add layer7 patch for kernel 2.6

git-svn-id: svn://svn.openwrt.org/openwrt/trunk/openwrt@1780 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 2028 insertions, 0 deletions

diff --git a/target/linux/linux-2.6/patches/generic/100-netfilter_layer7.patch b/target/linux/linux-2.6/patches/generic/100-netfilter_layer7.patch
new file mode 100644
index 0000000000..80a7b90b85
--- /dev/null
+++ b/target/linux/linux-2.6/patches/generic/100-netfilter_layer7.patch
@@ -0,0 +1,2028 @@
+--- linux-2.6.11.3-stock/include/linux/netfilter_ipv4/ip_conntrack.h	2005-03-13 00:44:41.000000000 -0600
++++ linux-2.6.11.3-layer7/include/linux/netfilter_ipv4/ip_conntrack.h	2005-03-13 20:30:01.000000000 -0600
+@@ -177,6 +177,15 @@ struct ip_conntrack
+ 	/* Traversed often, so hopefully in different cacheline to top */
+ 	/* These are my tuples; original and reply */
+ 	struct ip_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];
++
++#if defined(CONFIG_IP_NF_MATCH_LAYER7) || defined(CONFIG_IP_NF_MATCH_LAYER7_MODULE)
++        struct {
++                char * app_proto; /* e.g. "http". NULL before decision. "unknown" after decision if no match */
++                char * app_data;  /* application layer data so far.  NULL after match decision */
++                unsigned int app_data_len;
++        } layer7;
++#endif
++
+ };
+ 
+ struct ip_conntrack_expect
+--- linux-2.6.11.3-stock/include/linux/netfilter_ipv4/ipt_layer7.h	1969-12-31 18:00:00.000000000 -0600
++++ linux-2.6.11.3-layer7/include/linux/netfilter_ipv4/ipt_layer7.h	2005-03-13 20:30:01.000000000 -0600
+@@ -0,0 +1,26 @@
++/* 
++  By Matthew Strait <quadong@users.sf.net>, Dec 2003.
++  http://l7-filter.sf.net
++
++  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.
++  http://www.gnu.org/licenses/gpl.txt
++*/
++
++#ifndef _IPT_LAYER7_H
++#define _IPT_LAYER7_H
++
++#define MAX_PATTERN_LEN 8192
++#define MAX_PROTOCOL_LEN 256
++
++typedef char *(*proc_ipt_search) (char *, char, char *);
++
++struct ipt_layer7_info {
++    char protocol[MAX_PROTOCOL_LEN];
++    char invert:1;
++    char pattern[MAX_PATTERN_LEN];
++};
++
++#endif /* _IPT_LAYER7_H */
+--- linux-2.6.11.3-stock/net/ipv4/netfilter/Kconfig	2005-03-13 00:44:38.000000000 -0600
++++ linux-2.6.11.3-layer7/net/ipv4/netfilter/Kconfig	2005-03-13 20:30:01.000000000 -0600
+@@ -146,6 +146,33 @@ config IP_NF_MATCH_MAC
+ 
+ 	  To compile it as a module, choose M here.  If unsure, say N.
+ 
++config IP_NF_MATCH_LAYER7
++	tristate "Layer 7 match support (EXPERIMENTAL)"
++	depends on IP_NF_IPTABLES && IP_NF_CT_ACCT && IP_NF_CONNTRACK && EXPERIMENTAL
++	help
++ 	  Say Y if you want to be able to classify connections (and their 
++          packets) based on regular expression matching of their application 
++	  layer data.   This is one way to classify applications such as 
++	  peer-to-peer filesharing systems that do not always use the same 
++	  port.
++
++	  To compile it as a module, choose M here.  If unsure, say N.
++
++config IP_NF_MATCH_LAYER7_DEBUG
++	bool "Layer 7 debugging output"
++	depends on IP_NF_MATCH_LAYER7
++	help
++	  Say Y to get lots of debugging output.
++
++config IP_NF_MATCH_LAYER7_MAXDATALEN
++        int "Buffer size for application layer data" if IP_NF_MATCH_LAYER7
++        range 256 65536 
++        default 2048
++	help
++	  Size of the buffer that the application layer data is stored in.
++	  Unless you know what you're doing, leave it at the default of 2kB.
++
++
+ config IP_NF_MATCH_PKTTYPE
+ 	tristate "Packet type match support"
+ 	depends on IP_NF_IPTABLES
+--- linux-2.6.11.3-stock/net/ipv4/netfilter/Makefile	2005-03-13 00:44:14.000000000 -0600
++++ linux-2.6.11.3-layer7/net/ipv4/netfilter/Makefile	2005-03-13 20:30:01.000000000 -0600
+@@ -60,6 +60,8 @@ obj-$(CONFIG_IP_NF_MATCH_ADDRTYPE) += ip
+ obj-$(CONFIG_IP_NF_MATCH_PHYSDEV) += ipt_physdev.o
+ obj-$(CONFIG_IP_NF_MATCH_COMMENT) += ipt_comment.o
+ 
++obj-$(CONFIG_IP_NF_MATCH_LAYER7) += ipt_layer7.o
++
+ # targets
+ obj-$(CONFIG_IP_NF_TARGET_REJECT) += ipt_REJECT.o
+ obj-$(CONFIG_IP_NF_TARGET_TOS) += ipt_TOS.o
+--- linux-2.6.11.3-stock/net/ipv4/netfilter/ip_conntrack_core.c	2005-03-13 00:43:57.000000000 -0600
++++ linux-2.6.11.3-layer7/net/ipv4/netfilter/ip_conntrack_core.c	2005-03-13 22:09:32.000000000 -0600
+@@ -247,6 +247,13 @@ destroy_conntrack(struct nf_conntrack *n
+ 	 * too. */
+ 	remove_expectations(ct);
+ 
++	#if defined(CONFIG_IP_NF_MATCH_LAYER7) || defined(CONFIG_IP_NF_MATCH_LAYER7_MODULE)
++	if(ct->layer7.app_proto)
++		kfree(ct->layer7.app_proto);
++	if(ct->layer7.app_data)
++		kfree(ct->layer7.app_data);
++	#endif
++
+ 	/* We overload first tuple to link into unconfirmed list. */
+ 	if (!is_confirmed(ct)) {
+ 		BUG_ON(list_empty(&ct->tuplehash[IP_CT_DIR_ORIGINAL].list));
+--- linux-2.6.11.3-stock/net/ipv4/netfilter/ip_conntrack_standalone.c	2005-03-13 00:44:25.000000000 -0600
++++ linux-2.6.11.3-layer7/net/ipv4/netfilter/ip_conntrack_standalone.c	2005-03-13 20:30:01.000000000 -0600
+@@ -152,6 +152,12 @@ static int ct_seq_real_show(const struct
+ 		return 1;
+ #endif
+ 
++#if defined(CONFIG_IP_NF_MATCH_LAYER7) || defined(CONFIG_IP_NF_MATCH_LAYER7_MODULE)
++	if(conntrack->layer7.app_proto)
++		if (seq_printf(s, "l7proto=%s ",conntrack->layer7.app_proto))
++			return 1;
++#endif
++
+ 	if (seq_printf(s, "use=%u\n", atomic_read(&conntrack->ct_general.use)))
+ 		return 1;
+ 
+--- linux-2.6.11.3-stock/net/ipv4/netfilter/ipt_layer7.c	1969-12-31 18:00:00.000000000 -0600
++++ linux-2.6.11.3-layer7/net/ipv4/netfilter/ipt_layer7.c	2005-03-13 20:30:01.000000000 -0600
+@@ -0,0 +1,552 @@
++/* 
++  Kernel module to match application layer (OSI layer 7) 
++  data in connections.
++  
++  http://l7-filter.sf.net
++
++  By Matthew Strait and Ethan Sommer, 2003-2005.
++
++  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.
++  http://www.gnu.org/licenses/gpl.txt
++
++  Based on ipt_string.c (C) 2000 Emmanuel Roger <winfield@freegates.be>
++  and cls_layer7.c (C) 2003 Matthew Strait, Ethan Sommer, Justin Levandoski
++*/
++
++#include <linux/module.h>
++#include <linux/skbuff.h>
++#include <linux/netfilter_ipv4/ip_conntrack.h>
++#include <linux/proc_fs.h>
++#include <linux/ctype.h>
++#include <net/ip.h>
++#include <net/tcp.h>
++#include <linux/netfilter_ipv4/lockhelp.h>
++
++#include "regexp/regexp.c"
++
++#include <linux/netfilter_ipv4/ipt_layer7.h>
++#include <linux/netfilter_ipv4/ip_tables.h>
++
++MODULE_AUTHOR("Matthew Strait <quadong@users.sf.net>, Ethan Sommer <sommere@users.sf.net>");
++MODULE_LICENSE("GPL");
++MODULE_DESCRIPTION("iptables application layer match module");
++
++#if defined(CONFIG_IP_NF_MATCH_LAYER7_DEBUG)
++	#define DPRINTK(format,args...) printk(format,##args)
++#else
++	#define DPRINTK(format,args...)
