ethtool: helper functions for netlink interface
Add common request/reply header definition and helpers to parse request header and fill reply header. Provide ethnl_update_* helpers to update structure members from request attributes (to be used for *_SET requests). Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Michal Kubecek
David S. Miller
parent
2b4a8990b7
commit
041b1c5d4a
@ -29,6 +29,27 @@ enum {
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ETHTOOL_MSG_KERNEL_MAX = __ETHTOOL_MSG_KERNEL_CNT - 1
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ETHTOOL_MSG_KERNEL_MAX = __ETHTOOL_MSG_KERNEL_CNT - 1
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};
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};
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/* request header */
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/* use compact bitsets in reply */
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#define ETHTOOL_FLAG_COMPACT_BITSETS (1 << 0)
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/* provide optional reply for SET or ACT requests */
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#define ETHTOOL_FLAG_OMIT_REPLY (1 << 1)
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#define ETHTOOL_FLAG_ALL (ETHTOOL_FLAG_COMPACT_BITSETS | \
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ETHTOOL_FLAG_OMIT_REPLY)
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enum {
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ETHTOOL_A_HEADER_UNSPEC,
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ETHTOOL_A_HEADER_DEV_INDEX, /* u32 */
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ETHTOOL_A_HEADER_DEV_NAME, /* string */
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ETHTOOL_A_HEADER_FLAGS, /* u32 - ETHTOOL_FLAG_* */
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/* add new constants above here */
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__ETHTOOL_A_HEADER_CNT,
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ETHTOOL_A_HEADER_MAX = __ETHTOOL_A_HEADER_CNT - 1
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};
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/* generic netlink info */
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/* generic netlink info */
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#define ETHTOOL_GENL_NAME "ethtool"
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#define ETHTOOL_GENL_NAME "ethtool"
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#define ETHTOOL_GENL_VERSION 1
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#define ETHTOOL_GENL_VERSION 1
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@ -1,8 +1,174 @@
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// SPDX-License-Identifier: GPL-2.0-only
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// SPDX-License-Identifier: GPL-2.0-only
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#include <net/sock.h>
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#include <linux/ethtool_netlink.h>
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#include <linux/ethtool_netlink.h>
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#include "netlink.h"
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#include "netlink.h"
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static struct genl_family ethtool_genl_family;
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static const struct nla_policy ethnl_header_policy[ETHTOOL_A_HEADER_MAX + 1] = {
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[ETHTOOL_A_HEADER_UNSPEC] = { .type = NLA_REJECT },
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[ETHTOOL_A_HEADER_DEV_INDEX] = { .type = NLA_U32 },
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[ETHTOOL_A_HEADER_DEV_NAME] = { .type = NLA_NUL_STRING,
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.len = ALTIFNAMSIZ - 1 },
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[ETHTOOL_A_HEADER_FLAGS] = { .type = NLA_U32 },
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};
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/**
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* ethnl_parse_header() - parse request header
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* @req_info: structure to put results into
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* @header: nest attribute with request header
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* @net: request netns
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* @extack: netlink extack for error reporting
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* @require_dev: fail if no device identified in header
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*
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* Parse request header in nested attribute @nest and puts results into
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* the structure pointed to by @req_info. Extack from @info is used for error
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* reporting. If req_info->dev is not null on return, reference to it has
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* been taken. If error is returned, *req_info is null initialized and no
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* reference is held.
