2 uploader -- simplest form file uploader
3 Copyright (C) 2018-2019 Sergey Matveev <stargrave@stargrave.org>
26 "golang.org/x/crypto/blake2b"
27 "golang.org/x/net/netutil"
31 WriteBufSize = 1 << 20
32 FileFieldName = "fileupload"
33 CommentFieldName = "comment"
35 SendmailCmd = "/usr/sbin/sendmail"
39 Index = template.Must(template.New("index").Parse(`<html>
40 <head><title>Upload</title></head><body>
41 <form enctype="multipart/form-data" action="/upload/" method="post">
42 <input type="file" name="{{.}}" /><br/>
43 <label for="comment">Optional comment:</label>
44 <textarea name="comment" cols="80" rows="25" name="comment"></textarea><br/>
45 <input type="submit" />
46 </form></body></html>`))
47 NotifyFromAddr *string
51 func notify(timestamp string, size int64, comment string) {
52 if *NotifyToAddr == "" {
55 cmd := exec.Command(SendmailCmd, *NotifyToAddr)
56 cmd.Stdin = io.MultiReader(
57 strings.NewReader(fmt.Sprintf(
62 Content-Type: text/plain; charset=utf-8
63 Content-Transfer-Encoding: base64
68 mime.BEncoding.Encode("UTF-8", fmt.Sprintf(
69 "%s (%d KiB)", timestamp, size/1024,
72 strings.NewReader(base64.StdEncoding.EncodeToString([]byte(fmt.Sprintf(
73 "Timestamp: %s\nSize: %d bytes\nComment: %s\n",
82 func upload(w http.ResponseWriter, r *http.Request) {
83 log.Println(r.RemoteAddr, "connected")
84 if r.Method == http.MethodGet {
85 if err := Index.Execute(w, FileFieldName); err != nil {
86 log.Println(r.RemoteAddr, err)
90 mr, err := r.MultipartReader()
92 log.Println(r.RemoteAddr, err)
95 p, err := mr.NextPart()
97 log.Println(r.RemoteAddr, err)
100 if p.FormName() != FileFieldName {
101 log.Println(r.RemoteAddr, "non file form field")
104 h, err := blake2b.New256(nil)
108 fn := time.Now().Format(time.RFC3339Nano)
109 fd, err := os.OpenFile(fn+".part", os.O_WRONLY|os.O_CREATE, 0600)
111 log.Println(r.RemoteAddr, fn, p.FileName(), err)
114 fdBuf := bufio.NewWriterSize(fd, WriteBufSize)
115 mw := io.MultiWriter(fdBuf, h)
116 n, err := io.Copy(mw, p)
118 log.Println(r.RemoteAddr, fn, p.FileName(), err)
123 log.Println(r.RemoteAddr, fn, p.FileName(), "empty")
124 os.Remove(fn + ".part")
126 fmt.Fprintf(w, "Empty file")
129 if err = fdBuf.Flush(); err != nil {
130 log.Println(r.RemoteAddr, fn, p.FileName(), err)
135 sum := hex.EncodeToString(h.Sum(nil))
136 if err = os.Rename(fn+".part", fn); err != nil {
137 log.Println(r.RemoteAddr, fn, p.FileName(), n, sum, err)
140 fmt.Fprintf(w, "Timestamp: %s\nBytes: %d\nBLAKE2b: %s\n", fn, n, sum)
141 log.Println(r.RemoteAddr, fn, p.FileName(), n, sum)
142 p, err = mr.NextPart()
143 if err != nil || p.FormName() != CommentFieldName {
147 comment, err := ioutil.ReadAll(p)
148 if err != nil || len(comment) == 0 {
152 ioutil.WriteFile(fn+".txt", comment, os.FileMode(0600))
153 go notify(fn, n, string(comment))
157 bind := flag.String("bind", "[::]:8086", "Address to bind to")
158 conns := flag.Int("conns", 2, "Maximal number of connections")
159 NotifyFromAddr = flag.String("notify-from", "uploader@example.com", "Address notifications are send to")
160 NotifyToAddr = flag.String("notify-to", "", "Address notifications are send from")
162 if len(*NotifyFromAddr) == 0 && len(*NotifyToAddr) > 0 {
163 log.Fatalln("notify-from address can not be empty, if notify-to is set")
165 ln, err := net.Listen("tcp", *bind)
169 log.Println("listening", *bind)
170 ln = netutil.LimitListener(ln, *conns)
172 ReadHeaderTimeout: 10 * time.Second,
173 MaxHeaderBytes: 10 * (1 << 10),
175 http.HandleFunc("/upload/", upload)