[netfilter-cvslog] r3448 - trunk/iptables/libiptc

[gandalf at netfilter.org]

Author: gandalf at netfilter.org
Date: 2004-12-18 18:18:49 +0100 (Sat, 18 Dec 2004)
New Revision: 3448

Modified:
   trunk/iptables/libiptc/libiptc.c
Log:
Implement some optimization for finding rules to replace in TC_REPLACE_ENTRY.
Stolen from TC_DELETE_NUM_ENTRY.


Modified: trunk/iptables/libiptc/libiptc.c
===================================================================
--- trunk/iptables/libiptc/libiptc.c	2004-12-18 16:38:59 UTC (rev 3447)
+++ trunk/iptables/libiptc/libiptc.c	2004-12-18 17:18:49 UTC (rev 3448)
@@ -1,4 +1,4 @@
-/* Library which manipulates firewall rules.  Version $Revision: 1.56 $ */
+/* Library which manipulates firewall rules.  Version $Revision$ */
 
 /* Architecture of firewall rules is as follows:
  *
@@ -1319,11 +1319,18 @@
 		return 0;
 	}
 
-	if (!(old = iptcc_get_rule_num(c, rulenum + 1))) {
+	if (rulenum >= c->num_rules) {
 		errno = E2BIG;
 		return 0;
 	}
 
+	/* Take advantage of the double linked list if possible. */
+	if (rulenum + 1 <= c->num_rules/2) {
+		old = iptcc_get_rule_num(c, rulenum + 1);
+	} else {
+		old = iptcc_get_rule_num_reverse(c, c->num_rules - rulenum);
+	}
+
 	if (!(r = iptcc_alloc_rule(c, e->next_offset))) {
 		errno = ENOMEM;
 		return 0;