as weber notes in Bug 99:

if_nameindex doesnt list all of my interfaces!

this is because we are still using the old style ioctl(SIOCGIFINDEX) for
gathering interface names/indexes.  while this code is pretty small, the
kernel does not return all interfaces via this method.  so we import the
new style netlink code from glibc and make it optional so those people
who need the full functionality can get it.

1 files changed, 873 insertions, 0 deletions

diff --git a/libc/inet/ifaddrs.c b/libc/inet/ifaddrs.c
new file mode 100644
index 000000000..74f3622f8
--- /dev/null
+++ b/libc/inet/ifaddrs.c
@@ -0,0 +1,873 @@
+/* getifaddrs -- get names and addresses of all network interfaces
+   Copyright (C) 2003, 2004, 2005 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.  */
+
+#define time __time
+#define sendto __sendto
+#define recvmsg __recvmsg
+#define bind __bind
+#define mempcpy __mempcpy
+#define getsockname __getsockname
+
+#define __FORCE_GLIBC
+#include <features.h>
+#define __USE_GNU
+#include <alloca.h>
+#include <assert.h>
+#include <errno.h>
+/*#include <ifaddrs.h>*/
+#include <net/if.h>
+#include <netinet/in.h>
+#include <netpacket/packet.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <libc-internal.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "netlinkaccess.h"
+
+
+#ifndef __libc_use_alloca
+# define __libc_use_alloca(x) (x < __MAX_ALLOCA_CUTOFF)
+#endif
+
+
+#if __ASSUME_NETLINK_SUPPORT
+#if 0 /* unused code */
+/* struct to hold the data for one ifaddrs entry, so we can allocate
+   everything at once.  */
+struct ifaddrs_storage
+{
+  struct ifaddrs ifa;
+  union
+  {
+    /* Save space for the biggest of the four used sockaddr types and
+       avoid a lot of casts.  */
+    struct sockaddr sa;
+    struct sockaddr_ll sl;
+    struct sockaddr_in s4;
+    struct sockaddr_in6 s6;
+  } addr, netmask, broadaddr;
+  char name[IF_NAMESIZE + 1];
+};
+#endif /* unused code */
+
+
+void
+__netlink_free_handle (struct netlink_handle *h)
+{
+  struct netlink_res *ptr;
+  int saved_errno = errno;
+
+  ptr = h->nlm_list;
+  while (ptr != NULL)
+    {
+      struct netlink_res *tmpptr;
+
+      tmpptr = ptr->next;
+      free (ptr);
+      ptr = tmpptr;
+    }
+
+  __set_errno (saved_errno);
+}
+
+
+static int
+__netlink_sendreq (struct netlink_handle *h, int type)
+{
+  struct
+  {
+    struct nlmsghdr nlh;
+    struct rtgenmsg g;
+  } req;
+  struct sockaddr_nl nladdr;
+
+  if (h->seq == 0)
+    h->seq = time (NULL);
+
+  req.nlh.nlmsg_len = sizeof (req);
+  req.nlh.nlmsg_type = type;
+  req.nlh.nlmsg_flags = NLM_F_ROOT | NLM_F_MATCH | NLM_F_REQUEST;
+  req.nlh.nlmsg_pid = 0;
+  req.nlh.nlmsg_seq = h->seq;
+  req.g.rtgen_family = AF_UNSPEC;
+
+  memset (&nladdr, '\0', sizeof (nladdr));
+  nladdr.nl_family = AF_NETLINK;
+
+  return TEMP_FAILURE_RETRY (__sendto (h->fd, (void *) &req, sizeof (req), 0,
+				       (struct sockaddr *) &nladdr,
+				       sizeof (nladdr)));
+}
+
+
+int
+__netlink_request (struct netlink_handle *h, int type)
+{
+  struct netlink_res *nlm_next;
+  struct netlink_res **new_nlm_list;
+  static volatile size_t buf_size = 4096;
+  char *buf;
+  struct sockaddr_nl nladdr;
+  struct nlmsghdr *nlmh;
+  ssize_t read_len;
+  bool done = false;
+  bool use_malloc = false;
+
+  if (__netlink_sendreq (h, type) < 0)
+    return -1;
+
+  size_t this_buf_size = buf_size;
+  if (__libc_use_alloca (this_buf_size))
+    buf = alloca (this_buf_size);
+  else
+    {
+      buf = malloc (this_buf_size);
+      if (buf != NULL)
+	use_malloc = true;
+      else
+	goto out_fail;
+    }
+
+  struct iovec iov = { buf, this_buf_size };
+
