Adding upstream version 241.upstream/241upstream

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

1 files changed, 3480 insertions, 0 deletions

diff --git a/src/shared/json.c b/src/shared/json.c
new file mode 100644
index 0000000..3786ff1
--- /dev/null
+++ b/src/shared/json.c
@@ -0,0 +1,3480 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <math.h>
+#include <stdarg.h>
+#include <stdio_ext.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+
+#include "sd-messages.h"
+
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "float.h"
+#include "hexdecoct.h"
+#include "json-internal.h"
+#include "json.h"
+#include "macro.h"
+#include "string-table.h"
+#include "string-util.h"
+#include "strv.h"
+#include "terminal-util.h"
+#include "utf8.h"
+
+/* Refuse putting together variants with a larger depth than 4K by default (as a protection against overflowing stacks
+ * if code processes JSON objects recursively. Note that we store the depth in an uint16_t, hence make sure this
+ * remains under 2^16.
+ * The value was 16k, but it was discovered to be too high on llvm/x86-64. See also the issue #10738. */
+#define DEPTH_MAX (4U*1024U)
+assert_cc(DEPTH_MAX <= UINT16_MAX);
+
+typedef struct JsonSource {
+        /* When we parse from a file or similar, encodes the filename, to indicate the source of a json variant */
+        size_t n_ref;
+        unsigned max_line;
+        unsigned max_column;
+        char name[];
+} JsonSource;
+
+/* On x86-64 this whole structure should have a size of 6 * 64 bit = 48 bytes */
+struct JsonVariant {
+        union {
+                /* We either maintain a reference counter for this variant itself, or we are embedded into an
+                 * array/object, in which case only that surrounding object is ref-counted. (If 'embedded' is false,
+                 * see below.) */
+                size_t n_ref;
+
+                /* If this JsonVariant is part of an array/object, then this field points to the surrounding
+                 * JSON_VARIANT_ARRAY/JSON_VARIANT_OBJECT object. (If 'embedded' is true, see below.) */
+                JsonVariant *parent;
+        };
+
+        /* If this was parsed from some file or buffer, this stores where from, as well as the source line/column */
+        JsonSource *source;
+        unsigned line, column;
+
+        JsonVariantType type:5;
+
+        /* A marker whether this variant is embedded into in array/object or not. If true, the 'parent' pointer above
+         * is valid. If false, the 'n_ref' field above is valid instead. */
+        bool is_embedded:1;
+
+        /* In some conditions (for example, if this object is part of an array of strings or objects), we don't store
+         * any data inline, but instead simply reference an external object and act as surrogate of it. In that case
+         * this bool is set, and the external object is referenced through the .reference field below. */
+        bool is_reference:1;
+
+        /* While comparing two arrays, we use this for marking what we already have seen */
+        bool is_marked:1;
+
+        /* The current 'depth' of the JsonVariant, i.e. how many levels of member variants this has */
+        uint16_t depth;
+
+        union {
+                /* For simple types we store the value in-line. */
+                JsonValue value;
+
+                /* For objects and arrays we store the number of elements immediately following */
+                size_t n_elements;
+
+                /* If is_reference as indicated above is set, this is where the reference object is actually stored. */
+                JsonVariant *reference;
+
+                /* Strings are placed immediately after the structure. Note that when this is a JsonVariant embedded
+                 * into an array we might encode strings up to INLINE_STRING_LENGTH characters directly inside the
+                 * element, while longer strings are stored as references. When this object is not embedded into an
+                 * array, but stand-alone we allocate the right size for the whole structure, i.e. the array might be
+                 * much larger than INLINE_STRING_LENGTH.
+                 *
+                 * Note that because we want to allocate arrays of the JsonVariant structure we specify [0] here,
+                 * rather than the prettier []. If we wouldn't, then this char array would have undefined size, and so
+                 * would the union and then the struct this is included in. And of structures with undefined size we
+                 * can't allocate arrays (at least not easily). */
+                char string[0];
+        };
+};
+
+/* Inside string arrays we have a series of JasonVariant structures one after the other. In this case, strings longer
+ * than INLINE_STRING_MAX are stored as references, and all shorter ones inline. (This means — on x86-64 — strings up
+ * to 15 chars are stored within the array elements, and all others in separate allocations) */
+#define INLINE_STRING_MAX (sizeof(JsonVariant) - offsetof(JsonVariant, string) - 1U)
+
+/* Let's make sure this structure isn't increased in size accidentally. This check is only for our most relevant arch
+ * (x86-64). */
+#ifdef __x86_64__
+assert_cc(sizeof(JsonVariant) == 48U);
+assert_cc(INLINE_STRING_MAX == 15U);
+#endif
+
+static JsonSource* json_source_new(const char *name) {
+        JsonSource *s;
+
+        assert(name);
+
+        s = malloc(offsetof(JsonSource, name) + strlen(name) + 1);
+        if (!s)
+                return NULL;
+
+        *s = (JsonSource) {
+                .n_ref = 1,
+        };
+        strcpy(s->name, name);
+
+        return s;
+}
+
+DEFINE_PRIVATE_TRIVIAL_REF_UNREF_FUNC(JsonSource, json_source, mfree);
+
+static bool json_source_equal(JsonSource *a, JsonSource *b) {
+        if (a == b)
+                return true;
+
+        if (!a || !b)
+                return false;
+
+        return streq(a->name, b->name);
+}
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(JsonSource*, json_source_unref);
+
+/* There are four kind of JsonVariant* pointers:
+ *
+ *    1. NULL
+ *    2. A 'regular' one, i.e. pointing to malloc() memory
+ *    3. A 'magic' one, i.e. one of the special JSON_VARIANT_MAGIC_XYZ values, that encode a few very basic values directly in the pointer.
+ *    4. A 'const string' one, i.e. a pointer to a const string.
+ *
+ * The four kinds of pointers can be discerned like this:
+ *
+ *    Detecting #1 is easy, just compare with NULL. Detecting #3 is similarly easy: all magic pointers are below
+ *    _JSON_VARIANT_MAGIC_MAX (which is pretty low, within the first memory page, which is special on Linux and other
+ *    OSes, as it is a faulting page). In order to discern #2 and #4 we check the lowest bit. If it's off it's #2,
+ *    otherwise #4. This makes use of the fact that malloc() will return "maximum aligned" memory, which definitely
+ *    means the pointer is even. This means we can use the uneven pointers to reference static strings, as long as we
+ *    make sure that all static strings used like this are aligned to 2 (or higher), and that we mask the bit on
+ *    access. The JSON_VARIANT_STRING_CONST() macro encodes strings as JsonVariant* pointers, with the bit set. */
+
+static bool json_variant_is_magic(const JsonVariant *v) {
+        if (!v)
+                return false;
+
+        return v < _JSON_VARIANT_MAGIC_MAX;
+}
+
+static bool json_variant_is_const_string(const JsonVariant *v) {
+
+        if (v < _JSON_VARIANT_MAGIC_MAX)
+                return false;
+
+        /* A proper JsonVariant is aligned to whatever malloc() aligns things too, which is definitely not uneven. We
+         * hence use all uneven pointers as indicators for const strings. */
+
+        return (((uintptr_t) v) & 1) != 0;
+}
+
+static bool json_variant_is_regular(const JsonVariant *v) {
+
+        if (v < _JSON_VARIANT_MAGIC_MAX)
+                return false;
+
+        return (((uintptr_t) v) & 1) == 0;
+}
+
+static JsonVariant *json_variant_dereference(JsonVariant *v) {
+
+        /* Recursively dereference variants that are references to other variants */
+
+        if (!v)
+                return NULL;
+
+        if (!json_variant_is_regular(v))
+                return v;
+
+        if (!v->is_reference)
+                return v;
+
+        return json_variant_dereference(v->reference);
+}
+
+static uint16_t json_variant_depth(JsonVariant *v) {
+
+        v = json_variant_dereference(v);
+        if (!v)
+                return 0;
+
+        if (!json_variant_is_regular(v))
+                return 0;
+
+        return v->depth;
+}
+
+static JsonVariant *json_variant_normalize(JsonVariant *v) {
+
+        /* Converts json variants to their normalized form, i.e. fully dereferenced and wherever possible converted to
+         * the "magic" version if there is one */
+
+        if (!v)
+                return NULL;
+
+        v = json_variant_dereference(v);
+
+        switch (json_variant_type(v)) {
+
+        case JSON_VARIANT_BOOLEAN:
+                return json_variant_boolean(v) ? JSON_VARIANT_MAGIC_TRUE : JSON_VARIANT_MAGIC_FALSE;
+
+        case JSON_VARIANT_NULL:
+                return JSON_VARIANT_MAGIC_NULL;
+
+        case JSON_VARIANT_INTEGER:
+                return json_variant_integer(v) == 0 ? JSON_VARIANT_MAGIC_ZERO_INTEGER : v;
+
+        case JSON_VARIANT_UNSIGNED:
+                return json_variant_unsigned(v) == 0 ? JSON_VARIANT_MAGIC_ZERO_UNSIGNED : v;
+
+        case JSON_VARIANT_REAL:
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wfloat-equal"
+                return json_variant_real(v) == 0.0 ? JSON_VARIANT_MAGIC_ZERO_REAL : v;
+#pragma GCC diagnostic pop
+
+        case JSON_VARIANT_STRING:
+                return isempty(json_variant_string(v)) ? JSON_VARIANT_MAGIC_EMPTY_STRING : v;
+
+        case JSON_VARIANT_ARRAY:
+                return json_variant_elements(v) == 0 ? JSON_VARIANT_MAGIC_EMPTY_ARRAY : v;
+
+        case JSON_VARIANT_OBJECT:
+                return json_variant_elements(v) == 0 ? JSON_VARIANT_MAGIC_EMPTY_OBJECT : v;
+
+        default:
+                return v;
+        }
+}
+
+static JsonVariant *json_variant_conservative_normalize(JsonVariant *v) {
+
+        /* Much like json_variant_normalize(), but won't simplify if the variant has a source/line location attached to
+         * it, in order not to lose context */
+
+        if (!v)
+                return NULL;
+
+        if (!json_variant_is_regular(v))
+                return v;
+
+        if (v->source || v->line > 0 || v->column > 0)
+                return v;
+
+        return json_variant_normalize(v);
+}
+
+static int json_variant_new(JsonVariant **ret, JsonVariantType type, size_t space) {
+        JsonVariant *v;
+
+        assert_return(ret, -EINVAL);
+
+        v = malloc0(offsetof(JsonVariant, value) + space);
+        if (!v)
+                return -ENOMEM;
+
+        v->n_ref = 1;
+        v->type = type;
+
+        *ret = v;
+        return 0;
+}
+
+int json_variant_new_integer(JsonVariant **ret, intmax_t i) {
+        JsonVariant *v;
+        int r;
+
+        assert_return(ret, -EINVAL);
+
+        if (i == 0) {
+                *ret = JSON_VARIANT_MAGIC_ZERO_INTEGER;
+                return 0;
+        }
+
+        r = json_variant_new(&v, JSON_VARIANT_INTEGER, sizeof(i));
+        if (r < 0)
+                return r;
+
+        v->value.integer = i;
+        *ret = v;
+
+        return 0;
+}
+
+int json_variant_new_unsigned(JsonVariant **ret, uintmax_t u) {
+        JsonVariant *v;
+        int r;
+
+        assert_return(ret, -EINVAL);
+        if (u == 0) {
+                *ret = JSON_VARIANT_MAGIC_ZERO_UNSIGNED;
+                return 0;
+        }
+
+        r = json_variant_new(&v, JSON_VARIANT_UNSIGNED, sizeof(u));
+        if (r < 0)
+                return r;
+
+        v->value.unsig = u;
+        *ret = v;
+
+        return 0;
+}
+
+int json_variant_new_real(JsonVariant **ret, long double d) {
+        JsonVariant *v;
+        int r;
+
+        assert_return(ret, -EINVAL);
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wfloat-equal"
+        if (d == 0.0) {
+#pragma GCC diagnostic pop
+                *ret = JSON_VARIANT_MAGIC_ZERO_REAL;
+                return 0;
+        }
+
+        r = json_variant_new(&v, JSON_VARIANT_REAL, sizeof(d));
+        if (r < 0)
+                return r;
+
+        v->value.real = d;
+        *ret = v;
+
+        return 0;
+}
+
+int json_variant_new_boolean(JsonVariant **ret, bool b) {
+        assert_return(ret, -EINVAL);
+
+        if (b)
+                *ret = JSON_VARIANT_MAGIC_TRUE;
+        else
+                *ret = JSON_VARIANT_MAGIC_FALSE;
+
+        return 0;
+}
+
+int json_variant_new_null(JsonVariant **ret) {
+        assert_return(ret, -EINVAL);
+
+        *ret = JSON_VARIANT_MAGIC_NULL;
+        return 0;
+}
+
+int json_variant_new_stringn(JsonVariant **ret, const char *s, size_t n) {
+        JsonVariant *v;
+        int r;
+
+        assert_return(ret, -EINVAL);
+        if (!s) {
+                assert_return(n == 0, -EINVAL);
+                return json_variant_new_null(ret);
+        }
+        if (n == 0) {
+                *ret = JSON_VARIANT_MAGIC_EMPTY_STRING;
+                return 0;
+        }
+
+        r = json_variant_new(&v, JSON_VARIANT_STRING, n + 1);
+        if (r < 0)
+                return r;
+
+        memcpy(v->string, s, n);
+        v->string[n] = 0;
+
+        *ret = v;
+        return 0;
+}
+
+static void json_variant_set(JsonVariant *a, JsonVariant *b) {
+        assert(a);
+