++#endif
++
++#define TOTAL_PACKETS master_conntrack->counters[IP_CT_DIR_ORIGINAL].packets + \
++		      master_conntrack->counters[IP_CT_DIR_REPLY].packets
++
++/* Number of packets whose data we look at.
++This can be modified through /proc/net/layer7_numpackets */
++static int num_packets = 8;
++
++static struct pattern_cache {
++	char * regex_string;
++	regexp * pattern;
++	struct pattern_cache * next;
++} * first_pattern_cache = NULL;
++
++/* I'm new to locking.  Here are my assumptions:
++
++- No one will write to /proc/net/layer7_numpackets over and over very fast; 
++  if they did, nothing awful would happen.
++
++- This code will never be processing the same packet twice at the same time,
++  because iptables rules are traversed in order.
++
++- It doesn't matter if two packets from different connections are in here at 
++  the same time, because they don't share any data.
++
++- It _does_ matter if two packets from the same connection are here at the same
++  time.  In this case, we have to protect the conntracks and the list of 
++  compiled patterns.
++*/
++DECLARE_RWLOCK(ct_lock);
++DECLARE_LOCK(list_lock);
++
++#if CONFIG_IP_NF_MATCH_LAYER7_DEBUG
++/* Converts an unfriendly string into a friendly one by 
++replacing unprintables with periods and all whitespace with " ". */
++static char * friendly_print(unsigned char * s)
++{
++	char * f = kmalloc(strlen(s) + 1, GFP_ATOMIC);
++	int i;
++
++	if(!f) {
++		if (net_ratelimit()) 
++			printk(KERN_ERR "layer7: out of memory in friendly_print, bailing.\n");
++		return NULL;
++	}
++
++	for(i = 0; i < strlen(s); i++){
++		if(isprint(s[i]) && s[i] < 128)	f[i] = s[i];
++		else if(isspace(s[i]))		f[i] = ' ';
++		else 				f[i] = '.';
++	}
++	f[i] = '\0';
++	return f;
++}
++
++static char dec2hex(int i)
++{
++	switch (i) {
++		case 0 ... 9:
++			return (char)(i + '0');
++			break;
++		case 10 ... 15:
++			return (char)(i - 10 + 'a');
++			break;
++		default:
++			if (net_ratelimit()) 
++				printk("Problem in dec2hex\n");
++			return '\0';
++	}
++}
++
++static char * hex_print(unsigned char * s)
++{
++	char * g = kmalloc(strlen(s)*3 + 1, GFP_ATOMIC);
++	int i;
++
++	if(!g) {
++	       if (net_ratelimit()) 
++			printk(KERN_ERR "layer7: out of memory in hex_print, bailing.\n");
++	       return NULL;
++	}
++
++	for(i = 0; i < strlen(s); i++) {
++		g[i*3    ] = dec2hex(s[i]/16);
++		g[i*3 + 1] = dec2hex(s[i]%16);
++		g[i*3 + 2] = ' ';
++	}
++	g[i*3] = '\0';
++
++	return g;
++}
++#endif // DEBUG
++
++/* Use instead of regcomp.  As we expect to be seeing the same regexps over and
++over again, it make sense to cache the results. */
++static regexp * compile_and_cache(char * regex_string, char * protocol) 
++{
++	struct pattern_cache * node               = first_pattern_cache;
++	struct pattern_cache * last_pattern_cache = first_pattern_cache;
++	struct pattern_cache * tmp;
++	unsigned int len;
++
++	while (node != NULL) {
++		if (!strcmp(node->regex_string, regex_string)) 
++		return node->pattern;
++
++		last_pattern_cache = node;/* points at the last non-NULL node */
++		node = node->next;
++	}
++
++	/* If we reach the end of the list, then we have not yet cached
++	   the pattern for this regex. Let's do that now. 
++	   Be paranoid about running out of memory to avoid list corruption. */
++	tmp = kmalloc(sizeof(struct pattern_cache), GFP_ATOMIC);
++
++	if(!tmp) {
++		if (net_ratelimit()) 
++			printk(KERN_ERR "layer7: out of memory in compile_and_cache, bailing.\n");
++		return NULL;
++	}
++
++	tmp->regex_string  = kmalloc(strlen(regex_string) + 1, GFP_ATOMIC);
++	tmp->pattern       = kmalloc(sizeof(struct regexp),    GFP_ATOMIC);
++	tmp->next = NULL;
++
++	if(!tmp->regex_string || !tmp->pattern) {
++		if (net_ratelimit()) 
++			printk(KERN_ERR "layer7: out of memory in compile_and_cache, bailing.\n");
++		kfree(tmp->regex_string);
++		kfree(tmp->pattern);
++		kfree(tmp);
++		return NULL;
++	}
++
++	/* Ok.  The new node is all ready now. */
++	node = tmp;
++
++	if(first_pattern_cache == NULL) /* list is empty */
++		first_pattern_cache = node; /* make node the beginning */
++	else
++		last_pattern_cache->next = node; /* attach node to the end */
++
++	/* copy the string and compile the regex */
++	len = strlen(regex_string);
++	DPRINTK("About to compile this: \"%s\"\n", regex_string);
++	node->pattern = regcomp(regex_string, &len);
++	if ( !node->pattern ) {
++		if (net_ratelimit()) 
++			printk(KERN_ERR "layer7: Error compiling regexp \"%s\" (%s)\n", regex_string, protocol);
++		/* pattern is now cached as NULL, so we won't try again. */
++	}
++
++	strcpy(node->regex_string, regex_string);
++	return node->pattern;
++}
++
++static int can_handle(const struct sk_buff *skb)
++{
++	if(!skb->nh.iph) /* not IP */
++		return 0;
++	if(skb->nh.iph->protocol != IPPROTO_TCP &&
++	   skb->nh.iph->protocol != IPPROTO_UDP &&
++	   skb->nh.iph->protocol != IPPROTO_ICMP)
++		return 0;
++	return 1;
++}
++
++/* Returns offset the into the skb->data that the application data starts */
++static int app_data_offset(const struct sk_buff *skb)
++{
++	/* In case we are ported somewhere (ebtables?) where skb->nh.iph 
++	isn't set, this can be gotten from 4*(skb->data[0] & 0x0f) as well. */
++	int ip_hl = 4*skb->nh.iph->ihl;
++
++	if( skb->nh.iph->protocol == IPPROTO_TCP ) {
++		/* 12 == offset into TCP header for the header length field. 
