/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2002-2003, Network Appliance, Inc. All rights reserved.
 */

/*
 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"


/*
 *
 * MODULE: dat_sr_parser.c
 *
 * PURPOSE: static registry parser
 *
 * $Id: udat_sr_parser.c,v 1.1 2003/07/31 14:04:19 jlentini Exp $
 */


#include "udat_sr_parser.h"
#include "dat_sr.h"


/*
 *
 * Constants
 *
 */

#define	DAT_SR_CONF_ENV 		"DAT_OVERRIDE"
#define	DAT_SR_CONF_DEFAULT 		"/etc/dat/dat.conf"

#define	DAT_SR_TOKEN_THREADSAFE 	"threadsafe"
#define	DAT_SR_TOKEN_NONTHREADSAFE 	"nonthreadsafe"
#define	DAT_SR_TOKEN_DEFAULT 		"default"
#define	DAT_SR_TOKEN_NONDEFAULT 	"nondefault"

#define	DAT_SR_CHAR_NEWLINE 		'\n'
#define	DAT_SR_CHAR_COMMENT 		'#'
#define	DAT_SR_CHAR_QUOTE 		'"'
#define	DAT_SR_CHAR_BACKSLASH 		'\\'


/*
 *
 * Enumerations
 *
 */

typedef enum
{
	DAT_SR_TOKEN_STRING,	/* text field (both quoted or unquoted)	*/
	DAT_SR_TOKEN_EOR,	/* end of record (newline)		*/
	DAT_SR_TOKEN_EOF 	/* end of file				*/
} DAT_SR_TOKEN_TYPE;

typedef enum
{
	DAT_SR_API_UDAT,
	DAT_SR_API_KDAT
} DAT_SR_API_TYPE;


/*
 *
 * Structures
 *
 */

typedef struct
{
    DAT_SR_TOKEN_TYPE 	type;
    char		*value; /* valid if type is DAT_SR_TOKEN_STRING */
    DAT_OS_SIZE 	value_len;
} DAT_SR_TOKEN;

typedef struct DAT_SR_STACK_NODE
{
    DAT_SR_TOKEN 		token;
    struct DAT_SR_STACK_NODE    *next;
} DAT_SR_STACK_NODE;

typedef struct
{
    DAT_UINT32 			major;
    DAT_UINT32 			minor;
} DAT_SR_VERSION;

typedef struct
{
    char			*id;
    DAT_SR_VERSION 		version;
} DAT_SR_PROVIDER_VERSION;

typedef struct
{
    DAT_SR_API_TYPE 		type;
    DAT_SR_VERSION 		version;
} DAT_SR_API_VERSION;

typedef struct
{
    char			*ia_name;
    DAT_SR_API_VERSION 		api_version;
    DAT_BOOLEAN 		is_thread_safe;
    DAT_BOOLEAN 		is_default;
    char 			*lib_path;
    DAT_SR_PROVIDER_VERSION 	provider_version;
    char 			*ia_params;
    char  			*platform_params;
} DAT_SR_CONF_ENTRY;


/*
 *
 * Internal Function Declarations
 *
 */

static DAT_RETURN
dat_sr_load_entry(
    DAT_SR_CONF_ENTRY *entry);

static DAT_BOOLEAN
dat_sr_is_valid_entry(
    DAT_SR_CONF_ENTRY *entry);

static char *
dat_sr_type_to_str(
    DAT_SR_TOKEN_TYPE type);

static DAT_RETURN
dat_sr_parse_eof(
    DAT_OS_FILE *file);

static DAT_RETURN
dat_sr_parse_entry(
    DAT_OS_FILE *file);

static DAT_RETURN
dat_sr_parse_ia_name(
    DAT_OS_FILE *file,
    DAT_SR_CONF_ENTRY *entry);

static DAT_RETURN
dat_sr_parse_api(
    DAT_OS_FILE *file,
    DAT_SR_CONF_ENTRY *entry);

static DAT_RETURN
dat_sr_parse_thread_safety(
    DAT_OS_FILE *file,
    DAT_SR_CONF_ENTRY *entry);

static DAT_RETURN
dat_sr_parse_default(
    DAT_OS_FILE *file,
    DAT_SR_CONF_ENTRY *entry);

static DAT_RETURN
dat_sr_parse_lib_path(
    DAT_OS_FILE *file,
    DAT_SR_CONF_ENTRY *entry);

static DAT_RETURN
dat_sr_parse_provider_version(
    DAT_OS_FILE *file,
    DAT_SR_CONF_ENTRY *entry);

static DAT_RETURN
dat_sr_parse_ia_params(
    DAT_OS_FILE *file,
    DAT_SR_CONF_ENTRY *entry);

