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         "fmt"
  10         "html"
  11         "html/template"
  12         "io"
  13         "net/http"
  14         "net/url"
  15         "os"
  16         "path/filepath"
  17         "sort"
  18         "strconv"
  19         "strings"
  20         "sync"
  21
  22         "git.curoverse.com/arvados.git/sdk/go/arvados"
  23         "git.curoverse.com/arvados.git/sdk/go/arvadosclient"
  24         "git.curoverse.com/arvados.git/sdk/go/auth"
  25         "git.curoverse.com/arvados.git/sdk/go/health"
  26         "git.curoverse.com/arvados.git/sdk/go/httpserver"
  27         "git.curoverse.com/arvados.git/sdk/go/keepclient"
  28         log "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         h.clientPool = arvadosclient.MakeClientPool()
  80
  81         keepclient.RefreshServiceDiscoveryOnSIGHUP()
  82         keepclient.DefaultBlockCache.MaxBlocks = h.Config.cluster.Collections.WebDAVCache.MaxBlockEntries
  83
  84         h.healthHandler = &health.Handler{
  85                 Token:  h.Config.cluster.ManagementToken,
  86                 Prefix: "/_health/",
  87         }
  88
  89         // Even though we don't accept LOCK requests, every webdav
  90         // handler must have a non-nil LockSystem.
  91         h.webdavLS = &noLockSystem{}
  92 }
  93
  94 func (h *handler) serveStatus(w http.ResponseWriter, r *http.Request) {
  95         json.NewEncoder(w).Encode(struct{ Version string }{version})
  96 }
  97
  98 // updateOnSuccess wraps httpserver.ResponseWriter. If the handler
  99 // sends an HTTP header indicating success, updateOnSuccess first
 100 // calls the provided update func. If the update func fails, a 500
 101 // response is sent, and the status code and body sent by the handler
 102 // are ignored (all response writes return the update error).
 103 type updateOnSuccess struct {
 104         httpserver.ResponseWriter
 105         update     func() error
 106         sentHeader bool
 107         err        error
 108 }
 109
 110 func (uos *updateOnSuccess) Write(p []byte) (int, error) {
 111         if !uos.sentHeader {
 112                 uos.WriteHeader(http.StatusOK)
 113         }
 114         if uos.err != nil {
 115                 return 0, uos.err
 116         }
 117         return uos.ResponseWriter.Write(p)
 118 }
 119
 120 func (uos *updateOnSuccess) WriteHeader(code int) {
 121         if !uos.sentHeader {
 122                 uos.sentHeader = true
 123                 if code >= 200 && code < 400 {
 124                         if uos.err = uos.update(); uos.err != nil {
 125                                 code := http.StatusInternalServerError
 126                                 if err, ok := uos.err.(*arvados.TransactionError); ok {
 127                                         code = err.StatusCode
 128                                 }
 129                                 log.Printf("update() changes response to HTTP %d: %T %q", code, uos.err, uos.err)
 130                                 http.Error(uos.ResponseWriter, uos.err.Error(), code)
 131                                 return
 132                         }
 133                 }
 134         }
 135         uos.ResponseWriter.WriteHeader(code)
 136 }
 137
 138 var (
 139         corsAllowHeadersHeader = strings.Join([]string{
 140                 "Authorization", "Content-Type", "Range",
 141                 // WebDAV request headers:
 142                 "Depth", "Destination", "If", "Lock-Token", "Overwrite", "Timeout",
 143         }, ", ")
 144         writeMethod = map[string]bool{
 145                 "COPY":      true,
 146                 "DELETE":    true,
 147                 "LOCK":      true,
 148                 "MKCOL":     true,
 149                 "MOVE":      true,
 150                 "PROPPATCH": true,
 151                 "PUT":       true,
 152                 "RMCOL":     true,
 153                 "UNLOCK":    true,
 154         }
 155         webdavMethod = map[string]bool{
 156                 "COPY":      true,
 157                 "DELETE":    true,
 158                 "LOCK":      true,
 159                 "MKCOL":     true,
 160                 "MOVE":      true,
 161                 "OPTIONS":   true,
 162                 "PROPFIND":  true,
 163                 "PROPPATCH": true,
 164                 "PUT":       true,
 165                 "RMCOL":     true,
 166                 "UNLOCK":    true,
 167         }
 168         browserMethod = map[string]bool{
 169                 "GET":  true,
 170                 "HEAD": true,
 171                 "POST": true,
 172         }
 173         // top-level dirs to serve with siteFS
 174         siteFSDir = map[string]bool{
 175                 "":      true, // root directory
 176                 "by_id": true,
 177                 "users": true,
 178         }
 179 )
 180
 181 // ServeHTTP implements http.Handler.
