parse.c

DHCP服务器源码

	if (token == ARRAY) {
		token = next_token (&val, (unsigned *)0, cfile);
		if (token != OF) {
			parse_warn (cfile, "expecting \"of\".");
			skip_to_semi (cfile);
			return 0;
		}
		arrayp = 1;
		token = next_token (&val, (unsigned *)0, cfile);
	}

	if (token == LBRACE) {
		recordp = 1;
		token = next_token (&val, (unsigned *)0, cfile);
	}

	/* At this point we're expecting a data type. */
      next_type:
	if (has_encapsulation) {
		parse_warn (cfile,
			    "encapsulate must always be the last item.");
		skip_to_semi (cfile);
		return 0;
	}

	switch (token) {
	      case ARRAY:
		if (arrayp) {
			parse_warn (cfile, "no nested arrays.");
			skip_to_rbrace (cfile, recordp);
			if (recordp)
				skip_to_semi (cfile);
			return 0;
		}
		token = next_token (&val, (unsigned *)0, cfile);
		if (token != OF) {
			parse_warn (cfile, "expecting \"of\".");
			skip_to_semi (cfile);
			return 0;
		}
		arrayp = recordp + 1;
		token = next_token (&val, (unsigned *)0, cfile);
		if ((recordp) && (token == LBRACE)) {
			parse_warn (cfile,
				    "only uniform array inside record.");
			skip_to_rbrace (cfile, recordp + 1);
			skip_to_semi (cfile);
			return 0;
		}
		goto next_type;
	      case BOOLEAN:
		type = 'f';
		break;
	      case INTEGER:
		is_signed = 1;
	      parse_integer:
		token = next_token (&val, (unsigned *)0, cfile);
		if (token != NUMBER) {
			parse_warn (cfile, "expecting number.");
			skip_to_rbrace (cfile, recordp);
			if (recordp)
				skip_to_semi (cfile);
			return 0;
		}
		switch (atoi (val)) {
		      case 8:
			type = is_signed ? 'b' : 'B';
			break;
		      case 16:
			type = is_signed ? 's' : 'S';
			break;
		      case 32:
			type = is_signed ? 'l' : 'L';
			break;
		      default:
			parse_warn (cfile,
				    "%s bit precision is not supported.", val);
			skip_to_rbrace (cfile, recordp);
			if (recordp)
				skip_to_semi (cfile);
			return 0;
		}
		break;
	      case SIGNED:
		is_signed = 1;
	      parse_signed:
		token = next_token (&val, (unsigned *)0, cfile);
		if (token != INTEGER) {
			parse_warn (cfile, "expecting \"integer\" keyword.");
			skip_to_rbrace (cfile, recordp);
			if (recordp)
				skip_to_semi (cfile);
			return 0;
		}
		goto parse_integer;
	      case UNSIGNED:
		is_signed = 0;
		goto parse_signed;

	      case IP_ADDRESS:
		type = 'I';
		break;
	      case DOMAIN_NAME:
		type = 'd';
		goto no_arrays;
	      case TEXT:
		type = 't';
	      no_arrays:
		if (arrayp) {
			parse_warn (cfile, "arrays of text strings not %s",
				    "yet supported.");
			skip_to_rbrace (cfile, recordp);
			if (recordp)
				skip_to_semi (cfile);
			return 0;
		}
		no_more_in_record = 1;
		break;
	      case STRING_TOKEN:
		type = 'X';
		goto no_arrays;

	      case ENCAPSULATE:
		token = next_token (&val, (unsigned *)0, cfile);
		if (!is_identifier (token)) {
			parse_warn (cfile,
				    "expecting option space identifier");
			skip_to_semi (cfile);
			return 0;
		}
		if (strlen (val) + tokix + 2 > sizeof (tokbuf))
			goto toobig;
		tokbuf [tokix++] = 'E';
		strcpy (&tokbuf [tokix], val);
		tokix += strlen (val);
		type = '.';
		has_encapsulation = 1;
		break;

