virtio_blk: set the zone write granularitygrafted

virtblk_read_zoned_limits() reads the write granularity that the device
reports in virtio_blk_zoned_characteristics and assigns it to the
physical block size and to io_min, but never to the limit that is named
after it. queue_limits.zone_write_granularity is left at zero, so
blk_validate_zoned_limits() raises it to the logical block size:

	if (lim->zone_write_granularity < lim->logical_block_size)
		lim->zone_write_granularity = lim->logical_block_size;

A device that reports a granularity coarser than its logical block size,
which is what the field exists to express, therefore has it silently
reduced. A 512e host managed disk passed through to a guest reports a
logical block size of 512 and a write granularity of 4096, and the guest
ends up with a zone write granularity of 512.

bio_split_alignment() returns lim->zone_write_granularity if it is non-zero
and bio_split_io_at() may split a bio with as per bio_split_alignment().
This can real to the write getting rejected by the host drive, as the write
is not aligned to the physical block size.

zonefs also takes its block size from bdev_zone_write_granularity(), so it
would incorrectly use 512 on a disk that requires 4096.

sd_zbc_read_zones() sets the limit from the physical block size for the
same reason. NVMe ZNS and null_blk leave it unset, but the fallback
gives the right answer for them, as their write granularity is the
logical block size. virtio carries a separate value that may exceed it.

Set the zone write granularity from the value that the device reports.

Fixes: 95bfec41bd3d ("virtio-blk: add support for zoned block devices")
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Link: https://patch.msgid.link/20260918140641.2031075-2-cassel@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

3 files changed, 556 insertions, 0 deletions

diff --git a/net/psample/Kconfig b/net/psample/Kconfig
new file mode 100644
index 000000000..be0b83920
--- /dev/null
+++ b/net/psample/Kconfig
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# psample packet sampling configuration
+#
+
+menuconfig PSAMPLE
+	tristate "Packet-sampling netlink channel"
+	default n
+	help
+	  Say Y here to add support for packet-sampling netlink channel
+	  This netlink channel allows transferring packets alongside some
+	  metadata to userspace.
+
+	  To compile this support as a module, choose M here: the module will
+	  be called psample.
diff --git a/net/psample/Makefile b/net/psample/Makefile
new file mode 100644
index 000000000..a04367b9e
--- /dev/null
+++ b/net/psample/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for the psample netlink channel
+#
+
+obj-$(CONFIG_PSAMPLE) += psample.o
diff --git a/net/psample/psample.c b/net/psample/psample.c
new file mode 100644
index 000000000..c112e1f0c
--- /dev/null
+++ b/net/psample/psample.c
