X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Fovsdb-data.c;h=42fdf1ea4f305a1e043b83f03157b14c24cea2c1;hb=1ac981803fad658965714bf82fd6b17f910f4b33;hp=cb68d09dcf729c76b1d81a7f52a99d54bc53fd88;hpb=0194f33a6c734f0ff946fad9fb6b059b29ebf13e;p=sliver-openvswitch.git

diff --git a/lib/ovsdb-data.c b/lib/ovsdb-data.c
index cb68d09dc..42fdf1ea4 100644
--- a/lib/ovsdb-data.c
+++ b/lib/ovsdb-data.c
@@ -29,6 +29,7 @@
 #include "json.h"
 #include "shash.h"
 #include "sort.h"
+#include "unicode.h"
 
 static struct json *
 wrap_json(const char *name, struct json *wrapped)
@@ -228,14 +229,9 @@ parse_json_pair(const struct json *json,
     return NULL;
 }
 
-static struct ovsdb_error *
-ovsdb_atom_parse_uuid(struct uuid *uuid, const struct json *json,
-                      const struct ovsdb_symbol_table *symtab)
-    WARN_UNUSED_RESULT;
-
-static struct ovsdb_error *
+static struct ovsdb_error * WARN_UNUSED_RESULT
 ovsdb_atom_parse_uuid(struct uuid *uuid, const struct json *json,
-                      const struct ovsdb_symbol_table *symtab)
+                      struct ovsdb_symbol_table *symtab)
 {
     struct ovsdb_error *error0;
     const struct json *value;
@@ -253,18 +249,10 @@ ovsdb_atom_parse_uuid(struct uuid *uuid, const struct json *json,
         error1 = unwrap_json(json, "named-uuid", JSON_STRING, &value);
         if (!error1) {
             const char *name = json_string(value);
-            const struct ovsdb_symbol *symbol;
 
             ovsdb_error_destroy(error0);
-
-            symbol = ovsdb_symbol_table_get(symtab, name);
-            if (symbol) {
-                *uuid = symbol->uuid;
-                return NULL;
-            } else {
-                return ovsdb_syntax_error(json, NULL,
-                                          "unknown named-uuid \"%s\"", name);
-            }
+            *uuid = ovsdb_symbol_table_insert(symtab, name)->uuid;
+            return NULL;
         }
         ovsdb_error_destroy(error1);
     }
@@ -272,10 +260,10 @@ ovsdb_atom_parse_uuid(struct uuid *uuid, const struct json *json,
     return error0;
 }
 
-struct ovsdb_error *
-ovsdb_atom_from_json(union ovsdb_atom *atom, enum ovsdb_atomic_type type,
-                     const struct json *json,
-                     const struct ovsdb_symbol_table *symtab)
+static struct ovsdb_error * WARN_UNUSED_RESULT
+ovsdb_atom_from_json__(union ovsdb_atom *atom, enum ovsdb_atomic_type type,
+                       const struct json *json,
+                       struct ovsdb_symbol_table *symtab)
 {
     switch (type) {
     case OVSDB_TYPE_VOID:
@@ -327,6 +315,26 @@ ovsdb_atom_from_json(union ovsdb_atom *atom, enum ovsdb_atomic_type type,
                               ovsdb_atomic_type_to_string(type));
 }
 
+struct ovsdb_error *
+ovsdb_atom_from_json(union ovsdb_atom *atom,
+                     const struct ovsdb_base_type *base,
+                     const struct json *json,
+                     struct ovsdb_symbol_table *symtab)
+{
+    struct ovsdb_error *error;
+
+    error = ovsdb_atom_from_json__(atom, base->type, json, symtab);
+    if (error) {
+        return error;
+    }
+
+    error = ovsdb_atom_check_constraints(atom, base);
+    if (error) {
+        ovsdb_atom_destroy(atom, base->type);
+    }
+    return error;
+}
+
 struct json *
 ovsdb_atom_to_json(const union ovsdb_atom *atom, enum ovsdb_atomic_type type)
 {
@@ -356,25 +364,9 @@ ovsdb_atom_to_json(const union ovsdb_atom *atom, enum ovsdb_atomic_type type)
     }
 }
 
-/* Initializes 'atom' to a value of the given 'type' parsed from 's', which
- * takes one of the following forms:
- *
- *      - OVSDB_TYPE_INTEGER: A decimal integer optionally preceded by a sign.
- *
- *      - OVSDB_TYPE_REAL: A floating-point number in the format accepted by
- *        strtod().
- *
- *      - OVSDB_TYPE_BOOLEAN: "true", "yes", "on", "1" for true, or "false",
- *        "no", "off", or "0" for false.
- *
- *      - OVSDB_TYPE_STRING: A JSON string if it begins with a quote, otherwise
- *        an arbitrary string.
- *
- *      - OVSDB_TYPE_UUID: A UUID in RFC 4122 format.
- */
-void
-ovsdb_atom_from_string(union ovsdb_atom *atom, enum ovsdb_atomic_type type,
-                       const char *s)
+static char *
+ovsdb_atom_from_string__(union ovsdb_atom *atom, enum ovsdb_atomic_type type,
+                         const char *s)
 {
     switch (type) {
     case OVSDB_TYPE_VOID:
@@ -383,7 +375,7 @@ ovsdb_atom_from_string(union ovsdb_atom *atom, enum ovsdb_atomic_type type,
     case OVSDB_TYPE_INTEGER: {
         long long int integer;
         if (!str_to_llong(s, 10, &integer)) {
-            ovs_fatal(0, "%s is not a valid integer", s);
+            return xasprintf("\"%s\" is not a valid integer", s);
         }
         atom->integer = integer;
     }
@@ -391,7 +383,12 @@ ovsdb_atom_from_string(union ovsdb_atom *atom, enum ovsdb_atomic_type type,
 
     case OVSDB_TYPE_REAL:
         if (!str_to_double(s, &atom->real)) {
-            ovs_fatal(0, "%s is not a valid real number", s);
+            return xasprintf("\"%s\" is not a valid real number", s);
+        }
+        /* Our JSON input routines map negative zero to zero, so do that here
+         * too for consistency. */
+        if (atom->real == 0.0) {
+            atom->real = 0.0;
         }
         break;
 
