openpilot_comma/selfdrive/can/parser.cc

#include <cstdio>
#include <cstdint>
#include <cassert>
#include <cstring>

#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/mman.h>

#include <string>
#include <vector>
#include <algorithm>
#include <unordered_map>

#include <zmq.h>

#include <capnp/serialize.h>
#include "cereal/gen/cpp/log.capnp.h"

#include "common.h"

#define DEBUG(...)
// #define DEBUG printf
#define INFO printf

#define MAX_BAD_COUNTER 5

// Static lookup table for fast computation of CRC8 poly 0x2F, aka 8H2F/AUTOSAR
uint8_t crc8_lut_8h2f[256];

unsigned int honda_checksum(unsigned int address, uint64_t d, int l) {
  d >>= ((8-l)*8); // remove padding
  d >>= 4; // remove checksum

  int s = 0;
  while (address) { s += (address & 0xF); address >>= 4; }
  while (d) { s += (d & 0xF); d >>= 4; }
  s = 8-s;
  s &= 0xF;

  return s;
}

unsigned int toyota_checksum(unsigned int address, uint64_t d, int l) {
  d >>= ((8-l)*8); // remove padding
  d >>= 8; // remove checksum

  unsigned int s = l;
  while (address) { s += address & 0xff; address >>= 8; }
  while (d) { s += d & 0xff; d >>= 8; }

  return s & 0xFF;
}

unsigned int pedal_checksum(unsigned int address, uint64_t d, int l) {
  uint8_t crc = 0xFF;
  uint8_t poly = 0xD5; // standard crc8

  d >>= ((8-l)*8); // remove padding
  d >>= 8; // remove checksum

  uint8_t *dat = (uint8_t *)&d;

  int i, j;
  for (i = 0; i < l - 1; i++) {
    crc ^= dat[i];
    for (j = 0; j < 8; j++) {
      if ((crc & 0x80) != 0) {
        crc = (uint8_t)((crc << 1) ^ poly);
      }
      else {
        crc <<= 1;
      }
    }
  }
  return crc;
}

void gen_crc_lookup_table(uint8_t poly, uint8_t crc_lut[])
{
  uint8_t crc;
  int i, j;

  for (i = 0; i < 256; i++) {
    crc = i;
    for (j = 0; j < 8; j++) {
      if ((crc & 0x80) != 0)
        crc = (uint8_t)((crc << 1) ^ poly);
      else
        crc <<= 1;
    }
    crc_lut[i] = crc;
  }
}

void init_crc_lookup_tables()
{
  // At init time, set up static lookup tables for fast CRC computation.

  gen_crc_lookup_table(0x2F, crc8_lut_8h2f);    // CRC-8 8H2F/AUTOSAR for Volkswagen
}

unsigned int volkswagen_crc(unsigned int address, uint64_t d, int l)
{
  // Volkswagen uses standard CRC8 8H2F/AUTOSAR, but they compute it with
  // a magic variable padding byte tacked onto the end of the payload.
  // https://www.autosar.org/fileadmin/user_upload/standards/classic/4-3/AUTOSAR_SWS_CRCLibrary.pdf

  uint8_t *dat = (uint8_t *)&d;
  uint8_t crc = 0xFF; // Standard init value for CRC8 8H2F/AUTOSAR

  // CRC the payload first, skipping over the first byte where the CRC lives.
  for (int i = 1; i < l; i++) {
    crc ^= dat[i];
    crc = crc8_lut_8h2f[crc];
  }

