release/src/router/vsftpd/ascii.c

   1 /*
   2  * Part of Very Secure FTPd
   3  * Licence: GPL v2
   4  * Author: Chris Evans
   5  * ascii.c
   6  *
   7  * Routines to handle ASCII mode tranfers. Yuk.
   8  */
   9
  10 #include "ascii.h"
  11
  12 struct ascii_to_bin_ret
  13 vsf_ascii_ascii_to_bin(char* p_buf, unsigned int in_len, int prev_cr)
  14 {
  15   /* Task: translate all \r\n into plain \n. A plain \r not followed by \n must
  16    * not be removed.
  17    */
  18   struct ascii_to_bin_ret ret;
  19   unsigned int indexx = 0;
  20   unsigned int written = 0;
  21   char* p_out = p_buf + 1;
  22   ret.last_was_cr = 0;
  23   if (prev_cr && (!in_len || p_out[0] != '\n'))
  24   {
  25     p_buf[0] = '\r';
  26     ret.p_buf = p_buf;
  27     written++;
  28   }
  29   else
  30   {
  31     ret.p_buf = p_out;
  32   }
  33   while (indexx < in_len)
  34   {
  35     char the_char = p_buf[indexx + 1];
  36     if (the_char != '\r')
  37     {
  38       *p_out++ = the_char;
  39       written++;
  40     }
  41     else if (indexx == in_len - 1)
  42     {
  43       ret.last_was_cr = 1;
  44     }
  45     else if (p_buf[indexx + 2] != '\n')
  46     {
  47       *p_out++ = the_char;
  48       written++;
  49     }
  50     indexx++;
  51   }
  52   ret.stored = written;
  53   return ret;
  54 }
  55
  56 struct bin_to_ascii_ret
  57 vsf_ascii_bin_to_ascii(const char* p_in,
  58                        char* p_out,
  59                        unsigned int in_len,
  60                        int prev_cr)
  61 {
  62   /* Task: translate all \n not preceeded by \r into \r\n.
  63    * Note that \r\n stays as \r\n. We used to map it to \r\r\n like wu-ftpd
  64    * but have switched to leaving it, like the more popular proftpd.
  65    */
  66   struct bin_to_ascii_ret ret = { 0, 0 };
  67   unsigned int indexx = 0;
  68   unsigned int written = 0;
  69   char last_char = 0;
  70   if (prev_cr)
  71   {
  72     last_char = '\r';
  73     ret.last_was_cr = 1;
  74   }
  75   while (indexx < in_len)
  76   {
  77     char the_char = p_in[indexx];
  78     if (the_char == '\n' && last_char != '\r')
  79     {
  80       *p_out++ = '\r';
  81       written++;
  82     }
  83     *p_out++ = the_char;
  84     written++;
  85     indexx++;
  86     last_char = the_char;
  87     if (the_char == '\r')
  88     {
  89       ret.last_was_cr = 1;
  90     }
  91     else
  92     {
  93       ret.last_was_cr = 0;
  94     }
  95   }
  96   ret.stored = written;
  97   return ret;
  98 }
  99