[nft PATCH v4 25/32] netlink_delinearize: refactor stmt_payload_binop_postprocess

[Jeremy Sowden <jeremy@azazel.net>]

We are about to add support for a new payload binop that needs to be
post-processed, so move the contents of the two major cases (I and II)
into separate functions to keep the function size reasonable.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
---
 src/netlink_delinearize.c | 191 +++++++++++++++++++++-----------------
 1 file changed, 108 insertions(+), 83 deletions(-)

diff --git a/src/netlink_delinearize.c b/src/netlink_delinearize.c
index 8f19594a1633..4036646d57ac 100644
--- a/src/netlink_delinearize.c
+++ b/src/netlink_delinearize.c
@@ -2862,6 +2862,110 @@ static void stmt_payload_binop_pp(struct rule_pp_ctx *ctx, struct expr *binop)
 	}
 }
 
+static bool stmt_payload_binop_postprocess_i(struct rule_pp_ctx *ctx)
+{
+	struct expr *expr, *binop, *payload, *value, *mask;
+	struct stmt *stmt = ctx->stmt;
+	mpz_t tmp, bitmask;
+
+	expr = stmt->payload.val;
+
+	if (expr->op != OP_OR)
+		return false;
+
+	value = expr->right;
+	if (value->etype != EXPR_VALUE)
+		return false;
+
+	binop = expr->left;
+	if (binop->op != OP_AND)
+		return false;
+
+	payload = binop->left;
+	if (payload->etype != EXPR_PAYLOAD)
+		return false;
+
+	if (!payload_expr_cmp(stmt->payload.expr, payload))
+		return false;
+
+	mask = binop->right;
+	if (mask->etype != EXPR_VALUE)
+		return false;
+
+	mpz_init(tmp);
+	mpz_set(tmp, mask->value);
+
+	mpz_init_bitmask(bitmask, payload->len);
+	mpz_xor(bitmask, bitmask, mask->value);
+	mpz_xor(bitmask, bitmask, value->value);
+	mpz_set(mask->value, bitmask);
+	mpz_clear(bitmask);
+
+	binop_postprocess(ctx, expr, &expr->left);
+	if (!payload_is_known(payload))
+		mpz_set(mask->value, tmp);
+	else {
+		expr_free(stmt->payload.expr);
+		stmt->payload.expr = expr_get(payload);
+		stmt->payload.val = expr_get(expr->right);
+		expr_free(expr);
+	}
+
+	mpz_clear(tmp);
+
+	return true;
+}
+
+static bool stmt_payload_binop_postprocess_ii(struct rule_pp_ctx *ctx)
+{
+	struct expr *expr, *payload, *value;
+	struct stmt *stmt = ctx->stmt;
+	mpz_t bitmask;
+
+	expr = stmt->payload.val;
+
+	value = expr->right;
+	if (value->etype != EXPR_VALUE)
+		return false;
+
+	switch (expr->op) {
+	case OP_AND: /* IIa */
+		payload = expr->left;
+		mpz_init_bitmask(bitmask, payload->len);
+		mpz_xor(bitmask, bitmask, value->value);
+		mpz_set(value->value, bitmask);
+		mpz_clear(bitmask);
+		break;
+	case OP_OR: /* IIb */
+		break;
+	default: /* No idea */
+		return false;
+	}
+
+	stmt_payload_binop_pp(ctx, expr);
+	if (!payload_is_known(expr->left))
+		return false;
+
+	expr_free(stmt->payload.expr);
+
+	switch (expr->op) {
+	case OP_AND:
+		/* Mask was used to match payload, i.e.
+		 * user asked to set zero value.
+		 */
+		mpz_set_ui(value->value, 0);
+		break;
+	default:
+		break;
+	}
+
+	stmt->payload.expr = expr_get(expr->left);
+	stmt->payload.val = expr_get(expr->right);
+	expr_free(expr);
+
+	return true;
+}
+
 /**
  * stmt_payload_binop_postprocess - decode payload set binop
  *
@@ -2906,9 +3010,8 @@ static void stmt_payload_binop_pp(struct rule_pp_ctx *ctx, struct expr *binop)
  */
 static void stmt_payload_binop_postprocess(struct rule_pp_ctx *ctx)
 {
-	struct expr *expr, *binop, *payload, *value, *mask;
+	struct expr *expr;
 	struct stmt *stmt = ctx->stmt;
-	mpz_t bitmask;
 
 	expr = stmt->payload.val;
 
@@ -2916,93 +3019,15 @@ static void stmt_payload_binop_postprocess(struct rule_pp_ctx *ctx)
 		return;
 
 	switch (expr->left->etype) {
-	case EXPR_BINOP: {/* I? */
-		mpz_t tmp;
-
-		if (expr->op != OP_OR)
-			return;
-
-		value = expr->right;
-		if (value->etype != EXPR_VALUE)
-			return;
-
-		binop = expr->left;
-		if (binop->op != OP_AND)
-			return;
-
-		payload = binop->left;
-		if (payload->etype != EXPR_PAYLOAD)
-			return;
-
-		if (!payload_expr_cmp(stmt->payload.expr, payload))
+	case EXPR_BINOP: /* I? */
+		if (stmt_payload_binop_postprocess_i(ctx))
 			return;
 
-		mask = binop->right;
-		if (mask->etype != EXPR_VALUE)
-			return;
-
-		mpz_init(tmp);
-		mpz_set(tmp, mask->value);
-
-		mpz_init_bitmask(bitmask, payload->len);
-		mpz_xor(bitmask, bitmask, mask->value);
-		mpz_xor(bitmask, bitmask, value->value);
-		mpz_set(mask->value, bitmask);
-		mpz_clear(bitmask);
-
-		binop_postprocess(ctx, expr, &expr->left);
-		if (!payload_is_known(payload)) {
-			mpz_set(mask->value, tmp);
-			mpz_clear(tmp);
-			return;
-		}
-
-		mpz_clear(tmp);
-		expr_free(stmt->payload.expr);
-		stmt->payload.expr = expr_get(payload);
-		stmt->payload.val = expr_get(expr->right);
-		expr_free(expr);
 		break;
-	}
 	case EXPR_PAYLOAD: /* II? */
-		value = expr->right;
-		if (value->etype != EXPR_VALUE)
+		if (stmt_payload_binop_postprocess_ii(ctx))
 			return;
 
-		switch (expr->op) {
-		case OP_AND: /* IIa */
-			payload = expr->left;
-			mpz_init_bitmask(bitmask, payload->len);
-			mpz_xor(bitmask, bitmask, value->value);
-			mpz_set(value->value, bitmask);
-			mpz_clear(bitmask);
-			break;
-		case OP_OR: /* IIb */
-			break;
-		default: /* No idea */
-			return;
-		}
-
-		stmt_payload_binop_pp(ctx, expr);
-		if (!payload_is_known(expr->left))
-			return;
-
-		expr_free(stmt->payload.expr);
-
-		switch (expr->op) {
-		case OP_AND:
-			/* Mask was used to match payload, i.e.
-			 * user asked to set zero value.
-			 */
-			mpz_set_ui(value->value, 0);
-			break;
-		default:
-			break;
-		}
-
-		stmt->payload.expr = expr_get(expr->left);
-		stmt->payload.val = expr_get(expr->right);
-		expr_free(expr);
 		break;
 	default: /* No idea */
 		break;
-- 
2.35.1