Merge 15ef1d4739f1c7765bc3c6979040a584853786e2 into b2b489dbf4826c2c630717a77fd5e42774625410

Co-authored-by: Bo-Yi Wu <appleboy.tw@gmail.com>

.github/workflows/gin.yml

@@ -65,7 +65,7 @@ jobs:
         with:
           ref: ${{ github.ref }}
 
-      - uses: actions/cache@v4
+      - uses: actions/cache@v5
         with:
           path: |
             ${{ matrix.go-build }}

context.go

@@ -978,18 +978,32 @@ func (c *Context) ClientIP() string {
 		}
 	}
 
-	// It also checks if the remoteIP is a trusted proxy or not.
-	// In order to perform this validation, it will see if the IP is contained within at least one of the CIDR blocks
-	// defined by Engine.SetTrustedProxies()
-	remoteIP := net.ParseIP(c.RemoteIP())
-	if remoteIP == nil {
-		return ""
+	var (
+		trusted  bool
+		remoteIP net.IP
+	)
+	// If gin is listening a unix socket, always trust it.
+	localAddr, ok := c.Request.Context().Value(http.LocalAddrContextKey).(net.Addr)
+	if ok && strings.HasPrefix(localAddr.Network(), "unix") {
+		trusted = true
+	}
+
+	// Fallback
+	if !trusted {
+		// It also checks if the remoteIP is a trusted proxy or not.
+		// In order to perform this validation, it will see if the IP is contained within at least one of the CIDR blocks
+		// defined by Engine.SetTrustedProxies()
+		remoteIP = net.ParseIP(c.RemoteIP())
+		if remoteIP == nil {
+			return ""
+		}
+		trusted = c.engine.isTrustedProxy(remoteIP)
 	}
-	trusted := c.engine.isTrustedProxy(remoteIP)
 
 	if trusted && c.engine.ForwardedByClientIP && c.engine.RemoteIPHeaders != nil {
 		for _, headerName := range c.engine.RemoteIPHeaders {
-			ip, valid := c.engine.validateHeader(c.requestHeader(headerName))
+			headerValue := strings.Join(c.Request.Header.Values(headerName), ",")
+			ip, valid := c.engine.validateHeader(headerValue)
 			if valid {
 				return ip
 			}

context_test.go

@@ -1488,6 +1488,37 @@ func TestContextRenderNoContentIndentedJSON(t *testing.T) {
 	assert.Equal(t, "application/json; charset=utf-8", w.Header().Get("Content-Type"))
 }
 
+func TestContextClientIPWithMultipleHeaders(t *testing.T) {
+	c, _ := CreateTestContext(httptest.NewRecorder())
+	c.Request, _ = http.NewRequest(http.MethodGet, "/test", nil)
+
+	// Multiple X-Forwarded-For headers
+	c.Request.Header.Add("X-Forwarded-For", "1.2.3.4, "+localhostIP)
+	c.Request.Header.Add("X-Forwarded-For", "5.6.7.8")
+	c.Request.RemoteAddr = localhostIP + ":1234"
+
+	c.engine.ForwardedByClientIP = true
+	c.engine.RemoteIPHeaders = []string{"X-Forwarded-For"}
+	_ = c.engine.SetTrustedProxies([]string{localhostIP})
+
+	// Should return 5.6.7.8 (last non-trusted IP)
+	assert.Equal(t, "5.6.7.8", c.ClientIP())
+}
+
+func TestContextClientIPWithSingleHeader(t *testing.T) {
+	c, _ := CreateTestContext(httptest.NewRecorder())
+	c.Request, _ = http.NewRequest(http.MethodGet, "/test", nil)
+	c.Request.Header.Set("X-Forwarded-For", "1.2.3.4, "+localhostIP)
+	c.Request.RemoteAddr = localhostIP + ":1234"
+
+	c.engine.ForwardedByClientIP = true
+	c.engine.RemoteIPHeaders = []string{"X-Forwarded-For"}
+	_ = c.engine.SetTrustedProxies([]string{localhostIP})
+
+	// Should return 1.2.3.4
+	assert.Equal(t, "1.2.3.4", c.ClientIP())
+}
+
 // Tests that the response is serialized as Secure JSON
 // and Content-Type is set to application/json
 func TestContextRenderSecureJSON(t *testing.T) {
@@ -2229,6 +2260,16 @@ func TestContextClientIP(t *testing.T) {
 	c.engine.trustedCIDRs, _ = c.engine.prepareTrustedCIDRs()
 	resetContextForClientIPTests(c)
 
