ubusd_monitor.c

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/*
 * Copyright (C) 2015 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"
 
static struct ubus_object *monitor_obj;
static LIST_HEAD(monitors);
 
struct ubus_monitor {
        struct list_head list;
        struct ubus_client *cl;
        uint32_t seq;
};
 
static void
ubusd_monitor_free(struct ubus_monitor *m)
{
        list_del(&m->list);
        free(m);
}
 
static bool
ubusd_monitor_connect(struct ubus_client *cl, struct ubus_msg_buf *ub)
{
        struct ubus_monitor *m;
 
        ubusd_monitor_disconnect(cl);
 
        m = calloc(1, sizeof(*m));
        if (!m)
                return false;
 
        m->cl = cl;
        list_add_tail(&m->list, &monitors);
 
        return true;
}
 
static struct ubus_monitor*
ubusd_monitor_find(struct ubus_client *cl)
{
        struct ubus_monitor *m, *tmp;
 
        list_for_each_entry_safe(m, tmp, &monitors, list) {
                if (m->cl != cl)
                        continue;
 
                return m;
        }
 
        return NULL;
}
 
void
ubusd_monitor_disconnect(struct ubus_client *cl)
{
        struct ubus_monitor *m;
 
        m = ubusd_monitor_find(cl);
        if (!m)
                return;
 
        ubusd_monitor_free(m);
}
 
void
ubusd_monitor_message(struct ubus_client *cl, struct ubus_msg_buf *ub, bool send)
{
        static struct blob_buf mb;
        struct ubus_monitor *m;
 
        if (list_empty(&monitors))
                return;
 
        blob_buf_init(&mb, 0);
        blob_put_int32(&mb, UBUS_MONITOR_CLIENT, cl->id.id);
        blob_put_int32(&mb, UBUS_MONITOR_PEER, ub->hdr.peer);
        blob_put_int32(&mb, UBUS_MONITOR_SEQ, ub->hdr.seq);
        blob_put_int32(&mb, UBUS_MONITOR_TYPE, ub->hdr.type);
        blob_put_int8(&mb, UBUS_MONITOR_SEND, send);
        blob_put(&mb, UBUS_MONITOR_DATA, blob_data(ub->data), blob_len(ub->data));
 
        ub = ubus_msg_new(mb.head, blob_raw_len(mb.head), true);
        ub->hdr.type = UBUS_MSG_MONITOR;
 
        list_for_each_entry(m, &monitors, list) {
                ub->hdr.seq = ++m->seq;
                ubus_msg_send(m->cl, ub);
        }
 
        ubus_msg_free(ub);
}
 
static int
ubusd_monitor_recv(struct ubus_client *cl, struct ubus_msg_buf *ub,
                   const char *method, struct blob_attr *msg)
{
        /* Only root is allowed for now */
        if (cl->uid != 0 || cl->gid != 0)
                return UBUS_STATUS_PERMISSION_DENIED;
 
        if (!strcmp(method, "add")) {
                if (!ubusd_monitor_connect(cl, ub))
                        return UBUS_STATUS_UNKNOWN_ERROR;
 
                return UBUS_STATUS_OK;
        }
 
        if (!strcmp(method, "remove")) {
                ubusd_monitor_disconnect(cl);
                return UBUS_STATUS_OK;
        }
 
        return UBUS_STATUS_METHOD_NOT_FOUND;
}
 
void
ubusd_monitor_init(void)
{
        monitor_obj = ubusd_create_object_internal(NULL, UBUS_SYSTEM_OBJECT_MONITOR);
        if (monitor_obj != NULL)
                monitor_obj->recv_msg = ubusd_monitor_recv;
}