Added <ifaddrs.h> interface with functions `getifaddrs', `freeifaddrs'.

	This implementation supports only IPv4.
	* inet/ifaddrs.h: New file.
	* sysdeps/generic/ifaddrs.c: New file.
	* sysdeps/gnu/ifaddrs.c: New file.
	* inet/test-ifaddrs.c: New file.
	* inet/Makefile (routines): Add ifaddrs.
	(headers): Add ifaddrs.h here.
	(tests): Add test-ifaddrs.
	* inet/Versions (GLIBC_2.3): New set, add getifaddrs and freeifaddrs.

	* resolv/res_hconf.c (_res_hconf_reorder_addrs): Use an explicit
	socket call to get an AF_INET socket, instead of using __opensock.
	The SIOCGIFNETMASK ioctl will work only with a PF_INET socket.

	* sysdeps/generic/ifreq.h (__ifreq): Take third argument SOCKFD,
	if not -1 use it instead of calling __opensock.
	* sysdeps/unix/sysv/linux/ifreq.h (__ifreq): Likewise.
	* sysdeps/mach/hurd/ifreq.h (__ifreq): Take new argument and ignore it.
	* resolv/res_hconf.c (_res_hconf_reorder_addrs): Pass new argument.

	* sysdeps/mach/hurd/ifreq.h: New file.
	* sysdeps/generic/ifreq.h (__if_freereq): Take second argument NUM_IFS.
	* sysdeps/unix/sysv/linux/ifreq.h (__if_freereq): Likewise.
	* resolv/res_hconf.c (_res_hconf_reorder_addrs): Update caller.

4 files changed, 166 insertions, 4 deletions

diff --git a/inet/Makefile b/inet/Makefile
index ab922db4b6..be588d78b0 100644
--- a/inet/Makefile
+++ b/inet/Makefile
@@ -1,4 +1,4 @@
-# Copyright (C) 1991-1999, 2000, 2001 Free Software Foundation, Inc.
+# Copyright (C) 1991-1999,2000,01,02 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
@@ -24,7 +24,7 @@ subdir	:= inet
 headers	:= netinet/ether.h netinet/in.h netinet/in_systm.h \
 	   netinet/if_ether.h \
 	   netinet/tcp.h netinet/ip.h $(wildcard arpa/*.h protocols/*.h) \
-	   aliases.h netinet/ip6.h netinet/icmp6.h bits/in.h
+	   aliases.h ifaddrs.h netinet/ip6.h netinet/icmp6.h bits/in.h
 
 distribute := netgroup.h
 
@@ -45,10 +45,10 @@ routines := htonl htons		\
 	    rcmd rexec ruserpass \
 	    getnetgrent_r getnetgrent \
 	    getaliasent_r getaliasent getaliasname getaliasname_r \
-	    in6_addr getnameinfo if_index
+	    in6_addr getnameinfo if_index ifaddrs
 
 tests := htontest test_ifindex tst-ntoa tst-ether_aton tst-network \
-	 tst-gethnm
+	 tst-gethnm test-ifaddrs
 
 include ../Rules
 
diff --git a/inet/Versions b/inet/Versions
index eb3b13c9d2..0eb1e77838 100644
--- a/inet/Versions
+++ b/inet/Versions
@@ -64,6 +64,12 @@ libc {
     # r*
     rcmd_af; rexec_af; rresvport_af; ruserok_af;
   }
+  GLIBC_2.3 {
+    # f*
+    freeifaddrs;
+    # g*
+    getifaddrs;
+  }
   GLIBC_PRIVATE {
     # functions used in other libraries
     __internal_endnetgrent; __internal_getnetgrent_r;
diff --git a/inet/ifaddrs.h b/inet/ifaddrs.h
new file mode 100644
index 0000000000..ba6a1554b1
--- /dev/null
+++ b/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 */
diff --git a/inet/test-ifaddrs.c b/inet/test-ifaddrs.c
new file mode 100644
index 0000000000..42fb7e75bf
--- /dev/null
+++ b/inet/test-ifaddrs.c
@@ -0,0 +1,82 @@
+/* Test listing of 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.  */
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ifaddrs.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+int
+main (void)
+{
+  int failures = 0;
+  struct ifaddrs *ifaces, *ifa;
+
+  if (getifaddrs (&ifaces) < 0)
+    {
+      if (errno != ENOSYS)
+	{
+	  printf ("Couldn't get any interfaces: %s.\n", strerror (errno));
+	  exit (1);
+	}
+      /* The function is simply not implemented.  */
+      exit (0);
+    }
+
+  puts ("\
+Name           Flags   Address         Netmask         Broadcast/Destination");
+
+  for (ifa = ifaces; ifa != NULL; ifa = ifa->ifa_next)
+    {
+      char abuf[64], mbuf[64], dbuf[64];
+      inline const char *addr_string (struct sockaddr *sa, char *buf)
+	{
+	  switch (sa->sa_family)
+	    {
+	    case AF_INET:
+	      return inet_ntop (AF_INET,
+				&((struct sockaddr_in *) sa)->sin_addr,
+				buf, sizeof abuf);
+	    case AF_INET6:
+	      return inet_ntop (AF_INET6,
+				&((struct sockaddr_in6 *) sa)->sin6_addr,
+				buf, sizeof abuf);
+	    case AF_UNSPEC:
+	      return "---";
+	    default:
+	      ++failures;
+	      printf ("sa_family=%d %08x\n", sa->sa_family,
+		      *(int*)&((struct sockaddr_in *) sa)->sin_addr.s_addr);
+	      return "<unexpected sockaddr family>";
+	    }
+	}
+      printf ("%-15s%#.4x  %-15s %-15s %-15s\n",
+	      ifa->ifa_name, ifa->ifa_flags,
+	      addr_string (ifa->ifa_addr, abuf),
+	      addr_string (ifa->ifa_netmask, mbuf),
+	      addr_string (ifa->ifa_broadaddr, dbuf));
+    }
+
+  freeifaddrs (ifaces);
+
+  return failures ? 1 : 0;
+}