+	// unix address
+	addr := &net.UnixAddr{Net: "unix", Name: "@"}
+	c.Request = c.Request.WithContext(context.WithValue(c.Request.Context(), http.LocalAddrContextKey, addr))
+	c.Request.RemoteAddr = addr.String()
+	assert.Equal(t, "20.20.20.20", c.ClientIP())
+
+	// reset
+	c.Request = c.Request.WithContext(context.Background())
+	resetContextForClientIPTests(c)
+
 	// Legacy tests (validating that the defaults don't break the
 	// (insecure!) old behaviour)
 	assert.Equal(t, "20.20.20.20", c.ClientIP())
@@ -2255,7 +2296,7 @@ func TestContextClientIP(t *testing.T) {
 	resetContextForClientIPTests(c)
 
 	// IPv6 support
-	c.Request.RemoteAddr = "[::1]:12345"
+	c.Request.RemoteAddr = fmt.Sprintf("[%s]:12345", localhostIPv6)
 	assert.Equal(t, "20.20.20.20", c.ClientIP())
 
 	resetContextForClientIPTests(c)
@@ -3593,7 +3634,7 @@ func TestContextCopyShouldNotCancel(t *testing.T) {
 	}()
 
 	addr := strings.Split(l.Addr().String(), ":")
-	res, err := http.Get(fmt.Sprintf("http://127.0.0.1:%s/", addr[len(addr)-1]))
+	res, err := http.Get(fmt.Sprintf("http://%s:%s/", localhostIP, addr[len(addr)-1]))
 	if err != nil {
 		t.Error(fmt.Errorf("request error: %w", err))
 		return

gin_test.go

@@ -83,7 +83,7 @@ func TestLoadHTMLGlobDebugMode(t *testing.T) {
 }
 
 func TestH2c(t *testing.T) {
-	ln, err := net.Listen("tcp", "127.0.0.1:0")
+	ln, err := net.Listen("tcp", localhostIP+":0")
 	if err != nil {
 		t.Error(err)
 	}

recovery.go

@@ -12,12 +12,12 @@ import (
 	"fmt"
 	"io"
 	"log"
-	"net"
 	"net/http"
 	"net/http/httputil"
 	"os"
 	"runtime"
 	"strings"
+	"syscall"
 	"time"
 
