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libwinpr-utils: fix IPv4 checksum and TCP sequence numbers with wlog packet messages

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This commit is contained in:
Marc-André Moreau 2013-10-09 16:37:45 -04:00
parent 90b90ad496
commit 3d7d4c50db
1 changed files with 39 additions and 7 deletions
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46
winpr/libwinpr/utils/wlog/PacketMessage.c
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@ -243,7 +243,24 @@ int WLog_PacketMessage_Write_EthernetHeader(wPcap* pcap, wEthernetHeader* ethern
UINT16 IPv4Checksum(BYTE* ipv4, int length)
{
return 0;
UINT16 tmp16;
long checksum = 0;
while (length > 1)
{
tmp16 = *((UINT16*) ipv4);
checksum += tmp16;
length -= 2;
ipv4 += 2;
}
if (length > 0)
checksum += *ipv4;
while (checksum >> 16)
checksum = (checksum & 0xFFFF) + (checksum >> 16);
return (UINT16) (~checksum);
}
int WLog_PacketMessage_Write_IPv4Header(wPcap* pcap, wIPv4Header* ipv4)
@ -260,13 +277,13 @@ int WLog_PacketMessage_Write_IPv4Header(wPcap* pcap, wIPv4Header* ipv4)
Stream_Write_UINT16_BE(s, (ipv4->InternetProtocolFlags << 13) | ipv4->FragmentOffset);
Stream_Write_UINT8(s, ipv4->TimeToLive);
Stream_Write_UINT8(s, ipv4->Protocol);
Stream_Write_UINT16_BE(s, ipv4->HeaderChecksum);
Stream_Write_UINT16(s, ipv4->HeaderChecksum);
Stream_Write_UINT32_BE(s, ipv4->SourceAddress);
Stream_Write_UINT32_BE(s, ipv4->DestinationAddress);
ipv4->HeaderChecksum = IPv4Checksum((BYTE*) buffer, 20);
Stream_Rewind(s, 10);
Stream_Write_UINT16_BE(s, ipv4->HeaderChecksum);
Stream_Write_UINT16(s, ipv4->HeaderChecksum);
Stream_Seek(s, 8);
fwrite(buffer, 20, 1, pcap->fp);
@ -300,6 +317,9 @@ int WLog_PacketMessage_Write_TcpHeader(wPcap* pcap, wTcpHeader* tcp)
return 0;
}
static UINT32 g_InboundSequenceNumber = 0;
static UINT32 g_OutboundSequenceNumber = 0;
int WLog_PacketMessage_Write(wPcap* pcap, void* data, DWORD length, DWORD flags)
{
wTcpHeader tcp;
@ -371,12 +391,24 @@ int WLog_PacketMessage_Write(wPcap* pcap, void* data, DWORD length, DWORD flags)
tcp.SourcePort = 3389;
tcp.DestinationPort = 3389;
tcp.SequenceNumber = 0;
tcp.AcknowledgementNumber = 0;
if (flags & WLOG_PACKET_OUTBOUND)
{
tcp.SequenceNumber = g_OutboundSequenceNumber;
tcp.AcknowledgementNumber = g_InboundSequenceNumber;
g_OutboundSequenceNumber += length;
}
else
{
tcp.SequenceNumber = g_InboundSequenceNumber;
tcp.AcknowledgementNumber = g_OutboundSequenceNumber;
g_InboundSequenceNumber += length;
}
tcp.Offset = 5;
tcp.Reserved = 0;
tcp.TcpFlags = 0;
tcp.Window = 0xFFFF;
tcp.TcpFlags = 0x0018;
tcp.Window = 0x7FFF;
tcp.Checksum = 0;
tcp.UrgentPointer = 0;