netlink.c

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/*
 * Netlink inteface for IEEE 802.15.4 stack
 *
 * Copyright 2007, 2008 Siemens AG
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2
 * 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.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Written by:
 * Sergey Lapin <[email protected]>
 * Dmitry Eremin-Solenikov <[email protected]>
 * Maxim Osipov <[email protected]>
 */

#include <linux/kernel.h>
#include <linux/gfp.h>
#include <net/genetlink.h>
#include <linux/nl802154.h>

#include "ieee802154.h"

static unsigned int ieee802154_seq_num;
static DEFINE_SPINLOCK(ieee802154_seq_lock);

struct genl_family nl802154_family = {
    .id     = GENL_ID_GENERATE,
    .hdrsize    = 0,
    .name       = IEEE802154_NL_NAME,
    .version    = 1,
    .maxattr    = IEEE802154_ATTR_MAX,
};

/* Requests to userspace */
struct sk_buff *ieee802154_nl_create(int flags, u8 req)
{
    void *hdr;
    struct sk_buff *msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
    unsigned long f;

    if (!msg)
        return NULL;

    spin_lock_irqsave(&ieee802154_seq_lock, f);
    hdr = genlmsg_put(msg, 0, ieee802154_seq_num++,
            &nl802154_family, flags, req);
    spin_unlock_irqrestore(&ieee802154_seq_lock, f);
    if (!hdr) {
        nlmsg_free(msg);
        return NULL;
    }

    return msg;
}

int ieee802154_nl_mcast(struct sk_buff *msg, unsigned int group)
{
    /* XXX: nlh is right at the start of msg */
    void *hdr = genlmsg_data(NLMSG_DATA(msg->data));

    if (genlmsg_end(msg, hdr) < 0)
        goto out;

    return genlmsg_multicast(msg, 0, group, GFP_ATOMIC);
out:
    nlmsg_free(msg);
    return -ENOBUFS;
}

struct sk_buff *ieee802154_nl_new_reply(struct genl_info *info,
        int flags, u8 req)
{
    void *hdr;
    struct sk_buff *msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);

    if (!msg)
        return NULL;

    hdr = genlmsg_put_reply(msg, info,
            &nl802154_family, flags, req);
    if (!hdr) {
        nlmsg_free(msg);
        return NULL;
    }

    return msg;
}

int ieee802154_nl_reply(struct sk_buff *msg, struct genl_info *info)
{
    /* XXX: nlh is right at the start of msg */
    void *hdr = genlmsg_data(NLMSG_DATA(msg->data));

    if (genlmsg_end(msg, hdr) < 0)
        goto out;

    return genlmsg_reply(msg, info);
out:
    nlmsg_free(msg);
    return -ENOBUFS;
}

int __init ieee802154_nl_init(void)
{
    int rc;

    rc = genl_register_family(&nl802154_family);
    if (rc)
        goto fail;

    rc = nl802154_mac_register();
    if (rc)
        goto fail;

    rc = nl802154_phy_register();
    if (rc)
        goto fail;

    return 0;

fail:
    genl_unregister_family(&nl802154_family);
    return rc;
}

void __exit ieee802154_nl_exit(void)
{
    genl_unregister_family(&nl802154_family);
}