add ip filter for httpreverseproxy

go.mod

@@ -25,6 +25,7 @@ require (
 	github.com/spf13/cobra v1.8.0
 	github.com/things-go/go-socks5 v0.0.5
 	golang.org/x/crypto v0.21.0
+	golang.org/x/net v0.21.0
 	software.sslmate.com/src/go-pkcs12 v0.4.0
 
 )
@@ -39,7 +40,6 @@ require (
 	github.com/spf13/pflag v1.0.5 // indirect
 	golang.org/x/image v0.6.0 // indirect
 	golang.org/x/mod v0.14.0 // indirect
-	golang.org/x/net v0.21.0 // indirect
 	golang.org/x/sys v0.18.0 // indirect
 	golang.org/x/term v0.18.0 // indirect
 	golang.org/x/text v0.14.0 // indirect

httpreverse/cfg.ini

@@ -12,4 +12,9 @@ authuser=b612
 authpasswd=b612
 whiteip=
 blackip=
-wanringpage=
+wanringpage=
+ipfiltermode=3
+filterxforward=
+filterremoteaddr=
+filtermustkey=
+filterfile=

httpreverse/cmd.go

@@ -75,7 +75,7 @@ var Cmd = &cobra.Command{
 			SkipSSLVerify: skipsslverify,
 			Key:           key,
 			Cert:          cert,
-			XForwardMode:  1,
+			IPFilterMode:  1,
 		}
 		go func() {
 			sig := make(chan os.Signal)

httpreverse/reverse.go

@@ -1,35 +1,46 @@
 package httpreverse
 
 import (
+	"b612.me/apps/b612/httpreverse/rp"
+	"b612.me/starlog"
 	"b612.me/staros/sysconf"
+	"bufio"
 	"errors"
+	"io"
 	"io/ioutil"
+	"net"
 	"net/http"
-	"net/http/httputil"
 	"net/url"
+	"os"
 	"strings"
 	"sync"
 )
 
 type ReverseConfig struct {
-	Name          string
+	Name             string
-	Addr          string
+	Addr             string
-	ReverseURL    map[string]*url.URL
+	ReverseURL       map[string]*url.URL
-	Port          int
+	Port             int
-	UsingSSL      bool
+	UsingSSL         bool
-	Key           string
+	Key              string
-	Cert          string
+	Cert             string
-	Host          string
+	Host             string
-	SkipSSLVerify bool
+	SkipSSLVerify    bool
-	InHeader      [][2]string
+	InHeader         [][2]string
-	OutHeader     [][2]string
+	OutHeader        [][2]string
-	Cookie        [][3]string //[3]string should contains path::key::value
+	Cookie           [][3]string //[3]string should contains path::key::value
-	ReplaceList   [][2]string
+	ReplaceList      [][2]string
-	ReplaceOnce   bool
+	ReplaceOnce      bool
-	proxy         map[string]*httputil.ReverseProxy
+	proxy            map[string]*rp.ReverseProxy
-	XForwardMode  int //0=off 1=useremote 2=add
+	IPFilterMode     int //0=off 1=useremote 2=add 3=filter
-	httpmux       http.ServeMux
+	FilterXForward   bool
-	httpserver    http.Server
+	FilterRemoteAddr bool
+	FilterMustKey    string
+	FilterSetKey     string
+	FilterFile       string
+	httpmux          http.ServeMux
+	httpserver       http.Server
+	CIDR             []*net.IPNet
 
 	basicAuthUser   string
 	basicAuthPwd    string
@@ -53,18 +64,54 @@ func Parse(path string) (HttpReverseServer, error) {
 	}
 	for _, v := range ini.Data {
 		var ins = ReverseConfig{
-			Name:          v.Name,
+			Name:             v.Name,
-			Host:          v.Get("host"),
+			Host:             v.Get("host"),
-			Addr:          v.Get("addr"),
+			Addr:             v.Get("addr"),
-			Port:          v.Int("port"),
+			Port:             v.Int("port"),
-			UsingSSL:      v.Bool("enablessl"),
+			UsingSSL:         v.Bool("enablessl"),
-			Key:           v.Get("key"),
+			Key:              v.Get("key"),
-			Cert:          v.Get("cert"),
+			Cert:             v.Get("cert"),
-			ReplaceOnce:   v.Bool("replaceonce"),
+			ReplaceOnce:      v.Bool("replaceonce"),
-			XForwardMode:  v.Int("xforwardmode"),
+			IPFilterMode:     v.Int("ipfiltermode"),
-			basicAuthUser: v.Get("authuser"),
+			FilterXForward:   v.Bool("filterxforward"),
-			basicAuthPwd:  v.Get("authpasswd"),
+			FilterRemoteAddr: v.Bool("filterremoteaddr"),
-			warningpage:   v.Get("warnpage"),
+			FilterMustKey:    v.Get("filtermustkey"),
+			FilterSetKey:     v.Get("filtersetkey"),
+			FilterFile:       v.Get("filterfile"),
+			basicAuthUser:    v.Get("authuser"),
+			basicAuthPwd:     v.Get("authpasswd"),
+			warningpage:      v.Get("warnpage"),
+		}
+		if ins.IPFilterMode == 3 && ins.FilterFile != "" {
+			starlog.Infoln("IP Filter Mode 3, Load IP Filter File", ins.FilterFile)
+			f, err := os.Open(ins.FilterFile)
+			if err != nil {
+				return res, err
+			}
+			buf := bufio.NewReader(f)
+			count := 0
+			for {
+				line, err := buf.ReadString('\n')
+				if err != nil {
+					if err == io.EOF {
+						f.Close()
+						break
+					}
+					f.Close()
+					return res, err
+				}
+				line = strings.TrimSpace(line)
+				if !strings.Contains(line, "/") {
+					line += "/32" //todo：区分IPV6
+				}
+				_, cidr, err := net.ParseCIDR(line)
+				if err != nil {
+					return res, err
+				}
+				ins.CIDR = append(ins.CIDR, cidr)
+				count++
+			}
+			starlog.Infoln("Load", count, "CIDR")
 		}
 		if ins.warningpage != "" {
 			data, err := ioutil.ReadFile(ins.warningpage)
@@ -73,7 +120,7 @@ func Parse(path string) (HttpReverseServer, error) {
 			}
 			ins.warnpagedata = data
 		}
-		ins.proxy = make(map[string]*httputil.ReverseProxy)
+		ins.proxy = make(map[string]*rp.ReverseProxy)
 		ins.ReverseURL = make(map[string]*url.URL)
 		for _, reverse := range v.GetAll("reverse") {
 			kv := strings.SplitN(reverse, "::", 2)