@@ -0,0 +1,535 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * net/psample/psample.c - Netlink channel for packet sampling
+ * Copyright (c) 2017 Yotam Gigi <yotamg@mellanox.com>
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/module.h>
+#include <linux/timekeeping.h>
+#include <net/net_namespace.h>
+#include <net/sock.h>
+#include <net/netlink.h>
+#include <net/genetlink.h>
+#include <net/psample.h>
+#include <linux/spinlock.h>
+#include <net/ip_tunnels.h>
+#include <net/dst_metadata.h>
+
+#define PSAMPLE_MAX_PACKET_SIZE 0xffff
+
+static LIST_HEAD(psample_groups_list);
+static DEFINE_SPINLOCK(psample_groups_lock);
+
+/* multicast groups */
+enum psample_nl_multicast_groups {
+	PSAMPLE_NL_MCGRP_CONFIG,
+	PSAMPLE_NL_MCGRP_SAMPLE,
+};
+
+static const struct genl_multicast_group psample_nl_mcgrps[] = {
+	[PSAMPLE_NL_MCGRP_CONFIG] = { .name = PSAMPLE_NL_MCGRP_CONFIG_NAME },
+	[PSAMPLE_NL_MCGRP_SAMPLE] = { .name = PSAMPLE_NL_MCGRP_SAMPLE_NAME,
+				      .flags = GENL_MCAST_CAP_NET_ADMIN, },
+};
+
+static struct genl_family psample_nl_family __ro_after_init;
+
+static int psample_group_nl_fill(struct sk_buff *msg,
+				 struct psample_group *group,
+				 enum psample_command cmd, u32 portid, u32 seq,
+				 int flags)
+{
+	void *hdr;
+	int ret;
+
+	hdr = genlmsg_put(msg, portid, seq, &psample_nl_family, flags, cmd);
+	if (!hdr)
+		return -EMSGSIZE;
+
+	ret = nla_put_u32(msg, PSAMPLE_ATTR_SAMPLE_GROUP, group->group_num);
+	if (ret < 0)
+		goto error;
+
+	ret = nla_put_u32(msg, PSAMPLE_ATTR_GROUP_REFCOUNT, group->refcount);
+	if (ret < 0)
+		goto error;
+
+	ret = nla_put_u32(msg, PSAMPLE_ATTR_GROUP_SEQ, group->seq);
+	if (ret < 0)
+		goto error;
+
+	genlmsg_end(msg, hdr);
+	return 0;
+
+error:
+	genlmsg_cancel(msg, hdr);
+	return -EMSGSIZE;
+}
+
+static int psample_nl_cmd_get_group_dumpit(struct sk_buff *msg,
+					   struct netlink_callback *cb)
+{
+	struct psample_group *group;
+	int start = cb->args[0];
+	int idx = 0;
+	int err;
+
+	spin_lock_bh(&psample_groups_lock);
+	list_for_each_entry(group, &psample_groups_list, list) {
+		if (!net_eq(group->net, sock_net(msg->sk)))
+			continue;
+		if (idx < start) {
+			idx++;
+			continue;
+		}
+		err = psample_group_nl_fill(msg, group, PSAMPLE_CMD_NEW_GROUP,
+					    NETLINK_CB(cb->skb).portid,
+					    cb->nlh->nlmsg_seq, NLM_F_MULTI);
+		if (err)
+			break;
+		idx++;
+	}
+
+	spin_unlock_bh(&psample_groups_lock);
+	cb->args[0] = idx;
+	return msg->len;
+}
+
+static const struct genl_small_ops psample_nl_ops[] = {
+	{
+		.cmd = PSAMPLE_CMD_GET_GROUP,
+		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.dumpit = psample_nl_cmd_get_group_dumpit,
+		/* can be retrieved by unprivileged users */
+	}
+};
+
+static struct genl_family psample_nl_family __ro_after_init = {
+	.name		= PSAMPLE_GENL_NAME,
+	.version	= PSAMPLE_GENL_VERSION,
+	.maxattr	= PSAMPLE_ATTR_MAX,
+	.netnsok	= true,
+	.module		= THIS_MODULE,
+	.mcgrps		= psample_nl_mcgrps,
+	.small_ops	= psample_nl_ops,
+	.n_small_ops	= ARRAY_SIZE(psample_nl_ops),
