diff options
| -rw-r--r-- | src/netlink_linearize.c | 46 |
1 files changed, 44 insertions, 2 deletions
diff --git a/src/netlink_linearize.c b/src/netlink_linearize.c index 707df49c..63f77f65 100644 --- a/src/netlink_linearize.c +++ b/src/netlink_linearize.c @@ -99,6 +99,44 @@ static void netlink_gen_concat(struct netlink_linearize_ctx *ctx, } } +static void netlink_gen_payload_mask(struct netlink_linearize_ctx *ctx, + const struct expr *expr, + enum nft_registers dreg) +{ + struct nft_data_linearize nld, zero = {}; + struct nftnl_expr *nle; + unsigned int offset, len, masklen; + mpz_t mask; + + offset = expr->payload.offset % BITS_PER_BYTE; + masklen = expr->len + offset; + + if (masklen > 128) + BUG("expr mask length is %u (len %u, offset %u)\n", + masklen, expr->len, offset); + + mpz_init2(mask, masklen); + mpz_bitmask(mask, expr->len); + + if (offset) + mpz_lshift_ui(mask, offset); + + nle = alloc_nft_expr("bitwise"); + + len = div_round_up(expr->len, BITS_PER_BYTE); + + nftnl_expr_set_u32(nle, NFT_EXPR_BITWISE_SREG, dreg); + nftnl_expr_set_u32(nle, NFT_EXPR_BITWISE_DREG, dreg); + nftnl_expr_set_u32(nle, NFT_EXPR_BITWISE_LEN, len); + + netlink_gen_raw_data(mask, expr->byteorder, len, &nld); + nftnl_expr_set(nle, NFT_EXPR_BITWISE_MASK, nld.value, nld.len); + nftnl_expr_set(nle, NFT_EXPR_BITWISE_XOR, &zero.value, nld.len); + + mpz_clear(mask); + nftnl_rule_add_expr(ctx->nlr, nle); +} + static void netlink_gen_payload(struct netlink_linearize_ctx *ctx, const struct expr *expr, enum nft_registers dreg) @@ -111,9 +149,13 @@ static void netlink_gen_payload(struct netlink_linearize_ctx *ctx, expr->payload.base - 1); nftnl_expr_set_u32(nle, NFTNL_EXPR_PAYLOAD_OFFSET, expr->payload.offset / BITS_PER_BYTE); - nftnl_expr_set_u32(nle, NFTNL_EXPR_PAYLOAD_LEN, - expr->len / BITS_PER_BYTE); + nftnl_expr_set_u32(nle, NFT_EXPR_PAYLOAD_LEN, + div_round_up(expr->len, BITS_PER_BYTE)); + nftnl_rule_add_expr(ctx->nlr, nle); + + if (expr->len % BITS_PER_BYTE) + netlink_gen_payload_mask(ctx, expr, dreg); } static void netlink_gen_exthdr(struct netlink_linearize_ctx *ctx, |