httpreverse/reverse_test.go

@@ -2,9 +2,18 @@ package httpreverse
 
 import (
 	"fmt"
+	"net"
 	"testing"
 )
 
+func TestCIDR(t *testing.T) {
+	_, c, err := net.ParseCIDR("108.162.192.0/18")
+	if err != nil {
+		t.Fatal(err)
+	}
+	fmt.Println(c.Contains(net.ParseIP("108.162.245.124")))
+}
+
 func TestReverseParse(t *testing.T) {
 	data, err := Parse("./cfg.ini")
 	if err != nil {

httpreverse/rp/reverseproxy.go

@@ -0,0 +1,852 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// HTTP reverse proxy handler
+
+package rp
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"log"
+	"mime"
+	"net"
+	"net/http"
+	"net/http/httptrace"
+	"net/textproto"
+	"net/url"
+	"strings"
+	"sync"
+	"time"
+
+	"golang.org/x/net/http/httpguts"
+)
+
+func lower(b byte) byte {
+	if 'A' <= b && b <= 'Z' {
+		return b + ('a' - 'A')
+	}
+	return b
+}
+
+func EqualFold(s, t string) bool {
+	if len(s) != len(t) {
+		return false
+	}
+	for i := 0; i < len(s); i++ {
+		if lower(s[i]) != lower(t[i]) {
+			return false
+		}
+	}
+	return true
+}
+
+func IsPrint(s string) bool {
+	for i := 0; i < len(s); i++ {
+		if s[i] < ' ' || s[i] > '~' {
+			return false
+		}
+	}
+	return true
+}
+
+// A ProxyRequest contains a request to be rewritten by a ReverseProxy.
+type ProxyRequest struct {
+	// In is the request received by the proxy.
+	// The Rewrite function must not modify In.
+	In *http.Request
+
+	// Out is the request which will be sent by the proxy.
+	// The Rewrite function may modify or replace this request.
+	// Hop-by-hop headers are removed from this request
+	// before Rewrite is called.
+	Out *http.Request
+}
+
+// SetURL routes the outbound request to the scheme, host, and base path
+// provided in target. If the target's path is "/base" and the incoming
+// request was for "/dir", the target request will be for "/base/dir".
+//
+// SetURL rewrites the outbound Host header to match the target's host.
+// To preserve the inbound request's Host header (the default behavior
+// of NewSingleHostReverseProxy):
+//
+//	rewriteFunc := func(r *httputil.ProxyRequest) {
+//		r.SetURL(url)
+//		r.Out.Host = r.In.Host
+//	}
+func (r *ProxyRequest) SetURL(target *url.URL) {
+	rewriteRequestURL(r.Out, target)
+	r.Out.Host = ""
+}
+
+// SetXForwarded sets the X-Forwarded-For, X-Forwarded-Host, and
+// X-Forwarded-Proto headers of the outbound request.
+//
+//   - The X-Forwarded-For header is set to the client IP address.
+//   - The X-Forwarded-Host header is set to the host name requested
+//     by the client.
+//   - The X-Forwarded-Proto header is set to "http" or "https", depending
+//     on whether the inbound request was made on a TLS-enabled connection.
+//
+// If the outbound request contains an existing X-Forwarded-For header,
+// SetXForwarded appends the client IP address to it. To append to the
+// inbound request's X-Forwarded-For header (the default behavior of
+// ReverseProxy when using a Director function), copy the header
+// from the inbound request before calling SetXForwarded:
+//
+//	rewriteFunc := func(r *httputil.ProxyRequest) {
+//		r.Out.Header["X-Forwarded-For"] = r.In.Header["X-Forwarded-For"]
+//		r.SetXForwarded()
+//	}
+func (r *ProxyRequest) SetXForwarded() {
+	clientIP, _, err := net.SplitHostPort(r.In.RemoteAddr)
+	if err == nil {
+		prior := r.Out.Header["X-Forwarded-For"]
+		if len(prior) > 0 {
+			clientIP = strings.Join(prior, ", ") + ", " + clientIP
+		}
+		r.Out.Header.Set("X-Forwarded-For", clientIP)
+	} else {
+		r.Out.Header.Del("X-Forwarded-For")
+	}
+	r.Out.Header.Set("X-Forwarded-Host", r.In.Host)
+	if r.In.TLS == nil {
+		r.Out.Header.Set("X-Forwarded-Proto", "http")
+	} else {
+		r.Out.Header.Set("X-Forwarded-Proto", "https")
+	}
+}
+
+// ReverseProxy is an HTTP Handler that takes an incoming request and
+// sends it to another server, proxying the response back to the
+// client.
+//
+// 1xx responses are forwarded to the client if the underlying
+// transport supports ClientTrace.Got1xxResponse.
+type ReverseProxy struct {
+	// Rewrite must be a function which modifies
+	// the request into a new request to be sent
+	// using Transport. Its response is then copied
+	// back to the original client unmodified.
+	// Rewrite must not access the provided ProxyRequest
+	// or its contents after returning.
+	//
+	// The Forwarded, X-Forwarded, X-Forwarded-Host,
