1 files changed, 165 insertions, 0 deletions
diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
new file mode 100644
index 0000000000..c1aea8b756
--- /dev/null
+++ b/net/core/netdev-genl.c
@@ -0,0 +1,165 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/netdevice.h>
+#include <linux/notifier.h>
+#include <linux/rtnetlink.h>
+#include <net/net_namespace.h>
+#include <net/sock.h>
+
+#include "netdev-genl-gen.h"
+
+static int
+netdev_nl_dev_fill(struct net_device *netdev, struct sk_buff *rsp,
+		   const struct genl_info *info)
+{
+	void *hdr;
+
+	hdr = genlmsg_iput(rsp, info);
+	if (!hdr)
+		return -EMSGSIZE;
+
+	if (nla_put_u32(rsp, NETDEV_A_DEV_IFINDEX, netdev->ifindex) ||
+	    nla_put_u64_64bit(rsp, NETDEV_A_DEV_XDP_FEATURES,
+			      netdev->xdp_features, NETDEV_A_DEV_PAD)) {
+		genlmsg_cancel(rsp, hdr);
+		return -EINVAL;
+	}
+
+	if (netdev->xdp_features & NETDEV_XDP_ACT_XSK_ZEROCOPY) {
+		if (nla_put_u32(rsp, NETDEV_A_DEV_XDP_ZC_MAX_SEGS,
+				netdev->xdp_zc_max_segs)) {
+			genlmsg_cancel(rsp, hdr);
+			return -EINVAL;
+		}
+	}
+
+	genlmsg_end(rsp, hdr);
+
+	return 0;
+}
+
+static void
+netdev_genl_dev_notify(struct net_device *netdev, int cmd)
+{
+	struct genl_info info;
+	struct sk_buff *ntf;
+
+	if (!genl_has_listeners(&netdev_nl_family, dev_net(netdev),
+				NETDEV_NLGRP_MGMT))
+		return;
+
+	genl_info_init_ntf(&info, &netdev_nl_family, cmd);
+
+	ntf = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!ntf)
+		return;
+
+	if (netdev_nl_dev_fill(netdev, ntf, &info)) {
+		nlmsg_free(ntf);
+		return;
+	}
+
+	genlmsg_multicast_netns(&netdev_nl_family, dev_net(netdev), ntf,
+				0, NETDEV_NLGRP_MGMT, GFP_KERNEL);
+}
+
+int netdev_nl_dev_get_doit(struct sk_buff *skb, struct genl_info *info)
+{
+	struct net_device *netdev;
+	struct sk_buff *rsp;
+	u32 ifindex;
+	int err;
+
+	if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_DEV_IFINDEX))
+		return -EINVAL;
+
+	ifindex = nla_get_u32(info->attrs[NETDEV_A_DEV_IFINDEX]);
+
+	rsp = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!rsp)
+		return -ENOMEM;
+
+	rtnl_lock();
+
+	netdev = __dev_get_by_index(genl_info_net(info), ifindex);
+	if (netdev)
+		err = netdev_nl_dev_fill(netdev, rsp, info);
+	else
+		err = -ENODEV;
+
+	rtnl_unlock();
+
+	if (err)
+		goto err_free_msg;
+
+	return genlmsg_reply(rsp, info);
+
+err_free_msg:
+	nlmsg_free(rsp);
+	return err;
+}
+
+int netdev_nl_dev_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct net *net = sock_net(skb->sk);
+	struct net_device *netdev;
+	int err = 0;
+
+	rtnl_lock();
+	for_each_netdev_dump(net, netdev, cb->args[0]) {
+		err = netdev_nl_dev_fill(netdev, skb, genl_info_dump(cb));
+		if (err < 0)
+			break;
+	}
+	rtnl_unlock();
+
+	if (err != -EMSGSIZE)
+		return err;
+
+	return skb->len;
+}
+
+static int netdev_genl_netdevice_event(struct notifier_block *nb,
+				       unsigned long event, void *ptr)
+{
+	struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
+
+	switch (event) {
+	case NETDEV_REGISTER:
+		netdev_genl_dev_notify(netdev, NETDEV_CMD_DEV_ADD_NTF);
+		break;
+	case NETDEV_UNREGISTER:
+		netdev_genl_dev_notify(netdev, NETDEV_CMD_DEV_DEL_NTF);
+		break;
+	case NETDEV_XDP_FEAT_CHANGE:
+		netdev_genl_dev_notify(netdev, NETDEV_CMD_DEV_CHANGE_NTF);
+		break;
+	}
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block netdev_genl_nb = {
+	.notifier_call	= netdev_genl_netdevice_event,
+};
+
+static int __init netdev_genl_init(void)
+{
+	int err;
+
+	err = register_netdevice_notifier(&netdev_genl_nb);
+	if (err)
+		return err;
+
+	err = genl_register_family(&netdev_nl_family);
+	if (err)
+		goto err_unreg_ntf;
+
+	return 0;
+
+err_unreg_ntf:
+	unregister_netdevice_notifier(&netdev_genl_nb);
+	return err;
+}
+
+subsys_initcall(netdev_genl_init);