++		Can't get this with skb->h.th->doff because the tcphdr 
++		struct doesn't get set when routing (this is confirmed to be 
++		true in Netfilter as well as QoS.) */
++		int tcp_hl = 4*(skb->data[ip_hl + 12] >> 4);
++
++		return ip_hl + tcp_hl;
++	} else if( skb->nh.iph->protocol == IPPROTO_UDP  ) {
++		return ip_hl + 8; /* UDP header is always 8 bytes */
++	} else if( skb->nh.iph->protocol == IPPROTO_ICMP ) {
++		return ip_hl + 8; /* ICMP header is 8 bytes */
++	} else {
++		if (net_ratelimit()) 
++			printk(KERN_ERR "layer7: tried to handle unknown protocol!\n");
++		return ip_hl + 8; /* something reasonable */
++	}
++}
++
++/* handles whether there's a match when we aren't appending data anymore */
++static int match_no_append(struct ip_conntrack * conntrack, struct ip_conntrack * master_conntrack,
++			enum ip_conntrack_info ctinfo, enum ip_conntrack_info master_ctinfo,
++			struct ipt_layer7_info * info)
++{
++	/* If we're in here, throw the app data away */
++	WRITE_LOCK(&ct_lock);
++	if(master_conntrack->layer7.app_data != NULL) {
++
++	#ifdef CONFIG_IP_NF_MATCH_LAYER7_DEBUG
++		if(!master_conntrack->layer7.app_proto) {
++			char * f = friendly_print(master_conntrack->layer7.app_data);
++			char * g = hex_print(master_conntrack->layer7.app_data);
++			DPRINTK("\nl7-filter gave up after %d bytes (%llu packets):\n%s\n", 
++				strlen(f), 
++				TOTAL_PACKETS, f);
++			kfree(f); 
++			DPRINTK("In hex: %s\n", g);
++			kfree(g);
++		}
++	#endif
++
++		kfree(master_conntrack->layer7.app_data);
++		master_conntrack->layer7.app_data = NULL; /* don't free again */
++	}
++	WRITE_UNLOCK(&ct_lock);
++
++	if(master_conntrack->layer7.app_proto){
++		/* Here child connections set their .app_proto (for /proc/net/ip_conntrack) */
++		WRITE_LOCK(&ct_lock);
++		if(!conntrack->layer7.app_proto) {
++			conntrack->layer7.app_proto = kmalloc(strlen(master_conntrack->layer7.app_proto)+1, GFP_ATOMIC);
++			if(!conntrack->layer7.app_proto){
++				if (net_ratelimit()) 
++					printk(KERN_ERR "layer7: out of memory in match_no_append, bailing.\n");
++				WRITE_UNLOCK(&ct_lock);
++				return 1;
++			}
++			strcpy(conntrack->layer7.app_proto, master_conntrack->layer7.app_proto);
++		}
++		WRITE_UNLOCK(&ct_lock);
++	
++		return (!strcmp(master_conntrack->layer7.app_proto, info->protocol));
++	}
++	else {
++		/* If not classified, set to "unknown" to distinguish from 
++		connections that are still being tested. */
++		WRITE_LOCK(&ct_lock);
++		master_conntrack->layer7.app_proto = kmalloc(strlen("unknown")+1, GFP_ATOMIC);
++		if(!master_conntrack->layer7.app_proto){
++			if (net_ratelimit()) 
++				printk(KERN_ERR "layer7: out of memory in match_no_append, bailing.\n");
++			WRITE_UNLOCK(&ct_lock);
++			return 1;
++		}
++		strcpy(master_conntrack->layer7.app_proto, "unknown");
++		WRITE_UNLOCK(&ct_lock);
++		return 0;
++	}
++}
++
++/* add the new app data to the conntrack.  Return number of bytes added. */
++static int add_data(struct ip_conntrack * master_conntrack, 
++			char * app_data, int appdatalen)
++{
++	int length = 0, i;
++	int oldlength = master_conntrack->layer7.app_data_len;
++
++	/* Strip nulls. Make everything lower case (our regex lib doesn't
++	do case insensitivity).  Add it to the end of the current data. */
++	for(i = 0; i < CONFIG_IP_NF_MATCH_LAYER7_MAXDATALEN-oldlength-1 && 
++		   i < appdatalen; i++) {
++		if(app_data[i] != '\0') {
++			master_conntrack->layer7.app_data[length+oldlength] = 
++				/* the kernel version of tolower mungs 'upper ascii' */
++				isascii(app_data[i])? tolower(app_data[i]) : app_data[i];
++			length++;
++		}
++	}
++
++	master_conntrack->layer7.app_data[length+oldlength] = '\0';
++	master_conntrack->layer7.app_data_len = length + oldlength;
++
++	return length;
++}
++
++/* Returns true on match and false otherwise.  */
++static int match(/* const */struct sk_buff *skb, const struct net_device *in,
++		 const struct net_device *out, const void *matchinfo,
++		 int offset,		   int *hotdrop)
++{
++	struct ipt_layer7_info * info = (struct ipt_layer7_info *)matchinfo;
++	enum ip_conntrack_info master_ctinfo, ctinfo;
++	struct ip_conntrack *master_conntrack, *conntrack;
++	unsigned char * app_data;  
++	unsigned int pattern_result, appdatalen;
++	regexp * comppattern;
++
++	if(!can_handle(skb)){
++		DPRINTK("layer7: This is some protocol I can't handle.\n");
++		return info->invert;
++	}
++
++	/* Treat the parent and all its children together as one connection, 
++	except for the purpose of setting conntrack->layer7.app_proto in the 
++	actual connection. This makes /proc/net/ip_conntrack somewhat more 
++	satisfying. */
++	if(!(conntrack	= ip_conntrack_get((struct sk_buff *)skb, &ctinfo)) ||
++	   !(master_conntrack = ip_conntrack_get((struct sk_buff *)skb, &master_ctinfo))) {
++		DPRINTK("layer7: packet is not from a known connection, giving up.\n");
++		return info->invert;
++	}
++	
++	/* Try to get a master conntrack (and its master etc) for FTP, etc. */
++	while (master_ct(master_conntrack) != NULL)
++		master_conntrack = master_ct(master_conntrack);
++
++	/* if we've classified it or seen too many packets */
++	if(TOTAL_PACKETS > num_packets || 
++	   master_conntrack->layer7.app_proto) {
++	
++		pattern_result = match_no_append(conntrack, master_conntrack, ctinfo, master_ctinfo, info);
++	
++		/* skb->cb[0] == seen. Avoid doing things twice if there are two l7 
++		rules. I'm not sure that using cb for this purpose is correct, although
++		it says "put your private variables there". But it doesn't look like it
++		is being used for anything else in the skbs that make it here. How can
++		I write to cb without making the compiler angry? */
++		skb->cb[0] = 1; /* marking it seen here is probably irrelevant, but consistant */
++
++		return (pattern_result ^ info->invert);
++	}
++
++	if(skb_is_nonlinear(skb)){
++		if(skb_linearize(skb, GFP_ATOMIC) != 0){
++			if (net_ratelimit()) 
++				printk(KERN_ERR "layer7: failed to linearize packet, bailing.\n");
++			return info->invert;
++		}
++	}
++	
++	/* now that the skb is linearized, it's safe to set these. */
++	app_data = skb->data + app_data_offset(skb);
++	appdatalen = skb->tail - app_data;
++
++	LOCK_BH(&list_lock);
++	/* the return value gets checked later, when we're ready to use it */
++	comppattern = compile_and_cache(info->pattern, info->protocol);
++	UNLOCK_BH(&list_lock);
++
++	/* On the first packet of a connection, allocate space for app data */
++	WRITE_LOCK(&ct_lock);
++	if(TOTAL_PACKETS == 1 && !skb->cb[0] && !master_conntrack->layer7.app_data) {
++		master_conntrack->layer7.app_data = kmalloc(CONFIG_IP_NF_MATCH_LAYER7_MAXDATALEN, GFP_ATOMIC);
++		if(!master_conntrack->layer7.app_data){							 
++			if (net_ratelimit()) 
++				printk(KERN_ERR "layer7: out of memory in match, bailing.\n");
++			WRITE_UNLOCK(&ct_lock);
++			return info->invert;
++		}
++
++		master_conntrack->layer7.app_data[0] = '\0';
++	}
++	WRITE_UNLOCK(&ct_lock);
++
++	/* Can be here, but unallocated, if numpackets is increased near 
++	the beginning of a connection */
++	if(master_conntrack->layer7.app_data == NULL)
++		return (info->invert); /* unmatched */
++
++	if(!skb->cb[0]){
++		int newbytes;
++		WRITE_LOCK(&ct_lock);
++		newbytes = add_data(master_conntrack, app_data, appdatalen);
++		WRITE_UNLOCK(&ct_lock);
++
++		if(newbytes == 0) { /* didn't add any data */
++			skb->cb[0] = 1;
++			/* Didn't match before, not going to match now */
++			return info->invert;
++		}
++	}
++
++	/* If looking for "unknown", then never match.  "Unknown" means that
++	we've given up; we're still trying with these packets. */
++	if(!strcmp(info->protocol, "unknown")) {
++		pattern_result = 0;
++	/* If the regexp failed to compile, don't bother running it */
++	} else if(comppattern && regexec(comppattern, master_conntrack->layer7.app_data)) {
++		DPRINTK("layer7: regexec positive: %s!\n", info->protocol);
++		pattern_result = 1;
++	} else pattern_result = 0;
++
++	if(pattern_result) {
++		WRITE_LOCK(&ct_lock);
++		master_conntrack->layer7.app_proto = kmalloc(strlen(info->protocol)+1, GFP_ATOMIC);
++		if(!master_conntrack->layer7.app_proto){
++			if (net_ratelimit()) 
++				printk(KERN_ERR "layer7: out of memory in match, bailing.\n");
++			WRITE_UNLOCK(&ct_lock);
++			return (pattern_result ^ info->invert);
++		}
++		strcpy(master_conntrack->layer7.app_proto, info->protocol);
++		WRITE_UNLOCK(&ct_lock);
++	}
++
++	/* mark the packet seen */
++	skb->cb[0] = 1;
++
++	return (pattern_result ^ info->invert);
++}
++
++static int checkentry(const char *tablename, const struct ipt_ip *ip,
++	   void *matchinfo, unsigned int matchsize, unsigned int hook_mask)
++{
++	if (matchsize != IPT_ALIGN(sizeof(struct ipt_layer7_info))) 
++		return 0;
++	return 1;
++}
++
++static struct ipt_match layer7_match = { 
++	.name = "layer7", 
++	.match = &match, 
++	.checkentry = &checkentry, 
++	.me = THIS_MODULE 
++};
++
++/* taken from drivers/video/modedb.c */
++static int my_atoi(const char *s)
++{
++	int val = 0;
++
++	for (;; s++) {
++		switch (*s) {
++			case '0'...'9':
++			val = 10*val+(*s-'0');
++			break;
++		default:
++			return val;
++		}
++	}
++}
++
++/* write out num_packets to userland. */
++static int layer7_read_proc(char* page, char ** start, off_t off, int count, 
++		     int* eof, void * data) 
++{
++	if(num_packets > 99 && net_ratelimit()) 
++		printk(KERN_ERR "layer7: NOT REACHED. num_packets too big\n");
++	
++	page[0] = num_packets/10 + '0';
++	page[1] = num_packets%10 + '0';
++	page[2] = '\n';
++	page[3] = '\0';
++		
++	*eof=1;
++
++	return 3;
++}
++
++/* Read in num_packets from userland */
++static int layer7_write_proc(struct file* file, const char* buffer, 
++		      unsigned long count, void *data) 
++{
++	char * foo = kmalloc(count, GFP_ATOMIC);
++
++	if(!foo){
++		if (net_ratelimit()) 
++			printk(KERN_ERR "layer7: out of memory, bailing. num_packets unchanged.\n");
++		return count;
++	}
++
++	copy_from_user(foo, buffer, count);
++
++	num_packets = my_atoi(foo);
++	kfree (foo);
++
++	/* This has an arbitrary limit to make the math easier. I'm lazy. 