+  if (h->nlm_list != NULL)
+    new_nlm_list = &h->end_ptr->next;
+  else
+    new_nlm_list = &h->nlm_list;
+
+  while (! done)
+    {
+      struct msghdr msg =
+	{
+	  (void *) &nladdr, sizeof (nladdr),
+	  &iov, 1,
+	  NULL, 0,
+	  0
+	};
+
+      read_len = TEMP_FAILURE_RETRY (__recvmsg (h->fd, &msg, 0));
+      if (read_len < 0)
+	goto out_fail;
+
+      if (nladdr.nl_pid != 0)
+	continue;
+
+      if (__builtin_expect (msg.msg_flags & MSG_TRUNC, 0))
+	{
+	  if (this_buf_size >= SIZE_MAX / 2)
+	    goto out_fail;
+
+	  nlm_next = *new_nlm_list;
+	  while (nlm_next != NULL)
+	    {
+	      struct netlink_res *tmpptr;
+
+	      tmpptr = nlm_next->next;
+	      free (nlm_next);
+	      nlm_next = tmpptr;
+	    }
+	  *new_nlm_list = NULL;
+
+	  if (__libc_use_alloca (2 * this_buf_size))
+	    buf = extend_alloca (buf, this_buf_size, 2 * this_buf_size);
+	  else
+	    {
+	      this_buf_size *= 2;
+
+	      char *new_buf = realloc (use_malloc ? buf : NULL, this_buf_size);
+	      if (new_buf == NULL)
+		goto out_fail;
+	      new_buf = buf;
+
+	      use_malloc = true;
+	    }
+	  buf_size = this_buf_size;
+
+	  iov.iov_base = buf;
+	  iov.iov_len = this_buf_size;
+
+	  /* Increase sequence number, so that we can distinguish
+	     between old and new request messages.  */
+	  h->seq++;
+
+	  if (__netlink_sendreq (h, type) < 0)
+	    goto out_fail;
+
+	  continue;
+	}
+
+      size_t count = 0;
+      size_t remaining_len = read_len;
+      for (nlmh = (struct nlmsghdr *) buf;
+	   NLMSG_OK (nlmh, remaining_len);
+	   nlmh = (struct nlmsghdr *) NLMSG_NEXT (nlmh, remaining_len))
+	{
+	  if ((pid_t) nlmh->nlmsg_pid != h->pid
+	      || nlmh->nlmsg_seq != h->seq)
+	    continue;
+
+	  ++count;
+	  if (nlmh->nlmsg_type == NLMSG_DONE)
+	    {
+	      /* We found the end, leave the loop.  */
+	      done = true;
+	      break;
+	    }
+	  if (nlmh->nlmsg_type == NLMSG_ERROR)
+	    {
+	      struct nlmsgerr *nlerr = (struct nlmsgerr *) NLMSG_DATA (nlmh);
+	      if (nlmh->nlmsg_len < NLMSG_LENGTH (sizeof (struct nlmsgerr)))
+		errno = EIO;
+	      else
+		errno = -nlerr->error;
+	      goto out_fail;
+	    }
+	}
+
+      /* If there was nothing with the expected nlmsg_pid and nlmsg_seq,
+	 there is no point to record it.  */
+      if (count == 0)
+	continue;
+
+      nlm_next = (struct netlink_res *) malloc (sizeof (struct netlink_res)
+						+ read_len);
+      if (nlm_next == NULL)
+	goto out_fail;
+      nlm_next->next = NULL;
+      nlm_next->nlh = memcpy (nlm_next + 1, buf, read_len);
+      nlm_next->size = read_len;
+      nlm_next->seq = h->seq;
+      if (h->nlm_list == NULL)
+	h->nlm_list = nlm_next;
+      else
+	h->end_ptr->next = nlm_next;
+      h->end_ptr = nlm_next;
+    }
+
+  if (use_malloc)
+    free (buf);
+  return 0;
+
+out_fail:
+  if (use_malloc)
+    free (buf);
+  return -1;
+}
+
+
+void
+__netlink_close (struct netlink_handle *h)
+{
+  /* Don't modify errno.  */
+  int serrno = errno;
+  __close(h->fd);
+  __set_errno(serrno);
+}
+
+
+/* Open a NETLINK socket.  */
+int
+__netlink_open (struct netlink_handle *h)
+{
+  struct sockaddr_nl nladdr;
+
+  h->fd = __socket (PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+  if (h->fd < 0)
+    goto out;
+
+  memset (&nladdr, '\0', sizeof (nladdr));
+  nladdr.nl_family = AF_NETLINK;
+  if (__bind (h->fd, (struct sockaddr *) &nladdr, sizeof (nladdr)) < 0)
+    {
+    close_and_out:
+      __netlink_close (h);
+    out:
+#if __ASSUME_NETLINK_SUPPORT == 0
+      __no_netlink_support = 1;
+#endif
+      return -1;
+    }
+  /* Determine the ID the kernel assigned for this netlink connection.
