When activating a device, return PCAP_ERROR_IFACE_NOT_UP if the device

isn't up, so applications can report that differently from a generic
error (the latter could mean there's a bug somewhere in libpcap).

When capturing on a device without mmap on Linux, ignore ENETDOWN, so
that we can continue to capture traffic if the interface goes down and
comes back up again; comments in the kernel indicate that we'll just
block waiting for packets if we try to receive from a socket that
delivered ENETDOWN, and, if we're using a memory-mapped buffer, we won't
even get notified of "network down" events.

1 files changed, 4 insertions, 1 deletions

diff --git a/pcap.c b/pcap.c
index 01d12d90..3f9fa09e 100644
--- a/pcap.c
+++ b/pcap.c
@@ -33,7 +33,7 @@
 
 #ifndef lint
 static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/libpcap/pcap.c,v 1.122 2008-05-26 19:58:06 guy Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/libpcap/pcap.c,v 1.123 2008-07-01 08:02:33 guy Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -951,6 +951,9 @@ pcap_statustostr(int errnum)
 
 	case PCAP_ERROR_PERM_DENIED:
 		return ("You don't have permission to capture on that device");
+
+	case PCAP_ERROR_IFACE_NOT_UP:
+		return ("That device is not up");
 	}
 	(void)snprintf(ebuf, sizeof ebuf, "Unknown error: %d", errnum);
 	return(ebuf);