// SPDX-License-Identifier: GPL-2.0-only
/*
 * Netlink interface for IEEE 802.15.4 stack
 *
 * Copyright 2007, 2008 Siemens AG
 *
 * Written by:
 * Sergey Lapin <slapin@ossfans.org>
 * Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
 * Maxim Osipov <maxim.osipov@siemens.com>
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/if_arp.h>
#include <net/netlink.h>
#include <net/genetlink.h>
#include <net/cfg802154.h>
#include <net/af_ieee802154.h>
#include <net/ieee802154_netdev.h>
#include <net/rtnetlink.h> /* for rtnl_{un,}lock */
#include <linux/nl802154.h>

#include "ieee802154.h"
#include "rdev-ops.h"
#include "core.h"

static int ieee802154_nl_fill_phy(struct sk_buff *msg, u32 portid,
                                  u32 seq, int flags, struct wpan_phy *phy)
{
        void *hdr;
        int i, pages = 0;
        u32 *buf = kcalloc(IEEE802154_MAX_PAGE + 1, sizeof(u32), GFP_KERNEL);

        pr_debug("%s\n", __func__);

        if (!buf)
                return -EMSGSIZE;

        hdr = genlmsg_put(msg, 0, seq, &nl802154_family, flags,
                          IEEE802154_LIST_PHY);
        if (!hdr)
                goto out;

        rtnl_lock();
        if (nla_put_string(msg, IEEE802154_ATTR_PHY_NAME, wpan_phy_name(phy)) ||
            nla_put_u8(msg, IEEE802154_ATTR_PAGE, phy->current_page) ||
            nla_put_u8(msg, IEEE802154_ATTR_CHANNEL, phy->current_channel))
                goto nla_put_failure;
        for (i = 0; i <= IEEE802154_MAX_PAGE; i++) {
                if (phy->supported.channels[i])
                        buf[pages++] = phy->supported.channels[i] | (i << 27);
        }
        if (pages &&
            nla_put(msg, IEEE802154_ATTR_CHANNEL_PAGE_LIST,
                    pages * sizeof(uint32_t), buf))
                goto nla_put_failure;
        rtnl_unlock();
        kfree(buf);
        genlmsg_end(msg, hdr);
        return 0;

nla_put_failure:
        rtnl_unlock();
        genlmsg_cancel(msg, hdr);
out:
        kfree(buf);
        return -EMSGSIZE;
}

int ieee802154_list_phy(struct sk_buff *skb, struct genl_info *info)
{
        /* Request for interface name, index, type, IEEE address,
         * PAN Id, short address
         */
        struct sk_buff *msg;
        struct wpan_phy *phy;
        const char *name;
        int rc = -ENOBUFS;

        pr_debug("%s\n", __func__);

        if (!info->attrs[IEEE802154_ATTR_PHY_NAME])
                return -EINVAL;

        name = nla_data(info->attrs[IEEE802154_ATTR_PHY_NAME]);
        if (name[nla_len(info->attrs[IEEE802154_ATTR_PHY_NAME]) - 1] != '\0')
                return -EINVAL; /* phy name should be null-terminated */

        phy = wpan_phy_find(name);
        if (!phy)
                return -ENODEV;

        msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
        if (!msg)
                goto out_dev;

        rc = ieee802154_nl_fill_phy(msg, info->snd_portid, info->snd_seq,
                                    0, phy);
        if (rc < 0)
                goto out_free;

        wpan_phy_put(phy);

        return genlmsg_reply(msg, info);
out_free:
        nlmsg_free(msg);
out_dev:
        wpan_phy_put(phy);
        return rc;
}

struct dump_phy_data {
        struct sk_buff *skb;
        struct netlink_callback *cb;
        int idx, s_idx;
};

static int ieee802154_dump_phy_iter(struct wpan_phy *phy, void *_data)
{
        int rc;
        struct dump_phy_data *data = _data;

        pr_debug("%s\n", __func__);

        if (data->idx++ < data->s_idx)
                return 0;

        rc = ieee802154_nl_fill_phy(data->skb,
                                    NETLINK_CB(data->cb->skb).portid,
                                    data->cb->nlh->nlmsg_seq,
                                    NLM_F_MULTI,
                                    phy);

        if (rc < 0) {
                data->idx--;
                return rc;
        }

        return 0;
}

int ieee802154_dump_phy(struct sk_buff *skb, struct netlink_callback *cb)
{
        struct dump_phy_data data = {
                .cb = cb,
                .skb = skb,
                .s_idx = cb->args[0],
                .idx = 0,
        };

        pr_debug("%s\n", __func__);

        wpan_phy_for_each(ieee802154_dump_phy_iter, &data);

        cb->args[0] = data.idx;

        return skb->len;
}

int ieee802154_add_iface(struct sk_buff *skb, struct genl_info *info)
{
        struct sk_buff *msg;
        struct wpan_phy *phy;
        const char *name;
        const char *devname;
        int rc = -ENOBUFS;
        struct net_device *dev;
        int type = __IEEE802154_DEV_INVALID;
        unsigned char name_assign_type;

        pr_debug("%s\n", __func__);

        if (!info->attrs[IEEE802154_ATTR_PHY_NAME])
                return -EINVAL;

        name = nla_data(info->attrs[IEEE802154_ATTR_PHY_NAME]);
        if (name[nla_len(info->attrs[IEEE802154_ATTR_PHY_NAME]) - 1] != '\0')
                return -EINVAL; /* phy name should be null-terminated */

