handler.go

   1 /*
   2 godlighty -- highly-customizable HTTP, HTTP/2, HTTPS server
   3 Copyright (C) 2021 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         "fmt"
  24         "io/ioutil"
  25         "log"
  26         "net/http"
  27         "os"
  28         "path"
  29         "strconv"
  30         "strings"
  31         "sync"
  32         "time"
  33
  34         "github.com/klauspost/compress/zstd"
  35         "golang.org/x/net/webdav"
  36 )
  37
  38 const (
  39         Index    = "index.html"
  40         Readme   = "README"
  41         Meta4Ext = ".meta4"
  42 )
  43
  44 var (
  45         CompressibleContentTypes = make(map[string]struct{})
  46
  47         gzPool = sync.Pool{
  48                 New: func() interface{} { return gzip.NewWriter(ioutil.Discard) },
  49         }
  50         zstdPool = sync.Pool{
  51                 New: func() interface{} {
  52                         w, err := zstd.NewWriter(
  53                                 ioutil.Discard,
  54                                 zstd.WithEncoderLevel(zstd.SpeedDefault),
  55                         )
  56                         if err != nil {
  57                                 log.Fatalln(err)
  58                         }
  59                         return w
  60                 },
  61         }
  62
  63         MainHandler Handler
  64 )
  65
  66 type Handler struct{}
  67
  68 func (h Handler) Handle(
  69         w http.ResponseWriter, r *http.Request,
  70         host string, cfg *HostCfg,
  71 ) {
  72         notFound := func() {
  73                 fmt.Printf("%s %s \"%s %s %s\" %d \"%s\"\n",
  74                         r.RemoteAddr, host, r.Method, r.URL.Path, r.Proto,
  75                         http.StatusNotFound,
  76                         r.Header.Get("User-Agent"),
  77                 )
  78                 http.NotFound(w, r)
  79         }
  80         if cfg == nil {
  81                 notFound()
  82                 return
  83         }
  84
  85         for _, hook := range cfg.Hooks {
  86                 if done := hook(w, r); done {
  87                         return
  88                 }
  89         }
  90
  91         printErr := func(code int, err error) {
  92                 fmt.Printf("%s %s \"%s %s %s\" %d \"%s\" \"%s\"\n",
  93                         r.RemoteAddr, host, r.Method, r.URL.Path, r.Proto,
  94                         code, err.Error(),
  95                         r.Header.Get("User-Agent"),
  96                 )
  97         }
  98
  99         if cfg.Root == "" {
 100                 notFound()
 101                 return
 102         }
 103
 104         if cfg.WebDAV && (r.Method == http.MethodHead ||
 105                 r.Method == http.MethodOptions ||
 106                 r.Method == "PROPFIND") {
 107                 dav := webdav.Handler{
 108                         FileSystem: webdav.Dir(cfg.Root),
 109                         LockSystem: webdav.NewMemLS(),
 110                 }
 111                 wc := &CountResponseWriter{ResponseWriter: w}
 112                 dav.ServeHTTP(wc, r)
 113                 fmt.Printf("%s %s \"WebDAV %s\" %d %d \"%s\"\n",
 114                         r.RemoteAddr, host, r.URL.Path,
 115                         wc.Status, wc.Size,
 116                         r.Header.Get("User-Agent"),
 117                 )
 118                 return
 119         }
 120
 121         if !(r.Method == "" || r.Method == http.MethodGet) {
 122                 fmt.Printf("%s %s \"%s %s %s\" %d \"%s\"\n",
 123                         r.RemoteAddr, host, r.Method, r.URL.Path, r.Proto,
 124                         http.StatusMethodNotAllowed,
 125                         r.Header.Get("User-Agent"),
 126                 )
 127                 http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
 128                 return
 129         }
 130         var fd *os.File
 131         var contentType string
 132         var etag string
 133         pthOrig := path.Clean(path.Join(cfg.Root, r.URL.Path))
 134         pth := pthOrig
 135 IndexLookup:
 136         fi, err := os.Stat(pth)
 137         if err != nil {
 138                 notFound()
 139                 return
 140         }
 141         if fi.IsDir() {
 142                 if cfg.DirList {
 143                         entries, err := os.ReadDir(pth)
 144                         if err != nil {
 145                                 printErr(http.StatusInternalServerError, err)
 146                                 http.Error(w, "internal error", http.StatusInternalServerError)
 147                                 return
 148                         }
 149                         fd, err = os.Open(pth)
 150                         if err != nil {
 151                                 printErr(http.StatusInternalServerError, err)
 152                                 http.Error(w, "internal error", http.StatusInternalServerError)
 153                                 return
 154                         }
 155                         etag, err = ctimeETag(fd)
 156                         fd.Close()
 157                         if err != nil {
 158                                 printErr(http.StatusInternalServerError, err)
 159                                 http.Error(w, "internal error", http.StatusInternalServerError)
 160                                 return
 161                         }
 162                         var readme []byte
 163                         for _, f := range append(cfg.Readmes, Readme) {
 164                                 readme, _ = ioutil.ReadFile(path.Join(pth, f))