+        b = json_variant_dereference(b);
+        if (!b) {
+                a->type = JSON_VARIANT_NULL;
+                return;
+        }
+
+        a->type = json_variant_type(b);
+        switch (a->type) {
+
+        case JSON_VARIANT_INTEGER:
+                a->value.integer = json_variant_integer(b);
+                break;
+
+        case JSON_VARIANT_UNSIGNED:
+                a->value.unsig = json_variant_unsigned(b);
+                break;
+
+        case JSON_VARIANT_REAL:
+                a->value.real = json_variant_real(b);
+                break;
+
+        case JSON_VARIANT_BOOLEAN:
+                a->value.boolean = json_variant_boolean(b);
+                break;
+
+        case JSON_VARIANT_STRING: {
+                const char *s;
+
+                assert_se(s = json_variant_string(b));
+
+                /* Short strings we can store inline */
+                if (strnlen(s, INLINE_STRING_MAX+1) <= INLINE_STRING_MAX) {
+                        strcpy(a->string, s);
+                        break;
+                }
+
+                /* For longer strings, use a reference… */
+                _fallthrough_;
+        }
+
+        case JSON_VARIANT_ARRAY:
+        case JSON_VARIANT_OBJECT:
+                a->is_reference = true;
+                a->reference = json_variant_ref(json_variant_conservative_normalize(b));
+                break;
+
+        case JSON_VARIANT_NULL:
+                break;
+
+        default:
+                assert_not_reached("Unexpected variant type");
+        }
+}
+
+static void json_variant_copy_source(JsonVariant *v, JsonVariant *from) {
+        assert(v);
+        assert(from);
+
+        if (!json_variant_is_regular(from))
+                return;
+
+        v->line = from->line;
+        v->column = from->column;
+        v->source = json_source_ref(from->source);
+}
+
+int json_variant_new_array(JsonVariant **ret, JsonVariant **array, size_t n) {
+        _cleanup_(json_variant_unrefp) JsonVariant *v = NULL;
+
+        assert_return(ret, -EINVAL);
+        if (n == 0) {
+                *ret = JSON_VARIANT_MAGIC_EMPTY_ARRAY;
+                return 0;
+        }
+        assert_return(array, -EINVAL);
+
+        v = new(JsonVariant, n + 1);
+        if (!v)
+                return -ENOMEM;
+
+        *v = (JsonVariant) {
+                .n_ref = 1,
+                .type = JSON_VARIANT_ARRAY,
+        };
+
+        for (v->n_elements = 0; v->n_elements < n; v->n_elements++) {
+                JsonVariant *w = v + 1 + v->n_elements,
+                        *c = array[v->n_elements];
+                uint16_t d;
+
+                d = json_variant_depth(c);
+                if (d >= DEPTH_MAX) /* Refuse too deep nesting */
+                        return -ELNRNG;
+                if (d >= v->depth)
+                        v->depth = d + 1;
+
+                *w = (JsonVariant) {
+                        .is_embedded = true,
+                        .parent = v,
+                };
+
+                json_variant_set(w, c);
+                json_variant_copy_source(w, c);
+        }
+
+        *ret = TAKE_PTR(v);
+        return 0;
+}
+
+int json_variant_new_array_bytes(JsonVariant **ret, const void *p, size_t n) {
+        JsonVariant *v;
+        size_t i;
+
+        assert_return(ret, -EINVAL);
+        if (n == 0) {
+                *ret = JSON_VARIANT_MAGIC_EMPTY_ARRAY;
+                return 0;
+        }
+        assert_return(p, -EINVAL);
+
+        v = new(JsonVariant, n + 1);
+        if (!v)
+                return -ENOMEM;
+
+        *v = (JsonVariant) {
+                .n_ref = 1,
+                .type = JSON_VARIANT_ARRAY,
+                .n_elements = n,
+                .depth = 1,
+        };
+
+        for (i = 0; i < n; i++) {
+                JsonVariant *w = v + 1 + i;
+
+                *w = (JsonVariant) {
+                        .is_embedded = true,
+                        .parent = v,
+                        .type = JSON_VARIANT_UNSIGNED,
+                        .value.unsig = ((const uint8_t*) p)[i],
+                };
+        }
+
+        *ret = v;
+        return 0;
+}
+
+int json_variant_new_array_strv(JsonVariant **ret, char **l) {
+        _cleanup_(json_variant_unrefp) JsonVariant *v = NULL;
+        size_t n;
+        int r;
+
+        assert(ret);
+
+        n = strv_length(l);
+        if (n == 0) {
+                *ret = JSON_VARIANT_MAGIC_EMPTY_ARRAY;
+                return 0;
+        }
+
+        v = new(JsonVariant, n + 1);
+        if (!v)
+                return -ENOMEM;
+
+        *v = (JsonVariant) {
+                .n_ref = 1,
+                .type = JSON_VARIANT_ARRAY,
+                .depth = 1,
+        };
+
+        for (v->n_elements = 0; v->n_elements < n; v->n_elements++) {
+                JsonVariant *w = v + 1 + v->n_elements;
+                size_t k;
+
+                *w = (JsonVariant) {
+                        .is_embedded = true,
+                        .parent = v,
+                        .type = JSON_VARIANT_STRING,
+                };
+
+                k = strlen(l[v->n_elements]);
+
+                if (k > INLINE_STRING_MAX) {
+                        /* If string is too long, store it as reference. */
+
+                        r = json_variant_new_stringn(&w->reference, l[v->n_elements], k);
+                        if (r < 0)
+                                return r;
+
+                        w->is_reference = true;
+                } else
+                        memcpy(w->string, l[v->n_elements], k+1);
+        }
+
+        *ret = TAKE_PTR(v);
+        return 0;
+}
+
+int json_variant_new_object(JsonVariant **ret, JsonVariant **array, size_t n) {
+        _cleanup_(json_variant_unrefp) JsonVariant *v = NULL;
+
+        assert_return(ret, -EINVAL);
+        if (n == 0) {
+                *ret = JSON_VARIANT_MAGIC_EMPTY_OBJECT;
+                return 0;
+        }
+        assert_return(array, -EINVAL);
+        assert_return(n % 2 == 0, -EINVAL);
+
+        v = new(JsonVariant, n + 1);
+        if (!v)
+                return -ENOMEM;
+
+        *v = (JsonVariant) {
+                .n_ref = 1,
+                .type = JSON_VARIANT_OBJECT,
+        };
+
+        for (v->n_elements = 0; v->n_elements < n; v->n_elements++) {
+                JsonVariant *w = v + 1 + v->n_elements,
+                        *c = array[v->n_elements];
+                uint16_t d;
+
+                if ((v->n_elements & 1) == 0 &&
+                    !json_variant_is_string(c))
+                        return -EINVAL; /* Every second one needs to be a string, as it is the key name */
+
+                d = json_variant_depth(c);
+                if (d >= DEPTH_MAX) /* Refuse too deep nesting */
+                        return -ELNRNG;
+                if (d >= v->depth)
+                        v->depth = d + 1;
+
+                *w = (JsonVariant) {
+                        .is_embedded = true,
+                        .parent = v,
+                };
+
+                json_variant_set(w, c);
+                json_variant_copy_source(w, c);
+        }
+
+        *ret = TAKE_PTR(v);
+        return 0;
+}
+
+static void json_variant_free_inner(JsonVariant *v) {
+        assert(v);
+
+        if (!json_variant_is_regular(v))
+                return;
+
+        json_source_unref(v->source);
+
+        if (v->is_reference) {
+                json_variant_unref(v->reference);
+                return;
+        }
+
+        if (IN_SET(v->type, JSON_VARIANT_ARRAY, JSON_VARIANT_OBJECT)) {
+                size_t i;
+
+                for (i = 0; i < v->n_elements; i++)
+                        json_variant_free_inner(v + 1 + i);
+        }
+}
+
+JsonVariant *json_variant_ref(JsonVariant *v) {
+        if (!v)
+                return NULL;
+        if (!json_variant_is_regular(v))
+                return v;
+
+        if (v->is_embedded)
+                json_variant_ref(v->parent); /* ref the compounding variant instead */
+        else {
+                assert(v->n_ref > 0);
+                v->n_ref++;
+        }
+
+        return v;
+}
+
+JsonVariant *json_variant_unref(JsonVariant *v) {
+        if (!v)
+                return NULL;
+        if (!json_variant_is_regular(v))
+                return NULL;
+
+        if (v->is_embedded)
+                json_variant_unref(v->parent);
+        else {
+                assert(v->n_ref > 0);
+                v->n_ref--;
+
+                if (v->n_ref == 0) {
+                        json_variant_free_inner(v);
+                        free(v);
+                }
+        }
+
+        return NULL;
+}
+
+void json_variant_unref_many(JsonVariant **array, size_t n) {
+        size_t i;
+
+        assert(array || n == 0);
+
+        for (i = 0; i < n; i++)
+                json_variant_unref(array[i]);
+}
+
+const char *json_variant_string(JsonVariant *v) {
+        if (!v)
+                return NULL;
+        if (v == JSON_VARIANT_MAGIC_EMPTY_STRING)
+                return "";
+        if (json_variant_is_magic(v))
+                goto mismatch;
+        if (json_variant_is_const_string(v)) {
+                uintptr_t p = (uintptr_t) v;
+
+                assert((p & 1) != 0);
+                return (const char*) (p ^ 1U);
+        }
+
+        if (v->is_reference)
+                return json_variant_string(v->reference);
+        if (v->type != JSON_VARIANT_STRING)
+                goto mismatch;
+
+        return v->string;
+
+mismatch:
+        log_debug("Non-string JSON variant requested as string, returning NULL.");
+        return NULL;
+}
+
+bool json_variant_boolean(JsonVariant *v) {
+        if (!v)
+                goto mismatch;
+        if (v == JSON_VARIANT_MAGIC_TRUE)
+                return true;
+        if (v == JSON_VARIANT_MAGIC_FALSE)
+                return false;
+        if (!json_variant_is_regular(v))
+                goto mismatch;
+        if (v->type != JSON_VARIANT_BOOLEAN)
+                goto mismatch;
+        if (v->is_reference)
+                return json_variant_boolean(v->reference);
+
+        return v->value.boolean;
+
+mismatch:
+        log_debug("Non-boolean JSON variant requested as boolean, returning false.");
+        return false;
+}
+
+intmax_t json_variant_integer(JsonVariant *v) {
+        if (!v)
+                goto mismatch;
+        if (v == JSON_VARIANT_MAGIC_ZERO_INTEGER ||
+            v == JSON_VARIANT_MAGIC_ZERO_UNSIGNED ||
+            v == JSON_VARIANT_MAGIC_ZERO_REAL)
+                return 0;
+        if (!json_variant_is_regular(v))
+                goto mismatch;
+        if (v->is_reference)
+                return json_variant_integer(v->reference);
+
+        switch (v->type) {
+
+        case JSON_VARIANT_INTEGER:
+                return v->value.integer;
+
+        case JSON_VARIANT_UNSIGNED:
+                if (v->value.unsig <= INTMAX_MAX)
+                        return (intmax_t) v->value.unsig;
+
+                log_debug("Unsigned integer %ju requested as signed integer and out of range, returning 0.", v->value.unsig);
+                return 0;
+
+        case JSON_VARIANT_REAL: {
+                intmax_t converted;
+
+                converted = (intmax_t) v->value.real;
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wfloat-equal"
+                if ((long double) converted == v->value.real)
+#pragma GCC diagnostic pop
+                        return converted;
+
+                log_debug("Real %Lg requested as integer, and cannot be converted losslessly, returning 0.", v->value.real);
+                return 0;
+        }
+
+        default:
+                break;
+        }
+
+mismatch:
+        log_debug("Non-integer JSON variant requested as integer, returning 0.");
+        return 0;
+}
+
+uintmax_t json_variant_unsigned(JsonVariant *v) {
+        if (!v)
+                goto mismatch;
+        if (v == JSON_VARIANT_MAGIC_ZERO_INTEGER ||
+            v == JSON_VARIANT_MAGIC_ZERO_UNSIGNED ||
+            v == JSON_VARIANT_MAGIC_ZERO_REAL)
+                return 0;
+        if (!json_variant_is_regular(v))
+                goto mismatch;
+        if (v->is_reference)
+                return json_variant_integer(v->reference);
+
+        switch (v->type) {
+
+        case JSON_VARIANT_INTEGER:
+                if (v->value.integer >= 0)
+                        return (uintmax_t) v->value.integer;
+
+                log_debug("Signed integer %ju requested as unsigned integer and out of range, returning 0.", v->value.integer);
+                return 0;
+
+        case JSON_VARIANT_UNSIGNED:
+                return v->value.unsig;
+
+        case JSON_VARIANT_REAL: {
+                uintmax_t converted;
+
+                converted = (uintmax_t) v->value.real;
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wfloat-equal"
+                if ((long double) converted == v->value.real)
+#pragma GCC diagnostic pop
+                        return converted;
+
+                log_debug("Real %Lg requested as unsigned integer, and cannot be converted losslessly, returning 0.", v->value.real);
+                return 0;
+        }
+
+        default:
+                break;
+        }
+
+mismatch:
+        log_debug("Non-integer JSON variant requested as unsigned, returning 0.");
+        return 0;
+}
+
+long double json_variant_real(JsonVariant *v) {
+        if (!v)
+                return 0.0;
+        if (v == JSON_VARIANT_MAGIC_ZERO_INTEGER ||
+            v == JSON_VARIANT_MAGIC_ZERO_UNSIGNED ||
+            v == JSON_VARIANT_MAGIC_ZERO_REAL)
+                return 0.0;
+        if (!json_variant_is_regular(v))