+     It is not necessarily the PID if there is more than one socket
+     open.  */
+  socklen_t addr_len = sizeof (nladdr);
+  if (__getsockname (h->fd, (struct sockaddr *) &nladdr, &addr_len) < 0)
+    goto close_and_out;
+  h->pid = nladdr.nl_pid;
+  return 0;
+}
+
+
+#if 0 /* unused code */
+/* 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
+   a table to map kernel index entries to our index numbers.
+   Since we get at first all RTM_NEWLINK entries, it can never happen
+   that a RTM_NEWADDR index is not known to this map.  */
+static int
+internal_function
+map_newlink (int index, struct ifaddrs_storage *ifas, int *map, int max)
+{
+  int i;
+
+  for (i = 0; i < max; i++)
+    {
+      if (map[i] == -1)
+	{
+	  map[i] = index;
+	  if (i > 0)
+	    ifas[i - 1].ifa.ifa_next = &ifas[i].ifa;
+	  return i;
+	}
+      else if (map[i] == index)
+	return i;
+    }
+  /* This should never be reached. If this will be reached, we have
+     a very big problem.  */
+  abort ();
+}
+
+
+/* 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'.  */
+int
+getifaddrs (struct ifaddrs **ifap)
+{
+  struct netlink_handle nh = { 0, 0, 0, NULL, NULL };
+  struct netlink_res *nlp;
+  struct ifaddrs_storage *ifas;
+  unsigned int i, newlink, newaddr, newaddr_idx;
+  int *map_newlink_data;
+  size_t ifa_data_size = 0;  /* Size to allocate for all ifa_data.  */
+  char *ifa_data_ptr;	/* Pointer to the unused part of memory for
+				ifa_data.  */
+  int result = 0;
+
+  if (ifap)
+    *ifap = NULL;
+
+  if (! __no_netlink_support && __netlink_open (&nh) < 0)
+    {
+#if __ASSUME_NETLINK_SUPPORT != 0
+      return -1;
+#endif
+    }
+
+#if __ASSUME_NETLINK_SUPPORT == 0
+  if (__no_netlink_support)
+    return fallback_getifaddrs (ifap);
+#endif
+
+  /* Tell the kernel that we wish to get a list of all
+     active interfaces, collect all data for every interface.  */
+  if (__netlink_request (&nh, RTM_GETLINK) < 0)
+    {
+      result = -1;
+      goto exit_free;
+    }
+
+  /* Now ask the kernel for all addresses which are assigned
+     to an interface and collect all data for every interface.
