sysdeps/mach/hurd/if_index.c

   1 /* Find network interface names and index numbers.  Hurd version.
   2    Copyright (C) 2000-2024 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <error.h>
  20 #include <net/if.h>
  21 #include <string.h>
  22 #include <sys/ioctl.h>
  23 #include <unistd.h>
  24
  25 #include <hurd.h>
  26 #include <hurd/ioctl.h>
  27 #include <hurd/pfinet.h>
  28
  29 /* Return the interface index corresponding to interface IFNAME.
  30    On error, return 0.  */
  31 unsigned int
  32 __if_nametoindex (const char *ifname)
  33 {
  34   struct ifreq ifr;
  35   int fd = __socket (AF_INET, SOCK_DGRAM, 0);
  36
  37   if (fd < 0)
  38     return 0;
  39
  40   if (strlen (ifname) >= IFNAMSIZ)
  41     return __hurd_fail (ENODEV), 0;
  42
  43   strncpy (ifr.ifr_name, ifname, IFNAMSIZ);
  44   if (__ioctl (fd, SIOCGIFINDEX, &ifr) < 0)
  45     {
  46       int saved_errno = errno;
  47       __close (fd);
  48       if (saved_errno == EINVAL || saved_errno == ENOTTY)
  49         __hurd_fail (ENOSYS);
  50       return 0;
  51     }
  52   __close (fd);
  53   return ifr.ifr_ifindex;
  54 }
  55 libc_hidden_def (__if_nametoindex)
  56 weak_alias (__if_nametoindex, if_nametoindex)
  57 libc_hidden_weak (if_nametoindex)
  58
  59 /* Free the structure IFN returned by if_nameindex.  */
  60 void
  61 __if_freenameindex (struct if_nameindex *ifn)
  62 {
  63   struct if_nameindex *ptr = ifn;
  64   while (ptr->if_name || ptr->if_index)
  65     {
  66       free (ptr->if_name);
  67       ++ptr;
  68     }
  69   free (ifn);
  70 }
  71 libc_hidden_def (__if_freenameindex)
  72 weak_alias (__if_freenameindex, if_freenameindex)
  73 libc_hidden_weak (if_freenameindex)
  74
  75 /* Return an array of if_nameindex structures, one for each network
  76    interface present, plus one indicating the end of the array.  On
  77    error, return NULL.  */
  78 struct if_nameindex *
  79 __if_nameindex (void)
  80 {
  81   error_t err = 0;
  82   char data[2048];
  83   file_t server;
  84   int fd = __socket (AF_INET, SOCK_DGRAM, 0);
  85   struct ifconf ifc;
  86   unsigned int nifs, i;
  87   struct if_nameindex *idx = NULL;
  88
  89   ifc.ifc_buf = data;
  90
  91   if (fd < 0)
  92     return NULL;
  93
  94   server = _hurd_socket_server (PF_INET, 0);
  95   if (server == MACH_PORT_NULL)
  96     nifs = 0;
  97   else
  98     {
  99       mach_msg_type_number_t len = sizeof data;
 100       err = __pfinet_siocgifconf (server, -1, &ifc.ifc_buf, &len);
 101       if (err == MACH_SEND_INVALID_DEST || err == MIG_SERVER_DIED)
 102         {
 103           /* On the first use of the socket server during the operation,
 104              allow for the old server port dying.  */
 105           server = _hurd_socket_server (PF_INET, 1);
 106           if (server == MACH_PORT_NULL)
 107             goto out;
 108           err = __pfinet_siocgifconf (server, -1, &ifc.ifc_buf, &len);
 109         }
 110       if (err)
 111         goto out;
 112
 113       ifc.ifc_len = len;
 114       nifs = len / sizeof (struct ifreq);
 115     }
 116
 117   idx = malloc ((nifs + 1) * sizeof (struct if_nameindex));
 118   if (idx == NULL)
 119     {
 120       err = ENOBUFS;
 121       goto out;
 122     }
 123
 124   for (i = 0; i < nifs; ++i)
 125     {
 126       struct ifreq *ifr = &ifc.ifc_req[i];
 127       idx[i].if_name = __strdup (ifr->ifr_name);
 128       if (idx[i].if_name == NULL
 129           || __ioctl (fd, SIOCGIFINDEX, ifr) < 0)
 130         {
 131           unsigned int j;
 132           err = errno;
 133
 134           for (j =  0; j < i; ++j)
 135             free (idx[j].if_name);
 136           free (idx);
 137           idx = NULL;
 138
 139           if (err == EINVAL)
 140             err = ENOSYS;
 141           else if (err == ENOMEM)
 142             err = ENOBUFS;
 143           goto out;
 144         }
 145       idx[i].if_index = ifr->ifr_ifindex;
 146     }
 147
 148   idx[i].if_index = 0;
 149   idx[i].if_name = NULL;
 150
 151  out:
 152   __close (fd);
 153   if (data != ifc.ifc_buf)
 154     __vm_deallocate (__mach_task_self (), (vm_address_t) ifc.ifc_buf,
 155                      ifc.ifc_len);
 156   __set_errno (err);
 157   return idx;
 158 }
 159 weak_alias (__if_nameindex, if_nameindex)
 160 libc_hidden_weak (if_nameindex)
 161
 162 /* Store the name of the interface corresponding to index IFINDEX in
 163    IFNAME (which has space for at least IFNAMSIZ characters).  Return
 164    IFNAME, or NULL on error.  */
 165 char *
 166 __if_indextoname (unsigned int ifindex, char ifname[IF_NAMESIZE])
 167 {
 168   struct ifreq ifr;
 169   int fd = __socket (AF_INET, SOCK_DGRAM, 0);
 170
 171   if (fd < 0)
 172     return NULL;
 173
 174   ifr.ifr_ifindex = ifindex;
 175   if (__ioctl (fd, SIOCGIFNAME, &ifr) < 0)
 176     {
 177       int saved_errno = errno;
 178       __close (fd);
 179       if (saved_errno == EINVAL || saved_errno == ENOTTY)
 180         __hurd_fail (ENOSYS);
 181       else if (saved_errno == ENODEV)
 182         __hurd_fail (ENXIO);
 183       return NULL;
 184     }
 185   __close (fd);
 186   return strncpy (ifname, ifr.ifr_name, IFNAMSIZ);
 187 }
 188 weak_alias (__if_indextoname, if_indextoname)
 189 libc_hidden_weak (if_indextoname)
 190
 191 #if 0
 192 void
 193 __protocol_available (int *have_inet, int *have_inet6)
 194 {
 195   *have_inet = _hurd_socket_server (PF_INET, 0) != MACH_PORT_NULL;
 196   *have_inet6 = _hurd_socket_server (PF_INET6, 0) != MACH_PORT_NULL;
 197 }
 198 #endif