@@ -403,22 +400,26 @@ ovsdb_atom_from_string(union ovsdb_atom *atom, enum ovsdb_atomic_type type,
                    || !strcmp(s, "0")) {
             atom->boolean = false;
         } else {
-            ovs_fatal(0, "%s is not a valid boolean "
-                      "(use \"true\" or \"false\")", s);
+            return xasprintf("\"%s\" is not a valid boolean "
+                             "(use \"true\" or \"false\")", s);
         }
         break;
 
     case OVSDB_TYPE_STRING:
         if (*s == '\0') {
-            ovs_fatal(0, "use \"\" to represent the empty string");
+            return xstrdup("An empty string is not valid as input; "
+                           "use \"\" to represent the empty string");
         } else if (*s == '"') {
             size_t s_len = strlen(s);
 
             if (s_len < 2 || s[s_len - 1] != '"') {
-                ovs_fatal(0, "%s: missing quote at end of quoted string", s);
+                return xasprintf("%s: missing quote at end of "
+                                 "quoted string", s);
             } else if (!json_string_unescape(s + 1, s_len - 2,
                                              &atom->string)) {
-                ovs_fatal(0, "%s: %s", s, atom->string);
+                char *error = xasprintf("%s: %s", s, atom->string);
+                free(atom->string);
+                return error;
             }
         } else {
             atom->string = xstrdup(s);
@@ -427,7 +428,7 @@ ovsdb_atom_from_string(union ovsdb_atom *atom, enum ovsdb_atomic_type type,
 
     case OVSDB_TYPE_UUID:
         if (!uuid_from_string(&atom->uuid, s)) {
-            ovs_fatal(0, "%s is not a valid UUID", s);
+            return xasprintf("\"%s\" is not a valid UUID", s);
         }
         break;
 
@@ -435,6 +436,47 @@ ovsdb_atom_from_string(union ovsdb_atom *atom, enum ovsdb_atomic_type type,
     default:
         NOT_REACHED();
     }
+
+    return NULL;
+}
+
+/* Initializes 'atom' to a value of type 'base' parsed from 's', which takes
+ * one of the following forms:
+ *
+ *      - OVSDB_TYPE_INTEGER: A decimal integer optionally preceded by a sign.
+ *
+ *      - OVSDB_TYPE_REAL: A floating-point number in the format accepted by
+ *        strtod().
+ *
+ *      - OVSDB_TYPE_BOOLEAN: "true", "yes", "on", "1" for true, or "false",
+ *        "no", "off", or "0" for false.
+ *
+ *      - OVSDB_TYPE_STRING: A JSON string if it begins with a quote, otherwise
+ *        an arbitrary string.
+ *
+ *      - OVSDB_TYPE_UUID: A UUID in RFC 4122 format.
+ *
+ * Returns a null pointer if successful, otherwise an error message describing
+ * the problem.  The caller is responsible for freeing the error.
+ */
+char *
+ovsdb_atom_from_string(union ovsdb_atom *atom,
+                       const struct ovsdb_base_type *base, const char *s)
+{
+    struct ovsdb_error *error;
+    char *msg;
+
+    msg = ovsdb_atom_from_string__(atom, base->type, s);
+    if (msg) {
+        return msg;
+    }
+
+    error = ovsdb_atom_check_constraints(atom, base);
+    if (error) {
+        msg = ovsdb_error_to_string(error);
+        ovsdb_error_destroy(error);
+    }
+    return msg;
 }
 
