// Copyright (C) The Arvados Authors. All rights reserved. // // SPDX-License-Identifier: AGPL-3.0 package main import ( "encoding/json" "fmt" "html" "html/template" "io" "net/http" "net/url" "os" "path/filepath" "sort" "strconv" "strings" "sync" "git.curoverse.com/arvados.git/sdk/go/arvados" "git.curoverse.com/arvados.git/sdk/go/arvadosclient" "git.curoverse.com/arvados.git/sdk/go/auth" "git.curoverse.com/arvados.git/sdk/go/health" "git.curoverse.com/arvados.git/sdk/go/httpserver" "git.curoverse.com/arvados.git/sdk/go/keepclient" log "github.com/sirupsen/logrus" "golang.org/x/net/webdav" ) type handler struct { Config *Config MetricsAPI http.Handler clientPool *arvadosclient.ClientPool setupOnce sync.Once healthHandler http.Handler webdavLS webdav.LockSystem } // parseCollectionIDFromDNSName returns a UUID or PDH if s begins with // a UUID or URL-encoded PDH; otherwise "". func parseCollectionIDFromDNSName(s string) string { // Strip domain. if i := strings.IndexRune(s, '.'); i >= 0 { s = s[:i] } // Names like {uuid}--collections.example.com serve the same // purpose as {uuid}.collections.example.com but can reduce // cost/effort of using [additional] wildcard certificates. if i := strings.Index(s, "--"); i >= 0 { s = s[:i] } if arvadosclient.UUIDMatch(s) { return s } if pdh := strings.Replace(s, "-", "+", 1); arvadosclient.PDHMatch(pdh) { return pdh } return "" } var urlPDHDecoder = strings.NewReplacer(" ", "+", "-", "+") // parseCollectionIDFromURL returns a UUID or PDH if s is a UUID or a // PDH (even if it is a PDH with "+" replaced by " " or "-"); // otherwise "". func parseCollectionIDFromURL(s string) string { if arvadosclient.UUIDMatch(s) { return s } if pdh := urlPDHDecoder.Replace(s); arvadosclient.PDHMatch(pdh) { return pdh } return "" } func (h *handler) setup() { h.clientPool = arvadosclient.MakeClientPool() keepclient.RefreshServiceDiscoveryOnSIGHUP() h.healthHandler = &health.Handler{ Token: h.Config.ManagementToken, Prefix: "/_health/", } // Even though we don't accept LOCK requests, every webdav // handler must have a non-nil LockSystem. h.webdavLS = &noLockSystem{} } func (h *handler) serveStatus(w http.ResponseWriter, r *http.Request) { json.NewEncoder(w).Encode(struct{ Version string }{version}) } // updateOnSuccess wraps httpserver.ResponseWriter. If the handler // sends an HTTP header indicating success, updateOnSuccess first // calls the provided update func. If the update func fails, a 500 // response is sent, and the status code and body sent by the handler // are ignored (all response writes return the update error). type updateOnSuccess struct { httpserver.ResponseWriter update func() error sentHeader bool err error } func (uos *updateOnSuccess) Write(p []byte) (int, error) { if !uos.sentHeader { uos.WriteHeader(http.StatusOK) } if uos.err != nil { return 0, uos.err } return uos.ResponseWriter.Write(p) } func (uos *updateOnSuccess) WriteHeader(code int) { if !uos.sentHeader { uos.sentHeader = true if code >= 200 && code < 400 { if uos.err = uos.update(); uos.err != nil { code := http.StatusInternalServerError if err, ok := uos.err.(*arvados.TransactionError); ok { code = err.StatusCode } log.Printf("update() changes response to HTTP %d: %T %q", code, uos.err, uos.err) http.Error(uos.ResponseWriter, uos.err.Error(), code) return } } } uos.ResponseWriter.WriteHeader(code) } var ( corsAllowHeadersHeader = strings.Join([]string{ "Authorization", "Content-Type", "Range", // WebDAV request headers: "Depth", "Destination", "If", "Lock-Token", "Overwrite", "Timeout", }, ", ") writeMethod = map[string]bool{ "COPY": true, "DELETE": true, "LOCK": true, "MKCOL": true, "MOVE": true, "PROPPATCH": true, "PUT": true, "RMCOL": true, "UNLOCK": true, } webdavMethod = map[string]bool{ "COPY": true, "DELETE": true, "LOCK": true, "MKCOL": true, "MOVE": true, "OPTIONS": true, "PROPFIND": true, "PROPPATCH": true, "PUT": true, "RMCOL": true, "UNLOCK": true, } browserMethod = map[string]bool{ "GET": true, "HEAD": true, "POST": true, } // top-level dirs to serve with siteFS siteFSDir = map[string]bool{ "": true, // root directory "by_id": true, "users": true, } ) // ServeHTTP implements http.Handler. func (h *handler) ServeHTTP(wOrig http.ResponseWriter, r *http.Request) { h.setupOnce.Do(h.setup) var statusCode = 0 var statusText string remoteAddr := r.RemoteAddr if xff := r.Header.Get("X-Forwarded-For"); xff != "" { remoteAddr = xff + "," + remoteAddr } if xfp := r.Header.Get("X-Forwarded-Proto"); xfp != "" && xfp != "http" { r.URL.Scheme = xfp } w := httpserver.WrapResponseWriter(wOrig) defer func() { if statusCode == 0 { statusCode = w.WroteStatus() } else if w.WroteStatus() == 0 { w.WriteHeader(statusCode) } else if w.WroteStatus() != statusCode { log.WithField("RequestID", r.Header.Get("X-Request-Id")).Warn( fmt.Sprintf("Our status changed from %d to %d after we sent headers", w.WroteStatus(), statusCode)) } if statusText == "" { statusText = http.StatusText(statusCode) } }() if strings.HasPrefix(r.URL.Path, "/_health/") && r.Method == "GET" { h.healthHandler.ServeHTTP(w, r) return } if method := r.Header.Get("Access-Control-Request-Method"); method != "" && r.Method == "OPTIONS" { if !browserMethod[method] && !webdavMethod[method] { statusCode = http.StatusMethodNotAllowed return } w.Header().Set("Access-Control-Allow-Headers", corsAllowHeadersHeader) w.Header().Set("Access-Control-Allow-Methods", "COPY, DELETE, GET, LOCK, MKCOL, MOVE, OPTIONS, POST, PROPFIND, PROPPATCH, PUT, RMCOL, UNLOCK") w.Header().Set("Access-Control-Allow-Origin", "*") w.Header().Set("Access-Control-Max-Age", "86400") statusCode = http.StatusOK return } if !browserMethod[r.Method] && !webdavMethod[r.Method] { statusCode, statusText = http.StatusMethodNotAllowed, r.Method return } if r.Header.Get("Origin") != "" { // Allow simple cross-origin requests without user // credentials ("user credentials" as defined by CORS, // i.e., cookies, HTTP authentication, and client-side // SSL certificates. See // http://www.w3.org/TR/cors/#user-credentials). w.Header().Set("Access-Control-Allow-Origin", "*") w.Header().Set("Access-Control-Expose-Headers", "Content-Range") } pathParts := strings.Split(r.URL.Path[1:], "/") var stripParts int var collectionID string var tokens []string var reqTokens []string var pathToken bool var attachment bool var useSiteFS bool credentialsOK := h.Config.TrustAllContent if r.Host != "" && r.Host == h.Config.AttachmentOnlyHost { credentialsOK = true attachment = true } else if r.FormValue("disposition") == "attachment" { attachment = true } if collectionID = parseCollectionIDFromDNSName(r.Host); collectionID != "" { // http://ID.collections.example/PATH... credentialsOK = true } else if r.URL.Path == "/status.json" { h.serveStatus(w, r) return } else if strings.HasPrefix(r.URL.Path, "/metrics") { h.MetricsAPI.ServeHTTP(w, r) return } else if siteFSDir[pathParts[0]] { useSiteFS = true } else if len(pathParts) >= 1 && strings.HasPrefix(pathParts[0], "c=") { // /c=ID[/PATH...] collectionID = parseCollectionIDFromURL(pathParts[0][2:]) stripParts = 1 } else if len(pathParts) >= 2 && pathParts[0] == "collections" { if len(pathParts) >= 4 && pathParts[1] == "download" { // /collections/download/ID/TOKEN/PATH... collectionID = parseCollectionIDFromURL(pathParts[2]) tokens = []string{pathParts[3]} stripParts = 4 pathToken = true } else { // /collections/ID/PATH... collectionID = parseCollectionIDFromURL(pathParts[1]) tokens = h.Config.AnonymousTokens stripParts = 2 } } if collectionID == "" && !useSiteFS { statusCode = http.StatusNotFound return } forceReload := false if cc := r.Header.Get("Cache-Control"); strings.Contains(cc, "no-cache") || strings.Contains(cc, "must-revalidate") { forceReload = true } formToken := r.FormValue("api_token") if formToken != "" && r.Header.Get("Origin") != "" && attachment && r.URL.Query().Get("api_token") == "" { // The client provided an explicit token in the POST // body. The Origin header indicates this *might* be // an AJAX request, in which case redirect-with-cookie // won't work: we should just serve the content in the // POST response. This is safe because: // // * We're supplying an attachment, not inline // content, so we don't need to convert the POST to // a GET and avoid the "really resubmit form?" // problem. // // * The token isn't embedded in the URL, so we don't // need to worry about