101-netfilter_layer7_pktmatch.patch

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Index: linux-2.6.21.7/include/linux/netfilter/xt_layer7.h
===================================================================
--- linux-2.6.21.7.orig/include/linux/netfilter/xt_layer7.h
+++ linux-2.6.21.7/include/linux/netfilter/xt_layer7.h
@@ -8,6 +8,7 @@ struct xt_layer7_info {
     char protocol[MAX_PROTOCOL_LEN];
     char pattern[MAX_PATTERN_LEN];
     u_int8_t invert;
+    u_int8_t pkt;
 };
 
 #endif /* _XT_LAYER7_H */
Index: linux-2.6.21.7/net/netfilter/xt_layer7.c
===================================================================
--- linux-2.6.21.7.orig/net/netfilter/xt_layer7.c
+++ linux-2.6.21.7/net/netfilter/xt_layer7.c
@@ -297,34 +297,36 @@ static int match_no_append(struct nf_con
 }
 
 /* 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') {
 			/* the kernel version of tolower mungs 'upper ascii' */
-			master_conntrack->layer7.app_data[length+oldlength] =
+			target[length+offset] =
 				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;
 }
 
@@ -411,7 +413,7 @@ match(const struct sk_buff *skbin,
 	const struct xt_layer7_info * info = matchinfo;
 	enum ip_conntrack_info master_ctinfo, ctinfo;
 	struct nf_conn *master_conntrack, *conntrack;
-	unsigned char * app_data;
+	unsigned char *app_data, *tmp_data;
 	unsigned int pattern_result, appdatalen;
 	regexp * comppattern;
 
@@ -439,8 +441,8 @@ match(const struct sk_buff *skbin,
 		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);
@@ -473,6 +475,25 @@ match(const struct sk_buff *skbin,
 	/* the return value gets checked later, when we're ready to use it */
 	comppattern = compile_and_cache(info->pattern, info->protocol);
 
+	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;
+		spin_unlock_bh(&l7_lock);
+
+		return (pattern_result ^ info->invert);
+	}
+
 	/* On the first packet of a connection, allocate space for app data */
 	if(TOTAL_PACKETS == 1 && !skb->cb[0] && 
 	   !master_conntrack->layer7.app_data){