static DAT_RETURN
dat_sr_parse_platform_params(
    DAT_OS_FILE *file,
    DAT_SR_CONF_ENTRY *entry);

static DAT_RETURN
dat_sr_parse_eoe(
    DAT_OS_FILE *file,
    DAT_SR_CONF_ENTRY *entry);

static DAT_RETURN
dat_sr_convert_api(
    char *str,
    DAT_SR_API_VERSION *api_version);

static DAT_RETURN
dat_sr_convert_thread_safety(
    char *str,
    DAT_BOOLEAN *is_thread_safe);

static DAT_RETURN
dat_sr_convert_default(
    char *str,
    DAT_BOOLEAN *is_default);

static DAT_RETURN
dat_sr_convert_provider_version(
    char *str,
    DAT_SR_PROVIDER_VERSION *provider_version);

static DAT_RETURN
dat_sr_get_token(
    DAT_OS_FILE *file,
    DAT_SR_TOKEN *token);

static DAT_RETURN
dat_sr_put_token(
    DAT_OS_FILE *file,
    DAT_SR_TOKEN *token);

static DAT_RETURN
dat_sr_read_token(
    DAT_OS_FILE *file,
    DAT_SR_TOKEN *token);

static DAT_RETURN
dat_sr_read_str(
    DAT_OS_FILE *file,
    DAT_SR_TOKEN *token,
    DAT_OS_SIZE token_len);

static DAT_RETURN
dat_sr_read_quoted_str(
    DAT_OS_FILE *file,
    DAT_SR_TOKEN *token,
    DAT_OS_SIZE token_len,
    DAT_COUNT num_escape_seq);

static void
dat_sr_read_comment(
    DAT_OS_FILE *file);


/*
 *
 * Global Variables
 *
 */

static DAT_SR_STACK_NODE 	*g_token_stack = NULL;


/*
 *
 * External Function Definitions
 *
 */

/*
 * Function: dat_sr_load
 */

DAT_RETURN
dat_sr_load(void)
{
	char 			*sr_path;
	DAT_OS_FILE 		*sr_file;

	sr_path = dat_os_getenv(DAT_SR_CONF_ENV);
	if (sr_path == NULL) {
		sr_path = DAT_SR_CONF_DEFAULT;
	}

	dat_os_dbg_print(DAT_OS_DBG_TYPE_SR,
	    "DAT Registry: static registry file <%s> \n", sr_path);

	sr_file = dat_os_fopen(sr_path);
	if (sr_file == NULL) {
		return (DAT_INTERNAL_ERROR);
	}

	for (;;) {
		if (DAT_SUCCESS == dat_sr_parse_eof(sr_file)) {
			break;
		} else if (DAT_SUCCESS == dat_sr_parse_entry(sr_file)) {
			continue;
		} else {
			dat_os_assert(!"unable to parse static registry file");
			break;
		}
	}

	if (0 != dat_os_fclose(sr_file)) {
		return (DAT_INTERNAL_ERROR);
	}

	return (DAT_SUCCESS);
}


/*
 *
 * Internal Function Definitions
 *
 */

/*
 * Function: dat_sr_is_valid_entry
 */

DAT_BOOLEAN
dat_sr_is_valid_entry(
    DAT_SR_CONF_ENTRY *entry)
{
	if ((DAT_SR_API_UDAT == entry->api_version.type) &&
	    (entry->is_default)) {
		return (DAT_TRUE);
	} else {
		return (DAT_FALSE);
	}
}


/*
 * Function: dat_sr_load_entry
 */

DAT_RETURN
dat_sr_load_entry(
    DAT_SR_CONF_ENTRY *conf_entry)
{
	DAT_SR_ENTRY entry;

	if (DAT_NAME_MAX_LENGTH < (strlen(conf_entry->ia_name) + 1)) {
		dat_os_dbg_print(DAT_OS_DBG_TYPE_SR,
		    "DAT Registry: ia name %s is longer than "
		    "DAT_NAME_MAX_LENGTH (%i)\n",
		    conf_entry->ia_name, DAT_NAME_MAX_LENGTH);

		return (DAT_INSUFFICIENT_RESOURCES);
	}

	(void) dat_os_strncpy(entry.info.ia_name, conf_entry->ia_name,
	    DAT_NAME_MAX_LENGTH);
	entry.info.dapl_version_major = conf_entry->api_version.version.major;
	entry.info.dapl_version_minor = conf_entry->api_version.version.minor;
	entry.info.is_thread_safe = conf_entry->is_thread_safe;
	entry.lib_path = conf_entry->lib_path;
	entry.ia_params = conf_entry->ia_params;
	entry.lib_handle = NULL;
	entry.ref_count = 0;

	dat_os_dbg_print(DAT_OS_DBG_TYPE_SR,
	    "DAT Registry: loading provider for %s\n",
	    conf_entry->ia_name);