 182 func (h *handler) ServeHTTP(wOrig http.ResponseWriter, r *http.Request) {
 183         h.setupOnce.Do(h.setup)
 184
 185         var statusCode = 0
 186         var statusText string
 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         defer func() {
 198                 if statusCode == 0 {
 199                         statusCode = w.WroteStatus()
 200                 } else if w.WroteStatus() == 0 {
 201                         w.WriteHeader(statusCode)
 202                 } else if w.WroteStatus() != statusCode {
 203                         log.WithField("RequestID", r.Header.Get("X-Request-Id")).Warn(
 204                                 fmt.Sprintf("Our status changed from %d to %d after we sent headers", w.WroteStatus(), statusCode))
 205                 }
 206                 if statusText == "" {
 207                         statusText = http.StatusText(statusCode)
 208                 }
 209         }()
 210
 211         if strings.HasPrefix(r.URL.Path, "/_health/") && r.Method == "GET" {
 212                 h.healthHandler.ServeHTTP(w, r)
 213                 return
 214         }
 215
 216         if method := r.Header.Get("Access-Control-Request-Method"); method != "" && r.Method == "OPTIONS" {
 217                 if !browserMethod[method] && !webdavMethod[method] {
 218                         statusCode = http.StatusMethodNotAllowed
 219                         return
 220                 }
 221                 w.Header().Set("Access-Control-Allow-Headers", corsAllowHeadersHeader)
 222                 w.Header().Set("Access-Control-Allow-Methods", "COPY, DELETE, GET, LOCK, MKCOL, MOVE, OPTIONS, POST, PROPFIND, PROPPATCH, PUT, RMCOL, UNLOCK")
 223                 w.Header().Set("Access-Control-Allow-Origin", "*")
 224                 w.Header().Set("Access-Control-Max-Age", "86400")
 225                 statusCode = http.StatusOK
 226                 return
 227         }
 228
 229         if !browserMethod[r.Method] && !webdavMethod[r.Method] {
 230                 statusCode, statusText = http.StatusMethodNotAllowed, r.Method
 231                 return
 232         }
 233
 234         if r.Header.Get("Origin") != "" {
 235                 // Allow simple cross-origin requests without user
 236                 // credentials ("user credentials" as defined by CORS,
 237                 // i.e., cookies, HTTP authentication, and client-side
 238                 // SSL certificates. See
 239                 // http://www.w3.org/TR/cors/#user-credentials).
 240                 w.Header().Set("Access-Control-Allow-Origin", "*")
 241                 w.Header().Set("Access-Control-Expose-Headers", "Content-Range")
 242         }
 243
 244         pathParts := strings.Split(r.URL.Path[1:], "/")
 245
 246         var stripParts int
 247         var collectionID string
 248         var tokens []string
 249         var reqTokens []string
 250         var pathToken bool
 251         var attachment bool
 252         var useSiteFS bool
 253         credentialsOK := h.Config.cluster.Collections.TrustAllContent
 254
 255         if r.Host != "" && r.Host == h.Config.cluster.Services.WebDAVDownload.ExternalURL.Host {
 256                 credentialsOK = true
 257                 attachment = true
 258         } else if r.FormValue("disposition") == "attachment" {
 259                 attachment = true
 260         }
 261
 262         if collectionID = parseCollectionIDFromDNSName(r.Host); collectionID != "" {
 263                 // http://ID.collections.example/PATH...
 264                 credentialsOK = true
 265         } else if r.URL.Path == "/status.json" {
 266                 h.serveStatus(w, r)
 267                 return
 268         } else if strings.HasPrefix(r.URL.Path, "/metrics") {
 269                 h.MetricsAPI.ServeHTTP(w, r)
 270                 return
 271         } else if siteFSDir[pathParts[0]] {
 272                 useSiteFS = true
 273         } else if len(pathParts) >= 1 && strings.HasPrefix(pathParts[0], "c=") {
 274                 // /c=ID[/PATH...]
