Adding upstream version 252.22.upstream/252.22

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 435 insertions, 0 deletions

diff --git a/src/shared/json.h b/src/shared/json.h
new file mode 100644
index 0000000..5993e05
--- /dev/null
+++ b/src/shared/json.h
@@ -0,0 +1,435 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+#pragma once
+
+#include <fcntl.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+
+#include "sd-id128.h"
+
+#include "ether-addr-util.h"
+#include "in-addr-util.h"
+#include "log.h"
+#include "macro.h"
+#include "string-util.h"
+#include "strv.h"
+#include "time-util.h"
+
+/*
+  In case you wonder why we have our own JSON implementation, here are a couple of reasons why this implementation has
+  benefits over various other implementations:
+
+  - We need support for 64bit signed and unsigned integers, i.e. the full 64,5bit range of -9223372036854775808…18446744073709551615
+  - All our variants are immutable after creation
+  - Special values such as true, false, zero, null, empty strings, empty array, empty objects require zero dynamic memory
+  - Progressive parsing
+  - Our integer/real type implicitly converts, but only if that's safe and loss-lessly possible
+  - There's a "builder" for putting together objects easily in varargs function calls
+  - There's a "dispatcher" for mapping objects to C data structures
+  - Every variant optionally carries parsing location information, which simplifies debugging and parse log error generation
+  - Formatter has color, line, column support
+
+  Limitations:
+  - Doesn't allow embedded NUL in strings
+  - Can't store integers outside of the -9223372036854775808…18446744073709551615 range (it will use 'double' for
+    values outside this range, which is lossy)
+  - Can't store negative zero (will be treated identical to positive zero, and not retained across serialization)
+  - Can't store non-integer numbers that can't be stored in "double" losslessly
+  - Allows creation and parsing of objects with duplicate keys. The "dispatcher" will refuse them however. This means
+    we can parse and pass around such objects, but will carefully refuse them when we convert them into our own data.
+
+  (These limitations should be pretty much in line with those of other JSON implementations, in fact might be less
+  limiting in most cases even.)
+*/
+
+typedef struct JsonVariant JsonVariant;
+
+typedef enum JsonVariantType {
+        JSON_VARIANT_STRING,
+        JSON_VARIANT_INTEGER,
+        JSON_VARIANT_UNSIGNED,
+        JSON_VARIANT_REAL,
+        JSON_VARIANT_NUMBER, /* This a pseudo-type: we can never create variants of this type, but we use it as wildcard check for the above three types */
+        JSON_VARIANT_BOOLEAN,
+        JSON_VARIANT_ARRAY,
+        JSON_VARIANT_OBJECT,
+        JSON_VARIANT_NULL,
+        _JSON_VARIANT_TYPE_MAX,
+        _JSON_VARIANT_TYPE_INVALID = -EINVAL,
+} JsonVariantType;
+
+int json_variant_new_stringn(JsonVariant **ret, const char *s, size_t n);
+int json_variant_new_base64(JsonVariant **ret, const void *p, size_t n);
+int json_variant_new_base32hex(JsonVariant **ret, const void *p, size_t n);
+int json_variant_new_hex(JsonVariant **ret, const void *p, size_t n);
+int json_variant_new_octescape(JsonVariant **ret, const void *p, size_t n);
+int json_variant_new_integer(JsonVariant **ret, int64_t i);
+int json_variant_new_unsigned(JsonVariant **ret, uint64_t u);