        if (info->attrs[IEEE802154_ATTR_DEV_NAME]) {
                devname = nla_data(info->attrs[IEEE802154_ATTR_DEV_NAME]);
                if (devname[nla_len(info->attrs[IEEE802154_ATTR_DEV_NAME]) - 1]
                                != '\0')
                        return -EINVAL; /* phy name should be null-terminated */
                name_assign_type = NET_NAME_USER;
        } else  {
                devname = "wpan%d";
                name_assign_type = NET_NAME_ENUM;
        }

        if (strlen(devname) >= IFNAMSIZ)
                return -ENAMETOOLONG;

        phy = wpan_phy_find(name);
        if (!phy)
                return -ENODEV;

        msg = ieee802154_nl_new_reply(info, 0, IEEE802154_ADD_IFACE);
        if (!msg)
                goto out_dev;

        if (info->attrs[IEEE802154_ATTR_HW_ADDR] &&
            nla_len(info->attrs[IEEE802154_ATTR_HW_ADDR]) !=
                        IEEE802154_ADDR_LEN) {
                rc = -EINVAL;
                goto nla_put_failure;
        }

        if (info->attrs[IEEE802154_ATTR_DEV_TYPE]) {
                type = nla_get_u8(info->attrs[IEEE802154_ATTR_DEV_TYPE]);
                if (type >= __IEEE802154_DEV_MAX) {
                        rc = -EINVAL;
                        goto nla_put_failure;
                }
        }

        dev = rdev_add_virtual_intf_deprecated(wpan_phy_to_rdev(phy), devname,
                                               name_assign_type, type);
        if (IS_ERR(dev)) {
                rc = PTR_ERR(dev);
                goto nla_put_failure;
        }
        dev_hold(dev);

        if (info->attrs[IEEE802154_ATTR_HW_ADDR]) {
                struct sockaddr_storage addr;

                addr.ss_family = ARPHRD_IEEE802154;
                nla_memcpy(&addr.__data, info->attrs[IEEE802154_ATTR_HW_ADDR],
                           IEEE802154_ADDR_LEN);

                /* strangely enough, some callbacks (inetdev_event) from
                 * dev_set_mac_address require RTNL_LOCK
                 */
                rtnl_lock();
                rc = dev_set_mac_address(dev, &addr, NULL);
                rtnl_unlock();
                if (rc)
                        goto dev_unregister;
        }

        if (nla_put_string(msg, IEEE802154_ATTR_PHY_NAME, wpan_phy_name(phy)) ||
            nla_put_string(msg, IEEE802154_ATTR_DEV_NAME, dev->name)) {
                rc = -EMSGSIZE;
                goto nla_put_failure;
        }
        dev_put(dev);

        wpan_phy_put(phy);

        return ieee802154_nl_reply(msg, info);

dev_unregister:
        rtnl_lock(); /* del_iface must be called with RTNL lock */
        rdev_del_virtual_intf_deprecated(wpan_phy_to_rdev(phy), dev);
        dev_put(dev);
        rtnl_unlock();
nla_put_failure:
        nlmsg_free(msg);
out_dev:
        wpan_phy_put(phy);
        return rc;
}

int ieee802154_del_iface(struct sk_buff *skb, struct genl_info *info)
{
        struct sk_buff *msg;
        struct wpan_phy *phy;
        const char *name;
        int rc;
        struct net_device *dev;

        pr_debug("%s\n", __func__);

        if (!info->attrs[IEEE802154_ATTR_DEV_NAME])
                return -EINVAL;

        name = nla_data(info->attrs[IEEE802154_ATTR_DEV_NAME]);
        if (name[nla_len(info->attrs[IEEE802154_ATTR_DEV_NAME]) - 1] != '\0')
                return -EINVAL; /* name should be null-terminated */

        rc = -ENODEV;
        dev = dev_get_by_name(genl_info_net(info), name);
        if (!dev)
                return rc;
        if (dev->type != ARPHRD_IEEE802154)
                goto out;

        phy = dev->ieee802154_ptr->wpan_phy;
        BUG_ON(!phy);
        get_device(&phy->dev);

        rc = -EINVAL;
        /* phy name is optional, but should be checked if it's given */
        if (info->attrs[IEEE802154_ATTR_PHY_NAME]) {
                struct wpan_phy *phy2;

                const char *pname =
                        nla_data(info->attrs[IEEE802154_ATTR_PHY_NAME]);
                if (pname[nla_len(info->attrs[IEEE802154_ATTR_PHY_NAME]) - 1]
                                != '\0')
                        /* name should be null-terminated */
                        goto out_dev;

                phy2 = wpan_phy_find(pname);
                if (!phy2)
                        goto out_dev;

                if (phy != phy2) {
                        wpan_phy_put(phy2);
                        goto out_dev;
                }
        }

        rc = -ENOBUFS;

        msg = ieee802154_nl_new_reply(info, 0, IEEE802154_DEL_IFACE);
        if (!msg)
                goto out_dev;

        rtnl_lock();
        rdev_del_virtual_intf_deprecated(wpan_phy_to_rdev(phy), dev);

        /* We don't have device anymore */
        dev_put(dev);
        dev = NULL;

        rtnl_unlock();

        if (nla_put_string(msg, IEEE802154_ATTR_PHY_NAME, wpan_phy_name(phy)) ||
            nla_put_string(msg, IEEE802154_ATTR_DEV_NAME, name))
                goto nla_put_failure;
        wpan_phy_put(phy);

        return ieee802154_nl_reply(msg, info);

nla_put_failure:
        nlmsg_free(msg);
out_dev:
        wpan_phy_put(phy);
out:
        dev_put(dev);

        return rc;
}