14736 zfs: Improve sorted scan memory accounting

[illumos-gate.git] / usr / src / lib / libpicltree / picltree.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 (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
 */

/*
 * This module implements the PTree interface and the PICL to PTree calls
 */

/*
 * Note:
 * PICL Node and Property Handles Table:
 * A node or property in PICL tree has two handles: a ptree handle, which is
 * used by plug-ins and the libpicltree interface, and a picl handle
 * which is used by clients and the libpicl interface.
 * The mapping of ptree handles to the internal PICL object (picl_obj_t) is
 * kept in a ptree hash table (ptreetbl), and the mapping of a picl handle
 * to its ptree handle is kept in the picl hash table (picltbl).
 * The reader/writer lock, ptree_rwlock, is held when reading or modifying ptree
 * hash table (ptreetbl) and/or the PICL tree structure (nodes and linkages
 * between them). The reader/writer lock, picltbl_rwlock, is held when reading
 * or modifying picl hash table (picltbl).
 *
 * The mutex, ptreehdl_lock, is used to control allocation of ptree handles.
 * The mutex, piclhdl_lock, is used to control allocation of picl handles.
 *
 * The mutex, ptree_refresh_mutex, and the condition, ptree_refresh_cond,
 * are used to synchronize PICL refreshes (ptree_refresh) and to wait/signal
 * change in PICL tree structure.
 *
 * The counter, picl_hdl_hi, is the hi water mark for allocated picl handles.
 * The counter, ptree_hdl_hi, is the hi water mark for allocated ptree handles.
 * A stale handle error is returned for handle values below the hi water
 * mark, and invalid handles are returned for handle values above the hi water
 * mark or when the process id field of the handle does not match.
 *
 * Locking Scheme:
 * The structure of the PICL tree is controlled by the ptree_rwlock. The
 * properties of a node are controlled by individual node locks. The
 * piclize-ing or unpiclize-ing of a node is controlled by picltbl_rwlock.
 *
 * Two-Phase Locking scheme: lock acquire phase and lock release phase.
 *
 * Lock Ordering:
 * The ptree_rwlock and node locks are always acquired in the following order:
 *      lock ptree_rwlock
 *      lock node
 *
 * Lock Strategy:
 * There are three locks:
 *      ptree_rwlock:   a reader lock is obtained to do ptree hash table
 *                      lookups and traverse tree. A writer lock is obtained
 *                      when creating or destroying nodes from the ptree,
 *                      or when modifying node linkages: parent, peer, child.
 *      picltbl_rwlock: a reader lock is obtained for picl hash table lookups.
 *                      A writer lock is obtained when piclize-ing or
 *                      unpiclize-ing nodes or properties.
 *      node_lock:      This is a reader/writer lock for properties of a node.
 *                      A reader lock is obtained before reading property
 *                      values. A writer lock is obtained when adding or
 *                      removing properties and when modifying a property value.
 *
 * Never hold more than one node lock at a time.
 *
 * Event Locking:
 * There are two locks:
 *      evtq_lock:      this lock protects the event queue. It is obtained
 *                      to queue events that are posted and to unqueue
 *                      events to be dispatched.
 *      evtq_cv:        condition variable is protected by evtq_lock. It is
 *                      used by the ptree event thread to wait for events
 *                      until eventqp is not NULL.
 *      evtq_empty:     condition variable protected by evtq_lock. It is
 *                      used to signal when the eventq becomes empty. The
 *                      reinitialization process waits on this condition.
 *     evthandler_lock: this protects the event handler list. It is obtained
 *                      to add event handlers on registration and to remove
 *                      event handlers on unregistration.
 *      (handler)->cv:  condition variable per handler protected by
 *                      evthandler_lock.  It is used to wait until the
 *                      event handler completes execution (execflg == 0)
 *                      before unregistering the handler.
 */

#include <stdio.h>
#include <string.h>
#include <strings.h>
#include <stdlib.h>
#include <stdarg.h>
#include <alloca.h>
#include <assert.h>
#include <errno.h>
#include <unistd.h>
#include <limits.h>
#include <libintl.h>
#include <syslog.h>
#include <pthread.h>
#include <synch.h>
#include <setjmp.h>
#include <signal.h>
#include <dlfcn.h>
#include <dirent.h>
#include <door.h>
#include <time.h>
#include <inttypes.h>
#include <sys/systeminfo.h>
#include <sys/utsname.h>
#include <picl.h>
#include <picltree.h>
#include "picldefs.h"
#include "ptree_impl.h"

#define SO_VERS ".so.1"

static  hash_t          picltbl;        /* client handles to picl obj */
static  hash_t          ptreetbl;       /* ptree handles to picl obj */
static  pthread_mutex_t ptreehdl_lock;
static  pthread_mutex_t piclhdl_lock;
static  pthread_mutex_t ptree_refresh_mutex;
static  rwlock_t        picltbl_rwlock; /* PICL handle table lock */
static  rwlock_t        ptree_rwlock;   /* PICL tree lock */
static  pthread_cond_t  ptree_refresh_cond = PTHREAD_COND_INITIALIZER;
static  uint32_t        ptree_hdl_hi = 1;
static  uint32_t        picl_hdl_hi = 1;
static  picl_obj_t      *picl_root_obj = NULL;
static  picl_nodehdl_t  ptree_root_hdl = PICL_INVALID_PICLHDL;
static  int             ptree_generation = 0;
static  pid_t           picld_pid;
static  door_cred_t     picld_cred;
static  int             qempty_wait;    /* evtq_empty condition waiter flag */

static  picld_plugin_reg_list_t         *plugin_reg_list = NULL;
static  picld_plugin_desc_t             *plugin_desc;

static  eventq_t        *eventqp;       /* PICL events queue */
static  pthread_mutex_t evtq_lock = PTHREAD_MUTEX_INITIALIZER;
static  pthread_cond_t  evtq_cv = PTHREAD_COND_INITIALIZER;
static  pthread_cond_t  evtq_empty = PTHREAD_COND_INITIALIZER;
static  evt_handler_t   *evt_handlers;  /* Event handler list */
static  pthread_mutex_t evthandler_lock = PTHREAD_MUTEX_INITIALIZER;

/*
 * PICL daemon verbose level
 */
int     verbose_level;


/*
 * Event handler free functions
 */
static void
free_handler(evt_handler_t *evhp)
{
        if (evhp->ename)
                free(evhp->ename);
        (void) pthread_cond_broadcast(&evhp->cv);
        (void) pthread_cond_destroy(&evhp->cv);
        free(evhp);
}


/*
 * queue_event to events queue
 */
static void
queue_event(eventq_t *evt)
{
        eventq_t        *tmpp;

        evt->next = NULL;
        if (eventqp == NULL)
                eventqp = evt;
        else {
                tmpp = eventqp;
                while (tmpp->next != NULL)
                        tmpp = tmpp->next;
                tmpp->next = evt;
        }
}

/*
 * unqueue_event from the specified eventq
 */
static eventq_t *
unqueue_event(eventq_t **qp)
{
        eventq_t        *evtp;

        evtp = *qp;
        if (evtp != NULL)
                *qp = evtp->next;
        return (evtp);
}

/*
 * register an event handler by adding it to the list
 */
int
ptree_register_handler(const char *ename,
    void (*evt_handler)(const char *ename, const void *earg, size_t size,
    void *cookie), void *cookie)
{
        evt_handler_t   *ent;
        evt_handler_t   *iter;

        if (ename == NULL)
                return (PICL_INVALIDARG);

        /*
         * Initialize event handler entry
         */
        ent = malloc(sizeof (*ent));
        if (ent == NULL)
                return (PICL_FAILURE);
        ent->ename = strdup(ename);
        if (ent->ename == NULL) {
                free(ent);
                return (PICL_FAILURE);
        }
        ent->cookie = cookie;
        ent->evt_handler = evt_handler;
        ent->execflg = 0;
        ent->wakeupflg = 0;
        (void) pthread_cond_init(&ent->cv, NULL);
        ent->next = NULL;

        /*
         * add handler to the handler list
         */
        (void) pthread_mutex_lock(&evthandler_lock);
        if (evt_handlers == NULL) {
                evt_handlers = ent;
                (void) pthread_mutex_unlock(&evthandler_lock);
                return (PICL_SUCCESS);
        }
        iter = evt_handlers;
        while (iter->next != NULL)
                iter = iter->next;
        iter->next = ent;
        (void) pthread_mutex_unlock(&evthandler_lock);

        return (PICL_SUCCESS);
}

/*
 * unregister handler
 */
void
ptree_unregister_handler(const char *ename,
    void (*evt_handler)(const char *ename, const void *earg, size_t size,
    void *cookie), void *cookie)
{
        evt_handler_t   *evhdlrp, **evhdlrpp;

        if (ename == NULL)
                return;

        /*
         * unlink handler from handler list
         */
        (void) pthread_mutex_lock(&evthandler_lock);

retry:
        for (evhdlrpp = &evt_handlers; (evhdlrp = *evhdlrpp) != NULL;
            evhdlrpp = &evhdlrp->next) {
                if ((evhdlrp->cookie != cookie) ||
                    (strcmp(evhdlrp->ename, ename) != 0) ||
                    (evhdlrp->evt_handler != evt_handler))
                        continue;

                /*
                 * If the handler is in execution, release the lock
                 * and wait for it to complete and retry.
                 */
                if (evhdlrp->execflg) {
                        evhdlrp->wakeupflg = 1;
                        (void) pthread_cond_wait(&evhdlrp->cv,
                            &evthandler_lock);
                        goto retry;
                }

                /*
                 * Unlink this handler from the linked list
                 */
                *evhdlrpp = evhdlrp->next;
                free_handler(evhdlrp);
                break;
        }

        (void) pthread_mutex_unlock(&evthandler_lock);
}

/*
 * Call all registered handlers for the event
 */
static void
call_event_handlers(eventq_t *ev)
{
        evt_handler_t   *iter;
        void    (*evhandler)(const char *, const void *, size_t, void *);
        void    (*completion_handler)(char *ename, void *earg, size_t size);

        (void) pthread_mutex_lock(&evthandler_lock);
        iter = evt_handlers;
        while (iter != NULL) {
                if (strcmp(iter->ename, ev->ename) == 0) {
                        evhandler = iter->evt_handler;
                        iter->execflg = 1;
                        (void) pthread_mutex_unlock(&evthandler_lock);
                        if (evhandler) {
                                dbg_print(2, "ptree_evthr: Invoking evthdlr:%p"
                                    " ename:%s\n", evhandler, ev->ename);
                                (*evhandler)(ev->ename, ev->earg, ev->size,
                                    iter->cookie);
                                dbg_print(2, "ptree_evthr: done evthdlr:%p "
                                    "ename:%s\n", evhandler, ev->ename);
                        }
                        (void) pthread_mutex_lock(&evthandler_lock);
                        iter->execflg = 0;
                        if (iter->wakeupflg) {
                                iter->wakeupflg = 0;
                                (void) pthread_cond_broadcast(&iter->cv);
                        }
                }
                iter = iter->next;
        }
        (void) pthread_mutex_unlock(&evthandler_lock);
        if ((completion_handler = ev->completion_handler) != NULL) {
                dbg_print(2,
                    "ptree_evthr: Invoking completion hdlr:%p ename:%s\n",
                    completion_handler, ev->ename);
                (*completion_handler)((char *)ev->ename, (void *)ev->earg,
                    ev->size);
                dbg_print(2, "ptree_evthr: done completion hdlr:%p ename:%s\n",
                    completion_handler, ev->ename);
        }
        (void) pthread_mutex_lock(&ptree_refresh_mutex);
        ++ptree_generation;
        (void) pthread_cond_broadcast(&ptree_refresh_cond);
        (void) pthread_mutex_unlock(&ptree_refresh_mutex);
}

/*
 * This function is called by a plug-in to post an event
 */
int
ptree_post_event(const char *ename, const void *earg, size_t size,
    void (*completion_handler)(char *ename, void *earg, size_t size))
{
        eventq_t        *evt;

        if (ename == NULL)
                return (PICL_INVALIDARG);

        evt = malloc(sizeof (*evt));
        if (evt == NULL)
                return (PICL_FAILURE);
        evt->ename = ename;
        evt->earg = earg;
        evt->size = size;
        evt->completion_handler = completion_handler;

        (void) pthread_mutex_lock(&evtq_lock);
        queue_event(evt);
        (void) pthread_cond_broadcast(&evtq_cv);
        (void) pthread_mutex_unlock(&evtq_lock);
        return (PICL_SUCCESS);
}

/*
 * PICLTREE event thread
 */
/*ARGSUSED*/
static void *
ptree_event_thread(void *argp)
{
        eventq_t        *evt;

        for (;;) {
                (void) pthread_mutex_lock(&evtq_lock);
                while (eventqp == NULL) {
                        /*
                         * Signal empty queue
                         */
                        if (qempty_wait)
                                (void) pthread_cond_broadcast(&evtq_empty);
                        (void) pthread_cond_wait(&evtq_cv, &evtq_lock);
                }
                if ((evt = unqueue_event(&eventqp)) != NULL) {
                        (void) pthread_mutex_unlock(&evtq_lock);
                        call_event_handlers(evt);
                        free(evt);
                } else
                        (void) pthread_mutex_unlock(&evtq_lock);
        }
        /*NOTREACHED*/
        return (NULL);
}


/*
 * Create a new element
 */
static hash_elem_t *
hash_newobj(uint32_t hdl_val, void *obj_val)
{
        hash_elem_t     *n;

        n = malloc(sizeof (*n));
        if (n == NULL)
                return (NULL);
        n->hdl = hdl_val;
        n->hash_obj = obj_val;
        n->next = NULL;
        return (n);
}

static hash_elem_t *
hash_newhdl(uint32_t picl_hdl, uint32_t ptreeh)
{
        hash_elem_t     *n;

        n = malloc(sizeof (*n));
        if (n == NULL)
                return (NULL);
        n->hdl = picl_hdl;
        n->hash_hdl = ptreeh;
        n->next = NULL;
        return (n);
}

/*
 * Initialize a hash table by setting all entries to NULL
 */
static int
hash_init(hash_t *htbl)
{
        int     i;

        htbl->hash_size = HASH_TBL_SIZE;
        htbl->tbl = malloc(sizeof (hash_elem_t *) * HASH_TBL_SIZE);
        if (htbl->tbl == NULL)
                return (-1);
        for (i = 0; i < htbl->hash_size; ++i)
                htbl->tbl[i] = NULL;
        return (0);
}