+int json_variant_new_real(JsonVariant **ret, double d);
+int json_variant_new_boolean(JsonVariant **ret, bool b);
+int json_variant_new_array(JsonVariant **ret, JsonVariant **array, size_t n);
+int json_variant_new_array_bytes(JsonVariant **ret, const void *p, size_t n);
+int json_variant_new_array_strv(JsonVariant **ret, char **l);
+int json_variant_new_object(JsonVariant **ret, JsonVariant **array, size_t n);
+int json_variant_new_null(JsonVariant **ret);
+int json_variant_new_id128(JsonVariant **ret, sd_id128_t id);
+
+static inline int json_variant_new_string(JsonVariant **ret, const char *s) {
+        return json_variant_new_stringn(ret, s, SIZE_MAX);
+}
+
+JsonVariant *json_variant_ref(JsonVariant *v);
+JsonVariant *json_variant_unref(JsonVariant *v);
+void json_variant_unref_many(JsonVariant **array, size_t n);
+
+#define JSON_VARIANT_REPLACE(v, q)        \
+        do {                              \
+                typeof(v)* _v = &(v);     \
+                typeof(q) _q = (q);       \
+                json_variant_unref(*_v);  \
+                *_v = _q;                 \
+        } while(0)
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(JsonVariant *, json_variant_unref);
+
+const char *json_variant_string(JsonVariant *v);
+int64_t json_variant_integer(JsonVariant *v);
+uint64_t json_variant_unsigned(JsonVariant *v);
+double json_variant_real(JsonVariant *v);
+bool json_variant_boolean(JsonVariant *v);
+
+JsonVariantType json_variant_type(JsonVariant *v);
+bool json_variant_has_type(JsonVariant *v, JsonVariantType type);
+
+static inline bool json_variant_is_string(JsonVariant *v) {
+        return json_variant_has_type(v, JSON_VARIANT_STRING);
+}
+
+static inline bool json_variant_is_integer(JsonVariant *v) {
+        return json_variant_has_type(v, JSON_VARIANT_INTEGER);
+}
+
+static inline bool json_variant_is_unsigned(JsonVariant *v) {
+        return json_variant_has_type(v, JSON_VARIANT_UNSIGNED);
+}
+
+static inline bool json_variant_is_real(JsonVariant *v) {
+        return json_variant_has_type(v, JSON_VARIANT_REAL);
+}
+
+static inline bool json_variant_is_number(JsonVariant *v) {
+        return json_variant_has_type(v, JSON_VARIANT_NUMBER);
+}
+
+static inline bool json_variant_is_boolean(JsonVariant *v) {
+        return json_variant_has_type(v, JSON_VARIANT_BOOLEAN);
+}
+
+static inline bool json_variant_is_array(JsonVariant *v) {
+        return json_variant_has_type(v, JSON_VARIANT_ARRAY);
+}
+
+static inline bool json_variant_is_object(JsonVariant *v) {
+        return json_variant_has_type(v, JSON_VARIANT_OBJECT);
+}
+
+static inline bool json_variant_is_null(JsonVariant *v) {
+        return json_variant_has_type(v, JSON_VARIANT_NULL);
+}
+
+bool json_variant_is_negative(JsonVariant *v);
+bool json_variant_is_blank_object(JsonVariant *v);
+bool json_variant_is_blank_array(JsonVariant *v);
+bool json_variant_is_normalized(JsonVariant *v);
+bool json_variant_is_sorted(JsonVariant *v);
+
+size_t json_variant_elements(JsonVariant *v);
+JsonVariant *json_variant_by_index(JsonVariant *v, size_t index);
+JsonVariant *json_variant_by_key(JsonVariant *v, const char *key);
+JsonVariant *json_variant_by_key_full(JsonVariant *v, const char *key, JsonVariant **ret_key);
+
+bool json_variant_equal(JsonVariant *a, JsonVariant *b);
+
+void json_variant_sensitive(JsonVariant *v);
+bool json_variant_is_sensitive(JsonVariant *v);
+
+struct json_variant_foreach_state {