 275                 collectionID = parseCollectionIDFromURL(pathParts[0][2:])
 276                 stripParts = 1
 277         } else if len(pathParts) >= 2 && pathParts[0] == "collections" {
 278                 if len(pathParts) >= 4 && pathParts[1] == "download" {
 279                         // /collections/download/ID/TOKEN/PATH...
 280                         collectionID = parseCollectionIDFromURL(pathParts[2])
 281                         tokens = []string{pathParts[3]}
 282                         stripParts = 4
 283                         pathToken = true
 284                 } else {
 285                         // /collections/ID/PATH...
 286                         collectionID = parseCollectionIDFromURL(pathParts[1])
 287                         stripParts = 2
 288                         // This path is only meant to work for public
 289                         // data. Tokens provided with the request are
 290                         // ignored.
 291                         credentialsOK = false
 292                 }
 293         }
 294
 295         if collectionID == "" && !useSiteFS {
 296                 statusCode = http.StatusNotFound
 297                 return
 298         }
 299
 300         forceReload := false
 301         if cc := r.Header.Get("Cache-Control"); strings.Contains(cc, "no-cache") || strings.Contains(cc, "must-revalidate") {
 302                 forceReload = true
 303         }
 304
 305         if credentialsOK {
 306                 reqTokens = auth.CredentialsFromRequest(r).Tokens
 307         }
 308
 309         formToken := r.FormValue("api_token")
 310         if formToken != "" && r.Header.Get("Origin") != "" && attachment && r.URL.Query().Get("api_token") == "" {
 311                 // The client provided an explicit token in the POST
 312                 // body. The Origin header indicates this *might* be
 313                 // an AJAX request, in which case redirect-with-cookie
 314                 // won't work: we should just serve the content in the
 315                 // POST response. This is safe because:
 316                 //
 317                 // * We're supplying an attachment, not inline
 318                 //   content, so we don't need to convert the POST to
 319                 //   a GET and avoid the "really resubmit form?"
 320                 //   problem.
 321                 //
 322                 // * The token isn't embedded in the URL, so we don't
 323                 //   need to worry about bookmarks and copy/paste.
 324                 reqTokens = append(reqTokens, formToken)
 325         } else if formToken != "" && browserMethod[r.Method] {
 326                 // The client provided an explicit token in the query
 327                 // string, or a form in POST body. We must put the
 328                 // token in an HttpOnly cookie, and redirect to the
 329                 // same URL with the query param redacted and method =
 330                 // GET.
 331                 h.seeOtherWithCookie(w, r, "", credentialsOK)
 332                 return
 333         }
 334
 335         if useSiteFS {
 336                 h.serveSiteFS(w, r, reqTokens, credentialsOK, attachment)
 337                 return
 338         }
 339
 340         targetPath := pathParts[stripParts:]
 341         if tokens == nil && len(targetPath) > 0 && strings.HasPrefix(targetPath[0], "t=") {
 342                 // http://ID.example/t=TOKEN/PATH...
 343                 // /c=ID/t=TOKEN/PATH...
 344                 //
 345                 // This form must only be used to pass scoped tokens
 346                 // that give permission for a single collection. See
 347                 // FormValue case above.
 348                 tokens = []string{targetPath[0][2:]}
 349                 pathToken = true
 350                 targetPath = targetPath[1:]
 351                 stripParts++
 352         }
 353
 354         if tokens == nil {
 355                 tokens = append(reqTokens, h.Config.cluster.Users.AnonymousUserToken)
 356         }
 357
 358         if len(targetPath) > 0 && targetPath[0] == "_" {
 359                 // If a collection has a directory called "t=foo" or
 360                 // "_", it can be served at
 361                 // //collections.example/_/t=foo/ or
 362                 // //collections.example/_/_/ respectively:
 363                 // //collections.example/t=foo/ won't work because
 364                 // t=foo will be interpreted as a token "foo".
