/*
 * 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 2010 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#include <signal.h>
#include <errno.h>
#include <syslog.h>
#include <libuutil.h>
#include <errno.h>

#include "events.h"
#include "objects.h"
#include "util.h"

/*
 * objects.c - contains routines which manipulate object lists of NCUs,
 * locations, ENMs and known WLANs.
 */

typedef struct nwamd_object_list {
        nwam_object_type_t object_type;
        uu_list_t *object_list;
        nwamd_event_method_t *object_event_methods;
        pthread_rwlock_t object_list_lock;
} nwamd_object_list_t;

nwamd_event_method_t enm_event_methods[] =
{
        { NWAM_EVENT_TYPE_OBJECT_INIT, nwamd_enm_handle_init_event },
        { NWAM_EVENT_TYPE_OBJECT_FINI, nwamd_enm_handle_fini_event },
        { NWAM_EVENT_TYPE_OBJECT_ACTION, nwamd_enm_handle_action_event },
        { NWAM_EVENT_TYPE_OBJECT_STATE, nwamd_enm_handle_state_event },
        { NWAM_EVENT_TYPE_NOOP, NULL }
};

nwamd_event_method_t loc_event_methods[] =
{
        { NWAM_EVENT_TYPE_OBJECT_INIT, nwamd_loc_handle_init_event },
        { NWAM_EVENT_TYPE_OBJECT_FINI, nwamd_loc_handle_fini_event },
        { NWAM_EVENT_TYPE_OBJECT_ACTION, nwamd_loc_handle_action_event },
        { NWAM_EVENT_TYPE_OBJECT_STATE, nwamd_loc_handle_state_event },
        { NWAM_EVENT_TYPE_NOOP, NULL }
};

nwamd_event_method_t ncu_event_methods[] =
{
        { NWAM_EVENT_TYPE_IF_STATE, nwamd_ncu_handle_if_state_event },
        { NWAM_EVENT_TYPE_IF_ACTION, nwamd_ncu_handle_if_action_event },
        { NWAM_EVENT_TYPE_LINK_STATE, nwamd_ncu_handle_link_state_event },
        { NWAM_EVENT_TYPE_LINK_ACTION, nwamd_ncu_handle_link_action_event },
        { NWAM_EVENT_TYPE_OBJECT_INIT, nwamd_ncu_handle_init_event },
        { NWAM_EVENT_TYPE_OBJECT_FINI, nwamd_ncu_handle_fini_event },
        { NWAM_EVENT_TYPE_OBJECT_ACTION, nwamd_ncu_handle_action_event },
        { NWAM_EVENT_TYPE_OBJECT_STATE, nwamd_ncu_handle_state_event },
        { NWAM_EVENT_TYPE_PERIODIC_SCAN, nwamd_ncu_handle_periodic_scan_event },
        { NWAM_EVENT_TYPE_NOOP, NULL }
};

nwamd_event_method_t ncp_event_methods[] =
{
        { NWAM_EVENT_TYPE_OBJECT_ACTION, nwamd_ncp_handle_action_event },
        { NWAM_EVENT_TYPE_OBJECT_STATE, nwamd_ncp_handle_state_event },
        { NWAM_EVENT_TYPE_UPGRADE, nwamd_handle_upgrade },
        { NWAM_EVENT_TYPE_NOOP, NULL }
};

nwamd_event_method_t known_wlan_event_methods[] =
{
        { NWAM_EVENT_TYPE_OBJECT_INIT, nwamd_known_wlan_handle_init_event },
        { NWAM_EVENT_TYPE_OBJECT_FINI, NULL },
        { NWAM_EVENT_TYPE_OBJECT_ACTION, nwamd_known_wlan_handle_action_event },
        { NWAM_EVENT_TYPE_NOOP, NULL }
};

