ftp-basic.c

wget (command line browser) source code

{
  char *request, *respline, *s;
  int nwritten, i;
  uerr_t err;
  unsigned char addr4[4];

#ifdef ENABLE_IPV6
  if (ip_default_family == AF_INET6) 
    {
      err = ftp_epsv (rbuf, addr, port, "2");	/* try IPv6 with EPSV */
      if (FTPOK == err) 
        return FTPOK;
      err = ftp_epsv (rbuf, addr, port, "1");	/* try IPv4 with EPSV */
      if (FTPOK == err) 
        return FTPOK;
    }
#endif  
  /* Form the request.  */
  request = ftp_request ("PASV", NULL);
  /* And send it.  */
  nwritten = iwrite (RBUF_FD (rbuf), request, strlen (request));
  if (nwritten < 0)
    {
      xfree (request);
      return WRITEFAILED;
    }
  xfree (request);
  /* Get the server response.  */
  err = ftp_response (rbuf, &respline);
  if (err != FTPOK)
    {
      xfree (respline);
      return err;
    }
  if (*respline != '2')
    {
      xfree (respline);
      return FTPNOPASV;
    }
  /* Parse the request.  */
  /* respline::=227 Entering Passive Mode (h1,h2,h3,h4,p1,p2). 	*/
  s = respline;
  for (s += 4; *s && !ISDIGIT (*s); s++);
  if (!*s)
    return FTPINVPASV;
  for (i = 0; i < 4; i++)
    {
      addr4[i] = 0;
      for (; ISDIGIT (*s); s++)
        addr4[i] = (*s - '0') + 10 * addr4[i];
      if (*s == ',')
        s++;
      else
        {
          xfree (respline);
          return FTPINVPASV;
        }
    }

  /* Eventually make an IPv4 in IPv6 adress if needed */
  map_ipv4_to_ip ((ip4_address *)addr4, addr);

  *port=0;
  for (; ISDIGIT (*s); s++)
    *port = (*s - '0') + 10 * (*port);
  if (*s == ',') 
    s++;
  else
    {
      xfree (respline);
      return FTPINVPASV;
    }

  {
    unsigned short port2 = 0; 
    for (; ISDIGIT (*s); s++) 
      port2 = (*s - '0') + 10 * port2;
    *port = (*port) * 256 + port2;
  }
  xfree (respline);
  return FTPOK;
}

/* Sends the TYPE request to the server.  */
uerr_t
ftp_type (struct rbuf *rbuf, int type)
{
  char *request, *respline;
  int nwritten;
  uerr_t err;
  char stype[2];

  /* Construct argument.  */
  stype[0] = type;
  stype[1] = 0;
  /* Send TYPE request.  */
  request = ftp_request ("TYPE", stype);
  nwritten = iwrite (RBUF_FD (rbuf), request, strlen (request));
  if (nwritten < 0)
    {
      xfree (request);
      return WRITEFAILED;
    }
  xfree (request);
  /* Get appropriate response.  */
  err = ftp_response (rbuf, &respline);
  if (err != FTPOK)
    {
      xfree (respline);
      return err;
    }
  if (*respline != '2')
    {
      xfree (respline);
      return FTPUNKNOWNTYPE;
    }
  xfree (respline);
  /* All OK.  */
  return FTPOK;
}

/* Changes the working directory by issuing a CWD command to the
   server.  */
uerr_t
ftp_cwd (struct rbuf *rbuf, const char *dir)
{
  char *request, *respline;
  int nwritten;
  uerr_t err;

  /* Send CWD request.  */
  request = ftp_request ("CWD", dir);
  nwritten = iwrite (RBUF_FD (rbuf), request, strlen (request));
  if (nwritten < 0)
    {
      xfree (request);
      return WRITEFAILED;
    }
  xfree (request);
  /* Get appropriate response.  */
  err = ftp_response (rbuf, &respline);
  if (err != FTPOK)
    {
      xfree (respline);
      return err;
    }
  if (*respline == '5')
    {
      xfree (respline);
      return FTPNSFOD;
    }
  if (*respline != '2')
    {
      xfree (respline);
      return FTPRERR;
    }
  xfree (respline);
  /* All OK.  */
  return FTPOK;
}

/* Sends REST command to the FTP server.  */
uerr_t
ftp_rest (struct rbuf *rbuf, long offset)
{
  char *request, *respline;
  int nwritten;
  uerr_t err;
  static char numbuf[24]; /* Buffer for the number */

  number_to_string (numbuf, offset);
  request = ftp_request ("REST", numbuf);
  nwritten = iwrite (RBUF_FD (rbuf), request, strlen (request));
  if (nwritten < 0)
    {
      xfree (request);
      return WRITEFAILED;
    }
  xfree (request);
  /* Get appropriate response.  */
  err = ftp_response (rbuf, &respline);
  if (err != FTPOK)
    {
      xfree (respline);
      return err;
    }
  if (*respline != '3')
    {
      xfree (respline);
      return FTPRESTFAIL;
    }
  xfree (respline);
  /* All OK.  */
  return FTPOK;
}

/* Sends RETR command to the FTP server.  */
uerr_t
ftp_retr (struct rbuf *rbuf, const char *file)
{
  char *request, *respline;
  int nwritten;
  uerr_t err;

  /* Send RETR request.  */
  request = ftp_request ("RETR", file);
  nwritten = iwrite (RBUF_FD (rbuf), request, strlen (request));
  if (nwritten < 0)
    {
      xfree (request);
      return WRITEFAILED;
    }
  xfree (request);
  /* Get appropriate response.  */
  err = ftp_response (rbuf, &respline);
  if (err != FTPOK)
    {
      xfree (respline);
      return err;
    }
  if (*respline == '5')
    {
      xfree (respline);
      return FTPNSFOD;
    }
  if (*respline != '1')
    {
      xfree (respline);
      return FTPRERR;
    }
  xfree (respline);
  /* All OK.  */
  return FTPOK;
}

