UNREACH) {
+		switch (icmph->code & 15) {
+		case ICMP_NET_UNREACH:
+		case ICMP_HOST_UNREACH:
+		case ICMP_PROT_UNREACH:
+		case ICMP_PORT_UNREACH:
+			break;
+		case ICMP_FRAG_NEEDED:
+			if (ipv4_config.no_pmtu_disc) {
+				LIMIT_NETDEBUG(
+					printk(KERN_INFO "ICMP: %u.%u.%u.%u: "
+							 "fragmentation needed "
+							 "and DF set.\n",
+					       NIPQUAD(iph->daddr)));
+			} else {
+				info = ip_rt_frag_needed(iph,
+						     ntohs(icmph->un.frag.mtu));
+				if (!info)
+					goto out;
+			}
+			break;
+		case ICMP_SR_FAILED:
+			LIMIT_NETDEBUG(
+				printk(KERN_INFO "ICMP: %u.%u.%u.%u: Source "
+						 "Route Failed.\n",
+				       NIPQUAD(iph->daddr)));
+			break;
+		default:
+			break;
+		}
+		if (icmph->code > NR_ICMP_UNREACH)
+			goto out;
+	} else if (icmph->type == ICMP_PARAMETERPROB)
+		info = ntohl(icmph->un.gateway) >> 24;
+
+	/*
+	 *	Throw it at our lower layers
+	 *
+	 *	RFC 1122: 3.2.2 MUST extract the protocol ID from the passed
+	 *		  header.
+	 *	RFC 1122: 3.2.2.1 MUST pass ICMP unreach messages to the
+	 *		  transport layer.
+	 *	RFC 1122: 3.2.2.2 MUST pass ICMP time expired messages to
+	 *		  transport layer.
+	 */
+
+	/*
+	 *	Check the other end isnt violating RFC 1122. Some routers send
+	 *	bogus responses to broadcast frames. If you see this message
+	 *	first check your netmask matches at both ends, if it does then
+	 *	get the other vendor to fix their kit.
+	 */
+
+	if (!sysctl_icmp_ignore_bogus_error_responses &&
+	    inet_addr_type(iph->daddr) == RTN_BROADCAST) {
+		if (net_ratelimit())
+			printk(KERN_WARNING "%u.%u.%u.%u sent an invalid ICMP "
+					    "type %u, code %u "
+					    "error to a broadcast: %u.%u.%u.%u on %s\n",
+			       NIPQUAD(skb->nh.iph->saddr),
+			       icmph->type, icmph->code,
+			       NIPQUAD(iph->daddr),
+			       skb->dev->name);
+		goto out;
+	}
+
+	/* Checkin full IP header plus 8 bytes of protocol to
+	 * avoid additional coding at protocol handlers.
+	 */
+	if (!pskb_may_pull(skb, iph->ihl * 4 + 8))
+		goto out;
+
+	iph = (struct iphdr *)skb->data;
+	protocol = iph->protocol;
+
+	/*
+	 *	Deliver ICMP message to raw sockets. Pretty useless feature?
+	 */
+
+	/* Note: See raw.c and net/raw.h, RAWV4_HTABLE_SIZE==MAX_INET_PROTOS */
+	hash = protocol & (MAX_INET_PROTOS - 1);
+	read_lock(&raw_v4_lock);
+	if ((raw_sk = sk_head(&raw_v4_htable[hash])) != NULL) {
+		while ((raw_sk = __raw_v4_lookup(raw_sk, protocol, iph->daddr,
+						 iph->saddr,
+						 skb->dev->ifindex)) != NULL) {
+			raw_err(raw_sk, skb, info);
+			raw_sk = sk_next(raw_sk);
+			iph = (struct iphdr *)skb->data;
+		}
+	}
+	read_unlock(&raw_v4_lock);
+
+	rcu_read_lock();
+	ipprot = rcu_dereference(inet_protos[hash]);
+	if (ipprot && ipprot->err_handler)
+		ipprot->err_handler(skb, info);
+	rcu_read_unlock();
+
+out:
+	return;
+out_err:
+	ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
+	goto out;
+}
+
+
+/*
+ *	Handle ICMP_REDIRECT.
