Clash.Meta/adapters/inbound/http.go

package inbound

import (
	"net"
	"net/http"
	"strings"

	C "github.com/Dreamacro/clash/constant"
	"github.com/Dreamacro/clash/context"
)

// NewHTTP receive normal http request and return HTTPContext
func NewHTTP(request *http.Request, conn net.Conn) *context.HTTPContext {
	metadata := parseHTTPAddr(request)
	metadata.Type = C.HTTP
	if ip, port, err := parseAddr(conn.RemoteAddr().String()); err == nil {
		metadata.SrcIP = ip
		metadata.SrcPort = port
	}
	return context.NewHTTPContext(conn, request, metadata)
}

// RemoveHopByHopHeaders remove hop-by-hop header
func RemoveHopByHopHeaders(header http.Header) {
	// Strip hop-by-hop header based on RFC:
	// http://www.w3.org/Protocols/rfc2616/rfc2616-sec13.html#sec13.5.1
	// https://www.mnot.net/blog/2011/07/11/what_proxies_must_do

	header.Del("Proxy-Connection")
	header.Del("Proxy-Authenticate")
	header.Del("Proxy-Authorization")
	header.Del("TE")
	header.Del("Trailers")
	header.Del("Transfer-Encoding")
	header.Del("Upgrade")

	connections := header.Get("Connection")
	header.Del("Connection")
	if len(connections) == 0 {
		return
	}
	for _, h := range strings.Split(connections, ",") {
		header.Del(strings.TrimSpace(h))
	}
}

// RemoveExtraHTTPHostPort remove extra host port (example.com:80 --> example.com)
// It resolves the behavior of some HTTP servers that do not handle host:80 (e.g. baidu.com)
func RemoveExtraHTTPHostPort(req *http.Request) {
	host := req.Host
	if host == "" {
		host = req.URL.Host
	}

	if pHost, port, err := net.SplitHostPort(host); err == nil && port == "80" {
		host = pHost
	}

	req.Host = host
	req.URL.Host = host
}