+        JsonVariant *variant;
+        size_t idx;
+};
+
+#define _JSON_VARIANT_ARRAY_FOREACH(i, v, state)                        \
+        for (struct json_variant_foreach_state state = { (v), 0 };      \
+             json_variant_is_array(state.variant) &&                    \
+                     state.idx < json_variant_elements(state.variant) && \
+                     ({ i = json_variant_by_index(state.variant, state.idx); \
+                             true; });                                  \
+             state.idx++)
+#define JSON_VARIANT_ARRAY_FOREACH(i, v)                                \
+        _JSON_VARIANT_ARRAY_FOREACH(i, v, UNIQ_T(state, UNIQ))
+
+#define _JSON_VARIANT_OBJECT_FOREACH(k, e, v, state)                    \
+        for (struct json_variant_foreach_state state = { (v), 0 };      \
+             json_variant_is_object(state.variant) &&                   \
+                     state.idx < json_variant_elements(state.variant) && \
+                     ({ k = json_variant_string(json_variant_by_index(state.variant, state.idx)); \
+                             e = json_variant_by_index(state.variant, state.idx + 1); \
+                             true; });                                  \
+             state.idx += 2)
+#define JSON_VARIANT_OBJECT_FOREACH(k, e, v)                            \
+        _JSON_VARIANT_OBJECT_FOREACH(k, e, v, UNIQ_T(state, UNIQ))
+
+int json_variant_get_source(JsonVariant *v, const char **ret_source, unsigned *ret_line, unsigned *ret_column);
+
+typedef enum JsonFormatFlags {
+        JSON_FORMAT_NEWLINE     = 1 << 0, /* suffix with newline */
+        JSON_FORMAT_PRETTY      = 1 << 1, /* add internal whitespace to appeal to human readers */
+        JSON_FORMAT_PRETTY_AUTO = 1 << 2, /* same, but only if connected to a tty (and JSON_FORMAT_NEWLINE otherwise) */
+        JSON_FORMAT_COLOR       = 1 << 3, /* insert ANSI color sequences */
+        JSON_FORMAT_COLOR_AUTO  = 1 << 4, /* insert ANSI color sequences if colors_enabled() says so */
+        JSON_FORMAT_SOURCE      = 1 << 5, /* prefix with source filename/line/column */
+        JSON_FORMAT_SSE         = 1 << 6, /* prefix/suffix with W3C server-sent events */
+        JSON_FORMAT_SEQ         = 1 << 7, /* prefix/suffix with RFC 7464 application/json-seq */
+        JSON_FORMAT_FLUSH       = 1 << 8, /* call fflush() after dumping JSON */
+        JSON_FORMAT_OFF         = 1 << 9, /* make json_variant_format() fail with -ENOEXEC */
+} JsonFormatFlags;
+
+int json_variant_format(JsonVariant *v, JsonFormatFlags flags, char **ret);
+int json_variant_dump(JsonVariant *v, JsonFormatFlags flags, FILE *f, const char *prefix);
+
+int json_variant_filter(JsonVariant **v, char **to_remove);
+
+int json_variant_set_field(JsonVariant **v, const char *field, JsonVariant *value);
+int json_variant_set_field_string(JsonVariant **v, const char *field, const char *value);
+int json_variant_set_field_integer(JsonVariant **v, const char *field, int64_t value);
+int json_variant_set_field_unsigned(JsonVariant **v, const char *field, uint64_t value);
+int json_variant_set_field_boolean(JsonVariant **v, const char *field, bool b);
+int json_variant_set_field_strv(JsonVariant **v, const char *field, char **l);
+
+int json_variant_append_array(JsonVariant **v, JsonVariant *element);
+
+int json_variant_merge(JsonVariant **v, JsonVariant *m);
+
