comments and updates

diff --git a/src/lib/util/value.c b/src/lib/util/value.c
index d1417565a3e7ba566abf7b4e8e6abda6bf018886..c0336f887dd304e5a32b83a95a106ecfd87057d0 100644 (file)
--- a/src/lib/util/value.c
+++ b/src/lib/util/value.c
@@ -1352,7 +1352,10 @@ static bool dns_label_match(uint8_t const *start, uint8_t const *a, uint8_t cons
        return dns_label_match(start, a, b);
 }
 
-/** Compress "label" by looking at buffer in start..end
+/** Compress "label" by looking for other labels in start..end
+ *
+ *  We assume that the input is valid.  If it isn't valid, bad things
+ *  will happen.
  *
  * "label" MUST be uncompressed.
  */
@@ -1449,6 +1452,11 @@ ssize_t fr_value_box_to_dns_label(size_t *need, uint8_t *buf, size_t buf_len, ui
         */
        if (value->type != FR_TYPE_STRING) return -1;
 
+       if (value->vb_length > 255) {
+               fr_strerror_printf("Label is too long");
+               return -1;
+       }
+
        /*
         *      '.' or empty string is special, and is encoded as a
         *      plain zero byte.
@@ -1462,8 +1470,8 @@ ssize_t fr_value_box_to_dns_label(size_t *need, uint8_t *buf, size_t buf_len, ui
        }
 
        /*
-        *      For now we don't do compression.  We just encode the
-        *      label as-is.
+        *      For now, just encode the value as-is.  We do
+        *      compression as a second step.
         *
         *      We need a minimum length of string + beginning length
         *      + trailing zero.  Intermediate '.' are converted to
@@ -1483,7 +1491,7 @@ ssize_t fr_value_box_to_dns_label(size_t *need, uint8_t *buf, size_t buf_len, ui
 
        /*
         *      @todo - encode into a local buffer, and then try to
-        *      compress it into the output buffer.  This means that
+        *      compress that into the output buffer.  This means that
         *      the output buffer can be a little bit smaller.
         */
        while (q < strend) {