Patch #401196: Configuration machinery for IPv6.

Contributed by Jun-ichiro "itojun" Hagino. get{addr,name}info emulation
code taken from WIDE.

Modules/addrinfo.h

+/*
+ * Copyright (C) 1995, 1996, 1997, 1998, and 1999 WIDE Project.
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the project nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef HAVE_GETADDRINFO
+
+/*
+ * Error return codes from getaddrinfo()
+ */
+#ifndef EAI_ADDRFAMILY
+#define	EAI_ADDRFAMILY	 1	/* address family for hostname not supported */
+#define	EAI_AGAIN	 2	/* temporary failure in name resolution */
+#define	EAI_BADFLAGS	 3	/* invalid value for ai_flags */
+#define	EAI_FAIL	 4	/* non-recoverable failure in name resolution */
+#define	EAI_FAMILY	 5	/* ai_family not supported */
+#define	EAI_MEMORY	 6	/* memory allocation failure */
+#define	EAI_NODATA	 7	/* no address associated with hostname */
+#define	EAI_NONAME	 8	/* hostname nor servname provided, or not known */
+#define	EAI_SERVICE	 9	/* servname not supported for ai_socktype */
+#define	EAI_SOCKTYPE	10	/* ai_socktype not supported */
+#define	EAI_SYSTEM	11	/* system error returned in errno */
+#define EAI_BADHINTS	12
+#define EAI_PROTOCOL	13
+#define EAI_MAX		14
+#endif
+
+/*
+ * Flag values for getaddrinfo()
+ */
+#ifndef AI_PASSIVE
+#define	AI_PASSIVE	0x00000001 /* get address to use bind() */
+#define	AI_CANONNAME	0x00000002 /* fill ai_canonname */
+#define	AI_NUMERICHOST	0x00000004 /* prevent name resolution */
+/* valid flags for addrinfo */
+#define	AI_MASK		(AI_PASSIVE | AI_CANONNAME | AI_NUMERICHOST)
+
+#define	AI_ALL		0x00000100 /* IPv6 and IPv4-mapped (with AI_V4MAPPED) */
+#define	AI_V4MAPPED_CFG	0x00000200 /* accept IPv4-mapped if kernel supports */
+#define	AI_ADDRCONFIG	0x00000400 /* only if any address is assigned */
+#define	AI_V4MAPPED	0x00000800 /* accept IPv4-mapped IPv6 address */
+/* special recommended flags for getipnodebyname */
+#define	AI_DEFAULT	(AI_V4MAPPED_CFG | AI_ADDRCONFIG)
+#endif
+
+/*
+ * Constants for getnameinfo()
+ */
+#ifndef NI_MAXHOST
+#define	NI_MAXHOST	1025
+#define	NI_MAXSERV	32
+#endif
+
+/*
+ * Flag values for getnameinfo()
+ */
+#ifndef NI_NOFQDN
+#define	NI_NOFQDN	0x00000001
+#define	NI_NUMERICHOST	0x00000002
+#define	NI_NAMEREQD	0x00000004
+#define	NI_NUMERICSERV	0x00000008
+#define	NI_DGRAM	0x00000010
+#endif
+
+#ifndef HAVE_ADDRINFO
+struct addrinfo {
+	int	ai_flags;	/* AI_PASSIVE, AI_CANONNAME */
+	int	ai_family;	/* PF_xxx */
+	int	ai_socktype;	/* SOCK_xxx */
+	int	ai_protocol;	/* 0 or IPPROTO_xxx for IPv4 and IPv6 */
+	size_t	ai_addrlen;	/* length of ai_addr */
+	char	*ai_canonname;	/* canonical name for hostname */
+	struct sockaddr *ai_addr;	/* binary address */
+	struct addrinfo *ai_next;	/* next structure in linked list */
+};
+#endif
+
+#ifndef HAVE_SOCKADDR_STORAGE
+/*
+ * RFC 2553: protocol-independent placeholder for socket addresses
+ */
+#define _SS_MAXSIZE	128
+#ifdef HAVE_LONG_LONG
+#define _SS_ALIGNSIZE	(sizeof(long long))
+#else
+#define _SS_ALIGNSIZE	(sizeof(double))
+#endif
+#define _SS_PAD1SIZE	(_SS_ALIGNSIZE - sizeof(u_char) * 2)
+#define _SS_PAD2SIZE	(_SS_MAXSIZE - sizeof(u_char) * 2 - \
+				_SS_PAD1SIZE - _SS_ALIGNSIZE)
+
+struct sockaddr_storage {
+#ifdef HAVE_SOCKADDR_SA_LEN
+	unsigned char ss_len;		/* address length */
+	unsigned char ss_family;	/* address family */
+#else
+	unsigned short ss_family;	/* address family */
+#endif
+	char	__ss_pad1[_SS_PAD1SIZE];
+#ifdef HAVE_LONG_LONG
+	long long __ss_align;	/* force desired structure storage alignment */
+#else
+	double __ss_align;	/* force desired structure storage alignment */
+#endif
+	char	__ss_pad2[_SS_PAD2SIZE];
+};
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+extern void freehostent Py_PROTO((struct hostent *));
+#ifdef __cplusplus
+}
+#endif
+#endif

