diff options
Diffstat (limited to 'net/netfilter/nft_bitwise.c')
| -rw-r--r-- | net/netfilter/nft_bitwise.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/net/netfilter/nft_bitwise.c b/net/netfilter/nft_bitwise.c new file mode 100644 index 000000000000..4fb6ee2c1106 --- /dev/null +++ b/net/netfilter/nft_bitwise.c @@ -0,0 +1,146 @@ +/* + * Copyright (c) 2008-2009 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. + * + * Development of this code funded by Astaro AG (http://www.astaro.com/) + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/netlink.h> +#include <linux/netfilter.h> +#include <linux/netfilter/nf_tables.h> +#include <net/netfilter/nf_tables_core.h> +#include <net/netfilter/nf_tables.h> + +struct nft_bitwise { + enum nft_registers sreg:8; + enum nft_registers dreg:8; + u8 len; + struct nft_data mask; + struct nft_data xor; +}; + +static void nft_bitwise_eval(const struct nft_expr *expr, + struct nft_data data[NFT_REG_MAX + 1], + const struct nft_pktinfo *pkt) +{ + const struct nft_bitwise *priv = nft_expr_priv(expr); + const struct nft_data *src = &data[priv->sreg]; + struct nft_data *dst = &data[priv->dreg]; + unsigned int i; + + for (i = 0; i < DIV_ROUND_UP(priv->len, 4); i++) { + dst->data[i] = (src->data[i] & priv->mask.data[i]) ^ + priv->xor.data[i]; + } +} + +static const struct nla_policy nft_bitwise_policy[NFTA_BITWISE_MAX + 1] = { + [NFTA_BITWISE_SREG] = { .type = NLA_U32 }, + [NFTA_BITWISE_DREG] = { .type = NLA_U32 }, + [NFTA_BITWISE_LEN] = { .type = NLA_U32 }, + [NFTA_BITWISE_MASK] = { .type = NLA_NESTED }, + [NFTA_BITWISE_XOR] = { .type = NLA_NESTED }, +}; + +static int nft_bitwise_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_bitwise *priv = nft_expr_priv(expr); + struct nft_data_desc d1, d2; + int err; + + if (tb[NFTA_BITWISE_SREG] == NULL || + tb[NFTA_BITWISE_DREG] == NULL || + tb[NFTA_BITWISE_LEN] == NULL || + tb[NFTA_BITWISE_MASK] == NULL || + tb[NFTA_BITWISE_XOR] == NULL) + return -EINVAL; + + priv->sreg = ntohl(nla_get_be32(tb[NFTA_BITWISE_SREG])); + err = nft_validate_input_register(priv->sreg); + if (err < 0) + return err; + + priv->dreg = ntohl(nla_get_be32(tb[NFTA_BITWISE_DREG])); + err = nft_validate_output_register(priv->dreg); + if (err < 0) + return err; + err = nft_validate_data_load(ctx, priv->dreg, NULL, NFT_DATA_VALUE); + if (err < 0) + return err; + + priv->len = ntohl(nla_get_be32(tb[NFTA_BITWISE_LEN])); + + err = nft_data_init(NULL, &priv->mask, &d1, tb[NFTA_BITWISE_MASK]); + if (err < 0) + return err; + if (d1.len != priv->len) + return -EINVAL; + + err = nft_data_init(NULL, &priv->xor, &d2, tb[NFTA_BITWISE_XOR]); + if (err < 0) + return err; + if (d2.len != priv->len) + return -EINVAL; + + return 0; +} + +static int nft_bitwise_dump(struct sk_buff *skb, const struct nft_expr *expr) +{ + const struct nft_bitwise *priv = nft_expr_priv(expr); + + if (nla_put_be32(skb, NFTA_BITWISE_SREG, htonl(priv->sreg))) + goto nla_put_failure; + if (nla_put_be32(skb, NFTA_BITWISE_DREG, htonl(priv->dreg))) + goto nla_put_failure; + if (nla_put_be32(skb, NFTA_BITWISE_LEN, htonl(priv->len))) + goto nla_put_failure; + + if (nft_data_dump(skb, NFTA_BITWISE_MASK, &priv->mask, + NFT_DATA_VALUE, priv->len) < 0) + goto nla_put_failure; + + if (nft_data_dump(skb, NFTA_BITWISE_XOR, &priv->xor, + NFT_DATA_VALUE, priv->len) < 0) + goto nla_put_failure; + + return 0; + +nla_put_failure: + return -1; +} + +static struct nft_expr_type nft_bitwise_type; +static const struct nft_expr_ops nft_bitwise_ops = { + .type = &nft_bitwise_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_bitwise)), + .eval = nft_bitwise_eval, + .init = nft_bitwise_init, + .dump = nft_bitwise_dump, +}; + +static struct nft_expr_type nft_bitwise_type __read_mostly = { + .name = "bitwise", + .ops = &nft_bitwise_ops, + .policy = nft_bitwise_policy, + .maxattr = NFTA_BITWISE_MAX, + .owner = THIS_MODULE, +}; + +int __init nft_bitwise_module_init(void) +{ + return nft_register_expr(&nft_bitwise_type); +} + +void nft_bitwise_module_exit(void) +{ + nft_unregister_expr(&nft_bitwise_type); +} |