+	.resv_start_op	= PSAMPLE_CMD_GET_GROUP + 1,
+	.n_mcgrps	= ARRAY_SIZE(psample_nl_mcgrps),
+};
+
+static void psample_group_notify(struct psample_group *group,
+				 enum psample_command cmd)
+{
+	struct sk_buff *msg;
+	int err;
+
+	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
+	if (!msg)
+		return;
+
+	err = psample_group_nl_fill(msg, group, cmd, 0, 0, NLM_F_MULTI);
+	if (!err)
+		genlmsg_multicast_netns(&psample_nl_family, group->net, msg, 0,
+					PSAMPLE_NL_MCGRP_CONFIG, GFP_ATOMIC);
+	else
+		nlmsg_free(msg);
+}
+
+static struct psample_group *psample_group_create(struct net *net,
+						  u32 group_num)
+{
+	struct psample_group *group;
+
+	group = kzalloc_obj(*group, GFP_ATOMIC);
+	if (!group)
+		return NULL;
+
+	group->net = net;
+	group->group_num = group_num;
+	list_add_tail(&group->list, &psample_groups_list);
+
+	psample_group_notify(group, PSAMPLE_CMD_NEW_GROUP);
+	return group;
+}
+
+static void psample_group_destroy(struct psample_group *group)
+{
+	psample_group_notify(group, PSAMPLE_CMD_DEL_GROUP);
+	list_del(&group->list);
+	kfree_rcu(group, rcu);
+}
+
+static struct psample_group *
+psample_group_lookup(struct net *net, u32 group_num)
+{
+	struct psample_group *group;
+
+	list_for_each_entry(group, &psample_groups_list, list)
+		if ((group->group_num == group_num) && (group->net == net))
+			return group;
+	return NULL;
+}
+
+struct psample_group *psample_group_get(struct net *net, u32 group_num)
+{
+	struct psample_group *group;
+
+	spin_lock_bh(&psample_groups_lock);
+
+	group = psample_group_lookup(net, group_num);
+	if (!group) {
+		group = psample_group_create(net, group_num);
+		if (!group)
+			goto out;
+	}
+	group->refcount++;
+
+out:
+	spin_unlock_bh(&psample_groups_lock);
+	return group;
+}
+EXPORT_SYMBOL_GPL(psample_group_get);
+
+void psample_group_take(struct psample_group *group)
+{
+	spin_lock_bh(&psample_groups_lock);
+	group->refcount++;
+	spin_unlock_bh(&psample_groups_lock);
+}
+EXPORT_SYMBOL_GPL(psample_group_take);
+
+void psample_group_put(struct psample_group *group)
+{
+	spin_lock_bh(&psample_groups_lock);
+
+	if (--group->refcount == 0)
+		psample_group_destroy(group);
+
+	spin_unlock_bh(&psample_groups_lock);
+}
+EXPORT_SYMBOL_GPL(psample_group_put);
+
+#ifdef CONFIG_INET
+static int __psample_ip_tun_to_nlattr(struct sk_buff *skb,
+			      struct ip_tunnel_info *tun_info)
+{
+	unsigned short tun_proto = ip_tunnel_info_af(tun_info);
+	const void *tun_opts = ip_tunnel_info_opts(tun_info);
+	const struct ip_tunnel_key *tun_key = &tun_info->key;
+	int tun_opts_len = tun_info->options_len;
+
+	if (test_bit(IP_TUNNEL_KEY_BIT, tun_key->tun_flags) &&
+	    nla_put_be64(skb, PSAMPLE_TUNNEL_KEY_ATTR_ID, tun_key->tun_id,
+			 PSAMPLE_TUNNEL_KEY_ATTR_PAD))
+		return -EMSGSIZE;
+
+	if (tun_info->mode & IP_TUNNEL_INFO_BRIDGE &&
+	    nla_put_flag(skb, PSAMPLE_TUNNEL_KEY_ATTR_IPV4_INFO_BRIDGE))
+		return -EMSGSIZE;
+
