netlink: move binop postprocess to extra function

Just move the payload trim part to a separate function.
Next patch will add a second call site to deal with map ops
that use a lookup based on a binop result.

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

diff --git a/src/netlink_delinearize.c b/src/netlink_delinearize.c
index 3f01781658c476becb2b2b4e20c23576532fa163..724d52f76e6e8a55efe646318a0ab78e87c5d76e 100644 (file)
--- a/src/netlink_delinearize.c
+++ b/src/netlink_delinearize.c
@@ -1170,6 +1170,40 @@ static struct expr *binop_tree_to_list(struct expr *list, struct expr *expr)
        return list;
 }
 
+static void binop_postprocess(struct rule_pp_ctx *ctx, struct expr *expr)
+{
+       struct expr *binop = expr->left, *value = expr->right;
+
+       struct expr *payload = binop->left;
+       struct expr *mask = binop->right;
+       unsigned int shift;
+
+       if (payload_expr_trim(payload, mask, &ctx->pctx, &shift)) {
+               /* mask is implicit, binop needs to be removed.
+                *
+                * Fix all values of the expression according to the mask
+                * and then process the payload instruction using the real
+                * sizes and offsets we're interested in.
+                *
+                * Finally, convert the expression to 1) by replacing
+                * the binop with the binop payload expr.
+                */
+               if (value->ops->type == EXPR_VALUE) {
+                       assert(value->len >= expr->left->right->len);
+                       mpz_rshift_ui(value->value, shift);
+                       value->len = payload->len;
+               }
+
+               payload_match_postprocess(ctx, expr, payload);
+
+               assert(expr->left->ops->type == EXPR_BINOP);
+
+               assert(binop->left == payload);
+               expr->left = expr_get(payload);
+               expr_free(binop);
+       }
+}
+
 static void relational_binop_postprocess(struct rule_pp_ctx *ctx, struct expr *expr)
 {
        struct expr *binop = expr->left, *value = expr->right;
@@ -1202,10 +1236,6 @@ static void relational_binop_postprocess(struct rule_pp_ctx *ctx, struct expr *e
        } else if (binop->op == OP_AND &&
                   binop->left->ops->type == EXPR_PAYLOAD &&
                   binop->right->ops->type == EXPR_VALUE) {
-               struct expr *payload = binop->left;
-               struct expr *mask = binop->right;
-               unsigned int shift;
-
                /*
                 * This *might* be a payload match testing header fields that
                 * have non byte divisible offsets and/or bit lengths.
@@ -1229,30 +1259,7 @@ static void relational_binop_postprocess(struct rule_pp_ctx *ctx, struct expr *e
                 * payload_expr_trim will figure out if the mask is needed to match
                 * templates.
                 */
-               if (payload_expr_trim(payload, mask, &ctx->pctx, &shift)) {
-                       /* mask is implicit, binop needs to be removed.
-                        *
-                        * Fix all values of the expression according to the mask
-                        * and then process the payload instruction using the real
-                        * sizes and offsets we're interested in.
-                        *
-                        * Finally, convert the expression to 1) by replacing
-                        * the binop with the binop payload expr.
-                        */
-                       if (value->ops->type == EXPR_VALUE) {
-                               assert(value->len >= expr->left->right->len);
-                               mpz_rshift_ui(value->value, shift);
-                               value->len = payload->len;
-                       }
-
-                       payload_match_postprocess(ctx, expr, payload);
-
-                       assert(expr->left->ops->type == EXPR_BINOP);
-
-                       assert(binop->left == payload);
-                       expr->left = expr_get(payload);
-                       expr_free(binop);
-               }
+               binop_postprocess(ctx, expr);
        }
 }