+int json_variant_strv(JsonVariant *v, char ***ret);
+
+int json_variant_sort(JsonVariant **v);
+int json_variant_normalize(JsonVariant **v);
+
+typedef enum JsonParseFlags {
+        JSON_PARSE_SENSITIVE = 1 << 0, /* mark variant as "sensitive", i.e. something containing secret key material or such */
+} JsonParseFlags;
+
+int json_parse(const char *string, JsonParseFlags flags, JsonVariant **ret, unsigned *ret_line, unsigned *ret_column);
+int json_parse_continue(const char **p, JsonParseFlags flags, JsonVariant **ret, unsigned *ret_line, unsigned *ret_column);
+int json_parse_file_at(FILE *f, int dir_fd, const char *path, JsonParseFlags flags, JsonVariant **ret, unsigned *ret_line, unsigned *ret_column);
+
+static inline int json_parse_file(FILE *f, const char *path, JsonParseFlags flags, JsonVariant **ret, unsigned *ret_line, unsigned *ret_column) {
+        return json_parse_file_at(f, AT_FDCWD, path, flags, ret, ret_line, ret_column);
+}
+
+enum {
+        _JSON_BUILD_STRING,
+        _JSON_BUILD_INTEGER,
+        _JSON_BUILD_UNSIGNED,
+        _JSON_BUILD_REAL,
+        _JSON_BUILD_BOOLEAN,
+        _JSON_BUILD_ARRAY_BEGIN,
+        _JSON_BUILD_ARRAY_END,
+        _JSON_BUILD_OBJECT_BEGIN,
+        _JSON_BUILD_OBJECT_END,
+        _JSON_BUILD_PAIR,
+        _JSON_BUILD_PAIR_CONDITION,
+        _JSON_BUILD_NULL,
+        _JSON_BUILD_VARIANT,
+        _JSON_BUILD_VARIANT_ARRAY,
+        _JSON_BUILD_LITERAL,
+        _JSON_BUILD_STRV,
+        _JSON_BUILD_BASE64,
+        _JSON_BUILD_BASE32HEX,
+        _JSON_BUILD_HEX,
+        _JSON_BUILD_OCTESCAPE,
+        _JSON_BUILD_ID128,
+        _JSON_BUILD_BYTE_ARRAY,
+        _JSON_BUILD_HW_ADDR,
+        _JSON_BUILD_PAIR_UNSIGNED_NON_ZERO,
+        _JSON_BUILD_PAIR_FINITE_USEC,
+        _JSON_BUILD_PAIR_STRING_NON_EMPTY,
+        _JSON_BUILD_PAIR_STRV_NON_EMPTY,
+        _JSON_BUILD_PAIR_VARIANT_NON_NULL,
+        _JSON_BUILD_PAIR_VARIANT_ARRAY_NON_EMPTY,
+        _JSON_BUILD_PAIR_IN4_ADDR_NON_NULL,
+        _JSON_BUILD_PAIR_IN6_ADDR_NON_NULL,
+        _JSON_BUILD_PAIR_IN_ADDR_NON_NULL,
+        _JSON_BUILD_PAIR_ETHER_ADDR_NON_NULL,
+        _JSON_BUILD_PAIR_HW_ADDR_NON_NULL,
+        _JSON_BUILD_MAX,
+};
+
+#define JSON_BUILD_STRING(s) _JSON_BUILD_STRING, (const char*) { s }
+#define JSON_BUILD_INTEGER(i) _JSON_BUILD_INTEGER, (int64_t) { i }
+#define JSON_BUILD_UNSIGNED(u) _JSON_BUILD_UNSIGNED, (uint64_t) { u }
+#define JSON_BUILD_REAL(d) _JSON_BUILD_REAL, (double) { d }
+#define JSON_BUILD_BOOLEAN(b) _JSON_BUILD_BOOLEAN, (bool) { b }
+#define JSON_BUILD_ARRAY(...) _JSON_BUILD_ARRAY_BEGIN, __VA_ARGS__, _JSON_BUILD_ARRAY_END
+#define JSON_BUILD_EMPTY_ARRAY _JSON_BUILD_ARRAY_BEGIN, _JSON_BUILD_ARRAY_END
+#define JSON_BUILD_OBJECT(...) _JSON_BUILD_OBJECT_BEGIN, __VA_ARGS__, _JSON_BUILD_OBJECT_END
+#define JSON_BUILD_EMPTY_OBJECT _JSON_BUILD_OBJECT_BEGIN, _JSON_BUILD_OBJECT_END
+#define JSON_BUILD_PAIR(n, ...) _JSON_BUILD_PAIR, (const char*) { n }, __VA_ARGS__
+#define JSON_BUILD_PAIR_CONDITION(c, n, ...) _JSON_BUILD_PAIR_CONDITION, (bool) { c }, (const char*) { n }, __VA_ARGS__
+#define JSON_BUILD_NULL _JSON_BUILD_NULL
+#define JSON_BUILD_VARIANT(v) _JSON_BUILD_VARIANT, (JsonVariant*) { v }
+#define JSON_BUILD_VARIANT_ARRAY(v, n) _JSON_BUILD_VARIANT_ARRAY, (JsonVariant **) { v }, (size_t) { n }
+#define JSON_BUILD_LITERAL(l) _JSON_BUILD_LITERAL, (const char*) { l }
+#define JSON_BUILD_STRV(l) _JSON_BUILD_STRV, (char**) { l }