	return (dat_sr_insert(&entry.info, &entry));
}


/*
 * Function: dat_sr_type_to_str
 */

char *
dat_sr_type_to_str(
    DAT_SR_TOKEN_TYPE type)
{
	static char *str_array[] = { "string", "eor", "eof" };

	if ((type < 0) || (2 < type)) {
		return ("error: invalid token type");
	}

	return (str_array[type]);
}


/*
 * Function: dat_sr_parse_eof
 */

DAT_RETURN
dat_sr_parse_eof(
	DAT_OS_FILE 		*file)
{
	DAT_SR_TOKEN 	token;

	if (DAT_SUCCESS != dat_sr_get_token(file, &token)) {
		return (DAT_INTERNAL_ERROR);
	}

	if (DAT_SR_TOKEN_EOF == token.type) {
		return (DAT_SUCCESS);
	} else {
		(void) dat_sr_put_token(file, &token);
		return (DAT_INTERNAL_ERROR);
	}
}


/*
 * Function: dat_sr_parse_ia_name
 */

DAT_RETURN
dat_sr_parse_entry(
    DAT_OS_FILE 		*file)
{
	DAT_SR_CONF_ENTRY		entry;
	DAT_RETURN 			status;

	(void) dat_os_memset(&entry, 0, sizeof (DAT_SR_CONF_ENTRY));

	if ((DAT_SUCCESS == dat_sr_parse_ia_name(file, &entry)) &&
	    (DAT_SUCCESS == dat_sr_parse_api(file, &entry)) &&
	    (DAT_SUCCESS == dat_sr_parse_thread_safety(file, &entry)) &&
	    (DAT_SUCCESS == dat_sr_parse_default(file, &entry)) &&
	    (DAT_SUCCESS == dat_sr_parse_lib_path(file, &entry)) &&
	    (DAT_SUCCESS == dat_sr_parse_provider_version(file, &entry)) &&
	    (DAT_SUCCESS == dat_sr_parse_ia_params(file, &entry)) &&
	    (DAT_SUCCESS == dat_sr_parse_platform_params(file, &entry)) &&
	    (DAT_SUCCESS == dat_sr_parse_eoe(file, &entry))) {
		dat_os_dbg_print(DAT_OS_DBG_TYPE_SR,
		    "\n"
		    "DAT Registry: entry \n"
		    " ia_name %s\n"
		    " api_version\n"
		    "     type 0x%X\n"
		    "     major.minor %d.%d\n"
		    " is_thread_safe %d\n"
		    " is_default %d\n"
		    " lib_path %s\n"
		    " provider_version\n"
		    "     id %s\n"
		    "     major.minor %d.%d\n"
		    " ia_params %s\n"
		    "\n",
		    entry.ia_name,
		    entry.api_version.type,
		    entry.api_version.version.major,
		    entry.api_version.version.minor,
		    entry.is_thread_safe,
		    entry.is_default,
		    entry.lib_path,
		    entry.provider_version.id,
		    entry.provider_version.version.major,
		    entry.provider_version.version.minor,
		    entry.ia_params);

		if (DAT_TRUE == dat_sr_is_valid_entry(&entry)) {
			/*
			 * The static registry configuration file may have
			 * multiple entries with the same IA name. The first
			 * entry will be installed in the static registry
			 * causing subsequent attempts to register the same IA
			 * name to fail. Therefore the return code from
			 * dat_sr_load_entry() is ignored.
			 */
			(void) dat_sr_load_entry(&entry);
		}

		status = DAT_SUCCESS;
	} else { /* resync */
		DAT_SR_TOKEN 		token;

		/*
		 * The static registry format is specified in the DAT
		 * specification. While the registry file's contents may change
		 * between revisions of the specification, there is no way to
		 * determine the specification version to which the
		 * configuration file conforms. If an entry is found that does
		 * not match the expected format, the entry is discarded
		 * and the parsing of the file continues. There is no way to
		 * determine if the entry was an error or an entry confirming
		 * to an alternate version of specification.
		 */

		for (;;) {
			if (DAT_SUCCESS != dat_sr_get_token(file, &token)) {
				status = DAT_INTERNAL_ERROR;
				break;
			}

			if (DAT_SR_TOKEN_STRING != token.type) {
				status = DAT_SUCCESS;
				break;
			} else {
				dat_os_free(token.value,
				    (sizeof (char) *
					dat_os_strlen(token.value)) + 1);
				continue;
			}
		}
	}

