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 "blobmsg.h"
  17 #include "blobmsg_json.h"
  18
  19 bool blobmsg_add_object(struct blob_buf *b, json_object *obj)
  20 {
  21         json_object_object_foreach(obj, key, val) {
  22                 if (!blobmsg_add_json_element(b, key, val))
  23                         return false;
  24         }
  25         return true;
  26 }
  27
  28 static bool blobmsg_add_array(struct blob_buf *b, struct array_list *a)
  29 {
  30         int i, len;
  31
  32         for (i = 0, len = array_list_length(a); i < len; i++) {
  33                 if (!blobmsg_add_json_element(b, NULL, array_list_get_idx(a, i)))
  34                         return false;
  35         }
  36
  37         return true;
  38 }
  39
  40 bool blobmsg_add_json_element(struct blob_buf *b, const char *name, json_object *obj)
  41 {
  42         bool ret = true;
  43         void *c;
  44
  45         if (!obj)
  46                 return false;
  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                 blobmsg_add_u32(b, name, json_object_get_int(obj));
  67                 break;
  68         default:
  69                 return false;
  70         }
  71         return ret;
  72 }
  73
  74 static bool __blobmsg_add_json(struct blob_buf *b, json_object *obj)
  75 {
  76         bool ret = false;
  77
  78         if (is_error(obj))
  79                 return false;
  80
  81         if (json_object_get_type(obj) != json_type_object)
  82                 goto out;
  83
  84         ret = blobmsg_add_object(b, obj);
  85
  86 out:
  87         json_object_put(obj);
  88         return ret;
  89 }
  90
  91 bool blobmsg_add_json_from_file(struct blob_buf *b, const char *file)
  92 {
  93         return __blobmsg_add_json(b, json_object_from_file(file));
  94 }
  95
  96 bool blobmsg_add_json_from_string(struct blob_buf *b, const char *str)
  97 {
  98         return __blobmsg_add_json(b, json_tokener_parse(str));
  99 }
 100
 101
 102 struct strbuf {
 103         int len;
 104         int pos;
 105         char *buf;
 106
 107         blobmsg_json_format_t custom_format;
 108         void *priv;
 109         bool indent;
 110         int indent_level;
 111 };
 112
 113 static bool blobmsg_puts(struct strbuf *s, const char *c, int len)
 114 {
 115         if (len <= 0)
 116                 return true;
 117
 118         if (s->pos + len >= s->len) {
 119                 s->len += 16 + len;
 120                 s->buf = realloc(s->buf, s->len);
 121                 if (!s->buf)
 122                         return false;
 123         }
 124         memcpy(s->buf + s->pos, c, len);
 125         s->pos += len;
 126         return true;
 127 }
 128
 129 static void add_separator(struct strbuf *s)
 130 {
 131         static char indent_chars[17] = "\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t";
 132         static const char indent_space = ' ';
 133         int indent;
 134         char *start;
 135
 136         if (!s->indent) {
 137                 blobmsg_puts(s, &indent_space, 1);
 138                 return;
 139         }
 140
 141         indent = s->indent_level;
 142         if (indent > 16)
 143                 indent = 16;
 144
 145         start = &indent_chars[sizeof(indent_chars) - indent - 1];
 146         *start = '\n';
 147         blobmsg_puts(s, start, indent + 1);
 148         *start = '\t';
 149 }
 150
 151
 152 static void blobmsg_format_string(struct strbuf *s, const char *str)
 153 {
 154         const char *p, *last = str, *end = str + strlen(str);
 155         char buf[8] = "\\u00";
 156
 157         blobmsg_puts(s, "\"", 1);
 158         for (p = str; *p; p++) {
 159                 char escape = '\0';
 160                 int len;
 161
 162                 switch(*p) {
 163                 case '\b':
 164                         escape = 'b';
 165                         break;
 166                 case '\n':
 167                         escape = 'n';
 168                         break;
 169                 case '\t':
 170                         escape = 't';
 171                         break;
 172                 case '\r':
 173                         escape = 'r';
 174                         break;
 175                 case '"':
 176                 case '\\':
 177                 case '/':
 178                         escape = *p;
 179                         break;
 180                 default:
 181                         if (*p < ' ')
 182                                 escape = 'u';
 183                         break;
 184                 }
 185
 186                 if (!escape)
