services/keep-web/handler.go

   1 // Copyright (C) The Arvados Authors. All rights reserved.
   2 //
   3 // SPDX-License-Identifier: AGPL-3.0
   4
   5 package main
   6
   7 import (
   8         "encoding/json"
   9         "html"
  10         "html/template"
  11         "io"
  12         "net/http"
  13         "net/url"
  14         "os"
  15         "path/filepath"
  16         "sort"
  17         "strconv"
  18         "strings"
  19         "sync"
  20
  21         "git.arvados.org/arvados.git/sdk/go/arvados"
  22         "git.arvados.org/arvados.git/sdk/go/arvadosclient"
  23         "git.arvados.org/arvados.git/sdk/go/auth"
  24         "git.arvados.org/arvados.git/sdk/go/ctxlog"
  25         "git.arvados.org/arvados.git/sdk/go/health"
  26         "git.arvados.org/arvados.git/sdk/go/httpserver"
  27         "git.arvados.org/arvados.git/sdk/go/keepclient"
  28         "github.com/sirupsen/logrus"
  29         "golang.org/x/net/webdav"
  30 )
  31
  32 type handler struct {
  33         Config        *Config
  34         MetricsAPI    http.Handler
  35         clientPool    *arvadosclient.ClientPool
  36         setupOnce     sync.Once
  37         healthHandler http.Handler
  38         webdavLS      webdav.LockSystem
  39 }
  40
  41 // parseCollectionIDFromDNSName returns a UUID or PDH if s begins with
  42 // a UUID or URL-encoded PDH; otherwise "".
  43 func parseCollectionIDFromDNSName(s string) string {
  44         // Strip domain.
  45         if i := strings.IndexRune(s, '.'); i >= 0 {
  46                 s = s[:i]
  47         }
  48         // Names like {uuid}--collections.example.com serve the same
  49         // purpose as {uuid}.collections.example.com but can reduce
  50         // cost/effort of using [additional] wildcard certificates.
  51         if i := strings.Index(s, "--"); i >= 0 {
  52                 s = s[:i]
  53         }
  54         if arvadosclient.UUIDMatch(s) {
  55                 return s
  56         }
  57         if pdh := strings.Replace(s, "-", "+", 1); arvadosclient.PDHMatch(pdh) {
  58                 return pdh
  59         }
  60         return ""
  61 }
  62
  63 var urlPDHDecoder = strings.NewReplacer(" ", "+", "-", "+")
  64
  65 // parseCollectionIDFromURL returns a UUID or PDH if s is a UUID or a
  66 // PDH (even if it is a PDH with "+" replaced by " " or "-");
  67 // otherwise "".
  68 func parseCollectionIDFromURL(s string) string {
  69         if arvadosclient.UUIDMatch(s) {
  70                 return s
  71         }
  72         if pdh := urlPDHDecoder.Replace(s); arvadosclient.PDHMatch(pdh) {
  73                 return pdh
  74         }
  75         return ""
  76 }
  77
  78 func (h *handler) setup() {
  79         // Errors will be handled at the client pool.
  80         arv, _ := arvados.NewClientFromConfig(h.Config.cluster)
  81         h.clientPool = arvadosclient.MakeClientPoolWith(arv)
  82
  83         keepclient.RefreshServiceDiscoveryOnSIGHUP()
  84         keepclient.DefaultBlockCache.MaxBlocks = h.Config.cluster.Collections.WebDAVCache.MaxBlockEntries
  85
  86         h.healthHandler = &health.Handler{
  87                 Token:  h.Config.cluster.ManagementToken,
  88                 Prefix: "/_health/",
  89         }
  90
  91         // Even though we don't accept LOCK requests, every webdav
  92         // handler must have a non-nil LockSystem.
  93         h.webdavLS = &noLockSystem{}
  94 }
  95
  96 func (h *handler) serveStatus(w http.ResponseWriter, r *http.Request) {
  97         json.NewEncoder(w).Encode(struct{ Version string }{version})
  98 }
  99
 100 // updateOnSuccess wraps httpserver.ResponseWriter. If the handler
 101 // sends an HTTP header indicating success, updateOnSuccess first
 102 // calls the provided update func. If the update func fails, a 500
 103 // response is sent, and the status code and body sent by the handler
 104 // are ignored (all response writes return the update error).
