authd/reslist.c

   1 /*
   2  * reslist.c - get nameservers from windows *
   3  *
   4  * ircd-ratbox related changes are as follows
   5  *
   6  * Copyright (C) 2008 Aaron Sethman <androsyn@ratbox.org>
   7  * Copyright (C) 2008-2012 ircd-ratbox development team
   8  *
   9  * pretty much all of this was yanked from c-ares ares_init.c here is the original
  10  * header from there --
  11  *
  12  * Id: ares_init.c,v 1.72 2008-05-15 00:00:19 yangtse Exp $
  13  * Copyright 1998 by the Massachusetts Institute of Technology.
  14  * Copyright (C) 2007-2008 by Daniel Stenberg
  15  *
  16  * Permission to use, copy, modify, and distribute this
  17  * software and its documentation for any purpose and without
  18  * fee is hereby granted, provided that the above copyright
  19  * notice appear in all copies and that both that copyright
  20  * notice and this permission notice appear in supporting
  21  * documentation, and that the name of M.I.T. not be used in
  22  * advertising or publicity pertaining to distribution of the
  23  * software without specific, written prior permission.
  24  * M.I.T. makes no representations about the suitability of
  25  * this software for any purpose.  It is provided "as is"
  26  * without express or implied warranty.
  27  *
  28  *
  29  */
  30
  31 #ifdef _WIN32
  32 #include <rb_lib.h>
  33
  34 #include <windows.h>
  35 #include <iphlpapi.h>
  36
  37 const char *get_windows_nameservers(void);
  38
  39
  40 #define IS_NT()        ((int)GetVersion() > 0)
  41 #define WIN_NS_9X      "System\\CurrentControlSet\\Services\\VxD\\MSTCP"
  42 #define WIN_NS_NT_KEY  "System\\CurrentControlSet\\Services\\Tcpip\\Parameters"
  43 #define NAMESERVER     "NameServer"
  44 #define DHCPNAMESERVER "DhcpNameServer"
  45 #define DATABASEPATH   "DatabasePath"
  46 #define WIN_PATH_HOSTS  "\\hosts"
  47
  48 static int
  49 get_iphlpapi_dns_info(char *ret_buf, size_t ret_size)
  50 {
  51         FIXED_INFO *fi = alloca(sizeof(*fi));
  52         DWORD size = sizeof(*fi);
  53         typedef DWORD(WINAPI * get_net_param_func) (FIXED_INFO *, DWORD *);
  54         get_net_param_func xxGetNetworkParams;  /* available only on Win-98/2000+ */
  55         HMODULE handle;
  56         IP_ADDR_STRING *ipAddr;
  57         int i, count = 0;
  58         int debug = 0;
  59         size_t ip_size = sizeof("255.255.255.255,") - 1;
  60         size_t left = ret_size;
  61         char *ret = ret_buf;
  62         HRESULT res;
  63
  64         if(!fi)
  65                 return (0);
  66
  67         handle = LoadLibrary("iphlpapi.dll");
  68         if(!handle)
  69                 return (0);
  70
  71         xxGetNetworkParams = (get_net_param_func) GetProcAddress(handle, "GetNetworkParams");
  72         if(!xxGetNetworkParams)
  73                 goto quit;
  74
  75         res = (*xxGetNetworkParams) (fi, &size);
  76         if((res != ERROR_BUFFER_OVERFLOW) && (res != ERROR_SUCCESS))
  77                 goto quit;
  78
  79         fi = alloca(size);
  80         if(!fi || (*xxGetNetworkParams) (fi, &size) != ERROR_SUCCESS)
  81                 goto quit;
  82
  83         if(debug)
  84         {
  85                 printf("Host Name: %s\n", fi->HostName);
  86                 printf("Domain Name: %s\n", fi->DomainName);
  87                 printf("DNS Servers:\n" "    %s (primary)\n", fi->DnsServerList.IpAddress.String);
  88         }
  89         if(strlen(fi->DnsServerList.IpAddress.String) > 0 &&
  90            inet_addr(fi->DnsServerList.IpAddress.String) != INADDR_NONE && left > ip_size)
  91         {
  92                 ret += sprintf(ret, "%s,", fi->DnsServerList.IpAddress.String);
  93                 left -= ret - ret_buf;
  94                 count++;
  95         }
  96
  97         for(i = 0, ipAddr = fi->DnsServerList.Next; ipAddr && left > ip_size;
  98             ipAddr = ipAddr->Next, i++)
  99         {
 100                 if(inet_addr(ipAddr->IpAddress.String) != INADDR_NONE)
 101                 {
 102                         ret += sprintf(ret, "%s,", ipAddr->IpAddress.String);
 103                         left -= ret - ret_buf;
 104                         count++;
 105                 }
 106                 if(debug)
 107                         printf("    %s (secondary %d)\n", ipAddr->IpAddress.String, i + 1);
 108         }
 109
 110       quit:
 111         if(handle)
 112                 FreeLibrary(handle);
 113
 114         if(debug && left <= ip_size)
 115                 printf("Too many nameservers. Truncating to %d addressess", count);
 116         if(ret > ret_buf)
 117                 ret[-1] = '\0';
 118         return (count);
 119 }
 120
 121 /*
 122  * Warning: returns a dynamically allocated buffer, the user MUST
 123  * use free() / rb_free() if the function returns 1
 124  */
 125 static int
 126 get_res_nt(HKEY hKey, const char *subkey, char **obuf)
 127 {
 128         /* Test for the size we need */
 129         DWORD size = 0;
 130         int result;
 131
 132         result = RegQueryValueEx(hKey, subkey, 0, NULL, NULL, &size);
 133         if((result != ERROR_SUCCESS && result != ERROR_MORE_DATA) || !size)
 134                 return 0;
 135         *obuf = rb_malloc(size + 1);
 136         if(!*obuf)
 137                 return 0;
 138
 139         if(RegQueryValueEx(hKey, subkey, 0, NULL, (LPBYTE) * obuf, &size) != ERROR_SUCCESS)
 140         {
 141                 rb_free(*obuf);
 142                 return 0;
 143         }
 144         if(size == 1)
 145         {
