From 7c64eaf4b1b97ff69a7d9c5c13d4e9eff97d2cd1 Mon Sep 17 00:00:00 2001 From: Phil Sutter Date: Fri, 20 Sep 2019 11:19:15 +0200 Subject: nft: Fix add_bitwise_u16() on Big Endian Type used for 'mask' and 'xor' parameters was wrong, 'int' is four bytes on 32 or 64 bit architectures. After casting a uint16_t to int, on Big Endian the first two bytes of data are (the leading) zero which libnftnl then copies instead of the actual value. This problem was noticed when using '--fragment' option: | # iptables-nft -A FORWARD --fragment -j ACCEPT | # nft list ruleset | grep frag-off | ip frag-off & 0 != 0 counter packets 0 bytes 0 accept With this fix in place, the resulting nft rule is correct: | ip frag-off & 8191 != 0 counter packets 0 bytes 0 accept Fixes: 2f1fbab671576 ("iptables: nft: add -f support") Signed-off-by: Phil Sutter Acked-by: Pablo Neira Ayuso --- iptables/nft-shared.c | 2 +- iptables/nft-shared.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/iptables/nft-shared.c b/iptables/nft-shared.c index 1c09277d..62072520 100644 --- a/iptables/nft-shared.c +++ b/iptables/nft-shared.c @@ -69,7 +69,7 @@ void add_payload(struct nftnl_rule *r, int offset, int len, uint32_t base) } /* bitwise operation is = sreg & mask ^ xor */ -void add_bitwise_u16(struct nftnl_rule *r, int mask, int xor) +void add_bitwise_u16(struct nftnl_rule *r, uint16_t mask, uint16_t xor) { struct nftnl_expr *expr; diff --git a/iptables/nft-shared.h b/iptables/nft-shared.h index de889ead..9d629134 100644 --- a/iptables/nft-shared.h +++ b/iptables/nft-shared.h @@ -111,7 +111,7 @@ struct nft_family_ops { void add_meta(struct nftnl_rule *r, uint32_t key); void add_payload(struct nftnl_rule *r, int offset, int len, uint32_t base); void add_bitwise(struct nftnl_rule *r, uint8_t *mask, size_t len); -void add_bitwise_u16(struct nftnl_rule *r, int mask, int xor); +void add_bitwise_u16(struct nftnl_rule *r, uint16_t mask, uint16_t xor); void add_cmp_ptr(struct nftnl_rule *r, uint32_t op, void *data, size_t len); void add_cmp_u8(struct nftnl_rule *r, uint8_t val, uint32_t op); void add_cmp_u16(struct nftnl_rule *r, uint16_t val, uint32_t op); -- cgit v1.2.3