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/*
* Copyright (c) 2015 Patrick McHardy <kaber@trash.net>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.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>
struct nft_dynset {
struct nft_set *set;
struct nft_set_ext_tmpl tmpl;
enum nft_dynset_ops op:8;
enum nft_registers sreg_key:8;
enum nft_registers sreg_data:8;
bool invert;
u64 timeout;
struct nft_expr *expr;
struct nft_set_binding binding;
};
static void *nft_dynset_new(struct nft_set *set, const struct nft_expr *expr,
struct nft_regs *regs)
{
const struct nft_dynset *priv = nft_expr_priv(expr);
struct nft_set_ext *ext;
u64 timeout;
void *elem;
if (set->size && !atomic_add_unless(&set->nelems, 1, set->size))
return NULL;
timeout = priv->timeout ? : set->timeout;
elem = nft_set_elem_init(set, &priv->tmpl,
®s->data[priv->sreg_key],
®s->data[priv->sreg_data],
timeout, GFP_ATOMIC);
if (elem == NULL) {
if (set->size)
atomic_dec(&set->nelems);
return NULL;
}
ext = nft_set_elem_ext(set, elem);
if (priv->expr != NULL &&
nft_expr_clone(nft_set_ext_expr(ext), priv->expr) < 0)
return NULL;
return elem;
}
static void nft_dynset_eval(const struct nft_expr *expr,
struct nft_regs *regs,
const struct nft_pktinfo *pkt)
{
const struct nft_dynset *priv = nft_expr_priv(expr);
struct nft_set *set = priv->set;
const struct nft_set_ext *ext;
const struct nft_expr *sexpr;
u64 timeout;
if (set->ops->update(set, ®s->data[priv->sreg_key], nft_dynset_new,
expr, regs, &ext)) {
sexpr = NULL;
if (nft_set_ext_exists(ext, NFT_SET_EXT_EXPR))
sexpr = nft_set_ext_expr(ext);
if (priv->op == NFT_DYNSET_OP_UPDATE &&
nft_set_ext_exists(ext, NFT_SET_EXT_EXPIRATION)) {
timeout = priv->timeout ? : set->timeout;
*nft_set_ext_expiration(ext) = jiffies + timeout;
} else if (sexpr == NULL)
goto out;
if (sexpr != NULL)
sexpr->ops->eval(sexpr, regs, pkt);
if (priv->invert)
regs->verdict.code = NFT_BREAK;
return;
}
out:
if (!priv->invert)
regs->verdict.code = NFT_BREAK;
}
static const struct nla_policy nft_dynset_policy[NFTA_DYNSET_MAX + 1] = {
[NFTA_DYNSET_SET_NAME] = { .type = NLA_STRING },
[NFTA_DYNSET_SET_ID] = { .type = NLA_U32 },
[NFTA_DYNSET_OP] = { .type = NLA_U32 },
[NFTA_DYNSET_SREG_KEY] = { .type = NLA_U32 },
[NFTA_DYNSET_SREG_DATA] = { .type = NLA_U32 },
[NFTA_DYNSET_TIMEOUT] = { .type = NLA_U64 },
[NFTA_DYNSET_EXPR] = { .type = NLA_NESTED },
[NFTA_DYNSET_FLAGS] = { .type = NLA_U32 },
};
static int nft_dynset_init(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nlattr * const tb[])
{
struct nft_dynset *priv = nft_expr_priv(expr);
u8 genmask = nft_genmask_next(ctx->net);
struct nft_set *set;
u64 timeout;
int err;
if (tb[NFTA_DYNSET_SET_NAME] == NULL ||
tb[NFTA_DYNSET_OP] == NULL ||
tb[NFTA_DYNSET_SREG_KEY] == NULL)
return -EINVAL;
if (tb[NFTA_DYNSET_FLAGS]) {
u32 flags = ntohl(nla_get_be32(tb[NFTA_DYNSET_FLAGS]));
if (flags & ~NFT_DYNSET_F_INV)
return -EINVAL;
if (flags & NFT_DYNSET_F_INV)
priv->invert = true;
}
set = nf_tables_set_lookup(ctx->table, tb[NFTA_DYNSET_SET_NAME],
genmask);
if (IS_ERR(set)) {
if (tb[NFTA_DYNSET_SET_ID])
set = nf_tables_set_lookup_byid(ctx->net,
tb[NFTA_DYNSET_SET_ID],
genmask);
if (IS_ERR(set))
return PTR_ERR(set);
}
if (set->flags & NFT_SET_CONSTANT)
return -EBUSY;
priv->op = ntohl(nla_get_be32(tb[NFTA_DYNSET_OP]));
switch (priv->op) {
case NFT_DYNSET_OP_ADD:
break;
case NFT_DYNSET_OP_UPDATE:
if (!(set->flags & NFT_SET_TIMEOUT))
return -EOPNOTSUPP;
break;
default:
return -EOPNOTSUPP;
}
timeout = 0;
