Add support for an initialization counter value. With this option the
sysadmin is able to start the counter when used with the increment
type.
Example:
meta mark set numgen inc mod 2 sum 100
This will generate marks with the serie 100, 101, 100, 101, ...
The _until_ attribute is renamed to _modulus_ as the behaviour is similar to
other expresions with number limits(ex. nft_hash).
Signed-off-by: Laura Garcia Liebana <nev...@gmail.com>
---
include/uapi/linux/netfilter/nf_tables.h | 6 ++++--
net/netfilter/nft_numgen.c | 37 ++++++++++++++++++--------------
2 files changed, 25 insertions(+), 18 deletions(-)
diff --git a/include/uapi/linux/netfilter/nf_tables.h
b/include/uapi/linux/netfilter/nf_tables.h
index e941139..4dbeeed 100644
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@ -1151,14 +1151,16 @@ enum nft_trace_types {
* attributes
*
* @NFTA_NG_DREG: destination register (NLA_U32)
- * @NFTA_NG_UNTIL: source value to increment the counter until reset (NLA_U32)
+ * @NFTA_NG_MODULUS: maximum counter value (NLA_U32)
* @NFTA_NG_TYPE: operation type (NLA_U32)
+ * @NFTA_NG_SUM: Offset to initiate the counter (NLA_U32)
*/
enum nft_ng_attributes {
NFTA_NG_UNSPEC,
NFTA_NG_DREG,
- NFTA_NG_UNTIL,
+ NFTA_NG_MODULUS,
NFTA_NG_TYPE,
+ NFTA_NG_SUM,
__NFTA_NG_MAX
};
#define NFTA_NG_MAX (__NFTA_NG_MAX - 1)
diff --git a/net/netfilter/nft_numgen.c b/net/netfilter/nft_numgen.c
index e1d5a11..bfde6d0 100644
--- a/net/netfilter/nft_numgen.c
+++ b/net/netfilter/nft_numgen.c
@@ -21,7 +21,7 @@ static DEFINE_PER_CPU(struct rnd_state,
nft_numgen_prandom_state);
struct nft_ng_inc {
enum nft_registers dreg:8;
- u32 until;
+ u32 modulus;
atomic_t counter;
};
@@ -34,7 +34,7 @@ static void nft_ng_inc_eval(const struct nft_expr *expr,
do {
oval = atomic_read(&priv->counter);
- nval = (oval + 1 < priv->until) ? oval + 1 : 0;
+ nval = (oval + 1 < priv->modulus) ? oval + 1 : 0;
} while (atomic_cmpxchg(&priv->counter, oval, nval) != oval);
memcpy(®s->data[priv->dreg], &priv->counter, sizeof(u32));
@@ -42,8 +42,9 @@ static void nft_ng_inc_eval(const struct nft_expr *expr,
const struct nla_policy nft_ng_policy[NFTA_NG_MAX + 1] = {
[NFTA_NG_DREG] = { .type = NLA_U32 },
- [NFTA_NG_UNTIL] = { .type = NLA_U32 },
+ [NFTA_NG_MODULUS] = { .type = NLA_U32 },
[NFTA_NG_TYPE] = { .type = NLA_U32 },
+ [NFTA_NG_SUM] = { .type = NLA_U32 },
};
static int nft_ng_inc_init(const struct nft_ctx *ctx,
@@ -51,27 +52,31 @@ static int nft_ng_inc_init(const struct nft_ctx *ctx,
const struct nlattr * const tb[])
{
struct nft_ng_inc *priv = nft_expr_priv(expr);
+ u32 sum = 0;
- priv->until = ntohl(nla_get_be32(tb[NFTA_NG_UNTIL]));
- if (priv->until == 0)
+ if (tb[NFTA_NG_SUM])
+ sum = ntohl(nla_get_be32(tb[NFTA_NG_SUM]));
+
+ priv->modulus = ntohl(nla_get_be32(tb[NFTA_NG_MODULUS]));
+ if (priv->modulus == 0 || sum >= priv->modulus)
return -ERANGE;
priv->dreg = nft_parse_register(tb[NFTA_NG_DREG]);
if (priv->dreg < 0)
return -ERANGE;
- atomic_set(&priv->counter, 0);
+ atomic_set(&priv->counter, sum);
return nft_validate_register_store(ctx, priv->dreg, NULL,
NFT_DATA_VALUE, sizeof(u32));
}
static int nft_ng_dump(struct sk_buff *skb, enum nft_registers dreg,
- u32 until, enum nft_ng_types type)
+ u32 modulus, enum nft_ng_types type)
{
if (nft_dump_register(skb, NFTA_NG_DREG, dreg))
goto nla_put_failure;
- if (nft_dump_register(skb, NFTA_NG_UNTIL, until))
+ if (nft_dump_register(skb, NFTA_NG_MODULUS, modulus))
goto nla_put_failure;
if (nft_dump_register(skb, NFTA_NG_TYPE, type))
goto nla_put_failure;
@@ -86,12 +91,12 @@ static int nft_ng_inc_dump(struct sk_buff *skb, const
struct nft_expr *expr)
{
const struct nft_ng_inc *priv = nft_expr_priv(expr);
- return nft_ng_dump(skb, priv->dreg, priv->until, NFT_NG_INCREMENTAL);
+ return nft_ng_dump(skb, priv->dreg, priv->modulus, NFT_NG_INCREMENTAL);
}
struct nft_ng_random {
enum nft_registers dreg:8;
- u32 until;
+ u32 modulus;
};
static void nft_ng_random_eval(const struct nft_expr *expr,
@@ -102,7 +107,7 @@ static void nft_ng_random_eval(const struct nft_expr *expr,
struct rnd_state *state = this_cpu_ptr(&nft_numgen_prandom_state);
regs->data[priv->dreg] = reciprocal_scale(prandom_u32_state(state),
- priv->until);
+ priv->modulus);
}
static int nft_ng_random_init(const struct nft_ctx *ctx,
@@ -111,8 +116,8 @@ static int nft_ng_random_init(const struct nft_ctx *ctx,
{
struct nft_ng_random *priv = nft_expr_priv(expr);
- priv->until = ntohl(nla_get_be32(tb[NFTA_NG_UNTIL]));
- if (priv->until == 0)
+ priv->modulus = ntohl(nla_get_be32(tb[NFTA_NG_MODULUS]));
+ if (priv->modulus == 0)
return -ERANGE;
prandom_init_once(&nft_numgen_prandom_state);
@@ -129,7 +134,7 @@ static int nft_ng_random_dump(struct sk_buff *skb, const
struct nft_expr *expr)
{
const struct nft_ng_random *priv = nft_expr_priv(expr);
- return nft_ng_dump(skb, priv->dreg, priv->until, NFT_NG_RANDOM);
+ return nft_ng_dump(skb, priv->dreg, priv->modulus, NFT_NG_RANDOM);
}
static struct nft_expr_type nft_ng_type;
@@ -154,8 +159,8 @@ nft_ng_select_ops(const struct nft_ctx *ctx, const struct
nlattr * const tb[])
{
u32 type;
- if (!tb[NFTA_NG_DREG] ||
- !tb[NFTA_NG_UNTIL] ||
+ if (!tb[NFTA_NG_DREG] ||
+ !tb[NFTA_NG_MODULUS] ||
!tb[NFTA_NG_TYPE])
return ERR_PTR(-EINVAL);
--
2.8.1
--
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