	/* free resources */
	if (NULL != entry.ia_name) {
		dat_os_free(entry.ia_name,
		    sizeof (char) * (dat_os_strlen(entry.ia_name) + 1));
	}
	if (NULL != entry.lib_path) {
		dat_os_free(entry.lib_path,
		    sizeof (char) * (dat_os_strlen(entry.lib_path) + 1));
	}

	if (NULL != entry.provider_version.id) {
		dat_os_free(entry.provider_version.id,
		    sizeof (char) *
		    (dat_os_strlen(entry.provider_version.id) + 1));
	}

	if (NULL != entry.ia_params) {
		dat_os_free(entry.ia_params,
		    sizeof (char) * (dat_os_strlen(entry.ia_params) + 1));
	}

	return (status);
}


/*
 * Function: dat_sr_parse_ia_name
 */

DAT_RETURN
dat_sr_parse_ia_name(
    DAT_OS_FILE 	*file,
    DAT_SR_CONF_ENTRY 	*entry)
{
	DAT_SR_TOKEN 	token;
	DAT_RETURN 	status;

	if (DAT_SUCCESS != dat_sr_get_token(file, &token)) {
		return (DAT_INTERNAL_ERROR);
	}

	if (DAT_SR_TOKEN_STRING != token.type) {
		status = DAT_INTERNAL_ERROR;
	} else {
		entry->ia_name = token.value;

		status = DAT_SUCCESS;
	}

	if (DAT_SUCCESS != status) {
		DAT_RETURN 	status_success;

		status_success = dat_sr_put_token(file, &token);
		dat_os_assert(DAT_SUCCESS == status_success);
	}

	return (status);
}


/*
 * Function: dat_sr_parse_ia_name
 */

DAT_RETURN
dat_sr_parse_api(
    DAT_OS_FILE 	*file,
    DAT_SR_CONF_ENTRY 	*entry)
{
	DAT_SR_TOKEN 	token;
	DAT_RETURN 	status;

	if (DAT_SUCCESS != dat_sr_get_token(file, &token)) {
		return (DAT_INTERNAL_ERROR);
	}

	if (DAT_SR_TOKEN_STRING != token.type) {
		status = DAT_INTERNAL_ERROR;
	} else if (DAT_SUCCESS != dat_sr_convert_api(
		token.value, &entry->api_version)) {
		status = DAT_INTERNAL_ERROR;
	} else {
		dat_os_free(token.value,
		    (sizeof (char) * dat_os_strlen(token.value)) + 1);

		status = DAT_SUCCESS;
	}

	if (DAT_SUCCESS != status) {
		DAT_RETURN 	status_success;

		status_success = dat_sr_put_token(file, &token);
		dat_os_assert(DAT_SUCCESS == status_success);
	}

	return (status);
}


/*
 * Function: dat_sr_parse_thread_safety
 */

static DAT_RETURN
dat_sr_parse_thread_safety(
    DAT_OS_FILE 	*file,
    DAT_SR_CONF_ENTRY 	*entry)
{
	DAT_SR_TOKEN 	token;
	DAT_RETURN 	status;

	if (DAT_SUCCESS != dat_sr_get_token(file, &token)) {
		return (DAT_INTERNAL_ERROR);
	}

	if (DAT_SR_TOKEN_STRING != token.type) {
		status = DAT_INTERNAL_ERROR;
	} else if (DAT_SUCCESS != dat_sr_convert_thread_safety(
		token.value, &entry->is_thread_safe)) {
		status = DAT_INTERNAL_ERROR;
	} else {
		dat_os_free(token.value,
		    (sizeof (char) * dat_os_strlen(token.value)) + 1);

		status = DAT_SUCCESS;
	}

	if (DAT_SUCCESS != status) {
		DAT_RETURN 	status_success;

		status_success = dat_sr_put_token(file, &token);
		dat_os_assert(DAT_SUCCESS == status_success);
	}

	return (status);
}


/*
 * Function: dat_sr_parse_default
 */

DAT_RETURN
dat_sr_parse_default(
    DAT_OS_FILE 	*file,
    DAT_SR_CONF_ENTRY 	*entry)
{
	DAT_SR_TOKEN 	token;
	DAT_RETURN 	status;

	if (DAT_SUCCESS != dat_sr_get_token(file, &token)) {
		return (DAT_INTERNAL_ERROR);
	}

	if (DAT_SR_TOKEN_STRING != token.type) {
		status = DAT_INTERNAL_ERROR;
	} else if (DAT_SUCCESS != dat_sr_convert_default(
		token.value, &entry->is_default)) {
		status = DAT_INTERNAL_ERROR;
	} else {
		dat_os_free(token.value,
		    (sizeof (char) * dat_os_strlen(token.value)) + 1);

		status = DAT_SUCCESS;
	}

	if (DAT_SUCCESS != status) {
		DAT_RETURN 	status_success;

		status_success = dat_sr_put_token(file, &token);
		dat_os_assert(DAT_SUCCESS == status_success);
	}

