pjlib/src/pj/ip_helper_win32.c - pjproject - Gitiles

 /* $Id$ */
 /*
  * Copyright (C)2003-2007 Benny Prijono <benny@prijono.org>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 #include <pj/config.h>

 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>

 /* PMIB_ICMP_EX is not declared in VC6, causing error.
  * But EVC4, which also claims to be VC6, does have it!
  */
 #if defined(_MSC_VER) && _MSC_VER==1200 && !defined(PJ_WIN32_WINCE)
 #   define PMIB_ICMP_EX void*
 #endif
 #include <winsock2.h>

 /* If you encounter error "Cannot open include file: 'Iphlpapi.h' here,
  * you need to install newer Platform SDK. Presumably you're using
  * Microsoft Visual Studio 6?
  */
 #include <Iphlpapi.h>

 #include <pj/ip_helper.h>
 #include <pj/assert.h>
 #include <pj/errno.h>
 #include <pj/string.h>

 #ifndef PJ_IP_HELPER_IGNORE_LOOPBACK_IF
 #   define PJ_IP_HELPER_IGNORE_LOOPBACK_IF	1
 #endif

 typedef DWORD (WINAPI *PFN_GetIpAddrTable)(PMIB_IPADDRTABLE pIpAddrTable,
 					   PULONG pdwSize,
 					   BOOL bOrder);
 #if defined(PJ_HAS_IPV6) && PJ_HAS_IPV6!=0
 typedef DWORD (WINAPI *PFN_GetAdapterAddresses)(ULONG Family,
 					        ULONG Flags,
 					        PVOID Reserved,
 					        PIP_ADAPTER_ADDRESSES AdapterAddresses,
 					        PULONG SizePointer);
 #endif	/* PJ_HAS_IPV6 */
 typedef DWORD (WINAPI *PFN_GetIpForwardTable)(PMIB_IPFORWARDTABLE pIpForwardTable,
 					      PULONG pdwSize,
 					      BOOL bOrder);
 typedef DWORD (WINAPI *PFN_GetIfEntry)(PMIB_IFROW pIfRow);

 static HANDLE s_hDLL;
 static PFN_GetIpAddrTable s_pfnGetIpAddrTable;
 #if defined(PJ_HAS_IPV6) && PJ_HAS_IPV6!=0
     static PFN_GetAdapterAddresses s_pfnGetAdapterAddresses;
 #endif	/* PJ_HAS_IPV6 */
 static PFN_GetIpForwardTable s_pfnGetIpForwardTable;
 static PFN_GetIfEntry s_pfnGetIfEntry;


 static void unload_iphlp_module(void)
 {
     FreeLibrary(s_hDLL);
     s_hDLL = NULL;
     s_pfnGetIpAddrTable = NULL;
     s_pfnGetIpForwardTable = NULL;
     s_pfnGetIfEntry = NULL;
 #if defined(PJ_HAS_IPV6) && PJ_HAS_IPV6!=0
     s_pfnGetAdapterAddresses = NULL;
 #endif
 }

 static FARPROC GetIpHlpApiProc(pj_char_t *lpProcName)
 {
     if(NULL == s_hDLL) {
 	s_hDLL = LoadLibrary(PJ_T("IpHlpApi"));
 	if(NULL != s_hDLL) {
 	    pj_atexit(&unload_iphlp_module);
 	}
     }

     if(NULL != s_hDLL)
 	return GetProcAddress(s_hDLL, lpProcName);

     return NULL;
 }

 static DWORD MyGetIpAddrTable(PMIB_IPADDRTABLE pIpAddrTable,
 			      PULONG pdwSize,
 			      BOOL bOrder)
 {
     if(NULL == s_pfnGetIpAddrTable) {
 	s_pfnGetIpAddrTable = (PFN_GetIpAddrTable)
 	    GetIpHlpApiProc(PJ_T("GetIpAddrTable"));
     }

     if(NULL != s_pfnGetIpAddrTable) {
 	return s_pfnGetIpAddrTable(pIpAddrTable, pdwSize, bOrder);
     }

     return ERROR_NOT_SUPPORTED;
 }

 #if defined(PJ_HAS_IPV6) && PJ_HAS_IPV6!=0
 static DWORD MyGetAdapterAddresses(ULONG Family,
 				   ULONG Flags,
 				   PVOID Reserved,
 				   PIP_ADAPTER_ADDRESSES AdapterAddresses,
 				   PULONG SizePointer)
 {
     if(NULL == s_pfnGetAdapterAddresses) {
 	s_pfnGetAdapterAddresses = (PFN_GetAdapterAddresses)
 	    GetIpHlpApiProc(PJ_T("GetAdapterAddresses"));
     }