/* Should be kept in same order as object types */
nwamd_object_list_t object_lists[] = {
        { NWAM_OBJECT_TYPE_NCP, NULL, ncp_event_methods,
        PTHREAD_RWLOCK_INITIALIZER },
        { NWAM_OBJECT_TYPE_NCU, NULL, ncu_event_methods,
        PTHREAD_RWLOCK_INITIALIZER },
        { NWAM_OBJECT_TYPE_LOC, NULL, loc_event_methods,
        PTHREAD_RWLOCK_INITIALIZER },
        { NWAM_OBJECT_TYPE_ENM, NULL, enm_event_methods,
        PTHREAD_RWLOCK_INITIALIZER },
        { NWAM_OBJECT_TYPE_KNOWN_WLAN, NULL, known_wlan_event_methods,
        PTHREAD_RWLOCK_INITIALIZER }
};

uu_list_pool_t *object_list_pool = NULL;

/*
 * Comparison function for objects, passed in as callback to
 * uu_list_pool_create().
 */
/* ARGSUSED */
static int
nwamd_object_compare(const void *l_arg, const void *r_arg, void *private)
{
        nwamd_object_t l = (nwamd_object_t)l_arg;
        nwamd_object_t r = (nwamd_object_t)r_arg;
        int rv;

        (void) pthread_mutex_lock(&l->nwamd_object_mutex);
        if (l != r)
                (void) pthread_mutex_lock(&r->nwamd_object_mutex);

        rv = strcmp(l->nwamd_object_name, r->nwamd_object_name);
        if (l != r)
                (void) pthread_mutex_unlock(&r->nwamd_object_mutex);
        (void) pthread_mutex_unlock(&l->nwamd_object_mutex);

        return (rv);
}

void
nwamd_object_lists_init(void)
{
        int i;

        object_list_pool = uu_list_pool_create("object_list_pool",
            sizeof (struct nwamd_object),
            offsetof(struct nwamd_object, nwamd_object_node),
            nwamd_object_compare, UU_LIST_POOL_DEBUG);
        if (object_list_pool == NULL)
                pfail("uu_list_pool_create failed with error %d", uu_error());

        for (i = 0;
            i < sizeof (object_lists) / sizeof (struct nwamd_object_list);
            i++) {
                object_lists[i].object_list = uu_list_create(object_list_pool,
                    NULL, 0);
                if (object_lists[i].object_list == NULL)
                        pfail("uu_list_create failed with error %d",
                            uu_error());
        }
}

void
nwamd_object_lists_fini(void)
{
        int i;
        nwamd_object_t object;
        void *cookie = NULL;

        for (i = 0;
            i < sizeof (object_lists) / sizeof (struct nwamd_object_list);
            i++) {
                while ((object = uu_list_teardown(object_lists[i].object_list,
                    &cookie)) != NULL) {
                        free(object);
                }
                uu_list_destroy(object_lists[i].object_list);
        }
        if (object_list_pool != NULL)
                uu_list_pool_destroy(object_list_pool);
}

static nwamd_object_list_t *
nwamd_get_object_list(nwam_object_type_t type)
{
        assert(type < sizeof (object_lists) / sizeof (object_lists[0]));
        return (&object_lists[type]);
}

static int
nwamd_object_list_lock(nwam_object_type_t type)
{
        nwamd_object_list_t *object_list = nwamd_get_object_list(type);

        (void) pthread_rwlock_wrlock(&object_list->object_list_lock);
        return (0);
}

static int
nwamd_object_list_rlock(nwam_object_type_t type)
{
        nwamd_object_list_t *object_list = nwamd_get_object_list(type);

        if (pthread_rwlock_rdlock(&object_list->object_list_lock) == -1) {
                nlog(LOG_ERR, "cannot get lock for object list: %s",
                    strerror(errno));
                return (-1);
        }
        return (0);
}

static void
nwamd_object_list_unlock(nwam_object_type_t type)
{
        nwamd_object_list_t *object_list = nwamd_get_object_list(type);

        (void) pthread_rwlock_unlock(&object_list->object_list_lock);
}

/*
 * Initialize object and return it in locked state.
 */
nwamd_object_t
nwamd_object_init(nwam_object_type_t type, const char *name, void *handle,
    void *data)
{
        nwamd_object_t object;
        struct nwamd_object_list *object_list = nwamd_get_object_list(type);

        object = calloc(1, sizeof (struct nwamd_object));
        if (object == NULL)
                return (NULL);

