![Laura Garcia Liebana](/assets/img/avatar_default.png)
Fetch value and validate u32 netlink attribute. This validation is usually required when the u32 netlink attributes are being stored in a field whose size is smaller. This patch revisits4da449ae1d
("netfilter: nft_exthdr: Add size check on u8 nft_exthdr attributes"). Fixes:96518518cc
("netfilter: add nftables") Suggested-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Laura Garcia Liebana <nevola@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
198 lines
4.8 KiB
C
198 lines
4.8 KiB
C
/*
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* Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
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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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* Development of this code funded by Astaro AG (http://www.astaro.com/)
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*/
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#include <asm/unaligned.h>
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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_byteorder {
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enum nft_registers sreg:8;
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enum nft_registers dreg:8;
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enum nft_byteorder_ops op:8;
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u8 len;
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u8 size;
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};
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static void nft_byteorder_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_byteorder *priv = nft_expr_priv(expr);
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u32 *src = ®s->data[priv->sreg];
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u32 *dst = ®s->data[priv->dreg];
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union { u32 u32; u16 u16; } *s, *d;
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unsigned int i;
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s = (void *)src;
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d = (void *)dst;
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switch (priv->size) {
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case 8: {
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u64 src64;
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switch (priv->op) {
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case NFT_BYTEORDER_NTOH:
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for (i = 0; i < priv->len / 8; i++) {
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src64 = get_unaligned((u64 *)&src[i]);
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put_unaligned_be64(src64, &dst[i]);
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}
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break;
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case NFT_BYTEORDER_HTON:
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for (i = 0; i < priv->len / 8; i++) {
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src64 = get_unaligned_be64(&src[i]);
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put_unaligned(src64, (u64 *)&dst[i]);
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}
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break;
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}
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break;
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}
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case 4:
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switch (priv->op) {
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case NFT_BYTEORDER_NTOH:
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for (i = 0; i < priv->len / 4; i++)
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d[i].u32 = ntohl((__force __be32)s[i].u32);
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break;
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case NFT_BYTEORDER_HTON:
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for (i = 0; i < priv->len / 4; i++)
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d[i].u32 = (__force __u32)htonl(s[i].u32);
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break;
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}
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break;
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case 2:
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switch (priv->op) {
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case NFT_BYTEORDER_NTOH:
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for (i = 0; i < priv->len / 2; i++)
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d[i].u16 = ntohs((__force __be16)s[i].u16);
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break;
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case NFT_BYTEORDER_HTON:
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for (i = 0; i < priv->len / 2; i++)
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d[i].u16 = (__force __u16)htons(s[i].u16);
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break;
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}
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break;
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}
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}
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static const struct nla_policy nft_byteorder_policy[NFTA_BYTEORDER_MAX + 1] = {
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[NFTA_BYTEORDER_SREG] = { .type = NLA_U32 },
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[NFTA_BYTEORDER_DREG] = { .type = NLA_U32 },
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[NFTA_BYTEORDER_OP] = { .type = NLA_U32 },
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[NFTA_BYTEORDER_LEN] = { .type = NLA_U32 },
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[NFTA_BYTEORDER_SIZE] = { .type = NLA_U32 },
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};
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static int nft_byteorder_init(const struct nft_ctx *ctx,
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const struct nft_expr *expr,
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const struct nlattr * const tb[])
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{
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struct nft_byteorder *priv = nft_expr_priv(expr);
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u32 size, len;
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int err;
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if (tb[NFTA_BYTEORDER_SREG] == NULL ||
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tb[NFTA_BYTEORDER_DREG] == NULL ||
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tb[NFTA_BYTEORDER_LEN] == NULL ||
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tb[NFTA_BYTEORDER_SIZE] == NULL ||
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tb[NFTA_BYTEORDER_OP] == NULL)
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return -EINVAL;
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priv->op = ntohl(nla_get_be32(tb[NFTA_BYTEORDER_OP]));
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switch (priv->op) {
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case NFT_BYTEORDER_NTOH:
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case NFT_BYTEORDER_HTON:
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break;
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default:
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return -EINVAL;
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}
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err = nft_parse_u32_check(tb[NFTA_BYTEORDER_SIZE], U8_MAX, &size);
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if (err < 0)
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return err;
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priv->size = size;
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switch (priv->size) {
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case 2:
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case 4:
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case 8:
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break;
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default:
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return -EINVAL;
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}
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priv->sreg = nft_parse_register(tb[NFTA_BYTEORDER_SREG]);
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err = nft_parse_u32_check(tb[NFTA_BYTEORDER_LEN], U8_MAX, &len);
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if (err < 0)
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return err;
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priv->len = len;
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err = nft_validate_register_load(priv->sreg, priv->len);
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if (err < 0)
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return err;
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priv->dreg = nft_parse_register(tb[NFTA_BYTEORDER_DREG]);
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return nft_validate_register_store(ctx, priv->dreg, NULL,
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NFT_DATA_VALUE, priv->len);
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}
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static int nft_byteorder_dump(struct sk_buff *skb, const struct nft_expr *expr)
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{
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const struct nft_byteorder *priv = nft_expr_priv(expr);
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if (nft_dump_register(skb, NFTA_BYTEORDER_SREG, priv->sreg))
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goto nla_put_failure;
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if (nft_dump_register(skb, NFTA_BYTEORDER_DREG, priv->dreg))
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goto nla_put_failure;
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if (nla_put_be32(skb, NFTA_BYTEORDER_OP, htonl(priv->op)))
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goto nla_put_failure;
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if (nla_put_be32(skb, NFTA_BYTEORDER_LEN, htonl(priv->len)))
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goto nla_put_failure;
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if (nla_put_be32(skb, NFTA_BYTEORDER_SIZE, htonl(priv->size)))
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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 struct nft_expr_type nft_byteorder_type;
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static const struct nft_expr_ops nft_byteorder_ops = {
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.type = &nft_byteorder_type,
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.size = NFT_EXPR_SIZE(sizeof(struct nft_byteorder)),
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.eval = nft_byteorder_eval,
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.init = nft_byteorder_init,
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.dump = nft_byteorder_dump,
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};
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static struct nft_expr_type nft_byteorder_type __read_mostly = {
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.name = "byteorder",
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.ops = &nft_byteorder_ops,
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.policy = nft_byteorder_policy,
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.maxattr = NFTA_BYTEORDER_MAX,
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.owner = THIS_MODULE,
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};
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int __init nft_byteorder_module_init(void)
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{
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return nft_register_expr(&nft_byteorder_type);
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}
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void nft_byteorder_module_exit(void)
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{
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nft_unregister_expr(&nft_byteorder_type);
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}
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