#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/u64_stats_sync.h>
#include <linux/netlink.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables_core.h>
#include <net/netfilter/nf_tables_offload.h>
struct nft_counter {
u64_stats_t bytes;
u64_stats_t packets;
};
struct nft_counter_tot {
s64 bytes;
s64 packets;
};
struct nft_counter_percpu_priv {
struct nft_counter __percpu *counter;
};
static DEFINE_PER_CPU(struct u64_stats_sync, nft_counter_sync);
static DEFINE_SPINLOCK(nft_counter_lock);
static inline void nft_counter_do_eval(struct nft_counter_percpu_priv *priv,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
{
struct u64_stats_sync *nft_sync;
struct nft_counter *this_cpu;
local_bh_disable();
this_cpu = this_cpu_ptr(priv->counter);
nft_sync = this_cpu_ptr(&nft_counter_sync);
u64_stats_update_begin(nft_sync);
u64_stats_add(&this_cpu->bytes, pkt->skb->len);
u64_stats_inc(&this_cpu->packets);
u64_stats_update_end(nft_sync);
local_bh_enable();
}
static inline void nft_counter_obj_eval(struct nft_object *obj,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
{
struct nft_counter_percpu_priv *priv = nft_obj_data(obj);
nft_counter_do_eval(priv, regs, pkt);
}
static int nft_counter_do_init(const struct nlattr * const tb[],
struct nft_counter_percpu_priv *priv)
{
struct nft_counter __percpu *cpu_stats;
struct nft_counter *this_cpu;
cpu_stats = alloc_percpu_gfp(struct nft_counter, GFP_KERNEL_ACCOUNT);
if (cpu_stats == NULL)
return -ENOMEM;
this_cpu = raw_cpu_ptr(cpu_stats);
if (tb[NFTA_COUNTER_PACKETS]) {
u64_stats_set(&this_cpu->packets,
be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_PACKETS])));
}
if (tb[NFTA_COUNTER_BYTES]) {
u64_stats_set(&this_cpu->bytes,
be64_to_cpu(nla_get_be64(tb[NFTA_COUNTER_BYTES])));
}
priv->counter = cpu_stats;
return 0;
}
static int nft_counter_obj_init(const struct nft_ctx *ctx,
const struct nlattr * const tb[],
struct nft_object *obj)
{
struct nft_counter_percpu_priv *priv = nft_obj_data(obj);
return nft_counter_do_init(tb, priv);
}
static void nft_counter_do_destroy(struct nft_counter_percpu_priv *priv)
{
free_percpu(priv->counter);
}
static void nft_counter_obj_destroy(const struct nft_ctx *ctx,
struct nft_object *obj)
{
struct nft_counter_percpu_priv *priv = nft_obj_data(obj);
nft_counter_do_destroy(priv);
}
static void nft_counter_reset(struct nft_counter_percpu_priv *priv,
struct nft_counter_tot *total)
{
struct u64_stats_sync *nft_sync;
struct nft_counter *this_cpu;
local_bh_disable();
this_cpu = this_cpu_ptr(priv->counter);
nft_sync = this_cpu_ptr(&nft_counter_sync);
u64_stats_update_begin(nft_sync);
u64_stats_sub(&this_cpu->packets, total->packets);
u64_stats_sub(&this_cpu->bytes, total->bytes);
u64_stats_update_end(nft_sync);
local_bh_enable();
}
static void nft_counter_fetch(struct nft_counter_percpu_priv *priv,
struct nft_counter_tot *total)
{
struct nft_counter *this_cpu;
u64 bytes, packets;
unsigned int seq;
int cpu;
memset(total, 0, sizeof(*total));
for_each_possible_cpu(cpu) {
struct u64_stats_sync *nft_sync = per_cpu_ptr(&nft_counter_sync, cpu);
this_cpu = per_cpu_ptr(priv->counter, cpu);
do {
seq = u64_stats_fetch_begin(nft_sync);
bytes = u64_stats_read(&this_cpu->bytes);
packets = u64_stats_read(&this_cpu->packets);
} while (u64_stats_fetch_retry(nft_sync, seq));
total->bytes += bytes;
total->packets += packets;
}
}
static void nft_counter_fetch_and_reset(struct nft_counter_percpu_priv *priv,
struct nft_counter_tot *total)
{
spin_lock(&nft_counter_lock);
nft_counter_fetch(priv, total);
nft_counter_reset(priv, total);
spin_unlock(&nft_counter_lock);
}
static int nft_counter_do_dump(struct sk_buff *skb,
struct nft_counter_percpu_priv *priv,
bool reset)
{
struct nft_counter_tot total;
if (unlikely(reset))
nft_counter_fetch_and_reset(priv, &total);
else
nft_counter_fetch(priv, &total);
if (nla_put_be64(skb, NFTA_COUNTER_BYTES, cpu_to_be64(total.bytes),