	return (status);
}


/*
 * Function: dat_sr_parse_lib_path
 */

DAT_RETURN
dat_sr_parse_lib_path(
    DAT_OS_FILE 	*file,
    DAT_SR_CONF_ENTRY 	*entry)
{
	DAT_SR_TOKEN 	token;
	DAT_RETURN 	status;

	if (DAT_SUCCESS != dat_sr_get_token(file, &token)) {
		return (DAT_INTERNAL_ERROR);
	}

	if (DAT_SR_TOKEN_STRING != token.type) {
		status = DAT_INTERNAL_ERROR;
	} else {
		entry->lib_path = token.value;

		status = DAT_SUCCESS;
	}

	if (DAT_SUCCESS != status) {
		DAT_RETURN 	status_success;

		status_success = dat_sr_put_token(file, &token);
		dat_os_assert(DAT_SUCCESS == status_success);
	}

	return (status);
}

/*
 * Function: dat_sr_parse_provider_version
 */

DAT_RETURN
dat_sr_parse_provider_version(
    DAT_OS_FILE 	*file,
    DAT_SR_CONF_ENTRY 	*entry)
{
	DAT_SR_TOKEN 	token;
	DAT_RETURN 	status;

	if (DAT_SUCCESS != dat_sr_get_token(file, &token)) {
		return (DAT_INTERNAL_ERROR);
	}

	if (DAT_SR_TOKEN_STRING != token.type) {
		status = DAT_INTERNAL_ERROR;
	} else if (DAT_SUCCESS != dat_sr_convert_provider_version(
		token.value, &entry->provider_version)) {
		status = DAT_INTERNAL_ERROR;
	} else {
		dat_os_free(token.value,
		    (sizeof (char) * dat_os_strlen(token.value)) + 1);

		status = DAT_SUCCESS;
	}

	if (DAT_SUCCESS != status) {
		DAT_RETURN 	status_success;

		status_success = dat_sr_put_token(file, &token);
		dat_os_assert(DAT_SUCCESS == status_success);
	}

	return (status);
}


/*
 * Function: dat_sr_parse_ia_params
 */

DAT_RETURN
dat_sr_parse_ia_params(
    DAT_OS_FILE *file,
    DAT_SR_CONF_ENTRY *entry)
{
	DAT_SR_TOKEN 	token;
	DAT_RETURN 	status;

	if (DAT_SUCCESS != dat_sr_get_token(file, &token)) {
		return (DAT_INTERNAL_ERROR);
	}

	if (DAT_SR_TOKEN_STRING != token.type) {
		status = DAT_INTERNAL_ERROR;
	} else {
		entry->ia_params = token.value;

		status = DAT_SUCCESS;
	}

	if (DAT_SUCCESS != status) {
		DAT_RETURN 	status_success;

		status_success = dat_sr_put_token(file, &token);
		dat_os_assert(DAT_SUCCESS == status_success);
	}

	return (status);
}


/*
 * Function: dat_sr_parse_platform_params
 */

DAT_RETURN
dat_sr_parse_platform_params(
    DAT_OS_FILE *file,
    DAT_SR_CONF_ENTRY *entry)
{
	DAT_SR_TOKEN 	token;
	DAT_RETURN 	status;

	if (DAT_SUCCESS != dat_sr_get_token(file, &token)) {
		return (DAT_INTERNAL_ERROR);
	}

	if (DAT_SR_TOKEN_STRING != token.type) {
		status = DAT_INTERNAL_ERROR;
	} else {
		entry->platform_params = token.value;

		status = DAT_SUCCESS;
	}

	if (DAT_SUCCESS != status) {
		DAT_RETURN 	status_success;

		status_success = dat_sr_put_token(file, &token);
		dat_os_assert(DAT_SUCCESS == status_success);
	}

	return (status);
}


/*
 * Function: dat_sr_parse_eoe
 */

DAT_RETURN
dat_sr_parse_eoe(
    DAT_OS_FILE *file,
	DAT_SR_CONF_ENTRY *entry) /*ARGSUSED*/
{
	DAT_SR_TOKEN 	token;
	DAT_RETURN 	status;

	if (DAT_SUCCESS != dat_sr_get_token(file, &token)) {
		return (DAT_INTERNAL_ERROR);
	}

	if ((DAT_SR_TOKEN_EOF != token.type) &&
	    (DAT_SR_TOKEN_EOR != token.type)) {
		status = DAT_INTERNAL_ERROR;
	} else {
		status = DAT_SUCCESS;
	}

	if (DAT_SUCCESS != status) {
		DAT_RETURN 	status_success;

		status_success = dat_sr_put_token(file, &token);
		dat_os_assert(DAT_SUCCESS == status_success);
	}