 static bool
@@ -504,6 +546,139 @@ ovsdb_atom_to_string(const union ovsdb_atom *atom, enum ovsdb_atomic_type type,
         NOT_REACHED();
     }
 }
+
+static struct ovsdb_error *
+check_string_constraints(const char *s,
+                         const struct ovsdb_string_constraints *c)
+{
+    size_t n_chars;
+    char *msg;
+
+    msg = utf8_validate(s, &n_chars);
+    if (msg) {
+        struct ovsdb_error *error;
+
+        error = ovsdb_error("constraint violation",
+                            "\"%s\" is not a valid UTF-8 string: %s",
+                            s, msg);
+        free(msg);
+        return error;
+    }
+
+    if (n_chars < c->minLen) {
+        return ovsdb_error(
+            "constraint violation",
+            "\"%s\" length %zu is less than minimum allowed "
+            "length %u", s, n_chars, c->minLen);
+    } else if (n_chars > c->maxLen) {
+        return ovsdb_error(
+            "constraint violation",
+            "\"%s\" length %zu is greater than maximum allowed "
+            "length %u", s, n_chars, c->maxLen);
+    }
+
+    return NULL;
+}
+
+/* Checks whether 'atom' meets the constraints (if any) defined in 'base'.
+ * (base->type must specify 'atom''s type.)  Returns a null pointer if the
+ * constraints are met, otherwise an error that explains the violation.
+ *
+ * Checking UUID constraints is deferred to transaction commit time, so this
+ * function does nothing for UUID constraints. */
+struct ovsdb_error *
+ovsdb_atom_check_constraints(const union ovsdb_atom *atom,
+                             const struct ovsdb_base_type *base)
+{
+    if (base->enum_
+        && ovsdb_datum_find_key(base->enum_, atom, base->type) == UINT_MAX) {
+        struct ovsdb_error *error;
+        struct ds actual = DS_EMPTY_INITIALIZER;
+        struct ds valid = DS_EMPTY_INITIALIZER;
+
+        ovsdb_atom_to_string(atom, base->type, &actual);
+        ovsdb_datum_to_string(base->enum_,
+                              ovsdb_base_type_get_enum_type(base->type),
+                              &valid);
+        error = ovsdb_error("constraint violation",
+                            "%s is not one of the allowed values (%s)",
+                            ds_cstr(&actual), ds_cstr(&valid));
+        ds_destroy(&actual);
+        ds_destroy(&valid);
+
+        return error;
+    }
+
+    switch (base->type) {
+    case OVSDB_TYPE_VOID:
+        NOT_REACHED();
+
+    case OVSDB_TYPE_INTEGER:
+        if (atom->integer >= base->u.integer.min
+            && atom->integer <= base->u.integer.max) {
+            return NULL;
+        } else if (base->u.integer.min != INT64_MIN) {
+            if (base->u.integer.max != INT64_MAX) {
+                return ovsdb_error("constraint violation",
+                                   "%"PRId64" is not in the valid range "
+                                   "%"PRId64" to %"PRId64" (inclusive)",
+                                   atom->integer,
+                                   base->u.integer.min, base->u.integer.max);
+            } else {
+                return ovsdb_error("constraint violation",
+                                   "%"PRId64" is less than minimum allowed "
+                                   "value %"PRId64,
+                                   atom->integer, base->u.integer.min);
+            }
+        } else {
+            return ovsdb_error("constraint violation",
+                               "%"PRId64" is greater than maximum allowed "
+                               "value %"PRId64,
+                               atom->integer, base->u.integer.max);
+        }
+        NOT_REACHED();
+
+    case OVSDB_TYPE_REAL:
+        if (atom->real >= base->u.real.min && atom->real <= base->u.real.max) {
+            return NULL;
+        } else if (base->u.real.min != -DBL_MAX) {
+            if (base->u.real.max != DBL_MAX) {
+                return ovsdb_error("constraint violation",
+                                   "%.*g is not in the valid range "
+                                   "%.*g to %.*g (inclusive)",
+                                   DBL_DIG, atom->real,
+                                   DBL_DIG, base->u.real.min,
+                                   DBL_DIG, base->u.real.max);
+            } else {
+                return ovsdb_error("constraint violation",
+                                   "%.*g is less than minimum allowed "
+                                   "value %.*g",
+                                   DBL_DIG, atom->real,
+                                   DBL_DIG, base->u.real.min);
+            }
+        } else {
+            return ovsdb_error("constraint violation",
+                               "%.*g is greater than maximum allowed "
+                               "value %.*g",
+                               DBL_DIG, atom->real,
+                               DBL_DIG, base->u.real.max);
+        }
+        NOT_REACHED();
+
+    case OVSDB_TYPE_BOOLEAN:
+        return NULL;
+
+    case OVSDB_TYPE_STRING:
+        return check_string_constraints(atom->string, &base->u.string);
+
+    case OVSDB_TYPE_UUID:
+        return NULL;
+
+    case OVSDB_N_TYPES:
+    default:
+        NOT_REACHED();
+    }
+}
 
 static union ovsdb_atom *
 alloc_default_atoms(enum ovsdb_atomic_type type, size_t n)
@@ -537,8 +712,8 @@ ovsdb_datum_init_default(struct ovsdb_datum *datum,
                          const struct ovsdb_type *type)
 {
     datum->n = type->n_min;
-    datum->keys = alloc_default_atoms(type->key_type, datum->n);
-    datum->values = alloc_default_atoms(type->value_type, datum->n);
+    datum->keys = alloc_default_atoms(type->key.type, datum->n);
+    datum->values = alloc_default_atoms(type->value.type, datum->n);
 }
 
 bool
@@ -551,11 +726,11 @@ ovsdb_datum_is_default(const struct ovsdb_datum *datum,
         return false;
     }
     for (i = 0; i < datum->n; i++) {
-        if (!ovsdb_atom_is_default(&datum->keys[i], type->key_type)) {
+        if (!ovsdb_atom_is_default(&datum->keys[i], type->key.type)) {
             return false;
         }
-        if (type->value_type != OVSDB_TYPE_VOID
-            && !ovsdb_atom_is_default(&datum->values[i], type->value_type)) {
+        if (type->value.type != OVSDB_TYPE_VOID
+            && !ovsdb_atom_is_default(&datum->values[i], type->value.type)) {
             return false;
         }
     }
@@ -588,8 +763,8 @@ ovsdb_datum_clone(struct ovsdb_datum *new, const struct ovsdb_datum *old,
 {
     unsigned int n = old->n;
     new->n = n;
-    new->keys = clone_atoms(old->keys, type->key_type, n);
-    new->values = clone_atoms(old->values, type->value_type, n);
+    new->keys = clone_atoms(old->keys, type->key.type, n);
+    new->values = clone_atoms(old->values, type->value.type, n);
 }
 
 static void
@@ -608,8 +783,8 @@ free_data(enum ovsdb_atomic_type type,
 void
 ovsdb_datum_destroy(struct ovsdb_datum *datum, const struct ovsdb_type *type)
 {
-    free_data(type->key_type, datum->keys, datum->n);
-    free_data(type->value_type, datum->values, datum->n);
+    free_data(type->key.type, datum->keys, datum->n);
+    free_data(type->value.type, datum->values, datum->n);
 }
 
 void
@@ -621,7 +796,7 @@ ovsdb_datum_swap(struct ovsdb_datum *a, struct ovsdb_datum *b)
 }
 
 struct ovsdb_datum_sort_cbdata {
-    const struct ovsdb_type *type;
+    enum ovsdb_atomic_type key_type;
     struct ovsdb_datum *datum;
 };
 