/*
 * Lock free function to add an entry in the hash table
 */
static int
hash_add_newobj(hash_t *htbl, picl_hdl_t hdl, void *pobj)
{
        int             indx;
        hash_elem_t     *n;
        uint32_t        hash_val = HASH_VAL(hdl);

        n = hash_newobj(hash_val, pobj);
        if (n == NULL)
                return (-1);
        indx = HASH_INDEX(htbl->hash_size, hash_val);
        n->next = htbl->tbl[indx];
        htbl->tbl[indx] = n;
        return (0);
}

static int
hash_add_newhdl(hash_t *htbl, picl_hdl_t piclh, picl_hdl_t ptreeh)
{
        int             indx;
        hash_elem_t     *n;
        uint32_t        picl_val = HASH_VAL(piclh);
        uint32_t        ptree_val = HASH_VAL(ptreeh);

        n = hash_newhdl(picl_val, ptree_val);
        if (n == NULL)
                return (-1);

        indx = HASH_INDEX(htbl->hash_size, picl_val);
        n->next = htbl->tbl[indx];
        htbl->tbl[indx] = n;
        return (0);
}

/*
 * Lock free function to remove the handle from the hash table
 * Returns -1 if element not found, 0 if successful
 */
static int
hash_remove(hash_t *htbl, picl_hdl_t hdl)
{
        hash_elem_t     *nxt;
        hash_elem_t     *cur;
        int             i;
        uint32_t        hash_val = HASH_VAL(hdl);

        i = HASH_INDEX(htbl->hash_size, hash_val);
        if (htbl->tbl[i] == NULL)
                return (-1);

        cur = htbl->tbl[i];
        if (cur->hdl == hash_val) {
                htbl->tbl[i] = cur->next;
                free(cur);
                return (0);
        }
        nxt = cur->next;
        while (nxt != NULL) {
                if (nxt->hdl == hash_val) {
                        cur->next = nxt->next;
                        free(nxt);
                        return (0);
                }
                cur = nxt;
                nxt = nxt->next;
        }
        return (-1);
}

/*
 * Lock free function to lookup the hash table for a given handle
 * Returns NULL if not found
 */
static void *
hash_lookup_obj(hash_t *htbl, picl_hdl_t hdl)
{
        hash_elem_t     *tmp;
        int             i;
        uint32_t        hash_val;

        hash_val = HASH_VAL(hdl);
        i = HASH_INDEX(htbl->hash_size, hash_val);
        tmp = htbl->tbl[i];
        while (tmp != NULL) {
                if (tmp->hdl == hash_val)
                        return (tmp->hash_obj);
                tmp = tmp->next;
        }
        return (NULL);
}

static picl_hdl_t
hash_lookup_hdl(hash_t *htbl, picl_hdl_t hdl)
{
        hash_elem_t     *tmp;
        int             i;
        uint32_t        hash_val;

        hash_val = HASH_VAL(hdl);
        i = HASH_INDEX(htbl->hash_size, hash_val);
        tmp = htbl->tbl[i];
        while (tmp != NULL) {
                if (tmp->hdl == hash_val)
                        return (MAKE_HANDLE(picld_pid, tmp->hash_hdl));
                tmp = tmp->next;
        }
        return (PICL_INVALID_PICLHDL);
}

/*
 * Is the PICL handle stale or invalid handle?
 */
static int
picl_hdl_error(picl_hdl_t hdl)
{
        uint32_t        hash_val = HASH_VAL(hdl);
        pid_t           pid = GET_PID(hdl);
        int             err;

        (void) pthread_mutex_lock(&piclhdl_lock);
        err = PICL_STALEHANDLE;
        if ((pid != picld_pid) || (hash_val >= picl_hdl_hi) ||
            (hash_val == 0))
                err = PICL_INVALIDHANDLE;
        (void) pthread_mutex_unlock(&piclhdl_lock);
        return (err);
}

/*
 * Is the Ptree handle stale or invalid handle?
 */
static int
ptree_hdl_error(picl_hdl_t hdl)
{
        uint32_t        hash_val = HASH_VAL(hdl);
        pid_t           pid = GET_PID(hdl);
        int             err;

        (void) pthread_mutex_lock(&ptreehdl_lock);
        err = PICL_STALEHANDLE;
        if ((pid != picld_pid) || (hash_val >= ptree_hdl_hi) ||
            (hash_val == 0))
                err = PICL_INVALIDHANDLE;
        (void) pthread_mutex_unlock(&ptreehdl_lock);
        return (err);
}

/*
 * For a PICL handle, return the PTree handle and the PICL object
 * Locks and releases the PICL table.
 */
int
cvt_picl2ptree(picl_hdl_t hdl, picl_hdl_t *ptree_hdl)
{
        picl_hdl_t      tmph;
        int             err;

        (void) rw_rdlock(&picltbl_rwlock);              /* lock picl */
        tmph = hash_lookup_hdl(&picltbl, hdl);
        if (tmph == PICL_INVALID_PICLHDL) {
                err = picl_hdl_error(hdl);
                (void) rw_unlock(&picltbl_rwlock);      /* unlock picl */
                return (err);
        }
        *ptree_hdl = tmph;
        (void) rw_unlock(&picltbl_rwlock);              /* unlock picl */
        return (PICL_SUCCESS);
}

/*
 * Allocate a ptree handle
 */
static picl_hdl_t
alloc_ptreehdl(void)
{
        picl_hdl_t hdl;

        (void) pthread_mutex_lock(&ptreehdl_lock);      /* lock ptreehdl */
        hdl = MAKE_HANDLE(picld_pid, ptree_hdl_hi);
        ++ptree_hdl_hi;
        (void) pthread_mutex_unlock(&ptreehdl_lock); /* unlock ptreehdl */
        return (hdl);
}

/*
 * Allocate a picl handle
 * A PICL handle is ptree_hdl value with 1 in MSB of handle value.
 * If a ptree handle already has 1 in MSB, then it cannot be piclized
 * and the daemon must be restarted.
 */
static picl_hdl_t
alloc_piclhdl(void)
{
        picl_hdl_t hdl;

        (void) pthread_mutex_lock(&piclhdl_lock);       /* lock piclhdl */
        hdl = MAKE_HANDLE(picld_pid, picl_hdl_hi);
        ++picl_hdl_hi;
        (void) pthread_mutex_unlock(&piclhdl_lock);     /* unlock piclhdl */
        return (hdl);
}

/*
 * Allocate and add handle to PTree hash table
 */
static void
alloc_and_add_to_ptree(picl_obj_t *pobj)
{
        pobj->ptree_hdl = alloc_ptreehdl();
        (void) rw_wrlock(&ptree_rwlock);
        (void) hash_add_newobj(&ptreetbl, pobj->ptree_hdl, pobj);
        (void) rw_unlock(&ptree_rwlock);
}

/*
 * Lock a picl node object
 */
static int
lock_obj(int rw, picl_obj_t *nodep)
{
        if (rw == RDLOCK_NODE)
                (void) rw_rdlock(&nodep->node_lock);
        else if (rw == WRLOCK_NODE)
                (void) rw_wrlock(&nodep->node_lock);
        else
                return (-1);
        return (0);
}

/*
 * Release the picl node object.
 * This function may be called with a NULL object pointer.
 */
static void
unlock_node(picl_obj_t *nodep)
{
        if (nodep == NULL)
                return;
        (void) rw_unlock(&nodep->node_lock);
}

/*
 * This function locks the node of a property and returns the node object
 * and the property object.
 */
static int
lookup_and_lock_propnode(int rw, picl_prophdl_t proph, picl_obj_t **nodep,
    picl_obj_t **propp)
{
        picl_obj_t      *pobj;
        picl_obj_t      *nobj;

        pobj = hash_lookup_obj(&ptreetbl, proph);
        if (pobj == NULL)
                return (ptree_hdl_error(proph));

        /*
         * Get the property's or table entry's node object
         */
        nobj = NULL;
        if (pobj->obj_type == PICL_OBJ_PROP)
                nobj = pobj->prop_node;
        else if (pobj->obj_type == (PICL_OBJ_PROP|PICL_OBJ_TABLEENTRY))
                nobj = pobj->prop_table->prop_node;
        else {
                *propp = pobj;  /* return the prop */
                return (PICL_NOTPROP);
        }

        if (nobj && (lock_obj(rw, nobj) < 0))                   /* Lock node */
                return (PICL_FAILURE);

        *nodep = nobj;
        *propp = pobj;

        return (PICL_SUCCESS);
}

/*
 * This function locks the node of a table and returns the node object
 * and the table object.
 */
static int
lookup_and_lock_tablenode(int rw, picl_prophdl_t tblh, picl_obj_t **nodep,
    picl_obj_t **tblobj)
{
        picl_obj_t      *pobj;
        picl_obj_t      *nobj;

        pobj = hash_lookup_obj(&ptreetbl, tblh);
        if (pobj == NULL)
                return (ptree_hdl_error(tblh));

        /*
         * Get the property's or table entry's node object
         */
        nobj = NULL;
        if (pobj->obj_type != PICL_OBJ_TABLE)
                return (PICL_NOTTABLE);
        nobj = pobj->prop_node;

        if (nobj && (lock_obj(rw, nobj) < 0))                   /* Lock node */
                return (PICL_FAILURE);

        *nodep = nobj;
        *tblobj = pobj;

        return (PICL_SUCCESS);
}

/*
 * This locks the node of a table or a table entry and returns the
 * node object and the table or table entry object
 */
static int
lookup_and_lock_tableprop_node(int rw, picl_prophdl_t tblproph,
    picl_obj_t **nodep, picl_obj_t **tblpropp)
{
        picl_obj_t      *pobj;
        picl_obj_t      *nobj;

        pobj = hash_lookup_obj(&ptreetbl, tblproph);
        if (pobj == NULL)
                return (ptree_hdl_error(tblproph));

        /*
         * Get the property's or table entry's node object
         */
        nobj = NULL;
        if ((pobj->obj_type != PICL_OBJ_TABLE) &&       /* not a table */
            !(pobj->obj_type & PICL_OBJ_TABLEENTRY))    /* or an entry */
                return (PICL_NOTTABLE);
        if (pobj->obj_type == PICL_OBJ_TABLE)
                nobj = pobj->prop_node;
        else
                nobj = pobj->prop_table->prop_node;

        if (nobj && (lock_obj(rw, nobj) < 0))                   /* Lock node */
                return (PICL_FAILURE);

        *tblpropp = pobj;
        *nodep = nobj;

        return (PICL_SUCCESS);
}

/*
 * Lock the node corresponding to the given handle and return its object
 */
static int
lookup_and_lock_node(int rw, picl_nodehdl_t nodeh, picl_obj_t **nodep)
{
        picl_obj_t      *nobj;

        nobj = hash_lookup_obj(&ptreetbl, nodeh);
        if (nobj == NULL)
                return (ptree_hdl_error(nodeh));
        else if (nobj->obj_type != PICL_OBJ_NODE)
                return (PICL_NOTNODE);
        if (lock_obj(rw, nobj) < 0)                     /* Lock node */
                return (PICL_FAILURE);
        *nodep = nobj;
        return (PICL_SUCCESS);
}

/*
 * Is the property name a restricted property name?
 */
static int
picl_restricted(const char *name)
{
        if (strcmp(name, PICL_PROP_CLASSNAME) == 0)
                return (0);             /* not restricted */

        if ((name[0] == '_') && (strchr(&name[1], '_') == NULL))
                return (1);
        return (0);
}

/*
 * Check the value size with the property size
 * Return PICL_INVALIDARG if the size does not match exactly for strongly
 * typed properties.
 * For charstring reads allow sizes that match the value size
 * For bytearray return PICL_VALUETOOBIG
 * if the size is greater than the buffer size.
 */
static int
check_propsize(int op, picl_obj_t *propp, size_t sz)
{
        if (propp->prop_mode & PICL_VOLATILE) {
                if (sz != propp->prop_size)
                        return (PICL_INVALIDARG);
                else
                        return (PICL_SUCCESS);
        }

        /*
         * check size for non-volatile properties
         */
        switch (propp->prop_type) {
        case PICL_PTYPE_CHARSTRING:
                if ((op == PROP_READ) &&
                    (strlen(propp->prop_val) >= sz))
                        return (PICL_VALUETOOBIG);
                if ((op == PROP_WRITE) && (sz > propp->prop_size))
                        return (PICL_VALUETOOBIG);
                break;
        case PICL_PTYPE_BYTEARRAY:
                if (op == PROP_WRITE) {
                        if (sz > propp->prop_size)
                                return (PICL_VALUETOOBIG);
                        return (PICL_SUCCESS);  /* allow small writes */
                }
                /* FALLTHROUGH */
        default:
                if (propp->prop_size != sz)
                        return (PICL_INVALIDARG);
                break;
        }
        return (PICL_SUCCESS);
}

void
cvt_ptree2picl(picl_hdl_t *handlep)
{
        picl_obj_t      *pobj;

        (void) rw_rdlock(&ptree_rwlock);
        pobj = hash_lookup_obj(&ptreetbl, *handlep);
        if (pobj == NULL)
                *handlep = PICL_INVALID_PICLHDL;
        else
                (void) memcpy(handlep, &pobj->picl_hdl, sizeof (*handlep));
        (void) rw_unlock(&ptree_rwlock);
}

/*
 * The caller of the piclize() set of functions is assumed to hold
 * the ptree_rwlock().
 */
static void
piclize_obj(picl_obj_t *pobj)
{
        (void) rw_wrlock(&picltbl_rwlock);
        pobj->picl_hdl = alloc_piclhdl();
        (void) hash_add_newhdl(&picltbl, pobj->picl_hdl, pobj->ptree_hdl);
        (void) rw_unlock(&picltbl_rwlock);
}

static void
piclize_table(picl_obj_t  *tbl_obj)
{
        picl_obj_t      *rowp;
        picl_obj_t      *colp;

        for (rowp = tbl_obj->next_row; rowp != NULL; rowp = rowp->next_col)
                for (colp = rowp; colp != NULL; colp = colp->next_row)
                        piclize_obj(colp);
}

static void
piclize_prop(picl_obj_t *propp)
{
        picl_obj_t      *tbl_obj;
        picl_prophdl_t  tblh;

        piclize_obj(propp);
        if (!(propp->prop_mode & PICL_VOLATILE) &&
            (propp->prop_type == PICL_PTYPE_TABLE)) {
                tblh = *(picl_prophdl_t *)propp->prop_val;
                tbl_obj = hash_lookup_obj(&ptreetbl, tblh);
                if (tbl_obj == NULL)
                        return;
                piclize_obj(tbl_obj);
                piclize_table(tbl_obj);
        }
}

