Files
vps/.agents/skills/encrypted-dns-skill/cmd/ednsdiag/main.go
T

387 lines
12 KiB
Go

package main
import (
"context"
"encoding/json"
"fmt"
"io"
"os"
"strconv"
"strings"
"time"
"github.com/windyboy/encrypted-dns-skill/internal/edns"
)
const version = "0.1.0-dev"
const (
exitSuccess = 0
exitLocal = 1
exitUsage = 2
exitTransport = 3
exitUnsupported = 4
)
var (
runQuery = edns.Query
runProbe = edns.Probe
runCompare = edns.Compare
)
type capability struct {
Protocol string `json:"protocol"`
Status string `json:"status"`
Standard string `json:"standard,omitempty"`
Note string `json:"note,omitempty"`
}
type capabilitiesResult struct {
SchemaVersion int `json:"schema_version"`
Command string `json:"command"`
Version string `json:"version"`
Capabilities []capability `json:"capabilities"`
}
func main() {
os.Exit(run(os.Args[1:], os.Stdout, os.Stderr))
}
func run(args []string, stdout, stderr io.Writer) int {
if len(args) == 0 {
writeUsage(stderr)
return 2
}
switch args[0] {
case "capabilities":
if len(args) != 1 {
fmt.Fprintln(stderr, "capabilities does not accept arguments")
return 2
}
result := capabilitiesResult{
SchemaVersion: 1,
Command: "capabilities",
Version: version,
Capabilities: []capability{
{Protocol: "doh", Status: "available", Standard: "RFC 8484", Note: "RFC wire format over HTTP GET or POST"},
{Protocol: "dot", Status: "available", Standard: "RFC 7858 and RFC 8310", Note: "strict PKIX and authentication-domain validation"},
{Protocol: "doq", Status: "available", Standard: "RFC 9250", Note: "RFC wire format over dedicated QUIC streams"},
{Protocol: "doh3", Status: "available", Standard: "RFC 8484 over HTTP/3", Note: "RFC wire format over HTTP/3 GET or POST"},
{Protocol: "dnscrypt", Status: "available", Standard: "DNSCrypt protocol specification", Note: "DNSCrypt v2 with authenticated resolver certificates"},
{Protocol: "odoh", Status: "research", Standard: "RFC 9230", Note: "No maintained Go dependency has been selected."},
{Protocol: "anonymized-dnscrypt", Status: "research", Standard: "Anonymized DNSCrypt specification"},
},
}
return writeJSON(stdout, stderr, result)
case "version":
if len(args) != 1 {
fmt.Fprintln(stderr, "version does not accept arguments")
return 2
}
fmt.Fprintln(stdout, version)
return 0
case "query", "probe":
options, timeout, err := parseQueryArgs(args[1:])
if err != nil {
fmt.Fprintln(stderr, err)
writeQueryUsage(stderr)
return 2
}
ctx, cancel := context.WithTimeout(context.Background(), timeout)
defer cancel()
var result edns.Result
if args[0] == "probe" {
result = runProbe(ctx, options)
} else {
result = runQuery(ctx, options)
}
if code := writeJSON(stdout, stderr, result); code != 0 {
return code
}
return resultExitCode(result.Completed, result.Error)
case "compare":
options, timeout, err := parseCompareArgs(args[1:])
if err != nil {
fmt.Fprintln(stderr, err)
writeCompareUsage(stderr)
return exitUsage
}
ctx, cancel := context.WithTimeout(context.Background(), timeout)
defer cancel()
result := runCompare(ctx, options)
if code := writeJSON(stdout, stderr, result); code != 0 {
return code
}
return resultExitCode(result.Completed, result.Error)
default:
fmt.Fprintf(stderr, "unknown command %q\n", args[0])
writeUsage(stderr)
return 2
}
}
func parseQueryArgs(args []string) (edns.QueryOptions, time.Duration, error) {
options := edns.QueryOptions{
RecordType: "A",
Protocol: "doh",
Provider: "cloudflare",
Method: "post",
}
timeout := 5 * time.Second
positionals := make([]string, 0, 2)
for index := 0; index < len(args); index++ {
argument := args[index]
if !strings.HasPrefix(argument, "--") {
positionals = append(positionals, argument)
continue
}
key, value, found := strings.Cut(strings.TrimPrefix(argument, "--"), "=")
if !found {
index++
if index >= len(args) {
