/* $Id$ */ /* Copyright 1998 by the Massachusetts Institute of Technology. * * Permission to use, copy, modify, and distribute this * software and its documentation for any purpose and without * fee is hereby granted, provided that the above copyright * notice appear in all copies and that both that copyright * notice and this permission notice appear in supporting * documentation, and that the name of M.I.T. not be used in * advertising or publicity pertaining to distribution of the * software without specific, written prior permission. * M.I.T. makes no representations about the suitability of * this software for any purpose. It is provided "as is" * without express or implied warranty. */ #include "setup.h" #if defined(WIN32) && !defined(WATT32) #include "nameser.h" #else #include <sys/socket.h> #include <netinet/in.h> #include <netdb.h> #include <arpa/nameser.h> #ifdef HAVE_ARPA_NAMESER_COMPAT_H #include <arpa/nameser_compat.h> #endif #endif #include <stdio.h> #include <stdlib.h> #include <string.h> #include "ares.h" #include "ares_private.h" #include "inet_net_pton.h" #ifdef WATT32 #undef WIN32 #endif struct addr_query { /* Arguments passed to ares_gethostbyaddr() */ ares_channel channel; union ares_addr addr; int family; ares_host_callback callback; void *arg; const char *remaining_lookups; int timeouts; }; static void next_lookup(struct addr_query *aquery); static void addr_callback(void *arg, int status, int timeouts, unsigned char *abuf, int alen); static void end_aquery(struct addr_query *aquery, int status, struct hostent *host); static int file_lookup(union ares_addr *addr, int family, struct hostent **host); static void ptr_rr_name(char *name, int family, union ares_addr *addr); void ares_gethostbyaddr(ares_channel channel, const void *addr, int addrlen, int family, ares_host_callback callback, void *arg) { struct addr_query *aquery; if (family != AF_INET && family != AF_INET6) { callback(arg, ARES_ENOTIMP, 0, NULL); return; } if ((family == AF_INET && addrlen != sizeof(struct in_addr)) || (family == AF_INET6 && addrlen != sizeof(struct in6_addr))) { callback(arg, ARES_ENOTIMP, 0, NULL); return; } aquery = malloc(sizeof(struct addr_query)); if (!aquery) { callback(arg, ARES_ENOMEM, 0, NULL); return; } aquery->channel = channel; if (family == AF_INET) memcpy(&aquery->addr.addr4, addr, sizeof(struct in_addr)); else memcpy(&aquery->addr.addr6, addr, sizeof(struct in6_addr)); aquery->family = family; aquery->callback = callback; aquery->arg = arg; aquery->remaining_lookups = channel->lookups; aquery->timeouts = 0; next_lookup(aquery); } static void next_lookup(struct addr_query *aquery) { const char *p; char name[128]; int status; struct hostent *host; for (p = aquery->remaining_lookups; *p; p++) { switch (*p) { case 'b': ptr_rr_name(name, aquery->family, &aquery->addr); aquery->remaining_lookups = p + 1; ares_query(aquery->channel, name, C_IN, T_PTR, addr_callback, aquery); return; case 'f': status = file_lookup(&aquery->addr, aquery->family, &host); /* this status check below previously checked for !ARES_ENOTFOUND, but we should not assume that this single error code is the one that can occur, as that is in fact no longer the case */ if (status == ARES_SUCCESS) { end_aquery(aquery, status, host); return; } break; } } end_aquery(aquery, ARES_ENOTFOUND, NULL); } static void addr_callback(void *arg, int