 187                         continue;
 188
 189                 if (p > last)
 190                         blobmsg_puts(s, last, p - last);
 191                 last = p + 1;
 192                 buf[1] = escape;
 193
 194                 if (escape == 'u') {
 195                         sprintf(buf + 4, "%02x", (unsigned char) *p);
 196                         len = 4;
 197                 } else {
 198                         len = 2;
 199                 }
 200                 blobmsg_puts(s, buf, len);
 201         }
 202
 203         blobmsg_puts(s, last, end - last);
 204         blobmsg_puts(s, "\"", 1);
 205 }
 206
 207 static void blobmsg_format_json_list(struct strbuf *s, struct blob_attr *attr, int len, bool array);
 208
 209 static void blobmsg_format_element(struct strbuf *s, struct blob_attr *attr, bool array, bool head)
 210 {
 211         const char *data_str;
 212         char buf[32];
 213         void *data;
 214         int len;
 215
 216         if (!blobmsg_check_attr(attr, false))
 217                 return;
 218
 219         if (!array && blobmsg_name(attr)[0]) {
 220                 blobmsg_format_string(s, blobmsg_name(attr));
 221                 blobmsg_puts(s, ": ", 2);
 222         }
 223         if (head) {
 224                 data = blob_data(attr);
 225                 len = blob_len(attr);
 226         } else {
 227                 data = blobmsg_data(attr);
 228                 len = blobmsg_data_len(attr);
 229
 230                 if (s->custom_format) {
 231                         data_str = s->custom_format(s->priv, attr);
 232                         if (data_str)
 233                                 goto out;
 234                 }
 235         }
 236
 237         data_str = buf;
 238         switch(blob_id(attr)) {
 239         case BLOBMSG_TYPE_UNSPEC:
 240                 sprintf(buf, "null");
 241                 break;
 242         case BLOBMSG_TYPE_BOOL:
 243                 sprintf(buf, "%s", *(uint8_t *)data ? "true" : "false");
 244                 break;
 245         case BLOBMSG_TYPE_INT16:
 246                 sprintf(buf, "%d", be16_to_cpu(*(uint16_t *)data));
 247                 break;
 248         case BLOBMSG_TYPE_INT32:
 249                 sprintf(buf, "%d", be32_to_cpu(*(uint32_t *)data));
 250                 break;
 251         case BLOBMSG_TYPE_INT64:
 252                 sprintf(buf, "%lld", (long long int) be64_to_cpu(*(uint64_t *)data));
 253                 break;
 254         case BLOBMSG_TYPE_STRING:
 255                 blobmsg_format_string(s, data);
 256                 return;
 257         case BLOBMSG_TYPE_ARRAY:
 258                 blobmsg_format_json_list(s, data, len, true);
 259                 return;
 260         case BLOBMSG_TYPE_TABLE:
 261                 blobmsg_format_json_list(s, data, len, false);
 262                 return;
 263         }
 264
 265 out:
 266         blobmsg_puts(s, data_str, strlen(data_str));
 267 }
 268
 269 static void blobmsg_format_json_list(struct strbuf *s, struct blob_attr *attr, int len, bool array)
 270 {
 271         struct blob_attr *pos;
 272         bool first = true;
 273         int rem = len;
 274
 275         blobmsg_puts(s, (array ? "[" : "{" ), 1);
 276         s->indent_level++;
 277         add_separator(s);
 278         __blob_for_each_attr(pos, attr, rem) {
 279                 if (!first) {
 280                         blobmsg_puts(s, ",", 1);
 281                         add_separator(s);
 282                 }
 283
 284                 blobmsg_format_element(s, pos, array, false);
 285                 first = false;
 286         }
 287         s->indent_level--;
 288         add_separator(s);
 289         blobmsg_puts(s, (array ? "]" : "}"), 1);
 290 }
 291
 292 char *blobmsg_format_json_with_cb(struct blob_attr *attr, bool list, blobmsg_json_format_t cb, void *priv, int indent)
 293 {
 294         struct strbuf s;
 295
 296         s.len = blob_len(attr);
 297         s.buf = malloc(s.len);
 298         s.pos = 0;
 299         s.custom_format = cb;
 300         s.priv = priv;
 301         s.indent = false;
 302
 303         if (indent >= 0) {
 304                 s.indent = true;
 305                 s.indent_level = indent;
 306         }
 307
 308         if (list)
 309                 blobmsg_format_json_list(&s, blob_data(attr), blob_len(attr), false);
 310         else
 311                 blobmsg_format_element(&s, attr, false, false);
 312
 313         if (!s.len)
 314                 return NULL;
 315
 316         s.buf = realloc(s.buf, s.pos + 1);
 317         s.buf[s.pos] = 0;
 318
 319         return s.buf;
 320 }