	      default:
		parse_warn (cfile, "unknown data type %s", val);
		skip_to_rbrace (cfile, recordp);
		if (recordp)
			skip_to_semi (cfile);
		return 0;
	}

	if (tokix == sizeof tokbuf) {
	      toobig:
		parse_warn (cfile, "too many types in record.");
		skip_to_rbrace (cfile, recordp);
		if (recordp)
			skip_to_semi (cfile);
		return 0;
	}
	tokbuf [tokix++] = type;

	if (recordp) {
		token = next_token (&val, (unsigned *)0, cfile);
		if (arrayp > recordp) {
			if (tokix == sizeof tokbuf) {
				parse_warn (cfile,
					    "too many types in record.");
				skip_to_rbrace (cfile, 1);
				skip_to_semi (cfile);
				return 0;
			}
			arrayp = 0;
			tokbuf[tokix++] = 'a';
		}
		if (token == COMMA) {
			if (no_more_in_record) {
				parse_warn (cfile,
					    "%s must be at end of record.",
					    type == 't' ? "text" : "string");
				skip_to_rbrace (cfile, 1);
				if (recordp)
					skip_to_semi (cfile);
				return 0;
			}
			token = next_token (&val, (unsigned *)0, cfile);
			goto next_type;
		}
		if (token != RBRACE) {
			parse_warn (cfile, "expecting right brace.");
			skip_to_rbrace (cfile, 1);
			if (recordp)
				skip_to_semi (cfile);
			return 0;
		}
	}
	if (!parse_semi (cfile)) {
		parse_warn (cfile, "semicolon expected.");
		skip_to_semi (cfile);
		if (recordp)
			skip_to_semi (cfile);
		return 0;
	}
	if (has_encapsulation && arrayp) {
		parse_warn (cfile,
			    "Arrays of encapsulations don't make sense.");
		return 0;
	}
	if (has_encapsulation && tokbuf [0] == 'E')
		has_encapsulation = 0;
	s = dmalloc (tokix +
		     (arrayp ? 1 : 0) +
		     (has_encapsulation ? 1 : 0) + 1, MDL);
	if (!s)
		log_fatal ("no memory for option format.");
	if (has_encapsulation)
		s [0] = 'e';
	memcpy (s + has_encapsulation, tokbuf, tokix);
	tokix += has_encapsulation;
	if (arrayp)
		s [tokix++] = (arrayp > recordp) ? 'a' : 'A';
	s [tokix] = 0;
	option -> format = s;
	if (option -> universe -> options [option -> code]) {
		/* XXX Free the option, but we can't do that now because they
		   XXX may start out static. */
	}
	option -> universe -> options [option -> code] = option;
	option_hash_add (option -> universe -> hash,
			 (const char *)option -> name,
			 0, option, MDL);
	return 1;
}

/*
 * base64 :== NUMBER_OR_STRING
 */

int parse_base64 (data, cfile)
	struct data_string *data;
	struct parse *cfile;
{
	enum dhcp_token token;
	const char *val;
	int i, j, k;
	unsigned acc = 0;
	static unsigned char
		from64 [] = {64, 64, 64, 64, 64, 64, 64, 64,  /*  \"#$%&' */
			     64, 64, 64, 62, 64, 64, 64, 63,  /* ()*+,-./ */
			     52, 53, 54, 55, 56, 57, 58, 59,  /* 01234567 */
			     60, 61, 64, 64, 64, 64, 64, 64,  /* 89:;<=>? */
			     64, 0, 1, 2, 3, 4, 5, 6,	      /* @ABCDEFG */
			     7, 8, 9, 10, 11, 12, 13, 14,     /* HIJKLMNO */
			     15, 16, 17, 18, 19, 20, 21, 22,  /* PQRSTUVW */
			     23, 24, 25, 64, 64, 64, 64, 64,  /* XYZ[\]^_ */
			     64, 26, 27, 28, 29, 30, 31, 32,  /* 'abcdefg */
			     33, 34, 35, 36, 37, 38, 39, 40,  /* hijklmno */
			     41, 42, 43, 44, 45, 46, 47, 48,  /* pqrstuvw */
			     49, 50, 51, 64, 64, 64, 64, 64}; /* xyz{|}~  */
	struct string_list *bufs = (struct string_list *)0,
			   *last = (struct string_list *)0,
			   *t;
	int cc = 0;
	int terminated = 0;
	