     if(NULL != s_pfnGetAdapterAddresses) {
 	return s_pfnGetAdapterAddresses(Family, Flags, Reserved,
 					AdapterAddresses, SizePointer);
     }

     return ERROR_NOT_SUPPORTED;
 }
 #endif	/* PJ_HAS_IPV6 */

 #if PJ_IP_HELPER_IGNORE_LOOPBACK_IF
 static DWORD MyGetIfEntry(MIB_IFROW *pIfRow)
 {
     if(NULL == s_pfnGetIfEntry) {
 	s_pfnGetIfEntry = (PFN_GetIfEntry)
 	    GetIpHlpApiProc(PJ_T("GetIfEntry"));
     }

     if(NULL != s_pfnGetIfEntry) {
 	return s_pfnGetIfEntry(pIfRow);
     }

     return ERROR_NOT_SUPPORTED;
 }
 #endif


 static DWORD MyGetIpForwardTable(PMIB_IPFORWARDTABLE pIpForwardTable,
 				 PULONG pdwSize,
 				 BOOL bOrder)
 {
     if(NULL == s_pfnGetIpForwardTable) {
 	s_pfnGetIpForwardTable = (PFN_GetIpForwardTable)
 	    GetIpHlpApiProc(PJ_T("GetIpForwardTable"));
     }

     if(NULL != s_pfnGetIpForwardTable) {
 	return s_pfnGetIpForwardTable(pIpForwardTable, pdwSize, bOrder);
     }

     return ERROR_NOT_SUPPORTED;
 }

 /* Enumerate local IP interface using GetIpAddrTable()
  * for IPv4 addresses only.
  */
 static pj_status_t enum_ipv4_interface(unsigned *p_cnt,
 				       pj_sockaddr ifs[])
 {
     /* Provide enough buffer or otherwise it will fail with
      * error 22 ("Not Enough Buffer") error.
      */
     char ipTabBuff[1024];
     MIB_IPADDRTABLE *pTab;
     ULONG tabSize;
     unsigned i, count;
     DWORD rc = NO_ERROR;

     PJ_ASSERT_RETURN(p_cnt && ifs, PJ_EINVAL);

     pTab = (MIB_IPADDRTABLE*)ipTabBuff;

     /* Get IP address table */
     tabSize = sizeof(ipTabBuff);

     rc = MyGetIpAddrTable(pTab, &tabSize, FALSE);
     if (rc != NO_ERROR)
 	return PJ_RETURN_OS_ERROR(rc);

     /* Reset result */
     pj_bzero(ifs, sizeof(ifs[0]) * (*p_cnt));

     /* Now fill out the entries */
     count = (pTab->dwNumEntries < *p_cnt) ? pTab->dwNumEntries : *p_cnt;
     *p_cnt = 0;
     for (i=0; i<count; ++i) {
 	MIB_IFROW ifRow;

 	/* Ignore 0.0.0.0 address (interface is down?) */
 	if (pTab->table[i].dwAddr == 0)
 	    continue;

 #if PJ_IP_HELPER_IGNORE_LOOPBACK_IF
 	/* Investigate the type of this interface */
 	pj_bzero(&ifRow, sizeof(ifRow));
 	ifRow.dwIndex = pTab->table[i].dwIndex;
 	if (MyGetIfEntry(&ifRow) != 0)
 	    continue;

 	if (ifRow.dwType == MIB_IF_TYPE_LOOPBACK)
 	    continue;
 #endif

 	ifs[*p_cnt].ipv4.sin_family = PJ_AF_INET;
 	ifs[*p_cnt].ipv4.sin_addr.s_addr = pTab->table[i].dwAddr;
 	(*p_cnt)++;
     }

     return PJ_SUCCESS;
 }


 /* Enumerate local IP interface using GetAdapterAddresses(),
  * which works for both IPv4 and IPv6.
  */
 #if defined(PJ_HAS_IPV6) && PJ_HAS_IPV6!=0
 static pj_status_t enum_ipv4_ipv6_interface(int af,
 					    unsigned *p_cnt,
 					    pj_sockaddr ifs[])
 {
     pj_uint8_t buffer[1024];
     IP_ADAPTER_ADDRESSES *adapter = (IP_ADAPTER_ADDRESSES*)buffer;
     ULONG size = sizeof(buffer);
     unsigned i;
     DWORD rc;

