path: root/usr.sbin/dhcp/client/clparse.c

/* clparse.c

   Parser for dhclient config and lease files... */

/*
 * Copyright (c) 1997 The Internet Software Consortium.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of The Internet Software Consortium nor the names
 *    of its contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
 * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * This software has been written for the Internet Software Consortium
 * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
 * Enterprises.  To learn more about the Internet Software Consortium,
 * see ``http://www.vix.com/isc''.  To learn more about Vixie
 * Enterprises, see ``http://www.vix.com''.
 */

#ifndef lint
static char copyright[] =
"$Id: clparse.c,v 1.1 1998/08/18 03:43:22 deraadt Exp $ Copyright (c) 1997 The Internet Software Consortium.  All rights reserved.\n";
#endif /* not lint */

#include "dhcpd.h"
#include "dhctoken.h"

static TIME parsed_time;

struct client_config top_level_config;
u_int32_t requested_lease_time;

/* client-conf-file :== client-declarations EOF
   client-declarations :== <nil>
			 | client-declaration
			 | client-declarations client-declaration */

int read_client_conf ()
{
	FILE *cfile;
	char *val;
	int token;
	int declaration = 0;
	struct client_config *config;
	struct client_state *state;
	struct interface_info *ip;

	new_parse (path_dhclient_conf);

	/* Set up the initial dhcp option universe. */
	initialize_universes ();

	/* Initialize the top level client configuration. */
	memset (&top_level_config, 0, sizeof top_level_config);

	/* Set some defaults... */
	top_level_config.timeout = 60;
	top_level_config.select_interval = 0;
	top_level_config.reboot_timeout = 10;
	top_level_config.retry_interval = 300;
	top_level_config.backoff_cutoff = 120;
	top_level_config.initial_interval = 10;
	top_level_config.bootp_policy = ACCEPT;
	top_level_config.script_name = "/etc/dhclient-script";
	top_level_config.requested_options
		[top_level_config.requested_option_count++] =
			DHO_SUBNET_MASK;
	top_level_config.requested_options
		[top_level_config.requested_option_count++] =
			DHO_BROADCAST_ADDRESS;
	top_level_config.requested_options
		[top_level_config.requested_option_count++] =
			DHO_TIME_OFFSET;
	top_level_config.requested_options
		[top_level_config.requested_option_count++] =
			DHO_ROUTERS;
	top_level_config.requested_options
		[top_level_config.requested_option_count++] =
			DHO_DOMAIN_NAME;
	top_level_config.requested_options
		[top_level_config.requested_option_count++] =
			DHO_DOMAIN_NAME_SERVERS;
	top_level_config.requested_options
		[top_level_config.requested_option_count++] =
			DHO_HOST_NAME;
	requested_lease_time = 7200;
	top_level_config.send_options [DHO_DHCP_LEASE_TIME].data
		= (unsigned char *)&requested_lease_time;
	top_level_config.send_options [DHO_DHCP_LEASE_TIME].len
		= sizeof requested_lease_time;

	if ((cfile = fopen (path_dhclient_conf, "r")) == NULL)
		error ("Can't open %s: %m", path_dhclient_conf);
	do {
		token = peek_token (&val, cfile);
		if (token == EOF)
			break;
		parse_client_statement (cfile, (struct interface_info *)0,
					&top_level_config);
	} while (1);
	token = next_token (&val, cfile); /* Clear the peek buffer */

	/* Set up state and config structures for clients that don't
	   have per-interface configuration declarations. */
	config = (struct client_config *)0;
	for (ip = interfaces; ip; ip = ip -> next) {
		if (!ip -> client) {
			ip -> client = (struct client_state *)
				malloc (sizeof (struct client_state));
			if (!ip -> client)
				error ("no memory for client state.");
			memset (ip -> client, 0, sizeof *(ip -> client));
		}
		if (!ip -> client -> config) {
			if (!config) {
				config = (struct client_config *)
					malloc (sizeof (struct client_config));
				if (!config)
					error ("no memory for client config.");
				memcpy (config, &top_level_config,
					sizeof top_level_config);
			}
			ip -> client -> config = config;
		}
	}

	return !warnings_occurred;
}

/* lease-file :== client-lease-statements EOF
   client-lease-statements :== <nil>
		     | client-lease-statements LEASE client-lease-statement */

void read_client_leases ()
{
	FILE *cfile;
	char *val;
	int token;

	new_parse (path_dhclient_db);