        (void) strlcpy(object->nwamd_object_name, name, NWAM_MAX_NAME_LEN);

        /* 1 for the list and 1 for the returned object */
        object->nwamd_object_refcount = 2;
        object->nwamd_object_handle = handle;
        object->nwamd_object_data = data;
        object->nwamd_object_type = type;
        object->nwamd_object_state = NWAM_STATE_INITIALIZED;
        object->nwamd_object_aux_state = NWAM_AUX_STATE_INITIALIZED;

        /* Add object to appropriate object list */
        if (nwamd_object_list_lock(type) != 0) {
                nlog(LOG_ERR, "nwamd_object_init: could not lock list to init "
                    "object %s", name);
                free(object);
                return (NULL);
        }

        if (pthread_mutex_init(&object->nwamd_object_mutex, NULL) == -1) {
                nlog(LOG_ERR, "pthread_mutex_init failed: %s",
                    strerror(errno));
                free(object);
                nwamd_object_list_unlock(type);
                return (NULL);
        }
        (void) pthread_mutex_lock(&object->nwamd_object_mutex);

        uu_list_node_init(object, &object->nwamd_object_node, object_list_pool);
        (void) uu_list_insert_after(object_list->object_list,
            uu_list_last(object_list->object_list), object);

        nwamd_object_list_unlock(type);

        return (object);
}

/*
 * Find object in object list, returning it holding a lock and with the
 * reference count incremented.  The opposite function to this is
 * nwamd_object_release().
 */
nwamd_object_t
nwamd_object_find(nwam_object_type_t type, const char *name)
{
        nwamd_object_t object;
        struct nwamd_object_list *object_list = nwamd_get_object_list(type);

        assert(name != NULL);

        if (nwamd_object_list_rlock(type) != 0)
                return (NULL);

        for (object = uu_list_first(object_list->object_list);
            object != NULL;
            object = uu_list_next(object_list->object_list, object)) {
                if (strcmp(object->nwamd_object_name, name) == 0)
                        break;
        }
        if (object != NULL) {
                (void) pthread_mutex_lock(&object->nwamd_object_mutex);
                object->nwamd_object_refcount++;
        }
        nwamd_object_list_unlock(type);

        return (object);
}

/* Removes object from list, destroy mutex, and free storage. */
static void
nwamd_object_fini(nwamd_object_t object, nwam_object_type_t objtype)
{
        nwamd_object_t o;
        struct nwamd_object_list *object_list;

        assert(object != NULL);

        object_list = nwamd_get_object_list(objtype);

        for (o = uu_list_first(object_list->object_list);
            o != NULL;
            o = uu_list_next(object_list->object_list, o)) {
                if (o == object) {
                        uu_list_remove(object_list->object_list, object);
                        (void) pthread_mutex_unlock(
                            &object->nwamd_object_mutex);
                        (void) pthread_mutex_destroy(
                            &object->nwamd_object_mutex);
                        uu_list_node_fini(object, &object->nwamd_object_node,
                            object_list_pool);
                        switch (objtype) {
                        case NWAM_OBJECT_TYPE_NCU:
                                nwamd_ncu_free(object->nwamd_object_data);
                                nwam_ncu_free(object->nwamd_object_handle);
                                break;
                        case NWAM_OBJECT_TYPE_LOC:
                                nwam_loc_free(object->nwamd_object_handle);
                                break;
                        case NWAM_OBJECT_TYPE_ENM:
                                nwam_enm_free(object->nwamd_object_handle);
                                break;
                        default:
                                nlog(LOG_ERR, "nwamd_object_fini: "
                                    "got unexpected object type %d", objtype);
                                break;
                        }
                        free(object);
                        break;
                }
        }
}

static void
nwamd_object_decref(nwamd_object_t object, int num)
{
        nwam_object_type_t objtype;

