Re: ulogd2 and nflog prefix

[Philip Craig <philipc@snapgear.com>]

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On 05/15/2006 05:39 PM, Patrick McHardy wrote:
> I agree. A few nitpicks though ..

Okay, here's a better version.


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Null terminate the prefix in netfilter netlink log messages,
and remove the artificial limit on the prefix length.

Signed-off-by: Philip Craig <philipc@snapgear.com>

Index: linux-2.6.x/net/netfilter/nfnetlink_log.c
===================================================================
RCS file: /cvs/sw/linux-2.6.x/net/netfilter/nfnetlink_log.c,v
retrieving revision 1.1.1.3
diff -u -p -r1.1.1.3 nfnetlink_log.c
--- linux-2.6.x/net/netfilter/nfnetlink_log.c	21 Mar 2006 01:35:42 -0000	1.1.1.3
+++ linux-2.6.x/net/netfilter/nfnetlink_log.c	15 May 2006 07:54:59 -0000
@@ -386,7 +386,8 @@ __build_packet_message(struct nfulnl_ins
 			const struct net_device *indev,
 			const struct net_device *outdev,
 			const struct nf_loginfo *li,
-			const char *prefix)
+			const char *prefix,
+			unsigned int prefix_len)
 {
 	unsigned char *old_tail;
 	struct nfulnl_msg_packet_hdr pmsg;
@@ -410,12 +411,8 @@ __build_packet_message(struct nfulnl_ins
 
 	NFA_PUT(inst->skb, NFULA_PACKET_HDR, sizeof(pmsg), &pmsg);
 
-	if (prefix) {
-		int slen = strlen(prefix);
-		if (slen > NFULNL_PREFIXLEN)
-			slen = NFULNL_PREFIXLEN;
-		NFA_PUT(inst->skb, NFULA_PREFIX, slen, prefix);
-	}
+	if (prefix)
+		NFA_PUT(inst->skb, NFULA_PREFIX, prefix_len, prefix);
 
 	if (indev) {
 		tmp_uint = htonl(indev->ifindex);
@@ -565,7 +562,7 @@ nfulnl_log_packet(unsigned int pf,
 		  const struct nf_loginfo *li_user,
 		  const char *prefix)
 {
-	unsigned int size, data_len;
+	unsigned int size, data_len, prefix_len;
 	struct nfulnl_instance *inst;
 	const struct nf_loginfo *li;
 	unsigned int qthreshold;
@@ -599,10 +596,15 @@ nfulnl_log_packet(unsigned int pf,
 #endif
 		+ NFA_SPACE(sizeof(u_int32_t))	/* mark */
 		+ NFA_SPACE(sizeof(u_int32_t))	/* uid */
-		+ NFA_SPACE(NFULNL_PREFIXLEN)	/* prefix */
 		+ NFA_SPACE(sizeof(struct nfulnl_msg_packet_hw))
 		+ NFA_SPACE(sizeof(struct nfulnl_msg_packet_timestamp));
 
+	if (prefix) {
+		prefix_len = strlen(prefix) + 1;
+		size += NFA_SPACE(prefix_len);
+	} else
+		prefix_len = 0;
+
 	UDEBUG("initial size=%u\n", size);
 
 	spin_lock_bh(&inst->lock);
@@ -665,7 +667,7 @@ nfulnl_log_packet(unsigned int pf,
 	inst->qlen++;
 
 	__build_packet_message(inst, skb, data_len, pf,
-				hooknum, in, out, li, prefix);
+				hooknum, in, out, li, prefix, prefix_len);
 
 	/* timer_pending always called within inst->lock, so there
 	 * is no chance of a race here */