+	switch (tun_proto) {
+	case AF_INET:
+		if (tun_key->u.ipv4.src &&
+		    nla_put_in_addr(skb, PSAMPLE_TUNNEL_KEY_ATTR_IPV4_SRC,
+				    tun_key->u.ipv4.src))
+			return -EMSGSIZE;
+		if (tun_key->u.ipv4.dst &&
+		    nla_put_in_addr(skb, PSAMPLE_TUNNEL_KEY_ATTR_IPV4_DST,
+				    tun_key->u.ipv4.dst))
+			return -EMSGSIZE;
+		break;
+	case AF_INET6:
+		if (!ipv6_addr_any(&tun_key->u.ipv6.src) &&
+		    nla_put_in6_addr(skb, PSAMPLE_TUNNEL_KEY_ATTR_IPV6_SRC,
+				     &tun_key->u.ipv6.src))
+			return -EMSGSIZE;
+		if (!ipv6_addr_any(&tun_key->u.ipv6.dst) &&
+		    nla_put_in6_addr(skb, PSAMPLE_TUNNEL_KEY_ATTR_IPV6_DST,
+				     &tun_key->u.ipv6.dst))
+			return -EMSGSIZE;
+		break;
+	}
+	if (tun_key->tos &&
+	    nla_put_u8(skb, PSAMPLE_TUNNEL_KEY_ATTR_TOS, tun_key->tos))
+		return -EMSGSIZE;
+	if (nla_put_u8(skb, PSAMPLE_TUNNEL_KEY_ATTR_TTL, tun_key->ttl))
+		return -EMSGSIZE;
+	if (test_bit(IP_TUNNEL_DONT_FRAGMENT_BIT, tun_key->tun_flags) &&
+	    nla_put_flag(skb, PSAMPLE_TUNNEL_KEY_ATTR_DONT_FRAGMENT))
+		return -EMSGSIZE;
+	if (test_bit(IP_TUNNEL_CSUM_BIT, tun_key->tun_flags) &&
+	    nla_put_flag(skb, PSAMPLE_TUNNEL_KEY_ATTR_CSUM))
+		return -EMSGSIZE;
+	if (tun_key->tp_src &&
+	    nla_put_be16(skb, PSAMPLE_TUNNEL_KEY_ATTR_TP_SRC, tun_key->tp_src))
+		return -EMSGSIZE;
+	if (tun_key->tp_dst &&
+	    nla_put_be16(skb, PSAMPLE_TUNNEL_KEY_ATTR_TP_DST, tun_key->tp_dst))
+		return -EMSGSIZE;
+	if (test_bit(IP_TUNNEL_OAM_BIT, tun_key->tun_flags) &&
+	    nla_put_flag(skb, PSAMPLE_TUNNEL_KEY_ATTR_OAM))
+		return -EMSGSIZE;
+	if (tun_opts_len) {
+		if (test_bit(IP_TUNNEL_GENEVE_OPT_BIT, tun_key->tun_flags) &&
+		    nla_put(skb, PSAMPLE_TUNNEL_KEY_ATTR_GENEVE_OPTS,
+			    tun_opts_len, tun_opts))
+			return -EMSGSIZE;
+		else if (test_bit(IP_TUNNEL_ERSPAN_OPT_BIT,
+				  tun_key->tun_flags) &&
+			 nla_put(skb, PSAMPLE_TUNNEL_KEY_ATTR_ERSPAN_OPTS,
+				 tun_opts_len, tun_opts))
+			return -EMSGSIZE;
+	}
+
+	return 0;
+}
+
+static int psample_ip_tun_to_nlattr(struct sk_buff *skb,
+			    struct ip_tunnel_info *tun_info)
+{
+	struct nlattr *nla;
+	int err;
+
+	nla = nla_nest_start_noflag(skb, PSAMPLE_ATTR_TUNNEL);
+	if (!nla)
+		return -EMSGSIZE;
+
+	err = __psample_ip_tun_to_nlattr(skb, tun_info);
+	if (err) {
+		nla_nest_cancel(skb, nla);
+		return err;
+	}
+
+	nla_nest_end(skb, nla);
+
+	return 0;
+}
+
+static int psample_tunnel_meta_len(struct ip_tunnel_info *tun_info)
+{
+	unsigned short tun_proto = ip_tunnel_info_af(tun_info);
+	const struct ip_tunnel_key *tun_key = &tun_info->key;
+	int tun_opts_len = tun_info->options_len;
+	int sum = nla_total_size(0);	/* PSAMPLE_ATTR_TUNNEL */
+
+	if (test_bit(IP_TUNNEL_KEY_BIT, tun_key->tun_flags))
+		sum += nla_total_size_64bit(sizeof(u64));
+
+	if (tun_info->mode & IP_TUNNEL_INFO_BRIDGE)
+		sum += nla_total_size(0);
+
+	switch (tun_proto) {
+	case AF_INET:
+		if (tun_key->u.ipv4.src)
+			sum += nla_total_size(sizeof(u32));
+		if (tun_key->u.ipv4.dst)
