sd: remove 'ssd' driver support

[unleashed/tickless.git] / usr / src / lib / libpool / common / pool_xml.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (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 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <thread.h>
#include <time.h>
#include <unistd.h>

#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/utsname.h>

#include <libxml/debugXML.h>
#include <libxml/parser.h>
#include <libxml/tree.h>
#include <libxml/xmlerror.h>
#include <libxml/xpath.h>
#include <libxml/xmlmemory.h>

#include <pool.h>
#include "pool_internal.h"
#include "pool_impl.h"
#include "pool_xml_impl.h"

/*
 * libpool XML Manipulation Routines
 *
 * pool_xml.c implements the XML manipulation routines used by the libpool
 * XML datastore. The functions are grouped into the following logical areas
 * - Result Sets
 * The XPath API is used to search the XML document represented by a
 * configuration. The results of XPath queries are represented through
 * pool_result_set_t structures as part of the abstraction of the datastore
 * representation. (see pool.c comment for more details)
 *
 * - Property Manipulation
 * Validated XML (XML associated with a DTD) does not allow the introduction
 * of attributes which are not recognised by the DTD. This is a limitation
 * since we want to allow libpool to associate an arbitrary number of
 * properties with an element. The property manipulation code overcomes this
 * limitation by allowing property sub-elements to be created and manipulated
 * through a single API so that they are indistinguishable from attributes
 * to the libpool user.
 *
 * - XML Element/Attribute Manipulation
 * These routines manipulate XML elements and attributes and are the routines
 * which interact most directly with libxml.
 *
 * - File Processing/IO
 * Since libpool must present its data in a consistent fashion, we have to
 * implement file locking above libxml. These routines allow us to lock files
 * during processing and maintain data integrity between processes. Note
 * that locks are at the process scope and are advisory (see fcntl).
 *
 * - Utilities
 * Sundry utility functions that aren't easily categorised.
 */

#define MAX_PROP_SIZE   1024    /* Size of property buffer */
/*
 * The PAGE_READ_SIZE value is used to determine the size of the input buffer
 * used to parse XML files.
 */
#define PAGE_READ_SIZE  8192
#define ELEM_TYPE_COUNT 6       /* Count of Element types */

typedef struct dtype_tbl
{
        xmlChar *dt_name;
        int dt_type;
} dtype_tbl_t;

typedef struct elem_type_tbl
{
        xmlChar *ett_elem;
        dtype_tbl_t (*ett_dtype)[];
} elem_type_tbl_t;

extern int xmlDoValidityCheckingDefaultValue;

/*
 * The _xml_lock is used to lock the state of libpool during
 * xml initialisation operations.
 */
static mutex_t _xml_lock;

const char *element_class_tags[] = {
        "any",
        "system",
        "pool",
        "res_comp",
        "res_agg",
        "comp",
        NULL
};

static const char *data_type_tags[] = {
        "uint",
        "int",
        "float",
        "boolean",
        "string"
};

const char *dtd_location = "file:///usr/share/lib/xml/dtd/rm_pool.dtd.1";

static elem_type_tbl_t elem_tbl[ELEM_TYPE_COUNT] = {0};

/* libpool initialisation indicator */
static int _libpool_xml_initialised = PO_FALSE;

/*
 * Utility functions
 */
/*
 * Those functions which are not static are shared with pool_kernel.c
 * They provide the required XML support for exporting a kernel
 * configuration as an XML document.
 */
void xml_init(void);
static int create_shadow(xmlNodePtr node);
static int pool_xml_free_doc(pool_conf_t *conf);
static int prop_sort(const void *a, const void *b);
static int dtd_exists(const char *path);
static void build_dtype_accelerator(void);
static dtype_tbl_t (*build_dtype_tbl(const xmlChar *rawdata))[];
static int get_fast_dtype(xmlNodePtr node, xmlChar *name);
static int pool_assoc_default_resource_type(pool_t *,
    pool_resource_elem_class_t);

/*
 * XML Data access and navigation APIs
 */
static int pool_build_xpath_buf(pool_xml_connection_t *, const pool_elem_t *,
    pool_elem_class_t, pool_value_t **, char_buf_t *, int);
/*
 * SHARED WITH pool_kernel.c for XML export support
 */
xmlNodePtr node_create(xmlNodePtr parent, const xmlChar *name);
static xmlNodePtr node_create_with_id(xmlNodePtr parent, const xmlChar *name);

/* Configuration */
static int pool_xml_close(pool_conf_t *);
static int pool_xml_validate(const pool_conf_t *, pool_valid_level_t);
static int pool_xml_commit(pool_conf_t *conf);
static int pool_xml_export(const pool_conf_t *conf, const char *location,
    pool_export_format_t fmt);
static int pool_xml_rollback(pool_conf_t *conf);
static pool_result_set_t *pool_xml_exec_query(const pool_conf_t *conf,
    const pool_elem_t *src, const char *src_attr,
    pool_elem_class_t classes, pool_value_t **props);
static int pool_xml_remove(pool_conf_t *conf);
static int pool_xml_res_transfer(pool_resource_t *, pool_resource_t *,
    uint64_t);
static int pool_xml_res_xtransfer(pool_resource_t *, pool_resource_t *,
    pool_component_t **);

/* Connections */
static void pool_xml_connection_free(pool_xml_connection_t *prov);

/* Result Sets */
static pool_xml_result_set_t *pool_xml_result_set_alloc(const pool_conf_t *);
static void pool_xml_result_set_free(pool_xml_result_set_t *rs);
static pool_elem_t *pool_xml_rs_next(pool_result_set_t *set);
static pool_elem_t *pool_xml_rs_prev(pool_result_set_t *set);
static pool_elem_t *pool_xml_rs_first(pool_result_set_t *set);
static pool_elem_t *pool_xml_rs_last(pool_result_set_t *set);
static int pool_xml_rs_set_index(pool_result_set_t *set, int index);
static int pool_xml_rs_get_index(pool_result_set_t *set);
static int pool_xml_rs_count(pool_result_set_t *set);
static int pool_xml_rs_close(pool_result_set_t *set);

/* Element (and sub-type) */
static void pool_xml_elem_init(pool_conf_t *conf, pool_xml_elem_t *elem,
    pool_elem_class_t, pool_resource_elem_class_t, pool_component_elem_class_t);
static int pool_xml_elem_wrap(xmlNodePtr node, pool_elem_class_t class,
    pool_resource_elem_class_t, pool_component_elem_class_t);
static pool_elem_t *pool_xml_elem_create(pool_conf_t *, pool_elem_class_t,
    pool_resource_elem_class_t, pool_component_elem_class_t);
static int pool_xml_elem_remove(pool_elem_t *pe);
static int pool_xml_set_container(pool_elem_t *, pool_elem_t *);
static pool_elem_t *pool_xml_get_container(const pool_elem_t *);

/*
 * Pool element specific
 */
static int pool_xml_pool_associate(pool_t *, const pool_resource_t *);
static int pool_xml_pool_dissociate(pool_t *, const pool_resource_t *);

/*
 * Resource elements specific
 */
static int pool_xml_resource_is_system(const pool_resource_t *);
static int pool_xml_resource_can_associate(const pool_resource_t *);

/* Properties */
static pool_value_class_t pool_xml_get_property(const pool_elem_t *,
    const char *, pool_value_t *);
static int pool_xml_put_property(pool_elem_t *, const char *,
    const pool_value_t *);
static int pool_xml_rm_property(pool_elem_t *, const char *);
static xmlNodePtr property_create(xmlNodePtr, const char *,
    pool_value_class_t);

/* Internal Attribute/Property manipulation */
static int pool_is_xml_attr(xmlDocPtr, const char *, const char *);
static pool_value_class_t pool_xml_get_attr(xmlNodePtr node, xmlChar *name,
    pool_value_t *value);
int pool_xml_set_attr(xmlNodePtr node, xmlChar *name,
    const pool_value_t *value);
static pool_value_class_t pool_xml_get_prop(xmlNodePtr node, xmlChar *name,
    pool_value_t *value);
int pool_xml_set_prop(xmlNodePtr node, xmlChar *name,
    const pool_value_t *value);
static pool_value_t **pool_xml_get_properties(const pool_elem_t *, uint_t *);
/* XML Error handling */
void pool_error_func(void *ctx, const char *msg, ...);

/* XML File Input Processing */
static int pool_xml_open_file(pool_conf_t *conf);
static int pool_xml_parse_document(pool_conf_t *);

/*
 * Initialise this module
 */
void
xml_init()
{
        (void) mutex_lock(&_xml_lock);
        if (_libpool_xml_initialised == PO_TRUE) {
                (void) mutex_unlock(&_xml_lock);
                return;
        }
        xmlInitParser();

        /*
         * DTD validation, with line numbers.
         */
        (void) xmlLineNumbersDefault(1);
        xmlLoadExtDtdDefaultValue |= XML_DETECT_IDS;
        xmlDoValidityCheckingDefaultValue = 1;
        /* Try to improve indentation and readability */
        (void) xmlKeepBlanksDefault(0);
        /* Send all XML errors to our debug handler */
        xmlSetGenericErrorFunc(NULL, pool_error_func);
        /* Load up DTD element a-dtype data to improve performance */
        build_dtype_accelerator();
        _libpool_xml_initialised = PO_TRUE;
        (void) mutex_unlock(&_xml_lock);
}

/*
 * Get the next ID for this configuration
 */
static int
get_unique_id(xmlNodePtr node, char *id)
{
        pool_value_t val = POOL_VALUE_INITIALIZER;
        uint64_t nid = 0;
        if (node->doc->_private) {
                if (pool_get_ns_property(
                    pool_conf_to_elem((pool_conf_t *)node->doc->_private),
                    "_next_id", &val) == POC_UINT)
                        (void) pool_value_get_uint64(&val, &nid);
        }
        if (snprintf(id, KEY_BUFFER_SIZE, "id_%llx", nid) > KEY_BUFFER_SIZE) {
                pool_seterror(POE_SYSTEM);
                return (PO_FAIL);
        }
        pool_value_set_uint64(&val, ++nid);
        return (pool_put_ns_property(
            pool_conf_to_elem((pool_conf_t *)node->doc->_private), "_next_id",
            &val));
}

/* Document building functions */

/*
 * node_create() creates a child node of type name of the supplied parent in
 * the supplied document. If the parent or document is NULL, create the node
 * but do not associate it with a parent or document.
 */
xmlNodePtr
node_create(xmlNodePtr parent, const xmlChar *name)
{
        xmlNodePtr node;

        if (parent == NULL)
                node = xmlNewNode(NULL, name);
        else
                node = xmlNewChild(parent, NULL, name, NULL);
        return (node);
}

/*
 * node_create_with_id() creates a child node of type name of the supplied
 * parent with the ref_id generated by get_unique_id(). Actual node creation
 * is performed by node_create() and this function just sets the ref_id
 * property to the value of the id.
 */
static xmlNodePtr
node_create_with_id(xmlNodePtr parent, const xmlChar *name)
{
        char id[KEY_BUFFER_SIZE]; /* Must be big enough for key below */
        xmlNodePtr node = node_create(parent, name);
        if (node != NULL) {
                if (get_unique_id(node, id) != PO_SUCCESS) {
                        xmlUnlinkNode(node);
                        xmlFreeNode(node); /* recurses all children */
                        pool_seterror(POE_DATASTORE);
                        return (NULL);
                }
                if (xmlSetProp(node, BAD_CAST c_ref_id, BAD_CAST id) == NULL) {
                        xmlUnlinkNode(node);
                        xmlFreeNode(node); /* recurses all children */
                        pool_seterror(POE_DATASTORE);
                        return (NULL);
                }
        }
        return (node);
}

