curl: Add support for various DNS binding options.

(Passed on to c-ares.)

Allows something like this:

curl --dns-interface sta8 --dns-ipv4-addr 8.8.1.111 --interface sta8 \
--localaddr 8.8.1.111 --dns-servers 8.8.8.1 www.google.com

Signed-off-by: Ben Greear <greearb@candelatech.com>

src/tool_cfgable.c

@@ -57,6 +57,11 @@ void free_config_fields(struct Configurable *config)
   Curl_safefree(config->proxyuserpwd);
   Curl_safefree(config->proxy);
 
+  Curl_safefree(config->dns_ipv6_addr);
+  Curl_safefree(config->dns_ipv4_addr);
+  Curl_safefree(config->dns_interface);
+  Curl_safefree(config->dns_servers);
+
   Curl_safefree(config->noproxy);
 
   Curl_safefree(config->mail_from);
@@ -127,4 +132,3 @@ void free_config_fields(struct Configurable *config)
 
   Curl_safefree(config->libcurl);
 }
-

src/tool_cfgable.h

@@ -66,6 +66,10 @@ struct Configurable {
   char *range;
   long low_speed_limit;
   long low_speed_time;
+  char* dns_servers;   /* dot notation: 1.1.1.1;2.2.2.2 */
+  char* dns_interface; /* interface name */
+  char* dns_ipv4_addr; /* dot notation */
+  char* dns_ipv6_addr; /* dot notation */
   int showerror; /* -1 == unset, default => show errors
                     0 => -s is used to NOT show errors
                     1 => -S has been used to show errors */
@@ -214,4 +218,3 @@ struct Configurable {
 void free_config_fields(struct Configurable *config);
 
 #endif /* HEADER_CURL_TOOL_CFGABLE_H */
-

src/tool_getparam.c

@@ -73,11 +73,14 @@ static const struct LongShort aliases[]= {
   /* all these ones, starting with "*" or "$" as a short-option have *no*
      short option to mention. */
   {"*",  "url",                      TRUE},
+  {"*4", "dns-ipv4-addr",            TRUE},
+  {"*6", "dns-ipv6-addr",            TRUE},
   {"*a", "random-file",              TRUE},
   {"*b", "egd-file",                 TRUE},
   {"*B", "bearer",                   TRUE},
   {"*c", "connect-timeout",          TRUE},
   {"*d", "ciphers",                  TRUE},
+  {"*D", "dns-interface",                TRUE},
   {"*e", "disable-epsv",             FALSE},
   {"*E", "epsv",                     FALSE},
          /* 'epsv' made like this to make --no-epsv and --epsv to work
@@ -85,6 +88,7 @@ static const struct LongShort aliases[]= {
 #ifdef USE_ENVIRONMENT
   {"*f", "environment",              FALSE},
 #endif
+  {"*F", "dns-servers",              TRUE},
   {"*g", "trace",                    TRUE},
   {"*h", "trace-ascii",              TRUE},
   {"*i", "limit-rate",               TRUE},
@@ -496,6 +500,14 @@ ParameterError getparameter(char *flag,    /* f or -long-flag */
     switch(letter) {
     case '*': /* options without a short option */
       switch(subletter) {
+      case '4': /* --dns-ipv4-addr */
+        /* addr in dot notation */
+        GetStr(&config->dns_ipv4_addr, nextarg);
+        break;
+      case '6': /* --dns-ipv6-addr */
+        /* addr in dot notation */
+        GetStr(&config->dns_ipv6_addr, nextarg);
+        break;
       case 'a': /* random-file */
         GetStr(&config->random_file, nextarg);
         break;
@@ -513,6 +525,10 @@ ParameterError getparameter(char *flag,    /* f or -long-flag */
       case 'd': /* ciphers */
         GetStr(&config->cipher_list, nextarg);
         break;
+      case 'D': /* --dns-interface */
+        /* interface name */
+        GetStr(&config->dns_interface, nextarg);
+        break;
       case 'e': /* --disable-epsv */
         config->disable_epsv = toggle;
         break;
@@ -524,6 +540,10 @@ ParameterError getparameter(char *flag,    /* f or -long-flag */
         config->writeenv = toggle;
         break;
 #endif
+      case 'F': /* --dns-servers */
+        /* IP addrs of DNS servers */
+        GetStr(&config->dns_servers, nextarg);
+        break;
       case 'g': /* --trace */
         GetStr(&config->trace_dump, nextarg);
         if(config->tracetype && (config->tracetype != TRACE_BIN))
@@ -1802,4 +1822,3 @@ ParameterError getparameter(char *flag,    /* f or -long-flag */
 
   return PARAM_OK;
 }
-

src/tool_help.c

@@ -70,6 +70,10 @@ static const char *const helptext[] = {
   "     --digest        Use HTTP Digest Authentication (H)",
   "     --disable-eprt  Inhibit using EPRT or LPRT (F)",
   "     --disable-epsv  Inhibit using EPSV (F)",
+  "     --dns-servers    DNS server addrs to use: 1.1.1.1;2.2.2.2",
+  "     --dns-interface  Interface to use for DNS requests",
+  "     --dns-ipv4-addr  IPv4 address to use for DNS requests, dot notation",
+  "     --dns-ipv6-addr  IPv6 address to use for DNS requests, dot notation",
   " -D, --dump-header FILE  Write the headers to this file",
   "     --egd-file FILE  EGD socket path for random data (SSL)",
   "     --engine ENGINE  Crypto engine (SSL). \"--engine list\" for list",
@@ -246,4 +250,3 @@ void tool_help(void)
 #endif
   }
 }
-

src/tool_operate.c

@@ -1239,6 +1239,12 @@ int operate(struct Configurable *config, int argc, argv_item_t argv[])
           my_setopt(curl, CURLOPT_PROGRESSDATA, &progressbar);
         }
 
+        my_setopt_str(curl, CURLOPT_DNS_SERVERS, config->dns_servers);
+        /* new in libcurl 7.33.0: */
+        my_setopt_str(curl, CURLOPT_DNS_INTERFACE, config->dns_interface);
+        my_setopt_str(curl, CURLOPT_DNS_LOCAL_IP4, config->dns_ipv4_addr);
+        my_setopt_str(curl, CURLOPT_DNS_LOCAL_IP6, config->dns_ipv6_addr);
+
         /* new in libcurl 7.6.2: */
         my_setopt_slist(curl, CURLOPT_TELNETOPTIONS, config->telnet_options);
 
@@ -1899,4 +1905,3 @@ int operate(struct Configurable *config, int argc, argv_item_t argv[])
 
   return res;
 }
-