Fast and extensible multi-platform HTTP/1-2-3 web server with automatic HTTPS
Mirrored from https://github.com/Slazee/caddy.git
Synced Nov 11, 01:00 UTC
| 1 | // Copyright 2015 Matthew Holt and The Caddy Authors |
| 2 | // |
| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | // you may not use this file except in compliance with the License. |
| 5 | // You may obtain a copy of the License at |
| 6 | // |
| 7 | // http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | // |
| 9 | // Unless required by applicable law or agreed to in writing, software |
| 10 | // distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | // See the License for the specific language governing permissions and |
| 13 | // limitations under the License. |
| 14 | |
| 15 | package fileserver |
| 16 | |
| 17 | import ( |
| 18 | "bytes" |
| 19 | "context" |
| 20 | _ "embed" |
| 21 | "encoding/json" |
| 22 | "errors" |
| 23 | "fmt" |
| 24 | "io" |
| 25 | "io/fs" |
| 26 | "net/http" |
| 27 | "os" |
| 28 | "path" |
| 29 | "strings" |
| 30 | "sync" |
| 31 | "text/tabwriter" |
| 32 | "text/template" |
| 33 | "time" |
| 34 | |
| 35 | "go.uber.org/zap" |
| 36 | "go.uber.org/zap/zapcore" |
| 37 | |
| 38 | "github.com/caddyserver/caddy/v2" |
| 39 | "github.com/caddyserver/caddy/v2/modules/caddyhttp" |
| 40 | "github.com/caddyserver/caddy/v2/modules/caddyhttp/templates" |
| 41 | ) |
| 42 | |
| 43 | // BrowseTemplate is the default template document to use for |
| 44 | // file listings. By default, its default value is an embedded |
| 45 | // document. You can override this value at program start, or |
| 46 | // if you are running Caddy via config, you can specify a |
| 47 | // custom template_file in the browse configuration. |
| 48 | // |
| 49 | //go:embed browse.html |
| 50 | var BrowseTemplate string |
| 51 | |
| 52 | // Browse configures directory browsing. |
| 53 | type Browse struct { |
| 54 | // Filename of the template to use instead of the embedded browse template. |
| 55 | TemplateFile string `json:"template_file,omitempty"` |
| 56 | |
| 57 | // Determines whether or not targets of symlinks should be revealed. |
| 58 | RevealSymlinks bool `json:"reveal_symlinks,omitempty"` |
| 59 | |
| 60 | // Override the default sort. |
| 61 | // It includes the following options: |
| 62 | // - sort_by: name(default), namedirfirst, size, time |
| 63 | // - order: asc(default), desc |
| 64 | // eg.: |
| 65 | // - `sort time desc` will sort by time in descending order |
| 66 | // - `sort size` will sort by size in ascending order |
| 67 | // The first option must be `sort_by` and the second option must be `order` (if exists). |
| 68 | SortOptions []string `json:"sort,omitempty"` |
| 69 | |
| 70 | // FileLimit limits the number of up to n DirEntry values in directory order. |
| 71 | FileLimit int `json:"file_limit,omitempty"` |
| 72 | |
| 73 | // PlainTimeFormat specifies the Go time layout used for modification |
| 74 | // times in plain-text directory listings. The default layout is |
| 75 | // `January 2, 2006 at 15:04:05`. See |
| 76 | // [Go's time layout documentation](https://pkg.go.dev/time#pkg-constants). |
| 77 | PlainTimeFormat string `json:"plain_time_format,omitempty"` |
| 78 | } |
| 79 | |
| 80 | const ( |
| 81 | defaultDirEntryLimit = 10000 |
| 82 | defaultPlainTimeFormat = "January 2, 2006 at 15:04:05" |
| 83 | ) |
| 84 | |
| 85 | func (fsrv *FileServer) serveBrowse(fileSystem fs.FS, root, dirPath string, w http.ResponseWriter, r *http.Request, next caddyhttp.Handler) error { |
| 86 | if c := fsrv.logger.Check(zapcore.DebugLevel, "browse enabled; listing directory contents"); c != nil { |
| 87 | c.Write(zap.String("path", dirPath), zap.String("root", root)) |
| 88 | } |
| 89 | |
| 90 | // Navigation on the client-side gets messed up if the |
| 91 | // URL doesn't end in a trailing slash because hrefs to |
