root/net/ethtool/features.c
// SPDX-License-Identifier: GPL-2.0-only

#include <net/netdev_lock.h>

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

struct features_req_info {
        struct ethnl_req_info   base;
};

struct features_reply_data {
        struct ethnl_reply_data base;
        u32                     hw[ETHTOOL_DEV_FEATURE_WORDS];
        u32                     wanted[ETHTOOL_DEV_FEATURE_WORDS];
        u32                     active[ETHTOOL_DEV_FEATURE_WORDS];
        u32                     nochange[ETHTOOL_DEV_FEATURE_WORDS];
        u32                     all[ETHTOOL_DEV_FEATURE_WORDS];
};

#define FEATURES_REPDATA(__reply_base) \
        container_of(__reply_base, struct features_reply_data, base)

const struct nla_policy ethnl_features_get_policy[] = {
        [ETHTOOL_A_FEATURES_HEADER]     =
                NLA_POLICY_NESTED(ethnl_header_policy),
};

static void ethnl_features_to_bitmap32(u32 *dest, netdev_features_t src)
{
        unsigned int i;

        for (i = 0; i < ETHTOOL_DEV_FEATURE_WORDS; i++)
                dest[i] = src >> (32 * i);
}

static int features_prepare_data(const struct ethnl_req_info *req_base,
                                 struct ethnl_reply_data *reply_base,
                                 const struct genl_info *info)
{
        struct features_reply_data *data = FEATURES_REPDATA(reply_base);
        struct net_device *dev = reply_base->dev;
        netdev_features_t all_features;

        ethnl_features_to_bitmap32(data->hw, dev->hw_features);
        ethnl_features_to_bitmap32(data->wanted, dev->wanted_features);
        ethnl_features_to_bitmap32(data->active, dev->features);
        ethnl_features_to_bitmap32(data->nochange, NETIF_F_NEVER_CHANGE);
        all_features = GENMASK_ULL(NETDEV_FEATURE_COUNT - 1, 0);
        ethnl_features_to_bitmap32(data->all, all_features);

        return 0;
}

static int features_reply_size(const struct ethnl_req_info *req_base,
                               const struct ethnl_reply_data *reply_base)
{
        const struct features_reply_data *data = FEATURES_REPDATA(reply_base);
        bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
        unsigned int len = 0;
        int ret;

        ret = ethnl_bitset32_size(data->hw, data->all, NETDEV_FEATURE_COUNT,
                                  netdev_features_strings, compact);
        if (ret < 0)
                return ret;
        len += ret;
        ret = ethnl_bitset32_size(data->wanted, NULL, NETDEV_FEATURE_COUNT,
                                  netdev_features_strings, compact);
        if (ret < 0)
                return ret;
        len += ret;
        ret = ethnl_bitset32_size(data->active, NULL, NETDEV_FEATURE_COUNT,
                                  netdev_features_strings, compact);
        if (ret < 0)
                return ret;
        len += ret;
        ret = ethnl_bitset32_size(data->nochange, NULL, NETDEV_FEATURE_COUNT,
                                  netdev_features_strings, compact);
        if (ret < 0)
                return ret;
        len += ret;

        return len;
}

static int features_fill_reply(struct sk_buff *skb,
                               const struct ethnl_req_info *req_base,
                               const struct ethnl_reply_data *reply_base)
{
        const struct features_reply_data *data = FEATURES_REPDATA(reply_base);
        bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
        int ret;

        ret = ethnl_put_bitset32(skb, ETHTOOL_A_FEATURES_HW, data->hw,
                                 data->all, NETDEV_FEATURE_COUNT,
                                 netdev_features_strings, compact);
        if (ret < 0)
                return ret;
        ret = ethnl_put_bitset32(skb, ETHTOOL_A_FEATURES_WANTED, data->wanted,
                                 NULL, NETDEV_FEATURE_COUNT,
                                 netdev_features_strings, compact);
        if (ret < 0)
                return ret;
        ret = ethnl_put_bitset32(skb, ETHTOOL_A_FEATURES_ACTIVE, data->active,
                                 NULL, NETDEV_FEATURE_COUNT,
                                 netdev_features_strings, compact);
        if (ret < 0)
                return ret;
        return ethnl_put_bitset32(skb, ETHTOOL_A_FEATURES_NOCHANGE,
                                  data->nochange, NULL, NETDEV_FEATURE_COUNT,
                                  netdev_features_strings, compact);
}

