1 files changed, 611 insertions, 0 deletions

diff --git a/net/openvswitch/meter.c b/net/openvswitch/meter.c
new file mode 100644
index 000000000..9b0c54f07
--- /dev/null
+++ b/net/openvswitch/meter.c
@@ -0,0 +1,611 @@
+/*
+ * Copyright (c) 2017 Nicira, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/if.h>
+#include <linux/skbuff.h>
+#include <linux/ip.h>
+#include <linux/kernel.h>
+#include <linux/openvswitch.h>
+#include <linux/netlink.h>
+#include <linux/rculist.h>
+
+#include <net/netlink.h>
+#include <net/genetlink.h>
+
+#include "datapath.h"
+#include "meter.h"
+
+#define METER_HASH_BUCKETS 1024
+
+static const struct nla_policy meter_policy[OVS_METER_ATTR_MAX + 1] = {
+	[OVS_METER_ATTR_ID] = { .type = NLA_U32, },
+	[OVS_METER_ATTR_KBPS] = { .type = NLA_FLAG },
+	[OVS_METER_ATTR_STATS] = { .len = sizeof(struct ovs_flow_stats) },
+	[OVS_METER_ATTR_BANDS] = { .type = NLA_NESTED },
+	[OVS_METER_ATTR_USED] = { .type = NLA_U64 },
+	[OVS_METER_ATTR_CLEAR] = { .type = NLA_FLAG },
+	[OVS_METER_ATTR_MAX_METERS] = { .type = NLA_U32 },
+	[OVS_METER_ATTR_MAX_BANDS] = { .type = NLA_U32 },
+};
+
+static const struct nla_policy band_policy[OVS_BAND_ATTR_MAX + 1] = {
+	[OVS_BAND_ATTR_TYPE] = { .type = NLA_U32, },
+	[OVS_BAND_ATTR_RATE] = { .type = NLA_U32, },
+	[OVS_BAND_ATTR_BURST] = { .type = NLA_U32, },
+	[OVS_BAND_ATTR_STATS] = { .len = sizeof(struct ovs_flow_stats) },
+};
+
+static void ovs_meter_free(struct dp_meter *meter)
+{
+	if (!meter)
+		return;
+
+	kfree_rcu(meter, rcu);
+}
+
+static struct hlist_head *meter_hash_bucket(const struct datapath *dp,
+					    u32 meter_id)
+{
+	return &dp->meters[meter_id & (METER_HASH_BUCKETS - 1)];
+}
+
+/* Call with ovs_mutex or RCU read lock. */
+static struct dp_meter *lookup_meter(const struct datapath *dp,
+				     u32 meter_id)
+{
+	struct dp_meter *meter;
+	struct hlist_head *head;
+
+	head = meter_hash_bucket(dp, meter_id);
+	hlist_for_each_entry_rcu(meter, head, dp_hash_node) {
+		if (meter->id == meter_id)
+			return meter;
+	}
+	return NULL;
+}
+
+static void attach_meter(struct datapath *dp, struct dp_meter *meter)
+{
+	struct hlist_head *head = meter_hash_bucket(dp, meter->id);
+
+	hlist_add_head_rcu(&meter->dp_hash_node, head);
+}
+
+static void detach_meter(struct dp_meter *meter)
+{
+	ASSERT_OVSL();
+	if (meter)
+		hlist_del_rcu(&meter->dp_hash_node);
+}
+
+static struct sk_buff *
+ovs_meter_cmd_reply_start(struct genl_info *info, u8 cmd,
+			  struct ovs_header **ovs_reply_header)
+{
+	struct sk_buff *skb;
+	struct ovs_header *ovs_header = info->userhdr;
+
+	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
+	if (!skb)
+		return ERR_PTR(-ENOMEM);
+
+	*ovs_reply_header = genlmsg_put(skb, info->snd_portid,
+					info->snd_seq,
+					&dp_meter_genl_family, 0, cmd);
+	if (!*ovs_reply_header) {
+		nlmsg_free(skb);
+		return ERR_PTR(-EMSGSIZE);
+	}
+	(*ovs_reply_header)->dp_ifindex = ovs_header->dp_ifindex;
+
+	return skb;
+}
+
+static int ovs_meter_cmd_reply_stats(struct sk_buff *reply, u32 meter_id,
+				     struct dp_meter *meter)
+{
+	struct nlattr *nla;
+	struct dp_meter_band *band;
+	u16 i;
+
+	if (nla_put_u32(reply, OVS_METER_ATTR_ID, meter_id))
+		goto error;
+
+	if (!meter)
+		return 0;
+
+	if (nla_put(reply, OVS_METER_ATTR_STATS,
+		    sizeof(struct ovs_flow_stats), &meter->stats) ||
+	    nla_put_u64_64bit(reply, OVS_METER_ATTR_USED, meter->used,
+			      OVS_METER_ATTR_PAD))
