Files
LocalAI/core/http/app.go
Adira c2fe0a6475 fix(http): honor X-Forwarded-Prefix when proxy strips the prefix (#9614)
* fix(http): honor X-Forwarded-Prefix when proxy strips the prefix

Closes #9145.

Two related issues kept the React UI from loading when a reverse proxy
rewrites a sub-path with prefix-stripping (e.g. Caddy `handle_path`):

1. `BaseURL` only computed a prefix from the path StripPathPrefix had
   removed, so when the proxy strips the prefix before forwarding, the
   request arrives without it and the base URL was returned without a
   prefix. Extract a `BasePathPrefix` helper and add an
   `X-Forwarded-Prefix` header fallback so the prefix is recovered.
2. `<base href>` only changes how relative URLs resolve; the build
   emits path-absolute references like `/assets/...` and
   `/favicon.svg`, which still resolve against the origin and bypass
   the proxy prefix. Rewrite those references in the served
   `index.html` so the browser requests them through the proxy.

Adds unit coverage for `BaseURL` with a pre-stripped path and an
end-to-end test for the proxy-stripped scenario.

Assisted-by: Claude:claude-opus-4-7

* fix(http): gate X-Forwarded-Prefix through SafeForwardedPrefix in BasePathPrefix

BasePathPrefix consumed X-Forwarded-Prefix directly, so a value the
codebase elsewhere rejects (e.g. "//evil.com") slipped through and was
interpolated into the SPA index.html — both into the path-absolute asset
URL rewrite in serveIndex (turning "/assets/..." into "//evil.com/assets/...",
a protocol-relative URL that loads JS from a foreign origin) and into
<base href>. Route the header through the existing SafeForwardedPrefix
validator that StripPathPrefix and prefixRedirect already use, and
HTML-escape the prefix before injecting it into the asset rewrite as
defense in depth against attribute breakout.

Tests cover //evil.com, backslashes, control chars, CR/LF and a missing
leading slash; the integration test asserts an unsafe prefix can't poison
asset URLs.

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Assisted-by: claude-code:claude-opus-4-7-1m [Read] [Edit] [Bash]

---------

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
Co-authored-by: Ettore Di Giacinto <mudler@localai.io>
2026-05-13 21:59:33 +02:00