/* Supporting Data Conversion Routines */

/* XML Parser Utility Functions */

/*
 * Handler for XML Errors. Called by libxml at libxml Error.
 */
/*ARGSUSED*/
void
pool_error_func(void *ctx, const char *msg, ...)
{
        va_list ap;

        va_start(ap, msg);
        do_dprintf(msg, ap);
        va_end(ap);
}

/*
 * Free the shadowed elements from within the supplied document and then
 * free the document. This function should always be called when freeing
 * a pool document to ensure that all "shadow" resources are reclaimed.
 * Returns PO_SUCCESS/PO_FAIL
 */
static int
pool_xml_free_doc(pool_conf_t *conf)
{
        /* Only do any of this if there is a document */
        if (((pool_xml_connection_t *)conf->pc_prov)->pxc_doc != NULL) {
                pool_elem_t *pe;
                pool_result_set_t *rs;
                /* Delete all the "shadowed" children of the doc */
                rs = pool_exec_query(conf, NULL, NULL, PEC_QRY_ANY, NULL);
                if (rs == NULL) {
                        pool_seterror(POE_INVALID_CONF);
                        return (PO_FAIL);
                }
                for (pe = rs->prs_next(rs); pe != NULL; pe = rs->prs_next(rs)) {
                        /*
                         * Work out the element type and free the elem
                         */
                        free(pe);
                }
                (void) pool_rs_close(rs);
                xmlFreeDoc(((pool_xml_connection_t *)conf->pc_prov)->pxc_doc);
        }
        ((pool_xml_connection_t *)conf->pc_prov)->pxc_doc = NULL;
        return (PO_SUCCESS);
}

/*
 * Remove an element from the document. Note that only three types of elements
 * can be removed, res, comp and pools. comp are moved around to the
 * default res when a res is deleted.
 * Returns PO_SUCCESS/PO_FAIL
 */
static int
pool_xml_elem_remove(pool_elem_t *pe)
{
        pool_xml_elem_t *pxe = (pool_xml_elem_t *)pe;

        /*
         * You can only destroy three elements: pools, resources and
         * components.
         */
        switch (pe->pe_class) {
        case PEC_POOL:
        case PEC_RES_COMP:
        case PEC_RES_AGG:
        case PEC_COMP:
                if (pxe->pxe_node) {
                        xmlUnlinkNode(pxe->pxe_node);
                        xmlFreeNode(pxe->pxe_node); /* recurses all children */
                }
                free(pxe);
                break;
        default:
                break;
        }
        return (PO_SUCCESS);
}

/*
 * Create a property element.
 */
static xmlNodePtr
property_create(xmlNodePtr parent, const char *name, pool_value_class_t type)
{

        xmlNodePtr element;
        pool_value_t val = POOL_VALUE_INITIALIZER;

        if ((element = node_create(parent, BAD_CAST "property")) == NULL) {
                pool_seterror(POE_DATASTORE);
                return (NULL);
        }
        if (pool_value_set_string(&val, name) != PO_SUCCESS) {
                xmlFree(element);
                return (NULL);
        }
        (void) pool_xml_set_attr(element, BAD_CAST c_name, &val);
        if (pool_value_set_string(&val, data_type_tags[type]) != PO_SUCCESS) {
                xmlFree(element);
                return (NULL);
        }
        (void) pool_xml_set_attr(element, BAD_CAST c_type, &val);
        return (element);
}

/*
 * External clients need to be able to put/get properties and this is the
 * way to do it.
 * This function is an interceptor, since it will *always* try to manipulate
 * an attribute first. If the attribute doesn't exist, then it will treat
 * the request as a property request.
 */
static pool_value_class_t
pool_xml_get_property(const pool_elem_t *pe, const char *name,
    pool_value_t *val)
{
        pool_value_class_t type;
        pool_xml_elem_t *pxe = (pool_xml_elem_t *)pe;

        /*
         * "type" is a special attribute which is not visible ever outside of
         * libpool. Use the specific type accessor function.
         */
        if (strcmp(name, c_type) == 0) {
                return (pool_xml_get_attr(pxe->pxe_node, BAD_CAST name,
                    val));
        }
        if (is_ns_property(pe, name) != NULL) { /* in ns */
                if ((type = pool_xml_get_attr(pxe->pxe_node,
                    BAD_CAST property_name_minus_ns(pe, name), val))
                    == POC_INVAL)
                        return (pool_xml_get_prop(pxe->pxe_node, BAD_CAST name,
                            val));
        } else
                return (pool_xml_get_prop(pxe->pxe_node, BAD_CAST name, val));

        return (type);
}

/*
 * Put a property on an element. Check if the property is an attribute,
 * if it is update that value. If not add a property element.
 *
 * There are three possible conditions here:
 * - the name is a ns
 *      - the name is an attribute
 *      - the name isn't an attribute
 * - the name is not a ns
 * Returns PO_SUCCESS/PO_FAIL
 */
static int
pool_xml_put_property(pool_elem_t *pe, const char *name,
    const pool_value_t *val)
{
        pool_xml_elem_t *pxe = (pool_xml_elem_t *)pe;

        /*
         * "type" is a special attribute which is not visible ever outside of
         * libpool. Use the specific type accessor function.
         */
        if (strcmp(name, c_type) == 0) {
                return (pool_xml_set_attr(pxe->pxe_node, BAD_CAST name,
                    val));
        }
        if (is_ns_property(pe, name) != NULL) { /* in ns */
                if (pool_xml_set_attr(pxe->pxe_node,
                    BAD_CAST property_name_minus_ns(pe, name), val) == PO_FAIL)
                        return (pool_xml_set_prop(pxe->pxe_node, BAD_CAST name,
                            val));
        } else
                return (pool_xml_set_prop(pxe->pxe_node, BAD_CAST name, val));
        return (PO_SUCCESS);
}

/*
 * Remove a property from an element. Check if the property is an attribute,
 * if it is fail. Otherwise remove the property subelement.
 * Returns PO_SUCCESS/PO_FAIL
 */
static int
pool_xml_rm_property(pool_elem_t *pe, const char *name)
{
        pool_xml_elem_t *pxe = (pool_xml_elem_t *)pe;
        xmlXPathContextPtr ctx;
        xmlXPathObjectPtr path;
        char buf[MAX_PROP_SIZE];
        int ret;

        if (xmlHasProp(pxe->pxe_node, BAD_CAST name) != NULL) {
                pool_seterror(POE_BADPARAM);
                return (PO_FAIL);
        }

        /* use xpath to find the node with the appropriate value for name */
        (void) snprintf(buf, sizeof (buf), "property[@name=\"%s\"]", name);
        if ((ctx = xmlXPathNewContext(pxe->pxe_node->doc)) == NULL) {
                pool_seterror(POE_PUTPROP);
                return (PO_FAIL);
        }
        ctx->node = pxe->pxe_node;
        path = xmlXPathEval(BAD_CAST buf, ctx);

        if (path && (path->type == XPATH_NODESET) &&
            (path->nodesetval->nodeNr == 1)) {
                xmlUnlinkNode(path->nodesetval->nodeTab[0]);
                xmlFreeNode(path->nodesetval->nodeTab[0]);
                ret = PO_SUCCESS;
        } else {
                pool_seterror(POE_BADPARAM);
                ret = PO_FAIL;
        }
        xmlXPathFreeObject(path);
        xmlXPathFreeContext(ctx);
        return (ret);
}

/*
 * Get the data type for an attribute name from the element node. The data
 * type is returned and the value of the attribute updates the supplied value
 * pointer.
 */
static pool_value_class_t
pool_xml_get_attr(xmlNodePtr node, xmlChar *name, pool_value_t *value)
{
        pool_value_class_t data_type;
        xmlChar *data;
        uint64_t uval;
        int64_t ival;

        if (xmlHasProp(node, name) == NULL && pool_is_xml_attr(node->doc,
            (const char *) node->name, (const char *) name) == PO_FALSE) {
                pool_seterror(POE_BADPARAM);
                return (POC_INVAL);
        }
        if (xmlHasProp(node, BAD_CAST c_a_dtype) == NULL) {
                pool_seterror(POE_INVALID_CONF);
                return (POC_INVAL);
        }
        data = xmlGetProp(node, name);
        data_type = get_fast_dtype(node, name);
        if (data_type != POC_STRING && data == NULL) {
                pool_seterror(POE_INVALID_CONF);
                return (POC_INVAL);
        }
        switch (data_type) {
        case POC_UINT:
                errno = 0;
                uval = strtoull((char *)data, NULL, 0);
                if (errno != 0) {
                        data_type =  POC_INVAL;
                }
                else
                        pool_value_set_uint64(value, uval);
                break;
        case POC_INT:
                errno = 0;
                ival = strtoll((char *)data, NULL, 0);
                if (errno != 0) {
                        data_type =  POC_INVAL;
                }
                else
                        pool_value_set_int64(value, ival);
                break;
        case POC_DOUBLE:
                pool_value_set_double(value, atof((const char *)data));
                break;
        case POC_BOOL:
                if (strcmp((const char *)data, "true") == 0)
                        pool_value_set_bool(value, PO_TRUE);
                else
                        pool_value_set_bool(value, PO_FALSE);
                break;
        case POC_STRING:
                if (pool_value_set_string(value, data ?
                    (const char *)data : "") != PO_SUCCESS) {
                        xmlFree(data);
                        return (POC_INVAL);
                }
                break;
        case POC_INVAL:
        default:
                break;
        }
        xmlFree(data);
        return (data_type);
}

/*
 * Set the data type for an attribute name from the element node. The
 * supplied value is used to update the designated name using the data
 * type supplied.
 */
int
pool_xml_set_attr(xmlNodePtr node, xmlChar *name, const pool_value_t *value)
{
        xmlChar buf[MAX_PROP_SIZE] = {0};
        uint64_t ures;
        int64_t ires;
        uchar_t bres;
        double dres;
        const char *sres;

        pool_value_class_t data_type;

        if (xmlHasProp(node, name) == NULL && pool_is_xml_attr(node->doc,
            (const char *) node->name, (const char *) name) == PO_FALSE) {
                pool_seterror(POE_BADPARAM);
                return (PO_FAIL);
        }

        if (xmlHasProp(node, BAD_CAST c_a_dtype) == NULL) {
                pool_seterror(POE_INVALID_CONF);
                return (PO_FAIL);
        }
        data_type = get_fast_dtype(node, name);
        if (data_type != value->pv_class) {
                pool_seterror(POE_BADPARAM);
                return (PO_FAIL);
        }
        switch (value->pv_class) {
        case POC_UINT:
                (void) pool_value_get_uint64(value, &ures);
                (void) snprintf((char *)buf, sizeof (buf), "%llu",
                    (u_longlong_t)ures);
                break;
        case POC_INT:
                (void) pool_value_get_int64(value, &ires);
                (void) snprintf((char *)buf, sizeof (buf), "%lld",
                    (longlong_t)ires);
                break;
        case POC_DOUBLE:
                (void) pool_value_get_double(value, &dres);
                (void) snprintf((char *)buf, sizeof (buf), "%f", dres);
                break;
        case POC_BOOL:
                (void) pool_value_get_bool(value, &bres);
                if (bres == PO_FALSE)
                        (void) snprintf((char *)buf, sizeof (buf),
                            "false");
                else
                        (void) snprintf((char *)buf, sizeof (buf),
                            "true");
                break;
        case POC_STRING:
                (void) pool_value_get_string(value, &sres);
                if (sres != NULL)
                        (void) snprintf((char *)buf, sizeof (buf), "%s",
                            sres);
                break;
        case POC_INVAL:
        default:
                break;
        }
        if (xmlSetProp(node, name, buf) == NULL) {
                pool_seterror(POE_DATASTORE);
                return (PO_FAIL);
        }
        return (PO_SUCCESS);
}