+		goto error;
+
+	nla = nla_nest_start(reply, OVS_METER_ATTR_BANDS);
+	if (!nla)
+		goto error;
+
+	band = meter->bands;
+
+	for (i = 0; i < meter->n_bands; ++i, ++band) {
+		struct nlattr *band_nla;
+
+		band_nla = nla_nest_start(reply, OVS_BAND_ATTR_UNSPEC);
+		if (!band_nla || nla_put(reply, OVS_BAND_ATTR_STATS,
+					 sizeof(struct ovs_flow_stats),
+					 &band->stats))
+			goto error;
+		nla_nest_end(reply, band_nla);
+	}
+	nla_nest_end(reply, nla);
+
+	return 0;
+error:
+	return -EMSGSIZE;
+}
+
+static int ovs_meter_cmd_features(struct sk_buff *skb, struct genl_info *info)
+{
+	struct sk_buff *reply;
+	struct ovs_header *ovs_reply_header;
+	struct nlattr *nla, *band_nla;
+	int err;
+
+	reply = ovs_meter_cmd_reply_start(info, OVS_METER_CMD_FEATURES,
+					  &ovs_reply_header);
+	if (IS_ERR(reply))
+		return PTR_ERR(reply);
+
+	if (nla_put_u32(reply, OVS_METER_ATTR_MAX_METERS, U32_MAX) ||
+	    nla_put_u32(reply, OVS_METER_ATTR_MAX_BANDS, DP_MAX_BANDS))
+		goto nla_put_failure;
+
+	nla = nla_nest_start(reply, OVS_METER_ATTR_BANDS);
+	if (!nla)
+		goto nla_put_failure;
+
+	band_nla = nla_nest_start(reply, OVS_BAND_ATTR_UNSPEC);
+	if (!band_nla)
+		goto nla_put_failure;
+	/* Currently only DROP band type is supported. */
+	if (nla_put_u32(reply, OVS_BAND_ATTR_TYPE, OVS_METER_BAND_TYPE_DROP))
+		goto nla_put_failure;
+	nla_nest_end(reply, band_nla);
+	nla_nest_end(reply, nla);
+
+	genlmsg_end(reply, ovs_reply_header);
+	return genlmsg_reply(reply, info);
+
+nla_put_failure:
+	nlmsg_free(reply);
+	err = -EMSGSIZE;
+	return err;
+}
+
+static struct dp_meter *dp_meter_create(struct nlattr **a)
+{
+	struct nlattr *nla;
+	int rem;
+	u16 n_bands = 0;
+	struct dp_meter *meter;
+	struct dp_meter_band *band;
+	int err;
+
+	/* Validate attributes, count the bands. */
+	if (!a[OVS_METER_ATTR_BANDS])
+		return ERR_PTR(-EINVAL);
+
+	nla_for_each_nested(nla, a[OVS_METER_ATTR_BANDS], rem)
+		if (++n_bands > DP_MAX_BANDS)
+			return ERR_PTR(-EINVAL);
+
+	/* Allocate and set up the meter before locking anything. */
+	meter = kzalloc(n_bands * sizeof(struct dp_meter_band) +
+			sizeof(*meter), GFP_KERNEL);
+	if (!meter)
+		return ERR_PTR(-ENOMEM);
+
+	meter->id = nla_get_u32(a[OVS_METER_ATTR_ID]);
+	meter->used = div_u64(ktime_get_ns(), 1000 * 1000);
+	meter->kbps = a[OVS_METER_ATTR_KBPS] ? 1 : 0;
+	meter->keep_stats = !a[OVS_METER_ATTR_CLEAR];
+	spin_lock_init(&meter->lock);
+	if (meter->keep_stats && a[OVS_METER_ATTR_STATS]) {
+		meter->stats = *(struct ovs_flow_stats *)
+			nla_data(a[OVS_METER_ATTR_STATS]);
+	}
+	meter->n_bands = n_bands;
+
+	/* Set up meter bands. */
+	band = meter->bands;
+	nla_for_each_nested(nla, a[OVS_METER_ATTR_BANDS], rem) {
+		struct nlattr *attr[OVS_BAND_ATTR_MAX + 1];
+		u32 band_max_delta_t;
+
+		err = nla_parse((struct nlattr **)&attr, OVS_BAND_ATTR_MAX,
+				nla_data(nla), nla_len(nla), band_policy,
+				NULL);
+		if (err)
+			goto exit_free_meter;
+
+		if (!attr[OVS_BAND_ATTR_TYPE] ||
+		    !attr[OVS_BAND_ATTR_RATE] ||
+		    !attr[OVS_BAND_ATTR_BURST]) {
+			err = -EINVAL;
+			goto exit_free_meter;
+		}
+
+		band->type = nla_get_u32(attr[OVS_BAND_ATTR_TYPE]);
+		band->rate = nla_get_u32(attr[OVS_BAND_ATTR_RATE]);
+		if (band->rate == 0) {
+			err = -EINVAL;
+			goto exit_free_meter;
+		}
+
+		band->burst_size = nla_get_u32(attr[OVS_BAND_ATTR_BURST]);
+		/* Figure out max delta_t that is enough to fill any bucket.