	/* It's possible for a + or a / to cause a base64 quantity to be
	   tokenized into more than one token, so we have to parse them all
	   in before decoding. */
	do {
		unsigned l;

		token = next_token (&val, &l, cfile);
		t = dmalloc (l + sizeof *t, MDL);
		if (!t)
			log_fatal ("no memory for base64 buffer.");
		memset (t, 0, (sizeof *t) - 1);
		memcpy (t -> string, val, l + 1);
		cc += l;
		if (last)
			last -> next = t;
		else
			bufs = t;
		last = t;
		token = peek_token (&val, (unsigned *)0, cfile);
	} while (token == NUMBER_OR_NAME || token == NAME || token == EQUAL ||
		 token == NUMBER || token == PLUS || token == SLASH ||
		 token == STRING);

	data -> len = cc;
	data -> len = (data -> len * 3) / 4;
	if (!buffer_allocate (&data -> buffer, data -> len, MDL)) {
		parse_warn (cfile, "can't allocate buffer for base64 data.");
		data -> len = 0;
		data -> data = (unsigned char *)0;
		return 0;
	}
		
	j = k = 0;
	for (t = bufs; t; t = t -> next) {
	    for (i = 0; t -> string [i]; i++) {
		unsigned foo = t -> string [i];
		if (terminated && foo != '=') {
			parse_warn (cfile,
				    "stuff after base64 '=' terminator: %s.",
				    &t -> string [i]);
			goto bad;
		}
		if (foo < ' ' || foo > 'z') {
		      bad64:
			parse_warn (cfile,
				    "invalid base64 character %d.",
				    t -> string [i]);
		      bad:
			data_string_forget (data, MDL);
			goto out;
		}
		if (foo == '=')
			terminated = 1;
		else {
			foo = from64 [foo - ' '];
			if (foo == 64)
				goto bad64;
			acc = (acc << 6) + foo;
			switch (k % 4) {
			      case 0:
				break;
			      case 1:
				data -> buffer -> data [j++] = (acc >> 4);
				acc = acc & 0x0f;
				break;
				
			      case 2:
				data -> buffer -> data [j++] = (acc >> 2);
				acc = acc & 0x03;
				break;
			      case 3:
				data -> buffer -> data [j++] = acc;
				acc = 0;
				break;
			}
		}
		k++;
	    }
	}
	if (k % 4) {
		if (acc) {
			parse_warn (cfile,
				    "partial base64 value left over: %d.",
				    acc);
		}
	}
	data -> len = j;
	data -> data = data -> buffer -> data;
      out:
	for (t = bufs; t; t = last) {
		last = t -> next;
		dfree (t, MDL);
	}
	if (data -> len)
		return 1;
	else
		return 0;
}


/*
 * colon-seperated-hex-list :== NUMBER |
 *				NUMBER COLON colon-seperated-hex-list
 */

int parse_cshl (data, cfile)
	struct data_string *data;
	struct parse *cfile;
{
	u_int8_t ibuf [128];
	unsigned ilen = 0;
	unsigned tlen = 0;
	struct option_tag *sl = (struct option_tag *)0;
	struct option_tag *next, **last = &sl;
	enum dhcp_token token;
	const char *val;
	unsigned char *rvp;