+                goto mismatch;
+        if (v->is_reference)
+                return json_variant_real(v->reference);
+
+        switch (v->type) {
+
+        case JSON_VARIANT_REAL:
+                return v->value.real;
+
+        case JSON_VARIANT_INTEGER: {
+                long double converted;
+
+                converted = (long double) v->value.integer;
+
+                if ((intmax_t) converted == v->value.integer)
+                        return converted;
+
+                log_debug("Signed integer %ji requested as real, and cannot be converted losslessly, returning 0.", v->value.integer);
+                return 0.0;
+        }
+
+        case JSON_VARIANT_UNSIGNED: {
+                long double converted;
+
+                converted = (long double) v->value.unsig;
+
+                if ((uintmax_t) converted == v->value.unsig)
+                        return converted;
+
+                log_debug("Unsigned integer %ju requested as real, and cannot be converted losslessly, returning 0.", v->value.unsig);
+                return 0.0;
+        }
+
+        default:
+                break;
+        }
+
+mismatch:
+        log_debug("Non-integer JSON variant requested as integer, returning 0.");
+        return 0.0;
+}
+
+bool json_variant_is_negative(JsonVariant *v) {
+        if (!v)
+                goto mismatch;
+        if (v == JSON_VARIANT_MAGIC_ZERO_INTEGER ||
+            v == JSON_VARIANT_MAGIC_ZERO_UNSIGNED ||
+            v == JSON_VARIANT_MAGIC_ZERO_REAL)
+                return false;
+        if (!json_variant_is_regular(v))
+                goto mismatch;
+        if (v->is_reference)
+                return json_variant_is_negative(v->reference);
+
+        /* This function is useful as checking whether numbers are negative is pretty complex since we have three types
+         * of numbers. And some JSON code (OCI for example) uses negative numbers to mark "not defined" numeric
+         * values. */
+
+        switch (v->type) {
+
+        case JSON_VARIANT_REAL:
+                return v->value.real < 0;
+
+        case JSON_VARIANT_INTEGER:
+                return v->value.integer < 0;
+
+        case JSON_VARIANT_UNSIGNED:
+                return false;
+
+        default:
+                break;
+        }
+
+mismatch:
+        log_debug("Non-integer JSON variant tested for negativity, returning false.");
+        return false;
+}
+
+JsonVariantType json_variant_type(JsonVariant *v) {
+
+        if (!v)
+                return _JSON_VARIANT_TYPE_INVALID;
+
+        if (json_variant_is_const_string(v))
+                return JSON_VARIANT_STRING;
+
+        if (v == JSON_VARIANT_MAGIC_TRUE || v == JSON_VARIANT_MAGIC_FALSE)
+                return JSON_VARIANT_BOOLEAN;
+
+        if (v == JSON_VARIANT_MAGIC_NULL)
+                return JSON_VARIANT_NULL;
+
+        if (v == JSON_VARIANT_MAGIC_ZERO_INTEGER)
+                return JSON_VARIANT_INTEGER;
+
+        if (v == JSON_VARIANT_MAGIC_ZERO_UNSIGNED)
+                return JSON_VARIANT_UNSIGNED;
+
+        if (v == JSON_VARIANT_MAGIC_ZERO_REAL)
+                return JSON_VARIANT_REAL;
+
+        if (v == JSON_VARIANT_MAGIC_EMPTY_STRING)
+                return JSON_VARIANT_STRING;
+
+        if (v == JSON_VARIANT_MAGIC_EMPTY_ARRAY)
+                return JSON_VARIANT_ARRAY;
+
+        if (v == JSON_VARIANT_MAGIC_EMPTY_OBJECT)
+                return JSON_VARIANT_OBJECT;
+
+        return v->type;
+}
+
+bool json_variant_has_type(JsonVariant *v, JsonVariantType type) {
+        JsonVariantType rt;
+
+        v = json_variant_dereference(v);
+        if (!v)
+                return false;
+
+        rt = json_variant_type(v);
+        if (rt == type)
+                return true;
+
+        /* If it's a const string, then it only can be a string, and if it is not, it's not */
+        if (json_variant_is_const_string(v))
+                return false;
+
+        /* All three magic zeroes qualify as integer, unsigned and as real */
+        if ((v == JSON_VARIANT_MAGIC_ZERO_INTEGER || v == JSON_VARIANT_MAGIC_ZERO_UNSIGNED || v == JSON_VARIANT_MAGIC_ZERO_REAL) &&
+            IN_SET(type, JSON_VARIANT_INTEGER, JSON_VARIANT_UNSIGNED, JSON_VARIANT_REAL, JSON_VARIANT_NUMBER))
+                return true;
+
+        /* All other magic variant types are only equal to themselves */
+        if (json_variant_is_magic(v))
+                return false;
+
+        /* Handle the "number" pseudo type */
+        if (type == JSON_VARIANT_NUMBER)
+                return IN_SET(rt, JSON_VARIANT_INTEGER, JSON_VARIANT_UNSIGNED, JSON_VARIANT_REAL);
+
+        /* Integer conversions are OK in many cases */
+        if (rt == JSON_VARIANT_INTEGER && type == JSON_VARIANT_UNSIGNED)
+                return v->value.integer >= 0;
+        if (rt == JSON_VARIANT_UNSIGNED && type == JSON_VARIANT_INTEGER)
+                return v->value.unsig <= INTMAX_MAX;
+
+        /* Any integer that can be converted lossley to a real and back may also be considered a real */
+        if (rt == JSON_VARIANT_INTEGER && type == JSON_VARIANT_REAL)
+                return (intmax_t) (long double) v->value.integer == v->value.integer;
+        if (rt == JSON_VARIANT_UNSIGNED && type == JSON_VARIANT_REAL)
+                return (uintmax_t) (long double) v->value.unsig == v->value.unsig;
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wfloat-equal"
+        /* Any real that can be converted losslessly to an integer and back may also be considered an integer */
+        if (rt == JSON_VARIANT_REAL && type == JSON_VARIANT_INTEGER)
+                return (long double) (intmax_t) v->value.real == v->value.real;
+        if (rt == JSON_VARIANT_REAL && type == JSON_VARIANT_UNSIGNED)
+                return (long double) (uintmax_t) v->value.real == v->value.real;
+#pragma GCC diagnostic pop
+
+        return false;
+}
+
+size_t json_variant_elements(JsonVariant *v) {
+        if (!v)
+                return 0;
+        if (v == JSON_VARIANT_MAGIC_EMPTY_ARRAY ||
+            v == JSON_VARIANT_MAGIC_EMPTY_OBJECT)
+                return 0;
+        if (!json_variant_is_regular(v))
+                goto mismatch;
+        if (!IN_SET(v->type, JSON_VARIANT_ARRAY, JSON_VARIANT_OBJECT))
+                goto mismatch;
+        if (v->is_reference)
+                return json_variant_elements(v->reference);
+
+        return v->n_elements;
+
+mismatch:
+        log_debug("Number of elements in non-array/non-object JSON variant requested, returning 0.");
+        return 0;
+}
+
+JsonVariant *json_variant_by_index(JsonVariant *v, size_t idx) {
+        if (!v)
+                return NULL;
+        if (v == JSON_VARIANT_MAGIC_EMPTY_ARRAY ||
+            v == JSON_VARIANT_MAGIC_EMPTY_OBJECT)
+                return NULL;
+        if (!json_variant_is_regular(v))
+                goto mismatch;
+        if (!IN_SET(v->type, JSON_VARIANT_ARRAY, JSON_VARIANT_OBJECT))
+                goto mismatch;
+        if (v->is_reference)
+                return json_variant_by_index(v->reference, idx);
+        if (idx >= v->n_elements)
+                return NULL;
+
+        return json_variant_conservative_normalize(v + 1 + idx);
+
+mismatch:
+        log_debug("Element in non-array/non-object JSON variant requested by index, returning NULL.");
+        return NULL;
+}
+
+JsonVariant *json_variant_by_key_full(JsonVariant *v, const char *key, JsonVariant **ret_key) {
+        size_t i;
+
+        if (!v)
+                goto not_found;
+        if (!key)
+                goto not_found;
+        if (v == JSON_VARIANT_MAGIC_EMPTY_OBJECT)
+                goto not_found;
+        if (!json_variant_is_regular(v))
+                goto mismatch;
+        if (v->type != JSON_VARIANT_OBJECT)
+                goto mismatch;
+        if (v->is_reference)
+                return json_variant_by_key(v->reference, key);
+
+        for (i = 0; i < v->n_elements; i += 2) {
+                JsonVariant *p;
+
+                p = json_variant_dereference(v + 1 + i);
+
+                if (!json_variant_has_type(p, JSON_VARIANT_STRING))
+                        continue;
+
+                if (streq(json_variant_string(p), key)) {
+
+                        if (ret_key)
+                                *ret_key = json_variant_conservative_normalize(v + 1 + i);
+
+                        return json_variant_conservative_normalize(v + 1 + i + 1);
+                }
+        }
+
+not_found:
+        if (ret_key)
+                *ret_key = NULL;
+
+        return NULL;
+
+mismatch:
+        log_debug("Element in non-object JSON variant requested by key, returning NULL.");
+        if (ret_key)
+                *ret_key = NULL;
+
+        return NULL;
+}
+
+JsonVariant *json_variant_by_key(JsonVariant *v, const char *key) {
+        return json_variant_by_key_full(v, key, NULL);
+}
+
+bool json_variant_equal(JsonVariant *a, JsonVariant *b) {
+        JsonVariantType t;
+
+        a = json_variant_normalize(a);
+        b = json_variant_normalize(b);
+
+        if (a == b)
+                return true;
+
+        t = json_variant_type(a);
+        if (!json_variant_has_type(b, t))
+                return false;
+
+        switch (t) {
+
+        case JSON_VARIANT_STRING:
+                return streq(json_variant_string(a), json_variant_string(b));
+
+        case JSON_VARIANT_INTEGER:
+                return json_variant_integer(a) == json_variant_integer(b);
+
+        case JSON_VARIANT_UNSIGNED:
+                return json_variant_unsigned(a) == json_variant_unsigned(b);
+
+        case JSON_VARIANT_REAL:
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wfloat-equal"
+                return json_variant_real(a) == json_variant_real(b);
+#pragma GCC diagnostic pop
+
+        case JSON_VARIANT_BOOLEAN:
+                return json_variant_boolean(a) == json_variant_boolean(b);
+
+        case JSON_VARIANT_NULL:
+                return true;
+
+        case JSON_VARIANT_ARRAY: {
+                size_t i, n;
+
+                n = json_variant_elements(a);
+                if (n != json_variant_elements(b))
+                        return false;
+
+                for (i = 0; i < n; i++) {
+                        if (!json_variant_equal(json_variant_by_index(a, i), json_variant_by_index(b, i)))
+                                return false;
+                }
+
+                return true;
+        }
+
+        case JSON_VARIANT_OBJECT: {
+                size_t i, n;
+
+                n = json_variant_elements(a);
+                if (n != json_variant_elements(b))
+                        return false;
+
+                /* Iterate through all keys in 'a' */
+                for (i = 0; i < n; i += 2) {
+                        bool found = false;
+                        size_t j;
+
+                        /* Match them against all keys in 'b' */
+                        for (j = 0; j < n; j += 2) {
+                                JsonVariant *key_b;
+
+                                key_b = json_variant_by_index(b, j);
+
+                                /* During the first iteration unmark everything */
+                                if (i == 0)
+                                        key_b->is_marked = false;
+                                else if (key_b->is_marked) /* In later iterations if we already marked something, don't bother with it again */
+                                        continue;
+
+                                if (found)
+                                        continue;
+
+                                if (json_variant_equal(json_variant_by_index(a, i), key_b) &&
+                                    json_variant_equal(json_variant_by_index(a, i+1), json_variant_by_index(b, j+1))) {
+                                        /* Key and values match! */
+                                        key_b->is_marked = found = true;
+
+                                        /* In the first iteration we continue the inner loop since we want to mark
+                                         * everything, otherwise exit the loop quickly after we found what we were
+                                         * looking for. */
+                                        if (i != 0)
+                                                break;
+                                }
+                        }
+
+                        if (!found)
+                                return false;
+                }
+
+                return true;
+        }
+
+        default:
+                assert_not_reached("Unknown variant type.");
+        }
+}
+
+int json_variant_get_source(JsonVariant *v, const char **ret_source, unsigned *ret_line, unsigned *ret_column) {
+        assert_return(v, -EINVAL);
+
+        if (ret_source)
+                *ret_source = json_variant_is_regular(v) && v->source ? v->source->name : NULL;
+
+        if (ret_line)
+                *ret_line = json_variant_is_regular(v) ? v->line : 0;
+
+        if (ret_column)
+                *ret_column = json_variant_is_regular(v) ? v->column : 0;
+
+        return 0;
+}
+
+static int print_source(FILE *f, JsonVariant *v, JsonFormatFlags flags, bool whitespace) {
+        size_t w, k;
+
+        if (!FLAGS_SET(flags, JSON_FORMAT_SOURCE|JSON_FORMAT_PRETTY))
+                return 0;
+
+        if (!json_variant_is_regular(v))
+                return 0;
+
+        if (!v->source && v->line == 0 && v->column == 0)
+                return 0;
+
+        /* The max width we need to format the line numbers for this source file */
+        w = (v->source && v->source->max_line > 0) ?