+	// and X-Forwarded-Proto headers are removed from the
+	// outbound request before Rewrite is called. See also
+	// the ProxyRequest.SetXForwarded method.
+	//
+	// Unparsable query parameters are removed from the
+	// outbound request before Rewrite is called.
+	// The Rewrite function may copy the inbound URL's
+	// RawQuery to the outbound URL to preserve the original
+	// parameter string. Note that this can lead to security
+	// issues if the proxy's interpretation of query parameters
+	// does not match that of the downstream server.
+	//
+	// At most one of Rewrite or Director may be set.
+	Rewrite func(*ProxyRequest)
+
+	// Director is a function which modifies
+	// the request into a new request to be sent
+	// using Transport. Its response is then copied
+	// back to the original client unmodified.
+	// Director must not access the provided Request
+	// after returning.
+	//
+	// By default, the X-Forwarded-For header is set to the
+	// value of the client IP address. If an X-Forwarded-For
+	// header already exists, the client IP is appended to the
+	// existing values. As a special case, if the header
+	// exists in the Request.Header map but has a nil value
+	// (such as when set by the Director func), the X-Forwarded-For
+	// header is not modified.
+	//
+	// To prevent IP spoofing, be sure to delete any pre-existing
+	// X-Forwarded-For header coming from the client or
+	// an untrusted proxy.
+	//
+	// Hop-by-hop headers are removed from the request after
+	// Director returns, which can remove headers added by
+	// Director. Use a Rewrite function instead to ensure
+	// modifications to the request are preserved.
+	//
+	// Unparsable query parameters are removed from the outbound
+	// request if Request.Form is set after Director returns.
+	//
+	// At most one of Rewrite or Director may be set.
+	Director func(*http.Request)
+
+	// The transport used to perform proxy requests.
+	// If nil, http.DefaultTransport is used.
+	Transport http.RoundTripper
+
+	// FlushInterval specifies the flush interval
+	// to flush to the client while copying the
+	// response body.
+	// If zero, no periodic flushing is done.
+	// A negative value means to flush immediately
+	// after each write to the client.
+	// The FlushInterval is ignored when ReverseProxy
+	// recognizes a response as a streaming response, or
+	// if its ContentLength is -1; for such responses, writes
+	// are flushed to the client immediately.
+	FlushInterval time.Duration
+
+	// ErrorLog specifies an optional logger for errors
+	// that occur when attempting to proxy the request.
+	// If nil, logging is done via the log package's standard logger.
+	ErrorLog *log.Logger
+
+	// BufferPool optionally specifies a buffer pool to
+	// get byte slices for use by io.CopyBuffer when
+	// copying HTTP response bodies.
+	BufferPool BufferPool
+
+	// ModifyResponse is an optional function that modifies the
+	// Response from the backend. It is called if the backend
+	// returns a response at all, with any HTTP status code.
+	// If the backend is unreachable, the optional ErrorHandler is
+	// called without any call to ModifyResponse.
+	//
+	// If ModifyResponse returns an error, ErrorHandler is called
+	// with its error value. If ErrorHandler is nil, its default
+	// implementation is used.
+	ModifyResponse func(*http.Response) error
+
+	// ErrorHandler is an optional function that handles errors
+	// reaching the backend or errors from ModifyResponse.
+	//
+	// If nil, the default is to log the provided error and return
+	// a 502 Status Bad Gateway response.
+	ErrorHandler func(http.ResponseWriter, *http.Request, error)
+}
+
+// A BufferPool is an interface for getting and returning temporary
+// byte slices for use by io.CopyBuffer.
+type BufferPool interface {
+	Get() []byte
+	Put([]byte)
+}
+
+func singleJoiningSlash(a, b string) string {
+	aslash := strings.HasSuffix(a, "/")
+	bslash := strings.HasPrefix(b, "/")
+	switch {
+	case aslash && bslash:
+		return a + b[1:]
+	case !aslash && !bslash:
+		return a + "/" + b
+	}
+	return a + b
+}
+
+func joinURLPath(a, b *url.URL) (path, rawpath string) {
+	if a.RawPath == "" && b.RawPath == "" {
+		return singleJoiningSlash(a.Path, b.Path), ""
+	}
+	// Same as singleJoiningSlash, but uses EscapedPath to determine
+	// whether a slash should be added
+	apath := a.EscapedPath()
