Added support for the AI_ADDRCONFIG flag in the hints->ai_flags parameter to getaddrinfo(3).

extra/Configs/Config.in

@@ -1018,6 +1018,18 @@ config UCLIBC_USE_NETLINK
 
 	  Most people can safely answer N.
 
+config UCLIBC_SUPPORT_AI_ADDRCONFIG
+	bool "Support the AI_ADDRCONFIG flag"
+	depends on UCLIBC_USE_NETLINK
+	default n
+	help
+	  The implementation of AI_ADDRCONFIG is aligned with the glibc
+	  implementation using netlink to query interfaces to find both
+	  ipv4 and ipv6 support. This is only needed if an application uses
+	  the AI_ADDRCONFIG flag.
+
+	  Most people can safely answer N.
+
 config UCLIBC_HAS_BSD_RES_CLOSE
 	bool "Support res_close() (bsd-compat)"
 	default n

include/ifaddrs.h

@@ -0,0 +1,19 @@
+#ifndef _IFADDRS_H
+#include <libc/inet/ifaddrs.h>
+#include <stdbool.h>
+#include <stdint.h>
+
+struct in6addrinfo
+{
+  enum {
+    in6ai_deprecated = 1,
+    in6ai_temporary = 2,
+    in6ai_homeaddress = 4
+  } flags;
+  uint32_t addr[4];
+};
+
+extern void __check_pf (bool *seen_ipv4, bool *seen_ipv6)
+  attribute_hidden;
+
+#endif	/* ifaddrs.h */

libc/inet/Makefile.in

@@ -14,7 +14,7 @@ CSRC :=
 ifneq ($(UCLIBC_HAS_IPV4)$(UCLIBC_HAS_IPV6),)
 CSRC +=	getservice.c getproto.c hostid.c getnetent.c getnetbynm.c getnetbyad.c \
 	inet_net.c herror.c if_index.c gai_strerror.c getaddrinfo.c \
-	ether_addr.c ntohl.c ifaddrs.c ntop.c
+	ether_addr.c ntohl.c ifaddrs.c ntop.c check_pf.c
 endif
 ifeq ($(UCLIBC_HAS_IPV6),y)
 CSRC += in6_addr.c

libc/inet/check_pf.c

@@ -0,0 +1,65 @@
+/* Determine protocol families for which interfaces exist.  Generic version.
+   Copyright (C) 2003, 2006 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <features.h>
+#include <ifaddrs.h>
+#include <netdb.h>
+
+
+void
+attribute_hidden
+__check_pf (bool *seen_ipv4, bool *seen_ipv6)
+{
+  *seen_ipv4 = false;
+  *seen_ipv6 = false;
+#if __UCLIBC_SUPPORT_AI_ADDRCONFIG__
+  {
+    /* Get the interface list via getifaddrs.  */
+    struct ifaddrs *ifa = NULL;
+    struct ifaddrs *runp;
+    if (getifaddrs (&ifa) != 0)
+    {
+      /* We cannot determine what interfaces are available.  Be
+      optimistic.  */
+      *seen_ipv4 = true;
+#if __UCLIBC_HAS_IPV6__
+      *seen_ipv6 = true;
+#endif /* __UCLIBC_HAS_IPV6__ */
+      return;
+    }
+
+    for (runp = ifa; runp != NULL; runp = runp->ifa_next)
+      if (runp->ifa_addr->sa_family == PF_INET)
+        *seen_ipv4 = true;
+#if __UCLIBC_HAS_IPV6__
+      else if (runp->ifa_addr->sa_family == PF_INET6)
+        *seen_ipv6 = true;
+#endif /* __UCLIBC_HAS_IPV6__ */
+
+    (void) freeifaddrs (ifa);
+  }
+#else
+  /* AI_ADDRCONFIG is disabled, assume both ipv4 and ipv6 available. */
+  *seen_ipv4 = true;
+#if __UCLIBC_HAS_IPV6__
+  *seen_ipv6 = true;
+#endif /* __UCLIBC_HAS_IPV6__ */
+
+#endif /* __UCLIBC_SUPPORT_AI_ADDRCONFIG__ */
+}

libc/inet/getaddrinfo.c

@@ -66,6 +66,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <sys/un.h>
 #include <sys/utsname.h>
 #include <net/if.h>
+#include <ifaddrs.h>
 
 /* Experimentally off - libc_hidden_proto(memcpy) */
 /* Experimentally off - libc_hidden_proto(memset) */
@@ -156,19 +157,29 @@ static const struct addrinfo default_hints =
 { 0, PF_UNSPEC, 0, 0, 0, NULL, NULL, NULL };
 #endif
 
