51 #define LOG_MODULE "lwm2m-tlv" 52 #define LOG_LEVEL LOG_LEVEL_NONE 56 get_len_type(
const lwm2m_tlv_t *tlv)
60 }
else if(tlv->length < 256) {
62 }
else if(tlv->length < 0x10000) {
70 lwm2m_tlv_read(lwm2m_tlv_t *tlv,
const uint8_t *buffer,
size_t len)
76 tlv->type = (buffer[0] >> 6) & 3;
77 len_type = (buffer[0] >> 3) & 3;
78 len_pos = 1 + (((buffer[0] & (1 << 5)) != 0) ? 2 : 1);
83 tlv->id = (tlv->id << 8) + buffer[2];
87 tlv_len = buffer[0] & 7;
92 tlv_len = tlv_len << 8 | buffer[len_pos++];
97 tlv->length = tlv_len;
98 tlv->value = &buffer[len_pos];
100 return len_pos + tlv_len;
104 lwm2m_tlv_get_size(
const lwm2m_tlv_t *tlv)
108 size = 1 + get_len_type(tlv);
110 size += (tlv->id > 255) ? 2 : 1;
121 lwm2m_tlv_write(
const lwm2m_tlv_t *tlv, uint8_t *buffer,
size_t buffersize)
127 len_type = get_len_type(tlv);
130 if(tlv->value != NULL && buffersize < tlv->length + pos) {
131 LOG_WARN(
"Could not write the TLV - buffer overflow.\n");
135 if(buffersize < pos + 2) {
140 buffer[0] = (tlv->type << 6) |
141 (tlv->id > 255 ? (1 << 5) : 0) |
143 (len_type == 0 ? tlv->length : 0);
148 buffer[pos++] = (tlv->id >> 8) & 0xff;
150 buffer[pos++] = tlv->id & 0xff;
153 buffer[pos++] = (tlv->length >> 16) & 0xff;
156 buffer[pos++] = (tlv->length >> 8) & 0xff;
159 buffer[pos++] = tlv->length & 0xff;
163 if(tlv->value != NULL && tlv->length > 0) {
164 memcpy(&buffer[pos], tlv->value, tlv->length);
167 if(LOG_DBG_ENABLED) {
170 for(i = 0; i < pos + ((tlv->value != NULL) ? tlv->length : 0); i++) {
171 LOG_DBG_(
"%02x", buffer[i]);
176 return pos + ((tlv->value != NULL) ? tlv->length : 0);
180 lwm2m_tlv_get_int32(
const lwm2m_tlv_t *tlv)
185 for(i = 0; i < tlv->length; i++) {
186 value = (value << 8) | tlv->value[i];
190 if(tlv->value[0] & 0x80) {
192 value = value | (0xff << (i * 8));
201 lwm2m_tlv_write_int32(uint8_t type, int16_t
id, int32_t value, uint8_t *buffer,
size_t len)
208 LOG_DBG(
"Exporting int32 %d %"PRId32
" ",
id, value);
210 v = value < 0 ? -1 : 0;
213 buf[3 - i] = value & 0xff;
215 last_bit = (v == 0 && (value & 0x80) > 0) || (v == -1 && (value & 0x80) == 0);
218 }
while((value != v || last_bit) && i < 4);
221 LOG_DBG(
"len: %d\n", i);
224 tlv.value = &buf[3 - (i - 1)];
226 return lwm2m_tlv_write(&tlv, buffer, len);
231 lwm2m_tlv_write_float32(uint8_t type, int16_t
id, int32_t value,
int bits,
232 uint8_t *buffer,
size_t len)
249 val = val | (1L << 22);
255 LOG_DBG(
"Sign: %d, Fraction: %06"PRIx32
" 0b", value < 0, val);
256 for(i = 0; i < 23; i++) {
257 LOG_DBG_(
"%"PRId32
"", ((val >> (22 - i)) & 1));
259 LOG_DBG_(
"\nExp:%d\n", e);
269 b[0] = (value < 0 ? 0x80 : 0) | (e >> 1);
270 b[1] = ((e & 1) << 7) | ((val >> 16) & 0x7f);
271 b[2] = (val >> 8) & 0xff;
274 LOG_DBG(
"B=%02x%02x%02x%02x\n", b[0], b[1], b[2], b[3]);
281 return lwm2m_tlv_write(&tlv, buffer, len);
286 lwm2m_tlv_float32_to_fix(
const lwm2m_tlv_t *tlv, int32_t *value,
int bits)
291 int sign = (tlv->value[0] & 0x80) != 0;
292 e = ((tlv->value[0] << 1) & 0xff) | (tlv->value[1] >> 7);
293 val = (((long)tlv->value[1] & 0x7f) << 16) | (tlv->value[2] << 8) | tlv->value[3];
295 LOG_DBG(
"Sign: %d, Fraction: %06"PRIx32
" 0b", val < 0, val);
296 for(i = 0; i < 23; i++) {
297 LOG_DBG_(
"%"PRId32
"", ((val >> (22 - i)) & 1));
299 LOG_DBG(
"\nExp:%d => %d\n", e, e - 127);
305 LOG_DBG(
"Actual e=%d\n", e);
307 LOG_DBG(
"E after sub %d\n", e);
308 val = val | 1L << 23;
315 *value = sign ? -val : val;
322 int main(
int argc,
char *argv[])
332 printf(
"TLV:%d\n", lwm2m_tlv_get_int32(&tlv));
334 printf(
"Len: %d\n", lwm2m_tlv_write_int32(0, 1, -0x88987f, data, 24));
Header file for the Contiki OMA LWM2M TLV