++	But anyway, 99 is a LOT! If you want more, you're doing it wrong! */
++	if(num_packets > 99) {
++		printk(KERN_WARNING "layer7: num_packets can't be > 99.\n");
++		num_packets = 99;
++	} else if(num_packets < 1) {
++		printk(KERN_WARNING "layer7: num_packets can't be < 1.\n");
++		num_packets = 1;
++	}
++	
++	return count;
++}
++
++/* register the proc file */
++static void layer7_init_proc(void)
++{
++	struct proc_dir_entry* entry;
++	entry = create_proc_entry("layer7_numpackets", 0644, proc_net);
++	entry->read_proc = layer7_read_proc;
++	entry->write_proc = layer7_write_proc;
++}
++
++static void layer7_cleanup_proc(void)
++{
++	remove_proc_entry("layer7_numpackets", proc_net);
++}
++
++static int __init init(void)
++{
++	layer7_init_proc();
++	return ipt_register_match(&layer7_match);
++}
++
++static void __exit fini(void)
++{
++	layer7_cleanup_proc();
++	ipt_unregister_match(&layer7_match);
++}
++
++module_init(init);
++module_exit(fini);
+--- linux-2.6.11.3-stock/net/ipv4/netfilter/regexp/regexp.c	1969-12-31 18:00:00.000000000 -0600
++++ linux-2.6.11.3-layer7/net/ipv4/netfilter/regexp/regexp.c	2005-03-13 20:30:01.000000000 -0600
+@@ -0,0 +1,1195 @@
++/*
++ * regcomp and regexec -- regsub and regerror are elsewhere
++ * @(#)regexp.c	1.3 of 18 April 87
++ *
++ *	Copyright (c) 1986 by University of Toronto.
++ *	Written by Henry Spencer.  Not derived from licensed software.
++ *
++ *	Permission is granted to anyone to use this software for any
++ *	purpose on any computer system, and to redistribute it freely,
++ *	subject to the following restrictions:
++ *
++ *	1. The author is not responsible for the consequences of use of
++ *		this software, no matter how awful, even if they arise
++ *		from defects in it.
++ *
++ *	2. The origin of this software must not be misrepresented, either
++ *		by explicit claim or by omission.
++ *
++ *	3. Altered versions must be plainly marked as such, and must not
++ *		be misrepresented as being the original software.
++ *
++ * Beware that some of this code is subtly aware of the way operator
++ * precedence is structured in regular expressions.  Serious changes in
++ * regular-expression syntax might require a total rethink.
++ *
++ * This code was modified by Ethan Sommer to work within the kernel
++ * (it now uses kmalloc etc..)
++ * 
++ * Modified slightly by Matthew Strait to use more modern C.
++ */
++
++#include "regexp.h"
++#include "regmagic.h"
++
++/* added by ethan and matt.  Lets it work in both kernel and user space.
++(So iptables can use it, for instance.)  Yea, it goes both ways... */
++#if __KERNEL__
++  #define malloc(foo) kmalloc(foo,GFP_ATOMIC)
++#else
++  #define printk(format,args...) printf(format,##args)
++#endif
++
++void regerror(char * s)
++{
++        printk("<3>Regexp: %s\n", s);
++        /* NOTREACHED */
++}
++
++/*
++ * The "internal use only" fields in regexp.h are present to pass info from
++ * compile to execute that permits the execute phase to run lots faster on
++ * simple cases.  They are:
++ *
++ * regstart	char that must begin a match; '\0' if none obvious
++ * reganch	is the match anchored (at beginning-of-line only)?
++ * regmust	string (pointer into program) that match must include, or NULL
++ * regmlen	length of regmust string
++ *
++ * Regstart and reganch permit very fast decisions on suitable starting points
++ * for a match, cutting down the work a lot.  Regmust permits fast rejection
++ * of lines that cannot possibly match.  The regmust tests are costly enough
++ * that regcomp() supplies a regmust only if the r.e. contains something
++ * potentially expensive (at present, the only such thing detected is * or +
++ * at the start of the r.e., which can involve a lot of backup).  Regmlen is
++ * supplied because the test in regexec() needs it and regcomp() is computing
++ * it anyway.
++ */
++
++/*
++ * Structure for regexp "program".  This is essentially a linear encoding
++ * of a nondeterministic finite-state machine (aka syntax charts or
++ * "railroad normal form" in parsing technology).  Each node is an opcode
++ * plus a "next" pointer, possibly plus an operand.  "Next" pointers of
++ * all nodes except BRANCH implement concatenation; a "next" pointer with
++ * a BRANCH on both ends of it is connecting two alternatives.  (Here we
++ * have one of the subtle syntax dependencies:  an individual BRANCH (as
++ * opposed to a collection of them) is never concatenated with anything
++ * because of operator precedence.)  The operand of some types of node is
++ * a literal string; for others, it is a node leading into a sub-FSM.  In
++ * particular, the operand of a BRANCH node is the first node of the branch.
++ * (NB this is *not* a tree structure:  the tail of the branch connects
++ * to the thing following the set of BRANCHes.)  The opcodes are:
++ */
++
++/* definition	number	opnd?	meaning */
++#define	END	0	/* no	End of program. */
++#define	BOL	1	/* no	Match "" at beginning of line. */
++#define	EOL	2	/* no	Match "" at end of line. */
++#define	ANY	3	/* no	Match any one character. */
++#define	ANYOF	4	/* str	Match any character in this string. */
++#define	ANYBUT	5	/* str	Match any character not in this string. */
++#define	BRANCH	6	/* node	Match this alternative, or the next... */
++#define	BACK	7	/* no	Match "", "next" ptr points backward. */
++#define	EXACTLY	8	/* str	Match this string. */
++#define	NOTHING	9	/* no	Match empty string. */
++#define	STAR	10	/* node	Match this (simple) thing 0 or more times. */
++#define	PLUS	11	/* node	Match this (simple) thing 1 or more times. */
++#define	OPEN	20	/* no	Mark this point in input as start of #n. */
++			/*	OPEN+1 is number 1, etc. */
++#define	CLOSE	30	/* no	Analogous to OPEN. */
++
++/*
++ * Opcode notes:
++ *
++ * BRANCH	The set of branches constituting a single choice are hooked
++ *		together with their "next" pointers, since precedence prevents
++ *		anything being concatenated to any individual branch.  The
++ *		"next" pointer of the last BRANCH in a choice points to the
++ *		thing following the whole choice.  This is also where the
++ *		final "next" pointer of each individual branch points; each
++ *		branch starts with the operand node of a BRANCH node.
++ *
++ * BACK		Normal "next" pointers all implicitly point forward; BACK
++ *		exists to make loop structures possible.
++ *
++ * STAR,PLUS	'?', and complex '*' and '+', are implemented as circular
++ *		BRANCH structures using BACK.  Simple cases (one character
++ *		per match) are implemented with STAR and PLUS for speed
++ *		and to minimize recursive plunges.
++ *
++ * OPEN,CLOSE	...are numbered at compile time.
++ */
++
++/*
++ * A node is one char of opcode followed by two chars of "next" pointer.
++ * "Next" pointers are stored as two 8-bit pieces, high order first.  The
++ * value is a positive offset from the opcode of the node containing it.
++ * An operand, if any, simply follows the node.  (Note that much of the
++ * code generation knows about this implicit relationship.)
