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;
}