fix: prevent rate limit bypass in public file shares

Author: lan-yonghui

core/init/proxy/proxy.go

@@ -5,7 +5,12 @@ import (
 	"net"
 	"net/http"
 	"net/http/httputil"
+	"slices"
+	"strings"
 	"time"
+
+	"github.com/1Panel-dev/1Panel/core/utils/clientip"
+	"github.com/1Panel-dev/1Panel/core/utils/publicshare"
 )
 
 const SockPath = "/etc/1panel/agent.sock"
@@ -28,20 +33,26 @@ func Init() {
 		MaxIdleConnsPerHost: 50,
 		IdleConnTimeout:     30 * time.Second,
 	}
-	LocalAgentProxy = &httputil.ReverseProxy{
-		Director: func(req *http.Request) {
-			if req.Header.Get("X-Forwarded-Proto") == "" {
-				if req.TLS != nil {
-					req.Header.Set("X-Forwarded-Proto", "https")
-				} else {
-					req.Header.Set("X-Forwarded-Proto", "http")
-				}
+	LocalAgentProxy = newLocalAgentProxy(transport)
+}
+
+func newLocalAgentProxy(transport http.RoundTripper) *httputil.ReverseProxy {
+	return &httputil.ReverseProxy{
+		Rewrite: func(proxyReq *httputil.ProxyRequest) {
+			if proxyReq.In.Form == nil {
+				proxyReq.Out.URL.RawQuery = proxyReq.In.URL.RawQuery
 			}
-			if req.Header.Get("X-Forwarded-Host") == "" && req.Host != "" {
-				req.Header.Set("X-Forwarded-Host", req.Host)
+			if publicshare.IsAPI(proxyReq.In.URL.Path) {
+				proxyReq.SetXForwarded()
+				clientip.ReplaceForwardingHeaders(
+					proxyReq.Out.Header,
+					clientip.FromRemoteAddr(proxyReq.In.RemoteAddr),
+				)
+			} else {
+				restoreLegacyForwardingHeaders(proxyReq)
 			}
-			req.URL.Scheme = "http"
-			req.URL.Host = "unix"
+			proxyReq.Out.URL.Scheme = "http"
+			proxyReq.Out.URL.Host = "unix"
 		},
 		Transport: transport,
 		ErrorHandler: func(rw http.ResponseWriter, req *http.Request, err error) {
@@ -50,3 +61,64 @@ func Init() {
 		},
 	}
 }
+
+func restoreLegacyForwardingHeaders(proxyReq *httputil.ProxyRequest) {
+	restoreInboundHeader(proxyReq, "Forwarded")
+	restoreLegacyForwardedFor(proxyReq)
+	restoreLegacyForwardedMetadata(proxyReq, "X-Forwarded-Host", proxyReq.In.Host)
+
+	forwardedProto := "http"
+	if proxyReq.In.TLS != nil {
+		forwardedProto = "https"
+	}
+	restoreLegacyForwardedMetadata(proxyReq, "X-Forwarded-Proto", forwardedProto)
+}
+
+func restoreLegacyForwardedFor(proxyReq *httputil.ProxyRequest) {
+	restoreInboundHeader(proxyReq, "X-Forwarded-For")
+	clientIP, _, err := net.SplitHostPort(proxyReq.In.RemoteAddr)
+	if err != nil {
+		return
+	}
+	prior, ok := proxyReq.Out.Header["X-Forwarded-For"]
+	omit := ok && prior == nil
+	if len(prior) > 0 {
+		clientIP = strings.Join(prior, ", ") + ", " + clientIP
+	}
+	if !omit {
+		proxyReq.Out.Header.Set("X-Forwarded-For", clientIP)
+	}
+}
+
+func restoreLegacyForwardedMetadata(proxyReq *httputil.ProxyRequest, name, fallback string) {
+	if !isConnectionHeader(proxyReq.In.Header, name) && proxyReq.In.Header.Get(name) != "" {
+		restoreInboundHeader(proxyReq, name)
+		return
+	}
+	proxyReq.Out.Header.Del(name)
+	if fallback != "" {
+		proxyReq.Out.Header.Set(name, fallback)
+	}
+}
+
+func restoreInboundHeader(proxyReq *httputil.ProxyRequest, name string) {
+	proxyReq.Out.Header.Del(name)
+	if isConnectionHeader(proxyReq.In.Header, name) {
+		return
+	}
+	canonicalName := http.CanonicalHeaderKey(name)
+	if values, ok := proxyReq.In.Header[canonicalName]; ok {
+		proxyReq.Out.Header[canonicalName] = slices.Clone(values)
+	}
+}
+
+func isConnectionHeader(header http.Header, name string) bool {
+	for _, value := range header.Values("Connection") {
+		for _, token := range strings.Split(value, ",") {
+			if strings.EqualFold(strings.TrimSpace(token), name) {
+				return true
+			}
+		}
+	}
+	return false
+}

core/middleware/helper.go

@@ -1,6 +1,10 @@
 package middleware
 
-import "strings"
+import (
+	"strings"
+
+	"github.com/1Panel-dev/1Panel/core/utils/publicshare"
+)
 
 func ShouldProxyToAgent(reqPath string) bool {
 	if strings.HasPrefix(reqPath, "/1panel/swagger") || !strings.HasPrefix(reqPath, "/api/v2") {
@@ -13,12 +17,5 @@ func ShouldProxyToAgent(reqPath string) bool {
 }
 
 func IsPublicFileShareAPI(reqPath string) bool {
-	switch reqPath {
-	case "/api/v2/files/share/info",
-		"/api/v2/files/share/check",
-		"/api/v2/files/share/download":
-		return true
-	default:
-		return false
-	}
+	return publicshare.IsAPI(reqPath)
 }

core/utils/clientip/clientip.go

@@ -0,0 +1,51 @@
+package clientip
+
+import (
+	"net"
+	"net/http"
+	"strings"
+)
+
+const (
+	forwardedHeader     = "Forwarded"
+	forwardedForHeader  = "X-Forwarded-For"
+	realIPHeader        = "X-Real-IP"
+	panelClientIPHeader = "X-Panel-Client-IP"
+)
+
+func FromRemoteAddr(remoteAddr string) string {
+	host, _, err := net.SplitHostPort(strings.TrimSpace(remoteAddr))
+	if err != nil {
+		return ""
+	}
+	ip := net.ParseIP(strings.TrimSpace(host))
+	if ip == nil {
+		return ""
+	}
+	return ip.String()
+}
+
+func ReplaceForwardingHeaders(header http.Header, clientIP string) {
+	if header == nil {
+		return
+	}
+	RemoveForwardingHeaders(header)
+
+	ip := net.ParseIP(strings.TrimSpace(clientIP))
+	if ip == nil {
+		return
+	}
+	normalized := ip.String()
+	header.Set(forwardedForHeader, normalized)
+	header.Set(realIPHeader, normalized)
+}
+
+func RemoveForwardingHeaders(header http.Header) {
+	if header == nil {
+		return
+	}
+	header.Del(forwardedHeader)
+	header.Del(forwardedForHeader)
+	header.Del(realIPHeader)
+	header.Del(panelClientIPHeader)
+}

core/utils/publicshare/routes.go

@@ -0,0 +1,12 @@
+package publicshare
+
+func IsAPI(path string) bool {
+	switch path {
+	case "/api/v2/files/share/info",
+		"/api/v2/files/share/check",
+		"/api/v2/files/share/download":
+		return true
+	default:
+		return false
+	}
+}