[nft PATCH 1/4 v2] evaluate: refactor function to check the reject family in inet and bridge

[Alvaro Neira Ayuso <alvaroneay@gmail.com>]

This patch make a refactorization of the code to check the reject family in inet
and bridge. These changes will be used in follow up patches.

Signed-off-by: Alvaro Neira Ayuso <alvaroneay@gmail.com>
---
[changes in v2]
 * Refactor the functions in two functions more, to check the reject family in
   inet and bridge tables.

 src/evaluate.c |  134 ++++++++++++++++++++++++++++++++++++--------------------
 1 file changed, 86 insertions(+), 48 deletions(-)

diff --git a/src/evaluate.c b/src/evaluate.c
index ff46fda..e26e2f8 100644
--- a/src/evaluate.c
+++ b/src/evaluate.c
@@ -1202,12 +1202,94 @@ static int stmt_reject_gen_dependency(struct eval_ctx *ctx, struct stmt *stmt,
 	return 0;
 }
 
-static int stmt_evaluate_reject_family(struct eval_ctx *ctx, struct stmt *stmt,
+static int stmt_evaluate_reject_inet_family(struct eval_ctx *ctx,
+					    struct stmt *stmt,
+					    const struct proto_desc *desc)
+{
+	const struct proto_desc *base;
+	int protocol;
+
+	base = ctx->pctx.protocol[PROTO_BASE_LL_HDR].desc;
+	protocol = proto_find_num(base, desc);
+	switch (protocol) {
+	case NFPROTO_IPV4:
+		if (stmt->reject.family == NFPROTO_IPV4)
+			break;
+		return stmt_error(ctx, stmt,
+				  "conflicting protocols specified: ip vs ip6");
+	case NFPROTO_IPV6:
+		if (stmt->reject.family == NFPROTO_IPV6)
+			break;
+		return stmt_error(ctx, stmt,
+				  "conflicting protocols specified: ip vs ip6");
+	default:
+		BUG("unsupported family");
+	}
+
+	return 0;
+}
+
+static int stmt_evaluate_reject_inet(struct eval_ctx *ctx, struct stmt *stmt,
 				       struct expr *expr)
 {
-	const struct proto_desc *desc, *base;
+	const struct proto_desc *desc;
+
+	desc = ctx->pctx.protocol[PROTO_BASE_NETWORK_HDR].desc;
+	if (desc != NULL &&
+	    stmt_evaluate_reject_inet_family(ctx, stmt, desc) < 0)
+		return -1;
+	if (stmt->reject.type == NFT_REJECT_ICMPX_UNREACH)
+		return 0;
+	if (stmt_reject_gen_dependency(ctx, stmt, expr) < 0)
+		return -1;
+	return 0;
+}
+
+static int stmt_evaluate_reject_bridge_family(struct eval_ctx *ctx,
+					      struct stmt *stmt,
+					      const struct proto_desc *desc)
+{
+	const struct proto_desc *base;
 	int protocol;
 
+	base = ctx->pctx.protocol[PROTO_BASE_LL_HDR].desc;
+	protocol = proto_find_num(base, desc);
+	switch (protocol) {
+	case __constant_htons(ETH_P_IP):
+		if (NFPROTO_IPV4 == stmt->reject.family)
+			break;
+	case __constant_htons(ETH_P_IPV6):
+		if (NFPROTO_IPV6 == stmt->reject.family)
+			break;
+		return stmt_error(ctx, stmt,
+			  "conflicting protocols specified: ip vs ip6");
+	default:
+		return stmt_error(ctx, stmt,
+				  "cannot reject this ether type");
+	}
+
+	return 0;
+}
+
+static int stmt_evaluate_reject_bridge(struct eval_ctx *ctx, struct stmt *stmt,
+				       struct expr *expr)
+{
+	const struct proto_desc *desc;
+
+	desc = ctx->pctx.protocol[PROTO_BASE_NETWORK_HDR].desc;
+	if (desc != NULL &&
+	    stmt_evaluate_reject_bridge_family(ctx, stmt, desc) < 0)
+		return -1;
+	if (stmt->reject.type == NFT_REJECT_ICMPX_UNREACH)
+		return 0;
+	if (stmt_reject_gen_dependency(ctx, stmt, expr) < 0)
+		return -1;
+	return 0;
+}
+
+static int stmt_evaluate_reject_family(struct eval_ctx *ctx, struct stmt *stmt,
+				       struct expr *expr)
+{
 	switch (ctx->pctx.family) {
 	case NFPROTO_ARP:
 		return stmt_error(ctx, stmt, "cannot use reject with arp");
@@ -1229,55 +1311,11 @@ static int stmt_evaluate_reject_family(struct eval_ctx *ctx, struct stmt *stmt,
 		}
 		break;
 	case NFPROTO_BRIDGE:
-		base = ctx->pctx.protocol[PROTO_BASE_LL_HDR].desc;
-		desc = ctx->pctx.protocol[PROTO_BASE_NETWORK_HDR].desc;
-		if (desc != NULL) {
-			protocol = proto_find_num(base, desc);
-			switch (protocol) {
-			case __constant_htons(ETH_P_IP):
-				if (NFPROTO_IPV4 == stmt->reject.family)
-					break;
-			case __constant_htons(ETH_P_IPV6):
-				if (NFPROTO_IPV6 == stmt->reject.family)
-					break;
-				return stmt_error(ctx, stmt,
-				  "conflicting protocols specified: ip vs ip6");
-			default:
-				return stmt_error(ctx, stmt,
-						"cannot reject this ether type");
-			}
-			break;
-		}
-		if (stmt->reject.type == NFT_REJECT_ICMPX_UNREACH)
-			break;
-		if (stmt_reject_gen_dependency(ctx, stmt, expr) < 0)
+		if (stmt_evaluate_reject_bridge(ctx, stmt, expr) < 0)
 			return -1;
 		break;
 	case NFPROTO_INET:
-		base = ctx->pctx.protocol[PROTO_BASE_LL_HDR].desc;
-		desc = ctx->pctx.protocol[PROTO_BASE_NETWORK_HDR].desc;
-		if (desc != NULL) {
-			protocol = proto_find_num(base, desc);
-			switch (protocol) {
-			case NFPROTO_IPV4:
-				if (stmt->reject.family == NFPROTO_IPV4)
-					break;
-				return stmt_error(ctx, stmt,
-				  "conflicting protocols specified: ip vs ip6");
-				break;
-			case NFPROTO_IPV6:
-				if (stmt->reject.family == NFPROTO_IPV6)
-					break;
-				return stmt_error(ctx, stmt,
-				  "conflicting protocols specified: ip vs ip6");
-			default:
-				BUG("unsupported family");
-			}
-			break;
-		}
-		if (stmt->reject.type == NFT_REJECT_ICMPX_UNREACH)
-			break;
-		if (stmt_reject_gen_dependency(ctx, stmt, expr) < 0)
+		if (stmt_evaluate_reject_inet(ctx, stmt, expr) < 0)
 			return -1;
 		break;
 	}
-- 
1.7.10.4