/*
 * Get the data type for a property name from the element node. The data
 * type is returned and the value of the property updates the supplied value
 * pointer. The user is responsible for freeing the memory associated with
 * a string.
 */
static pool_value_class_t
pool_xml_get_prop(xmlNodePtr node, xmlChar *name, pool_value_t *value)
{
        pool_value_class_t data_type;
        xmlChar *data, *node_data;
        xmlXPathContextPtr ctx;
        xmlXPathObjectPtr path;
        char buf[MAX_PROP_SIZE];
        int64_t uval;
        int64_t ival;

        /* use xpath to find the node with the appropriate value for name */
        (void) snprintf(buf, sizeof (buf), "property[@name=\"%s\"]", name);
        if ((ctx = xmlXPathNewContext(node->doc)) == NULL) {
                pool_seterror(POE_BADPARAM);
                return (POC_INVAL);
        }
        ctx->node = node;
        path = xmlXPathEval(BAD_CAST buf, ctx);

        if (path && (path->type == XPATH_NODESET) &&
            (path->nodesetval->nodeNr == 1)) {
                int i;
                if (xmlHasProp(path->nodesetval->nodeTab[0],
                    BAD_CAST c_type) == NULL) {
                        xmlXPathFreeObject(path);
                        xmlXPathFreeContext(ctx);
                        pool_seterror(POE_INVALID_CONF);
                        return (POC_INVAL);
                }
                /* type is a string representation of the type */
                data = xmlGetProp(path->nodesetval->nodeTab[0],
                    BAD_CAST c_type);
                node_data = xmlNodeGetContent(path->nodesetval->nodeTab[0]);
                data_type = POC_INVAL;
                for (i = 0; i < (sizeof (data_type_tags) /
                    sizeof (data_type_tags[0])); i++) {
                        if (strcmp((char *)data, data_type_tags[i]) == 0) {
                                data_type = i;
                                break;
                        }
                }
                switch (data_type) {
                case POC_UINT:
                        errno = 0;
                        uval = strtoull((char *)node_data, NULL, 0);
                        if (errno != 0)
                                data_type =  POC_INVAL;
                        else
                                pool_value_set_uint64(value, uval);
                        break;
                case POC_INT:
                        errno = 0;
                        ival = strtoll((char *)node_data, NULL, 0);
                        if (errno != 0)
                                data_type =  POC_INVAL;
                        else
                                pool_value_set_int64(value, ival);
                        break;
                case POC_DOUBLE:
                        pool_value_set_double(value,
                            atof((const char *)node_data));
                        break;
                case POC_BOOL:
                        if (strcmp((const char *)node_data, "true")
                            == 0)
                                pool_value_set_bool(value, PO_TRUE);
                        else
                                pool_value_set_bool(value, PO_FALSE);
                        break;
                case POC_STRING:
                        if (pool_value_set_string(value,
                            (const char *)node_data) != PO_SUCCESS) {
                                data_type = POC_INVAL;
                                break;
                        }
                        break;
                case POC_INVAL:
                default:
                        break;
                }
                xmlFree(data);
                xmlFree(node_data);
                xmlXPathFreeObject(path);
                xmlXPathFreeContext(ctx);
                return (data_type);
        } else { /* No property exists, clean up and return */
                xmlXPathFreeObject(path);
                xmlXPathFreeContext(ctx);
                pool_seterror(POE_BADPARAM);
                return (POC_INVAL);
        }
}

/*
 * Set the data type for a property name from the element node. The
 * supplied value is used to update the designated name using the data
 * type supplied.
 */
int
pool_xml_set_prop(xmlNodePtr node, xmlChar *name, const pool_value_t *value)
{
/* First check if we have a property with this name (and type???). */
        xmlXPathContextPtr ctx;
        xmlXPathObjectPtr path;
        xmlChar buf[MAX_PROP_SIZE];
        xmlNodePtr element;
        uint64_t ures;
        int64_t ires;
        uchar_t bres;
        double dres;
        const char *sres;

        /* use xpath to find the node with the appropriate value for name */
        (void) snprintf((char *)buf, sizeof (buf), "property[@name=\"%s\"]",
            name);
        if ((ctx = xmlXPathNewContext(node->doc)) == NULL) {
                pool_seterror(POE_BADPARAM);
                return (PO_FAIL);
        }
        ctx->node = node;
        path = xmlXPathEval(buf, ctx);
        if (path == NULL || path->type != XPATH_NODESET) {
                xmlXPathFreeObject(path);
                xmlXPathFreeContext(ctx);
                pool_seterror(POE_BADPARAM);
                return (PO_FAIL);
        } else {
                if (path->nodesetval->nodeNr == 0)
                        element = property_create
                            (node, (const char *)name, value->pv_class);
                else if (path->nodesetval->nodeNr == 1) {
                        int i;
                        xmlChar *data;

                        element = path->nodesetval->nodeTab[0];
                        if (xmlHasProp(element, BAD_CAST c_type) == NULL) {
                                xmlXPathFreeObject(path);
                                xmlXPathFreeContext(ctx);
                                pool_seterror(POE_INVALID_CONF);
                                return (PO_FAIL);
                        }
                        data = xmlGetProp(element, BAD_CAST c_type);
                        for (i = 0; i < (sizeof (data_type_tags) /
                            sizeof (data_type_tags[0])); i++)
                                if (strcmp((char *)data, data_type_tags[i])
                                    == 0) {
                                        break;
                                }
                        xmlFree(data);
                        if (value->pv_class != i) {
                                xmlXPathFreeObject(path);
                                xmlXPathFreeContext(ctx);
                                pool_seterror(POE_BADPARAM);
                                return (PO_FAIL);
                        }
                } else {
                        xmlXPathFreeObject(path);
                        xmlXPathFreeContext(ctx);
                        pool_seterror(POE_BADPARAM);
                        return (PO_FAIL);
                }
        }

        switch (value->pv_class) {
        case POC_UINT:
                (void) pool_value_get_uint64(value, &ures);
                (void) snprintf((char *)buf, sizeof (buf), "%llu",
                    (u_longlong_t)ures);
                break;
        case POC_INT:
                (void) pool_value_get_int64(value, &ires);
                (void) snprintf((char *)buf, sizeof (buf), "%lld",
                    (longlong_t)ires);
                break;
        case POC_DOUBLE:
                (void) pool_value_get_double(value, &dres);
                (void) snprintf((char *)buf, sizeof (buf), "%f", dres);
                break;
        case POC_BOOL:
                (void) pool_value_get_bool(value, &bres);
                if (bres == PO_FALSE)
                        (void) snprintf((char *)buf, sizeof (buf),
                            "false");
                else
                        (void) snprintf((char *)buf, sizeof (buf),
                            "true");
                break;
        case POC_STRING:
                (void) pool_value_get_string(value, &sres);
                (void) snprintf((char *)buf, sizeof (buf), "%s", sres);
                break;
        case POC_INVAL:
        default:
                break;
        }
        xmlNodeSetContent(element, buf);
        xmlXPathFreeObject(path);
        xmlXPathFreeContext(ctx);
        return (PO_SUCCESS);
}

/*
 * Return a NULL terminated array of pool_value_t which represents all
 * of the properties stored for an element
 *
 * Return NULL on failure. It is the caller's responsibility to free
 * the returned array of values.
 */
pool_value_t **
pool_xml_get_properties(const pool_elem_t *pe, uint_t *nprops)
{
        pool_value_t **result;
        pool_xml_elem_t *pxe = (pool_xml_elem_t *)pe;
        int i, j;
        pool_conf_t *conf = TO_CONF(pe);
        xmlElementPtr elemDTD;
        xmlAttributePtr attr;
        xmlXPathContextPtr ctx;
        xmlXPathObjectPtr path;
        char_buf_t *cb = NULL;

        *nprops = 0;

        elemDTD = xmlGetDtdElementDesc(pxe->pxe_node->doc->extSubset,
            pxe->pxe_node->name);
        for (attr = elemDTD->attributes; attr != NULL; attr = attr->nexth) {
                if (strcmp((const char *)attr->name, c_a_dtype) != 0 ||
                    strcmp((const char *)attr->name, c_type) != 0)
                        (*nprops)++;
        }
        if ((ctx = xmlXPathNewContext(
            ((pool_xml_connection_t *)conf->pc_prov)->pxc_doc)) == NULL) {
                pool_seterror(POE_BADPARAM);
                return (NULL);
        }
        ctx->node = pxe->pxe_node;
        path = xmlXPathEval(BAD_CAST "property", ctx);

        if (path != NULL && path->type == XPATH_NODESET &&
            path->nodesetval != NULL)
                (*nprops) += path->nodesetval->nodeNr;

        if ((result = calloc(*nprops + 1, sizeof (pool_value_t *))) == NULL) {
                xmlXPathFreeObject(path);
                xmlXPathFreeContext(ctx);
                pool_seterror(POE_SYSTEM);
                return (NULL);
        }
        if ((cb = alloc_char_buf(CB_DEFAULT_LEN)) == NULL) {
                xmlXPathFreeObject(path);
                xmlXPathFreeContext(ctx);
                free(result);
                return (NULL);
        }
        /*
         * Now store our attributes and properties in result
         */
        for (i = 0, attr = elemDTD->attributes; attr != NULL;
            attr = attr->nexth, i++) {
                if (strcmp((const char *)attr->name, c_a_dtype) == 0 ||
                    strcmp((const char *)attr->name, c_type) == 0) {
                        i--;
                        continue;
                }
                result[i] = pool_value_alloc();
                if (pool_xml_get_attr(pxe->pxe_node,
                    BAD_CAST attr->name, result[i]) == POC_INVAL) {
                        xmlXPathFreeObject(path);
                        xmlXPathFreeContext(ctx);
                        while (i-- >= 0)
                                pool_value_free(result[i]);
                        free(result);
                        free_char_buf(cb);
                        return (NULL);
                }
                if (strcmp((const char *)attr->name, c_type) != 0) {
                        if (set_char_buf(cb, "%s.%s",
                            pool_elem_class_string(pe), attr->name) !=
                            PO_SUCCESS) {
                                xmlXPathFreeObject(path);
                                xmlXPathFreeContext(ctx);
                                while (i-- >= 0)
                                        pool_value_free(result[i]);
                                free(result);
                                free_char_buf(cb);
                                return (NULL);
                        }
                        if (pool_value_set_name(result[i], cb->cb_buf) !=
                            PO_SUCCESS) {
                                xmlXPathFreeObject(path);
                                xmlXPathFreeContext(ctx);
                                while (i-- >= 0)
                                        pool_value_free(result[i]);
                                free(result);
                                free_char_buf(cb);
                                return (NULL);
                        }
                } else {
                        if (pool_value_set_name(result[i],
                            (const char *)attr->name) != PO_SUCCESS) {
                                xmlXPathFreeObject(path);
                                xmlXPathFreeContext(ctx);
                                while (i-- >= 0)
                                        pool_value_free(result[i]);
                                free(result);
                                free_char_buf(cb);
                                return (NULL);
                        }
                }
        }
        free_char_buf(cb);
        for (j = 0; j < path->nodesetval->nodeNr; j++, i++) {
                xmlChar *name = xmlGetProp(path->nodesetval->nodeTab[j],
                    BAD_CAST c_name);

                result[i] = pool_value_alloc();

                if (pool_xml_get_prop(pxe->pxe_node, name, result[i]) ==
                    POC_INVAL) {
                        xmlFree(name);
                        xmlXPathFreeObject(path);
                        xmlXPathFreeContext(ctx);
                        while (i-- >= 0)
                                pool_value_free(result[i]);
                        free(result);
                        return (NULL);
                }
                if (pool_value_set_name(result[i], (const char *)name) !=
                    PO_SUCCESS) {
                        xmlFree(name);
                        xmlXPathFreeObject(path);
                        xmlXPathFreeContext(ctx);
                        while (i-- >= 0)
                                pool_value_free(result[i]);
                        free(result);
                        return (NULL);
                }
                xmlFree(name);
        }
        xmlXPathFreeObject(path);
        xmlXPathFreeContext(ctx);
        return (result);
}