return options, 0, fmt.Errorf("--%s requires a value", key)
}
value = args[index]
}
switch key {
case "protocol":
options.Protocol = strings.ToLower(value)
case "provider":
options.Provider = strings.ToLower(value)
case "method":
options.Method = strings.ToLower(value)
case "timeout":
parsed, err := time.ParseDuration(value)
if err != nil {
return options, 0, fmt.Errorf("invalid timeout %q: %w", value, err)
}
timeout = parsed
case "proxy":
options.Proxy = value
default:
return options, 0, fmt.Errorf("unknown query option --%s", key)
}
}
if len(positionals) < 1 || len(positionals) > 2 {
return options, 0, fmt.Errorf("query requires a domain and optional record type")
}
if timeout < 250*time.Millisecond || timeout > 30*time.Second {
return options, 0, fmt.Errorf("timeout must be between 250ms and 30s")
}
options.Name = positionals[0]
if len(positionals) == 2 {
options.RecordType = strings.ToUpper(positionals[1])
}
if !knownRecordType(options.RecordType) {
return options, 0, fmt.Errorf("unsupported record type %q", options.RecordType)
}
if !knownProtocol(options.Protocol) {
return options, 0, fmt.Errorf("unknown protocol %q", options.Protocol)
}
if _, err := edns.FindProvider(options.Provider); err != nil {
return options, 0, err
}
if options.Method != "get" && options.Method != "post" {
return options, 0, fmt.Errorf("DoH method must be get or post")
}
if options.Protocol != "doh" && options.Protocol != "doh3" && options.Method != "post" {
return options, 0, fmt.Errorf("--method applies only to DoH and DoH3")
}
if err := edns.ValidateProxyURL(options.Proxy); err != nil {
return options, 0, err
}
if options.Proxy != "" && options.Protocol != "doh" && options.Protocol != "dot" {
return options, 0, fmt.Errorf("--proxy applies only to DoH and DoT")
}
return options, timeout, nil
}
func parseCompareArgs(args []string) (edns.CompareOptions, time.Duration, error) {
options := edns.CompareOptions{RecordType: "A", AttemptTimeout: 5 * time.Second, MaxAttempts: 4}
totalTimeout := 30 * time.Second
positionals := make([]string, 0, 2)
seenTargets := map[string]bool{}
for index := 0; index < len(args); index++ {
argument := args[index]
if !strings.HasPrefix(argument, "--") {
positionals = append(positionals, argument)
continue
}
key, value, found := strings.Cut(strings.TrimPrefix(argument, "--"), "=")
if !found {
index++
if index >= len(args) {
return options, 0, fmt.Errorf("--%s requires a value", key)
}
value = args[index]
}
switch key {
case "target":
target, err := parseCompareTarget(value)
if err != nil {
return options, 0, err
}
identity := target.Protocol + ":" + target.Provider + ":" + target.Method
if seenTargets[identity] {
return options, 0, fmt.Errorf("duplicate comparison target %q", value)
}
seenTargets[identity] = true
options.Targets = append(options.Targets, target)
case "timeout":
parsed, err := time.ParseDuration(value)
if err != nil {
return options, 0, fmt.Errorf("invalid timeout %q: %w", value, err)
}
totalTimeout = parsed
case "attempt-timeout":
parsed, err := time.ParseDuration(value)
if err != nil {
return options, 0, fmt.Errorf("invalid attempt timeout %q: %w", value, err)
}
options.AttemptTimeout = parsed
case "max-attempts":
parsed, err := strconv.Atoi(value)
if err != nil {
return options, 0, fmt.Errorf("invalid max attempts %q", value)
}
options.MaxAttempts = parsed
case "proxy":
options.Proxy = value
default:
return options, 0, fmt.Errorf("unknown compare option --%s", key)
}
}
if len(positionals) < 1 || len(positionals) > 2 {
return options, 0, fmt.Errorf("compare requires a domain and optional record type")
}
options.Name = positionals[0]
if len(positionals) == 2 {
options.RecordType = strings.ToUpper(positionals[1])
}
if !knownRecordType(options.RecordType) {
return options, 0, fmt.Errorf("unsupported record type %q", options.RecordType)