+		 * Keep max_delta_t size to the bucket units:
+		 * pkts => 1/1000 packets, kilobits => bits.
+		 *
+		 * Start with a full bucket.
+		 */
+		band->bucket = (band->burst_size + band->rate) * 1000ULL;
+		band_max_delta_t = div_u64(band->bucket, band->rate);
+		if (band_max_delta_t > meter->max_delta_t)
+			meter->max_delta_t = band_max_delta_t;
+		band++;
+	}
+
+	return meter;
+
+exit_free_meter:
+	kfree(meter);
+	return ERR_PTR(err);
+}
+
+static int ovs_meter_cmd_set(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nlattr **a = info->attrs;
+	struct dp_meter *meter, *old_meter;
+	struct sk_buff *reply;
+	struct ovs_header *ovs_reply_header;
+	struct ovs_header *ovs_header = info->userhdr;
+	struct datapath *dp;
+	int err;
+	u32 meter_id;
+	bool failed;
+
+	if (!a[OVS_METER_ATTR_ID]) {
+		return -ENODEV;
+	}
+
+	meter = dp_meter_create(a);
+	if (IS_ERR_OR_NULL(meter))
+		return PTR_ERR(meter);
+
+	reply = ovs_meter_cmd_reply_start(info, OVS_METER_CMD_SET,
+					  &ovs_reply_header);
+	if (IS_ERR(reply)) {
+		err = PTR_ERR(reply);
+		goto exit_free_meter;
+	}
+
+	ovs_lock();
+	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
+	if (!dp) {
+		err = -ENODEV;
+		goto exit_unlock;
+	}
+
+	meter_id = nla_get_u32(a[OVS_METER_ATTR_ID]);
+
+	/* Cannot fail after this. */
+	old_meter = lookup_meter(dp, meter_id);
+	detach_meter(old_meter);
+	attach_meter(dp, meter);
+	ovs_unlock();
+
+	/* Build response with the meter_id and stats from
+	 * the old meter, if any.
