prot-a-parse.c

/*
 * $Id: prot-a-parse.c,v 0.7 1991/09/15 10:30:12 linus Exp $
 * Copyright (C) 1991  Lysator Academic Computer Association.
 *
 * This file is part of the LysKOM server.
 * 
 * LysKOM 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 1, or (at your option) 
 * any later version.
 * 
 * LysKOM 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 LysKOM; see the file COPYING.  If not, write to
 * Lysator, c/o ISY, Linkoping University, S-581 83 Linkoping, SWEDEN,
 * or the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, 
 * MA 02139, USA.
 *
 * Please mail bug reports to bug-lyskom@lysator.liu.se. 
 */
/*
 * prot-a-parse.c - parse protocol-A messages.
 *
 * BUG: Not all functions are used, I think. /ceder
 */

static char *rcsid = "$Id: prot-a-parse.c,v 0.7 1991/09/15 10:30:12 linus Exp $";


#include <setjmp.h>
#include <string.h>

#include "s-string.h"
#include <kom-types.h>
#include "lyskomd.h"
#include "com.h"
#include "connections.h"
#include "prot-a-parse.h"
#include "isc-parse.h"
#include <server/smalloc.h>
#include "minmax.h"
#include "prot-a.h"
#include "config.h"
#include "log.h"

long
prot_a_parse_long(Connection *client)
{
    String	token;
    String_size end;
    long	res;

    token = prot_a_get_token(client);
    res = s_strtol(token, &end, PROTOCOL_NUMBER_BASE);
    if (end != s_strlen(token))
	longjmp(parse_env, ISC_PROTOCOL_ERR);
    
    return res;
}

void
prot_a_parse_priv_bits(Connection *client,
		       Priv_bits      *res)
{
    String token;

    token = prot_a_get_token(client);

    if ( s_strlen(token) != 16 )
	longjmp(parse_env, ISC_PROTOCOL_ERR);
    
    res->wheel = token.string[ 0 ] != '0';
    res->admin = token.string[ 1 ] != '0';
    res->statistic = token.string[ 2 ] != '0';
    res->create_pers = token.string[ 3 ] != '0';
    res->create_conf = token.string[ 4 ] != '0';
    res->change_name = token.string[ 5 ] != '0';
    res->flg7 = token.string[ 6 ] != '0';
    res->flg8 = token.string[ 7 ] != '0';
    res->flg9 = token.string[ 8 ] != '0';
    res->flg10 = token.string[ 9 ] != '0';
    res->flg11 = token.string[ 10 ] != '0';
    res->flg12 = token.string[ 11 ] != '0';
    res->flg13 = token.string[ 12 ] != '0';
    res->flg14 = token.string[ 13 ] != '0';
    res->flg15 = token.string[ 14 ] != '0';
    res->flg16 = token.string[ 15 ] != '0';
}

void
prot_a_parse_conf_type(Connection *client,
		Conf_type      *res)
{
    String token;

    token = prot_a_get_token(client);
    
    if ( s_strlen(token) != 4 )
	longjmp(parse_env, ISC_PROTOCOL_ERR);
  
    res->rd_prot = token.string[ 0 ] != '0';
    res->original = token.string[ 1 ] != '0';
    res->secret = token.string[ 2 ] != '0';
    res->letter_box = token.string[ 3 ] != '0';
}

/*
 * Parse a string. At most 'maxlen' characters are allowed. If the
 * client sends a longer string only the first 'maxlen+1' characters
 * are read. Any remaining characters are discarded.
 */
/*
 * +++ This needs cleaning up. See comments in and above mux_parse_string.
 */
void
prot_a_parse_string(Connection  *client,
		    String	*result,
		    int		 maxlen)
{
    String_size hptr;		/* Pointer to 'H' */
    String_size client_len;	/* The len the client is sending. */
    String_size truncated_len;	/* How much the server will receive. */
    String_size to_skip;
    static u_long err_cnt = 0;

    switch ( client->string_parse_pos )
    {
    case 0:
	if ( (result->len != 0 || result->string != NULL) && err_cnt++ < 20 )
	{
	    log ("prot_a_parse_string(): result->len == %lu, "
		 "result->string == %lu. This memory will not be free()'d.\n",
		 (u_long)result->len, (u_long)result->string);
	    *result = EMPTY_STRING;
	    if ( err_cnt == 20 )
		log("Won't log the above warning no more.");
	}