Modules/getnameinfo.c

+/*
+ * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the project nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * Issues to be discussed:
+ * - Thread safe-ness must be checked
+ * - Return values.  There seems to be no standard for return value (RFC2133)
+ *   but INRIA implementation returns EAI_xxx defined for getaddrinfo().
+ */
+
+#if 0
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <arpa/nameser.h>
+#include <netdb.h>
+#include <resolv.h>
+#include <string.h>
+#include <stddef.h>
+
+#include "addrinfo.h"
+#endif
+
+#define SUCCESS 0
+#define YES 1
+#define NO  0
+
+static struct gni_afd {
+	int a_af;
+	int a_addrlen;
+	int a_socklen;
+	int a_off;
+} gni_afdl [] = {
+#ifdef INET6
+	{PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6),
+		offsetof(struct sockaddr_in6, sin6_addr)},
+#endif
+	{PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in),
+		offsetof(struct sockaddr_in, sin_addr)},
+	{0, 0, 0},
+};
+
+struct gni_sockinet {
+	u_char	si_len;
+	u_char	si_family;
+	u_short	si_port;
+};
+
+#define ENI_NOSOCKET 	0
+#define ENI_NOSERVNAME	1
+#define ENI_NOHOSTNAME	2
+#define ENI_MEMORY	3
+#define ENI_SYSTEM	4
+#define ENI_FAMILY	5
+#define ENI_SALEN	6
+
+int
+getnameinfo(sa, salen, host, hostlen, serv, servlen, flags)
+	const struct sockaddr *sa;
+	size_t salen;
+	char *host;
+	size_t hostlen;
+	char *serv;
+	size_t servlen;
+	int flags;
+{
+	struct gni_afd *gni_afd;
+	struct servent *sp;
+	struct hostent *hp;
+	u_short port;
+	int family, len, i;
+	char *addr, *p;
+	u_long v4a;
+	u_char pfx;
+	int h_error;
+	char numserv[512];
+	char numaddr[512];
+
+	if (sa == NULL)
+		return ENI_NOSOCKET;
+
+#ifdef HAVE_SOCKADDR_SA_LEN
+	len = sa->sa_len;
+	if (len != salen) return ENI_SALEN;
+#else
+	len = salen;
+#endif
+	
+	family = sa->sa_family;
+	for (i = 0; gni_afdl[i].a_af; i++)
+		if (gni_afdl[i].a_af == family) {
+			gni_afd = &gni_afdl[i];
+			goto found;
+		}
+	return ENI_FAMILY;
+	
+ found:
+	if (len != gni_afd->a_socklen) return ENI_SALEN;
+	
+	port = ((struct gni_sockinet *)sa)->si_port; /* network byte order */
+	addr = (char *)sa + gni_afd->a_off;
+
+	if (serv == NULL || servlen == 0) {
+		/* what we should do? */
+	} else if (flags & NI_NUMERICSERV) {
+		snprintf(numserv, sizeof(numserv), "%d", ntohs(port));
+		if (strlen(numserv) > servlen)
+			return ENI_MEMORY;
+		strcpy(serv, numserv);
+	} else {
+		sp = getservbyport(port, (flags & NI_DGRAM) ? "udp" : "tcp");
+		if (sp) {
+			if (strlen(sp->s_name) > servlen)
+				return ENI_MEMORY;
+			strcpy(serv, sp->s_name);
+		} else
+			return ENI_NOSERVNAME;
+	}
+
+	switch (sa->sa_family) {
+	case AF_INET:
+		v4a = ((struct sockaddr_in *)sa)->sin_addr.s_addr;
+		if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a))
+			flags |= NI_NUMERICHOST;
+		v4a >>= IN_CLASSA_NSHIFT;
+		if (v4a == 0 || v4a == IN_LOOPBACKNET)
+			flags |= NI_NUMERICHOST;			
+		break;
+#ifdef INET6
+	case AF_INET6:
+		pfx = ((struct sockaddr_in6 *)sa)->sin6_addr.s6_addr8[0];
+		if (pfx == 0 || pfx == 0xfe || pfx == 0xff)
+			flags |= NI_NUMERICHOST;
+		break;
+#endif
+	}
+	if (host == NULL || hostlen == 0) {
+		/* what should we do? */
+	} else if (flags & NI_NUMERICHOST) {
+		if (inet_ntop(gni_afd->a_af, addr, numaddr, sizeof(numaddr))
+		    == NULL)
+			return ENI_SYSTEM;
+		if (strlen(numaddr) > hostlen)
+			return ENI_MEMORY;
+		strcpy(host, numaddr);
+	} else {
+#ifdef INET6
+		hp = getipnodebyaddr(addr, gni_afd->a_addrlen, gni_afd->a_af, &h_error);
+#else
+		hp = gethostbyaddr(addr, gni_afd->a_addrlen, gni_afd->a_af);
+		h_error = h_errno;
+#endif
+
+		if (hp) {
+			if (flags & NI_NOFQDN) {
+				p = strchr(hp->h_name, '.');
+				if (p) *p = '\0';
+			}
+			if (strlen(hp->h_name) > hostlen) {
+#ifdef INET6
+				freehostent(hp);
+#endif
+				return ENI_MEMORY;
+			}
+			strcpy(host, hp->h_name);
+#ifdef INET6
+			freehostent(hp);
+#endif
+		} else {
+			if (flags & NI_NAMEREQD)
+				return ENI_NOHOSTNAME;
+			if (inet_ntop(gni_afd->a_af, addr, numaddr, sizeof(numaddr))
+			    == NULL)
+				return ENI_NOHOSTNAME;
+			if (strlen(numaddr) > hostlen)
+				return ENI_MEMORY;
+			strcpy(host, numaddr);
+		}
+	}
+	return SUCCESS;
+}