/*
 * Function to create PICL handles for a subtree and add them to
 * the table
 */
static void
piclize_node(picl_obj_t  *nodep)
{
        picl_obj_t      *propp;
        picl_obj_t      *chdp;

        piclize_obj(nodep);
        propp = nodep->first_prop;
        while (propp != NULL) {
                piclize_prop(propp);
                propp = propp->next_prop;
        }

        /* go through the children */
        for (chdp = nodep->child_node; chdp != NULL; chdp = chdp->sibling_node)
                piclize_node(chdp);
}

/*
 * Function to remove PICL handles
 */
static void
unpiclize_obj(picl_obj_t *pobj)
{
        (void) rw_wrlock(&picltbl_rwlock);
        (void) hash_remove(&picltbl, pobj->picl_hdl);
        pobj->picl_hdl = PICL_INVALID_PICLHDL;
        (void) rw_unlock(&picltbl_rwlock);
}

static void
unpiclize_table(picl_obj_t  *tbl_obj)
{
        picl_obj_t      *rowp;
        picl_obj_t      *colp;

        for (rowp = tbl_obj->next_row; rowp != NULL; rowp = rowp->next_col)
                for (colp = rowp; colp != NULL; colp = colp->next_row)
                        unpiclize_obj(colp);
        unpiclize_obj(tbl_obj);
}

static void
unpiclize_prop(picl_obj_t *propp)
{
        picl_obj_t      *tbl_obj;
        picl_prophdl_t  tblh;

        if (!IS_PICLIZED(propp))
                return;
        unpiclize_obj(propp);
        if (!(propp->prop_mode & PICL_VOLATILE) &&
            (propp->prop_type == PICL_PTYPE_TABLE)) {
                tblh = *(picl_prophdl_t *)propp->prop_val;
                tbl_obj = hash_lookup_obj(&ptreetbl, tblh);
                unpiclize_table(tbl_obj);
        }
}

/*
 * Function to remove PICL handles for a subtree and its
 * properties
 */
static void
unpiclize_node(picl_obj_t  *nodep)
{
        picl_obj_t      *propp;
        picl_obj_t      *chdp;


        if (!IS_PICLIZED(nodep))
                return;

        unpiclize_obj(nodep);
        propp = nodep->first_prop;
        while (propp != NULL) {
                unpiclize_prop(propp);
                propp = propp->next_prop;
        }

        /* go through the children */
        for (chdp = nodep->child_node; chdp != NULL; chdp = chdp->sibling_node)
                unpiclize_node(chdp);
}


/*
 * The caller holds the lock on the ptree_lock when calling this.
 * If ret is not NULL then this function returns the referenced object.
 */
static int
lookup_verify_ref_prop(picl_obj_t *propp, picl_obj_t **ret)
{
        picl_nodehdl_t  refh;
        picl_obj_t      *refobj;

        refh = *(picl_nodehdl_t *)propp->prop_val;
        refobj = hash_lookup_obj(&ptreetbl, refh);
        if (refobj == NULL)
                return (ptree_hdl_error(refh));
        else if (refobj->obj_type != PICL_OBJ_NODE)
                return (PICL_INVREFERENCE);
        if (ret)
                *ret = refobj;
        return (PICL_SUCCESS);
}

/*
 * The caller holds the lock on ptree_lock when calling this.
 * If ret is not NULL, then this function returns the table object
 */
static int
lookup_verify_table_prop(picl_obj_t *propp, picl_obj_t **ret)
{
        picl_prophdl_t  tblh;
        picl_obj_t      *tbl_obj;

        tblh = *(picl_prophdl_t *)propp->prop_val;
        tbl_obj = hash_lookup_obj(&ptreetbl, tblh);
        if (tbl_obj == NULL)
                return (ptree_hdl_error(tblh));
        else if (!(tbl_obj->obj_type & PICL_OBJ_TABLE))
                return (PICL_NOTTABLE);
        if (ret)
                *ret = tbl_obj;
        return (PICL_SUCCESS);
}

static int
lookup_verify_prop_handle(picl_prophdl_t proph, picl_obj_t **ret)
{
        picl_obj_t      *propp;

        propp = hash_lookup_obj(&ptreetbl, proph);
        if (propp == NULL)
                return (ptree_hdl_error(proph));
        else if (!(propp->obj_type & PICL_OBJ_PROP))
                return (PICL_NOTPROP);
        if (ret)
                *ret = propp;
        return (PICL_SUCCESS);
}

static int
lookup_verify_node_handle(picl_nodehdl_t nodeh, picl_obj_t **ret)
{
        picl_obj_t      *nodep;

        nodep = hash_lookup_obj(&ptreetbl, nodeh);
        if (nodep == NULL)
                return (ptree_hdl_error(nodeh));
        else if (nodep->obj_type != PICL_OBJ_NODE)
                return (PICL_NOTNODE);
        if (ret)
                *ret = nodep;
        return (PICL_SUCCESS);
}

static int
lookup_prop_by_name(picl_obj_t *nodep, const char *pname, picl_obj_t **ret)
{
        picl_obj_t      *propp;

        if (strcmp(pname, PICL_PROP_PARENT) == 0) {
                if (nodep->parent_node == NULL)
                        return (PICL_PROPNOTFOUND);
                else
                        return (PICL_SUCCESS);
        }
        if (strcmp(pname, PICL_PROP_CHILD) == 0) {
                if (nodep->child_node == NULL)
                        return (PICL_PROPNOTFOUND);
                else
                        return (PICL_SUCCESS);
        }
        if (strcmp(pname, PICL_PROP_PEER) == 0) {
                if (nodep->sibling_node == NULL)
                        return (PICL_PROPNOTFOUND);
                else
                        return (PICL_SUCCESS);
        }

        propp = nodep->first_prop;
        while (propp != NULL) {
                if (strcmp(propp->prop_name, pname) == 0) {
                        if (ret)
                                *ret = propp;
                        return (PICL_SUCCESS);
                }
                propp = propp->next_prop;
        }
        return (PICL_PROPNOTFOUND);
}

/*
 * This function locks the ptree, verifies that the handle is a reference
 * to a node of specified class name, releases the lock
 */
static int
check_ref_handle(picl_nodehdl_t refh, char *clname)
{
        picl_obj_t      *refobj;
        picl_obj_t      *propp;
        int             err;

        (void) rw_rdlock(&ptree_rwlock);        /* Lock ptree */
        refobj = hash_lookup_obj(&ptreetbl, refh);
        if ((refobj == NULL) || !(refobj->obj_type & PICL_OBJ_NODE)) {
                (void) rw_unlock(&ptree_rwlock);
                return (PICL_INVREFERENCE);
        }

        err = lookup_prop_by_name(refobj, PICL_PROP_CLASSNAME, &propp);
        if ((err != PICL_SUCCESS) || (propp->prop_val == NULL) ||
            (strcmp(propp->prop_val, clname) != 0))
                err = PICL_INVREFERENCE;
        (void) rw_unlock(&ptree_rwlock);        /* unlock ptree */
        return (err);
}

static int
check_table_handle(picl_prophdl_t tblh)
{
        picl_obj_t      *tbl_obj;
        int             err;

        (void) rw_rdlock(&ptree_rwlock);
        err = PICL_SUCCESS;
        tbl_obj = hash_lookup_obj(&ptreetbl, tblh);
        if ((tbl_obj == NULL) || !(tbl_obj->obj_type & PICL_OBJ_TABLE))
                err = PICL_NOTTABLE;
        (void) rw_unlock(&ptree_rwlock);
        return (err);
}

/*
 * PICLTree Interface routines for plug-in modules
 */
int
ptree_get_root(picl_nodehdl_t *rooth)
{
        *rooth = ptree_root_hdl;
        return (PICL_SUCCESS);
}

/*
 * Lock free create a property object
 */
static int
create_propobj(const ptree_propinfo_t *pinfo, const void *valbuf,
    picl_obj_t **pobjp)
{
        picl_obj_t      *pobj;

        if (pinfo->version != PTREE_PROPINFO_VERSION_1)
                return (PICL_NOTSUPPORTED);

        if (!(pinfo->piclinfo.accessmode & PICL_VOLATILE) &&
            (pinfo->piclinfo.type != PICL_PTYPE_VOID) &&
            (valbuf == NULL))
                return (PICL_INVALIDARG);

        pobj = malloc(sizeof (picl_obj_t));
        if (pobj == NULL)
                return (PICL_FAILURE);

        pobj->obj_type = PICL_OBJ_PROP;
        pobj->pinfo_ver = pinfo->version;
        pobj->prop_type = pinfo->piclinfo.type;
        pobj->prop_mode = pinfo->piclinfo.accessmode;
        pobj->prop_size = pinfo->piclinfo.size;
        (void) strcpy(pobj->prop_name, pinfo->piclinfo.name);
        pobj->read_func = pinfo->read;
        pobj->write_func = pinfo->write;

        pobj->prop_val = NULL;
        if (!(pinfo->piclinfo.accessmode & PICL_VOLATILE)) {
                pobj->prop_val = malloc(pinfo->piclinfo.size);
                if (pobj->prop_val == NULL) {
                        free(pobj);
                        return (PICL_FAILURE);
                }
                if (pobj->prop_type == PICL_PTYPE_CHARSTRING)
                        (void) strlcpy(pobj->prop_val, valbuf,
                            pinfo->piclinfo.size);
                else
                        (void) memcpy(pobj->prop_val, valbuf,
                            pinfo->piclinfo.size);
        }
        pobj->prop_node = NULL;
        pobj->ptree_hdl = PICL_INVALID_PICLHDL;
        pobj->picl_hdl = PICL_INVALID_PICLHDL;
        pobj->next_prop = NULL;
        pobj->next_row = NULL;
        pobj->next_col = NULL;

        *pobjp = pobj;
        return (PICL_SUCCESS);
}

/*
 * Check for valid arguments, create a property object,
 * Lock ptree_rwlock, add the new property handle, release the lock
 * For reference properties and table properties, the handles are verified
 * before creating the property.
 */
int
ptree_create_prop(const ptree_propinfo_t *pinfo, const void *valbuf,
    picl_prophdl_t *proph)
{
        picl_obj_t      *pobj;
        picl_nodehdl_t  refh;
        picl_prophdl_t  tblh;
        int             err;
        char            *ptr;
        int             refflag;
        char            classname[PICL_PROPNAMELEN_MAX];

        if (pinfo == NULL)
                return (PICL_INVALIDARG);
        if (pinfo->version != PTREE_PROPINFO_VERSION_1)
                return (PICL_NOTSUPPORTED);
        if (pinfo->piclinfo.size >= PICL_PROPSIZE_MAX)
                return (PICL_VALUETOOBIG);
        if (picl_restricted(pinfo->piclinfo.name))
                return (PICL_RESERVEDNAME);

        refflag = 0;
        if ((pinfo->piclinfo.name[0] == '_') &&
            (strchr(&pinfo->piclinfo.name[1], '_') != NULL))
                refflag = 1;

        if (pinfo->piclinfo.type == PICL_PTYPE_REFERENCE) {
                if (refflag == 0)
                        return (PICL_INVREFERENCE);
                /*
                 * check valid reference handle for non-volatiles
                 */
                if (!(pinfo->piclinfo.accessmode & PICL_VOLATILE)) {
                        if (valbuf == NULL)
                                return (PICL_INVREFERENCE);
                        if (pinfo->piclinfo.size != sizeof (picl_nodehdl_t))
                                return (PICL_INVREFERENCE);
                        (void) strcpy(classname, pinfo->piclinfo.name);
                        ptr = strchr(&classname[1], '_');
                        *ptr = '\0';
                        refh = *(picl_hdl_t *)valbuf;
                        err = check_ref_handle(refh, &classname[1]);
                        if (err != PICL_SUCCESS)
                                return (err);
                }
        } else if (refflag == 1)
                return (PICL_INVREFERENCE);
        else if ((pinfo->piclinfo.type == PICL_PTYPE_TABLE) &&
            (!(pinfo->piclinfo.accessmode & PICL_VOLATILE))) {
                if (pinfo->piclinfo.size != sizeof (picl_prophdl_t))
                        return (PICL_INVALIDARG);
                tblh = *(picl_prophdl_t *)valbuf;
                err = check_table_handle(tblh);
                if (err != PICL_SUCCESS)
                        return (err);
        } else if ((strcmp(pinfo->piclinfo.name, PICL_PROP_CLASSNAME) == 0) &&
            ((pinfo->piclinfo.type != PICL_PTYPE_CHARSTRING) ||
            (strlen(valbuf) >= PICL_CLASSNAMELEN_MAX)))
                return (PICL_RESERVEDNAME);
        else if ((strcmp(pinfo->piclinfo.name, PICL_PROP_NAME) == 0) &&
            (pinfo->piclinfo.type != PICL_PTYPE_CHARSTRING))
                return (PICL_RESERVEDNAME);
        /*
         * No locks held when you get here
         */
        err = create_propobj(pinfo, valbuf, &pobj);
        if (err != PICL_SUCCESS)
                return (err);

        alloc_and_add_to_ptree(pobj);
        *proph = pobj->ptree_hdl;
        return (PICL_SUCCESS);
}

/*
 * Lock free routine to destroy table entries
 * This function removes the destroyed handles from the hash table
 * Uses lock free routines: hash_lookup() and hash_remove()
 */
static void
destroy_table(picl_obj_t *pobj)
{
        picl_prophdl_t  tblh;
        picl_obj_t      *tbl_obj;
        picl_obj_t      *rowp;
        picl_obj_t      *colp;
        picl_obj_t      *freep;

        tblh = *(picl_prophdl_t *)pobj->prop_val;
        tbl_obj = hash_lookup_obj(&ptreetbl, tblh);
        if (tbl_obj == NULL)
                return;

        assert(tbl_obj->obj_type & PICL_OBJ_TABLE);

