ubusd_obj.c

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/*
 * Copyright (C) 2011 Felix Fietkau <nbd@openwrt.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */
 
#include "ubusd.h"
#include "ubusd_obj.h"
 
struct avl_tree obj_types;
struct avl_tree objects;
struct avl_tree path;
 
static void ubus_unref_object_type(struct ubus_object_type *type)
{
        struct ubus_method *m, *tmp;
 
        if (--type->refcount > 0)
                return;
 
        list_for_each_entry_safe(m, tmp, &type->methods, list) {
                list_del(&m->list);
                free(m);
        }
 
        ubus_free_id(&obj_types, &type->id);
        free(type);
}
 
static bool ubus_create_obj_method(struct ubus_object_type *type, struct blob_attr *attr)
{
        struct ubus_method *m;
        int bloblen = blob_raw_len(attr);
 
        m = calloc(1, sizeof(*m) + bloblen);
        if (!m)
                return false;
 
        list_add_tail(&m->list, &type->methods);
        memcpy(m->data, attr, bloblen);
        m->name = blobmsg_name(m->data);
 
        return true;
}
 
static struct ubus_object_type *ubus_create_obj_type(struct blob_attr *sig)
{
        struct ubus_object_type *type;
        struct blob_attr *pos;
        size_t rem;
 
        type = calloc(1, sizeof(*type));
        if (!type)
                return NULL;
 
        type->refcount = 1;
 
        if (!ubus_alloc_id(&obj_types, &type->id, 0))
                goto error_free;
 
        INIT_LIST_HEAD(&type->methods);
 
        blob_for_each_attr(pos, sig, rem) {
                if (!blobmsg_check_attr(pos, true))
                        goto error_unref;
 
                if (!ubus_create_obj_method(type, pos))
                        goto error_unref;
        }
 
        return type;
 
error_unref:
        ubus_unref_object_type(type);
        return NULL;
 
error_free:
        free(type);
        return NULL;
}
 
static struct ubus_object_type *ubus_get_obj_type(uint32_t obj_id)
{
        struct ubus_object_type *type;
        struct ubus_id *id;
 
        id = ubus_find_id(&obj_types, obj_id);
        if (!id)
                return NULL;
 
        type = container_of(id, struct ubus_object_type, id);
        type->refcount++;
        return type;
}
 
struct ubus_object *ubusd_create_object_internal(struct ubus_object_type *type, uint32_t id)
{
        struct ubus_object *obj;
 
        obj = calloc(1, sizeof(*obj));
        if (!obj)
                return NULL;
 
        if (!ubus_alloc_id(&objects, &obj->id, id))
                goto error_free;
 
        obj->type = type;
        INIT_LIST_HEAD(&obj->list);
        INIT_LIST_HEAD(&obj->events);
        INIT_LIST_HEAD(&obj->subscribers);
        INIT_LIST_HEAD(&obj->target_list);
        if (type)
                type->refcount++;
 
        return obj;
 
error_free:
        free(obj);
        return NULL;
}
 
struct ubus_object *ubusd_create_object(struct ubus_client *cl, struct blob_attr **attr)
{
        struct ubus_object *obj;
        struct ubus_object_type *type = NULL;
 
        if (attr[UBUS_ATTR_OBJTYPE])
                type = ubus_get_obj_type(blob_get_u32(attr[UBUS_ATTR_OBJTYPE]));
        else if (attr[UBUS_ATTR_SIGNATURE])
                type = ubus_create_obj_type(attr[UBUS_ATTR_SIGNATURE]);
 
        obj = ubusd_create_object_internal(type, 0);
        if (type)
                ubus_unref_object_type(type);
 
        if (!obj)
                return NULL;
 
        if (attr[UBUS_ATTR_OBJPATH]) {
                if (ubusd_acl_check(cl, blob_data(attr[UBUS_ATTR_OBJPATH]), NULL, UBUS_ACL_PUBLISH))
                        goto free;
 
                obj->path.key = strdup(blob_data(attr[UBUS_ATTR_OBJPATH]));
                if (!obj->path.key)
                        goto free;
 
                if (avl_insert(&path, &obj->path) != 0) {
                        free((void *) obj->path.key);
                        obj->path.key = NULL;
                        goto free;
                }
                ubusd_send_obj_event(obj, true);
        }
 
        obj->client = cl;
        list_add(&obj->list, &cl->objects);
 
        return obj;
 
free:
        ubusd_free_object(obj);
        return NULL;
}
 
void ubus_subscribe(struct ubus_object *obj, struct ubus_object *target)
{
        struct ubus_subscription *s;
        bool first = list_empty(&target->subscribers);
 
        s = calloc(1, sizeof(*s));
        if (!s)
                return;
 
        s->subscriber = obj;
        s->target = target;
        list_add(&s->list, &target->subscribers);
        list_add(&s->target_list, &obj->target_list);
 
        if (first)
                ubus_notify_subscription(target);
}
 
void ubus_unsubscribe(struct ubus_subscription *s)
{
        struct ubus_object *obj = s->target;
 
        list_del(&s->list);
        list_del(&s->target_list);
        free(s);
 
        if (list_empty(&obj->subscribers))
                ubus_notify_subscription(obj);
}
 
void ubusd_free_object(struct ubus_object *obj)
{
        struct ubus_subscription *s, *tmp;
 
        list_for_each_entry_safe(s, tmp, &obj->target_list, target_list) {
                ubus_unsubscribe(s);
        }
        list_for_each_entry_safe(s, tmp, &obj->subscribers, list) {
                ubus_notify_unsubscribe(s);
        }
 
        ubusd_event_cleanup_object(obj);
        if (obj->path.key) {
                ubusd_send_obj_event(obj, false);
                avl_delete(&path, &obj->path);
                free((void *) obj->path.key);
        }
        if (!list_empty(&obj->list))
                list_del(&obj->list);
        ubus_free_id(&objects, &obj->id);
        if (obj->type)
                ubus_unref_object_type(obj->type);
        free(obj);
}
 
static void __constructor ubusd_obj_init(void)
{
        ubus_init_id_tree(&objects);
        ubus_init_id_tree(&obj_types);
        ubus_init_string_tree(&path, false);
        ubusd_event_init();
        ubusd_acl_init();
        ubusd_monitor_init();
}