if (tb[NFTA_DYNSET_TIMEOUT] != NULL) {
if (!(set->flags & NFT_SET_TIMEOUT))
return -EINVAL;
timeout = be64_to_cpu(nla_get_be64(tb[NFTA_DYNSET_TIMEOUT]));
}
priv->sreg_key = nft_parse_register(tb[NFTA_DYNSET_SREG_KEY]);
err = nft_validate_register_load(priv->sreg_key, set->klen);;
if (err < 0)
return err;
if (tb[NFTA_DYNSET_SREG_DATA] != NULL) {
if (!(set->flags & NFT_SET_MAP))
return -EINVAL;
if (set->dtype == NFT_DATA_VERDICT)
return -EOPNOTSUPP;
priv->sreg_data = nft_parse_register(tb[NFTA_DYNSET_SREG_DATA]);
err = nft_validate_register_load(priv->sreg_data, set->dlen);
if (err < 0)
return err;
} else if (set->flags & NFT_SET_MAP)
return -EINVAL;
if (tb[NFTA_DYNSET_EXPR] != NULL) {
if (!(set->flags & NFT_SET_EVAL))
return -EINVAL;
if (!(set->flags & NFT_SET_ANONYMOUS))
return -EOPNOTSUPP;
priv->expr = nft_expr_init(ctx, tb[NFTA_DYNSET_EXPR]);
if (IS_ERR(priv->expr))
return PTR_ERR(priv->expr);
err = -EOPNOTSUPP;
if (!(priv->expr->ops->type->flags & NFT_EXPR_STATEFUL))
goto err1;
} else if (set->flags & NFT_SET_EVAL)
return -EINVAL;
nft_set_ext_prepare(&priv->tmpl);
nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_KEY, set->klen);
if (set->flags & NFT_SET_MAP)
nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_DATA, set->dlen);
if (priv->expr != NULL)
nft_set_ext_add_length(&priv->tmpl, NFT_SET_EXT_EXPR,
priv->expr->ops->size);
if (set->flags & NFT_SET_TIMEOUT) {
if (timeout || set->timeout)
nft_set_ext_add(&priv->tmpl, NFT_SET_EXT_EXPIRATION);
}
priv->timeout = timeout;
err = nf_tables_bind_set(ctx, set, &priv->binding);
if (err < 0)
goto err1;
priv->set = set;
return 0;
err1:
if (priv->expr != NULL)
nft_expr_destroy(ctx, priv->expr);
return err;
}
static void nft_dynset_destroy(const struct nft_ctx *ctx,
const struct nft_expr *expr)
{
struct nft_dynset *priv = nft_expr_priv(expr);
nf_tables_unbind_set(ctx, priv->set, &priv->binding);
if (priv->expr != NULL)
nft_expr_destroy(ctx, priv->expr);
}
static int nft_dynset_dump(struct sk_buff *skb, const struct nft_expr *expr)
{
const struct nft_dynset *priv = nft_expr_priv(expr);
u32 flags = priv->invert ? NFT_DYNSET_F_INV : 0;
if (nft_dump_register(skb, NFTA_DYNSET_SREG_KEY, priv->sreg_key))
goto nla_put_failure;
if (priv->set->flags & NFT_SET_MAP &&
nft_dump_register(skb, NFTA_DYNSET_SREG_DATA, priv->sreg_data))
goto nla_put_failure;
if (nla_put_be32(skb, NFTA_DYNSET_OP, htonl(priv->op)))
goto nla_put_failure;
if (nla_put_string(skb, NFTA_DYNSET_SET_NAME, priv->set->name))
goto nla_put_failure;
if (nla_put_be64(skb, NFTA_DYNSET_TIMEOUT, cpu_to_be64(priv->timeout),
NFTA_DYNSET_PAD))
goto nla_put_failure;
if (priv->expr && nft_expr_dump(skb, NFTA_DYNSET_EXPR, priv->expr))
goto nla_put_failure;
if (nla_put_be32(skb, NFTA_DYNSET_FLAGS, htonl(flags)))
goto nla_put_failure;
return 0;
nla_put_failure:
return -1;
}
static struct nft_expr_type nft_dynset_type;
static const struct nft_expr_ops nft_dynset_ops = {
.type = &nft_dynset_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_dynset)),
.eval = nft_dynset_eval,
.init = nft_dynset_init,
.destroy = nft_dynset_destroy,
.dump = nft_dynset_dump,
};
static struct nft_expr_type nft_dynset_type __read_mostly = {
.name = "dynset",
.ops = &nft_dynset_ops,
.policy = nft_dynset_policy,
.maxattr = NFTA_DYNSET_MAX,
.owner = THIS_MODULE,
};
int __init nft_dynset_module_init(void)
{
return nft_register_expr(&nft_dynset_type);
}
void nft_dynset_module_exit(void)
{
nft_unregister_expr(&nft_dynset_type);
}
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