	return (status);
}


/*
 * Function: dat_sr_convert_api
 */

DAT_RETURN
dat_sr_convert_api(
    char *str,
    DAT_SR_API_VERSION *api_version)
{
	int i;
	int minor_i;

	dat_os_assert(0 < dat_os_strlen(str));

	if ('u' == str[0]) {
		api_version->type = DAT_SR_API_UDAT;
	} else if ('k' == str[0]) {
		api_version->type = DAT_SR_API_KDAT;
	} else {
		return (DAT_INTERNAL_ERROR);
	}

	for (i = 1 /* move past initial [u|k] */; '\0' != str[i]; i++) {
		if ('.' == str[i]) {
			break;
		} else if (DAT_TRUE != dat_os_isdigit(str[i])) {
			return (DAT_INTERNAL_ERROR);
		}
	}

	api_version->version.major = (DAT_UINT32)dat_os_strtol(str + 1, NULL,
	    10);

	/* move past '.' */
	minor_i = ++i;

	for (; '\0' != str[i]; i++) {
		if (DAT_TRUE != dat_os_isdigit(str[i])) {
			return (DAT_INTERNAL_ERROR);
		}
	}

	api_version->version.minor = (DAT_UINT32)dat_os_strtol(str + minor_i,
	    NULL, 10);

	if ('\0' != str[i]) {
		return (DAT_INTERNAL_ERROR);
	}

	return (DAT_SUCCESS);
}


/*
 * Function: dat_sr_convert_thread_safety
 */

static DAT_RETURN
dat_sr_convert_thread_safety(
    char *str,
    DAT_BOOLEAN *is_thread_safe)
{
	if (!dat_os_strncmp(str,
	    DAT_SR_TOKEN_THREADSAFE,
	    dat_os_strlen(DAT_SR_TOKEN_THREADSAFE))) {
		*is_thread_safe = DAT_TRUE;
		return (DAT_SUCCESS);
	} else if (!dat_os_strncmp(str,
	    DAT_SR_TOKEN_NONTHREADSAFE,
	    dat_os_strlen(DAT_SR_TOKEN_NONTHREADSAFE))) {
		*is_thread_safe = DAT_FALSE;
		return (DAT_SUCCESS);
	} else {
		return (DAT_INTERNAL_ERROR);
	}
}


/*
 * Function: dat_sr_convert_default
 */

static DAT_RETURN
dat_sr_convert_default(
    char *str,
    DAT_BOOLEAN *is_default)
{
	if (!dat_os_strncmp(str,
	    DAT_SR_TOKEN_DEFAULT,
	    dat_os_strlen(DAT_SR_TOKEN_DEFAULT))) {
		*is_default = DAT_TRUE;
		return (DAT_SUCCESS);
	} else if (!dat_os_strncmp(str,
	    DAT_SR_TOKEN_NONDEFAULT,
	    dat_os_strlen(DAT_SR_TOKEN_NONDEFAULT))) {
		*is_default = DAT_FALSE;
		return (DAT_SUCCESS);
	} else {
		return (DAT_INTERNAL_ERROR);
	}
}


/*
 * Function: dat_sr_convert_provider_version
 */

DAT_RETURN
dat_sr_convert_provider_version(
    char *str,
    DAT_SR_PROVIDER_VERSION *provider_version)
{
	DAT_RETURN 	status;
	int 		i;
	int 		decimal_i;

	dat_os_assert(0 < dat_os_strlen(str));
	dat_os_assert(NULL == provider_version->id);

	status = DAT_SUCCESS;

	for (i = 0; '\0' != str[i]; i++) {
		if ('.' == str[i]) {
			break;
		}
	}

	/* if no id value was found */
	if (0 == i) {
		status = DAT_INTERNAL_ERROR;
		goto exit;
	}

	if (NULL == (provider_version->id = dat_os_alloc(sizeof (char) *
	    (i + 1)))) {
		status = DAT_INSUFFICIENT_RESOURCES | DAT_RESOURCE_MEMORY;
		goto exit;
	}

	(void) dat_os_strncpy(provider_version->id, str, i);
	provider_version->id[i] = '\0';

	/* move past '.' */
	decimal_i = ++i;

	for (; '\0' != str[i]; i++) {
		if ('.' == str[i]) {
			break;
		} else if (DAT_TRUE != dat_os_isdigit(str[i])) {
			status = DAT_INTERNAL_ERROR;
			goto exit;
		}
	}

	/* if no version value was found */
	if (decimal_i == i) {
		status = DAT_INTERNAL_ERROR;
		goto exit;
	}

	provider_version->version.major = (DAT_UINT32)
	    dat_os_strtol(str + decimal_i, NULL, 10);