NFTA_COUNTER_PAD) ||
nla_put_be64(skb, NFTA_COUNTER_PACKETS, cpu_to_be64(total.packets),
NFTA_COUNTER_PAD))
goto nla_put_failure;
return 0;
nla_put_failure:
return -1;
}
static int nft_counter_obj_dump(struct sk_buff *skb,
struct nft_object *obj, bool reset)
{
struct nft_counter_percpu_priv *priv = nft_obj_data(obj);
return nft_counter_do_dump(skb, priv, reset);
}
static const struct nla_policy nft_counter_policy[NFTA_COUNTER_MAX + 1] = {
[NFTA_COUNTER_PACKETS] = { .type = NLA_U64 },
[NFTA_COUNTER_BYTES] = { .type = NLA_U64 },
};
struct nft_object_type nft_counter_obj_type;
static const struct nft_object_ops nft_counter_obj_ops = {
.type = &nft_counter_obj_type,
.size = sizeof(struct nft_counter_percpu_priv),
.eval = nft_counter_obj_eval,
.init = nft_counter_obj_init,
.destroy = nft_counter_obj_destroy,
.dump = nft_counter_obj_dump,
};
struct nft_object_type nft_counter_obj_type __read_mostly = {
.type = NFT_OBJECT_COUNTER,
.ops = &nft_counter_obj_ops,
.maxattr = NFTA_COUNTER_MAX,
.policy = nft_counter_policy,
.owner = THIS_MODULE,
};
void nft_counter_eval(const struct nft_expr *expr, struct nft_regs *regs,
const struct nft_pktinfo *pkt)
{
struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
nft_counter_do_eval(priv, regs, pkt);
}
static int nft_counter_dump(struct sk_buff *skb,
const struct nft_expr *expr, bool reset)
{
struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
return nft_counter_do_dump(skb, priv, reset);
}
static int nft_counter_init(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nlattr * const tb[])
{
struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
return nft_counter_do_init(tb, priv);
}
static void nft_counter_destroy(const struct nft_ctx *ctx,
const struct nft_expr *expr)
{
struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
nft_counter_do_destroy(priv);
}
static int nft_counter_clone(struct nft_expr *dst, const struct nft_expr *src, gfp_t gfp)
{
struct nft_counter_percpu_priv *priv = nft_expr_priv(src);
struct nft_counter_percpu_priv *priv_clone = nft_expr_priv(dst);
struct nft_counter __percpu *cpu_stats;
struct nft_counter *this_cpu;
struct nft_counter_tot total;
nft_counter_fetch(priv, &total);
cpu_stats = alloc_percpu_gfp(struct nft_counter, gfp);
if (cpu_stats == NULL)
return -ENOMEM;
this_cpu = raw_cpu_ptr(cpu_stats);
u64_stats_set(&this_cpu->packets, total.packets);
u64_stats_set(&this_cpu->bytes, total.bytes);
priv_clone->counter = cpu_stats;
return 0;
}
static int nft_counter_offload(struct nft_offload_ctx *ctx,
struct nft_flow_rule *flow,
const struct nft_expr *expr)
{
return 0;
}
static void nft_counter_offload_stats(struct nft_expr *expr,
const struct flow_stats *stats)
{
struct nft_counter_percpu_priv *priv = nft_expr_priv(expr);
struct u64_stats_sync *nft_sync;
struct nft_counter *this_cpu;
local_bh_disable();
this_cpu = this_cpu_ptr(priv->counter);
nft_sync = this_cpu_ptr(&nft_counter_sync);
u64_stats_update_begin(nft_sync);
u64_stats_add(&this_cpu->packets, stats->pkts);
u64_stats_add(&this_cpu->bytes, stats->bytes);
u64_stats_update_end(nft_sync);
local_bh_enable();
}
void nft_counter_init_seqcount(void)
{
int cpu;
for_each_possible_cpu(cpu)
u64_stats_init(per_cpu_ptr(&nft_counter_sync, cpu));
}
struct nft_expr_type nft_counter_type;
static const struct nft_expr_ops nft_counter_ops = {
.type = &nft_counter_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_counter_percpu_priv)),
.eval = nft_counter_eval,
.init = nft_counter_init,
.destroy = nft_counter_destroy,
.destroy_clone = nft_counter_destroy,
.dump = nft_counter_dump,
.clone = nft_counter_clone,
.reduce = NFT_REDUCE_READONLY,
.offload = nft_counter_offload,
.offload_stats = nft_counter_offload_stats,
};
struct nft_expr_type nft_counter_type __read_mostly = {
.name = "counter",
.ops = &nft_counter_ops,
.policy = nft_counter_policy,
.maxattr = NFTA_COUNTER_MAX,
.flags = NFT_EXPR_STATEFUL,
.owner = THIS_MODULE,
};
