The comment documenting how bitwise expressions work includes a table
which summarizes the mask and xor arguments combined to express the
supported boolean operations. However, the row for OR:
mask xor
0 x
is incorrect.
dreg = (sreg & 0) ^ x
is not equivalent to:
dreg = sreg | x
What the code actually does is:
dreg = (sreg & ~x) ^ x
Update the documentation to match.
Signed-off-by: Jeremy Sowden <jeremy@xxxxxxxxxx>
---
include/uapi/linux/netfilter/nf_tables.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h
index e237ecbdcd8a..dd4611767933 100644
--- a/include/uapi/linux/netfilter/nf_tables.h
+++ b/include/uapi/linux/netfilter/nf_tables.h
@@ -501,7 +501,7 @@ enum nft_immediate_attributes {
*
* mask xor
* NOT: 1 1
- * OR: 0 x
+ * OR: ~x x
* XOR: 1 x
* AND: x 0
*/
--
2.24.1
