source: trunk/essentials/net-misc/wget/src/ftp-basic.c@ 3609

/* Basic FTP routines.
   Copyright (C) 1995, 1996, 1997, 1998, 2000 Free Software Foundation, Inc.

This file is part of GNU Wget.

GNU Wget is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
 (at your option) any later version.

GNU Wget is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with Wget; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

In addition, as a special exception, the Free Software Foundation
gives permission to link the code of its release of Wget with the
OpenSSL project's "OpenSSL" library (or with modified versions of it
that use the same license as the "OpenSSL" library), and distribute
the linked executables.  You must obey the GNU General Public License
in all respects for all of the code used other than "OpenSSL".  If you
modify this file, you may extend this exception to your version of the
file, but you are not obligated to do so.  If you do not wish to do
so, delete this exception statement from your version.  */

#include <config.h>

#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>

#ifdef HAVE_STRING_H
# include <string.h>
#else
# include <strings.h>
#endif
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif
#include <sys/types.h>

#include "wget.h"
#include "utils.h"
#include "connect.h"
#include "host.h"
#include "ftp.h"
#include "retr.h"

char ftp_last_respline[128];



/* Get the response of FTP server and allocate enough room to handle
   it.  <CR> and <LF> characters are stripped from the line, and the
   line is 0-terminated.  All the response lines but the last one are
   skipped.  The last line is determined as described in RFC959.

   If the line is successfully read, FTPOK is returned, and *ret_line
   is assigned a freshly allocated line.  Otherwise, FTPRERR is
   returned, and the value of *ret_line should be ignored.  */

uerr_t
ftp_response (int fd, char **ret_line)
{
  while (1)
    {
      char *p;
      char *line = fd_read_line (fd);
      if (!line)
        return FTPRERR;

      /* Strip trailing CRLF before printing the line, so that
         escnonprint doesn't include bogus \012 and \015. */
      p = strchr (line, '\0');
      if (p > line && p[-1] == '\n')
        *--p = '\0';
      if (p > line && p[-1] == '\r')
        *--p = '\0';

      if (opt.server_response)
        logprintf (LOG_NOTQUIET, "%s\n", escnonprint (line));
      else
        DEBUGP (("%s\n", escnonprint (line)));

      /* The last line of output is the one that begins with "ddd ". */
      if (ISDIGIT (line[0]) && ISDIGIT (line[1]) && ISDIGIT (line[2])
          && line[3] == ' ')
        {
          strncpy (ftp_last_respline, line, sizeof (ftp_last_respline));
          ftp_last_respline[sizeof (ftp_last_respline) - 1] = '\0';
          *ret_line = line;
          return FTPOK;
        }
      xfree (line);
    }
}

/* Returns the malloc-ed FTP request, ending with <CR><LF>, printing
   it if printing is required.  If VALUE is NULL, just use
   command<CR><LF>.  */
static char *
ftp_request (const char *command, const char *value)
{
  char *res;
  if (value)
    {
      /* Check for newlines in VALUE (possibly injected by the %0A URL
         escape) making the callers inadvertently send multiple FTP
         commands at once.  Without this check an attacker could
         intentionally redirect to ftp://server/fakedir%0Acommand.../
         and execute arbitrary FTP command on a remote FTP server.  */
      if (strpbrk (value, "\r\n"))
        {
          /* Copy VALUE to the stack and modify CR/LF to space. */
          char *defanged, *p;
          STRDUP_ALLOCA (defanged, value);
          for (p = defanged; *p; p++)
            if (*p == '\r' || *p == '\n')
              *p = ' ';
          DEBUGP (("\nDetected newlines in %s \"%s\"; changing to %s \"%s\"\n",
                   command, escnonprint (value), command, escnonprint (defanged)));
          /* Make VALUE point to the defanged copy of the string. */
          value = defanged;
        }
      res = concat_strings (command, " ", value, "\r\n", (char *) 0);
    }
  else
    res = concat_strings (command, "\r\n", (char *) 0);
  if (opt.server_response)
    {
      /* Hack: don't print out password.  */
      if (strncmp (res, "PASS", 4) != 0)
        logprintf (LOG_ALWAYS, "--> %s\n", res);
      else
        logputs (LOG_ALWAYS, "--> PASS Turtle Power!\n\n");
    }
  else
    DEBUGP (("\n--> %s\n", res));
  return res;
}

/* Sends the USER and PASS commands to the server, to control
   connection socket csock.  */
uerr_t
ftp_login (int csock, const char *acc, const char *pass)
{
  uerr_t err;
  char *request, *respline;
  int nwritten;

  /* Get greeting.  */
  err = ftp_response (csock, &respline);
  if (err != FTPOK)
    return err;
  if (*respline != '2')
    {
      xfree (respline);
      return FTPSRVERR;
    }
  xfree (respline);
  /* Send USER username.  */
  request = ftp_request ("USER", acc);
  nwritten = fd_write (csock, request, strlen (request), -1.0);
  if (nwritten < 0)
    {
      xfree (request);
      return WRITEFAILED;
    }
  xfree (request);
  /* Get appropriate response.  */
  err = ftp_response (csock, &respline);
  if (err != FTPOK)
    return err;
  /* An unprobable possibility of logging without a password.  */
  if (*respline == '2')
    {
      xfree (respline);
      return FTPOK;
    }
  /* Else, only response 3 is appropriate.  */
  if (*respline != '3')
    {
      xfree (respline);
      return FTPLOGREFUSED;
    }
#ifdef ENABLE_OPIE
  {