mirror of https://github.com/tongzx/nt5src
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
233 lines
5.8 KiB
233 lines
5.8 KiB
/*++
|
|
|
|
Copyright(c) 1998,99 Microsoft Corporation
|
|
|
|
Module Name:
|
|
|
|
tcpip.c
|
|
|
|
Abstract:
|
|
|
|
Windows Load Balancing Service (WLBS)
|
|
Driver - IP/TCP/UDP support
|
|
|
|
Author:
|
|
|
|
kyrilf
|
|
|
|
--*/
|
|
|
|
#include <ndis.h>
|
|
|
|
#include "wlbsip.h"
|
|
#include "univ.h"
|
|
#include "wlbsparm.h"
|
|
#include "params.h"
|
|
#include "log.h"
|
|
|
|
|
|
/* GLOBALS */
|
|
|
|
|
|
static ULONG log_module_id = LOG_MODULE_TCPIP;
|
|
|
|
/* constant encoded shadow computer name that will replace our cluster name */
|
|
|
|
static UCHAR nbt_encoded_shadow_name [NBT_ENCODED_NAME_LEN] =
|
|
NBT_ENCODED_NAME_SHADOW;
|
|
|
|
|
|
/* PROCEDURES */
|
|
|
|
|
|
BOOLEAN Tcpip_init (
|
|
PTCPIP_CTXT ctxtp,
|
|
PVOID parameters)
|
|
{
|
|
ULONG i, j;
|
|
PCVY_PARAMS params = (PCVY_PARAMS) parameters;
|
|
|
|
|
|
/* extract cluster computer name from full internet name */
|
|
|
|
j = 0;
|
|
|
|
while (params -> domain_name [j] != 0)
|
|
{
|
|
if (params -> domain_name [j] == L'.' ||
|
|
params -> domain_name [j] == 0)
|
|
break;
|
|
|
|
j ++;
|
|
}
|
|
|
|
/* build encoded cluster computer name for checking against arriving NBT
|
|
session requests */
|
|
|
|
for (i = 0; i < NBT_NAME_LEN; i ++)
|
|
{
|
|
if (i >= j)
|
|
{
|
|
ctxtp -> nbt_encoded_cluster_name [2 * i] =
|
|
NBT_ENCODE_FIRST (' ');
|
|
ctxtp -> nbt_encoded_cluster_name [2 * i + 1] =
|
|
NBT_ENCODE_SECOND (' ');
|
|
}
|
|
else
|
|
{
|
|
ctxtp -> nbt_encoded_cluster_name [2 * i] =
|
|
NBT_ENCODE_FIRST (toupper ((UCHAR) (params -> domain_name [i])));
|
|
ctxtp -> nbt_encoded_cluster_name [2 * i + 1] =
|
|
NBT_ENCODE_SECOND (toupper ((UCHAR) (params -> domain_name [i])));
|
|
}
|
|
}
|
|
|
|
return TRUE;
|
|
|
|
} /* Tcpip_init */
|
|
|
|
|
|
VOID Tcpip_nbt_handle (
|
|
PTCPIP_CTXT ctxtp,
|
|
PIP_HDR ip_hdrp,
|
|
PTCP_HDR tcp_hdrp,
|
|
ULONG len,
|
|
PNBT_HDR nbt_hdrp)
|
|
{
|
|
PUCHAR called_name;
|
|
ULONG i;
|
|
|
|
|
|
/* if this is an NBT session request packet, check to see if it's calling
|
|
the cluster machine name, which should be replaced with the shadow name */
|
|
|
|
if (len >= sizeof (NBT_HDR) &&
|
|
NBT_GET_PKT_TYPE (nbt_hdrp) == NBT_SESSION_REQUEST)
|
|
{
|
|
/* pass the field length byte - assume all names are
|
|
NBT_ENCODED_NAME_LEN bytes long */
|
|
|
|
called_name = NBT_GET_CALLED_NAME (nbt_hdrp) + 1;
|
|
|
|
/* match called name to cluster name */
|
|
|
|
for (i = 0; i < NBT_ENCODED_NAME_LEN; i ++)
|
|
{
|
|
if (called_name [i] != ctxtp -> nbt_encoded_cluster_name [i])
|
|
break;
|
|
}
|
|
|
|
/* replace cluster computer name with the shadom name */
|
|
|
|
if (i >= NBT_ENCODED_NAME_LEN)
|
|
{
|
|
USHORT checksum;
|
|
|