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*
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* Return: 0 on success or negative error code
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*/
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int ethnl_parse_header(struct ethnl_req_info *req_info,
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const struct nlattr *header, struct net *net,
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struct netlink_ext_ack *extack, bool require_dev)
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{
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struct nlattr *tb[ETHTOOL_A_HEADER_MAX + 1];
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const struct nlattr *devname_attr;
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struct net_device *dev = NULL;
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int ret;
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if (!header) {
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NL_SET_ERR_MSG(extack, "request header missing");
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return -EINVAL;
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}
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ret = nla_parse_nested(tb, ETHTOOL_A_HEADER_MAX, header,
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ethnl_header_policy, extack);
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if (ret < 0)
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return ret;
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devname_attr = tb[ETHTOOL_A_HEADER_DEV_NAME];
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if (tb[ETHTOOL_A_HEADER_DEV_INDEX]) {
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u32 ifindex = nla_get_u32(tb[ETHTOOL_A_HEADER_DEV_INDEX]);
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dev = dev_get_by_index(net, ifindex);
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if (!dev) {
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NL_SET_ERR_MSG_ATTR(extack,
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tb[ETHTOOL_A_HEADER_DEV_INDEX],
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"no device matches ifindex");
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return -ENODEV;
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}
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/* if both ifindex and ifname are passed, they must match */
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if (devname_attr &&
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strncmp(dev->name, nla_data(devname_attr), IFNAMSIZ)) {
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dev_put(dev);
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NL_SET_ERR_MSG_ATTR(extack, header,
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"ifindex and name do not match");
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return -ENODEV;
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}
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} else if (devname_attr) {
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dev = dev_get_by_name(net, nla_data(devname_attr));
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if (!dev) {
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NL_SET_ERR_MSG_ATTR(extack, devname_attr,
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"no device matches name");
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return -ENODEV;
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}
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} else if (require_dev) {
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NL_SET_ERR_MSG_ATTR(extack, header,
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"neither ifindex nor name specified");
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return -EINVAL;
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}
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if (dev && !netif_device_present(dev)) {
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dev_put(dev);
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NL_SET_ERR_MSG(extack, "device not present");
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return -ENODEV;
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}
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req_info->dev = dev;
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if (tb[ETHTOOL_A_HEADER_FLAGS])
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req_info->flags = nla_get_u32(tb[ETHTOOL_A_HEADER_FLAGS]);
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return 0;
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}
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/**
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* ethnl_fill_reply_header() - Put common header into a reply message
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* @skb: skb with the message
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* @dev: network device to describe in header
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* @attrtype: attribute type to use for the nest
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*
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* Create a nested attribute with attributes describing given network device.
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*
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* Return: 0 on success, error value (-EMSGSIZE only) on error
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*/
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int ethnl_fill_reply_header(struct sk_buff *skb, struct net_device *dev,
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u16 attrtype)
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{
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struct nlattr *nest;
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if (!dev)
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return 0;
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nest = nla_nest_start(skb, attrtype);
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if (!nest)
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return -EMSGSIZE;
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if (nla_put_u32(skb, ETHTOOL_A_HEADER_DEV_INDEX, (u32)dev->ifindex) ||
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nla_put_string(skb, ETHTOOL_A_HEADER_DEV_NAME, dev->name))
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goto nla_put_failure;
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/* If more attributes are put into reply header, ethnl_header_size()
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* must be updated to account for them.
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*/
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nla_nest_end(skb, nest);
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return 0;
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nla_put_failure:
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nla_nest_cancel(skb, nest);
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return -EMSGSIZE;
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}
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/**
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* ethnl_reply_init() - Create skb for a reply and fill device identification
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* @payload: payload length (without netlink and genetlink header)
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* @dev: device the reply is about (may be null)
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* @cmd: ETHTOOL_MSG_* message type for reply
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* @info: genetlink info of the received packet we respond to
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* @ehdrp: place to store payload pointer returned by genlmsg_new()
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*
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* Return: pointer to allocated skb on success, NULL on error
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*/
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struct sk_buff *ethnl_reply_init(size_t payload, struct net_device *dev, u8 cmd,
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u16 hdr_attrtype, struct genl_info *info,
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void **ehdrp)
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{
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struct sk_buff *skb;
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skb = genlmsg_new(payload, GFP_KERNEL);
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if (!skb)
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goto err;
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*ehdrp = genlmsg_put_reply(skb, info, ðtool_genl_family, 0, cmd);
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if (!*ehdrp)
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goto err_free;
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if (dev) {
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int ret;
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ret = ethnl_fill_reply_header(skb, dev, hdr_attrtype);
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if (ret < 0)
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goto err_free;
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}
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return skb;
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err_free:
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nlmsg_free(skb);
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err:
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if (info)
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GENL_SET_ERR_MSG(info, "failed to setup reply message");
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return NULL;
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}
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/* genetlink setup */
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/* genetlink setup */
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static const struct genl_ops ethtool_genl_ops[] = {
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static const struct genl_ops ethtool_genl_ops[] = {
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@ -6,5 +6,210 @@
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#include <linux/ethtool_netlink.h>
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#include <linux/ethtool_netlink.h>
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#include <linux/netdevice.h>
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#include <linux/netdevice.h>
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#include <net/genetlink.h>
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#include <net/genetlink.h>
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#include <net/sock.h>
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struct ethnl_req_info;
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int ethnl_parse_header(struct ethnl_req_info *req_info,
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const struct nlattr *nest, struct net *net,
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struct netlink_ext_ack *extack, bool require_dev);
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int ethnl_fill_reply_header(struct sk_buff *skb, struct net_device *dev,
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u16 attrtype);
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struct sk_buff *ethnl_reply_init(size_t payload, struct net_device *dev, u8 cmd,
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u16 hdr_attrtype, struct genl_info *info,
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void **ehdrp);
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/**
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* ethnl_strz_size() - calculate attribute length for fixed size string
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* @s: ETH_GSTRING_LEN sized string (may not be null terminated)
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*
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* Return: total length of an attribute with null terminated string from @s
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*/
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static inline int ethnl_strz_size(const char *s)
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{
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return nla_total_size(strnlen(s, ETH_GSTRING_LEN) + 1);
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}
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/**
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* ethnl_put_strz() - put string attribute with fixed size string
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* @skb: skb with the message
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* @attrype: attribute type
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* @s: ETH_GSTRING_LEN sized string (may not be null terminated)
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*
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* Puts an attribute with null terminated string from @s into the message.
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*
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* Return: 0 on success, negative error code on failure
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*/
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static inline int ethnl_put_strz(struct sk_buff *skb, u16 attrtype,
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const char *s)
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{
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unsigned int len = strnlen(s, ETH_GSTRING_LEN);
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struct nlattr *attr;
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attr = nla_reserve(skb, attrtype, len + 1);
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if (!attr)
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return -EMSGSIZE;
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memcpy(nla_data(attr), s, len);
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((char *)nla_data(attr))[len] = '\0';
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return 0;
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}
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/**
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* ethnl_update_u32() - update u32 value from NLA_U32 attribute
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* @dst: value to update
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* @attr: netlink attribute with new value or null
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* @mod: pointer to bool for modification tracking
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*
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* Copy the u32 value from NLA_U32 netlink attribute @attr into variable
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* pointed to by @dst; do nothing if @attr is null. Bool pointed to by @mod
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* is set to true if this function changed the value of *dst, otherwise it
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* is left as is.
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*/
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static inline void ethnl_update_u32(u32 *dst, const struct nlattr *attr,
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bool *mod)
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{
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u32 val;
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if (!attr)
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return;
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val = nla_get_u32(attr);
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if (*dst == val)
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return;
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*dst = val;
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*mod = true;
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}
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/**
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* ethnl_update_u8() - update u8 value from NLA_U8 attribute
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* @dst: value to update
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* @attr: netlink attribute with new value or null
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* @mod: pointer to bool for modification tracking
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*
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* Copy the u8 value from NLA_U8 netlink attribute @attr into variable
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* pointed to by @dst; do nothing if @attr is null. Bool pointed to by @mod
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* is set to true if this function changed the value of *dst, otherwise it
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* is left as is.
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*/
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static inline void ethnl_update_u8(u8 *dst, const struct nlattr *attr,
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bool *mod)
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{
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u8 val;
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if (!attr)
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return;
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val = nla_get_u8(attr);
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if (*dst == val)
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return;
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*dst = val;
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*mod = true;
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}
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/**
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* ethnl_update_bool32() - update u32 used as bool from NLA_U8 attribute
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* @dst: value to update
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* @attr: netlink attribute with new value or null
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* @mod: pointer to bool for modification tracking
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*
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* Use the u8 value from NLA_U8 netlink attribute @attr to set u32 variable
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* pointed to by @dst to 0 (if zero) or 1 (if not); do nothing if @attr is
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* null. Bool pointed to by @mod is set to true if this function changed the
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* logical value of *dst, otherwise it is left as is.