}
if len(options.Targets) < 2 {
return options, 0, fmt.Errorf("compare requires at least two --target values")
}
if options.MaxAttempts < 2 || options.MaxAttempts > 8 {
return options, 0, fmt.Errorf("max attempts must be between 2 and 8")
}
if len(options.Targets) > options.MaxAttempts {
return options, 0, fmt.Errorf("comparison targets exceed max attempts")
}
if totalTimeout < 250*time.Millisecond || totalTimeout > 60*time.Second {
return options, 0, fmt.Errorf("compare timeout must be between 250ms and 60s")
}
if options.AttemptTimeout < 250*time.Millisecond || options.AttemptTimeout > 30*time.Second {
return options, 0, fmt.Errorf("attempt timeout must be between 250ms and 30s")
}
if options.AttemptTimeout > totalTimeout {
return options, 0, fmt.Errorf("attempt timeout cannot exceed compare timeout")
}
if err := edns.ValidateProxyURL(options.Proxy); err != nil {
return options, 0, err
}
if options.Proxy != "" {
for _, target := range options.Targets {
if target.Protocol != "doh" && target.Protocol != "dot" {
return options, 0, fmt.Errorf("--proxy cannot be used with %s comparison targets", target.Protocol)
}
}
}
return options, totalTimeout, nil
}
func parseCompareTarget(value string) (edns.CompareTarget, error) {
parts := strings.Split(value, ":")
if len(parts) < 2 || len(parts) > 3 {
return edns.CompareTarget{}, fmt.Errorf("target %q must be protocol:provider[:method]", value)
}
target := edns.CompareTarget{Protocol: strings.ToLower(parts[0]), Provider: strings.ToLower(parts[1]), Method: "post"}
if len(parts) == 3 {
target.Method = strings.ToLower(parts[2])
}
if !knownProtocol(target.Protocol) {
return target, fmt.Errorf("unknown protocol %q", target.Protocol)
}
if _, err := edns.FindProvider(target.Provider); err != nil {
return target, err
}
if target.Method != "get" && target.Method != "post" {
return target, fmt.Errorf("target method must be get or post")
}
if target.Protocol != "doh" && target.Protocol != "doh3" && target.Method != "post" {
return target, fmt.Errorf("GET method applies only to DoH and DoH3 targets")
}
return target, nil
}
func knownProtocol(protocol string) bool {
switch protocol {
case "doh", "dot", "doq", "doh3", "dnscrypt", "odoh", "anonymized-dnscrypt":
return true
default:
return false
}
}
func knownRecordType(recordType string) bool {
switch recordType {
case "A", "AAAA", "CNAME", "MX", "TXT", "NS", "SOA", "CAA", "SRV", "PTR", "HTTPS", "SVCB":
return true
default:
return false
}
}
func resultExitCode(completed bool, resultError *edns.ErrorInfo) int {
if completed {
return exitSuccess
}
if resultError == nil {
return exitLocal
}
switch resultError.Class {
case "internal":
return exitLocal
case "input":
return exitUsage
case "unsupported":
return exitUnsupported
case "transport", "protocol":
return exitTransport
default:
return exitLocal
}
}
func writeJSON(stdout, stderr io.Writer, value any) int {
encoder := json.NewEncoder(stdout)
encoder.SetIndent("", " ")
if err := encoder.Encode(value); err != nil {
fmt.Fprintf(stderr, "encode JSON result: %v\n", err)
return 1
}
return 0
}
func writeUsage(writer io.Writer) {
fmt.Fprintln(writer, "usage: ednsdiag <capabilities|version|query|probe|compare>")
}
func writeQueryUsage(writer io.Writer) {
fmt.Fprintln(writer, "usage: ednsdiag <query|probe> <domain> [type] [--protocol doh|dot|doq|doh3|dnscrypt|odoh|anonymized-dnscrypt] [--provider cloudflare|google|quad9|adguard] [--method post|get] [--proxy http://host:port] [--timeout 5s]")
}
func writeCompareUsage(writer io.Writer) {
fmt.Fprintln(writer, "usage: ednsdiag compare <domain> [type] --target protocol:provider[:method] --target protocol:provider[:method] [--proxy http://host:port] [--attempt-timeout 5s] [--timeout 30s] [--max-attempts 4]")
}