Fixed a bug in IPv4 pseudoIP cksum calculation which would cause invalid TCP and UDP cksums in certain cases

2010-05-23 22:30:32 +05:30 · 2010-05-23 22:30:32 +05:30 · 7327fbb58d
commit 7327fbb58d
parent 956455137c
1 changed files with 3 additions and 0 deletions
--- a/common/ip4.cpp
+++ b/common/ip4.cpp
@ -622,6 +622,9 @@ quint32 Ip4Protocol::protocolFrameCksum(int streamIndex,
            sum += fieldData(ip4_proto, FieldValue, streamIndex).toUInt() & 0x00FF;
            sum += (fieldData(ip4_totLen, FieldValue, streamIndex).toUInt() & 0xFFFF) - 20;

+            while(sum>>16)
+                sum = (sum & 0xFFFF) + (sum >> 16);
+
            // Above calculation done assuming 'big endian' 
            // - so convert to host order
            //return qFromBigEndian(sum);