+                DECIMAL_STR_WIDTH(v->source->max_line) :
+                DECIMAL_STR_MAX(unsigned)-1;
+        k = (v->source && v->source->max_column > 0) ?
+                DECIMAL_STR_WIDTH(v->source->max_column) :
+                DECIMAL_STR_MAX(unsigned) -1;
+
+        if (whitespace) {
+                size_t i, n;
+
+                n = 1 + (v->source ? strlen(v->source->name) : 0) +
+                        ((v->source && (v->line > 0 || v->column > 0)) ? 1 : 0) +
+                        (v->line > 0 ? w : 0) +
+                        (((v->source || v->line > 0) && v->column > 0) ? 1 : 0) +
+                        (v->column > 0 ? k : 0) +
+                        2;
+
+                for (i = 0; i < n; i++)
+                        fputc(' ', f);
+        } else {
+                fputc('[', f);
+
+                if (v->source)
+                        fputs(v->source->name, f);
+                if (v->source && (v->line > 0 || v->column > 0))
+                        fputc(':', f);
+                if (v->line > 0)
+                        fprintf(f, "%*u", (int) w, v->line);
+                if ((v->source || v->line > 0) || v->column > 0)
+                        fputc(':', f);
+                if (v->column > 0)
+                        fprintf(f, "%*u", (int) k, v->column);
+
+                fputc(']', f);
+                fputc(' ', f);
+        }
+
+        return 0;
+}
+
+static int json_format(FILE *f, JsonVariant *v, JsonFormatFlags flags, const char *prefix) {
+        int r;
+
+        assert(f);
+        assert(v);
+
+        switch (json_variant_type(v)) {
+
+        case JSON_VARIANT_REAL: {
+                locale_t loc;
+
+                loc = newlocale(LC_NUMERIC_MASK, "C", (locale_t) 0);
+                if (loc == (locale_t) 0)
+                        return -errno;
+
+                if (flags & JSON_FORMAT_COLOR)
+                        fputs(ANSI_HIGHLIGHT_BLUE, f);
+
+                fprintf(f, "%.*Le", DECIMAL_DIG, json_variant_real(v));
+
+                if (flags & JSON_FORMAT_COLOR)
+                        fputs(ANSI_NORMAL, f);
+
+                freelocale(loc);
+                break;
+        }
+
+        case JSON_VARIANT_INTEGER:
+                if (flags & JSON_FORMAT_COLOR)
+                        fputs(ANSI_HIGHLIGHT_BLUE, f);
+
+                fprintf(f, "%" PRIdMAX, json_variant_integer(v));
+
+                if (flags & JSON_FORMAT_COLOR)
+                        fputs(ANSI_NORMAL, f);
+                break;
+
+        case JSON_VARIANT_UNSIGNED:
+                if (flags & JSON_FORMAT_COLOR)
+                        fputs(ANSI_HIGHLIGHT_BLUE, f);
+
+                fprintf(f, "%" PRIuMAX, json_variant_unsigned(v));
+
+                if (flags & JSON_FORMAT_COLOR)
+                        fputs(ANSI_NORMAL, f);
+                break;
+
+        case JSON_VARIANT_BOOLEAN:
+
+                if (flags & JSON_FORMAT_COLOR)
+                        fputs(ANSI_HIGHLIGHT, f);
+
+                if (json_variant_boolean(v))
+                        fputs("true", f);
+                else
+                        fputs("false", f);
+
+                if (flags & JSON_FORMAT_COLOR)
+                        fputs(ANSI_NORMAL, f);
+
+                break;
+
+        case JSON_VARIANT_NULL:
+                if (flags & JSON_FORMAT_COLOR)
+                        fputs(ANSI_HIGHLIGHT, f);
+
+                fputs("null", f);
+
+                if (flags & JSON_FORMAT_COLOR)
+                        fputs(ANSI_NORMAL, f);
+                break;
+
+        case JSON_VARIANT_STRING: {
+                const char *q;
+
+                fputc('"', f);
+
+                if (flags & JSON_FORMAT_COLOR)
+                        fputs(ANSI_GREEN, f);
+
+                for (q = json_variant_string(v); *q; q++) {
+
+                        switch (*q) {
+
+                        case '"':
+                                fputs("\\\"", f);
+                                break;
+
+                        case '\\':
+                                fputs("\\\\", f);
+                                break;
+
+                        case '\b':
+                                fputs("\\b", f);
+                                break;
+
+                        case '\f':
+                                fputs("\\f", f);
+                                break;
+
+                        case '\n':
+                                fputs("\\n", f);
+                                break;
+
+                        case '\r':
+                                fputs("\\r", f);
+                                break;
+
+                        case '\t':
+                                fputs("\\t", f);
+                                break;
+
+                        default:
+                                if ((signed char) *q >= 0 && *q < ' ')
+                                        fprintf(f, "\\u%04x", *q);
+                                else
+                                        fputc(*q, f);
+                                break;
+                        }
+                }
+
+                if (flags & JSON_FORMAT_COLOR)
+                        fputs(ANSI_NORMAL, f);
+
+                fputc('"', f);
+                break;
+        }
+
+        case JSON_VARIANT_ARRAY: {
+                size_t i, n;
+
+                n = json_variant_elements(v);
+
+                if (n == 0)
+                        fputs("[]", f);
+                else {
+                        _cleanup_free_ char *joined = NULL;
+                        const char *prefix2;
+
+                        if (flags & JSON_FORMAT_PRETTY) {
+                                joined = strjoin(strempty(prefix), "\t");
+                                if (!joined)
+                                        return -ENOMEM;
+
+                                prefix2 = joined;
+                                fputs("[\n", f);
+                        } else {
+                                prefix2 = strempty(prefix);
+                                fputc('[', f);
+                        }
+
+                        for (i = 0; i < n; i++) {
+                                JsonVariant *e;
+
+                                assert_se(e = json_variant_by_index(v, i));
+
+                                if (i > 0) {
+                                        if (flags & JSON_FORMAT_PRETTY)
+                                                fputs(",\n", f);
+                                        else
+                                                fputc(',', f);
+                                }
+
+                                if (flags & JSON_FORMAT_PRETTY) {
+                                        print_source(f, e, flags, false);
+                                        fputs(prefix2, f);
+                                }
+
+                                r = json_format(f, e, flags, prefix2);
+                                if (r < 0)
+                                        return r;
+                        }
+
+                        if (flags & JSON_FORMAT_PRETTY) {
+                                fputc('\n', f);
+                                print_source(f, v, flags, true);
+                                fputs(strempty(prefix), f);
+                        }
+
+                        fputc(']', f);
+                }
+                break;
+        }
+
+        case JSON_VARIANT_OBJECT: {
+                size_t i, n;
+
+                n = json_variant_elements(v);
+
+                if (n == 0)
+                        fputs("{}", f);
+                else {
+                        _cleanup_free_ char *joined = NULL;
+                        const char *prefix2;
+
+                        if (flags & JSON_FORMAT_PRETTY) {
+                                joined = strjoin(strempty(prefix), "\t");
+                                if (!joined)
+                                        return -ENOMEM;
+
+                                prefix2 = joined;
+                                fputs("{\n", f);
+                        } else {
+                                prefix2 = strempty(prefix);
+                                fputc('{', f);
+                        }
+
+                        for (i = 0; i < n; i += 2) {
+                                JsonVariant *e;
+
+                                e = json_variant_by_index(v, i);
+
+                                if (i > 0) {
+                                        if (flags & JSON_FORMAT_PRETTY)
+                                                fputs(",\n", f);
+                                        else
+                                                fputc(',', f);
+                                }
+
+                                if (flags & JSON_FORMAT_PRETTY) {
+                                        print_source(f, e, flags, false);
+                                        fputs(prefix2, f);
+                                }
+
+                                r = json_format(f, e, flags, prefix2);
+                                if (r < 0)
+                                        return r;
+
+                                fputs(flags & JSON_FORMAT_PRETTY ? " : " : ":", f);
+
+                                r = json_format(f, json_variant_by_index(v, i+1), flags, prefix2);
+                                if (r < 0)
+                                        return r;
+                        }
+
+                        if (flags & JSON_FORMAT_PRETTY) {
+                                fputc('\n', f);
+                                print_source(f, v, flags, true);
+                                fputs(strempty(prefix), f);
+                        }
+
+                        fputc('}', f);
+                }
+                break;
+        }
+
+        default:
+                assert_not_reached("Unexpected variant type.");
+        }
+
+        return 0;
+}
+
+int json_variant_format(JsonVariant *v, JsonFormatFlags flags, char **ret) {
+        _cleanup_free_ char *s = NULL;
+        size_t sz = 0;
+        int r;
+
+        assert_return(v, -EINVAL);
+        assert_return(ret, -EINVAL);
+
+        {
+                _cleanup_fclose_ FILE *f = NULL;
+
+                f = open_memstream(&s, &sz);
+                if (!f)
+                        return -ENOMEM;
+
+                (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
+
+                json_variant_dump(v, flags, f, NULL);
+
+                r = fflush_and_check(f);
+        }
+        if (r < 0)
+                return r;
+
+        assert(s);
+        *ret = TAKE_PTR(s);
+
+        return (int) sz;
+}
+
+void json_variant_dump(JsonVariant *v, JsonFormatFlags flags, FILE *f, const char *prefix) {
+        if (!v)
+                return;
+
+        if (!f)
+                f = stdout;
+
+        print_source(f, v, flags, false);
+
+        if (((flags & (JSON_FORMAT_COLOR_AUTO|JSON_FORMAT_COLOR)) == JSON_FORMAT_COLOR_AUTO) && colors_enabled())
+                flags |= JSON_FORMAT_COLOR;
+
+        if (flags & JSON_FORMAT_SSE)
+                fputs("data: ", f);
+        if (flags & JSON_FORMAT_SEQ)
+                fputc('\x1e', f); /* ASCII Record Separator */
+
+        json_format(f, v, flags, prefix);
+
+        if (flags & (JSON_FORMAT_PRETTY|JSON_FORMAT_SEQ|JSON_FORMAT_SSE|JSON_FORMAT_NEWLINE))
+                fputc('\n', f);
+        if (flags & JSON_FORMAT_SSE)
+                fputc('\n', f); /* In case of SSE add a second newline */
+}
+
+static int json_variant_copy(JsonVariant **nv, JsonVariant *v) {
+        JsonVariantType t;
+        JsonVariant *c;
+        JsonValue value;
+        const void *source;
+        size_t k;
+
+        assert(nv);
+        assert(v);
+
+        /* Let's copy the simple types literally, and the larger types by references */
+        t = json_variant_type(v);
+        switch (t) {
+        case JSON_VARIANT_INTEGER:
+                k = sizeof(intmax_t);
+                value.integer = json_variant_integer(v);
+                source = &value;
+                break;
+
+        case JSON_VARIANT_UNSIGNED:
+                k = sizeof(uintmax_t);
+                value.unsig = json_variant_unsigned(v);
+                source = &value;
+                break;
+
+        case JSON_VARIANT_REAL:
+                k = sizeof(long double);
+                value.real = json_variant_real(v);
+                source = &value;
+                break;
+
+        case JSON_VARIANT_BOOLEAN:
+                k = sizeof(bool);
+                value.boolean = json_variant_boolean(v);
+                source = &value;
+                break;
+
+        case JSON_VARIANT_NULL:
+                k = 0;
+                source = NULL;
+                break;
+
+        case JSON_VARIANT_STRING:
+                source = json_variant_string(v);
+                k = strnlen(source, INLINE_STRING_MAX + 1);
+                if (k <= INLINE_STRING_MAX) {
+                        k ++;
+                        break;
+                }
+
+                _fallthrough_;
+
+        default:
+                /* Everything else copy by reference */
+
+                c = malloc0(offsetof(JsonVariant, reference) + sizeof(JsonVariant*));
+                if (!c)
+                        return -ENOMEM;
+
+                c->n_ref = 1;
+                c->type = t;
+                c->is_reference = true;
+                c->reference = json_variant_ref(json_variant_normalize(v));
+
+                *nv = c;
+                return 0;
+        }
+
+        c = malloc0(offsetof(JsonVariant, value) + k);
+        if (!c)
+                return -ENOMEM;
+
+        c->n_ref = 1;
+        c->type = t;
+
+        memcpy_safe(&c->value, source, k);
+
+        *nv = c;
+        return 0;
+}
+
+static bool json_single_ref(JsonVariant *v) {
+
+        /* Checks whether the caller is the single owner of the object, i.e. can get away with changing it */
+
+        if (!json_variant_is_regular(v))
+                return false;
+
+        if (v->is_embedded)
+                return json_single_ref(v->parent);
+
+        assert(v->n_ref > 0);
+        return v->n_ref == 1;
+}
+
+static int json_variant_set_source(JsonVariant **v, JsonSource *source, unsigned line, unsigned column) {
+        JsonVariant *w;
+        int r;
+
+        assert(v);
+
+        /* Patch in source and line/column number. Tries to do this in-place if the caller is the sole referencer of
+         * the object. If not, allocates a new object, possibly a surrogate for the original one */
+
+        if (!*v)
+                return 0;
+
+        if (source && line > source->max_line)
+                source->max_line = line;
+        if (source && column > source->max_column)
+                source->max_column = column;
+
+        if (!json_variant_is_regular(*v)) {
+
+                if (!source && line == 0 && column == 0)
+                        return 0;
+
+        } else {
+                if (json_source_equal((*v)->source, source) &&
+                    (*v)->line == line &&
+                    (*v)->column == column)
+                        return 0;
+
+                if (json_single_ref(*v)) { /* Sole reference? */
+                        json_source_unref((*v)->source);
+                        (*v)->source = json_source_ref(source);
