Add a config option to block "expensive" pages for anonymous users (#34024)

Fix #33966

```
;; User must sign in to view anything.
;; It could be set to "expensive" to block anonymous users accessing some pages which consume a lot of resources,
;; for example: block anonymous AI crawlers from accessing repo code pages.
;; The "expensive" mode is experimental and subject to change.
;REQUIRE_SIGNIN_VIEW = false
```

routers/api/packages/cargo/cargo.go

@@ -51,7 +51,7 @@ func apiError(ctx *context.Context, status int, obj any) {
 
 // https://rust-lang.github.io/rfcs/2789-sparse-index.html
 func RepositoryConfig(ctx *context.Context) {
-	ctx.JSON(http.StatusOK, cargo_service.BuildConfig(ctx.Package.Owner, setting.Service.RequireSignInView || ctx.Package.Owner.Visibility != structs.VisibleTypePublic))
+	ctx.JSON(http.StatusOK, cargo_service.BuildConfig(ctx.Package.Owner, setting.Service.RequireSignInViewStrict || ctx.Package.Owner.Visibility != structs.VisibleTypePublic))
 }
 
 func EnumeratePackageVersions(ctx *context.Context) {

routers/api/packages/container/container.go

@@ -126,7 +126,7 @@ func apiUnauthorizedError(ctx *context.Context) {
 
 // ReqContainerAccess is a middleware which checks the current user valid (real user or ghost if anonymous access is enabled)
 func ReqContainerAccess(ctx *context.Context) {
-	if ctx.Doer == nil || (setting.Service.RequireSignInView && ctx.Doer.IsGhost()) {
+	if ctx.Doer == nil || (setting.Service.RequireSignInViewStrict && ctx.Doer.IsGhost()) {
 		apiUnauthorizedError(ctx)
 	}
 }
@@ -152,7 +152,7 @@ func Authenticate(ctx *context.Context) {
 	u := ctx.Doer
 	packageScope := auth_service.GetAccessScope(ctx.Data)
 	if u == nil {
-		if setting.Service.RequireSignInView {
+		if setting.Service.RequireSignInViewStrict {
 			apiUnauthorizedError(ctx)
 			return
 		}

routers/api/v1/api.go

@@ -355,7 +355,7 @@ func reqToken() func(ctx *context.APIContext) {
 
 func reqExploreSignIn() func(ctx *context.APIContext) {
 	return func(ctx *context.APIContext) {
-		if (setting.Service.RequireSignInView || setting.Service.Explore.RequireSigninView) && !ctx.IsSigned {
+		if (setting.Service.RequireSignInViewStrict || setting.Service.Explore.RequireSigninView) && !ctx.IsSigned {
 			ctx.APIError(http.StatusUnauthorized, "you must be signed in to search for users")
 		}
 	}
@@ -886,7 +886,7 @@ func Routes() *web.Router {
 	m.Use(apiAuth(buildAuthGroup()))
 
 	m.Use(verifyAuthWithOptions(&common.VerifyOptions{
-		SignInRequired: setting.Service.RequireSignInView,
+		SignInRequired: setting.Service.RequireSignInViewStrict,
 	}))
 
 	addActionsRoutes := func(

routers/common/blockexpensive.go

@@ -0,0 +1,90 @@
+// Copyright 2025 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package common
+
+import (
+	"net/http"
+	"strings"
+
+	user_model "code.gitea.io/gitea/models/user"
+	"code.gitea.io/gitea/modules/reqctx"
+	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/web/middleware"
+
+	"github.com/go-chi/chi/v5"
+)
+
+func BlockExpensive() func(next http.Handler) http.Handler {
+	if !setting.Service.BlockAnonymousAccessExpensive {
+		return nil
+	}
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+			ret := determineRequestPriority(reqctx.FromContext(req.Context()))
+			if !ret.SignedIn {
+				if ret.Expensive || ret.LongPolling {
+					http.Redirect(w, req, setting.AppSubURL+"/user/login", http.StatusSeeOther)
+					return
+				}
+			}
+			next.ServeHTTP(w, req)
+		})
+	}
+}
+
+func isRoutePathExpensive(routePattern string) bool {
+	if strings.HasPrefix(routePattern, "/user/") || strings.HasPrefix(routePattern, "/login/") {
+		return false
+	}
+
+	expensivePaths := []string{
+		// code related
+		"/{username}/{reponame}/archive/",
+		"/{username}/{reponame}/blame/",
+		"/{username}/{reponame}/commit/",
+		"/{username}/{reponame}/commits/",
+		"/{username}/{reponame}/graph",
+		"/{username}/{reponame}/media/",
+		"/{username}/{reponame}/raw/",
+		"/{username}/{reponame}/src/",
+
+		// issue & PR related (no trailing slash)
+		"/{username}/{reponame}/issues",
+		"/{username}/{reponame}/{type:issues}",
+		"/{username}/{reponame}/pulls",
+		"/{username}/{reponame}/{type:pulls}",
+
+		// wiki
+		"/{username}/{reponame}/wiki/",
+
+		// activity
+		"/{username}/{reponame}/activity/",
+	}
+	for _, path := range expensivePaths {
+		if strings.HasPrefix(routePattern, path) {
+			return true
+		}
+	}
+	return false
+}
+
+func isRoutePathForLongPolling(routePattern string) bool {
+	return routePattern == "/user/events"
+}
+
+func determineRequestPriority(reqCtx reqctx.RequestContext) (ret struct {
+	SignedIn    bool
+	Expensive   bool
+	LongPolling bool
+},
+) {
+	chiRoutePath := chi.RouteContext(reqCtx).RoutePattern()
+	if _, ok := reqCtx.GetData()[middleware.ContextDataKeySignedUser].(*user_model.User); ok {
+		ret.SignedIn = true
+	} else {
+		ret.Expensive = isRoutePathExpensive(chiRoutePath)
+		ret.LongPolling = isRoutePathForLongPolling(chiRoutePath)
+	}
+	return ret
+}

