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                 int64_t i64 = json_object_get_int64(obj);
  71                 if (i64 >= INT32_MIN && i64 <= INT32_MAX) {
  72                         blobmsg_add_u32(b, name, (uint32_t)i64);
  73                 } else {
  74                         blobmsg_add_u64(b, name, (uint64_t)i64);
  75                 }
  76                 break;
  77         }
  78         case json_type_double:
  79                 blobmsg_add_double(b, name, json_object_get_double(obj));
  80                 break;
  81         case json_type_null:
  82                 blobmsg_add_field(b, BLOBMSG_TYPE_UNSPEC, name, NULL, 0);
  83                 break;
  84         default:
  85                 return false;
  86         }
  87         return ret;
  88 }
  89
  90 static bool __blobmsg_add_json(struct blob_buf *b, json_object *obj)
  91 {
  92         bool ret = false;
  93
  94         if (!obj)
  95                 return false;
  96
  97         if (json_object_get_type(obj) != json_type_object)
  98                 goto out;
  99
 100         ret = blobmsg_add_object(b, obj);
 101
 102 out:
 103         json_object_put(obj);
 104         return ret;
 105 }
 106
 107 bool blobmsg_add_json_from_file(struct blob_buf *b, const char *file)
 108 {
 109         return __blobmsg_add_json(b, json_object_from_file(file));
 110 }
 111
 112 bool blobmsg_add_json_from_string(struct blob_buf *b, const char *str)
 113 {
 114         return __blobmsg_add_json(b, json_tokener_parse(str));
 115 }
 116
 117
 118 struct strbuf {
 119         int len;
 120         int pos;
 121         char *buf;
 122
 123         blobmsg_json_format_t custom_format;
 124         void *priv;
 125         bool indent;
 126         int indent_level;
 127 };
 128
 129 static bool blobmsg_puts(struct strbuf *s, const char *c, int len)
 130 {
 131         size_t new_len;
 132         char *new_buf;
 133
 134         if (len <= 0)
 135                 return true;
 136
 137         if (s->pos + len >= s->len) {
 138                 new_len = s->len + 16 + len;
 139                 new_buf = realloc(s->buf, new_len);
 140                 if (!new_buf)
 141                         return false;
 142
 143                 s->len = new_len;
 144                 s->buf = new_buf;
 145         }
 146
 147         memcpy(s->buf + s->pos, c, len);
 148         s->pos += len;
 149         return true;
 150 }
 151
 152 static void add_separator(struct strbuf *s)
 153 {
 154         const char *indent_chars = "\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t";
 155         size_t len;
 156
 157         if (!s->indent)
 158                 return;
 159
 160         len = s->indent_level + 1;
 161         if (len > strlen(indent_chars))
 162                 len = strlen(indent_chars);
 163
 164         blobmsg_puts(s, indent_chars, len);
 165 }
 166
 167
 168 static void blobmsg_format_string(struct strbuf *s, const char *str)
 169 {
 170         const unsigned char *p, *last, *end;
 171         char buf[8] = "\\u00";
 172
 173         end = (unsigned char *) str + strlen(str);
 174         blobmsg_puts(s, "\"", 1);
 175         for (p = (unsigned char *) str, last = p; *p; p++) {
 176                 char escape = '\0';
 177                 int len;
 178
 179                 switch(*p) {
 180                 case '\b':
 181                         escape = 'b';
 182                         break;
 183                 case '\n':
 184                         escape = 'n';
 185                         break;
 186                 case '\t':
 187                         escape = 't';
 188                         break;
 189                 case '\r':
 190                         escape = 'r';
 191                         break;
 192                 case '"':
 193                 case '\\':
 194                         escape = *p;
 195                         break;
 196                 default:
 197                         if (*p < ' ')
 198                                 escape = 'u';
 199                         break;
 200                 }
 201
 202                 if (!escape)
 203                         continue;
 204
 205                 if (p > last)
 206                         blobmsg_puts(s, (char *) last, p - last);
 207                 last = p + 1;
 208                 buf[1] = escape;
 209
 210                 if (escape == 'u') {
 211                         snprintf(buf + 4, sizeof(buf) - 4, "%02x", (unsigned char) *p);
 212                         len = 6;
 213                 } else {
 214                         len = 2;
 215                 }
 216                 blobmsg_puts(s, buf, len);
 217         }
 218
 219         blobmsg_puts(s, (char *) last, end - last);
 220         blobmsg_puts(s, "\"", 1);
 221 }
 222
 223 static void blobmsg_format_json_list(struct strbuf *s, struct blob_attr *attr, int len, bool array);
 224
 225 static void blobmsg_format_element(struct strbuf *s, struct blob_attr *attr, bool without_name, bool head)
 226 {
 227         const char *data_str;
 228         char buf[317];
 229         void *data;
 230         int len;
 231
 232         if (!blobmsg_check_attr(attr, false))
 233                 return;
 234
 235         if (!without_name && blobmsg_name(attr)[0]) {
 236                 blobmsg_format_string(s, blobmsg_name(attr));
 237                 blobmsg_puts(s, ": ", s->indent ? 2 : 1);
 238         }
 239
 240         data = blobmsg_data(attr);
 241         len = blobmsg_data_len(attr);
 242
 243         if (!head && s->custom_format) {
 244                 data_str = s->custom_format(s->priv, attr);
 245                 if (data_str)
 246                         goto out;
 247         }
 248
 249         data_str = buf;
 250         switch(blob_id(attr)) {
 251         case BLOBMSG_TYPE_UNSPEC:
 252                 snprintf(buf, sizeof(buf), "null");
 253                 break;
 254         case BLOBMSG_TYPE_BOOL:
 255                 snprintf(buf, sizeof(buf), "%s", *(uint8_t *)data ? "true" : "false");
 256                 break;
 257         case BLOBMSG_TYPE_INT16:
 258                 snprintf(buf, sizeof(buf), "%" PRId16, (int16_t) be16_to_cpu(*(uint16_t *)data));
 259                 break;
 260         case BLOBMSG_TYPE_INT32:
 261                 snprintf(buf, sizeof(buf), "%" PRId32, (int32_t) be32_to_cpu(*(uint32_t *)data));
 262                 break;
 263         case BLOBMSG_TYPE_INT64:
 264                 snprintf(buf, sizeof(buf), "%" PRId64, (int64_t) be64_to_cpu(*(uint64_t *)data));
 265                 break;
 266         case BLOBMSG_TYPE_DOUBLE:
 267                 snprintf(buf, sizeof(buf), "%lf", blobmsg_get_double(attr));
 268                 break;
 269         case BLOBMSG_TYPE_STRING:
 270                 blobmsg_format_string(s, data);
 271                 return;
 272         case BLOBMSG_TYPE_ARRAY:
 273                 blobmsg_format_json_list(s, data, len, true);
 274                 return;
 275         case BLOBMSG_TYPE_TABLE:
 276                 blobmsg_format_json_list(s, data, len, false);
 277                 return;
 278         }
 279
 280 out:
 281         blobmsg_puts(s, data_str, strlen(data_str));
 282 }
 283
 284 static void blobmsg_format_json_list(struct strbuf *s, struct blob_attr *attr, int len, bool array)
 285 {
 286         struct blob_attr *pos;
 287         bool first = true;
 288         size_t rem = len;
 289
 290         blobmsg_puts(s, (array ? "[" : "{" ), 1);
 291         s->indent_level++;
 292         add_separator(s);
 293         __blob_for_each_attr(pos, attr, rem) {
 294                 if (!first) {
 295                         blobmsg_puts(s, ",", 1);
 296                         add_separator(s);
 297                 }
 298
 299                 blobmsg_format_element(s, pos, array, false);
 300                 first = false;
 301         }
 302         s->indent_level--;
 303         add_separator(s);
 304         blobmsg_puts(s, (array ? "]" : "}"), 1);
 305 }
 306
 307 static void setup_strbuf(struct strbuf *s, struct blob_attr *attr, blobmsg_json_format_t cb, void *priv, int indent)
 308 {
 309         s->len = blob_len(attr);
 310         s->buf = malloc(s->len);
 311         s->pos = 0;
 312         s->custom_format = cb;
 313         s->priv = priv;
 314         s->indent = false;
 315
 316         if (indent >= 0) {
 317                 s->indent = true;
 318                 s->indent_level = indent;
 319         }
 320 }
 321
 322 char *blobmsg_format_json_with_cb(struct blob_attr *attr, bool list, blobmsg_json_format_t cb, void *priv, int indent)
 323 {
 324         struct strbuf s = {0};
 325         bool array;
 326         char *ret;
 327
 328         setup_strbuf(&s, attr, cb, priv, indent);
 329         if (!s.buf)
 330                 return NULL;
 331
 332         array = blob_is_extended(attr) &&
 333                 blobmsg_type(attr) == BLOBMSG_TYPE_ARRAY;
 334
 335         if (list)
 336                 blobmsg_format_json_list(&s, blobmsg_data(attr), blobmsg_data_len(attr), array);
 337         else
 338                 blobmsg_format_element(&s, attr, false, false);
 339
 340         if (!s.len) {
 341                 free(s.buf);
 342                 return NULL;
 343         }
 344
 345         ret = realloc(s.buf, s.pos + 1);
 346         if (!ret) {
 347                 free(s.buf);
 348                 return NULL;
 349         }
 350
 351         ret[s.pos] = 0;
 352
 353         return ret;
 354 }
 355
 356 char *blobmsg_format_json_value_with_cb(struct blob_attr *attr, blobmsg_json_format_t cb, void *priv, int indent)
 357 {
 358         struct strbuf s = {0};
 359         char *ret;
 360
 361         setup_strbuf(&s, attr, cb, priv, indent);
 362         if (!s.buf)
 363                 return NULL;
 364
 365         blobmsg_format_element(&s, attr, true, false);
 366
 367         if (!s.len) {
 368                 free(s.buf);
 369                 return NULL;
 370         }
 371
 372         ret = realloc(s.buf, s.pos + 1);
 373         if (!ret) {
 374                 free(s.buf);
 375                 return NULL;
 376         }
 377
 378         ret[s.pos] = 0;
 379
 380         return ret;
 381 }