![Florian Westphal](/assets/img/avatar_default.png)
This un-breaks lookups in sets that have the 'dynamic' flag set.
Given this active example configuration:
table filter {
set set1 {
type ipv4_addr
size 64
flags dynamic,timeout
timeout 1m
}
chain input {
type filter hook input priority 0; policy accept;
}
}
... this works:
nft add rule ip filter input add @set1 { ip saddr }
-> whenever rule is triggered, the source ip address is inserted
into the set (if it did not exist).
This won't work:
nft add rule ip filter input ip saddr @set1 counter
Error: Could not process rule: Operation not supported
In other words, we can add entries to the set, but then can't make
matching decision based on that set.
That is just wrong -- all set backends support lookups (else they would
not be very useful).
The failure comes from an explicit rejection in nft_lookup.c.
Looking at the history, it seems like NFT_SET_EVAL used to mean
'set contains expressions' (aka. "is a meter"), for instance something like
nft add rule ip filter input meter example { ip saddr limit rate 10/second }
or
nft add rule ip filter input meter example { ip saddr counter }
The actual meaning of NFT_SET_EVAL however, is
'set can be updated from the packet path'.
'meters' and packet-path insertions into sets, such as
'add @set { ip saddr }' use exactly the same kernel code (nft_dynset.c)
and thus require a set backend that provides the ->update() function.
The only set that provides this also is the only one that has the
NFT_SET_EVAL feature flag.
Removing the wrong check makes the above example work.
While at it, also fix the flag check during set instantiation to
allow supported combinations only.
Fixes: 8aeff920dc
("netfilter: nf_tables: add stateful object reference to set elements")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
237 lines
5.8 KiB
C
237 lines
5.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Copyright (c) 2009 Patrick McHardy <kaber@trash.net>
|
|
*
|
|
* Development of this code funded by Astaro AG (http://www.astaro.com/)
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/init.h>
|
|
#include <linux/list.h>
|
|
#include <linux/rbtree.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_lookup {
|
|
struct nft_set *set;
|
|
enum nft_registers sreg:8;
|
|
enum nft_registers dreg:8;
|
|
bool invert;
|
|
struct nft_set_binding binding;
|
|
};
|
|
|
|
void nft_lookup_eval(const struct nft_expr *expr,
|
|
struct nft_regs *regs,
|
|
const struct nft_pktinfo *pkt)
|
|
{
|
|
const struct nft_lookup *priv = nft_expr_priv(expr);
|
|
const struct nft_set *set = priv->set;
|
|
const struct nft_set_ext *ext;
|
|
bool found;
|
|
|
|
found = set->ops->lookup(nft_net(pkt), set, ®s->data[priv->sreg],
|
|
&ext) ^ priv->invert;
|
|
if (!found) {
|
|
regs->verdict.code = NFT_BREAK;
|
|
return;
|
|
}
|
|
|
|
if (set->flags & NFT_SET_MAP)
|
|
nft_data_copy(®s->data[priv->dreg],
|
|
nft_set_ext_data(ext), set->dlen);
|
|
|
|
}
|
|
|
|
static const struct nla_policy nft_lookup_policy[NFTA_LOOKUP_MAX + 1] = {
|
|
[NFTA_LOOKUP_SET] = { .type = NLA_STRING,
|
|
.len = NFT_SET_MAXNAMELEN - 1 },
|
|
[NFTA_LOOKUP_SET_ID] = { .type = NLA_U32 },
|
|
[NFTA_LOOKUP_SREG] = { .type = NLA_U32 },
|
|
[NFTA_LOOKUP_DREG] = { .type = NLA_U32 },
|
|
[NFTA_LOOKUP_FLAGS] = { .type = NLA_U32 },
|
|
};
|
|
|
|
static int nft_lookup_init(const struct nft_ctx *ctx,
|
|
const struct nft_expr *expr,
|
|
const struct nlattr * const tb[])
|
|
{
|
|
struct nft_lookup *priv = nft_expr_priv(expr);
|
|
u8 genmask = nft_genmask_next(ctx->net);
|
|
struct nft_set *set;
|
|
u32 flags;
|
|
int err;
|
|
|
|
if (tb[NFTA_LOOKUP_SET] == NULL ||
|
|
tb[NFTA_LOOKUP_SREG] == NULL)
|
|
return -EINVAL;
|
|
|
|
set = nft_set_lookup_global(ctx->net, ctx->table, tb[NFTA_LOOKUP_SET],
|
|
tb[NFTA_LOOKUP_SET_ID], genmask);
|
|
if (IS_ERR(set))
|
|
return PTR_ERR(set);
|
|
|
|
priv->sreg = nft_parse_register(tb[NFTA_LOOKUP_SREG]);
|
|
err = nft_validate_register_load(priv->sreg, set->klen);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
if (tb[NFTA_LOOKUP_FLAGS]) {
|
|
