initial commit

.idea/.gitignore

@@ -0,0 +1,8 @@
+# Default ignored files
+/shelf/
+/workspace.xml
+# Editor-based HTTP Client requests
+/httpRequests/
+# Datasource local storage ignored files
+/dataSources/
+/dataSources.local.xml

.idea/modules.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/.idea/pancheri.iml" filepath="$PROJECT_DIR$/.idea/pancheri.iml" />
+    </modules>
+  </component>
+</project>

.idea/pancheri.iml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="WEB_MODULE" version="4">
+  <component name="Go" enabled="true" />
+  <component name="NewModuleRootManager">
+    <content url="file://$MODULE_DIR$" />
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>

README.md

@@ -0,0 +1,3 @@
+# Pancheri
+A custom-built authoritative DNS server and proxy server built for the e3team internal network.
+Capable of serving arbitrary custom domains and asking an upstream DNS server for all other queries.

cmd/pancheri/main.go

@@ -0,0 +1,52 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"git.e3t.cc/e3team/pancheri"
+	"github.com/miekg/dns"
+	"github.com/sirupsen/logrus"
+	"os"
+)
+
+func main() {
+	configPath := flag.String("config", "/etc/pancheri/config.yml", "Path to enter a file or directory to load configuration from")
+	printUsage := flag.Bool("help", false, "Print command line usage")
+
+	flag.Parse()
+
+	if *printUsage {
+		flag.Usage()
+		os.Exit(0)
+	}
+
+	c, err := pancheri.LoadConfig(*configPath)
+
+	if err != nil {
+		fmt.Printf("failed to load config: %s", err)
+	}
+
+	if c.Logging.Format == "json" {
+		logrus.SetFormatter(&logrus.JSONFormatter{})
+	}
+	logrus.SetLevel(c.Logging.Level)
+
+	logrus.WithFields(logrus.Fields{
+		"host": c.Server.Host,
+		"port": c.Server.Port,
+	}).Info("starting DNS listener")
+
+	var r *pancheri.Resolver
+
+	if c.Resolver.Enable {
+		logrus.WithFields(logrus.Fields{
+			"upstream": c.Resolver.Upstream,
+		}).Info("enabling upstream resolver")
+
+		r = pancheri.NewResolver(c.Resolver.Upstream)
+		err = r.Resolve("example.com", dns.TypeA)
+		if err != nil {
+			logrus.Errorf("failed to resolve: %s", err)
+		}
+	}
+}

config.example.yml

@@ -0,0 +1,3 @@
+server:
+  host: "0.0.0.0"
+  port: 53

config.go

@@ -0,0 +1,44 @@
+package pancheri
+
+import (
+	"github.com/sirupsen/logrus"
+	"gopkg.in/yaml.v2"
+	"os"
+)
+
+type Config struct {
+	Server struct {
+		Host string `yaml:"host"`
+		Port string `yaml:"port"`
+	} `yaml:"server"`
+	Resolver struct {
+		Enable   bool   `yaml:"enable"`
+		Upstream string `yaml:"upstream"`
+	}
+	Logging struct {
+		Format string       `yaml:"format"`
+		Level  logrus.Level `yaml:"level"`
+	}
+}
+
+func LoadConfig(path string) (*Config, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+
+	var cfg Config
+	decoder := yaml.NewDecoder(f)
+
+	err = decoder.Decode(&cfg)
+	if err != nil {
+		return nil, err
+	}
+
+	err = f.Close()
+	if err != nil {
+		return nil, err
+	}
+
+	return &cfg, nil
+}

go.mod

@@ -0,0 +1,13 @@
+module git.e3t.cc/e3team/pancheri
+
+go 1.21
+
+require (
+	github.com/miekg/dns v1.1.56 // indirect
+	github.com/sirupsen/logrus v1.9.3 // indirect
+	golang.org/x/mod v0.12.0 // indirect
+	golang.org/x/net v0.15.0 // indirect
+	golang.org/x/sys v0.12.0 // indirect
+	golang.org/x/tools v0.13.0 // indirect
+	gopkg.in/yaml.v2 v2.4.0 // indirect
+)

go.sum

@@ -0,0 +1,22 @@
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/miekg/dns v1.1.56 h1:5imZaSeoRNvpM9SzWNhEcP9QliKiz20/dA2QabIGVnE=
+github.com/miekg/dns v1.1.56/go.mod h1:cRm6Oo2C8TY9ZS/TqsSrseAcncm74lfK5G+ikN2SWWY=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/sirupsen/logrus v1.9.3 h1:dueUQJ1C2q9oE3F7wvmSGAaVtTmUizReu6fjN8uqzbQ=
+github.com/sirupsen/logrus v1.9.3/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+golang.org/x/mod v0.12.0 h1:rmsUpXtvNzj340zd98LZ4KntptpfRHwpFOHG188oHXc=
+golang.org/x/mod v0.12.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
+golang.org/x/net v0.15.0 h1:ugBLEUaxABaB5AJqW9enI0ACdci2RUd4eP51NTBvuJ8=
+golang.org/x/net v0.15.0/go.mod h1:idbUs1IY1+zTqbi8yxTbhexhEEk5ur9LInksu6HrEpk=
+golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.12.0 h1:CM0HF96J0hcLAwsHPJZjfdNzs0gftsLfgKt57wWHJ0o=
+golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/tools v0.13.0 h1:Iey4qkscZuv0VvIt8E0neZjtPVQFSc870HQ448QgEmQ=
+golang.org/x/tools v0.13.0/go.mod h1:HvlwmtVNQAhOuCjW7xxvovg8wbNq7LwfXh/k7wXUl58=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
+gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

main.go

@@ -0,0 +1 @@
+package pancheri

resolver.go

@@ -0,0 +1,41 @@
+package pancheri
+
+import (
+	"github.com/miekg/dns"
+	"github.com/sirupsen/logrus"
+)
+
+type Resolver struct {
+	client   *dns.Client
+	upstream string
+}
+
+func NewResolver(upstream string) *Resolver {
+	return &Resolver{
+		client:   new(dns.Client),
+		upstream: upstream,
+	}
+}
+
+func (r *Resolver) Resolve(domain string, qtype uint16) error {
+	logrus.WithFields(logrus.Fields{
+		"domain": domain,
+		"qtype":  qtype,
+	}).Trace("performing upstream resolution")
+
+	m := new(dns.Msg)
+	m.SetQuestion(dns.Fqdn(domain), qtype)
+	m.RecursionDesired = true
+
+	in, _, err := r.client.Exchange(m, r.upstream)
+
+	if err != nil {
+		return err
+	}
+
+	for _, ans := range in.Answer {
+		logrus.Debug(ans)
+	}
+
+	return nil
+}