+                        (*v)->line = line;
+                        (*v)->column = column;
+                        return 1;
+                }
+        }
+
+        r = json_variant_copy(&w, *v);
+        if (r < 0)
+                return r;
+
+        assert(json_variant_is_regular(w));
+        assert(!w->is_embedded);
+        assert(w->n_ref == 1);
+        assert(!w->source);
+
+        w->source = json_source_ref(source);
+        w->line = line;
+        w->column = column;
+
+        json_variant_unref(*v);
+        *v = w;
+
+        return 1;
+}
+
+static void inc_lines_columns(unsigned *line, unsigned *column, const char *s, size_t n) {
+        assert(line);
+        assert(column);
+        assert(s || n == 0);
+
+        while (n > 0) {
+
+                if (*s == '\n') {
+                        (*line)++;
+                        *column = 1;
+                } else if ((signed char) *s >= 0 && *s < 127) /* Process ASCII chars quickly */
+                        (*column)++;
+                else {
+                        int w;
+
+                        w = utf8_encoded_valid_unichar(s);
+                        if (w < 0) /* count invalid unichars as normal characters */
+                                w = 1;
+                        else if ((size_t) w > n) /* never read more than the specified number of characters */
+                                w = (int) n;
+
+                        (*column)++;
+
+                        s += w;
+                        n -= w;
+                        continue;
+                }
+
+                s++;
+                n--;
+        }
+}
+
+static int unhex_ucs2(const char *c, uint16_t *ret) {
+        int aa, bb, cc, dd;
+        uint16_t x;
+
+        assert(c);
+        assert(ret);
+
+        aa = unhexchar(c[0]);
+        if (aa < 0)
+                return -EINVAL;
+
+        bb = unhexchar(c[1]);
+        if (bb < 0)
+                return -EINVAL;
+
+        cc = unhexchar(c[2]);
+        if (cc < 0)
+                return -EINVAL;
+
+        dd = unhexchar(c[3]);
+        if (dd < 0)
+                return -EINVAL;
+
+        x =     ((uint16_t) aa << 12) |
+                ((uint16_t) bb << 8) |
+                ((uint16_t) cc << 4) |
+                ((uint16_t) dd);
+
+        if (x <= 0)
+                return -EINVAL;
+
+        *ret = x;
+
+        return 0;
+}
+
+static int json_parse_string(const char **p, char **ret) {
+        _cleanup_free_ char *s = NULL;
+        size_t n = 0, allocated = 0;
+        const char *c;
+
+        assert(p);
+        assert(*p);
+        assert(ret);
+
+        c = *p;
+
+        if (*c != '"')
+                return -EINVAL;
+
+        c++;
+
+        for (;;) {
+                int len;
+
+                /* Check for EOF */
+                if (*c == 0)
+                        return -EINVAL;
+
+                /* Check for control characters 0x00..0x1f */
+                if (*c > 0 && *c < ' ')
+                        return -EINVAL;
+
+                /* Check for control character 0x7f */
+                if (*c == 0x7f)
+                        return -EINVAL;
+
+                if (*c == '"') {
+                        if (!s) {
+                                s = strdup("");
+                                if (!s)
+                                        return -ENOMEM;
+                        } else
+                                s[n] = 0;
+
+                        *p = c + 1;
+
+                        *ret = TAKE_PTR(s);
+                        return JSON_TOKEN_STRING;
+                }
+
+                if (*c == '\\') {
+                        char ch = 0;
+                        c++;
+
+                        if (*c == 0)
+                                return -EINVAL;
+
+                        if (IN_SET(*c, '"', '\\', '/'))
+                                ch = *c;
+                        else if (*c == 'b')
+                                ch = '\b';
+                        else if (*c == 'f')
+                                ch = '\f';
+                        else if (*c == 'n')
+                                ch = '\n';
+                        else if (*c == 'r')
+                                ch = '\r';
+                        else if (*c == 't')
+                                ch = '\t';
+                        else if (*c == 'u') {
+                                char16_t x;
+                                int r;
+
+                                r = unhex_ucs2(c + 1, &x);
+                                if (r < 0)
+                                        return r;
+
+                                c += 5;
+
+                                if (!GREEDY_REALLOC(s, allocated, n + 5))
+                                        return -ENOMEM;
+
+                                if (!utf16_is_surrogate(x))
+                                        n += utf8_encode_unichar(s + n, (char32_t) x);
+                                else if (utf16_is_trailing_surrogate(x))
+                                        return -EINVAL;
+                                else {
+                                        char16_t y;
+
+                                        if (c[0] != '\\' || c[1] != 'u')
+                                                return -EINVAL;
+
+                                        r = unhex_ucs2(c + 2, &y);
+                                        if (r < 0)
+                                                return r;
+
+                                        c += 6;
+
+                                        if (!utf16_is_trailing_surrogate(y))
+                                                return -EINVAL;
+
+                                        n += utf8_encode_unichar(s + n, utf16_surrogate_pair_to_unichar(x, y));
+                                }
+
+                                continue;
+                        } else
+                                return -EINVAL;
+
+                        if (!GREEDY_REALLOC(s, allocated, n + 2))
+                                return -ENOMEM;
+
+                        s[n++] = ch;
+                        c ++;
+                        continue;
+                }
+
+                len = utf8_encoded_valid_unichar(c);
+                if (len < 0)
+                        return len;
+
+                if (!GREEDY_REALLOC(s, allocated, n + len + 1))
+                        return -ENOMEM;
+
+                memcpy(s + n, c, len);
+                n += len;
+                c += len;
+        }
+}
+
+static int json_parse_number(const char **p, JsonValue *ret) {
+        bool negative = false, exponent_negative = false, is_real = false;
+        long double x = 0.0, y = 0.0, exponent = 0.0, shift = 1.0;
+        intmax_t i = 0;
+        uintmax_t u = 0;
+        const char *c;
+
+        assert(p);
+        assert(*p);
+        assert(ret);
+
+        c = *p;
+
+        if (*c == '-') {
+                negative = true;
+                c++;
+        }
+
+        if (*c == '0')
+                c++;
+        else {
+                if (!strchr("123456789", *c) || *c == 0)
+                        return -EINVAL;
+
+                do {
+                        if (!is_real) {
+                                if (negative) {
+
+                                        if (i < INTMAX_MIN / 10) /* overflow */
+                                                is_real = true;
+                                        else {
+                                                intmax_t t = 10 * i;
+
+                                                if (t < INTMAX_MIN + (*c - '0')) /* overflow */
+                                                        is_real = true;
+                                                else
+                                                        i = t - (*c - '0');
+                                        }
+                                } else {
+                                        if (u > UINTMAX_MAX / 10) /* overflow */
+                                                is_real = true;
+                                        else {
+                                                uintmax_t t = 10 * u;
+
+                                                if (t > UINTMAX_MAX - (*c - '0')) /* overflow */
+                                                        is_real = true;
+                                                else
+                                                        u = t + (*c - '0');
+                                        }
+                                }
+                        }
+
+                        x = 10.0 * x + (*c - '0');
+
+                        c++;
+                } while (strchr("0123456789", *c) && *c != 0);
+        }
+
+        if (*c == '.') {
+                is_real = true;
+                c++;
+
+                if (!strchr("0123456789", *c) || *c == 0)
+                        return -EINVAL;
+
+                do {
+                        y = 10.0 * y + (*c - '0');
+                        shift = 10.0 * shift;
+                        c++;
+                } while (strchr("0123456789", *c) && *c != 0);
+        }
+
+        if (IN_SET(*c, 'e', 'E')) {
+                is_real = true;
+                c++;
+
+                if (*c == '-') {
+                        exponent_negative = true;
+                        c++;
+                } else if (*c == '+')
+                        c++;
+
+                if (!strchr("0123456789", *c) || *c == 0)
+                        return -EINVAL;
+
+                do {
+                        exponent = 10.0 * exponent + (*c - '0');
+                        c++;
+                } while (strchr("0123456789", *c) && *c != 0);
+        }
+
+        *p = c;
+
+        if (is_real) {
+                ret->real = ((negative ? -1.0 : 1.0) * (x + (y / shift))) * exp10l((exponent_negative ? -1.0 : 1.0) * exponent);
+                return JSON_TOKEN_REAL;
+        } else if (negative) {
+                ret->integer = i;
+                return JSON_TOKEN_INTEGER;
+        } else  {
+                ret->unsig = u;
+                return JSON_TOKEN_UNSIGNED;
+        }
+}
+
+int json_tokenize(
+                const char **p,
+                char **ret_string,
+                JsonValue *ret_value,
+                unsigned *ret_line,   /* 'ret_line' returns the line at the beginning of this token */
+                unsigned *ret_column,
+                void **state,
+                unsigned *line,       /* 'line' is used as a line state, it always reflect the line we are at after the token was read */
+                unsigned *column) {
+
+        unsigned start_line, start_column;
+        const char *start, *c;
+        size_t n;
+        int t, r;
+
+        enum {
+                STATE_NULL,
+                STATE_VALUE,
+                STATE_VALUE_POST,
+        };
+
+        assert(p);
+        assert(*p);
+        assert(ret_string);
+        assert(ret_value);
+        assert(ret_line);
+        assert(ret_column);
+        assert(line);
+        assert(column);
+        assert(state);
+
+        t = PTR_TO_INT(*state);
+        if (t == STATE_NULL) {
+                *line = 1;
+                *column = 1;
+                t = STATE_VALUE;
+        }
+
+        /* Skip over the whitespace */
+        n = strspn(*p, WHITESPACE);
+        inc_lines_columns(line, column, *p, n);
+        c = *p + n;
+
+        /* Remember where we started processing this token */
+        start = c;
+        start_line = *line;
+        start_column = *column;
+
+        if (*c == 0) {
+                *ret_string = NULL;
+                *ret_value = JSON_VALUE_NULL;
+                r = JSON_TOKEN_END;
+                goto finish;
+        }
+
+        switch (t) {
+
+        case STATE_VALUE:
+
+                if (*c == '{') {
+                        c++;
+                        *state = INT_TO_PTR(STATE_VALUE);
+                        r = JSON_TOKEN_OBJECT_OPEN;
+                        goto null_return;
+
+                } else if (*c == '}') {
+                        c++;
+                        *state = INT_TO_PTR(STATE_VALUE_POST);
+                        r = JSON_TOKEN_OBJECT_CLOSE;
+                        goto null_return;
+
+                } else if (*c == '[') {
+                        c++;
+                        *state = INT_TO_PTR(STATE_VALUE);
+                        r = JSON_TOKEN_ARRAY_OPEN;
+                        goto null_return;
+
+                } else if (*c == ']') {
+                        c++;
+                        *state = INT_TO_PTR(STATE_VALUE_POST);
+                        r = JSON_TOKEN_ARRAY_CLOSE;
+                        goto null_return;
+
+                } else if (*c == '"') {
+
+                        r = json_parse_string(&c, ret_string);
+                        if (r < 0)
+                                return r;
+
+                        *ret_value = JSON_VALUE_NULL;
+                        *state = INT_TO_PTR(STATE_VALUE_POST);
+                        goto finish;
+
+                } else if (strchr("-0123456789", *c)) {
+
+                        r = json_parse_number(&c, ret_value);
+                        if (r < 0)
+                                return r;
+
+                        *ret_string = NULL;
+                        *state = INT_TO_PTR(STATE_VALUE_POST);
+                        goto finish;
+
+                } else if (startswith(c, "true")) {
+                        *ret_string = NULL;
+                        ret_value->boolean = true;
+                        c += 4;
+                        *state = INT_TO_PTR(STATE_VALUE_POST);
+                        r = JSON_TOKEN_BOOLEAN;
+                        goto finish;
+
+                } else if (startswith(c, "false")) {
+                        *ret_string = NULL;
+                        ret_value->boolean = false;
+                        c += 5;
+                        *state = INT_TO_PTR(STATE_VALUE_POST);
+                        r = JSON_TOKEN_BOOLEAN;
+                        goto finish;
+
+                } else if (startswith(c, "null")) {
+                        *ret_string = NULL;
+                        *ret_value = JSON_VALUE_NULL;
+                        c += 4;
+                        *state = INT_TO_PTR(STATE_VALUE_POST);
+                        r = JSON_TOKEN_NULL;
+                        goto finish;
+
+                }
+
+                return -EINVAL;
+
+        case STATE_VALUE_POST:
+
+                if (*c == ':') {
+                        c++;
+                        *state = INT_TO_PTR(STATE_VALUE);
+                        r = JSON_TOKEN_COLON;
+                        goto null_return;
+
+                } else if (*c == ',') {
+                        c++;
+                        *state = INT_TO_PTR(STATE_VALUE);
+                        r = JSON_TOKEN_COMMA;
+                        goto null_return;
+
+                } else if (*c == '}') {
+                        c++;
+                        *state = INT_TO_PTR(STATE_VALUE_POST);
+                        r = JSON_TOKEN_OBJECT_CLOSE;
+                        goto null_return;
+
+                } else if (*c == ']') {
+                        c++;
+                        *state = INT_TO_PTR(STATE_VALUE_POST);
