handler.go

   1 /*
   2 godlighty -- highly-customizable HTTP, HTTP/2, HTTPS server
   3 Copyright (C) 2021-2022 Sergey Matveev <stargrave@stargrave.org>
   4
   5 This program is free software: you can redistribute it and/or modify
   6 it under the terms of the GNU General Public License as published by
   7 the Free Software Foundation, version 3 of the License.
   8
   9 This program is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 GNU General Public License for more details.
  13
  14 You should have received a copy of the GNU General Public License
  15 along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16 */
  17
  18 package godlighty
  19
  20 import (
  21         "bytes"
  22         "compress/gzip"
  23         "encoding/base64"
  24         "errors"
  25         "fmt"
  26         "io/ioutil"
  27         "log"
  28         "net"
  29         "net/http"
  30         "net/url"
  31         "os"
  32         "path"
  33         "strconv"
  34         "strings"
  35         "sync"
  36         "time"
  37
  38         "github.com/klauspost/compress/zstd"
  39         "go.stargrave.org/godlighty/meta4"
  40         "golang.org/x/net/webdav"
  41 )
  42
  43 const (
  44         Index  = "index.html"
  45         Readme = "README"
  46 )
  47
  48 var (
  49         gzPool = sync.Pool{
  50                 New: func() interface{} { return gzip.NewWriter(ioutil.Discard) },
  51         }
  52         zstdPool = sync.Pool{
  53                 New: func() interface{} {
  54                         w, err := zstd.NewWriter(
  55                                 ioutil.Discard,
  56                                 zstd.WithEncoderLevel(zstd.SpeedDefault),
  57                         )
  58                         if err != nil {
  59                                 log.Fatalln(err)
  60                         }
  61                         return w
  62                 },
  63         }
  64
  65         MainHandler Handler
  66 )
  67
  68 func PathWithQuery(u *url.URL) string {
  69         if u.RawQuery == "" {
  70                 return u.EscapedPath()
  71         }
  72         return u.EscapedPath() + "?" + u.RawQuery
  73 }
  74
  75 type Handler struct{}
  76
  77 func (h Handler) Handle(
  78         w http.ResponseWriter, r *http.Request,
  79         host string, cfg *HostCfg,
  80 ) {
  81         notFound := func() {
  82                 fmt.Printf("%s %s \"%s %+q %s\" %d \"%s\"\n",
  83                         r.RemoteAddr, host, r.Method, PathWithQuery(r.URL), r.Proto,
  84                         http.StatusNotFound,
  85                         r.Header.Get("User-Agent"),
  86                 )
  87                 http.NotFound(w, r)
  88         }
  89         if cfg == nil {
  90                 notFound()
  91                 return
  92         }
  93
  94         var username string
  95         var err error
  96         if cfg.Auth != nil {
  97                 username, err = performAuth(w, r, cfg.Auth)
  98         }
  99         if username != "" {
 100                 username = "user:" + username + " "
 101         }
 102         printErr := func(code int, err error) {
 103                 fmt.Printf("%s %s \"%s %+q %s\" %d \"%s\" %s\"%s\"\n",
 104                         r.RemoteAddr, host, r.Method, PathWithQuery(r.URL), r.Proto,
 105                         code, err.Error(),
 106                         username, r.Header.Get("User-Agent"),
 107                 )
 108         }
 109         switch err {
 110         case nil:
 111                 break
 112         case Unauthorized:
 113                 printErr(http.StatusUnauthorized, err)
 114                 return
 115         default:
 116                 printErr(http.StatusInternalServerError, err)
 117                 http.Error(w, "internal error", http.StatusInternalServerError)
 118                 return
 119         }
 120
 121         if cfg.TLS != nil && len(cfg.TLS.ClientCAs) > 0 {
 122                 if r.TLS == nil {
 123                         err = errors.New("TLS client authentication required")
 124                         printErr(http.StatusForbidden, err)
 125                         http.Error(w, err.Error(), http.StatusForbidden)
 126                         return
 127                 } else {
 128                         username += r.TLS.PeerCertificates[0].Subject.String() + " "
 129                 }
 130         }
 131
 132         for _, hook := range cfg.Hooks {
 133                 if done := hook(w, r); done {
 134                         return
 135                 }
 136         }
 137
 138         if cfg.Root == "" {
 139                 notFound()
 140                 return
 141         }
 142
 143         if cfg.WebDAV && (r.Method == http.MethodHead ||
 144                 r.Method == http.MethodOptions ||
 145                 r.Method == "PROPFIND") {