        /* Delete all entries */
        rowp = tbl_obj->next_row;
        while (rowp != NULL) {
                colp = rowp;
                rowp = rowp->next_col;
                while (colp != NULL) {
                        freep = colp;
                        colp = colp->next_row;
                        (void) hash_remove(&ptreetbl, freep->ptree_hdl);
                        if (freep->prop_val)
                                free(freep->prop_val);
                        free(freep);
                }
        }

        (void) hash_remove(&ptreetbl, tbl_obj->ptree_hdl);
        free(tbl_obj);
}


/*
 * Lock free function that frees up a property object and removes the
 * handles from Ptree table
 */
static void
destroy_propobj(picl_obj_t *propp)
{
        if (propp->prop_type == PICL_PTYPE_TABLE)
                destroy_table(propp);

        (void) hash_remove(&ptreetbl, propp->ptree_hdl);
        if (propp->prop_val)
                free(propp->prop_val);
        free(propp);
}

/*
 * This function destroys a previously deleted property.
 * A deleted property does not have an associated node.
 * All memory allocated for this property are freed
 */
int
ptree_destroy_prop(picl_prophdl_t proph)
{
        picl_obj_t      *propp;

        (void) rw_wrlock(&ptree_rwlock);        /* Exclusive Lock ptree */

        propp = hash_lookup_obj(&ptreetbl, proph);
        if (propp == NULL) {
                (void) rw_unlock(&ptree_rwlock);        /* Unlock ptree */
                return (ptree_hdl_error(proph));
        }

        /* Is the prop still attached to a node? */
        if (propp->prop_node != NULL) {
                (void) rw_unlock(&ptree_rwlock);        /* Unlock ptree */
                return (PICL_CANTDESTROY);
        }

        destroy_propobj(propp);

        (void) rw_unlock(&ptree_rwlock);                /* Unlock ptree */
        return (PICL_SUCCESS);
}

/*
 * This function adds a property to the property list of a node and adds
 * it to the PICL table if the node has a PICL handle.
 * This function locks the picl_rwlock and ptree_rwlock.
 */
int
ptree_add_prop(picl_nodehdl_t nodeh, picl_prophdl_t proph)
{
        int             err;
        picl_obj_t      *nodep;
        picl_obj_t      *propp;
        picl_obj_t      *tbl_obj;
        picl_obj_t      *refobj;

        (void) rw_rdlock(&ptree_rwlock);                /* RDLock ptree */

        /*
         * Verify property handle
         */
        err = lookup_verify_prop_handle(proph, &propp);
        if (err != PICL_SUCCESS) {
                (void) rw_unlock(&ptree_rwlock);        /* Unlock ptree */
                return (err);
        }

        if (propp->prop_node != NULL) {
                (void) rw_unlock(&ptree_rwlock);
                return (PICL_INVALIDARG);
        }

        nodep = NULL;
        /*
         * Exclusive Lock the node's properties
         */
        err = lookup_and_lock_node(WRLOCK_NODE, nodeh, &nodep);
        if (err != PICL_SUCCESS) {
                (void) rw_unlock(&ptree_rwlock);        /* Unlock ptree */
                return (err);
        }

        /*
         * check if prop already exists
         */
        err = lookup_prop_by_name(nodep, propp->prop_name, NULL);
        if (err == PICL_SUCCESS) {
                unlock_node(nodep);                     /* Unlock node */
                (void) rw_unlock(&ptree_rwlock);        /* Unlock table */
                return (PICL_PROPEXISTS);
        }

        /*
         * Verify property's value
         */
        tbl_obj = NULL;
        switch (propp->prop_type) {
        case PICL_PTYPE_TABLE:
                if (propp->prop_mode & PICL_VOLATILE)
                        break;
                err = lookup_verify_table_prop(propp, &tbl_obj);
                if (err != PICL_SUCCESS) {
                        unlock_node(nodep);
                        (void) rw_unlock(&ptree_rwlock);
                        return (err);
                }
                tbl_obj->prop_node = nodep;     /* set table's nodep */
                tbl_obj->table_prop = propp;    /* set table prop */
                break;
        case PICL_PTYPE_REFERENCE:
                if (propp->prop_mode & PICL_VOLATILE)
                        break;
                err = lookup_verify_ref_prop(propp, &refobj);
                if (err != PICL_SUCCESS) {
                        unlock_node(nodep);
                        (void) rw_unlock(&ptree_rwlock);
                        return (err);
                }
                if (IS_PICLIZED(nodep) && !IS_PICLIZED(refobj)) {
                        unlock_node(nodep);
                        (void) rw_unlock(&ptree_rwlock);
                        return (err);
                }
                break;
        default:
                break;
        }

        if (IS_PICLIZED(nodep))
                piclize_prop(propp);
        /*
         * Add prop to beginning of list
         */
        propp->prop_node = nodep;               /* set prop's nodep */
        propp->next_prop = nodep->first_prop;
        nodep->first_prop = propp;

        unlock_node(nodep);                             /* Unlock node */
        (void) rw_unlock(&ptree_rwlock);                /* Unlock table */
        return (PICL_SUCCESS);
}

/*
 * Lock free function that unlinks a property from its node
 */
static int
unlink_prop(picl_obj_t *nodep, picl_obj_t *propp)
{
        picl_obj_t      *iterp;

        iterp = nodep->first_prop;
        if (iterp == propp) {   /* first property */
                nodep->first_prop = iterp->next_prop;
                return (PICL_SUCCESS);
        }
        while ((iterp != NULL) && (iterp->next_prop != propp))
                iterp = iterp->next_prop;
        if (iterp == NULL)
                return (PICL_PROPNOTFOUND);
        iterp->next_prop = propp->next_prop;
        return (PICL_SUCCESS);
}

/*
 * This function deletes the specified property from the property list
 * of its node and removes the handle from PICL table, if the node
 * was piclized.
 */
int
ptree_delete_prop(picl_prophdl_t proph)
{
        int             err;
        picl_obj_t      *nodep;
        picl_obj_t      *propp;

        (void) rw_rdlock(&ptree_rwlock);                /* lock ptree */
        /*
         * Lookup the property's node and lock it if there is one
         * return the objects for the property and the node
         */
        nodep = propp = NULL;
        err = lookup_and_lock_propnode(WRLOCK_NODE, proph, &nodep, &propp);
        if (err != PICL_SUCCESS) {
                (void) rw_unlock(&ptree_rwlock);        /* unlock ptree */
                return (err);
        } else if (nodep == NULL) {
                /* Nothing to do - already deleted! */
                (void) rw_unlock(&ptree_rwlock);        /* unlock ptree */
                return (PICL_SUCCESS);
        }

        if (propp->obj_type & PICL_OBJ_TABLEENTRY) {
                unlock_node(nodep);                     /* Unlock node */
                (void) rw_unlock(&ptree_rwlock);        /* unlock ptree */
                return (PICL_NOTPROP);
        }

        err = unlink_prop(nodep, propp);
        if (err != PICL_SUCCESS) {
                unlock_node(nodep);                     /* Unlock node */
                (void) rw_unlock(&ptree_rwlock);        /* unlock ptree */
                return (err);
        }

        propp->prop_node = NULL;        /* reset prop's nodep */
        propp->next_prop = NULL;

        unpiclize_prop(propp);

        unlock_node(nodep);                             /* Unlock node */
        (void) rw_unlock(&ptree_rwlock);                /* unlock ptree */
        return (PICL_SUCCESS);
}

/*
 * Create a table object and return its handle
 */
int
ptree_create_table(picl_prophdl_t *tblh)
{
        picl_obj_t      *pobj;

        pobj = malloc(sizeof (picl_obj_t));
        if (pobj == NULL)
                return (PICL_FAILURE);
        pobj->obj_type = PICL_OBJ_TABLE;
        pobj->prop_val = NULL;
        pobj->prop_node = NULL;
        pobj->ptree_hdl = PICL_INVALID_PICLHDL;
        pobj->picl_hdl = PICL_INVALID_PICLHDL;
        pobj->table_prop = NULL;
        pobj->next_row = NULL;
        pobj->next_col = NULL;

        alloc_and_add_to_ptree(pobj);
        *tblh = pobj->ptree_hdl;
        return (PICL_SUCCESS);
}

/*
 * Add the properties in <props> array as a row in the table
 * Add PICL handles if the table has a valid PICL handle
 */
int
ptree_add_row_to_table(picl_prophdl_t tblh, int nprops,
    const picl_prophdl_t *props)
{
        picl_obj_t      *tbl_obj;
        picl_obj_t      *nodep;
        picl_obj_t      *lastrow;
        picl_obj_t      **newrow;
        int             i;
        int             err;
        picl_obj_t      *pobj;
        int             picl_it;

        if (nprops < 1)
                return (PICL_INVALIDARG);

        newrow = malloc(sizeof (picl_obj_t *) * nprops);
        if (newrow == NULL)
                return (PICL_FAILURE);

        (void) rw_rdlock(&ptree_rwlock);                /* Lock ptree */

        err = lookup_and_lock_tablenode(WRLOCK_NODE, tblh, &nodep, &tbl_obj);
        if (err != PICL_SUCCESS) {
                free(newrow);
                (void) rw_unlock(&ptree_rwlock);        /* Unlock table */
                return (err);
        }

        /*
         * make sure all are either props or table handles
         */
        for (i = 0; i < nprops; ++i) {
                pobj = newrow[i] = hash_lookup_obj(&ptreetbl, props[i]);
                if (pobj == NULL) {     /* no object */
                        err = ptree_hdl_error(props[i]);
                        break;
                }
                if ((!(pobj->obj_type & PICL_OBJ_PROP)) &&
                    (!(pobj->obj_type & PICL_OBJ_TABLE))) {
                        err = PICL_NOTPROP;
                        break;
                }
                if (IS_PICLIZED(pobj) || (pobj->prop_table != NULL) ||
                    (pobj->prop_node != NULL)) {
                        err = PICL_INVALIDARG;
                        break;
                }

        }
        if (err != PICL_SUCCESS) {
                free(newrow);
                unlock_node(nodep);
                (void) rw_unlock(&ptree_rwlock);        /* Unlock table */
                return (err);
        }

        /*
         * Mark all props as table entries, set up row linkages
         */
        picl_it = 0;
        if (IS_PICLIZED(tbl_obj))
                picl_it = 1;
        for (i = 0; i < nprops; ++i) {
                newrow[i]->obj_type |= PICL_OBJ_TABLEENTRY;
                newrow[i]->prop_table = tbl_obj;
                newrow[i]->next_prop = NULL;
                newrow[i]->next_col =  NULL;
                if (picl_it)
                        piclize_obj(newrow[i]);
                if (i != nprops - 1)
                        newrow[i]->next_row = newrow[i+1];
        }
        newrow[nprops - 1]->next_row = NULL;

        if (tbl_obj->next_row == NULL) {        /* add first row */
                tbl_obj->next_row = newrow[0];
                tbl_obj->next_col = newrow[0];
        } else {
                lastrow = tbl_obj->next_row;
                while (lastrow->next_col != NULL)
                        lastrow = lastrow->next_col;
                i = 0;
                while (lastrow != NULL) {
                        lastrow->next_col = newrow[i];
                        lastrow = lastrow->next_row;
                        ++i;
                }
        }

        unlock_node(nodep);                     /* unlock node */
        (void) rw_unlock(&ptree_rwlock);        /* Unlock ptree */
        free(newrow);
        return (PICL_SUCCESS);
}

/*
 * This function returns the handle of the next property in the row
 */
int
ptree_get_next_by_row(picl_prophdl_t proph, picl_prophdl_t *nextrowh)
{
        int             err;
        picl_obj_t      *nodep;
        picl_obj_t      *propp;

        (void) rw_rdlock(&ptree_rwlock);                /* lock ptree */

        nodep = propp = NULL;
        /*
         * proph could be a table handle or a table entry handle
         * Look it up as a table entry handle first, check error code
         * to see if it is a table handle
         */
        err = lookup_and_lock_tableprop_node(RDLOCK_NODE, proph, &nodep,
            &propp);
        if (err != PICL_SUCCESS) {
                (void) rw_unlock(&ptree_rwlock);
                return (err);
        }

        if (propp->next_row)
                *nextrowh = propp->next_row->ptree_hdl;
        else
                err = PICL_ENDOFLIST;

        unlock_node(nodep);                     /* unlock node */
        (void) rw_unlock(&ptree_rwlock);                /* unlock ptree */
        return (err);
}

int
ptree_get_next_by_col(picl_prophdl_t proph, picl_prophdl_t *nextcolh)
{
        int             err;
        picl_obj_t      *propp;
        picl_obj_t      *nodep;

        (void) rw_rdlock(&ptree_rwlock);                /* lock ptree */
        nodep = propp = NULL;
        /*
         * proph could be a table handle or a table entry handle
         * Look it up as a table entry handle first, check error code
         * to see if it is a table handle
         */
        err = lookup_and_lock_tableprop_node(RDLOCK_NODE, proph, &nodep,
            &propp);
        if (err != PICL_SUCCESS) {
                (void) rw_unlock(&ptree_rwlock);
                return (err);
        }

        if (propp->next_col)
                *nextcolh = propp->next_col->ptree_hdl;
        else
                err = PICL_ENDOFLIST;

        unlock_node(nodep);                     /* unlock node */
        (void) rw_unlock(&ptree_rwlock);                /* unlock ptree */
        return (err);
}

/*
 * This function creates node object and adds its handle to the Ptree
 */
int
ptree_create_node(const char *name, const char *clname, picl_nodehdl_t *nodeh)
{
        picl_obj_t              *pobj;
        ptree_propinfo_t        propinfo;
        picl_prophdl_t          phdl;
        picl_prophdl_t          cphdl;
        int                     err;

        if ((name == NULL) || (*name == '\0') ||
            (clname == NULL) || (*clname == '\0'))
                return (PICL_INVALIDARG);

        if ((strlen(name) >= PICL_PROPNAMELEN_MAX) ||
            (strlen(clname) >= PICL_CLASSNAMELEN_MAX))
                return (PICL_VALUETOOBIG);

