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
  83         h.healthHandler = &health.Handler{
  84                 Token:  h.Config.ManagementToken,
  85                 Prefix: "/_health/",
  86         }
  87
  88         // Even though we don't accept LOCK requests, every webdav
  89         // handler must have a non-nil LockSystem.
  90         h.webdavLS = &noLockSystem{}
  91 }
  92
  93 func (h *handler) serveStatus(w http.ResponseWriter, r *http.Request) {
  94         json.NewEncoder(w).Encode(struct{ Version string }{version})
  95 }
  96
  97 // updateOnSuccess wraps httpserver.ResponseWriter. If the handler
  98 // sends an HTTP header indicating success, updateOnSuccess first
  99 // calls the provided update func. If the update func fails, a 500
 100 // response is sent, and the status code and body sent by the handler
 101 // are ignored (all response writes return the update error).
 102 type updateOnSuccess struct {
 103         httpserver.ResponseWriter
 104         update     func() error
 105         sentHeader bool
 106         err        error
 107 }
 108
 109 func (uos *updateOnSuccess) Write(p []byte) (int, error) {
 110         if !uos.sentHeader {
 111                 uos.WriteHeader(http.StatusOK)
 112         }
 113         if uos.err != nil {
 114                 return 0, uos.err
 115         }
 116         return uos.ResponseWriter.Write(p)
 117 }
 118
 119 func (uos *updateOnSuccess) WriteHeader(code int) {
 120         if !uos.sentHeader {
 121                 uos.sentHeader = true
 122                 if code >= 200 && code < 400 {
 123                         if uos.err = uos.update(); uos.err != nil {
 124                                 code := http.StatusInternalServerError
 125                                 if err, ok := uos.err.(*arvados.TransactionError); ok {
 126                                         code = err.StatusCode
 127                                 }
 128                                 log.Printf("update() changes response to HTTP %d: %T %q", code, uos.err, uos.err)
 129                                 http.Error(uos.ResponseWriter, uos.err.Error(), code)
 130                                 return
 131                         }
 132                 }
 133         }
 134         uos.ResponseWriter.WriteHeader(code)
 135 }
 136
 137 var (
 138         corsAllowHeadersHeader = strings.Join([]string{
 139                 "Authorization", "Content-Type", "Range",
 140                 // WebDAV request headers:
 141                 "Depth", "Destination", "If", "Lock-Token", "Overwrite", "Timeout",
 142         }, ", ")
 143         writeMethod = map[string]bool{
 144                 "COPY":      true,
 145                 "DELETE":    true,
 146                 "LOCK":      true,
 147                 "MKCOL":     true,
 148                 "MOVE":      true,
 149                 "PROPPATCH": true,
 150                 "PUT":       true,
 151                 "RMCOL":     true,
 152                 "UNLOCK":    true,
 153         }
 154         webdavMethod = map[string]bool{
 155                 "COPY":      true,
 156                 "DELETE":    true,
 157                 "LOCK":      true,
 158                 "MKCOL":     true,
 159                 "MOVE":      true,
 160                 "OPTIONS":   true,
 161                 "PROPFIND":  true,
 162                 "PROPPATCH": true,
 163                 "PUT":       true,
 164                 "RMCOL":     true,
 165                 "UNLOCK":    true,
 166         }
 167         browserMethod = map[string]bool{
 168                 "GET":  true,
 169                 "HEAD": true,
 170                 "POST": true,
 171         }
 172         // top-level dirs to serve with siteFS
 173         siteFSDir = map[string]bool{
 174                 "":      true, // root directory
 175                 "by_id": true,
 176                 "users": true,
 177         }
 178 )
 179
 180 // ServeHTTP implements http.Handler.
