From: Samuel Thibault <samuel.thibault@ens-lyon.org>
Subject: [PATCH] Workaround to add IPv6 support to getifaddrs

ifreq only contains sockaddr structures, which are not big enough for
IPv6 addresses. This takes another, ugly, approach, by parsing fsysopts
/servers/socket/2 options...

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

---
 sysdeps/mach/hurd/ifaddrs.c | 310 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 310 insertions(+)

diff --git a/sysdeps/mach/hurd/ifaddrs.c b/sysdeps/mach/hurd/ifaddrs.c
new file mode 100644
index 0000000000..a07bd97715
--- /dev/null
+++ b/sysdeps/mach/hurd/ifaddrs.c
@@ -0,0 +1,310 @@
+/* getifaddrs -- get names and addresses of all network interfaces
+   Copyright (C) 2013-2015 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 <ifaddrs.h>
+#include <net/if.h>
+#include <sys/socket.h>
+#include <sys/mman.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <hurd.h>
+#include <hurd/paths.h>
+#include <hurd/lookup.h>
+#include <hurd/fs.h>
+
+/* 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)
+{
+  /* XXX: Hackish.  This assumes pfinet parameter style, and that the same
+     pfinet is on /servers/socket/2 and /servers/socket/26.
+
+     To be replaced by something like a netlink protocol, or fix ifreq into
+     using sockaddr_storage (but break existing compiled programs using it).  */
+
+  file_t node;
+  char *argz = 0, *cur;
+  size_t argz_len = 0;
+  unsigned naddrs;
+  const char *ifa_name = NULL;
+  char *addr, *cidr_a;
+  int cidr;
+
+  node = __file_name_lookup (_SERVERS_SOCKET "/2", 0, 0666);
+
+  if (node == MACH_PORT_NULL)
+    return -1;
+
+  __file_get_fs_options (node, &argz, &argz_len);
+
+  __mach_port_deallocate (__mach_task_self (), node);
+
+  /* XXX: Two hardcoded for lo */
+  naddrs = 2;
+
+  for (cur = argz; cur < argz + argz_len; cur = cur + strlen (cur) + 1)
+    {
+      if (!strncmp (cur, "--address=", 10))
+	  naddrs++;
+      else if (!strncmp (cur, "--address6=", 11))
+	  naddrs++;
+    }
+
+    {
+      struct
+      {
+	struct ifaddrs ia;
+	struct sockaddr_storage addr, netmask, broadaddr;
+	char name[IF_NAMESIZE];
+      } *storage;
+      int i;
+      struct sockaddr_in *sin;
+      struct sockaddr_in6 *sin6;
+
+      storage = malloc (naddrs * sizeof storage[0]);
+      if (storage == NULL)
+	{
+	  __munmap (argz, argz_len);
+	  return -1;
+	}
+
+      i = 0;
+
+      /* XXX: Hardcoded lo interface */
+      ifa_name = "lo";
+
+      /* 127.0.0.1/8 */
+      storage[i].ia.ifa_next = &storage[i + 1].ia;
+      storage[i].ia.ifa_name = strncpy (storage[i].name, ifa_name, sizeof (storage[i].name));
+
+      storage[i].ia.ifa_addr = (struct sockaddr *) &storage[i].addr;
+      sin = ((struct sockaddr_in *) &storage[i].addr);
+      sin->sin_family = AF_INET;
+      sin->sin_len = sizeof(*sin);
+      sin->sin_port = 0;
+      sin->sin_addr.s_addr = htonl (INADDR_LOOPBACK);
+
+      storage[i].ia.ifa_netmask = (struct sockaddr *) &storage[i].netmask;
+      sin = ((struct sockaddr_in *) &storage[i].netmask);
+      sin->sin_family = AF_INET;
+      sin->sin_len = sizeof(*sin);
+      sin->sin_port = 0;
+      sin->sin_addr.s_addr = htonl (IN_CLASSA_NET);
+
+      storage[i].ia.ifa_broadaddr = (struct sockaddr *) &storage[i].addr;
+
