2 uploader -- simplest form file uploader
3 Copyright (C) 2018 Sergey Matveev <stargrave@stargrave.org>
21 "golang.org/x/crypto/blake2s"
22 "golang.org/x/net/netutil"
26 WriteBufSize = 1 << 20
27 FileFieldName = "fileupload"
31 Index = template.Must(template.New("index").Parse(`<html>
32 <head><title>Upload</title></head><body>
33 <form enctype="multipart/form-data" action="/upload/" method="post">
34 <input type="file" name="{{.}}" /><input type="submit" />
35 </form></body></html>`))
38 func upload(w http.ResponseWriter, r *http.Request) {
39 log.Println(r.RemoteAddr, "connected")
40 if r.Method == http.MethodGet {
41 if err := Index.Execute(w, FileFieldName); err != nil {
42 log.Println(r.RemoteAddr, err)
46 mr, err := r.MultipartReader()
48 log.Println(r.RemoteAddr, err)
51 p, err := mr.NextPart()
53 log.Println(r.RemoteAddr, err)
56 if p.FormName() != FileFieldName {
57 log.Println(r.RemoteAddr, "non file form field")
60 h, err := blake2s.New256(nil)
64 fn := time.Now().Format(time.RFC3339Nano)
65 fd, err := os.OpenFile(fn+".part", os.O_WRONLY|os.O_CREATE, 0600)
67 log.Println(r.RemoteAddr, fn, p.FileName(), err)
70 fdBuf := bufio.NewWriterSize(fd, WriteBufSize)
71 mw := io.MultiWriter(fdBuf, h)
72 n, err := io.Copy(mw, p)
74 log.Println(r.RemoteAddr, fn, p.FileName(), err)
78 if err = fdBuf.Flush(); err != nil {
79 log.Println(r.RemoteAddr, fn, p.FileName(), err)
84 sum := hex.EncodeToString(h.Sum(nil))
85 if err = os.Rename(fn+".part", fn); err != nil {
86 log.Println(r.RemoteAddr, fn, p.FileName(), n, sum, err)
89 fmt.Fprintf(w, "bytes: %d\nBLAKE2s: %s\n", n, sum)
90 log.Println(r.RemoteAddr, fn, p.FileName(), n, sum)
94 bind := flag.String("bind", "[::]:8086", "Address to bind to")
95 conns := flag.Int("conns", 2, "Maximal number of connections")
97 ln, err := net.Listen("tcp", *bind)
101 log.Println("listening", *bind)
102 ln = netutil.LimitListener(ln, *conns)
104 ReadHeaderTimeout: 10 * time.Second,
105 MaxHeaderBytes: 10 * (1 << 10),
107 http.HandleFunc("/upload/", upload)