blobmsg.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
  18 static const int blob_type[__BLOBMSG_TYPE_LAST] = {
  19         [BLOBMSG_TYPE_INT8] = BLOB_ATTR_INT8,
  20         [BLOBMSG_TYPE_INT16] = BLOB_ATTR_INT16,
  21         [BLOBMSG_TYPE_INT32] = BLOB_ATTR_INT32,
  22         [BLOBMSG_TYPE_INT64] = BLOB_ATTR_INT64,
  23         [BLOBMSG_TYPE_DOUBLE] = BLOB_ATTR_DOUBLE,
  24         [BLOBMSG_TYPE_STRING] = BLOB_ATTR_STRING,
  25         [BLOBMSG_TYPE_UNSPEC] = BLOB_ATTR_BINARY,
  26 };
  27
  28 static uint16_t
  29 blobmsg_namelen(const struct blobmsg_hdr *hdr)
  30 {
  31         return be16_to_cpu(hdr->namelen);
  32 }
  33
  34 bool blobmsg_check_attr(const struct blob_attr *attr, bool name)
  35 {
  36         const struct blobmsg_hdr *hdr;
  37         const char *data;
  38         size_t len;
  39         int id;
  40
  41         if (blob_len(attr) < sizeof(struct blobmsg_hdr))
  42                 return false;
  43
  44         hdr = (void *) attr->data;
  45         if (!hdr->namelen && name)
  46                 return false;
  47
  48         if (blobmsg_namelen(hdr) > blob_len(attr) - sizeof(struct blobmsg_hdr))
  49                 return false;
  50
  51         if (hdr->name[blobmsg_namelen(hdr)] != 0)
  52                 return false;
  53
  54         id = blob_id(attr);
  55         len = blobmsg_data_len(attr);
  56         if (len > blob_raw_len(attr))
  57                 return false;
  58
  59         data = blobmsg_data(attr);
  60
  61         if (id > BLOBMSG_TYPE_LAST)
  62                 return false;
  63
  64         if (!blob_type[id])
  65                 return true;
  66
  67         return blob_check_type(data, len, blob_type[id]);
  68 }
  69
  70 int blobmsg_check_array(const struct blob_attr *attr, int type)
  71 {
  72         struct blob_attr *cur;
  73         bool name;
  74         size_t rem;
  75         int size = 0;
  76
  77         switch (blobmsg_type(attr)) {
  78         case BLOBMSG_TYPE_TABLE:
  79                 name = true;
  80                 break;
  81         case BLOBMSG_TYPE_ARRAY:
  82                 name = false;
  83                 break;
  84         default:
  85                 return -1;
  86         }
  87
  88         blobmsg_for_each_attr(cur, attr, rem) {
  89                 if (type != BLOBMSG_TYPE_UNSPEC && blobmsg_type(cur) != type)
  90                         return -1;
  91
  92                 if (!blobmsg_check_attr(cur, name))
  93                         return -1;
  94
  95                 size++;
  96         }
  97
  98         return size;
  99 }
 100
 101 bool blobmsg_check_attr_list(const struct blob_attr *attr, int type)
 102 {
 103         return blobmsg_check_array(attr, type) >= 0;
 104 }
 105
 106 int blobmsg_parse_array(const struct blobmsg_policy *policy, int policy_len,
 107                         struct blob_attr **tb, void *data, unsigned int len)
 108 {
 109         struct blob_attr *attr;
 110         int i = 0;
 111
 112         memset(tb, 0, policy_len * sizeof(*tb));
 113         __blob_for_each_attr(attr, data, len) {
 114                 if (policy[i].type != BLOBMSG_TYPE_UNSPEC &&
 115                     blob_id(attr) != policy[i].type)
 116                         continue;
 117
 118                 if (!blobmsg_check_attr(attr, false))
 119                         return -1;
 120
 121                 if (tb[i])
 122                         continue;
 123
 124                 tb[i++] = attr;
 125                 if (i == policy_len)
 126                         break;
 127         }
 128
 129         return 0;
 130 }
 131
 132
 133 int blobmsg_parse(const struct blobmsg_policy *policy, int policy_len,
 134                   struct blob_attr **tb, void *data, unsigned int len)
 135 {
 136         struct blobmsg_hdr *hdr;
 137         struct blob_attr *attr;
 138         uint8_t *pslen;
 139         int i;
 140
 141         memset(tb, 0, policy_len * sizeof(*tb));
 142         if (!data || !len)
 143                 return -EINVAL;
 144         pslen = alloca(policy_len);
 145         for (i = 0; i < policy_len; i++) {
 146                 if (!policy[i].name)
 147                         continue;
 148
 149                 pslen[i] = strlen(policy[i].name);
 150         }
 151
 152         __blob_for_each_attr(attr, data, len) {
 153                 hdr = blob_data(attr);
 154                 for (i = 0; i < policy_len; i++) {
 155                         if (!policy[i].name)
 156                                 continue;
 157
 158                         if (policy[i].type != BLOBMSG_TYPE_UNSPEC &&
 159                             blob_id(attr) != policy[i].type)
 160                                 continue;
 161
 162                         if (blobmsg_namelen(hdr) != pslen[i])
 163                                 continue;
 164
 165                         if (!blobmsg_check_attr(attr, true))
 166                                 return -1;
 167
 168                         if (tb[i])
 169                                 continue;
 170
 171                         if (strcmp(policy[i].name, (char *) hdr->name) != 0)
