1  /* Copyright (C) 1996-2023 Free Software Foundation, Inc.
       2     This file is part of the GNU C Library.
       3  
       4     The GNU C Library is free software; you can redistribute it and/or
       5     modify it under the terms of the GNU Lesser General Public
       6     License as published by the Free Software Foundation; either
       7     version 2.1 of the License, or (at your option) any later version.
       8  
       9     The GNU C Library is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      12     Lesser General Public License for more details.
      13  
      14     You should have received a copy of the GNU Lesser General Public
      15     License along with the GNU C Library; if not, see
      16     <https://www.gnu.org/licenses/>.  */
      17  
      18  #include <errno.h>
      19  #include <netinet/ether.h>
      20  #include <netinet/if_ether.h>
      21  #include <string.h>
      22  
      23  #include "../nss/nsswitch.h"
      24  
      25  /* Type of the lookup function we need here.  */
      26  typedef int (*lookup_function) (const char *, struct etherent *, char *, int,
      27  				int *);
      28  
      29  int
      30  ether_hostton (const char *hostname, struct ether_addr *addr)
      31  {
      32    nss_action_list nip;
      33    union
      34    {
      35      lookup_function f;
      36      void *ptr;
      37    } fct;
      38    int no_more;
      39    enum nss_status status = NSS_STATUS_UNAVAIL;
      40    struct etherent etherent;
      41  
      42    no_more = __nss_ethers_lookup2 (&nip, "gethostton_r", NULL, &fct.ptr);
      43  
      44    while (no_more == 0)
      45      {
      46        char buffer[1024];
      47  
      48        status = (*fct.f) (hostname, &etherent, buffer, sizeof buffer, &errno);
      49  
      50        no_more = __nss_next2 (&nip, "gethostton_r", NULL, &fct.ptr, status, 0);
      51      }
      52  
      53    if (status == NSS_STATUS_SUCCESS)
      54      memcpy (addr, etherent.e_addr.ether_addr_octet,
      55  	    sizeof (struct ether_addr));
      56  
      57    return status == NSS_STATUS_SUCCESS ? 0 : -1;
      58  }