 105 type updateOnSuccess struct {
 106         httpserver.ResponseWriter
 107         logger     logrus.FieldLogger
 108         update     func() error
 109         sentHeader bool
 110         err        error
 111 }
 112
 113 func (uos *updateOnSuccess) Write(p []byte) (int, error) {
 114         if !uos.sentHeader {
 115                 uos.WriteHeader(http.StatusOK)
 116         }
 117         if uos.err != nil {
 118                 return 0, uos.err
 119         }
 120         return uos.ResponseWriter.Write(p)
 121 }
 122
 123 func (uos *updateOnSuccess) WriteHeader(code int) {
 124         if !uos.sentHeader {
 125                 uos.sentHeader = true
 126                 if code >= 200 && code < 400 {
 127                         if uos.err = uos.update(); uos.err != nil {
 128                                 code := http.StatusInternalServerError
 129                                 if err, ok := uos.err.(*arvados.TransactionError); ok {
 130                                         code = err.StatusCode
 131                                 }
 132                                 uos.logger.WithError(uos.err).Errorf("update() returned error type %T, changing response to HTTP %d", uos.err, code)
 133                                 http.Error(uos.ResponseWriter, uos.err.Error(), code)
 134                                 return
 135                         }
 136                 }
 137         }
 138         uos.ResponseWriter.WriteHeader(code)
 139 }
 140
 141 var (
 142         corsAllowHeadersHeader = strings.Join([]string{
 143                 "Authorization", "Content-Type", "Range",
 144                 // WebDAV request headers:
 145                 "Depth", "Destination", "If", "Lock-Token", "Overwrite", "Timeout",
 146         }, ", ")
 147         writeMethod = map[string]bool{
 148                 "COPY":      true,
 149                 "DELETE":    true,
 150                 "LOCK":      true,
 151                 "MKCOL":     true,
 152                 "MOVE":      true,
 153                 "PROPPATCH": true,
 154                 "PUT":       true,
 155                 "RMCOL":     true,
 156                 "UNLOCK":    true,
 157         }
 158         webdavMethod = map[string]bool{
 159                 "COPY":      true,
 160                 "DELETE":    true,
 161                 "LOCK":      true,
 162                 "MKCOL":     true,
 163                 "MOVE":      true,
 164                 "OPTIONS":   true,
 165                 "PROPFIND":  true,
 166                 "PROPPATCH": true,
 167                 "PUT":       true,
 168                 "RMCOL":     true,
 169                 "UNLOCK":    true,
 170         }
 171         browserMethod = map[string]bool{
 172                 "GET":  true,
 173                 "HEAD": true,
 174                 "POST": true,
 175         }
 176         // top-level dirs to serve with siteFS
 177         siteFSDir = map[string]bool{
 178                 "":      true, // root directory
 179                 "by_id": true,
 180                 "users": true,
 181         }
 182 )
 183
 184 // ServeHTTP implements http.Handler.