     rc = MyGetAdapterAddresses(af, 0, NULL, adapter, &size);
     if (rc != ERROR_SUCCESS)
 	return PJ_RETURN_OS_ERROR(rc);

     for (i=0; i<*p_cnt && adapter; ++i, adapter = adapter->Next) {
 	SOCKET_ADDRESS *pAddr = &adapter->FirstUnicastAddress->Address;
 	ifs[i].addr.sa_family = pAddr->lpSockaddr->sa_family;
 	pj_memcpy(&ifs[i], pAddr->lpSockaddr, pAddr->iSockaddrLength);
     }

     return PJ_SUCCESS;
 }
 #endif


 /*
  * Enumerate the local IP interface currently active in the host.
  */
 PJ_DEF(pj_status_t) pj_enum_ip_interface(int af,
 					 unsigned *p_cnt,
 					 pj_sockaddr ifs[])
 {
     pj_status_t status = -1;

     PJ_ASSERT_RETURN(p_cnt && ifs, PJ_EINVAL);
     PJ_ASSERT_RETURN(af==PJ_AF_UNSPEC || af==PJ_AF_INET || af==PJ_AF_INET6,
 		     PJ_EAFNOTSUP);

 #if defined(PJ_HAS_IPV6) && PJ_HAS_IPV6!=0
     status = enum_ipv4_ipv6_interface(af, p_cnt, ifs);
     if (status != PJ_SUCCESS && (af==PJ_AF_INET || af==PJ_AF_UNSPEC))
 	status = enum_ipv4_interface(p_cnt, ifs);
     return status;
 #else
     if (af==PJ_AF_INET6)
 	return PJ_EIPV6NOTSUP;
     else if (af != PJ_AF_INET && af != PJ_AF_UNSPEC)
 	return PJ_EAFNOTSUP;

     status = enum_ipv4_interface(p_cnt, ifs);
     return status;
 #endif
 }

 /*
  * Enumerate the IP routing table for this host.
  */
 PJ_DEF(pj_status_t) pj_enum_ip_route(unsigned *p_cnt,
 				     pj_ip_route_entry routes[])
 {
     char ipTabBuff[1024];
     MIB_IPADDRTABLE *pIpTab;
     char rtabBuff[1024];
     MIB_IPFORWARDTABLE *prTab;
     ULONG tabSize;
     unsigned i, count;
     DWORD rc = NO_ERROR;

     PJ_ASSERT_RETURN(p_cnt && routes, PJ_EINVAL);

     pIpTab = (MIB_IPADDRTABLE *)ipTabBuff;
     prTab = (MIB_IPFORWARDTABLE *)rtabBuff;

     /* First get IP address table */
     tabSize = sizeof(ipTabBuff);
     rc = MyGetIpAddrTable(pIpTab, &tabSize, FALSE);
     if (rc != NO_ERROR)
 	return PJ_RETURN_OS_ERROR(rc);

     /* Next get IP route table */
     tabSize = sizeof(rtabBuff);

     rc = MyGetIpForwardTable(prTab, &tabSize, 1);
     if (rc != NO_ERROR)
 	return PJ_RETURN_OS_ERROR(rc);

     /* Reset routes */
     pj_bzero(routes, sizeof(routes[0]) * (*p_cnt));

     /* Now fill out the route entries */
     count = (prTab->dwNumEntries < *p_cnt) ? prTab->dwNumEntries : *p_cnt;
     *p_cnt = 0;
     for (i=0; i<count; ++i) {
 	unsigned j;

 	/* Find interface entry */
 	for (j=0; j<pIpTab->dwNumEntries; ++j) {
 	    if (pIpTab->table[j].dwIndex == prTab->table[i].dwForwardIfIndex)
 		break;
 	}

 	if (j==pIpTab->dwNumEntries)
 	    continue;	/* Interface not found */

 	routes[*p_cnt].ipv4.if_addr.s_addr = pIpTab->table[j].dwAddr;
 	routes[*p_cnt].ipv4.dst_addr.s_addr = prTab->table[i].dwForwardDest;
 	routes[*p_cnt].ipv4.mask.s_addr = prTab->table[i].dwForwardMask;