+#define JSON_BUILD_BASE64(p, n) _JSON_BUILD_BASE64, (const void*) { p }, (size_t) { n }
+#define JSON_BUILD_BASE32HEX(p, n) _JSON_BUILD_BASE32HEX, (const void*) { p }, (size_t) { n }
+#define JSON_BUILD_HEX(p, n) _JSON_BUILD_HEX, (const void*) { p }, (size_t) { n }
+#define JSON_BUILD_OCTESCAPE(p, n) _JSON_BUILD_OCTESCAPE, (const void*) { p }, (size_t) { n }
+#define JSON_BUILD_ID128(id) _JSON_BUILD_ID128, (const sd_id128_t*) { &(id) }
+#define JSON_BUILD_BYTE_ARRAY(v, n) _JSON_BUILD_BYTE_ARRAY, (const void*) { v }, (size_t) { n }
+#define JSON_BUILD_CONST_STRING(s) _JSON_BUILD_VARIANT, JSON_VARIANT_STRING_CONST(s)
+#define JSON_BUILD_IN4_ADDR(v) JSON_BUILD_BYTE_ARRAY((const struct in_addr*) { v }, sizeof(struct in_addr))
+#define JSON_BUILD_IN6_ADDR(v) JSON_BUILD_BYTE_ARRAY((const struct in6_addr*) { v }, sizeof(struct in6_addr))
+#define JSON_BUILD_IN_ADDR(v, f) JSON_BUILD_BYTE_ARRAY(((const union in_addr_union*) { v })->bytes, FAMILY_ADDRESS_SIZE_SAFE(f))
+#define JSON_BUILD_ETHER_ADDR(v) JSON_BUILD_BYTE_ARRAY(((const struct ether_addr*) { v })->ether_addr_octet, sizeof(struct ether_addr))
+#define JSON_BUILD_HW_ADDR(v) _JSON_BUILD_HW_ADDR, (const struct hw_addr_data*) { v }
+
+#define JSON_BUILD_PAIR_STRING(name, s) JSON_BUILD_PAIR(name, JSON_BUILD_STRING(s))
+#define JSON_BUILD_PAIR_INTEGER(name, i) JSON_BUILD_PAIR(name, JSON_BUILD_INTEGER(i))
+#define JSON_BUILD_PAIR_UNSIGNED(name, u) JSON_BUILD_PAIR(name, JSON_BUILD_UNSIGNED(u))
+#define JSON_BUILD_PAIR_REAL(name, d) JSON_BUILD_PAIR(name, JSON_BUILD_REAL(d))
+#define JSON_BUILD_PAIR_BOOLEAN(name, b) JSON_BUILD_PAIR(name, JSON_BUILD_BOOLEAN(b))
+#define JSON_BUILD_PAIR_ARRAY(name, ...) JSON_BUILD_PAIR(name, JSON_BUILD_ARRAY(__VA_ARGS__))
+#define JSON_BUILD_PAIR_EMPTY_ARRAY(name) JSON_BUILD_PAIR(name, JSON_BUILD_EMPTY_ARRAY)
+#define JSON_BUILD_PAIR_OBJECT(name, ...) JSON_BUILD_PAIR(name, JSON_BUILD_OBJECT(__VA_ARGS__))
+#define JSON_BUILD_PAIR_EMPTY_OBJECT(name) JSON_BUILD_PAIR(name, JSON_BUILD_EMPTY_OBJECT)
+#define JSON_BUILD_PAIR_NULL(name) JSON_BUILD_PAIR(name, JSON_BUILD_NULL)
+#define JSON_BUILD_PAIR_VARIANT(name, v) JSON_BUILD_PAIR(name, JSON_BUILD_VARIANT(v))
+#define JSON_BUILD_PAIR_VARIANT_ARRAY(name, v, n) JSON_BUILD_PAIR(name, JSON_BUILD_VARIANT_ARRAY(v, n))
+#define JSON_BUILD_PAIR_LITERAL(name, l) JSON_BUILD_PAIR(name, JSON_BUILD_LITERAL(l))
+#define JSON_BUILD_PAIR_STRV(name, l) JSON_BUILD_PAIR(name, JSON_BUILD_STRV(l))
+#define JSON_BUILD_PAIR_BASE64(name, p, n) JSON_BUILD_PAIR(name, JSON_BUILD_BASE64(p, n))
+#define JSON_BUILD_PAIR_HEX(name, p, n) JSON_BUILD_PAIR(name, JSON_BUILD_HEX(p, n))
+#define JSON_BUILD_PAIR_ID128(name, id) JSON_BUILD_PAIR(name, JSON_BUILD_ID128(id))
+#define JSON_BUILD_PAIR_BYTE_ARRAY(name, v, n) JSON_BUILD_PAIR(name, JSON_BUILD_BYTE_ARRAY(v, n))
+#define JSON_BUILD_PAIR_IN4_ADDR(name, v) JSON_BUILD_PAIR(name, JSON_BUILD_IN4_ADDR(v))
+#define JSON_BUILD_PAIR_IN6_ADDR(name, v) JSON_BUILD_PAIR(name, JSON_BUILD_IN6_ADDR(v))
+#define JSON_BUILD_PAIR_IN_ADDR(name, v, f) JSON_BUILD_PAIR(name, JSON_BUILD_IN_ADDR(v, f))
+#define JSON_BUILD_PAIR_ETHER_ADDR(name, v) JSON_BUILD_PAIR(name, JSON_BUILD_ETHER_ADDR(v))
+#define JSON_BUILD_PAIR_HW_ADDR(name, v) JSON_BUILD_PAIR(name, JSON_BUILD_HW_ADDR(v))
+
+#define JSON_BUILD_PAIR_UNSIGNED_NON_ZERO(name, u) _JSON_BUILD_PAIR_UNSIGNED_NON_ZERO, (const char*) { name }, (uint64_t) { u }
+#define JSON_BUILD_PAIR_FINITE_USEC(name, u) _JSON_BUILD_PAIR_FINITE_USEC, (const char*) { name }, (usec_t) { u }