 146                 dav := webdav.Handler{
 147                         FileSystem: webdav.Dir(cfg.Root),
 148                         LockSystem: webdav.NewMemLS(),
 149                 }
 150                 wc := &CountResponseWriter{ResponseWriter: w}
 151                 dav.ServeHTTP(wc, r)
 152                 fmt.Printf("%s %s \"WebDAV %+q\" %d %d %s\"%s\"\n",
 153                         r.RemoteAddr, host, PathWithQuery(r.URL),
 154                         wc.Status, wc.Size,
 155                         username, r.Header.Get("User-Agent"),
 156                 )
 157                 return
 158         }
 159
 160         if !(r.Method == "" || r.Method == http.MethodGet || r.Method == http.MethodHead) {
 161                 fmt.Printf("%s %s \"%s %+q %s\" %d %s\"%s\"\n",
 162                         r.RemoteAddr, host, r.Method, PathWithQuery(r.URL), r.Proto,
 163                         http.StatusMethodNotAllowed,
 164                         username, r.Header.Get("User-Agent"),
 165                 )
 166                 http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
 167                 return
 168         }
 169         var fd *os.File
 170         var contentType string
 171         var etag string
 172         pthOrig := path.Clean(path.Join(cfg.Root, r.URL.Path))
 173         pth := pthOrig
 174 IndexLookup:
 175         fi, err := os.Stat(pth)
 176         if err != nil {
 177                 notFound()
 178                 return
 179         }
 180         if fi.IsDir() {
 181                 if cfg.DirList {
 182                         entries, err := os.ReadDir(pth)
 183                         if err != nil {
 184                                 printErr(http.StatusInternalServerError, err)
 185                                 http.Error(w, "internal error", http.StatusInternalServerError)
 186                                 return
 187                         }
 188                         fd, err = os.Open(pth)
 189                         if err != nil {
 190                                 printErr(http.StatusInternalServerError, err)
 191                                 http.Error(w, "internal error", http.StatusInternalServerError)
 192                                 return
 193                         }
 194                         etag, err = ctimeETag(fd)
 195                         fd.Close()
 196                         if err != nil {
 197                                 printErr(http.StatusInternalServerError, err)
 198                                 http.Error(w, "internal error", http.StatusInternalServerError)
 199                                 return
 200                         }
 201                         var readme []byte
 202                         for _, f := range append(cfg.Readmes, Readme) {
 203                                 readme, _ = ioutil.ReadFile(path.Join(pth, f))
 204                                 if readme != nil {
 205                                         break
 206                                 }
 207                         }
 208                         fd, err = dirList(cfg, r.URL.Path, entries, string(readme))
 209                         if err != nil {
 210                                 printErr(http.StatusInternalServerError, err)
 211                                 http.Error(w, "internal error", http.StatusInternalServerError)
 212                                 return
 213                         }
 214                         contentType = "text/html; charset=utf-8"
 215                 } else {
 216                         for _, index := range append(cfg.Indices, Index) {
 217                                 p := path.Join(pth, index)
 218                                 if _, err := os.Stat(p); err == nil {
 219                                         pth = p
 220                                         goto IndexLookup
 221                                 }
 222                         }
 223                         notFound()
 224                         return
 225                 }
 226         }
 227
 228         if fd == nil {
 229                 fd, err = os.Open(pth)
 230                 if err != nil {
 231                         printErr(http.StatusInternalServerError, err)
 232                         http.Error(w, "internal error", http.StatusInternalServerError)
 233                         return
 234                 }
 235                 etag, err = ctimeETag(fd)
 236                 if err != nil {
 237                         printErr(http.StatusInternalServerError, err)
 238                         http.Error(w, "internal error", http.StatusInternalServerError)
 239                         return
 240                 }
 241         }
 242         defer fd.Close()
 243
 244         if meta4fi, err := os.Stat(pth + meta4.Ext); err == nil {
