Hi Christian,
On Sat, Nov 23, 2019 at 05:22:39PM +0100, Christian Göttsche wrote:
[...]
> v2: - incorporate changes suggested by Pablo Neira Ayuso
> - invalidate setting ct secmark to a constant value, like:
> ct secmark set 12
> Note:
> statements setting the meta secmark, like
> meta secmark set 12
> must accept constant values, cause the secmark object identifier
> is a string
> meta secmark set "icmp_client"
This is represented as a object reference statement from the parser.
It should be safe to do the same check from stmt_evaluate_meta() that
this patch does for stmt_evaluate_ct().
> 12 is probably not a used secmark object identifier, so it will
> fail:
> nft add rule inet filter input meta secmark set 12
> Error: Could not process rule: No such file or directory
> add rule inet filter input meta secmark set 12
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> src/ct.c | 2 ++
> src/evaluate.c | 24 ++++++++++++++++++++++--
> src/meta.c | 2 ++
> src/parser_bison.y | 14 +++++++++++---
> 4 files changed, 37 insertions(+), 5 deletions(-)
>
> diff --git a/src/ct.c b/src/ct.c
> index ed458e6b..9e6a8351 100644
> --- a/src/ct.c
> +++ b/src/ct.c
> @@ -299,6 +299,8 @@ const struct ct_template ct_templates[__NFT_CT_MAX] = {
> BYTEORDER_BIG_ENDIAN, 128),
> [NFT_CT_DST_IP6] = CT_TEMPLATE("ip6 daddr", &ip6addr_type,
> BYTEORDER_BIG_ENDIAN, 128),
> + [NFT_CT_SECMARK] = CT_TEMPLATE("secmark", &integer_type,
> + BYTEORDER_HOST_ENDIAN, 32),
> };
>
> static void ct_print(enum nft_ct_keys key, int8_t dir, uint8_t nfproto,
> diff --git a/src/evaluate.c b/src/evaluate.c
> index e54eaf1a..a865902c 100644
> --- a/src/evaluate.c
> +++ b/src/evaluate.c
> @@ -1784,6 +1784,18 @@ static int expr_evaluate_relational(struct eval_ctx *ctx, struct expr **expr)
> left->dtype->desc,
> right->dtype->desc);
>
> + /*
> + * Statements like 'ct secmark 12' are parsed as relational,
> + * disallow constant value on the right hand side.
> + */
> + if (((left->etype == EXPR_META &&
> + left->meta.key == NFT_META_SECMARK) ||
> + (left->etype == EXPR_CT &&
> + left->ct.key == NFT_CT_SECMARK)) &&
> + right->flags & EXPR_F_CONSTANT)
> + return expr_binary_error(ctx->msgs, right, left,
> + "Cannot be used with right hand side constant value");
> +
> switch (rel->op) {
> case OP_EQ:
> case OP_IMPLICIT:
> @@ -2319,11 +2331,19 @@ static int stmt_evaluate_meta(struct eval_ctx *ctx, struct stmt *stmt)
>
> static int stmt_evaluate_ct(struct eval_ctx *ctx, struct stmt *stmt)
> {
> - return stmt_evaluate_arg(ctx, stmt,
> + if (stmt_evaluate_arg(ctx, stmt,
> stmt->ct.tmpl->dtype,
> stmt->ct.tmpl->len,
> stmt->ct.tmpl->byteorder,
> - &stmt->ct.expr);
> + &stmt->ct.expr) < 0)
> + return -1;
> +
> + if (stmt->ct.key == NFT_CT_SECMARK &&
> + expr_is_constant(stmt->ct.expr))
> + return stmt_error(ctx, stmt,
> + "ct secmark must not be set to constant value");
> +
> + return 0;
> }
>
> static int reject_payload_gen_dependency_tcp(struct eval_ctx *ctx,
> diff --git a/src/meta.c b/src/meta.c
> index 69a897a9..796d8e94 100644
> --- a/src/meta.c
> +++ b/src/meta.c
> @@ -698,6 +698,8 @@ const struct meta_template meta_templates[] = {
> [NFT_META_TIME_HOUR] = META_TEMPLATE("hour", &hour_type,
> 4 * BITS_PER_BYTE,
> BYTEORDER_HOST_ENDIAN),
> + [NFT_META_SECMARK] = META_TEMPLATE("secmark", &integer_type,
> + 32, BYTEORDER_HOST_ENDIAN),
> };
>
> static bool meta_key_is_unqualified(enum nft_meta_keys key)
> diff --git a/src/parser_bison.y b/src/parser_bison.y
> index 631b7d68..707f4671 100644
> --- a/src/parser_bison.y
> +++ b/src/parser_bison.y
> @@ -4190,9 +4190,16 @@ meta_stmt : META meta_key SET stmt_expr
> {
> switch ($2) {
> case NFT_META_SECMARK:
> - $$ = objref_stmt_alloc(&@$);
> - $$->objref.type = NFT_OBJECT_SECMARK;
> - $$->objref.expr = $4;
> + switch ($4->etype) {
> + case EXPR_CT:
> + $$ = meta_stmt_alloc(&@$, $2, $4);
> + break;
> + default:
> + $$ = objref_stmt_alloc(&@$);
> + $$->objref.type = NFT_OBJECT_SECMARK;
> + $$->objref.expr = $4;
> + break;
> + }
> break;
> default:
> $$ = meta_stmt_alloc(&@$, $2, $4);
> @@ -4388,6 +4395,7 @@ ct_key : L3PROTOCOL { $$ = NFT_CT_L3PROTOCOL; }
> | PROTO_DST { $$ = NFT_CT_PROTO_DST; }
> | LABEL { $$ = NFT_CT_LABELS; }
> | EVENT { $$ = NFT_CT_EVENTMASK; }
> + | SECMARK { $$ = NFT_CT_SECMARK; }
> | ct_key_dir_optional
> ;
>
> --
> 2.24.0
>