+	 */
+	failed = nla_put_u32(reply, OVS_METER_ATTR_ID, meter_id);
+	WARN_ON(failed);
+	if (old_meter) {
+		spin_lock_bh(&old_meter->lock);
+		if (old_meter->keep_stats) {
+			err = ovs_meter_cmd_reply_stats(reply, meter_id,
+							old_meter);
+			WARN_ON(err);
+		}
+		spin_unlock_bh(&old_meter->lock);
+		ovs_meter_free(old_meter);
+	}
+
+	genlmsg_end(reply, ovs_reply_header);
+	return genlmsg_reply(reply, info);
+
+exit_unlock:
+	ovs_unlock();
+	nlmsg_free(reply);
+exit_free_meter:
+	kfree(meter);
+	return err;
+}
+
+static int ovs_meter_cmd_get(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nlattr **a = info->attrs;
+	u32 meter_id;
+	struct ovs_header *ovs_header = info->userhdr;
+	struct ovs_header *ovs_reply_header;
+	struct datapath *dp;
+	int err;
+	struct sk_buff *reply;
+	struct dp_meter *meter;
+
+	if (!a[OVS_METER_ATTR_ID])
+		return -EINVAL;
+
+	meter_id = nla_get_u32(a[OVS_METER_ATTR_ID]);
+
+	reply = ovs_meter_cmd_reply_start(info, OVS_METER_CMD_GET,
+					  &ovs_reply_header);
+	if (IS_ERR(reply))
+		return PTR_ERR(reply);
+
+	ovs_lock();
+
+	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
+	if (!dp) {
+		err = -ENODEV;
+		goto exit_unlock;
+	}
+
+	/* Locate meter, copy stats. */
+	meter = lookup_meter(dp, meter_id);
+	if (!meter) {
+		err = -ENOENT;
+		goto exit_unlock;
+	}
+
+	spin_lock_bh(&meter->lock);
+	err = ovs_meter_cmd_reply_stats(reply, meter_id, meter);
+	spin_unlock_bh(&meter->lock);
+	if (err)
+		goto exit_unlock;
+
+	ovs_unlock();
+
+	genlmsg_end(reply, ovs_reply_header);
+	return genlmsg_reply(reply, info);
+
+exit_unlock:
+	ovs_unlock();
+	nlmsg_free(reply);
+	return err;
+}
+
+static int ovs_meter_cmd_del(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nlattr **a = info->attrs;
+	u32 meter_id;
+	struct ovs_header *ovs_header = info->userhdr;
+	struct ovs_header *ovs_reply_header;
+	struct datapath *dp;
+	int err;
+	struct sk_buff *reply;
+	struct dp_meter *old_meter;
+
+	if (!a[OVS_METER_ATTR_ID])
+		return -EINVAL;
+	meter_id = nla_get_u32(a[OVS_METER_ATTR_ID]);
+
+	reply = ovs_meter_cmd_reply_start(info, OVS_METER_CMD_DEL,
+					  &ovs_reply_header);
+	if (IS_ERR(reply))
+		return PTR_ERR(reply);
+
+	ovs_lock();
+
+	dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
+	if (!dp) {
+		err = -ENODEV;
+		goto exit_unlock;
+	}
+
+	old_meter = lookup_meter(dp, meter_id);
+	if (old_meter) {
+		spin_lock_bh(&old_meter->lock);
+		err = ovs_meter_cmd_reply_stats(reply, meter_id, old_meter);
+		WARN_ON(err);
+		spin_unlock_bh(&old_meter->lock);
+		detach_meter(old_meter);
+	}
+	ovs_unlock();
+	ovs_meter_free(old_meter);
+	genlmsg_end(reply, ovs_reply_header);
+	return genlmsg_reply(reply, info);
+
+exit_unlock:
+	ovs_unlock();
+	nlmsg_free(reply);
+	return err;
+}
+
+/* Meter action execution.
+ *
+ * Return true 'meter_id' drop band is triggered. The 'skb' should be
+ * dropped by the caller'.
+ */
+bool ovs_meter_execute(struct datapath *dp, struct sk_buff *skb,
+		       struct sw_flow_key *key, u32 meter_id)
+{
+	struct dp_meter *meter;
+	struct dp_meter_band *band;
+	long long int now_ms = div_u64(ktime_get_ns(), 1000 * 1000);
+	long long int long_delta_ms;
+	u32 delta_ms;
+	u32 cost;
+	int i, band_exceeded_max = -1;
+	u32 band_exceeded_rate = 0;
+
+	meter = lookup_meter(dp, meter_id);
+	/* Do not drop the packet when there is no meter. */
+	if (!meter)
+		return false;
+
+	/* Lock the meter while using it. */
+	spin_lock(&meter->lock);
+
+	long_delta_ms = (now_ms - meter->used); /* ms */
+	if (long_delta_ms < 0) {
+		/* This condition means that we have several threads fighting
+		 * for a meter lock, and the one who received the packets a
+		 * bit later wins. Assuming that all racing threads received
+		 * packets at the same time to avoid overflow.
+		 */
+		long_delta_ms = 0;
+	}
+
+	/* Make sure delta_ms will not be too large, so that bucket will not
+	 * wrap around below.
+	 */
+	delta_ms = (long_delta_ms > (long long int)meter->max_delta_t)
+		   ? meter->max_delta_t : (u32)long_delta_ms;
+
+	/* Update meter statistics.