+#define JSON_BUILD_PAIR_STRING_NON_EMPTY(name, s) _JSON_BUILD_PAIR_STRING_NON_EMPTY, (const char*) { name }, (const char*) { s }
+#define JSON_BUILD_PAIR_STRV_NON_EMPTY(name, l) _JSON_BUILD_PAIR_STRV_NON_EMPTY, (const char*) { name }, (char**) { l }
+#define JSON_BUILD_PAIR_VARIANT_NON_NULL(name, v) _JSON_BUILD_PAIR_VARIANT_NON_NULL, (const char*) { name }, (JsonVariant*) { v }
+#define JSON_BUILD_PAIR_IN4_ADDR_NON_NULL(name, v) _JSON_BUILD_PAIR_IN4_ADDR_NON_NULL, (const char*) { name }, (const struct in_addr*) { v }
+#define JSON_BUILD_PAIR_IN6_ADDR_NON_NULL(name, v) _JSON_BUILD_PAIR_IN6_ADDR_NON_NULL, (const char*) { name }, (const struct in6_addr*) { v }
+#define JSON_BUILD_PAIR_IN_ADDR_NON_NULL(name, v, f) _JSON_BUILD_PAIR_IN_ADDR_NON_NULL, (const char*) { name }, (const union in_addr_union*) { v }, (int) { f }
+#define JSON_BUILD_PAIR_ETHER_ADDR_NON_NULL(name, v) _JSON_BUILD_PAIR_ETHER_ADDR_NON_NULL, (const char*) { name }, (const struct ether_addr*) { v }
+#define JSON_BUILD_PAIR_HW_ADDR_NON_NULL(name, v) _JSON_BUILD_PAIR_HW_ADDR_NON_NULL, (const char*) { name }, (const struct hw_addr_data*) { v }
+
+int json_build(JsonVariant **ret, ...);
+int json_buildv(JsonVariant **ret, va_list ap);
+ /* These two functions below are equivalent to json_build() (or json_buildv()) and json_variant_merge(). */
+int json_append(JsonVariant **v, ...);
+int json_appendv(JsonVariant **v, va_list ap);
+
+/* A bitmask of flags used by the dispatch logic. Note that this is a combined bit mask, that is generated from the bit
+ * mask originally passed into json_dispatch(), the individual bitmask associated with the static JsonDispatch callout
+ * entry, as well the bitmask specified for json_log() calls */
+typedef enum JsonDispatchFlags {
+        /* The following three may be set in JsonDispatch's .flags field or the json_dispatch() flags parameter  */
+        JSON_PERMISSIVE = 1 << 0, /* Shall parsing errors be considered fatal for this property? */
+        JSON_MANDATORY  = 1 << 1, /* Should existence of this property be mandatory? */
+        JSON_LOG        = 1 << 2, /* Should the parser log about errors? */
+        JSON_SAFE       = 1 << 3, /* Don't accept "unsafe" strings in json_dispatch_string() + json_dispatch_string() */
+        JSON_RELAX      = 1 << 4, /* Use relaxed user name checking in json_dispatch_user_group_name */
+
+        /* The following two may be passed into log_json() in addition to those above */
+        JSON_DEBUG      = 1 << 5, /* Indicates that this log message is a debug message */
+        JSON_WARNING    = 1 << 6, /* Indicates that this log message is a warning message */
+} JsonDispatchFlags;
+
+typedef int (*JsonDispatchCallback)(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
+
+typedef struct JsonDispatch {
+        const char *name;
+        JsonVariantType type;
+        JsonDispatchCallback callback;
+        size_t offset;
+        JsonDispatchFlags flags;
+} JsonDispatch;
+
+int json_dispatch(JsonVariant *v, const JsonDispatch table[], JsonDispatchCallback bad, JsonDispatchFlags flags, void *userdata);
+
+int json_dispatch_string(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
+int json_dispatch_const_string(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
+int json_dispatch_strv(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