@@ -632,7 +807,7 @@ ovsdb_datum_sort_compare_cb(size_t a, size_t b, void *cbdata_)
 
     return ovsdb_atom_compare_3way(&cbdata->datum->keys[a],
                                    &cbdata->datum->keys[b],
-                                   cbdata->type->key_type);
+                                   cbdata->key_type);
 }
 
 static void
@@ -641,13 +816,13 @@ ovsdb_datum_sort_swap_cb(size_t a, size_t b, void *cbdata_)
     struct ovsdb_datum_sort_cbdata *cbdata = cbdata_;
 
     ovsdb_atom_swap(&cbdata->datum->keys[a], &cbdata->datum->keys[b]);
-    if (cbdata->type->value_type != OVSDB_TYPE_VOID) {
+    if (cbdata->datum->values) {
         ovsdb_atom_swap(&cbdata->datum->values[a], &cbdata->datum->values[b]);
     }
 }
 
 struct ovsdb_error *
-ovsdb_datum_sort(struct ovsdb_datum *datum, const struct ovsdb_type *type)
+ovsdb_datum_sort(struct ovsdb_datum *datum, enum ovsdb_atomic_type key_type)
 {
     if (datum->n < 2) {
         return NULL;
@@ -655,15 +830,15 @@ ovsdb_datum_sort(struct ovsdb_datum *datum, const struct ovsdb_type *type)
         struct ovsdb_datum_sort_cbdata cbdata;
         size_t i;
 
-        cbdata.type = type;
+        cbdata.key_type = key_type;
         cbdata.datum = datum;
         sort(datum->n, ovsdb_datum_sort_compare_cb, ovsdb_datum_sort_swap_cb,
              &cbdata);
 
         for (i = 0; i < datum->n - 1; i++) {
             if (ovsdb_atom_equals(&datum->keys[i], &datum->keys[i + 1],
-                                  type->key_type)) {
-                if (ovsdb_type_is_map(type)) {
+                                  key_type)) {
+                if (datum->values) {
                     return ovsdb_error(NULL, "map contains duplicate key");
                 } else {
                     return ovsdb_error(NULL, "set contains duplicate");
@@ -675,34 +850,69 @@ ovsdb_datum_sort(struct ovsdb_datum *datum, const struct ovsdb_type *type)
     }
 }
 
+void
+ovsdb_datum_sort_assert(struct ovsdb_datum *datum,
+                        enum ovsdb_atomic_type key_type)
+{
+    struct ovsdb_error *error = ovsdb_datum_sort(datum, key_type);
+    if (error) {
+        NOT_REACHED();
+    }
+}
+
+/* Checks that each of the atoms in 'datum' conforms to the constraints
+ * specified by its 'type'.  Returns an error if a constraint is violated,
+ * otherwise a null pointer.
+ *
+ * This function is not commonly useful because the most ordinary way to obtain
+ * a datum is ultimately via ovsdb_atom_from_string() or
+ * ovsdb_atom_from_json(), which check constraints themselves. */
+struct ovsdb_error *
+ovsdb_datum_check_constraints(const struct ovsdb_datum *datum,
+                              const struct ovsdb_type *type)
+{
+    struct ovsdb_error *error;
+    unsigned int i;
+
+    for (i = 0; i < datum->n; i++) {
+        error = ovsdb_atom_check_constraints(&datum->keys[i], &type->key);
+        if (error) {
+            return error;
+        }
+    }
+
+    if (type->value.type != OVSDB_TYPE_VOID) {
+        for (i = 0; i < datum->n; i++) {
+            error = ovsdb_atom_check_constraints(&datum->values[i],
+                                                 &type->value);
+            if (error) {
+                return error;
+            }
+        }
+    }
+
+    return NULL;
+}
+
 struct ovsdb_error *
 ovsdb_datum_from_json(struct ovsdb_datum *datum,
                       const struct ovsdb_type *type,
                       const struct json *json,
-                      const struct ovsdb_symbol_table *symtab)
+                      struct ovsdb_symbol_table *symtab)
 {
     struct ovsdb_error *error;
 
-    if (ovsdb_type_is_scalar(type)) {
-        datum->n = 1;
-        datum->keys = xmalloc(sizeof *datum->keys);
-        datum->values = NULL;
-
-        error = ovsdb_atom_from_json(&datum->keys[0], type->key_type,
-                                     json, symtab);
-        if (error) {
-            free(datum->keys);
-        }
-        return error;
-    } else {
+    if (ovsdb_type_is_map(type)
+        || (json->type == JSON_ARRAY
+            && json->u.array.n > 0
+            && json->u.array.elems[0]->type == JSON_STRING
+            && !strcmp(json->u.array.elems[0]->u.string, "set"))) {
         bool is_map = ovsdb_type_is_map(type);
         const char *class = is_map ? "map" : "set";
         const struct json *inner;
         unsigned int i;
         size_t n;
 
-        assert(is_map || ovsdb_type_is_set(type));
-
         error = unwrap_json(json, class, JSON_ARRAY, &inner);
         if (error) {
             return error;
@@ -732,7 +942,7 @@ ovsdb_datum_from_json(struct ovsdb_datum *datum,
                 }
             }
 