status, int timeouts, unsigned char *abuf, int alen) { struct addr_query *aquery = (struct addr_query *) arg; struct hostent *host; aquery->timeouts += timeouts; if (status == ARES_SUCCESS) { if (aquery->family == AF_INET) status = ares_parse_ptr_reply(abuf, alen, &aquery->addr.addr4, sizeof(struct in_addr), AF_INET, &host); else status = ares_parse_ptr_reply(abuf, alen, &aquery->addr.addr6, sizeof(struct in6_addr), AF_INET6, &host); end_aquery(aquery, status, host); } else if (status == ARES_EDESTRUCTION) end_aquery(aquery, status, NULL); else next_lookup(aquery); } static void end_aquery(struct addr_query *aquery, int status, struct hostent *host) { aquery->callback(aquery->arg, status, aquery->timeouts, host); if (host) ares_free_hostent(host); free(aquery); } static int file_lookup(union ares_addr *addr, int family, struct hostent **host) { FILE *fp; int status; int error; #ifdef WIN32 char PATH_HOSTS[MAX_PATH]; if (IS_NT()) { char tmp[MAX_PATH]; HKEY hkeyHosts; if (RegOpenKeyEx(HKEY_LOCAL_MACHINE, WIN_NS_NT_KEY, 0, KEY_READ, &hkeyHosts) == ERROR_SUCCESS) { DWORD dwLength = MAX_PATH; RegQueryValueEx(hkeyHosts, DATABASEPATH, NULL, NULL, (LPBYTE)tmp, &dwLength); ExpandEnvironmentStrings(tmp, PATH_HOSTS, MAX_PATH); RegCloseKey(hkeyHosts); } } else GetWindowsDirectory(PATH_HOSTS, MAX_PATH); strcat(PATH_HOSTS, WIN_PATH_HOSTS); #elif defined(WATT32) extern const char *_w32_GetHostsFile (void); const char *PATH_HOSTS = _w32_GetHostsFile(); if (!PATH_HOSTS) return ARES_ENOTFOUND; #endif fp = fopen(PATH_HOSTS, "r"); if (!fp) { error = ERRNO; switch(error) { case ENOENT: case ESRCH: return ARES_ENOTFOUND; default: DEBUGF(fprintf(stderr, "fopen() failed with error: %d %s\n", error, strerror(error))); DEBUGF(fprintf(stderr, "Error opening file: %s\n", PATH_HOSTS)); *host = NULL; return ARES_EFILE; } } while ((status = ares__get_hostent(fp, family, host)) == ARES_SUCCESS) { if (family != (*host)->h_addrtype) { ares_free_hostent(*host); continue; } if (family == AF_INET) { if (memcmp((*host)->h_addr, &addr->addr4, sizeof(struct in_addr)) == 0) break; } else if (family == AF_INET6) { if (memcmp((*host)->h_addr, &addr->addr6, sizeof(struct in6_addr)) == 0) break; } ares_free_hostent(*host); } fclose(fp); if (status == ARES_EOF) status = ARES_ENOTFOUND; if (status != ARES_SUCCESS) *host = NULL; return status; } static void ptr_rr_name(char *name, int family, union ares_addr *addr) { if (family == AF_INET) { unsigned long laddr = ntohl(addr->addr4.s_addr); int a1 = (int)((laddr >> 24) & 0xff); int a2 = (int)((laddr >> 16) & 0xff); int a3 = (int)((laddr >> 8) & 0xff); int a4 = (int)(laddr & 0xff); sprintf(name, "%d.%d.%d.%d.in-addr.arpa", a4, a3, a2, a1); } else { unsigned char *bytes = (unsigned char *)&addr->addr6.s6_addr; sprintf(name, "%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x." "%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.ip6.arpa", bytes[15]&0xf, bytes[15] >> 4, bytes[14]&0xf, bytes[14] >> 4, bytes[13]&0xf, bytes[13] >> 4, bytes[12]&0xf, bytes[12] >> 4, bytes[11]&0xf, bytes[11] >> 4, bytes[10]&0xf, bytes[10] >> 4, bytes[9]&0xf, bytes[9] >> 4, bytes[8]&0xf, bytes[8] >> 4, bytes[7]&0xf, bytes[7] >> 4, bytes[6]&0xf, bytes[6] >> 4, bytes[5]&0xf, bytes[5] >> 4, bytes[4]&0xf, bytes[4] >> 4, bytes[3]&0xf, bytes[3] >> 4, bytes[2]&0xf, bytes[2] >> 4, bytes[1]&0xf, bytes[1] >> 4, bytes[0]&0xf, bytes[0] >> 4); } }