add "print" xlat, which produces a printable string

using double-escaping rules when we have tainted inputs

diff --git a/src/lib/unlang/xlat_builtin.c b/src/lib/unlang/xlat_builtin.c
index 6d7bc79ba3a5db61067802b9b27e772c4956d7f7..91a406000753ba7b9fb2f0488343ea131e908bb2 100644 (file)
--- a/src/lib/unlang/xlat_builtin.c
+++ b/src/lib/unlang/xlat_builtin.c
@@ -2552,6 +2552,56 @@ static xlat_action_t xlat_func_pairs(TALLOC_CTX *ctx, fr_dcursor_t *out,
 }
 
 
+static xlat_arg_parser_t const xlat_func_print_args[] = {
+       { .required = true, .variadic = true, .type = FR_TYPE_VOID },
+       XLAT_ARG_PARSER_TERMINATOR
+};
+
+/** Create printable versions of things.
+ *
+@verbatim
+%(print:&Tmp-Octets-0) results in the printable version of the attribute.
+@endverbatim
+ *
+ * @ingroup xlat_functions
+ */
+static xlat_action_t xlat_func_print(UNUSED TALLOC_CTX *ctx, fr_dcursor_t *out,
+                                   UNUSED xlat_ctx_t const *xctx,
+                                   request_t *request, fr_value_box_list_t *in)
+{
+       fr_sbuff_t *agg;
+       fr_value_box_t *dst;
+
+       FR_SBUFF_TALLOC_THREAD_LOCAL(&agg, 256, 8192);
+
+       fr_dlist_foreach(in, fr_value_box_t, arg) {
+               fr_assert(arg->type == FR_TYPE_GROUP);
+
+               fr_dlist_foreach(&arg->vb_group, fr_value_box_t, vb) {
+                       ssize_t slen;
+
+                       /*
+                        *      If the input is tainted, escape it using the normal double-quoting rules.
+                        *
+                        *      The resulting output string is not tainted.
+                        */
+                       slen = fr_value_box_print(agg, vb, vb->tainted ? &fr_value_escape_double : NULL);
+                       if (slen < 0) {
+                               RPEDEBUG("Failed printing %pV to data type 'string'", vb);
+                               return XLAT_ACTION_FAIL;
+                       }
+               }
+       }
+
+       MEM(dst = fr_value_box_alloc_null(ctx));
+       fr_value_box_bstrndup_shallow(dst, NULL, fr_sbuff_start(agg), fr_sbuff_used(agg), false);
+       fr_dcursor_append(out, dst);
+
+       fr_dlist_talloc_free(in);
+
+       return XLAT_ACTION_DONE;
+}
+
 static xlat_arg_parser_t const xlat_func_rand_arg = {
        .required = true,
        .single = true,
@@ -3771,6 +3821,7 @@ do { \
        XLAT_REGISTER_ARGS("length", xlat_func_length, xlat_func_length_args);
        XLAT_REGISTER_ARGS("lpad", xlat_func_lpad, xlat_func_pad_args);
        XLAT_REGISTER_ARGS("rpad", xlat_func_rpad, xlat_func_pad_args);
+       XLAT_REGISTER_ARGS("print", xlat_func_print, xlat_func_print_args);
 
        /*
         *      The inputs to these functions are variable.