++ *
++ * Using two bytes for the "next" pointer is vast overkill for most things,
++ * but allows patterns to get big without disasters.
++ */
++#define	OP(p)	(*(p))
++#define	NEXT(p)	(((*((p)+1)&0377)<<8) + (*((p)+2)&0377))
++#define	OPERAND(p)	((p) + 3)
++
++/*
++ * See regmagic.h for one further detail of program structure.
++ */
++
++
++/*
++ * Utility definitions.
++ */
++#ifndef CHARBITS
++#define	UCHARAT(p)	((int)*(unsigned char *)(p))
++#else
++#define	UCHARAT(p)	((int)*(p)&CHARBITS)
++#endif
++
++#define	FAIL(m)	{ regerror(m); return(NULL); }
++#define	ISMULT(c)	((c) == '*' || (c) == '+' || (c) == '?')
++#define	META	"^$.[()|?+*\\"
++
++/*
++ * Flags to be passed up and down.
++ */
++#define	HASWIDTH	01	/* Known never to match null string. */
++#define	SIMPLE		02	/* Simple enough to be STAR/PLUS operand. */
++#define	SPSTART		04	/* Starts with * or +. */
++#define	WORST		0	/* Worst case. */
++
++/*
++ * Global work variables for regcomp().
++ */
++static char *regparse;		/* Input-scan pointer. */
++static int regnpar;		/* () count. */
++static char regdummy;
++static char *regcode;		/* Code-emit pointer; &regdummy = don't. */
++static long regsize;		/* Code size. */
++
++/*
++ * Forward declarations for regcomp()'s friends.
++ */
++#ifndef STATIC
++#define	STATIC	static
++#endif
++STATIC char *reg(int paren,int *flagp);
++STATIC char *regbranch(int *flagp);
++STATIC char *regpiece(int *flagp);
++STATIC char *regatom(int *flagp);
++STATIC char *regnode(char op);
++STATIC char *regnext(char *p);
++STATIC void regc(char b);
++STATIC void reginsert(char op, char *opnd);
++STATIC void regtail(char *p, char *val);
++STATIC void regoptail(char *p, char *val);
++
++
++__kernel_size_t my_strcspn(const char *s1,const char *s2)
++{
++        char *scan1;
++        char *scan2;
++        int count;
++
++        count = 0;
++        for (scan1 = (char *)s1; *scan1 != '\0'; scan1++) {
++                for (scan2 = (char *)s2; *scan2 != '\0';)       /* ++ moved down. */
++                        if (*scan1 == *scan2++)
++                                return(count);
++                count++;
++        }
++        return(count);
++}
++
++/*
++ - regcomp - compile a regular expression into internal code
++ *
++ * We can't allocate space until we know how big the compiled form will be,
++ * but we can't compile it (and thus know how big it is) until we've got a
++ * place to put the code.  So we cheat:  we compile it twice, once with code
++ * generation turned off and size counting turned on, and once "for real".
++ * This also means that we don't allocate space until we are sure that the
++ * thing really will compile successfully, and we never have to move the
++ * code and thus invalidate pointers into it.  (Note that it has to be in
++ * one piece because free() must be able to free it all.)
++ *
++ * Beware that the optimization-preparation code in here knows about some
++ * of the structure of the compiled regexp.
++ */
++regexp *
++regcomp(char *exp,int *patternsize)
++{
++	register regexp *r;
++	register char *scan;
++	register char *longest;
++	register int len;
++	int flags;
++	/* commented out by ethan
++	   extern char *malloc();
++	*/
++
++	if (exp == NULL)
++		FAIL("NULL argument");
++
++	/* First pass: determine size, legality. */
++	regparse = exp;
++	regnpar = 1;
++	regsize = 0L;
++	regcode = &regdummy;
++	regc(MAGIC);
++	if (reg(0, &flags) == NULL)
++		return(NULL);
++
++	/* Small enough for pointer-storage convention? */
++	if (regsize >= 32767L)		/* Probably could be 65535L. */
++		FAIL("regexp too big");
++
++	/* Allocate space. */
++	*patternsize=sizeof(regexp) + (unsigned)regsize;
++	r = (regexp *)malloc(sizeof(regexp) + (unsigned)regsize);
++	if (r == NULL)
++		FAIL("out of space");
++
++	/* Second pass: emit code. */
++	regparse = exp;
++	regnpar = 1;
++	regcode = r->program;
++	regc(MAGIC);
++	if (reg(0, &flags) == NULL)
++		return(NULL);
++
++	/* Dig out information for optimizations. */
++	r->regstart = '\0';	/* Worst-case defaults. */
++	r->reganch = 0;
++	r->regmust = NULL;
++	r->regmlen = 0;
++	scan = r->program+1;			/* First BRANCH. */
++	if (OP(regnext(scan)) == END) {		/* Only one top-level choice. */
++		scan = OPERAND(scan);
++
++		/* Starting-point info. */
++		if (OP(scan) == EXACTLY)
++			r->regstart = *OPERAND(scan);
++		else if (OP(scan) == BOL)
++			r->reganch++;
++
++		/*
++		 * If there's something expensive in the r.e., find the
++		 * longest literal string that must appear and make it the
++		 * regmust.  Resolve ties in favor of later strings, since
++		 * the regstart check works with the beginning of the r.e.
++		 * and avoiding duplication strengthens checking.  Not a
++		 * strong reason, but sufficient in the absence of others.
++		 */
++		if (flags&SPSTART) {
++			longest = NULL;
++			len = 0;
++			for (; scan != NULL; scan = regnext(scan))
++				if (OP(scan) == EXACTLY && strlen(OPERAND(scan)) >= len) {
++					longest = OPERAND(scan);
++					len = strlen(OPERAND(scan));
++				}
++			r->regmust = longest;
++			r->regmlen = len;
++		}
++	}
++
++	return(r);
++}
++
++/*
++ - reg - regular expression, i.e. main body or parenthesized thing
++ *
++ * Caller must absorb opening parenthesis.
++ *
++ * Combining parenthesis handling with the base level of regular expression
++ * is a trifle forced, but the need to tie the tails of the branches to what
++ * follows makes it hard to avoid.
++ */
++static char *
++reg(int paren, int *flagp /* Parenthesized? */ )
++{
++	register char *ret;
++	register char *br;
++	register char *ender;
++	register int parno = 0; /* 0 makes gcc happy */
++	int flags;
++
++	*flagp = HASWIDTH;	/* Tentatively. */
++
++	/* Make an OPEN node, if parenthesized. */
++	if (paren) {
++		if (regnpar >= NSUBEXP)
++			FAIL("too many ()");
++		parno = regnpar;
++		regnpar++;
++		ret = regnode(OPEN+parno);
++	} else
++		ret = NULL;
++
++	/* Pick up the branches, linking them together. */
++	br = regbranch(&flags);
++	if (br == NULL)
++		return(NULL);
++	if (ret != NULL)
++		regtail(ret, br);	/* OPEN -> first. */
++	else
++		ret = br;
++	if (!(flags&HASWIDTH))
++		*flagp &= ~HASWIDTH;
++	*flagp |= flags&SPSTART;
++	while (*regparse == '|') {
++		regparse++;
++		br = regbranch(&flags);
++		if (br == NULL)
++			return(NULL);
++		regtail(ret, br);	/* BRANCH -> BRANCH. */
++		if (!(flags&HASWIDTH))
++			*flagp &= ~HASWIDTH;
++		*flagp |= flags&SPSTART;
++	}
++
++	/* Make a closing node, and hook it on the end. */
++	ender = regnode((paren) ? CLOSE+parno : END);	
++	regtail(ret, ender);
++
++	/* Hook the tails of the branches to the closing node. */
++	for (br = ret; br != NULL; br = regnext(br))
++		regoptail(br, ender);
++
++	/* Check for proper termination. */
++	if (paren && *regparse++ != ')') {
++		FAIL("unmatched ()");
++	} else if (!paren && *regparse != '\0') {
++		if (*regparse == ')') {
++			FAIL("unmatched ()");
++		} else
++			FAIL("junk on end");	/* "Can't happen". */
++		/* NOTREACHED */
++	}
++
++	return(ret);
++}
++
++/*
++ - regbranch - one alternative of an | operator
++ *
++ * Implements the concatenation operator.
++ */
++static char *
++regbranch(int *flagp)
++{
++	register char *ret;
++	register char *chain;
++	register char *latest;
++	int flags;
++
++	*flagp = WORST;		/* Tentatively. */
++
++	ret = regnode(BRANCH);
++	chain = NULL;
++	while (*regparse != '\0' && *regparse != '|' && *regparse != ')') {
++		latest = regpiece(&flags);
++		if (latest == NULL)
++			return(NULL);
++		*flagp |= flags&HASWIDTH;
++		if (chain == NULL)	/* First piece. */
++			*flagp |= flags&SPSTART;
++		else
++			regtail(chain, latest);
++		chain = latest;
++	}
++	if (chain == NULL)	/* Loop ran zero times. */
++		(void) regnode(NOTHING);
++
++	return(ret);
++}
++
++/*
++ - regpiece - something followed by possible [*+?]