+	bpath := b.EscapedPath()
+
+	aslash := strings.HasSuffix(apath, "/")
+	bslash := strings.HasPrefix(bpath, "/")
+
+	switch {
+	case aslash && bslash:
+		return a.Path + b.Path[1:], apath + bpath[1:]
+	case !aslash && !bslash:
+		return a.Path + "/" + b.Path, apath + "/" + bpath
+	}
+	return a.Path + b.Path, apath + bpath
+}
+
+// NewSingleHostReverseProxy returns a new ReverseProxy that routes
+// URLs to the scheme, host, and base path provided in target. If the
+// target's path is "/base" and the incoming request was for "/dir",
+// the target request will be for /base/dir.
+//
+// NewSingleHostReverseProxy does not rewrite the Host header.
+//
+// To customize the ReverseProxy behavior beyond what
+// NewSingleHostReverseProxy provides, use ReverseProxy directly
+// with a Rewrite function. The ProxyRequest SetURL method
+// may be used to route the outbound request. (Note that SetURL,
+// unlike NewSingleHostReverseProxy, rewrites the Host header
+// of the outbound request by default.)
+//
+//	proxy := &ReverseProxy{
+//		Rewrite: func(r *ProxyRequest) {
+//			r.SetURL(target)
+//			r.Out.Host = r.In.Host // if desired
+//		}
+//	}
+func NewSingleHostReverseProxy(target *url.URL) *ReverseProxy {
+	director := func(req *http.Request) {
+		rewriteRequestURL(req, target)
+	}
+	return &ReverseProxy{Director: director}
+}
+
+func rewriteRequestURL(req *http.Request, target *url.URL) {
+	targetQuery := target.RawQuery
+	req.URL.Scheme = target.Scheme
+	req.URL.Host = target.Host
+	req.URL.Path, req.URL.RawPath = joinURLPath(target, req.URL)
+	if targetQuery == "" || req.URL.RawQuery == "" {
+		req.URL.RawQuery = targetQuery + req.URL.RawQuery
+	} else {
+		req.URL.RawQuery = targetQuery + "&" + req.URL.RawQuery
+	}
+}
+
+func copyHeader(dst, src http.Header) {
+	for k, vv := range src {
+		for _, v := range vv {
+			dst.Add(k, v)
+		}
+	}
+}
+
+// Hop-by-hop headers. These are removed when sent to the backend.
+// As of RFC 7230, hop-by-hop headers are required to appear in the
+// Connection header field. These are the headers defined by the
+// obsoleted RFC 2616 (section 13.5.1) and are used for backward
+// compatibility.
+var hopHeaders = []string{
+	"Connection",
+	"Proxy-Connection", // non-standard but still sent by libcurl and rejected by e.g. google
+	"Keep-Alive",
+	"Proxy-Authenticate",
+	"Proxy-Authorization",
+	"Te",      // canonicalized version of "TE"
+	"Trailer", // not Trailers per URL above; https://www.rfc-editor.org/errata_search.php?eid=4522
+	"Transfer-Encoding",
+	"Upgrade",
+}
+
+func (p *ReverseProxy) defaultErrorHandler(rw http.ResponseWriter, req *http.Request, err error) {
+	p.logf("http: proxy error: %v", err)
+	rw.WriteHeader(http.StatusBadGateway)
+}
+
+func (p *ReverseProxy) getErrorHandler() func(http.ResponseWriter, *http.Request, error) {
+	if p.ErrorHandler != nil {
+		return p.ErrorHandler
+	}
+	return p.defaultErrorHandler
+}
+
+// modifyResponse conditionally runs the optional ModifyResponse hook
+// and reports whether the request should proceed.
+func (p *ReverseProxy) modifyResponse(rw http.ResponseWriter, res *http.Response, req *http.Request) bool {
+	if p.ModifyResponse == nil {
+		return true
+	}
+	if err := p.ModifyResponse(res); err != nil {
+		res.Body.Close()
+		p.getErrorHandler()(rw, req, err)
+		return false
+	}
+	return true
+}
+
+func (p *ReverseProxy) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
+	transport := p.Transport
+	if transport == nil {
+		transport = http.DefaultTransport
+	}
+
+	ctx := req.Context()
+	if ctx.Done() != nil {
+		// CloseNotifier predates context.Context, and has been
+		// entirely superseded by it. If the request contains
+		// a Context that carries a cancellation signal, don't
+		// bother spinning up a goroutine to watch the CloseNotify
+		// channel (if any).
+		//
+		// If the request Context has a nil Done channel (which
+		// means it is either context.Background, or a custom
+		// Context implementation with no cancellation signal),
+		// then consult the CloseNotifier if available.
+	} else if cn, ok := rw.(http.CloseNotifier); ok {
+		var cancel context.CancelFunc
+		ctx, cancel = context.WithCancel(ctx)
+		defer cancel()
+		notifyChan := cn.CloseNotify()
+		go func() {
+			select {
+			case <-notifyChan:
+				cancel()
+			case <-ctx.Done():
+			}
+		}()
+	}
+
+	outreq := req.Clone(ctx)
