On Wed, Sep 02, 2020 at 05:44:11PM +0100, Chris Hall wrote:
>
> I have constructed the file 'tryx' containing:
>
> #---------------------------------------------------
> flush ruleset
> add table ip MAIN
>
> add set ip MAIN tcp_good_flags { type tcp_flag ; flags constant ; \
> elements = { \
> ( 0 | 0 | 0 |ack| 0 | 0 ), \
> ( 0 | 0 | 0 |ack| 0 |urg), \
> ( 0 | 0 | 0 |ack|psh| 0 ), \
> ( 0 | 0 | 0 |ack|psh|urg), \
> ( 0 | 0 |rst| 0 | 0 | 0 ), \
> ( 0 | 0 |rst|ack| 0 | 0 ), \
> ( 0 | 0 |rst|ack| 0 |urg), \
> ( 0 | 0 |rst|ack|psh| 0 ), \
> ( 0 | 0 |rst|ack|psh|urg), \
> ( 0 |syn| 0 | 0 | 0 | 0 ), \
> ( 0 |syn| 0 |ack| 0 | 0 ), \
> ( 0 |syn| 0 |ack| 0 |urg), \
> ( 0 |syn| 0 |ack|psh| 0 ), \
> ( 0 |syn| 0 |ack|psh|urg), \
> (fin| 0 | 0 |ack| 0 | 0 ), \
> (fin| 0 | 0 |ack| 0 |urg), \
> (fin| 0 | 0 |ack|psh| 0 ), \
> (fin| 0 | 0 |ack|psh|urg) \
> } ; }
>
> list ruleset
> #---------------------------------------------------
>
> With a view to using this to filter out invalid combinations of TCP flags.
>
> When I give that to nft I get:
>
> # nft -f tryx
> table ip MAIN {
> set tcp_good_flags {
> type tcp_flag
> flags constant
> elements = { ack, 0x30, 0x18, 0x38, rst,
> 0x14, 0x34, 0x1c, 0x3c, syn,
> 0x12, 0x32, 0x1a, 0x3a, 0x11,
> 0x31, 0x19, 0x39 }
> }
> }
>
> ...which suggests that all is well so far... but it isn't. And if I try to
> check the state of the ruleset again:
>
> # nft list ruleset
> BUG: Unknown expression binop
> nft: mergesort.c:47: expr_msort_cmp: Assertion `0' failed.
> Aborted (core dumped)
>
> Indeed, nothing seems to work until I 'flush ruleset' again !
>
> Am I asking for the impossible here ?
It's a bug, I'll apply this patch to git.
diff --git a/src/mergesort.c b/src/mergesort.c
index 02094b486aeb..4d5bdbd414db 100644
--- a/src/mergesort.c
+++ b/src/mergesort.c
@@ -44,7 +44,15 @@ static int expr_msort_cmp(const struct expr *e1, const struct expr *e2)
case EXPR_MAPPING:
return expr_msort_cmp(e1->left, e2->left);
case EXPR_BINOP:
- return expr_msort_cmp(e1->left, e2->left);
+ switch (e2->etype) {
+ case EXPR_VALUE:
+ return expr_msort_cmp(e1->left, e2);
+ case EXPR_BINOP:
+ return expr_msort_cmp(e1->left, e2->left);
+ default:
+ break;
+ }
+ /* fall through */
default:
BUG("Unknown expression %s\n", expr_name(e1));
}