        /*
         * Create the picl object for node
         */
        pobj = malloc(sizeof (picl_obj_t));
        if (pobj == NULL)
                return (PICL_FAILURE);
        pobj->obj_type = PICL_OBJ_NODE;
        pobj->first_prop = NULL;
        pobj->ptree_hdl = PICL_INVALID_PICLHDL;
        pobj->picl_hdl = PICL_INVALID_PICLHDL;
        pobj->parent_node = NULL;
        pobj->sibling_node = NULL;
        pobj->child_node = NULL;
        pobj->node_classname = strdup(clname);
        if (pobj->node_classname == NULL) {
                free(pobj);
                return (PICL_FAILURE);
        }
        (void) rwlock_init(&pobj->node_lock, USYNC_THREAD, NULL);

        alloc_and_add_to_ptree(pobj);   /* commit the node */

        /*
         * create name property
         */
        propinfo.version = PTREE_PROPINFO_VERSION_1;
        propinfo.piclinfo.type = PICL_PTYPE_CHARSTRING;
        propinfo.piclinfo.accessmode = PICL_READ;
        propinfo.piclinfo.size = strlen(name) + 1;
        (void) strcpy(propinfo.piclinfo.name, PICL_PROP_NAME);
        propinfo.read = NULL;
        propinfo.write = NULL;
        err = ptree_create_prop(&propinfo, (const void *)name, &phdl);
        if (err != PICL_SUCCESS) {
                (void) ptree_destroy_node(pobj->ptree_hdl);
                return (err);
        }
        err = ptree_add_prop(pobj->ptree_hdl, phdl);
        if (err != PICL_SUCCESS) {
                (void) ptree_destroy_prop(phdl);
                (void) ptree_destroy_node(pobj->ptree_hdl);
                return (err);
        }

        /*
         * create picl classname property
         */
        propinfo.piclinfo.size = strlen(clname) + 1;
        (void) strcpy(propinfo.piclinfo.name, PICL_PROP_CLASSNAME);
        propinfo.read = NULL;
        propinfo.write = NULL;
        err = ptree_create_prop(&propinfo, (const void *)clname, &cphdl);
        if (err != PICL_SUCCESS) {
                (void) ptree_destroy_node(pobj->ptree_hdl);
                return (err);
        }
        err = ptree_add_prop(pobj->ptree_hdl, cphdl);
        if (err != PICL_SUCCESS) {
                (void) ptree_destroy_prop(cphdl);
                (void) ptree_destroy_node(pobj->ptree_hdl);
                return (err);
        }

        *nodeh = pobj->ptree_hdl;
        return (PICL_SUCCESS);
}

/*
 * Destroy a node/subtree freeing up space
 * Removed destroyed objects' handles from PTree table
 */
static void
destroy_subtree(picl_obj_t *nodep)
{
        picl_obj_t      *iterp;
        picl_obj_t      *freep;
        picl_obj_t      *chdp;

        if (nodep == NULL)
                return;

        chdp = nodep->child_node;
        while (chdp != NULL) {
                freep = chdp;
                chdp = chdp->sibling_node;
                destroy_subtree(freep);
        }

        /*
         * Lock the node
         */
        (void) lock_obj(WRLOCK_NODE, nodep);

        /*
         * destroy all properties associated with this node
         */
        iterp = nodep->first_prop;
        while (iterp != NULL) {
                freep = iterp;
                iterp = iterp->next_prop;
                destroy_propobj(freep);
        }

        (void) hash_remove(&ptreetbl, nodep->ptree_hdl);
        (void) rwlock_destroy(&nodep->node_lock);
        free(nodep->node_classname);
        free(nodep);
}

/*
 * This function destroys a previously deleted node/subtree. All the properties
 * are freed and removed from the PTree table.
 * Only one destroy is in progress at any time.
 */
int
ptree_destroy_node(picl_nodehdl_t nodeh)
{
        picl_obj_t      *nodep;
        picl_obj_t      *parp;
        picl_obj_t      *np;
        int             err;

        (void) rw_wrlock(&ptree_rwlock);        /* exclusive wrlock ptree */
        nodep = NULL;
        err = lookup_verify_node_handle(nodeh, &nodep);
        if (err != PICL_SUCCESS) {
                (void) rw_unlock(&ptree_rwlock);        /* unlock ptree */
                return (err);
        }

        /*
         * Has this node/subtree been deleted?
         */
        if (IS_PICLIZED(nodep)) {
                (void) rw_unlock(&ptree_rwlock);        /* unlock ptree */
                return (PICL_CANTDESTROY);
        }

        /*
         * update parent's child list to repair the tree when
         * parent is not null
         */
        parp = nodep->parent_node;
        if (parp == NULL) {                     /* root */
                destroy_subtree(nodep);
                (void) rw_unlock(&ptree_rwlock);        /* unlock ptree */
                return (PICL_SUCCESS);
        }

        np = parp->child_node;
        if (np == nodep) {  /* first child */
                parp->child_node = nodep->sibling_node;
        } else {
                while ((np != NULL) && (np->sibling_node != nodep))
                        np = np->sibling_node;
                if (np != NULL)
                        np->sibling_node = nodep->sibling_node;
        }

        destroy_subtree(nodep);
        (void) rw_unlock(&ptree_rwlock);                /* unlock ptree */
        return (PICL_SUCCESS);
}

/*
 * This function deletes a node/subtree from the tree and removes the handles
 * from PICL table
 */
int
ptree_delete_node(picl_nodehdl_t nodeh)
{
        picl_obj_t      *nodep;
        picl_obj_t      *parp;
        picl_obj_t      *np;
        int             err;

        (void) rw_wrlock(&ptree_rwlock);        /* exclusive wrlock ptree */

        nodep = NULL;
        err = lookup_verify_node_handle(nodeh, &nodep);
        if (err != PICL_SUCCESS) {
                (void) rw_unlock(&ptree_rwlock);        /* unlock ptree */
                return (err);
        }

        /*
         * unparent it
         */
        parp = nodep->parent_node;
        if (parp != NULL) {
                np = parp->child_node;
                if (np == nodep)        /* first child */
                        parp->child_node = nodep->sibling_node;
                else {
                        while ((np != NULL) && (np->sibling_node != nodep))
                                np = np->sibling_node;
                        if (np != NULL)
                                np->sibling_node = nodep->sibling_node;
                }
        }

        nodep->parent_node = NULL;
        nodep->sibling_node = NULL;

        unpiclize_node(nodep);

        (void) rw_unlock(&ptree_rwlock);                /* unlock ptree */
        return (PICL_SUCCESS);
}

/*
 * This function adds a node as a child of another node
 */
int
ptree_add_node(picl_nodehdl_t parh, picl_nodehdl_t chdh)
{
        picl_obj_t      *pnodep;
        picl_obj_t      *cnodep;
        picl_obj_t      *nodep;
        int             err;

        (void) rw_wrlock(&ptree_rwlock);        /* exclusive lock ptree */

        pnodep = cnodep = NULL;
        err = lookup_verify_node_handle(parh, &pnodep);
        if (err != PICL_SUCCESS) {
                (void) rw_unlock(&ptree_rwlock);        /* unlock ptree */
                return (err);
        }

        err = lookup_verify_node_handle(chdh, &cnodep);
        if (err != PICL_SUCCESS) {
                (void) rw_unlock(&ptree_rwlock);        /* unlock ptree */
                return (err);
        }

        /* is chdh already a child? */
        if (cnodep->parent_node != NULL) {
                (void) rw_unlock(&ptree_rwlock);        /* unlock ptree */
                return (PICL_CANTPARENT);
        }

        /*
         * append child to children list
         */
        cnodep->parent_node = pnodep;
        if (pnodep->child_node == NULL)
                pnodep->child_node = cnodep;
        else {
                for (nodep = pnodep->child_node; nodep->sibling_node != NULL;
                    nodep = nodep->sibling_node)
                        continue;
                nodep->sibling_node = cnodep;

        }

        /* piclize */
        if (IS_PICLIZED(pnodep))
                piclize_node(cnodep);
        (void) rw_unlock(&ptree_rwlock);                /* unlock ptree */
        return (PICL_SUCCESS);
}

static void
copy_propinfo_ver_1(ptree_propinfo_t *pinfo, picl_obj_t *propp)
{
        pinfo->version = propp->pinfo_ver;
        pinfo->piclinfo.type = propp->prop_type;
        pinfo->piclinfo.accessmode = propp->prop_mode;
        pinfo->piclinfo.size = propp->prop_size;
        (void) strcpy(pinfo->piclinfo.name, propp->prop_name);
        pinfo->read = propp->read_func;
        pinfo->write = propp->write_func;
}

static void
copy_reserved_propinfo_ver_1(ptree_propinfo_t *pinfo, const char *pname)
{
        pinfo->version = PTREE_PROPINFO_VERSION_1;
        pinfo->piclinfo.type = PICL_PTYPE_REFERENCE;
        pinfo->piclinfo.accessmode = PICL_READ;
        pinfo->piclinfo.size = sizeof (picl_nodehdl_t);
        (void) strcpy(pinfo->piclinfo.name, pname);
        pinfo->read = NULL;
        pinfo->write = NULL;
}

/*
 * This function returns the property information to a plug-in
 */
int
ptree_get_propinfo(picl_prophdl_t proph, ptree_propinfo_t *pinfo)
{
        int             err;
        picl_obj_t      *nodep;
        picl_obj_t      *propp;

        (void) rw_rdlock(&ptree_rwlock);                /* lock ptree */
        nodep = propp = NULL;
        err = lookup_and_lock_propnode(RDLOCK_NODE, proph, &nodep, &propp);
        if (err != PICL_SUCCESS) {
                (void) rw_unlock(&ptree_rwlock);        /* unlock ptree */
                return (err);
        }

        if (propp->pinfo_ver == PTREE_PROPINFO_VERSION_1)
                copy_propinfo_ver_1(pinfo, propp);
        else
                err = PICL_FAILURE;

        unlock_node(nodep);                     /* unlock node */
        (void) rw_unlock(&ptree_rwlock);                /* unlock ptree */
        return (err);
}

/*
 * This function returns the property information to a plug-in
 */
int
xptree_get_propinfo_by_name(picl_nodehdl_t nodeh, const char *pname,
    ptree_propinfo_t *pinfo)
{
        int             err;
        picl_obj_t      *nodep;
        picl_obj_t      *propp;

        (void) rw_rdlock(&ptree_rwlock);                /* lock ptree */
        nodep = propp = NULL;
        err = lookup_and_lock_node(RDLOCK_NODE, nodeh, &nodep); /* lock node */
        if (err != PICL_SUCCESS) {
                (void) rw_unlock(&ptree_rwlock);        /* unlock ptree */
                return (err);
        }

        err = lookup_prop_by_name(nodep, pname, &propp);
        if (err != PICL_SUCCESS) {
                unlock_node(nodep);
                (void) rw_unlock(&ptree_rwlock);
                return (err);
        }

        if (picl_restricted(pname))
                copy_reserved_propinfo_ver_1(pinfo, pname);
        else if (propp->pinfo_ver == PTREE_PROPINFO_VERSION_1)
                copy_propinfo_ver_1(pinfo, propp);
        else
                err = PICL_FAILURE;

        unlock_node(nodep);                     /* unlock node */
        (void) rw_unlock(&ptree_rwlock);                /* unlock ptree */
        return (err);
}

/*
 * This function must be called only after a lookup_prop_by_name() returns
 * success and only if picl_restricted() returns true.
 */
static int
read_reserved_propval_and_unlock(picl_obj_t *nodep, const char *pname,
    void *vbuf, size_t size)
{
        void            *srcp;

        if (size != sizeof (picl_nodehdl_t))
                return (PICL_VALUETOOBIG);

        if (strcmp(pname, PICL_PROP_PARENT) == 0)
                srcp = &nodep->parent_node->ptree_hdl;
        else if (strcmp(pname, PICL_PROP_CHILD) == 0)
                srcp = &nodep->child_node->ptree_hdl;
        else if (strcmp(pname, PICL_PROP_PEER) == 0)
                srcp = &nodep->sibling_node->ptree_hdl;
        else
                return (PICL_FAILURE);

        (void) memcpy(vbuf, srcp, sizeof (picl_nodehdl_t));
        unlock_node(nodep);
        (void) rw_unlock(&ptree_rwlock);
        return (PICL_SUCCESS);
}

/*
 * Returns the property value in the buffer and releases the node and
 * ptree locks.
 * For volatile properties, this function releases the locks on ptree
 * table and the node before calling the plug-in provided access function
 */
static int
read_propval_and_unlock(picl_obj_t *nodep, picl_obj_t *propp, void *vbuf,
    door_cred_t cred)
{
        int             err;
        int             (*volrd)(ptree_rarg_t *arg, void *buf);

        err = PICL_SUCCESS;
        if (propp->prop_mode & PICL_VOLATILE) {
                ptree_rarg_t  rarg;

                if (nodep)
                        rarg.nodeh = nodep->ptree_hdl;
                else
                        rarg.nodeh = PICL_INVALID_PICLHDL;
                rarg.proph = propp->ptree_hdl;
                rarg.cred = cred;
                volrd = propp->read_func;

                unlock_node(nodep);             /* unlock node */
                (void) rw_unlock(&ptree_rwlock);        /* unlock ptree */

                if (volrd == NULL)
                        err = PICL_FAILURE;
                else
                        err = (volrd)(&rarg, vbuf);
                return (err);
        } else if (propp->prop_type == PICL_PTYPE_CHARSTRING)
                (void) strlcpy(vbuf, propp->prop_val, propp->prop_size);
        else
                (void) memcpy(vbuf, propp->prop_val, propp->prop_size);

        unlock_node(nodep);
        (void) rw_unlock(&ptree_rwlock);
        return (err);
}

int
xptree_get_propval_with_cred(picl_prophdl_t proph, void *vbuf, size_t size,
    door_cred_t cred)
{
        picl_obj_t      *propp;
        picl_obj_t      *nodep;
        int             err;