 165                                 if readme != nil {
 166                                         break
 167                                 }
 168                         }
 169                         fd, err = dirList(cfg, r.URL.Path, entries, string(readme))
 170                         if err != nil {
 171                                 printErr(http.StatusInternalServerError, err)
 172                                 http.Error(w, "internal error", http.StatusInternalServerError)
 173                                 return
 174                         }
 175                         contentType = "text/html; charset=utf-8"
 176                 } else {
 177                         for _, index := range append(cfg.Indexes, Index) {
 178                                 p := path.Join(pth, index)
 179                                 if _, err := os.Stat(p); err == nil {
 180                                         pth = p
 181                                         goto IndexLookup
 182                                 }
 183                         }
 184                         notFound()
 185                         return
 186                 }
 187         }
 188
 189         if fd == nil {
 190                 fd, err = os.Open(pth)
 191                 if err != nil {
 192                         printErr(http.StatusInternalServerError, err)
 193                         http.Error(w, "internal error", http.StatusInternalServerError)
 194                         return
 195                 }
 196                 etag, err = ctimeETag(fd)
 197                 if err != nil {
 198                         printErr(http.StatusInternalServerError, err)
 199                         http.Error(w, "internal error", http.StatusInternalServerError)
 200                         return
 201                 }
 202         }
 203         defer fd.Close()
 204
 205         if _, err = os.Stat(pth + Meta4Ext); err == nil {
 206                 w.Header().Set("Link", "<"+path.Base(pth)+Meta4Ext+`>; rel=describedby; type="application/metalink4+xml"`)
 207         }
 208
 209         if contentType == "" {
 210                 contentType = mediaType(path.Base(pth), cfg.MIMEs)
 211         }
 212         contentTypeBase := strings.SplitN(contentType, ";", 2)[0]
 213         w.Header().Set("Content-Type", contentType)
 214
 215         w.Header().Set("Server", Version)
 216         if etag != "" {
 217                 w.Header().Set("ETag", etag)
 218         }
 219         var wc http.ResponseWriter
 220         var bufCompressed *bytes.Buffer
 221         var gz *gzip.Writer
 222         var zstdW *zstd.Encoder
 223         if _, ok := CompressibleContentTypes[contentTypeBase]; ok {
 224                 if strings.Contains(r.Header.Get("Accept-Encoding"), "zstd") {
 225                         w.Header().Set("Content-Encoding", "zstd")
 226                         zstdW = zstdPool.Get().(*zstd.Encoder)
 227                         defer zstdPool.Put(zstdW)
 228                         bufCompressed = &bytes.Buffer{}
 229                         zstdW.Reset(bufCompressed)
 230                         defer zstdW.Close()
 231                         wc = &gzipResponseWriter{ResponseWriter: w, Writer: zstdW}
 232                 } else if strings.Contains(r.Header.Get("Accept-Encoding"), "gzip") {
 233                         w.Header().Set("Content-Encoding", "gzip")
 234                         gz = gzPool.Get().(*gzip.Writer)
 235                         defer gzPool.Put(gz)
 236                         bufCompressed = &bytes.Buffer{}
 237                         gz.Reset(bufCompressed)
 238                         defer gz.Close()
 239                         wc = &gzipResponseWriter{ResponseWriter: w, Writer: gz}
 240                 } else {
 241                         wc = &CountResponseWriter{ResponseWriter: w}
 242                 }
 243         } else {
 244                 wc = &CountResponseWriter{ResponseWriter: w}
 245         }
 246         http.ServeContent(wc, r, "", fi.ModTime().UTC().Truncate(time.Second), fd)
 247         if bufCompressed != nil {
 248                 if gz != nil {
 249                         gz.Close()
 250                 }
 251                 if zstdW != nil {
 252                         zstdW.Close()
 253                 }
 254                 size := bufCompressed.Len()
 255                 w.Header().Set("Content-Length", strconv.Itoa(size))
 256                 wr := wc.(*gzipResponseWriter)
 257                 w.WriteHeader(wr.status)
 258                 w.Write(bufCompressed.Bytes())
 259                 fmt.Printf("%s %s \"%s %s %s\" %d %d \"%s\"\n",
 260                         r.RemoteAddr, host, r.Method, r.URL.Path, r.Proto,
 261                         wr.status, size,
 262                         r.Header.Get("User-Agent"),
 263                 )
 264                 return
 265         }
 266         wr := wc.(*CountResponseWriter)
 267         fmt.Printf("%s %s \"%s %s %s\" %d %d \"%s\"\n",
 268                 r.RemoteAddr, host, r.Method, r.URL.Path, r.Proto,
 269                 wr.Status, wr.Size,
 270                 r.Header.Get("User-Agent"),
 271         )
 272 }
 273
 274 func (h Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 275         if containsDotDot(r.URL.Path) {
 276                 http.Error(w, "invalid URL path", http.StatusBadRequest)
 277                 return
 278         }
 279         host := strings.SplitN(r.Host, ":", 2)[0]
 280         h.Handle(w, r, host, Hosts[host])
 281 }