	/* Open the lease file.   If we can't open it, just return -
	   we can safely trust the server to remember our state. */
	if ((cfile = fopen (path_dhclient_db, "r")) == NULL)
		return;
	do {
		token = next_token (&val, cfile);
		if (token == EOF)
			break;
		if (token != LEASE) {
			warn ("Corrupt lease file - possible data loss!");
			skip_to_semi (cfile);
			break;
		} else
			parse_client_lease_statement (cfile, 0);

	} while (1);
}

/* client-declaration :== 
	SEND option-decl |
	DEFAULT option-decl |
	SUPERSEDE option-decl |
	PREPEND option-decl |
	APPEND option-decl |
	hardware-declaration |
	REQUEST option-list |
	REQUIRE option-list |
	TIMEOUT number |
	RETRY number |
	REBOOT number |
	SELECT_TIMEOUT number |
	SCRIPT string |
	interface-declaration |
	LEASE client-lease-statement |
	ALIAS client-lease-statement */

void parse_client_statement (cfile, ip, config)
	FILE *cfile;
	struct interface_info *ip;
	struct client_config *config;
{
	int token;
	char *val;
	struct option *option;

	switch (next_token (&val, cfile)) {
	      case SEND:
		parse_option_decl (cfile, &config -> send_options [0]);
		return;

	      case DEFAULT:
		option = parse_option_decl (cfile, &config -> defaults [0]);
		if (option)
			config -> default_actions [option -> code] =
				ACTION_DEFAULT;
		return;

	      case SUPERSEDE:
		option = parse_option_decl (cfile, &config -> defaults [0]);
		if (option)
			config -> default_actions [option -> code] =
				ACTION_SUPERSEDE;
		return;

	      case APPEND:
		option = parse_option_decl (cfile, &config -> defaults [0]);
		if (option)
			config -> default_actions [option -> code] =
				ACTION_APPEND;
		return;

	      case PREPEND:
		option = parse_option_decl (cfile, &config -> defaults [0]);
		if (option)
			config -> default_actions [option -> code] =
				ACTION_PREPEND;
		return;

	      case MEDIA:
		parse_string_list (cfile, &config -> media, 1);
		return;

	      case HARDWARE:
		if (ip) {
			parse_hardware_param (cfile, &ip -> hw_address);
		} else {
			parse_warn ("hardware address parameter %s",
				    "not allowed here.");
			skip_to_semi (cfile);
		}
		return;

	      case REQUEST:
		config -> requested_option_count =
			parse_option_list (cfile, config -> requested_options);
		return;

	      case REQUIRE:
		memset (config -> required_options, 0,
			sizeof config -> required_options);
		parse_option_list (cfile, config -> required_options);
		return;

	      case TIMEOUT:
		parse_lease_time (cfile, &config -> timeout);
		return;

	      case RETRY:
		parse_lease_time (cfile, &config -> retry_interval);
		return;

	      case SELECT_TIMEOUT:
		parse_lease_time (cfile, &config -> select_interval);
		return;

	      case REBOOT:
		parse_lease_time (cfile, &config -> reboot_timeout);
		return;

	      case BACKOFF_CUTOFF:
		parse_lease_time (cfile, &config -> backoff_cutoff);
		return;

	      case INITIAL_INTERVAL:
		parse_lease_time (cfile, &config -> initial_interval);
		return;

	      case SCRIPT:
		config -> script_name = parse_string (cfile);
		return;

	      case INTERFACE:
		if (ip)
			parse_warn ("nested interface declaration.");
		parse_interface_declaration (cfile, config);
		return;

	      case LEASE:
		parse_client_lease_statement (cfile, 1);
		return;

	      case ALIAS:
		parse_client_lease_statement (cfile, 2);
		return;

	      case REJECT:
		parse_reject_statement (cfile, config);
		return;

	      default:
		parse_warn ("expecting a statement.");
		skip_to_semi (cfile);
		break;
	}
	token = next_token (&val, cfile);
	if (token != SEMI) {
		parse_warn ("semicolon expected.");
		skip_to_semi (cfile);
	}
}

int parse_X (cfile, buf, max)
	FILE *cfile;
	u_int8_t *buf;
	int max;
{
	int token;
	char *val;
	int len;
	u_int8_t *s;

	token = peek_token (&val, cfile);
	if (token == NUMBER_OR_NAME || token == NUMBER) {
		len = 0;
		do {
			token = next_token (&val, cfile);
			if (token != NUMBER && token != NUMBER_OR_NAME) {
				parse_warn ("expecting hexadecimal constant.");
				skip_to_semi (cfile);
				return 0;
			}
			convert_num (&buf [len], val, 16, 8);
			if (len++ > max) {
				parse_warn ("hexadecimal constant too long.");
				skip_to_semi (cfile);
				return 0;
			}
			token = peek_token (&val, cfile);
			if (token == COLON)
				token = next_token (&val, cfile);
		} while (token == COLON);
		val = (char *)buf;
	} else if (token == STRING) {
		token = next_token (&val, cfile);
		len = strlen (val);
		if (len + 1 > max) {
			parse_warn ("string constant too long.");
			skip_to_semi (cfile);
			return 0;
		}
		memcpy (buf, val, len + 1);
	} else {
		parse_warn ("expecting string or hexadecimal data");
		skip_to_semi (cfile);
		return 0;
	}
	return len;
}

/* option-list :== option_name |
   		   option_list COMMA option_name */

int parse_option_list (cfile, list)
	FILE *cfile;
	u_int8_t *list;
{
	int ix, i;
	int token;
	char *val;

	ix = 0;
	do {
		token = next_token (&val, cfile);
		if (!is_identifier (token)) {
			parse_warn ("expected option name.");
			skip_to_semi (cfile);
			return 0;
		}
		for (i = 0; i < 256; i++) {
			if (!strcasecmp (dhcp_options [i].name, val))
				break;
		}
		if (i == 256) {
			parse_warn ("%s: expected option name.");
			skip_to_semi (cfile);
			return 0;
		}
		list [ix++] = i;
		if (ix == 256) {
			parse_warn ("%s: too many options.", val);
			skip_to_semi (cfile);
			return 0;
		}
		token = next_token (&val, cfile);
	} while (token == COMMA);
	if (token != SEMI) {
		parse_warn ("expecting semicolon.");
		skip_to_semi (cfile);
		return 0;
	}
	return ix;
}

/* interface-declaration :==
   	INTERFACE string LBRACE client-declarations RBRACE */

void parse_interface_declaration (cfile, outer_config)
	FILE *cfile;
	struct client_config *outer_config;
{
	int token;
	char *val;

	struct interface_info dummy_interface, *ip;
	struct client_state dummy_state;
	struct client_config dummy_config;

	token = next_token (&val, cfile);
	if (token != STRING) {
		parse_warn ("expecting interface name (in quotes).");
		skip_to_semi (cfile);
		return;
	}

	ip = interface_or_dummy (val);

	if (!ip -> client)
		make_client_state (ip);

	if (!ip -> client -> config)
		make_client_config (ip, outer_config);

	ip -> flags &= ~INTERFACE_AUTOMATIC;
	interfaces_requested = 1;

	token = next_token (&val, cfile);
	if (token != LBRACE) {
		parse_warn ("expecting left brace.");
		skip_to_semi (cfile);
		return;
	}

	do {
		token = peek_token (&val, cfile);
		if (token == EOF) {
			parse_warn ("unterminated interface declaration.");
			return;
		}
		if (token == RBRACE)
			break;
		parse_client_statement (cfile, ip, ip -> client -> config);
	} while (1);
	token = next_token (&val, cfile);
}

struct interface_info *interface_or_dummy (name)
	char *name;
{
	struct interface_info *ip;

	/* Find the interface (if any) that matches the name. */
	for (ip = interfaces; ip; ip = ip -> next) {
		if (!strcmp (ip -> name, name))
			break;
	}

	/* If it's not a real interface, see if it's on the dummy list. */
	if (!ip) {
		for (ip = dummy_interfaces; ip; ip = ip -> next) {
			if (!strcmp (ip -> name, name))
				break;
		}
	}

	/* If we didn't find an interface, make a dummy interface as
	   a placeholder. */
	if (!ip) {
		ip = ((struct interface_info *)malloc (sizeof *ip));
		if (!ip)
			error ("Insufficient memory to record interface %s",
			       name);
		memset (ip, 0, sizeof *ip);
		strcpy (ip -> name, name);
		ip -> next = dummy_interfaces;
		dummy_interfaces = ip;
	}
	return ip;
}

void make_client_state (ip)
	struct interface_info *ip;
{
	ip -> client =
		((struct client_state *)malloc (sizeof *(ip -> client)));
	if (!ip -> client)
		error ("no memory for state on %s\n", ip -> name);
	memset (ip -> client, 0, sizeof *(ip -> client));
}

void make_client_config (ip, config)
	struct interface_info *ip;
	struct client_config *config;
{
	ip -> client -> config =
		((struct client_config *)
		 malloc (sizeof (struct client_config)));
	if (!ip -> client -> config)
		error ("no memory for config for %s\n", ip -> name);
	memset (ip -> client -> config, 0,
		sizeof *(ip -> client -> config));
	memcpy (ip -> client -> config, config, sizeof *config);
}

/* client-lease-statement :==
	RBRACE client-lease-declarations LBRACE

	client-lease-declarations :==
		<nil> |
		client-lease-declaration |
		client-lease-declarations client-lease-declaration */


void parse_client_lease_statement (cfile, is_static)
	FILE *cfile;
	int is_static;
{
	struct client_lease *lease, *lp, *pl;
	struct interface_info *ip;
	int token;
	char *val;

	token = next_token (&val, cfile);
	if (token != LBRACE) {
		parse_warn ("expecting left brace.");
		skip_to_semi (cfile);
		return;
	}

	lease = (struct client_lease *)malloc (sizeof (struct client_lease));
	if (!lease)
		error ("no memory for lease.\n");
	memset (lease, 0, sizeof *lease);
	lease -> is_static = is_static;

	ip = (struct interface_info *)0;

	do {
		token = peek_token (&val, cfile);
		if (token == EOF) {
			parse_warn ("unterminated lease declaration.");
			return;
		}
		if (token == RBRACE)
			break;
		parse_client_lease_declaration (cfile, lease, &ip);
	} while (1);
	token = next_token (&val, cfile);

	/* If the lease declaration didn't include an interface
	   declaration that we recognized, it's of no use to us. */
	if (!ip) {
		free_client_lease (lease);
		return;
	}

	/* Make sure there's a client state structure... */
	if (!ip -> client)
		make_client_state (ip);

	/* If this is an alias lease, it doesn't need to be sorted in. */
	if (is_static == 2) {
		ip -> client -> alias = lease;
		return;
	}

	/* The new lease may supersede a lease that's not the
	   active lease but is still on the lease list, so scan the
	   lease list looking for a lease with the same address, and
	   if we find it, toss it. */
	pl = (struct client_lease *)0;
	for (lp = ip -> client -> leases; lp; lp = lp -> next) {
		if (lp -> address.len == lease -> address.len &&
		    !memcmp (lp -> address.iabuf, lease -> address.iabuf,
			     lease -> address.len)) {
			if (pl)
				pl -> next = lp -> next;
			else
				ip -> client -> leases = lp -> next;
			free_client_lease (lp);
			break;
		}
	}

	/* If this is a preloaded lease, just put it on the list of recorded
	   leases - don't make it the active lease. */
	if (is_static) {
		lease -> next = ip -> client -> leases;
		ip -> client -> leases = lease;
		return;
	}
		
	/* The last lease in the lease file on a particular interface is
	   the active lease for that interface.    Of course, we don't know
	   what the last lease in the file is until we've parsed the whole
	   file, so at this point, we assume that the lease we just parsed
	   is the active lease for its interface.   If there's already
	   an active lease for the interface, and this lease is for the same
	   ip address, then we just toss the old active lease and replace
	   it with this one.   If this lease is for a different address,
	   then if the old active lease has expired, we dump it; if not,
	   we put it on the list of leases for this interface which are
	   still valid but no longer active. */
	if (ip -> client -> active) {
		if (ip -> client -> active -> expiry < cur_time)
			free_client_lease (ip -> client -> active);
		else if (ip -> client -> active -> address.len ==
			 lease -> address.len &&
			 !memcmp (ip -> client -> active -> address.iabuf,
				  lease -> address.iabuf,
				  lease -> address.len))
			free_client_lease (ip -> client -> active);
		else {
			ip -> client -> active -> next =
				ip -> client -> leases;
			ip -> client -> leases = ip -> client -> active;
		}
	}
	ip -> client -> active = lease;

	/* phew. */
}

/* client-lease-declaration :==
	BOOTP |
	INTERFACE string |
	FIXED_ADDR ip_address |
	FILENAME string |
	SERVER_NAME string |
	OPTION option-decl |
	RENEW time-decl |
	REBIND time-decl |
	EXPIRE time-decl */

void parse_client_lease_declaration (cfile, lease, ipp)
	FILE *cfile;
	struct client_lease *lease;
	struct interface_info **ipp;
{
	int token;
	char *val;
	char *t, *n;
	struct interface_info *ip;

	switch (next_token (&val, cfile)) {
	      case BOOTP:
		lease -> is_bootp = 1;
		break;

	      case INTERFACE:
		token = next_token (&val, cfile);
		if (token != STRING) {
			parse_warn ("expecting interface name (in quotes).");
			skip_to_semi (cfile);
			break;
		}
		ip = interface_or_dummy (val);
		*ipp = ip;
		break;

	      case FIXED_ADDR:
		if (!parse_ip_addr (cfile, &lease -> address))
			return;
		break;

	      case MEDIUM:
		parse_string_list (cfile, &lease -> medium, 0);
		return;

	      case FILENAME:
		lease -> filename = parse_string (cfile);
		return;

	      case SERVER_NAME:
		lease -> server_name = parse_string (cfile);
		return;

	      case RENEW:
		lease -> renewal = parse_date (cfile);
		return;

	      case REBIND:
		lease -> rebind = parse_date (cfile);
		return;

	      case EXPIRE:
		lease -> expiry = parse_date (cfile);
		return;

	      case OPTION:
		parse_option_decl (cfile, lease -> options);
		return;

	      default:
		parse_warn ("expecting lease declaration.");
		skip_to_semi (cfile);
		break;
	}
	token = next_token (&val, cfile);
	if (token != SEMI) {
		parse_warn ("expecting semicolon.");
		skip_to_semi (cfile);
	}
}

struct option *parse_option_decl (cfile, options)
	FILE *cfile;
	struct option_data *options;
{
	char *val;
	int token;
	u_int8_t buf [4];
	u_int8_t hunkbuf [1024];
	int hunkix = 0;
	char *vendor;
	char *fmt;
	struct universe *universe;
	struct option *option;
	struct iaddr ip_addr;
	u_int8_t *dp;
	int len;
	int nul_term = 0;