/*
 * Store a pointer to one of our data types in the _private member of each
 * XML data node contained within the passed node. Note this function is
 * recursive and so all sub-nodes are also shadowed. Only shadow the nodes
 * which we are interested in, i.e. system, pool, res and comp
 */
static int
create_shadow(xmlNodePtr node)
{
        xmlNodePtr sib;
        int ret = PO_SUCCESS;
        /* Create a data structure of the appropriate type */

        if (0 == (xmlStrcmp(node->name,
            BAD_CAST element_class_tags[PEC_SYSTEM]))) {
                ret = pool_xml_elem_wrap(node, PEC_SYSTEM, PREC_INVALID,
                    PCEC_INVALID);
        } else if (0 == (xmlStrcmp(node->name,
            BAD_CAST element_class_tags[PEC_POOL]))) {
                ret = pool_xml_elem_wrap(node, PEC_POOL, PREC_INVALID,
                    PCEC_INVALID);
        } else if (0 == (xmlStrcmp(node->name,
            BAD_CAST element_class_tags[PEC_RES_COMP]))) {
                xmlChar *data;
                pool_resource_elem_class_t res_class;
                data = xmlGetProp(node, BAD_CAST c_type);

                res_class = pool_resource_elem_class_from_string((char *)data);
                xmlFree(data);
                ret = pool_xml_elem_wrap(node, PEC_RES_COMP, res_class,
                    PCEC_INVALID);
        } else if (0 == (xmlStrcmp(node->name,
            BAD_CAST element_class_tags[PEC_RES_AGG]))) {
                xmlChar *data;
                pool_resource_elem_class_t res_class;
                data = xmlGetProp(node, BAD_CAST c_type);

                res_class = pool_resource_elem_class_from_string((char *)data);
                xmlFree(data);
                ret = pool_xml_elem_wrap(node, PEC_RES_AGG, res_class,
                    PCEC_INVALID);
        } else if (0 == (xmlStrcmp(node->name,
            BAD_CAST element_class_tags[PEC_COMP]))) {
                xmlChar *data;
                pool_component_elem_class_t comp_class;
                data = xmlGetProp(node, BAD_CAST c_type);

                comp_class = pool_component_elem_class_from_string(
                    (char *)data);
                xmlFree(data);
                ret = pool_xml_elem_wrap(node, PEC_COMP, PREC_INVALID,
                    comp_class);
        }
        /* Have to shadow all children and all siblings */
        for (sib = node->children; sib != NULL; sib = sib->next) {
                if ((ret = create_shadow(sib)) != PO_SUCCESS)
                        break;
        }
        return (ret);
}


/*
 * XML Data access and navigation APIs
 */

/*
 * Close the configuration. There are a few steps to closing a configuration:
 * - Unlock the backing file (if there is one)
 * - Close the file (if there is one)
 * - Free the shadow memory     }Done in pool_xml_free_doc
 * - Free the document          }
 * - Free the data provider for this configuration
 * - Free the configuration location specifier
 * Returns PO_SUCCESS/PO_FAIL
 */
static int
pool_xml_close(pool_conf_t *conf)
{
        pool_xml_connection_t *pxc = (pool_xml_connection_t *)conf->pc_prov;
        int ret = PO_SUCCESS;

        if (pxc->pxc_file != NULL) {
                /* Close (and implicitly) unlock the file */
                if (fclose(pxc->pxc_file) != 0) {
                        pool_seterror(POE_SYSTEM);
                        ret = PO_FAIL;
                }
                pxc->pxc_file = NULL;
        }
        /* Close the xml specific parts */
        (void) pool_xml_free_doc(conf);
        pool_xml_connection_free((pool_xml_connection_t *)conf->pc_prov);
        return (ret);
}

/*
 * Remove the configuration from the backing store. In XML terms delete
 * the file backing the configuration. You need a copy of the location
 * since the pool_conf_close function, frees the location.
 * Returns PO_SUCCESS/PO_FAIL
 */
static int
pool_xml_remove(pool_conf_t *conf)
{
        if (pool_conf_location(conf) != NULL) {
                /* First unlink the file, to prevent races on open */
                if (unlink(pool_conf_location(conf)) != 0) {
                        pool_seterror(POE_SYSTEM);
                        return (PO_FAIL);
                }
                /* Now close the configuration */
                (void) pool_conf_close(conf);
                return (PO_SUCCESS);
        }
        return (PO_FAIL);
}

/*
 * Validate the configuration. There are three levels of validation, loose,
 * strict and runtime. In this, XML, implementation, loose is mapped to XML
 * validation, strict implements additional application level validation
 * checks, e.g. all pools must have unique names, runtime ensures that this
 * configuration would instantiate on the current system.
 *
 * Returns PO_SUCCESS/PO_FAIL
 */
static int
pool_xml_validate(const pool_conf_t *conf, pool_valid_level_t level)
{
        pool_xml_connection_t *pxc = (pool_xml_connection_t *)conf->pc_prov;
        xmlValidCtxtPtr cvp;

        if ((cvp = xmlNewValidCtxt()) == NULL) {
                pool_seterror(POE_INVALID_CONF);
                return (PO_FAIL);
        }
        cvp->error    = pool_error_func;
        cvp->warning  = pool_error_func;

        if (xmlValidateDocument(cvp, pxc->pxc_doc) == 0) {
                xmlFreeValidCtxt(cvp);
                pool_seterror(POE_INVALID_CONF);
                return (PO_FAIL);
        }
        xmlFreeValidCtxt(cvp);

        if (level >= POV_RUNTIME) {
                /*
                 * Note: This is resource specific.
                 */
                return (((pool_validate_resource(conf, "pset", c_min_prop, 0) ==
                    PO_SUCCESS) &&
                    (pool_validate_resource(conf, "pset", c_max_prop, 0) ==
                    PO_SUCCESS)) ? PO_SUCCESS : PO_FAIL);
        }
        return (PO_SUCCESS);
}

/*
 * Commit the configuration to the backing store. In XML terms this means
 * write the changes to the backing file. Read the comments below for details
 * on exactly how this operation is performed.
 * Returns PO_SUCCESS/PO_FAIL
 */
static int
pool_xml_commit(pool_conf_t *conf)
{
        pool_xml_connection_t *prov = (pool_xml_connection_t *)conf->pc_prov;
        xmlOutputBufferPtr buf;

        /*
         * Ensure that the configuration file has no contents
         */
        if (fseek(prov->pxc_file, 0, SEEK_SET) != 0) {
                pool_seterror(POE_SYSTEM);
                return (PO_FAIL);
        }

        if (ftruncate(fileno(prov->pxc_file), 0) == -1) {
                pool_seterror(POE_SYSTEM);
                return (PO_FAIL);
        }
        /*
         * Create an XML output buffer and write out the contents of the
         * configuration to the file.
         */
        if ((buf = xmlOutputBufferCreateFile(prov->pxc_file, NULL)) == NULL) {
                pool_seterror(POE_DATASTORE);
                return (PO_FAIL);
        }

        if (xmlSaveFormatFileTo(buf, prov->pxc_doc, NULL, 1) == -1) {
                pool_seterror(POE_DATASTORE);
                return (PO_FAIL);
        }

        return (PO_SUCCESS);
}

/*
 * Export the configuration in the specified format to the specified location.
 * The only format implemented now is the native format, which saves the
 * active configuration to the supplied location.
 * Returns PO_SUCCESS/PO_FAIL
 */
static int
pool_xml_export(const pool_conf_t *conf, const char *location,
    pool_export_format_t fmt)
{
        int ret;

        switch (fmt) {
        case POX_NATIVE:
                ret = xmlSaveFormatFile(location,
                    ((pool_xml_connection_t *)conf->pc_prov)->pxc_doc,
                    1);
                if (ret == -1) {
                        pool_seterror(POE_SYSTEM);
                        return (PO_FAIL);
                } else
                        return (PO_SUCCESS);

        default:
                pool_seterror(POE_BADPARAM);
                return (PO_FAIL);
        }
}

/*
 * Discard the configuration and restore the configuration to the values
 * specified in the configuration location.
 * Returns PO_SUCCESS/PO_FAIL
 */
static int
pool_xml_rollback(pool_conf_t *conf)
{
        pool_xml_connection_t *prov = (pool_xml_connection_t *)conf->pc_prov;

        /* Rollback the file pointer ready for the reparse */
        if (fseek(prov->pxc_file, 0, SEEK_SET) != 0) {
                pool_seterror(POE_SYSTEM);
                return (PO_FAIL);
        }
        /* Reparse the document */
        /* In XML terms this means, discard and reparse the document */
        (void) pool_xml_free_doc(conf);
        if (pool_xml_parse_document(conf) == PO_FAIL)
                return (PO_FAIL);
        return (PO_SUCCESS);
}

/*
 * Allocate a new pool_elem_t in the supplied configuration of the specified
 * class.
 * Returns element pointer/NULL
 */
static void
pool_xml_elem_init(pool_conf_t *conf, pool_xml_elem_t *elem,
    pool_elem_class_t class, pool_resource_elem_class_t res_class,
    pool_component_elem_class_t comp_class)
{
        pool_elem_t *pe = TO_ELEM(elem);
        pe->pe_conf = conf;
        pe->pe_class = class;
        pe->pe_resource_class = res_class;
        pe->pe_component_class = comp_class;
        /* Set up the function pointers for element manipulation */
        pe->pe_get_prop = pool_xml_get_property;
        pe->pe_put_prop = pool_xml_put_property;
        pe->pe_rm_prop = pool_xml_rm_property;
        pe->pe_get_props = pool_xml_get_properties;
        pe->pe_remove = pool_xml_elem_remove;
        pe->pe_get_container = pool_xml_get_container;
        pe->pe_set_container = pool_xml_set_container;
        /*
         * Specific initialisation for different types of element
         */
        if (class == PEC_POOL) {
                pool_xml_pool_t *pp = (pool_xml_pool_t *)elem;
                pp->pp_associate = pool_xml_pool_associate;
                pp->pp_dissociate = pool_xml_pool_dissociate;
        }
        if (class == PEC_RES_COMP || class == PEC_RES_AGG) {
                pool_xml_resource_t *pr = (pool_xml_resource_t *)elem;
                pr->pr_is_system = pool_xml_resource_is_system;
                pr->pr_can_associate = pool_xml_resource_can_associate;
        }
}

/*
 * "Wrap" a suplied XML node with a pool_elem_t sub-type of the supplied
 * class.
 * Returns PO_SUCCESS/PO_FAIL
 */
static int
pool_xml_elem_wrap(xmlNodePtr node, pool_elem_class_t class,
    pool_resource_elem_class_t res_class,
    pool_component_elem_class_t comp_class)
{
        pool_conf_t *conf = node->doc->_private;
        pool_xml_elem_t *elem;
        /* Need to do some messing about to support SubTypes */
        switch (class) {
        case PEC_SYSTEM:
                if ((elem = malloc(sizeof (pool_xml_system_t))) == NULL) {
                        pool_seterror(POE_SYSTEM);
                        return (PO_FAIL);
                }
                (void) memset(elem, 0, sizeof (pool_xml_system_t));
                break;
        case PEC_POOL:
                if ((elem = malloc(sizeof (pool_xml_pool_t))) == NULL) {
                        pool_seterror(POE_SYSTEM);
                        return (PO_FAIL);
                }
                (void) memset(elem, 0, sizeof (pool_xml_pool_t));
                break;
        case PEC_RES_COMP:
        case PEC_RES_AGG:
                if ((elem = malloc(sizeof (pool_xml_resource_t))) == NULL) {
                        pool_seterror(POE_SYSTEM);
                        return (PO_FAIL);
                }
                (void) memset(elem, 0, sizeof (pool_xml_resource_t));
                break;
        case PEC_COMP:
                if ((elem = malloc(sizeof (pool_xml_component_t))) == NULL) {
                        pool_seterror(POE_SYSTEM);
                        return (PO_FAIL);
                }
                (void) memset(elem, 0, sizeof (pool_xml_component_t));
                break;
        }
        pool_xml_elem_init(conf, elem, class, res_class, comp_class);
        node->_private = elem;
        elem->pxe_node = node;
        return (PO_SUCCESS);
}

