netlink_delinearize: Replace some BUG()s by error messages

Netlink parser tries to keep going despite errors. Faced with an
incompatible ruleset, this is much more user-friendly than exiting the
program upon the first obstacle. This patch fixes three more spots to
support this.

Signed-off-by: Phil Sutter <phil@nwl.cc>
Reviewed-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/src/netlink_delinearize.c b/src/netlink_delinearize.c
index f7c10fb5af316a1a85c55c37eeadbe84e26c0422..48a3e33adc8fb7fb48491676f51162d2deef03b7 100644 (file)
--- a/src/netlink_delinearize.c
+++ b/src/netlink_delinearize.c
@@ -605,7 +605,8 @@ static void netlink_parse_bitwise(struct netlink_parse_ctx *ctx,
                                                   sreg, left);
                break;
        default:
-               BUG("invalid bitwise operation %u\n", op);
+               return netlink_error(ctx, loc,
+                                    "Invalid bitwise operation %u", op);
        }
 
        dreg = netlink_parse_register(nle, NFTNL_EXPR_BITWISE_DREG);
@@ -616,6 +617,7 @@ static void netlink_parse_byteorder(struct netlink_parse_ctx *ctx,
                                    const struct location *loc,
                                    const struct nftnl_expr *nle)
 {
+       uint32_t opval = nftnl_expr_get_u32(nle, NFTNL_EXPR_BYTEORDER_OP);
        enum nft_registers sreg, dreg;
        struct expr *expr, *arg;
        enum ops op;
@@ -627,7 +629,7 @@ static void netlink_parse_byteorder(struct netlink_parse_ctx *ctx,
                                     "Byteorder expression has no left "
                                     "hand side");
 
-       switch (nftnl_expr_get_u32(nle, NFTNL_EXPR_BYTEORDER_OP)) {
+       switch (opval) {
        case NFT_BYTEORDER_NTOH:
                op = OP_NTOH;
                break;
@@ -635,8 +637,9 @@ static void netlink_parse_byteorder(struct netlink_parse_ctx *ctx,
                op = OP_HTON;
                break;
        default:
-               BUG("invalid byteorder operation %u\n",
-                   nftnl_expr_get_u32(nle, NFTNL_EXPR_BYTEORDER_OP));
+               expr_free(arg);
+               return netlink_error(ctx, loc,
+                                    "Invalid byteorder operation %u", opval);
        }
 
        expr = unary_expr_alloc(loc, op, arg);
@@ -733,8 +736,10 @@ static void netlink_parse_inner(struct netlink_parse_ctx *ctx,
                expr->meta.inner_desc = inner_desc;
                break;
        default:
-               assert(0);
-               break;
+               netlink_error(ctx, loc, "Unsupported inner expression type %s",
+                             expr_ops(expr)->name);
+               expr_free(expr);
+               return;
        }
 
        netlink_set_register(ctx, ctx->inner_reg, expr);