549 lines
20 KiB
Go

package http
import (
"embed"
"errors"
"fmt"
"io/fs"
"mime"
"net/http"
"os"
"path/filepath"
"strings"
"time"
"github.com/labstack/echo/v4"
"github.com/labstack/echo/v4/middleware"
"github.com/mudler/LocalAI/core/http/auth"
"github.com/mudler/LocalAI/core/http/endpoints/localai"
httpMiddleware "github.com/mudler/LocalAI/core/http/middleware"
"github.com/mudler/LocalAI/core/http/routes"
"github.com/mudler/LocalAI/core/application"
"github.com/mudler/LocalAI/core/schema"
"github.com/mudler/LocalAI/core/services/finetune"
"github.com/mudler/LocalAI/core/services/galleryop"
"github.com/mudler/LocalAI/core/services/monitoring"
"github.com/mudler/LocalAI/core/services/nodes"
"github.com/mudler/LocalAI/core/services/quantization"
"github.com/mudler/xlog"
)
// Embed a directory
//
//go:embed static/*
var embedDirStatic embed.FS
// Embed React UI build output
//
//go:embed react-ui/dist/*
var reactUI embed.FS
var quietPaths = []string{"/api/operations", "/api/resources", "/healthz", "/readyz"}
// @title LocalAI API
// @version 2.0.0
// @description The LocalAI Rest API.
// @termsOfService
// @contact.name LocalAI
// @contact.url https://localai.io
// @license.name MIT
// @license.url https://raw.githubusercontent.com/mudler/LocalAI/master/LICENSE
// @BasePath /
// @schemes http https
// @securityDefinitions.apikey BearerAuth
// @in header
// @name Authorization
// @tag.name inference
// @tag.description Chat completions, text completions, edits, and responses (OpenAI-compatible)
// @tag.name embeddings
// @tag.description Vector embeddings (OpenAI-compatible)
// @tag.name audio
// @tag.description Text-to-speech, transcription, voice activity detection, sound generation
// @tag.name images
// @tag.description Image generation and inpainting
// @tag.name video
// @tag.description Video generation from prompts
// @tag.name detection
// @tag.description Object detection in images
// @tag.name tokenize
// @tag.description Tokenization and token metrics
// @tag.name models
// @tag.description Model gallery browsing, installation, deletion, and listing
// @tag.name backends
// @tag.description Backend gallery browsing, installation, deletion, and listing
// @tag.name config
// @tag.description Model configuration metadata, autocomplete, PATCH updates, VRAM estimation
// @tag.name monitoring
// @tag.description Prometheus metrics, backend status, system information
// @tag.name mcp
// @tag.description Model Context Protocol — tool-augmented chat with MCP servers
// @tag.name agent-jobs
// @tag.description Agent task and job management
// @tag.name p2p
// @tag.description Peer-to-peer networking nodes and tokens
// @tag.name rerank
// @tag.description Document reranking
// @tag.name instructions
// @tag.description API instruction discovery — browse instruction areas and get endpoint guides
func API(application *application.Application) (*echo.Echo, error) {
e := echo.New()
// Set body limit
if application.ApplicationConfig().UploadLimitMB > 0 {
e.Use(middleware.BodyLimit(fmt.Sprintf("%dM", application.ApplicationConfig().UploadLimitMB)))
}
// SPA fallback handler, set later when React UI is available
var spaFallback func(echo.Context) error
// Set error handler
if !application.ApplicationConfig().OpaqueErrors {
e.HTTPErrorHandler = func(err error, c echo.Context) {
code := http.StatusInternalServerError
var he *echo.HTTPError
if errors.As(err, &he) {
code = he.Code
}
// Handle 404 errors: serve React SPA for HTML requests, JSON otherwise
if code == http.StatusNotFound {
if spaFallback != nil {
accept := c.Request().Header.Get("Accept")
contentType := c.Request().Header.Get("Content-Type")
if strings.Contains(accept, "text/html") && !strings.Contains(contentType, "application/json") {
spaFallback(c)
return
}
}
notFoundHandler(c)
return
}
// Send custom error page
c.JSON(code, schema.ErrorResponse{