+     Since we store the addresses after the interfaces in the
+     list, we will later always find the interface before the
+     corresponding addresses.  */
+  ++nh.seq;
+  if (__netlink_request (&nh, RTM_GETADDR) < 0)
+    {
+      result = -1;
+      goto exit_free;
+    }
+
+  /* Count all RTM_NEWLINK and RTM_NEWADDR entries to allocate
+     enough memory.  */
+  newlink = newaddr = 0;
+  for (nlp = nh.nlm_list; nlp; nlp = nlp->next)
+    {
+      struct nlmsghdr *nlh;
+      size_t size = nlp->size;
+
+      if (nlp->nlh == NULL)
+	continue;
+
+      /* Walk through all entries we got from the kernel and look, which
+	 message type they contain.  */
+      for (nlh = nlp->nlh; NLMSG_OK (nlh, size); nlh = NLMSG_NEXT (nlh, size))
+	{
+	  /* Check if the message is what we want.  */
+	  if ((pid_t) nlh->nlmsg_pid != nh.pid || nlh->nlmsg_seq != nlp->seq)
+	    continue;
+
+	  if (nlh->nlmsg_type == NLMSG_DONE)
+	    break;		/* ok */
+
+	  if (nlh->nlmsg_type == RTM_NEWLINK)
+	    {
+	      /* A RTM_NEWLINK message can have IFLA_STATS data. We need to
+		 know the size before creating the list to allocate enough
+		 memory.  */
+	      struct ifinfomsg *ifim = (struct ifinfomsg *) NLMSG_DATA (nlh);
+	      struct rtattr *rta = IFLA_RTA (ifim);
+	      size_t rtasize = IFLA_PAYLOAD (nlh);
+
+	      while (RTA_OK (rta, rtasize))
+		{
+		  size_t rta_payload = RTA_PAYLOAD (rta);
+
+		  if (rta->rta_type == IFLA_STATS)
+		    {
+		      ifa_data_size += rta_payload;
+		      break;
+		    }
+		  else
+		    rta = RTA_NEXT (rta, rtasize);
+		}
+	      ++newlink;
+	    }
+	  else if (nlh->nlmsg_type == RTM_NEWADDR)
+	    ++newaddr;
+	}
+    }
+
+  /* Return if no interface is up.  */
+  if ((newlink + newaddr) == 0)
+    goto exit_free;
+
+  /* Allocate memory for all entries we have and initialize next
+     pointer.  */
+  ifas = (struct ifaddrs_storage *) calloc (1,
+					    (newlink + newaddr)
+					    * sizeof (struct ifaddrs_storage)
+					    + ifa_data_size);
+  if (ifas == NULL)
+    {
+      result = -1;
+      goto exit_free;
+    }
+
+  /* Table for mapping kernel index to entry in our list.  */
+  map_newlink_data = alloca (newlink * sizeof (int));
+  memset (map_newlink_data, '\xff', newlink * sizeof (int));
+
+  ifa_data_ptr = (char *) &ifas[newlink + newaddr];
+  newaddr_idx = 0;		/* Counter for newaddr index.  */
+
+  /* Walk through the list of data we got from the kernel.  */
+  for (nlp = nh.nlm_list; nlp; nlp = nlp->next)
+    {
+      struct nlmsghdr *nlh;
+      size_t size = nlp->size;
+
+      if (nlp->nlh == NULL)
+	continue;
+
+      /* Walk through one message and look at the type: If it is our
+	 message, we need RTM_NEWLINK/RTM_NEWADDR and stop if we reach
+	 the end or we find the end marker (in this case we ignore the
+	 following data.  */
+      for (nlh = nlp->nlh; NLMSG_OK (nlh, size); nlh = NLMSG_NEXT (nlh, size))
+	{
+	  int ifa_index = 0;
+
+	  /* Check if the message is the one we want */
+	  if ((pid_t) nlh->nlmsg_pid != nh.pid || nlh->nlmsg_seq != nlp->seq)
+	    continue;
+
+	  if (nlh->nlmsg_type == NLMSG_DONE)
+	    break;		/* ok */
+
+	  if (nlh->nlmsg_type == RTM_NEWLINK)
+	    {
+	      /* We found a new interface. Now extract everything from the
+		 interface data we got and need.  */
+	      struct ifinfomsg *ifim = (struct ifinfomsg *) NLMSG_DATA (nlh);
+	      struct rtattr *rta = IFLA_RTA (ifim);
+	      size_t rtasize = IFLA_PAYLOAD (nlh);