++ *
++ * Note that the branching code sequences used for ? and the general cases
++ * of * and + are somewhat optimized:  they use the same NOTHING node as
++ * both the endmarker for their branch list and the body of the last branch.
++ * It might seem that this node could be dispensed with entirely, but the
++ * endmarker role is not redundant.
++ */
++static char *
++regpiece(int *flagp)
++{
++	register char *ret;
++	register char op;
++	register char *next;
++	int flags;
++
++	ret = regatom(&flags);
++	if (ret == NULL)
++		return(NULL);
++
++	op = *regparse;
++	if (!ISMULT(op)) {
++		*flagp = flags;
++		return(ret);
++	}
++
++	if (!(flags&HASWIDTH) && op != '?')
++		FAIL("*+ operand could be empty");
++	*flagp = (op != '+') ? (WORST|SPSTART) : (WORST|HASWIDTH);
++
++	if (op == '*' && (flags&SIMPLE))
++		reginsert(STAR, ret);
++	else if (op == '*') {
++		/* Emit x* as (x&|), where & means "self". */
++		reginsert(BRANCH, ret);			/* Either x */
++		regoptail(ret, regnode(BACK));		/* and loop */
++		regoptail(ret, ret);			/* back */
++		regtail(ret, regnode(BRANCH));		/* or */
++		regtail(ret, regnode(NOTHING));		/* null. */
++	} else if (op == '+' && (flags&SIMPLE))
++		reginsert(PLUS, ret);
++	else if (op == '+') {
++		/* Emit x+ as x(&|), where & means "self". */
++		next = regnode(BRANCH);			/* Either */
++		regtail(ret, next);
++		regtail(regnode(BACK), ret);		/* loop back */
++		regtail(next, regnode(BRANCH));		/* or */
++		regtail(ret, regnode(NOTHING));		/* null. */
++	} else if (op == '?') {
++		/* Emit x? as (x|) */
++		reginsert(BRANCH, ret);			/* Either x */
++		regtail(ret, regnode(BRANCH));		/* or */
++		next = regnode(NOTHING);		/* null. */
++		regtail(ret, next);
++		regoptail(ret, next);
++	}
++	regparse++;
++	if (ISMULT(*regparse))
++		FAIL("nested *?+");
++
++	return(ret);
++}
++
++/*
++ - regatom - the lowest level
++ *
++ * Optimization:  gobbles an entire sequence of ordinary characters so that
++ * it can turn them into a single node, which is smaller to store and
++ * faster to run.  Backslashed characters are exceptions, each becoming a
++ * separate node; the code is simpler that way and it's not worth fixing.
++ */
++static char *
++regatom(int *flagp)
++{
++	register char *ret;
++	int flags;
++
++	*flagp = WORST;		/* Tentatively. */
++
++	switch (*regparse++) {
++	case '^':
++		ret = regnode(BOL);
++		break;
++	case '$':
++		ret = regnode(EOL);
++		break;
++	case '.':
++		ret = regnode(ANY);
++		*flagp |= HASWIDTH|SIMPLE;
++		break;
++	case '[': {
++			register int class;
++			register int classend;
++
++			if (*regparse == '^') {	/* Complement of range. */
++				ret = regnode(ANYBUT);
++				regparse++;
++			} else
++				ret = regnode(ANYOF);
++			if (*regparse == ']' || *regparse == '-')
++				regc(*regparse++);
++			while (*regparse != '\0' && *regparse != ']') {
++				if (*regparse == '-') {
++					regparse++;
++					if (*regparse == ']' || *regparse == '\0')
++						regc('-');
++					else {
++						class = UCHARAT(regparse-2)+1;
++						classend = UCHARAT(regparse);
++						if (class > classend+1)
++							FAIL("invalid [] range");
++						for (; class <= classend; class++)
++							regc(class);
++						regparse++;
++					}
++				} else
++					regc(*regparse++);
++			}
++			regc('\0');
++			if (*regparse != ']')
++				FAIL("unmatched []");
++			regparse++;
++			*flagp |= HASWIDTH|SIMPLE;
++		}
++		break;
++	case '(':
++		ret = reg(1, &flags);
++		if (ret == NULL)
++			return(NULL);
++		*flagp |= flags&(HASWIDTH|SPSTART);
++		break;
++	case '\0':
++	case '|':
++	case ')':
++		FAIL("internal urp");	/* Supposed to be caught earlier. */
++		break;
++	case '?':
++	case '+':
++	case '*':
++		FAIL("?+* follows nothing");
++		break;
++	case '\\':
++		if (*regparse == '\0')
++			FAIL("trailing \\");
++		ret = regnode(EXACTLY);
++		regc(*regparse++);
++		regc('\0');
++		*flagp |= HASWIDTH|SIMPLE;
++		break;
++	default: {
++			register int len;
++			register char ender;
++
++			regparse--;
++			len = my_strcspn((const char *)regparse, (const char *)META);
++			if (len <= 0)
++				FAIL("internal disaster");
++			ender = *(regparse+len);
++			if (len > 1 && ISMULT(ender))
++				len--;		/* Back off clear of ?+* operand. */
++			*flagp |= HASWIDTH;
++			if (len == 1)
++				*flagp |= SIMPLE;
++			ret = regnode(EXACTLY);
++			while (len > 0) {
++				regc(*regparse++);
++				len--;
++			}
++			regc('\0');
++		}
++		break;
++	}
++
++	return(ret);
++}
++
++/*
++ - regnode - emit a node
++ */
++static char *			/* Location. */
++regnode(char op)
++{
++	register char *ret;
++	register char *ptr;
++
++	ret = regcode;
++	if (ret == &regdummy) {
++		regsize += 3;
++		return(ret);
++	}
++
++	ptr = ret;
++	*ptr++ = op;
++	*ptr++ = '\0';		/* Null "next" pointer. */
++	*ptr++ = '\0';
++	regcode = ptr;
++
++	return(ret);
++}
++
++/*
++ - regc - emit (if appropriate) a byte of code
++ */
++static void
++regc(char b)
++{
++	if (regcode != &regdummy)
++		*regcode++ = b;
++	else
++		regsize++;
++}
++
++/*
++ - reginsert - insert an operator in front of already-emitted operand
++ *
++ * Means relocating the operand.
++ */
++static void
++reginsert(char op, char* opnd)
++{
++	register char *src;
++	register char *dst;
++	register char *place;
++
++	if (regcode == &regdummy) {
++		regsize += 3;
++		return;
++	}
++
++	src = regcode;
++	regcode += 3;
++	dst = regcode;
++	while (src > opnd)
++		*--dst = *--src;
++
++	place = opnd;		/* Op node, where operand used to be. */
++	*place++ = op;
++	*place++ = '\0';
++	*place++ = '\0';
++}
++
++/*
++ - regtail - set the next-pointer at the end of a node chain
++ */
++static void
++regtail(char *p, char *val)
++{
++	register char *scan;
++	register char *temp;
++	register int offset;
++
++	if (p == &regdummy)
++		return;
++
++	/* Find last node. */
++	scan = p;
++	for (;;) {
++		temp = regnext(scan);
++		if (temp == NULL)
++			break;
++		scan = temp;
++	}
++
++	if (OP(scan) == BACK)
++		offset = scan - val;
++	else
++		offset = val - scan;
++	*(scan+1) = (offset>>8)&0377;
++	*(scan+2) = offset&0377;
++}
++
++/*
++ - regoptail - regtail on operand of first argument; nop if operandless
++ */
++static void
++regoptail(char *p, char *val)
++{
++	/* "Operandless" and "op != BRANCH" are synonymous in practice. */
++	if (p == NULL || p == &regdummy || OP(p) != BRANCH)
++		return;
++	regtail(OPERAND(p), val);
++}
++
++/*
++ * regexec and friends
++ */
++
++/*
++ * Global work variables for regexec().
++ */
++static char *reginput;		/* String-input pointer. */
++static char *regbol;		/* Beginning of input, for ^ check. */
++static char **regstartp;	/* Pointer to startp array. */
++static char **regendp;		/* Ditto for endp. */
++
++/*
++ * Forwards.
