[PATCH nft] evaluate: postpone transport protocol match check after nat expression evaluation

[PATCH nft] evaluate: postpone transport protocol match check after nat expression evaluation

[Pablo Neira Ayuso]

Fix bogus error report when using transport protocol as map key.

Fixes: 50780456a01a ("evaluate: check for missing transport protocol match in nat map with concatenations")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 src/evaluate.c                | 13 +++++++------
 tests/py/ip/dnat.t            |  1 +
 tests/py/ip/dnat.t.payload.ip | 13 +++++++++++++
 tests/py/ip/snat.t.payload    | 13 +++++++++++++
 4 files changed, 34 insertions(+), 6 deletions(-)

diff --git a/src/evaluate.c b/src/evaluate.c
index 609e171d8993..6a8c396f33c4 100644
--- a/src/evaluate.c
+++ b/src/evaluate.c
@@ -3170,12 +3170,6 @@ static int stmt_evaluate_nat_map(struct eval_ctx *ctx, struct stmt *stmt)
 	const struct datatype *dtype;
 	int addr_type, err;
 
-	if (pctx->protocol[PROTO_BASE_TRANSPORT_HDR].desc == NULL &&
-	    !nat_evaluate_addr_has_th_expr(stmt->nat.addr))
-		return stmt_binary_error(ctx, stmt->nat.addr, stmt,
-					 "transport protocol mapping is only "
-					 "valid after transport protocol match");
-
 	switch (stmt->nat.family) {
 	case NFPROTO_IPV4:
 		addr_type = TYPE_IPADDR;
@@ -3192,6 +3186,13 @@ static int stmt_evaluate_nat_map(struct eval_ctx *ctx, struct stmt *stmt)
 	if (expr_evaluate(ctx, &stmt->nat.addr))
 		return -1;
 
+	if (pctx->protocol[PROTO_BASE_TRANSPORT_HDR].desc == NULL &&
+	    !nat_evaluate_addr_has_th_expr(stmt->nat.addr)) {
+		return stmt_binary_error(ctx, stmt->nat.addr, stmt,
+					 "transport protocol mapping is only "
+					 "valid after transport protocol match");
+	}
+
 	if (stmt->nat.addr->etype != EXPR_MAP)
 		return 0;
 
diff --git a/tests/py/ip/dnat.t b/tests/py/ip/dnat.t
index c5ca4c40db1b..889f0fd7bf6c 100644
--- a/tests/py/ip/dnat.t
+++ b/tests/py/ip/dnat.t
@@ -18,3 +18,4 @@ dnat to ct mark . ip daddr map { 0x00000014 . 1.1.1.1 : 1.2.3.4};ok
 dnat ip to ip saddr . tcp dport map { 192.168.1.2 . 80 : 10.141.10.0/24  . 8888 - 8999 };ok
 dnat ip to ip saddr . tcp dport map { 192.168.1.2 . 80 : 10.141.10.0/24  . 80 };ok
 dnat ip to ip saddr . tcp dport map { 192.168.1.2 . 80 : 10.141.10.2 . 8888 - 8999 };ok
+ip daddr 192.168.0.1 dnat ip to tcp dport map { 443 : 10.141.10.4 . 8443, 80 : 10.141.10.4 . 8080 };ok
diff --git a/tests/py/ip/dnat.t.payload.ip b/tests/py/ip/dnat.t.payload.ip
index 4872545a85a1..e53838a32262 100644
--- a/tests/py/ip/dnat.t.payload.ip
+++ b/tests/py/ip/dnat.t.payload.ip
@@ -167,3 +167,16 @@ ip
   [ immediate reg 4 0x00002723 ]
   [ nat dnat ip addr_min reg 1 addr_max reg 2 proto_min reg 3 proto_max reg 4 flags 0x2 ]
 
+# ip daddr 192.168.0.1 dnat ip to tcp dport map { 443 : 10.141.10.4 . 8443, 80 : 10.141.10.4 . 8080 }
+__map%d test-ip4 b size 2
+__map%d test-ip4 0
+        element 0000bb01  : 040a8d0a 0000fb20 0 [end]   element 00005000  : 040a8d0a 0000901f 0 [end]
+ip
+  [ payload load 4b @ network header + 16 => reg 1 ]
+  [ cmp eq reg 1 0x0100a8c0 ]
+  [ meta load l4proto => reg 1 ]
+  [ cmp eq reg 1 0x00000006 ]
+  [ payload load 2b @ transport header + 2 => reg 1 ]
+  [ lookup reg 1 set __map%d dreg 1 ]
+  [ nat dnat ip addr_min reg 1 proto_min reg 9 ]
+
diff --git a/tests/py/ip/snat.t.payload b/tests/py/ip/snat.t.payload
index 48ae46b31121..71a5e2f1a54e 100644
--- a/tests/py/ip/snat.t.payload
+++ b/tests/py/ip/snat.t.payload
@@ -139,3 +139,16 @@ ip
   [ lookup reg 1 set __map%d dreg 1 ]
   [ nat snat ip addr_min reg 1 proto_min reg 9 ]
 
+# ip daddr 192.168.0.1 dnat to tcp dport map { 443 : 10.141.10.4 . 8443, 80 : 10.141.10.4 . 8080 }
+__map%d x b size 2
+__map%d x 0
+        element 0000bb01  : 040a8d0a 0000fb20 0 [end]   element 00005000  : 040a8d0a 0000901f 0 [end]
+ip
+  [ payload load 4b @ network header + 16 => reg 1 ]
+  [ cmp eq reg 1 0x0100a8c0 ]
+  [ meta load l4proto => reg 1 ]
+  [ cmp eq reg 1 0x00000006 ]
+  [ payload load 2b @ transport header + 2 => reg 1 ]
+  [ lookup reg 1 set __map%d dreg 1 ]
+  [ nat dnat ip addr_min reg 1 proto_min reg 9 ]
+
-- 
2.30.2