Error: &schema.APIError{Message: err.Error(), Code: code},
})
}
} else {
e.HTTPErrorHandler = func(err error, c echo.Context) {
code := http.StatusInternalServerError
var he *echo.HTTPError
if errors.As(err, &he) {
code = he.Code
}
c.NoContent(code)
}
}
// Set renderer
e.Renderer = renderEngine()
// Hide banner
e.HideBanner = true
e.HidePort = true
// Middleware - StripPathPrefix must be registered early as it uses Rewrite which runs before routing
e.Pre(httpMiddleware.StripPathPrefix())
e.Pre(middleware.RemoveTrailingSlash())
if application.ApplicationConfig().MachineTag != "" {
e.Use(func(next echo.HandlerFunc) echo.HandlerFunc {
return func(c echo.Context) error {
c.Response().Header().Set("Machine-Tag", application.ApplicationConfig().MachineTag)
return next(c)
}
})
}
// Security headers (CSP, X-Content-Type-Options, X-Frame-Options,
// Referrer-Policy). Set early so every response — including 404s and
// errors — picks them up.
e.Use(httpMiddleware.SecurityHeaders())
// Custom logger middleware using xlog
e.Use(func(next echo.HandlerFunc) echo.HandlerFunc {
return func(c echo.Context) error {
req := c.Request()
res := c.Response()
err := next(c)
// Echo's central HTTPErrorHandler runs *after* this middleware
// returns, so res.Status still reads the default 200 here when a
// handler returned an error without writing a response. Mirror
// echo.DefaultHTTPErrorHandler's status derivation so the access
// log reflects the status the client actually receives — without
// this, every silent handler error logs as 200.
status := res.Status
if err != nil && !res.Committed {
status = http.StatusInternalServerError
var he *echo.HTTPError
if errors.As(err, &he) {
status = he.Code
}
}
// Fix for #7989: Reduce log verbosity of Web UI polling, resources API, and health checks
// These paths are logged at DEBUG level (hidden by default) instead of INFO.
isQuietPath := false
for _, path := range quietPaths {
if req.URL.Path == path {
isQuietPath = true
break
}
}
if isQuietPath && status == 200 {
xlog.Debug("HTTP request", "method", req.Method, "path", req.URL.Path, "status", status)
} else {
xlog.Info("HTTP request", "method", req.Method, "path", req.URL.Path, "status", status)
}
return err
}
})
// Recover middleware
if !application.ApplicationConfig().Debug {
e.Use(middleware.Recover())
}
// Metrics middleware
if !application.ApplicationConfig().DisableMetrics {
metricsService, err := monitoring.NewLocalAIMetricsService()
if err != nil {
return nil, err
}
if metricsService != nil {
e.Use(localai.LocalAIMetricsAPIMiddleware(metricsService))
e.Server.RegisterOnShutdown(func() {
metricsService.Shutdown()
})
}
}
// Health Checks should always be exempt from auth, so register these first
routes.HealthRoutes(e)
// Build auth middleware: use the new auth.Middleware when auth is enabled or
// as a unified replacement for the legacy key-auth middleware.
authMiddleware := auth.Middleware(application.AuthDB(), application.ApplicationConfig())
// Favicon handler
e.GET("/favicon.svg", func(c echo.Context) error {
data, err := embedDirStatic.ReadFile("static/favicon.svg")
if err != nil {
return c.NoContent(http.StatusNotFound)
}
c.Response().Header().Set("Content-Type", "image/svg+xml")
return c.Blob(http.StatusOK, "image/svg+xml", data)
})
// Static files - use fs.Sub to create a filesystem rooted at "static"
staticFS, err := fs.Sub(embedDirStatic, "static")
if err != nil {
return nil, fmt.Errorf("failed to create static filesystem: %w", err)
}
e.StaticFS("/static", staticFS)
// Generated content directories
if application.ApplicationConfig().GeneratedContentDir != "" {
os.MkdirAll(application.ApplicationConfig().GeneratedContentDir, 0750)
audioPath := filepath.Join(application.ApplicationConfig().GeneratedContentDir, "audio")
imagePath := filepath.Join(application.ApplicationConfig().GeneratedContentDir, "images")
videoPath := filepath.Join(application.ApplicationConfig().GeneratedContentDir, "videos")
