netlink: fix nat stmt linearization/parsing

Fix invalid register use when parsing NAT statements and handle range expressions
during postprocessing. When linearizing, allocate all registers for both proto and
address expressions at once to avoid double use.

Signed-off-by: Patrick McHardy <kaber@trash.net>

diff --git a/src/netlink_delinearize.c b/src/netlink_delinearize.c
index a8f700aa69b2445fe21e1623689d0964bb096930..d75df215cf97d6ad5d23e54916f9da9c7807b5b2 100644 (file)
--- a/src/netlink_delinearize.c
+++ b/src/netlink_delinearize.c
@@ -408,14 +408,13 @@ static void netlink_parse_nat(struct netlink_parse_ctx *ctx,
 
        reg2 = nfnl_nft_nat_get_sreg_proto_max(nle);
        if (reg2 && reg2 != reg1) {
-               proto = netlink_get_register(ctx, loc, reg1);
+               proto = netlink_get_register(ctx, loc, reg2);
                if (proto == NULL)
                        return netlink_error(ctx, loc,
                                             "NAT statement has no proto "
                                             "expression");
 
                expr_set_type(proto, &inet_service_type, BYTEORDER_BIG_ENDIAN);
-               stmt->nat.proto = proto;
                if (stmt->nat.proto != NULL)
                        proto = range_expr_alloc(loc, stmt->nat.proto, proto);
                stmt->nat.proto = proto;
@@ -629,6 +628,10 @@ static void expr_postprocess(struct rule_pp_ctx *ctx,
                        expr->len = len;
                }
                break;
+       case EXPR_RANGE:
+               expr_postprocess(ctx, stmt, &expr->left);
+               expr_postprocess(ctx, stmt, &expr->right);
+               break;
        case EXPR_SET_REF:
        case EXPR_EXTHDR:
        case EXPR_META:

diff --git a/src/netlink_linearize.c b/src/netlink_linearize.c
index f3ff7d146a5cf22ee89b443f122f0cb31f2e34ad..a3841fb9e3e2b4f02f034263f9eac62c44653d9c 100644 (file)
--- a/src/netlink_linearize.c
+++ b/src/netlink_linearize.c
@@ -500,53 +500,53 @@ static void netlink_gen_nat_stmt(struct netlink_linearize_ctx *ctx,
        struct nfnl_nft_expr *nle;
        enum nft_registers amin_reg, amax_reg;
        enum nft_registers pmin_reg, pmax_reg;
+       int registers = 0;
 
        nle = alloc_nft_expr(nfnl_nft_nat_init);
        nfnl_nft_nat_set_type(nle, stmt->nat.type);
 
        if (stmt->nat.addr) {
-               switch (stmt->nat.addr->ops->type) {
-               default:
-                       amin_reg = amax_reg = get_register(ctx);
-                       netlink_gen_expr(ctx, stmt->nat.addr, amin_reg);
-                       nfnl_nft_nat_set_sreg_addr_min(nle, amin_reg);
-                       release_register(ctx);
-                       break;
-               case EXPR_RANGE:
-                       amin_reg = get_register(ctx);
+               amin_reg = get_register(ctx);
+               registers++;
+
+               if (stmt->nat.addr->ops->type == EXPR_RANGE) {
                        amax_reg = get_register(ctx);
+                       registers++;
+
                        netlink_gen_expr(ctx, stmt->nat.addr->left, amin_reg);
                        netlink_gen_expr(ctx, stmt->nat.addr->right, amax_reg);
                        nfnl_nft_nat_set_sreg_addr_min(nle, amin_reg);
                        nfnl_nft_nat_set_sreg_addr_max(nle, amax_reg);
-                       release_register(ctx);
-                       release_register(ctx);
-                       break;
+               } else {
+                       netlink_gen_expr(ctx, stmt->nat.addr, amin_reg);
+                       nfnl_nft_nat_set_sreg_addr_min(nle, amin_reg);
                }
 
        }
 
        if (stmt->nat.proto) {
-               switch (stmt->nat.proto->ops->type) {
-               default:
-                       pmin_reg = pmax_reg = get_register(ctx);
-                       netlink_gen_expr(ctx, stmt->nat.proto, pmin_reg);
-                       nfnl_nft_nat_set_sreg_proto_min(nle, pmin_reg);
-                       release_register(ctx);
-                       break;
-               case EXPR_RANGE:
-                       pmin_reg = get_register(ctx);
+               pmin_reg = get_register(ctx);
+               registers++;
+
+               if (stmt->nat.proto->ops->type == EXPR_RANGE) {
                        pmax_reg = get_register(ctx);
+                       registers++;
+
                        netlink_gen_expr(ctx, stmt->nat.proto->left, pmin_reg);
                        netlink_gen_expr(ctx, stmt->nat.proto->right, pmax_reg);
                        nfnl_nft_nat_set_sreg_proto_min(nle, pmin_reg);
                        nfnl_nft_nat_set_sreg_proto_max(nle, pmax_reg);
-                       release_register(ctx);
-                       release_register(ctx);
-                       break;
+               } else {
+                       netlink_gen_expr(ctx, stmt->nat.proto, pmin_reg);
+                       nfnl_nft_nat_set_sreg_proto_min(nle, pmin_reg);
                }
        }
 
+       while (registers > 0) {
+               release_register(ctx);
+               registers--;
+       }
+
        nfnl_nft_rule_add_expr(ctx->nlr, nle);
 }