+      storage[i].ia.ifa_flags = IFF_UP | IFF_LOOPBACK | IFF_RUNNING;
+
+      storage[i].ia.ifa_data = NULL; /* Nothing here for now.  */
+
+      i++;
+
+      /* ::1/128 */
+      storage[i].ia.ifa_next = &storage[i + 1].ia;
+      storage[i].ia.ifa_name = strncpy (storage[i].name, ifa_name, sizeof (storage[i].name));
+
+      storage[i].ia.ifa_addr = (struct sockaddr *) &storage[i].addr;
+      sin6 = ((struct sockaddr_in6 *) &storage[i].addr);
+      sin6->sin6_family = AF_INET6;
+      sin6->sin6_len = sizeof(*sin6);
+      sin6->sin6_port = 0;
+      sin6->sin6_flowinfo = 0;
+      inet_pton (AF_INET6, "::1", &sin6->sin6_addr);
+      sin6->sin6_scope_id = 0;
+
+      storage[i].ia.ifa_netmask = (struct sockaddr *) &storage[i].netmask;
+      sin6 = ((struct sockaddr_in6 *) &storage[i].netmask);
+      sin6->sin6_family = AF_INET6;
+      sin6->sin6_len = sizeof(*sin6);
+      sin6->sin6_port = 0;
+      sin6->sin6_flowinfo = 0;
+      inet_pton (AF_INET6, "ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff", &sin6->sin6_addr);
+      sin6->sin6_scope_id = 0;
+
+      storage[i].ia.ifa_broadaddr = NULL;
+
+      storage[i].ia.ifa_flags = IFF_UP | IFF_LOOPBACK | IFF_RUNNING;
+
+      storage[i].ia.ifa_data = NULL; /* Nothing here for now.  */
+
+      for (cur = argz; cur < argz + argz_len; cur = cur + strlen (cur) + 1)
+	{
+	  if (!strncmp (cur, "--interface=", 12))
+	    {
+	      ifa_name = cur + 12;
+	      continue;
+	    }
+
+	  else if (!strncmp (cur, "--address=", 10))
+	    {
+	      i++;
+	      /* IPv4 address */
+	      addr = cur + 10;
+
+	      storage[i].ia.ifa_next = &storage[i + 1].ia;
+	      storage[i].ia.ifa_name = strncpy (storage[i].name, ifa_name, sizeof (storage[i].name));
+
+	      storage[i].ia.ifa_addr = (struct sockaddr *) &storage[i].addr;
+	      sin = ((struct sockaddr_in *) &storage[i].addr);
+	      sin->sin_family = AF_INET;
+	      sin->sin_len = sizeof(*sin);
+	      sin->sin_port = 0;
+	      inet_pton (AF_INET, addr, &sin->sin_addr);
+
+	      storage[i].ia.ifa_netmask = NULL;
+	      storage[i].ia.ifa_broadaddr = NULL;
+
+	      storage[i].ia.ifa_flags = IFF_UP | IFF_BROADCAST | IFF_RUNNING | IFF_MULTICAST;
+	      storage[i].ia.ifa_data = NULL; /* Nothing here for now.  */
+	    }
+
+	  else if (!strncmp (cur, "--netmask=", 10))
+	    {
+	      /* IPv4 netmask */
+	      addr = cur + 10;
+
+	      storage[i].ia.ifa_netmask = (struct sockaddr *) &storage[i].netmask;
+	      sin = ((struct sockaddr_in *) &storage[i].netmask);
+	      sin->sin_family = AF_INET;
+	      sin->sin_len = sizeof(*sin);
+	      sin->sin_port = 0;
+	      inet_pton (AF_INET, addr, &sin->sin_addr);
+
+	      storage[i].ia.ifa_broadaddr = (struct sockaddr *) &storage[i].broadaddr;
+	      sin = ((struct sockaddr_in *) &storage[i].broadaddr);
+	      sin->sin_family = AF_INET;
+	      sin->sin_len = sizeof(*sin);
+	      sin->sin_port = 0;
+	      sin->sin_addr.s_addr =
+		  ((struct sockaddr_in *) &storage[i].addr)->sin_addr.s_addr
+		| ~(((struct sockaddr_in *) &storage[i].netmask)->sin_addr.s_addr);
+	    }
+
+	  else if (!strncmp (cur, "--peer=", 7))
+	    {
+	      /* IPv4 peer */
+	      addr = cur + 7;
+
+	      storage[i].ia.ifa_dstaddr = (struct sockaddr *) &storage[i].broadaddr;
+	      sin = ((struct sockaddr_in *) &storage[i].broadaddr);
