Re: getaddrinfo: finding gethostbyname in mingw32

[Simon Josefsson]

The follow patch make getaddrinfo work (it seems Windows has a
getaddrinfo implementation, although it doesn't have gai_strerror)
_except_ that applications need to initialize Windows' socket code
manually, by calling WSAStartup.  I'm not sure how to handle that.
One solution is to create gl_getaddrinfo which make sure WSAStartup is
called, and then invoke getaddrinfo.  But that forces all applications
to call gl_getaddrinfo rather than getaddrinfo.  That seem rather
ugly.  Ideas?

Unless there is a simple concrete solution to this, I'm inclined to
install the patch below and document that people using this module
will have to call WSAStartup manually, if that function exists in
-lws2_32.

PS. mingw32 doesn't have netdb.h either.  Perhaps something similar as
the sys_socket module should be done for it, to avoid the HAVE_NETDB_H
stuff.  I think ws2tcpip.h contain most of the useful definitions.

Index: m4/getaddrinfo.m4
===================================================================
RCS file: /sources/gnulib/gnulib/m4/getaddrinfo.m4,v
retrieving revision 1.12
diff -u -p -r1.12 getaddrinfo.m4
--- m4/getaddrinfo.m4   5 Oct 2005 21:41:31 -0000       1.12
+++ m4/getaddrinfo.m4   19 Jan 2006 15:25:33 -0000
@@ -1,36 +1,72 @@
 # getaddrinfo.m4 serial 7
-dnl Copyright (C) 2004, 2005 Free Software Foundation, Inc.
+dnl Copyright (C) 2004, 2005, 2006 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
 
 AC_DEFUN([gl_GETADDRINFO],
 [
+  AC_MSG_NOTICE([checking how to do getaddrinfo])
+
   AC_SEARCH_LIBS(getaddrinfo, [nsl socket])
-  AC_SEARCH_LIBS(gethostbyname, [inet nsl])
-  AC_SEARCH_LIBS(getservbyname, [inet nsl socket xnet])
-  AC_REPLACE_FUNCS(getaddrinfo gai_strerror)
+  AC_CHECK_FUNCS(getaddrinfo,, [
+    AC_CACHE_CHECK(for getaddrinfo in ws2tcpip.h and -lws2_32,
+                   gl_cv_w32_getaddrinfo, [
+      gl_cv_w32_getaddrinfo=no
+      am_save_LIBS="$LIBS"
+      LIBS="$LIBS -lws2_32"
+      AC_TRY_LINK([
+#define WINVER 0x0501
+#include <ws2tcpip.h>
+], [getaddrinfo(0, 0, 0, 0);], gl_cv_w32_getaddrinfo=yes)
+      LIBS="$am_save_LIBS"
+      if test "$gl_cv_w32_getaddrinfo" = "yes"; then
+        LIBS="$LIBS -lws2_32"
+      else
+        AC_LIBOBJ(getaddrinfo)
+      fi
+    ])])
+
+  AC_REPLACE_FUNCS(gai_strerror)
   gl_PREREQ_GETADDRINFO
 ])
 
 # Prerequisites of lib/getaddrinfo.h and lib/getaddrinfo.c.
 AC_DEFUN([gl_PREREQ_GETADDRINFO], [
+  AC_SEARCH_LIBS(gethostbyname, [inet nsl])
+  AC_SEARCH_LIBS(getservbyname, [inet nsl socket xnet])
   AC_REQUIRE([gl_C_RESTRICT])
   AC_REQUIRE([gl_SOCKET_FAMILIES])
   AC_REQUIRE([AC_C_INLINE])
   AC_REQUIRE([AC_GNU_SOURCE])
-  AC_CHECK_HEADERS_ONCE(netinet/in.h)
+  AC_CHECK_HEADERS_ONCE(netinet/in.h sys/socket.h netdb.h ws2tcpip.h)
   AC_CHECK_DECLS([getaddrinfo, freeaddrinfo, gai_strerror],,,[
   /* sys/types.h is not needed according to POSIX, but the
      sys/socket.h in i386-unknown-freebsd4.10 and
      powerpc-apple-darwin5.5 required it. */
 #include <sys/types.h>
+#ifdef HAVE_SYS_SOCKET_H
 #include <sys/socket.h>
+#endif
+#ifdef HAVE_NETDB_H
 #include <netdb.h>
+#endif
+#ifdef HAVE_WS2TCPIP_H
+#define WINVER 0x0501
+#include <ws2tcpip.h>
+#endif
 ])
   AC_CHECK_TYPES([struct addrinfo],,,[
 #include <sys/types.h>
+#ifdef HAVE_SYS_SOCKET_H
 #include <sys/socket.h>
+#endif
+#ifdef HAVE_NETDB_H
 #include <netdb.h>
+#endif
+#ifdef HAVE_WS2TCPIP_H
+#define WINVER 0x0501
+#include <ws2tcpip.h>
+#endif
 ])
 ])
Index: lib/socket_.h
===================================================================
RCS file: /sources/gnulib/gnulib/lib/socket_.h,v
retrieving revision 1.2
diff -u -p -r1.2 socket_.h
--- lib/socket_.h       19 Jan 2006 13:45:37 -0000      1.2
+++ lib/socket_.h       19 Jan 2006 15:25:33 -0000
@@ -27,6 +27,7 @@
    winsock2.h and ws2tcpip.h that declare the sys/socket.h definitions
    we need. */
 
