Labeling established and related packets requires the secmark to be stored in the connection.
Add the ability to store and retrieve secmarks like:
...
chain input {
...
# label new incoming packets
ct state new meta secmark set tcp dport map @secmapping_in
# add label to connection
ct state new ct secmark set meta secmark
# set label for est/rel packets from connection
ct state established,related meta secmark set ct secmark
...
}
...
chain output {
...
# label new outgoing packets
ct state new meta secmark set tcp dport map @secmapping_out
# add label to connection
ct state new ct secmark set meta secmark
# set label for est/rel packets from connection
ct state established,related meta secmark set ct secmark
...
}
...
This patch also disallow constant value on the right hand side.
# nft add rule x y meta secmark 12
Error: Cannot be used with right hand side constant value
add rule x y meta secmark 12
~~~~~~~~~~~~ ^^
# nft add rule x y ct secmark 12
Error: Cannot be used with right hand side constant value
add rule x y ct secmark 12
~~~~~~~~~~ ^^
# nft add rule x y ct secmark set 12
Error: ct secmark must not be set to constant value
add rule x y ct secmark set 12
^^^^^^^^^^^^^^^^^
This patch improves 3bc84e5c1fdd ("src: add support for setting secmark").
Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
---
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"
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