  // Look up and apply the magic final CRC padding byte, which permutes by CAN
  // address, and additionally (for SOME addresses) by the message counter.
  uint8_t counter = dat[1] & 0x0F;
  switch(address) {
    case 0x86:  // LWI_01 Steering Angle
      crc ^= (uint8_t[]){0x86,0x86,0x86,0x86,0x86,0x86,0x86,0x86,0x86,0x86,0x86,0x86,0x86,0x86,0x86,0x86}[counter];
      break;
    case 0x9F:  // EPS_01 Electric Power Steering
      crc ^= (uint8_t[]){0xF5,0xF5,0xF5,0xF5,0xF5,0xF5,0xF5,0xF5,0xF5,0xF5,0xF5,0xF5,0xF5,0xF5,0xF5,0xF5}[counter];
      break;
    case 0xAD:  // Getriebe_11 Automatic Gearbox
      crc ^= (uint8_t[]){0x3F,0x69,0x39,0xDC,0x94,0xF9,0x14,0x64,0xD8,0x6A,0x34,0xCE,0xA2,0x55,0xB5,0x2C}[counter];
      break;
    case 0xFD:  // ESP_21 Electronic Stability Program
      crc ^= (uint8_t[]){0xB4,0xEF,0xF8,0x49,0x1E,0xE5,0xC2,0xC0,0x97,0x19,0x3C,0xC9,0xF1,0x98,0xD6,0x61}[counter];
      break;
    case 0x106: // ESP_05 Electronic Stability Program
      crc ^= (uint8_t[]){0x07,0x07,0x07,0x07,0x07,0x07,0x07,0x07,0x07,0x07,0x07,0x07,0x07,0x07,0x07,0x07}[counter];
      break;
    case 0x117: // ACC_10 Automatic Cruise Control
      crc ^= (uint8_t[]){0xAC,0xAC,0xAC,0xAC,0xAC,0xAC,0xAC,0xAC,0xAC,0xAC,0xAC,0xAC,0xAC,0xAC,0xAC,0xAC}[counter];
      break;
    case 0x122: // ACC_06 Automatic Cruise Control
      crc ^= (uint8_t[]){0x37,0x7D,0xF3,0xA9,0x18,0x46,0x6D,0x4D,0x3D,0x71,0x92,0x9C,0xE5,0x32,0x10,0xB9}[counter];
      break;
    case 0x126: // HCA_01 Heading Control Assist
      crc ^= (uint8_t[]){0xDA,0xDA,0xDA,0xDA,0xDA,0xDA,0xDA,0xDA,0xDA,0xDA,0xDA,0xDA,0xDA,0xDA,0xDA,0xDA}[counter];
      break;
    case 0x12B: // GRA_ACC_01 Steering wheel controls for ACC
      crc ^= (uint8_t[]){0x6A,0x38,0xB4,0x27,0x22,0xEF,0xE1,0xBB,0xF8,0x80,0x84,0x49,0xC7,0x9E,0x1E,0x2B}[counter];
      break;
    case 0x187: // EV_Gearshift "Gear" selection data for EVs with no gearbox
      crc ^= (uint8_t[]){0x7F,0xED,0x17,0xC2,0x7C,0xEB,0x44,0x21,0x01,0xFA,0xDB,0x15,0x4A,0x6B,0x23,0x05}[counter];
      break;
    case 0x30C: // ACC_02 Automatic Cruise Control
      crc ^= (uint8_t[]){0x0F,0x0F,0x0F,0x0F,0x0F,0x0F,0x0F,0x0F,0x0F,0x0F,0x0F,0x0F,0x0F,0x0F,0x0F,0x0F}[counter];
      break;
    case 0x3C0: // Klemmen_Status_01 ignition and starting status
      crc ^= (uint8_t[]){0xC3,0xC3,0xC3,0xC3,0xC3,0xC3,0xC3,0xC3,0xC3,0xC3,0xC3,0xC3,0xC3,0xC3,0xC3,0xC3}[counter];
      break;
    case 0x65D: // ESP_20 Electronic Stability Program
      crc ^= (uint8_t[]){0xAC,0xB3,0xAB,0xEB,0x7A,0xE1,0x3B,0xF7,0x73,0xBA,0x7C,0x9E,0x06,0x5F,0x02,0xD9}[counter];
      break;
    default:    // As-yet undefined CAN message, CRC check expected to fail
      INFO("Attempt to CRC check undefined Volkswagen message 0x%02X\n", address);
      crc ^= (uint8_t[]){0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00}[counter];
      break;
  }
  crc = crc8_lut_8h2f[crc];

