mtmediasrv/main.go

160 lines
3.4 KiB
Go

//
// mtmediasrv - a Minetest Media server implementation done right
//
// Copyright (C) 2017 - Auke Kok <sofar@foo-projects.org>
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as
// published by the Free Software Foundation, either version 3 of the
// License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
//
package main
import (
"bytes"
"crypto/sha1"
"encoding/hex"
"fmt"
"io"
"io/ioutil"
"log"
"net"
"net/http"
"net/http/fcgi"
"os"
"strings"
)
var (
Version string
Build string
arr []string
)
type FastCGIServer struct{}
func (s FastCGIServer) ServeHTTP(w http.ResponseWriter, req *http.Request) {
header := make([]byte, 4)
version := make([]byte, 2)
req.Body.Read(header)
req.Body.Read(version)
if !bytes.Equal(header, []byte("MTHS")) {
log.Print("Request: invalid header\n")
return
}
if !bytes.Equal(version, []byte {0, 1}) {
log.Print("Request: unsupported version\n")
return
}
// read client needed hashes
clientarr := make([]string, 0)
for {
h := make([]byte, 20)
_, err := req.Body.Read(h)
if err != nil {
break
}
clientarr = append(clientarr, hex.EncodeToString(h))
}
// Iterate over client hashes and remove hashes that we don't have from it
resultarr := make([]string, 0)
for _, v := range clientarr {
for _, w := range arr {
if v == w {
resultarr = append(resultarr, v)
break
}
}
}
// formulate response
headers := w.Header()
headers.Add("Content-Type", "octet/stream")
headers.Add("Content-Length", fmt.Sprintf("%d", 6 + (len(resultarr) * 20)))
c1, _ := w.Write([]byte(header))
c2, _ := w.Write([]byte(version))
c := c1 + c2
for _, v := range resultarr {
b, _ := hex.DecodeString(v)
c3, _ := w.Write([]byte(b))
c = c + c3
}
// log transaction
log.Print("mtmediasrv: ", req.RemoteAddr, " '", req.UserAgent(), "' ", len(resultarr), "/", len(clientarr), " ", c)
}
func getHash(path string) (string, error) {
var hashStr string
f, err := os.Open(path)
if err != nil {
return hashStr, err
}
defer f.Close()
h := sha1.New()
if _, err := io.Copy(h, f); err != nil {
return hashStr, err
}
hashStr = hex.EncodeToString(h.Sum(nil)[:20])
return hashStr, nil
}
func parseMedia(path string) {
arr = make([]string, 0)
files, _ := ioutil.ReadDir(path)
for _, f := range files {
h, err := getHash(strings.Join([]string{path, "/" , f.Name()}, ""))
if err != nil {
log.Print("parseMedia(): ", f.Name(), err)
continue
}
arr = append(arr, h)
}
}
func main() {
p := "/var/www/media"
parseMedia(p)
log.Print("mtmediasrv: Number of media files: ", len(arr))
s := "/run/mtmediasrv/sock"
os.Remove(s)
listener, err := net.Listen("unix", s)
if err != nil {
log.Fatal("mtmediasrv: net.Listen: ", err)
}
os.Chmod(s, 666)
defer listener.Close()
h := new(FastCGIServer)
log.Print("mtmediasrv: version ", Version, " (", Build, ") started")
err = fcgi.Serve(listener, h)
}