get_machine_name.c

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/* $Id: get_machine_name.c,v 1.12 2006/02/15 16:43:15 seymour Exp $ */
/* $UTK_Copyright: $ */

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

#include "portability.h"
#include "utility.h"
#include "proxylib.h"

#define GS_HOST_NAME_MAX 1024
#define GS_DOMAIN_NAME_MAX 1024

char *gs_fallback_get_machine_name();

char *
gs_get_machine_name()
{
  const unsigned char *p;
  static char buf[16];
  struct hostent *hp;
  ipaddr_t myip; 

  myip = proxy_get_my_ipaddr();

  p = (const unsigned char *) &myip;
  sprintf(buf, "%u.%u.%u.%u",
          (unsigned int) (p[0] & 0xff), (unsigned int) (p[1] & 0xff),
          (unsigned int) (p[2] & 0xff), (unsigned int) (p[3] & 0xff));

  if(myip > 0) {
    if((hp = gethostbyaddr((char*)&myip, sizeof(myip), AF_INET)) != NULL) {
      if(!strstr(hp->h_name, ".")) {
        hp = gethostbyname(hp->h_name);
        if(hp && strstr(hp->h_name, "."))
          return strdup(hp->h_name);
      }
      else
        return strdup(hp->h_name);
    }
  }

  /* if the above failed, fall back to the old method */

  return gs_fallback_get_machine_name();
}

char *
gs_fallback_get_machine_name()
{
  char name[GS_HOST_NAME_MAX], domain[GS_DOMAIN_NAME_MAX],
     hostname[GS_HOST_NAME_MAX+GS_DOMAIN_NAME_MAX], *retval;

  if(gethostname(name, GS_HOST_NAME_MAX-1) == -1)
    return(strdup("localhost.localdomain"));

  name[GS_HOST_NAME_MAX-1] = 0;

  if(strlen(name) == 0)
    sprintf(name, "localhost");

  if(!strstr(name,".")) {
    if(getdomainname(domain, GS_DOMAIN_NAME_MAX-1) == -1)
      return(strdup("localhost.localdomain"));

    domain[GS_DOMAIN_NAME_MAX-1] = 0;

    if((strlen(domain) == 0) || !strcmp(domain, "(none)"))
      sprintf(domain, "localdomain");

    sprintf(hostname, "%s.%s", name, domain);

    retval = strdup(hostname);
  }
  else
    retval = strdup(name);

  return retval ? retval : strdup("localhost.localdomain");
}