addons/Socket/source/LocalNameServers.c

   1 /*
   2  docCopyright("Steve Dekorte", 2002)
   3  docLicense("BSD revised")
   4  docDescription("Windows code by Mike Austin.")
   5  docCategory("Networking")
   6  */
   7
   8 #include "LocalNameServers.h"
   9 #include <ctype.h>
  10
  11 void LocalNameServers_findIps(LocalNameServers *self);
  12
  13 LocalNameServers *LocalNameServers_new(void)
  14 {
  15         LocalNameServers *self = (LocalNameServers *)calloc(1, sizeof(LocalNameServers));
  16         return self;
  17 }
  18
  19 void LocalNameServers_free(LocalNameServers *self)
  20 {
  21         if (self->ips)
  22         {
  23                 List_do_(self->ips, (ListDoCallback *)free);
  24         }
  25
  26         List_free(self->ips);
  27         free(self);
  28 }
  29
  30 List *LocalNameServers_ips(LocalNameServers *self)
  31 {
  32         if (!self->ips)
  33         {
  34                 self->ips = List_new();
  35                 LocalNameServers_findIps(self);
  36         }
  37
  38         return self->ips;
  39 }
  40
  41 void LocalNameServers_addIPAddress_(LocalNameServers *self, const char *s)
  42 {
  43         char *newIPAddress = strcpy(malloc(strlen(s) + 1), s);
  44         List_append_(self->ips, newIPAddress);
  45 }
  46
  47 // --- generic -----------------------------
  48
  49 #include <string.h>
  50 #include <stdlib.h>
  51 #include <stdio.h>
  52 #include "UArray.h"
  53
  54 static char *stringDeleteHashComment(char *s)
  55 {
  56         char *commentBeginning = strchr(s, '#');
  57
  58         if(!commentBeginning)
  59         {
  60                 commentBeginning = s + strlen(s);
  61         }
  62
  63         while(!isdigit(*commentBeginning))
  64         {
  65                 *commentBeginning-- = '\0';
  66         }
  67
  68         return s;
  69 }
  70
  71 static char *lastWhiteSpaceInString(char *s)
  72 {
  73         char *lastSpace = strrchr(s, ' ');
  74         char *lastTab = strrchr(s, '\t');
  75         char *lastWhiteSpace = lastSpace > lastTab ? lastSpace : lastTab;
  76         return lastWhiteSpace;
  77 }
  78
  79 static char *local_strdup(char *s) // because OSXs is buggy
  80 {
  81         return strcpy(malloc(strlen(s)+1), s);
  82 }
  83
  84 void LocalNameServers_findIpsViaResolveConf(LocalNameServers *self)
  85 {
  86         FILE *fp = fopen("/etc/resolv.conf", "r");
  87
  88         if (fp)
  89         {
  90                 UArray *ba = UArray_new();
  91
  92                 while (UArray_readLineFromCStream_(ba, fp))
  93                 {
  94                         char *line = (char *)UArray_bytes(ba);
  95
  96                         /*printf("line = %s\n", line);*/
  97                         if (strstr(line, "nameserver") == line)
  98                         {
  99                                 char *ip;
 100                                 char *s = local_strdup(line);
 101
 102                                 stringDeleteHashComment(s);
 103                                 ip = lastWhiteSpaceInString(s) + 1;
 104
 105                                 if (*ip)
 106                                 {
 107                                         //printf("LocalNameServers_findIps() found ip '%s'\n", ip);
 108                                         LocalNameServers_addIPAddress_(self, ip);
 109                                 }
 110
 111                                 free(s);
 112                         }
 113                         UArray_setSize_(ba, 0);
 114                 }
 115                 UArray_free(ba);
 116         }
 117 }
 118
 119
 120 #if defined(WIN32) || defined(__CYGWIN__)
 121
 122 // Windows -----------------------------------------
 123
 124 #include <winsock2.h>
 125 #include <iphlpapi.h>
 126
 127 void LocalNameServers_findIps(LocalNameServers *self)
 128 {
 129         FIXED_INFO info[16];
 130         ULONG len = sizeof(FIXED_INFO) * 16;
 131
 132         if (GetNetworkParams(info, &len) != ERROR_SUCCESS)
 133         {
 134                 printf("LocalNameServers error: GetNetworkParams() failed");
 135                 /*exit(1);*/
 136                 return;
 137         }
 138
 139
 140         {
 141                 IP_ADDR_STRING *addr = &info->DnsServerList;
 142
 143                 while (addr)
 144                 {
 145                         LocalNameServers_addIPAddress_(self, addr->IpAddress.String);
 146                         /*printf("%s\n", addr->IpIPAddress.String);*/
 147                         addr = addr->Next;
 148                 }
 149         }
 150 }
 151
 152 #elif defined(__APPLE__)
 153
 154 // OSX ----------------------------------------
 155
 156 void LocalNameServers_findIps(LocalNameServers *self)
 157 {
 158         char *path = tmpnam(NULL);
 159         char *command = malloc(1024);
 160         char *answerBuffer = calloc(1, 1024);
 161         char *answer = answerBuffer;
 162         FILE *fp;
 163
 164         sprintf(command, "dig | grep SERVER: > %s", path);
 165
 166         system(command);
 167
 168         fp = fopen(path, "r");
 169         fread(answer, 1, 1024, fp);
 170         fclose(fp);
 171         remove(path);
 172
 173         if (strlen(answer) < strlen(";; SERVER: "))
 174         {
 175                 //printf("LocalNameServers warning: unable to find nameservers using 'dig | grep SERVER:'\nParsing resolve.conf instead.");
 176                 LocalNameServers_findIpsViaResolveConf(self);
 177                 goto done;
 178         }
 179
 180         answer = answer + strlen(";; SERVER: ");
 181
 182         {
 183                 char *s = strstr(answer, "#");
 184                 if(s) s[0] = 0;
 185         }
 186
 187         LocalNameServers_addIPAddress_(self, answer);
 188
 189         done:
 190         free(command);
 191         free(answerBuffer);
 192 }
 193
 194 #else
 195
 196 // Unix ----------------------------------------
 197
 198
 199 void LocalNameServers_findIps(LocalNameServers *self)
 200 {
 201         LocalNameServers_findIpsViaResolveConf(self);
 202 }
 203
 204 #endif