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