++ */
++STATIC int regtry(regexp *prog, char *string);
++STATIC int regmatch(char *prog);
++STATIC int regrepeat(char *p);
++
++#ifdef DEBUG
++int regnarrate = 0;
++void regdump();
++STATIC char *regprop(char *op);
++#endif
++
++/*
++ - regexec - match a regexp against a string
++ */
++int
++regexec(regexp *prog, char *string)
++{
++	register char *s;
++
++	/* Be paranoid... */
++	if (prog == NULL || string == NULL) {
++		printk("<3>Regexp: NULL parameter\n");
++		return(0);
++	}
++
++	/* Check validity of program. */
++	if (UCHARAT(prog->program) != MAGIC) {
++		printk("<3>Regexp: corrupted program\n");
++		return(0);
++	}
++
++	/* If there is a "must appear" string, look for it. */
++	if (prog->regmust != NULL) {
++		s = string;
++		while ((s = strchr(s, prog->regmust[0])) != NULL) {
++			if (strncmp(s, prog->regmust, prog->regmlen) == 0)
++				break;	/* Found it. */
++			s++;
++		}
++		if (s == NULL)	/* Not present. */
++			return(0);
++	}
++
++	/* Mark beginning of line for ^ . */
++	regbol = string;
++
++	/* Simplest case:  anchored match need be tried only once. */
++	if (prog->reganch)
++		return(regtry(prog, string));
++
++	/* Messy cases:  unanchored match. */
++	s = string;
++	if (prog->regstart != '\0')
++		/* We know what char it must start with. */
++		while ((s = strchr(s, prog->regstart)) != NULL) {
++			if (regtry(prog, s))
++				return(1);
++			s++;
++		}
++	else
++		/* We don't -- general case. */
++		do {
++			if (regtry(prog, s))
++				return(1);
++		} while (*s++ != '\0');
++
++	/* Failure. */
++	return(0);
++}
++
++/*
++ - regtry - try match at specific point
++ */
++static int			/* 0 failure, 1 success */
++regtry(regexp *prog, char *string)
++{
++	register int i;
++	register char **sp;
++	register char **ep;
++
++	reginput = string;
++	regstartp = prog->startp;
++	regendp = prog->endp;
++
++	sp = prog->startp;
++	ep = prog->endp;
++	for (i = NSUBEXP; i > 0; i--) {
++		*sp++ = NULL;
++		*ep++ = NULL;
++	}
++	if (regmatch(prog->program + 1)) {
++		prog->startp[0] = string;
++		prog->endp[0] = reginput;
++		return(1);
++	} else
++		return(0);
++}
++
++/*
++ - regmatch - main matching routine
++ *
++ * Conceptually the strategy is simple:  check to see whether the current
++ * node matches, call self recursively to see whether the rest matches,
++ * and then act accordingly.  In practice we make some effort to avoid
++ * recursion, in particular by going through "ordinary" nodes (that don't
++ * need to know whether the rest of the match failed) by a loop instead of
++ * by recursion.
++ */
++static int			/* 0 failure, 1 success */
++regmatch(char *prog)
++{
++	register char *scan = prog; /* Current node. */
++	char *next;		    /* Next node. */
++
++#ifdef DEBUG
++	if (scan != NULL && regnarrate)
++		fprintf(stderr, "%s(\n", regprop(scan));
++#endif
++	while (scan != NULL) {
++#ifdef DEBUG
++		if (regnarrate)
++			fprintf(stderr, "%s...\n", regprop(scan));
++#endif
++		next = regnext(scan);
++
++		switch (OP(scan)) {
++		case BOL:
++			if (reginput != regbol)
++				return(0);
++			break;
++		case EOL:
++			if (*reginput != '\0')
++				return(0);
++			break;
++		case ANY:
++			if (*reginput == '\0')
++				return(0);
++			reginput++;
++			break;
++		case EXACTLY: {
++				register int len;
++				register char *opnd;
++
++				opnd = OPERAND(scan);
++				/* Inline the first character, for speed. */
++				if (*opnd != *reginput)
++					return(0);
++				len = strlen(opnd);
++				if (len > 1 && strncmp(opnd, reginput, len) != 0)
++					return(0);
++				reginput += len;
++			}
++			break;
++		case ANYOF:
++			if (*reginput == '\0' || strchr(OPERAND(scan), *reginput) == NULL)
++				return(0);
++			reginput++;
++			break;
++		case ANYBUT:
++			if (*reginput == '\0' || strchr(OPERAND(scan), *reginput) != NULL)
++				return(0);
++			reginput++;
++			break;
++		case NOTHING:
++		case BACK:
++			break;
++		case OPEN+1:
++		case OPEN+2:
++		case OPEN+3:
++		case OPEN+4:
++		case OPEN+5:
++		case OPEN+6:
++		case OPEN+7:
++		case OPEN+8:
++		case OPEN+9: {
++				register int no;
++				register char *save;
++
++				no = OP(scan) - OPEN;
++				save = reginput;
++
++				if (regmatch(next)) {
++					/*
++					 * Don't set startp if some later
++					 * invocation of the same parentheses
++					 * already has.
++					 */
++					if (regstartp[no] == NULL)
++						regstartp[no] = save;
++					return(1);
++				} else
++					return(0);
++			}
++			break;
++		case CLOSE+1:
++		case CLOSE+2:
++		case CLOSE+3:
++		case CLOSE+4:
++		case CLOSE+5:
++		case CLOSE+6:
++		case CLOSE+7:
++		case CLOSE+8:
++		case CLOSE+9:
++			{
++				register int no;
++				register char *save;
++
++				no = OP(scan) - CLOSE;
++				save = reginput;
++
++				if (regmatch(next)) {
++					/*
++					 * Don't set endp if some later
++					 * invocation of the same parentheses
++					 * already has.
++					 */
++					if (regendp[no] == NULL)
++						regendp[no] = save;
++					return(1);
++				} else
++					return(0);
++			}
++			break;
++		case BRANCH: {
++				register char *save;
++
++				if (OP(next) != BRANCH)		/* No choice. */
++					next = OPERAND(scan);	/* Avoid recursion. */
++				else {
++					do {
++						save = reginput;
++						if (regmatch(OPERAND(scan)))
++							return(1);
++						reginput = save;
++						scan = regnext(scan);
++					} while (scan != NULL && OP(scan) == BRANCH);
++					return(0);
++					/* NOTREACHED */
++				}
++			}
++			break;
++		case STAR:
++		case PLUS: {
++				register char nextch;
++				register int no;
++				register char *save;
++				register int min;
++
++				/*
++				 * Lookahead to avoid useless match attempts
++				 * when we know what character comes next.
++				 */
++				nextch = '\0';
++				if (OP(next) == EXACTLY)
++					nextch = *OPERAND(next);
++				min = (OP(scan) == STAR) ? 0 : 1;
++				save = reginput;
++				no = regrepeat(OPERAND(scan));
++				while (no >= min) {
++					/* If it could work, try it. */
++					if (nextch == '\0' || *reginput == nextch)
++						if (regmatch(next))
++							return(1);
++					/* Couldn't or didn't -- back up. */
++					no--;
++					reginput = save + no;
++				}
++				return(0);
++			}
++			break;
++		case END:
++			return(1);	/* Success! */
++			break;
++		default:
++			printk("<3>Regexp: memory corruption\n");
++			return(0);
++			break;
++		}
++
++		scan = next;
++	}
++
++	/*
++	 * We get here only if there's trouble -- normally "case END" is
++	 * the terminating point.
