path: root/net/ethtool/netlink.c

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

#include <net/sock.h>
#include <linux/ethtool_netlink.h>
#include "netlink.h"

static struct genl_family ethtool_genl_family;

static bool ethnl_ok __read_mostly;
static u32 ethnl_bcast_seq;

#define ETHTOOL_FLAGS_BASIC (ETHTOOL_FLAG_COMPACT_BITSETS |	\
			     ETHTOOL_FLAG_OMIT_REPLY)
#define ETHTOOL_FLAGS_STATS (ETHTOOL_FLAGS_BASIC | ETHTOOL_FLAG_STATS)

const struct nla_policy ethnl_header_policy[] = {
	[ETHTOOL_A_HEADER_DEV_INDEX]	= { .type = NLA_U32 },
	[ETHTOOL_A_HEADER_DEV_NAME]	= { .type = NLA_NUL_STRING,
					    .len = ALTIFNAMSIZ - 1 },
	[ETHTOOL_A_HEADER_FLAGS]	= NLA_POLICY_MASK(NLA_U32,
							  ETHTOOL_FLAGS_BASIC),
};

const struct nla_policy ethnl_header_policy_stats[] = {
	[ETHTOOL_A_HEADER_DEV_INDEX]	= { .type = NLA_U32 },
	[ETHTOOL_A_HEADER_DEV_NAME]	= { .type = NLA_NUL_STRING,
					    .len = ALTIFNAMSIZ - 1 },
	[ETHTOOL_A_HEADER_FLAGS]	= NLA_POLICY_MASK(NLA_U32,
							  ETHTOOL_FLAGS_STATS),
};

/**
 * ethnl_parse_header_dev_get() - parse request header
 * @req_info:    structure to put results into
 * @header:      nest attribute with request header
 * @net:         request netns
 * @extack:      netlink extack for error reporting
 * @require_dev: fail if no device identified in header
 *
 * Parse request header in nested attribute @nest and puts results into
 * the structure pointed to by @req_info. Extack from @info is used for error
 * reporting. If req_info->dev is not null on return, reference to it has
 * been taken. If error is returned, *req_info is null initialized and no
 * reference is held.
 *
 * Return: 0 on success or negative error code
 */
int ethnl_parse_header_dev_get(struct ethnl_req_info *req_info,
			       const struct nlattr *header, struct net *net,
			       struct netlink_ext_ack *extack, bool require_dev)
{
	struct nlattr *tb[ARRAY_SIZE(ethnl_header_policy)];
	const struct nlattr *devname_attr;
	struct net_device *dev = NULL;
	u32 flags = 0;
	int ret;

	if (!header) {
		NL_SET_ERR_MSG(extack, "request header missing");
		return -EINVAL;
	}
	/* No validation here, command policy should have a nested policy set
	 * for the header, therefore validation should have already been done.
	 */
	ret = nla_parse_nested(tb, ARRAY_SIZE(ethnl_header_policy) - 1, header,
			       NULL, extack);
	if (ret < 0)
		return ret;
	if (tb[ETHTOOL_A_HEADER_FLAGS])
		flags = nla_get_u32(tb[ETHTOOL_A_HEADER_FLAGS]);

	devname_attr = tb[ETHTOOL_A_HEADER_DEV_NAME];
	if (tb[ETHTOOL_A_HEADER_DEV_INDEX]) {
		u32 ifindex = nla_get_u32(tb[ETHTOOL_A_HEADER_DEV_INDEX]);

		dev = dev_get_by_index(net, ifindex);
		if (!dev) {
			NL_SET_ERR_MSG_ATTR(extack,
					    tb[ETHTOOL_A_HEADER_DEV_INDEX],
					    "no device matches ifindex");
			return -ENODEV;
		}
		/* if both ifindex and ifname are passed, they must match */
		if (devname_attr &&
		    strncmp(dev->name, nla_data(devname_attr), IFNAMSIZ)) {
			dev_put(dev);
			NL_SET_ERR_MSG_ATTR(extack, header,
					    "ifindex and name do not match");
			return -ENODEV;
		}
	} else if (devname_attr) {
		dev = dev_get_by_name(net, nla_data(devname_attr));
		if (!dev) {
			NL_SET_ERR_MSG_ATTR(extack, devname_attr,
					    "no device matches name");
			return -ENODEV;
		}
	} else if (require_dev) {
		NL_SET_ERR_MSG_ATTR(extack, header,
				    "neither ifindex nor name specified");
		return -EINVAL;
	}

	if (dev && !netif_device_present(dev)) {
		dev_put(dev);
		NL_SET_ERR_MSG(extack, "device not present");
		return -ENODEV;
	}

	req_info->dev = dev;
	req_info->flags = flags;
	return 0;
}

/**
 * ethnl_fill_reply_header() - Put common header into a reply message
 * @skb:      skb with the message
 * @dev:      network device to describe in header
 * @attrtype: attribute type to use for the nest
 *
 * Create a nested attribute with attributes describing given network device.
 *
 * Return: 0 on success, error value (-EMSGSIZE only) on error
 */
int ethnl_fill_reply_header(struct sk_buff *skb, struct net_device *dev,
			    u16 attrtype)
{
	struct nlattr *nest;

	if (!dev)
		return 0;
	nest = nla_nest_start(skb, attrtype);
	if (!nest)
		return -EMSGSIZE;

	if (nla_put_u32(skb, ETHTOOL_A_HEADER_DEV_INDEX, (u32)dev->ifindex) ||
	    nla_put_string(skb, ETHTOOL_A_HEADER_DEV_NAME, dev->name))
		goto nla_put_failure;
	/* If more attributes are put into reply header, ethnl_header_size()
	 * must be updated to account for them.
	 */

	nla_nest_end(skb, nest);
	return 0;

nla_put_failure:
	nla_nest_cancel(skb,</