	/* move past '.' */
	decimal_i = ++i;

	for (; '\0' != str[i]; i++) {
		if (DAT_TRUE != dat_os_isdigit(str[i])) {
			status = DAT_INTERNAL_ERROR;
			goto exit;
		}
	}

	/* if no version value was found */
	if (decimal_i == i) {
		status = DAT_INTERNAL_ERROR;
		goto exit;
	}

	provider_version->version.minor = (DAT_UINT32)
	    dat_os_strtol(str + decimal_i, NULL, 10);

	if ('\0' != str[i]) {
		status = DAT_INTERNAL_ERROR;
		goto exit;
	}

exit:
	if (DAT_SUCCESS != status) {
		if (NULL != provider_version->id) {
			dat_os_free(provider_version->id,
			    sizeof (char) *
			    (dat_os_strlen(provider_version->id) + 1));
			provider_version->id = NULL;
		}
	}

	return (status);
}


/*
 * Function: dat_sr_get_token
 */

DAT_RETURN
dat_sr_get_token(
    DAT_OS_FILE *file,
    DAT_SR_TOKEN *token)
{
	if (NULL == g_token_stack) {
		return (dat_sr_read_token(file, token));
	} else {
		DAT_SR_STACK_NODE *top;

		top = g_token_stack;

		*token = top->token;
		g_token_stack = top->next;

		dat_os_free(top, sizeof (DAT_SR_STACK_NODE));

		return (DAT_SUCCESS);
	}
}


/*
 * Function: dat_sr_put_token
 */

DAT_RETURN
dat_sr_put_token(
    DAT_OS_FILE *file,
	DAT_SR_TOKEN *token) /*ARGSUSED*/
{
	DAT_SR_STACK_NODE *top;

	if (NULL == (top = dat_os_alloc(sizeof (DAT_SR_STACK_NODE)))) {
		return (DAT_INSUFFICIENT_RESOURCES | DAT_RESOURCE_MEMORY);
	}

	top->token = *token;
	top->next = g_token_stack;
	g_token_stack = top;

	return (DAT_SUCCESS);
}


/*
 * Function: dat_sr_read_token
 */

DAT_RETURN
dat_sr_read_token(
    DAT_OS_FILE 		*file,
    DAT_SR_TOKEN 		*token)
{
	DAT_OS_FILE_POS 	pos;
	DAT_OS_SIZE 		token_len;
	DAT_COUNT 		num_escape_seq;
	DAT_BOOLEAN 		is_quoted_str;
	DAT_BOOLEAN 		is_prev_char_backslash;

	/*
	 * The DAT standard does not specify a maximum size for quoted strings.
	 * Therefore the tokenizer must be able to read in a token of arbitrary
	 * size. Instead of allocating a fixed length buffer, the tokenizer
	 * first scans the input a single character at a time looking for the
	 * begining and end of the token. Once the these positions are found,
	 * the entire token is read into memory. By using this algorithm, the
	 * implementation does not place an arbitrary maximum on the token size.
	 */

	token_len = 0;
	num_escape_seq = 0;
	is_quoted_str = DAT_FALSE;
	is_prev_char_backslash = DAT_FALSE;

	for (;;) {
		DAT_OS_FILE_POS cur_pos;
		int c;

		/* if looking for start of the token */
		if (0 == token_len) {
			if (DAT_SUCCESS != dat_os_fgetpos(file, &cur_pos)) {
				return (DAT_INTERNAL_ERROR);
			}
		}

		c = dat_os_fgetc(file);

		/* if looking for start of the token */
		if (0 == token_len) {
			if (EOF == c) {
				token->type = DAT_SR_TOKEN_EOF;
				token->value = NULL;
				token->value_len = 0;
				goto success;
			} else if (DAT_SR_CHAR_NEWLINE == c) {
				token->type = DAT_SR_TOKEN_EOR;
				token->value = NULL;
				token->value_len = 0;
				goto success;
			} else if (dat_os_isblank(c)) {
				continue;
			} else if (DAT_SR_CHAR_COMMENT == c) {
				dat_sr_read_comment(file);
				continue;
			} else {
				if (DAT_SR_CHAR_QUOTE == c) {
					is_quoted_str = DAT_TRUE;
				}

				pos = cur_pos;
				token_len++;
			}
		} else { /* looking for the end of the token */
			if (EOF == c) {
				break;
			} else if (DAT_SR_CHAR_NEWLINE == c) {
				/* put back the newline */
				(void) dat_os_fungetc(file);
				break;
			} else if (!is_quoted_str && dat_os_isblank(c)) {
				break;
			} else {
				token_len++;

				if ((DAT_SR_CHAR_QUOTE == c) &&
				    !is_prev_char_backslash) {
					break;
				} else if ((DAT_SR_CHAR_BACKSLASH == c) &&
				    !is_prev_char_backslash) {
					is_prev_char_backslash = DAT_TRUE;
					num_escape_seq++;
				} else {
					is_prev_char_backslash = DAT_FALSE;
				}
			}
		}
	}

