dns: make dns.setServers support customized port

allow `dns.setServers` parameter to contain port e.g. ``` dns.setServers([ '103.238.225.181:666' ]); ``` And `dns.getServers` will return IP with port if not the default port. PR-URL: #13723 Refs: #7903 Reviewed-By: Refael Ackermann <[email protected]> Reviewed-By: Matteo Collina <[email protected]>

Author: XadillaX

doc/api/dns.md

@@ -59,8 +59,21 @@ the [Implementation considerations section][] for more information.
 added: v0.11.3
 -->
 
-Returns an array of IP address strings that are being used for name
-resolution.
+Returns an array of IP address strings, formatted according to [rfc5952][],
+that are currently configured for DNS resolution. A string will include a port
+section if a custom port is used.
+
+For example:
+
+<!-- eslint-disable -->
+```js
+[
+'4.4.4.4',
+'2001:4860:4860::8888',
+'4.4.4.4:1053',
+'[2001:4860:4860::8888]:1053'
+]
+```
 
 ## dns.lookup(hostname[, options], callback)
 <!-- YAML
@@ -436,12 +449,22 @@ one of the [DNS error codes][].
 <!-- YAML
 added: v0.11.3
 -->
--`servers`{string[]}
+-`servers`{string[]} array of [rfc5952][] formatted addresses
+
+Sets the IP address and port of servers to be used when performing DNS
+resolution. The `servers` argument is an array of [rfc5952][] formatted
+addresses. If the port is the IANA default DNS port (53) it can be omitted.
 
-Sets the IP addresses of the servers to be used when resolving. The `servers`
-argument is an array of IPv4 or IPv6 addresses.
+For example:
 
-If a port is specified on the address, it will be removed.
+```js
+dns.setServers([
+'4.4.4.4',
+'[2001:4860:4860::8888]',
+'4.4.4.4:1053',
+'[2001:4860:4860::8888]:1053'
+]);
+```
 
 An error will be thrown if an invalid address is provided.
 
@@ -536,3 +559,4 @@ uses. For instance, _they do not use the configuration from `/etc/hosts`_.
 [supported `getaddrinfo` flags]: #dns_supported_getaddrinfo_flags
 [the official libuv documentation]: http://docs.libuv.org/en/latest/threadpool.html
 [`util.promisify()`]: util.html#util_util_promisify_original
+[rfc5952]: https://tools.ietf.org/html/rfc5952#section-6

lib/dns.js

@@ -60,6 +60,7 @@ function errnoException(err, syscall, hostname){
 returnex;
 }
 
+constIANA_DNS_PORT=53;
 constdigits=[
 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,// 0-15
 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,// 16-31
@@ -301,7 +302,13 @@ function resolve(hostname, type_, callback_){
 
 
 functiongetServers(){
-returncares.getServers();
+constret=cares.getServers();
+returnret.map((val)=>{
+if(!val[1]||val[1]===IANA_DNS_PORT)returnval[0];
+
+consthost=isIP(val[0])===6 ? `[${val[0]}]` : val[0];
+return`${host}:${val[1]}`;
+});
 }
 
 
@@ -311,26 +318,31 @@ function setServers(servers){
 constorig=cares.getServers();
 constnewSet=[];
 constIPv6RE=/\[(.*)\]/;
-constaddrSplitRE=/:\d+$/;
+constaddrSplitRE=/(^.+?)(?::(\d+))?$/;
 
 servers.forEach((serv)=>{
 varipVersion=isIP(serv);
 if(ipVersion!==0)
-returnnewSet.push([ipVersion,serv]);
+returnnewSet.push([ipVersion,serv,IANA_DNS_PORT]);
 
 constmatch=serv.match(IPv6RE);
 // we have an IPv6 in brackets
 if(match){
 ipVersion=isIP(match[1]);
-if(ipVersion!==0)
-returnnewSet.push([ipVersion,match[1]]);
+if(ipVersion!==0){
+constport=
+parseInt(serv.replace(addrSplitRE,'$2'))||
+IANA_DNS_PORT;
+returnnewSet.push([ipVersion,match[1],port]);
+}
 }
 
-consts=serv.split(addrSplitRE)[0];
+const[,s,p]=serv.match(addrSplitRE);
 ipVersion=isIP(s);
 
-if(ipVersion!==0)
-returnnewSet.push([ipVersion,s]);
+if(ipVersion!==0){
+returnnewSet.push([ipVersion,s,parseInt(p)]);
+}
 
 thrownewError(`IP address is not properly formatted: ${serv}`);
 });

src/cares_wrap.cc

@@ -419,9 +419,9 @@ void AresEnsureServers(Environment* env){
  }
 
  ares_channel channel = env->cares_channel();
-ares_addr_node* servers = nullptr;
+ares_addr_port_node* servers = nullptr;
 
-ares_get_servers(channel, &servers);
+ares_get_servers_ports(channel, &servers);
 
 /* if no server or multi-servers, ignore */
 if (servers == nullptr) return;
@@ -433,7 +433,9 @@ void AresEnsureServers(Environment* env){
 
