// 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 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;
+}
+
/* genetlink setup */
static const struct genl_ops ethtool_genl_ops[] = {
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