os.MkdirAll(audioPath, 0750)
os.MkdirAll(imagePath, 0750)
os.MkdirAll(videoPath, 0750)
e.Static("/generated-audio", audioPath)
e.Static("/generated-images", imagePath)
e.Static("/generated-videos", videoPath)
}
// Initialize usage recording when auth DB is available
if application.AuthDB() != nil {
httpMiddleware.InitUsageRecorder(application.AuthDB())
}
// Auth is applied to _all_ endpoints. Filtering out endpoints to bypass is
// the role of the exempt-path logic inside the middleware.
e.Use(authMiddleware)
// Feature and model access control (after auth middleware, before routes)
if application.AuthDB() != nil {
e.Use(auth.RequireRouteFeature(application.AuthDB()))
e.Use(auth.RequireModelAccess(application.AuthDB()))
e.Use(auth.RequireQuota(application.AuthDB()))
}
// CORS middleware. When CORS=true the operator must also specify the
// allowed origins; an empty allowlist would otherwise let Echo fall back
// to AllowOrigins=["*"], which is almost never what someone enabling
// "strict CORS" intended.
if application.ApplicationConfig().CORS {
if application.ApplicationConfig().CORSAllowOrigins == "" {
xlog.Warn("LOCALAI_CORS=true but LOCALAI_CORS_ALLOW_ORIGINS is empty; refusing to register a wildcard CORS policy. Set the allowlist or unset LOCALAI_CORS.")
} else {
corsConfig := middleware.CORSConfig{
AllowOrigins: strings.Split(application.ApplicationConfig().CORSAllowOrigins, ","),
}
e.Use(middleware.CORSWithConfig(corsConfig))
}
} else {
e.Use(middleware.CORS())
}
// CSRF middleware (enabled by default, disable with LOCALAI_DISABLE_CSRF=true)
//
// Protection relies on Echo's Sec-Fetch-Site header check (supported by all
// modern browsers). The legacy cookie+token approach is removed because
// Echo's Sec-Fetch-Site short-circuit never sets the cookie, so the frontend
// could never read a token to send back.
if !application.ApplicationConfig().DisableCSRF {
xlog.Debug("Enabling CSRF middleware (Sec-Fetch-Site mode)")
e.Use(middleware.CSRFWithConfig(middleware.CSRFConfig{
Skipper: func(c echo.Context) bool {
// Skip CSRF for API clients using auth headers (may be cross-origin)
if c.Request().Header.Get("Authorization") != "" {
return true
}
if c.Request().Header.Get("x-api-key") != "" || c.Request().Header.Get("xi-api-key") != "" {
return true
}
// Skip when Sec-Fetch-Site header is absent (older browsers, reverse
// proxies that strip the header). The SameSite=Lax cookie attribute
// provides baseline CSRF protection for these clients.
if c.Request().Header.Get("Sec-Fetch-Site") == "" {
return true
}
return false
},
// Allow same-site requests (subdomains / different ports) in addition
// to same-origin which Echo already permits by default.
AllowSecFetchSiteFunc: func(c echo.Context) (bool, error) {
secFetchSite := c.Request().Header.Get("Sec-Fetch-Site")
if secFetchSite == "same-site" {
return true, nil
}
// cross-site: block
return false, nil
},
}))
}
// Admin middleware: enforces admin role when auth is enabled, no-op otherwise
var adminMiddleware echo.MiddlewareFunc
if application.AuthDB() != nil {
adminMiddleware = auth.RequireAdmin()
} else {
adminMiddleware = auth.NoopMiddleware()
}
// Feature middlewares: per-feature access control
agentsMw := auth.RequireFeature(application.AuthDB(), auth.FeatureAgents)
skillsMw := auth.RequireFeature(application.AuthDB(), auth.FeatureSkills)
collectionsMw := auth.RequireFeature(application.AuthDB(), auth.FeatureCollections)
mcpJobsMw := auth.RequireFeature(application.AuthDB(), auth.FeatureMCPJobs)
requestExtractor := httpMiddleware.NewRequestExtractor(application.ModelConfigLoader(), application.ModelLoader(), application.ApplicationConfig())
// Register auth routes (login, callback, API keys, user management)
routes.RegisterAuthRoutes(e, application)
routes.RegisterElevenLabsRoutes(e, requestExtractor, application.ModelConfigLoader(), application.ModelLoader(), application.ApplicationConfig())
