dnscrypt-proxy/dnscrypt-proxy/plugin_block_name.go

133 lines
3.7 KiB
Go

package main
import (
"errors"
"fmt"
"io/ioutil"
"net"
"strings"
"time"
"unicode"
"github.com/jedisct1/dlog"
"github.com/miekg/dns"
lumberjack "gopkg.in/natefinch/lumberjack.v2"
)
type PluginBlockName struct {
allWeeklyRanges *map[string]WeeklyRanges
patternMatcher *PatternMatcher
logger *lumberjack.Logger
format string
}
func (plugin *PluginBlockName) Name() string {
return "block_name"
}
func (plugin *PluginBlockName) Description() string {
return "Block DNS queries matching name patterns"
}
func (plugin *PluginBlockName) Init(proxy *Proxy) error {
dlog.Noticef("Loading the set of blocking rules from [%s]", proxy.blockNameFile)
bin, err := ioutil.ReadFile(proxy.blockNameFile)
if err != nil {
return err
}
plugin.allWeeklyRanges = proxy.allWeeklyRanges
plugin.patternMatcher = NewPatternPatcher()
for lineNo, line := range strings.Split(string(bin), "\n") {
line = strings.TrimFunc(line, unicode.IsSpace)
if len(line) == 0 || strings.HasPrefix(line, "#") {
continue
}
parts := strings.Split(line, "@")
timeRangeName := ""
if len(parts) == 2 {
line = strings.TrimFunc(parts[0], unicode.IsSpace)
timeRangeName = strings.TrimFunc(parts[1], unicode.IsSpace)
} else if len(parts) > 2 {
dlog.Errorf("Syntax error in block rules at line %d -- Unexpected @ character", 1+lineNo)
continue
}
var weeklyRanges *WeeklyRanges
if len(timeRangeName) > 0 {
weeklyRangesX, ok := (*plugin.allWeeklyRanges)[timeRangeName]
if !ok {
dlog.Errorf("Time range [%s] not found at line %d", timeRangeName, 1+lineNo)
} else {
weeklyRanges = &weeklyRangesX
}
}
if _, err := plugin.patternMatcher.Add(line, weeklyRanges, lineNo+1); err != nil {
dlog.Error(err)
continue
}
}
if len(proxy.blockNameLogFile) == 0 {
return nil
}
plugin.logger = &lumberjack.Logger{LocalTime: true, MaxSize: proxy.logMaxSize, MaxAge: proxy.logMaxAge, MaxBackups: proxy.logMaxBackups, Filename: proxy.blockNameLogFile, Compress: true}
plugin.format = proxy.blockNameFormat
return nil
}
func (plugin *PluginBlockName) Drop() error {
return nil
}
func (plugin *PluginBlockName) Reload() error {
return nil
}
func (plugin *PluginBlockName) Eval(pluginsState *PluginsState, msg *dns.Msg) error {
if pluginsState.sessionData["whitelisted"] != nil {
return nil
}
questions := msg.Question
if len(questions) != 1 {
return nil
}
qName := strings.ToLower(StripTrailingDot(questions[0].Name))
reject, reason, xweeklyRanges := plugin.patternMatcher.Eval(qName)
var weeklyRanges *WeeklyRanges
if xweeklyRanges != nil {
weeklyRanges = xweeklyRanges.(*WeeklyRanges)
}
if reject {
if weeklyRanges != nil && !weeklyRanges.Match() {
reject = false
}
}
if reject {
pluginsState.action = PluginsActionReject
if plugin.logger != nil {
var clientIPStr string
if pluginsState.clientProto == "udp" {
clientIPStr = (*pluginsState.clientAddr).(*net.UDPAddr).IP.String()
} else {
clientIPStr = (*pluginsState.clientAddr).(*net.TCPAddr).IP.String()
}
var line string
if plugin.format == "tsv" {
now := time.Now()
year, month, day := now.Date()
hour, minute, second := now.Clock()
tsStr := fmt.Sprintf("[%d-%02d-%02d %02d:%02d:%02d]", year, int(month), day, hour, minute, second)
line = fmt.Sprintf("%s\t%s\t%s\t%s\n", tsStr, clientIPStr, StringQuote(qName), StringQuote(reason))
} else if plugin.format == "ltsv" {
line = fmt.Sprintf("time:%d\thost:%s\tqname:%s\tmessage:%s\n", time.Now().Unix(), clientIPStr, StringQuote(qName), StringQuote(reason))
} else {
dlog.Fatalf("Unexpected log format: [%s]", plugin.format)
}
if plugin.logger == nil {
return errors.New("Log file not initialized")
}
plugin.logger.Write([]byte(line))
}
}
return nil
}