+
+	      /* Interfaces are stored in the first "newlink" entries
+		 of our list, starting in the order as we got from the
+		 kernel.  */
+	      ifa_index = map_newlink (ifim->ifi_index - 1, ifas,
+				       map_newlink_data, newlink);
+	      ifas[ifa_index].ifa.ifa_flags = ifim->ifi_flags;
+
+	      while (RTA_OK (rta, rtasize))
+		{
+		  char *rta_data = RTA_DATA (rta);
+		  size_t rta_payload = RTA_PAYLOAD (rta);
+
+		  switch (rta->rta_type)
+		    {
+		    case IFLA_ADDRESS:
+		      if (rta_payload <= sizeof (ifas[ifa_index].addr))
+			{
+			  ifas[ifa_index].addr.sl.sll_family = AF_PACKET;
+			  memcpy (ifas[ifa_index].addr.sl.sll_addr,
+				  (char *) rta_data, rta_payload);
+			  ifas[ifa_index].addr.sl.sll_halen = rta_payload;
+			  ifas[ifa_index].addr.sl.sll_ifindex
+			    = ifim->ifi_index;
+			  ifas[ifa_index].addr.sl.sll_hatype = ifim->ifi_type;
+
+			  ifas[ifa_index].ifa.ifa_addr
+			    = &ifas[ifa_index].addr.sa;
+			}
+		      break;
+
+		    case IFLA_BROADCAST:
+		      if (rta_payload <= sizeof (ifas[ifa_index].broadaddr))
+			{
+			  ifas[ifa_index].broadaddr.sl.sll_family = AF_PACKET;
+			  memcpy (ifas[ifa_index].broadaddr.sl.sll_addr,
+				  (char *) rta_data, rta_payload);
+			  ifas[ifa_index].broadaddr.sl.sll_halen = rta_payload;
+			  ifas[ifa_index].broadaddr.sl.sll_ifindex
+			    = ifim->ifi_index;
+			  ifas[ifa_index].broadaddr.sl.sll_hatype
+			    = ifim->ifi_type;
+
+			  ifas[ifa_index].ifa.ifa_broadaddr
+			    = &ifas[ifa_index].broadaddr.sa;
+			}
+		      break;
+
+		    case IFLA_IFNAME:	/* Name of Interface */
+		      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,
+					       rta_payload) = '\0';
+			}
+		      break;
+
+		    case IFLA_STATS:	/* Statistics of Interface */
+		      ifas[ifa_index].ifa.ifa_data = ifa_data_ptr;
+		      ifa_data_ptr += rta_payload;
+		      memcpy (ifas[ifa_index].ifa.ifa_data, rta_data,
+			      rta_payload);
+		      break;
+
+		    case IFLA_UNSPEC:
+		      break;
+		    case IFLA_MTU:
+		      break;
+		    case IFLA_LINK:
+		      break;
+		    case IFLA_QDISC:
+		      break;
+		    default:
+		      break;
+		    }
+
+		  rta = RTA_NEXT (rta, rtasize);
+		}
+	    }
+	  else if (nlh->nlmsg_type == RTM_NEWADDR)
+	    {
+	      struct ifaddrmsg *ifam = (struct ifaddrmsg *) NLMSG_DATA (nlh);
+	      struct rtattr *rta = IFA_RTA (ifam);
+	      size_t rtasize = IFA_PAYLOAD (nlh);
+
+	      /* New Addresses are stored in the order we got them from
+		 the kernel after the interfaces. Theoretically it is possible
+		 that we have holes in the interface part of the list,
+		 but we always have already the interface for this address.  */
+	      ifa_index = newlink + newaddr_idx;
+	      ifas[ifa_index].ifa.ifa_flags
+		= ifas[map_newlink (ifam->ifa_index - 1, ifas,
+				    map_newlink_data, newlink)].ifa.ifa_flags;
+	      if (ifa_index > 0)
+		ifas[ifa_index - 1].ifa.ifa_next = &ifas[ifa_index].ifa;
+	      ++newaddr_idx;
+
+	      while (RTA_OK (rta, rtasize))
+		{
+		  char *rta_data = RTA_DATA (rta);
+		  size_t rta_payload = RTA_PAYLOAD (rta);
+
+		  switch (rta->rta_type)
+		    {
+		    case IFA_ADDRESS:
+		      {
+			struct sockaddr *sa;
+
+			if (ifas[ifa_index].ifa.ifa_addr != NULL)
+			  {
+			    /* In a point-to-poing network IFA_ADDRESS
+			       contains the destination address, local
+			       address is supplied in IFA_LOCAL attribute.