 181 func (h *handler) ServeHTTP(wOrig http.ResponseWriter, r *http.Request) {
 182         h.setupOnce.Do(h.setup)
 183
 184         var statusCode = 0
 185         var statusText string
 186
 187         remoteAddr := r.RemoteAddr
 188         if xff := r.Header.Get("X-Forwarded-For"); xff != "" {
 189                 remoteAddr = xff + "," + remoteAddr
 190         }
 191         if xfp := r.Header.Get("X-Forwarded-Proto"); xfp != "" && xfp != "http" {
 192                 r.URL.Scheme = xfp
 193         }
 194
 195         w := httpserver.WrapResponseWriter(wOrig)
 196         defer func() {
 197                 if statusCode == 0 {
 198                         statusCode = w.WroteStatus()
 199                 } else if w.WroteStatus() == 0 {
 200                         w.WriteHeader(statusCode)
 201                 } else if w.WroteStatus() != statusCode {
 202                         log.WithField("RequestID", r.Header.Get("X-Request-Id")).Warn(
 203                                 fmt.Sprintf("Our status changed from %d to %d after we sent headers", w.WroteStatus(), statusCode))
 204                 }
 205                 if statusText == "" {
 206                         statusText = http.StatusText(statusCode)
 207                 }
 208         }()
 209
 210         if strings.HasPrefix(r.URL.Path, "/_health/") && r.Method == "GET" {
 211                 h.healthHandler.ServeHTTP(w, r)
 212                 return
 213         }
 214
 215         if method := r.Header.Get("Access-Control-Request-Method"); method != "" && r.Method == "OPTIONS" {
 216                 if !browserMethod[method] && !webdavMethod[method] {
 217                         statusCode = http.StatusMethodNotAllowed
 218                         return
 219                 }
 220                 w.Header().Set("Access-Control-Allow-Headers", corsAllowHeadersHeader)
 221                 w.Header().Set("Access-Control-Allow-Methods", "COPY, DELETE, GET, LOCK, MKCOL, MOVE, OPTIONS, POST, PROPFIND, PROPPATCH, PUT, RMCOL, UNLOCK")
 222                 w.Header().Set("Access-Control-Allow-Origin", "*")
 223                 w.Header().Set("Access-Control-Max-Age", "86400")
 224                 statusCode = http.StatusOK
 225                 return
 226         }
 227
 228         if !browserMethod[r.Method] && !webdavMethod[r.Method] {
 229                 statusCode, statusText = http.StatusMethodNotAllowed, r.Method
 230                 return
 231         }
 232
 233         if r.Header.Get("Origin") != "" {
 234                 // Allow simple cross-origin requests without user
 235                 // credentials ("user credentials" as defined by CORS,
 236                 // i.e., cookies, HTTP authentication, and client-side
 237                 // SSL certificates. See
 238                 // http://www.w3.org/TR/cors/#user-credentials).
 239                 w.Header().Set("Access-Control-Allow-Origin", "*")
 240                 w.Header().Set("Access-Control-Expose-Headers", "Content-Range")
 241         }
 242
 243         pathParts := strings.Split(r.URL.Path[1:], "/")
 244
 245         var stripParts int
 246         var collectionID string
 247         var tokens []string
 248         var reqTokens []string
 249         var pathToken bool
 250         var attachment bool
 251         var useSiteFS bool
 252         credentialsOK := h.Config.TrustAllContent
 253
 254         if r.Host != "" && r.Host == h.Config.AttachmentOnlyHost {
 255                 credentialsOK = true
 256                 attachment = true
 257         } else if r.FormValue("disposition") == "attachment" {
 258                 attachment = true
 259         }
 260
 261         if collectionID = parseCollectionIDFromDNSName(r.Host); collectionID != "" {
 262                 // http://ID.collections.example/PATH...
 263                 credentialsOK = true
 264         } else if r.URL.Path == "/status.json" {
 265                 h.serveStatus(w, r)
 266                 return
 267         } else if strings.HasPrefix(r.URL.Path, "/metrics") {
 268                 h.MetricsAPI.ServeHTTP(w, r)
 269                 return
 270         } else if siteFSDir[pathParts[0]] {
 271                 useSiteFS = true
 272         } else if len(pathParts) >= 1 && strings.HasPrefix(pathParts[0], "c=") {
 273                 // /c=ID[/PATH...]
 274                 collectionID = parseCollectionIDFromURL(pathParts[0][2:])
 275                 stripParts = 1
 276         } else if len(pathParts) >= 2 && pathParts[0] == "collections" {
 277                 if len(pathParts) >= 4 && pathParts[1] == "download" {
 278                         // /collections/download/ID/TOKEN/PATH...