-            error = ovsdb_atom_from_json(&datum->keys[i], type->key_type,
+            error = ovsdb_atom_from_json(&datum->keys[i], &type->key,
                                          key, symtab);
             if (error) {
                 goto error;
@@ -740,9 +950,9 @@ ovsdb_datum_from_json(struct ovsdb_datum *datum,
 
             if (is_map) {
                 error = ovsdb_atom_from_json(&datum->values[i],
-                                             type->value_type, value, symtab);
+                                             &type->value, value, symtab);
                 if (error) {
-                    ovsdb_atom_destroy(&datum->keys[i], type->key_type);
+                    ovsdb_atom_destroy(&datum->keys[i], type->key.type);
                     goto error;
                 }
             }
@@ -750,7 +960,7 @@ ovsdb_datum_from_json(struct ovsdb_datum *datum,
             datum->n++;
         }
 
-        error = ovsdb_datum_sort(datum, type);
+        error = ovsdb_datum_sort(datum, type->key.type);
         if (error) {
             goto error;
         }
@@ -760,6 +970,17 @@ ovsdb_datum_from_json(struct ovsdb_datum *datum,
     error:
         ovsdb_datum_destroy(datum, type);
         return error;
+    } else {
+        datum->n = 1;
+        datum->keys = xmalloc(sizeof *datum->keys);
+        datum->values = NULL;
+
+        error = ovsdb_atom_from_json(&datum->keys[0], &type->key,
+                                     json, symtab);
+        if (error) {
+            free(datum->keys);
+        }
+        return error;
     }
 }
 
@@ -769,15 +990,15 @@ ovsdb_datum_to_json(const struct ovsdb_datum *datum,
 {
     /* These tests somewhat tolerate a 'datum' that does not exactly match
      * 'type', in particular a datum with 'n' not in the allowed range. */
-    if (datum->n == 1 && ovsdb_type_is_scalar(type)) {
-        return ovsdb_atom_to_json(&datum->keys[0], type->key_type);
-    } else if (type->value_type == OVSDB_TYPE_VOID) {
+    if (datum->n == 1 && !ovsdb_type_is_map(type)) {
+        return ovsdb_atom_to_json(&datum->keys[0], type->key.type);
+    } else if (type->value.type == OVSDB_TYPE_VOID) {
         struct json **elems;
         size_t i;
 
         elems = xmalloc(datum->n * sizeof *elems);
         for (i = 0; i < datum->n; i++) {
-            elems[i] = ovsdb_atom_to_json(&datum->keys[i], type->key_type);
+            elems[i] = ovsdb_atom_to_json(&datum->keys[i], type->key.type);
         }
 
         return wrap_json("set", json_array_create(elems, datum->n));
@@ -788,8 +1009,8 @@ ovsdb_datum_to_json(const struct ovsdb_datum *datum,
         elems = xmalloc(datum->n * sizeof *elems);
         for (i = 0; i < datum->n; i++) {
             elems[i] = json_array_create_2(
-                ovsdb_atom_to_json(&datum->keys[i], type->key_type),
-                ovsdb_atom_to_json(&datum->values[i], type->value_type));
+                ovsdb_atom_to_json(&datum->keys[i], type->key.type),
+                ovsdb_atom_to_json(&datum->values[i], type->value.type));
         }
 
         return wrap_json("map", json_array_create(elems, datum->n));
@@ -799,43 +1020,58 @@ ovsdb_datum_to_json(const struct ovsdb_datum *datum,
 static const char *
 skip_spaces(const char *p)
 {
-    return p + strspn(p, " ");
+    while (isspace((unsigned char) *p)) {
+        p++;
+    }
+    return p;
 }
 
-static const char *
-parse_key_value(const char *s, const struct ovsdb_type *type,
-                union ovsdb_atom *key, union ovsdb_atom *value)
+static char *
+parse_atom_token(const char **s, const struct ovsdb_base_type *base,
+                 union ovsdb_atom *atom)
 {
-    char *key_string;
-    const char *p;
+    char *token, *error;
 
-    /* Parse key. */
-    p = ovsdb_token_parse(s, &key_string);
-    ovsdb_atom_from_string(key, type->key_type, key_string);
-    free(key_string);
-
-    /* Parse value. */
-    if (type->value_type != OVSDB_TYPE_VOID) {
-        char *value_string;
+    error = ovsdb_token_parse(s, &token);
+    if (!error) {
+        error = ovsdb_atom_from_string(atom, base, token);
+        free(token);
+    }
+    return error;
+}
 
-        if (*p != '=') {
-            ovs_fatal(0, "%s: syntax error at \"%c\" expecting \"=\"",
-                      s, *p);
+static char *
+parse_key_value(const char **s, const struct ovsdb_type *type,
+                union ovsdb_atom *key, union ovsdb_atom *value)
+{
+    const char *start = *s;
+    char *error;
+
+    error = parse_atom_token(s, &type->key, key);
+    if (!error && type->value.type != OVSDB_TYPE_VOID) {
+        *s = skip_spaces(*s);
+        if (**s == '=') {
+            (*s)++;
+            *s = skip_spaces(*s);
+            error = parse_atom_token(s, &type->value, value);
+        } else {
+            error = xasprintf("%s: syntax error at \"%c\" expecting \"=\"",
+                              start, **s);
+        }
+        if (error) {
+            ovsdb_atom_destroy(key, type->key.type);
         }
-        p = ovsdb_token_parse(p + 1, &value_string);
-        ovsdb_atom_from_string(value, type->value_type, value_string);
-        free(value_string);
     }
-    return p;
+    return error;
 }
 
 static void
 free_key_value(const struct ovsdb_type *type,
                union ovsdb_atom *key, union ovsdb_atom *value)
 {
-    ovsdb_atom_destroy(key, type->key_type);
-    if (type->value_type != OVSDB_TYPE_VOID) {
-        ovsdb_atom_destroy(value, type->value_type);
+    ovsdb_atom_destroy(key, type->key.type);
+    if (type->value.type != OVSDB_TYPE_VOID) {
+        ovsdb_atom_destroy(value, type->value.type);
     }
 }
 
