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 #include <json.h>
  21
  22 bool blobmsg_add_object(struct blob_buf *b, json_object *obj)
  23 {
  24         json_object_object_foreach(obj, key, val) {
  25                 if (!blobmsg_add_json_element(b, key, val))
  26                         return false;
  27         }
  28         return true;
  29 }
  30
  31 static bool blobmsg_add_array(struct blob_buf *b, struct array_list *a)
  32 {
  33         int i, len;
  34
  35         for (i = 0, len = array_list_length(a); i < len; i++) {
  36                 if (!blobmsg_add_json_element(b, NULL, array_list_get_idx(a, i)))
  37                         return false;
  38         }
  39
  40         return true;
  41 }
  42
  43 bool blobmsg_add_json_element(struct blob_buf *b, const char *name, json_object *obj)
  44 {
  45         bool ret = true;
  46         void *c;
  47
  48         switch (json_object_get_type(obj)) {
  49         case json_type_object:
  50                 c = blobmsg_open_table(b, name);
  51                 ret = blobmsg_add_object(b, obj);
  52                 blobmsg_close_table(b, c);
  53                 break;
  54         case json_type_array:
  55                 c = blobmsg_open_array(b, name);
  56                 ret = blobmsg_add_array(b, json_object_get_array(obj));
  57                 blobmsg_close_array(b, c);
  58                 break;
  59         case json_type_string:
  60                 blobmsg_add_string(b, name, json_object_get_string(obj));
  61                 break;
  62         case json_type_boolean:
  63                 blobmsg_add_u8(b, name, json_object_get_boolean(obj));
  64                 break;
  65         case json_type_int: {
  66                 int64_t i64 = json_object_get_int64(obj);
  67                 if (i64 >= INT32_MIN && i64 <= INT32_MAX) {
  68                         blobmsg_add_u32(b, name, (uint32_t)i64);
  69                 } else {
  70                         blobmsg_add_u64(b, name, (uint64_t)i64);
  71                 }
  72                 break;
  73         }
  74         case json_type_double:
  75                 blobmsg_add_double(b, name, json_object_get_double(obj));
  76                 break;
  77         case json_type_null:
  78                 blobmsg_add_field(b, BLOBMSG_TYPE_UNSPEC, name, NULL, 0);
  79                 break;
  80         default:
  81                 return false;
  82         }
  83         return ret;
  84 }
  85
  86 static bool __blobmsg_add_json(struct blob_buf *b, json_object *obj)
  87 {
  88         bool ret = false;
  89
  90         if (!obj)
  91                 return false;
  92
  93         if (json_object_get_type(obj) != json_type_object)
  94                 goto out;
  95
  96         ret = blobmsg_add_object(b, obj);
  97
  98 out:
  99         json_object_put(obj);
 100         return ret;
 101 }
 102
 103 bool blobmsg_add_json_from_file(struct blob_buf *b, const char *file)
 104 {
 105         return __blobmsg_add_json(b, json_object_from_file(file));
 106 }
 107
 108 bool blobmsg_add_json_from_string(struct blob_buf *b, const char *str)
 109 {
 110         return __blobmsg_add_json(b, json_tokener_parse(str));
 111 }
 112
 113
 114 struct strbuf {
 115         int len;
 116         int pos;
 117         char *buf;
 118
 119         blobmsg_json_format_t custom_format;
 120         void *priv;
 121         bool indent;
 122         int indent_level;
 123 };
 124
 125 static bool blobmsg_puts(struct strbuf *s, const char *c, int len)
 126 {
 127         size_t new_len;
 128         char *new_buf;
 129
 130         if (len <= 0)
 131                 return true;
 132
 133         if (s->pos + len >= s->len) {
 134                 new_len = s->len + 16 + len;
 135                 new_buf = realloc(s->buf, new_len);
 136                 if (!new_buf)
 137                         return false;
 138
 139                 s->len = new_len;
 140                 s->buf = new_buf;
 141         }
 142
 143         memcpy(s->buf + s->pos, c, len);
 144         s->pos += len;
 145         return true;
 146 }
 147
 148 static void add_separator(struct strbuf *s)
 149 {
 150         const char indent_chars[] = "\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t";
 151         size_t len;
 152
 153         if (!s->indent)
 154                 return;
 155
 156         len = s->indent_level + 1;
 157         if (len > sizeof(indent_chars) - 1)
 158                 len = sizeof(indent_chars) - 1;
 159
 160         blobmsg_puts(s, indent_chars, len);
 161 }
 162
 163
 164 static void blobmsg_format_string(struct strbuf *s, const char *str)
 165 {
 166         const unsigned char *p, *last, *end;
 167         char buf[8] = "\\u00";
 168
 169         end = (unsigned char *) str + strlen(str);
 170         blobmsg_puts(s, "\"", 1);
 171         for (p = (unsigned char *) str, last = p; *p; p++) {
 172                 char escape = '\0';
 173                 int len;
 174
 175                 switch(*p) {
 176                 case '\b':
 177                         escape = 'b';
 178                         break;
 179                 case '\n':
 180                         escape = 'n';
 181                         break;
 182                 case '\t':
 183                         escape = 't';
 184                         break;
 185                 case '\r':
 186                         escape = 'r';
 187                         break;
 188                 case '"':
 189                 case '\\':
 190                         escape = *p;
 191                         break;
 192                 default:
 193                         if (*p < ' ')
 194                                 escape = 'u';
 195                         break;
 196                 }
 197
 198                 if (!escape)
 199                         continue;
 200
 201                 if (p > last)
 202                         blobmsg_puts(s, (char *) last, p - last);
 203                 last = p + 1;
 204                 buf[1] = escape;
 205
 206                 if (escape == 'u') {
 207                         snprintf(buf + 4, sizeof(buf) - 4, "%02x", (unsigned char) *p);
 208                         len = 6;
 209                 } else {
 210                         len = 2;
 211                 }
 212                 blobmsg_puts(s, buf, len);
 213         }
 214
 215         blobmsg_puts(s, (char *) last, end - last);
 216         blobmsg_puts(s, "\"", 1);
 217 }
 218
 219 static void blobmsg_format_json_list(struct strbuf *s, struct blob_attr *attr, int len, bool array);
 220
 221 static void blobmsg_format_element(struct strbuf *s, struct blob_attr *attr, bool without_name, bool head)
 222 {
 223         const char *data_str;
 224         char buf[317];
 225         void *data;
 226         int len;
 227
 228         if (!blobmsg_check_attr(attr, false))
 229                 return;
 230
 231         if (!without_name && blobmsg_name(attr)[0]) {
 232                 blobmsg_format_string(s, blobmsg_name(attr));
 233                 blobmsg_puts(s, ": ", s->indent ? 2 : 1);
 234         }
 235
 236         data = blobmsg_data(attr);
 237         len = blobmsg_data_len(attr);
 238
 239         if (!head && s->custom_format) {
 240                 data_str = s->custom_format(s->priv, attr);
 241                 if (data_str)
 242                         goto out;
 243         }
 244
 245         data_str = buf;
 246         switch(blob_id(attr)) {
 247         case BLOBMSG_TYPE_UNSPEC:
 248                 snprintf(buf, sizeof(buf), "null");
 249                 break;
 250         case BLOBMSG_TYPE_BOOL:
 251                 snprintf(buf, sizeof(buf), "%s", *(uint8_t *)data ? "true" : "false");
 252                 break;
 253         case BLOBMSG_TYPE_INT16:
 254                 snprintf(buf, sizeof(buf), "%" PRId16, (int16_t) be16_to_cpu(*(uint16_t *)data));
 255                 break;
 256         case BLOBMSG_TYPE_INT32:
 257                 snprintf(buf, sizeof(buf), "%" PRId32, (int32_t) be32_to_cpu(*(uint32_t *)data));
 258                 break;
 259         case BLOBMSG_TYPE_INT64:
 260                 snprintf(buf, sizeof(buf), "%" PRId64, (int64_t) be64_to_cpu(*(uint64_t *)data));
 261                 break;
 262         case BLOBMSG_TYPE_DOUBLE:
 263                 snprintf(buf, sizeof(buf), "%lf", blobmsg_get_double(attr));
 264                 break;
 265         case BLOBMSG_TYPE_STRING:
 266                 blobmsg_format_string(s, data);
 267                 return;
 268         case BLOBMSG_TYPE_ARRAY:
 269                 blobmsg_format_json_list(s, data, len, true);
 270                 return;
 271         case BLOBMSG_TYPE_TABLE:
 272                 blobmsg_format_json_list(s, data, len, false);
 273                 return;
 274         }
 275
 276 out:
 277         blobmsg_puts(s, data_str, strlen(data_str));
 278 }
 279
 280 static void blobmsg_format_json_list(struct strbuf *s, struct blob_attr *attr, int len, bool array)
 281 {
 282         struct blob_attr *pos;
 283         bool first = true;
 284         size_t rem = len;
 285
 286         blobmsg_puts(s, (array ? "[" : "{" ), 1);
 287         s->indent_level++;
 288         add_separator(s);
 289         __blob_for_each_attr(pos, attr, rem) {
 290                 if (!first) {
 291                         blobmsg_puts(s, ",", 1);
 292                         add_separator(s);
 293                 }
 294
 295                 blobmsg_format_element(s, pos, array, false);
 296                 first = false;
 297         }
 298         s->indent_level--;
 299         add_separator(s);
 300         blobmsg_puts(s, (array ? "]" : "}"), 1);
 301 }
 302
 303 static void setup_strbuf(struct strbuf *s, struct blob_attr *attr, blobmsg_json_format_t cb, void *priv, int indent)
 304 {
 305         s->len = blob_len(attr);
 306         s->buf = malloc(s->len);
 307         s->pos = 0;
 308         s->custom_format = cb;
 309         s->priv = priv;
 310         s->indent = false;
 311
 312         if (indent >= 0) {
 313                 s->indent = true;
 314                 s->indent_level = indent;
 315         }
 316 }
 317
 318 char *blobmsg_format_json_with_cb(struct blob_attr *attr, bool list, blobmsg_json_format_t cb, void *priv, int indent)
 319 {
 320         struct strbuf s = {0};
 321         bool array;
 322         char *ret;
 323
 324         setup_strbuf(&s, attr, cb, priv, indent);
 325         if (!s.buf)
 326                 return NULL;
 327
 328         array = blob_is_extended(attr) &&
 329                 blobmsg_type(attr) == BLOBMSG_TYPE_ARRAY;
 330
 331         if (list)
 332                 blobmsg_format_json_list(&s, blobmsg_data(attr), blobmsg_data_len(attr), array);
 333         else
 334                 blobmsg_format_element(&s, attr, false, false);
 335
 336         if (!s.len) {
 337                 free(s.buf);
 338                 return NULL;
 339         }
 340
 341         ret = realloc(s.buf, s.pos + 1);
 342         if (!ret) {
 343                 free(s.buf);
 344                 return NULL;
 345         }
 346
 347         ret[s.pos] = 0;
 348
 349         return ret;
 350 }
 351
 352 char *blobmsg_format_json_value_with_cb(struct blob_attr *attr, blobmsg_json_format_t cb, void *priv, int indent)
 353 {
 354         struct strbuf s = {0};
 355         char *ret;
 356
 357         setup_strbuf(&s, attr, cb, priv, indent);
 358         if (!s.buf)
 359                 return NULL;
 360
 361         blobmsg_format_element(&s, attr, true, false);
 362
 363         if (!s.len) {
 364                 free(s.buf);
 365                 return NULL;
 366         }
 367
 368         ret = realloc(s.buf, s.pos + 1);
 369         if (!ret) {
 370                 free(s.buf);
 371                 return NULL;
 372         }
 373
 374         ret[s.pos] = 0;
 375
 376         return ret;
 377 }