        (void) rw_rdlock(&ptree_rwlock);                /* lock ptree */
        nodep = propp = NULL;
        err = lookup_and_lock_propnode(RDLOCK_NODE, proph, &nodep, &propp);
        if (err != PICL_SUCCESS) {
                (void) rw_unlock(&ptree_rwlock);        /* unlock ptree */
                return (err);
        }

        err = check_propsize(PROP_READ, propp, size);
        if (err != PICL_SUCCESS) {
                unlock_node(nodep);             /* unlock node */
                (void) rw_unlock(&ptree_rwlock);        /* unlock ptree */
                return (err);
        }

        return (read_propval_and_unlock(nodep, propp, vbuf, cred));
}

/*
 * This function gets the credentials and  calls get_propval_with_cred.
 */
int
ptree_get_propval(picl_prophdl_t proph, void *vbuf, size_t size)
{
        return (xptree_get_propval_with_cred(proph, vbuf, size, picld_cred));
}

/*
 * This function retrieves a property's value by by its name
 * For volatile properties, the locks on ptree and node are released
 * before calling the plug-in provided access function
 */
int
xptree_get_propval_by_name_with_cred(picl_nodehdl_t nodeh, const char *pname,
    void *vbuf, size_t size, door_cred_t cred)
{
        picl_obj_t      *nodep;
        picl_obj_t      *propp;
        int             err;

        (void) rw_rdlock(&ptree_rwlock);                /* lock ptree */

        nodep = NULL;
        err = lookup_and_lock_node(RDLOCK_NODE, nodeh, &nodep); /* lock node */
        if (err != PICL_SUCCESS) {
                (void) rw_unlock(&ptree_rwlock);        /* unlock ptree */
                return (err);
        }

        err = lookup_prop_by_name(nodep, pname, &propp);
        if (err != PICL_SUCCESS) {
                unlock_node(nodep);
                (void) rw_unlock(&ptree_rwlock);
                return (err);
        }

        if (picl_restricted(pname))
                return (read_reserved_propval_and_unlock(nodep, pname, vbuf,
                    size));

        err = check_propsize(PROP_READ, propp, size);
        if (err != PICL_SUCCESS) {
                unlock_node(nodep);
                (void) rw_unlock(&ptree_rwlock);
                return (err);
        }

        return (read_propval_and_unlock(nodep, propp, vbuf, cred));
}

/*
 * This function is used by plugins to get a value of a property
 * looking it up by its name.
 */
int
ptree_get_propval_by_name(picl_nodehdl_t nodeh, const char *pname, void *vbuf,
    size_t size)
{
        return (xptree_get_propval_by_name_with_cred(nodeh, pname, vbuf, size,
            picld_cred));
}

/*
 * This function updates a property's value.
 * For volatile properties, the locks on the node and the ptree table
 * are released before calling the plug-in provided access function.
 */
static int
write_propval_and_unlock(picl_obj_t *nodep, picl_obj_t *propp, const void *vbuf,
    size_t size, door_cred_t cred)
{
        int             err;
        int             (*volwr)(ptree_warg_t *arg, const void *buf);

        err = PICL_SUCCESS;
        if (propp->prop_mode & PICL_VOLATILE) {
                ptree_warg_t  warg;

                if (nodep)
                        warg.nodeh = nodep->ptree_hdl;
                else
                        warg.nodeh = PICL_INVALID_PICLHDL;
                warg.proph = propp->ptree_hdl;
                warg.cred = cred;
                volwr = propp->write_func;

                unlock_node(nodep);             /* unlock node */
                (void) rw_unlock(&ptree_rwlock);        /* unlock ptree */

                if (volwr == NULL)
                        err = PICL_FAILURE;
                else
                        err = (volwr)(&warg, vbuf);
                return (err);
        } else
                (void) memcpy(propp->prop_val, vbuf, size);

        unlock_node(nodep);             /* unlock node */
        (void) rw_unlock(&ptree_rwlock);        /* unlock ptree */
        return (err);
}

int
xptree_update_propval_with_cred(picl_prophdl_t proph, const void *vbuf,
    size_t size, door_cred_t cred)
{
        picl_obj_t      *nodep;
        picl_obj_t      *propp;
        int             err;

        (void) rw_rdlock(&ptree_rwlock);                /* lock ptree */
        nodep = propp = NULL;
        err = lookup_and_lock_propnode(WRLOCK_NODE, proph, &nodep, &propp);
        if (err != PICL_SUCCESS) {
                (void) rw_unlock(&ptree_rwlock);        /* unlock ptree */
                return (err);
        }

        err = check_propsize(PROP_WRITE, propp, size);
        if (err != PICL_SUCCESS) {
                unlock_node(nodep);             /* unlock node */
                (void) rw_unlock(&ptree_rwlock);        /* unlock ptree */
                return (err);
        }

        return (write_propval_and_unlock(nodep, propp, vbuf, size, cred));
}

/*
 * Ptree function used by plug-ins to update a property's value
 * calls update_propval_with_cred(), which releases locks for volatile props
 */
int
ptree_update_propval(picl_prophdl_t proph, const void *vbuf, size_t size)
{
        return (xptree_update_propval_with_cred(proph, vbuf, size, picld_cred));
}

/*
 * This function writes/updates a property's value by looking it up
 * by its name.
 * For volatile properties this function releases the locks on the
 * node and the ptree table.
 */
int
xptree_update_propval_by_name_with_cred(picl_nodehdl_t nodeh, const char *pname,
    const void *vbuf, size_t size, door_cred_t cred)
{
        picl_obj_t      *nodep;
        picl_obj_t      *propp;
        int             err;

        (void) rw_rdlock(&ptree_rwlock);                /* lock ptree */
        nodep = NULL;
        err = lookup_and_lock_node(WRLOCK_NODE, nodeh, &nodep); /* lock node */
        if (err != PICL_SUCCESS) {
                (void) rw_unlock(&ptree_rwlock);        /* unlock ptree */
                return (err);
        }

        if (picl_restricted(pname)) {
                unlock_node(nodep);
                (void) rw_unlock(&ptree_rwlock);
                return (PICL_RESERVEDNAME);
        }

        err = lookup_prop_by_name(nodep, pname, &propp);
        if (err != PICL_SUCCESS) {
                unlock_node(nodep);
                (void) rw_unlock(&ptree_rwlock);
                return (err);
        }

        err = check_propsize(PROP_WRITE, propp, size);
        if (err != PICL_SUCCESS) {
                unlock_node(nodep);
                (void) rw_unlock(&ptree_rwlock);
                return (err);
        }

        return (write_propval_and_unlock(nodep, propp, vbuf, size, cred));
}

/*
 * This function updates the value of a property specified by its name
 */
int
ptree_update_propval_by_name(picl_nodehdl_t nodeh, const char *pname,
    const void *vbuf, size_t size)
{
        return (xptree_update_propval_by_name_with_cred(nodeh, pname, vbuf,
            size, picld_cred));
}

/*
 * This function retrieves the handle of a property by its name
 */
int
ptree_get_prop_by_name(picl_nodehdl_t nodeh, const char *pname,
    picl_prophdl_t *proph)
{
        picl_obj_t      *nodep;
        picl_obj_t      *propp;
        int             err;

        (void) rw_rdlock(&ptree_rwlock);                /* lock ptree */
        nodep = NULL;
        err = lookup_and_lock_node(RDLOCK_NODE, nodeh, &nodep); /* lock node */
        if (err != PICL_SUCCESS) {
                (void) rw_unlock(&ptree_rwlock);        /* unlock ptree */
                return (err);
        }

        if (picl_restricted(pname)) {
                err = PICL_RESERVEDNAME;
                unlock_node(nodep);                     /* unlock node */
                (void) rw_unlock(&ptree_rwlock);        /* unlock ptree */
                return (err);
        }

        err = lookup_prop_by_name(nodep, pname, &propp);
        if (err == PICL_SUCCESS)
                *proph = propp->ptree_hdl;

        unlock_node(nodep);                     /* unlock node */
        (void) rw_unlock(&ptree_rwlock);                /* unlock ptree */
        return (err);
}

/*
 * This function returns the handle of the first property
 */
int
ptree_get_first_prop(picl_nodehdl_t nodeh, picl_prophdl_t *proph)
{
        picl_obj_t      *pobj;
        int             err;

        (void) rw_rdlock(&ptree_rwlock);                /* lock ptree */
        pobj = NULL;
        err = lookup_and_lock_node(RDLOCK_NODE, nodeh, &pobj);  /* lock node */
        if (err != PICL_SUCCESS) {
                (void) rw_unlock(&ptree_rwlock);        /* unlock ptree */
                return (err);
        }

        if (pobj->first_prop)
                *proph = pobj->first_prop->ptree_hdl;
        else
                err = PICL_ENDOFLIST;

        unlock_node(pobj);                      /* unlock node */
        (void) rw_unlock(&ptree_rwlock);        /* unlock ptree */
        return (err);
}

/*
 * This function returns the handle of next property in the list
 */
int
ptree_get_next_prop(picl_prophdl_t proph, picl_prophdl_t *nextproph)
{
        picl_obj_t      *nodep;
        picl_obj_t      *propp;
        int             err;

        (void) rw_rdlock(&ptree_rwlock);                /* lock ptree */
        nodep = propp = NULL;
        err = lookup_and_lock_propnode(RDLOCK_NODE, proph, &nodep, &propp);
        if (err != PICL_SUCCESS) {
                (void) rw_unlock(&ptree_rwlock);        /* unlock ptree */
                return (err);
        }

        if (propp->next_prop) {
                *nextproph = propp->next_prop->ptree_hdl;
        } else
                err = PICL_ENDOFLIST;

        unlock_node(nodep);                             /* unlock node */
        (void) rw_unlock(&ptree_rwlock);                /* unlock ptree */
        return (err);
}

/*
 * These functions are called by ptree_get_node_by_path()
 * Append a prop expression entry to the list
 */
static prop_list_t *
append_entry_to_list(prop_list_t *el, prop_list_t *list)
{
        prop_list_t     *ptr;

        if (el == NULL)
                return (list);

        if (list == NULL) {
                list = el;
                return (list);
        }

        /*
         * Add it to the end of list
         */
        ptr = list;

        while (ptr->next != NULL)
                ptr = ptr->next;

        ptr->next = el;

        return (list);
}

/*
 * Free the property expression list
 */
static void
free_list(prop_list_t *list)
{
        prop_list_t     *ptr;
        prop_list_t     *tmp;

        for (ptr = list; ptr != NULL; ptr = tmp) {
                tmp = ptr->next;
                free(ptr);
        }
}

static int
parse_prl(char *prl, char **name, char **baddr, prop_list_t **plist)
{
        char            *propptr;
        char            *ptr;
        char            *pname;
        char            *pval;
        prop_list_t     *el;

        if (prl == NULL)
                return (PICL_FAILURE);

        if ((prl[0] == '@') || (prl[0] == '?'))
                return (PICL_FAILURE);

        *name = prl;

        /*
         * get property expression
         */
        ptr = strchr(prl, '?');

        if (ptr != NULL) {
                *ptr = '\0';
                propptr = ptr + 1;
        } else
                propptr = NULL;

        /*
         * get bus value
         */
        ptr = strchr(prl, '@');

        if (ptr != NULL) {
                *ptr = '\0';
                *baddr = ptr + 1;
                if (strlen(*baddr) == 0)        /* no bus value after @ */
                        return (PICL_FAILURE);
        }

        /*
         * create the prop list
         */
        while (propptr != NULL) {
                pname = propptr;
                pval = NULL;

                ptr = strchr(propptr, '?');

                if (ptr != NULL) {  /* more ?<prop>=<propval> */
                        *ptr = '\0';
                        propptr = ptr + 1;
                } else
                        propptr = NULL;

                if (strlen(pname) == 0) /* no prop exp after ? */
                        return (PICL_FAILURE);

                ptr = strchr(pname, '=');
                if (ptr != NULL) { /* not void prop */
                        *ptr = '\0';
                        pval = ptr + 1;
                        /*
                         * <prop>= is treated as void property
                         */
                        if (strlen(pval) == 0)
                                pval = NULL;
                }

                el = (prop_list_t *)malloc(sizeof (prop_list_t));
                el->pname = pname;
                el->pval = pval;
                el->next = NULL;
                *plist = append_entry_to_list(el, *plist);
        }

        return (PICL_SUCCESS);
}

static int
prop_match(ptree_propinfo_t pinfo, void *vbuf, char *val)
{
        int8_t          cval;
        uint8_t         ucval;
        int16_t         sval;
        uint16_t        usval;
        int32_t         intval;
        uint32_t        uintval;
        int64_t         llval;
        uint64_t        ullval;
        float           fval;
        double          dval;

        switch (pinfo.piclinfo.type) {
        case PICL_PTYPE_CHARSTRING:
                if (strcasecmp(pinfo.piclinfo.name, PICL_PROP_CLASSNAME) == 0) {
                        if (strcmp(val, PICL_CLASS_PICL) == 0)
                                return (1);
                }
                if (strcmp(val, (char *)vbuf) == 0)
                        return (1);
                else
                        return (0);
        case PICL_PTYPE_INT:
                switch (pinfo.piclinfo.size) {
                case sizeof (int8_t):
                        cval = (int8_t)strtol(val, (char **)NULL, 0);
                        return (cval == *(char *)vbuf);
                case sizeof (int16_t):
                        sval = (int16_t)strtol(val, (char **)NULL, 0);
                        return (sval == *(int16_t *)vbuf);
                case sizeof (int32_t):
                        intval = (int32_t)strtol(val, (char **)NULL, 0);
                        return (intval == *(int32_t *)vbuf);
                case sizeof (int64_t):
                        llval = strtoll(val, (char **)NULL, 0);
                        return (llval == *(int64_t *)vbuf);
                default:
                        return (0);
                }
        case PICL_PTYPE_UNSIGNED_INT:
                switch (pinfo.piclinfo.size) {
                case sizeof (uint8_t):
                        ucval = (uint8_t)strtoul(val, (char **)NULL, 0);
                        return (ucval == *(uint8_t *)vbuf);
                case sizeof (uint16_t):
                        usval = (uint16_t)strtoul(val, (char **)NULL, 0);
                        return (usval == *(uint16_t *)vbuf);
                case sizeof (uint32_t):
                        uintval = (uint32_t)strtoul(val, (char **)NULL, 0);
                        return (uintval == *(uint32_t *)vbuf);
                case sizeof (uint64_t):
                        ullval = strtoull(val, (char **)NULL, 0);
                        return (ullval == *(uint64_t *)vbuf);
                default:
                        return (0);
                }
        case PICL_PTYPE_FLOAT:
                switch (pinfo.piclinfo.size) {
                case sizeof (float):
                        fval = (float)strtod(val, (char **)NULL);
                        return (fval == *(float *)vbuf);
                case sizeof (double):
                        dval = strtod(val, (char **)NULL);
                        return (dval == *(double *)vbuf);
                default:
                        return (0);
                }
        case PICL_PTYPE_VOID:
        case PICL_PTYPE_TIMESTAMP:
        case PICL_PTYPE_TABLE:
        case PICL_PTYPE_REFERENCE:
        case PICL_PTYPE_BYTEARRAY:
        case PICL_PTYPE_UNKNOWN:
        default:
                return (0);
        }
}

