send_file-linux.c

   1 /*
   2  * User FTP Server,  Share folders over FTP without being root.
   3  * Copyright (C) 2008  Isaac Jurado
   4  *
   5  * This program is free software; you can redistribute it and/or modify it under
   6  * the terms of the GNU General Public License as published by the Free Software
   7  * Foundation; either version 2 of the License, or (at your option) any later
   8  * version.
   9  *
  10  * This program is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  12  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  13  * details.
  14  *
  15  * You should have received a copy of the GNU General Public License along with
  16  * this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
  18  */
  19
  20 #include "uftps.h"
  21 #include <sys/sendfile.h>
  22 #include <unistd.h>
  23 #include <fcntl.h>
  24
  25
  26 /*
  27  * RETR command implementation usin Linux sendfile() to minimize memory copies.
  28  * Due to the nature of the system call, it is not even necessary to perform the
  29  * initial seek in case a REST command was issued.
  30  */
  31 void send_file (void)
  32 {
  33         int    f, e;
  34         off_t  size;
  35
  36         f = open_file(&size);
  37         if (f == -1)
  38                 return;
  39
  40         e = open_data_channel();
  41         if (e == -1)
  42         {
  43                 close(f);
  44                 return;
  45         }
  46
  47         debug("Initial offset is %lld", (long long) SS.file_offset);
  48         reply_c("150 Sending file content.\r\n");
  49
  50         /* Main transfer loop */
  51         while (SS.file_offset < size && e != -1)
  52                 e = sendfile(SS.data_sk, f, &SS.file_offset, INT_MAX);
  53
  54         if (e != -1)
  55                 reply_c("226 File content sent.\r\n");
  56         else
  57         {
  58                 error("Sending file %s", SS.aux);
  59                 reply_c("426 Connection closed, transfer aborted.\r\n");
  60         }
  61
  62         close(f);
  63         close(SS.data_sk);
  64         SS.data_sk     = -1;
  65         SS.file_offset = 0;
  66 }
  67