-
 static int addrconfig (sa_family_t af)
 {
     int s;
     int ret;
     int saved_errno = errno;
-    s = socket(af, SOCK_DGRAM, 0);
-    if (s < 0)
-	ret = (errno == EMFILE) ? 1 : 0;
+    bool seen_ipv4;
+    bool seen_ipv6;
+
+    __check_pf(&seen_ipv4, &seen_ipv6);
+    if (af == AF_INET)
+	ret = (int)seen_ipv4;
+    else if (af == AF_INET6)
+	ret = (int)seen_ipv6;
     else
     {
-	close(s);
-	ret = 1;
+	s = socket(af, SOCK_DGRAM, 0);
+	if (s < 0)
+	    ret = (errno == EMFILE) ? 1 : 0;
+	else
+	{
+	    close(s);
+	    ret = 1;
+	}
     }
     __set_errno (saved_errno);
     return ret;
@@ -373,6 +384,9 @@ gaih_inet (const char *name, const struct gaih_service *service,
     int rc;
     int v4mapped = (req->ai_family == PF_UNSPEC || req->ai_family == PF_INET6) &&
 	(req->ai_flags & AI_V4MAPPED);
+    bool seen_ipv4;
+    bool seen_ipv6;
+    __check_pf(&seen_ipv4, &seen_ipv6);
 
     if (req->ai_protocol || req->ai_socktype)
     {
@@ -560,14 +574,16 @@ gaih_inet (const char *name, const struct gaih_service *service,
 
 #if defined __UCLIBC_HAS_IPV6__
 	    if (req->ai_family == AF_UNSPEC || req->ai_family == AF_INET6)
-		gethosts (AF_INET6, struct in6_addr);
+		if (!(req->ai_flags & AI_ADDRCONFIG) || seen_ipv6)
+		    gethosts (AF_INET6, struct in6_addr);
 #endif
 	    no_inet6_data = no_data;
 
 	    if (req->ai_family == AF_INET ||
 		(!v4mapped && req->ai_family == AF_UNSPEC) ||
 		(v4mapped && (no_inet6_data != 0 || (req->ai_flags & AI_ALL))))
-		gethosts (AF_INET, struct in_addr);
+		if (!(req->ai_flags & AI_ADDRCONFIG) || seen_ipv4)
+		    gethosts (AF_INET, struct in_addr);
 
 	    if (no_data != 0 && no_inet6_data != 0)
 	    {
@@ -698,6 +714,14 @@ gaih_inet (const char *name, const struct gaih_service *service,
 #endif
 	    for (st2 = st; st2 != NULL; st2 = st2->next)
 	    {
+		if (req->ai_flags & AI_ADDRCONFIG) {
+		    if (family == AF_INET && !seen_ipv4)
+			break;
+#if defined __UCLIBC_HAS_IPV6__
+		    else if (family == AF_INET6 && !seen_ipv6)
+			break;
+#endif
+		}
 		*pai = malloc (sizeof (struct addrinfo) + socklen + namelen);
 		if (*pai == NULL)
 		    return -EAI_MEMORY;
@@ -859,7 +883,10 @@ getaddrinfo (const char *name, const char *service,
 	if (hints->ai_family == g->family || hints->ai_family == AF_UNSPEC)
 	{
 	    if ((hints->ai_flags & AI_ADDRCONFIG) && !addrconfig(g->family))
+	    {
+		++g;
 		continue;
+	    }
 	    j++;
 	    if (pg == NULL || pg->gaih != g->gaih)
 	    {

libc/inet/ifaddrs.c

@@ -22,7 +22,7 @@
 #include <alloca.h>
 #include <assert.h>
 #include <errno.h>
-/*#include <ifaddrs.h>*/
+#include <ifaddrs.h>
 #include <net/if.h>
 #include <netinet/in.h>
 #include <netpacket/packet.h>
@@ -57,7 +57,7 @@ libc_hidden_proto(abort)
 
 
 #if __ASSUME_NETLINK_SUPPORT
-#if 0 /* unused code */
+#ifdef __UCLIBC_SUPPORT_AI_ADDRCONFIG__
 /* struct to hold the data for one ifaddrs entry, so we can allocate
    everything at once.  */
 struct ifaddrs_storage
@@ -74,7 +74,7 @@ struct ifaddrs_storage
   } addr, netmask, broadaddr;
   char name[IF_NAMESIZE + 1];
 };
-#endif /* unused code */
+#endif /* __UCLIBC_SUPPORT_AI_ADDRCONFIG__ */
 