 279                         collectionID = parseCollectionIDFromURL(pathParts[2])
 280                         tokens = []string{pathParts[3]}
 281                         stripParts = 4
 282                         pathToken = true
 283                 } else {
 284                         // /collections/ID/PATH...
 285                         collectionID = parseCollectionIDFromURL(pathParts[1])
 286                         tokens = h.Config.AnonymousTokens
 287                         stripParts = 2
 288                 }
 289         }
 290
 291         if collectionID == "" && !useSiteFS {
 292                 statusCode = http.StatusNotFound
 293                 return
 294         }
 295
 296         forceReload := false
 297         if cc := r.Header.Get("Cache-Control"); strings.Contains(cc, "no-cache") || strings.Contains(cc, "must-revalidate") {
 298                 forceReload = true
 299         }
 300
 301         formToken := r.FormValue("api_token")
 302         if formToken != "" && r.Header.Get("Origin") != "" && attachment && r.URL.Query().Get("api_token") == "" {
 303                 // The client provided an explicit token in the POST
 304                 // body. The Origin header indicates this *might* be
 305                 // an AJAX request, in which case redirect-with-cookie
 306                 // won't work: we should just serve the content in the
 307                 // POST response. This is safe because:
 308                 //
 309                 // * We're supplying an attachment, not inline
 310                 //   content, so we don't need to convert the POST to
 311                 //   a GET and avoid the "really resubmit form?"
 312                 //   problem.
 313                 //
 314                 // * The token isn't embedded in the URL, so we don't
 315                 //   need to worry about bookmarks and copy/paste.
 316                 tokens = append(tokens, formToken)
 317         } else if formToken != "" && browserMethod[r.Method] {
 318                 // The client provided an explicit token in the query
 319                 // string, or a form in POST body. We must put the
 320                 // token in an HttpOnly cookie, and redirect to the
 321                 // same URL with the query param redacted and method =
 322                 // GET.
 323                 h.seeOtherWithCookie(w, r, "", credentialsOK)
 324                 return
 325         }
 326
 327         if useSiteFS {
 328                 if tokens == nil {
 329                         tokens = auth.CredentialsFromRequest(r).Tokens
 330                 }
 331                 h.serveSiteFS(w, r, tokens, credentialsOK, attachment)
 332                 return
 333         }
 334
 335         targetPath := pathParts[stripParts:]
 336         if tokens == nil && len(targetPath) > 0 && strings.HasPrefix(targetPath[0], "t=") {
 337                 // http://ID.example/t=TOKEN/PATH...
 338                 // /c=ID/t=TOKEN/PATH...
 339                 //
 340                 // This form must only be used to pass scoped tokens
 341                 // that give permission for a single collection. See
 342                 // FormValue case above.
 343                 tokens = []string{targetPath[0][2:]}
 344                 pathToken = true
 345                 targetPath = targetPath[1:]
 346                 stripParts++
 347         }
 348
 349         if tokens == nil {
 350                 if credentialsOK {
 351                         reqTokens = auth.CredentialsFromRequest(r).Tokens
 352                 }
 353                 tokens = append(reqTokens, h.Config.AnonymousTokens...)
 354         }
 355
 356         if len(targetPath) > 0 && targetPath[0] == "_" {
 357                 // If a collection has a directory called "t=foo" or
 358                 // "_", it can be served at
 359                 // //collections.example/_/t=foo/ or
 360                 // //collections.example/_/_/ respectively:
 361                 // //collections.example/t=foo/ won't work because
 362                 // t=foo will be interpreted as a token "foo".