+			       destination address and broadcast address
+			       are stored in an union, so it doesn't matter
+			       which name we use.  */
+			    ifas[ifa_index].ifa.ifa_broadaddr
+			      = &ifas[ifa_index].broadaddr.sa;
+			    sa = &ifas[ifa_index].broadaddr.sa;
+			  }
+			else
+			  {
+			    ifas[ifa_index].ifa.ifa_addr
+			      = &ifas[ifa_index].addr.sa;
+			    sa = &ifas[ifa_index].addr.sa;
+			  }
+
+			sa->sa_family = ifam->ifa_family;
+
+			switch (ifam->ifa_family)
+			  {
+			  case AF_INET:
+			    /* Size must match that of an address for IPv4.  */
+			    if (rta_payload == 4)
+			      memcpy (&((struct sockaddr_in *) sa)->sin_addr,
+				      rta_data, rta_payload);
+			    break;
+
+			  case AF_INET6:
+			    /* Size must match that of an address for IPv6.  */
+			    if (rta_payload == 16)
+			      {
+				memcpy (&((struct sockaddr_in6 *) sa)->sin6_addr,
+					rta_data, rta_payload);
+				if (IN6_IS_ADDR_LINKLOCAL (rta_data)
+				    || IN6_IS_ADDR_MC_LINKLOCAL (rta_data))
+				  ((struct sockaddr_in6 *) sa)->sin6_scope_id
+				    = ifam->ifa_index;
+			      }
+			    break;
+
+			  default:
+			    if (rta_payload <= sizeof (ifas[ifa_index].addr))
+			      memcpy (sa->sa_data, rta_data, rta_payload);
+			    break;
+			  }
+		      }
+		      break;
+
+		    case IFA_LOCAL:
+		      if (ifas[ifa_index].ifa.ifa_addr != NULL)
+			{
+			  /* If ifa_addr is set and we get IFA_LOCAL,
+			     assume we have a point-to-point network.
+			     Move address to correct field.  */
+			  ifas[ifa_index].broadaddr = ifas[ifa_index].addr;
+			  ifas[ifa_index].ifa.ifa_broadaddr
+			    = &ifas[ifa_index].broadaddr.sa;
+			  memset (&ifas[ifa_index].addr, '\0',
+				  sizeof (ifas[ifa_index].addr));
+			}
+
+		      ifas[ifa_index].ifa.ifa_addr = &ifas[ifa_index].addr.sa;
+		      ifas[ifa_index].ifa.ifa_addr->sa_family
+			= ifam->ifa_family;
+
+		      switch (ifam->ifa_family)
+			{
+			case AF_INET:
+			  /* Size must match that of an address for IPv4.  */
+			  if (rta_payload == 4)
+			    memcpy (&ifas[ifa_index].addr.s4.sin_addr,
+				  rta_data, rta_payload);
+			  break;
+
+			case AF_INET6:
+			  /* Size must match that of an address for IPv6.  */
+			  if (rta_payload == 16)
+			    {
+			      memcpy (&ifas[ifa_index].addr.s6.sin6_addr,
+				      rta_data, rta_payload);
+			      if (IN6_IS_ADDR_LINKLOCAL (rta_data)
+				  || IN6_IS_ADDR_MC_LINKLOCAL (rta_data))
+				ifas[ifa_index].addr.s6.sin6_scope_id =
+				  ifam->ifa_index;
+			    }
+			  break;
+
+			default:
+			  if (rta_payload <= sizeof (ifas[ifa_index].addr))
+			    memcpy (ifas[ifa_index].addr.sa.sa_data,
+				    rta_data, rta_payload);
+			  break;
+			}
+		      break;
+
+		    case IFA_BROADCAST:
+		      /* We get IFA_BROADCAST, so IFA_LOCAL was too much.  */
+		      if (ifas[ifa_index].ifa.ifa_broadaddr != NULL)
+			memset (&ifas[ifa_index].broadaddr, '\0',
+				sizeof (ifas[ifa_index].broadaddr));
+
+		      ifas[ifa_index].ifa.ifa_broadaddr
+			= &ifas[ifa_index].broadaddr.sa;
+		      ifas[ifa_index].ifa.ifa_broadaddr->sa_family
+			= ifam->ifa_family;
+
+		      switch (ifam->ifa_family)
+			{
+			case AF_INET:
+			  /* Size must match that of an address for IPv4.  */
+			  if (rta_payload == 4)
+			    memcpy (&ifas[ifa_index].broadaddr.s4.sin_addr,
+				    rta_data, rta_payload);
