Handle too-short snapshot lengths in cooked mode.

[libpcap] / pcap-linux.c

diff --git a/pcap-linux.c b/pcap-linux.c
index 9c5d7c9b32dee34fe9a440b10aa0f199dfce2572..c66ed9860c6f7e79565d44821046664cd0f02013 100644 (file)
--- a/pcap-linux.c
+++ b/pcap-linux.c
@@ -27,7 +27,7 @@
 
 #ifndef lint
 static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/libpcap/pcap-linux.c,v 1.116 2005-08-16 04:18:32 guy Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/libpcap/pcap-linux.c,v 1.117 2005-10-08 11:30:26 guy Exp $ (LBL)";
 #endif
 
 /*
@@ -394,7 +394,16 @@ pcap_open_live(const char *device, int snaplen, int promisc, int to_ms,
                 *
                 * We can safely pass "recvfrom()" a byte count
                 * based on the snapshot length.
+                *
+                * If we're in cooked mode, make the snapshot length
+                * large enough to hold a "cooked mode" header plus
+                * 1 byte of packet data (so we don't pass a byte
+                * count of 0 to "recvfrom()").
                 */
+               if (handle->md.cooked) {
+                       if (handle->snapshot < SLL_HDR_LEN + 1)
+                               handle->snapshot = SLL_HDR_LEN + 1;
+               }
                handle->bufsize = handle->snapshot;
        }