flags = ntohl(nla_get_be32(tb[NFTA_LOOKUP_FLAGS]));
|
|
|
|
if (flags & ~NFT_LOOKUP_F_INV)
|
|
return -EINVAL;
|
|
|
|
if (flags & NFT_LOOKUP_F_INV) {
|
|
if (set->flags & NFT_SET_MAP)
|
|
return -EINVAL;
|
|
priv->invert = true;
|
|
}
|
|
}
|
|
|
|
if (tb[NFTA_LOOKUP_DREG] != NULL) {
|
|
if (priv->invert)
|
|
return -EINVAL;
|
|
if (!(set->flags & NFT_SET_MAP))
|
|
return -EINVAL;
|
|
|
|
priv->dreg = nft_parse_register(tb[NFTA_LOOKUP_DREG]);
|
|
err = nft_validate_register_store(ctx, priv->dreg, NULL,
|
|
set->dtype, set->dlen);
|
|
if (err < 0)
|
|
return err;
|
|
} else if (set->flags & NFT_SET_MAP)
|
|
return -EINVAL;
|
|
|
|
priv->binding.flags = set->flags & NFT_SET_MAP;
|
|
|
|
err = nf_tables_bind_set(ctx, set, &priv->binding);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
priv->set = set;
|
|
return 0;
|
|
}
|
|
|
|
static void nft_lookup_deactivate(const struct nft_ctx *ctx,
|
|
const struct nft_expr *expr,
|
|
enum nft_trans_phase phase)
|
|
{
|
|
struct nft_lookup *priv = nft_expr_priv(expr);
|
|
|
|
nf_tables_deactivate_set(ctx, priv->set, &priv->binding, phase);
|
|
}
|
|
|
|
static void nft_lookup_activate(const struct nft_ctx *ctx,
|
|
const struct nft_expr *expr)
|
|
{
|
|
struct nft_lookup *priv = nft_expr_priv(expr);
|
|
|
|
priv->set->use++;
|
|
}
|
|
|
|
static void nft_lookup_destroy(const struct nft_ctx *ctx,
|
|
const struct nft_expr *expr)
|
|
{
|
|
struct nft_lookup *priv = nft_expr_priv(expr);
|
|
|
|
nf_tables_destroy_set(ctx, priv->set);
|
|
}
|
|
|
|
static int nft_lookup_dump(struct sk_buff *skb, const struct nft_expr *expr)
|
|
{
|
|
const struct nft_lookup *priv = nft_expr_priv(expr);
|
|
u32 flags = priv->invert ? NFT_LOOKUP_F_INV : 0;
|
|
|
|
if (nla_put_string(skb, NFTA_LOOKUP_SET, priv->set->name))
|
|
goto nla_put_failure;
|
|
if (nft_dump_register(skb, NFTA_LOOKUP_SREG, priv->sreg))
|
|
goto nla_put_failure;
|
|
if (priv->set->flags & NFT_SET_MAP)
|
|
if (nft_dump_register(skb, NFTA_LOOKUP_DREG, priv->dreg))
|
|
goto nla_put_failure;
|
|
if (nla_put_be32(skb, NFTA_LOOKUP_FLAGS, htonl(flags)))
|
|
goto nla_put_failure;
|
|
return 0;
|
|
|
|
nla_put_failure:
|
|
return -1;
|
|
}
|
|
|
|
static int nft_lookup_validate_setelem(const struct nft_ctx *ctx,
|
|
struct nft_set *set,
|
|
const struct nft_set_iter *iter,
|
|
struct nft_set_elem *elem)
|
|
{
|
|
const struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv);
|
|
struct nft_ctx *pctx = (struct nft_ctx *)ctx;
|
|
const struct nft_data *data;
|
|
int err;
|
|
|
|
if (nft_set_ext_exists(ext, NFT_SET_EXT_FLAGS) &&
|
|
*nft_set_ext_flags(ext) & NFT_SET_ELEM_INTERVAL_END)
|
|
return 0;
|
|
|
|
data = nft_set_ext_data(ext);
|
|
switch (data->verdict.code) {
|
|
case NFT_JUMP:
|
|
case NFT_GOTO:
|
|
pctx->level++;
|
|
err = nft_chain_validate(ctx, data->verdict.chain);
|
|
if (err < 0)
|
|
return err;
|
|
pctx->level--;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int nft_lookup_validate(const struct nft_ctx *ctx,
|
|
const struct nft_expr *expr,
|
|
const struct nft_data **d)
|
|
{
|
|
const struct nft_lookup *priv = nft_expr_priv(expr);
|
|
struct nft_set_iter iter;
|
|
|
|
if (!(priv->set->flags & NFT_SET_MAP) ||
|
|
priv->set->dtype != NFT_DATA_VERDICT)
|
|
return 0;
|
|
|
|
iter.genmask = nft_genmask_next(ctx->net);
|
|
iter.skip = 0;
|
|
iter.count = 0;
|
|
iter.err = 0;
|
|
iter.fn = nft_lookup_validate_setelem;
|
|
|
|
priv->set->ops->walk(ctx, priv->set, &iter);
|
|
if (iter.err < 0)
|
|
return iter.err;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct nft_expr_ops nft_lookup_ops = {
|
|
.type = &nft_lookup_type,
|
|
.size = NFT_EXPR_SIZE(sizeof(struct nft_lookup)),
|
|
.eval = nft_lookup_eval,
|
|
.init = nft_lookup_init,
|
|
.activate = nft_lookup_activate,
|
|
.deactivate = nft_lookup_deactivate,
|
|
.destroy = nft_lookup_destroy,
|
|
.dump = nft_lookup_dump,
|
|
.validate = nft_lookup_validate,
|
|
};
|
|
|
|
struct nft_expr_type nft_lookup_type __read_mostly = {
|
|
.name = "lookup",
|
|
.ops = &nft_lookup_ops,
|
|
.policy = nft_lookup_policy,
|
|
.maxattr = NFTA_LOOKUP_MAX,
|
|
.owner = THIS_MODULE,
|
|
};
|