| 92 | // "b/c" at path "/a" end up going to "/b/c" instead |
| 93 | // of "/a/b/c" - so we have to redirect in this case |
| 94 | // so that the path is "/a/" and the client constructs |
| 95 | // relative hrefs "b/c" to be "/a/b/c". |
| 96 | // |
| 97 | // Only redirect if the last element of the path (the filename) was not |
| 98 | // rewritten; if the admin wanted to rewrite to the canonical path, they |
| 99 | // would have, and we have to be very careful not to introduce unwanted |
| 100 | // redirects and especially redirect loops! (Redirecting using the |
| 101 | // original URI is necessary because that's the URI the browser knows, |
| 102 | // we don't want to redirect from internally-rewritten URIs.) |
| 103 | // See https://github.com/caddyserver/caddy/issues/4205. |
| 104 | // We also redirect if the path is empty, because this implies the path |
| 105 | // prefix was fully stripped away by a `handle_path` handler for example. |
| 106 | // See https://github.com/caddyserver/caddy/issues/4466. |
| 107 | origReq := r.Context().Value(caddyhttp.OriginalRequestCtxKey).(http.Request) |
| 108 | if r.URL.Path == "" || path.Base(origReq.URL.Path) == path.Base(r.URL.Path) { |
| 109 | if !strings.HasSuffix(origReq.URL.Path, "/") { |
| 110 | if c := fsrv.logger.Check(zapcore.DebugLevel, "redirecting to trailing slash to preserve hrefs"); c != nil { |
| 111 | c.Write(zap.String("request_path", r.URL.Path)) |
| 112 | } |
| 113 | return redirect(w, r, origReq.URL.Path+"/") |
| 114 | } |
| 115 | } |
| 116 | |
| 117 | dir, err := fsrv.openFile(fileSystem, dirPath, w) |
| 118 | if err != nil { |
| 119 | return err |
| 120 | } |
| 121 | defer dir.Close() |
| 122 | |
| 123 | repl := r.Context().Value(caddy.ReplacerCtxKey).(*caddy.Replacer) |
| 124 | |
| 125 | // TODO: not entirely sure if path.Clean() is necessary here but seems like a safe plan (i.e. /%2e%2e%2f) - someone could verify this |
| 126 | listing, err := fsrv.loadDirectoryContents(r.Context(), fileSystem, dir.(fs.ReadDirFile), dirPath, path.Clean(r.URL.EscapedPath()), repl) |
| 127 | switch { |
| 128 | case errors.Is(err, fs.ErrPermission): |
| 129 | return caddyhttp.Error(http.StatusForbidden, err) |
| 130 | case errors.Is(err, fs.ErrNotExist): |
| 131 | return fsrv.notFound(w, r, next) |
| 132 | case err != nil: |
| 133 | return caddyhttp.Error(http.StatusInternalServerError, err) |
| 134 | } |
| 135 | |
| 136 | w.Header().Add("Vary", "Accept, Accept-Encoding") |
| 137 | |
| 138 | // speed up browser/client experience and caching by supporting If-Modified-Since |
| 139 | if ifModSinceStr := r.Header.Get("If-Modified-Since"); ifModSinceStr != "" { |
| 140 | // basically a copy of stdlib file server's handling of If-Modified-Since |
| 141 | ifModSince, err := http.ParseTime(ifModSinceStr) |
| 142 | if err == nil && listing.lastModified.Truncate(time.Second).Compare(ifModSince) <= 0 { |
| 143 | w.WriteHeader(http.StatusNotModified) |
| 144 | return nil |
| 145 | } |
| 146 | } |
| 147 | |
| 148 | fsrv.browseApplyQueryParams(w, r, listing) |
| 149 | |
| 150 | buf := bufPool.Get().(*bytes.Buffer) |
| 151 | buf.Reset() |
| 152 | defer bufPool.Put(buf) |
| 153 | |
| 154 | acceptHeader := strings.ToLower(strings.Join(r.Header["Accept"], ",")) |
| 155 | w.Header().Set("Last-Modified", listing.lastModified.Format(http.TimeFormat)) |
| 156 | |
| 157 | switch { |
| 158 | case strings.Contains(acceptHeader, "application/json"): |
| 159 | if err := json.NewEncoder(buf).Encode(listing.Items); err != nil { |
| 160 | return caddyhttp.Error(http.StatusInternalServerError, err) |
| 161 | } |
| 162 | w.Header().Set("Content-Type", "application/json; charset=utf-8") |
| 163 | |
| 164 | case strings.Contains(acceptHeader, "text/plain"): |
| 165 | writer := tabwriter.NewWriter(buf, 0, 8, 1, '\t', tabwriter.AlignRight) |
