source: trunk/third/moira/lib/fixhost.c @ 24319

/* $Id: fixhost.c 3956 2010-01-05 20:56:56Z zacheiss $
 *
 * Canonicalize a hostname
 *
 * Copyright (C) 1987-1998 by the Massachusetts Institute of Technology
 * For copying and distribution information, please see the file
 * <mit-copyright.h>.
 */

#include <mit-copyright.h>
#include <moira.h>

#include <sys/types.h>

#ifdef HAVE_UNAME
#include <sys/utsname.h>
#endif

#ifndef _WIN32
#include <sys/socket.h>
#include <netdb.h>
#include <netinet/in.h>
#endif /* _WIN32 */

#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

RCSID("$HeadURL: svn+ssh://svn.mit.edu/moira/trunk/moira/lib/fixhost.c $ $Id: fixhost.c 3956 2010-01-05 20:56:56Z zacheiss $");

static struct hostent *local_gethostbyname(void)
{
#ifdef HAVE_UNAME
  struct utsname name;
  uname(&name);
  return gethostbyname(name.nodename);
#else
  char hostname[128];
  gethostname(hostname, sizeof(hostname));
  hostname[sizeof(hostname)-1] = 0;
  return gethostbyname(hostname);
#endif
}

static char *local_domain(void)
{
  static char *domain = NULL;
  char *cp;
  struct hostent *hp;

  if (domain == NULL)
    {
      char hostbuf[256];

      if (mr_host(hostbuf, sizeof(hostbuf)) == MR_SUCCESS)
        {
          cp = strchr(hostbuf, '.');
          if (cp)
            domain = strdup(++cp);
        }
      else
        {
          hp = local_gethostbyname();
          if (hp)
            {
              cp = strchr(hp->h_name, '.');
              if (cp)
                domain = strdup(++cp);
            }
        }
      if (!domain)
        domain = "";
    }

  return domain;
}

/*
 * Canonicalize hostname:
 *  if it is in double-quotes, then strip the quotes and return the name.
 *  if it is in the namespace, call the nameserver to expand it
 *  otherwise uppercase it and append the default domain (using an, er,
 *    undocumented global of the nameserver).
 *
 * Assumes that host was allocated using malloc(); it may be freed or
 * realloc'ed, so the old pointer should not be considered valid.
 */

char *canonicalize_hostname(char *host)
{
  struct hostent *hp;
  int len;
  char *tbuf, *cp;

  len = strlen(host);
  if (len > 2 && host[0] == '"' && host[len - 1] == '"')
    {
      tbuf = malloc(len - 1);
      if (!tbuf)
        return NULL;
      strncpy(tbuf, host + 1, len - 2);
      tbuf[len - 2] = '\0';
      free(host);
      return tbuf;
    }

  if (strchr(host, '*') || strchr(host, '?') || *host == '[')
    return host;

  hp = gethostbyname(host);

  if (hp)
    {
      host = realloc(host, strlen(hp->h_name) + 1);
      if (host)
        strcpy(host, hp->h_name);
      return host;
    }
  else
    {
      /* can't get name from nameserver; fix up the format a bit */
      cp = strchr(host, '.');
      if (!cp)
        {
          tbuf = malloc(strlen(host) + strlen(local_domain()) + 2);
          if (!tbuf)
            return NULL;
          sprintf(tbuf, "%s.%s", host, local_domain());
          free(host);
          host = tbuf;
        }
      else if (strcasecmp(cp + 1, local_domain()) != 0)
        return host;

      /* This is a host in our local domain, so capitalize it. */
      for (cp = host; *cp; cp++)
        *cp = toupper(*cp);
      return host;
    }
}