 185 func (h *handler) ServeHTTP(wOrig http.ResponseWriter, r *http.Request) {
 186         h.setupOnce.Do(h.setup)
 187
 188         remoteAddr := r.RemoteAddr
 189         if xff := r.Header.Get("X-Forwarded-For"); xff != "" {
 190                 remoteAddr = xff + "," + remoteAddr
 191         }
 192         if xfp := r.Header.Get("X-Forwarded-Proto"); xfp != "" && xfp != "http" {
 193                 r.URL.Scheme = xfp
 194         }
 195
 196         w := httpserver.WrapResponseWriter(wOrig)
 197
 198         if strings.HasPrefix(r.URL.Path, "/_health/") && r.Method == "GET" {
 199                 h.healthHandler.ServeHTTP(w, r)
 200                 return
 201         }
 202
 203         if method := r.Header.Get("Access-Control-Request-Method"); method != "" && r.Method == "OPTIONS" {
 204                 if !browserMethod[method] && !webdavMethod[method] {
 205                         w.WriteHeader(http.StatusMethodNotAllowed)
 206                         return
 207                 }
 208                 w.Header().Set("Access-Control-Allow-Headers", corsAllowHeadersHeader)
 209                 w.Header().Set("Access-Control-Allow-Methods", "COPY, DELETE, GET, LOCK, MKCOL, MOVE, OPTIONS, POST, PROPFIND, PROPPATCH, PUT, RMCOL, UNLOCK")
 210                 w.Header().Set("Access-Control-Allow-Origin", "*")
 211                 w.Header().Set("Access-Control-Max-Age", "86400")
 212                 return
 213         }
 214
 215         if !browserMethod[r.Method] && !webdavMethod[r.Method] {
 216                 w.WriteHeader(http.StatusMethodNotAllowed)
 217                 return
 218         }
 219
 220         if r.Header.Get("Origin") != "" {
 221                 // Allow simple cross-origin requests without user
 222                 // credentials ("user credentials" as defined by CORS,
 223                 // i.e., cookies, HTTP authentication, and client-side
 224                 // SSL certificates. See
 225                 // http://www.w3.org/TR/cors/#user-credentials).
 226                 w.Header().Set("Access-Control-Allow-Origin", "*")
 227                 w.Header().Set("Access-Control-Expose-Headers", "Content-Range")
 228         }
 229
 230         pathParts := strings.Split(r.URL.Path[1:], "/")
 231
 232         var stripParts int
 233         var collectionID string
 234         var tokens []string
 235         var reqTokens []string
 236         var pathToken bool
 237         var attachment bool
 238         var useSiteFS bool
 239         credentialsOK := h.Config.cluster.Collections.TrustAllContent
 240
 241         if r.Host != "" && r.Host == h.Config.cluster.Services.WebDAVDownload.ExternalURL.Host {
 242                 credentialsOK = true
 243                 attachment = true
 244         } else if r.FormValue("disposition") == "attachment" {
 245                 attachment = true
 246         }
 247
 248         if collectionID = parseCollectionIDFromDNSName(r.Host); collectionID != "" {
 249                 // http://ID.collections.example/PATH...
 250                 credentialsOK = true
 251         } else if r.URL.Path == "/status.json" {
 252                 h.serveStatus(w, r)
 253                 return
 254         } else if strings.HasPrefix(r.URL.Path, "/metrics") {
 255                 h.MetricsAPI.ServeHTTP(w, r)
 256                 return
 257         } else if siteFSDir[pathParts[0]] {
 258                 useSiteFS = true
 259         } else if len(pathParts) >= 1 && strings.HasPrefix(pathParts[0], "c=") {
 260                 // /c=ID[/PATH...]
 261                 collectionID = parseCollectionIDFromURL(pathParts[0][2:])
 262                 stripParts = 1
 263         } else if len(pathParts) >= 2 && pathParts[0] == "collections" {
 264                 if len(pathParts) >= 4 && pathParts[1] == "download" {
 265                         // /collections/download/ID/TOKEN/PATH...
 266                         collectionID = parseCollectionIDFromURL(pathParts[2])
 267                         tokens = []string{pathParts[3]}
 268                         stripParts = 4
 269                         pathToken = true
 270                 } else {
 271                         // /collections/ID/PATH...
 272                         collectionID = parseCollectionIDFromURL(pathParts[1])
 273                         stripParts = 2
 274                         // This path is only meant to work for public
 275                         // data. Tokens provided with the request are
 276                         // ignored.
 277                         credentialsOK = false
 278                 }
 279         }
 280
 281         if collectionID == "" && !useSiteFS {
 282                 w.WriteHeader(http.StatusNotFound)
 283                 return
 284         }
 285
 286         forceReload := false
 287         if cc := r.Header.Get("Cache-Control"); strings.Contains(cc, "no-cache") || strings.Contains(cc, "must-revalidate") {
 288                 forceReload = true
 289         }
 290
 291         if credentialsOK {
 292                 reqTokens = auth.CredentialsFromRequest(r).Tokens
 293         }
 294
 295         formToken := r.FormValue("api_token")
 296         if formToken != "" && r.Header.Get("Origin") != "" && attachment && r.URL.Query().Get("api_token") == "" {
 297                 // The client provided an explicit token in the POST
 298                 // body. The Origin header indicates this *might* be
 299                 // an AJAX request, in which case redirect-with-cookie
 300                 // won't work: we should just serve the content in the
 301                 // POST response. This is safe because:
 302                 //
 303                 // * We're supplying an attachment, not inline
 304                 //   content, so we don't need to convert the POST to
 305                 //   a GET and avoid the "really resubmit form?"