 363                 targetPath = targetPath[1:]
 364                 stripParts++
 365         }
 366
 367         arv := h.clientPool.Get()
 368         if arv == nil {
 369                 statusCode, statusText = http.StatusInternalServerError, "Pool failed: "+h.clientPool.Err().Error()
 370                 return
 371         }
 372         defer h.clientPool.Put(arv)
 373
 374         var collection *arvados.Collection
 375         tokenResult := make(map[string]int)
 376         for _, arv.ApiToken = range tokens {
 377                 var err error
 378                 collection, err = h.Config.Cache.Get(arv, collectionID, forceReload)
 379                 if err == nil {
 380                         // Success
 381                         break
 382                 }
 383                 if srvErr, ok := err.(arvadosclient.APIServerError); ok {
 384                         switch srvErr.HttpStatusCode {
 385                         case 404, 401:
 386                                 // Token broken or insufficient to
 387                                 // retrieve collection
 388                                 tokenResult[arv.ApiToken] = srvErr.HttpStatusCode
 389                                 continue
 390                         }
 391                 }
 392                 // Something more serious is wrong
 393                 statusCode, statusText = http.StatusInternalServerError, err.Error()
 394                 return
 395         }
 396         if collection == nil {
 397                 if pathToken || !credentialsOK {
 398                         // Either the URL is a "secret sharing link"
 399                         // that didn't work out (and asking the client
 400                         // for additional credentials would just be
 401                         // confusing), or we don't even accept
 402                         // credentials at this path.
 403                         statusCode = http.StatusNotFound
 404                         return
 405                 }
 406                 for _, t := range reqTokens {
 407                         if tokenResult[t] == 404 {
 408                                 // The client provided valid token(s), but the
 409                                 // collection was not found.
 410                                 statusCode = http.StatusNotFound
 411                                 return
 412                         }
 413                 }
 414                 // The client's token was invalid (e.g., expired), or
 415                 // the client didn't even provide one.  Propagate the
 416                 // 401 to encourage the client to use a [different]
 417                 // token.
 418                 //
 419                 // TODO(TC): This response would be confusing to
 420                 // someone trying (anonymously) to download public
 421                 // data that has been deleted.  Allow a referrer to
 422                 // provide this context somehow?
 423                 w.Header().Add("WWW-Authenticate", "Basic realm=\"collections\"")
 424                 statusCode = http.StatusUnauthorized
 425                 return
 426         }
 427
 428         kc, err := keepclient.MakeKeepClient(arv)
 429         if err != nil {
 430                 statusCode, statusText = http.StatusInternalServerError, err.Error()
 431                 return
 432         }
 433         kc.RequestID = r.Header.Get("X-Request-Id")
 434
 435         var basename string
 436         if len(targetPath) > 0 {
 437                 basename = targetPath[len(targetPath)-1]
 438         }
 439         applyContentDispositionHdr(w, r, basename, attachment)
 440
 441         client := (&arvados.Client{
 442                 APIHost:   arv.ApiServer,
 443                 AuthToken: arv.ApiToken,
 444                 Insecure:  arv.ApiInsecure,
 445         }).WithRequestID(r.Header.Get("X-Request-Id"))
 446
 447         fs, err := collection.FileSystem(client, kc)
 448         if err != nil {
 449                 statusCode, statusText = http.StatusInternalServerError, err.Error()
 450                 return
 451         }
 452
 453         writefs, writeOK := fs.(arvados.CollectionFileSystem)
 454         targetIsPDH := arvadosclient.PDHMatch(collectionID)
 455         if (targetIsPDH || !writeOK) && writeMethod[r.Method] {
 456                 statusCode, statusText = http.StatusMethodNotAllowed, errReadOnly.Error()
 457                 return
 458         }
 459
 460         if webdavMethod[r.Method] {
 461                 if writeMethod[r.Method] {
 462                         // Save the collection only if/when all
 463                         // webdav->filesystem operations succeed --
 464                         // and send a 500 error if the modified
 465                         // collection can't be saved.
 466                         w = &updateOnSuccess{
 467                                 ResponseWriter: w,
 468                                 update: func() error {
 469                                         return h.Config.Cache.Update(client, *collection, writefs)
 470                                 }}
 471                 }
 472                 h := webdav.Handler{
 473                         Prefix: "/" + strings.Join(pathParts[:stripParts], "/"),
 474                         FileSystem: &webdavFS{
 475                                 collfs:        fs,
 476                                 writing:       writeMethod[r.Method],
 477                                 alwaysReadEOF: r.Method == "PROPFIND",
 478                         },
 479                         LockSystem: h.webdavLS,
 480                         Logger: func(_ *http.Request, err error) {
 481                                 if err != nil {
 482                                         log.Printf("error from webdav handler: %q", err)
 483                                 }
 484                         },
 485                 }
 486                 h.ServeHTTP(w, r)
 487                 return
 488         }
 489
 490         openPath := "/" + strings.Join(targetPath, "/")
 491         if f, err := fs.Open(openPath); os.IsNotExist(err) {
 492                 // Requested non-existent path
 493                 statusCode = http.StatusNotFound
 494         } else if err != nil {
 495                 // Some other (unexpected) error
 496                 statusCode, statusText = http.StatusInternalServerError, err.Error()
 497         } else if stat, err := f.Stat(); err != nil {
 498                 // Can't get Size/IsDir (shouldn't happen with a collectionFS!)
