/** 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 /* inet_ntoa */ #include /* 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 #include #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; }