Modules/socketmodule.c

@@ -187,6 +187,8 @@ Socket methods:
 #include <GUSI.h>
 #endif
 
+#include "addrinfo.h"
+
 #ifdef USE_SSL
 #include "openssl/rsa.h"
 #include "openssl/crypto.h"
@@ -196,6 +198,14 @@ Socket methods:
 #include "openssl/err.h"
 #endif /* USE_SSL */
 
+/* I know this is a bad practice, but it is the easiest... */
+#ifndef HAVE_GETADDRINFO
+#include "getaddrinfo.c"
+#endif
+#ifndef HAVE_GETNAMEINFO
+#include "getnameinfo.c"
+#endif
+
 #if defined(MS_WINDOWS) || defined(__BEOS__)
 /* BeOS suffers from the same socket dichotomy as Win32... - [cjh] */
 /* seem to be a few differences in the API */

acconfig.h

@@ -35,6 +35,18 @@
 /* Define this if your time.h defines altzone */
 #undef HAVE_ALTZONE
 
+/* Define if --enable-ipv6 is specified */
+#undef ENABLE_IPV6
+
+/* Define if sockaddr has sa_len member */
+#undef HAVE_SOCKADDR_SA_LEN
+
+/* struct addrinfo (netdb.h) */
+#undef HAVE_ADDRINFO
+
+/* struct sockaddr_storage (sys/socket.h) */
+#undef HAVE_SOCKADDR_STORAGE
+
 /* Defined when any dynamic module loading is enabled */
 #undef HAVE_DYNAMIC_LOADING
 

config.h.in

@@ -100,6 +100,18 @@
 /* Define this if your time.h defines altzone */
 #undef HAVE_ALTZONE
 
