In "add_or_find_if()", first check whether we already have an entry in

the list for the interface, and try to open the interface only if we
don't already have an interface, so if you have multiple addresses for
an interface, you don't open the interface for each of them.  (See
Wireshark bug 1151:

	http://bugs.wireshark.org/bugzilla/show_bug.cgi?id=1151

for the reason to do this; pcap_findalldevs() spent a *lot* of time and
energy opening en0 over and over again for all 64K-128K(!) addresses.)

diff --git a/inet.c b/inet.c
index 948f01240c32a6d593ade4fdc7bf00f96b29c294..9c5f716ac0306d12372cfec57836fa79d9a1fcf5 100644 (file)
--- a/inet.c
+++ b/inet.c
@@ -34,7 +34,7 @@
 
 #ifndef lint
 static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/libpcap/inet.c,v 1.69 2006-01-21 10:45:18 guy Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/libpcap/inet.c,v 1.70 2006-10-10 07:09:14 guy Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -134,28 +134,6 @@ add_or_find_if(pcap_if_t **curdev_ret, pcap_if_t **alldevs, const char *name,
        pcap_if_t *curdev, *prevdev, *nextdev;
        int this_instance;
 
-       /*
-        * Can we open this interface for live capture?
-        *
-        * We do this check so that interfaces that ae supplied
-        * by the interface enumeration mechanism we're using
-        * but that don't support packet capture aren't included
-        * in the list.  An example of this is loopback interfaces
-        * on Solaris; we don't just omit loopback interfaces
-        * becaue you *can* capture on loopback interfaces on some
-        * OSes.
-        */
-       p = pcap_open_live(name, 68, 0, 0, errbuf);
-       if (p == NULL) {
-               /*
-                * No.  Don't bother including it.
-                * Don't treat this as an error, though.
-                */
-               *curdev_ret = NULL;
-               return (0);
-       }
-       pcap_close(p);
-
        /*
         * Is there already an entry in the list for this interface?
         */
@@ -163,9 +141,35 @@ add_or_find_if(pcap_if_t **curdev_ret, pcap_if_t **alldevs, const char *name,
                if (strcmp(name, curdev->name) == 0)
                        break;  /* yes, we found it */
        }
+
        if (curdev == NULL) {
                /*
                 * No, we didn't find it.
+                *
+                * Can we open this interface for live capture?
+                *
+                * We do this check so that interfaces that are
+                * supplied by the interface enumeration mechanism
+                * we're using but that don't support packet capture
+                * aren't included in the list.  Loopback interfaces
+                * on Solaris are an example of this; we don't just
+                * omit loopback interfaces on all platforms because
+                * you *can* capture on loopback interfaces on some
+                * OSes.
+                */
+               p = pcap_open_live(name, 68, 0, 0, errbuf);
+               if (p == NULL) {
+                       /*
+                        * No.  Don't bother including it.
+                        * Don't treat this as an error, though.
+                        */
+                       *curdev_ret = NULL;
+                       return (0);
+               }
+               pcap_close(p);
+
+               /*
+                * Yes, we can open it.
                 * Allocate a new entry.
                 */
                curdev = malloc(sizeof(pcap_if_t));