+ */
+
+static void icmp_redirect(struct sk_buff *skb)
+{
+	struct iphdr *iph;
+	unsigned long ip;
+
+	if (skb->len < sizeof(struct iphdr))
+		goto out_err;
+
+	/*
+	 *	Get the copied header of the packet that caused the redirect
+	 */
+	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
+		goto out;
+
+	iph = (struct iphdr *)skb->data;
+	ip = iph->daddr;
+
+	switch (skb->h.icmph->code & 7) {
+	case ICMP_REDIR_NET:
+	case ICMP_REDIR_NETTOS:
+		/*
+		 * As per RFC recommendations now handle it as a host redirect.
+		 */
+	case ICMP_REDIR_HOST:
+	case ICMP_REDIR_HOSTTOS:
+		ip_rt_redirect(skb->nh.iph->saddr, ip, skb->h.icmph->un.gateway,
+			       iph->saddr, iph->tos, skb->dev);
+		break;
+  	}
+out:
+	return;
+out_err:
+	ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
+	goto out;
+}
+
+/*
+ *	Handle ICMP_ECHO ("ping") requests.
+ *
+ *	RFC 1122: 3.2.2.6 MUST have an echo server that answers ICMP echo
+ *		  requests.
+ *	RFC 1122: 3.2.2.6 Data received in the ICMP_ECHO request MUST be
+ *		  included in the reply.
+ *	RFC 1812: 4.3.3.6 SHOULD have a config option for silently ignoring
+ *		  echo requests, MUST have default=NOT.
+ *	See also WRT handling of options once they are done and working.
+ */
+
+static void icmp_echo(struct sk_buff *skb)
+{
+	if (!sysctl_icmp_echo_ignore_all) {
+		struct icmp_bxm icmp_param;
+
+		icmp_param.data.icmph	   = *skb->h.icmph;
+		icmp_param.data.icmph.type = ICMP_ECHOREPLY;
+		icmp_param.skb		   = skb;
+		icmp_param.offset	   = 0;
+		icmp_param.data_len	   = skb->len;
+		icmp_param.head_len	   = sizeof(struct icmphdr);
+		icmp_reply(&icmp_param, skb);
+	}
+}
+
+/*
+ *	Handle ICMP Timestamp requests.
+ *	RFC 1122: 3.2.2.8 MAY implement ICMP timestamp requests.
+ *		  SHOULD be in the kernel for minimum random latency.
+ *		  MUST be accurate to a few minutes.
+ *		  MUST be updated at least at 15Hz.
+ */
+static void icmp_timestamp(struct sk_buff *skb)
+{
+	struct timeval tv;
+	struct icmp_bxm icmp_param;
+	/*
+	 *	Too short.
+	 */
+	if (skb->len < 4)
+		goto out_err;
+
+	/*
+	 *	Fill in the current time as ms since midnight UT:
+	 */
+	do_gettimeofday(&tv);
+	icmp_param.data.times[1] = htonl((tv.tv_sec % 86400) * 1000 +
+					 tv.tv_usec / 1000);
+	icmp_param.data.times[2] = icmp_param.data.times[1];
+	if (skb_copy_bits(skb, 0, &icmp_param.data.times[0], 4))
+		BUG();
+	icmp_param.data.icmph	   = *skb->h.icmph;
+	icmp_param.data.icmph.type = ICMP_TIMESTAMPREPLY;
+	icmp_param.data.icmph.code = 0;
+	icmp_param.skb		   = skb;
+	icmp_param.offset	   = 0;
+	icmp_param.data_len	   = 0;
+	icmp_param.head_len	   = sizeof(struct icmphdr) + 12;
+	icmp_reply(&icmp_param, skb);
+out:
+	return;
+out_err:
+	ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
+	goto out;
+}
+
+
+/*
+ *	Handle ICMP_ADDRESS_MASK requests.  (RFC950)
+ *
+ * RFC1122 (3.2.2.9).  A host MUST only send replies to
+ * ADDRESS_MASK requests if it's been configured as an address mask
+ * agent.  Receiving a request doesn't constitute implicit permission to
+ * act as one. Of course, implementing this correctly requires (SHOULD)
+ * a way to turn the functionality on and off.  Another one for sysctl(),
+ * I guess. -- MS
+ *
+ * RFC1812 (4.3.3.9).	A router MUST implement it.
+ *			A router SHOULD have switch turning it on/off.
+ *		      	This switch MUST be ON by default.
+ *
+ * Gratuitous replies, zero-source replies are not implemented,
+ * that complies with RFC. DO NOT implement them!!! All the idea
+ * of broadcast addrmask replies as specified in RFC950 is broken.
+ * The problem is that it is not uncommon to have several prefixes
+ * on one physical interface. Moreover, addrmask agent can even be
+ * not aware of existing another prefixes.
+ * If source is zero, addrmask agent cannot choose correct prefix.
+ * Gratuitous mask announcements suffer from the same problem.
+ * RFC1812 explains it, but still allows to use ADDRMASK,
+ * that is pretty silly. --ANK
+ *
+ * All these rules are so bizarre, that I removed kernel addrmask
+ * support at all. It is wrong, it is obsolete, nobody uses it in
+ * any case. --ANK
+ *
+ * Furthermore you can do it with a usermode address agent program
+ * anyway...
+ */
+
+static void icmp_address(struct sk_buff *skb)
+{
+#if 0
+	if (net_ratelimit())
+		printk(KERN_DEBUG "a guy asks for address mask. Who is it?\n");
+#endif
+}
+
+/*
+ * RFC1812 (4.3.3.9).	A router SHOULD listen all replies, and complain
+ *			loudly if an inconsistency is found.
+ */
+
+static void icmp_address_reply(struct sk_buff *skb)
+{
+	struct rtable *rt = (struct rtable *)skb->dst;
+	struct net_device *dev = skb->dev;
+	struct in_device *in_dev;
+	struct in_ifaddr *ifa;
+
+	if (skb->len < 4 || !(rt->rt_flags&RTCF_DIRECTSRC))
+		goto out;
+
+	in_dev = in_dev_get(dev);
+	if (!in_dev)
+		goto out;
+	rcu_read_lock();
+	if (in_dev->ifa_list &&
+	    IN_DEV_LOG_MARTIANS(in_dev) &&
+	    IN_DEV_FORWARD(in_dev)) {
+		u32 _mask, *mp;
+
+		mp = skb_header_pointer(skb, 0, sizeof(_mask), &_mask);
+		if (mp == NULL)
+			BUG();
+		for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) {
+			if (*mp == ifa->ifa_mask &&
+			    inet_ifa_match(rt->rt_src, ifa))
+				break;
+		}
+		if (!ifa && net_ratelimit()) {
+			printk(KERN_INFO "Wrong address mask %u.%u.%u.%u from "
+					 "%s/%u.%u.%u.%u\n",
+			       NIPQUAD(*mp), dev->name, NIPQUAD(rt->rt_src));
+		}
+	}
+	rcu_read_unlock();
+	in_dev_put(in_dev);
+out:;
+}
+
+static void icmp_discard(struct sk_buff *skb)
+{
+}
+
+/*
+ *	Deal with incoming ICMP packets.
+ */
+int icmp_rcv(struct sk_buff *skb)
+{
+	struct icmphdr *icmph;
+	struct rtable *rt = (struct rtable *)skb->dst;
+
+	ICMP_INC_STATS_BH(ICMP_MIB_INMSGS);
+
+	switch (skb->ip_summed) {
+	case CHECKSUM_HW:
+		if (!(u16)csum_fold(skb->csum))
+			break;
+		NETDEBUG(if (net_ratelimit())
+				printk(KERN_DEBUG "icmp v4 hw csum failure\n"));
+	case CHECKSUM_NONE:
+		if ((u16)csum_fold(skb_checksum(skb, 0, skb->len, 0)))
+			goto error;
+	default:;
+	}
+
+	if (!pskb_pull(skb, sizeof(struct icmphdr)))
+		goto error;
+
+	icmph = skb->h.icmph;
+
+	/*
+	 *	18 is the highest 'known' ICMP type. Anything else is a mystery
+	 *
+	 *	RFC 1122: 3.2.2  Unknown ICMP messages types MUST be silently
+	 *		  discarded.