 	(*p_cnt)++;
     }

     return PJ_SUCCESS;
 }
	/* $Id$ */
	/*
	* Copyright (C)2003-2007 Benny Prijono <benny@prijono.org>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*/
	#include <pj/config.h>

	#define WIN32_LEAN_AND_MEAN
	#include <windows.h>

	/* PMIB_ICMP_EX is not declared in VC6, causing error.
	* But EVC4, which also claims to be VC6, does have it!
	*/
	#if defined(_MSC_VER) && _MSC_VER==1200 && !defined(PJ_WIN32_WINCE)
	# define PMIB_ICMP_EX void*
	#endif
	#include <winsock2.h>

	/* If you encounter error "Cannot open include file: 'Iphlpapi.h' here,
	* you need to install newer Platform SDK. Presumably you're using
	* Microsoft Visual Studio 6?
	*/
	#include <Iphlpapi.h>

	#include <pj/ip_helper.h>
	#include <pj/assert.h>
	#include <pj/errno.h>
	#include <pj/string.h>

	#ifndef PJ_IP_HELPER_IGNORE_LOOPBACK_IF
	# define PJ_IP_HELPER_IGNORE_LOOPBACK_IF 1
	#endif

	typedef DWORD (WINAPI *PFN_GetIpAddrTable)(PMIB_IPADDRTABLE pIpAddrTable,
	PULONG pdwSize,
	BOOL bOrder);
	#if defined(PJ_HAS_IPV6) && PJ_HAS_IPV6!=0
	typedef DWORD (WINAPI *PFN_GetAdapterAddresses)(ULONG Family,
	ULONG Flags,
	PVOID Reserved,
	PIP_ADAPTER_ADDRESSES AdapterAddresses,
	PULONG SizePointer);
	#endif /* PJ_HAS_IPV6 */
	typedef DWORD (WINAPI *PFN_GetIpForwardTable)(PMIB_IPFORWARDTABLE pIpForwardTable,
	PULONG pdwSize,
	BOOL bOrder);
	typedef DWORD (WINAPI *PFN_GetIfEntry)(PMIB_IFROW pIfRow);

	static HANDLE s_hDLL;
	static PFN_GetIpAddrTable s_pfnGetIpAddrTable;
	#if defined(PJ_HAS_IPV6) && PJ_HAS_IPV6!=0
	static PFN_GetAdapterAddresses s_pfnGetAdapterAddresses;
	#endif /* PJ_HAS_IPV6 */
	static PFN_GetIpForwardTable s_pfnGetIpForwardTable;
	static PFN_GetIfEntry s_pfnGetIfEntry;


	static void unload_iphlp_module(void)
	{
	FreeLibrary(s_hDLL);
	s_hDLL = NULL;
	s_pfnGetIpAddrTable = NULL;
	s_pfnGetIpForwardTable = NULL;
	s_pfnGetIfEntry = NULL;
	#if defined(PJ_HAS_IPV6) && PJ_HAS_IPV6!=0
	s_pfnGetAdapterAddresses = NULL;
	#endif
	}

	static FARPROC GetIpHlpApiProc(pj_char_t *lpProcName)
	{
	if(NULL == s_hDLL) {
	s_hDLL = LoadLibrary(PJ_T("IpHlpApi"));
	if(NULL != s_hDLL) {
	pj_atexit(&unload_iphlp_module);
	}
	}

	if(NULL != s_hDLL)
	return GetProcAddress(s_hDLL, lpProcName);

	return NULL;
	}

	static DWORD MyGetIpAddrTable(PMIB_IPADDRTABLE pIpAddrTable,
	PULONG pdwSize,
	BOOL bOrder)
	{
	if(NULL == s_pfnGetIpAddrTable) {
	s_pfnGetIpAddrTable = (PFN_GetIpAddrTable)
	GetIpHlpApiProc(PJ_T("GetIpAddrTable"));
	}

	if(NULL != s_pfnGetIpAddrTable) {
	return s_pfnGetIpAddrTable(pIpAddrTable, pdwSize, bOrder);
	}

