clash/component/sniffer/http_sniffer.go
2022-05-02 05:10:18 +08:00

109 lines
2.1 KiB
Go

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