// SPDX-License-Identifier: GPL-2.0-only

#include "netlink.h"
#include "common.h"
#include "bitset.h"

struct privflags_req_info {
        struct ethnl_req_info           base;
};

struct privflags_reply_data {
        struct ethnl_reply_data         base;
        const char                      (*priv_flag_names)[ETH_GSTRING_LEN];
        unsigned int                    n_priv_flags;
        u32                             priv_flags;
};

#define PRIVFLAGS_REPDATA(__reply_base) \
        container_of(__reply_base, struct privflags_reply_data, base)

const struct nla_policy ethnl_privflags_get_policy[] = {
        [ETHTOOL_A_PRIVFLAGS_HEADER]            =
                NLA_POLICY_NESTED(ethnl_header_policy),
};

static int ethnl_get_priv_flags_info(struct net_device *dev,
                                     unsigned int *count,
                                     const char (**names)[ETH_GSTRING_LEN])
{
        const struct ethtool_ops *ops = dev->ethtool_ops;
        int nflags;

        nflags = ops->get_sset_count(dev, ETH_SS_PRIV_FLAGS);
        if (nflags < 0)
                return nflags;

        if (names) {
                *names = kcalloc(nflags, ETH_GSTRING_LEN, GFP_KERNEL);
                if (!*names)
                        return -ENOMEM;
                ops->get_strings(dev, ETH_SS_PRIV_FLAGS, (u8 *)*names);
        }

        /* We can pass more than 32 private flags to userspace via netlink but
         * we cannot get more with ethtool_ops::get_priv_flags(). Note that we
         * must not adjust nflags before allocating the space for flag names
         * as the buffer must be large enough for all flags.
         */
        if (WARN_ONCE(nflags > 32,
                      "device %s reports more than 32 private flags (%d)\n",
                      netdev_name(dev), nflags))
                nflags = 32;
        *count = nflags;

        return 0;
}

static int privflags_prepare_data(const struct ethnl_req_info *req_base,
                                  struct ethnl_reply_data *reply_base,
                                  const struct genl_info *info)
{
        struct privflags_reply_data *data = PRIVFLAGS_REPDATA(reply_base);
        struct net_device *dev = reply_base->dev;
        const char (*names)[ETH_GSTRING_LEN];
        const struct ethtool_ops *ops;
        unsigned int nflags;
        int ret;

        ops = dev->ethtool_ops;
        if (!ops->get_priv_flags || !ops->get_sset_count || !ops->get_strings)
                return -EOPNOTSUPP;
        ret = ethnl_ops_begin(dev);
        if (ret < 0)
                return ret;

        ret = ethnl_get_priv_flags_info(dev, &nflags, &names);
        if (ret < 0)
                goto out_ops;
        data->priv_flags = ops->get_priv_flags(dev);
        data->priv_flag_names = names;
        data->n_priv_flags = nflags;

out_ops:
        ethnl_ops_complete(dev);
        return ret;
}

static int privflags_reply_size(const struct ethnl_req_info *req_base,
                                const struct ethnl_reply_data *reply_base)
{
        const struct privflags_reply_data *data = PRIVFLAGS_REPDATA(reply_base);
        bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
        const u32 all_flags = ~(u32)0 >> (32 - data->n_priv_flags);

        return ethnl_bitset32_size(&data->priv_flags, &all_flags,
                                   data->n_priv_flags,
                                   data->priv_flag_names, compact);
}

static int privflags_fill_reply(struct sk_buff *skb,
                                const struct ethnl_req_info *req_base,
                                const struct ethnl_reply_data *reply_base)
{
        const struct privflags_reply_data *data = PRIVFLAGS_REPDATA(reply_base);
        bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
        const u32 all_flags = ~(u32)0 >> (32 - data->n_priv_flags);

        return ethnl_put_bitset32(skb, ETHTOOL_A_PRIVFLAGS_FLAGS,
                                  &data->priv_flags, &all_flags,
                                  data->n_priv_flags, data->priv_flag_names,
                                  compact);
}

static void privflags_cleanup_data(struct ethnl_reply_data *reply_data)
{
        struct privflags_reply_data *data = PRIVFLAGS_REPDATA(reply_data);

        kfree(data->priv_flag_names);
}

/* PRIVFLAGS_SET */

const struct nla_policy ethnl_privflags_set_policy[] = {
        [ETHTOOL_A_PRIVFLAGS_HEADER]            =
                NLA_POLICY_NESTED(ethnl_header_policy),
        [ETHTOOL_A_PRIVFLAGS_FLAGS]             = { .type = NLA_NESTED },
};

static int
ethnl_set_privflags_validate(struct ethnl_req_info *req_info,
                             struct genl_info *info)
{
        const struct ethtool_ops *ops = req_info->dev->ethtool_ops;

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

        if (!ops->get_priv_flags || !ops->set_priv_flags ||
            !ops->get_sset_count || !ops->get_strings)
                return -EOPNOTSUPP;
        return 1;
}

static int
ethnl_set_privflags(struct ethnl_req_info *req_info, struct genl_info *info)
{
        const char (*names)[ETH_GSTRING_LEN] = NULL;
        struct net_device *dev = req_info->dev;
        struct nlattr **tb = info->attrs;
        unsigned int nflags;
        bool mod = false;
        bool compact;
        u32 flags;
        int ret;

        ret = ethnl_bitset_is_compact(tb[ETHTOOL_A_PRIVFLAGS_FLAGS], &compact);
        if (ret < 0)
                return ret;

        ret = ethnl_get_priv_flags_info(dev, &nflags, compact ? NULL : &names);
        if (ret < 0)
                return ret;
        flags = dev->ethtool_ops->get_priv_flags(dev);

        ret = ethnl_update_bitset32(&flags, nflags,
                                    tb[ETHTOOL_A_PRIVFLAGS_FLAGS], names,
                                    info->extack, &mod);
        if (ret < 0 || !mod)
                goto out_free;
        ret = dev->ethtool_ops->set_priv_flags(dev, flags);
        if (ret < 0)
                goto out_free;
        ret = 1;

out_free:
        kfree(names);
        return ret;
}

const struct ethnl_request_ops ethnl_privflags_request_ops = {
        .request_cmd            = ETHTOOL_MSG_PRIVFLAGS_GET,
        .reply_cmd              = ETHTOOL_MSG_PRIVFLAGS_GET_REPLY,
        .hdr_attr               = ETHTOOL_A_PRIVFLAGS_HEADER,
        .req_info_size          = sizeof(struct privflags_req_info),
        .reply_data_size        = sizeof(struct privflags_reply_data),

        .prepare_data           = privflags_prepare_data,
        .reply_size             = privflags_reply_size,
        .fill_reply             = privflags_fill_reply,
        .cleanup_data           = privflags_cleanup_data,

        .set_validate           = ethnl_set_privflags_validate,
        .set                    = ethnl_set_privflags,
        .set_ntf_cmd            = ETHTOOL_MSG_PRIVFLAGS_NTF,
};