 306                 //   problem.
 307                 //
 308                 // * The token isn't embedded in the URL, so we don't
 309                 //   need to worry about bookmarks and copy/paste.
 310                 reqTokens = append(reqTokens, formToken)
 311         } else if formToken != "" && browserMethod[r.Method] {
 312                 // The client provided an explicit token in the query
 313                 // string, or a form in POST body. We must put the
 314                 // token in an HttpOnly cookie, and redirect to the
 315                 // same URL with the query param redacted and method =
 316                 // GET.
 317                 h.seeOtherWithCookie(w, r, "", credentialsOK)
 318                 return
 319         }
 320
 321         if useSiteFS {
 322                 h.serveSiteFS(w, r, reqTokens, credentialsOK, attachment)
 323                 return
 324         }
 325
 326         targetPath := pathParts[stripParts:]
 327         if tokens == nil && len(targetPath) > 0 && strings.HasPrefix(targetPath[0], "t=") {
 328                 // http://ID.example/t=TOKEN/PATH...
 329                 // /c=ID/t=TOKEN/PATH...
 330                 //
 331                 // This form must only be used to pass scoped tokens
 332                 // that give permission for a single collection. See
 333                 // FormValue case above.
 334                 tokens = []string{targetPath[0][2:]}
 335                 pathToken = true
 336                 targetPath = targetPath[1:]
 337                 stripParts++
 338         }
 339
 340         if tokens == nil {
 341                 tokens = append(reqTokens, h.Config.cluster.Users.AnonymousUserToken)
 342         }
 343
 344         if len(targetPath) > 0 && targetPath[0] == "_" {
 345                 // If a collection has a directory called "t=foo" or
 346                 // "_", it can be served at
 347                 // //collections.example/_/t=foo/ or
 348                 // //collections.example/_/_/ respectively:
 349                 // //collections.example/t=foo/ won't work because
 350                 // t=foo will be interpreted as a token "foo".
 351                 targetPath = targetPath[1:]
 352                 stripParts++
 353         }
 354
 355         arv := h.clientPool.Get()
 356         if arv == nil {
 357                 http.Error(w, "client pool error: "+h.clientPool.Err().Error(), http.StatusInternalServerError)
 358                 return
 359         }
 360         defer h.clientPool.Put(arv)
 361
 362         var collection *arvados.Collection
 363         tokenResult := make(map[string]int)
 364         for _, arv.ApiToken = range tokens {
 365                 var err error
 366                 collection, err = h.Config.Cache.Get(arv, collectionID, forceReload)
 367                 if err == nil {
 368                         // Success
 369                         break
 370                 }
 371                 if srvErr, ok := err.(arvadosclient.APIServerError); ok {
 372                         switch srvErr.HttpStatusCode {
 373                         case 404, 401:
 374                                 // Token broken or insufficient to
 375                                 // retrieve collection
 376                                 tokenResult[arv.ApiToken] = srvErr.HttpStatusCode
 377                                 continue
 378                         }
 379                 }
 380                 // Something more serious is wrong
 381                 http.Error(w, "cache error: "+err.Error(), http.StatusInternalServerError)
 382                 return
 383         }
 384         if collection == nil {
 385                 if pathToken || !credentialsOK {
 386                         // Either the URL is a "secret sharing link"
 387                         // that didn't work out (and asking the client
 388                         // for additional credentials would just be
 389                         // confusing), or we don't even accept
 390                         // credentials at this path.
 391                         w.WriteHeader(http.StatusNotFound)
 392                         return
 393                 }
 394                 for _, t := range reqTokens {
 395                         if tokenResult[t] == 404 {
 396                                 // The client provided valid token(s), but the
 397                                 // collection was not found.