// Create opcache for tracking UI operations (used by both UI and LocalAI routes)
var opcache *galleryop.OpCache
if !application.ApplicationConfig().DisableWebUI {
opcache = galleryop.NewOpCache(application.GalleryService())
}
mcpMw := auth.RequireFeature(application.AuthDB(), auth.FeatureMCP)
routes.RegisterLocalAIRoutes(e, requestExtractor, application.ModelConfigLoader(), application.ModelLoader(), application.ApplicationConfig(), application.GalleryService(), opcache, application.TemplatesEvaluator(), application, adminMiddleware, mcpJobsMw, mcpMw)
routes.RegisterAgentPoolRoutes(e, application, agentsMw, skillsMw, collectionsMw)
// Fine-tuning routes
fineTuningMw := auth.RequireFeature(application.AuthDB(), auth.FeatureFineTuning)
ftService := finetune.NewFineTuneService(
application.ApplicationConfig(),
application.ModelLoader(),
application.ModelConfigLoader(),
)
if d := application.Distributed(); d != nil {
ftService.SetNATSClient(d.Nats)
if d.DistStores != nil && d.DistStores.FineTune != nil {
ftService.SetFineTuneStore(d.DistStores.FineTune)
}
}
routes.RegisterFineTuningRoutes(e, ftService, application.ApplicationConfig(), fineTuningMw)
// Quantization routes
quantizationMw := auth.RequireFeature(application.AuthDB(), auth.FeatureQuantization)
qService := quantization.NewQuantizationService(
application.ApplicationConfig(),
application.ModelLoader(),
application.ModelConfigLoader(),
)
routes.RegisterQuantizationRoutes(e, qService, application.ApplicationConfig(), quantizationMw)
// Node management routes (distributed mode)
distCfg := application.ApplicationConfig().Distributed
var registry *nodes.NodeRegistry
var remoteUnloader nodes.NodeCommandSender
if d := application.Distributed(); d != nil {
registry = d.Registry
if d.Router != nil {
remoteUnloader = d.Router.Unloader()
}
}
routes.RegisterNodeSelfServiceRoutes(e, registry, distCfg.RegistrationToken, distCfg.AutoApproveNodes, application.AuthDB(), application.ApplicationConfig().Auth.APIKeyHMACSecret)
routes.RegisterNodeAdminRoutes(e, registry, remoteUnloader, adminMiddleware, application.AuthDB(), application.ApplicationConfig().Auth.APIKeyHMACSecret, application.ApplicationConfig().Distributed.RegistrationToken)
// Distributed SSE routes (job progress + agent events via NATS)
if d := application.Distributed(); d != nil {
if d.Dispatcher != nil {
e.GET("/api/agent/jobs/:id/progress", d.Dispatcher.SSEHandler(), mcpJobsMw)
}
if d.AgentBridge != nil {
e.GET("/api/agents/:name/sse/distributed", d.AgentBridge.SSEHandler(), agentsMw)
}
}
routes.RegisterOpenAIRoutes(e, requestExtractor, application)
routes.RegisterAnthropicRoutes(e, requestExtractor, application)
routes.RegisterOpenResponsesRoutes(e, requestExtractor, application)
routes.RegisterOllamaRoutes(e, requestExtractor, application)
if application.ApplicationConfig().OllamaAPIRootEndpoint {
routes.RegisterOllamaRootEndpoint(e)
}
if !application.ApplicationConfig().DisableWebUI {
routes.RegisterUIAPIRoutes(e, application.ModelConfigLoader(), application.ModelLoader(), application.ApplicationConfig(), application.GalleryService(), opcache, application, adminMiddleware)
routes.RegisterUIRoutes(e, application.ModelConfigLoader(), application.ApplicationConfig(), application.GalleryService(), adminMiddleware)
// Serve React SPA from / with SPA fallback via 404 handler
reactFS, fsErr := fs.Sub(reactUI, "react-ui/dist")
if fsErr != nil {
xlog.Warn("React UI not available (build with 'make core/http/react-ui/dist')", "error", fsErr)
} else {
serveIndex := func(c echo.Context) error {
indexHTML, err := reactUI.ReadFile("react-ui/dist/index.html")
if err != nil {
return c.String(http.StatusNotFound, "React UI not built")
}
// Inject <base href> for reverse-proxy support; baseURL comes
// from attacker-controllable Host / X-Forwarded-Host headers.
baseURL := httpMiddleware.BaseURL(c)
