Add max_telegram_length option to dsmr (#2674)

Co-authored-by: Maurice Makaay <mmakaay1@xs4all.net>
Co-authored-by: Oxan van Leeuwen <oxan@oxanvanleeuwen.nl>
This commit is contained in:
Maurice Makaay 2021-11-17 18:24:02 +01:00 committed by GitHub
parent df6730be55
commit dee5d639e2
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
4 changed files with 50 additions and 27 deletions

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@ -15,6 +15,7 @@ CONF_DSMR_ID = "dsmr_id"
CONF_DECRYPTION_KEY = "decryption_key"
CONF_CRC_CHECK = "crc_check"
CONF_GAS_MBUS_ID = "gas_mbus_id"
CONF_MAX_TELEGRAM_LENGTH = "max_telegram_length"
# Hack to prevent compile error due to ambiguity with lib namespace
dsmr_ns = cg.esphome_ns.namespace("esphome::dsmr")
@ -46,6 +47,7 @@ CONFIG_SCHEMA = cv.All(
cv.Optional(CONF_DECRYPTION_KEY): _validate_key,
cv.Optional(CONF_CRC_CHECK, default=True): cv.boolean,
cv.Optional(CONF_GAS_MBUS_ID, default=1): cv.int_,
cv.Optional(CONF_MAX_TELEGRAM_LENGTH, default=1500): cv.int_,
}
).extend(uart.UART_DEVICE_SCHEMA),
cv.only_with_arduino,
@ -55,6 +57,7 @@ CONFIG_SCHEMA = cv.All(
async def to_code(config):
uart_component = await cg.get_variable(config[CONF_UART_ID])
var = cg.new_Pvariable(config[CONF_ID], uart_component, config[CONF_CRC_CHECK])
cg.add(var.set_max_telegram_length(config[CONF_MAX_TELEGRAM_LENGTH]))
if CONF_DECRYPTION_KEY in config:
cg.add(var.set_decryption_key(config[CONF_DECRYPTION_KEY]))
await cg.register_component(var, config)