/*
 * Associate a pool to the default resource for the supplied resource
 * type.
 */
int
pool_assoc_default_resource_type(pool_t *pool, pool_resource_elem_class_t type)
{
        pool_value_t *props[] = { NULL, NULL, NULL };
        uint_t rl_size;
        pool_resource_t **rsl;
        pool_conf_t *conf = TO_ELEM(pool)->pe_conf;
        char_buf_t *cb = NULL;
        pool_value_t val0 = POOL_VALUE_INITIALIZER;
        pool_value_t val1 = POOL_VALUE_INITIALIZER;

        props[0] = &val0;
        props[1] = &val1;


        if (pool_value_set_string(props[0], pool_resource_type_string(type)) !=
            PO_SUCCESS ||
            pool_value_set_name(props[0], c_type) != PO_SUCCESS) {
                return (PO_FAIL);
        }

        if ((cb = alloc_char_buf(CB_DEFAULT_LEN)) == NULL) {
                return (PO_FAIL);
        }

        if (set_char_buf(cb, "%s.default",
            pool_resource_type_string(type)) !=
            PO_SUCCESS) {
                free_char_buf(cb);
                return (PO_FAIL);
        }
        if (pool_value_set_name(props[1], cb->cb_buf) != PO_SUCCESS) {
                free_char_buf(cb);
                return (PO_FAIL);
        }
        pool_value_set_bool(props[1], PO_TRUE);
        free_char_buf(cb);

        if ((rsl = pool_query_resources(conf, &rl_size, props)) == NULL) {
                pool_seterror(POE_INVALID_CONF);
                return (PO_FAIL);
        }

        /*
         * One default resource set per type
         */
        if (rl_size != 1) {
                free(rsl);
                pool_seterror(POE_INVALID_CONF);
                return (PO_FAIL);
        }
        if (pool_associate(conf, pool, rsl[0])  < 0) {
                free(rsl);
                pool_seterror(POE_INVALID_CONF);
                return (PO_FAIL);
        }
        free(rsl);
        return (PO_SUCCESS);
}

/*
 * Create an XML node in the supplied configuration with a pool_elem_t
 * sub-type of the supplied class.
 * Returns pool_elem_t pointer/NULL
 */
static pool_elem_t *
pool_xml_elem_create(pool_conf_t *conf, pool_elem_class_t class,
    pool_resource_elem_class_t res_class,
    pool_component_elem_class_t comp_class)
{
        /* In XML terms, create an element of the appropriate class */
        pool_xml_elem_t *elem;
        pool_elem_t *parent;
        pool_system_t *parent_system;

        if (class == PEC_INVALID) {
                pool_seterror(POE_BADPARAM);
                return (NULL);
        }

        /* Now create the XML component and add to it's parent */
        /*
         * If we know the class of an element, we know it's parent.
         * PEC_POOL, the parent must be the system node
         * PEC_RES, treat as pool.
         * PEC_COMP, we don't know the parent, leave this up to the
         * create_comp function.
         */
        /* Since we know the subtype we can create and populate the sub-type */
        switch (class) {
        case PEC_POOL:
                if ((parent_system = pool_conf_system(conf)) == NULL) {
                        pool_seterror(POE_INVALID_CONF);
                        return (NULL);
                }
                if ((parent = pool_system_elem(parent_system)) == NULL) {
                        pool_seterror(POE_INVALID_CONF);
                        return (NULL);
                }
                if ((elem = malloc(sizeof (pool_xml_system_t))) == NULL) {
                        pool_seterror(POE_SYSTEM);
                        return (NULL);
                }
                (void) memset(elem, 0, sizeof (pool_xml_system_t));
                if ((elem->pxe_node = node_create_with_id(
                    ((pool_xml_elem_t *)parent)->pxe_node,
                    BAD_CAST element_class_tags[class])) == NULL) {
                        pool_seterror(POE_DATASTORE);
                        (void) pool_xml_elem_remove((pool_elem_t *)elem);
                        return (NULL);
                }
                break;
        case PEC_RES_COMP:
        case PEC_RES_AGG:
                if ((parent_system = pool_conf_system(conf)) == NULL) {
                        pool_seterror(POE_INVALID_CONF);
                        return (NULL);
                }
                if ((parent = pool_system_elem(parent_system)) == NULL) {
                        pool_seterror(POE_INVALID_CONF);
                        return (NULL);
                }
                if ((elem = malloc(sizeof (pool_xml_resource_t))) == NULL) {
                        pool_seterror(POE_SYSTEM);
                        return (NULL);
                }
                (void) memset(elem, 0, sizeof (pool_xml_resource_t));
                if ((elem->pxe_node = node_create_with_id
                    (((pool_xml_elem_t *)parent)->pxe_node,
                    BAD_CAST element_class_tags[class])) == NULL) {
                        pool_seterror(POE_DATASTORE);
                        (void) pool_xml_elem_remove((pool_elem_t *)elem);
                        return (NULL);
                }
                break;
        case PEC_COMP:
                if ((elem = malloc(sizeof (pool_xml_component_t))) == NULL) {
                        pool_seterror(POE_SYSTEM);
                        return (NULL);
                }
                (void) memset(elem, 0, sizeof (pool_xml_component_t));
                if ((elem->pxe_node = node_create(NULL,
                    BAD_CAST element_class_tags[class])) == NULL) {
                        pool_seterror(POE_DATASTORE);
                        (void) pool_xml_elem_remove((pool_elem_t *)elem);
                        return (NULL);
                }
                break;
        default:
                pool_seterror(POE_BADPARAM);
                return (NULL);
        }
        pool_xml_elem_init(conf, elem, class, res_class, comp_class);
        elem->pxe_node->_private = elem;
        if (class == PEC_RES_COMP || class == PEC_RES_AGG ||
            class == PEC_COMP) {
                /*
                 * Put the type and an invalid sys_id on the node.
                 */
                if (xmlSetProp(elem->pxe_node, BAD_CAST c_sys_prop,
                    BAD_CAST POOL_SYSID_BAD_STRING) == NULL) {
                        pool_seterror(POE_DATASTORE);
                        (void) pool_xml_elem_remove((pool_elem_t *)elem);
                        return (NULL);
                }
                if (xmlSetProp(elem->pxe_node, BAD_CAST c_type,
                    BAD_CAST pool_elem_class_string(
                    (pool_elem_t *)elem)) == NULL) {
                        pool_seterror(POE_DATASTORE);
                        (void) pool_xml_elem_remove((pool_elem_t *)elem);
                        return (NULL);
                }
        }
        if (class == PEC_POOL) {
                /*
                 * Note: This is resource specific.
                 */
                if (pool_assoc_default_resource_type(pool_elem_pool(
                    (pool_elem_t *)elem), PREC_PSET) == PO_FAIL) {
                        (void) pool_xml_elem_remove((pool_elem_t *)elem);
                        return (NULL);
                }
        }
        return ((pool_elem_t *)elem);
}

/*
 * Allocate a data provider for the supplied configuration and optionally
 * discover resources.
 * The data provider is the cross over point from the "abstract" configuration
 * functions into the data representation specific manipulation routines.
 * This function sets up all the required pointers to create an XML aware
 * data provider.
 * Returns PO_SUCCESS/PO_FAIL
 */
int
pool_xml_connection_alloc(pool_conf_t *conf, int oflags)
{
        pool_xml_connection_t *prov;

        xml_init();
        if ((prov = malloc(sizeof (pool_xml_connection_t))) == NULL) {
                pool_seterror(POE_SYSTEM);
                return (PO_FAIL);
        }
        (void) memset(prov, 0, sizeof (pool_xml_connection_t));
        /*
         * Initialise data members
         */
        prov->pc_name = strdup("LIBXML 2.4.0");
        prov->pc_store_type = XML_DATA_STORE;
        prov->pc_oflags = oflags;
        /*
         * Initialise function pointers
         */
        prov->pc_close = pool_xml_close;
        prov->pc_validate = pool_xml_validate;
        prov->pc_commit = pool_xml_commit;
        prov->pc_export = pool_xml_export;
        prov->pc_rollback = pool_xml_rollback;
        prov->pc_exec_query = pool_xml_exec_query;
        prov->pc_elem_create = pool_xml_elem_create;
        prov->pc_remove = pool_xml_remove;
        prov->pc_res_xfer = pool_xml_res_transfer;
        prov->pc_res_xxfer = pool_xml_res_xtransfer;
        /*
         * End of common initialisation
         */
        /*
         * Associate the provider to it's configuration
         */
        conf->pc_prov = (pool_connection_t *)prov;
        /*
         * At this point the configuration provider has been initialized,
         * mark the configuration as valid so that the various routines
         * which rely on a valid configuration will work correctly.
         */
        conf->pc_state = POF_VALID;

        if ((oflags & PO_CREAT) != 0) {
                pool_conf_t *dyn;

                if ((dyn = pool_conf_alloc()) == NULL)
                        return (PO_FAIL);

                if (pool_conf_open(dyn, pool_dynamic_location(),
                    PO_RDONLY) != PO_SUCCESS) {
                        pool_conf_free(dyn);
                        return (PO_FAIL);
                }

                if (pool_conf_export(dyn, conf->pc_location,
                    POX_NATIVE) != PO_SUCCESS) {
                        (void) pool_conf_close(dyn);
                        pool_conf_free(dyn);
                        return (PO_FAIL);
                }
                (void) pool_conf_close(dyn);
                pool_conf_free(dyn);
        }

        if (pool_xml_open_file(conf) == PO_FAIL) {
                (void) pool_xml_close(conf);
                return (PO_FAIL);
        }

        return (PO_SUCCESS);
}

/*
 * Free the resources for an XML data provider.
 */
static void
pool_xml_connection_free(pool_xml_connection_t *prov)
{
        free((void *)prov->pc_name);
        free(prov);
}

/*
 * Allocate a result set. The Result Set stores the result of an XPath
 * query along with the parameters used to create the result set (for
 * debugging purposes).
 * Returns pool_xml_result_set_t pointer/NULL
 */
static pool_xml_result_set_t *
pool_xml_result_set_alloc(const pool_conf_t *conf)
{
        pool_xml_result_set_t *rs;

        if ((rs = malloc(sizeof (pool_xml_result_set_t))) == NULL) {
                pool_seterror(POE_SYSTEM);
                return (NULL);
        }
        (void) memset(rs, 0, sizeof (pool_xml_result_set_t));
        rs->prs_conf = conf;
        rs->prs_index = -1;
        rs->prs_active = PO_TRUE;
        /* Fix up the result set accessor functions to the xml specfic ones */
        rs->prs_next = pool_xml_rs_next;
        rs->prs_prev = pool_xml_rs_prev;
        rs->prs_first = pool_xml_rs_first;
        rs->prs_last = pool_xml_rs_last;
        rs->prs_get_index = pool_xml_rs_get_index;
        rs->prs_set_index = pool_xml_rs_set_index;
        rs->prs_close = pool_xml_rs_close;
        rs->prs_count = pool_xml_rs_count;
        return (rs);
}