+	if req.ContentLength == 0 {
+		outreq.Body = nil // Issue 16036: nil Body for http.Transport retries
+	}
+	if outreq.Body != nil {
+		// Reading from the request body after returning from a handler is not
+		// allowed, and the RoundTrip goroutine that reads the Body can outlive
+		// this handler. This can lead to a crash if the handler panics (see
+		// Issue 46866). Although calling Close doesn't guarantee there isn't
+		// any Read in flight after the handle returns, in practice it's safe to
+		// read after closing it.
+		defer outreq.Body.Close()
+	}
+	if outreq.Header == nil {
+		outreq.Header = make(http.Header) // Issue 33142: historical behavior was to always allocate
+	}
+
+	if (p.Director != nil) == (p.Rewrite != nil) {
+		p.getErrorHandler()(rw, req, errors.New("ReverseProxy must have exactly one of Director or Rewrite set"))
+		return
+	}
+
+	if p.Director != nil {
+		p.Director(outreq)
+		if outreq.Form != nil {
+			outreq.URL.RawQuery = cleanQueryParams(outreq.URL.RawQuery)
+		}
+	}
+	outreq.Close = false
+
+	reqUpType := upgradeType(outreq.Header)
+	if !IsPrint(reqUpType) {
+		p.getErrorHandler()(rw, req, fmt.Errorf("client tried to switch to invalid protocol %q", reqUpType))
+		return
+	}
+	removeHopByHopHeaders(outreq.Header)
+
+	// Issue 21096: tell backend applications that care about trailer support
+	// that we support trailers. (We do, but we don't go out of our way to
+	// advertise that unless the incoming client request thought it was worth
+	// mentioning.) Note that we look at req.Header, not outreq.Header, since
+	// the latter has passed through removeHopByHopHeaders.
+	if httpguts.HeaderValuesContainsToken(req.Header["Te"], "trailers") {
+		outreq.Header.Set("Te", "trailers")
+	}
+
+	// After stripping all the hop-by-hop connection headers above, add back any
+	// necessary for protocol upgrades, such as for websockets.
+	if reqUpType != "" {
+		outreq.Header.Set("Connection", "Upgrade")
+		outreq.Header.Set("Upgrade", reqUpType)
+	}
+
+	if p.Rewrite != nil {
+		// Strip client-provided forwarding headers.
+		// The Rewrite func may use SetXForwarded to set new values
+		// for these or copy the previous values from the inbound request.
+		outreq.Header.Del("Forwarded")
+		outreq.Header.Del("X-Forwarded-For")
+		outreq.Header.Del("X-Forwarded-Host")
+		outreq.Header.Del("X-Forwarded-Proto")
+
+		// Remove unparsable query parameters from the outbound request.
+		outreq.URL.RawQuery = cleanQueryParams(outreq.URL.RawQuery)
+
+		pr := &ProxyRequest{
+			In:  req,
+			Out: outreq,
+		}
+		p.Rewrite(pr)
+		outreq = pr.Out
+	}
+
+	if _, ok := outreq.Header["User-Agent"]; !ok {
+		// If the outbound request doesn't have a User-Agent header set,
+		// don't send the default Go HTTP client User-Agent.
+		outreq.Header.Set("User-Agent", "")
+	}
+
+	trace := &httptrace.ClientTrace{
+		Got1xxResponse: func(code int, header textproto.MIMEHeader) error {
+			h := rw.Header()
+			copyHeader(h, http.Header(header))
+			rw.WriteHeader(code)
+
+			// Clear headers, it's not automatically done by ResponseWriter.WriteHeader() for 1xx responses
+			for k := range h {
+				delete(h, k)
+			}
+
+			return nil
+		},
+	}
+	outreq = outreq.WithContext(httptrace.WithClientTrace(outreq.Context(), trace))
+
+	res, err := transport.RoundTrip(outreq)
+	if err != nil {
+		p.getErrorHandler()(rw, outreq, err)
+		return
+	}
+
+	// Deal with 101 Switching Protocols responses: (WebSocket, h2c, etc)
+	if res.StatusCode == http.StatusSwitchingProtocols {
+		if !p.modifyResponse(rw, res, outreq) {
+			return
+		}
+		p.handleUpgradeResponse(rw, outreq, res)
+		return
+	}
+
+	removeHopByHopHeaders(res.Header)
+
+	if !p.modifyResponse(rw, res, outreq) {
+		return
+	}
+
+	copyHeader(rw.Header(), res.Header)
+
+	// The "Trailer" header isn't included in the Transport's response,
+	// at least for *http.Transport. Build it up from Trailer.
+	announcedTrailers := len(res.Trailer)
+	if announcedTrailers > 0 {
+		trailerKeys := make([]string, 0, len(res.Trailer))
+		for k := range res.Trailer {
+			trailerKeys = append(trailerKeys, k)
+		}
+		rw.Header().Add("Trailer", strings.Join(trailerKeys, ", "))
+	}
+
+	rw.WriteHeader(res.StatusCode)
+
+	err = p.copyResponse(rw, res.Body, p.flushInterval(res))
+	if err != nil {
+		defer res.Body.Close()
+		// Since we're streaming the response, if we run into an error all we can do