	return ERROR_NOT_SUPPORTED;
	}

	#if defined(PJ_HAS_IPV6) && PJ_HAS_IPV6!=0
	static DWORD MyGetAdapterAddresses(ULONG Family,
	ULONG Flags,
	PVOID Reserved,
	PIP_ADAPTER_ADDRESSES AdapterAddresses,
	PULONG SizePointer)
	{
	if(NULL == s_pfnGetAdapterAddresses) {
	s_pfnGetAdapterAddresses = (PFN_GetAdapterAddresses)
	GetIpHlpApiProc(PJ_T("GetAdapterAddresses"));
	}

	if(NULL != s_pfnGetAdapterAddresses) {
	return s_pfnGetAdapterAddresses(Family, Flags, Reserved,
	AdapterAddresses, SizePointer);
	}

	return ERROR_NOT_SUPPORTED;
	}
	#endif /* PJ_HAS_IPV6 */

	#if PJ_IP_HELPER_IGNORE_LOOPBACK_IF
	static DWORD MyGetIfEntry(MIB_IFROW *pIfRow)
	{
	if(NULL == s_pfnGetIfEntry) {
	s_pfnGetIfEntry = (PFN_GetIfEntry)
	GetIpHlpApiProc(PJ_T("GetIfEntry"));
	}

	if(NULL != s_pfnGetIfEntry) {
	return s_pfnGetIfEntry(pIfRow);
	}

	return ERROR_NOT_SUPPORTED;
	}
	#endif


	static DWORD MyGetIpForwardTable(PMIB_IPFORWARDTABLE pIpForwardTable,
	PULONG pdwSize,
	BOOL bOrder)
	{
	if(NULL == s_pfnGetIpForwardTable) {
	s_pfnGetIpForwardTable = (PFN_GetIpForwardTable)
	GetIpHlpApiProc(PJ_T("GetIpForwardTable"));
	}

	if(NULL != s_pfnGetIpForwardTable) {
	return s_pfnGetIpForwardTable(pIpForwardTable, pdwSize, bOrder);
	}

	return ERROR_NOT_SUPPORTED;
	}

	/* Enumerate local IP interface using GetIpAddrTable()
	* for IPv4 addresses only.
	*/
	static pj_status_t enum_ipv4_interface(unsigned *p_cnt,
	pj_sockaddr ifs[])
	{
	/* Provide enough buffer or otherwise it will fail with
	* error 22 ("Not Enough Buffer") error.
	*/
	char ipTabBuff[1024];
	MIB_IPADDRTABLE *pTab;
	ULONG tabSize;
	unsigned i, count;
	DWORD rc = NO_ERROR;

	PJ_ASSERT_RETURN(p_cnt && ifs, PJ_EINVAL);

	pTab = (MIB_IPADDRTABLE*)ipTabBuff;

	/* Get IP address table */
	tabSize = sizeof(ipTabBuff);

	rc = MyGetIpAddrTable(pTab, &tabSize, FALSE);
	if (rc != NO_ERROR)
	return PJ_RETURN_OS_ERROR(rc);

	/* Reset result */
	pj_bzero(ifs, sizeof(ifs[0]) * (*p_cnt));

	/* Now fill out the entries */
	count = (pTab->dwNumEntries < p_cnt) ? pTab->dwNumEntries : p_cnt;
	*p_cnt = 0;
	for (i=0; i<count; ++i) {
	MIB_IFROW ifRow;

	/* Ignore 0.0.0.0 address (interface is down?) */
	if (pTab->table[i].dwAddr == 0)
	continue;

	#if PJ_IP_HELPER_IGNORE_LOOPBACK_IF
	/* Investigate the type of this interface */
	pj_bzero(&ifRow, sizeof(ifRow));
	ifRow.dwIndex = pTab->table[i].dwIndex;
	if (MyGetIfEntry(&ifRow) != 0)
	continue;

	if (ifRow.dwType == MIB_IF_TYPE_LOOPBACK)
	continue;
	#endif

	ifs[*p_cnt].ipv4.sin_family = PJ_AF_INET;
	ifs[*p_cnt].ipv4.sin_addr.s_addr = pTab->table[i].dwAddr;
	(*p_cnt)++;
	}

	return PJ_SUCCESS;
	}


	/* Enumerate local IP interface using GetAdapterAddresses(),
	* which works for both IPv4 and IPv6.
	*/
	#if defined(PJ_HAS_IPV6) && PJ_HAS_IPV6!=0
	static pj_status_t enum_ipv4_ipv6_interface(int af,
	unsigned *p_cnt,
	pj_sockaddr ifs[])
	{
	pj_uint8_t buffer[1024];
	IP_ADAPTER_ADDRESSES adapter = (IP_ADAPTER_ADDRESSES)buffer;
	ULONG size = sizeof(buffer);
	unsigned i;
	DWORD rc;