+			sum += nla_total_size(sizeof(u32));
+		break;
+	case AF_INET6:
+		if (!ipv6_addr_any(&tun_key->u.ipv6.src))
+			sum += nla_total_size(sizeof(struct in6_addr));
+		if (!ipv6_addr_any(&tun_key->u.ipv6.dst))
+			sum += nla_total_size(sizeof(struct in6_addr));
+		break;
+	}
+	if (tun_key->tos)
+		sum += nla_total_size(sizeof(u8));
+	sum += nla_total_size(sizeof(u8));	/* TTL */
+	if (test_bit(IP_TUNNEL_DONT_FRAGMENT_BIT, tun_key->tun_flags))
+		sum += nla_total_size(0);
+	if (test_bit(IP_TUNNEL_CSUM_BIT, tun_key->tun_flags))
+		sum += nla_total_size(0);
+	if (tun_key->tp_src)
+		sum += nla_total_size(sizeof(u16));
+	if (tun_key->tp_dst)
+		sum += nla_total_size(sizeof(u16));
+	if (test_bit(IP_TUNNEL_OAM_BIT, tun_key->tun_flags))
+		sum += nla_total_size(0);
+	if (tun_opts_len) {
+		if (test_bit(IP_TUNNEL_GENEVE_OPT_BIT, tun_key->tun_flags))
+			sum += nla_total_size(tun_opts_len);
+		else if (test_bit(IP_TUNNEL_ERSPAN_OPT_BIT,
+				  tun_key->tun_flags))
+			sum += nla_total_size(tun_opts_len);
+	}
+
+	return sum;
+}
+#endif
+
+void psample_sample_packet(struct psample_group *group,
+			   const struct sk_buff *skb, u32 sample_rate,
+			   const struct psample_metadata *md)
+{
+	ktime_t tstamp = ktime_get_real();
+	int out_ifindex = md->out_ifindex;
+	int in_ifindex = md->in_ifindex;
+	u32 trunc_size = md->trunc_size;
+#ifdef CONFIG_INET
+	struct ip_tunnel_info *tun_info;
+#endif
+	struct sk_buff *nl_skb;
+	int data_len;
+	int meta_len;
+	void *data;
+	int ret;
+
+	if (!genl_has_listeners(&psample_nl_family, group->net,
+				PSAMPLE_NL_MCGRP_SAMPLE))
+		return;
+
+	meta_len = (in_ifindex ? nla_total_size(sizeof(u16)) : 0) +
+		   (out_ifindex ? nla_total_size(sizeof(u16)) : 0) +
+		   (md->out_tc_valid ? nla_total_size(sizeof(u16)) : 0) +
+		   (md->out_tc_occ_valid ? nla_total_size_64bit(sizeof(u64)) : 0) +
+		   (md->latency_valid ? nla_total_size_64bit(sizeof(u64)) : 0) +
+		   nla_total_size(sizeof(u32)) +	/* sample_rate */
+		   nla_total_size(sizeof(u32)) +	/* orig_size */
+		   nla_total_size(sizeof(u32)) +	/* group_num */
+		   nla_total_size(sizeof(u32)) +	/* seq */
+		   nla_total_size_64bit(sizeof(u64)) +	/* timestamp */
+		   nla_total_size(sizeof(u16)) +	/* protocol */
+		   (md->user_cookie_len ?
+		    nla_total_size(md->user_cookie_len) : 0) + /* user cookie */
+		   (md->rate_as_probability ?
+		    nla_total_size(0) : 0);	/* rate as probability */
+
+#ifdef CONFIG_INET
+	tun_info = skb_tunnel_info(skb);
+	if (tun_info)
+		meta_len += psample_tunnel_meta_len(tun_info);
+#endif
+
+	data_len = min(skb->len, trunc_size);
+	if (meta_len + nla_total_size(data_len) > PSAMPLE_MAX_PACKET_SIZE)
+		data_len = PSAMPLE_MAX_PACKET_SIZE - meta_len - NLA_HDRLEN
+			    - NLA_ALIGNTO;
+
+	nl_skb = genlmsg_new(meta_len + nla_total_size(data_len), GFP_ATOMIC);
+	if (unlikely(!nl_skb))
+		return;
+
+	data = genlmsg_put(nl_skb, 0, 0, &psample_nl_family, 0,
+			   PSAMPLE_CMD_SAMPLE);