static int
check_propval(picl_nodehdl_t nodeh, char *pname, char *pval)
{
        int                     err;
        picl_prophdl_t          proph;
        ptree_propinfo_t        pinfo;
        void                    *vbuf;

        err = ptree_get_prop_by_name(nodeh, pname, &proph);
        if (err != PICL_SUCCESS)
                return (err);

        err = ptree_get_propinfo(proph, &pinfo);
        if (err != PICL_SUCCESS)
                return (err);

        if (pval == NULL) {     /* void type */
                if (pinfo.piclinfo.type != PICL_PTYPE_VOID)
                        return (PICL_FAILURE);
        } else {
                vbuf = alloca(pinfo.piclinfo.size);
                if (vbuf == NULL)
                        return (PICL_FAILURE);
                err = ptree_get_propval(proph, vbuf,
                    pinfo.piclinfo.size);
                if (err != PICL_SUCCESS)
                        return (err);

                if (!prop_match(pinfo, vbuf, pval))
                        return (PICL_FAILURE);
        }
        return (PICL_SUCCESS);
}

static int
get_child_by_path(picl_nodehdl_t rooth, char *prl,
    picl_nodehdl_t *nodeh, char *pname)
{
        picl_nodehdl_t          chdh;
        int                     err;
        char                    *nameval;
        char                    *nodename;
        char                    *path;
        char                    *baddr;
        char                    *busval;
        prop_list_t             *plist;
        prop_list_t             *ptr;

        if (prl == NULL)
                return (PICL_FAILURE);

        path = strdupa(prl);
        if (path == NULL)
                return (PICL_FAILURE);

        plist = NULL;
        nodename = NULL;
        baddr = NULL;

        err = parse_prl(path, &nodename, &baddr, &plist);
        if (err != PICL_SUCCESS) {
                free_list(plist);
                return (err);
        }

        if (nodename == NULL)
                return (PICL_FAILURE);

        nameval = alloca(strlen(nodename) + 1);
        if (nameval == NULL) {
                free_list(plist);
                return (PICL_FAILURE);
        }

        if (baddr != NULL) {
                busval = alloca(strlen(baddr) + 1);
                if (busval == NULL) {
                        free_list(plist);
                        return (PICL_FAILURE);
                }
        }

        for (err = ptree_get_propval_by_name(rooth, PICL_PROP_CHILD, &chdh,
            sizeof (picl_nodehdl_t)); err != PICL_PROPNOTFOUND;
            err = ptree_get_propval_by_name(chdh, PICL_PROP_PEER, &chdh,
            sizeof (picl_nodehdl_t))) {
                if (err != PICL_SUCCESS) {
                        free_list(plist);
                        return (PICL_FAILURE);
                }

                /*
                 * compare name
                 */
                if ((strcmp(pname, PICL_PROP_CLASSNAME) != 0) ||
                    (strcmp(nodename, PICL_CLASS_PICL) != 0)) {
                        err = ptree_get_propval_by_name(chdh, pname,
                            nameval, (strlen(nodename) + 1));

                        if (err != PICL_SUCCESS)
                                continue;
                        if (strcmp(nameval, nodename) != 0)
                                continue;
                }

                /*
                 * compare device address with bus-addr prop first
                 * then with UnitAddress property
                 */
                if (baddr != NULL) { /* compare bus-addr prop */
                        if ((ptree_get_propval_by_name(chdh, PICL_PROP_BUS_ADDR,
                            busval, (strlen(baddr) + 1)) != PICL_SUCCESS) &&
                            (ptree_get_propval_by_name(chdh,
                            PICL_PROP_UNIT_ADDRESS, busval,
                            (strlen(baddr) + 1)) != PICL_SUCCESS))
                                continue;

                        if (strcmp(busval, baddr) != 0)
                                continue; /* not match */
                }

                if (plist == NULL) { /* no prop expression */
                        *nodeh = chdh;
                        return (PICL_SUCCESS);
                }

                /*
                 * compare the property expression list
                 */
                ptr = plist;

                while (ptr != NULL) {
                        err = check_propval(chdh, ptr->pname, ptr->pval);
                        if (err != PICL_SUCCESS)
                                break;

                        ptr = ptr->next;
                }
                if (ptr == NULL) {
                        *nodeh = chdh;
                        free_list(plist);
                        return (PICL_SUCCESS);
                }
        }
        free_list(plist);
        return (PICL_NOTNODE);
}

/*
 * This functions returns the handle of node specified by its path
 */
int
ptree_get_node_by_path(const char *piclprl, picl_nodehdl_t *handle)
{
        picl_nodehdl_t  rooth;
        picl_nodehdl_t  chdh;
        char            *path;
        char            *ptr;
        char            *defprop;
        char            *tokindex;
        int             err;
        int             len;
        int             npflg;  /* namepath flag */


        path = strdupa(piclprl);
        if (path == NULL)
                return (PICL_FAILURE);

        npflg = 1;      /* default */
        defprop = path;
        if (path[0] == '/') {
                ptr = &path[1];
        } else if ((tokindex = strchr(path, ':')) != NULL) {
                *tokindex = '\0';
                ++tokindex;
                if (*tokindex == '/')
                        ptr = tokindex + 1;
                else
                        return (PICL_NOTNODE);
                npflg = 0;
        } else
                return (PICL_NOTNODE);

        err = ptree_get_root(&rooth);
        if (err != PICL_SUCCESS)
                return (err);

        for (chdh = rooth, tokindex = strchr(ptr, '/');
            tokindex != NULL;
            ptr = tokindex + 1, tokindex = strchr(ptr, '/')) {
                *tokindex = '\0';
                if (npflg)
                        err = get_child_by_path(chdh, ptr, &chdh,
                            PICL_PROP_NAME);
                else
                        err = get_child_by_path(chdh, ptr, &chdh,
                            defprop);

                if (err != PICL_SUCCESS)
                        return (err);
        }

        /*
         * check if last token is empty or not
         * eg. /a/b/c/ or /a/b/c
         */
        if (*ptr == '\0') {
                *handle = chdh;
                return (PICL_SUCCESS);
        }

        len = strcspn(ptr, " \t\n");
        if (len == 0) {
                *handle = chdh;
                return (PICL_SUCCESS);
        }

        ptr[len] = '\0';
        if (npflg)
                err = get_child_by_path(chdh, ptr, &chdh, PICL_PROP_NAME);
        else
                err = get_child_by_path(chdh, ptr, &chdh, defprop);

        if (err != PICL_SUCCESS)
                return (err);

        *handle = chdh;
        return (PICL_SUCCESS);
}

/*
 * Initialize propinfo
 */
int
ptree_init_propinfo(ptree_propinfo_t *infop, int version, int ptype, int pmode,
    size_t psize, char *pname, int (*readfn)(ptree_rarg_t *, void *),
    int (*writefn)(ptree_warg_t *, const void *))
{
        if (version != PTREE_PROPINFO_VERSION_1)
                return (PICL_NOTSUPPORTED);
        if ((infop == NULL) || (pname == NULL))
                return (PICL_INVALIDARG);
        infop->version = version;
        infop->piclinfo.type = ptype;
        infop->piclinfo.accessmode = pmode;
        infop->piclinfo.size = psize;
        infop->read = readfn;
        infop->write = writefn;
        (void) strlcpy(infop->piclinfo.name, pname, PICL_PROPNAMELEN_MAX);
        return (PICL_SUCCESS);
}

/*
 * Creates a property, adds it to the node, and returns the property
 * handle to the caller if successful and proph is not NULL
 */
int
ptree_create_and_add_prop(picl_nodehdl_t nodeh, ptree_propinfo_t *infop,
    void *vbuf, picl_prophdl_t *proph)
{
        int             err;
        picl_prophdl_t  tmph;

        err = ptree_create_prop(infop, vbuf, &tmph);
        if (err != PICL_SUCCESS)
                return (err);
        err = ptree_add_prop(nodeh, tmph);
        if (err != PICL_SUCCESS) {
                (void) ptree_destroy_prop(tmph);
                return (err);
        }
        if (proph)
                *proph = tmph;
        return (PICL_SUCCESS);
}

/*
 * Creates a node, adds it to its parent node, and returns the node
 * handle to the caller if successful
 */
int
ptree_create_and_add_node(picl_nodehdl_t rooth, const char *name,
    const char *classname, picl_nodehdl_t *nodeh)
{
        picl_nodehdl_t  tmph;
        int             err;

        err = ptree_create_node(name, classname, &tmph);

        if (err != PICL_SUCCESS)
                return (err);

        err = ptree_add_node(rooth, tmph);
        if (err != PICL_SUCCESS) {
                (void) ptree_destroy_node(tmph);
                return (err);
        }

        *nodeh = tmph;
        return (PICL_SUCCESS);
}


/*
 * recursively visit all nodes
 */
static int
do_walk(picl_nodehdl_t rooth, const char *classname,
    void *c_args, int (*callback_fn)(picl_nodehdl_t hdl, void *args))
{
        int             err;
        picl_nodehdl_t  chdh;
        char            classval[PICL_CLASSNAMELEN_MAX];

        err = ptree_get_propval_by_name(rooth, PICL_PROP_CHILD, &chdh,
            sizeof (chdh));
        while (err == PICL_SUCCESS) {
                err = ptree_get_propval_by_name(chdh, PICL_PROP_CLASSNAME,
                    classval, sizeof (classval));
                if (err != PICL_SUCCESS)
                        return (err);

                if ((classname == NULL) || (strcmp(classname, classval) == 0)) {
                        err = callback_fn(chdh, c_args);
                        if (err != PICL_WALK_CONTINUE)
                                return (err);
                }

                if ((err = do_walk(chdh, classname, c_args, callback_fn)) !=
                    PICL_WALK_CONTINUE)
                        return (err);

                err = ptree_get_propval_by_name(chdh, PICL_PROP_PEER, &chdh,
                    sizeof (chdh));
        }
        if (err == PICL_PROPNOTFOUND)   /* end of a branch */
                return (PICL_WALK_CONTINUE);
        return (err);

}

/*
 * This function visits all the nodes in the subtree rooted at <rooth>.
 * For each node that matches the class name specified, the callback
 * function is invoked.
 */
int
ptree_walk_tree_by_class(picl_nodehdl_t rooth, const char *classname,
    void *c_args, int (*callback_fn)(picl_nodehdl_t hdl, void *args))
{
        int             err;

        if (callback_fn == NULL)
                return (PICL_INVALIDARG);
        err = do_walk(rooth, classname, c_args, callback_fn);
        if ((err == PICL_WALK_CONTINUE) || (err == PICL_WALK_TERMINATE))
                return (PICL_SUCCESS);
        return (err);
}

static int
compare_propval(picl_nodehdl_t nodeh, char *pname, picl_prop_type_t ptype,
    void *pval, size_t valsize)
{
        int                     err;
        picl_prophdl_t          proph;
        ptree_propinfo_t        propinfo;
        void                    *vbuf;

        err = ptree_get_prop_by_name(nodeh, pname, &proph);
        if (err != PICL_SUCCESS)
                return (0);
        err = ptree_get_propinfo(proph, &propinfo);
        if (err != PICL_SUCCESS)
                return (0);
        if (propinfo.piclinfo.type != ptype)
                return (0);
        if (propinfo.piclinfo.type == PICL_PTYPE_VOID)
                return (1);
        if (pval == NULL)
                return (0);
        if (valsize > propinfo.piclinfo.size)
                return (0);
        vbuf = alloca(propinfo.piclinfo.size);
        if (vbuf == NULL)
                return (0);
        err = ptree_get_propval(proph, vbuf, propinfo.piclinfo.size);
        if (err != PICL_SUCCESS)
                return (0);
        if (memcmp(vbuf, pval, valsize) == 0)
                return (1);
        return (0);
}


/*
 * This function traverses the subtree and finds a node that has a property
 * of the specified name and type with the specified value.
 * The matched node in the tree is returned in retnodeh. If there is
 * no node with that property, then PICL_NODENOTFOUND is returned.
 */
int
ptree_find_node(picl_nodehdl_t rooth, char *pname, picl_prop_type_t ptype,
    void *pval, size_t valsize, picl_nodehdl_t *retnodeh)
{
        int                     err;
        picl_nodehdl_t          chdh;

        if (pname == NULL)
                return (PICL_INVALIDARG);
        err = ptree_get_propval_by_name(rooth, PICL_PROP_CHILD, &chdh,
            sizeof (chdh));

        while (err == PICL_SUCCESS) {
                if (compare_propval(chdh, pname, ptype, pval, valsize)) {
                        if (retnodeh)
                                *retnodeh = chdh;
                        return (PICL_SUCCESS);
                }

                err = ptree_find_node(chdh, pname, ptype, pval, valsize,
                    retnodeh);
                if (err != PICL_NODENOTFOUND)
                        return (err);

                err = ptree_get_propval_by_name(chdh, PICL_PROP_PEER, &chdh,
                    sizeof (chdh));
        }
        if (err == PICL_PROPNOTFOUND)
                return (PICL_NODENOTFOUND);
        return (err);
}

/*
 * This function gets the frutree parent for a given node.
 * Traverse up the tree and look for the following properties:
 * Frutree parent reference properties:
 *  _fru_parent
 *  _location_parent
 *  _port_parent
 * If the frutree reference property is found, return its value.
 * Else, return the handle of /frutree/chassis.
 */
int
ptree_get_frutree_parent(picl_nodehdl_t nodeh, picl_nodehdl_t *fruh)
{
        int             err;
        picl_nodehdl_t  nparh;
        picl_nodehdl_t  fruparh;

        err = PICL_SUCCESS;
        nparh = nodeh;
        while (err == PICL_SUCCESS) {
                err = ptree_get_propval_by_name(nparh, PICL_REFPROP_FRU_PARENT,
                    &fruparh, sizeof (fruparh));
                if (err == PICL_SUCCESS) {
                        *fruh = fruparh;
                        return (PICL_SUCCESS);
                }
                err = ptree_get_propval_by_name(nparh,
                    PICL_REFPROP_LOC_PARENT, &fruparh, sizeof (fruparh));
                if (err == PICL_SUCCESS) {
                        *fruh = fruparh;
                        return (PICL_SUCCESS);
                }
                err = ptree_get_propval_by_name(nparh, PICL_REFPROP_PORT_PARENT,
                    &fruparh, sizeof (fruparh));
                if (err == PICL_SUCCESS) {
                        *fruh = fruparh;
                        return (PICL_SUCCESS);
                }

                err = ptree_get_propval_by_name(nparh, PICL_PROP_PARENT, &nparh,
                    sizeof (nparh));
        }

        if (err == PICL_PROPNOTFOUND) { /* return /frutree/chassis handle */
                err = ptree_get_node_by_path(PICL_FRUTREE_CHASSIS, &fruparh);
                if (err == PICL_SUCCESS) {
                        *fruh = fruparh;
                        return (PICL_SUCCESS);
                }
        }
        return (err);
}

/*
 * This function is called by plug-ins to register with the daemon
 */
int
picld_plugin_register(picld_plugin_reg_t *regp)
{
        picld_plugin_reg_list_t *el;
        picld_plugin_reg_list_t *tmp;

        if (regp == NULL)
                return (PICL_FAILURE);

        if (regp->version != PICLD_PLUGIN_VERSION_1)
                return (PICL_NOTSUPPORTED);

        el = malloc(sizeof (picld_plugin_reg_list_t));
        if (el == NULL)
                return (PICL_FAILURE);
        el->reg.version = regp->version;
        el->reg.critical = regp->critical;
        if (regp->name)
                el->reg.name = strdup(regp->name);
        if (el->reg.name == NULL)
                return (PICL_FAILURE);

        el->reg.plugin_init = regp->plugin_init;
        el->reg.plugin_fini = regp->plugin_fini;
        el->next = NULL;

        if (plugin_reg_list == NULL) {
                plugin_reg_list = el;
        } else {        /* add to end */
                tmp = plugin_reg_list;
                while (tmp->next != NULL)
                        tmp = tmp->next;
                tmp->next = el;
        }

        return (PICL_SUCCESS);
}

/*
 * Call fini routines of the registered plugins
 */
static void
plugin_fini(picld_plugin_reg_list_t *p)
{
        if (p == NULL)
                return;

        plugin_fini(p->next);
        if (p->reg.plugin_fini)
                (p->reg.plugin_fini)();
}

/*
 * Create PICL Tree
 */

static void
init_plugin_reg_list(void)
{
        plugin_reg_list = NULL;
}

static int
picltree_set_root(picl_nodehdl_t rooth)
{
        picl_obj_t      *pobj;
        int             err;

        (void) rw_rdlock(&ptree_rwlock);                /* lock ptree */
        pobj = NULL;
        err = lookup_and_lock_node(RDLOCK_NODE, rooth, &pobj); /* lock node */
        if (err != PICL_SUCCESS) {
                (void) rw_unlock(&ptree_rwlock);
                return (PICL_FAILURE);
        }
        piclize_node(pobj);
        picl_root_obj = pobj;
        ptree_root_hdl = pobj->ptree_hdl;
        unlock_node(pobj);                      /* unlock node */
        (void) rw_unlock(&ptree_rwlock);                /* unlock ptree */
        return (PICL_SUCCESS);
}

static int
picltree_init(void)
{
        (void) rwlock_init(&ptree_rwlock, USYNC_THREAD, NULL);
        (void) rwlock_init(&picltbl_rwlock, USYNC_THREAD, NULL);

        if (hash_init(&picltbl) < 0)
                return (PICL_FAILURE);
        if (hash_init(&ptreetbl) < 0)
                return (PICL_FAILURE);

        if (pthread_mutex_init(&ptreehdl_lock, NULL) != 0)
                return (PICL_FAILURE);

        if (pthread_mutex_init(&piclhdl_lock, NULL) != 0)
                return (PICL_FAILURE);

        if (pthread_mutex_init(&evtq_lock, NULL) != 0)
                return (PICL_FAILURE);
        if (pthread_cond_init(&evtq_cv, NULL) != 0)
                return (PICL_FAILURE);
        if (pthread_mutex_init(&evthandler_lock, NULL) != 0)
                return (PICL_FAILURE);

        picl_root_obj = NULL;
        eventqp = NULL;
        evt_handlers = NULL;
        ptree_root_hdl = PICL_INVALID_PICLHDL;

        return (PICL_SUCCESS);
}

static void
add_unique_plugin_to_list(char *path, char *name)
{
        char    *buf;
        picld_plugin_desc_t     *pl;
        picld_plugin_desc_t     *tmp;

        pl = plugin_desc;
        while (pl != NULL) {
                if (strcmp(pl->libname, name) == 0)
                        return;
                else
                        pl = pl->next;
        }

        pl = malloc(sizeof (picld_plugin_desc_t));
        if (pl == NULL)
                return;

        pl->libname = strdup(name);
        if (pl->libname == NULL)
                return;
        buf = alloca(strlen(name) + strlen(path) + 2);
        if (buf == NULL)
                return;
        (void) strcpy(buf, path);
        (void) strcat(buf, name);
        pl->pathname = strdup(buf);
        if (pl->pathname == NULL)
                return;

        pl->next = NULL;

        if (plugin_desc == NULL)
                plugin_desc = pl;
        else {
                tmp = plugin_desc;
                while (tmp->next != NULL)
                        tmp = tmp->next;
                tmp->next = pl;
        }
}

static void
get_plugins_from_dir(char *dirname)
{
        struct dirent   *ent;
        DIR     *dir;
        int     len;
        int     solen = strlen(SO_VERS) + 1;

        if ((dir = opendir(dirname)) == NULL)
                return;

        while ((ent = readdir(dir)) != NULL) {
                if ((strcmp(ent->d_name, ".") == 0) ||
                    (strcmp(ent->d_name, "..") == 0))
                        continue;

                len = strlen(ent->d_name) + 1;
                if (len < solen)
                        continue;

                if (strcmp(ent->d_name + (len - solen), SO_VERS) == 0)
                        add_unique_plugin_to_list(dirname, ent->d_name);
        }

        (void) closedir(dir);
}


static void
init_plugin_list(void)
{
        char    nmbuf[SYS_NMLN];
        char    pname[PATH_MAX];

        plugin_desc = NULL;
        if (sysinfo(SI_PLATFORM, nmbuf, sizeof (nmbuf)) != -1) {
                (void) snprintf(pname, PATH_MAX, PICLD_PLAT_PLUGIN_DIRF, nmbuf);
                if (access(pname, R_OK) == 0)
                        get_plugins_from_dir(pname);
        }

        if (sysinfo(SI_MACHINE, nmbuf, sizeof (nmbuf)) != -1) {
                (void) snprintf(pname, PATH_MAX, PICLD_PLAT_PLUGIN_DIRF, nmbuf);
                if (access(pname, R_OK) == 0)
                        get_plugins_from_dir(pname);
        }

        (void) snprintf(pname, PATH_MAX, "%s/", PICLD_COMMON_PLUGIN_DIR);
        if (access(pname, R_OK) == 0)
                get_plugins_from_dir(pname);
}

static void
load_plugins(void)
{
        picld_plugin_desc_t     *pl;

        pl = plugin_desc;
        while (pl != NULL) {
                pl->dlh = dlopen(pl->pathname, RTLD_LAZY|RTLD_LOCAL);
                if (pl->dlh == NULL) {
                        syslog(LOG_CRIT, dlerror());
                        return;
                }
                pl = pl->next;
        }
}



static int
add_root_props(picl_nodehdl_t rooth)
{
        int                     err;
        picl_prophdl_t          proph;
        ptree_propinfo_t        pinfo;
        float                   picl_vers;

#define PICL_PROP_PICL_VERSION          "PICLVersion"
#define PICL_VERSION                    1.1

        err = ptree_init_propinfo(&pinfo, PTREE_PROPINFO_VERSION_1,
            PICL_PTYPE_FLOAT, PICL_READ, sizeof (picl_vers),
            PICL_PROP_PICL_VERSION, NULL, NULL);
        if (err != PICL_SUCCESS)
                return (err);

        picl_vers = PICL_VERSION;
        err = ptree_create_and_add_prop(rooth, &pinfo, &picl_vers, &proph);
        return (err);
}

static int
construct_picltree(void)
{
        int                     err;
        picld_plugin_reg_list_t *iter;
        picl_nodehdl_t          rhdl;

        /*
         * Create "/" node
         */
        if ((err = ptree_create_node(PICL_NODE_ROOT, PICL_CLASS_PICL,
            &rhdl)) != PICL_SUCCESS) {
                return (err);
        }

        if (picltree_set_root(rhdl) != PICL_SUCCESS) {
                return (PICL_FAILURE);
        }

        err = add_root_props(rhdl);
        if (err != PICL_SUCCESS)
                return (err);

        /*
         * Initialize the registered plug-in modules
         */
        iter = plugin_reg_list;
        while (iter != NULL) {
                if (iter->reg.plugin_init)
                        (iter->reg.plugin_init)();
                iter = iter->next;
        }
        return (PICL_SUCCESS);
}

void
xptree_destroy(void)
{
        dbg_print(1, "xptree_destroy: picl_root_obj = %s\n",
            (picl_root_obj == NULL ? "NULL" : "not-NULL"));

        if (picl_root_obj == NULL)
                return;

        dbg_print(1, "xptree_destroy: call plugin_fini\n");
        plugin_fini(plugin_reg_list);
        dbg_print(1, "xptree_destroy: plugin_fini DONE\n");

        (void) ptree_delete_node(picl_root_obj->ptree_hdl);
        (void) ptree_destroy_node(picl_root_obj->ptree_hdl);

        (void) rw_wrlock(&ptree_rwlock);
        picl_root_obj = NULL;
        (void) rw_unlock(&ptree_rwlock);
}

/*ARGSUSED*/
int
xptree_initialize(int flg)
{
        int             err;
        pthread_attr_t  attr;
        pthread_t       tid;

        picld_pid = getpid();
        picld_cred.dc_euid = geteuid();
        picld_cred.dc_egid = getegid();
        picld_cred.dc_ruid = getuid();
        picld_cred.dc_rgid = getgid();
        picld_cred.dc_pid = getpid();

        picl_hdl_hi = 1;
        ptree_hdl_hi = 1;
        ptree_generation = 1;
        qempty_wait = 0;

        if (pthread_mutex_init(&ptree_refresh_mutex, NULL) != 0)
                return (PICL_FAILURE);

        if (picltree_init() != PICL_SUCCESS)
                return (PICL_FAILURE);

        init_plugin_reg_list();
        init_plugin_list();
        load_plugins();

        err = construct_picltree();
        if (err != PICL_SUCCESS)
                return (err);

        /*
         * Dispatch events after all plug-ins have initialized
         */
        if (pthread_attr_init(&attr) != 0)
                return (PICL_FAILURE);

        (void) pthread_attr_setscope(&attr, PTHREAD_SCOPE_SYSTEM);
        if (pthread_create(&tid, &attr, ptree_event_thread, NULL))
                return (PICL_FAILURE);

        return (PICL_SUCCESS);
}

int
xptree_reinitialize(void)
{
        int     err;

        /*
         * Wait for eventq to become empty
         */
        dbg_print(1, "xptree_reinitialize: wait for evtq empty\n");
        (void) pthread_mutex_lock(&evtq_lock);
        qempty_wait = 1;
        while (eventqp != NULL)
                (void) pthread_cond_wait(&evtq_empty, &evtq_lock);
        qempty_wait = 0;
        (void) pthread_mutex_unlock(&evtq_lock);
        dbg_print(1, "xptree_reinitialize: evtq empty is EMPTY\n");

        (void) rw_wrlock(&ptree_rwlock);
        picl_root_obj = NULL;
        ptree_root_hdl = PICL_INVALID_PICLHDL;
        (void) rw_unlock(&ptree_rwlock);
        (void) pthread_mutex_lock(&ptree_refresh_mutex);
        ++ptree_generation;
        (void) pthread_mutex_unlock(&ptree_refresh_mutex);

        err = construct_picltree();
        (void) pthread_mutex_lock(&ptree_refresh_mutex);
        (void) pthread_cond_broadcast(&ptree_refresh_cond);
        (void) pthread_mutex_unlock(&ptree_refresh_mutex);

        (void) pthread_mutex_lock(&evtq_lock);
        (void) pthread_cond_broadcast(&evtq_cv);
        (void) pthread_mutex_unlock(&evtq_lock);

        return (err);
}

/*
 * This function is called by the PICL daemon on behalf of clients to
 * wait for a tree refresh
 */
int
xptree_refresh_notify(uint32_t secs)
{
        int     curgen;
        int     ret;
        timespec_t      to;

        if (secs != 0) {
                if (pthread_mutex_lock(&ptree_refresh_mutex) != 0)
                        return (PICL_FAILURE);

                curgen = ptree_generation;

                while (curgen == ptree_generation) {
                        if (secs == UINT32_MAX) /* wait forever */
                                (void) pthread_cond_wait(&ptree_refresh_cond,
                                    &ptree_refresh_mutex);
                        else {
                                to.tv_sec = secs;
                                to.tv_nsec = 0;
                                ret = pthread_cond_reltimedwait_np(
                                    &ptree_refresh_cond,
                                    &ptree_refresh_mutex, &to);
                                if (ret == ETIMEDOUT)
                                        break;
                        }
                }

                (void) pthread_mutex_unlock(&ptree_refresh_mutex);
        }

        return (PICL_SUCCESS);
}

/*VARARGS2*/
void
dbg_print(int level, const char *fmt, ...)
{
        if (verbose_level >= level) {
                va_list ap;

                va_start(ap, fmt);
                (void) vprintf(fmt, ap);
                va_end(ap);
        }
}

/*ARGSUSED*/
void
dbg_exec(int level, void (*fn)(void *args), void *args)
{
        if (verbose_level > level)
                (*fn)(args);
}