+	 */
+	meter->used = now_ms;
+	meter->stats.n_packets += 1;
+	meter->stats.n_bytes += skb->len;
+
+	/* Bucket rate is either in kilobits per second, or in packets per
+	 * second.  We maintain the bucket in the units of either bits or
+	 * 1/1000th of a packet, correspondingly.
+	 * Then, when rate is multiplied with milliseconds, we get the
+	 * bucket units:
+	 * msec * kbps = bits, and
+	 * msec * packets/sec = 1/1000 packets.
+	 *
+	 * 'cost' is the number of bucket units in this packet.
+	 */
+	cost = (meter->kbps) ? skb->len * 8 : 1000;
+
+	/* Update all bands and find the one hit with the highest rate. */
+	for (i = 0; i < meter->n_bands; ++i) {
+		long long int max_bucket_size;
+
+		band = &meter->bands[i];
+		max_bucket_size = (band->burst_size + band->rate) * 1000LL;
+
+		band->bucket += delta_ms * band->rate;
+		if (band->bucket > max_bucket_size)
+			band->bucket = max_bucket_size;
+
+		if (band->bucket >= cost) {
+			band->bucket -= cost;
+		} else if (band->rate > band_exceeded_rate) {
+			band_exceeded_rate = band->rate;
+			band_exceeded_max = i;
+		}
+	}
+
+	if (band_exceeded_max >= 0) {
+		/* Update band statistics. */
+		band = &meter->bands[band_exceeded_max];
+		band->stats.n_packets += 1;
+		band->stats.n_bytes += skb->len;
+
+		/* Drop band triggered, let the caller drop the 'skb'.  */
+		if (band->type == OVS_METER_BAND_TYPE_DROP) {
+			spin_unlock(&meter->lock);
+			return true;
+		}
+	}
+
+	spin_unlock(&meter->lock);
+	return false;
+}
+
+static struct genl_ops dp_meter_genl_ops[] = {
+	{ .cmd = OVS_METER_CMD_FEATURES,
+		.flags = 0,		  /* OK for unprivileged users. */
+		.policy = meter_policy,
+		.doit = ovs_meter_cmd_features
+	},
+	{ .cmd = OVS_METER_CMD_SET,
+		.flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN
+					   *  privilege.
+					   */
+		.policy = meter_policy,
+		.doit = ovs_meter_cmd_set,
+	},
+	{ .cmd = OVS_METER_CMD_GET,
+		.flags = 0,		  /* OK for unprivileged users. */
+		.policy = meter_policy,
+		.doit = ovs_meter_cmd_get,
+	},
+	{ .cmd = OVS_METER_CMD_DEL,
+		.flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN
+					   *  privilege.
+					   */
+		.policy = meter_policy,
+		.doit = ovs_meter_cmd_del
+	},
+};
+
+static const struct genl_multicast_group ovs_meter_multicast_group = {
+	.name = OVS_METER_MCGROUP,
+};
+
+struct genl_family dp_meter_genl_family __ro_after_init = {
+	.hdrsize = sizeof(struct ovs_header),
+	.name = OVS_METER_FAMILY,
+	.version = OVS_METER_VERSION,
+	.maxattr = OVS_METER_ATTR_MAX,
+	.netnsok = true,
+	.parallel_ops = true,
+	.ops = dp_meter_genl_ops,
+	.n_ops = ARRAY_SIZE(dp_meter_genl_ops),
+	.mcgrps = &ovs_meter_multicast_group,
+	.n_mcgrps = 1,
+	.module = THIS_MODULE,
+};
+
+int ovs_meters_init(struct datapath *dp)
+{
+	int i;
+
+	dp->meters = kmalloc_array(METER_HASH_BUCKETS,
+				   sizeof(struct hlist_head), GFP_KERNEL);
+
+	if (!dp->meters)
+		return -ENOMEM;
+
+	for (i = 0; i < METER_HASH_BUCKETS; i++)
+		INIT_HLIST_HEAD(&dp->meters[i]);
+
+	return 0;
+}
+
+void ovs_meters_exit(struct datapath *dp)
+{
+	int i;
+
+	for (i = 0; i < METER_HASH_BUCKETS; i++) {
+		struct hlist_head *head = &dp->meters[i];
+		struct dp_meter *meter;
+		struct hlist_node *n;
+
+		hlist_for_each_entry_safe(meter, n, head, dp_hash_node)
+			kfree(meter);
+	}
+
+	kfree(dp->meters);
+}