config.go

package main

import (
	"fmt"
	"io"
	"log"
	"os"
	"path/filepath"
	"strings"

	"github.com/BurntSushi/toml"
	"github.com/jonboulle/clockwork"
)

// BuildVersion returns the build version of grimd, this should be incremented every new release
var BuildVersion = "1.0.7"

// ConfigVersion returns the version of grimd, this should be incremented every time the config changes so grimd presents a warning
var ConfigVersion = "1.0.9"

// Config holds the configuration parameters
type Config struct {
	Version           string
	Sources           []string
	SourceDirs        []string
	LogConfig         string
	Bind              string
	API               string
	NXDomain          bool
	Nullroute         string
	Nullroutev6       string
	Nameservers       []string
	Interval          int
	Timeout           int
	Expire            uint32
	Maxcount          int
	QuestionCacheCap  int
	TTL               uint32
	Blocklist         []string
	Whitelist         []string
	CustomDNSRecords  []string
	ToggleName        string
	ReactivationDelay uint
	Dashboard         bool
	APIDebug          bool
	DoH               string
	UseDrbl           int
	DrblPeersFilename string
	DrblBlockWeight   int64
	DrblTimeout       int
	DrblDebug         int
}

var defaultConfig = `# version this config was generated from
version = "%s"

# list of sources to pull blocklists from, stores them in ./sources
sources = [
"https://mirror1.malwaredomains.com/files/justdomains",
"https://raw.githubusercontent.com/StevenBlack/hosts/master/hosts",
"https://sysctl.org/cameleon/hosts",
"https://s3.amazonaws.com/lists.disconnect.me/simple_tracking.txt",
"https://s3.amazonaws.com/lists.disconnect.me/simple_ad.txt",
"https://gitlab.com/quidsup/notrack-blocklists/raw/master/notrack-blocklist.txt"
]

# list of locations to recursively read blocklists from (warning, every file found is assumed to be a hosts-file or domain list)
sourcedirs = [
"sources"
]

# log configuration
# format: comma separated list of options, where options is one of 
#   file:<filename>@<loglevel>
#   stderr>@<loglevel>
#   syslog@<loglevel>
# loglevel: 0 = errors and important operations, 1 = dns queries, 2 = debug
# e.g. logconfig = "file:grimd.log@2,syslog@1,stderr@2"
logconfig = "file:grimd.log@2,stderr@2"

# apidebug enables the debug mode of the http api library
apidebug = false

# enable the web interface by default
dashboard = true

# address to bind to for the DNS server
bind = "0.0.0.0:53"

# address to bind to for the API server
api = "127.0.0.1:8080"

# response to blocked queries with a NXDOMAIN
nxdomain = false

# ipv4 address to forward blocked queries to
nullroute = "0.0.0.0"

# ipv6 address to forward blocked queries to
nullroutev6 = "0:0:0:0:0:0:0:0"

# nameservers to forward queries to
nameservers = ["1.1.1.1:53", "1.0.0.1:53"]

# concurrency interval for lookups in miliseconds
interval = 200

# query timeout for dns lookups in seconds
timeout = 5

# cache entry lifespan in seconds
expire = 600

# cache capacity, 0 for infinite
maxcount = 0

# question cache capacity, 0 for infinite but not recommended (this is used for storing logs)
questioncachecap = 5000

# manual blocklist entries
blocklist = []

# Drbl related settings
usedrbl = 0
drblpeersfilename = "drblpeers.yaml"
drblblockweight = 128
drbltimeout = 30
drbldebug = 0

# manual whitelist entries
whitelist = [
	"getsentry.com",
	"www.getsentry.com"
]

# manual custom dns entries
customdnsrecords = []

# When this string is queried, toggle grimd on and off
togglename = ""

# If not zero, the delay in seconds before grimd automaticall reactivates after
# having been turned off.
reactivationdelay = 300

#Dns over HTTPS provider to use.
DoH = "https://cloudflare-dns.com/dns-query"
`

// WallClock is the wall clock
var WallClock = clockwork.NewRealClock()

// LoadConfig loads the given config file
func LoadConfig(path string) (*Config, error) {

	var config Config

	if _, err := os.Stat(path); os.IsNotExist(err) {
		if err := generateConfig(path); err != nil {
			return nil, err
		}
	}

	if _, err := toml.DecodeFile(path, &config); err != nil {
		return nil, fmt.Errorf("could not load config: %s", err)
	}

	if config.Version != ConfigVersion {
		if config.Version == "" {
			config.Version = "none"
		}

		log.Printf("warning, grimd.toml is out of date!\nconfig v%s\ngrimd config v%s\ngrimd v%s\nplease update your config\n", config.Version, ConfigVersion, BuildVersion)
	} else {
		log.Printf("grimd v%s\n", BuildVersion)
	}

	return &config, nil
}

func generateConfig(path string) error {
	output, err := os.Create(path)
	if err != nil {
		return fmt.Errorf("could not generate config: %s", err)
	}

	defer func() {
		if err := output.Close(); err != nil {
			logger.Criticalf("Error closing file: %s\n", err)
		}
	}()

	r := strings.NewReader(fmt.Sprintf(defaultConfig, ConfigVersion))
	if _, err := io.Copy(output, r); err != nil {
		return fmt.Errorf("could not copy default config: %s", err)
	}

	if abs, err := filepath.Abs(path); err == nil {
		log.Printf("generated default config %s\n", abs)
	}

	return nil
}