 499                 statusCode, statusText = http.StatusInternalServerError, err.Error()
 500         } else if stat.IsDir() && !strings.HasSuffix(r.URL.Path, "/") {
 501                 // If client requests ".../dirname", redirect to
 502                 // ".../dirname/". This way, relative links in the
 503                 // listing for "dirname" can always be "fnm", never
 504                 // "dirname/fnm".
 505                 h.seeOtherWithCookie(w, r, r.URL.Path+"/", credentialsOK)
 506         } else if stat.IsDir() {
 507                 h.serveDirectory(w, r, collection.Name, fs, openPath, true)
 508         } else {
 509                 http.ServeContent(w, r, basename, stat.ModTime(), f)
 510                 if r.Header.Get("Range") == "" && int64(w.WroteBodyBytes()) != stat.Size() {
 511                         // If we wrote fewer bytes than expected, it's
 512                         // too late to change the real response code
 513                         // or send an error message to the client, but
 514                         // at least we can try to put some useful
 515                         // debugging info in the logs.
 516                         n, err := f.Read(make([]byte, 1024))
 517                         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)
 518
 519                 }
 520         }
 521 }
 522
 523 func (h *handler) serveSiteFS(w http.ResponseWriter, r *http.Request, tokens []string, credentialsOK, attachment bool) {
 524         if len(tokens) == 0 {
 525                 w.Header().Add("WWW-Authenticate", "Basic realm=\"collections\"")
 526                 http.Error(w, http.StatusText(http.StatusUnauthorized), http.StatusUnauthorized)
 527                 return
 528         }
 529         if writeMethod[r.Method] {
 530                 http.Error(w, errReadOnly.Error(), http.StatusMethodNotAllowed)
 531                 return
 532         }
 533         arv := h.clientPool.Get()
 534         if arv == nil {
 535                 http.Error(w, "Pool failed: "+h.clientPool.Err().Error(), http.StatusInternalServerError)
 536                 return
 537         }
 538         defer h.clientPool.Put(arv)
 539         arv.ApiToken = tokens[0]
 540
 541         kc, err := keepclient.MakeKeepClient(arv)
 542         if err != nil {
 543                 http.Error(w, err.Error(), http.StatusInternalServerError)
 544                 return
 545         }
 546         kc.RequestID = r.Header.Get("X-Request-Id")
 547         client := (&arvados.Client{
 548                 APIHost:   arv.ApiServer,
 549                 AuthToken: arv.ApiToken,
 550                 Insecure:  arv.ApiInsecure,
 551         }).WithRequestID(r.Header.Get("X-Request-Id"))
 552         fs := client.SiteFileSystem(kc)
 553         f, err := fs.Open(r.URL.Path)
 554         if os.IsNotExist(err) {
 555                 http.Error(w, err.Error(), http.StatusNotFound)
 556                 return
 557         } else if err != nil {
 558                 http.Error(w, err.Error(), http.StatusInternalServerError)
 559                 return
 560         }
 561         defer f.Close()
 562         if fi, err := f.Stat(); err == nil && fi.IsDir() && r.Method == "GET" {
 563                 if !strings.HasSuffix(r.URL.Path, "/") {
 564                         h.seeOtherWithCookie(w, r, r.URL.Path+"/", credentialsOK)
 565                 } else {
 566                         h.serveDirectory(w, r, fi.Name(), fs, r.URL.Path, false)
 567                 }
 568                 return
 569         }
 570         if r.Method == "GET" {
 571                 _, basename := filepath.Split(r.URL.Path)
 572                 applyContentDispositionHdr(w, r, basename, attachment)
 573         }
 574         wh := webdav.Handler{
 575                 Prefix: "/",
 576                 FileSystem: &webdavFS{
 577                         collfs:        fs,
 578                         writing:       writeMethod[r.Method],
 579                         alwaysReadEOF: r.Method == "PROPFIND",
 580                 },
 581                 LockSystem: h.webdavLS,
 582                 Logger: func(_ *http.Request, err error) {