+	      sin->sin_family = AF_INET;
+	      sin->sin_len = sizeof(*sin);
+	      sin->sin_port = 0;
+	      inet_pton (AF_INET, addr, &sin->sin_addr);
+
+	      storage[i].ia.ifa_flags &= ~IFF_BROADCAST;
+	      storage[i].ia.ifa_flags |= IFF_POINTOPOINT;
+	    }
+
+	  else if (!strncmp (cur, "--address6=", 11))
+	    {
+	      i++;
+	      /* IPv6 address */
+	      addr = cur + 11;
+	      cidr_a = strchr (addr, '/');
+	      if (!cidr_a)
+		{
+		  /* No CIDR length?! Assume 64.  */
+		  addr = __strdup (addr);
+		  cidr = 64;
+		}
+	      else
+		{
+		  addr = __strndup (addr, cidr_a - addr);
+		  cidr = atoi (cidr_a + 1);
+		}
+
+	      storage[i].ia.ifa_next = &storage[i + 1].ia;
+	      storage[i].ia.ifa_name = strncpy (storage[i].name, ifa_name, sizeof (storage[i].name));
+
+	      storage[i].ia.ifa_addr = (struct sockaddr *) &storage[i].addr;
+	      sin6 = ((struct sockaddr_in6 *) &storage[i].addr);
+	      sin6->sin6_family = AF_INET6;
+	      sin6->sin6_len = sizeof(*sin6);
+	      sin6->sin6_port = 0;
+	      sin6->sin6_flowinfo = 0;
+	      inet_pton (AF_INET6, addr, &sin6->sin6_addr);
+	      sin6->sin6_scope_id = 0;
+
+	      storage[i].ia.ifa_netmask = (struct sockaddr *) &storage[i].netmask;
+	      sin6 = ((struct sockaddr_in6 *) &storage[i].netmask);
+	      sin6->sin6_family = AF_INET6;
+	      sin6->sin6_len = sizeof(*sin6);
+	      sin6->sin6_port = 0;
+	      sin6->sin6_flowinfo = 0;
+	      sin6->sin6_addr.s6_addr32[0] = htonl (cidr >=  32 ? 0xffffffffUL : cidr <=  0 ? 0 : ~((1UL << ( 32 - cidr)) - 1));
+	      sin6->sin6_addr.s6_addr32[1] = htonl (cidr >=  64 ? 0xffffffffUL : cidr <= 32 ? 0 : ~((1UL << ( 64 - cidr)) - 1));
+	      sin6->sin6_addr.s6_addr32[2] = htonl (cidr >=  96 ? 0xffffffffUL : cidr <= 64 ? 0 : ~((1UL << ( 96 - cidr)) - 1));
+	      sin6->sin6_addr.s6_addr32[3] = htonl (cidr >= 128 ? 0xffffffffUL : cidr <= 96 ? 0 : ~((1UL << (128 - cidr)) - 1));
+	      sin6->sin6_scope_id = 0;
+
+	      storage[i].ia.ifa_broadaddr = NULL;
+	      storage[i].ia.ifa_flags = IFF_UP | IFF_BROADCAST | IFF_RUNNING | IFF_MULTICAST;
+	      storage[i].ia.ifa_data = NULL; /* Nothing here for now.  */
+	      free (addr);
+	    }
+
+	  else if (!strncmp (cur, "--peer6=", 8))
+	    {
+	      /* IPv6 peer */
+	      addr = cur + 8;
+
+	      storage[i].ia.ifa_dstaddr = (struct sockaddr *) &storage[i].broadaddr;
+	      sin6 = ((struct sockaddr_in6 *) &storage[i].broadaddr);
+	      sin6->sin6_family = AF_INET6;
+	      sin6->sin6_len = sizeof(*sin6);
+	      sin6->sin6_port = 0;
+	      sin6->sin6_flowinfo = 0;
+	      inet_pton (AF_INET6, addr, &sin6->sin6_addr);
+	      sin6->sin6_scope_id = 0;
+
+	      storage[i].ia.ifa_flags &= ~IFF_BROADCAST;
+	      storage[i].ia.ifa_flags |= IFF_POINTOPOINT;
+	    }
+	}
+
+      storage[i].ia.ifa_next = NULL;
+
+      *ifap = &storage[0].ia;
+    }
+
+  __munmap (argz, argz_len);
+
+  return 0;
+}
+weak_alias (__getifaddrs, getifaddrs)
+libc_hidden_def (__getifaddrs)
+#ifndef getifaddrs
+libc_hidden_weak (getifaddrs)
+#endif
+
+void
+__freeifaddrs (struct ifaddrs *ifa)
+{
+  free (ifa);
+}
+weak_alias (__freeifaddrs, freeifaddrs)
+libc_hidden_def (__freeifaddrs)
+libc_hidden_weak (freeifaddrs)
-- 
tg: (7bb5f8a836..) t/ifaddrs_v6 (depends on: baseline)