+			  break;
+
+			case AF_INET6:
+			  /* Size must match that of an address for IPv6.  */
+			  if (rta_payload == 16)
+			    {
+			      memcpy (&ifas[ifa_index].broadaddr.s6.sin6_addr,
+				      rta_data, rta_payload);
+			      if (IN6_IS_ADDR_LINKLOCAL (rta_data)
+				  || IN6_IS_ADDR_MC_LINKLOCAL (rta_data))
+				ifas[ifa_index].broadaddr.s6.sin6_scope_id
+				  = ifam->ifa_index;
+			    }
+			  break;
+
+			default:
+			  if (rta_payload <= sizeof (ifas[ifa_index].addr))
+			    memcpy (&ifas[ifa_index].broadaddr.sa.sa_data,
+				    rta_data, rta_payload);
+			  break;
+			}
+		      break;
+
+		    case IFA_LABEL:
+		      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,
+					       rta_payload) = '\0';
+			}
+		      else
+			abort ();
+		      break;
+
+		    case IFA_UNSPEC:
+		      break;
+		    case IFA_CACHEINFO:
+		      break;
+		    default:
+		      break;
+		    }
+
+		  rta = RTA_NEXT (rta, rtasize);
+		}
+
+	      /* If we didn't get the interface name with the
+		 address, use the name from the interface entry.  */
+	      if (ifas[ifa_index].ifa.ifa_name == NULL)
+		ifas[ifa_index].ifa.ifa_name
+		  = ifas[map_newlink (ifam->ifa_index - 1, ifas,
+				      map_newlink_data, newlink)].ifa.ifa_name;
+
+	      /* Calculate the netmask.  */
+	      if (ifas[ifa_index].ifa.ifa_addr
+		  && ifas[ifa_index].ifa.ifa_addr->sa_family != AF_UNSPEC
+		  && ifas[ifa_index].ifa.ifa_addr->sa_family != AF_PACKET)
+		{
+		  uint32_t max_prefixlen = 0;
+		  char *cp = NULL;
+
+		  ifas[ifa_index].ifa.ifa_netmask
+		    = &ifas[ifa_index].netmask.sa;
+
+		  switch (ifas[ifa_index].ifa.ifa_addr->sa_family)
+		    {
+		    case AF_INET:
+		      cp = (char *) &ifas[ifa_index].netmask.s4.sin_addr;
+		      max_prefixlen = 32;
+		      break;
+
+		    case AF_INET6:
+		      cp = (char *) &ifas[ifa_index].netmask.s6.sin6_addr;
+		      max_prefixlen = 128;
+		      break;
+		    }
+
+		  ifas[ifa_index].ifa.ifa_netmask->sa_family
+		    = ifas[ifa_index].ifa.ifa_addr->sa_family;
+
+		  if (cp != NULL)
+		    {
+		      char c;
+		      unsigned int preflen;
+
+		      if ((max_prefixlen > 0) &&
+			  (ifam->ifa_prefixlen > max_prefixlen))
+			preflen = max_prefixlen;
+		      else
+			preflen = ifam->ifa_prefixlen;
+
+		      for (i = 0; i < (preflen / 8); i++)
+			*cp++ = 0xff;
+		      c = 0xff;
+		      c <<= (8 - (preflen % 8));
+		      *cp = c;
+		    }
+		}
+	    }
+	}
+    }
+
+  assert (ifa_data_ptr <= (char *) &ifas[newlink + newaddr] + ifa_data_size);
+
+  if (newaddr_idx > 0)
+    {
+      for (i = 0; i < newlink; ++i)
+	if (map_newlink_data[i] == -1)
+	  {
+	    /* We have fewer links then we anticipated.  Adjust the
+	       forward pointer to the first address entry.  */
+	    ifas[i - 1].ifa.ifa_next = &ifas[newlink].ifa;
+	  }
+
+      if (i == 0 && newlink > 0)
+	/* No valid link, but we allocated memory.  We have to
+	   populate the first entry.  */
+	memmove (ifas, &ifas[newlink], sizeof (struct ifaddrs_storage));
+    }
+
+  if (ifap != NULL)
+    *ifap = &ifas[0].ifa;
+
+ exit_free:
+  __netlink_free_handle (&nh);
+  __netlink_close (&nh);
+
+  return result;
+}
+
+
+#if __ASSUME_NETLINK_SUPPORT != 0
+void
+freeifaddrs (struct ifaddrs *ifa)
+{
+  free (ifa);
+}
+#endif
+
+#endif /* unused code */
+
+#endif /* __ASSUME_NETLINK_SUPPORT */