 245                 if meta4fi.Size() > meta4.MaxSize {
 246                         goto SkipMeta4
 247                 }
 248                 meta4Raw, err := ioutil.ReadFile(pth + meta4.Ext)
 249                 if err != nil {
 250                         goto SkipMeta4
 251                 }
 252                 base := path.Base(pth)
 253                 forHTTP, err := meta4.Parse(base, meta4Raw)
 254                 if err != nil {
 255                         goto SkipMeta4
 256                 }
 257                 w.Header().Add("Link", "<"+base+meta4.Ext+
 258                         `>; rel=describedby; type="application/metalink4+xml"`,
 259                 )
 260                 for _, u := range forHTTP.URLs {
 261                         w.Header().Add("Link", "<"+u+">; rel=duplicate")
 262                 }
 263                 if forHTTP.SHA256 != nil {
 264                         w.Header().Add("Digest", "SHA-256="+
 265                                 base64.StdEncoding.EncodeToString(forHTTP.SHA256))
 266                 }
 267                 if forHTTP.SHA512 != nil {
 268                         w.Header().Add("Digest", "SHA-512="+
 269                                 base64.StdEncoding.EncodeToString(forHTTP.SHA512))
 270                 }
 271         }
 272 SkipMeta4:
 273
 274         if contentType == "" {
 275                 contentType = mediaType(path.Base(pth), cfg.MIMEs)
 276         }
 277         contentTypeBase := strings.SplitN(contentType, ";", 2)[0]
 278         w.Header().Set("Content-Type", contentType)
 279
 280         w.Header().Set("Server", Version)
 281         if etag != "" {
 282                 w.Header().Set("ETag", etag)
 283         }
 284         var wc http.ResponseWriter
 285         var bufCompressed *bytes.Buffer
 286         var gz *gzip.Writer
 287         var zstdW *zstd.Encoder
 288         if _, ok := CompressibleContentTypes[contentTypeBase]; ok {
 289                 if strings.Contains(r.Header.Get("Accept-Encoding"), "zstd") {
 290                         w.Header().Set("Content-Encoding", "zstd")
 291                         zstdW = zstdPool.Get().(*zstd.Encoder)
 292                         defer zstdPool.Put(zstdW)
 293                         bufCompressed = &bytes.Buffer{}
 294                         zstdW.Reset(bufCompressed)
 295                         defer zstdW.Close()
 296                         wc = &gzipResponseWriter{ResponseWriter: w, Writer: zstdW}
 297                 } else if strings.Contains(r.Header.Get("Accept-Encoding"), "gzip") {
 298                         w.Header().Set("Content-Encoding", "gzip")
 299                         gz = gzPool.Get().(*gzip.Writer)
 300                         defer gzPool.Put(gz)
 301                         bufCompressed = &bytes.Buffer{}
 302                         gz.Reset(bufCompressed)
 303                         defer gz.Close()
 304                         wc = &gzipResponseWriter{ResponseWriter: w, Writer: gz}
 305                 } else {
 306                         wc = &CountResponseWriter{ResponseWriter: w}
 307                 }
 308         } else {
 309                 wc = &CountResponseWriter{ResponseWriter: w}
 310         }
 311         http.ServeContent(wc, r, "", fi.ModTime().UTC().Truncate(time.Second), fd)
 312         if bufCompressed != nil {
 313                 if gz != nil {
 314                         gz.Close()
 315                 }
 316                 if zstdW != nil {
 317                         zstdW.Close()
 318                 }
 319                 size := bufCompressed.Len()
 320                 w.Header().Set("Content-Length", strconv.Itoa(size))
 321                 wr := wc.(*gzipResponseWriter)
 322                 w.WriteHeader(wr.status)
 323                 w.Write(bufCompressed.Bytes())
 324                 fmt.Printf("%s %s \"%s %+q %s\" %d %d %s\"%s\"\n",
 325                         r.RemoteAddr, host, r.Method, PathWithQuery(r.URL), r.Proto,
 326                         wr.status, size,
 327                         username, r.Header.Get("User-Agent"),
 328                 )
 329                 return
 330         }
 331         wr := wc.(*CountResponseWriter)
 332         fmt.Printf("%s %s \"%s %+q %s\" %d %d %s\"%s\"\n",
 333                 r.RemoteAddr, host, r.Method, PathWithQuery(r.URL), r.Proto,
 334                 wr.Status, wr.Size,
 335                 username, r.Header.Get("User-Agent"),
 336         )
 337 }
 338
 339 func (h Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 340         if containsDotDot(r.URL.Path) {
 341                 http.Error(w, "invalid URL path", http.StatusBadRequest)
 342                 return
 343         }
 344         host, _, err := net.SplitHostPort(r.Host)
 345         if err != nil {
 346                 host = r.Host
 347         }
 348         h.Handle(w, r, host, Hosts[host])
 349 }