// 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 const struct nla_policy ethnl_header_policy[ETHTOOL_A_HEADER_MAX + 1] = {
[ETHTOOL_A_HEADER_UNSPEC] = { .type = NLA_REJECT },
[ETHTOOL_A_HEADER_DEV_INDEX] = { .type = NLA_U32 },
[ETHTOOL_A_HEADER_DEV_NAME] = { .type = NLA_NUL_STRING,
.len = ALTIFNAMSIZ - 1 },
[ETHTOOL_A_HEADER_FLAGS] = { .type = NLA_U32 },
};
/**
* ethnl_parse_header() - 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(struct ethnl_req_info *req_info,
const struct nlattr *header, struct net *net,
struct netlink_ext_ack *extack, bool require_dev)
{
struct nlattr *tb[ETHTOOL_A_HEADER_MAX + 1];
const struct nlattr *devname_attr;
struct net_device *dev = NULL;
int ret;
if (!header) {
NL_SET_ERR_MSG(extack, "request header missing");
return -EINVAL;
}
ret = nla_parse_nested(tb, ETHTOOL_A_HEADER_MAX, header,
ethnl_header_policy, extack);
if (ret < 0)
return ret;
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;
if (tb[ETHTOOL_A_HEADER_FLAGS])
req_info->flags = nla_get_u32(tb[ETHTOOL_A_HEADER_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, nest);
return -EMSGSIZE;
}
/**
* ethnl_reply_init() - Create skb for a reply and fill device identification
* @payload: payload length (without netlink and genetlink header)
* @dev: device the reply is about (may be null)
* @cmd: ETHTOOL_MSG_* message type for reply
* @info: genetlink info of the received packet we respond to
* @ehdrp: place to store payload pointer returned by genlmsg_new()
*
* Return: pointer to allocated skb on success, NULL on error
*/
struct sk_buff *ethnl_reply_init(size_t payload, struct net_device *dev, u8 cmd,
u16 hdr_attrtype, struct genl_info *info,
void **ehdrp)
{
struct sk_buff *skb;
skb = genlmsg_new(payload, GFP_KERNEL);
if (!skb)
goto err;
*ehdrp = genlmsg_put_reply(skb, info, ðtool_genl_family, 0, cmd);
if (!*ehdrp)
goto err_free;
if (dev) {
int ret;
ret = ethnl_fill_reply_header(skb, dev, hdr_attrtype);
if (ret < 0)
goto err_free;
}
return skb;
err_free:
nlmsg_free(skb);
err:
if (info)
GENL_SET_ERR_MSG(info, "failed to setup reply message");
return NULL;
}
/* notifications */
typedef void (*ethnl_notify_handler_t)(struct net_device *dev, unsigned int cmd,
const void *data);
static const ethnl_notify_handler_t ethnl_notify_handlers[] = {
};
void ethtool_notify(struct net_device *dev, unsigned int cmd, const void *data)
{
if (unlikely(!ethnl_ok))
return;
ASSERT_RTNL();
if (likely(cmd < ARRAY_SIZE(ethnl_notify_handlers) &&
ethnl_notify_handlers[cmd]))
ethnl_notify_handlers[cmd](dev, cmd, data);
else
WARN_ONCE(1, "notification %u not implemented (dev=%s)\n",
cmd, netdev_name(dev));
}
EXPORT_SYMBOL(ethtool_notify);
/* genetlink setup */
static const struct genl_ops ethtool_genl_ops[] = {
};
static const struct genl_multicast_group ethtool_nl_mcgrps[] = {
[ETHNL_MCGRP_MONITOR] = { .name = ETHTOOL_MCGRP_MONITOR_NAME },
};
static struct genl_family ethtool_genl_family = {
.name = ETHTOOL_GENL_NAME,
.version = ETHTOOL_GENL_VERSION,
.netnsok = true,
.parallel_ops = true,
.ops = ethtool_genl_ops,
.n_ops = ARRAY_SIZE(ethtool_genl_ops),
.mcgrps = ethtool_nl_mcgrps,
.n_mcgrps = ARRAY_SIZE(ethtool_nl_mcgrps),
};
/* module setup */
static int __init ethnl_init(void)
{
int ret;
ret = genl_register_family(ðtool_genl_family);
if (WARN(ret < 0, "ethtool: genetlink family registration failed"))
return ret;
ethnl_ok = true;
return 0;
}
subsys_initcall(ethnl_init);