+                        r = JSON_TOKEN_ARRAY_CLOSE;
+                        goto null_return;
+                }
+
+                return -EINVAL;
+
+        default:
+                assert_not_reached("Unexpected tokenizer state");
+        }
+
+null_return:
+        *ret_string = NULL;
+        *ret_value = JSON_VALUE_NULL;
+
+finish:
+        inc_lines_columns(line, column, start, c - start);
+        *p = c;
+
+        *ret_line = start_line;
+        *ret_column = start_column;
+
+        return r;
+}
+
+typedef enum JsonExpect {
+        /* The following values are used by json_parse() */
+        EXPECT_TOPLEVEL,
+        EXPECT_END,
+        EXPECT_OBJECT_FIRST_KEY,
+        EXPECT_OBJECT_NEXT_KEY,
+        EXPECT_OBJECT_COLON,
+        EXPECT_OBJECT_VALUE,
+        EXPECT_OBJECT_COMMA,
+        EXPECT_ARRAY_FIRST_ELEMENT,
+        EXPECT_ARRAY_NEXT_ELEMENT,
+        EXPECT_ARRAY_COMMA,
+
+        /* And these are used by json_build() */
+        EXPECT_ARRAY_ELEMENT,
+        EXPECT_OBJECT_KEY,
+} JsonExpect;
+
+typedef struct JsonStack {
+        JsonExpect expect;
+        JsonVariant **elements;
+        size_t n_elements, n_elements_allocated;
+        unsigned line_before;
+        unsigned column_before;
+        size_t n_suppress; /* When building: if > 0, suppress this many subsequent elements. If == (size_t) -1, suppress all subsequent elements */
+} JsonStack;
+
+static void json_stack_release(JsonStack *s) {
+        assert(s);
+
+        json_variant_unref_many(s->elements, s->n_elements);
+        s->elements = mfree(s->elements);
+}
+
+static int json_parse_internal(
+                const char **input,
+                JsonSource *source,
+                JsonVariant **ret,
+                unsigned *line,
+                unsigned *column,
+                bool continue_end) {
+
+        size_t n_stack = 1, n_stack_allocated = 0, i;
+        unsigned line_buffer = 0, column_buffer = 0;
+        void *tokenizer_state = NULL;
+        JsonStack *stack = NULL;
+        const char *p;
+        int r;
+
+        assert_return(input, -EINVAL);
+        assert_return(ret, -EINVAL);
+
+        p = *input;
+
+        if (!GREEDY_REALLOC(stack, n_stack_allocated, n_stack))
+                return -ENOMEM;
+
+        stack[0] = (JsonStack) {
+                .expect = EXPECT_TOPLEVEL,
+        };
+
+        if (!line)
+                line = &line_buffer;
+        if (!column)
+                column = &column_buffer;
+
+        for (;;) {
+                _cleanup_free_ char *string = NULL;
+                unsigned line_token, column_token;
+                JsonVariant *add = NULL;
+                JsonStack *current;
+                JsonValue value;
+                int token;
+
+                assert(n_stack > 0);
+                current = stack + n_stack - 1;
+
+                if (continue_end && current->expect == EXPECT_END)
+                        goto done;
+
+                token = json_tokenize(&p, &string, &value, &line_token, &column_token, &tokenizer_state, line, column);
+                if (token < 0) {
+                        r = token;
+                        goto finish;
+                }
+
+                switch (token) {
+
+                case JSON_TOKEN_END:
+                        if (current->expect != EXPECT_END) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        assert(current->n_elements == 1);
+                        assert(n_stack == 1);
+                        goto done;
+
+                case JSON_TOKEN_COLON:
+
+                        if (current->expect != EXPECT_OBJECT_COLON) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        current->expect = EXPECT_OBJECT_VALUE;
+                        break;
+
+                case JSON_TOKEN_COMMA:
+
+                        if (current->expect == EXPECT_OBJECT_COMMA)
+                                current->expect = EXPECT_OBJECT_NEXT_KEY;
+                        else if (current->expect == EXPECT_ARRAY_COMMA)
+                                current->expect = EXPECT_ARRAY_NEXT_ELEMENT;
+                        else {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        break;
+
+                case JSON_TOKEN_OBJECT_OPEN:
+
+                        if (!IN_SET(current->expect, EXPECT_TOPLEVEL, EXPECT_OBJECT_VALUE, EXPECT_ARRAY_FIRST_ELEMENT, EXPECT_ARRAY_NEXT_ELEMENT)) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        if (!GREEDY_REALLOC(stack, n_stack_allocated, n_stack+1)) {
+                                r = -ENOMEM;
+                                goto finish;
+                        }
+                        current = stack + n_stack - 1;
+
+                        /* Prepare the expect for when we return from the child */
+                        if (current->expect == EXPECT_TOPLEVEL)
+                                current->expect = EXPECT_END;
+                        else if (current->expect == EXPECT_OBJECT_VALUE)
+                                current->expect = EXPECT_OBJECT_COMMA;
+                        else {
+                                assert(IN_SET(current->expect, EXPECT_ARRAY_FIRST_ELEMENT, EXPECT_ARRAY_NEXT_ELEMENT));
+                                current->expect = EXPECT_ARRAY_COMMA;
+                        }
+
+                        stack[n_stack++] = (JsonStack) {
+                                .expect = EXPECT_OBJECT_FIRST_KEY,
+                                .line_before = line_token,
+                                .column_before = column_token,
+                        };
+
+                        current = stack + n_stack - 1;
+                        break;
+
+                case JSON_TOKEN_OBJECT_CLOSE:
+                        if (!IN_SET(current->expect, EXPECT_OBJECT_FIRST_KEY, EXPECT_OBJECT_COMMA)) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        assert(n_stack > 1);
+
+                        r = json_variant_new_object(&add, current->elements, current->n_elements);
+                        if (r < 0)
+                                goto finish;
+
+                        line_token = current->line_before;
+                        column_token = current->column_before;
+
+                        json_stack_release(current);
+                        n_stack--, current--;
+
+                        break;
+
+                case JSON_TOKEN_ARRAY_OPEN:
+                        if (!IN_SET(current->expect, EXPECT_TOPLEVEL, EXPECT_OBJECT_VALUE, EXPECT_ARRAY_FIRST_ELEMENT, EXPECT_ARRAY_NEXT_ELEMENT)) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        if (!GREEDY_REALLOC(stack, n_stack_allocated, n_stack+1)) {
+                                r = -ENOMEM;
+                                goto finish;
+                        }
+                        current = stack + n_stack - 1;
+
+                        /* Prepare the expect for when we return from the child */
+                        if (current->expect == EXPECT_TOPLEVEL)
+                                current->expect = EXPECT_END;
+                        else if (current->expect == EXPECT_OBJECT_VALUE)
+                                current->expect = EXPECT_OBJECT_COMMA;
+                        else {
+                                assert(IN_SET(current->expect, EXPECT_ARRAY_FIRST_ELEMENT, EXPECT_ARRAY_NEXT_ELEMENT));
+                                current->expect = EXPECT_ARRAY_COMMA;
+                        }
+
+                        stack[n_stack++] = (JsonStack) {
+                                .expect = EXPECT_ARRAY_FIRST_ELEMENT,
+                                .line_before = line_token,
+                                .column_before = column_token,
+                        };
+
+                        break;
+
+                case JSON_TOKEN_ARRAY_CLOSE:
+                        if (!IN_SET(current->expect, EXPECT_ARRAY_FIRST_ELEMENT, EXPECT_ARRAY_COMMA)) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        assert(n_stack > 1);
+
+                        r = json_variant_new_array(&add, current->elements, current->n_elements);
+                        if (r < 0)
+                                goto finish;
+
+                        line_token = current->line_before;
+                        column_token = current->column_before;
+
+                        json_stack_release(current);
+                        n_stack--, current--;
+                        break;
+
+                case JSON_TOKEN_STRING:
+                        if (!IN_SET(current->expect, EXPECT_TOPLEVEL, EXPECT_OBJECT_FIRST_KEY, EXPECT_OBJECT_NEXT_KEY, EXPECT_OBJECT_VALUE, EXPECT_ARRAY_FIRST_ELEMENT, EXPECT_ARRAY_NEXT_ELEMENT)) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        r = json_variant_new_string(&add, string);
+                        if (r < 0)
+                                goto finish;
+
+                        if (current->expect == EXPECT_TOPLEVEL)
+                                current->expect = EXPECT_END;
+                        else if (IN_SET(current->expect, EXPECT_OBJECT_FIRST_KEY, EXPECT_OBJECT_NEXT_KEY))
+                                current->expect = EXPECT_OBJECT_COLON;
+                        else if (current->expect == EXPECT_OBJECT_VALUE)
+                                current->expect = EXPECT_OBJECT_COMMA;
+                        else {
+                                assert(IN_SET(current->expect, EXPECT_ARRAY_FIRST_ELEMENT, EXPECT_ARRAY_NEXT_ELEMENT));
+                                current->expect = EXPECT_ARRAY_COMMA;
+                        }
+
+                        break;
+
+                case JSON_TOKEN_REAL:
+                        if (!IN_SET(current->expect, EXPECT_TOPLEVEL, EXPECT_OBJECT_VALUE, EXPECT_ARRAY_FIRST_ELEMENT, EXPECT_ARRAY_NEXT_ELEMENT)) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        r = json_variant_new_real(&add, value.real);
+                        if (r < 0)
+                                goto finish;
+
+                        if (current->expect == EXPECT_TOPLEVEL)
+                                current->expect = EXPECT_END;
+                        else if (current->expect == EXPECT_OBJECT_VALUE)
+                                current->expect = EXPECT_OBJECT_COMMA;
+                        else {
+                                assert(IN_SET(current->expect, EXPECT_ARRAY_FIRST_ELEMENT, EXPECT_ARRAY_NEXT_ELEMENT));
+                                current->expect = EXPECT_ARRAY_COMMA;
+                        }
+
+                        break;
+
+                case JSON_TOKEN_INTEGER:
+                        if (!IN_SET(current->expect, EXPECT_TOPLEVEL, EXPECT_OBJECT_VALUE, EXPECT_ARRAY_FIRST_ELEMENT, EXPECT_ARRAY_NEXT_ELEMENT)) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        r = json_variant_new_integer(&add, value.integer);
+                        if (r < 0)
+                                goto finish;
+
+                        if (current->expect == EXPECT_TOPLEVEL)
+                                current->expect = EXPECT_END;
+                        else if (current->expect == EXPECT_OBJECT_VALUE)
+                                current->expect = EXPECT_OBJECT_COMMA;
+                        else {
+                                assert(IN_SET(current->expect, EXPECT_ARRAY_FIRST_ELEMENT, EXPECT_ARRAY_NEXT_ELEMENT));
+                                current->expect = EXPECT_ARRAY_COMMA;
+                        }
+
+                        break;
+
+                case JSON_TOKEN_UNSIGNED:
+                        if (!IN_SET(current->expect, EXPECT_TOPLEVEL, EXPECT_OBJECT_VALUE, EXPECT_ARRAY_FIRST_ELEMENT, EXPECT_ARRAY_NEXT_ELEMENT)) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        r = json_variant_new_unsigned(&add, value.unsig);
+                        if (r < 0)
+                                goto finish;
+
+                        if (current->expect == EXPECT_TOPLEVEL)
+                                current->expect = EXPECT_END;
+                        else if (current->expect == EXPECT_OBJECT_VALUE)
+                                current->expect = EXPECT_OBJECT_COMMA;
+                        else {
+                                assert(IN_SET(current->expect, EXPECT_ARRAY_FIRST_ELEMENT, EXPECT_ARRAY_NEXT_ELEMENT));
+                                current->expect = EXPECT_ARRAY_COMMA;
+                        }
+
+                        break;
+
+                case JSON_TOKEN_BOOLEAN:
+                        if (!IN_SET(current->expect, EXPECT_TOPLEVEL, EXPECT_OBJECT_VALUE, EXPECT_ARRAY_FIRST_ELEMENT, EXPECT_ARRAY_NEXT_ELEMENT)) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        r = json_variant_new_boolean(&add, value.boolean);
+                        if (r < 0)
+                                goto finish;
+
+                        if (current->expect == EXPECT_TOPLEVEL)
+                                current->expect = EXPECT_END;
+                        else if (current->expect == EXPECT_OBJECT_VALUE)
+                                current->expect = EXPECT_OBJECT_COMMA;
+                        else {
+                                assert(IN_SET(current->expect, EXPECT_ARRAY_FIRST_ELEMENT, EXPECT_ARRAY_NEXT_ELEMENT));
+                                current->expect = EXPECT_ARRAY_COMMA;
+                        }
+
+                        break;
+
+                case JSON_TOKEN_NULL:
+                        if (!IN_SET(current->expect, EXPECT_TOPLEVEL, EXPECT_OBJECT_VALUE, EXPECT_ARRAY_FIRST_ELEMENT, EXPECT_ARRAY_NEXT_ELEMENT)) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        r = json_variant_new_null(&add);
+                        if (r < 0)
+                                goto finish;
+
+                        if (current->expect == EXPECT_TOPLEVEL)
+                                current->expect = EXPECT_END;
+                        else if (current->expect == EXPECT_OBJECT_VALUE)
+                                current->expect = EXPECT_OBJECT_COMMA;
+                        else {
+                                assert(IN_SET(current->expect, EXPECT_ARRAY_FIRST_ELEMENT, EXPECT_ARRAY_NEXT_ELEMENT));
+                                current->expect = EXPECT_ARRAY_COMMA;
+                        }
+
+                        break;
+
+                default:
+                        assert_not_reached("Unexpected token");
+                }
+
+                if (add) {
+                        (void) json_variant_set_source(&add, source, line_token, column_token);
+
+                        if (!GREEDY_REALLOC(current->elements, current->n_elements_allocated, current->n_elements + 1)) {
+                                r = -ENOMEM;
+                                goto finish;
+                        }
+
+                        current->elements[current->n_elements++] = add;
+                }
+        }
+
+done:
+        assert(n_stack == 1);
+        assert(stack[0].n_elements == 1);
+
+        *ret = json_variant_ref(stack[0].elements[0]);
+        *input = p;
+        r = 0;
+
+finish:
+        for (i = 0; i < n_stack; i++)
+                json_stack_release(stack + i);
+
+        free(stack);
+
+        return r;
+}
+
+int json_parse(const char *input, JsonVariant **ret, unsigned *ret_line, unsigned *ret_column) {
+        return json_parse_internal(&input, NULL, ret, ret_line, ret_column, false);
+}
+