+int json_dispatch_boolean(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
+int json_dispatch_tristate(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
+int json_dispatch_variant(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
+int json_dispatch_int64(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
+int json_dispatch_uint64(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
+int json_dispatch_uint32(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
+int json_dispatch_int32(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
+int json_dispatch_uint16(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
+int json_dispatch_int16(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
+int json_dispatch_uid_gid(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
+int json_dispatch_user_group_name(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
+int json_dispatch_id128(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
+int json_dispatch_unsupported(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata);
+
+assert_cc(sizeof(uint32_t) == sizeof(unsigned));
+#define json_dispatch_uint json_dispatch_uint32
+
+assert_cc(sizeof(int32_t) == sizeof(int));
+#define json_dispatch_int json_dispatch_int32
+
+static inline int json_dispatch_level(JsonDispatchFlags flags) {
+
+        /* Did the user request no logging? If so, then never log higher than LOG_DEBUG. Also, if this is marked as
+         * debug message, then also log at debug level. */
+
+        if (!(flags & JSON_LOG) ||
+            (flags & JSON_DEBUG))
+                return LOG_DEBUG;
+
+        /* Are we invoked in permissive mode, or is this explicitly marked as warning message? Then this should be
+         * printed at LOG_WARNING */
+        if (flags & (JSON_PERMISSIVE|JSON_WARNING))
+                return LOG_WARNING;
+
+        /* Otherwise it's an error. */
+        return LOG_ERR;
+}
+
+int json_log_internal(JsonVariant *variant, int level, int error, const char *file, int line, const char *func, const char *format, ...)  _printf_(7, 8);
+
+#define json_log(variant, flags, error, ...)                            \
+        ({                                                              \
+                int _level = json_dispatch_level(flags), _e = (error);  \
+                (log_get_max_level() >= LOG_PRI(_level))                \
+                        ? json_log_internal(variant, _level, _e, PROJECT_FILE, __LINE__, __func__, __VA_ARGS__) \
+                        : -ERRNO_VALUE(_e);                             \
+        })
+
+#define json_log_oom(variant, flags) \
+        json_log(variant, flags, SYNTHETIC_ERRNO(ENOMEM), "Out of memory.")
+
+#define JSON_VARIANT_STRING_CONST(x) _JSON_VARIANT_STRING_CONST(UNIQ, (x))
+
+#define _JSON_VARIANT_STRING_CONST(xq, x)                               \
+        ({                                                              \
+                _align_(2) static const char UNIQ_T(json_string_const, xq)[] = (x); \
+                assert((((uintptr_t) UNIQ_T(json_string_const, xq)) & 1) == 0); \
+                (JsonVariant*) ((uintptr_t) UNIQ_T(json_string_const, xq) + 1); \
+        })
+
+int json_variant_unbase64(JsonVariant *v, void **ret, size_t *ret_size);
+int json_variant_unhex(JsonVariant *v, void **ret, size_t *ret_size);
+
+const char *json_variant_type_to_string(JsonVariantType t);
+JsonVariantType json_variant_type_from_string(const char *s);