	do {
		token = next_token (&val, (unsigned *)0, cfile);
		if (token != NUMBER && token != NUMBER_OR_NAME) {
			parse_warn (cfile, "expecting hexadecimal number.");
			skip_to_semi (cfile);
			for (; sl; sl = next) {
				next = sl -> next;
				dfree (sl, MDL);
			}
			return 0;
		}
		if (ilen == sizeof ibuf) {
			next = (struct option_tag *)
				dmalloc (ilen - 1 +
					 sizeof (struct option_tag), MDL);
			if (!next)
				log_fatal ("no memory for string list.");
			memcpy (next -> data, ibuf, ilen);
			*last = next;
			last = &next -> next;
			tlen += ilen;
			ilen = 0;
		}
		convert_num (cfile, &ibuf [ilen++], val, 16, 8);

		token = peek_token (&val, (unsigned *)0, cfile);
		if (token != COLON)
			break;
		token = next_token (&val, (unsigned *)0, cfile);
	} while (1);

	if (!buffer_allocate (&data -> buffer, tlen + ilen, MDL))
		log_fatal ("no memory to store octet data.");
	data -> data = &data -> buffer -> data [0];
	data -> len = tlen + ilen;
	data -> terminated = 0;

	rvp = &data -> buffer -> data [0];
	while (sl) {
		next = sl -> next;
		memcpy (rvp, sl -> data, sizeof ibuf);
		rvp += sizeof ibuf;
		dfree (sl, MDL);
		sl = next;
	}
	
	memcpy (rvp, ibuf, ilen);
	return 1;
}

/*
 * executable-statements :== executable-statement executable-statements |
 *			     executable-statement
 *
 * executable-statement :==
 *	IF if-statement |
 * 	ADD class-name SEMI |
 *	BREAK SEMI |
 *	OPTION option-parameter SEMI |
 *	SUPERSEDE option-parameter SEMI |
 *	PREPEND option-parameter SEMI |
 *	APPEND option-parameter SEMI
 */

int parse_executable_statements (statements, cfile, lose, case_context)
	struct executable_statement **statements;
	struct parse *cfile;
	int *lose;
	enum expression_context case_context;
{
	struct executable_statement **next;

	next = statements;
	while (parse_executable_statement (next, cfile, lose, case_context))
		next = &((*next) -> next);
	if (!*lose)
		return 1;
	return 0;
}

int parse_executable_statement (result, cfile, lose, case_context)
	struct executable_statement **result;
	struct parse *cfile;
	int *lose;
	enum expression_context case_context;
{
	enum dhcp_token token;
	const char *val;
	struct executable_statement base;
	struct class *cta;
	struct option *option;
	struct option_cache *cache;
	int known;
	int flag;
	int i;
	struct dns_zone *zone;
	isc_result_t status;
	char *s;

	token = peek_token (&val, (unsigned *)0, cfile);
	switch (token) {
	      case IF:
		next_token (&val, (unsigned *)0, cfile);
		return parse_if_statement (result, cfile, lose);

	      case TOKEN_ADD:
		token = next_token (&val, (unsigned *)0, cfile);
		token = next_token (&val, (unsigned *)0, cfile);
		if (token != STRING) {
			parse_warn (cfile, "expecting class name.");
			skip_to_semi (cfile);
			*lose = 1;
			return 0;
		}
		cta = (struct class *)0;
		status = find_class (&cta, val, MDL);
		if (status != ISC_R_SUCCESS) {
			parse_warn (cfile, "class %s: %s",
				    val, isc_result_totext (status));
			skip_to_semi (cfile);
			*lose = 1;
			return 0;
		}
		if (!parse_semi (cfile)) {
			*lose = 1;
			return 0;
		}
		if (!executable_statement_allocate (result, MDL))
			log_fatal ("no memory for new statement.");
		(*result) -> op = add_statement;
		(*result) -> data.add = cta;
		break;

	      case BREAK:
		token = next_token (&val, (unsigned *)0, cfile);
		if (!parse_semi (cfile)) {
			*lose = 1;
			return 0;
		}
		if (!executable_statement_allocate (result, MDL))
			log_fatal ("no memory for new statement.");
		(*result) -> op = break_statement;
		break;

	      case SEND: