From: Ted Lemon <source@isc.org>
Date: Tue, 18 Feb 1997 14:27:53 +0000 (+0000)
Subject: Parser for DHCP client config files
X-Git-Tag: DHCP_970222~64
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7d5f3f4a40794cf250b2dc6588200303d015f899;p=thirdparty%2Fdhcp.git

Parser for DHCP client config files
---

diff --git a/client/clparse.c b/client/clparse.c
new file mode 100644
index 000000000..7d4b1e454
--- /dev/null
+++ b/client/clparse.c
@@ -0,0 +1,781 @@
+/* clparse.c
+
+   Parser for dhclient config and lease files... */
+
+/*
+ * Copyright (c) 1995, 1996, 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 1997/02/18 14:27:53 mellon Exp $ Copyright (c) 1995, 1996 The Internet Software Consortium.  All rights reserved.\n";
+#endif /* not lint */
+
+#include "dhcpd.h"
+#include "dhctoken.h"
+
+static TIME parsed_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);
+
+	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 (!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 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);
+
+	} while (1);
+}
+
+/* client-declaration :== 
+	HOSTNAME string |
+	hardware-declaration |
+	client-identifier-declaration |
+	REQUEST option-list |
+	REQUIRE option-list |
+	TIMEOUT number |
+	RETRY number |
+	SELECT_TIMEOUT number |
+	SCRIPT string |
+	interface-declaration |
+	client-lease-statement */
+
+void parse_client_statement (cfile, ip, config)
+	FILE *cfile;
+	struct interface_info *ip;
+	struct client_config *config;
+{
+	int token;
+	char *val;
+	char *t, *n;
+	struct hardware hardware;
+
+	switch (next_token (&val, cfile)) {
+	      case HOSTNAME:
+		config -> dns_hostname = parse_string (cfile);
+		return;
+
+	      case CLIENT_IDENTIFIER:
+		config -> cid_len = parse_X (cfile,
+					     &config -> client_identifier);
+		break;
+
+	      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 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);
+		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, p)
+	FILE *cfile;
+	u_int8_t **p;
+{
+	int token;
+	char *val;
+	unsigned char buf [1024];
+	int buflen;
+	unsigned char *s;
+
+	token = peek_token (&val, cfile);
+	if (token == NUMBER_OR_NAME || token == NUMBER) {
+		do {
+			token = next_token (&val, cfile);
+			if (token != NUMBER && token != NUMBER_OR_NAME) {
+				parse_warn ("expecting hexadecimal constant.");
+				skip_to_semi (cfile);
+				*p = (u_int8_t *)0;
+				return 0;
+			}
+			convert_num (&buf [buflen], val, 16, 8);
+			if (buflen++ > sizeof buf) {
+				parse_warn ("hexadecimal constant too long.");
+				skip_to_semi (cfile);
+				*p = (u_int8_t *)0;
+				return 0;
+			}
+			token = peek_token (&val, cfile);
+			if (token == COLON)
+				token = next_token (&val, cfile);
+		} while (token == COLON);
+		val = buf;
+	} else if (token == STRING) {
+		token = next_token (&val, cfile);
+		buflen = strlen (val) + 1;
+	} else {
+		parse_warn ("expecting string or hexadecimal data");
+		skip_to_semi (cfile);
+		*p = (u_int8_t *)0;
+		return 0;
+	}
+	*p = malloc (buflen);
+	if (!*p)
+		error ("out of memory allocating client id.\n");
+	memcpy (*p, val, buflen);
+	return buflen;
+}
+
+/* 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;
+	}
+
+	/* Find the interface (if any) that matches the name. */
+	for (ip = interfaces; ip; ip = ip -> next) {
+		if (!strcmp (ip -> name, val))
+			break;
+	}
+
+	/* If we didn't find an interface, put up a dummy interface so
+	   that we have some place to parse the bogus data.   Otherwise,
+	   allocate a client state and client config structure for the
+	   interface. */
+	if (!ip) {
+		parse_warn ("interface %s not found.", val);
+		ip = &dummy_interface;
+		memset (ip, 0, sizeof dummy_interface);
+		ip -> client = &dummy_state;
+		memset (ip -> client, 0, sizeof dummy_state);
+		ip -> client -> config = &dummy_config;
+	} else {
+		ip -> client = ((struct client_state *)
+				malloc (sizeof (struct client_state)));
+		if (!ip -> client)
+			error ("no memory for state for %s\n", val);
+		memset (ip -> client, 0, sizeof *(ip -> client));
+		ip -> client -> config =
+			((struct client_config *)
+			 malloc (sizeof (struct client_config)));
+		if (!ip -> client -> config)
+			error ("no memory for config for %s\n", val);
+		memset (ip -> client -> config, 0,
+			sizeof *(ip -> client -> config));
+	}
+	memcpy (ip -> client -> config, outer_config, sizeof *outer_config);
+
+	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);
+}
+
+/* client-lease-statement :==
+	LEASE RBRACE client-lease-declarations LBRACE
+
+	client-lease-declarations :==
+		<nil> |
+		client-lease-declaration |
+		client-lease-declarations client-lease-declaration */
+
+
+void parse_client_lease_statement (cfile)
+	FILE *cfile;
+{
+	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);
+
+	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;
+	}
+
+	/* 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;
+
+	/* The current 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;
+		}
+	}
+	/* phew. */
+}
+
+/* client-lease-declaration :==
+	INTERFACE string |
+	FIXED_ADDR ip_address |
+	FILENAME string |
+	SERVER_NAME string |
+	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 INTERFACE:
+		token = next_token (&val, cfile);
+		if (token != STRING) {
+			parse_warn ("expecting interface name (in quotes).");
+			skip_to_semi (cfile);
+			break;
+		}
+		for (ip = interfaces; ip; ip = ip -> next) {
+			if (!strcmp (ip -> name, val))
+				break;
+		}
+		*ipp = ip;
+		break;
+
+	      case FIXED_ADDR:
+		parse_ip_addr (cfile, &lease -> address);
+		break;
+
+	      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);
+	}
+}
+
+void parse_ip_addr (cfile, addr)
+	FILE *cfile;
+	struct iaddr *addr;
+{
+	char *val;
+	int token;
+
+	addr -> len = 4;
+	parse_numeric_aggregate (cfile, addr -> iabuf,
+				 &addr -> len, DOT, 10, 8);
+}	
+
+void parse_option_decl (cfile, options)
+	FILE *cfile;
+	struct option_data *options;
+{
+	char *val;
+	int token;
+	unsigned char buf [4];
+	char *vendor;
+	char *fmt;
+	struct universe *universe;
+	struct option *option;
+	struct iaddr ip_addr;
+	char *dp;
+	int len;
+
+	token = next_token (&val, cfile);
+	if (!is_identifier (token)) {
+		parse_warn ("expecting identifier after option keyword.");
+		if (token != SEMI)
+			skip_to_semi (cfile);
+		return;
+	}
+	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;
+		}
+
+		/* 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;
+		}
+	} 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;
+	}
+
+	/* 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':
+				options [option -> code].len =
+					parse_X (cfile,
+						 (&options
+						  [option -> code].data));
+				break;
+					
+			      case 't': /* Text string... */
+				options [option -> code].data =
+					parse_string (cfile);
+				options [option -> code].len =
+					strlen (options [option -> code].data);
+				break;
+
+			      case 'I': /* IP address. */
+				parse_ip_addr (cfile, &ip_addr);
+				len = ip_addr.len;
+				dp = ip_addr.iabuf;
+
+			      alloc:
+				options [option -> code].data =	malloc (len);
+				if (!options [option -> code].data)
+					error ("no memory for option data.");
+				memcpy (options [option -> code].data,
+					dp, len);
+				options [option -> code].len = 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;
+				}
+				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;
+				}
+				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;
+			}
+		}
+		if (*fmt == 'A') {
+			token = peek_token (&val, cfile);
+			if (token == COMMA) {
+				token = next_token (&val, cfile);
+				continue;
+			}
+			break;
+		}
+	} while (*fmt == 'A');
+
+	token = next_token (&val, cfile);
+	if (token != SEMI) {
+		parse_warn ("semicolon expected.");
+		skip_to_semi (cfile);
+		return;
+	}
+}
+
diff --git a/clparse.c b/clparse.c
new file mode 100644
index 000000000..7d4b1e454
--- /dev/null
+++ b/clparse.c
@@ -0,0 +1,781 @@
+/* clparse.c
+
+   Parser for dhclient config and lease files... */
+
+/*
+ * Copyright (c) 1995, 1996, 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 1997/02/18 14:27:53 mellon Exp $ Copyright (c) 1995, 1996 The Internet Software Consortium.  All rights reserved.\n";
+#endif /* not lint */
+
+#include "dhcpd.h"
+#include "dhctoken.h"
+
+static TIME parsed_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);
+
+	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 (!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 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);
+
+	} while (1);
+}
+
+/* client-declaration :== 
+	HOSTNAME string |
+	hardware-declaration |
+	client-identifier-declaration |
+	REQUEST option-list |
+	REQUIRE option-list |
+	TIMEOUT number |
+	RETRY number |
+	SELECT_TIMEOUT number |
+	SCRIPT string |
+	interface-declaration |
+	client-lease-statement */
+
+void parse_client_statement (cfile, ip, config)
+	FILE *cfile;
+	struct interface_info *ip;
+	struct client_config *config;
+{
+	int token;
+	char *val;
+	char *t, *n;
+	struct hardware hardware;
+
+	switch (next_token (&val, cfile)) {
+	      case HOSTNAME:
+		config -> dns_hostname = parse_string (cfile);
+		return;
+
+	      case CLIENT_IDENTIFIER:
+		config -> cid_len = parse_X (cfile,
+					     &config -> client_identifier);
+		break;
+
+	      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 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);
+		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, p)
+	FILE *cfile;
+	u_int8_t **p;
+{
+	int token;
+	char *val;
+	unsigned char buf [1024];
+	int buflen;
+	unsigned char *s;
+
+	token = peek_token (&val, cfile);
+	if (token == NUMBER_OR_NAME || token == NUMBER) {
+		do {
+			token = next_token (&val, cfile);
+			if (token != NUMBER && token != NUMBER_OR_NAME) {
+				parse_warn ("expecting hexadecimal constant.");
+				skip_to_semi (cfile);
+				*p = (u_int8_t *)0;
+				return 0;
+			}
+			convert_num (&buf [buflen], val, 16, 8);
+			if (buflen++ > sizeof buf) {
+				parse_warn ("hexadecimal constant too long.");
+				skip_to_semi (cfile);
+				*p = (u_int8_t *)0;
+				return 0;
+			}
+			token = peek_token (&val, cfile);
+			if (token == COLON)
+				token = next_token (&val, cfile);
+		} while (token == COLON);
+		val = buf;
+	} else if (token == STRING) {
+		token = next_token (&val, cfile);
+		buflen = strlen (val) + 1;
+	} else {
+		parse_warn ("expecting string or hexadecimal data");
+		skip_to_semi (cfile);
+		*p = (u_int8_t *)0;
+		return 0;
+	}
+	*p = malloc (buflen);
+	if (!*p)
+		error ("out of memory allocating client id.\n");
+	memcpy (*p, val, buflen);
+	return buflen;
+}
+
+/* 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;
+	}
+
+	/* Find the interface (if any) that matches the name. */
+	for (ip = interfaces; ip; ip = ip -> next) {
+		if (!strcmp (ip -> name, val))
+			break;
+	}
+
+	/* If we didn't find an interface, put up a dummy interface so
+	   that we have some place to parse the bogus data.   Otherwise,
+	   allocate a client state and client config structure for the
+	   interface. */
+	if (!ip) {
+		parse_warn ("interface %s not found.", val);
+		ip = &dummy_interface;
+		memset (ip, 0, sizeof dummy_interface);
+		ip -> client = &dummy_state;
+		memset (ip -> client, 0, sizeof dummy_state);
+		ip -> client -> config = &dummy_config;
+	} else {
+		ip -> client = ((struct client_state *)
+				malloc (sizeof (struct client_state)));
+		if (!ip -> client)
+			error ("no memory for state for %s\n", val);