+		// is abort the request. Issue 23643: ReverseProxy should use ErrAbortHandler
+		// on read error while copying body.
+		if !shouldPanicOnCopyError(req) {
+			p.logf("suppressing panic for copyResponse error in test; copy error: %v", err)
+			return
+		}
+		panic(http.ErrAbortHandler)
+	}
+	res.Body.Close() // close now, instead of defer, to populate res.Trailer
+
+	if len(res.Trailer) > 0 {
+		// Force chunking if we saw a response trailer.
+		// This prevents net/http from calculating the length for short
+		// bodies and adding a Content-Length.
+		if fl, ok := rw.(http.Flusher); ok {
+			fl.Flush()
+		}
+	}
+
+	if len(res.Trailer) == announcedTrailers {
+		copyHeader(rw.Header(), res.Trailer)
+		return
+	}
+
+	for k, vv := range res.Trailer {
+		k = http.TrailerPrefix + k
+		for _, v := range vv {
+			rw.Header().Add(k, v)
+		}
+	}
+}
+
+var inOurTests bool // whether we're in our own tests
+
+// shouldPanicOnCopyError reports whether the reverse proxy should
+// panic with http.ErrAbortHandler. This is the right thing to do by
+// default, but Go 1.10 and earlier did not, so existing unit tests
+// weren't expecting panics. Only panic in our own tests, or when
+// running under the HTTP server.
+func shouldPanicOnCopyError(req *http.Request) bool {
+	if inOurTests {
+		// Our tests know to handle this panic.
+		return true
+	}
+	if req.Context().Value(http.ServerContextKey) != nil {
+		// We seem to be running under an HTTP server, so
+		// it'll recover the panic.
+		return true
+	}
+	// Otherwise act like Go 1.10 and earlier to not break
+	// existing tests.
+	return false
+}
+
+// removeHopByHopHeaders removes hop-by-hop headers.
+func removeHopByHopHeaders(h http.Header) {
+	// RFC 7230, section 6.1: Remove headers listed in the "Connection" header.
+	for _, f := range h["Connection"] {
+		for _, sf := range strings.Split(f, ",") {
+			if sf = textproto.TrimString(sf); sf != "" {
+				h.Del(sf)
+			}
+		}
+	}
+	// RFC 2616, section 13.5.1: Remove a set of known hop-by-hop headers.
+	// This behavior is superseded by the RFC 7230 Connection header, but
+	// preserve it for backwards compatibility.
+	for _, f := range hopHeaders {
+		h.Del(f)
+	}
+}
+
+// flushInterval returns the p.FlushInterval value, conditionally
+// overriding its value for a specific request/response.
+func (p *ReverseProxy) flushInterval(res *http.Response) time.Duration {
+	resCT := res.Header.Get("Content-Type")
+
+	// For Server-Sent Events responses, flush immediately.
+	// The MIME type is defined in https://www.w3.org/TR/eventsource/#text-event-stream
+	if baseCT, _, _ := mime.ParseMediaType(resCT); baseCT == "text/event-stream" {
+		return -1 // negative means immediately
+	}
+
+	// We might have the case of streaming for which Content-Length might be unset.
+	if res.ContentLength == -1 {
+		return -1
+	}
+
+	return p.FlushInterval
+}
+
+func (p *ReverseProxy) copyResponse(dst io.Writer, src io.Reader, flushInterval time.Duration) error {
+	if flushInterval != 0 {
+		if wf, ok := dst.(writeFlusher); ok {
+			mlw := &maxLatencyWriter{
+				dst:     wf,
+				latency: flushInterval,
+			}
+			defer mlw.stop()
+
+			// set up initial timer so headers get flushed even if body writes are delayed
+			mlw.flushPending = true
+			mlw.t = time.AfterFunc(flushInterval, mlw.delayedFlush)
+
+			dst = mlw
+		}
+	}
+
+	var buf []byte
+	if p.BufferPool != nil {
+		buf = p.BufferPool.Get()
+		defer p.BufferPool.Put(buf)
+	}
+	_, err := p.copyBuffer(dst, src, buf)
+	return err
+}
+
+// copyBuffer returns any write errors or non-EOF read errors, and the amount
+// of bytes written.
+func (p *ReverseProxy) copyBuffer(dst io.Writer, src io.Reader, buf []byte) (int64, error) {
+	if len(buf) == 0 {
+		buf = make([]byte, 32*1024)
+	}
+	var written int64
+	for {
+		nr, rerr := src.Read(buf)
+		if rerr != nil && rerr != io.EOF && rerr != context.Canceled {
+			p.logf("httputil: ReverseProxy read error during body copy: %v", rerr)
+		}
+		if nr > 0 {
+			nw, werr := dst.Write(buf[:nr])
+			if nw > 0 {
+				written += int64(nw)
+			}
+			if werr != nil {
+				return written, werr
+			}
+			if nr != nw {
+				return written, io.ErrShortWrite
+			}
+		}
+		if rerr != nil {
+			if rerr == io.EOF {
+				rerr = nil
+			}
+			return written, rerr
+		}
+	}
+}
+
+func (p *ReverseProxy) logf(format string, args ...any) {