| 166 | |
| 167 | // Header on top |
| 168 | if _, err := fmt.Fprintln(writer, "Name\tSize\tModified"); err != nil { |
| 169 | return caddyhttp.Error(http.StatusInternalServerError, err) |
| 170 | } |
| 171 | |
| 172 | // Lines to separate the header |
| 173 | if _, err := fmt.Fprintln(writer, "----\t----\t--------"); err != nil { |
| 174 | return caddyhttp.Error(http.StatusInternalServerError, err) |
| 175 | } |
| 176 | |
| 177 | // Use the configured time format if specified, otherwise use the default |
| 178 | plainTimeFormat := defaultPlainTimeFormat |
| 179 | if fsrv.Browse.PlainTimeFormat != "" { |
| 180 | plainTimeFormat = fsrv.Browse.PlainTimeFormat |
| 181 | } |
| 182 | |
| 183 | // Actual files |
| 184 | for _, item := range listing.Items { |
| 185 | //nolint:gosec // not sure how this could be XSS unless you lose control of the file system (like aren't sanitizing) and client ignores Content-Type of text/plain |
| 186 | if _, err := fmt.Fprintf(writer, "%s\t%s\t%s\n", |
| 187 | item.Name, |
| 188 | item.HumanSize(), |
| 189 | item.HumanModTime(plainTimeFormat), |
| 190 | ); err != nil { |
| 191 | return caddyhttp.Error(http.StatusInternalServerError, err) |
| 192 | } |
| 193 | } |
| 194 | |
| 195 | if err := writer.Flush(); err != nil { |
| 196 | return caddyhttp.Error(http.StatusInternalServerError, err) |
| 197 | } |
| 198 | |
| 199 | w.Header().Set("Content-Type", "text/plain; charset=utf-8") |
| 200 | |
| 201 | default: |
| 202 | var fs http.FileSystem |
| 203 | if fsrv.Root != "" { |
| 204 | fs = http.Dir(repl.ReplaceAll(fsrv.Root, ".")) |
| 205 | } |
| 206 | |
| 207 | tplCtx := &templateContext{ |
| 208 | TemplateContext: templates.TemplateContext{ |
| 209 | Root: fs, |
| 210 | Req: r, |
| 211 | RespHeader: templates.WrappedHeader{Header: w.Header()}, |
| 212 | }, |
| 213 | browseTemplateContext: listing, |
| 214 | } |
| 215 | |
| 216 | tpl, err := fsrv.makeBrowseTemplate(tplCtx) |
| 217 | if err != nil { |
| 218 | return fmt.Errorf("parsing browse template: %v", err) |
| 219 | } |
| 220 | if err := tpl.Execute(buf, tplCtx); err != nil { |
| 221 | return caddyhttp.Error(http.StatusInternalServerError, err) |
| 222 | } |
| 223 | w.Header().Set("Content-Type", "text/html; charset=utf-8") |
| 224 | } |
| 225 | |
| 226 | _, _ = buf.WriteTo(w) |
| 227 | |
| 228 | return nil |
| 229 | } |
| 230 | |
| 231 | func (fsrv *FileServer) loadDirectoryContents(ctx context.Context, fileSystem fs.FS, dir fs.ReadDirFile, dirPath, urlPath string, repl *caddy.Replacer) (*browseTemplateContext, error) { |
| 232 | // modTime for the directory itself |
| 233 | stat, err := dir.Stat() |
| 234 | if err != nil { |
| 235 | return nil, err |
| 236 | } |
| 237 | dirLimit := defaultDirEntryLimit |
| 238 | if fsrv.Browse.FileLimit != 0 { |
| 239 | dirLimit = fsrv.Browse.FileLimit |
| 240 | } |
| 241 | files, err := dir.ReadDir(dirLimit) |
| 242 | if err != nil && err != io.EOF { |
| 243 | return nil, err |
| 244 | } |
| 245 | |
| 246 | // user can presumably browse "up" to parent folder if path is longer than "/" |
| 247 | canGoUp := len(urlPath) > 1 |
| 248 | |
| 249 | return fsrv.directoryListing(ctx, fileSystem, stat.ModTime(), files, canGoUp, dirPath, urlPath, repl), nil |
| 250 | } |
| 251 | |
| 252 | // browseApplyQueryParams applies query parameters to the listing. |
| 253 | // It mutates the listing and may set cookies. |
| 254 | func (fsrv *FileServer) browseApplyQueryParams(w http.ResponseWriter, r *http.Request, listing *browseTemplateContext) { |
| 255 | var orderParam, sortParam string |
| 256 | |
| 257 | // The configs in Caddyfile have lower priority than Query params, |
| 258 | // so put it at first. |
| 259 | for idx, item := range fsrv.Browse.SortOptions { |
| 260 | // Only `sort` & `order`, 2 params are allowed |
| 261 | if idx >= 2 { |