 172                                 continue;
 173
 174                         tb[i] = attr;
 175                 }
 176         }
 177
 178         return 0;
 179 }
 180
 181
 182 static struct blob_attr *
 183 blobmsg_new(struct blob_buf *buf, int type, const char *name, int payload_len, void **data)
 184 {
 185         struct blob_attr *attr;
 186         struct blobmsg_hdr *hdr;
 187         int attrlen, namelen;
 188         char *pad_start, *pad_end;
 189
 190         if (!name)
 191                 name = "";
 192
 193         namelen = strlen(name);
 194         attrlen = blobmsg_hdrlen(namelen) + payload_len;
 195         attr = blob_new(buf, type, attrlen);
 196         if (!attr)
 197                 return NULL;
 198
 199         attr->id_len |= be32_to_cpu(BLOB_ATTR_EXTENDED);
 200         hdr = blob_data(attr);
 201         hdr->namelen = cpu_to_be16(namelen);
 202         strcpy((char *) hdr->name, (const char *)name);
 203         pad_end = *data = blobmsg_data(attr);
 204         pad_start = (char *) &hdr->name[namelen];
 205         if (pad_start < pad_end)
 206                 memset(pad_start, 0, pad_end - pad_start);
 207
 208         return attr;
 209 }
 210
 211 static inline int
 212 attr_to_offset(struct blob_buf *buf, struct blob_attr *attr)
 213 {
 214         return (char *)attr - (char *) buf->buf + BLOB_COOKIE;
 215 }
 216
 217
 218 void *
 219 blobmsg_open_nested(struct blob_buf *buf, const char *name, bool array)
 220 {
 221         struct blob_attr *head;
 222         int type = array ? BLOBMSG_TYPE_ARRAY : BLOBMSG_TYPE_TABLE;
 223         unsigned long offset = attr_to_offset(buf, buf->head);
 224         void *data;
 225
 226         if (!name)
 227                 name = "";
 228
 229         head = blobmsg_new(buf, type, name, 0, &data);
 230         if (!head)
 231                 return NULL;
 232         blob_set_raw_len(buf->head, blob_pad_len(buf->head) - blobmsg_hdrlen(strlen(name)));
 233         buf->head = head;
 234         return (void *)offset;
 235 }
 236
 237 __attribute__((format(printf, 3, 0)))
 238 int blobmsg_vprintf(struct blob_buf *buf, const char *name, const char *format, va_list arg)
 239 {
 240         va_list arg2;
 241         char cbuf;
 242         char *sbuf;
 243         int len, ret;
 244
 245         va_copy(arg2, arg);
 246         len = vsnprintf(&cbuf, sizeof(cbuf), format, arg2);
 247         va_end(arg2);
 248
 249         sbuf = blobmsg_alloc_string_buffer(buf, name, len + 1);
 250         if (!sbuf)
 251                 return -1;
 252         ret = vsprintf(sbuf, format, arg);
 253         blobmsg_add_string_buffer(buf);
 254
 255         return ret;
 256 }
 257
 258 __attribute__((format(printf, 3, 4)))
 259 int blobmsg_printf(struct blob_buf *buf, const char *name, const char *format, ...)
 260 {
 261         va_list ap;
 262         int ret;
 263
 264         va_start(ap, format);
 265         ret = blobmsg_vprintf(buf, name, format, ap);
 266         va_end(ap);
 267
 268         return ret;
 269 }
 270
 271 void *
 272 blobmsg_alloc_string_buffer(struct blob_buf *buf, const char *name, unsigned int maxlen)
 273 {
 274         struct blob_attr *attr;
 275         void *data_dest;
 276
 277         attr = blobmsg_new(buf, BLOBMSG_TYPE_STRING, name, maxlen, &data_dest);
 278         if (!attr)
 279                 return NULL;
 280
 281         blob_set_raw_len(buf->head, blob_pad_len(buf->head) - blob_pad_len(attr));
 282         blob_set_raw_len(attr, blob_raw_len(attr) - maxlen);
 283
 284         return data_dest;
 285 }
 286
 287 void *
 288 blobmsg_realloc_string_buffer(struct blob_buf *buf, unsigned int maxlen)
 289 {
 290         struct blob_attr *attr = blob_next(buf->head);
 291         int offset = attr_to_offset(buf, blob_next(buf->head)) + blob_pad_len(attr) - BLOB_COOKIE;
 292         int required = maxlen - (buf->buflen - offset);
 293
 294         if (required <= 0)
 295                 goto out;
 296
 297         if (!blob_buf_grow(buf, required))
 298                 return NULL;
 299         attr = blob_next(buf->head);
 300
 301 out:
 302         return blobmsg_data(attr);
 303 }
 304
 305 void
 306 blobmsg_add_string_buffer(struct blob_buf *buf)
 307 {
 308         struct blob_attr *attr;
 309         int len, attrlen;
 310
 311         attr = blob_next(buf->head);
 312         len = strlen(blobmsg_data(attr)) + 1;
 313
 314         attrlen = blob_raw_len(attr) + len;
 315         blob_set_raw_len(attr, attrlen);
 316         blob_fill_pad(attr);
 317
 318         blob_set_raw_len(buf->head, blob_raw_len(buf->head) + blob_pad_len(attr));
 319 }
 320
 321 int
 322 blobmsg_add_field(struct blob_buf *buf, int type, const char *name,
 323                   const void *data, unsigned int len)
 324 {
 325         struct blob_attr *attr;
 326         void *data_dest;
 327
 328         attr = blobmsg_new(buf, type, name, len, &data_dest);
 329         if (!attr)
 330                 return -1;
 331
 332         if (len > 0)
 333                 memcpy(data_dest, data, len);
 334
 335         return 0;
 336 }