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@ -12,11 +12,15 @@ namespace dsmr {
static const char *const TAG = "dsmr";
void Dsmr::setup() {
telegram_ = new char[max_telegram_len_]; // NOLINT
}
void Dsmr::loop() {
if (this->decryption_key_.empty())
this->receive_telegram_();
if (decryption_key_.empty())
receive_telegram_();
else
this->receive_encrypted_();
receive_encrypted_();
}
bool Dsmr::available_within_timeout_() {
@ -51,10 +55,10 @@ void Dsmr::receive_telegram_() {
continue;
// Check for buffer overflow.
if (telegram_len_ >= MAX_TELEGRAM_LENGTH) {
if (telegram_len_ >= max_telegram_len_) {
header_found_ = false;
footer_found_ = false;
ESP_LOGE(TAG, "Error: telegram larger than buffer (%d bytes)", MAX_TELEGRAM_LENGTH);
ESP_LOGE(TAG, "Error: telegram larger than buffer (%d bytes)", max_telegram_len_);
return;
}
@ -86,9 +90,7 @@ void Dsmr::receive_telegram_() {
}
void Dsmr::receive_encrypted_() {
// Encrypted buffer
uint8_t buffer[MAX_TELEGRAM_LENGTH];
size_t buffer_length = 0;
encrypted_telegram_len_ = 0;
size_t packet_size = 0;
while (true) {
@ -114,39 +116,39 @@ void Dsmr::receive_encrypted_() {
}
// Check for buffer overflow.
if (buffer_length >= MAX_TELEGRAM_LENGTH) {
if (encrypted_telegram_len_ >= max_telegram_len_) {
header_found_ = false;
ESP_LOGE(TAG, "Error: encrypted telegram larger than buffer (%d bytes)", MAX_TELEGRAM_LENGTH);
ESP_LOGE(TAG, "Error: encrypted telegram larger than buffer (%d bytes)", max_telegram_len_);
return;
}
buffer[buffer_length++] = c;
encrypted_telegram_[encrypted_telegram_len_++] = c;
if (packet_size == 0 && buffer_length > 20) {
if (packet_size == 0 && encrypted_telegram_len_ > 20) {
// Complete header + data bytes
packet_size = 13 + (buffer[11] << 8 | buffer[12]);
packet_size = 13 + (encrypted_telegram_[11] << 8 | encrypted_telegram_[12]);
ESP_LOGV(TAG, "Encrypted telegram size: %d bytes", packet_size);
}
if (buffer_length == packet_size && packet_size > 0) {
if (encrypted_telegram_len_ == packet_size && packet_size > 0) {
ESP_LOGV(TAG, "End of encrypted telegram found");
GCM<AES128> *gcmaes128{new GCM<AES128>()};
gcmaes128->setKey(this->decryption_key_.data(), gcmaes128->keySize());
gcmaes128->setKey(decryption_key_.data(), gcmaes128->keySize());
// the iv is 8 bytes of the system title + 4 bytes frame counter
// system title is at byte 2 and frame counter at byte 15
for (int i = 10; i < 14; i++)
buffer[i] = buffer[i + 4];
encrypted_telegram_[i] = encrypted_telegram_[i + 4];
constexpr uint16_t iv_size{12};
gcmaes128->setIV(&buffer[2], iv_size);
gcmaes128->decrypt(reinterpret_cast<uint8_t *>(this->telegram_),
gcmaes128->setIV(&encrypted_telegram_[2], iv_size);
gcmaes128->decrypt(reinterpret_cast<uint8_t *>(telegram_),
// the ciphertext start at byte 18
&buffer[18],
&encrypted_telegram_[18],
// cipher size
buffer_length - 17);
encrypted_telegram_len_ - 17);
delete gcmaes128; // NOLINT(cppcoreguidelines-owning-memory)
telegram_len_ = strnlen(this->telegram_, sizeof(this->telegram_));
telegram_len_ = strnlen(telegram_, max_telegram_len_);
ESP_LOGV(TAG, "Decrypted telegram size: %d bytes", telegram_len_);
ESP_LOGVV(TAG, "Decrypted telegram: %s", this->telegram_);
ESP_LOGVV(TAG, "Decrypted telegram: %s", telegram_);
parse_telegram();
@ -162,7 +164,7 @@ bool Dsmr::parse_telegram() {
ESP_LOGV(TAG, "Trying to parse telegram");
::dsmr::ParseResult<void> res =
::dsmr::P1Parser::parse(&data, telegram_, telegram_len_, false,
this->crc_check_); // Parse telegram according to data definition. Ignore unknown values.
crc_check_); // Parse telegram according to data definition. Ignore unknown values.
if (res.err) {
// Parsing error, show it
auto err_str = res.fullError(telegram_, telegram_ + telegram_len_);
@ -177,6 +179,7 @@ bool Dsmr::parse_telegram() {
void Dsmr::dump_config() {
ESP_LOGCONFIG(TAG, "DSMR:");
ESP_LOGCONFIG(TAG, " Max telegram length: %d", max_telegram_len_);
#define DSMR_LOG_SENSOR(s) LOG_SENSOR(" ", #s, this->s_##s##_);
DSMR_SENSOR_LIST(DSMR_LOG_SENSOR, )
@ -188,7 +191,11 @@ void Dsmr::dump_config() {
void Dsmr::set_decryption_key(const std::string &decryption_key) {
if (decryption_key.length() == 0) {
ESP_LOGI(TAG, "Disabling decryption");
this->decryption_key_.clear();
decryption_key_.clear();
if (encrypted_telegram_ != nullptr) {
delete[] encrypted_telegram_;
encrypted_telegram_ = nullptr;
}
return;
}
@ -196,7 +203,7 @@ void Dsmr::set_decryption_key(const std::string &decryption_key) {
ESP_LOGE(TAG, "Error, decryption key must be 32 character long");
return;
}
this->decryption_key_.clear();
decryption_key_.clear();
ESP_LOGI(TAG, "Decryption key is set");
// Verbose level prints decryption key
@ -207,8 +214,14 @@ void Dsmr::set_decryption_key(const std::string &decryption_key) {
strncpy(temp, &(decryption_key.c_str()[i * 2]), 2);
decryption_key_.push_back(std::strtoul(temp, nullptr, 16));
}
if (encrypted_telegram_ == nullptr) {
encrypted_telegram_ = new uint8_t[max_telegram_len_]; // NOLINT
}
}
void Dsmr::set_max_telegram_length(size_t length) { max_telegram_len_ = length; }
} // namespace dsmr
} // namespace esphome

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@ -16,7 +16,6 @@
namespace esphome {
namespace dsmr {
static constexpr uint32_t MAX_TELEGRAM_LENGTH = 1500;
static constexpr uint32_t READ_TIMEOUT_MS = 200;
using namespace ::dsmr::fields;
@ -52,6 +51,8 @@ class Dsmr : public Component, public uart::UARTDevice {
public:
Dsmr(uart::UARTComponent *uart, bool crc_check) : uart::UARTDevice(uart), crc_check_(crc_check) {}
void setup() override;
void loop() override;
bool parse_telegram();
@ -72,6 +73,8 @@ class Dsmr : public Component, public uart::UARTDevice {
void set_decryption_key(const std::string &decryption_key);
void set_max_telegram_length(size_t length);
// Sensor setters
#define DSMR_SET_SENSOR(s) \
void set_##s(sensor::Sensor *sensor) { s_##s##_ = sensor; }
@ -97,8 +100,11 @@ class Dsmr : public Component, public uart::UARTDevice {
bool available_within_timeout_();
// Telegram buffer
char telegram_[MAX_TELEGRAM_LENGTH];
size_t max_telegram_len_;
char *telegram_{nullptr};
int telegram_len_{0};
uint8_t *encrypted_telegram_{nullptr};
int encrypted_telegram_len_{0};
// Serial parser
bool header_found_{false};

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@ -1308,6 +1308,7 @@ fingerprint_grow:
dsmr:
decryption_key: 00112233445566778899aabbccddeeff
uart_id: uart6
max_telegram_length: 1000
daly_bms:
update_interval: 20s