+#define WINVER 0x0501
 #if HAVE_WINSOCK2_H
 # include <winsock2.h>
 #endif
Index: lib/getaddrinfo.h
===================================================================
RCS file: /sources/gnulib/gnulib/lib/getaddrinfo.h,v
retrieving revision 1.11
diff -u -p -r1.11 getaddrinfo.h
--- lib/getaddrinfo.h   8 Nov 2005 19:20:59 -0000       1.11
+++ lib/getaddrinfo.h   19 Jan 2006 15:25:33 -0000
@@ -1,5 +1,5 @@
 /* Get address information.
-   Copyright (C) 1996-2002, 2003, 2004, 2005 Free Software Foundation, Inc.
+   Copyright (C) 1996-2002, 2003, 2004, 2005, 2006 Free Software Foundation, 
Inc.
    Contributed by Simon Josefsson <address@hidden>.
 
    This program is free software; you can redistribute it and/or modify
@@ -26,7 +26,9 @@
 # include <sys/types.h>
 /* Get all getaddrinfo related declarations, if available.  */
 # include <sys/socket.h>
+#ifdef HAVE_NETDB_H
 # include <netdb.h>
+#endif
 
 # ifndef HAVE_STRUCT_ADDRINFO
 
@@ -65,10 +67,16 @@ struct addrinfo
 #  define EAI_FAMILY     -6    /* `ai_family' not supported.  */
 #  define EAI_SOCKTYPE   -7    /* `ai_socktype' not supported.  */
 #  define EAI_SERVICE    -8    /* SERVICE not supported for `ai_socktype'.  */
-#  define EAI_ADDRFAMILY  -9   /* Address family for NAME not supported.  */
 #  define EAI_MEMORY     -10   /* Memory allocation failure.  */
-#  define EAI_SYSTEM     -11   /* System error returned in `errno'.  */
 #  define EAI_OVERFLOW   -12   /* Argument buffer overflow.  */
+#endif
+# ifndef EAI_ADDRFAMILY
+/* Not define on mingw32. */
+#  define EAI_ADDRFAMILY  -9   /* Address family for NAME not supported.  */
+# endif
+# ifndef EAI_SYSTEM
+/* Not define on mingw32. */
+#  define EAI_SYSTEM     -11   /* System error returned in `errno'.  */
 # endif
 
 # ifdef __USE_GNU
Index: lib/gai_strerror.c
===================================================================
RCS file: /sources/gnulib/gnulib/lib/gai_strerror.c,v
retrieving revision 1.4
diff -u -p -r1.4 gai_strerror.c
--- lib/gai_strerror.c  12 Sep 2005 14:25:04 -0000      1.4
+++ lib/gai_strerror.c  19 Jan 2006 15:25:33 -0000
@@ -1,4 +1,4 @@
-/* Copyright (C) 1997, 2001, 2002, 2004, 2005 Free Software Foundation, Inc.
+/* Copyright (C) 1997, 2001, 2002, 2004, 2005, 2006 Free Software Foundation, 
Inc.
    This file is part of the GNU C Library.
    Contributed by Philip Blundell <address@hidden>, 1997.
 
@@ -25,7 +25,9 @@
 #endif
 
 #include <stdio.h>
-#include <netdb.h>
+#ifdef HAVE_NETDB_H
+# include <netdb.h>
+#endif
 
 #ifdef _LIBC
 # include <libintl.h>