++	 */
++	printk("<3>Regexp: corrupted pointers\n");
++	return(0);
++}
++
++/*
++ - regrepeat - repeatedly match something simple, report how many
++ */
++static int
++regrepeat(char *p)
++{
++	register int count = 0;
++	register char *scan;
++	register char *opnd;
++
++	scan = reginput;
++	opnd = OPERAND(p);
++	switch (OP(p)) {
++	case ANY:
++		count = strlen(scan);
++		scan += count;
++		break;
++	case EXACTLY:
++		while (*opnd == *scan) {
++			count++;
++			scan++;
++		}
++		break;
++	case ANYOF:
++		while (*scan != '\0' && strchr(opnd, *scan) != NULL) {
++			count++;
++			scan++;
++		}
++		break;
++	case ANYBUT:
++		while (*scan != '\0' && strchr(opnd, *scan) == NULL) {
++			count++;
++			scan++;
++		}
++		break;
++	default:		/* Oh dear.  Called inappropriately. */
++		printk("<3>Regexp: internal foulup\n");
++		count = 0;	/* Best compromise. */
++		break;
++	}
++	reginput = scan;
++
++	return(count);
++}
++
++/*
++ - regnext - dig the "next" pointer out of a node
++ */
++static char* 
++regnext(char *p)
++{
++	register int offset;
++
++	if (p == &regdummy)
++		return(NULL);
++
++	offset = NEXT(p);
++	if (offset == 0)
++		return(NULL);
++
++	if (OP(p) == BACK)
++		return(p-offset);
++	else
++		return(p+offset);
++}
++
++#ifdef DEBUG
++
++STATIC char *regprop();
++
++/*
++ - regdump - dump a regexp onto stdout in vaguely comprehensible form
++ */
++void
++regdump(regexp *r)
++{
++	register char *s;
++	register char op = EXACTLY;	/* Arbitrary non-END op. */
++	register char *next;
++	/* extern char *strchr(); */
++
++
++	s = r->program + 1;
++	while (op != END) {	/* While that wasn't END last time... */
++		op = OP(s);
++		printf("%2d%s", s-r->program, regprop(s));	/* Where, what. */
++		next = regnext(s);
++		if (next == NULL)		/* Next ptr. */
++			printf("(0)");
++		else 
++			printf("(%d)", (s-r->program)+(next-s));
++		s += 3;
++		if (op == ANYOF || op == ANYBUT || op == EXACTLY) {
++			/* Literal string, where present. */
++			while (*s != '\0') {
++				putchar(*s);
++				s++;
++			}
++			s++;
++		}
++		putchar('\n');
++	}
++
++	/* Header fields of interest. */
++	if (r->regstart != '\0')
++		printf("start `%c' ", r->regstart);
++	if (r->reganch)
++		printf("anchored ");
++	if (r->regmust != NULL)
++		printf("must have \"%s\"", r->regmust);
++	printf("\n");
++}
++
++/*
++ - regprop - printable representation of opcode
++ */
++static char *
++regprop(char *op)
++{
++#define BUFLEN 50
++	register char *p;
++	static char buf[BUFLEN];
++
++	strcpy(buf, ":");
++
++	switch (OP(op)) {
++	case BOL:
++		p = "BOL";
++		break;
++	case EOL:
++		p = "EOL";
++		break;
++	case ANY:
++		p = "ANY";
++		break;
++	case ANYOF:
++		p = "ANYOF";
++		break;
++	case ANYBUT:
++		p = "ANYBUT";
++		break;
++	case BRANCH:
++		p = "BRANCH";
++		break;
++	case EXACTLY:
++		p = "EXACTLY";
++		break;
++	case NOTHING:
++		p = "NOTHING";
++		break;
++	case BACK:
++		p = "BACK";
++		break;
++	case END:
++		p = "END";
++		break;
++	case OPEN+1:
++	case OPEN+2:
++	case OPEN+3:
++	case OPEN+4:
++	case OPEN+5:
++	case OPEN+6:
++	case OPEN+7:
++	case OPEN+8:
++	case OPEN+9:
++		snprintf(buf+strlen(buf),BUFLEN-strlen(buf), "OPEN%d", OP(op)-OPEN);
++		p = NULL;
++		break;
++	case CLOSE+1:
++	case CLOSE+2:
++	case CLOSE+3:
++	case CLOSE+4:
++	case CLOSE+5:
++	case CLOSE+6:
++	case CLOSE+7:
++	case CLOSE+8:
++	case CLOSE+9:
++		snprintf(buf+strlen(buf),BUFLEN-strlen(buf), "CLOSE%d", OP(op)-CLOSE);
++		p = NULL;
++		break;
++	case STAR:
++		p = "STAR";
++		break;
++	case PLUS:
++		p = "PLUS";
++		break;
++	default:
++		printk("<3>Regexp: corrupted opcode\n");
++		break;
++	}
++	if (p != NULL)
++		strncat(buf, p, BUFLEN-strlen(buf));
++	return(buf);
++}
++#endif
++
++
+--- linux-2.6.11.3-stock/net/ipv4/netfilter/regexp/regexp.h	1969-12-31 18:00:00.000000000 -0600
++++ linux-2.6.11.3-layer7/net/ipv4/netfilter/regexp/regexp.h	2005-03-13 20:30:01.000000000 -0600
+@@ -0,0 +1,41 @@
++/*
++ * Definitions etc. for regexp(3) routines.
++ *
++ * Caveat:  this is V8 regexp(3) [actually, a reimplementation thereof],
++ * not the System V one.
++ */
++
++#ifndef REGEXP_H
++#define REGEXP_H
++
++
++/* 
++http://www.opensource.apple.com/darwinsource/10.3/expect-1/expect/expect.h , 
++which contains a version of this library, says:
++
++ *
++ * NSUBEXP must be at least 10, and no greater than 117 or the parser
++ * will not work properly.
++ *
++
++However, it looks rather like this library is limited to 10.  If you think
++otherwise, let us know.
++*/
++
++#define NSUBEXP  10
++typedef struct regexp {
++	char *startp[NSUBEXP];
++	char *endp[NSUBEXP];
++	char regstart;		/* Internal use only. */
++	char reganch;		/* Internal use only. */
++	char *regmust;		/* Internal use only. */
++	int regmlen;		/* Internal use only. */
++	char program[1];	/* Unwarranted chumminess with compiler. */
++} regexp;
++
++regexp * regcomp(char *exp, int *patternsize);
++int regexec(regexp *prog, char *string);
++void regsub(regexp *prog, char *source, char *dest);
++void regerror(char *s);
++
++#endif
+--- linux-2.6.11.3-stock/net/ipv4/netfilter/regexp/regmagic.h	1969-12-31 18:00:00.000000000 -0600
++++ linux-2.6.11.3-layer7/net/ipv4/netfilter/regexp/regmagic.h	2005-03-13 20:30:01.000000000 -0600
+@@ -0,0 +1,5 @@
++/*
++ * The first byte of the regexp internal "program" is actually this magic
++ * number; the start node begins in the second byte.
++ */
++#define	MAGIC	0234
+--- linux-2.6.11.3-stock/net/ipv4/netfilter/regexp/regsub.c	1969-12-31 18:00:00.000000000 -0600
++++ linux-2.6.11.3-layer7/net/ipv4/netfilter/regexp/regsub.c	2005-03-13 20:30:01.000000000 -0600
+@@ -0,0 +1,95 @@
++/*
++ * regsub
++ * @(#)regsub.c	1.3 of 2 April 86
++ *
++ *	Copyright (c) 1986 by University of Toronto.
++ *	Written by Henry Spencer.  Not derived from licensed software.
++ *
++ *	Permission is granted to anyone to use this software for any
++ *	purpose on any computer system, and to redistribute it freely,
++ *	subject to the following restrictions:
++ *
++ *	1. The author is not responsible for the consequences of use of
++ *		this software, no matter how awful, even if they arise
++ *		from defects in it.
++ *
++ *	2. The origin of this software must not be misrepresented, either
++ *		by explicit claim or by omission.
++ *
++ *	3. Altered versions must be plainly marked as such, and must not
++ *		be misrepresented as being the original software.
++ *
++ *
++ * This code was modified by Ethan Sommer to work within the kernel
++ * (it now uses kmalloc etc..)
++ *
++ */
++#include "regexp.h"
++#include "regmagic.h"
++#include <linux/string.h>
++
++
++#ifndef CHARBITS
++#define	UCHARAT(p)	((int)*(unsigned char *)(p))
++#else
++#define	UCHARAT(p)	((int)*(p)&CHARBITS)
++#endif
++
++#if 0
++//void regerror(char * s)
++//{
++//        printk("regexp(3): %s", s);
++//        /* NOTREACHED */
++//}
++#endif
++
++/*
++ - regsub - perform substitutions after a regexp match
++ */
++void
++regsub(regexp * prog, char * source, char * dest)
++{
++	register char *src;
++	register char *dst;
++	register char c;
++	register int no;
++	register int len;
++	
++	/* Not necessary and gcc doesn't like it -MLS */
++	/*extern char *strncpy();*/
++
++	if (prog == NULL || source == NULL || dest == NULL) {
++		regerror("NULL parm to regsub");
++		return;
++	}
++	if (UCHARAT(prog->program) != MAGIC) {
++		regerror("damaged regexp fed to regsub");
++		return;
++	}
++
++	src = source;
++	dst = dest;
++	while ((c = *src++) != '\0') {
++		if (c == '&')
++			no = 0;
++		else if (c == '\\' && '0' <= *src && *src <= '9')
++			no = *src++ - '0';
++		else
++			no = -1;
++
++		if (no < 0) {	/* Ordinary character. */
++			if (c == '\\' && (*src == '\\' || *src == '&'))
++				c = *src++;
++			*dst++ = c;
++		} else if (prog->startp[no] != NULL && prog->endp[no] != NULL) {
++			len = prog->endp[no] - prog->startp[no];
++			(void) strncpy(dst, prog->startp[no], len);
++			dst += len;
++			if (len != 0 && *(dst-1) == '\0') {	/* strncpy hit NUL. */
++				regerror("damaged match string");
++				return;
++			}
++		}
++	}
++	*dst++ = '\0';
++}