	token = next_token (&val, cfile);
	if (!is_identifier (token)) {
		parse_warn ("expecting identifier after option keyword.");
		if (token != SEMI)
			skip_to_semi (cfile);
		return (struct option *)0;
	}
	vendor = malloc (strlen (val) + 1);
	if (!vendor)
		error ("no memory for vendor information.");
	strcpy (vendor, val);
	token = peek_token (&val, cfile);
	if (token == DOT) {
		/* Go ahead and take the DOT token... */
		token = next_token (&val, cfile);

		/* The next token should be an identifier... */
		token = next_token (&val, cfile);
		if (!is_identifier (token)) {
			parse_warn ("expecting identifier after '.'");
			if (token != SEMI)
				skip_to_semi (cfile);
			return (struct option *)0;
		}

		/* Look up the option name hash table for the specified
		   vendor. */
		universe = (struct universe *)hash_lookup (&universe_hash,
							   vendor, 0);
		/* If it's not there, we can't parse the rest of the
		   declaration. */
		if (!universe) {
			parse_warn ("no vendor named %s.", vendor);
			skip_to_semi (cfile);
			return (struct option *)0;
		}
	} else {
		/* Use the default hash table, which contains all the
		   standard dhcp option names. */
		val = vendor;
		universe = &dhcp_universe;
	}

	/* Look up the actual option info... */
	option = (struct option *)hash_lookup (universe -> hash, val, 0);

	/* If we didn't get an option structure, it's an undefined option. */
	if (!option) {
		if (val == vendor)
			parse_warn ("no option named %s", val);
		else
			parse_warn ("no option named %s for vendor %s",
				    val, vendor);
		skip_to_semi (cfile);
		return (struct option *)0;
	}

	/* Free the initial identifier token. */
	free (vendor);

	/* Parse the option data... */
	do {
		/* Set a flag if this is an array of a simple type (i.e.,
		   not an array of pairs of IP addresses, or something
		   like that. */
		int uniform = option -> format [1] == 'A';

		for (fmt = option -> format; *fmt; fmt++) {
			if (*fmt == 'A')
				break;
			switch (*fmt) {
			      case 'X':
				len = parse_X (cfile, &hunkbuf [hunkix],
					       sizeof hunkbuf - hunkix);
				hunkix += len;
				break;
					
			      case 't': /* Text string... */
				token = next_token (&val, cfile);
				if (token != STRING) {
					parse_warn ("expecting string.");
					skip_to_semi (cfile);
					return (struct option *)0;
				}
				len = strlen (val);
				if (hunkix + len + 1 > sizeof hunkbuf) {
					parse_warn ("option data buffer %s",
						    "overflow");
					skip_to_semi (cfile);
					return (struct option *)0;
				}
				memcpy (&hunkbuf [hunkix], val, len + 1);
				nul_term = 1;
				hunkix += len;
				break;

			      case 'I': /* IP address. */
				if (!parse_ip_addr (cfile, &ip_addr))
					return (struct option *)0;
				len = ip_addr.len;
				dp = ip_addr.iabuf;

			      alloc:
				if (hunkix + len > sizeof hunkbuf) {
					parse_warn ("option data buffer %s",
						    "overflow");
					skip_to_semi (cfile);
					return (struct option *)0;
				}
				memcpy (&hunkbuf [hunkix], dp, len);
				hunkix += len;
				break;

			      case 'L': /* Unsigned 32-bit integer... */
			      case 'l':	/* Signed 32-bit integer... */
				token = next_token (&val, cfile);
				if (token != NUMBER) {
				      need_number:
					parse_warn ("expecting number.");
					if (token != SEMI)
						skip_to_semi (cfile);
					return (struct option *)0;
				}
				convert_num (buf, val, 0, 32);
				len = 4;
				dp = buf;
				goto alloc;