	/* Get number and discard trailing 'H' */
	client_len = s_strtol(s_fsubstr(client->unparsed,
					client->first_to_parse,
					END_OF_STRING),
			      &hptr, PROTOCOL_NUMBER_BASE);

	if ( hptr == -1
	    || client->first_to_parse + hptr
	    >= s_strlen(client->unparsed) )
	{
	    longjmp(parse_env, ISC_MSG_INCOMPLETE);
	}
	
	/* Check that
	      a) there is a trailing H
	      b) there was at least one digit before the H */

	if ( client->unparsed.string[ client->first_to_parse
					  + hptr ] != 'H'
	    || hptr <= 0 )
	{
	    longjmp(parse_env, ISC_PROTOCOL_ERR);
	}

	client->first_to_parse += 1 + hptr;
	client->string_parse_pos = 1;
	result->len = client_len; /* +++ Transfer */
	/* Fall through */
    case 1:
	client_len = result->len;
	/* Check that the entire string is transmitted. */
	/* (Don't care about the trailing part that will be skipped if the
	 *  string is longer than maxlen) */
	truncated_len = min(maxlen + 1, client_len);
	
	if ( client->first_to_parse + truncated_len
	    > s_strlen(client->unparsed) )
	{
	    longjmp(parse_env, ISC_MSG_INCOMPLETE);
	}

	*result = EMPTY_STRING;

	s_mem_crea_str(result,
		       client->unparsed.string + client->first_to_parse,
		       truncated_len);
	result->len = client_len; /* Ugly! +++ */

	client->first_to_parse += truncated_len;
	client->string_parse_pos = 2;
	/* Fall through */
    case 2:
	/* Was the string too long? If so, skip the truncated data. */

	client_len = result->len;
	truncated_len = min(maxlen+1, client_len);
	
	if ( client_len > truncated_len )
	{
	    to_skip = min(client_len - truncated_len,
			   client->unparsed.len - client->first_to_parse);
	    client_len -= to_skip;
	    client->first_to_parse += to_skip;
	}

	result->len = client_len;
	
	if ( client_len > truncated_len )
	    longjmp(parse_env, ISC_MSG_INCOMPLETE);
	/* Fall through */
    default:
	client->string_parse_pos = 0;
    }
}


extern void
prot_a_parse_misc_info(Connection *client,
		       Misc_info      *result)
{
    switch ( client->struct_parse_pos )
    {
    case 0:
	result->type = prot_a_parse_long(client);
	client->struct_parse_pos = 1;
	/* Fall through */
    case 1:
	switch( result->type )
	{
	case recpt:
	    result->datum.recipient = prot_a_parse_long(client);
	    break;

	case cc_recpt:
	    result->datum.cc_recipient = prot_a_parse_long(client);
	    break;
	    
	case loc_no:
	    result->datum.local_no = prot_a_parse_long(client);
	    break;
	    
	case comm_to:
	    result->datum.comment_to = prot_a_parse_long(client);
	    break;
	    
	case footn_to:
	    result->datum.footnote_to = prot_a_parse_long(client);
	    break;

	case comm_in:
	case footn_in:
	case rec_time:
	case sent_by:
	case sent_at:
	    /* Fall through */
	    
#ifndef COMPILE_CHECKS
	default:
#endif
	    longjmp(parse_env, ISC_PROTOCOL_ERR);
	}
    default:
	client->struct_parse_pos = 0;
    }
}


String
prot_a_get_token(Connection *client)
{
    String result;
    String_size old_first;

    old_first = client->first_to_parse;
    
    result = s_strtok(client->unparsed, &client->first_to_parse,
		      s_fcrea_str(WHITESPACE));

    /* Check that there was at least one trailing blank. */
    
    if ( client->first_to_parse >= s_strlen(client->unparsed) )
    {
	client->first_to_parse = old_first;
	longjmp(parse_env, ISC_MSG_INCOMPLETE);
    }

    return result;
}