blobmsg_json.c

   1 /*
   2  * Copyright (C) 2010-2012 Felix Fietkau <nbd@openwrt.org>
   3  *
   4  * Permission to use, copy, modify, and/or distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16 #include <inttypes.h>
  17 #include "blobmsg.h"
  18 #include "blobmsg_json.h"
  19
  20 #ifdef JSONC
  21         #include <json.h>
  22 #else
  23         #include <json/json.h>
  24 #endif
  25
  26 bool blobmsg_add_object(struct blob_buf *b, json_object *obj)
  27 {
  28         json_object_object_foreach(obj, key, val) {
  29                 if (!blobmsg_add_json_element(b, key, val))
  30                         return false;
  31         }
  32         return true;
  33 }
  34
  35 static bool blobmsg_add_array(struct blob_buf *b, struct array_list *a)
  36 {
  37         int i, len;
  38
  39         for (i = 0, len = array_list_length(a); i < len; i++) {
  40                 if (!blobmsg_add_json_element(b, NULL, array_list_get_idx(a, i)))
  41                         return false;
  42         }
  43
  44         return true;
  45 }
  46
  47 bool blobmsg_add_json_element(struct blob_buf *b, const char *name, json_object *obj)
  48 {
  49         bool ret = true;
  50         void *c;
  51
  52         switch (json_object_get_type(obj)) {
  53         case json_type_object:
  54                 c = blobmsg_open_table(b, name);
  55                 ret = blobmsg_add_object(b, obj);
  56                 blobmsg_close_table(b, c);
  57                 break;
  58         case json_type_array:
  59                 c = blobmsg_open_array(b, name);
  60                 ret = blobmsg_add_array(b, json_object_get_array(obj));
  61                 blobmsg_close_array(b, c);
  62                 break;
  63         case json_type_string:
  64                 blobmsg_add_string(b, name, json_object_get_string(obj));
  65                 break;
  66         case json_type_boolean:
  67                 blobmsg_add_u8(b, name, json_object_get_boolean(obj));
  68                 break;
  69         case json_type_int:
  70                 blobmsg_add_u32(b, name, json_object_get_int(obj));
  71                 break;
  72         case json_type_null:
  73                 blobmsg_add_field(b, BLOBMSG_TYPE_UNSPEC, name, NULL, 0);
  74                 break;
  75         default:
  76                 return false;
  77         }
  78         return ret;
  79 }
  80
  81 static bool __blobmsg_add_json(struct blob_buf *b, json_object *obj)
  82 {
  83         bool ret = false;
  84
  85         if (!obj)
  86                 return false;
  87
  88         if (json_object_get_type(obj) != json_type_object)
  89                 goto out;
  90
  91         ret = blobmsg_add_object(b, obj);
  92
  93 out:
  94         json_object_put(obj);
  95         return ret;
  96 }
  97
  98 bool blobmsg_add_json_from_file(struct blob_buf *b, const char *file)
  99 {
 100         return __blobmsg_add_json(b, json_object_from_file(file));
 101 }
 102
 103 bool blobmsg_add_json_from_string(struct blob_buf *b, const char *str)
 104 {
 105         return __blobmsg_add_json(b, json_tokener_parse(str));
 106 }
 107
 108
 109 struct strbuf {
 110         int len;
 111         int pos;
 112         char *buf;
 113
 114         blobmsg_json_format_t custom_format;
 115         void *priv;
 116         bool indent;
 117         int indent_level;
 118 };
 119
 120 static bool blobmsg_puts(struct strbuf *s, const char *c, int len)
 121 {
 122         if (len <= 0)
 123                 return true;
 124
 125         if (s->pos + len >= s->len) {
 126                 s->len += 16 + len;
 127                 s->buf = realloc(s->buf, s->len);
 128                 if (!s->buf)
 129                         return false;
 130         }
 131         memcpy(s->buf + s->pos, c, len);
 132         s->pos += len;
 133         return true;
 134 }
 135
 136 static void add_separator(struct strbuf *s)
 137 {
 138         const char *indent_chars = "\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t";
 139         int len;
 140
 141         if (!s->indent)
 142                 return;
 143
 144         len = s->indent_level + 1;
 145         if (len > strlen(indent_chars))
 146                 len = strlen(indent_chars);
 147
 148         blobmsg_puts(s, indent_chars, len);
 149 }
 150
 151
 152 static void blobmsg_format_string(struct strbuf *s, const char *str)
 153 {
 154         const unsigned char *p, *last, *end;
 155         char buf[8] = "\\u00";
 156
 157         end = (unsigned char *) str + strlen(str);
 158         blobmsg_puts(s, "\"", 1);
 159         for (p = (unsigned char *) str, last = p; *p; p++) {
 160                 char escape = '\0';
 161                 int len;
 162
 163                 switch(*p) {
 164                 case '\b':
 165                         escape = 'b';
 166                         break;
 167                 case '\n':
 168                         escape = 'n';
 169                         break;
 170                 case '\t':
 171                         escape = 't';
 172                         break;
 173                 case '\r':
 174                         escape = 'r';
 175                         break;
 176                 case '"':
 177                 case '\\':
 178                 case '/':
 179                         escape = *p;
 180                         break;
 181                 default:
 182                         if (*p < ' ')
 183                                 escape = 'u';
 184                         break;
 185                 }
 186
 187                 if (!escape)
 188                         continue;
 189
 190                 if (p > last)
 191                         blobmsg_puts(s, (char *) last, p - last);
 192                 last = p + 1;
 193                 buf[1] = escape;
 194
 195                 if (escape == 'u') {
 196                         sprintf(buf + 4, "%02x", (unsigned char) *p);
 197                         len = 6;
 198                 } else {
 199                         len = 2;
 200                 }
 201                 blobmsg_puts(s, buf, len);
 202         }
 203
 204         blobmsg_puts(s, (char *) last, end - last);
 205         blobmsg_puts(s, "\"", 1);
 206 }
 207
 208 static void blobmsg_format_json_list(struct strbuf *s, struct blob_attr *attr, int len, bool array);
 209
 210 static void blobmsg_format_element(struct strbuf *s, struct blob_attr *attr, bool array, bool head)
 211 {
 212         const char *data_str;
 213         char buf[32];
 214         void *data;
 215         int len;
 216
 217         if (!blobmsg_check_attr(attr, false))
 218                 return;
 219
 220         if (!array && blobmsg_name(attr)[0]) {
 221                 blobmsg_format_string(s, blobmsg_name(attr));
 222                 blobmsg_puts(s, ": ", s->indent ? 2 : 1);
 223         }
 224
 225         data = blobmsg_data(attr);
 226         len = blobmsg_data_len(attr);
 227
 228         if (!head && s->custom_format) {
 229                 data_str = s->custom_format(s->priv, attr);
 230                 if (data_str)
 231                         goto out;
 232         }
 233
 234         data_str = buf;
 235         switch(blob_id(attr)) {
 236         case BLOBMSG_TYPE_UNSPEC:
 237                 sprintf(buf, "null");
 238                 break;
 239         case BLOBMSG_TYPE_BOOL:
 240                 sprintf(buf, "%s", *(uint8_t *)data ? "true" : "false");
 241                 break;
 242         case BLOBMSG_TYPE_INT16:
 243                 sprintf(buf, "%d", be16_to_cpu(*(uint16_t *)data));
 244                 break;
 245         case BLOBMSG_TYPE_INT32:
 246                 sprintf(buf, "%d", (int32_t) be32_to_cpu(*(uint32_t *)data));
 247                 break;
 248         case BLOBMSG_TYPE_INT64:
 249                 sprintf(buf, "%" PRId64, (int64_t) be64_to_cpu(*(uint64_t *)data));
 250                 break;
 251         case BLOBMSG_TYPE_STRING:
 252                 blobmsg_format_string(s, data);
 253                 return;
 254         case BLOBMSG_TYPE_ARRAY:
 255                 blobmsg_format_json_list(s, data, len, true);
 256                 return;
 257         case BLOBMSG_TYPE_TABLE:
 258                 blobmsg_format_json_list(s, data, len, false);
 259                 return;
 260         }
 261
 262 out:
 263         blobmsg_puts(s, data_str, strlen(data_str));
 264 }
 265
 266 static void blobmsg_format_json_list(struct strbuf *s, struct blob_attr *attr, int len, bool array)
 267 {
 268         struct blob_attr *pos;
 269         bool first = true;
 270         int rem = len;
 271
 272         blobmsg_puts(s, (array ? "[" : "{" ), 1);
 273         s->indent_level++;
 274         add_separator(s);
 275         __blob_for_each_attr(pos, attr, rem) {
 276                 if (!first) {
 277                         blobmsg_puts(s, ",", 1);
 278                         add_separator(s);
 279                 }
 280
 281                 blobmsg_format_element(s, pos, array, false);
 282                 first = false;
 283         }
 284         s->indent_level--;
 285         add_separator(s);
 286         blobmsg_puts(s, (array ? "]" : "}"), 1);
 287 }
 288
 289 char *blobmsg_format_json_with_cb(struct blob_attr *attr, bool list, blobmsg_json_format_t cb, void *priv, int indent)
 290 {
 291         struct strbuf s;
 292         bool array;
 293
 294         s.len = blob_len(attr);
 295         s.buf = malloc(s.len);
 296         s.pos = 0;
 297         s.custom_format = cb;
 298         s.priv = priv;
 299         s.indent = false;
 300
 301         if (indent >= 0) {
 302                 s.indent = true;
 303                 s.indent_level = indent;
 304         }
 305
 306         array = blob_is_extended(attr) &&
 307                 blobmsg_type(attr) == BLOBMSG_TYPE_ARRAY;
 308
 309         if (list)
 310                 blobmsg_format_json_list(&s, blobmsg_data(attr), blobmsg_data_len(attr), array);
 311         else
 312                 blobmsg_format_element(&s, attr, false, false);
 313
 314         if (!s.len) {
 315                 free(s.buf);
 316                 return NULL;
 317         }
 318
 319         s.buf = realloc(s.buf, s.pos + 1);
 320         s.buf[s.pos] = 0;
 321
 322         return s.buf;
 323 }