 
 void
@@ -324,7 +324,7 @@ __netlink_open (struct netlink_handle *h)
 }
 
 
-#if 0 /* unused code */
+#ifdef __UCLIBC_SUPPORT_AI_ADDRCONFIG__
 /* We know the number of RTM_NEWLINK entries, so we reserve the first
    # of entries for this type. All RTM_NEWADDR entries have an index
    pointer to the RTM_NEWLINK entry.  To find the entry, create
@@ -562,7 +562,7 @@ getifaddrs (struct ifaddrs **ifap)
 		      if ((rta_payload + 1) <= sizeof (ifas[ifa_index].name))
 			{
 			  ifas[ifa_index].ifa.ifa_name = ifas[ifa_index].name;
-			  *(char *) __mempcpy (ifas[ifa_index].name, rta_data,
+			  *(char *) mempcpy (ifas[ifa_index].name, rta_data,
 					       rta_payload) = '\0';
 			}
 		      break;
@@ -761,7 +761,7 @@ getifaddrs (struct ifaddrs **ifap)
 		      if (rta_payload + 1 <= sizeof (ifas[ifa_index].name))
 			{
 			  ifas[ifa_index].ifa.ifa_name = ifas[ifa_index].name;
-			  *(char *) __mempcpy (ifas[ifa_index].name, rta_data,
+			  *(char *) mempcpy (ifas[ifa_index].name, rta_data,
 					       rta_payload) = '\0';
 			}
 		      else
@@ -872,6 +872,6 @@ freeifaddrs (struct ifaddrs *ifa)
 }
 #endif
 
-#endif /* unused code */
+#endif /* __UCLIBC_SUPPORT_AI_ADDRCONFIG__ */
 
 #endif /* __ASSUME_NETLINK_SUPPORT */

libc/inet/ifaddrs.h

@@ -0,0 +1,74 @@
+/* ifaddrs.h -- declarations for getting network interface addresses
+   Copyright (C) 2002 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#ifndef _IFADDRS_H
+#define _IFADDRS_H	1
+
+#include <features.h>
+#include <sys/socket.h>
+
+__BEGIN_DECLS
+
+/* The `getifaddrs' function generates a linked list of these structures.
+   Each element of the list describes one network interface.  */
+struct ifaddrs
+{
+  struct ifaddrs *ifa_next;	/* Pointer to the next structure.  */
+
+  char *ifa_name;		/* Name of this network interface.  */
+  unsigned int ifa_flags;	/* Flags as from SIOCGIFFLAGS ioctl.  */
+
+  struct sockaddr *ifa_addr;	/* Network address of this interface.  */
+  struct sockaddr *ifa_netmask; /* Netmask of this interface.  */
+  union
+  {
+    /* At most one of the following two is valid.  If the IFF_BROADCAST
+       bit is set in `ifa_flags', then `ifa_broadaddr' is valid.  If the
+       IFF_POINTOPOINT bit is set, then `ifa_dstaddr' is valid.
+       It is never the case that both these bits are set at once.  */
+    struct sockaddr *ifu_broadaddr; /* Broadcast address of this interface. */
+    struct sockaddr *ifu_dstaddr; /* Point-to-point destination address.  */
+  } ifa_ifu;
+  /* These very same macros are defined by <net/if.h> for `struct ifaddr'.
+     So if they are defined already, the existing definitions will be fine.  */
+# ifndef ifa_broadaddr
+#  define ifa_broadaddr	ifa_ifu.ifu_broadaddr
+# endif
+# ifndef ifa_dstaddr
+#  define ifa_dstaddr	ifa_ifu.ifu_dstaddr
+# endif
+
+  void *ifa_data;		/* Address-specific data (may be unused).  */
+};
+
+
+/* Create a linked list of `struct ifaddrs' structures, one for each
+   network interface on the host machine.  If successful, store the
+   list in *IFAP and return 0.  On errors, return -1 and set `errno'.
+
+   The storage returned in *IFAP is allocated dynamically and can
+   only be properly freed by passing it to `freeifaddrs'.  */
+extern int getifaddrs (struct ifaddrs **__ifap) __THROW;
+
+/* Reclaim the storage allocated by a previous `getifaddrs' call.  */
+extern void freeifaddrs (struct ifaddrs *__ifa)  __THROW;
+
+__END_DECLS
+
+#endif /* ifaddrs.h */

libc/inet/netlinkaccess.h

@@ -62,13 +62,13 @@ struct netlink_handle
 };
 
 
-#if 0 /* unused code */
+#ifdef __UCLIBC_SUPPORT_AI_ADDRCONFIG__
 #if __ASSUME_NETLINK_SUPPORT == 0
 extern smallint __no_netlink_support attribute_hidden;
 #else
 # define __no_netlink_support 0
 #endif
-#endif /* unused code */
+#endif /* __UCLIBC_SUPPORT_AI_ADDRCONFIG__ */
 
 
 extern int __netlink_open (struct netlink_handle *h) attribute_hidden;