 365                 targetPath = targetPath[1:]
 366                 stripParts++
 367         }
 368
 369         arv := h.clientPool.Get()
 370         if arv == nil {
 371                 statusCode, statusText = http.StatusInternalServerError, "Pool failed: "+h.clientPool.Err().Error()
 372                 return
 373         }
 374         defer h.clientPool.Put(arv)
 375
 376         var collection *arvados.Collection
 377         tokenResult := make(map[string]int)
 378         for _, arv.ApiToken = range tokens {
 379                 var err error
 380                 collection, err = h.Config.Cache.Get(arv, collectionID, forceReload)
 381                 if err == nil {
 382                         // Success
 383                         break
 384                 }
 385                 if srvErr, ok := err.(arvadosclient.APIServerError); ok {
 386                         switch srvErr.HttpStatusCode {
 387                         case 404, 401:
 388                                 // Token broken or insufficient to
 389                                 // retrieve collection
 390                                 tokenResult[arv.ApiToken] = srvErr.HttpStatusCode
 391                                 continue
 392                         }
 393                 }
 394                 // Something more serious is wrong
 395                 statusCode, statusText = http.StatusInternalServerError, err.Error()
 396                 return
 397         }
 398         if collection == nil {
 399                 if pathToken || !credentialsOK {
 400                         // Either the URL is a "secret sharing link"
 401                         // that didn't work out (and asking the client
 402                         // for additional credentials would just be
 403                         // confusing), or we don't even accept
 404                         // credentials at this path.
 405                         statusCode = http.StatusNotFound
 406                         return
 407                 }
 408                 for _, t := range reqTokens {
 409                         if tokenResult[t] == 404 {
 410                                 // The client provided valid token(s), but the
 411                                 // collection was not found.
 412                                 statusCode = http.StatusNotFound
 413                                 return
 414                         }
 415                 }
 416                 // The client's token was invalid (e.g., expired), or
 417                 // the client didn't even provide one.  Propagate the
 418                 // 401 to encourage the client to use a [different]
 419                 // token.
 420                 //
 421                 // TODO(TC): This response would be confusing to
 422                 // someone trying (anonymously) to download public
 423                 // data that has been deleted.  Allow a referrer to
 424                 // provide this context somehow?
 425                 w.Header().Add("WWW-Authenticate", "Basic realm=\"collections\"")
 426                 statusCode = http.StatusUnauthorized
 427                 return
 428         }
 429
 430         kc, err := keepclient.MakeKeepClient(arv)
 431         if err != nil {
 432                 statusCode, statusText = http.StatusInternalServerError, err.Error()
 433                 return
 434         }
 435         kc.RequestID = r.Header.Get("X-Request-Id")
 436
 437         var basename string
 438         if len(targetPath) > 0 {
 439                 basename = targetPath[len(targetPath)-1]
 440         }
 441         applyContentDispositionHdr(w, r, basename, attachment)
 442
 443         client := (&arvados.Client{
 444                 APIHost:   arv.ApiServer,
 445                 AuthToken: arv.ApiToken,
 446                 Insecure:  arv.ApiInsecure,
 447         }).WithRequestID(r.Header.Get("X-Request-Id"))
 448
 449         fs, err := collection.FileSystem(client, kc)
 450         if err != nil {
 451                 statusCode, statusText = http.StatusInternalServerError, err.Error()
 452                 return
 453         }
 454
 455         writefs, writeOK := fs.(arvados.CollectionFileSystem)
 456         targetIsPDH := arvadosclient.PDHMatch(collectionID)
 457         if (targetIsPDH || !writeOK) && writeMethod[r.Method] {
 458                 statusCode, statusText = http.StatusMethodNotAllowed, errReadOnly.Error()
 459                 return
 460         }
 461
 462         if webdavMethod[r.Method] {
 463                 if writeMethod[r.Method] {
 464                         // Save the collection only if/when all
 465                         // webdav->filesystem operations succeed --
 466                         // and send a 500 error if the modified
 467                         // collection can't be saved.