/*
 * Free a result set. Ensure that the resources are all released at this point.
 */
static void
pool_xml_result_set_free(pool_xml_result_set_t *rs)
{
        if (rs->pxr_path != NULL)
                xmlXPathFreeObject(rs->pxr_path);
        if (rs->pxr_ctx != NULL)
                xmlXPathFreeContext(rs->pxr_ctx);
        free(rs);
}

/*
 * Transfer size from one resource to another.
 * Returns PO_SUCCESS/PO_FAIL
 */
/* ARGSUSED */
int
pool_xml_res_transfer(pool_resource_t *src, pool_resource_t *tgt, uint64_t size)
{
        return (PO_SUCCESS);
}

/*
 * Transfer components rl from one resource to another.
 * Returns PO_SUCCESS/PO_FAIL
 */
/* ARGSUSED */
int
pool_xml_res_xtransfer(pool_resource_t *src, pool_resource_t *tgt,
    pool_component_t **rl) {
        int i;

        /*
         * Walk the Result Set and move the resource components
         */
        for (i = 0; rl[i] != NULL; i++) {
                if (pool_set_container(TO_ELEM(tgt), TO_ELEM(rl[i])) ==
                    PO_FAIL) {
                        return (PO_FAIL);
                }
        }
        return (PO_SUCCESS);
}

/*
 * Return the next element in a result set.
 * Returns pool_elem_t pointer/NULL
 */
static pool_elem_t *
pool_xml_rs_next(pool_result_set_t *set)
{
        pool_elem_t *next;
        /* Since I know this is an XML result set */
        pool_xml_result_set_t *xset = (pool_xml_result_set_t *)set;

        /* Update the context node */
        if (xset->prs_index == xset->pxr_path->nodesetval->nodeNr - 1)
                return (NULL);
        next =
            xset->pxr_path->nodesetval->nodeTab[++xset->prs_index]->_private;
        return (next);
}

/*
 * Return the previous element in a result set.
 * Returns pool_elem_t pointer/NULL
 */
static pool_elem_t *
pool_xml_rs_prev(pool_result_set_t *set)
{
        pool_elem_t *prev;
        /* Since I know this is an XML result set */
        pool_xml_result_set_t *xset = (pool_xml_result_set_t *)set;

        /* Update the context node */
        if (xset->prs_index < 0)
                return (NULL);
        prev =
            xset->pxr_path->nodesetval->nodeTab[xset->prs_index--]->_private;
        return (prev);
}

/*
 * Sets the current index in a result set.
 * Returns PO_SUCCESS/PO_FAIL
 */
static int
pool_xml_rs_set_index(pool_result_set_t *set, int index)
{
        /* Since I know this is an XML result set */
        pool_xml_result_set_t *xset = (pool_xml_result_set_t *)set;

        if (index < 0 || index >= xset->pxr_path->nodesetval->nodeNr) {
                pool_seterror(POE_BADPARAM);
                return (PO_FAIL);
        }
        xset->prs_index = index;
        return (PO_SUCCESS);
}

/*
 * Return the current index in a result set.
 * Returns current index
 */
static int
pool_xml_rs_get_index(pool_result_set_t *set)
{
        /* Since I know this is an XML result set */
        pool_xml_result_set_t *xset = (pool_xml_result_set_t *)set;

        return (xset->prs_index);
}

/*
 * Return the first element in a result set.
 * Returns pool_elem_t pointer/NULL
 */
static pool_elem_t *
pool_xml_rs_first(pool_result_set_t *set)
{
        /* Since I know this is an XML result set */
        pool_xml_result_set_t *xset = (pool_xml_result_set_t *)set;

        /* Update the context node */
        return (xset->pxr_path->nodesetval->nodeTab[0]->_private);
}

/*
 * Return the last element in a result set.
 * Returns pool_elem_t pointer/NULL
 */
static pool_elem_t *
pool_xml_rs_last(pool_result_set_t *set)
{
        /* Since I know this is an XML result set */
        pool_xml_result_set_t *xset = (pool_xml_result_set_t *)set;

        /* Update the context node */
        return (xset->pxr_path->nodesetval->
            nodeTab[xset->pxr_path->nodesetval->nodeNr-1]->_private);
}

/*
 * Return the number of results in a result set.
 * Returns result count
 */
static int
pool_xml_rs_count(pool_result_set_t *set)
{
        pool_xml_result_set_t *xset = (pool_xml_result_set_t *)set;

        return (xset->pxr_path->nodesetval->nodeNr);
}


/*
 * Close a result set. Remove this result set from the list of results and
 * free the resources
 * Returns PO_SUCCESS/PO_FAIL
 */
static int
pool_xml_rs_close(pool_result_set_t *set)
{
        pool_xml_result_set_t *xset = (pool_xml_result_set_t *)set;

        pool_xml_result_set_free(xset);
        return (PO_SUCCESS);
}

/*
 * Set the container for a node.
 * Returns PO_SUCCESS/PO_FAIL
 */
static int
pool_xml_set_container(pool_elem_t *pp, pool_elem_t *pc)
{
        pool_xml_elem_t *pxp;
        pool_xml_elem_t *pxc;
        xmlNodePtr parent;

        pxp = (pool_xml_elem_t *)pp;
        pxc = (pool_xml_elem_t *)pc;
        parent = pxc->pxe_node->parent;

        xmlUnlinkNode(pxc->pxe_node);
        if (xmlAddChild(pxp->pxe_node, pxc->pxe_node) == NULL) {
                /* Try to move back */
                (void) xmlAddChild(parent, pxc->pxe_node);
                pool_seterror(POE_INVALID_CONF);
                return (PO_FAIL);
        }
        pc->pe_conf = pp->pe_conf;
        return (PO_SUCCESS);
}
/*
 * Get the container for a node.
 * Returns Container/NULL
 */
static pool_elem_t *
pool_xml_get_container(const pool_elem_t *pc)
{
        pool_xml_elem_t *pxc = (pool_xml_elem_t *)pc;

        return ((pool_elem_t *)pxc->pxe_node->parent->_private);
}

/*
 * Note: This function is resource specific, needs extending for other
 * resource types.
 */
int
pool_xml_resource_is_system(const pool_resource_t *pr)
{
        switch (pool_resource_elem_class(TO_ELEM(pr))) {
        case PREC_PSET:
                return (PSID_IS_SYSSET(
                    elem_get_sysid(TO_ELEM(pr))));
        default:
                return (PO_FALSE);
        }
}

/*
 * Note: This function is resource specific, needs extending for other
 * resource types.
 */
int
pool_xml_resource_can_associate(const pool_resource_t *pr)
{
        switch (pool_resource_elem_class(TO_ELEM(pr))) {
        case PREC_PSET:
                return (PO_TRUE);
        default:
                return (PO_FALSE);
        }
}

/*
 * Note: This function is resource specific. It must be extended to support
 * multiple resource types.
 */
int
pool_xml_pool_associate(pool_t *pool, const pool_resource_t *pr)
{
        pool_value_t val = POOL_VALUE_INITIALIZER;

        if (pool_xml_get_property(TO_ELEM(pr),
            "pset.ref_id", &val) != POC_STRING)
                return (PO_FAIL);
        if (pool_xml_put_property(TO_ELEM(pool), "pool.res", &val) !=
            PO_SUCCESS)
                return (PO_FAIL);
        return (PO_SUCCESS);
}

/*
 * pool_xml_pool_dissociate() simply finds the default resource for
 * the type of resource being dissociated and then calls
 * pool_xml_pool_associate() to associate to the default resource.
 */
int
pool_xml_pool_dissociate(pool_t *pool, const pool_resource_t *pr)
{
        const pool_resource_t *default_res;

        if ((default_res = get_default_resource(pr)) == NULL)
                return (PO_FAIL);
        if (default_res == pr)
                return (PO_SUCCESS);
        return (pool_xml_pool_associate(pool, default_res));
}

/*
 * pool_xml_open_file() opens a file for a configuration. This establishes
 * the locks required to ensure data integrity when manipulating a
 * configuration.
 * Returns PO_SUCCESS/PO_FAIL
 */
static int
pool_xml_open_file(pool_conf_t *conf)
{
        struct flock lock;
        struct stat s;

        pool_xml_connection_t *prov = (pool_xml_connection_t *)conf->pc_prov;

        /*
         * Always close the pxc_file in case there was a previously failed open
         */
        if (prov->pxc_file != NULL) {
                (void) fclose(prov->pxc_file);
                prov->pxc_file = NULL;
        }

        /*
         * Check that the DTD required for this operation is present.
         * If it isn't fail
         */
        if (dtd_exists(dtd_location) == PO_FALSE) {
                pool_seterror(POE_DATASTORE);
                return (PO_FAIL);
        }

        if ((prov->pc_oflags & PO_RDWR) != 0)
                prov->pxc_file = fopen(conf->pc_location, "r+F");
        else /* Assume opening PO_RDONLY */
                prov->pxc_file = fopen(conf->pc_location, "rF");

        if (prov->pxc_file == NULL) {
                pool_seterror(POE_SYSTEM);
                return (PO_FAIL);
        }

        /*
         * Setup the lock for the file
         */
        lock.l_type = (prov->pc_oflags & PO_RDWR) ? F_WRLCK : F_RDLCK;
        lock.l_whence = SEEK_SET;
        lock.l_start = 0;
        lock.l_len = 0;
        if (fcntl(fileno(prov->pxc_file), F_SETLKW, &lock) == -1) {
                pool_seterror(POE_SYSTEM);
                return (PO_FAIL);
        }
        /*
         * Check to see if the document was removed whilst waiting for
         * the lock. If it was return an error.
         */
        if (stat(conf->pc_location, &s) == -1) {
                (void) fclose(prov->pxc_file);
                prov->pxc_file = NULL;
                pool_seterror(POE_SYSTEM);
                return (PO_FAIL);
        }
        /* Parse the document */
        if (pool_xml_parse_document(conf) != PO_SUCCESS)
                return (PO_FAIL);
        return (PO_SUCCESS);
}

/*
 * Try to work out if an element contains an attribute of the supplied name.
 * Search the internal subset first and then the external subset.
 * Return PO_TRUE if there is an attribute of that name declared for that
 * element.
 */
int
pool_is_xml_attr(xmlDocPtr doc, const char *elem, const char *attr)
{
        xmlDtdPtr internal = xmlGetIntSubset(doc);
        xmlDtdPtr external = doc->extSubset;

        if (xmlGetDtdAttrDesc(internal, BAD_CAST elem, BAD_CAST attr) == NULL)
                if (xmlGetDtdAttrDesc(external,
                    BAD_CAST elem, BAD_CAST attr) == NULL)
                        return (PO_FALSE);
        return (PO_TRUE);
}

/*
 * Execute the specified query using XPath. This complex function relies on
 * a couple of helpers to build up an XPath query, pool_build_xpath_buf in
 * particular.
 * conf - the pool configuration being manipulated
 * src - the root of the search, if NULL that means whole document
 * src_attr - if supplied means an IDREF(S) search on this attribute
 * classes - target classes
 * props - target properties
 * Returns pool_result_set_t pointer/NULL
 */
pool_result_set_t *
pool_xml_exec_query(const pool_conf_t *conf, const pool_elem_t *src,
    const char *src_attr, pool_elem_class_t classes, pool_value_t **props)
{
        char *buf = NULL;
        char_buf_t *cb = NULL;
        pool_xml_result_set_t *rs;
        pool_xml_elem_t *pxe = (pool_xml_elem_t *)src;
        pool_xml_connection_t *prov = (pool_xml_connection_t *)conf->pc_prov;

        if ((cb = alloc_char_buf(CB_DEFAULT_LEN)) == NULL)
                return (NULL);

        /*
         * Prior to building up the complex XPath query, check to see if
         * src_attr is an IDREF(S). If it is use the IDREF(S) information
         * to generate the query rather than the other data
         */
        if (src_attr != NULL) {
                char *tok;
                char *lasts;
                char *or = "";
                xmlChar *id;

