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/** BEGIN COPYRIGHT BLOCK
* Copyright 2001 Sun Microsystems, Inc.
* Portions copyright 1999, 2001-2003 Netscape Communications Corporation.
* All rights reserved.
* END COPYRIGHT BLOCK **/
/*
* dns.c: DNS resolution routines
*
* Rob McCool
*/
#define DNS_GUESSING
#include "netsite.h"
#ifdef XP_UNIX
#include "systems.h"
#else /* XP_WIN32 */
#include "base/systems.h"
#endif /* XP_WIN32 */
#include "net.h" /* SYS_NETFD, various headers to do DNS */
/* Under NT, these are taken care of by net.h including winsock.h */
#ifdef XP_UNIX
#include <arpa/inet.h> /* inet_ntoa */
#include <netdb.h> /* struct hostent */
#ifdef NEED_GHN_PROTO
extern "C" int gethostname (char *name, size_t namelen);
#endif
#endif
#ifdef DNS_CACHE
#include "base/dns_cache.h"
#include "base/ereport.h"
#endif /* DNS_CACHE */
#include <stdio.h>
#include <nspr.h>
#include "frame/conf.h"
/* ---------------------------- dns_find_fqdn ----------------------------- */
/* defined in dnsdmain.c */
extern "C" NSAPI_PUBLIC char *dns_guess_domain(char * hname);
char *net_find_fqdn(PRHostEnt *p)
{
int x;
if((!p->h_name) || (!p->h_aliases))
return NULL;
if(!strchr(p->h_name, '.')) {
for(x = 0; p->h_aliases[x]; ++x) {
if((strchr(p->h_aliases[x], '.')) &&
(!strncmp(p->h_aliases[x], p->h_name, strlen(p->h_name))))
{
return STRDUP(p->h_aliases[x]);
}
}
#ifdef DNS_GUESSING
return dns_guess_domain(p->h_name);
#else
return NULL;
#endif /* DNS_GUESSING */
}
else
return STRDUP(p->h_name);
}
/* ----------------------------- dns_ip2host ------------------------------ */
char *dns_ip2host(char *ip, int verify)
{
/* struct in_addr iaddr; */
PRNetAddr iaddr;
char *hn;
#ifdef DNS_CACHE
dns_cache_entry_t *dns_entry;
#endif
static unsigned long laddr = 0;
static char myhostname[256];
PRHostEnt hent;
char buf[PR_NETDB_BUF_SIZE];
PRStatus err;
err = PR_InitializeNetAddr(PR_IpAddrNull, 0, &iaddr);
if((iaddr.inet.ip = inet_addr(ip)) == -1)
goto bong;
#ifdef DNS_CACHE
if ( (dns_entry = dns_cache_lookup_ip((unsigned int)iaddr.inet.ip)) ) {
hn = NULL;
if ( dns_entry->host &&
/* Only use entry if the cache entry has been verified or if
* verify is off...
*/
(dns_entry->verified || !verify) ) {
hn = STRDUP( dns_entry->host );
(void)dns_cache_use_decrement(dns_entry);
return hn;
}
dns_cache_delete(dns_entry);
dns_entry = 0;
}
#endif
/*
* See if it happens to be the localhost IP address, and try
* the local host name if so.
*/
if (laddr == 0) {
laddr = inet_addr("127.0.0.1");
myhostname[0] = 0;
PR_GetSystemInfo(PR_SI_HOSTNAME, myhostname, sizeof(myhostname));
}
/* Have to match the localhost IP address and have a hostname */
if ((iaddr.inet.ip == laddr) && (myhostname[0] != 0)) {
/*
* Now try for a fully-qualified domain name, starting with
* the local hostname.
*/
err = PR_GetHostByName(myhostname,
buf,
PR_NETDB_BUF_SIZE,
&hent);
/* Don't verify if we get a fully-qualified name this way */
verify = 0;
}
else {
err = PR_GetHostByAddr(&iaddr,
buf,
PR_NETDB_BUF_SIZE,
&hent);
}
if ((err == PR_FAILURE) || !(hn = net_find_fqdn(&hent))) goto bong;
if(verify) {
char **haddr = 0;
err = PR_GetHostByName(hn,
buf,
PR_NETDB_BUF_SIZE,
&hent);
if(err == PR_SUCCESS) {
for(haddr = hent.h_addr_list; *haddr; haddr++) {
if(((struct in_addr *)(*haddr))->s_addr == iaddr.inet.ip)
break;
}
}
if((err == PR_FAILURE) || (!(*haddr)))
goto bong;
}
#ifdef DNS_CACHE
if ( (dns_entry = dns_cache_insert(hn, (unsigned int)iaddr.inet.ip, verify)) ) {
(void) dns_cache_use_decrement(dns_entry);
}
#endif /* DNS_CACHE */
return hn;
bong:
#ifdef DNS_CACHE
/* Insert the lookup failure */
if ( (dns_entry = dns_cache_insert(NULL, (unsigned int)iaddr.inet.ip, verify)) ) {
(void) dns_cache_use_decrement(dns_entry);
}
#endif /* DNS_CACHE */
return NULL;
}
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