json: add APIs for quickly inserting hex blobs into as JSON strings

This is similar to the base64 support, but fixed-size hash values are
typically preferably presented as series of hex values, hence store them
here like that too.

diff --git a/src/shared/json.c b/src/shared/json.c
index 6ea246a22b914a39f680c7f0dd74aeb38662633e..6beb56cfa0c547d6df2a6877056efec6b4be50c3 100644 (file)
--- a/src/shared/json.c
+++ b/src/shared/json.c
@@ -433,6 +433,19 @@ int json_variant_new_base64(JsonVariant **ret, const void *p, size_t n) {
         return json_variant_new_stringn(ret, s, k);
 }
 
+int json_variant_new_hex(JsonVariant **ret, const void *p, size_t n) {
+        _cleanup_free_ char *s = NULL;
+
+        assert_return(ret, -EINVAL);
+        assert_return(n == 0 || p, -EINVAL);
+
+        s = hexmem(p, n);
+        if (!s)
+                return -ENOMEM;
+
+        return json_variant_new_stringn(ret, s, n*2);
+}
+
 int json_variant_new_id128(JsonVariant **ret, sd_id128_t id) {
         char s[SD_ID128_STRING_MAX];
 
@@ -3603,6 +3616,36 @@ int json_buildv(JsonVariant **ret, va_list ap) {
                         break;
                 }
 
+                case _JSON_BUILD_HEX: {
+                        const void *p;
+                        size_t n;
+
+                        if (!IN_SET(current->expect, EXPECT_TOPLEVEL, EXPECT_OBJECT_VALUE, EXPECT_ARRAY_ELEMENT)) {
+                                r = -EINVAL;
+                                goto finish;
+                        }
+
+                        p = va_arg(ap, const void *);
+                        n = va_arg(ap, size_t);
+
+                        if (current->n_suppress == 0) {
+                                r = json_variant_new_hex(&add, p, n);
+                                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_ID128: {
                         sd_id128_t id;
 
@@ -4405,6 +4448,14 @@ int json_variant_unbase64(JsonVariant *v, void **ret, size_t *ret_size) {
         return unbase64mem(json_variant_string(v), (size_t) -1, ret, ret_size);
 }
 
+int json_variant_unhex(JsonVariant *v, void **ret, size_t *ret_size) {
+
+        if (!json_variant_is_string(v))
+                return -EINVAL;
+
+        return unhexmem(json_variant_string(v), (size_t) -1, ret, ret_size);
+}
+
 static const char* const json_variant_type_table[_JSON_VARIANT_TYPE_MAX] = {
         [JSON_VARIANT_STRING] = "string",
         [JSON_VARIANT_INTEGER] = "integer",

diff --git a/src/shared/json.h b/src/shared/json.h
index 0809f3187e38f5e6202fc82d41382b1767f78859..abc0dccddbfa9a42206993c74d13841577873c1d 100644 (file)
--- a/src/shared/json.h
+++ b/src/shared/json.h
@@ -58,6 +58,7 @@ typedef enum JsonVariantType {
 
 int json_variant_new_stringn(JsonVariant **ret, const char *s, size_t n);
 int json_variant_new_base64(JsonVariant **ret, const void *p, size_t n);
+int json_variant_new_hex(JsonVariant **ret, const void *p, size_t n);
 int json_variant_new_integer(JsonVariant **ret, intmax_t i);
 int json_variant_new_unsigned(JsonVariant **ret, uintmax_t u);
 int json_variant_new_real(JsonVariant **ret, long double d);
@@ -227,6 +228,7 @@ enum {
         _JSON_BUILD_LITERAL,
         _JSON_BUILD_STRV,
         _JSON_BUILD_BASE64,
+        _JSON_BUILD_HEX,
         _JSON_BUILD_ID128,
         _JSON_BUILD_BYTE_ARRAY,
         _JSON_BUILD_MAX,
@@ -249,6 +251,7 @@ enum {
 #define JSON_BUILD_LITERAL(l) _JSON_BUILD_LITERAL, ({ const char *_x = l; _x; })
 #define JSON_BUILD_STRV(l) _JSON_BUILD_STRV, ({ char **_x = l; _x; })
 #define JSON_BUILD_BASE64(p, n) _JSON_BUILD_BASE64, ({ const void *_x = p; _x; }), ({ size_t _y = n; _y; })
+#define JSON_BUILD_HEX(p, n) _JSON_BUILD_HEX, ({ const void *_x = p; _x; }), ({ size_t _y = n; _y; })
 #define JSON_BUILD_ID128(id) _JSON_BUILD_ID128, ({ sd_id128_t _x = id; _x; })
 #define JSON_BUILD_BYTE_ARRAY(v, n) _JSON_BUILD_BYTE_ARRAY, ({ const void *_x = v; _x; }), ({ size_t _y = n; _y; })
 
@@ -351,6 +354,7 @@ int json_log_internal(JsonVariant *variant, int level, int error, const char *fi
         })
 
 int json_variant_unbase64(JsonVariant *v, void **ret, size_t *ret_size);
+int json_variant_unhex(JsonVariant *v, void **ret, size_t *ret_size);
 
 const char *json_variant_type_to_string(JsonVariantType t);
 JsonVariantType json_variant_type_from_string(const char *s);