|
|
|
for (i = 0; i < NBT_ENCODED_NAME_LEN; i ++)
|
|
called_name [i] = nbt_encoded_shadow_name [i];
|
|
|
|
/* re-compute checksum */
|
|
|
|
checksum = Tcpip_chksum (ctxtp, ip_hdrp, (PUCHAR) tcp_hdrp,
|
|
TCPIP_PROTOCOL_TCP);
|
|
TCP_SET_CHKSUM (tcp_hdrp, checksum);
|
|
}
|
|
}
|
|
|
|
} /* end Tcpip_nbt_handle */
|
|
|
|
|
|
USHORT Tcpip_chksum (
|
|
PTCPIP_CTXT ctxtp,
|
|
PIP_HDR ip_hdrp,
|
|
PUCHAR prot_hdrp,
|
|
ULONG prot)
|
|
{
|
|
ULONG checksum = 0, i, len;
|
|
PUCHAR ptr;
|
|
USHORT original, tmp;
|
|
|
|
|
|
/* preserve original checksum */
|
|
|
|
if (prot == TCPIP_PROTOCOL_TCP)
|
|
{
|
|
original = TCP_GET_CHKSUM ((PTCP_HDR) prot_hdrp);
|
|
TCP_SET_CHKSUM ((PTCP_HDR) prot_hdrp, 0);
|
|
}
|
|
else if (prot == TCPIP_PROTOCOL_UDP)
|
|
{
|
|
original = UDP_GET_CHKSUM ((PUDP_HDR) prot_hdrp);
|
|
UDP_SET_CHKSUM ((PUDP_HDR) prot_hdrp, 0);
|
|
}
|
|
else
|
|
{
|
|
original = IP_GET_CHKSUM (ip_hdrp);
|
|
IP_SET_CHKSUM (ip_hdrp, 0);
|
|
}
|
|
|
|
/* computer appropriate checksum for specified protocol */
|
|
|
|
if (prot != TCPIP_PROTOCOL_IP)
|
|
{
|
|
/* checksum in computed over the source IP address, destination IP address,
|
|
protocol (6 for TCP), TCP segment length value and entire TCP segment
|
|
(setting checksum field within TCP header to 0). code is taken from
|
|
page 185 of "Internetworking with TCP/IP: Volume II" by
|
|
Comer/Stevens, 1991 */
|
|
|
|
ptr = (PUCHAR) IP_GET_SRC_ADDR_PTR (ip_hdrp);
|
|
|
|
/* 2*IP_ADDR_LEN bytes = IP_ADDR_LEN shorts */
|
|
|
|
for (i = 0; i < IP_ADDR_LEN; i ++, ptr += 2)
|
|
checksum += (ULONG) ((ptr [0] << 8) | ptr [1]);
|
|
}
|
|
|
|
if (prot == TCPIP_PROTOCOL_TCP)
|
|
{
|
|
len = IP_GET_PLEN (ip_hdrp) - IP_GET_HLEN (ip_hdrp) * sizeof (ULONG);
|
|
checksum += TCPIP_PROTOCOL_TCP + len;
|
|
ptr = prot_hdrp;
|
|
}
|
|
else if (prot == TCPIP_PROTOCOL_UDP)
|
|
{
|
|
len = IP_GET_PLEN (ip_hdrp) - IP_GET_HLEN (ip_hdrp) * sizeof (ULONG);
|
|
checksum += TCPIP_PROTOCOL_UDP + UDP_GET_LEN ((PUDP_HDR) prot_hdrp);
|
|
ptr = prot_hdrp;
|
|
}
|
|
else
|
|
{
|
|
len = IP_GET_HLEN (ip_hdrp) * sizeof (ULONG);
|
|
ptr = (PUCHAR) ip_hdrp;
|
|
prot_hdrp = (PUCHAR) ip_hdrp;
|
|
}
|
|
|
|
for (i = 0; i < len / 2; i ++, ptr += 2)
|
|
checksum += (ULONG) ((ptr [0] << 8) | ptr [1]);
|
|
|
|
if (len % 2)
|
|
checksum += (ULONG) (prot_hdrp [len - 1] << 8);
|
|
|
|
checksum = (checksum >> 16) + (checksum & 0xffff);
|
|
checksum += (checksum >> 16);
|
|
|
|
/* restore original checksum */
|
|
|
|
if (prot == TCPIP_PROTOCOL_TCP)
|
|
{
|
|
TCP_SET_CHKSUM ((PTCP_HDR) prot_hdrp, original);
|
|
}
|
|
else if (prot == TCPIP_PROTOCOL_UDP)
|
|
{
|
|
UDP_SET_CHKSUM ((PUDP_HDR) prot_hdrp, original);
|
|
}
|
|
else
|
|
{
|
|
IP_SET_CHKSUM (ip_hdrp, original);
|
|
}
|
|
|
|
return (USHORT) (~checksum & 0xffff);
|
|
|
|
} /* end Tcpip_chksum */
|