 398                                 w.WriteHeader(http.StatusNotFound)
 399                                 return
 400                         }
 401                 }
 402                 // The client's token was invalid (e.g., expired), or
 403                 // the client didn't even provide one.  Propagate the
 404                 // 401 to encourage the client to use a [different]
 405                 // token.
 406                 //
 407                 // TODO(TC): This response would be confusing to
 408                 // someone trying (anonymously) to download public
 409                 // data that has been deleted.  Allow a referrer to
 410                 // provide this context somehow?
 411                 w.Header().Add("WWW-Authenticate", "Basic realm=\"collections\"")
 412                 w.WriteHeader(http.StatusUnauthorized)
 413                 return
 414         }
 415
 416         kc, err := keepclient.MakeKeepClient(arv)
 417         if err != nil {
 418                 http.Error(w, "error setting up keep client: "+err.Error(), http.StatusInternalServerError)
 419                 return
 420         }
 421         kc.RequestID = r.Header.Get("X-Request-Id")
 422
 423         var basename string
 424         if len(targetPath) > 0 {
 425                 basename = targetPath[len(targetPath)-1]
 426         }
 427         applyContentDispositionHdr(w, r, basename, attachment)
 428
 429         client := (&arvados.Client{
 430                 APIHost:   arv.ApiServer,
 431                 AuthToken: arv.ApiToken,
 432                 Insecure:  arv.ApiInsecure,
 433         }).WithRequestID(r.Header.Get("X-Request-Id"))
 434
 435         fs, err := collection.FileSystem(client, kc)
 436         if err != nil {
 437                 http.Error(w, "error creating collection filesystem: "+err.Error(), http.StatusInternalServerError)
 438                 return
 439         }
 440
 441         writefs, writeOK := fs.(arvados.CollectionFileSystem)
 442         targetIsPDH := arvadosclient.PDHMatch(collectionID)
 443         if (targetIsPDH || !writeOK) && writeMethod[r.Method] {
 444                 http.Error(w, errReadOnly.Error(), http.StatusMethodNotAllowed)
 445                 return
 446         }
 447
 448         if webdavMethod[r.Method] {
 449                 if writeMethod[r.Method] {
 450                         // Save the collection only if/when all
 451                         // webdav->filesystem operations succeed --
 452                         // and send a 500 error if the modified
 453                         // collection can't be saved.
 454                         w = &updateOnSuccess{
 455                                 ResponseWriter: w,
 456                                 logger:         ctxlog.FromContext(r.Context()),
 457                                 update: func() error {
 458                                         return h.Config.Cache.Update(client, *collection, writefs)
 459                                 }}
 460                 }
 461                 h := webdav.Handler{
 462                         Prefix: "/" + strings.Join(pathParts[:stripParts], "/"),
 463                         FileSystem: &webdavFS{
 464                                 collfs:        fs,
 465                                 writing:       writeMethod[r.Method],
 466                                 alwaysReadEOF: r.Method == "PROPFIND",
 467                         },
 468                         LockSystem: h.webdavLS,
 469                         Logger: func(_ *http.Request, err error) {
 470                                 if err != nil {
 471                                         ctxlog.FromContext(r.Context()).WithError(err).Error("error reported by webdav handler")
 472                                 }
 473                         },
 474                 }
 475                 h.ServeHTTP(w, r)
 476                 return
 477         }
 478
 479         openPath := "/" + strings.Join(targetPath, "/")
 480         if f, err := fs.Open(openPath); os.IsNotExist(err) {
 481                 // Requested non-existent path
 482                 w.WriteHeader(http.StatusNotFound)
 483         } else if err != nil {
 484                 // Some other (unexpected) error
 485                 http.Error(w, "open: "+err.Error(), http.StatusInternalServerError)
 486         } else if stat, err := f.Stat(); err != nil {
 487                 // Can't get Size/IsDir (shouldn't happen with a collectionFS!)
