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 bool blobmsg_add_object(struct blob_buf *b, json_object *obj)
  21 {
  22         json_object_object_foreach(obj, key, val) {
  23                 if (!blobmsg_add_json_element(b, key, val))
  24                         return false;
  25         }
  26         return true;
  27 }
  28
  29 static bool blobmsg_add_array(struct blob_buf *b, struct array_list *a)
  30 {
  31         int i, len;
  32
  33         for (i = 0, len = array_list_length(a); i < len; i++) {
  34                 if (!blobmsg_add_json_element(b, NULL, array_list_get_idx(a, i)))
  35                         return false;
  36         }
  37
  38         return true;
  39 }
  40
  41 bool blobmsg_add_json_element(struct blob_buf *b, const char *name, json_object *obj)
  42 {
  43         bool ret = true;
  44         void *c;
  45
  46         if (!obj)
  47                 return false;
  48
  49         switch (json_object_get_type(obj)) {
  50         case json_type_object:
  51                 c = blobmsg_open_table(b, name);
  52                 ret = blobmsg_add_object(b, obj);
  53                 blobmsg_close_table(b, c);
  54                 break;
  55         case json_type_array:
  56                 c = blobmsg_open_array(b, name);
  57                 ret = blobmsg_add_array(b, json_object_get_array(obj));
  58                 blobmsg_close_array(b, c);
  59                 break;
  60         case json_type_string:
  61                 blobmsg_add_string(b, name, json_object_get_string(obj));
  62                 break;
  63         case json_type_boolean:
  64                 blobmsg_add_u8(b, name, json_object_get_boolean(obj));
  65                 break;
  66         case json_type_int:
  67                 blobmsg_add_u32(b, name, json_object_get_int(obj));
  68                 break;
  69         default:
  70                 return false;
  71         }
  72         return ret;
  73 }
  74
  75 static bool __blobmsg_add_json(struct blob_buf *b, json_object *obj)
  76 {
  77         bool ret = false;
  78
  79         if (is_error(obj))
  80                 return false;
  81
  82         if (json_object_get_type(obj) != json_type_object)
  83                 goto out;
  84
  85         ret = blobmsg_add_object(b, obj);
  86
  87 out:
  88         json_object_put(obj);
  89         return ret;
  90 }
  91
  92 bool blobmsg_add_json_from_file(struct blob_buf *b, const char *file)
  93 {
  94         return __blobmsg_add_json(b, json_object_from_file(file));
  95 }
  96
  97 bool blobmsg_add_json_from_string(struct blob_buf *b, const char *str)
  98 {
  99         return __blobmsg_add_json(b, json_tokener_parse(str));
 100 }
 101
 102
 103 struct strbuf {
 104         int len;
 105         int pos;
 106         char *buf;
 107
 108         blobmsg_json_format_t custom_format;
 109         void *priv;
 110         bool indent;
 111         int indent_level;
 112 };
 113
 114 static bool blobmsg_puts(struct strbuf *s, const char *c, int len)
 115 {
 116         if (len <= 0)
 117                 return true;
 118
 119         if (s->pos + len >= s->len) {
 120                 s->len += 16 + len;
 121                 s->buf = realloc(s->buf, s->len);
 122                 if (!s->buf)
 123                         return false;
 124         }
 125         memcpy(s->buf + s->pos, c, len);
 126         s->pos += len;
 127         return true;
 128 }
 129
 130 static void add_separator(struct strbuf *s)
 131 {
 132         static char indent_chars[17] = "\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t";
 133         int indent;
 134         char *start;
 135
 136         if (!s->indent)
 137                 return;
 138
 139         indent = s->indent_level;
 140         if (indent > 16)
 141                 indent = 16;
 142
 143         start = &indent_chars[sizeof(indent_chars) - indent - 1];
 144         *start = '\n';
 145         blobmsg_puts(s, start, indent + 1);
 146         *start = '\t';
 147 }
 148
 149
 150 static void blobmsg_format_string(struct strbuf *s, const char *str)
 151 {
 152         const unsigned char *p, *last, *end;
 153         char buf[8] = "\\u00";
 154
 155         end = (unsigned char *) str + strlen(str);
 156         blobmsg_puts(s, "\"", 1);
 157         for (p = (unsigned char *) str, last = p; *p; p++) {
 158                 char escape = '\0';
 159                 int len;
 160
 161                 switch(*p) {
 162                 case '\b':
 163                         escape = 'b';
 164                         break;
 165                 case '\n':
 166                         escape = 'n';
 167                         break;
 168                 case '\t':
 169                         escape = 't';
 170                         break;
 171                 case '\r':
 172                         escape = 'r';
 173                         break;
 174                 case '"':
 175                 case '\\':
 176                 case '/':
