linux_dsm_epyc7002/net/openvswitch/meter.c

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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;
netlink: make validation more configurable for future strictness We currently have two levels of strict validation: 1) liberal (default) - undefined (type >= max) & NLA_UNSPEC attributes accepted - attribute length >= expected accepted - garbage at end of message accepted 2) strict (opt-in) - NLA_UNSPEC attributes accepted - attribute length >= expected accepted Split out parsing strictness into four different options: * TRAILING - check that there's no trailing data after parsing attributes (in message or nested) * MAXTYPE - reject attrs > max known type * UNSPEC - reject attributes with NLA_UNSPEC policy entries * STRICT_ATTRS - strictly validate attribute size The default for future things should be *everything*. The current *_strict() is a combination of TRAILING and MAXTYPE, and is renamed to _deprecated_strict(). The current regular parsing has none of this, and is renamed to *_parse_deprecated(). Additionally it allows us to selectively set one of the new flags even on old policies. Notably, the UNSPEC flag could be useful in this case, since it can be arranged (by filling in the policy) to not be an incompatible userspace ABI change, but would then going forward prevent forgetting attribute entries. Similar can apply to the POLICY flag. We end up with the following renames: * nla_parse -> nla_parse_deprecated * nla_parse_strict -> nla_parse_deprecated_strict * nlmsg_parse -> nlmsg_parse_deprecated * nlmsg_parse_strict -> nlmsg_parse_deprecated_strict * nla_parse_nested -> nla_parse_nested_deprecated * nla_validate_nested -> nla_validate_nested_deprecated Using spatch, of course: @@ expression TB, MAX, HEAD, LEN, POL, EXT; @@ -nla_parse(TB, MAX, HEAD, LEN, POL, EXT) +nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression TB, MAX, NLA, POL, EXT; @@ -nla_parse_nested(TB, MAX, NLA, POL, EXT) +nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT) @@ expression START, MAX, POL, EXT; @@ -nla_validate_nested(START, MAX, POL, EXT) +nla_validate_nested_deprecated(START, MAX, POL, EXT) @@ expression NLH, HDRLEN, MAX, POL, EXT; @@ -nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT) +nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT) For this patch, don't actually add the strict, non-renamed versions yet so that it breaks compile if I get it wrong. Also, while at it, make nla_validate and nla_parse go down to a common __nla_validate_parse() function to avoid code duplication. Ultimately, this allows us to have very strict validation for every new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the next patch, while existing things will continue to work as is. In effect then, this adds fully strict validation for any new command. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-26 19:07:28 +07:00
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;
} 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,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.flags = 0, /* OK for unprivileged users. */
.doit = ovs_meter_cmd_features
},
{ .cmd = OVS_METER_CMD_SET,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN
* privilege.
*/
.doit = ovs_meter_cmd_set,
},
{ .cmd = OVS_METER_CMD_GET,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.flags = 0, /* OK for unprivileged users. */
.doit = ovs_meter_cmd_get,
},
{ .cmd = OVS_METER_CMD_DEL,
.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
.flags = GENL_ADMIN_PERM, /* Requires CAP_NET_ADMIN
* privilege.
*/
.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,
.policy = meter_policy,
.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);
}