From: Martin Schwenke <martin@meltin.net>
Date: Fri, 17 Aug 2018 05:36:41 +0000 (+1000)
Subject: ctdb-common: Fix a bug in non-Linux (PCAP) TCP packet capturing
X-Git-Tag: tdb-1.3.17~1965
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f3a1f1e1fa9a8a0fe6ffd3809a64d8185cb561b7;p=thirdparty%2Fsamba.git

ctdb-common: Fix a bug in non-Linux (PCAP) TCP packet capturing

Captured packets include a link-layer header, which is considered in
the Linux code but not the PCAP code.  Also, the actual captured
length is in caplen, not len.

Signed-off-by: Martin Schwenke <martin@meltin.net>
Reviewed-by: Amitay Isaacs <amitay@gmail.com>
---

diff --git a/ctdb/common/system_socket.c b/ctdb/common/system_socket.c
index 4617be48bd7..c72c61ad978 100644
--- a/ctdb/common/system_socket.c
+++ b/ctdb/common/system_socket.c
@@ -962,7 +962,7 @@ int ctdb_sys_read_tcp_packet(int s,
 
 		/* make sure its not a short packet */
 		if (offsetof(struct tcphdr, th_ack) + 4 +
-		    (ip->ip_hl*4) > pkthdr.len) {
+		    (ip->ip_hl*4) + sizeof(*eth) > pkthdr.caplen) {
 			return -1;
 		}
 		/* TCP */