veles_labs/iaq_sensor_wired
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Fixed non-deterministic buffer pos increments

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mj 2021-12-22 17:18:43 +01:00
parent 0ed535bb76
commit e36c06aae8
1 changed files with 11 additions and 10 deletions
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21
fw/Core/Src/modbus.c
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@ -162,6 +162,7 @@ static int8_t modbus_transaction_to_buffer(uint8_t *buffer, uint8_t *msg_len, mo
crc16 = modbus_CRC16(buffer, buffer_pos); /* last two bytes is the checksum itself */
buffer[buffer_pos++] = crc16 & 0xff;
buffer[buffer_pos++] = crc16 >> 8;
return MODBUS_OK;
}
static int8_t modbus_process_device_id_request(const uint8_t *buffer, int len, modbus_transaction_t *transaction)
@ -169,8 +170,6 @@ static int8_t modbus_process_device_id_request(const uint8_t *buffer, int len, m
uint8_t MEI_type;
uint8_t read_device_id_code;
uint8_t object_id;
uint8_t conformity_masked;
uint8_t individual_object_access;
uint8_t buffer_pos = 0;
if (transaction->broadcast == 1) {
@ -199,9 +198,6 @@ static int8_t modbus_process_device_id_request(const uint8_t *buffer, int len, m
transaction->exception = MODBUS_EXCEPTION_ILLEGAL_DEVICE_ID_CODE;
return MODBUS_OK;
}
if (read_device_id_code == MODBUS_INDIVIDUAL_ACCESS) {
individual_object_access = 1;
}
transaction->read_device_id_code = read_device_id_code;
/* next byte is object id */
object_id = buffer[buffer_pos++];
@ -267,14 +263,17 @@ static int8_t modbus_process_read_write_request(const uint8_t *buffer, int len,
/* buffer too short to contain everything we need */
return MODBUS_ERROR;
}
transaction->register_address = (buffer[buffer_pos++] << 8) | buffer[buffer_pos++];
transaction->register_address = (buffer[buffer_pos + 1] << 8) | buffer[buffer_pos + 2];
buffer += 2;
// TODO check length!
if (flags & MODBUS_FLAG_WRITE) {
if (flags & MODBUS_FLAG_SINGLE) {
transaction->holding_registers[0] = (buffer[buffer_pos++] << 8) | buffer[buffer_pos++];
transaction->holding_registers[0] = (buffer[buffer_pos + 1] << 8) | buffer[buffer_pos + 2];
buffer_pos += 2;
} else {
/* Write multiple registers */
transaction->register_count = (buffer[buffer_pos++] << 8) | buffer[buffer_pos++];
transaction->register_count = (buffer[buffer_pos + 1] << 8) | buffer[buffer_pos + 2];
buffer_pos += 2;
if (len < MODBUS_MINIMAL_WRITE_MULTIPLE_LEN) {
return MODBUS_ERROR;
}
@ -287,12 +286,14 @@ static int8_t modbus_process_read_write_request(const uint8_t *buffer, int len,
return MODBUS_ERROR;
}
for (uint8_t i = 0; i < transaction->register_count; i++) {
transaction->holding_registers[i] = (buffer[buffer_pos++] << 8) | buffer[buffer_pos++];
transaction->holding_registers[i] = (buffer[buffer_pos + 1] << 8) | buffer[buffer_pos + 2];
buffer_pos += 2;
}
}
}
} else {
transaction->register_count = (buffer[buffer_pos++] << 8) | buffer[buffer_pos++];
transaction->register_count = (buffer[buffer_pos + 1] << 8) | buffer[buffer_pos + 2];
buffer_pos += 2;
if (
transaction->register_count < 1 ||
transaction->register_count > MODBUS_MAX_REGISTERS