 	"github.com/gin-gonic/gin/internal/bytesconv"
@@ -57,40 +57,33 @@ func CustomRecoveryWithWriter(out io.Writer, handle RecoveryFunc) HandlerFunc {
 	}
 	return func(c *Context) {
 		defer func() {
-			if err := recover(); err != nil {
+			if rec := recover(); rec != nil {
 				// Check for a broken connection, as it is not really a
 				// condition that warrants a panic stack trace.
-				var brokenPipe bool
-				if ne, ok := err.(*net.OpError); ok {
-					var se *os.SyscallError
-					if errors.As(ne, &se) {
-						seStr := strings.ToLower(se.Error())
-						if strings.Contains(seStr, "broken pipe") ||
-							strings.Contains(seStr, "connection reset by peer") {
-							brokenPipe = true
-						}
-					}
-				}
-				if e, ok := err.(error); ok && errors.Is(e, http.ErrAbortHandler) {
-					brokenPipe = true
+				var isBrokenPipe bool
+				err, ok := rec.(error)
+				if ok {
+					isBrokenPipe = errors.Is(err, syscall.EPIPE) ||
+						errors.Is(err, syscall.ECONNRESET) ||
+						errors.Is(err, http.ErrAbortHandler)
 				}
 				if logger != nil {
-					if brokenPipe {
-						logger.Printf("%s\n%s%s", err, secureRequestDump(c.Request), reset)
+					if isBrokenPipe {
+						logger.Printf("%s\n%s%s", rec, secureRequestDump(c.Request), reset)
 					} else if IsDebugging() {
 						logger.Printf("[Recovery] %s panic recovered:\n%s\n%s\n%s%s",
-							timeFormat(time.Now()), secureRequestDump(c.Request), err, stack(stackSkip), reset)
+							timeFormat(time.Now()), secureRequestDump(c.Request), rec, stack(stackSkip), reset)
 					} else {
 						logger.Printf("[Recovery] %s panic recovered:\n%s\n%s%s",
-							timeFormat(time.Now()), err, stack(stackSkip), reset)
+							timeFormat(time.Now()), rec, stack(stackSkip), reset)
 					}
 				}
-				if brokenPipe {
+				if isBrokenPipe {
 					// If the connection is dead, we can't write a status to it.
-					c.Error(err.(error)) //nolint: errcheck
+					c.Error(err) //nolint: errcheck
 					c.Abort()
 				} else {
-					handle(c, err)
+					handle(c, rec)
 				}
 			}
 		}()

recovery_test.go

@@ -98,13 +98,13 @@ func TestFunction(t *testing.T) {
 func TestPanicWithBrokenPipe(t *testing.T) {
 	const expectCode = 204
 
-	expectMsgs := map[syscall.Errno]string{
-		syscall.EPIPE:      "broken pipe",
-		syscall.ECONNRESET: "connection reset by peer",
+	expectErrnos := []syscall.Errno{
+		syscall.EPIPE,
+		syscall.ECONNRESET,
 	}
 
-	for errno, expectMsg := range expectMsgs {
-		t.Run(expectMsg, func(t *testing.T) {
+	for _, errno := range expectErrnos {
+		t.Run("Recovery from "+errno.Error(), func(t *testing.T) {
 			var buf strings.Builder
 
 			router := New()
@@ -122,7 +122,8 @@ func TestPanicWithBrokenPipe(t *testing.T) {
 			w := PerformRequest(router, http.MethodGet, "/recovery")
 			// TEST
 			assert.Equal(t, expectCode, w.Code)
-			assert.Contains(t, strings.ToLower(buf.String()), expectMsg)
+			assert.Contains(t, strings.ToLower(buf.String()), errno.Error())
+			assert.NotContains(t, strings.ToLower(buf.String()), "[Recovery]")
 		})
 	}
 }

response_writer.go

@@ -128,7 +128,9 @@ func (w *responseWriter) CloseNotify() <-chan bool {
 // Flush implements the http.Flusher interface.
 func (w *responseWriter) Flush() {
 	w.WriteHeaderNow()
-	w.ResponseWriter.(http.Flusher).Flush()
+	if f, ok := w.ResponseWriter.(http.Flusher); ok {
+		f.Flush()
+	}
 }
 
 func (w *responseWriter) Pusher() (pusher http.Pusher) {

utils.go

@@ -19,6 +19,12 @@ import (
 // BindKey indicates a default bind key.
 const BindKey = "_gin-gonic/gin/bindkey"
 
+// localhostIP indicates the default localhost IP address.
+const localhostIP = "127.0.0.1"
+
+// localhostIPv6 indicates the default localhost IPv6 address.
+const localhostIPv6 = "::1"
+
 // Bind is a helper function for given interface object and returns a Gin middleware.
 func Bind(val any) HandlerFunc {
 	value := reflect.ValueOf(val)