On 02/16/2014 01:09 PM, Nikolay Aleksandrov wrote: > On 02/16/2014 01:07 PM, Patrick McHardy wrote: >> On Sun, Feb 16, 2014 at 12:54:40PM +0100, Nikolay Aleksandrov wrote: >>> Add a check if payload's offset is a power of 2 when selecting ops. >>> The fast ops were meant for well aligned offsets, also this fixes a >>> small bug when using unaligned offset and length of 3 which causes >>> only 1 byte to be loaded because the fast ops are chosen. >>> >>> Signed-off-by: Nikolay Aleksandrov <nikolay@xxxxxxxxxx> >>> --- >>> I broke the line since it was >80 chars. >>> This patch applies to Dave's -net tree. >>> >>> net/netfilter/nft_payload.c | 4 +++- >>> 1 file changed, 3 insertions(+), 1 deletion(-) >>> >>> diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c >>> index a2aeb31..15a3dcb 100644 >>> --- a/net/netfilter/nft_payload.c >>> +++ b/net/netfilter/nft_payload.c >>> @@ -135,7 +135,9 @@ nft_payload_select_ops(const struct nft_ctx *ctx, >>> if (len == 0 || len > FIELD_SIZEOF(struct nft_data, data)) >>> return ERR_PTR(-EINVAL); >>> >>> - if (len <= 4 && IS_ALIGNED(offset, len) && base != NFT_PAYLOAD_LL_HEADER) >>> + if (len <= 4 && IS_ALIGNED(offset, len) && >>> + base != NFT_PAYLOAD_LL_HEADER && >>> + !(offset & (offset - 1))) >> >> Small cosmetic note: we have is_power_of_2(), which does exactly this. >> > I didn't choose is_power_of_2 because it also checks if x is != 0, so I > thought we can allow for 0 offset with the fast ops. > ugh, forget this, I'll fix it. >> Also I think the more logical order would be: >> >> len <= 4 && is_power_of_2 && IS_ALIGNED && base ... >> > Okay :-) > >>> return &nft_payload_fast_ops; >>> else >>> return &nft_payload_ops; >>> -- >>> 1.8.4.2 > > -- > To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
