Proposed patch to getaddrinfo.c to support IPv6 on Windows

["Chuck McDevitt" <cmcdevitt(at)greenplum(dot)com>]

I'm proposing this change to /src/port/getaddrinfo.c to support IPv6
under windows.

 

10a11,14

>  * Windows may or may not have these routines, so we handle Windows
special

>  * by dynamically checking for their existence.  If they already
exist, we

>  * use the Windows native routines, but if not, we use our own.

>  *

31a36,121

> 

> #ifdef WIN32

> 

> #define WIN32_LEAN_AND_MEAN

> /* Bring in windows.h for LoadLibrary, FreeLibrary, and GetProcAddress
routines */

> #include <windows.h>

> 

> /* 

>  * The native routines may or may not exist on the Windows platform we
are on,

>  * so we dynamically look up the routines, and call them via function
pointers.

>  * Here we need to declare what the function pointers look like

>  */

> typedef

> int

> (__stdcall * getaddrinfo_ptr_t)(const char * nodename, const char *
servname,

>      const struct addrinfo * hints, struct addrinfo ** res);

> 

> typedef

> void

> (__stdcall * freeaddrinfo_ptr_t)(struct addrinfo * ai);

> 

> typedef

> int

> (__stdcall * getnameinfo_ptr_t)(const struct sockaddr * sa, int salen,

>      char *  host, int hostlen, char * serv, int servlen, int flags);

> 

> /* static pointers to the native Windows IPv6 routines, so we only do
the lookup once. */

> static getaddrinfo_ptr_t getaddrinfo_ptr = NULL;

> static freeaddrinfo_ptr_t freeaddrinfo_ptr = NULL;

> static getnameinfo_ptr_t getnameinfo_ptr = NULL;

> 

> static

> bool haveNativeWindowsIPv6routines(void)

> {

>     void * hLibrary  = NULL;

>     static bool  alreadyLookedForIpv6routines    = FALSE;

>    

>     if (alreadyLookedForIpv6routines)            

>         return (getaddrinfo_ptr != NULL);

> 

>     /* 

>      * For Windows XP and Windows 2003 (and longhorn/vista), the IPv6

>      * routines are present the WinSock 2 library (ws2_32.dll).  Try
that first

>      */

> 

>     hLibrary = LoadLibraryA("ws2_32");

> 

>     if (hLibrary == NULL || GetProcAddress(hLibrary, "getaddrinfo") ==
NULL)

>     {

>           /* Well, ws2_32 doesn't exist, or more likely doesn't have
getaddrinfo. */

>           if (hLibrary != NULL)

>                 FreeLibrary(hLibrary);

> 

>           /* In Windows 2000, there was only the IPv6 Technology
Preview        

>            * look in the IPv6 WinSock library (wship6.dll).

>            */

> 

>           hLibrary = LoadLibraryA("wship6");

>     }

> 

>     /* If hLibrary is null, we couldn't find a dll that supports the
functions */

>     if (hLibrary != NULL)

>     {

>           /* We found a dll, so now get the addresses of the routines
*/

> 

>         getaddrinfo_ptr = GetProcAddress(hLibrary, "getaddrinfo");

>           freeaddrinfo_ptr = GetProcAddress(hLibrary, "freeaddrinfo");

>           getnameinfo_ptr = GetProcAddress(hLibrary, "getnameinfo");

> 

>           /* If any one of the routines is missing, let's play it safe
and ignore them all */

>         if (getaddrinfo_ptr == NULL || freeaddrinfo_ptr == NULL ||
getnameinfo_ptr == NULL)

>         {

>             FreeLibrary(hLibrary);

>             hLibrary = NULL;

>                 getaddrinfo_ptr = NULL;

>                 freeaddrinfo_ptr = NULL;

>                 getnameinfo_ptr = NULL;

>         }

>     }

>         

>     alreadyLookedForIpv6routines = TRUE;

>     return (getaddrinfo_ptr != NULL); 

> }

> #endif 

> 

> 

49a140,148

> #ifdef WIN32

>     /* 

>      * If Windows has native IPv6 support, use the native Windows
routine.

>      * Otherwise, fall through and use our own code.

>      */

>     if (haveNativeWindowsIPv6routines())

>           return (*getaddrinfo_ptr)(node,service,hintp,res);

> #endif

> 

162a262,272

> #ifdef WIN32

>           /* 

>            * If Windows has native IPv6 support, use the native
Windows routine.

>            * Otherwise, fall through and use our own code.

>            */

>           if (haveNativeWindowsIPv6routines())

>           {

>                 (*freeaddrinfo_ptr)(node,service,hintp,res);

>                 return;

>           }

> #endif

218a329,338

> 

> #ifdef WIN32

>     /* 

>      * If Windows has native IPv6 support, use the native Windows
routine.

>      * Otherwise, fall through and use our own code.

>      */

>     if (haveNativeWindowsIPv6routines())

>           return
(*getnameinfo_ptr)(sa,salen,node,nodelen,service,servicelen,flags);

> #endif

>

Attachment: getaddrinfo.patch
Description: getaddrinfo.patch