52 #define LOG_MODULE "lwm2m-tlv" 53 #define LOG_LEVEL LOG_LEVEL_NONE 57 get_len_type(
const lwm2m_tlv_t *tlv)
61 }
else if(tlv->length < 256) {
63 }
else if(tlv->length < 0x10000) {
71 lwm2m_tlv_read(lwm2m_tlv_t *tlv,
const uint8_t *buffer,
size_t len)
77 tlv->type = (buffer[0] >> 6) & 3;
78 len_type = (buffer[0] >> 3) & 3;
79 len_pos = 1 + (((buffer[0] & (1 << 5)) != 0) ? 2 : 1);
84 tlv->id = (tlv->id << 8) + buffer[2];
88 tlv_len = buffer[0] & 7;
93 tlv_len = tlv_len << 8 | buffer[len_pos++];
98 tlv->length = tlv_len;
99 tlv->value = &buffer[len_pos];
101 return len_pos + tlv_len;
105 lwm2m_tlv_get_size(
const lwm2m_tlv_t *tlv)
109 size = 1 + get_len_type(tlv);
111 size += (tlv->id > 255) ? 2 : 1;
122 lwm2m_tlv_write(
const lwm2m_tlv_t *tlv, uint8_t *buffer,
size_t buffersize)
128 len_type = get_len_type(tlv);
131 if(tlv->value != NULL && buffersize < tlv->length + pos) {
132 LOG_WARN(
"Could not write the TLV - buffer overflow.\n");
136 if(buffersize < pos + 2) {
141 buffer[0] = (tlv->type << 6) |
142 (tlv->id > 255 ? (1 << 5) : 0) |
144 (len_type == 0 ? tlv->length : 0);
149 buffer[pos++] = (tlv->id >> 8) & 0xff;
151 buffer[pos++] = tlv->id & 0xff;
154 buffer[pos++] = (tlv->length >> 16) & 0xff;
157 buffer[pos++] = (tlv->length >> 8) & 0xff;
160 buffer[pos++] = tlv->length & 0xff;
164 if(tlv->value != NULL && tlv->length > 0) {
165 memcpy(&buffer[pos], tlv->value, tlv->length);
168 if(LOG_DBG_ENABLED) {
171 for(i = 0; i < pos + ((tlv->value != NULL) ? tlv->length : 0); i++) {
172 LOG_DBG_(
"%02x", buffer[i]);
177 return pos + ((tlv->value != NULL) ? tlv->length : 0);
181 lwm2m_tlv_get_int32(
const lwm2m_tlv_t *tlv)
186 for(i = 0; i < tlv->length; i++) {
187 value = (value << 8) | tlv->value[i];
191 if(tlv->value[0] & 0x80) {
193 value = value | (0xff << (i * 8));
202 lwm2m_tlv_write_int32(uint8_t type, int16_t
id, int32_t value, uint8_t *buffer,
size_t len)
209 LOG_DBG(
"Exporting int32 %d %"PRId32
" ",
id, value);
211 v = value < 0 ? -1 : 0;
214 buf[3 - i] = value & 0xff;
216 last_bit = (v == 0 && (value & 0x80) > 0) || (v == -1 && (value & 0x80) == 0);
219 }
while((value != v || last_bit) && i < 4);
222 LOG_DBG(
"len: %d\n", i);
225 tlv.value = &buf[3 - (i - 1)];
227 return lwm2m_tlv_write(&tlv, buffer, len);
232 lwm2m_tlv_write_float32(uint8_t type, int16_t
id, int32_t value,
int bits,
233 uint8_t *buffer,
size_t len)
250 val = val | (1L << 22);
256 LOG_DBG(
"Sign: %d, Fraction: %06"PRIx32
" 0b", value < 0, val);
257 for(i = 0; i < 23; i++) {
258 LOG_DBG_(
"%"PRId32
"", ((val >> (22 - i)) & 1));
260 LOG_DBG_(
"\nExp:%d\n", e);
270 b[0] = (value < 0 ? 0x80 : 0) | (e >> 1);
271 b[1] = ((e & 1) << 7) | ((val >> 16) & 0x7f);
272 b[2] = (val >> 8) & 0xff;
275 LOG_DBG(
"B=%02x%02x%02x%02x\n", b[0], b[1], b[2], b[3]);
282 return lwm2m_tlv_write(&tlv, buffer, len);
287 lwm2m_tlv_float32_to_fix(
const lwm2m_tlv_t *tlv, int32_t *value,
int bits)
292 int sign = (tlv->value[0] & 0x80) != 0;
293 e = ((tlv->value[0] << 1) & 0xff) | (tlv->value[1] >> 7);
294 val = (((long)tlv->value[1] & 0x7f) << 16) | (tlv->value[2] << 8) | tlv->value[3];
296 LOG_DBG(
"Sign: %d, Fraction: %06"PRIx32
" 0b", val < 0, val);
297 for(i = 0; i < 23; i++) {
298 LOG_DBG_(
"%"PRId32
"", ((val >> (22 - i)) & 1));
300 LOG_DBG(
"\nExp:%d => %d\n", e, e - 127);
306 LOG_DBG(
"Actual e=%d\n", e);
308 LOG_DBG(
"E after sub %d\n", e);
309 val = val | 1L << 23;
316 *value = sign ? -val : val;
323 int main(
int argc,
char *argv[])
333 printf(
"TLV:%d\n", lwm2m_tlv_get_int32(&tlv));
335 printf(
"Len: %d\n", lwm2m_tlv_write_int32(0, 1, -0x88987f, data, 24));
Header file for the Contiki OMA LWM2M TLV