591054469b
Andreas reports that the following incremental update using our commit
protocol doesn't work.
# nft -f incremental-update.nft
delete element ip filter client_to_any { 10.180.86.22 : goto CIn_1 }
delete chain ip filter CIn_1
... Error: Could not process rule: Device or resource busy
The existing code is not well-integrated into the commit phase protocol,
since element deletions do not result in refcount decrement from the
preparation phase. This results in bogus EBUSY errors like the one
above.
Two new functions come with this patch:
* nft_set_elem_activate() function is used from the abort path, to
restore the set element refcounting on objects that occurred from
the preparation phase.
* nft_set_elem_deactivate() that is called from nft_del_setelem() to
decrement set element refcounting on objects from the preparation
phase in the commit protocol.
The nft_data_uninit() has been renamed to nft_data_release() since this
function does not uninitialize any data store in the data register,
instead just releases the references to objects. Moreover, a new
function nft_data_hold() has been introduced to be used from
nft_set_elem_activate().
Reported-by: Andreas Schultz <aschultz@tpip.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
146 lines
3.6 KiB
C
146 lines
3.6 KiB
C
/*
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* Copyright (c) 2016 Pablo Neira Ayuso <pablo@netfilter.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/netlink.h>
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#include <linux/netfilter.h>
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#include <linux/netfilter/nf_tables.h>
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#include <net/netfilter/nf_tables_core.h>
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#include <net/netfilter/nf_tables.h>
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struct nft_range_expr {
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struct nft_data data_from;
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struct nft_data data_to;
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enum nft_registers sreg:8;
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u8 len;
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enum nft_range_ops op:8;
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};
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static void nft_range_eval(const struct nft_expr *expr,
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struct nft_regs *regs,
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const struct nft_pktinfo *pkt)
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{
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const struct nft_range_expr *priv = nft_expr_priv(expr);
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int d1, d2;
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d1 = memcmp(®s->data[priv->sreg], &priv->data_from, priv->len);
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d2 = memcmp(®s->data[priv->sreg], &priv->data_to, priv->len);
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switch (priv->op) {
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case NFT_RANGE_EQ:
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if (d1 < 0 || d2 > 0)
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regs->verdict.code = NFT_BREAK;
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break;
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case NFT_RANGE_NEQ:
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if (d1 >= 0 && d2 <= 0)
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regs->verdict.code = NFT_BREAK;
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break;
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}
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}
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static const struct nla_policy nft_range_policy[NFTA_RANGE_MAX + 1] = {
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[NFTA_RANGE_SREG] = { .type = NLA_U32 },
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[NFTA_RANGE_OP] = { .type = NLA_U32 },
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[NFTA_RANGE_FROM_DATA] = { .type = NLA_NESTED },
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[NFTA_RANGE_TO_DATA] = { .type = NLA_NESTED },
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};
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static int nft_range_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
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const struct nlattr * const tb[])
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{
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struct nft_range_expr *priv = nft_expr_priv(expr);
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struct nft_data_desc desc_from, desc_to;
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int err;
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u32 op;
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if (!tb[NFTA_RANGE_SREG] ||
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!tb[NFTA_RANGE_OP] ||
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!tb[NFTA_RANGE_FROM_DATA] ||
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!tb[NFTA_RANGE_TO_DATA])
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return -EINVAL;
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err = nft_data_init(NULL, &priv->data_from, sizeof(priv->data_from),
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&desc_from, tb[NFTA_RANGE_FROM_DATA]);
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if (err < 0)
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return err;
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err = nft_data_init(NULL, &priv->data_to, sizeof(priv->data_to),
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&desc_to, tb[NFTA_RANGE_TO_DATA]);
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if (err < 0)
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goto err1;
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if (desc_from.len != desc_to.len) {
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err = -EINVAL;
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goto err2;
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}
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priv->sreg = nft_parse_register(tb[NFTA_RANGE_SREG]);
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err = nft_validate_register_load(priv->sreg, desc_from.len);
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if (err < 0)
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goto err2;
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err = nft_parse_u32_check(tb[NFTA_RANGE_OP], U8_MAX, &op);
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if (err < 0)
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goto err2;
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switch (op) {
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case NFT_RANGE_EQ:
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case NFT_RANGE_NEQ:
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break;
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default:
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err = -EINVAL;
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goto err2;
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}
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priv->op = op;
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priv->len = desc_from.len;
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return 0;
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err2:
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nft_data_release(&priv->data_to, desc_to.type);
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err1:
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nft_data_release(&priv->data_from, desc_from.type);
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return err;
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}
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static int nft_range_dump(struct sk_buff *skb, const struct nft_expr *expr)
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{
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const struct nft_range_expr *priv = nft_expr_priv(expr);
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if (nft_dump_register(skb, NFTA_RANGE_SREG, priv->sreg))
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goto nla_put_failure;
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if (nla_put_be32(skb, NFTA_RANGE_OP, htonl(priv->op)))
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goto nla_put_failure;
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if (nft_data_dump(skb, NFTA_RANGE_FROM_DATA, &priv->data_from,
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NFT_DATA_VALUE, priv->len) < 0 ||
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nft_data_dump(skb, NFTA_RANGE_TO_DATA, &priv->data_to,
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NFT_DATA_VALUE, priv->len) < 0)
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goto nla_put_failure;
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return 0;
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nla_put_failure:
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return -1;
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}
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static const struct nft_expr_ops nft_range_ops = {
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.type = &nft_range_type,
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.size = NFT_EXPR_SIZE(sizeof(struct nft_range_expr)),
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.eval = nft_range_eval,
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.init = nft_range_init,
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.dump = nft_range_dump,
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};
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struct nft_expr_type nft_range_type __read_mostly = {
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.name = "range",
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.ops = &nft_range_ops,
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.policy = nft_range_policy,
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.maxattr = NFTA_RANGE_MAX,
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.owner = THIS_MODULE,
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};
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