+	if (unlikely(!data))
+		goto error;
+
+	if (in_ifindex) {
+		ret = nla_put_u16(nl_skb, PSAMPLE_ATTR_IIFINDEX, in_ifindex);
+		if (unlikely(ret < 0))
+			goto error;
+	}
+
+	if (out_ifindex) {
+		ret = nla_put_u16(nl_skb, PSAMPLE_ATTR_OIFINDEX, out_ifindex);
+		if (unlikely(ret < 0))
+			goto error;
+	}
+
+	ret = nla_put_u32(nl_skb, PSAMPLE_ATTR_SAMPLE_RATE, sample_rate);
+	if (unlikely(ret < 0))
+		goto error;
+
+	ret = nla_put_u32(nl_skb, PSAMPLE_ATTR_ORIGSIZE, skb->len);
+	if (unlikely(ret < 0))
+		goto error;
+
+	ret = nla_put_u32(nl_skb, PSAMPLE_ATTR_SAMPLE_GROUP, group->group_num);
+	if (unlikely(ret < 0))
+		goto error;
+
+	ret = nla_put_u32(nl_skb, PSAMPLE_ATTR_GROUP_SEQ, group->seq++);
+	if (unlikely(ret < 0))
+		goto error;
+
+	if (md->out_tc_valid) {
+		ret = nla_put_u16(nl_skb, PSAMPLE_ATTR_OUT_TC, md->out_tc);
+		if (unlikely(ret < 0))
+			goto error;
+	}
+
+	if (md->out_tc_occ_valid) {
+		ret = nla_put_u64_64bit(nl_skb, PSAMPLE_ATTR_OUT_TC_OCC,
+					md->out_tc_occ, PSAMPLE_ATTR_PAD);
+		if (unlikely(ret < 0))
+			goto error;
+	}
+
+	if (md->latency_valid) {
+		ret = nla_put_u64_64bit(nl_skb, PSAMPLE_ATTR_LATENCY,
+					md->latency, PSAMPLE_ATTR_PAD);
+		if (unlikely(ret < 0))
+			goto error;
+	}
+
+	ret = nla_put_u64_64bit(nl_skb, PSAMPLE_ATTR_TIMESTAMP,
+				ktime_to_ns(tstamp), PSAMPLE_ATTR_PAD);
+	if (unlikely(ret < 0))
+		goto error;
+
+	ret = nla_put_u16(nl_skb, PSAMPLE_ATTR_PROTO,
+			  be16_to_cpu(skb->protocol));
+	if (unlikely(ret < 0))
+		goto error;
+
+	if (data_len) {
+		int nla_len = nla_attr_size(data_len);
+		struct nlattr *nla;
+
+		nla = skb_put(nl_skb, nla_len);
+		nla->nla_type = PSAMPLE_ATTR_DATA;
+		nla->nla_len = nla_len;
+
+		if (skb_copy_bits(skb, 0, nla_data(nla), data_len))
+			goto error;
+
+		skb_put_zero(nl_skb, nla_padlen(data_len));
+	}
+
+#ifdef CONFIG_INET
+	if (tun_info) {
+		ret = psample_ip_tun_to_nlattr(nl_skb, tun_info);
+		if (unlikely(ret < 0))
+			goto error;
+	}
+#endif
+
+	if (md->user_cookie && md->user_cookie_len &&
+	    nla_put(nl_skb, PSAMPLE_ATTR_USER_COOKIE, md->user_cookie_len,
+		    md->user_cookie))
+		goto error;
+
+	if (md->rate_as_probability &&
+	    nla_put_flag(nl_skb, PSAMPLE_ATTR_SAMPLE_PROBABILITY))
+		goto error;
+
+	genlmsg_end(nl_skb, data);
+	genlmsg_multicast_netns(&psample_nl_family, group->net, nl_skb, 0,
+				PSAMPLE_NL_MCGRP_SAMPLE, GFP_ATOMIC);
+
+	return;
+error:
+	pr_err_ratelimited("Could not create psample log message\n");
+	nlmsg_free(nl_skb);
+}
+EXPORT_SYMBOL_GPL(psample_sample_packet);
+
+static int __init psample_module_init(void)
+{
+	return genl_register_family(&psample_nl_family);
+}
+
+static void __exit psample_module_exit(void)
+{
+	genl_unregister_family(&psample_nl_family);
+}
+
+module_init(psample_module_init);
+module_exit(psample_module_exit);
+
+MODULE_AUTHOR("Yotam Gigi <yotam.gi@gmail.com>");
+MODULE_DESCRIPTION("netlink channel for packet sampling");
+MODULE_LICENSE("GPL v2");