	/* the token was a string */
	if (DAT_SUCCESS != dat_os_fsetpos(file, &pos)) {
		return (DAT_INTERNAL_ERROR);
	}

	if (is_quoted_str) {
		if (DAT_SUCCESS != dat_sr_read_quoted_str(file,
		    token,
		    token_len,
		    num_escape_seq)) {
			return (DAT_INTERNAL_ERROR);
		}
	} else {
		if (DAT_SUCCESS != dat_sr_read_str(file,
		    token,
		    token_len)) {
			return (DAT_INTERNAL_ERROR);
		}
	}

success:
	dat_os_dbg_print(DAT_OS_DBG_TYPE_SR,
	    "\n"
	    "DAT Registry: token\n"
	    " type  %s\n"
	    " value <%s>\n"
	    "\n",
	    dat_sr_type_to_str(token->type),
	    ((DAT_SR_TOKEN_STRING == token->type) ? token->value : ""));

	return (DAT_SUCCESS);
}


/*
 * Function: dat_sr_read_str
 */

DAT_RETURN
dat_sr_read_str(
    DAT_OS_FILE *file,
    DAT_SR_TOKEN *token,
    DAT_OS_SIZE token_len)
{
	token->type = DAT_SR_TOKEN_STRING;
	/* +1 for null termination */
	token->value_len = sizeof (char) * (token_len + 1);
	if (NULL == (token->value = dat_os_alloc(token->value_len))) {
		return (DAT_INSUFFICIENT_RESOURCES | DAT_RESOURCE_MEMORY);
	}

	if (token_len != dat_os_fread(file, token->value, token_len)) {
		dat_os_free(token->value, token->value_len);
		token->value = NULL;

		return (DAT_INTERNAL_ERROR);
	}

	token->value[token->value_len - 1] = '\0';

	return (DAT_SUCCESS);
}


/*
 * Function: dat_sr_read_quoted_str
 */

DAT_RETURN
dat_sr_read_quoted_str(
    DAT_OS_FILE 	*file,
    DAT_SR_TOKEN 	*token,
    DAT_OS_SIZE 	token_len,
    DAT_COUNT 		num_escape_seq)
{
	DAT_OS_SIZE 	str_len;
	DAT_OS_SIZE 	i;
	DAT_OS_SIZE 	j;
	int 		c;
	DAT_RETURN 	status;
	DAT_BOOLEAN 	is_prev_char_backslash;

	str_len = token_len - 2; /* minus 2 " characters */
	is_prev_char_backslash = DAT_FALSE;
	status = DAT_SUCCESS;

	token->type = DAT_SR_TOKEN_STRING;
	/* +1 for null termination */
	token->value_len = sizeof (char) * (str_len - num_escape_seq + 1);

	if (NULL == (token->value = dat_os_alloc(token->value_len))) {
		status = DAT_INSUFFICIENT_RESOURCES | DAT_RESOURCE_MEMORY;
		goto exit;
	}

	/* throw away " */
	if (DAT_SR_CHAR_QUOTE != dat_os_fgetc(file)) {
		status = DAT_INTERNAL_ERROR;
		goto exit;
	}

	for (i = 0, j = 0; i < str_len; i++) {
		c = dat_os_fgetc(file);

		if (EOF == c) {
			status = DAT_INTERNAL_ERROR;
			goto exit;
		} else if ((DAT_SR_CHAR_BACKSLASH == c) &&
		    !is_prev_char_backslash) {
			is_prev_char_backslash = DAT_TRUE;
		} else {
			token->value[j] = c;
			j++;

			is_prev_char_backslash = DAT_FALSE;
		}
	}

	/* throw away " */
	if (DAT_SR_CHAR_QUOTE != dat_os_fgetc(file)) {
		status = DAT_INTERNAL_ERROR;
		goto exit;
	}

	token->value[token->value_len - 1] = '\0';

exit:
	if (DAT_SUCCESS != status) {
		if (NULL != token->value) {
			dat_os_free(token->value, token->value_len);
			token->value = NULL;
		}
	}

	return (status);
}


/*
 * Function: dat_sr_read_comment
 */

void
dat_sr_read_comment(
    DAT_OS_FILE *file)
{
	int c;

	/* read up to an EOR or EOF to move past the comment */
	do {
		c = dat_os_fgetc(file);
	} while ((DAT_SR_CHAR_NEWLINE != c) && (EOF != c));

	/* put back the newline */
	(void) dat_os_fungetc(file);
}