lib/getfullhostname.c

   1 /*
   2  * Copyright (C) 1996-2021 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 #include "squid.h"
  10 #include "getfullhostname.h"
  11
  12 #if HAVE_UNISTD_H
  13 /* for gethostname() function */
  14 #include <unistd.h>
  15 #endif
  16 #if HAVE_NETDB_H
  17 /* for gethostbyname() */
  18 #include <netdb.h>
  19 #endif
  20
  21 /* for RFC 2181 constants */
  22 #include "rfc2181.h"
  23
  24 /* for xstrncpy() - may need breaking out of there. */
  25 #include "util.h"
  26
  27 /**
  28  * \retval nullptr  An error occurred.
  29  * \retval *        The fully qualified name (FQDN) of the current host.
  30  *                  Pointer is only valid until the next call to the
  31  *                  gethost*() functions.
  32  */
  33 const char *
  34 getfullhostname(void)
  35 {
  36     const struct hostent *hp = NULL;
  37     // TODO: make this dynamic so the duration limit is flexible
  38     static char buf[RFC2181_MAXHOSTNAMELEN + 1];
  39
  40     if (gethostname(buf, RFC2181_MAXHOSTNAMELEN) < 0)
  41         return NULL;
  42     // TODO: convert this to a getaddrinfo() call
  43     if ((hp = gethostbyname(buf)) != NULL)
  44         xstrncpy(buf, hp->h_name, RFC2181_MAXHOSTNAMELEN);
  45     return buf;
  46 }
  47