 146                 rb_free(*obuf);
 147                 return 0;
 148         }
 149         return 1;
 150 }
 151
 152 static int
 153 get_res_interfaces_nt(HKEY hKey, const char *subkey, char **obuf)
 154 {
 155         char enumbuf[39];       /* GUIDs are 38 chars + 1 for NULL */
 156         DWORD enum_size = 39;
 157         int idx = 0;
 158         HKEY hVal;
 159
 160         while(RegEnumKeyEx(hKey, idx++, enumbuf, &enum_size, 0,
 161                            NULL, NULL, NULL) != ERROR_NO_MORE_ITEMS)
 162         {
 163                 int rc;
 164
 165                 enum_size = 39;
 166                 if(RegOpenKeyEx(hKey, enumbuf, 0, KEY_QUERY_VALUE, &hVal) != ERROR_SUCCESS)
 167                         continue;
 168                 rc = get_res_nt(hVal, subkey, obuf);
 169                 RegCloseKey(hVal);
 170                 if(rc)
 171                         return 1;
 172         }
 173         return 0;
 174 }
 175
 176 const char *
 177 get_windows_nameservers(void)
 178 {
 179         /*
 180            NameServer info via IPHLPAPI (IP helper API):
 181            GetNetworkParams() should be the trusted source for this.
 182            Available in Win-98/2000 and later. If that fail, fall-back to
 183            registry information.
 184
 185            NameServer Registry:
 186
 187            On Windows 9X, the DNS server can be found in:
 188            HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\VxD\MSTCP\NameServer
 189
 190            On Windows NT/2000/XP/2003:
 191            HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\NameServer
 192            or
 193            HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\DhcpNameServer
 194            or
 195            HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\{AdapterID}\
 196            NameServer
 197            or
 198            HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\{AdapterID}\
 199            DhcpNameServer
 200          */
 201         static char namelist[512];
 202         HKEY mykey;
 203         HKEY subkey;
 204         DWORD data_type;
 205         DWORD bytes;
 206         DWORD result;
 207         char *line = NULL;
 208         memset(&namelist, 0, sizeof(namelist));
 209         if(get_iphlpapi_dns_info(namelist, sizeof(namelist)) > 0)
 210         {
 211                 return namelist;
 212         }
 213
 214         if(IS_NT())
 215         {
 216                 if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, WIN_NS_NT_KEY, 0,
 217                                 KEY_READ, &mykey) == ERROR_SUCCESS)
 218                 {
 219                         RegOpenKeyEx(mykey, "Interfaces", 0,
 220                                      KEY_QUERY_VALUE | KEY_ENUMERATE_SUB_KEYS, &subkey);
 221                         if(get_res_nt(mykey, NAMESERVER, &line))
 222                         {
 223                                 rb_strlcpy(namelist, line, sizeof(namelist));
 224                                 return namelist;
 225                         }
 226                         else if(get_res_nt(mykey, DHCPNAMESERVER, &line))
 227                         {
 228                                 rb_strlcpy(namelist, line, sizeof(namelist));
 229                                 rb_free(line);
 230                         }
 231                         /* Try the interfaces */
 232                         else if(get_res_interfaces_nt(subkey, NAMESERVER, &line))
 233                         {
 234                                 rb_strlcpy(namelist, line, sizeof(namelist));
 235                                 rb_free(line);
 236                         }
 237                         else if(get_res_interfaces_nt(subkey, DHCPNAMESERVER, &line))
 238                         {
 239                                 rb_strlcpy(namelist, line, sizeof(namelist));
 240                                 rb_free(line);
 241                         }
 242                         RegCloseKey(subkey);
 243                         RegCloseKey(mykey);
 244                 }
 245         }
 246         else
 247         {
 248                 if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, WIN_NS_9X, 0,
 249                                 KEY_READ, &mykey) == ERROR_SUCCESS)
 250                 {
 251                         if((result = RegQueryValueEx(mykey, NAMESERVER, NULL, &data_type,
 252                                                      NULL, &bytes)) == ERROR_SUCCESS ||
 253                            result == ERROR_MORE_DATA)
 254                         {
 255                                 if(bytes)
 256                                 {
 257                                         line = (char *)rb_malloc(bytes + 1);
 258                                         if(RegQueryValueEx(mykey, NAMESERVER, NULL, &data_type,
 259                                                            (unsigned char *)line, &bytes) ==
 260                                            ERROR_SUCCESS)
 261                                         {
 262                                                 rb_strlcpy(namelist, line, sizeof(namelist));
 263                                         }
 264                                         free(line);
 265                                 }
 266                         }
 267                 }
 268                 RegCloseKey(mykey);
 269         }
 270         if(strlen(namelist) > 0)
 271                 return namelist;
 272         return NULL;
 273 }
 274
 275
 276 #endif