bookmarks and copy/paste. tokens = append(tokens, formToken) } else if formToken != "" && browserMethod[r.Method] { // The client provided an explicit token in the query // string, or a form in POST body. We must put the // token in an HttpOnly cookie, and redirect to the // same URL with the query param redacted and method = // GET. h.seeOtherWithCookie(w, r, "", credentialsOK) return } if useSiteFS { if tokens == nil { tokens = auth.CredentialsFromRequest(r).Tokens } h.serveSiteFS(w, r, tokens, credentialsOK, attachment) return } targetPath := pathParts[stripParts:] if tokens == nil && len(targetPath) > 0 && strings.HasPrefix(targetPath[0], "t=") { // http://ID.example/t=TOKEN/PATH... // /c=ID/t=TOKEN/PATH... // // This form must only be used to pass scoped tokens // that give permission for a single collection. See // FormValue case above. tokens = []string{targetPath[0][2:]} pathToken = true targetPath = targetPath[1:] stripParts++ } if tokens == nil { if credentialsOK { reqTokens = auth.CredentialsFromRequest(r).Tokens } tokens = append(reqTokens, h.Config.AnonymousTokens...) } if len(targetPath) > 0 && targetPath[0] == "_" { // If a collection has a directory called "t=foo" or // "_", it can be served at // //collections.example/_/t=foo/ or // //collections.example/_/_/ respectively: // //collections.example/t=foo/ won't work because // t=foo will be interpreted as a token "foo". targetPath = targetPath[1:] stripParts++ } arv := h.clientPool.Get() if arv == nil { statusCode, statusText = http.StatusInternalServerError, "Pool failed: "+h.clientPool.Err().Error() return } defer h.clientPool.Put(arv) var collection *arvados.Collection tokenResult := make(map[string]int) for _, arv.ApiToken = range tokens { var err error collection, err = h.Config.Cache.Get(arv, collectionID, forceReload) if err == nil { // Success break } if srvErr, ok := err.(arvadosclient.APIServerError); ok { switch srvErr.HttpStatusCode { case 404, 401: // Token broken or insufficient to // retrieve collection tokenResult[arv.ApiToken] = srvErr.HttpStatusCode continue } } // Something more serious is wrong statusCode, statusText = http.StatusInternalServerError, err.Error() return } if collection == nil { if pathToken || !credentialsOK { // Either the URL is a "secret sharing link" // that didn't work out (and asking the client // for additional credentials would just be // confusing), or we don't even accept // credentials at this path. statusCode = http.StatusNotFound return } for _, t := range reqTokens { if tokenResult[t] == 404 { // The client provided valid token(s), but the // collection was not found. statusCode = http.StatusNotFound return } } // The client's token was invalid (e.g., expired), or // the client didn't even provide one. Propagate the // 401 to encourage the client to use a [different] // token. // // TODO(TC): This response would be confusing to // someone trying (anonymously) to download public // data that has been deleted. Allow a referrer to // provide this context somehow? w.Header().Add("WWW-Authenticate", "Basic realm=\"collections\"") statusCode = http.StatusUnauthorized return } kc, err := keepclient.MakeKeepClient(arv) if err != nil { statusCode, statusText = http.StatusInternalServerError, err.Error() return } kc.RequestID = r.Header.Get("X-Request-Id") var basename string if len(targetPath) > 0 { basename = targetPath[len(targetPath)-1] } applyContentDispositionHdr(w, r, basename, attachment) client := (&arvados.Client{ APIHost: arv.ApiServer, AuthToken: arv.ApiToken, Insecure: arv.ApiInsecure, }).WithRequestID(r.Header.Get("X-Request-Id")) fs, err := collection.FileSystem(client, kc) if err != nil { statusCode, statusText = http.StatusInternalServerError, err.Error() return } writefs, writeOK := fs.