send_file-sendfile.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/stat.h>
  22 #include <sys/sendfile.h>
  23 #include <unistd.h>
  24 #include <fcntl.h>
  25
  26
  27 /*
  28  * RETR command implementation.  It uses sendfile() because seems quite optimal,
  29  * just as vsftpd does.
  30  */
  31 void send_file (void)
  32 {
  33         int          fd, e;
  34         struct stat  s;
  35
  36         if (SS.arg == NULL)
  37         {
  38                 reply_c("501 Argument required.\r\n");
  39                 return;
  40         }
  41         expand_arg();
  42
  43         e = lstat(SS.arg, &s);
  44         if (e == -1 || !S_ISREG(s.st_mode))
  45         {
  46                 reply_c("550 Not a file.\r\n");
  47                 return;
  48         }
  49
  50         fd = open(SS.arg, O_RDONLY, 0);
  51         if (fd == -1)
  52         {
  53                 reply_c("550 Could not open file.\r\n");
  54                 return;
  55         }
  56
  57         e = open_data_channel();
  58         if (e == -1)
  59         {
  60                 close(fd);
  61                 return;
  62         }
  63
  64         reply_c("150 Sending file content.\r\n");
  65
  66         /* Apply a possible previous REST command.  Ignore errors, is it allowd
  67          * by the RFC? */
  68         if (SS.file_offset > 0)
  69                 lseek(fd, SS.file_offset, SEEK_SET);
  70
  71         e = 0;
  72         while (SS.file_offset < s.st_size && e != -1)
  73         {
  74                 debug("Offset step: %lld", (long long) SS.file_offset);
  75
  76                 e = sendfile(SS.data_sk, fd, &SS.file_offset, INT_MAX);
  77                 if (e == -1)
  78                         error("Sending file");
  79         }
  80
  81         debug("Offset end: %lld", (long long) SS.file_offset);
  82
  83         if (e != -1)
  84                 reply_c("226 File content sent.\r\n");
  85         else
  86                 reply_c("426 Connection closed, transfer aborted.\r\n");
  87
  88         close(fd);
  89         close(SS.data_sk);
  90         SS.data_sk     = -1;
  91         SS.file_offset = 0;
  92 }
  93