+/* Define if --enable-ipv6 is specified */
+#undef ENABLE_IPV6
+
+/* Define if sockaddr has sa_len member */
+#undef HAVE_SOCKADDR_SA_LEN
+
+/* struct addrinfo (netdb.h) */
+#undef HAVE_ADDRINFO
+
+/* struct sockaddr_storage (sys/socket.h) */
+#undef HAVE_SOCKADDR_STORAGE
+
 /* Defined when any dynamic module loading is enabled */
 #undef HAVE_DYNAMIC_LOADING
 
@@ -341,6 +353,9 @@
 /* Define if you have the ftruncate function.  */
 #undef HAVE_FTRUNCATE
 
+/* Define if you have the getaddrinfo function.  */
+#undef HAVE_GETADDRINFO
+
 /* Define if you have the getcwd function.  */
 #undef HAVE_GETCWD
 
@@ -353,6 +368,9 @@
 /* Define if you have the getlogin function.  */
 #undef HAVE_GETLOGIN
 
+/* Define if you have the getnameinfo function.  */
+#undef HAVE_GETNAMEINFO
+
 /* Define if you have the getpeername function.  */
 #undef HAVE_GETPEERNAME
 

configure.in

@@ -368,6 +368,151 @@ else
   fi
 fi
 
+# Check for enable-ipv6
+OPT="$OPT -Dss_family=__ss_family -Dss_len=__ss_len"
+AC_MSG_CHECKING([whether to enable ipv6])
+AC_ARG_ENABLE(ipv6,
+[  --enable-ipv6		Enable ipv6 (with ipv4) support
+  --disable-ipv6		Disable ipv6 support],
+[ case "$enableval" in
+  no)
+       AC_MSG_RESULT(no)
+       ipv6=no
+       ;;
+  *)   AC_MSG_RESULT(yes)
+       AC_DEFINE(ENABLE_IPV6)
+       ipv6=yes
+       ;;
+  esac ],
+
+  AC_TRY_RUN([ /* AF_INET6 avalable check */
+#include <sys/types.h>
+#include <sys/socket.h>
+main()
+{
+ if (socket(AF_INET6, SOCK_STREAM, 0) < 0)
+   exit(1);
+ else
+   exit(0);
+}
+],
+  AC_MSG_RESULT(yes)
+  AC_DEFINE(ENABLE_IPV6)
+  ipv6=yes,
+  AC_MSG_RESULT(no)
+  ipv6=no,
+  AC_MSG_RESULT(no)
+  ipv6=no
+))
+
+ipv6type=unknown
+ipv6lib=none
+ipv6trylibc=no
+
+if test "$ipv6" = "yes"; then
+	AC_MSG_CHECKING([ipv6 stack type])
+	for i in inria kame linux-glibc linux-inet6 toshiba v6d zeta; do
+		case $i in
+		inria)
+			dnl http://www.kame.net/
+			AC_EGREP_CPP(yes, [dnl
+#include <netinet/in.h>
+#ifdef IPV6_INRIA_VERSION
+yes
+#endif],
+				[ipv6type=$i;
+				OPT="-DINET6 $OPT"])
+			;;
+		kame)
+			dnl http://www.kame.net/
+			AC_EGREP_CPP(yes, [dnl
+#include <netinet/in.h>
+#ifdef __KAME__
+yes
+#endif],
+				[ipv6type=$i;
+				ipv6lib=inet6
+				ipv6libdir=/usr/local/v6/lib
+				ipv6trylibc=yes
+				OPT="-DINET6 $OPT"])
+			;;
+		linux-glibc)
+			dnl http://www.v6.linux.or.jp/
+			AC_EGREP_CPP(yes, [dnl
+#include <features.h>
+#if defined(__GLIBC__) && ((__GLIBC__ == 2 && __GLIBC_MINOR__ >= 1) || (__GLIBC__ > 2))
+yes
+#endif],
+				[ipv6type=$i;
+				ipv6trylibc=yes
+				OPT="-DINET6 $OPT"])
+			;;
+		linux-inet6)
+			dnl http://www.v6.linux.or.jp/
+			if test -d /usr/inet6; then
+				ipv6type=$i
+				ipv6lib=inet6
+				ipv6libdir=/usr/inet6/lib
+				OPT="-DINET6 -I/usr/inet6/include $OPT"
+			fi
+			;;
+		toshiba)
+			AC_EGREP_CPP(yes, [dnl
+#include <sys/param.h>
+#ifdef _TOSHIBA_INET6
+yes
+#endif],
+				[ipv6type=$i;
+				ipv6lib=inet6;
+				ipv6libdir=/usr/local/v6/lib;
+				OPT="-DINET6 $OPT"])
+			;;
+		v6d)
+			AC_EGREP_CPP(yes, [dnl
+#include </usr/local/v6/include/sys/v6config.h>
+#ifdef __V6D__
+yes
+#endif],
+				[ipv6type=$i;
+				ipv6lib=v6;
+				ipv6libdir=/usr/local/v6/lib;
+				OPT="-I/usr/local/v6/include $OPT"])
+			;;
+		zeta)
+			AC_EGREP_CPP(yes, [dnl
+#include <sys/param.h>
+#ifdef _ZETA_MINAMI_INET6
+yes
+#endif],
+				[ipv6type=$i;
+				ipv6lib=inet6;
+				ipv6libdir=/usr/local/v6/lib;
+				OPT="-DINET6 $OPT"])
+			;;
+		esac
+		if test "$ipv6type" != "unknown"; then
+			break
+		fi
+	done
+	AC_MSG_RESULT($ipv6type)
+fi
+
+if test "$ipv6" = "yes" -a "$ipv6lib" != "none"; then
+	if test -d $ipv6libdir -a -f $ipv6libdir/lib$ipv6lib.a; then
+		LIBS="-L$ipv6libdir -l$ipv6lib $LIBS"
+		echo "using lib$ipv6lib"
+	else
+		if test $ipv6trylibc = "yes"; then
+			echo "using libc"
+		else
+			echo 'Fatal: no $ipv6lib library found.  cannot continue.'
+			echo "You need to fetch lib$ipv6lib.a from appropriate"
+			echo 'ipv6 kit and compile beforehand.'
+			exit 1
+		fi
+	fi
+fi
+
 dnl # check for ANSI or K&R ("traditional") preprocessor
 dnl AC_MSG_CHECKING(for C preprocessor type)
 dnl AC_TRY_COMPILE([
@@ -1039,6 +1184,110 @@ AC_CHECK_FUNCS(getpgrp, AC_TRY_COMPILE([#include <unistd.h>], [getpgrp(0);], AC_
 AC_CHECK_FUNCS(setpgrp, AC_TRY_COMPILE([#include <unistd.h>], [setpgrp(0,0);], AC_DEFINE(SETPGRP_HAVE_ARG)))
 AC_CHECK_FUNCS(gettimeofday, AC_TRY_COMPILE([#include <sys/time.h>], [gettimeofday((struct timeval*)0,(struct timezone*)0);], ,AC_DEFINE(GETTIMEOFDAY_NO_TZ)))
 