 583                         if err != nil {
 584                                 log.Printf("error from webdav handler: %q", err)
 585                         }
 586                 },
 587         }
 588         wh.ServeHTTP(w, r)
 589 }
 590
 591 var dirListingTemplate = `<!DOCTYPE HTML>
 592 <HTML><HEAD>
 593   <META name="robots" content="NOINDEX">
 594   <TITLE>{{ .CollectionName }}</TITLE>
 595   <STYLE type="text/css">
 596     body {
 597       margin: 1.5em;
 598     }
 599     pre {
 600       background-color: #D9EDF7;
 601       border-radius: .25em;
 602       padding: .75em;
 603       overflow: auto;
 604     }
 605     .footer p {
 606       font-size: 82%;
 607     }
 608     ul {
 609       padding: 0;
 610     }
 611     ul li {
 612       font-family: monospace;
 613       list-style: none;
 614     }
 615   </STYLE>
 616 </HEAD>
 617 <BODY>
 618
 619 <H1>{{ .CollectionName }}</H1>
 620
 621 <P>This collection of data files is being shared with you through
 622 Arvados.  You can download individual files listed below.  To download
 623 the entire directory tree with wget, try:</P>
 624
 625 <PRE>$ wget --mirror --no-parent --no-host --cut-dirs={{ .StripParts }} https://{{ .Request.Host }}{{ .Request.URL.Path }}</PRE>
 626
 627 <H2>File Listing</H2>
 628
 629 {{if .Files}}
 630 <UL>
 631 {{range .Files}}
 632 {{if .IsDir }}
 633   <LI>{{" " | printf "%15s  " | nbsp}}<A href="{{print "./" .Name}}/">{{.Name}}/</A></LI>
 634 {{else}}
 635   <LI>{{.Size | printf "%15d  " | nbsp}}<A href="{{print "./" .Name}}">{{.Name}}</A></LI>
 636 {{end}}
 637 {{end}}
 638 </UL>
 639 {{else}}
 640 <P>(No files; this collection is empty.)</P>
 641 {{end}}
 642
 643 <HR noshade>
 644 <DIV class="footer">
 645   <P>
 646     About Arvados:
 647     Arvados is a free and open source software bioinformatics platform.
 648     To learn more, visit arvados.org.
 649     Arvados is not responsible for the files listed on this page.
 650   </P>
 651 </DIV>
 652
 653 </BODY>
 654 `
 655
 656 type fileListEnt struct {
 657         Name  string
 658         Size  int64
 659         IsDir bool
 660 }
 661
 662 func (h *handler) serveDirectory(w http.ResponseWriter, r *http.Request, collectionName string, fs http.FileSystem, base string, recurse bool) {
 663         var files []fileListEnt
 664         var walk func(string) error
 665         if !strings.HasSuffix(base, "/") {
 666                 base = base + "/"
 667         }
 668         walk = func(path string) error {
 669                 dirname := base + path
 670                 if dirname != "/" {
 671                         dirname = strings.TrimSuffix(dirname, "/")
 672                 }
 673                 d, err := fs.Open(dirname)
 674                 if err != nil {
 675                         return err
 676                 }
 677                 ents, err := d.Readdir(-1)
 678                 if err != nil {
 679                         return err
 680                 }
 681                 for _, ent := range ents {
 682                         if recurse && ent.IsDir() {
 683                                 err = walk(path + ent.Name() + "/")
 684                                 if err != nil {
 685                                         return err
 686                                 }
 687                         } else {
 688                                 files = append(files, fileListEnt{
 689                                         Name:  path + ent.Name(),
 690                                         Size:  ent.Size(),
 691                                         IsDir: ent.IsDir(),
 692                                 })
 693                         }
 694                 }
 695                 return nil
 696         }
 697         if err := walk(""); err != nil {
 698                 http.Error(w, err.Error(), http.StatusInternalServerError)
 699                 return
 700         }
 701
 702         funcs := template.FuncMap{
 703                 "nbsp": func(s string) template.HTML {
 704                         return template.HTML(strings.Replace(s, " ", "&nbsp;", -1))
 705                 },
 706         }