/* Sends the LIST command to the server.  If FILE is NULL, send just
   `LIST' (no space).  */
uerr_t
ftp_list (struct rbuf *rbuf, const char *file)
{
  char *request, *respline;
  int nwritten;
  uerr_t err;

  /* Send LIST request.  */
  request = ftp_request ("LIST", file);
  nwritten = iwrite (RBUF_FD (rbuf), request, strlen (request));
  if (nwritten < 0)
    {
      xfree (request);
      return WRITEFAILED;
    }
  xfree (request);
  /* Get appropriate respone.  */
  err = ftp_response (rbuf, &respline);
  if (err != FTPOK)
    {
      xfree (respline);
      return err;
    }
  if (*respline == '5')
    {
      xfree (respline);
      return FTPNSFOD;
    }
  if (*respline != '1')
    {
      xfree (respline);
      return FTPRERR;
    }
  xfree (respline);
  /* All OK.  */
  return FTPOK;
}

/* Sends the SYST command to the server. */
uerr_t
ftp_syst (struct rbuf *rbuf, enum stype *server_type)
{
  char *request, *respline;
  int nwritten;
  uerr_t err;

  /* Send SYST request.  */
  request = ftp_request ("SYST", NULL);
  nwritten = iwrite (RBUF_FD (rbuf), request, strlen (request));
  if (nwritten < 0)
    {
      xfree (request);
      return WRITEFAILED;
    }
  xfree (request);

  /* Get appropriate response.  */
  err = ftp_response (rbuf, &respline);
  if (err != FTPOK)
    {
      xfree (respline);
      return err;
    }
  if (*respline == '5')
    {
      xfree (respline);
      return FTPSRVERR;
    }

  /* Skip the number (215, but 200 (!!!) in case of VMS) */
  strtok (respline, " ");
  
  /* Which system type has been reported (we are interested just in the
     first word of the server response)?  */
  request = strtok (NULL, " ");

  if (!strcasecmp (request, "VMS"))
    *server_type = ST_VMS;
  else if (!strcasecmp (request, "UNIX"))
    *server_type = ST_UNIX;
  else if (!strcasecmp (request, "WINDOWS_NT")
	   || !strcasecmp (request, "WINDOWS2000"))
    *server_type = ST_WINNT;
  else if (!strcasecmp (request, "MACOS"))
    *server_type = ST_MACOS;
  else if (!strcasecmp (request, "OS/400"))
    *server_type = ST_OS400;
  else
    *server_type = ST_OTHER;

  xfree (respline);
  /* All OK.  */
  return FTPOK;
}

/* Sends the PWD command to the server. */
uerr_t
ftp_pwd (struct rbuf *rbuf, char **pwd)
{
  char *request, *respline;
  int nwritten;
  uerr_t err;

  /* Send PWD request.  */
  request = ftp_request ("PWD", NULL);
  nwritten = iwrite (RBUF_FD (rbuf), request, strlen (request));
  if (nwritten < 0)
    {
      xfree (request);
      return WRITEFAILED;
    }
  xfree (request);
  /* Get appropriate response.  */
  err = ftp_response (rbuf, &respline);
  if (err != FTPOK)
    {
      xfree (respline);
      return err;
    }
  if (*respline == '5')
    {
      xfree (respline);
      return FTPSRVERR;
    }

  /* Skip the number (257), leading citation mark, trailing citation mark
     and everything following it. */
  strtok (respline, "\"");
  request = strtok (NULL, "\"");
  
  /* Has the `pwd' been already allocated?  Free! */
  FREE_MAYBE (*pwd);

  *pwd = xstrdup (request);

  xfree (respline);
  /* All OK.  */
  return FTPOK;
}

/* Sends the SIZE command to the server, and returns the value in 'size'.
 * If an error occurs, size is set to zero. */
uerr_t
ftp_size (struct rbuf *rbuf, const char *file, long int *size)
{
  char *request, *respline;
  int nwritten;
  uerr_t err;

  /* Send PWD request.  */
  request = ftp_request ("SIZE", file);
  nwritten = iwrite (RBUF_FD (rbuf), request, strlen (request));
  if (nwritten < 0)
    {
      xfree (request);
      *size = 0;
      return WRITEFAILED;
    }
  xfree (request);
  /* Get appropriate response.  */
  err = ftp_response (rbuf, &respline);
  if (err != FTPOK)
    {
      xfree (respline);
      *size = 0;
      return err;
    }
  if (*respline == '5')
    {
      /* 
       * Probably means SIZE isn't supported on this server.
       * Error is nonfatal since SIZE isn't in RFC 959 
       */
      xfree (respline);
      *size = 0;
      return FTPOK;
    }

  errno = 0;
  *size = strtol (respline + 4, NULL, 0);
  if (errno) 
    {
      /* 
       * Couldn't parse the response for some reason.  On the (few)
       * tests I've done, the response is 213 <SIZE> with nothing else -
       * maybe something a bit more resilient is necessary.  It's not a
       * fatal error, however.
       */
      xfree (respline);
      *size = 0;
      return FTPOK;
    }

  xfree (respline);
  /* All OK.  */
  return FTPOK;
}

/* If URL's params are of the form "type=X", return character X.
   Otherwise, return 'I' (the default type).  */
char
ftp_process_type (const char *params)
{
  if (params
      && 0 == strncasecmp (params, "type=", 5)
      && params[5] != '\0')
    return TOUPPER (params[5]);
  else
    return 'I';
}