New function to allow casting value boxes in place

diff --git a/src/include/value.h b/src/include/value.h
index 25ec14347516a2ade3bc860ad574b66ed3bfe10b..075c435213e883eea6d2582831d771004efb0162 100644 (file)
--- a/src/include/value.h
+++ b/src/include/value.h
@@ -474,6 +474,9 @@ int         fr_value_box_cast(TALLOC_CTX *ctx, fr_value_box_t *dst,
                                  fr_type_t dst_type, fr_dict_attr_t const *dst_enumv,
                                  fr_value_box_t const *src);
 
+int            fr_value_box_cast_in_place(TALLOC_CTX *ctx, fr_value_box_t *vb,
+                                          fr_type_t dst_type, fr_dict_attr_t const *dst_enumv);
+
 int            fr_value_box_ipaddr(fr_value_box_t *dst, fr_dict_attr_t const *enumv,
                                         fr_ipaddr_t const *ipaddr, bool tainted);
 

diff --git a/src/lib/util/value.c b/src/lib/util/value.c
index 2597b0f0f6e87426ad6e90e7dda5cecff2ae0085..b9f9867b1632a458e6922923f8bd0b090451ed94 100644 (file)
--- a/src/lib/util/value.c
+++ b/src/lib/util/value.c
@@ -2217,6 +2217,8 @@ static inline int fr_value_box_cast_to_uint64(TALLOC_CTX *ctx, fr_value_box_t *d
  *
  * If you want to convert from PRESENTATION format, use #fr_value_box_from_str.
  *
+ * @note src and dst must not be the same box.  We do not support casting in place.
+ *
  * @param ctx          to allocate buffers in (usually the same as dst)
  * @param dst          Where to write result of casting.
  * @param dst_type     to cast to.
@@ -2234,6 +2236,7 @@ int fr_value_box_cast(TALLOC_CTX *ctx, fr_value_box_t *dst,
 {
        if (!fr_cond_assert(dst_type != FR_TYPE_INVALID)) return -1;
        if (!fr_cond_assert(src->type != FR_TYPE_INVALID)) return -1;
+       if (!fr_cond_assert(src != dst)) return -1;
 
        if (fr_dict_non_data_types[dst_type]) {
                fr_strerror_printf("Invalid cast from %s to %s.  Can only cast simple data types.",
@@ -2243,9 +2246,30 @@ int fr_value_box_cast(TALLOC_CTX *ctx, fr_value_box_t *dst,
        }
 
        /*
-        *      If it's the same type, copy.
+        *      If it's the same type, copy, but set the enumv
+        *      in the destination box to be the one provided.
+        *
+        *      The theory here is that the attribute value isn't
+        *      being converted into its presentation format and
+        *      re-parsed, and the enumv aliases only get applied
+        *      when converting internal values to/from strings,
+        *      so it's OK just to swap out the enumv.
+        *
+        *      If there's a compelling case in the future we
+        *      might revisit this, but it'd likely mean fixing
+        *      all the casting functions to treat any value
+        *      with an enumv as a string, which seems weird.
         */
-       if (dst_type == src->type) return fr_value_box_copy(ctx, dst, src);
+       if (dst_type == src->type) {
+               int ret;
+
+               ret = fr_value_box_copy(ctx, dst, src);
+               if (ret < 0) return ret;
+
+               dst->enumv = dst_enumv;
+
+               return ret;
+       }
 
        /*
         *      Initialise dst
@@ -2499,6 +2523,51 @@ int fr_value_box_cast(TALLOC_CTX *ctx, fr_value_box_t *dst,
        return 0;
 }
 
+/** Convert one type of fr_value_box_t to another in place
+ *
+ * This should be the canonical function used to convert between INTERNAL data formats.
+ *
+ * If you want to convert from PRESENTATION format, use #fr_value_box_from_str.
+ *
+ * @param ctx          to allocate buffers in (usually the same as dst)
+ * @param vb           to cast.
+ * @param dst_type     to cast to.
+ * @param dst_enumv    Aliases for values contained within this fr_value_box_t.
+ *                     If #fr_value_box_t is passed to #fr_value_box_asprint
+ *                     aliases will be printed instead of actual value.
+ * @return
+ *     - 0 on success.
+ *     - -1 on failure.
+ */
+int fr_value_box_cast_in_place(TALLOC_CTX *ctx, fr_value_box_t *vb,
+                              fr_type_t dst_type, fr_dict_attr_t const *dst_enumv)
+{
+       fr_value_box_t tmp;
+
+       /*
+        *      Simple case, destination type and current
+        *      type are the same.
+        */
+       if (vb->type == dst_type) {
+               vb->enumv = dst_enumv;  /* Update the enumv as this may be different */
+               return 0;
+       }
+
+       /*
+        *      Copy meta data and any existing buffers to
+        *      a temporary box.  We then clear that value
+        *      box after the cast has been completed,
+        *      freeing any old buffers.
+        */
+       fr_value_box_copy_shallow(ctx, &tmp, vb, false);
+
+       if (fr_value_box_cast(vb, vb, dst_type, dst_enumv, &tmp) < 0) return -1;
+
+       fr_value_box_clear(&tmp);       /* Clear out any old buffers */
+
+       return 0;
+}
+
 /** Assign a #fr_value_box_t value from an #fr_ipaddr_t
  *
  * Automatically determines the type of the value box from the ipaddr address family