+	 */
+	if (icmph->type > NR_ICMP_TYPES)
+		goto error;
+
+
+	/*
+	 *	Parse the ICMP message
+	 */
+
+ 	if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) {
+		/*
+		 *	RFC 1122: 3.2.2.6 An ICMP_ECHO to broadcast MAY be
+		 *	  silently ignored (we let user decide with a sysctl).
+		 *	RFC 1122: 3.2.2.8 An ICMP_TIMESTAMP MAY be silently
+		 *	  discarded if to broadcast/multicast.
+		 */
+		if (icmph->type == ICMP_ECHO &&
+		    sysctl_icmp_echo_ignore_broadcasts) {
+			goto error;
+		}
+		if (icmph->type != ICMP_ECHO &&
+		    icmph->type != ICMP_TIMESTAMP &&
+		    icmph->type != ICMP_ADDRESS &&
+		    icmph->type != ICMP_ADDRESSREPLY) {
+			goto error;
+  		}
+	}
+
+	ICMP_INC_STATS_BH(icmp_pointers[icmph->type].input_entry);
+	icmp_pointers[icmph->type].handler(skb);
+
+drop:
+	kfree_skb(skb);
+	return 0;
+error:
+	ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
+	goto drop;
+}
+
+/*
+ *	This table is the definition of how we handle ICMP.
+ */
+static struct icmp_control icmp_pointers[NR_ICMP_TYPES + 1] = {
+	[ICMP_ECHOREPLY] = {
+		.output_entry = ICMP_MIB_OUTECHOREPS,
+		.input_entry = ICMP_MIB_INECHOREPS,
+		.handler = icmp_discard,
+	},
+	[1] = {
+		.output_entry = ICMP_MIB_DUMMY,
+		.input_entry = ICMP_MIB_INERRORS,
+		.handler = icmp_discard,
+		.error = 1,
+	},
+	[2] = {
+		.output_entry = ICMP_MIB_DUMMY,
+		.input_entry = ICMP_MIB_INERRORS,
+		.handler = icmp_discard,
+		.error = 1,
+	},
+	[ICMP_DEST_UNREACH] = {
+		.output_entry = ICMP_MIB_OUTDESTUNREACHS,
+		.input_entry = ICMP_MIB_INDESTUNREACHS,
+		.handler = icmp_unreach,
+		.error = 1,
+	},
+	[ICMP_SOURCE_QUENCH] = {
+		.output_entry = ICMP_MIB_OUTSRCQUENCHS,
+		.input_entry = ICMP_MIB_INSRCQUENCHS,
+		.handler = icmp_unreach,
+		.error = 1,
+	},
+	[ICMP_REDIRECT] = {
+		.output_entry = ICMP_MIB_OUTREDIRECTS,
+		.input_entry = ICMP_MIB_INREDIRECTS,
+		.handler = icmp_redirect,
+		.error = 1,
+	},
+	[6] = {
+		.output_entry = ICMP_MIB_DUMMY,
+		.input_entry = ICMP_MIB_INERRORS,
+		.handler = icmp_discard,
+		.error = 1,
+	},
+	[7] = {
+		.output_entry = ICMP_MIB_DUMMY,
+		.input_entry = ICMP_MIB_INERRORS,
+		.handler = icmp_discard,
+		.error = 1,
+	},
+	[ICMP_ECHO] = {
+		.output_entry = ICMP_MIB_OUTECHOS,
+		.input_entry = ICMP_MIB_INECHOS,
+		.handler = icmp_echo,
+	},
+	[9] = {
+		.output_entry = ICMP_MIB_DUMMY,
+		.input_entry = ICMP_MIB_INERRORS,
+		.handler = icmp_discard,