+		memset (ip -> client, 0, sizeof *(ip -> client));
+		ip -> client -> config =
+			((struct client_config *)
+			 malloc (sizeof (struct client_config)));
+		if (!ip -> client -> config)
+			error ("no memory for config for %s\n", val);
+		memset (ip -> client -> config, 0,
+			sizeof *(ip -> client -> config));
+	}
+	memcpy (ip -> client -> config, outer_config, sizeof *outer_config);
+
+	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);
+}
+
+/* client-lease-statement :==
+	LEASE RBRACE client-lease-declarations LBRACE
+
+	client-lease-declarations :==
+		<nil> |
+		client-lease-declaration |
+		client-lease-declarations client-lease-declaration */
+
+
+void parse_client_lease_statement (cfile)
+	FILE *cfile;
+{
+	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);
+
+	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;
+	}
+
+	/* 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;
+
+	/* The current 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;
+		}
+	}
+	/* phew. */
+}
+
+/* client-lease-declaration :==
+	INTERFACE string |
+	FIXED_ADDR ip_address |
+	FILENAME string |
+	SERVER_NAME string |
+	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 INTERFACE:
+		token = next_token (&val, cfile);
+		if (token != STRING) {
+			parse_warn ("expecting interface name (in quotes).");
+			skip_to_semi (cfile);
+			break;
+		}
+		for (ip = interfaces; ip; ip = ip -> next) {
+			if (!strcmp (ip -> name, val))
+				break;
+		}
+		*ipp = ip;
+		break;
+
+	      case FIXED_ADDR:
+		parse_ip_addr (cfile, &lease -> address);
+		break;
+
+	      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);
+	}
+}
+
+void parse_ip_addr (cfile, addr)
+	FILE *cfile;
+	struct iaddr *addr;
+{
+	char *val;
+	int token;
+
+	addr -> len = 4;
+	parse_numeric_aggregate (cfile, addr -> iabuf,
+				 &addr -> len, DOT, 10, 8);
+}	
+
+void parse_option_decl (cfile, options)
+	FILE *cfile;
+	struct option_data *options;
+{
+	char *val;
+	int token;
+	unsigned char buf [4];
+	char *vendor;
+	char *fmt;
+	struct universe *universe;
+	struct option *option;
+	struct iaddr ip_addr;
+	char *dp;
+	int len;
+
+	token = next_token (&val, cfile);
+	if (!is_identifier (token)) {
+		parse_warn ("expecting identifier after option keyword.");
+		if (token != SEMI)
+			skip_to_semi (cfile);
+		return;
+	}
+	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;
+		}
+
+		/* 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;
+		}
+	} 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;
+	}
+
+	/* 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':
+				options [option -> code].len =
+					parse_X (cfile,
+						 (&options
+						  [option -> code].data));
+				break;
+					
+			      case 't': /* Text string... */
+				options [option -> code].data =
+					parse_string (cfile);
+				options [option -> code].len =
+					strlen (options [option -> code].data);
+				break;
+
+			      case 'I': /* IP address. */
+				parse_ip_addr (cfile, &ip_addr);
+				len = ip_addr.len;
+				dp = ip_addr.iabuf;
+
+			      alloc:
+				options [option -> code].data =	malloc (len);
+				if (!options [option -> code].data)
+					error ("no memory for option data.");
+				memcpy (options [option -> code].data,
+					dp, len);
+				options [option -> code].len = 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;
+				}
+				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;
+				}
+				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;
+			}
+		}
+		if (*fmt == 'A') {
+			token = peek_token (&val, cfile);
+			if (token == COMMA) {
+				token = next_token (&val, cfile);
+				continue;
+			}
+			break;
+		}
+	} while (*fmt == 'A');
+
+	token = next_token (&val, cfile);
+	if (token != SEMI) {
+		parse_warn ("semicolon expected.");
+		skip_to_semi (cfile);
+		return;
+	}
+}
+