 /* if the only server is not 127.0.0.1, ignore */
 if (servers[0].family != AF_INET ||
- servers[0].addr.addr4.s_addr != htonl(INADDR_LOOPBACK)){
+ servers[0].addr.addr4.s_addr != htonl(INADDR_LOOPBACK) ||
+ servers[0].tcp_port != 0 ||
+ servers[0].udp_port != 0){
 ares_free_data(servers);
  env->set_cares_is_servers_default(false);
 return;
@@ -1384,12 +1386,12 @@ void GetServers(const FunctionCallbackInfo<Value>& args){
 
  Local<Array> server_array = Array::New(env->isolate());
 
-ares_addr_node* servers;
+ares_addr_port_node* servers;
 
-int r = ares_get_servers(env->cares_channel(), &servers);
+int r = ares_get_servers_ports(env->cares_channel(), &servers);
 CHECK_EQ(r, ARES_SUCCESS);
 
-ares_addr_node* cur = servers;
+ares_addr_port_node* cur = servers;
 
 for (uint32_t i = 0; cur != nullptr; ++i, cur = cur->next){
 char ip[INET6_ADDRSTRLEN];
@@ -1398,8 +1400,11 @@ void GetServers(const FunctionCallbackInfo<Value>& args){
 int err = uv_inet_ntop(cur->family, caddr, ip, sizeof(ip));
 CHECK_EQ(err, 0);
 
- Local<String> addr = OneByteString(env->isolate(), ip);
- server_array->Set(i, addr);
+ Local<Array> ret = Array::New(env->isolate(), 2);
+ ret->Set(0, OneByteString(env->isolate(), ip));
+ ret->Set(1, Integer::New(env->isolate(), cur->udp_port));
+
+ server_array->Set(i, ret);
  }
 
 ares_free_data(servers);
@@ -1422,8 +1427,8 @@ void SetServers(const FunctionCallbackInfo<Value>& args){
 return args.GetReturnValue().Set(rv);
  }
 
-ares_addr_node* servers = newares_addr_node[len];
-ares_addr_node* last = nullptr;
+ares_addr_port_node* servers = newares_addr_port_node[len];
+ares_addr_port_node* last = nullptr;
 
 int err;
 
@@ -1434,12 +1439,15 @@ void SetServers(const FunctionCallbackInfo<Value>& args){
 
 CHECK(elm->Get(0)->Int32Value());
 CHECK(elm->Get(1)->IsString());
+CHECK(elm->Get(2)->Int32Value());
 
 int fam = elm->Get(0)->Int32Value();
  node::Utf8Value ip(env->isolate(), elm->Get(1));
+int port = elm->Get(2)->Int32Value();
 
-ares_addr_node* cur = &servers[i];
+ares_addr_port_node* cur = &servers[i];
 
+ cur->tcp_port = cur->udp_port = port;
 switch (fam){
 case4:
  cur->family = AF_INET;
@@ -1465,7 +1473,7 @@ void SetServers(const FunctionCallbackInfo<Value>& args){
  }
 
 if (err == 0)
- err = ares_set_servers(env->cares_channel(), &servers[0]);
+ err = ares_set_servers_ports(env->cares_channel(), &servers[0]);
 else
  err = ARES_EBADSTR;
 

test/parallel/test-dns.js

@@ -35,6 +35,8 @@ assert.doesNotThrow(() =>{
 servers[0]='127.0.0.1';
 servers[2]='0.0.0.0';
 dns.setServers(servers);
+
+assert.deepStrictEqual(dns.getServers(),['127.0.0.1','0.0.0.0']);
 });
 
 assert.doesNotThrow(()=>{
@@ -53,6 +55,11 @@ assert.doesNotThrow(() =>{
 });
 
 dns.setServers(servers);
+assert.deepStrictEqual(dns.getServers(),[
+'127.0.0.1',
+'192.168.1.1',
+'0.0.0.0'
+]);
 });
 
 constgoog=[
@@ -63,6 +70,8 @@ assert.doesNotThrow(() => dns.setServers(goog));
 assert.deepStrictEqual(dns.getServers(),goog);
 assert.throws(()=>dns.setServers(['foobar']),
 /^Error:IPaddressisnotproperlyformatted:foobar$/);
+assert.throws(()=>dns.setServers(['127.0.0.1:va']),
+/^Error:IPaddressisnotproperlyformatted:127\.0\.0\.1:va$/);
 assert.deepStrictEqual(dns.getServers(),goog);
 
 constgoog6=[
@@ -79,10 +88,14 @@ assert.deepStrictEqual(dns.getServers(), goog6);
 constports=[
 '4.4.4.4:53',
 '[2001:4860:4860::8888]:53',
+'103.238.225.181:666',
+'[fe80::483a:5aff:fee6:1f04]:666'
 ];
 constportsExpected=[
 '4.4.4.4',
 '2001:4860:4860::8888',
+'103.238.225.181:666',
+'[fe80::483a:5aff:fee6:1f04]:666'
 ];
 dns.setServers(ports);
 assert.deepStrictEqual(dns.getServers(),portsExpected);