Clients/dnsctl.c

   1 /* -*- Mode: C; tab-width: 4 -*-
   2  *
   3  * Copyright (c) 2012 Apple Inc. All rights reserved.
   4  *
   5  * dnsctl.c
   6  * Command-line tool using libdns_services.dylib
   7  *
   8  * To build only this tool, copy and paste the following on the command line:
   9  * On Apple 64bit Platforms ONLY OSX/iOS:
  10  * clang -Wall dnsctl.c /usr/lib/libdns_services.dylib -o dnsctl
  11  *
  12  */
  13
  14 #include <stdio.h>
  15 #include <stdlib.h>
  16 #include <string.h>
  17 #include <sys/time.h>
  18 #include <net/if.h> // if_nametoindex()
  19
  20 #include <dispatch/dispatch.h>
  21 #include "dns_services.h"
  22
  23 //*************************************************************************************************************
  24 // Globals:
  25 //*************************************************************************************************************
  26
  27 static const char kFilePathSep   =  '/';
  28 static DNSXConnRef ClientRef     =  NULL;
  29
  30 //*************************************************************************************************************
  31 // Utility Funcs:
  32 //*************************************************************************************************************
  33
  34 static void printtimestamp(void)
  35 {
  36     struct tm tm;
  37     int ms;
  38     static char date[16];
  39     static char new_date[16];
  40     struct timeval tv;
  41     gettimeofday(&tv, NULL);
  42     localtime_r((time_t*)&tv.tv_sec, &tm);
  43     ms = tv.tv_usec/1000;
  44     strftime(new_date, sizeof(new_date), "%a %d %b %Y", &tm);
  45     //display date only if it has changed
  46     if (strncmp(date, new_date, sizeof(new_date)))
  47     {
  48         printf("DATE: ---%s---\n", new_date);
  49         strncpy(date, new_date, sizeof(date));
  50     }
  51     printf("%2d:%02d:%02d.%03d  ", tm.tm_hour, tm.tm_min, tm.tm_sec, ms);
  52 }
  53
  54 static void print_usage(const char *arg0)
  55 {
  56     fprintf(stderr, "%s USAGE:                                                                  \n", arg0);
  57     fprintf(stderr, "%s -DP Enable DNS Proxy with Default Parameters                            \n", arg0);
  58     fprintf(stderr, "%s -DP [-o <output interface>] [-i <input interface(s)>] Enable DNS Proxy  \n", arg0);
  59 }
  60
  61 //*************************************************************************************************************
  62 // CallBack Funcs:
  63 //*************************************************************************************************************
  64
  65 // DNSXEnableProxy Callback from the Daemon
  66 static void dnsproxy_reply(DNSXConnRef connRef, DNSXErrorType errCode)
  67 {
  68     (void) connRef;
  69     printtimestamp();
  70     switch (errCode)
  71     {
  72         case kDNSX_NoError          :  printf("  SUCCESS   \n");     break;
  73         case kDNSX_DictError        :  printf(" DICT ERROR \n");     break;
  74         case kDNSX_DaemonNotRunning :  printf(" NO DAEMON  \n");
  75                                        DNSXRefDeAlloc(ClientRef);    break;
  76         case kDNSX_Engaged          :  printf(" ENGAGED    \n");
  77                                        DNSXRefDeAlloc(ClientRef);    break;
  78         case kDNSX_UnknownErr       :
  79         default                     :  printf("UNKNOWN ERR \n");
  80                                        DNSXRefDeAlloc(ClientRef);    break;
  81     }
  82
  83 }
  84
  85 //*************************************************************************************************************
  86
  87 int main(int argc, char **argv)
  88 {
  89     DNSXErrorType err;
  90
  91     // Default i/p intf is lo0 and o/p intf is primary interface
  92     IfIndex Ipintfs[MaxInputIf] =  {1, 0, 0, 0, 0};
  93     IfIndex Opintf = kDNSIfindexAny;
  94
  95     // Extract program name from argv[0], which by convention contains the path to this executable
  96     const char *a0 = strrchr(argv[0], kFilePathSep) + 1;
  97     if (a0 == (const char *)1)
  98         a0 = argv[0];
  99
 100     // Must run as root
 101     if (0 != geteuid())
 102     {
 103         fprintf(stderr, "%s MUST run as root!!\n", a0);
 104         exit(-1);
 105     }
 106     if ((sizeof(argv) == 8))
 107         printf("dnsctl running in 64-bit mode\n");
 108     else if ((sizeof(argv) == 4))
 109         printf("dnsctl running in 32-bit mode\n");
 110
 111     // expects atleast one argument
 112     if (argc < 2)
 113         goto Usage;
 114
 115     if ( !strcmp(argv[1], "-DP") || !strcmp(argv[1], "-dp") )
 116     {
 117         if (argc == 2)
 118         {
 119             printtimestamp();
 120             printf("Proceeding to Enable DNSProxy on mDNSResponder with Default Parameters\n");
 121             dispatch_queue_t my_Q = dispatch_queue_create("com.apple.dnsctl.callback_queue", NULL);
 122             err = DNSXEnableProxy(&ClientRef, kDNSProxyEnable, Ipintfs, Opintf, my_Q, dnsproxy_reply);
 123         }
 124         else if (argc > 2)
 125         {
 126             argc--;
 127             argv++;
 128             if (!strcmp(argv[1], "-o"))
 129             {
 130                 Opintf = if_nametoindex(argv[2]);
 131                 if (!Opintf)
 132                     Opintf = atoi(argv[2]);
 133                 if (!Opintf)
 134                 {
 135                     fprintf(stderr, "Could not parse o/p interface [%s]: Passing default primary \n", argv[2]);
 136                     Opintf = kDNSIfindexAny;
 137                 }
 138                 argc -= 2;
 139                 argv += 2;
 140             }
 141             if (argc > 2 && !strcmp(argv[1], "-i"))
 142             {
 143                 int i;
 144                 argc--;
 145                 argv++;
 146                 for (i = 0; i < MaxInputIf && argc > 1; i++)
 147                 {
 148                     Ipintfs[i] = if_nametoindex(argv[1]);
 149                     if (!Ipintfs[i])
 150                         Ipintfs[i] = atoi(argv[1]);
 151                     if (!Ipintfs[i])
 152                     {
 153                         fprintf(stderr, "Could not parse i/p interface [%s]: Passing default lo0 \n", argv[2]);
 154                         Ipintfs[i] = 1;
 155                     }
 156                     argc--;
 157                     argv++;
 158                 }
 159             }
 160             printtimestamp();
 161             printf("Proceeding to Enable DNSProxy on mDNSResponder \n");
 162             dispatch_queue_t my_Q = dispatch_queue_create("com.apple.dnsctl.callback_queue", NULL);
 163             err = DNSXEnableProxy(&ClientRef, kDNSProxyEnable, Ipintfs, Opintf, my_Q, dnsproxy_reply);
 164         }
 165     }
 166     else
 167     {
 168         goto Usage;
 169     }
 170
 171     dispatch_main();
 172
 173 Usage:
 174     print_usage(a0);
 175     return 0;
 176 }
 177