 488                 http.Error(w, "stat: "+err.Error(), http.StatusInternalServerError)
 489         } else if stat.IsDir() && !strings.HasSuffix(r.URL.Path, "/") {
 490                 // If client requests ".../dirname", redirect to
 491                 // ".../dirname/". This way, relative links in the
 492                 // listing for "dirname" can always be "fnm", never
 493                 // "dirname/fnm".
 494                 h.seeOtherWithCookie(w, r, r.URL.Path+"/", credentialsOK)
 495         } else if stat.IsDir() {
 496                 h.serveDirectory(w, r, collection.Name, fs, openPath, true)
 497         } else {
 498                 http.ServeContent(w, r, basename, stat.ModTime(), f)
 499                 if wrote := int64(w.WroteBodyBytes()); wrote != stat.Size() && r.Header.Get("Range") == "" {
 500                         // If we wrote fewer bytes than expected, it's
 501                         // too late to change the real response code
 502                         // or send an error message to the client, but
 503                         // at least we can try to put some useful
 504                         // debugging info in the logs.
 505                         n, err := f.Read(make([]byte, 1024))
 506                         ctxlog.FromContext(r.Context()).Errorf("stat.Size()==%d but only wrote %d bytes; read(1024) returns %d, %s", stat.Size(), wrote, n, err)
 507
 508                 }
 509         }
 510 }
 511
 512 func (h *handler) serveSiteFS(w http.ResponseWriter, r *http.Request, tokens []string, credentialsOK, attachment bool) {
 513         if len(tokens) == 0 {
 514                 w.Header().Add("WWW-Authenticate", "Basic realm=\"collections\"")
 515                 http.Error(w, http.StatusText(http.StatusUnauthorized), http.StatusUnauthorized)
 516                 return
 517         }
 518         if writeMethod[r.Method] {
 519                 http.Error(w, errReadOnly.Error(), http.StatusMethodNotAllowed)
 520                 return
 521         }
 522         arv := h.clientPool.Get()
 523         if arv == nil {
 524                 http.Error(w, "Pool failed: "+h.clientPool.Err().Error(), http.StatusInternalServerError)
 525                 return
 526         }
 527         defer h.clientPool.Put(arv)
 528         arv.ApiToken = tokens[0]
 529
 530         kc, err := keepclient.MakeKeepClient(arv)
 531         if err != nil {
 532                 http.Error(w, "error setting up keep client: "+err.Error(), http.StatusInternalServerError)
 533                 return
 534         }
 535         kc.RequestID = r.Header.Get("X-Request-Id")
 536         client := (&arvados.Client{
 537                 APIHost:   arv.ApiServer,
 538                 AuthToken: arv.ApiToken,
 539                 Insecure:  arv.ApiInsecure,
 540         }).WithRequestID(r.Header.Get("X-Request-Id"))
 541         fs := client.SiteFileSystem(kc)
 542         fs.ForwardSlashNameSubstitution(h.Config.cluster.Collections.ForwardSlashNameSubstitution)
 543         f, err := fs.Open(r.URL.Path)
 544         if os.IsNotExist(err) {
 545                 http.Error(w, err.Error(), http.StatusNotFound)
 546                 return
 547         } else if err != nil {
 548                 http.Error(w, err.Error(), http.StatusInternalServerError)
 549                 return
 550         }
 551         defer f.Close()
 552         if fi, err := f.Stat(); err == nil && fi.IsDir() && r.Method == "GET" {
 553                 if !strings.HasSuffix(r.URL.Path, "/") {
 554                         h.seeOtherWithCookie(w, r, r.URL.Path+"/", credentialsOK)
 555                 } else {
 556                         h.serveDirectory(w, r, fi.Name(), fs, r.URL.Path, false)
 557                 }
 558                 return
 559         }
 560         if r.Method == "GET" {
 561                 _, basename := filepath.Split(r.URL.Path)
 562                 applyContentDispositionHdr(w, r, basename, attachment)
 563         }
 564         wh := webdav.Handler{
 565                 Prefix: "/",
 566                 FileSystem: &webdavFS{
 567                         collfs:        fs,
 568                         writing:       writeMethod[r.Method],
 569                         alwaysReadEOF: r.Method == "PROPFIND",
 570                 },
 571                 LockSystem: h.webdavLS,
