109 lines
2.1 KiB
Go
109 lines
2.1 KiB
Go
package sniffer
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import (
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"bytes"
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"errors"
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C "github.com/Dreamacro/clash/constant"
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"net"
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"strconv"
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"strings"
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)
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var (
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// refer to https://pkg.go.dev/net/http@master#pkg-constants
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methods = [...]string{"get", "post", "head", "put", "delete", "options", "connect", "patch", "trace"}
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errNotHTTPMethod = errors.New("not an HTTP method")
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)
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type version byte
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const (
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HTTP1 version = iota
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HTTP2
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)
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type HTTPSniffer struct {
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version version
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host string
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}
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func (http *HTTPSniffer) Protocol() string {
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switch http.version {
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case HTTP1:
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return "http1"
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case HTTP2:
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return "http2"
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default:
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return "unknown"
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}
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}
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func (http *HTTPSniffer) SupportNetwork() C.NetWork {
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return C.TCP
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}
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func (http *HTTPSniffer) SniffTCP(bytes []byte) (string, error) {
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domain, err := SniffHTTP(bytes)
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if err == nil {
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return *domain, nil
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} else {
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return "", err
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}
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}
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func beginWithHTTPMethod(b []byte) error {
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for _, m := range &methods {
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if len(b) >= len(m) && strings.EqualFold(string(b[:len(m)]), m) {
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return nil
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}
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if len(b) < len(m) {
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return ErrNoClue
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}
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}
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return errNotHTTPMethod
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}
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func SniffHTTP(b []byte) (*string, error) {
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if err := beginWithHTTPMethod(b); err != nil {
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return nil, err
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}
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_ = &HTTPSniffer{
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version: HTTP1,
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}
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headers := bytes.Split(b, []byte{'\n'})
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for i := 1; i < len(headers); i++ {
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header := headers[i]
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if len(header) == 0 {
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break
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}
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parts := bytes.SplitN(header, []byte{':'}, 2)
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if len(parts) != 2 {
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continue
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}
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key := strings.ToLower(string(parts[0]))
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if key == "host" {
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port := 80
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rawHost := strings.ToLower(string(bytes.TrimSpace(parts[1])))
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host, rawPort, err := net.SplitHostPort(rawHost)
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if err != nil {
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if addrError, ok := err.(*net.AddrError); ok && strings.Contains(addrError.Err, "missing port") {
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host = rawHost
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} else {
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return nil, err
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}
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} else if len(rawPort) > 0 {
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intPort, err := strconv.ParseUint(rawPort, 0, 16)
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if err != nil {
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return nil, err
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}
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port = int(intPort)
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}
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host = net.JoinHostPort(host, strconv.Itoa(port))
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return &host, nil
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}
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}
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return nil, ErrNoClue
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}
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