 468                         w = &updateOnSuccess{
 469                                 ResponseWriter: w,
 470                                 update: func() error {
 471                                         return h.Config.Cache.Update(client, *collection, writefs)
 472                                 }}
 473                 }
 474                 h := webdav.Handler{
 475                         Prefix: "/" + strings.Join(pathParts[:stripParts], "/"),
 476                         FileSystem: &webdavFS{
 477                                 collfs:        fs,
 478                                 writing:       writeMethod[r.Method],
 479                                 alwaysReadEOF: r.Method == "PROPFIND",
 480                         },
 481                         LockSystem: h.webdavLS,
 482                         Logger: func(_ *http.Request, err error) {
 483                                 if err != nil {
 484                                         log.Printf("error from webdav handler: %q", err)
 485                                 }
 486                         },
 487                 }
 488                 h.ServeHTTP(w, r)
 489                 return
 490         }
 491
 492         openPath := "/" + strings.Join(targetPath, "/")
 493         if f, err := fs.Open(openPath); os.IsNotExist(err) {
 494                 // Requested non-existent path
 495                 statusCode = http.StatusNotFound
 496         } else if err != nil {
 497                 // Some other (unexpected) error
 498                 statusCode, statusText = http.StatusInternalServerError, err.Error()
 499         } else if stat, err := f.Stat(); err != nil {
 500                 // Can't get Size/IsDir (shouldn't happen with a collectionFS!)
 501                 statusCode, statusText = http.StatusInternalServerError, err.Error()
 502         } else if stat.IsDir() && !strings.HasSuffix(r.URL.Path, "/") {
 503                 // If client requests ".../dirname", redirect to
 504                 // ".../dirname/". This way, relative links in the
 505                 // listing for "dirname" can always be "fnm", never
 506                 // "dirname/fnm".
 507                 h.seeOtherWithCookie(w, r, r.URL.Path+"/", credentialsOK)
 508         } else if stat.IsDir() {
 509                 h.serveDirectory(w, r, collection.Name, fs, openPath, true)
 510         } else {
 511                 http.ServeContent(w, r, basename, stat.ModTime(), f)
 512                 if r.Header.Get("Range") == "" && int64(w.WroteBodyBytes()) != stat.Size() {
 513                         // If we wrote fewer bytes than expected, it's
 514                         // too late to change the real response code
 515                         // or send an error message to the client, but
 516                         // at least we can try to put some useful
 517                         // debugging info in the logs.
 518                         n, err := f.Read(make([]byte, 1024))
 519                         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)
 520
 521                 }
 522         }
 523 }
 524
 525 func (h *handler) serveSiteFS(w http.ResponseWriter, r *http.Request, tokens []string, credentialsOK, attachment bool) {
 526         if len(tokens) == 0 {
 527                 w.Header().Add("WWW-Authenticate", "Basic realm=\"collections\"")
 528                 http.Error(w, http.StatusText(http.StatusUnauthorized), http.StatusUnauthorized)
 529                 return
 530         }
 531         if writeMethod[r.Method] {
 532                 http.Error(w, errReadOnly.Error(), http.StatusMethodNotAllowed)
 533                 return
 534         }
 535         arv := h.clientPool.Get()
 536         if arv == nil {