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*/
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static inline void ethnl_update_bool32(u32 *dst, const struct nlattr *attr,
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bool *mod)
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{
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u8 val;
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if (!attr)
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return;
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val = !!nla_get_u8(attr);
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if (!!*dst == val)
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return;
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*dst = val;
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*mod = true;
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}
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/**
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* ethnl_update_binary() - update binary data from NLA_BINARY atribute
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* @dst: value to update
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* @len: destination buffer length
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* @attr: netlink attribute with new value or null
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* @mod: pointer to bool for modification tracking
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*
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* Use the u8 value from NLA_U8 netlink attribute @attr to rewrite data block
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* of length @len at @dst by attribute payload; do nothing if @attr is null.
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* Bool pointed to by @mod is set to true if this function changed the logical
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* value of *dst, otherwise it is left as is.
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*/
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static inline void ethnl_update_binary(void *dst, unsigned int len,
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const struct nlattr *attr, bool *mod)
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{
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if (!attr)
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return;
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if (nla_len(attr) < len)
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len = nla_len(attr);
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if (!memcmp(dst, nla_data(attr), len))
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return;
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memcpy(dst, nla_data(attr), len);
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*mod = true;
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}
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/**
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* ethnl_update_bitfield32() - update u32 value from NLA_BITFIELD32 attribute
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* @dst: value to update
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* @attr: netlink attribute with new value or null
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* @mod: pointer to bool for modification tracking
|
||||||
|
*
|
||||||
|
* Update bits in u32 value which are set in attribute's mask to values from
|
||||||
|
* attribute's value. Do nothing if @attr is null or the value wouldn't change;
|
||||||
|
* otherwise, set bool pointed to by @mod to true.
|
||||||
|
*/
|
||||||
|
static inline void ethnl_update_bitfield32(u32 *dst, const struct nlattr *attr,
|
||||||
|
bool *mod)
|
||||||
|
{
|
||||||
|
struct nla_bitfield32 change;
|
||||||
|
u32 newval;
|
||||||
|
|
||||||
|
if (!attr)
|
||||||
|
return;
|
||||||
|
change = nla_get_bitfield32(attr);
|
||||||
|
newval = (*dst & ~change.selector) | (change.value & change.selector);
|
||||||
|
if (*dst == newval)
|
||||||
|
return;
|
||||||
|
|
||||||
|
*dst = newval;
|
||||||
|
*mod = true;
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* ethnl_reply_header_size() - total size of reply header
|
||||||
|
*
|
||||||
|
* This is an upper estimate so that we do not need to hold RTNL lock longer
|
||||||
|
* than necessary (to prevent rename between size estimate and composing the
|
||||||
|
* message). Accounts only for device ifindex and name as those are the only
|
||||||
|
* attributes ethnl_fill_reply_header() puts into the reply header.
|
||||||
|
*/
|
||||||
|
static inline unsigned int ethnl_reply_header_size(void)
|
||||||
|
{
|
||||||
|
return nla_total_size(nla_total_size(sizeof(u32)) +
|
||||||
|
nla_total_size(IFNAMSIZ));
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* struct ethnl_req_info - base type of request information for GET requests
|
||||||
|
* @dev: network device the request is for (may be null)
|
||||||
|
* @flags: request flags common for all request types
|
||||||
|
*
|
||||||
|
* This is a common base, additional members may follow after this structure.
|
||||||
|
*/
|
||||||
|
struct ethnl_req_info {
|
||||||
|
struct net_device *dev;
|
||||||
|
u32 flags;
|
||||||
|
};
|
||||||
|
|
||||||
#endif /* _NET_ETHTOOL_NETLINK_H */
|
#endif /* _NET_ETHTOOL_NETLINK_H */
|
||||||
|
|||||||
Loading…
Reference in New Issue
Block a user