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/** BEGIN COPYRIGHT BLOCK
* Copyright (C) 2001 Sun Microsystems, Inc. Used by permission.
* Copyright (C) 2005 Red Hat, Inc.
* All rights reserved.
* END COPYRIGHT BLOCK **/
/*
* dnsdmain.c: DNS domain guessing stuff moved out of dns.c because of the
* string ball problems
*/
#include "netsite.h"
#include <string.h>
#include <stdio.h>
#ifdef XP_UNIX
#include <unistd.h>
#endif
#include <ctype.h>
#include "util.h"
/* Under NT, this is taken care of by net.h including winsock.h */
#ifdef XP_UNIX
#include <netdb.h> /* struct hostent */
#endif
extern "C" {
#include <nspr.h>
}
/* This is contained in resolv.h on most systems. */
#define _PATH_RESCONF "/etc/resolv.conf"
#ifdef XP_UNIX
NSPR_BEGIN_EXTERN_C
#ifdef Linux
extern int getdomainname(char *, size_t);
#else
extern int getdomainname(char *, int);
#endif /* Linux */
#if defined(HPUX) || defined (UnixWare) || defined(Linux) || defined(IRIX6_5)
extern int gethostname (char *name, size_t namelen);
#else
#ifndef AIX
extern int gethostname (char *name, int namelen);
#endif
#endif
NSPR_END_EXTERN_C
#endif
/* ---------------------------- dns_guess_domain -------------------------- */
extern "C" NSAPI_PUBLIC char *dns_guess_domain(char * hname)
{
FILE *f;
char * cp;
int hnlen;
char line[256];
static int dnlen = 0;
static char * domain = 0;
PRHostEnt hent;
char buf[PR_NETDB_BUF_SIZE];
PRStatus err;
/* Sanity check */
if (strchr(hname, '.')) {
return STRDUP(hname);
}
if (dnlen == 0) {
/* First try a little trick that seems to often work... */
/*
* Get the local host name, even it doesn't come back
* fully qualified.
*/
line[0] = 0;
gethostname(line, sizeof(line));
if (line[0] != 0) {
/* Is it fully qualified? */
domain = strchr(line, '.');
if (domain == 0) {
/* No, try gethostbyname() */
err = PR_GetHostByName(line,
buf,
PR_NETDB_BUF_SIZE,
&hent);
if (err == PR_SUCCESS) {
/* See if h_name is fully-qualified */
if (hent.h_name) domain = strchr(hent.h_name, '.');
/* Otherwise look for a fully qualified alias */
if ((domain == 0) &&
(hent.h_aliases && hent.h_aliases[0])) {
char **p;
for (p = hent.h_aliases; *p; ++p) {
domain = strchr(*p, '.');
if (domain) break;
}
}
}
}
}
/* Still no luck? */
if (domain == 0) {
f = fopen(_PATH_RESCONF, "r");
/* See if there's a domain entry in their resolver configuration */
if(f) {
while(fgets(line, sizeof(line), f)) {
if(!strncasecmp(line, "domain ", 7)) {
for (cp = &line[7]; *cp && isspace(*cp); ++cp) ;
if (*cp) {
domain = cp;
for (; *cp && !isspace(*cp); ++cp) ;
*cp = 0;
}
break;
}
}
fclose(f);
}
}
#ifndef NO_DOMAINNAME
if (domain == 0) {
/* No domain found. Try getdomainname. */
getdomainname(line, sizeof(line));
if (line[0] != 0) domain = &line[0];
}
#endif
if (domain != 0) {
if (domain[0] == '.') ++domain;
domain = STRDUP(domain);
dnlen = strlen(domain);
}
else dnlen = -1;
}
if (domain != 0) {
hnlen = strlen(hname);
if ((hnlen + dnlen + 2) <= sizeof(line)) {
strcpy(line, hname);
line[hnlen] = '.';
strcpy(&line[hnlen+1], domain);
return STRDUP(line);
}
}
return 0;
}
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