diff options
-rw-r--r-- | include/uapi/linux/netfilter/nf_tables.h | 9 | ||||
-rw-r--r-- | net/netfilter/nft_bitwise.c | 77 |
2 files changed, 84 insertions, 2 deletions
diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h index 8bef0620bc4f..261864736b26 100644 --- a/include/uapi/linux/netfilter/nf_tables.h +++ b/include/uapi/linux/netfilter/nf_tables.h @@ -489,9 +489,13 @@ enum nft_immediate_attributes { * * @NFT_BITWISE_BOOL: mask-and-xor operation used to implement NOT, AND, OR and * XOR boolean operations + * @NFT_BITWISE_LSHIFT: left-shift operation + * @NFT_BITWISE_RSHIFT: right-shift operation */ enum nft_bitwise_ops { NFT_BITWISE_BOOL, + NFT_BITWISE_LSHIFT, + NFT_BITWISE_RSHIFT, }; /** @@ -506,11 +510,12 @@ enum nft_bitwise_ops { * @NFTA_BITWISE_DATA: argument for non-boolean operations * (NLA_NESTED: nft_data_attributes) * - * The bitwise expression performs the following operation: + * The bitwise expression supports boolean and shift operations. It implements + * the boolean operations by performing the following operation: * * dreg = (sreg & mask) ^ xor * - * which allow to express all bitwise operations: + * with these mask and xor values: * * mask xor * NOT: 1 1 diff --git a/net/netfilter/nft_bitwise.c b/net/netfilter/nft_bitwise.c index 744008a527fb..0ed2281f03be 100644 --- a/net/netfilter/nft_bitwise.c +++ b/net/netfilter/nft_bitwise.c @@ -34,6 +34,32 @@ static void nft_bitwise_eval_bool(u32 *dst, const u32 *src, dst[i] = (src[i] & priv->mask.data[i]) ^ priv->xor.data[i]; } +static void nft_bitwise_eval_lshift(u32 *dst, const u32 *src, + const struct nft_bitwise *priv) +{ + u32 shift = priv->data.data[0]; + unsigned int i; + u32 carry = 0; + + for (i = DIV_ROUND_UP(priv->len, sizeof(u32)); i > 0; i--) { + dst[i - 1] = (src[i - 1] << shift) | carry; + carry = src[i - 1] >> (BITS_PER_TYPE(u32) - shift); + } +} + +static void nft_bitwise_eval_rshift(u32 *dst, const u32 *src, + const struct nft_bitwise *priv) +{ + u32 shift = priv->data.data[0]; + unsigned int i; + u32 carry = 0; + + for (i = 0; i < DIV_ROUND_UP(priv->len, sizeof(u32)); i++) { + dst[i] = carry | (src[i] >> shift); + carry = src[i] << (BITS_PER_TYPE(u32) - shift); + } +} + void nft_bitwise_eval(const struct nft_expr *expr, struct nft_regs *regs, const struct nft_pktinfo *pkt) { @@ -45,6 +71,12 @@ void nft_bitwise_eval(const struct nft_expr *expr, case NFT_BITWISE_BOOL: nft_bitwise_eval_bool(dst, src, priv); break; + case NFT_BITWISE_LSHIFT: + nft_bitwise_eval_lshift(dst, src, priv); + break; + case NFT_BITWISE_RSHIFT: + nft_bitwise_eval_rshift(dst, src, priv); + break; } } @@ -97,6 +129,32 @@ err1: return err; } +static int nft_bitwise_init_shift(struct nft_bitwise *priv, + const struct nlattr *const tb[]) +{ + struct nft_data_desc d; + int err; + + if (tb[NFTA_BITWISE_MASK] || + tb[NFTA_BITWISE_XOR]) + return -EINVAL; + + if (!tb[NFTA_BITWISE_DATA]) + return -EINVAL; + + err = nft_data_init(NULL, &priv->data, sizeof(priv->data), &d, + tb[NFTA_BITWISE_DATA]); + if (err < 0) + return err; + if (d.type != NFT_DATA_VALUE || d.len != sizeof(u32) || + priv->data.data[0] >= BITS_PER_TYPE(u32)) { + nft_data_release(&priv->data, d.type); + return -EINVAL; + } + + return 0; +} + static int nft_bitwise_init(const struct nft_ctx *ctx, const struct nft_expr *expr, const struct nlattr * const tb[]) @@ -131,6 +189,8 @@ static int nft_bitwise_init(const struct nft_ctx *ctx, priv->op = ntohl(nla_get_be32(tb[NFTA_BITWISE_OP])); switch (priv->op) { case NFT_BITWISE_BOOL: + case NFT_BITWISE_LSHIFT: + case NFT_BITWISE_RSHIFT: break; default: return -EOPNOTSUPP; @@ -143,6 +203,10 @@ static int nft_bitwise_init(const struct nft_ctx *ctx, case NFT_BITWISE_BOOL: err = nft_bitwise_init_bool(priv, tb); break; + case NFT_BITWISE_LSHIFT: + case NFT_BITWISE_RSHIFT: + err = nft_bitwise_init_shift(priv, tb); + break; } return err; @@ -162,6 +226,15 @@ static int nft_bitwise_dump_bool(struct sk_buff *skb, return 0; } +static int nft_bitwise_dump_shift(struct sk_buff *skb, + const struct nft_bitwise *priv) +{ + if (nft_data_dump(skb, NFTA_BITWISE_DATA, &priv->data, + NFT_DATA_VALUE, sizeof(u32)) < 0) + return -1; + 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); @@ -180,6 +253,10 @@ static int nft_bitwise_dump(struct sk_buff *skb, const struct nft_expr *expr) case NFT_BITWISE_BOOL: err = nft_bitwise_dump_bool(skb, priv); break; + case NFT_BITWISE_LSHIFT: + case NFT_BITWISE_RSHIFT: + err = nft_bitwise_dump_shift(skb, priv); + break; } return err; |