 177                         escape = *p;
 178                         break;
 179                 default:
 180                         if (*p < ' ')
 181                                 escape = 'u';
 182                         break;
 183                 }
 184
 185                 if (!escape)
 186                         continue;
 187
 188                 if (p > last)
 189                         blobmsg_puts(s, (char *) last, p - last);
 190                 last = p + 1;
 191                 buf[1] = escape;
 192
 193                 if (escape == 'u') {
 194                         sprintf(buf + 4, "%02x", (unsigned char) *p);
 195                         len = 6;
 196                 } else {
 197                         len = 2;
 198                 }
 199                 blobmsg_puts(s, buf, len);
 200         }
 201
 202         blobmsg_puts(s, (char *) last, end - last);
 203         blobmsg_puts(s, "\"", 1);
 204 }
 205
 206 static void blobmsg_format_json_list(struct strbuf *s, struct blob_attr *attr, int len, bool array);
 207
 208 static void blobmsg_format_element(struct strbuf *s, struct blob_attr *attr, bool array, bool head)
 209 {
 210         const char *data_str;
 211         char buf[32];
 212         void *data;
 213         int len;
 214
 215         if (!blobmsg_check_attr(attr, false))
 216                 return;
 217
 218         if (!array && blobmsg_name(attr)[0]) {
 219                 blobmsg_format_string(s, blobmsg_name(attr));
 220                 blobmsg_puts(s, ": ", s->indent ? 2 : 1);
 221         }
 222
 223         data = blobmsg_data(attr);
 224         len = blobmsg_data_len(attr);
 225
 226         if (!head && s->custom_format) {
 227                 data_str = s->custom_format(s->priv, attr);
 228                 if (data_str)
 229                         goto out;
 230         }
 231
 232         data_str = buf;
 233         switch(blob_id(attr)) {
 234         case BLOBMSG_TYPE_UNSPEC:
 235                 sprintf(buf, "null");
 236                 break;
 237         case BLOBMSG_TYPE_BOOL:
 238                 sprintf(buf, "%s", *(uint8_t *)data ? "true" : "false");
 239                 break;
 240         case BLOBMSG_TYPE_INT16:
 241                 sprintf(buf, "%d", be16_to_cpu(*(uint16_t *)data));
 242                 break;
 243         case BLOBMSG_TYPE_INT32:
 244                 sprintf(buf, "%d", (int32_t) be32_to_cpu(*(uint32_t *)data));
 245                 break;
 246         case BLOBMSG_TYPE_INT64:
 247                 sprintf(buf, "%" PRId64, (int64_t) be64_to_cpu(*(uint64_t *)data));
 248                 break;
 249         case BLOBMSG_TYPE_STRING:
 250                 blobmsg_format_string(s, data);
 251                 return;
 252         case BLOBMSG_TYPE_ARRAY:
 253                 blobmsg_format_json_list(s, data, len, true);
 254                 return;
 255         case BLOBMSG_TYPE_TABLE:
 256                 blobmsg_format_json_list(s, data, len, false);
 257                 return;
 258         }
 259
 260 out:
 261         blobmsg_puts(s, data_str, strlen(data_str));
 262 }
 263
 264 static void blobmsg_format_json_list(struct strbuf *s, struct blob_attr *attr, int len, bool array)
 265 {
 266         struct blob_attr *pos;
 267         bool first = true;
 268         int rem = len;
 269
 270         blobmsg_puts(s, (array ? "[" : "{" ), 1);
 271         s->indent_level++;
 272         add_separator(s);
 273         __blob_for_each_attr(pos, attr, rem) {
 274                 if (!first) {
 275                         blobmsg_puts(s, ",", 1);
 276                         add_separator(s);
 277                 }
 278
 279                 blobmsg_format_element(s, pos, array, false);
 280                 first = false;
 281         }
 282         s->indent_level--;
 283         add_separator(s);
 284         blobmsg_puts(s, (array ? "]" : "}"), 1);
 285 }
 286
 287 char *blobmsg_format_json_with_cb(struct blob_attr *attr, bool list, blobmsg_json_format_t cb, void *priv, int indent)
 288 {
 289         struct strbuf s;
 290         bool array;
 291
 292         s.len = blob_len(attr);
 293         s.buf = malloc(s.len);
 294         s.pos = 0;
 295         s.custom_format = cb;
 296         s.priv = priv;
 297         s.indent = false;
 298
 299         if (indent >= 0) {
 300                 s.indent = true;
 301                 s.indent_level = indent;
 302         }
 303
 304         array = blob_is_extended(attr) &&
 305                 blobmsg_type(attr) == BLOBMSG_TYPE_ARRAY;
 306
 307         if (list)
 308                 blobmsg_format_json_list(&s, blobmsg_data(attr), blobmsg_data_len(attr), array);
 309         else
 310                 blobmsg_format_element(&s, attr, false, false);
 311
 312         if (!s.len) {
 313                 free(s.buf);
 314                 return NULL;
 315         }
 316
 317         s.buf = realloc(s.buf, s.pos + 1);
 318         s.buf[s.pos] = 0;
 319
 320         return s.buf;
 321 }