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         size_t new_len;
 123         char *new_buf;
 124
 125         if (len <= 0)
 126                 return true;
 127
 128         if (s->pos + len >= s->len) {
 129                 new_len = s->len + 16 + len;
 130                 new_buf = realloc(s->buf, new_len);
 131                 if (!new_buf)
 132                         return false;
 133
 134                 s->len = new_len;
 135                 s->buf = new_buf;
 136         }
 137
 138         memcpy(s->buf + s->pos, c, len);
 139         s->pos += len;
 140         return true;
 141 }
 142
 143 static void add_separator(struct strbuf *s)
 144 {
 145         const char *indent_chars = "\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t";
 146         int len;
 147
 148         if (!s->indent)
 149                 return;
 150
 151         len = s->indent_level + 1;
 152         if (len > strlen(indent_chars))
 153                 len = strlen(indent_chars);
 154
 155         blobmsg_puts(s, indent_chars, len);
 156 }
 157
 158
 159 static void blobmsg_format_string(struct strbuf *s, const char *str)
 160 {
 161         const unsigned char *p, *last, *end;
 162         char buf[8] = "\\u00";
 163
 164         end = (unsigned char *) str + strlen(str);
 165         blobmsg_puts(s, "\"", 1);
 166         for (p = (unsigned char *) str, last = p; *p; p++) {
 167                 char escape = '\0';
 168                 int len;
 169
 170                 switch(*p) {
 171                 case '\b':
 172                         escape = 'b';
 173                         break;
 174                 case '\n':
 175                         escape = 'n';
 176                         break;
 177                 case '\t':
 178                         escape = 't';
 179                         break;
 180                 case '\r':
 181                         escape = 'r';
 182                         break;
 183                 case '"':
 184                 case '\\':
 185                 case '/':
 186                         escape = *p;
 187                         break;
 188                 default:
 189                         if (*p < ' ')
 190                                 escape = 'u';
 191                         break;
 192                 }
 193
 194                 if (!escape)
 195                         continue;
 196
 197                 if (p > last)
 198                         blobmsg_puts(s, (char *) last, p - last);
 199                 last = p + 1;
 200                 buf[1] = escape;
 201
 202                 if (escape == 'u') {
 203                         sprintf(buf + 4, "%02x", (unsigned char) *p);
 204                         len = 6;
 205                 } else {
 206                         len = 2;
 207                 }
 208                 blobmsg_puts(s, buf, len);
 209         }
 210
 211         blobmsg_puts(s, (char *) last, end - last);
 212         blobmsg_puts(s, "\"", 1);
 213 }
 214
 215 static void blobmsg_format_json_list(struct strbuf *s, struct blob_attr *attr, int len, bool array);
 216
 217 static void blobmsg_format_element(struct strbuf *s, struct blob_attr *attr, bool without_name, bool head)
 218 {
 219         const char *data_str;
 220         char buf[32];
 221         void *data;
 222         int len;
 223
 224         if (!blobmsg_check_attr(attr, false))
 225                 return;
 226
 227         if (!without_name && blobmsg_name(attr)[0]) {
 228                 blobmsg_format_string(s, blobmsg_name(attr));
 229                 blobmsg_puts(s, ": ", s->indent ? 2 : 1);
 230         }
 231
 232         data = blobmsg_data(attr);
 233         len = blobmsg_data_len(attr);
 234
 235         if (!head && s->custom_format) {
 236                 data_str = s->custom_format(s->priv, attr);
 237                 if (data_str)
 238                         goto out;
 239         }
 240
 241         data_str = buf;
 242         switch(blob_id(attr)) {
 243         case BLOBMSG_TYPE_UNSPEC:
 244                 sprintf(buf, "null");
 245                 break;
 246         case BLOBMSG_TYPE_BOOL:
 247                 sprintf(buf, "%s", *(uint8_t *)data ? "true" : "false");
 248                 break;
 249         case BLOBMSG_TYPE_INT16:
 250                 sprintf(buf, "%d", be16_to_cpu(*(uint16_t *)data));
 251                 break;
 252         case BLOBMSG_TYPE_INT32:
 253                 sprintf(buf, "%d", (int32_t) be32_to_cpu(*(uint32_t *)data));
 254                 break;
 255         case BLOBMSG_TYPE_INT64:
 256                 sprintf(buf, "%" PRId64, (int64_t) be64_to_cpu(*(uint64_t *)data));
 257                 break;
 258         case BLOBMSG_TYPE_STRING:
 259                 blobmsg_format_string(s, data);
 260                 return;
 261         case BLOBMSG_TYPE_ARRAY:
 262                 blobmsg_format_json_list(s, data, len, true);
 263                 return;
 264         case BLOBMSG_TYPE_TABLE:
 265                 blobmsg_format_json_list(s, data, len, false);
 266                 return;
 267         }
 268
 269 out:
 270         blobmsg_puts(s, data_str, strlen(data_str));
 271 }
 272
 273 static void blobmsg_format_json_list(struct strbuf *s, struct blob_attr *attr, int len, bool array)
 274 {
 275         struct blob_attr *pos;
 276         bool first = true;
 277         int rem = len;
 278
 279         blobmsg_puts(s, (array ? "[" : "{" ), 1);
 280         s->indent_level++;
 281         add_separator(s);
 282         __blob_for_each_attr(pos, attr, rem) {
 283                 if (!first) {
 284                         blobmsg_puts(s, ",", 1);
 285                         add_separator(s);
 286                 }
 287
 288                 blobmsg_format_element(s, pos, array, false);
 289                 first = false;
 290         }
 291         s->indent_level--;
 292         add_separator(s);
 293         blobmsg_puts(s, (array ? "]" : "}"), 1);
 294 }
 295
 296 static void setup_strbuf(struct strbuf *s, struct blob_attr *attr, blobmsg_json_format_t cb, void *priv, int indent)
 297 {
 298         s->len = blob_len(attr);
 299         s->buf = malloc(s->len);
 300         s->pos = 0;
 301         s->custom_format = cb;
 302         s->priv = priv;
 303         s->indent = false;
 304
 305         if (indent >= 0) {
 306                 s->indent = true;
 307                 s->indent_level = indent;
 308         }
 309 }
 310
 311 char *blobmsg_format_json_with_cb(struct blob_attr *attr, bool list, blobmsg_json_format_t cb, void *priv, int indent)
 312 {
 313         struct strbuf s;
 314         bool array;
 315         char *ret;
 316
 317         setup_strbuf(&s, attr, cb, priv, indent);
 318         if (!s.buf)
 319                 return NULL;
 320
 321         array = blob_is_extended(attr) &&
 322                 blobmsg_type(attr) == BLOBMSG_TYPE_ARRAY;
 323
 324         if (list)
 325                 blobmsg_format_json_list(&s, blobmsg_data(attr), blobmsg_data_len(attr), array);
 326         else
 327                 blobmsg_format_element(&s, attr, false, false);
 328
 329         if (!s.len) {
 330                 free(s.buf);
 331                 return NULL;
 332         }
 333
 334         ret = realloc(s.buf, s.pos + 1);
 335         if (!ret) {
 336                 free(s.buf);
 337                 return NULL;
 338         }
 339
 340         ret[s.pos] = 0;
 341
 342         return ret;
 343 }
 344
 345 char *blobmsg_format_json_value_with_cb(struct blob_attr *attr, blobmsg_json_format_t cb, void *priv, int indent)
 346 {
 347         struct strbuf s;
 348         char *ret;
 349
 350         setup_strbuf(&s, attr, cb, priv, indent);
 351         if (!s.buf)
 352                 return NULL;
 353
 354         blobmsg_format_element(&s, attr, true, false);
 355
 356         if (!s.len) {
 357                 free(s.buf);
 358                 return NULL;
 359         }
 360
 361         ret = realloc(s.buf, s.pos + 1);
 362         if (!ret) {
 363                 free(s.buf);
 364                 return NULL;
 365         }
 366
 367         ret[s.pos] = 0;
 368
 369         return ret;
 370 }