if baseURL != "" {
baseTag := `<base href="` + httpMiddleware.SecureBaseHref(baseURL) + `" />`
indexHTML = []byte(strings.Replace(string(indexHTML), "<head>", "<head>\n "+baseTag, 1))
}
// <base href> only changes how relative URLs resolve; path-absolute
// URLs (those starting with `/`) still resolve against the origin
// and would bypass the reverse-proxy prefix. Rewrite the internal
// path-absolute references emitted by the build so the browser
// requests them through the proxy under the prefix.
//
// HTML-escape the prefix before interpolating it into attributes:
// BasePathPrefix already gates X-Forwarded-Prefix via
// SafeForwardedPrefix, but the validator only blocks open-redirect
// shapes (// prefix, backslashes, control chars), not attribute
// breakout characters like `"`. Escaping makes this resilient
// even if the validator ever loosens.
if prefix := httpMiddleware.BasePathPrefix(c); prefix != "/" {
safePrefix := httpMiddleware.SecureBaseHref(prefix)
html := string(indexHTML)
html = strings.ReplaceAll(html, `="/assets/`, `="`+safePrefix+`assets/`)
html = strings.ReplaceAll(html, `="/favicon.svg"`, `="`+safePrefix+`favicon.svg"`)
indexHTML = []byte(html)
}
return c.HTMLBlob(http.StatusOK, indexHTML)
}
// Enable SPA fallback in the 404 handler for client-side routing
spaFallback = serveIndex
// Serve React SPA at /app
e.GET("/app", serveIndex)
e.GET("/app/*", serveIndex)
// prefixRedirect performs a redirect that preserves X-Forwarded-Prefix
// for reverse-proxy support. The prefix is forgeable on misconfigured
// proxy chains, so reject anything that isn't a same-origin path.
prefixRedirect := func(c echo.Context, target string) error {
if prefix, ok := httpMiddleware.SafeForwardedPrefix(c.Request().Header.Get("X-Forwarded-Prefix")); ok {
target = strings.TrimSuffix(prefix, "/") + target
}
return c.Redirect(http.StatusMovedPermanently, target)
}
// Redirect / to /app
e.GET("/", func(c echo.Context) error {
return prefixRedirect(c, "/app")
})
// Backward compatibility: redirect /browse/* to /app/*
e.GET("/browse", func(c echo.Context) error {
return prefixRedirect(c, "/app")
})
e.GET("/browse/*", func(c echo.Context) error {
p := c.Param("*")
return prefixRedirect(c, "/app/"+p)
})
// Serve React static assets (JS, CSS, etc.) and i18n locale JSONs
// from the embedded React build.
serveReactSubdir := func(subdir string) echo.HandlerFunc {
return func(c echo.Context) error {
p := subdir + "/" + c.Param("*")
f, err := reactFS.Open(p)
if err == nil {
defer f.Close()
stat, statErr := f.Stat()
if statErr == nil && !stat.IsDir() {
contentType := mime.TypeByExtension(filepath.Ext(p))
if contentType == "" {
contentType = echo.MIMEOctetStream
}
return c.Stream(http.StatusOK, contentType, f)
}
}
return echo.NewHTTPError(http.StatusNotFound)
}
}
e.GET("/assets/*", serveReactSubdir("assets"))
e.GET("/locales/*", serveReactSubdir("locales"))
}
}
routes.RegisterJINARoutes(e, requestExtractor, application.ModelConfigLoader(), application.ModelLoader(), application.ApplicationConfig())
// Note: 404 handling is done via HTTPErrorHandler above, no need for catch-all route
// HTTP server timeouts.
//
// - ReadHeaderTimeout: bounds the slow-headers Slowloris case. 30s is
// enough for a real client on a poor connection but cuts off a
// drip-feeding attacker.
// - IdleTimeout: bounds idle keep-alive connections.
//
// We deliberately leave ReadTimeout and WriteTimeout at 0:
// - Request bodies can be multi-GB model/dataset uploads.
// - Chat-completion and SSE responses can stream for many minutes.
// Operators who need stricter limits should front the server with a
// reverse proxy that terminates slow clients per-request.
e.Server.ReadHeaderTimeout = 30 * time.Second
e.Server.IdleTimeout = 120 * time.Second
// Log startup message
e.Server.RegisterOnShutdown(func() {
xlog.Info("LocalAI API server shutting down")
})
return e, nil
}