+		.error = 1,
+	},
+	[10] = {
+		.output_entry = ICMP_MIB_DUMMY,
+		.input_entry = ICMP_MIB_INERRORS,
+		.handler = icmp_discard,
+		.error = 1,
+	},
+	[ICMP_TIME_EXCEEDED] = {
+		.output_entry = ICMP_MIB_OUTTIMEEXCDS,
+		.input_entry = ICMP_MIB_INTIMEEXCDS,
+		.handler = icmp_unreach,
+		.error = 1,
+	},
+	[ICMP_PARAMETERPROB] = {
+		.output_entry = ICMP_MIB_OUTPARMPROBS,
+		.input_entry = ICMP_MIB_INPARMPROBS,
+		.handler = icmp_unreach,
+		.error = 1,
+	},
+	[ICMP_TIMESTAMP] = {
+		.output_entry = ICMP_MIB_OUTTIMESTAMPS,
+		.input_entry = ICMP_MIB_INTIMESTAMPS,
+		.handler = icmp_timestamp,
+	},
+	[ICMP_TIMESTAMPREPLY] = {
+		.output_entry = ICMP_MIB_OUTTIMESTAMPREPS,
+		.input_entry = ICMP_MIB_INTIMESTAMPREPS,
+		.handler = icmp_discard,
+	},
+	[ICMP_INFO_REQUEST] = {
+		.output_entry = ICMP_MIB_DUMMY,
+		.input_entry = ICMP_MIB_DUMMY,
+		.handler = icmp_discard,
+	},
+ 	[ICMP_INFO_REPLY] = {
+		.output_entry = ICMP_MIB_DUMMY,
+		.input_entry = ICMP_MIB_DUMMY,
+		.handler = icmp_discard,
+	},
+	[ICMP_ADDRESS] = {
+		.output_entry = ICMP_MIB_OUTADDRMASKS,
+		.input_entry = ICMP_MIB_INADDRMASKS,
+		.handler = icmp_address,
+	},
+	[ICMP_ADDRESSREPLY] = {
+		.output_entry = ICMP_MIB_OUTADDRMASKREPS,
+		.input_entry = ICMP_MIB_INADDRMASKREPS,
+		.handler = icmp_address_reply,
+	},
+};
+
+void __init icmp_init(struct net_proto_family *ops)
+{
+	struct inet_sock *inet;
+	int i;
+
+	for (i = 0; i < NR_CPUS; i++) {
+		int err;
+
+		if (!cpu_possible(i))
+			continue;
+
+		err = sock_create_kern(PF_INET, SOCK_RAW, IPPROTO_ICMP,
+				       &per_cpu(__icmp_socket, i));
+
+		if (err < 0)
+			panic("Failed to create the ICMP control socket.\n");
+
+		per_cpu(__icmp_socket, i)->sk->sk_allocation = GFP_ATOMIC;
+
+		/* Enough space for 2 64K ICMP packets, including
+		 * sk_buff struct overhead.
+		 */
+		per_cpu(__icmp_socket, i)->sk->sk_sndbuf =
+			(2 * ((64 * 1024) + sizeof(struct sk_buff)));
+
+		inet = inet_sk(per_cpu(__icmp_socket, i)->sk);
+		inet->uc_ttl = -1;
+		inet->pmtudisc = IP_PMTUDISC_DONT;
+
+		/* Unhash it so that IP input processing does not even
+		 * see it, we do not wish this socket to see incoming
+		 * packets.
+		 */
+		per_cpu(__icmp_socket, i)->sk->sk_prot->unhash(per_cpu(__icmp_socket, i)->sk);
+	}
+}
+
+EXPORT_SYMBOL(icmp_err_convert);
+EXPORT_SYMBOL(icmp_send);
+EXPORT_SYMBOL(icmp_statistics);
+EXPORT_SYMBOL(xrlim_allow);