| Message ID | 20230322215303.239763-5-pablo@netfilter.org |
|---|---|
| State | Changes Requested |
| Delegated to: | Pablo Neira |
| Headers | show |
| Series | mark statement support for non-constant expression | expand |
diff --git a/src/evaluate.c b/src/evaluate.c index dfb1236e3b8a..613daa974971 100644 --- a/src/evaluate.c +++ b/src/evaluate.c @@ -1325,7 +1325,7 @@ static int expr_evaluate_bitwise(struct eval_ctx *ctx, struct expr **expr) op->dtype = left->dtype; op->byteorder = left->byteorder; - op->len = left->len; + op->len = ctx->ectx.len; if (expr_is_constant(left)) return constant_binop_simplify(ctx, expr);
Get length from statement, instead infering it from the expression that is used to set the value. In the particular case of {ct|meta} mark, this is 32 bits. Otherwise, bytecode generation is not correct: # nft -c --debug=netlink 'add rule ip6 x y ct mark set ip6 dscp << 2 | 0x10' [ payload load 2b @ network header + 0 => reg 1 ] [ bitwise reg 1 = ( reg 1 & 0x0000c00f ) ^ 0x00000000 ] [ bitwise reg 1 = ( reg 1 >> 0x00000006 ) ] [ byteorder reg 1 = ntoh(reg 1, 2, 1) ] [ bitwise reg 1 = ( reg 1 << 0x00000002 ) ] [ bitwise reg 1 = ( reg 1 & 0x00000fef ) ^ 0x00000010 ] <--- incorrect! [ ct set mark with reg 1 ] the previous bitwise shift already upgraded to 32-bits (not visible from the netlink debug output above). After this patch, the last | 0x10 uses 32-bits: [ bitwise reg 1 = ( reg 1 & 0xffffffef ) ^ 0x00000010 ] note that mask 0xffffffef is used instead of 0x00000fef. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> --- src/evaluate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)