- BUG FIX: IP Groups: blank timetable was not allowed; timetable & cfg con now be blank or undefined

- FIX: enable response compression by default to be compatible with bogus DNS clients not understanding responses split to multiple UDP packets (FIX failure of Amazon PrimeVideo on LG WebOS)
- new conf-specific setting "cache": allows disabling cache on configuration basis (default: cache is enabled)
- updated documentation
- added more debug logs

01.conf.go

@@ -113,6 +113,11 @@ func init() {
 		conf.ZabovAddBL = net.ParseIP(confRaw["blackholeip"].(string))
 		conf.ZabovHostsFile = confRaw["hostsfile"].(string)
 
+		if confRaw["cache"] != nil {
+			conf.ZabovCache = confRaw["cache"].(bool)
+		} else {
+			conf.ZabovCache = true
+		}
 		conf.ZabovDNSArray = fileByLines(conf.ZabovUpDNS)
 		ZabovConfigs[name] = &conf
 
@@ -219,8 +224,16 @@ func init() {
 				}
 				groupStruct.ips = append(groupStruct.ips, ip)
 			}
+			if groupMap["cfg"] != nil {
 				groupStruct.cfg = groupMap["cfg"].(string)
+			}
+			if groupMap["timetable"] != nil {
 				groupStruct.timetable = groupMap["timetable"].(string)
+			}
+			if len(groupStruct.cfg) == 0 && len(groupStruct.timetable) == 0 {
+				log.Println("ip group error: specify cfg or timetable")
+				os.Exit(1)
+			}
 			if len(groupStruct.cfg) > 0 {
 				refConfig, ok := ZabovConfigs[groupStruct.cfg]
 				if !ok {
@@ -229,14 +242,17 @@ func init() {
 				} else {
 					refConfig.references++
 				}
-			}
 				fmt.Println("cfg:", groupStruct.cfg)
+			}
+			if len(groupStruct.timetable) > 0 {
 				fmt.Println("timetable:", groupStruct.timetable)
 				_, ok := ZabovTimetables[groupStruct.timetable]
 				if !ok {
 					log.Println("inexistent timetable:", groupStruct.timetable)
 					os.Exit(1)
 				}
+			}
+
 			ZabovIPGroups = append(ZabovIPGroups, groupStruct)
 		}
 	}

README.md

@@ -62,7 +62,8 @@ Minimal config file should look like:
             "singlefilters":"./urls-domains.txt",
             "doublefilters":"./urls-hosts.txt", 
             "blackholeip":"127.0.0.1",
-            "hostsfile":"./urls-local.txt"
+            "hostsfile":"./urls-local.txt",
+            "cache":true
         },
     }
 }
@@ -84,7 +85,7 @@ configs:
 - doublefilters: name of the file, for blacklists following the "doublefilter" schema.(one URL per line)
 - blackholeip: IP address to return when the IP is banned. This is because you may want to avoid MX issues, mail loops on localhost, or you have a web server running on localhost
 - hostsfile: path where you keep your local blacklistfile : this is in the format "singlefilter", meaning one domain per line, unlike hosts file.
-
+- cache: if set to false disable the cache for this configuration. Boolean, defaults true
 
 Advanced configuration includes support for multiple configurations based on IP Source and timetables:
 <pre>
@@ -104,6 +105,7 @@ Advanced configuration includes support for multiple configurations based on IP
     },
     "ipaliases":{
         "pc8":"192.168.178.29",
+        "lg-tv":"192.168.178.10",
         "localhost":"127.0.0.1"
     },
     "ipgroups":[
@@ -111,6 +113,11 @@ Advanced configuration includes support for multiple configurations based on IP
             "ips":["localhost", "::1", "192.168.178.30", "192.168.178.31", "pc8"],
             "cfg":"",
             "timetable":"tt_children"
+        },
+        {
+            "ips":["lg-tv"],
+            "cfg":"tv",
+            "timetable":""
         }
     ],
     "timetables":{
@@ -146,6 +153,14 @@ Advanced configuration includes support for multiple configurations based on IP
             "doublefilters":"./urls-hosts-restricted.txt", 
             "blackholeip":"127.0.0.1",
             "hostsfile":"./urls-local.txt"
+        },
+        "tv":{
+            "upstream":"./dns-upstream.txt",
+            "singlefilters":"",
+            "doublefilters":"", 
+            "blackholeip":"127.0.0.1",
+            "hostsfile":"",
+            "cache":false
         }
     }
 }

dns_client.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"log"
 	"time"
 
 	"math/rand"
@@ -14,7 +15,9 @@ import (
 //first server to answer wins
 //accepts config name to select the UP DNS source list
 func ForwardQuery(query *dns.Msg, config string, nocache bool) *dns.Msg {
-
+	if ZabovDebug {
+		log.Println("ForwardQuery: nocache", nocache)
+	}
 	go incrementStats("ForwardQueries", 1)
 
 	r := new(dns.Msg)
@@ -29,6 +32,10 @@ func ForwardQuery(query *dns.Msg, config string, nocache bool) *dns.Msg {
 			go incrementStats("CacheHit", 1)
 			cached.SetReply(query)
 			cached.Authoritative = true
+			if ZabovDebug {
+				log.Println("ForwardQuery: CacheHit")
+			}
+			cached.Compress = true
 			return cached
 
 		}
@@ -60,7 +67,12 @@ func ForwardQuery(query *dns.Msg, config string, nocache bool) *dns.Msg {
 			go incrementStats(d, 1)
 			in.SetReply(query)
 			in.Authoritative = true
+			in.Compress = true
 			go DomainCache(lfqdn, in)
+			if ZabovDebug {
+				log.Println("ForwardQuery: OK!")
+			}
+
 			return in
 
 		}

dns_handler.go

@@ -287,7 +287,7 @@ func (mydns *handler) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
 			go logQuery(remIP, fqdn, QType, config, timetable, "killed")
 		} else {
 			go logQuery(remIP, fqdn, QType, config, timetable, "forwarded")
-			ret := ForwardQuery(r, config, false)
+			ret := ForwardQuery(r, config, !ZabovConfig.ZabovCache)
 			w.WriteMsg(ret)
 		}
 	case dns.TypePTR:
@@ -303,7 +303,7 @@ func (mydns *handler) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
 		w.WriteMsg(ret)
 		go logQuery(remIP, msg.Question[0].Name, QType, config, timetable, "localresponder")
 	default:
-		ret := ForwardQuery(r, config, false)
+		ret := ForwardQuery(r, config, !ZabovConfig.ZabovCache)
 		w.WriteMsg(ret)
 		if len(ZabovDebugDBPath) > 0 {
 			go logQuery(remIP, msg.Question[0].Name, QType, config, timetable, "forwarded")

main.go

@@ -41,6 +41,7 @@ type ZabovConfig struct {
 	ZabovHostsFile string   // json:hostsfile -> ZabovHostsFile is the file we use to keep our hosts
 	ZabovUpDNS     string   // json:upstream -> ZabovUpDNS keeps the name of upstream DNSs
 	ZabovDNSArray  []string // contains all the DNS we mention, parsed from ZabovUpDNS file
+	ZabovCache     bool     // allows to disable cache
 	references     int      // contains references to this config; if zero, config shall be removed
 }