 707         tmpl, err := template.New("dir").Funcs(funcs).Parse(dirListingTemplate)
 708         if err != nil {
 709                 http.Error(w, err.Error(), http.StatusInternalServerError)
 710                 return
 711         }
 712         sort.Slice(files, func(i, j int) bool {
 713                 return files[i].Name < files[j].Name
 714         })
 715         w.WriteHeader(http.StatusOK)
 716         tmpl.Execute(w, map[string]interface{}{
 717                 "CollectionName": collectionName,
 718                 "Files":          files,
 719                 "Request":        r,
 720                 "StripParts":     strings.Count(strings.TrimRight(r.URL.Path, "/"), "/"),
 721         })
 722 }
 723
 724 func applyContentDispositionHdr(w http.ResponseWriter, r *http.Request, filename string, isAttachment bool) {
 725         disposition := "inline"
 726         if isAttachment {
 727                 disposition = "attachment"
 728         }
 729         if strings.ContainsRune(r.RequestURI, '?') {
 730                 // Help the UA realize that the filename is just
 731                 // "filename.txt", not
 732                 // "filename.txt?disposition=attachment".
 733                 //
 734                 // TODO(TC): Follow advice at RFC 6266 appendix D
 735                 disposition += "; filename=" + strconv.QuoteToASCII(filename)
 736         }
 737         if disposition != "inline" {
 738                 w.Header().Set("Content-Disposition", disposition)
 739         }
 740 }
 741
 742 func (h *handler) seeOtherWithCookie(w http.ResponseWriter, r *http.Request, location string, credentialsOK bool) {
 743         if formToken := r.FormValue("api_token"); formToken != "" {
 744                 if !credentialsOK {
 745                         // It is not safe to copy the provided token
 746                         // into a cookie unless the current vhost
 747                         // (origin) serves only a single collection or
 748                         // we are in TrustAllContent mode.
 749                         w.WriteHeader(http.StatusBadRequest)
 750                         return
 751                 }
 752
 753                 // The HttpOnly flag is necessary to prevent
 754                 // JavaScript code (included in, or loaded by, a page
 755                 // in the collection being served) from employing the
 756                 // user's token beyond reading other files in the same
 757                 // domain, i.e., same collection.
 758                 //
 759                 // The 303 redirect is necessary in the case of a GET
 760                 // request to avoid exposing the token in the Location
 761                 // bar, and in the case of a POST request to avoid
 762                 // raising warnings when the user refreshes the
 763                 // resulting page.
 764                 http.SetCookie(w, &http.Cookie{
 765                         Name:     "arvados_api_token",
 766                         Value:    auth.EncodeTokenCookie([]byte(formToken)),
 767                         Path:     "/",
 768                         HttpOnly: true,
 769                 })
 770         }
 771
 772         // Propagate query parameters (except api_token) from
 773         // the original request.
 774         redirQuery := r.URL.Query()
 775         redirQuery.Del("api_token")
 776
 777         u := r.URL
 778         if location != "" {
 779                 newu, err := u.Parse(location)
 780                 if err != nil {
 781                         w.WriteHeader(http.StatusInternalServerError)
 782                         return
 783                 }
 784                 u = newu
 785         }
 786         redir := (&url.URL{
 787                 Scheme:   r.URL.Scheme,
 788                 Host:     r.Host,
 789                 Path:     u.Path,
 790                 RawQuery: redirQuery.Encode(),
 791         }).String()
 792
 793         w.Header().Add("Location", redir)
 794         w.WriteHeader(http.StatusSeeOther)
 795         io.WriteString(w, `<A href="`)
 796         io.WriteString(w, html.EscapeString(redir))
 797         io.WriteString(w, `">Continue</A>`)
 798 }