+AC_CHECK_FUNCS(getaddrinfo, [dnl
+AC_MSG_CHECKING(getaddrinfo bug)
+AC_TRY_RUN([
+#include <sys/types.h>
+#include <netdb.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+
+main()
+{
+  int passive, gaierr, inet4 = 0, inet6 = 0;
+  struct addrinfo hints, *ai, *aitop;
+  char straddr[INET6_ADDRSTRLEN], strport[16];
+
+  for (passive = 0; passive <= 1; passive++) {
+    memset(&hints, 0, sizeof(hints));
+    hints.ai_family = AF_UNSPEC;
+    hints.ai_flags = passive ? AI_PASSIVE : 0;
+    hints.ai_socktype = SOCK_STREAM;
+    if ((gaierr = getaddrinfo(NULL, "54321", &hints, &aitop)) != 0) {
+      (void)gai_strerror(gaierr);
+      goto bad;
+    }
+    for (ai = aitop; ai; ai = ai->ai_next) {
+      if (ai->ai_addr == NULL ||
+          ai->ai_addrlen == 0 ||
+          getnameinfo(ai->ai_addr, ai->ai_addrlen,
+                      straddr, sizeof(straddr), strport, sizeof(strport),
+                      NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
+        goto bad;
+      }
+      switch (ai->ai_family) {
+      case AF_INET:
+        if (strcmp(strport, "54321") != 0) {
+          goto bad;
+        }
+        if (passive) {
+          if (strcmp(straddr, "0.0.0.0") != 0) {
+            goto bad;
+          }
+        } else {
+          if (strcmp(straddr, "127.0.0.1") != 0) {
+            goto bad;
+          }
+        }
+        inet4++;
+        break;
+      case AF_INET6:
+        if (strcmp(strport, "54321") != 0) {
+          goto bad;
+        }
+        if (passive) {
+          if (strcmp(straddr, "::") != 0) {
+            goto bad;
+          }
+        } else {
+          if (strcmp(straddr, "::1") != 0) {
+            goto bad;
+          }
+        }
+        inet6++;
+        break;
+      case AF_UNSPEC:
+        goto bad;
+        break;
+      default:
+        /* another family support? */
+        break;
+      }
+    }
+  }
+
+  if (!(inet4 == 0 || inet4 == 2))
+    goto bad;
+  if (!(inet6 == 0 || inet6 == 2))
+    goto bad;
+
+  if (aitop)
+    freeaddrinfo(aitop);
+  exit(0);
+
+ bad:
+  if (aitop)
+    freeaddrinfo(aitop);
+  exit(1);
+}
+],
+AC_MSG_RESULT(good)
+buggygetaddrinfo=no,
+AC_MSG_RESULT(buggy)
+buggygetaddrinfo=yes,
+AC_MSG_RESULT(buggy)
+buggygetaddrinfo=yes)], [buggygetaddrinfo=yes])
+
+if test "$buggygetaddrinfo" = "yes"; then
+	if test "$ipv6" = "yes"; then
+		echo 'Fatal: You must get working getaddrinfo() function.'
+		echo '       or you can specify "--disable-ipv6"'.
+		exit 1
+	fi
+fi
+AC_CHECK_FUNCS(getaddrinfo getnameinfo)
+
 # checks for structures
 AC_HEADER_TIME
 AC_STRUCT_TM
@@ -1063,6 +1312,31 @@ AC_TRY_COMPILE([
 ], [;], [AC_DEFINE(SYS_SELECT_WITH_SYS_TIME) was_it_defined=yes])
 AC_MSG_RESULT($was_it_defined)
 