 572                 Logger: func(_ *http.Request, err error) {
 573                         if err != nil {
 574                                 ctxlog.FromContext(r.Context()).WithError(err).Error("error reported by webdav handler")
 575                         }
 576                 },
 577         }
 578         wh.ServeHTTP(w, r)
 579 }
 580
 581 var dirListingTemplate = `<!DOCTYPE HTML>
 582 <HTML><HEAD>
 583   <META name="robots" content="NOINDEX">
 584   <TITLE>{{ .CollectionName }}</TITLE>
 585   <STYLE type="text/css">
 586     body {
 587       margin: 1.5em;
 588     }
 589     pre {
 590       background-color: #D9EDF7;
 591       border-radius: .25em;
 592       padding: .75em;
 593       overflow: auto;
 594     }
 595     .footer p {
 596       font-size: 82%;
 597     }
 598     ul {
 599       padding: 0;
 600     }
 601     ul li {
 602       font-family: monospace;
 603       list-style: none;
 604     }
 605   </STYLE>
 606 </HEAD>
 607 <BODY>
 608
 609 <H1>{{ .CollectionName }}</H1>
 610
 611 <P>This collection of data files is being shared with you through
 612 Arvados.  You can download individual files listed below.  To download
 613 the entire directory tree with wget, try:</P>
 614
 615 <PRE>$ wget --mirror --no-parent --no-host --cut-dirs={{ .StripParts }} https://{{ .Request.Host }}{{ .Request.URL.Path }}</PRE>
 616
 617 <H2>File Listing</H2>
 618
 619 {{if .Files}}
 620 <UL>
 621 {{range .Files}}
 622 {{if .IsDir }}
 623   <LI>{{" " | printf "%15s  " | nbsp}}<A href="{{print "./" .Name}}/">{{.Name}}/</A></LI>
 624 {{else}}
 625   <LI>{{.Size | printf "%15d  " | nbsp}}<A href="{{print "./" .Name}}">{{.Name}}</A></LI>
 626 {{end}}
 627 {{end}}
 628 </UL>
 629 {{else}}
 630 <P>(No files; this collection is empty.)</P>
 631 {{end}}
 632
 633 <HR noshade>
 634 <DIV class="footer">
 635   <P>
 636     About Arvados:
 637     Arvados is a free and open source software bioinformatics platform.
 638     To learn more, visit arvados.org.
 639     Arvados is not responsible for the files listed on this page.
 640   </P>
 641 </DIV>
 642
 643 </BODY>
 644 `
 645
 646 type fileListEnt struct {
 647         Name  string
 648         Size  int64
 649         IsDir bool
 650 }
 651
 652 func (h *handler) serveDirectory(w http.ResponseWriter, r *http.Request, collectionName string, fs http.FileSystem, base string, recurse bool) {
 653         var files []fileListEnt
 654         var walk func(string) error
 655         if !strings.HasSuffix(base, "/") {
 656                 base = base + "/"
 657         }
 658         walk = func(path string) error {
 659                 dirname := base + path
 660                 if dirname != "/" {
 661                         dirname = strings.TrimSuffix(dirname, "/")
 662                 }
 663                 d, err := fs.Open(dirname)
 664                 if err != nil {
 665                         return err
 666                 }
 667                 ents, err := d.Readdir(-1)
 668                 if err != nil {
 669                         return err
 670                 }
 671                 for _, ent := range ents {
 672                         if recurse && ent.IsDir() {
 673                                 err = walk(path + ent.Name() + "/")
 674                                 if err != nil {
 675                                         return err
 676                                 }
 677                         } else {
 678                                 files = append(files, fileListEnt{
 679                                         Name:  path + ent.Name(),
 680                                         Size:  ent.Size(),
 681                                         IsDir: ent.IsDir(),
 682                                 })
 683                         }
 684                 }
 685                 return nil
 686         }
 687         if err := walk(""); err != nil {
 688                 http.Error(w, "error getting directory listing: "+err.Error(), http.StatusInternalServerError)
 689                 return
 690         }
 691
 692         funcs := template.FuncMap{
 693                 "nbsp": func(s string) template.HTML {
 694                         return template.HTML(strings.Replace(s, " ", "&nbsp;", -1))
 695                 },
 696         }
 697         tmpl, err := template.New("dir").Funcs(funcs).Parse(dirListingTemplate)