 537                 http.Error(w, "Pool failed: "+h.clientPool.Err().Error(), http.StatusInternalServerError)
 538                 return
 539         }
 540         defer h.clientPool.Put(arv)
 541         arv.ApiToken = tokens[0]
 542
 543         kc, err := keepclient.MakeKeepClient(arv)
 544         if err != nil {
 545                 http.Error(w, err.Error(), http.StatusInternalServerError)
 546                 return
 547         }
 548         kc.RequestID = r.Header.Get("X-Request-Id")
 549         client := (&arvados.Client{
 550                 APIHost:   arv.ApiServer,
 551                 AuthToken: arv.ApiToken,
 552                 Insecure:  arv.ApiInsecure,
 553         }).WithRequestID(r.Header.Get("X-Request-Id"))
 554         fs := client.SiteFileSystem(kc)
 555         f, err := fs.Open(r.URL.Path)
 556         if os.IsNotExist(err) {
 557                 http.Error(w, err.Error(), http.StatusNotFound)
 558                 return
 559         } else if err != nil {
 560                 http.Error(w, err.Error(), http.StatusInternalServerError)
 561                 return
 562         }
 563         defer f.Close()
 564         if fi, err := f.Stat(); err == nil && fi.IsDir() && r.Method == "GET" {
 565                 if !strings.HasSuffix(r.URL.Path, "/") {
 566                         h.seeOtherWithCookie(w, r, r.URL.Path+"/", credentialsOK)
 567                 } else {
 568                         h.serveDirectory(w, r, fi.Name(), fs, r.URL.Path, false)
 569                 }
 570                 return
 571         }
 572         if r.Method == "GET" {
 573                 _, basename := filepath.Split(r.URL.Path)
 574                 applyContentDispositionHdr(w, r, basename, attachment)
 575         }
 576         wh := webdav.Handler{
 577                 Prefix: "/",
 578                 FileSystem: &webdavFS{
 579                         collfs:        fs,
 580                         writing:       writeMethod[r.Method],
 581                         alwaysReadEOF: r.Method == "PROPFIND",
 582                 },
 583                 LockSystem: h.webdavLS,
 584                 Logger: func(_ *http.Request, err error) {
 585                         if err != nil {
 586                                 log.Printf("error from webdav handler: %q", err)
 587                         }
 588                 },
 589         }
 590         wh.ServeHTTP(w, r)
 591 }
 592
 593 var dirListingTemplate = `<!DOCTYPE HTML>
 594 <HTML><HEAD>
 595   <META name="robots" content="NOINDEX">
 596   <TITLE>{{ .CollectionName }}</TITLE>
 597   <STYLE type="text/css">
 598     body {
 599       margin: 1.5em;
 600     }
 601     pre {
 602       background-color: #D9EDF7;
 603       border-radius: .25em;
 604       padding: .75em;
 605       overflow: auto;
 606     }
 607     .footer p {
 608       font-size: 82%;
 609     }
 610     ul {
 611       padding: 0;
 612     }
 613     ul li {
 614       font-family: monospace;
 615       list-style: none;
 616     }
 617   </STYLE>
 618 </HEAD>
 619 <BODY>
 620
 621 <H1>{{ .CollectionName }}</H1>
 622
 623 <P>This collection of data files is being shared with you through
 624 Arvados.  You can download individual files listed below.  To download
 625 the entire directory tree with wget, try:</P>
 626
 627 <PRE>$ wget --mirror --no-parent --no-host --cut-dirs={{ .StripParts }} https://{{ .Request.Host }}{{ .Request.URL.Path }}</PRE>
 628
 629 <H2>File Listing</H2>
 630
 631 {{if .Files}}
 632 <UL>
 633 {{range .Files}}
 634 {{if .IsDir }}
 635   <LI>{{" " | printf "%15s  " | nbsp}}<A href="{{print "./" .Name}}/">{{.Name}}/</A></LI>
 636 {{else}}
 637   <LI>{{.Size | printf "%15d  " | nbsp}}<A href="{{print "./" .Name}}">{{.Name}}</A></LI>