@@ -845,13 +1081,15 @@ free_key_value(const struct ovsdb_type *type,
  * acceptable to ovsdb_atom_from_string().  Optionally, a set may be enclosed
  * in "[]" or a map in "{}"; for an empty set or map these punctuators are
  * required. */
-void
+char *
 ovsdb_datum_from_string(struct ovsdb_datum *datum,
                         const struct ovsdb_type *type, const char *s)
 {
     bool is_map = ovsdb_type_is_map(type);
+    struct ovsdb_error *dberror;
     const char *p;
     int end_delim;
+    char *error;
 
     ovsdb_datum_init_empty(datum);
 
@@ -862,9 +1100,9 @@ ovsdb_datum_from_string(struct ovsdb_datum *datum,
         p = skip_spaces(p + 1);
     } else if (!*p) {
         if (is_map) {
-            ovs_fatal(0, "use \"{}\" to specify the empty map");
+            return xstrdup("use \"{}\" to specify the empty map");
         } else {
-            ovs_fatal(0, "use \"[]\" to specify the empty set");
+            return xstrdup("use \"[]\" to specify the empty set");
         }
     } else {
         end_delim = 0;
@@ -874,12 +1112,16 @@ ovsdb_datum_from_string(struct ovsdb_datum *datum,
         union ovsdb_atom key, value;
 
         if (ovsdb_token_is_delim(*p)) {
-            ovs_fatal(0, "%s: unexpected \"%c\" parsing %s",
-                      s, *p, ovsdb_type_to_english(type));
+            error = xasprintf("%s: unexpected \"%c\" parsing %s",
+                              s, *p, ovsdb_type_to_english(type));
+            goto error;
         }
 
         /* Add to datum. */
-        p = parse_key_value(p, type, &key, &value);
+        error = parse_key_value(&p, type, &key, &value);
+        if (error) {
+            goto error;
+        }
         ovsdb_datum_add_unsafe(datum, &key, &value, type);
         free_key_value(type, &key, &value);
 
@@ -891,34 +1133,47 @@ ovsdb_datum_from_string(struct ovsdb_datum *datum,
     }
 
     if (*p != end_delim) {
-        ovs_fatal(0, "%s: missing \"%c\" at end of data", s, end_delim);
+        error = xasprintf("%s: missing \"%c\" at end of data", s, end_delim);
+        goto error;
     }
     if (end_delim) {
         p = skip_spaces(p + 1);
         if (*p) {
-            ovs_fatal(0, "%s: trailing garbage after \"%c\"", s, end_delim);
+            error = xasprintf("%s: trailing garbage after \"%c\"",
+                              s, end_delim);
+            goto error;
         }
     }
 
     if (datum->n < type->n_min) {
-        ovs_fatal(0, "%s: %u %s were specified but at least %u are required",
-                  s, datum->n,
-                  type->value_type == OVSDB_TYPE_VOID ? "values" : "pairs",
-                  type->n_min);
+        error = xasprintf("%s: %u %s specified but the minimum number is %u",
+                          s, datum->n, is_map ? "pair(s)" : "value(s)",
+                          type->n_min);
+        goto error;
     } else if (datum->n > type->n_max) {
-        ovs_fatal(0, "%s: %u %s were specified but at most %u are allowed",
-                  s, datum->n,
-                  type->value_type == OVSDB_TYPE_VOID ? "values" : "pairs",
-                  type->n_max);
+        error = xasprintf("%s: %u %s specified but the maximum number is %u",
+                          s, datum->n, is_map ? "pair(s)" : "value(s)",
+            type->n_max);
+        goto error;
     }
 
-    if (ovsdb_datum_sort(datum, type)) {
+    dberror = ovsdb_datum_sort(datum, type->key.type);
+    if (dberror) {
+        ovsdb_error_destroy(dberror);
         if (ovsdb_type_is_map(type)) {
-            ovs_fatal(0, "%s: map contains duplicate key", s);
+            error = xasprintf("%s: map contains duplicate key", s);
         } else {
-            ovs_fatal(0, "%s: set contains duplicate value", s);
+            error = xasprintf("%s: set contains duplicate value", s);
         }
+        goto error;
     }
+
+    return NULL;
+
+error:
+    ovsdb_datum_destroy(datum, type);
+    ovsdb_datum_init_empty(datum);
+    return error;
 }
 
 /* Appends to 'out' the 'datum' (with the given 'type') in a format acceptable
@@ -938,10 +1193,10 @@ ovsdb_datum_to_string(const struct ovsdb_datum *datum,
             ds_put_cstr(out, ", ");
         }
 
