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// SPDX-License-Identifier: GPL-2.0-only/* * Copyright (c) 2017 Nicira, Inc. */ #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_noflag(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_noflag(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_noflag(reply, OVS_METER_ATTR_BANDS);	if (!nla)		goto nla_put_failure; 	band_nla = nla_nest_start_noflag(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(struct_size(meter, bands, n_bands), 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_deprecated((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) * 1000;		band_max_delta_t = 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 */ 	/* 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;

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