+	if p.ErrorLog != nil {
+		p.ErrorLog.Printf(format, args...)
+	} else {
+		log.Printf(format, args...)
+	}
+}
+
+type writeFlusher interface {
+	io.Writer
+	http.Flusher
+}
+
+type maxLatencyWriter struct {
+	dst     writeFlusher
+	latency time.Duration // non-zero; negative means to flush immediately
+
+	mu           sync.Mutex // protects t, flushPending, and dst.Flush
+	t            *time.Timer
+	flushPending bool
+}
+
+func (m *maxLatencyWriter) Write(p []byte) (n int, err error) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	n, err = m.dst.Write(p)
+	if m.latency < 0 {
+		m.dst.Flush()
+		return
+	}
+	if m.flushPending {
+		return
+	}
+	if m.t == nil {
+		m.t = time.AfterFunc(m.latency, m.delayedFlush)
+	} else {
+		m.t.Reset(m.latency)
+	}
+	m.flushPending = true
+	return
+}
+
+func (m *maxLatencyWriter) delayedFlush() {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	if !m.flushPending { // if stop was called but AfterFunc already started this goroutine
+		return
+	}
+	m.dst.Flush()
+	m.flushPending = false
+}
+
+func (m *maxLatencyWriter) stop() {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	m.flushPending = false
+	if m.t != nil {
+		m.t.Stop()
+	}
+}
+
+func upgradeType(h http.Header) string {
+	if !httpguts.HeaderValuesContainsToken(h["Connection"], "Upgrade") {
+		return ""
+	}
+	return h.Get("Upgrade")
+}
+
+func (p *ReverseProxy) handleUpgradeResponse(rw http.ResponseWriter, req *http.Request, res *http.Response) {
+	reqUpType := upgradeType(req.Header)
+	resUpType := upgradeType(res.Header)
+	if !IsPrint(resUpType) { // We know reqUpType is ASCII, it's checked by the caller.
+		p.getErrorHandler()(rw, req, fmt.Errorf("backend tried to switch to invalid protocol %q", resUpType))
+	}
+	if !EqualFold(reqUpType, resUpType) {
+		p.getErrorHandler()(rw, req, fmt.Errorf("backend tried to switch protocol %q when %q was requested", resUpType, reqUpType))
+		return
+	}
+
+	hj, ok := rw.(http.Hijacker)
+	if !ok {
+		p.getErrorHandler()(rw, req, fmt.Errorf("can't switch protocols using non-Hijacker ResponseWriter type %T", rw))
+		return
+	}
+	backConn, ok := res.Body.(io.ReadWriteCloser)
+	if !ok {
+		p.getErrorHandler()(rw, req, fmt.Errorf("internal error: 101 switching protocols response with non-writable body"))
+		return
+	}
+
+	backConnCloseCh := make(chan bool)
+	go func() {
+		// Ensure that the cancellation of a request closes the backend.
+		// See issue https://golang.org/issue/35559.
+		select {
+		case <-req.Context().Done():
+		case <-backConnCloseCh:
+		}
+		backConn.Close()
+	}()
+
+	defer close(backConnCloseCh)
+
+	conn, brw, err := hj.Hijack()
+	if err != nil {
+		p.getErrorHandler()(rw, req, fmt.Errorf("Hijack failed on protocol switch: %v", err))
+		return
+	}
+	defer conn.Close()
+
+	copyHeader(rw.Header(), res.Header)
+
+	res.Header = rw.Header()
+	res.Body = nil // so res.Write only writes the headers; we have res.Body in backConn above
+	if err := res.Write(brw); err != nil {
+		p.getErrorHandler()(rw, req, fmt.Errorf("response write: %v", err))
+		return
+	}
+	if err := brw.Flush(); err != nil {
+		p.getErrorHandler()(rw, req, fmt.Errorf("response flush: %v", err))
+		return
+	}
+	errc := make(chan error, 1)
+	spc := switchProtocolCopier{user: conn, backend: backConn}
+	go spc.copyToBackend(errc)
+	go spc.copyFromBackend(errc)
+	<-errc
+}
+
+// switchProtocolCopier exists so goroutines proxying data back and
+// forth have nice names in stacks.
+type switchProtocolCopier struct {
+	user, backend io.ReadWriter
+}
+
+func (c switchProtocolCopier) copyFromBackend(errc chan<- error) {
+	_, err := io.Copy(c.user, c.backend)
+	errc <- err
+}
+
+func (c switchProtocolCopier) copyToBackend(errc chan<- error) {
+	_, err := io.Copy(c.backend, c.user)
+	errc <- err
+}
+
+func cleanQueryParams(s string) string {
+	reencode := func(s string) string {
+		v, _ := url.ParseQuery(s)
+		return v.Encode()
+	}
+	for i := 0; i < len(s); {
+		switch s[i] {
+		case ';':
+			return reencode(s)
+		case '%':
+			if i+2 >= len(s) || !ishex(s[i+1]) || !ishex(s[i+2]) {
+				return reencode(s)
+			}
+			i += 3
+		default:
+			i++
+		}
+	}
+	return s
+}
+
+func ishex(c byte) bool {
+	switch {
+	case '0' <= c && c <= '9':
+		return true
+	case 'a' <= c && c <= 'f':
+		return true
+	case 'A' <= c && c <= 'F':
+		return true
+	}
+	return false
+}

