openwrt-xburst/target/linux/generic-2.6/patches-2.6.22/101-netfilter_layer7_pktmatch.patch

Index: linux-2.6.22-rc6/include/linux/netfilter_ipv4/ipt_layer7.h
===================================================================
--- linux-2.6.22-rc6.orig/include/linux/netfilter_ipv4/ipt_layer7.h	2007-07-02 03:23:28.597194750 +0200
+++ linux-2.6.22-rc6/include/linux/netfilter_ipv4/ipt_layer7.h	2007-07-02 03:23:44.730203000 +0200
@@ -21,6 +21,7 @@
     char protocol[MAX_PROTOCOL_LEN];
     char invert:1;
     char pattern[MAX_PATTERN_LEN];
+    char pkt;
 };
 
 #endif /* _IPT_LAYER7_H */
Index: linux-2.6.22-rc6/net/ipv4/netfilter/ipt_layer7.c
===================================================================
--- linux-2.6.22-rc6.orig/net/ipv4/netfilter/ipt_layer7.c	2007-07-02 03:23:28.609195500 +0200
+++ linux-2.6.22-rc6/net/ipv4/netfilter/ipt_layer7.c	2007-07-02 03:23:54.234797000 +0200
@@ -300,33 +300,34 @@
 }
 
 /* add the new app data to the conntrack.  Return number of bytes added. */
-static int add_data(struct nf_conn * master_conntrack,
-			char * app_data, int appdatalen)
+static int add_datastr(char *target, int offset, char *app_data, int len)
 {
 	int length = 0, i;
-	int oldlength = master_conntrack->layer7.app_data_len;
-
-	// This is a fix for a race condition by Deti Fliegl. However, I'm not
-	// clear on whether the race condition exists or whether this really
-	// fixes it.  I might just be being dense... Anyway, if it's not really
-	// a fix, all it does is waste a very small amount of time.
-	if(!master_conntrack->layer7.app_data) return 0;
+	if(!target) return 0;
 
 	/* 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 < maxdatalen-oldlength-1 &&
-		   i < appdatalen; i++) {
+	for(i = 0; i < maxdatalen-offset-1 && i < len; i++) {
 		if(app_data[i] != '\0') {
-			master_conntrack->layer7.app_data[length+oldlength] =
+			target[length+offset] =
 				/* the kernel version of tolower mungs 'upper ascii' */
 				isascii(app_data[i])? tolower(app_data[i]) : app_data[i];
 			length++;
 		}
 	}
+	target[length+offset] = '\0';
+
+	return length;
+}
 
-	master_conntrack->layer7.app_data[length+oldlength] = '\0';
-	master_conntrack->layer7.app_data_len = length + oldlength;
+/* add the new app data to the conntrack.  Return number of bytes added. */
+static int add_data(struct nf_conn * master_conntrack,
+			char * app_data, int appdatalen)
+{
+	int length;
 
+	length = add_datastr(master_conntrack->layer7.app_data, master_conntrack->layer7.app_data_len, app_data, appdatalen);
+	master_conntrack->layer7.app_data_len += length;
 	return length;
 }
 
@@ -343,7 +344,7 @@
 	enum ip_conntrack_info master_ctinfo, ctinfo;
 	struct nf_conn *master_conntrack;
 	struct nf_conn *conntrack;
-	unsigned char * app_data;
+	unsigned char *app_data, *tmp_data;
 	unsigned int pattern_result, appdatalen;
 	regexp * comppattern;
 
@@ -365,8 +366,8 @@
 		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) {
+	if(!info->pkt && (TOTAL_PACKETS > num_packets ||
+		master_conntrack->layer7.app_proto)) {
 
 		pattern_result = match_no_append(conntrack, master_conntrack, ctinfo, master_ctinfo, info);
 
@@ -396,6 +397,23 @@
 	comppattern = compile_and_cache(info->pattern, info->protocol);
 	spin_unlock_bh(&list_lock);
 
+	if (info->pkt) {
+		tmp_data = kmalloc(maxdatalen, GFP_ATOMIC);
+		if(!tmp_data){
+			if (net_ratelimit())
+				printk(KERN_ERR "layer7: out of memory in match, bailing.\n");
+			return info->invert;
+		}
+
+		tmp_data[0] = '\0';
+		add_datastr(tmp_data, 0, app_data, appdatalen);
+		pattern_result = ((comppattern && regexec(comppattern, tmp_data)) ? 1 : 0);
+		kfree(tmp_data);
+		tmp_data = NULL;
+
+		return (pattern_result ^ info->invert);
+	}
+
 	/* 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) {