| /* 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" |
| #include <sys/types.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> |
| #endif |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #include "ares.h" |
| #include "ares_private.h" |
| |
| #ifdef WATT32 |
| #undef WIN32 |
| #endif |
| |
| struct addr_query { |
| /* Arguments passed to ares_gethostbyaddr() */ |
| ares_channel channel; |
| struct in_addr addr; |
| ares_host_callback callback; |
| void *arg; |
| |
| const char *remaining_lookups; |
| }; |
| |
| static void next_lookup(struct addr_query *aquery); |
| static void addr_callback(void *arg, int status, unsigned char *abuf, |
| int alen); |
| static void end_aquery(struct addr_query *aquery, int status, |
| struct hostent *host); |
| static int file_lookup(struct in_addr *addr, struct hostent **host); |
| |
| 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 || addrlen != sizeof(struct in_addr)) |
| { |
| callback(arg, ARES_ENOTIMP, NULL); |
| return; |
| } |
| |
| aquery = malloc(sizeof(struct addr_query)); |
| if (!aquery) |
| { |
| callback(arg, ARES_ENOMEM, NULL); |
| return; |
| } |
| aquery->channel = channel; |
| memcpy(&aquery->addr, addr, sizeof(aquery->addr)); |
| aquery->callback = callback; |
| aquery->arg = arg; |
| aquery->remaining_lookups = channel->lookups; |
| |
| next_lookup(aquery); |
| } |
| |
| static void next_lookup(struct addr_query *aquery) |
| { |
| const char *p; |
| char name[64]; |
| int a1, a2, a3, a4, status; |
| struct hostent *host; |
| unsigned long addr; |
| |
| for (p = aquery->remaining_lookups; *p; p++) |
| { |
| switch (*p) |
| { |
| case 'b': |
| addr = ntohl(aquery->addr.s_addr); |
| a1 = (int)((addr >> 24) & 0xff); |
| a2 = (int)((addr >> 16) & 0xff); |
| a3 = (int)((addr >> 8) & 0xff); |
| a4 = (int)(addr & 0xff); |
| sprintf(name, "%d.%d.%d.%d.in-addr.arpa", a4, a3, a2, a1); |
| 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, &host); |
| if (status != ARES_ENOTFOUND) |
| { |
| end_aquery(aquery, status, host); |
| return; |
| } |
| break; |
| } |
| } |
| end_aquery(aquery, ARES_ENOTFOUND, NULL); |
| } |
| |
| static void addr_callback(void *arg, int status, unsigned char *abuf, int alen) |
| { |
| struct addr_query *aquery = (struct addr_query *) arg; |
| struct hostent *host; |
| |
| if (status == ARES_SUCCESS) |
| { |
| status = ares_parse_ptr_reply(abuf, alen, &aquery->addr, |
| sizeof(struct in_addr), AF_INET, &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, host); |
| if (host) |
| ares_free_hostent(host); |
| free(aquery); |
| } |
| |
| static int file_lookup(struct in_addr *addr, struct hostent **host) |
| { |
| FILE *fp; |
| int status; |
| |
| #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, 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) |
| return ARES_ENOTFOUND; |
| |
| while ((status = ares__get_hostent(fp, host)) == ARES_SUCCESS) |
| { |
| if (memcmp((*host)->h_addr, addr, sizeof(struct in_addr)) == 0) |
| break; |
| ares_free_hostent(*host); |
| } |
| fclose(fp); |
| if (status == ARES_EOF) |
| status = ARES_ENOTFOUND; |
| if (status != ARES_SUCCESS) |
| *host = NULL; |
| return status; |
| } |