 698         if err != nil {
 699                 http.Error(w, "error parsing template: "+err.Error(), http.StatusInternalServerError)
 700                 return
 701         }
 702         sort.Slice(files, func(i, j int) bool {
 703                 return files[i].Name < files[j].Name
 704         })
 705         w.WriteHeader(http.StatusOK)
 706         tmpl.Execute(w, map[string]interface{}{
 707                 "CollectionName": collectionName,
 708                 "Files":          files,
 709                 "Request":        r,
 710                 "StripParts":     strings.Count(strings.TrimRight(r.URL.Path, "/"), "/"),
 711         })
 712 }
 713
 714 func applyContentDispositionHdr(w http.ResponseWriter, r *http.Request, filename string, isAttachment bool) {
 715         disposition := "inline"
 716         if isAttachment {
 717                 disposition = "attachment"
 718         }
 719         if strings.ContainsRune(r.RequestURI, '?') {
 720                 // Help the UA realize that the filename is just
 721                 // "filename.txt", not
 722                 // "filename.txt?disposition=attachment".
 723                 //
 724                 // TODO(TC): Follow advice at RFC 6266 appendix D
 725                 disposition += "; filename=" + strconv.QuoteToASCII(filename)
 726         }
 727         if disposition != "inline" {
 728                 w.Header().Set("Content-Disposition", disposition)
 729         }
 730 }
 731
 732 func (h *handler) seeOtherWithCookie(w http.ResponseWriter, r *http.Request, location string, credentialsOK bool) {
 733         if formToken := r.FormValue("api_token"); formToken != "" {
 734                 if !credentialsOK {
 735                         // It is not safe to copy the provided token
 736                         // into a cookie unless the current vhost
 737                         // (origin) serves only a single collection or
 738                         // we are in TrustAllContent mode.
 739                         http.Error(w, "cannot serve inline content at this URL (possible configuration error; see https://doc.arvados.org/install/install-keep-web.html#dns)", http.StatusBadRequest)
 740                         return
 741                 }
 742
 743                 // The HttpOnly flag is necessary to prevent
 744                 // JavaScript code (included in, or loaded by, a page
 745                 // in the collection being served) from employing the
 746                 // user's token beyond reading other files in the same
 747                 // domain, i.e., same collection.
 748                 //
 749                 // The 303 redirect is necessary in the case of a GET
 750                 // request to avoid exposing the token in the Location
 751                 // bar, and in the case of a POST request to avoid
 752                 // raising warnings when the user refreshes the
 753                 // resulting page.
 754                 http.SetCookie(w, &http.Cookie{
 755                         Name:     "arvados_api_token",
 756                         Value:    auth.EncodeTokenCookie([]byte(formToken)),
 757                         Path:     "/",
 758                         HttpOnly: true,
 759                 })
 760         }
 761
 762         // Propagate query parameters (except api_token) from
 763         // the original request.
 764         redirQuery := r.URL.Query()
 765         redirQuery.Del("api_token")
 766
 767         u := r.URL
 768         if location != "" {
 769                 newu, err := u.Parse(location)
 770                 if err != nil {
 771                         http.Error(w, "error resolving redirect target: "+err.Error(), http.StatusInternalServerError)
 772                         return
 773                 }
 774                 u = newu
 775         }
 776         redir := (&url.URL{
 777                 Scheme:   r.URL.Scheme,
 778                 Host:     r.Host,
 779                 Path:     u.Path,
 780                 RawQuery: redirQuery.Encode(),
 781         }).String()
 782
 783         w.Header().Add("Location", redir)
 784         w.WriteHeader(http.StatusSeeOther)
 785         io.WriteString(w, `<A href="`)
 786         io.WriteString(w, html.EscapeString(redir))
 787         io.WriteString(w, `">Continue</A>`)
 788 }