httpreverse/service.go

@@ -1,6 +1,7 @@
 package httpreverse
 
 import (
+	"b612.me/apps/b612/httpreverse/rp"
 	"b612.me/starlog"
 	"bytes"
 	"context"
@@ -10,7 +11,6 @@ import (
 	"io/ioutil"
 	"net"
 	"net/http"
-	"net/http/httputil"
 	"net/url"
 	"strconv"
 	"strings"
@@ -111,31 +111,27 @@ func (h *ReverseConfig) dialTLS(ctx context.Context, network, addr string) (net.
 }
 
 func (h *ReverseConfig) init() error {
-	h.proxy = make(map[string]*httputil.ReverseProxy)
+	h.proxy = make(map[string]*rp.ReverseProxy)
 	for key, val := range h.ReverseURL {
-		h.proxy[key] = &httputil.ReverseProxy{
+		h.proxy[key] = &rp.ReverseProxy{
 			Transport: &http.Transport{DialTLSContext: h.dialTLS},
-			Director: func(req *http.Request) {
-				targetQuery := val.RawQuery
-				req.URL.Scheme = val.Scheme
-				if h.Host == "" {
-					req.Host = val.Host
-				} else {
-					req.Host = h.Host
-				}
-				req.URL.Host = val.Host
-				req.URL.Path, req.URL.RawPath = joinURLPath(val, req.URL)
-				if targetQuery == "" || req.URL.RawQuery == "" {
-					req.URL.RawQuery = targetQuery + req.URL.RawQuery
-				} else {
-					req.URL.RawQuery = targetQuery + "&" + req.URL.RawQuery
-				}
-			},
 		}
 		h.proxy[key].ModifyResponse = h.ModifyResponse()
-		originalDirector := h.proxy[key].Director
 		h.proxy[key].Director = func(req *http.Request) {
-			originalDirector(req)
+			targetQuery := val.RawQuery
+			req.URL.Scheme = val.Scheme
+			if h.Host == "" {
+				req.Host = val.Host
+			} else {
+				req.Host = h.Host
+			}
+			req.URL.Host = val.Host
+			req.URL.Path, req.URL.RawPath = joinURLPath(val, req.URL, key)
+			if targetQuery == "" || req.URL.RawQuery == "" {
+				req.URL.RawQuery = targetQuery + req.URL.RawQuery
+			} else {
+				req.URL.RawQuery = targetQuery + "&" + req.URL.RawQuery
+			}
 			h.ModifyRequest(req, val)
 		}
 	}
@@ -181,13 +177,54 @@ func (h *ReverseConfig) ModifyResponse() func(*http.Response) error {
 	}
 }
 
+func (h *ReverseConfig) isInCIDR(ip string) bool {
+	nip := net.ParseIP(strings.TrimSpace(ip))
+	if nip == nil {
+		return false
+	}
+	for _, c := range h.CIDR {
+		if c.Contains(nip) {
+			return true
+		}
+	}
+	return false
+}
+
 func (h *ReverseConfig) ModifyRequest(req *http.Request, remote *url.URL) {
-	if h.XForwardMode == 1 {
+	switch h.IPFilterMode {
+	case 1:
 		req.Header.Set("X-Forwarded-For", strings.Split(req.RemoteAddr, ":")[0])
-	} else if h.XForwardMode == 2 {
+	case 2:
 		xforward := strings.Split(strings.TrimSpace(req.Header.Get("X-Forwarded-For")), ",")
 		xforward = append(xforward, strings.Split(req.RemoteAddr, ":")[0])
 		req.Header.Set("X-Forwarded-For", strings.Join(xforward, ", "))
+	case 3:
+		var lastForwardIP string
+		var xforward []string
+		if h.FilterMustKey != "" && req.Header.Get(h.FilterMustKey) != "" {
+			lastForwardIP = req.Header.Get(h.FilterMustKey)
+			xforward = []string{lastForwardIP}
+		} else {
+			for _, ip := range append(strings.Split(strings.TrimSpace(req.Header.Get("X-Forwarded-For")), ","), strings.Split(req.RemoteAddr, ":")[0]) {
+				ip = strings.TrimSpace(ip)
+				if !h.isInCIDR(ip) {
+					xforward = append(xforward, ip)
+					lastForwardIP = ip
+				}
+			}
+		}
+		if lastForwardIP == "" {
+			lastForwardIP = strings.Split(req.RemoteAddr, ":")[0]
+		}
+		if h.FilterXForward {
+			req.Header.Set("X-Forwarded-For", strings.Join(xforward, ", "))
+		}
+		if h.FilterRemoteAddr {
+			req.Header.Set("X-Real-IP", lastForwardIP)
+		}
+		if h.FilterSetKey != "" {
+			req.Header.Set(h.FilterSetKey, lastForwardIP)
+		}
 	}
 	for _, v := range h.Cookie {
 		req.AddCookie(&http.Cookie{
@@ -196,20 +233,6 @@ func (h *ReverseConfig) ModifyRequest(req *http.Request, remote *url.URL) {
 			Path:  v[0],
 		})
 	}
-	host := h.Host
-	if host == "" {
-		host = remote.Host
-	}
-	targetQuery := remote.RawQuery
-	req.URL.Scheme = remote.Scheme
-	req.URL.Host = remote.Host
-	req.Host = host
-	req.URL.Path, req.URL.RawPath = joinURLPath(remote, req.URL)
-	if targetQuery == "" || req.URL.RawQuery == "" {
-		req.URL.RawQuery = targetQuery + req.URL.RawQuery
-	} else {
-		req.URL.RawQuery = targetQuery + "&" + req.URL.RawQuery
-	}
 	for _, v := range h.InHeader {
 		req.Header.Set(v[0], v[1])
 	}
@@ -281,12 +304,15 @@ func (h *ReverseConfig) filter(w http.ResponseWriter, r *http.Request) bool {
 	return true
 }
 
-func joinURLPath(a, b *url.URL) (path, rawpath string) {
+func joinURLPath(a, b *url.URL, hpath string) (path, rawpath string) {
+	b.Path = strings.TrimPrefix(b.Path, hpath)
+	b.RawPath = strings.TrimPrefix(b.RawPath, hpath)
 	if a.RawPath == "" && b.RawPath == "" {
 		return singleJoiningSlash(a.Path, b.Path), ""
 	}
 	// Same as singleJoiningSlash, but uses EscapedPath to determine
 	// whether a slash should be added
+
 	apath := a.EscapedPath()
 	bpath := b.EscapedPath()