+int json_parse_continue(const char **p, JsonVariant **ret, unsigned *ret_line, unsigned *ret_column) {
+        return json_parse_internal(p, NULL, ret, ret_line, ret_column, true);
+}
+
+int json_parse_file(FILE *f, const char *path, JsonVariant **ret, unsigned *ret_line, unsigned *ret_column) {
+        _cleanup_(json_source_unrefp) JsonSource *source = NULL;
+        _cleanup_free_ char *text = NULL;
+        const char *p;
+        int r;
+
+        if (f)
+                r = read_full_stream(f, &text, NULL);
+        else if (path)
+                r = read_full_file(path, &text, NULL);
+        else
+                return -EINVAL;
+        if (r < 0)
+                return r;
+
+        if (path) {
+                source = json_source_new(path);
+                if (!source)
+                        return -ENOMEM;
+        }
+
+        p = text;
+        return json_parse_internal(&p, source, ret, ret_line, ret_column, false);
+}
+
+int json_buildv(JsonVariant **ret, va_list ap) {
+        JsonStack *stack = NULL;
+        size_t n_stack = 1, n_stack_allocated = 0, i;
+        int r;
+
+        assert_return(ret, -EINVAL);
+
+        if (!GREEDY_REALLOC(stack, n_stack_allocated, n_stack))
+                return -ENOMEM;
+
+        stack[0] = (JsonStack) {
+                .expect = EXPECT_TOPLEVEL,
+        };
+
+        for (;;) {
+                _cleanup_(json_variant_unrefp) JsonVariant *add = NULL;
+                size_t n_subtract = 0; /* how much to subtract from current->n_suppress, i.e. how many elements would
+                                        * have been added to the current variant */
+                JsonStack *current;
+                int command;
+
+                assert(n_stack > 0);
+                current = stack + n_stack - 1;
+
+                if (current->expect == EXPECT_END)
+                        goto done;
+
+                command = va_arg(ap, int);
+
+                switch (command) {
+
+                case _JSON_BUILD_STRING: {
+                        const char *p;
+
+                        if (!IN_SET(current->expect, EXPECT_TOPLEVEL, EXPECT_OBJECT_VALUE, EXPECT_ARRAY_ELEMENT)) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        p = va_arg(ap, const char *);
+
+                        if (current->n_suppress == 0) {
+                                r = json_variant_new_string(&add, p);
+                                if (r < 0)
+                                        goto finish;
+                        }
+
+                        n_subtract = 1;
+
+                        if (current->expect == EXPECT_TOPLEVEL)
+                                current->expect = EXPECT_END;
+                        else if (current->expect == EXPECT_OBJECT_VALUE)
+                                current->expect = EXPECT_OBJECT_KEY;
+                        else
+                                assert(current->expect == EXPECT_ARRAY_ELEMENT);
+
+                        break;
+                }
+
+                case _JSON_BUILD_INTEGER: {
+                        intmax_t j;
+
+                        if (!IN_SET(current->expect, EXPECT_TOPLEVEL, EXPECT_OBJECT_VALUE, EXPECT_ARRAY_ELEMENT)) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        j = va_arg(ap, intmax_t);
+
+                        if (current->n_suppress == 0) {
+                                r = json_variant_new_integer(&add, j);
+                                if (r < 0)
+                                        goto finish;
+                        }
+
+                        n_subtract = 1;
+
+                        if (current->expect == EXPECT_TOPLEVEL)
+                                current->expect = EXPECT_END;
+                        else if (current->expect == EXPECT_OBJECT_VALUE)
+                                current->expect = EXPECT_OBJECT_KEY;
+                        else
+                                assert(current->expect == EXPECT_ARRAY_ELEMENT);
+
+                        break;
+                }
+
+                case _JSON_BUILD_UNSIGNED: {
+                        uintmax_t j;
+
+                        if (!IN_SET(current->expect, EXPECT_TOPLEVEL, EXPECT_OBJECT_VALUE, EXPECT_ARRAY_ELEMENT)) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        j = va_arg(ap, uintmax_t);
+
+                        if (current->n_suppress == 0) {
+                                r = json_variant_new_unsigned(&add, j);
+                                if (r < 0)
+                                        goto finish;
+                        }
+
+                        n_subtract = 1;
+
+                        if (current->expect == EXPECT_TOPLEVEL)
+                                current->expect = EXPECT_END;
+                        else if (current->expect == EXPECT_OBJECT_VALUE)
+                                current->expect = EXPECT_OBJECT_KEY;
+                        else
+                                assert(current->expect == EXPECT_ARRAY_ELEMENT);
+
+                        break;
+                }
+
+                case _JSON_BUILD_REAL: {
+                        long double d;
+
+                        if (!IN_SET(current->expect, EXPECT_TOPLEVEL, EXPECT_OBJECT_VALUE, EXPECT_ARRAY_ELEMENT)) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        d = va_arg(ap, long double);
+
+                        if (current->n_suppress == 0) {
+                                r = json_variant_new_real(&add, d);
+                                if (r < 0)
+                                        goto finish;
+                        }
+
+                        n_subtract = 1;
+
+                        if (current->expect == EXPECT_TOPLEVEL)
+                                current->expect = EXPECT_END;
+                        else if (current->expect == EXPECT_OBJECT_VALUE)
+                                current->expect = EXPECT_OBJECT_KEY;
+                        else
+                                assert(current->expect == EXPECT_ARRAY_ELEMENT);
+
+                        break;
+                }
+
+                case _JSON_BUILD_BOOLEAN: {
+                        bool b;
+
+                        if (!IN_SET(current->expect, EXPECT_TOPLEVEL, EXPECT_OBJECT_VALUE, EXPECT_ARRAY_ELEMENT)) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        b = va_arg(ap, int);
+
+                        if (current->n_suppress == 0) {
+                                r = json_variant_new_boolean(&add, b);
+                                if (r < 0)
+                                        goto finish;
+                        }
+
+                        n_subtract = 1;
+
+                        if (current->expect == EXPECT_TOPLEVEL)
+                                current->expect = EXPECT_END;
+                        else if (current->expect == EXPECT_OBJECT_VALUE)
+                                current->expect = EXPECT_OBJECT_KEY;
+                        else
+                                assert(current->expect == EXPECT_ARRAY_ELEMENT);
+
+                        break;
+                }
+
+                case _JSON_BUILD_NULL:
+
+                        if (!IN_SET(current->expect, EXPECT_TOPLEVEL, EXPECT_OBJECT_VALUE, EXPECT_ARRAY_ELEMENT)) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        if (current->n_suppress == 0) {
+                                r = json_variant_new_null(&add);
+                                if (r < 0)
+                                        goto finish;
+                        }
+
+                        n_subtract = 1;
+
+                        if (current->expect == EXPECT_TOPLEVEL)
+                                current->expect = EXPECT_END;
+                        else if (current->expect == EXPECT_OBJECT_VALUE)
+                                current->expect = EXPECT_OBJECT_KEY;
+                        else
+                                assert(current->expect == EXPECT_ARRAY_ELEMENT);
+
+                        break;
+
+                case _JSON_BUILD_VARIANT:
+
+                        if (!IN_SET(current->expect, EXPECT_TOPLEVEL, EXPECT_OBJECT_VALUE, EXPECT_ARRAY_ELEMENT)) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        /* Note that we don't care for current->n_suppress here, after all the variant is already
+                         * allocated anyway... */
+                        add = va_arg(ap, JsonVariant*);
+                        if (!add)
+                                add = JSON_VARIANT_MAGIC_NULL;
+                        else
+                                json_variant_ref(add);
+
+                        n_subtract = 1;
+
+                        if (current->expect == EXPECT_TOPLEVEL)
+                                current->expect = EXPECT_END;
+                        else if (current->expect == EXPECT_OBJECT_VALUE)
+                                current->expect = EXPECT_OBJECT_KEY;
+                        else
+                                assert(current->expect == EXPECT_ARRAY_ELEMENT);
+
+                        break;
+
+                case _JSON_BUILD_LITERAL: {
+                        const char *l;
+
+                        if (!IN_SET(current->expect, EXPECT_TOPLEVEL, EXPECT_OBJECT_VALUE, EXPECT_ARRAY_ELEMENT)) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        l = va_arg(ap, const char *);
+
+                        if (l) {
+                                /* Note that we don't care for current->n_suppress here, we should generate parsing
+                                 * errors even in suppressed object properties */
+
+                                r = json_parse(l, &add, NULL, NULL);
+                                if (r < 0)
+                                        goto finish;
+                        } else
+                                add = JSON_VARIANT_MAGIC_NULL;
+
+                        n_subtract = 1;
+
+                        if (current->expect == EXPECT_TOPLEVEL)
+                                current->expect = EXPECT_END;
+                        else if (current->expect == EXPECT_OBJECT_VALUE)
+                                current->expect = EXPECT_OBJECT_KEY;
+                        else
+                                assert(current->expect == EXPECT_ARRAY_ELEMENT);
+
+                        break;
+                }
+
+                case _JSON_BUILD_ARRAY_BEGIN:
+
+                        if (!IN_SET(current->expect, EXPECT_TOPLEVEL, EXPECT_OBJECT_VALUE, EXPECT_ARRAY_ELEMENT)) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        if (!GREEDY_REALLOC(stack, n_stack_allocated, n_stack+1)) {
+                                r = -ENOMEM;
+                                goto finish;
+                        }
+                        current = stack + n_stack - 1;
+
+                        if (current->expect == EXPECT_TOPLEVEL)
+                                current->expect = EXPECT_END;
+                        else if (current->expect == EXPECT_OBJECT_VALUE)
+                                current->expect = EXPECT_OBJECT_KEY;
+                        else
+                                assert(current->expect == EXPECT_ARRAY_ELEMENT);
+
+                        stack[n_stack++] = (JsonStack) {
+                                .expect = EXPECT_ARRAY_ELEMENT,
+                                .n_suppress = current->n_suppress != 0 ? (size_t) -1 : 0, /* if we shall suppress the
+                                                                                           * new array, then we should
+                                                                                           * also suppress all array
+                                                                                           * members */
+                        };
+
+                        break;
+
+                case _JSON_BUILD_ARRAY_END:
+                        if (current->expect != EXPECT_ARRAY_ELEMENT) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        assert(n_stack > 1);
+
+                        if (current->n_suppress == 0) {
+                                r = json_variant_new_array(&add, current->elements, current->n_elements);
+                                if (r < 0)
+                                        goto finish;
+                        }
+
+                        n_subtract = 1;
+
+                        json_stack_release(current);
+                        n_stack--, current--;
+
+                        break;
+
+                case _JSON_BUILD_STRV: {
+                        char **l;
+
+                        if (!IN_SET(current->expect, EXPECT_TOPLEVEL, EXPECT_OBJECT_VALUE, EXPECT_ARRAY_ELEMENT)) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        l = va_arg(ap, char **);
+
+                        if (current->n_suppress == 0) {
+                                r = json_variant_new_array_strv(&add, l);
+                                if (r < 0)
+                                        goto finish;
+                        }
+
+                        n_subtract = 1;
+
+                        if (current->expect == EXPECT_TOPLEVEL)
+                                current->expect = EXPECT_END;
+                        else if (current->expect == EXPECT_OBJECT_VALUE)
+                                current->expect = EXPECT_OBJECT_KEY;
+                        else
+                                assert(current->expect == EXPECT_ARRAY_ELEMENT);
+
+                        break;
+                }
+
+                case _JSON_BUILD_OBJECT_BEGIN:
+
+                        if (!IN_SET(current->expect, EXPECT_TOPLEVEL, EXPECT_OBJECT_VALUE, EXPECT_ARRAY_ELEMENT)) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        if (!GREEDY_REALLOC(stack, n_stack_allocated, n_stack+1)) {
+                                r = -ENOMEM;
+                                goto finish;
+                        }
+                        current = stack + n_stack - 1;
+
+                        if (current->expect == EXPECT_TOPLEVEL)
+                                current->expect = EXPECT_END;
+                        else if (current->expect == EXPECT_OBJECT_VALUE)
+                                current->expect = EXPECT_OBJECT_KEY;
+                        else
+                                assert(current->expect == EXPECT_ARRAY_ELEMENT);
+
+                        stack[n_stack++] = (JsonStack) {
+                                .expect = EXPECT_OBJECT_KEY,
+                                .n_suppress = current->n_suppress != 0 ? (size_t) -1 : 0, /* if we shall suppress the
+                                                                                           * new object, then we should
+                                                                                           * also suppress all object
+                                                                                           * members */
+                        };
+
+                        break;
+
+                case _JSON_BUILD_OBJECT_END:
+
+                        if (current->expect != EXPECT_OBJECT_KEY) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        assert(n_stack > 1);
+
+                        if (current->n_suppress == 0) {
+                                r = json_variant_new_object(&add, current->elements, current->n_elements);
+                                if (r < 0)
+                                        goto finish;
+                        }
+
+                        n_subtract = 1;
+
+                        json_stack_release(current);
+                        n_stack--, current--;
+
+                        break;
+
+                case _JSON_BUILD_PAIR: {
+                        const char *n;
+
+                        if (current->expect != EXPECT_OBJECT_KEY) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        n = va_arg(ap, const char *);
+
+                        if (current->n_suppress == 0) {
+                                r = json_variant_new_string(&add, n);
+                                if (r < 0)
+                                        goto finish;
+                        }
+
+                        n_subtract = 1;
+
+                        current->expect = EXPECT_OBJECT_VALUE;
+                        break;
+                }
+
+                case _JSON_BUILD_PAIR_CONDITION: {
+                        const char *n;
+                        bool b;
+
+                        if (current->expect != EXPECT_OBJECT_KEY) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        b = va_arg(ap, int);
+                        n = va_arg(ap, const char *);
+
+                        if (b && current->n_suppress == 0) {
+                                r = json_variant_new_string(&add, n);
+                                if (r < 0)
+                                        goto finish;
+                        }
+
+                        n_subtract = 1; /* we generated one item */
+
+                        if (!b && current->n_suppress != (size_t) -1)
+                                current->n_suppress += 2; /* Suppress this one and the next item */
+
+                        current->expect = EXPECT_OBJECT_VALUE;
+                        break;
+                }}
+
+                /* If a variant was generated, add it to our current variant, but only if we are not supposed to suppress additions */
+                if (add && current->n_suppress == 0) {
+                        if (!GREEDY_REALLOC(current->elements, current->n_elements_allocated, current->n_elements + 1)) {
+                                r = -ENOMEM;
+                                goto finish;
+                        }
+
+                        current->elements[current->n_elements++] = TAKE_PTR(add);
+                }
+
+                /* If we are supposed to suppress items, let's subtract how many items where generated from that
+                 * counter. Except if the counter is (size_t) -1, i.e. we shall suppress an infinite number of elements
+                 * on this stack level */
+                if (current->n_suppress != (size_t) -1) {
+                        if (current->n_suppress <= n_subtract) /* Saturated */
+                                current->n_suppress = 0;
+                        else
+                                current->n_suppress -= n_subtract;
+                }
+        }
+
+done:
+        assert(n_stack == 1);
+        assert(stack[0].n_elements == 1);
+
+        *ret = json_variant_ref(stack[0].elements[0]);
+        r = 0;
+
+finish:
+        for (i = 0; i < n_stack; i++)
+                json_stack_release(stack + i);
+
+        free(stack);
+
+        va_end(ap);
+
+        return r;
+}
+
+int json_build(JsonVariant **ret, ...) {
+        va_list ap;
+        int r;
+
+        va_start(ap, ret);
+        r = json_buildv(ret, ap);
+        va_end(ap);
+
+        return r;
+}
+
+int json_log_internal(
+                JsonVariant *variant,
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *format, ...) {
+
+        PROTECT_ERRNO;
+
+        unsigned source_line, source_column;
+        char buffer[LINE_MAX];
+        const char *source;
+        va_list ap;
+        int r;
+
+        errno = ERRNO_VALUE(error);
+
+        va_start(ap, format);
+        (void) vsnprintf(buffer, sizeof buffer, format, ap);
+        va_end(ap);
+
+        if (variant) {
+                r = json_variant_get_source(variant, &source, &source_line, &source_column);
+                if (r < 0)
+                        return r;
+        } else {
+                source = NULL;
+                source_line = 0;
+                source_column = 0;
+        }
+
+        if (source && source_line > 0 && source_column > 0)
+                return log_struct_internal(
+                                LOG_REALM_PLUS_LEVEL(LOG_REALM_SYSTEMD, level),
+                                error,
+                                file, line, func,
+                                "MESSAGE_ID=" SD_MESSAGE_INVALID_CONFIGURATION_STR,
+                                "CONFIG_FILE=%s", source,
+                                "CONFIG_LINE=%u", source_line,
+                                "CONFIG_COLUMN=%u", source_column,
+                                LOG_MESSAGE("%s:%u: %s", source, line, buffer),
+                                NULL);
+        else
+                return log_struct_internal(
+                                LOG_REALM_PLUS_LEVEL(LOG_REALM_SYSTEMD, level),
+                                error,
+                                file, line, func,
+                                "MESSAGE_ID=" SD_MESSAGE_INVALID_CONFIGURATION_STR,
+                                LOG_MESSAGE("%s", buffer),
+                                NULL);
+}
+
+int json_dispatch(JsonVariant *v, const JsonDispatch table[], JsonDispatchCallback bad, JsonDispatchFlags flags, void *userdata) {
+        const JsonDispatch *p;
+        size_t i, n, m;
+        int r, done = 0;
+        bool *found;
+
+        if (!json_variant_is_object(v)) {
+                json_log(v, flags, 0, "JSON variant is not an object.");
+
+                if (flags & JSON_PERMISSIVE)
+                        return 0;
+
+                return -EINVAL;
+        }
+
+        for (p = table, m = 0; p->name; p++)
+                m++;
+
+        found = newa0(bool, m);
+
+        n = json_variant_elements(v);
+        for (i = 0; i < n; i += 2) {
+                JsonVariant *key, *value;
+
+                assert_se(key = json_variant_by_index(v, i));
+                assert_se(value = json_variant_by_index(v, i+1));
+
+                for (p = table; p->name; p++)
+                        if (p->name == (const char*) -1 ||
+                            streq_ptr(json_variant_string(key), p->name))
+                                break;
+
+                if (p->name) { /* Found a matching entry! :-) */
+                        JsonDispatchFlags merged_flags;
+
+                        merged_flags = flags | p->flags;
+
+                        if (p->type != _JSON_VARIANT_TYPE_INVALID &&
+                            !json_variant_has_type(value, p->type)) {
+
+                                json_log(value, merged_flags, 0,
+                                         "Object field '%s' has wrong type %s, expected %s.", json_variant_string(key),
+                                         json_variant_type_to_string(json_variant_type(value)), json_variant_type_to_string(p->type));
+
+                                if (merged_flags & JSON_PERMISSIVE)
+                                        continue;
+
+                                return -EINVAL;
+                        }
+
+                        if (found[p-table]) {
+                                json_log(value, merged_flags, 0, "Duplicate object field '%s'.", json_variant_string(key));
+
+                                if (merged_flags & JSON_PERMISSIVE)
+                                        continue;
+
+                                return -ENOTUNIQ;
+                        }
+
+                        found[p-table] = true;
+
+                        if (p->callback) {
+                                r = p->callback(json_variant_string(key), value, merged_flags, (uint8_t*) userdata + p->offset);
+                                if (r < 0) {
+                                        if (merged_flags & JSON_PERMISSIVE)
+                                                continue;
+
+                                        return r;
+                                }
+                        }
+
+                        done ++;
+
+                } else { /* Didn't find a matching entry! :-( */
+
+                        if (bad) {
+                                r = bad(json_variant_string(key), value, flags, userdata);
+                                if (r < 0) {
+                                        if (flags & JSON_PERMISSIVE)
+                                                continue;
+
+                                        return r;
+                                } else
+                                        done ++;
+
+                        } else  {
+                                json_log(value, flags, 0, "Unexpected object field '%s'.", json_variant_string(key));
+
+                                if (flags & JSON_PERMISSIVE)
+                                        continue;
+
+                                return -EADDRNOTAVAIL;
+                        }
+                }
+        }
+
+        for (p = table; p->name; p++) {
+                JsonDispatchFlags merged_flags = p->flags | flags;
+
+                if ((merged_flags & JSON_MANDATORY) && !found[p-table]) {
+                        json_log(v, merged_flags, 0, "Missing object field '%s'.", p->name);
+
+                        if ((merged_flags & JSON_PERMISSIVE))
+                                continue;
+
+                        return -ENXIO;
+                }
+        }
+
+        return done;
+}
+
+int json_dispatch_boolean(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata) {
+        bool *b = userdata;
+
+        assert(variant);
+        assert(b);
+
+        if (!json_variant_is_boolean(variant)) {
+                json_log(variant, flags, 0, "JSON field '%s' is not a boolean.", strna(name));
+                return -EINVAL;
+        }
+
+        *b = json_variant_boolean(variant);
+        return 0;
+}
+
+int json_dispatch_tristate(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata) {
+        int *b = userdata;
+
+        assert(variant);
+        assert(b);
+
+        if (!json_variant_is_boolean(variant)) {
+                json_log(variant, flags, 0, "JSON field '%s' is not a boolean.", strna(name));
+                return -EINVAL;
+        }
+
+        *b = json_variant_boolean(variant);
+        return 0;
+}
+
+int json_dispatch_integer(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata) {
+        intmax_t *i = userdata;
+
+        assert(variant);
+        assert(i);
+
+        if (!json_variant_is_integer(variant)) {
+                json_log(variant, flags, 0, "JSON field '%s' is not an integer.", strna(name));
+                return -EINVAL;
+        }
+
+        *i = json_variant_integer(variant);
+        return 0;
+}
+
+int json_dispatch_unsigned(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata) {
+        uintmax_t *u = userdata;
+
+        assert(variant);
+        assert(u);
+
+        if (!json_variant_is_unsigned(variant)) {
+                json_log(variant, flags, 0, "JSON field '%s' is not an unsigned integer.", strna(name));
+                return -EINVAL;
+        }
+
+        *u = json_variant_unsigned(variant);
+        return 0;
+}
+
+int json_dispatch_uint32(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata) {
+        uint32_t *u = userdata;
+
+        assert(variant);
+        assert(u);
+
+        if (!json_variant_is_unsigned(variant)) {
+                json_log(variant, flags, 0, "JSON field '%s' is not an unsigned integer.", strna(name));
+                return -EINVAL;
+        }
+
+        if (json_variant_unsigned(variant) > UINT32_MAX) {
+                json_log(variant, flags, 0, "JSON field '%s' out of bounds.", strna(name));
+                return -ERANGE;
+        }
+
+        *u = (uint32_t) json_variant_unsigned(variant);
+        return 0;
+}
+
+int json_dispatch_int32(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata) {
+        int32_t *i = userdata;
+
+        assert(variant);
+        assert(i);
+
+        if (!json_variant_is_integer(variant)) {
+                json_log(variant, flags, 0, "JSON field '%s' is not an integer.", strna(name));
+                return -EINVAL;
+        }
+
+        if (json_variant_integer(variant) < INT32_MIN || json_variant_integer(variant) > INT32_MAX) {
+                json_log(variant, flags, 0, "JSON field '%s' out of bounds.", strna(name));
+                return -ERANGE;
+        }
+
+        *i = (int32_t) json_variant_integer(variant);
+        return 0;
+}
+
+int json_dispatch_string(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata) {
+        char **s = userdata;
+        int r;
+
+        assert(variant);
+        assert(s);
+
+        if (json_variant_is_null(variant)) {
+                *s = mfree(*s);
+                return 0;
+        }
+
+        if (!json_variant_is_string(variant)) {
+                json_log(variant, flags, 0, "JSON field '%s' is not a string.", strna(name));
+                return -EINVAL;
+        }
+
+        r = free_and_strdup(s, json_variant_string(variant));
+        if (r < 0)
+                return json_log(variant, flags, r, "Failed to allocate string: %m");
+
+        return 0;
+}
+
+int json_dispatch_strv(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata) {
+        _cleanup_strv_free_ char **l = NULL;
+        char ***s = userdata;
+        size_t i;
+        int r;
+
+        assert(variant);
+        assert(s);
+
+        if (json_variant_is_null(variant)) {
+                *s = strv_free(*s);
+                return 0;
+        }
+
+        if (!json_variant_is_array(variant)) {
+                json_log(variant, 0, flags, "JSON field '%s' is not an array.", strna(name));
+                return -EINVAL;
+        }
+
+        for (i = 0; i < json_variant_elements(variant); i++) {
+                JsonVariant *e;
+
+                assert_se(e = json_variant_by_index(variant, i));
+
+                if (!json_variant_is_string(e)) {
+                        json_log(e, 0, flags, "JSON array element is not a string.");
+                        return -EINVAL;
+                }
+
+                r = strv_extend(&l, json_variant_string(e));
+                if (r < 0)
+                        return json_log(variant, flags, r, "Failed to append array element: %m");
+        }
+
+        strv_free_and_replace(*s, l);
+        return 0;
+}
+
+int json_dispatch_variant(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata) {
+        JsonVariant **p = userdata;
+
+        assert(variant);
+        assert(p);
+
+        json_variant_unref(*p);
+        *p = json_variant_ref(variant);
+
+        return 0;
+}
+
+static const char* const json_variant_type_table[_JSON_VARIANT_TYPE_MAX] = {
+        [JSON_VARIANT_STRING] = "string",
+        [JSON_VARIANT_INTEGER] = "integer",
+        [JSON_VARIANT_UNSIGNED] = "unsigned",
+        [JSON_VARIANT_REAL] = "real",
+        [JSON_VARIANT_NUMBER] = "number",
+        [JSON_VARIANT_BOOLEAN] = "boolean",
+        [JSON_VARIANT_ARRAY] = "array",
+        [JSON_VARIANT_OBJECT] = "object",
+        [JSON_VARIANT_NULL] = "null",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(json_variant_type, JsonVariantType);