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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 <linux/swap.h> #include <net/netlink.h>#include <net/genetlink.h> #include "datapath.h"#include "meter.h" 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 u32 meter_hash(struct dp_meter_instance *ti, u32 id){	return id % ti->n_meters;} static void ovs_meter_free(struct dp_meter *meter){	if (!meter)		return; 	kfree_rcu(meter, rcu);} /* Call with ovs_mutex or RCU read lock. */static struct dp_meter *lookup_meter(const struct dp_meter_table *tbl,				     u32 meter_id){	struct dp_meter_instance *ti = rcu_dereference_ovsl(tbl->ti);	u32 hash = meter_hash(ti, meter_id);	struct dp_meter *meter; 	meter = rcu_dereference_ovsl(ti->dp_meters[hash]);	if (meter && likely(meter->id == meter_id))		return meter; 	return NULL;} static struct dp_meter_instance *dp_meter_instance_alloc(const u32 size){	struct dp_meter_instance *ti; 	ti = kvzalloc(sizeof(*ti) +		      sizeof(struct dp_meter *) * size,		      GFP_KERNEL);	if (!ti)		return NULL; 	ti->n_meters = size; 	return ti;} static void dp_meter_instance_free(struct dp_meter_instance *ti){	kvfree(ti);} static void dp_meter_instance_free_rcu(struct rcu_head *rcu){	struct dp_meter_instance *ti; 	ti = container_of(rcu, struct dp_meter_instance, rcu);	kvfree(ti);} static intdp_meter_instance_realloc(struct dp_meter_table *tbl, u32 size){	struct dp_meter_instance *ti = rcu_dereference_ovsl(tbl->ti);	int n_meters = min(size, ti->n_meters);	struct dp_meter_instance *new_ti;	int i; 	new_ti = dp_meter_instance_alloc(size);	if (!new_ti)		return -ENOMEM; 	for (i = 0; i < n_meters; i++)		if (rcu_dereference_ovsl(ti->dp_meters[i]))			new_ti->dp_meters[i] = ti->dp_meters[i]; 	rcu_assign_pointer(tbl->ti, new_ti);	call_rcu(&ti->rcu, dp_meter_instance_free_rcu); 	return 0;} static void dp_meter_instance_insert(struct dp_meter_instance *ti,				     struct dp_meter *meter){	u32 hash; 	hash = meter_hash(ti, meter->id);	rcu_assign_pointer(ti->dp_meters[hash], meter);} static void dp_meter_instance_remove(struct dp_meter_instance *ti,				     struct dp_meter *meter){	u32 hash; 	hash = meter_hash(ti, meter->id);	RCU_INIT_POINTER(ti->dp_meters[hash], NULL);} static int attach_meter(struct dp_meter_table *tbl, struct dp_meter *meter){	struct dp_meter_instance *ti = rcu_dereference_ovsl(tbl->ti);	u32 hash = meter_hash(ti, meter->id);	int err; 	/* In generally, slots selected should be empty, because	 * OvS uses id-pool to fetch a available id.	 */	if (unlikely(rcu_dereference_ovsl(ti->dp_meters[hash])))		return -EBUSY; 	dp_meter_instance_insert(ti, meter); 	/* That function is thread-safe. */	tbl->count++;	if (tbl->count >= tbl->max_meters_allowed) {		err = -EFBIG;		goto attach_err;	} 	if (tbl->count >= ti->n_meters &&	    dp_meter_instance_realloc(tbl, ti->n_meters * 2)) {		err = -ENOMEM;		goto attach_err;	} 	return 0; attach_err:	dp_meter_instance_remove(ti, meter);	tbl->count--;	return err;} static int detach_meter(struct dp_meter_table *tbl, struct dp_meter *meter){	struct dp_meter_instance *ti; 	ASSERT_OVSL();	if (!meter)		return 0; 	ti = rcu_dereference_ovsl(tbl->ti);	dp_meter_instance_remove(ti, meter); 	tbl->count--; 	/* Shrink the meter array if necessary. */	if (ti->n_meters > DP_METER_ARRAY_SIZE_MIN &&	    tbl->count <= (ti->n_meters / 4)) {		int half_size = ti->n_meters / 2;		int i; 		/* Avoid hash collision, don't move slots to other place.		 * Make sure there are no references of meters in array		 * which will be released.		 */		for (i = half_size; i < ti->n_meters; i++)			if (rcu_dereference_ovsl(ti->dp_meters[i]))				goto out; 		if (dp_meter_instance_realloc(tbl, half_size))			goto shrink_err;	} out:	return 0; shrink_err:	dp_meter_instance_insert(ti, meter);	tbl->count++;	return -ENOMEM;} 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 (nla_put(reply, OVS_METER_ATTR_STATS,		    sizeof(struct ovs_flow_stats), &meter->stats))		goto error; 	if (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 ovs_header *ovs_header = info->userhdr;	struct ovs_header *ovs_reply_header;	struct nlattr *nla, *band_nla;	struct sk_buff *reply;	struct datapath *dp;	int err = -EMSGSIZE; 	reply = ovs_meter_cmd_reply_start(info, OVS_METER_CMD_FEATURES,					  &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;	} 	if (nla_put_u32(reply, OVS_METER_ATTR_MAX_METERS,			dp->meter_tbl.max_meters_allowed))		goto exit_unlock; 	ovs_unlock(); 	if (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); exit_unlock:	ovs_unlock();nla_put_failure:	nlmsg_free(reply);	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) * 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 dp_meter_table *meter_tbl;	struct datapath *dp;	int err;	u32 meter_id;	bool failed; 	if (!a[OVS_METER_ATTR_ID])		return -EINVAL; 	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_tbl = &dp->meter_tbl;	meter_id = nla_get_u32(a[OVS_METER_ATTR_ID]); 	old_meter = lookup_meter(meter_tbl, meter_id);	err = detach_meter(meter_tbl, old_meter);	if (err)		goto exit_unlock; 	err = attach_meter(meter_tbl, meter);	if (err)		goto exit_unlock; 	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 ovs_header *ovs_header = info->userhdr;	struct ovs_header *ovs_reply_header;	struct nlattr **a = info->attrs;	struct dp_meter *meter;	struct sk_buff *reply;	struct datapath *dp;	u32 meter_id;	int err; 	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,

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