			      case 's':	/* Signed 16-bit integer. */
			      case 'S':	/* Unsigned 16-bit integer. */
				token = next_token (&val, cfile);
				if (token != NUMBER)
					goto need_number;
				convert_num (buf, val, 0, 16);
				len = 2;
				dp = buf;
				goto alloc;

			      case 'b':	/* Signed 8-bit integer. */
			      case 'B':	/* Unsigned 8-bit integer. */
				token = next_token (&val, cfile);
				if (token != NUMBER)
					goto need_number;
				convert_num (buf, val, 0, 8);
				len = 1;
				dp = buf;
				goto alloc;

			      case 'f': /* Boolean flag. */
				token = next_token (&val, cfile);
				if (!is_identifier (token)) {
					parse_warn ("expecting identifier.");
				      bad_flag:
					if (token != SEMI)
						skip_to_semi (cfile);
					return (struct option *)0;
				}
				if (!strcasecmp (val, "true")
				    || !strcasecmp (val, "on"))
					buf [0] = 1;
				else if (!strcasecmp (val, "false")
					 || !strcasecmp (val, "off"))
					buf [0] = 0;
				else {
					parse_warn ("expecting boolean.");
					goto bad_flag;
				}
				len = 1;
				dp = buf;
				goto alloc;

			      default:
				warn ("Bad format %c in parse_option_param.",
				      *fmt);
				skip_to_semi (cfile);
				return (struct option *)0;
			}
		}
		token = next_token (&val, cfile);
	} while (*fmt == 'A' && token == COMMA);

	if (token != SEMI) {
		parse_warn ("semicolon expected.");
		skip_to_semi (cfile);
		return (struct option *)0;
	}

	options [option -> code].data =
		(unsigned char *)malloc (hunkix + nul_term);
	if (!options [option -> code].data)
		error ("out of memory allocating option data.");
	memcpy (options [option -> code].data, hunkbuf, hunkix + nul_term);
	options [option -> code].len = hunkix;
	return option;
}

void parse_string_list (cfile, lp, multiple)
	FILE *cfile;
	struct string_list **lp;
	int multiple;
{
	int token;
	char *val;
	struct string_list *cur, *tmp;

	/* Find the last medium in the media list. */
	if (*lp) {
		for (cur = *lp; cur -> next; cur = cur -> next)
			;
	} else {
		cur = (struct string_list *)0;
	}

	do {
		token = next_token (&val, cfile);
		if (token != STRING) {
			parse_warn ("Expecting media options.");
			skip_to_semi (cfile);
			return;
		}

		tmp = (struct string_list *)malloc (strlen (val) + 1 +
						    sizeof
						    (struct string_list *));
		if (!tmp)
			error ("no memory for string list entry.");

		strcpy (tmp -> string, val);
		tmp -> next = (struct string_list *)0;

		/* Store this medium at the end of the media list. */
		if (cur)
			cur -> next = tmp;
		else
			*lp = tmp;
		cur = tmp;

		token = next_token (&val, cfile);
	} while (multiple && token == COMMA);

	if (token != SEMI) {
		parse_warn ("expecting semicolon.");
		skip_to_semi (cfile);
	}
}

void parse_reject_statement (cfile, config)
	FILE *cfile;
	struct client_config *config;
{
	int token;
	char *val;
	struct iaddr addr;
	struct iaddrlist *list;

	do {
		if (!parse_ip_addr (cfile, &addr)) {
			parse_warn ("expecting IP address.");
			skip_to_semi (cfile);
			return;
		}

		list = (struct iaddrlist *)malloc (sizeof (struct iaddrlist));
		if (!list)
			error ("no memory for reject list!");

		list -> addr = addr;
		list -> next = config -> reject_list;
		config -> reject_list = list;

		token = next_token (&val, cfile);
	} while (token == COMMA);

	if (token != SEMI) {
		parse_warn ("expecting semicolon.");
		skip_to_semi (cfile);
	}
}