        assert(object->nwamd_object_refcount >= num);
        object->nwamd_object_refcount -= num;
        if (object->nwamd_object_refcount == 0) {
                /*
                 * We need to maintain the locking hierarchy of owning the
                 * list lock before we get the object lock when we are
                 * destroying the object.  If we merely release and then
                 * reacquire in the right order we might not find the right
                 * object.  Instead we bump the ref count so that it can't
                 * be destroyed, we drop the object lock, we acquire the
                 * list lock, we acquire the object lock, decrement the ref
                 * count, check to make sure we are really destroying it and
                 * somebody else hasn't gotten it, and then, if its unref'd,
                 * destroying it.
                 */
                object->nwamd_object_refcount++;
                objtype = object->nwamd_object_type;
                (void) pthread_mutex_unlock(&object->nwamd_object_mutex);
                (void) nwamd_object_list_lock(objtype);
                (void) pthread_mutex_lock(&object->nwamd_object_mutex);
                if (--object->nwamd_object_refcount != 0)
                        (void) pthread_mutex_unlock(
                            &object->nwamd_object_mutex);
                else
                        nwamd_object_fini(object, objtype);
                nwamd_object_list_unlock(objtype);
        } else {
                (void) pthread_mutex_unlock(&object->nwamd_object_mutex);
        }
}

/*
 * Drop mutex without decreasing reference count.  Used where we wish to
 * let go of an object but ensure it will not go away.
 */
void
nwamd_object_release_and_preserve(nwamd_object_t object)
{
        (void) pthread_mutex_unlock(&object->nwamd_object_mutex);
}

void
nwamd_object_release(nwamd_object_t object)
{
        nwamd_object_decref(object, 1);
}

void
nwamd_object_release_and_destroy(nwamd_object_t object)
{
        nwamd_object_decref(object, 2);
}

void
nwamd_object_release_and_destroy_after_preserve(nwamd_object_t object)
{
        nwamd_object_decref(object, 3);
}

void
nwamd_object_release_after_preserve(nwamd_object_t object)
{
        nwamd_object_decref(object, 2);
}

void
nwamd_object_set_state_timed(nwam_object_type_t type, const char *name,
    nwam_state_t state, nwam_aux_state_t aux_state, uint32_t when)
{
        nwamd_event_t event = nwamd_event_init_object_state(type, name,
            state, aux_state);

        nlog(LOG_INFO, "nwamd_object_set_state: state event (%s, %s) for %s",
            nwam_state_to_string(state),
            nwam_aux_state_to_string(aux_state), name);
        if (event != NULL)
                nwamd_event_enqueue_timed(event, when);
}

void
nwamd_object_set_state(nwam_object_type_t type, const char *name,
    nwam_state_t state, nwam_aux_state_t aux_state)
{
        nwamd_object_set_state_timed(type, name, state, aux_state, 0);
}

nwamd_event_method_t *
nwamd_object_event_methods(nwam_object_type_t type)
{
        struct nwamd_object_list *object_list = nwamd_get_object_list(type);

        return (object_list->object_event_methods);
}

/*
 * Walk all objects of specified type calling callback function cb.
 * Object is locked for duration of callback.
 */
int
nwamd_walk_objects(nwam_object_type_t type, int (*cb)(nwamd_object_t, void *),
    void *data)
{
        nwamd_object_t object;
        struct nwamd_object_list *object_list = nwamd_get_object_list(type);
        int ret = 0;

        if (nwamd_object_list_rlock(type) != 0)
                return (-1);

        for (object = uu_list_first(object_list->object_list);
            object != NULL;
            object = uu_list_next(object_list->object_list, object)) {
                (void) pthread_mutex_lock(&object->nwamd_object_mutex);
                ret = cb(object, data);
                (void) pthread_mutex_unlock(&object->nwamd_object_mutex);
                if (ret != 0) {
                        nwamd_object_list_unlock(type);
                        return (ret);
                }
        }
        nwamd_object_list_unlock(type);

        return (0);
}