| 262 | break |
| 263 | } |
| 264 | switch item { |
| 265 | case sortByName, sortByNameDirFirst, sortBySize, sortByTime: |
| 266 | sortParam = item |
| 267 | case sortOrderAsc, sortOrderDesc: |
| 268 | orderParam = item |
| 269 | } |
| 270 | } |
| 271 | |
| 272 | layoutParam := r.URL.Query().Get("layout") |
| 273 | limitParam := r.URL.Query().Get("limit") |
| 274 | offsetParam := r.URL.Query().Get("offset") |
| 275 | sortParamTmp := r.URL.Query().Get("sort") |
| 276 | if sortParamTmp != "" { |
| 277 | sortParam = sortParamTmp |
| 278 | } |
| 279 | orderParamTmp := r.URL.Query().Get("order") |
| 280 | if orderParamTmp != "" { |
| 281 | orderParam = orderParamTmp |
| 282 | } |
| 283 | |
| 284 | switch layoutParam { |
| 285 | case "list", "grid", "": |
| 286 | listing.Layout = layoutParam |
| 287 | default: |
| 288 | listing.Layout = "list" |
| 289 | } |
| 290 | |
| 291 | // figure out what to sort by |
| 292 | switch sortParam { |
| 293 | case "": |
| 294 | sortParam = sortByNameDirFirst |
| 295 | if sortCookie, sortErr := r.Cookie("sort"); sortErr == nil { |
| 296 | sortParam = sortCookie.Value |
| 297 | } |
| 298 | case sortByName, sortByNameDirFirst, sortBySize, sortByTime: |
| 299 | http.SetCookie(w, &http.Cookie{ //nolint:gosec // Secure depends on whether the request itself used TLS |
| 300 | Name: "sort", |
| 301 | Value: sortParam, |
| 302 | Secure: r.TLS != nil, |
| 303 | HttpOnly: true, |
| 304 | SameSite: http.SameSiteLaxMode, |
| 305 | }) |
| 306 | } |
| 307 | |
| 308 | // then figure out the order |
| 309 | switch orderParam { |
| 310 | case "": |
| 311 | orderParam = sortOrderAsc |
| 312 | if orderCookie, orderErr := r.Cookie("order"); orderErr == nil { |
| 313 | orderParam = orderCookie.Value |
| 314 | } |
| 315 | case sortOrderAsc, sortOrderDesc: |
| 316 | http.SetCookie(w, &http.Cookie{ //nolint:gosec // Secure depends on whether the request itself used TLS |
| 317 | Name: "order", |
| 318 | Value: orderParam, |
| 319 | Secure: r.TLS != nil, |
| 320 | HttpOnly: true, |
| 321 | SameSite: http.SameSiteLaxMode, |
| 322 | }) |
| 323 | } |
| 324 | |
| 325 | // finally, apply the sorting and limiting |
| 326 | listing.applySortAndLimit(sortParam, orderParam, limitParam, offsetParam) |
| 327 | } |
| 328 | |
| 329 | // makeBrowseTemplate creates the template to be used for directory listings. |
| 330 | func (fsrv *FileServer) makeBrowseTemplate(tplCtx *templateContext) (*template.Template, error) { |
| 331 | var tpl *template.Template |
| 332 | var err error |
| 333 | |
| 334 | if fsrv.Browse.TemplateFile != "" { |
| 335 | tpl = tplCtx.NewTemplate(path.Base(fsrv.Browse.TemplateFile)) |
| 336 | tpl, err = tpl.ParseFiles(fsrv.Browse.TemplateFile) |
| 337 | if err != nil { |
| 338 | return nil, fmt.Errorf("parsing browse template file: %v", err) |
| 339 | } |
| 340 | } else { |
| 341 | tpl = tplCtx.NewTemplate("default_listing") |
| 342 | tpl, err = tpl.Parse(BrowseTemplate) |
| 343 | if err != nil { |
| 344 | return nil, fmt.Errorf("parsing default browse template: %v", err) |
| 345 | } |
| 346 | } |
| 347 | |
| 348 | return tpl, nil |
| 349 | } |
| 350 | |
| 351 | // isSymlink return true if f is a symbolic link. |
| 352 | func isSymlink(f fs.FileInfo) bool { |
| 353 | return f.Mode()&os.ModeSymlink != 0 |
| 354 | } |
| 355 | |
| 356 | // templateContext powers the context used when evaluating the browse template. |
| 357 | // It combines browse-specific features with the standard templates handler |
| 358 | // features. |
| 359 | type templateContext struct { |
| 360 | templates.TemplateContext |
| 361 | *browseTemplateContext |
| 362 | } |
| 363 | |
| 364 | // bufPool is used to increase the efficiency of file listings. |
| 365 | var bufPool = sync.Pool{ |
| 366 | New: func() any { |
| 367 | return new(bytes.Buffer) |
| 368 | }, |
| 369 | } |