                /*
                 * Check the arguments for consistency
                 */
                if (pool_is_xml_attr(prov->pxc_doc,
                    element_class_tags[src->pe_class], src_attr) != PO_TRUE) {
                        free_char_buf(cb);
                        pool_seterror(POE_BADPARAM);
                        return (NULL);
                }

                if ((id = xmlGetProp(pxe->pxe_node, BAD_CAST src_attr))
                    == NULL) {
                        free_char_buf(cb);
                        pool_seterror(POE_DATASTORE);
                        return (NULL);
                }
                for (tok = strtok_r((char *)id, "        ", &lasts);
                    tok != NULL; tok = strtok_r(NULL, "  ", &lasts)) {
                        (void) append_char_buf(cb, "%s//*[@ref_id=\"%s\"]",
                            or, tok);
                        or = " | ";
                        if ((classes & PEC_QRY_SYSTEM) != 0) {
                                if (pool_build_xpath_buf(prov, src, PEC_SYSTEM,
                                    props, cb, PO_TRUE) == PO_FAIL) {
                                        free_char_buf(cb);
                                        return (NULL);
                                }
                        }
                        if ((classes & PEC_QRY_POOL) != 0) {
                                if (pool_build_xpath_buf(prov, src, PEC_POOL,
                                    props, cb, PO_TRUE) == PO_FAIL) {
                                        free_char_buf(cb);
                                        return (NULL);
                                }
                        }
                        if ((classes & PEC_QRY_RES_COMP) != 0) {
                                if (pool_build_xpath_buf(prov, src,
                                    PEC_RES_COMP, props, cb, PO_TRUE)
                                    == PO_FAIL) {
                                        free_char_buf(cb);
                                        return (NULL);
                                }
                        } else if ((classes & PEC_QRY_RES_AGG) != 0) {
                                if (pool_build_xpath_buf(prov, src,
                                    PEC_RES_AGG, props, cb, PO_TRUE)
                                    == PO_FAIL) {
                                        free_char_buf(cb);
                                        return (NULL);
                                }
                        }
                }
                xmlFree(id);
        } else {
                /*
                 * Build up an XPath query using the supplied parameters.
                 * The basic logic is to:
                 * - Identify which classes are the targets of the query
                 * - For each class work out if the props are attributes or not
                 * - Build up a piece of XPath for each class
                 * - Combine the results into one large XPath query.
                 * - Execute the query.
                 */
                if ((classes & PEC_QRY_SYSTEM) != 0) {
                        if (pool_build_xpath_buf(prov, src, PEC_SYSTEM, props,
                            cb, PO_FALSE) == PO_FAIL) {
                                free_char_buf(cb);
                                return (NULL);
                        }
                }
                if ((classes & PEC_QRY_POOL) != 0) {
                        if (pool_build_xpath_buf(prov, src, PEC_POOL, props,
                            cb, PO_FALSE) == PO_FAIL) {
                                free_char_buf(cb);
                                return (NULL);
                        }
                }
                if ((classes & PEC_QRY_RES_COMP) != 0) {
                        if (pool_build_xpath_buf(prov, src, PEC_RES_COMP, props,
                            cb, PO_FALSE) == PO_FAIL) {
                                free_char_buf(cb);
                                return (NULL);
                        }
                }
                if ((classes & PEC_QRY_RES_AGG) != 0) {
                        if (pool_build_xpath_buf(prov, src, PEC_RES_AGG, props,
                            cb, PO_FALSE) == PO_FAIL) {
                                free_char_buf(cb);
                                return (NULL);
                        }
                }
                if ((classes & PEC_QRY_COMP) != 0) {
                        if (pool_build_xpath_buf(prov, src, PEC_COMP, props,
                            cb, PO_FALSE) == PO_FAIL) {
                                free_char_buf(cb);
                                return (NULL);
                        }
                }
        }
        buf = strdup(cb->cb_buf);
        free_char_buf(cb);
        /*
         * Have a buffer at this point, that we can use
         */
        if ((rs = pool_xml_result_set_alloc(conf)) == NULL) {
                free(buf);
                return (NULL);
        }
        /*
         * Set up the XPath Query
         */
        if ((rs->pxr_ctx = xmlXPathNewContext(
            ((pool_xml_connection_t *)conf->pc_prov)->pxc_doc)) == NULL) {
                free(buf);
                (void) pool_xml_rs_close((pool_result_set_t *)rs);
                pool_seterror(POE_DATASTORE);
                return (NULL);
        }
        if (src == NULL)
                rs->pxr_ctx->node = xmlDocGetRootElement
                    (((pool_xml_connection_t *)conf->pc_prov)->pxc_doc);
        else
                rs->pxr_ctx->node = pxe->pxe_node;
        /*
         * Select
         */
        rs->pxr_path = xmlXPathEval(BAD_CAST buf, rs->pxr_ctx);
        free(buf);
        /*
         * Generate the result set and wrap the results as pool_elem_t
         */
        if (rs->pxr_path->nodesetval->nodeNr == 0)
                pool_seterror(POE_INVALID_SEARCH);
        return ((pool_result_set_t *)rs);
}

/*
 * Build an XPath query buffer. This is complex and a little fragile, but
 * I'm trying to accomplish something complex with as little code as possible.
 * I wait the implementation of XMLQuery with baited breath...
 * Returns PO_SUCCESS/PO_FAIL
 */
static int
pool_build_xpath_buf(pool_xml_connection_t *prov, const pool_elem_t *src,
    pool_elem_class_t class, pool_value_t *props[], char_buf_t *cb, int is_ref)
{
        int i;
        const char *ATTR_FMTS[] = {
                "[ @%s=\"%llu\" ]",     /* POC_UINT */
                "[ @%s=\"%lld\" ]",     /* POC_INT */
                "[ @%s=\"%f\" ]",       /* POC_DOUBLE */
                "[ @%s=\"%s\" ]",       /* POC_BOOL */
                "[ @%s=\"%s\" ]",       /* POC_STRING */
        };
        const char *PROP_FMTS[] = {
                "[ property[@name=\"%s\"][text()=\"%llu\"] ]",  /* POC_UINT */
                "[ property[@name=\"%s\"][text()=\"%lld\"] ]",  /* POC_INT */
                "[ property[@name=\"%s\"][text()=\"%f\"] ]",    /* POC_DOUBLE */
                "[ property[@name=\"%s\"][text()=\"%s\"] ]",    /* POC_BOOL */
                "[ property[@name=\"%s\"][text()=\"%s\"] ]"     /* POC_STRING */
        };
        const char **fmts;
        int nprop;
        const char *last_prop_name = NULL;
        char *type_prefix = NULL;
        int has_type = PO_FALSE;

        if (is_ref == PO_FALSE) {
                if (cb->cb_buf != NULL && strlen(cb->cb_buf) > 0)
                        (void) append_char_buf(cb, " |");
                if (src != NULL)
                        (void) append_char_buf(cb, " ./");
                else
                        (void) append_char_buf(cb, "//");
                (void) append_char_buf(cb, element_class_tags[class]);
        }
        if (props == NULL || props[0] == NULL)
                return (PO_SUCCESS);
        for (nprop = 0; props[nprop] != NULL; nprop++)
                /* Count properties */;
        /*
         * Sort the attributes and properties by name.
         */
        qsort(props, nprop, sizeof (pool_value_t *), prop_sort);
        for (i = 0; i < nprop; i++) {
                int is_attr = 0;
                const char *prefix;
                const char *prop_name;
                uint64_t uval;
                int64_t ival;
                double dval;
                uchar_t bval;
                const char *sval;
                pool_value_class_t pvc;

                prop_name = pool_value_get_name(props[i]);
                if ((prefix = is_a_known_prefix(class, prop_name)) != NULL) {
                        const char *attr_name;
                        /*
                         * Possibly an attribute. Strip off the prefix.
                         */
                        if (strcmp(prop_name, c_type) == 0) {
                                has_type = PO_TRUE;
                                attr_name = prop_name;
                        } else
                                attr_name = prop_name + strlen(prefix) + 1;
                        if (pool_is_xml_attr(prov->pxc_doc,
                            element_class_tags[class], attr_name)) {
                                is_attr = 1;
                                prop_name = attr_name;
                                if (class == PEC_RES_COMP ||
                                    class == PEC_RES_AGG ||
                                    class == PEC_COMP) {
                                        free(type_prefix);
                                        type_prefix = strdup(prefix);
                                }
                        }
                }
                if (is_attr)  {
                        fmts = ATTR_FMTS;
                } else {
                        fmts = PROP_FMTS;
                }
                /*
                 * Add attributes/properties to the search buffer
                 */
                switch ((pvc = pool_value_get_type(props[i]))) {
                case POC_UINT:
                        (void) pool_value_get_uint64(props[i], &uval);
                        if (append_char_buf(cb, fmts[pvc], prop_name, uval)
                            == PO_FAIL) {
                                free(type_prefix);
                                return (PO_FAIL);
                        }
                        break;
                case POC_INT:
                        (void) pool_value_get_int64(props[i], &ival);
                        if (append_char_buf(cb, fmts[pvc], prop_name, ival)
                            == PO_FAIL) {
                                free(type_prefix);
                                return (PO_FAIL);
                        }
                        break;
                case POC_DOUBLE:
                        (void) pool_value_get_double(props[i], &dval);
                        if (append_char_buf(cb, fmts[pvc], prop_name, dval)
                            == PO_FAIL) {
                                free(type_prefix);
                                return (PO_FAIL);
                        }
                        break;
                case POC_BOOL:
                        (void) pool_value_get_bool(props[i], &bval);
                        if (append_char_buf(cb, fmts[pvc], prop_name,
                            bval ? "true" : "false") == PO_FAIL) {
                                free(type_prefix);
                                return (PO_FAIL);
                        }
                        break;
                case POC_STRING:
                        (void) pool_value_get_string(props[i], &sval);
                        if (append_char_buf(cb, fmts[pvc], prop_name, sval)
                            == PO_FAIL) {
                                free(type_prefix);
                                return (PO_FAIL);
                        }
                        break;
                default:
                        free(type_prefix);
                        pool_seterror(POE_INVALID_SEARCH);
                        return (PO_FAIL);
                }
                if (last_prop_name != NULL) {
                        const char *suffix1, *suffix2;
                        /*
                         * Extra fiddling for namespaces
                         */
                        suffix1 = strrchr(prop_name, '.');
                        suffix2 = strrchr(last_prop_name, '.');

                        if (suffix1 != NULL || suffix2 != NULL) {
                                if (suffix1 == NULL)
                                        suffix1 = prop_name;
                                else
                                        suffix1++;
                                if (suffix2 == NULL)
                                        suffix2 = last_prop_name;
                                else
                                        suffix2++;
                        } else {
                                suffix1 = prop_name;
                                suffix2 = last_prop_name;
                        }
                        if (strcmp(suffix1, suffix2) == 0) {
                                char *where = strrchr(cb->cb_buf, '[');
                                if (is_attr != PO_TRUE) {
                                        /* repeat */
                                        while (*--where != '[')
                                                ;
                                        while (*--where != '[')
                                                ;
                                }
                                *(where - 1) = 'o';
                                *where = 'r';
                        }
                }
                last_prop_name = prop_name;
        }
        if (has_type == PO_FALSE) {
                if (type_prefix) {
                        if (append_char_buf(cb, ATTR_FMTS[POC_STRING],
                            c_type, type_prefix) == PO_FAIL) {
                                free(type_prefix);
                                return (PO_FAIL);
                        }
                }
        }
        free(type_prefix);
        return (PO_SUCCESS);
}