(arvados.CollectionFileSystem) targetIsPDH := arvadosclient.PDHMatch(collectionID) if (targetIsPDH || !writeOK) && writeMethod[r.Method] { statusCode, statusText = http.StatusMethodNotAllowed, errReadOnly.Error() return } if webdavMethod[r.Method] { if writeMethod[r.Method] { // Save the collection only if/when all // webdav->filesystem operations succeed -- // and send a 500 error if the modified // collection can't be saved. w = &updateOnSuccess{ ResponseWriter: w, update: func() error { return h.Config.Cache.Update(client, *collection, writefs) }} } h := webdav.Handler{ Prefix: "/" + strings.Join(pathParts[:stripParts], "/"), FileSystem: &webdavFS{ collfs: fs, writing: writeMethod[r.Method], alwaysReadEOF: r.Method == "PROPFIND", }, LockSystem: h.webdavLS, Logger: func(_ *http.Request, err error) { if err != nil { log.Printf("error from webdav handler: %q", err) } }, } h.ServeHTTP(w, r) return } openPath := "/" + strings.Join(targetPath, "/") if f, err := fs.Open(openPath); os.IsNotExist(err) { // Requested non-existent path statusCode = http.StatusNotFound } else if err != nil { // Some other (unexpected) error statusCode, statusText = http.StatusInternalServerError, err.Error() } else if stat, err := f.Stat(); err != nil { // Can't get Size/IsDir (shouldn't happen with a collectionFS!) statusCode, statusText = http.StatusInternalServerError, err.Error() } else if stat.IsDir() && !strings.HasSuffix(r.URL.Path, "/") { // If client requests ".../dirname", redirect to // ".../dirname/". This way, relative links in the // listing for "dirname" can always be "fnm", never // "dirname/fnm". h.seeOtherWithCookie(w, r, r.URL.Path+"/", credentialsOK) } else if stat.IsDir() { h.serveDirectory(w, r, collection.Name, fs, openPath, true) } else { http.ServeContent(w, r, basename, stat.ModTime(), f) if r.Header.Get("Range") == "" && int64(w.WroteBodyBytes()) != stat.Size() { // If we wrote fewer bytes than expected, it's // too late to change the real response code // or send an error message to the client, but // at least we can try to put some useful // debugging info in the logs. n, err := f.Read(make([]byte, 1024)) statusCode, statusText = http.StatusInternalServerError, fmt.Sprintf("f.Size()==%d but only wrote %d bytes; read(1024) returns %d, %s", stat.Size(), w.WroteBodyBytes(), n, err) } } } func (h *handler) serveSiteFS(w http.ResponseWriter, r *http.Request, tokens []string, credentialsOK, attachment bool) { if len(tokens) == 0 { w.Header().Add("WWW-Authenticate", "Basic realm=\"collections\"") http.Error(w, http.StatusText(http.StatusUnauthorized), http.StatusUnauthorized) return } if writeMethod[r.Method] { http.Error(w, errReadOnly.Error(), http.StatusMethodNotAllowed) return } arv := h.clientPool.Get() if arv == nil { http.Error(w, "Pool failed: "+h.clientPool.Err().Error(), http.StatusInternalServerError) return } defer h.clientPool.Put(arv) arv.ApiToken = tokens[0] kc, err := keepclient.MakeKeepClient(arv) if err != nil { http.Error(w, err.Error(), http.StatusInternalServerError) return } kc.RequestID = r.Header.Get("X-Request-Id") client := (&arvados.Client{ APIHost: arv.ApiServer, AuthToken: arv.ApiToken, Insecure: arv.ApiInsecure, }).WithRequestID(r.Header.Get("X-Request-Id")) fs := client.SiteFileSystem(kc) f, err := fs.Open(r.URL.Path) if os.IsNotExist(err) { http.Error(w, err.Error(), http.StatusNotFound) return } else if err != nil { http.Error(w, err.Error(), http.StatusInternalServerError) return } defer f.Close() if fi, err := f.Stat(); err == nil && fi.IsDir() && r.Method == "GET" { if !strings.HasSuffix(r.URL.Path, "/") { h.seeOtherWithCookie(w, r, r.URL.Path+"/", credentialsOK) } else { h.serveDirectory(w, r, fi.Name(), fs, r.URL.Path, false) } return } if r.Method == "GET" { _, basename := filepath.Split(r.URL.Path) applyContentDispositionHdr(w, r, basename, attachment) } wh := webdav.Handler{ Prefix: "/", FileSystem: &webdavFS{ collfs: fs, writing: writeMethod[r.Method], alwaysReadEOF: r.Method == "PROPFIND", }, LockSystem: h.webdavLS, Logger: func(_ *http.Request, err error) { if err != nil { log.Printf("error from webdav handler: %q", err) } }, } wh.ServeHTTP(w, r) } var dirListingTemplate = ` {{ .CollectionName }}

{{ .CollectionName }}

This collection of data files is being shared with you through Arvados. You can download individual files listed below. To download the entire directory tree with wget, try:

$ wget --mirror --no-parent --no-host --cut-dirs={{ .StripParts }} https://{{ .Request.Host }}{{ .Request.URL.Path }}

File Listing

{{if .Files}} {{else}}

(No files; this collection is empty.)

