diff options
author | Phil Sutter <phil@nwl.cc> | 2017-12-09 16:52:29 +0100 |
---|---|---|
committer | Florian Westphal <fw@strlen.de> | 2017-12-12 13:24:01 +0100 |
commit | a2c55e04d5a1187914cba2c02810db94de499ace (patch) | |
tree | eb7af207d40217a842ee487ba2c49d0eeda7064a /src/ct.c | |
parent | 80f5d7fd66895c651c9d1e35b2353f3020ffb538 (diff) |
src: fix protocol context update on big-endian systems
There is an obscure bug on big-endian systems when trying to list a rule
containing the expression 'ct helper tftp' which triggers the assert()
call in mpz_get_type().
Florian identified the cause: ct_expr_pctx_update() is called for the
relational expression which calls mpz_get_uint32() to get RHS value
(assuming it is a protocol number). On big-endian systems, the
misinterpreted value exceeds UINT_MAX.
Expressions' pctx_update() callback should only be called for protocol
matches, so ct_meta_common_postprocess() lacked a check for 'left->flags
& EXPR_F_PROTOCOL' like the one already present in
payload_expr_pctx_update().
In order to fix this in a clean way, this patch introduces a wrapper
relational_expr_pctx_update() to be used instead of directly calling
LHS's pctx_update() callback which unifies the necessary checks (and
adds one more assert):
- assert(expr->ops->type == EXPR_RELATIONAL)
-> This is new, just to ensure the wrapper is called properly.
- assert(expr->op == OP_EQ)
-> This was moved from {ct,meta,payload}_expr_pctx_update().
- left->ops->pctx_update != NULL
-> This was taken from expr_evaluate_relational(), a necessary
requirement for the introduced wrapper to function at all.
- (left->flags & EXPR_F_PROTOCOL) != 0
-> The crucial missing check which led to the problem.
Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Florian Westphal <fw@strlen.de>
Diffstat (limited to 'src/ct.c')
-rw-r--r-- | src/ct.c | 2 |
1 files changed, 0 insertions, 2 deletions
@@ -327,8 +327,6 @@ static void ct_expr_pctx_update(struct proto_ctx *ctx, const struct expr *expr) const struct proto_desc *base = NULL, *desc; uint32_t nhproto; - assert(expr->op == OP_EQ); - nhproto = mpz_get_uint32(right->value); base = ctx->protocol[left->ct.base].desc; |