'vlan ...' implies 8021Q frame. In case the expression tests something else
(802.1AD for example) its not an implictly added one, so keep it.
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
---
src/payload.c | 29 ++++++++++++++++++++++++++---
1 file changed, 26 insertions(+), 3 deletions(-)
diff --git a/src/payload.c b/src/payload.c
index a77ca5500550..cfa952248a15 100644
--- a/src/payload.c
+++ b/src/payload.c
@@ -661,6 +661,24 @@ static bool payload_may_dependency_kill_icmp(struct payload_dep_ctx *ctx, struct
return ctx->icmp_type == icmp_type;
}
+static bool payload_may_dependency_kill_ll(struct payload_dep_ctx *ctx, struct expr *expr)
+{
+ const struct expr *dep = ctx->pdep->expr;
+
+ /* Never remove a 'vlan type 0x...' expression, they are never added implicitly */
+ if (dep->left->payload.desc == &proto_vlan)
+ return false;
+
+ /* 'vlan id 2' implies 'ether type 8021Q'. If a different protocol is
+ * tested, this is not a redundant expression.
+ */
+ if (dep->left->payload.desc == &proto_eth &&
+ dep->right->etype == EXPR_VALUE && dep->right->len == 16)
+ return mpz_get_uint16(dep->right->value) == ETH_P_8021Q;
+
+ return true;
+}
+
static bool payload_may_dependency_kill(struct payload_dep_ctx *ctx,
unsigned int family, struct expr *expr)
{
@@ -689,9 +707,14 @@ static bool payload_may_dependency_kill(struct payload_dep_ctx *ctx,
* for stacked protocols if we only have protcol type matches.
*/
if (dep->left->etype == EXPR_PAYLOAD && dep->op == OP_EQ &&
- expr->flags & EXPR_F_PROTOCOL &&
- expr->payload.base == dep->left->payload.base)
- return false;
+ expr->payload.base == dep->left->payload.base) {
+ if (expr->flags & EXPR_F_PROTOCOL)
+ return false;
+
+ if (expr->payload.base == PROTO_BASE_LL_HDR)
+ return payload_may_dependency_kill_ll(ctx, expr);
+ }
+
break;
}
--
2.26.3