routers/common/blockexpensive_test.go

@@ -0,0 +1,30 @@
+// Copyright 2025 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package common
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestBlockExpensive(t *testing.T) {
+	cases := []struct {
+		expensive bool
+		routePath string
+	}{
+		{false, "/user/xxx"},
+		{false, "/login/xxx"},
+		{true, "/{username}/{reponame}/archive/xxx"},
+		{true, "/{username}/{reponame}/graph"},
+		{true, "/{username}/{reponame}/src/xxx"},
+		{true, "/{username}/{reponame}/wiki/xxx"},
+		{true, "/{username}/{reponame}/activity/xxx"},
+	}
+	for _, c := range cases {
+		assert.Equal(t, c.expensive, isRoutePathExpensive(c.routePath), "routePath: %s", c.routePath)
+	}
+
+	assert.True(t, isRoutePathForLongPolling("/user/events"))
+}

routers/install/install.go

@@ -151,7 +151,7 @@ func Install(ctx *context.Context) {
 	form.DisableRegistration = setting.Service.DisableRegistration
 	form.AllowOnlyExternalRegistration = setting.Service.AllowOnlyExternalRegistration
 	form.EnableCaptcha = setting.Service.EnableCaptcha
-	form.RequireSignInView = setting.Service.RequireSignInView
+	form.RequireSignInView = setting.Service.RequireSignInViewStrict
 	form.DefaultKeepEmailPrivate = setting.Service.DefaultKeepEmailPrivate
 	form.DefaultAllowCreateOrganization = setting.Service.DefaultAllowCreateOrganization
 	form.DefaultEnableTimetracking = setting.Service.DefaultEnableTimetracking

routers/private/serv.go

@@ -286,7 +286,7 @@ func ServCommand(ctx *context.PrivateContext) {
 			repo.IsPrivate ||
 			owner.Visibility.IsPrivate() ||
 			(user != nil && user.IsRestricted) || // user will be nil if the key is a deploykey
-			setting.Service.RequireSignInView) {
+			setting.Service.RequireSignInViewStrict) {
 		if key.Type == asymkey_model.KeyTypeDeploy {
 			if deployKey.Mode < mode {
 				ctx.JSON(http.StatusUnauthorized, private.Response{

routers/web/repo/githttp.go

@@ -127,7 +127,7 @@ func httpBase(ctx *context.Context) *serviceHandler {
 	// Only public pull don't need auth.
 	isPublicPull := repoExist && !repo.IsPrivate && isPull
 	var (
-		askAuth = !isPublicPull || setting.Service.RequireSignInView
+		askAuth = !isPublicPull || setting.Service.RequireSignInViewStrict
 		environ []string
 	)
 

routers/web/web.go

@@ -283,23 +283,23 @@ func Routes() *web.Router {
 	mid = append(mid, goGet)
 	mid = append(mid, common.PageTmplFunctions)
 
-	others := web.NewRouter()
-	others.Use(mid...)
-	registerRoutes(others)
-	routes.Mount("", others)
+	webRoutes := web.NewRouter()
+	webRoutes.Use(mid...)
+	webRoutes.Group("", func() { registerWebRoutes(webRoutes) }, common.BlockExpensive())
+	routes.Mount("", webRoutes)
 	return routes
 }
 
 var optSignInIgnoreCsrf = verifyAuthWithOptions(&common.VerifyOptions{DisableCSRF: true})
 
-// registerRoutes register routes
-func registerRoutes(m *web.Router) {
+// registerWebRoutes register routes
+func registerWebRoutes(m *web.Router) {
 	// required to be signed in or signed out
 	reqSignIn := verifyAuthWithOptions(&common.VerifyOptions{SignInRequired: true})
 	reqSignOut := verifyAuthWithOptions(&common.VerifyOptions{SignOutRequired: true})
 	// optional sign in (if signed in, use the user as doer, if not, no doer)
-	optSignIn := verifyAuthWithOptions(&common.VerifyOptions{SignInRequired: setting.Service.RequireSignInView})
-	optExploreSignIn := verifyAuthWithOptions(&common.VerifyOptions{SignInRequired: setting.Service.RequireSignInView || setting.Service.Explore.RequireSigninView})
+	optSignIn := verifyAuthWithOptions(&common.VerifyOptions{SignInRequired: setting.Service.RequireSignInViewStrict})
+	optExploreSignIn := verifyAuthWithOptions(&common.VerifyOptions{SignInRequired: setting.Service.RequireSignInViewStrict || setting.Service.Explore.RequireSigninView})
 
 	validation.AddBindingRules()