	rc = MyGetAdapterAddresses(af, 0, NULL, adapter, &size);
	if (rc != ERROR_SUCCESS)
	return PJ_RETURN_OS_ERROR(rc);

	for (i=0; i<*p_cnt && adapter; ++i, adapter = adapter->Next) {
	SOCKET_ADDRESS *pAddr = &adapter->FirstUnicastAddress->Address;
	ifs[i].addr.sa_family = pAddr->lpSockaddr->sa_family;
	pj_memcpy(&ifs[i], pAddr->lpSockaddr, pAddr->iSockaddrLength);
	}

	return PJ_SUCCESS;
	}
	#endif


	/*
	* Enumerate the local IP interface currently active in the host.
	*/
	PJ_DEF(pj_status_t) pj_enum_ip_interface(int af,
	unsigned *p_cnt,
	pj_sockaddr ifs[])
	{
	pj_status_t status = -1;

	PJ_ASSERT_RETURN(p_cnt && ifs, PJ_EINVAL);
	PJ_ASSERT_RETURN(af==PJ_AF_UNSPEC \|\| af==PJ_AF_INET \|\| af==PJ_AF_INET6,
	PJ_EAFNOTSUP);

	#if defined(PJ_HAS_IPV6) && PJ_HAS_IPV6!=0
	status = enum_ipv4_ipv6_interface(af, p_cnt, ifs);
	if (status != PJ_SUCCESS && (af==PJ_AF_INET \|\| af==PJ_AF_UNSPEC))
	status = enum_ipv4_interface(p_cnt, ifs);
	return status;
	#else
	if (af==PJ_AF_INET6)
	return PJ_EIPV6NOTSUP;
	else if (af != PJ_AF_INET && af != PJ_AF_UNSPEC)
	return PJ_EAFNOTSUP;

	status = enum_ipv4_interface(p_cnt, ifs);
	return status;
	#endif
	}

	/*
	* Enumerate the IP routing table for this host.
	*/
	PJ_DEF(pj_status_t) pj_enum_ip_route(unsigned *p_cnt,
	pj_ip_route_entry routes[])
	{
	char ipTabBuff[1024];
	MIB_IPADDRTABLE *pIpTab;
	char rtabBuff[1024];
	MIB_IPFORWARDTABLE *prTab;
	ULONG tabSize;
	unsigned i, count;
	DWORD rc = NO_ERROR;

	PJ_ASSERT_RETURN(p_cnt && routes, PJ_EINVAL);

	pIpTab = (MIB_IPADDRTABLE *)ipTabBuff;
	prTab = (MIB_IPFORWARDTABLE *)rtabBuff;

	/* First get IP address table */
	tabSize = sizeof(ipTabBuff);
	rc = MyGetIpAddrTable(pIpTab, &tabSize, FALSE);
	if (rc != NO_ERROR)
	return PJ_RETURN_OS_ERROR(rc);

	/* Next get IP route table */
	tabSize = sizeof(rtabBuff);

	rc = MyGetIpForwardTable(prTab, &tabSize, 1);
	if (rc != NO_ERROR)
	return PJ_RETURN_OS_ERROR(rc);

	/* Reset routes */
	pj_bzero(routes, sizeof(routes[0]) * (*p_cnt));

	/* Now fill out the route entries */
	count = (prTab->dwNumEntries < p_cnt) ? prTab->dwNumEntries : p_cnt;
	*p_cnt = 0;
	for (i=0; i<count; ++i) {
	unsigned j;

	/* Find interface entry */
	for (j=0; j<pIpTab->dwNumEntries; ++j) {
	if (pIpTab->table[j].dwIndex == prTab->table[i].dwForwardIfIndex)
	break;
	}

	if (j==pIpTab->dwNumEntries)
	continue; /* Interface not found */

	routes[*p_cnt].ipv4.if_addr.s_addr = pIpTab->table[j].dwAddr;
	routes[*p_cnt].ipv4.dst_addr.s_addr = prTab->table[i].dwForwardDest;
	routes[*p_cnt].ipv4.mask.s_addr = prTab->table[i].dwForwardMask;

	(*p_cnt)++;
	}

	return PJ_SUCCESS;
	}