+AC_MSG_CHECKING(for addrinfo)
+AC_CACHE_VAL(ac_cv_struct_addrinfo,
+AC_TRY_COMPILE([
+#		include <netdb.h>],
+	[struct addrinfo a],
+	ac_cv_struct_addrinfo=yes,
+	ac_cv_struct_addrinfo=no))
+AC_MSG_RESULT($ac_cv_struct_addrinfo)
+if test $ac_cv_struct_addrinfo = yes; then
+	AC_DEFINE(HAVE_ADDRINFO)
+fi
+
+AC_MSG_CHECKING(for sockaddr_storage)
+AC_CACHE_VAL(ac_cv_struct_sockaddr_storage,
+AC_TRY_COMPILE([
+#		include <sys/types.h>
+#		include <sys/socket.h>],
+	[struct sockaddr_storage s],
+	ac_cv_struct_sockaddr_storage=yes,
+	ac_cv_struct_sockaddr_storage=no))
+AC_MSG_RESULT($ac_cv_struct_sockaddr_storage)
+if test $ac_cv_struct_sockaddr_storage = yes; then
+	AC_DEFINE(HAVE_SOCKADDR_STORAGE)
+fi
+
 # checks for compiler characteristics
 
 AC_C_CHAR_UNSIGNED
@@ -1108,6 +1382,16 @@ AC_TRY_COMPILE([#include <unistd.h>], [char **t;execve("@",t,t);], ,
 AC_MSG_RESULT($bad_prototypes)
 fi
 
+# check if sockaddr has sa_len member
+AC_MSG_CHECKING(if sockaddr has sa_len member)
+AC_TRY_COMPILE([#include <sys/types.h>
+#include <sys/socket.h>],
+[struct sockaddr x;
+x.sa_len = 0;],
+	AC_MSG_RESULT(yes)
+	AC_DEFINE(HAVE_SOCKADDR_SA_LEN),
+	AC_MSG_RESULT(no))
+
 bad_forward=no
 AC_MSG_CHECKING(for bad static forward)
 AC_TRY_RUN([