-        ovsdb_atom_to_string(&datum->keys[i], type->key_type, out);
+        ovsdb_atom_to_string(&datum->keys[i], type->key.type, out);
         if (is_map) {
             ds_put_char(out, '=');
-            ovsdb_atom_to_string(&datum->values[i], type->value_type, out);
+            ovsdb_atom_to_string(&datum->values[i], type->value.type, out);
         }
     }
     if (type->n_max > 1 || !datum->n) {
@@ -967,9 +1222,9 @@ uint32_t
 ovsdb_datum_hash(const struct ovsdb_datum *datum,
                  const struct ovsdb_type *type, uint32_t basis)
 {
-    basis = hash_atoms(type->key_type, datum->keys, datum->n, basis);
-    basis ^= (type->key_type << 24) | (type->value_type << 16) | datum->n;
-    basis = hash_atoms(type->value_type, datum->values, datum->n, basis);
+    basis = hash_atoms(type->key.type, datum->keys, datum->n, basis);
+    basis ^= (type->key.type << 24) | (type->value.type << 16) | datum->n;
+    basis = hash_atoms(type->value.type, datum->values, datum->n, basis);
     return basis;
 }
 
@@ -1010,18 +1265,18 @@ ovsdb_datum_compare_3way(const struct ovsdb_datum *a,
         return a->n < b->n ? -1 : 1;
     }
 
-    cmp = atom_arrays_compare_3way(a->keys, b->keys, type->key_type, a->n);
+    cmp = atom_arrays_compare_3way(a->keys, b->keys, type->key.type, a->n);
     if (cmp) {
         return cmp;
     }
 
-    return (type->value_type == OVSDB_TYPE_VOID ? 0
-            : atom_arrays_compare_3way(a->values, b->values, type->value_type,
+    return (type->value.type == OVSDB_TYPE_VOID ? 0
+            : atom_arrays_compare_3way(a->values, b->values, type->value.type,
                                        a->n));
 }
 
 /* If 'key' is one of the keys in 'datum', returns its index within 'datum',
- * otherwise UINT_MAX.  'key_type' must be the type of the atoms stored in the
+ * otherwise UINT_MAX.  'key.type' must be the type of the atoms stored in the
  * 'keys' array in 'datum'.
  */
 unsigned int
@@ -1046,7 +1301,7 @@ ovsdb_datum_find_key(const struct ovsdb_datum *datum,
 }
 
 /* If 'key' and 'value' is one of the key-value pairs in 'datum', returns its
- * index within 'datum', otherwise UINT_MAX.  'key_type' must be the type of
+ * index within 'datum', otherwise UINT_MAX.  'key.type' must be the type of
  * the atoms stored in the 'keys' array in 'datum'.  'value_type' may be the
  * type of the 'values' atoms or OVSDB_TYPE_VOID to compare only keys.
  */
@@ -1068,7 +1323,7 @@ ovsdb_datum_find_key_value(const struct ovsdb_datum *datum,
 
 /* If atom 'i' in 'a' is also in 'b', returns its index in 'b', otherwise
  * UINT_MAX.  'type' must be the type of 'a' and 'b', except that
- * type->value_type may be set to OVSDB_TYPE_VOID to compare keys but not
+ * type->value.type may be set to OVSDB_TYPE_VOID to compare keys but not
  * values. */
 static unsigned int
 ovsdb_datum_find(const struct ovsdb_datum *a, int i,
@@ -1076,9 +1331,9 @@ ovsdb_datum_find(const struct ovsdb_datum *a, int i,
                  const struct ovsdb_type *type)
 {
     return ovsdb_datum_find_key_value(b,
-                                      &a->keys[i], type->key_type,
+                                      &a->keys[i], type->key.type,
                                       a->values ? &a->values[i] : NULL,
-                                      type->value_type);
+                                      type->value.type);
 }
 
 /* Returns true if every element in 'a' is also in 'b', false otherwise. */
@@ -1118,7 +1373,7 @@ ovsdb_datum_reallocate(struct ovsdb_datum *a, const struct ovsdb_type *type,
                        unsigned int capacity)
 {
     a->keys = xrealloc(a->keys, capacity * sizeof *a->keys);
-    if (type->value_type != OVSDB_TYPE_VOID) {
+    if (type->value.type != OVSDB_TYPE_VOID) {
         a->values = xrealloc(a->values, capacity * sizeof *a->values);
     }
 }
@@ -1133,10 +1388,10 @@ void
 ovsdb_datum_remove_unsafe(struct ovsdb_datum *datum, size_t idx,
                           const struct ovsdb_type *type)
 {
-    ovsdb_atom_destroy(&datum->keys[idx], type->key_type);
+    ovsdb_atom_destroy(&datum->keys[idx], type->key.type);
     datum->keys[idx] = datum->keys[datum->n - 1];
-    if (type->value_type != OVSDB_TYPE_VOID) {
-        ovsdb_atom_destroy(&datum->values[idx], type->value_type);
+    if (type->value.type != OVSDB_TYPE_VOID) {
+        ovsdb_atom_destroy(&datum->values[idx], type->value.type);
         datum->values[idx] = datum->values[datum->n - 1];
     }
     datum->n--;
@@ -1159,11 +1414,11 @@ ovsdb_datum_add_unsafe(struct ovsdb_datum *datum,
 {
     size_t idx = datum->n++;
     datum->keys = xrealloc(datum->keys, datum->n * sizeof *datum->keys);
-    ovsdb_atom_clone(&datum->keys[idx], key, type->key_type);
-    if (type->value_type != OVSDB_TYPE_VOID) {
+    ovsdb_atom_clone(&datum->keys[idx], key, type->key.type);
+    if (type->value.type != OVSDB_TYPE_VOID) {
         datum->values = xrealloc(datum->values,
                                  datum->n * sizeof *datum->values);
-        ovsdb_atom_clone(&datum->values[idx], value, type->value_type);
+        ovsdb_atom_clone(&datum->values[idx], value, type->value.type);
     }
 }
 
