--- /dev/null
+/*
+ * 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 rcu_free_ovs_meter_callback(struct rcu_head *rcu)
+{
+ struct dp_meter *meter = container_of(rcu, struct dp_meter, rcu);
+
+ kfree(meter);
+}
+
+static void ovs_meter_free(struct dp_meter *meter)
+{
+ if (!meter)
+ return;
+
+ call_rcu(&meter->rcu, rcu_free_ovs_meter_callback);
+}
+
+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 (!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->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]);
+ 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.
+ */
+ band_max_delta_t = (band->burst_size + band->rate) * 1000;
+ /* Start with a full bucket. */
+ band->bucket = band_max_delta_t;
+ 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;
+
+ 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;
+ }
+
+ if (!a[OVS_METER_ATTR_ID]) {
+ 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 */
+
+ /* 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) * 1000;
+
+ 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);
+}
projects / mirror_ubuntu-kernels.git / commitdiff