 638 {{end}}
 639 {{end}}
 640 </UL>
 641 {{else}}
 642 <P>(No files; this collection is empty.)</P>
 643 {{end}}
 644
 645 <HR noshade>
 646 <DIV class="footer">
 647   <P>
 648     About Arvados:
 649     Arvados is a free and open source software bioinformatics platform.
 650     To learn more, visit arvados.org.
 651     Arvados is not responsible for the files listed on this page.
 652   </P>
 653 </DIV>
 654
 655 </BODY>
 656 `
 657
 658 type fileListEnt struct {
 659         Name  string
 660         Size  int64
 661         IsDir bool
 662 }
 663
 664 func (h *handler) serveDirectory(w http.ResponseWriter, r *http.Request, collectionName string, fs http.FileSystem, base string, recurse bool) {
 665         var files []fileListEnt
 666         var walk func(string) error
 667         if !strings.HasSuffix(base, "/") {
 668                 base = base + "/"
 669         }
 670         walk = func(path string) error {
 671                 dirname := base + path
 672                 if dirname != "/" {
 673                         dirname = strings.TrimSuffix(dirname, "/")
 674                 }
 675                 d, err := fs.Open(dirname)
 676                 if err != nil {
 677                         return err
 678                 }
 679                 ents, err := d.Readdir(-1)
 680                 if err != nil {
 681                         return err
 682                 }
 683                 for _, ent := range ents {
 684                         if recurse && ent.IsDir() {
 685                                 err = walk(path + ent.Name() + "/")
 686                                 if err != nil {
 687                                         return err
 688                                 }
 689                         } else {
 690                                 files = append(files, fileListEnt{
 691                                         Name:  path + ent.Name(),
 692                                         Size:  ent.Size(),
 693                                         IsDir: ent.IsDir(),
 694                                 })
 695                         }
 696                 }
 697                 return nil
 698         }
 699         if err := walk(""); err != nil {
 700                 http.Error(w, err.Error(), http.StatusInternalServerError)
 701                 return
 702         }
 703
 704         funcs := template.FuncMap{
 705                 "nbsp": func(s string) template.HTML {
 706                         return template.HTML(strings.Replace(s, " ", "&nbsp;", -1))
 707                 },
 708         }
 709         tmpl, err := template.New("dir").Funcs(funcs).Parse(dirListingTemplate)
 710         if err != nil {
 711                 http.Error(w, err.Error(), http.StatusInternalServerError)
 712                 return
 713         }
 714         sort.Slice(files, func(i, j int) bool {
 715                 return files[i].Name < files[j].Name
 716         })
 717         w.WriteHeader(http.StatusOK)
 718         tmpl.Execute(w, map[string]interface{}{
 719                 "CollectionName": collectionName,
 720                 "Files":          files,
 721                 "Request":        r,
 722                 "StripParts":     strings.Count(strings.TrimRight(r.URL.Path, "/"), "/"),
 723         })
 724 }
 725
 726 func applyContentDispositionHdr(w http.ResponseWriter, r *http.Request, filename string, isAttachment bool) {
 727         disposition := "inline"
 728         if isAttachment {
 729                 disposition = "attachment"
 730         }
 731         if strings.ContainsRune(r.RequestURI, '?') {
 732                 // Help the UA realize that the filename is just
 733                 // "filename.txt", not
 734                 // "filename.txt?disposition=attachment".
 735                 //
 736                 // TODO(TC): Follow advice at RFC 6266 appendix D
 737                 disposition += "; filename=" + strconv.QuoteToASCII(filename)
 738         }
 739         if disposition != "inline" {
 740                 w.Header().Set("Content-Disposition", disposition)
 741         }
 742 }
 743
 744 func (h *handler) seeOtherWithCookie(w http.ResponseWriter, r *http.Request, location string, credentialsOK bool) {
 745         if formToken := r.FormValue("api_token"); formToken != "" {
 746                 if !credentialsOK {
 747                         // It is not safe to copy the provided token
 748                         // into a cookie unless the current vhost
 749                         // (origin) serves only a single collection or
 750                         // we are in TrustAllContent mode.
 751                         w.WriteHeader(http.StatusBadRequest)
 752                         return
 753                 }
 754
 755                 // The HttpOnly flag is necessary to prevent
 756                 // JavaScript code (included in, or loaded by, a page
 757                 // in the collection being served) from employing the
 758                 // user's token beyond reading other files in the same
 759                 // domain, i.e., same collection.
 760                 //
 761                 // The 303 redirect is necessary in the case of a GET
 762                 // request to avoid exposing the token in the Location
 763                 // bar, and in the case of a POST request to avoid
 764                 // raising warnings when the user refreshes the
 765                 // resulting page.
 766                 http.SetCookie(w, &http.Cookie{
 767                         Name:     "arvados_api_token",
 768                         Value:    auth.EncodeTokenCookie([]byte(formToken)),
 769                         Path:     "/",
 770                         HttpOnly: true,
 771                 })
 772         }
 773
 774         // Propagate query parameters (except api_token) from
 775         // the original request.
 776         redirQuery := r.URL.Query()
 777         redirQuery.Del("api_token")
 778
 779         u := r.URL
 780         if location != "" {
 781                 newu, err := u.Parse(location)
 782                 if err != nil {
 783                         w.WriteHeader(http.StatusInternalServerError)
 784                         return
 785                 }
 786                 u = newu
 787         }
 788         redir := (&url.URL{
 789                 Scheme:   r.URL.Scheme,
 790                 Host:     r.Host,
 791                 Path:     u.Path,
 792                 RawQuery: redirQuery.Encode(),
 793         }).String()
 794
 795         w.Header().Add("Location", redir)
 796         w.WriteHeader(http.StatusSeeOther)
 797         io.WriteString(w, `<A href="`)
 798         io.WriteString(w, html.EscapeString(redir))
 799         io.WriteString(w, `">Continue</A>`)
 800 }