src: expr: add and use internal expr_ops helper

This helper will eventually lookup the correct expr_ops
struct, so we can get rid of the expr->ops pointer.

Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/src/expression.c b/src/expression.c
index 37b106f82b39cb8366359ea7f11007ae02835c05..309a0f133b4550b6ca7ea9375dff7403bb4cc2d5 100644 (file)
--- a/src/expression.c
+++ b/src/expression.c
@@ -25,6 +25,11 @@
 #include <erec.h>
 #include <json.h>
 
+static const struct expr_ops *expr_ops(const struct expr *e)
+{
+       return e->ops;
+}
+
 struct expr *expr_alloc(const struct location *loc, const struct expr_ops *ops,
                        const struct datatype *dtype, enum byteorder byteorder,
                        unsigned int len)
@@ -60,20 +65,31 @@ struct expr *expr_get(struct expr *expr)
        return expr;
 }
 
+static void expr_destroy(struct expr *e)
+{
+       const struct expr_ops *ops = expr_ops(e);
+
+       if (ops && ops->destroy)
+               ops->destroy(e);
+}
+
 void expr_free(struct expr *expr)
 {
        if (expr == NULL)
                return;
        if (--expr->refcnt > 0)
                return;
-       if (expr->ops && expr->ops->destroy)
-               expr->ops->destroy(expr);
+
+       expr_destroy(expr);
        xfree(expr);
 }
 
 void expr_print(const struct expr *expr, struct output_ctx *octx)
 {
-       expr->ops->print(expr, octx);
+       const struct expr_ops *ops = expr_ops(expr);
+
+       if (ops->print)
+               ops->print(expr, octx);
 }
 
 bool expr_cmp(const struct expr *e1, const struct expr *e2)
@@ -84,7 +100,7 @@ bool expr_cmp(const struct expr *e1, const struct expr *e2)
        if (e1->ops->type != e2->ops->type)
                return false;
 
-       return e1->ops->cmp(e1, e2);
+       return expr_ops(e1)->cmp(e1, e2);
 }
 
 const char *expr_name(const struct expr *e)
@@ -98,7 +114,7 @@ void expr_describe(const struct expr *expr, struct output_ctx *octx)
        const char *delim = "";
 
        nft_print(octx, "%s expression, datatype %s (%s)",
-                 expr->ops->name, dtype->name, dtype->desc);
+                 expr_name(expr), dtype->name, dtype->desc);
        if (dtype->basetype != NULL) {
                nft_print(octx, " (basetype ");
                for (dtype = dtype->basetype; dtype != NULL;
@@ -134,8 +150,10 @@ void expr_describe(const struct expr *expr, struct output_ctx *octx)
 void expr_set_type(struct expr *expr, const struct datatype *dtype,
                   enum byteorder byteorder)
 {
-       if (expr->ops->set_type)
-               expr->ops->set_type(expr, dtype, byteorder);
+       const struct expr_ops *ops = expr_ops(expr);
+
+       if (ops->set_type)
+               ops->set_type(expr, dtype, byteorder);
        else {
                expr->dtype     = dtype;
                expr->byteorder = byteorder;
@@ -654,13 +672,15 @@ void relational_expr_pctx_update(struct proto_ctx *ctx,
                                 const struct expr *expr)
 {
        const struct expr *left = expr->left;
+       const struct expr_ops *ops;
 
        assert(expr->ops->type == EXPR_RELATIONAL);
        assert(expr->op == OP_EQ || expr->op == OP_IMPLICIT);
 
-       if (left->ops->pctx_update &&
+       ops = expr_ops(left);
+       if (ops->pctx_update &&
            (left->flags & EXPR_F_PROTOCOL))
-               left->ops->pctx_update(ctx, expr);
+               ops->pctx_update(ctx, expr);
 }
 
 static void range_expr_print(const struct expr *expr, struct output_ctx *octx)