const struct ethnl_request_ops ethnl_features_request_ops = {
        .request_cmd            = ETHTOOL_MSG_FEATURES_GET,
        .reply_cmd              = ETHTOOL_MSG_FEATURES_GET_REPLY,
        .hdr_attr               = ETHTOOL_A_FEATURES_HEADER,
        .req_info_size          = sizeof(struct features_req_info),
        .reply_data_size        = sizeof(struct features_reply_data),

        .prepare_data           = features_prepare_data,
        .reply_size             = features_reply_size,
        .fill_reply             = features_fill_reply,
};

/* FEATURES_SET */

const struct nla_policy ethnl_features_set_policy[] = {
        [ETHTOOL_A_FEATURES_HEADER]     =
                NLA_POLICY_NESTED(ethnl_header_policy),
        [ETHTOOL_A_FEATURES_WANTED]     = { .type = NLA_NESTED },
};

static void ethnl_features_to_bitmap(unsigned long *dest, netdev_features_t val)
{
        const unsigned int words = BITS_TO_LONGS(NETDEV_FEATURE_COUNT);
        unsigned int i;

        for (i = 0; i < words; i++)
                dest[i] = (unsigned long)(val >> (i * BITS_PER_LONG));
}

static netdev_features_t ethnl_bitmap_to_features(unsigned long *src)
{
        const unsigned int nft_bits = sizeof(netdev_features_t) * BITS_PER_BYTE;
        const unsigned int words = BITS_TO_LONGS(NETDEV_FEATURE_COUNT);
        netdev_features_t ret = 0;
        unsigned int i;

        for (i = 0; i < words; i++)
                ret |= (netdev_features_t)(src[i]) << (i * BITS_PER_LONG);
        ret &= ~(netdev_features_t)0 >> (nft_bits - NETDEV_FEATURE_COUNT);
        return ret;
}

static int features_send_reply(struct net_device *dev, struct genl_info *info,
                               const unsigned long *wanted,
                               const unsigned long *wanted_mask,
                               const unsigned long *active,
                               const unsigned long *active_mask, bool compact)
{
        struct sk_buff *rskb;
        void *reply_payload;
        int reply_len = 0;
        int ret;

        reply_len = ethnl_reply_header_size();
        ret = ethnl_bitset_size(wanted, wanted_mask, NETDEV_FEATURE_COUNT,
                                netdev_features_strings, compact);
        if (ret < 0)
                goto err;
        reply_len += ret;
        ret = ethnl_bitset_size(active, active_mask, NETDEV_FEATURE_COUNT,
                                netdev_features_strings, compact);
        if (ret < 0)
                goto err;
        reply_len += ret;

        ret = -ENOMEM;
        rskb = ethnl_reply_init(reply_len, dev, ETHTOOL_MSG_FEATURES_SET_REPLY,
                                ETHTOOL_A_FEATURES_HEADER, info,
                                &reply_payload);
        if (!rskb)
                goto err;

        ret = ethnl_put_bitset(rskb, ETHTOOL_A_FEATURES_WANTED, wanted,
                               wanted_mask, NETDEV_FEATURE_COUNT,
                               netdev_features_strings, compact);
        if (ret < 0)
                goto nla_put_failure;
        ret = ethnl_put_bitset(rskb, ETHTOOL_A_FEATURES_ACTIVE, active,
                               active_mask, NETDEV_FEATURE_COUNT,
                               netdev_features_strings, compact);
        if (ret < 0)
                goto nla_put_failure;

        genlmsg_end(rskb, reply_payload);
        ret = genlmsg_reply(rskb, info);
        return ret;

nla_put_failure:
        nlmsg_free(rskb);
        WARN_ONCE(1, "calculated message payload length (%d) not sufficient\n",
                  reply_len);
err:
        GENL_SET_ERR_MSG(info, "failed to send reply message");
        return ret;
}