@@ -1178,27 +1433,27 @@ ovsdb_datum_union(struct ovsdb_datum *a, const struct ovsdb_datum *b,
     for (bi = 0; bi < b->n; bi++) {
         unsigned int ai;
 
-        ai = ovsdb_datum_find_key(a, &b->keys[bi], type->key_type);
+        ai = ovsdb_datum_find_key(a, &b->keys[bi], type->key.type);
         if (ai == UINT_MAX) {
             if (n == a->n) {
                 ovsdb_datum_reallocate(a, type, a->n + (b->n - bi));
             }
-            ovsdb_atom_clone(&a->keys[n], &b->keys[bi], type->key_type);
-            if (type->value_type != OVSDB_TYPE_VOID) {
+            ovsdb_atom_clone(&a->keys[n], &b->keys[bi], type->key.type);
+            if (type->value.type != OVSDB_TYPE_VOID) {
                 ovsdb_atom_clone(&a->values[n], &b->values[bi],
-                                 type->value_type);
+                                 type->value.type);
             }
             n++;
-        } else if (replace && type->value_type != OVSDB_TYPE_VOID) {
-            ovsdb_atom_destroy(&a->values[ai], type->value_type);
+        } else if (replace && type->value.type != OVSDB_TYPE_VOID) {
+            ovsdb_atom_destroy(&a->values[ai], type->value.type);
             ovsdb_atom_clone(&a->values[ai], &b->values[bi],
-                             type->value_type);
+                             type->value.type);
         }
     }
     if (n != a->n) {
         struct ovsdb_error *error;
         a->n = n;
-        error = ovsdb_datum_sort(a, type);
+        error = ovsdb_datum_sort(a, type->key.type);
         assert(!error);
     }
 }
@@ -1211,9 +1466,9 @@ ovsdb_datum_subtract(struct ovsdb_datum *a, const struct ovsdb_type *a_type,
     bool changed = false;
     size_t i;
 
-    assert(a_type->key_type == b_type->key_type);
-    assert(a_type->value_type == b_type->value_type
-           || b_type->value_type == OVSDB_TYPE_VOID);
+    assert(a_type->key.type == b_type->key.type);
+    assert(a_type->value.type == b_type->value.type
+           || b_type->value.type == OVSDB_TYPE_VOID);
 
     /* XXX The big-O of this could easily be improved. */
     for (i = 0; i < a->n; ) {
@@ -1226,8 +1481,7 @@ ovsdb_datum_subtract(struct ovsdb_datum *a, const struct ovsdb_type *a_type,
         }
     }
     if (changed) {
-        struct ovsdb_error *error = ovsdb_datum_sort(a, a_type);
-        assert(!error);
+        ovsdb_datum_sort_assert(a, a_type->key.type);
     }
 }
 
@@ -1266,7 +1520,7 @@ ovsdb_symbol_table_get(const struct ovsdb_symbol_table *symtab,
     return shash_find_data(&symtab->sh, name);
 }
 
-void
+struct ovsdb_symbol *
 ovsdb_symbol_table_put(struct ovsdb_symbol_table *symtab, const char *name,
                        const struct uuid *uuid, bool used)
 {
@@ -1277,6 +1531,23 @@ ovsdb_symbol_table_put(struct ovsdb_symbol_table *symtab, const char *name,
     symbol->uuid = *uuid;
     symbol->used = used;
     shash_add(&symtab->sh, name, symbol);
+    return symbol;
+}
+
+struct ovsdb_symbol *
+ovsdb_symbol_table_insert(struct ovsdb_symbol_table *symtab,
+                          const char *name)
+{
+    struct ovsdb_symbol *symbol;
+
+    symbol = ovsdb_symbol_table_get(symtab, name);
+    if (!symbol) {
+        struct uuid uuid;
+
+        uuid_generate(&uuid);
+        symbol = ovsdb_symbol_table_put(symtab, name, &uuid, false);
+    }
+    return symbol;
 }
 
 /* Extracts a token from the beginning of 's' and returns a pointer just after
@@ -1292,23 +1563,25 @@ ovsdb_symbol_table_put(struct ovsdb_symbol_table *symtab, const char *name,
  * quotes are retained in the output.  (Backslashes inside double quotes are
  * not removed, either.)
  */
-const char *
-ovsdb_token_parse(const char *s, char **outp)
+char *
+ovsdb_token_parse(const char **s, char **outp)
 {
     const char *p;
     struct ds out;
     bool in_quotes;
+    char *error;
 
     ds_init(&out);
     in_quotes = false;
-    for (p = s; *p != '\0'; ) {
+    for (p = *s; *p != '\0'; ) {
         int c = *p++;
         if (c == '\\') {
             if (in_quotes) {
                 ds_put_char(&out, '\\');
             }
             if (!*p) {
-                ovs_fatal(0, "%s: backslash at end of argument", s);
+                error = xasprintf("%s: backslash at end of argument", *s);
+                goto error;
             }
             ds_put_char(&out, *p++);
         } else if (!in_quotes && ovsdb_token_is_delim(c)) {
@@ -1322,10 +1595,18 @@ ovsdb_token_parse(const char *s, char **outp)
         }
     }
     if (in_quotes) {
-        ovs_fatal(0, "%s: quoted string extends past end of argument", s);
+        error = xasprintf("%s: quoted string extends past end of argument",
+                          *s);
+        goto error;
     }
     *outp = ds_cstr(&out);
-    return p;
+    *s = p;
+    return NULL;
+
+error:
+    ds_destroy(&out);
+    *outp = NULL;
+    return error;
 }
 
 /* Returns true if 'c' delimits tokens, or if 'c' is 0, and false otherwise. */