{{end}}
` type fileListEnt struct { Name string Size int64 IsDir bool } func (h *handler) serveDirectory(w http.ResponseWriter, r *http.Request, collectionName string, fs http.FileSystem, base string, recurse bool) { var files []fileListEnt var walk func(string) error if !strings.HasSuffix(base, "/") { base = base + "/" } walk = func(path string) error { dirname := base + path if dirname != "/" { dirname = strings.TrimSuffix(dirname, "/") } d, err := fs.Open(dirname) if err != nil { return err } ents, err := d.Readdir(-1) if err != nil { return err } for _, ent := range ents { if recurse && ent.IsDir() { err = walk(path + ent.Name() + "/") if err != nil { return err } } else { files = append(files, fileListEnt{ Name: path + ent.Name(), Size: ent.Size(), IsDir: ent.IsDir(), }) } } return nil } if err := walk(""); err != nil { http.Error(w, err.Error(), http.StatusInternalServerError) return } funcs := template.FuncMap{ "nbsp": func(s string) template.HTML { return template.HTML(strings.Replace(s, " ", " ", -1)) }, } tmpl, err := template.New("dir").Funcs(funcs).Parse(dirListingTemplate) if err != nil { http.Error(w, err.Error(), http.StatusInternalServerError) return } sort.Slice(files, func(i, j int) bool { return files[i].Name < files[j].Name }) w.WriteHeader(http.StatusOK) tmpl.Execute(w, map[string]interface{}{ "CollectionName": collectionName, "Files": files, "Request": r, "StripParts": strings.Count(strings.TrimRight(r.URL.Path, "/"), "/"), }) } func applyContentDispositionHdr(w http.ResponseWriter, r *http.Request, filename string, isAttachment bool) { disposition := "inline" if isAttachment { disposition = "attachment" } if strings.ContainsRune(r.RequestURI, '?') { // Help the UA realize that the filename is just // "filename.txt", not // "filename.txt?disposition=attachment". // // TODO(TC): Follow advice at RFC 6266 appendix D disposition += "; filename=" + strconv.QuoteToASCII(filename) } if disposition != "inline" { w.Header().Set("Content-Disposition", disposition) } } func (h *handler) seeOtherWithCookie(w http.ResponseWriter, r *http.Request, location string, credentialsOK bool) { if formToken := r.FormValue("api_token"); formToken != "" { if !credentialsOK { // It is not safe to copy the provided token // into a cookie unless the current vhost // (origin) serves only a single collection or // we are in TrustAllContent mode. w.WriteHeader(http.StatusBadRequest) return } // The HttpOnly flag is necessary to prevent // JavaScript code (included in, or loaded by, a page // in the collection being served) from employing the // user's token beyond reading other files in the same // domain, i.e., same collection. // // The 303 redirect is necessary in the case of a GET // request to avoid exposing the token in the Location // bar, and in the case of a POST request to avoid // raising warnings when the user refreshes the // resulting page. http.SetCookie(w, &http.Cookie{ Name: "arvados_api_token", Value: auth.EncodeTokenCookie([]byte(formToken)), Path: "/", HttpOnly: true, }) } // Propagate query parameters (except api_token) from // the original request. redirQuery := r.URL.Query() redirQuery.Del("api_token") u := r.URL if location != "" { newu, err := u.Parse(location) if err != nil { w.WriteHeader(http.StatusInternalServerError) return } u = newu } redir := (&url.URL{ Scheme: r.URL.Scheme, Host: r.Host, Path: u.Path, RawQuery: redirQuery.Encode(), }).String() w.Header().Add("Location", redir) w.WriteHeader(http.StatusSeeOther) io.WriteString(w, `Continue`) }