int ethnl_set_features(struct sk_buff *skb, struct genl_info *info)
{
        DECLARE_BITMAP(wanted_diff_mask, NETDEV_FEATURE_COUNT);
        DECLARE_BITMAP(active_diff_mask, NETDEV_FEATURE_COUNT);
        DECLARE_BITMAP(old_active, NETDEV_FEATURE_COUNT);
        DECLARE_BITMAP(old_wanted, NETDEV_FEATURE_COUNT);
        DECLARE_BITMAP(new_active, NETDEV_FEATURE_COUNT);
        DECLARE_BITMAP(new_wanted, NETDEV_FEATURE_COUNT);
        DECLARE_BITMAP(req_wanted, NETDEV_FEATURE_COUNT);
        DECLARE_BITMAP(req_mask, NETDEV_FEATURE_COUNT);
        struct ethnl_req_info req_info = {};
        struct nlattr **tb = info->attrs;
        struct net_device *dev;
        bool mod;
        int ret;

        if (!tb[ETHTOOL_A_FEATURES_WANTED])
                return -EINVAL;
        ret = ethnl_parse_header_dev_get(&req_info,
                                         tb[ETHTOOL_A_FEATURES_HEADER],
                                         genl_info_net(info), info->extack,
                                         true);
        if (ret < 0)
                return ret;
        dev = req_info.dev;

        rtnl_lock();
        netdev_lock_ops(dev);
        ret = ethnl_ops_begin(dev);
        if (ret < 0)
                goto out_unlock;
        ethnl_features_to_bitmap(old_active, dev->features);
        ethnl_features_to_bitmap(old_wanted, dev->wanted_features);
        ret = ethnl_parse_bitset(req_wanted, req_mask, NETDEV_FEATURE_COUNT,
                                 tb[ETHTOOL_A_FEATURES_WANTED],
                                 netdev_features_strings, info->extack);
        if (ret < 0)
                goto out_ops;
        if (ethnl_bitmap_to_features(req_mask) & ~NETIF_F_ETHTOOL_BITS) {
                GENL_SET_ERR_MSG(info, "attempt to change non-ethtool features");
                ret = -EINVAL;
                goto out_ops;
        }

        /* set req_wanted bits not in req_mask from old_wanted */
        bitmap_and(req_wanted, req_wanted, req_mask, NETDEV_FEATURE_COUNT);
        bitmap_andnot(new_wanted, old_wanted, req_mask, NETDEV_FEATURE_COUNT);
        bitmap_or(req_wanted, new_wanted, req_wanted, NETDEV_FEATURE_COUNT);
        if (!bitmap_equal(req_wanted, old_wanted, NETDEV_FEATURE_COUNT)) {
                dev->wanted_features &= ~dev->hw_features;
                dev->wanted_features |= ethnl_bitmap_to_features(req_wanted) & dev->hw_features;
                __netdev_update_features(dev);
        }
        ethnl_features_to_bitmap(new_active, dev->features);
        mod = !bitmap_equal(old_active, new_active, NETDEV_FEATURE_COUNT);

        ret = 0;
        if (!(req_info.flags & ETHTOOL_FLAG_OMIT_REPLY)) {
                bool compact = req_info.flags & ETHTOOL_FLAG_COMPACT_BITSETS;

                bitmap_xor(wanted_diff_mask, req_wanted, new_active,
                           NETDEV_FEATURE_COUNT);
                bitmap_xor(active_diff_mask, old_active, new_active,
                           NETDEV_FEATURE_COUNT);
                bitmap_and(wanted_diff_mask, wanted_diff_mask, req_mask,
                           NETDEV_FEATURE_COUNT);
                bitmap_and(req_wanted, req_wanted, wanted_diff_mask,
                           NETDEV_FEATURE_COUNT);
                bitmap_and(new_active, new_active, active_diff_mask,
                           NETDEV_FEATURE_COUNT);

                ret = features_send_reply(dev, info, req_wanted,
                                          wanted_diff_mask, new_active,
                                          active_diff_mask, compact);
        }
        if (mod)
                netdev_features_change(dev);

out_ops:
        ethnl_ops_complete(dev);
out_unlock:
        netdev_unlock_ops(dev);
        rtnl_unlock();
        ethnl_parse_header_dev_put(&req_info);
        return ret;
}