/*
 * Utility routine for use by quicksort. Assumes that the supplied data
 * are pool values and compares the names of the two pool values.
 * Returns an integer greater than, equal to, or less than 0.
 */
static int
prop_sort(const void *a, const void *b)
{
        pool_value_t **prop_a = (pool_value_t **)a;
        pool_value_t **prop_b = (pool_value_t **)b;
        const char *str_a;
        const char *str_b;
        const char *suffix1, *suffix2;

        str_a = pool_value_get_name(*prop_a);
        str_b = pool_value_get_name(*prop_b);
        /*
         * Extra fiddling for namespaces
         */
        suffix1 = strrchr(str_a, '.');
        suffix2 = strrchr(str_b, '.');

        if (suffix1 != NULL || suffix2 != NULL) {
                if (suffix1 == NULL)
                        suffix1 = str_a;
                else
                        suffix1++;
                if (suffix2 == NULL)
                        suffix2 = str_b;
                else
                        suffix2++;
        } else {
                suffix1 = str_a;
                suffix2 = str_b;
        }
        return (strcmp(suffix1, suffix2));
}

/*
 * Order the elements by (ref_id)
 */

/*
 * Returns PO_TRUE/PO_FALSE to indicate whether the supplied path exists on the
 * system. It is assumed that the supplied path is in URL format and represents
 * a file and so file:// is stripped from the start of the search.
 */
static int
dtd_exists(const char *path)
{
        struct stat buf;

        if (strstr(path, "file://") != path)
                return (PO_FALSE);

        if (path[7] == 0)
                return (PO_FALSE);

        if (stat(&path[7], &buf) == 0)
                return (PO_TRUE);
        return (PO_FALSE);
}

/*
 * Build the dtype structures to accelerate data type lookup operations. The
 * purpose is to avoid expensive XML manipulations on data which will not
 * change over the life of a library invocation. It is designed to be invoked
 * once from the library init function.
 */
static void
build_dtype_accelerator(void)
{
        xmlDtdPtr dtd;
        const xmlChar *elem_list[ELEM_TYPE_COUNT] = {
                BAD_CAST "res_comp",
                BAD_CAST "res_agg",
                BAD_CAST "comp",
                BAD_CAST "pool",
                BAD_CAST "property",
                BAD_CAST "system" };
        int i;

        if (_libpool_xml_initialised == PO_TRUE)
                return;

        /* Load up the d-type data for each element */
        /*
         * Store data type information in nested lists
         * Top level list contains attribute declaration pointers which
         * can be used to match with supplied nodes.
         * Second level list contains attribute type information for each
         * element declaration
         */
        /*
         * Unfortunately, there's no easy way to get a list of all DTD
         * element descriptions as there is no libxml API to do this (they
         * are stored in a hash, which I guess is why). Explicitly seek
         * for descriptions for elements that are known to hold an a-dtype
         * attribute and build accelerators for those elements.
         * If the DTD changes, the library may have to change as well now,
         * since this code makes explicit assumptions about which elements
         * contain a-dtype information.
         */

        if ((dtd = xmlParseDTD(BAD_CAST "-//Sun Microsystems Inc//DTD Resource"
            " Management All//EN", BAD_CAST dtd_location)) == NULL)
                return;
        for (i = 0; i < ELEM_TYPE_COUNT; i++) {
                xmlElementPtr elem;
                xmlAttributePtr attr;

                if ((elem = xmlGetDtdElementDesc(dtd, elem_list[i])) == NULL)
                        return;
                elem_tbl[i].ett_elem = xmlStrdup(elem->name);
                /* Walk the list of attributes looking for a-dtype */
                for (attr = elem->attributes; attr != NULL;
                    attr = attr->nexth) {
                        if (strcmp((const char *)attr->name, c_a_dtype) == 0) {
                                /*
                                 * Allocate a dtype_tbl_t
                                 */
                                elem_tbl[i].ett_dtype =
                                    build_dtype_tbl(attr->defaultValue);
                                /* This could have returned NULL */
                        }
                }
        }
        xmlFreeDtd(dtd);
}

/*
 * build_dtype_tbl() parses the supplied data and returns an array (max size
 * of 10, increase if required) of dtype_tbl_t structures holding data type
 * information for an element. The supplied data is assumed to be in "a-dtype"
 * format. The dtype_tbl_t array is NULL terminated, which is why space for
 * 11 members is allocated.
 */
static dtype_tbl_t
(*build_dtype_tbl(const xmlChar *rawdata))[]
{
        char *tok;
        char *lasts;
        dtype_tbl_t (*tbl)[];
        int j = 0;
        xmlChar *data;
        const int max_attr = 11; /* Not more than 10 types per element */

        /*
         * Parse the supplied data, assumed to be in a-dtype format, and
         * generate a lookup table which is indexed by the name and contains
         * the data type
         */
        if (rawdata == NULL)
        return (NULL);
        if ((data = xmlStrdup(rawdata)) == NULL)
        return (NULL);
        if ((tbl = calloc(max_attr, sizeof (dtype_tbl_t))) == NULL) {
                xmlFree(data);
                return (NULL);
        }
        for (tok = strtok_r((char *)data, "      ", &lasts); tok != NULL;
            tok = strtok_r(NULL, "       ", &lasts)) {
                    int i;
                    (*tbl)[j].dt_name  = xmlStrdup(BAD_CAST tok);
                    if ((tok = strtok_r(NULL, "  ", &lasts)) == NULL) {
                            int k = j;
                            for (j = 0; j < k; j++)
                                    free((*tbl)[j].dt_name);
                            pool_seterror(POE_DATASTORE);
                            xmlFree(data);
                            free(tbl);
                            return (NULL);
                    }
                    for (i = 0; i < (sizeof (data_type_tags) /
                        sizeof (data_type_tags[0])); i++) {
                                if (strcmp(tok, data_type_tags[i]) == 0)
                                (*tbl)[j++].dt_type = i;
                        }
                    if (j == max_attr) { /* too many attributes, bail out */
                            for (j = 0; j < max_attr; j++)
                            free((*tbl)[j].dt_name);
                            free(tbl);
                            xmlFree(data);
                            return (NULL);
                    }
            }
        (*tbl)[j].dt_name = NULL; /* Terminate the table */
        xmlFree(data);
        return (tbl);
}

/*
 * get_fast_dtype() finds the data type for a supplied attribute name on a
 * supplied node. This is called get_fast_dtype() because it uses the cached
 * data type information created at library initialisation.
 */
static int
get_fast_dtype(xmlNodePtr node, xmlChar *name)
{
        int i;
        xmlElementPtr elem;

        if ((elem = xmlGetDtdElementDesc(node->doc->extSubset, node->name))
            == NULL) {
                pool_seterror(POE_BADPARAM);
                return (POC_INVAL);
        }

        for (i = 0; i < ELEM_TYPE_COUNT; i++) {
                if (xmlStrcmp(elem_tbl[i].ett_elem, elem->name) == 0) {
                        dtype_tbl_t (*tbl)[] = elem_tbl[i].ett_dtype;
                        int j = 0;

                        if (tbl == NULL)
                                break;
                        for (j = 0; (*tbl)[j].dt_name != NULL; j++)
                                if (xmlStrcmp(name, (*tbl)[j].dt_name) == 0)
                                        return ((*tbl)[j].dt_type); /* found */
                        break; /* if we didn't find it in the elem, break */
                }
        }
        /* If we can't find it, say it's a string */
        return (POC_STRING);
}

/*
 * pool_xml_parse_document() parses the file associated with a supplied
 * configuration to regenerate the runtime representation. The supplied
 * configuration must reference an already opened file and this is used
 * to generate the XML representation via the configuration provider's
 * pxc_doc member.
 * size must be >=4 in order for "content encoding detection" to work.
 */
static int
pool_xml_parse_document(pool_conf_t *conf)
{
        int res;
        char chars[PAGE_READ_SIZE];
        struct stat f_stat;
        xmlParserCtxtPtr ctxt;
        size_t size;
        pool_xml_connection_t *prov = (pool_xml_connection_t *)conf->pc_prov;
        xmlNodePtr root;
        pool_resource_t **rsl;
        uint_t nelem;
        int i;

        if (fstat(fileno(prov->pxc_file), &f_stat) == -1) {
                pool_seterror(POE_SYSTEM);
                return (PO_FAIL);
        }

        if (f_stat.st_size == 0) {
                pool_seterror(POE_INVALID_CONF);
                return (PO_FAIL);
        } else
                size = f_stat.st_size < 4 ? 4 : PAGE_READ_SIZE;

        res = fread(chars, 1, size, prov->pxc_file);

        if (res >= 4) {
                xmlValidCtxtPtr cvp;

                if ((ctxt = xmlCreatePushParserCtxt(NULL, NULL,
                    chars, res, conf->pc_location)) == NULL) {
                        pool_seterror(POE_INVALID_CONF);
                        return (PO_FAIL);
                }

                while ((res = fread(chars, 1, size, prov->pxc_file)) > 0) {
                        if (xmlParseChunk(ctxt, chars, res, 0) != 0) {
                                xmlFreeParserCtxt(ctxt);
                                pool_seterror(POE_INVALID_CONF);
                                return (PO_FAIL);
                        }
                }
                if (xmlParseChunk(ctxt, chars, 0, 1) != 0) {
                        xmlFreeParserCtxt(ctxt);
                        pool_seterror(POE_INVALID_CONF);
                        return (PO_FAIL);
                }

                if ((cvp = xmlNewValidCtxt()) == NULL) {
                        pool_seterror(POE_INVALID_CONF);
                        return (PO_FAIL);
                }
                cvp->error    = pool_error_func;
                cvp->warning  = pool_error_func;

                if (xmlValidateDocument(cvp, ctxt->myDoc) == 0) {
                        xmlFreeValidCtxt(cvp);
                        xmlFreeParserCtxt(ctxt);
                        pool_seterror(POE_INVALID_CONF);
                        return (PO_FAIL);
                }
                prov->pxc_doc = ctxt->myDoc;
                xmlFreeValidCtxt(cvp);
                xmlFreeParserCtxt(ctxt);
        }
        if (prov->pxc_doc == NULL) {
                pool_seterror(POE_INVALID_CONF);
                return (PO_FAIL);
        }
        prov->pxc_doc->_private = conf;

        /* Get the root element */
        if ((root = xmlDocGetRootElement(prov->pxc_doc)) == NULL) {
                pool_seterror(POE_INVALID_CONF);
                return (PO_FAIL);
        }
        /*
         * Ensure that the parsed tree has been contained within
         * our shadow tree.
         */
        if (create_shadow(root) != PO_SUCCESS) {
                pool_seterror(POE_INVALID_CONF);
                return (PO_FAIL);
        }

        if (pool_xml_validate(conf, POV_STRICT) != PO_SUCCESS) {
                return (PO_FAIL);
        }
        /*
         * For backwards compatibility with S9, make sure that all
         * resources have a size and that it is correct.
         */
        if ((rsl = pool_query_resources(conf, &nelem, NULL)) != NULL) {
                pool_value_t val = POOL_VALUE_INITIALIZER;
                for (i = 0; i < nelem; i++) {
                        if (pool_get_ns_property(TO_ELEM(rsl[i]), c_size_prop,
                            &val) != POC_UINT) {
                                pool_component_t **cs;
                                uint_t size;
                                if ((cs = pool_query_resource_components(conf,
                                    rsl[i], &size, NULL)) != NULL) {
                                        free(cs);
                                        pool_value_set_uint64(&val, size);
                                } else
                                        pool_value_set_uint64(&val, 0);
                                if (pool_put_any_ns_property(TO_ELEM(rsl[i]),
                                    c_size_prop, &val)  != PO_SUCCESS) {
                                        free(rsl);
                                        return (PO_FAIL);
                                }
                        }
                }
                free(rsl);
        }
        return (PO_SUCCESS);
}