Patch for routing socket bug, please review and test...

[gnn at freebsd.org]

Hi Folks,

Courtesy of OpenBSD, I have taken their changes and modified them to
fit our kernel.  Please test and let me know about this patch.

Thanks,
George

Index: rtsock.c
===================================================================
RCS file: /home/ncvs/src/sys/net/rtsock.c,v
retrieving revision 1.123
diff -u -r1.123 rtsock.c
--- rtsock.c	9 Jun 2005 12:20:50 -0000	1.123
+++ rtsock.c	11 Jul 2005 13:37:38 -0000
@@ -27,7 +27,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)rtsock.c	8.7 (Berkeley) 10/12/95
- * $FreeBSD: src/sys/net/rtsock.c,v 1.123 2005/06/09 12:20:50 harti Exp $
+ * $FreeBSD$
  */
 
 #include <sys/param.h>
@@ -434,6 +434,25 @@
 		RT_LOCK(rt);
 		RT_ADDREF(rt);
 
+		/* 
+		 * Fix for PR: 82974
+		 *
+		 * RTM_CHANGE/LOCK need a perfect match, rn_lookup()
+		 * returns a perfect match in case a netmask is
+		 * specified.  For host routes only a longest prefix
+		 * match is returned so it is necessary to compare the
+		 * existence of the netmaks.  If both have a netmask
+		 * rnh_lookup() did a perfect match and if non of them
+		 * have a netmask both are host routes which is also a
+		 * perfect match.
+		 */
+
+		if (rtm->rtm_type != RTM_GET && 
+		    (!rt_mask(rt) != !info.rti_info[RTAX_NETMASK])) {
+			RT_UNLOCK(rt);
+			senderr(ESRCH);
+		}
+
 		switch(rtm->rtm_type) {
 
 		case RTM_GET: