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         if (!obj)
  53                 return false;
  54
  55         switch (json_object_get_type(obj)) {
  56         case json_type_object:
  57                 c = blobmsg_open_table(b, name);
  58                 ret = blobmsg_add_object(b, obj);
  59                 blobmsg_close_table(b, c);
  60                 break;
  61         case json_type_array:
  62                 c = blobmsg_open_array(b, name);
  63                 ret = blobmsg_add_array(b, json_object_get_array(obj));
  64                 blobmsg_close_array(b, c);
  65                 break;
  66         case json_type_string:
  67                 blobmsg_add_string(b, name, json_object_get_string(obj));
  68                 break;
  69         case json_type_boolean:
  70                 blobmsg_add_u8(b, name, json_object_get_boolean(obj));
  71                 break;
  72         case json_type_int:
  73                 blobmsg_add_u32(b, name, json_object_get_int(obj));
  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         static char indent_chars[17] = "\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t";
 139         int indent;
 140         char *start;
 141
 142         if (!s->indent)
 143                 return;
 144
 145         indent = s->indent_level;
 146         if (indent > 16)
 147                 indent = 16;
 148
 149         start = &indent_chars[sizeof(indent_chars) - indent - 1];
 150         *start = '\n';
 151         blobmsg_puts(s, start, indent + 1);
 152         *start = '\t';
 153 }
 154
 155
 156 static void blobmsg_format_string(struct strbuf *s, const char *str)
 157 {
 158         const unsigned char *p, *last, *end;
 159         char buf[8] = "\\u00";
 160
 161         end = (unsigned char *) str + strlen(str);
 162         blobmsg_puts(s, "\"", 1);
 163         for (p = (unsigned char *) str, last = p; *p; p++) {
 164                 char escape = '\0';
 165                 int len;
 166
 167                 switch(*p) {
 168                 case '\b':
 169                         escape = 'b';
 170                         break;
 171                 case '\n':
 172                         escape = 'n';
 173                         break;
 174                 case '\t':
 175                         escape = 't';
 176                         break;
 177                 case '\r':
 178                         escape = 'r';
 179                         break;
 180                 case '"':
 181                 case '\\':
 182                 case '/':
 183                         escape = *p;
 184                         break;
 185                 default:
 186                         if (*p < ' ')
 187                                 escape = 'u';
 188                         break;
 189                 }
 190
 191                 if (!escape)
 192                         continue;
 193
 194                 if (p > last)
 195                         blobmsg_puts(s, (char *) last, p - last);
 196                 last = p + 1;
 197                 buf[1] = escape;
 198
 199                 if (escape == 'u') {
 200                         sprintf(buf + 4, "%02x", (unsigned char) *p);
 201                         len = 6;
 202                 } else {
 203                         len = 2;
 204                 }
 205                 blobmsg_puts(s, buf, len);
 206         }
 207
 208         blobmsg_puts(s, (char *) last, end - last);
 209         blobmsg_puts(s, "\"", 1);
 210 }
 211
 212 static void blobmsg_format_json_list(struct strbuf *s, struct blob_attr *attr, int len, bool array);
 213
 214 static void blobmsg_format_element(struct strbuf *s, struct blob_attr *attr, bool array, bool head)
 215 {
 216         const char *data_str;
 217         char buf[32];
 218         void *data;
 219         int len;
 220
 221         if (!blobmsg_check_attr(attr, false))
 222                 return;
 223
 224         if (!array && blobmsg_name(attr)[0]) {
 225                 blobmsg_format_string(s, blobmsg_name(attr));
 226                 blobmsg_puts(s, ": ", s->indent ? 2 : 1);
 227         }
 228
 229         data = blobmsg_data(attr);
 230         len = blobmsg_data_len(attr);
 231
 232         if (!head && s->custom_format) {
 233                 data_str = s->custom_format(s->priv, attr);
 234                 if (data_str)
 235                         goto out;
 236         }
 237
 238         data_str = buf;
 239         switch(blob_id(attr)) {
 240         case BLOBMSG_TYPE_UNSPEC:
 241                 sprintf(buf, "null");
 242                 break;
 243         case BLOBMSG_TYPE_BOOL:
 244                 sprintf(buf, "%s", *(uint8_t *)data ? "true" : "false");
 245                 break;
 246         case BLOBMSG_TYPE_INT16:
 247                 sprintf(buf, "%d", be16_to_cpu(*(uint16_t *)data));
 248                 break;
 249         case BLOBMSG_TYPE_INT32:
 250                 sprintf(buf, "%d", (int32_t) be32_to_cpu(*(uint32_t *)data));
 251                 break;
 252         case BLOBMSG_TYPE_INT64:
 253                 sprintf(buf, "%" PRId64, (int64_t) be64_to_cpu(*(uint64_t *)data));
 254                 break;
 255         case BLOBMSG_TYPE_STRING:
 256                 blobmsg_format_string(s, data);
 257                 return;
 258         case BLOBMSG_TYPE_ARRAY:
 259                 blobmsg_format_json_list(s, data, len, true);
 260                 return;
 261         case BLOBMSG_TYPE_TABLE:
 262                 blobmsg_format_json_list(s, data, len, false);
 263                 return;
 264         }
 265
 266 out:
 267         blobmsg_puts(s, data_str, strlen(data_str));
 268 }
 269
 270 static void blobmsg_format_json_list(struct strbuf *s, struct blob_attr *attr, int len, bool array)
 271 {
 272         struct blob_attr *pos;
 273         bool first = true;
 274         int rem = len;
 275
 276         blobmsg_puts(s, (array ? "[" : "{" ), 1);
 277         s->indent_level++;
 278         add_separator(s);
 279         __blob_for_each_attr(pos, attr, rem) {
 280                 if (!first) {
 281                         blobmsg_puts(s, ",", 1);
 282                         add_separator(s);
 283                 }
 284
 285                 blobmsg_format_element(s, pos, array, false);
 286                 first = false;
 287         }
 288         s->indent_level--;
 289         add_separator(s);
 290         blobmsg_puts(s, (array ? "]" : "}"), 1);
 291 }
 292
 293 char *blobmsg_format_json_with_cb(struct blob_attr *attr, bool list, blobmsg_json_format_t cb, void *priv, int indent)
 294 {
 295         struct strbuf s;
 296         bool array;
 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         array = blob_is_extended(attr) &&
 311                 blobmsg_type(attr) == BLOBMSG_TYPE_ARRAY;
 312
 313         if (list)
 314                 blobmsg_format_json_list(&s, blobmsg_data(attr), blobmsg_data_len(attr), array);
 315         else
 316                 blobmsg_format_element(&s, attr, false, false);
 317
 318         if (!s.len) {
 319                 free(s.buf);
 320                 return NULL;
 321         }
 322
 323         s.buf = realloc(s.buf, s.pos + 1);
 324         s.buf[s.pos] = 0;
 325
 326         return s.buf;
 327 }