  return crc ^ 0xFF; // Return after standard final XOR for CRC8 8H2F/AUTOSAR
}

namespace {

uint64_t read_u64_be(const uint8_t* v) {
  return (((uint64_t)v[0] << 56)
          | ((uint64_t)v[1] << 48)
          | ((uint64_t)v[2] << 40)
          | ((uint64_t)v[3] << 32)
          | ((uint64_t)v[4] << 24)
          | ((uint64_t)v[5] << 16)
          | ((uint64_t)v[6] << 8)
          | (uint64_t)v[7]);
}

uint64_t read_u64_le(const uint8_t* v) {
  return ((uint64_t)v[0]
          | ((uint64_t)v[1] << 8)
          | ((uint64_t)v[2] << 16)
          | ((uint64_t)v[3] << 24)
          | ((uint64_t)v[4] << 32)
          | ((uint64_t)v[5] << 40)
          | ((uint64_t)v[6] << 48)
          | ((uint64_t)v[7] << 56));
}


struct MessageState {
  uint32_t address;
  unsigned int size;

  std::vector<Signal> parse_sigs;
  std::vector<double> vals;

  uint16_t ts;
  uint64_t seen;
  uint64_t check_threshold;

  uint8_t counter;
  uint8_t counter_fail;

  bool parse(uint64_t sec, uint16_t ts_, uint64_t dat) {
    for (int i=0; i < parse_sigs.size(); i++) {
      auto& sig = parse_sigs[i];
      int64_t tmp;

      if (sig.is_little_endian){
        tmp = (dat >> sig.b1) & ((1ULL << sig.b2)-1);
      } else {
        tmp = (dat >> sig.bo) & ((1ULL << sig.b2)-1);
      }

      if (sig.is_signed) {
        tmp -= (tmp >> (sig.b2-1)) ? (1ULL << sig.b2) : 0; //signed
      }

      DEBUG("parse 0x%X %s -> %lld\n", address, sig.name, tmp);

      if (sig.type == SignalType::HONDA_CHECKSUM) {
        if (honda_checksum(address, dat, size) != tmp) {
          INFO("0x%X CHECKSUM FAIL\n", address);
          return false;
        }
      } else if (sig.type == SignalType::HONDA_COUNTER) {
        if (!update_counter_generic(tmp, sig.b2)) {
          return false;
        }
      } else if (sig.type == SignalType::TOYOTA_CHECKSUM) {
        if (toyota_checksum(address, dat, size) != tmp) {
          INFO("0x%X CHECKSUM FAIL\n", address);
          return false;
        }
      } else if (sig.type == SignalType::VOLKSWAGEN_CHECKSUM) {
        if (volkswagen_crc(address, dat, size) != tmp) {
          INFO("0x%X CRC FAIL\n", address);
          return false;
        }
      } else if (sig.type == SignalType::VOLKSWAGEN_COUNTER) {
        if (!update_counter_generic(tmp, sig.b2)) {
          return false;
        }
      } else if (sig.type == SignalType::PEDAL_CHECKSUM) {
        if (pedal_checksum(address, dat, size) != tmp) {
          INFO("0x%X PEDAL CHECKSUM FAIL\n", address);
          return false;
        }
      } else if (sig.type == SignalType::PEDAL_COUNTER) {
        if (!update_counter_generic(tmp, sig.b2)) {
          return false;
        }
      }

      vals[i] = tmp * sig.factor + sig.offset;
    }
    ts = ts_;
    seen = sec;

    return true;
  }


  bool update_counter_generic(int64_t v, int cnt_size) {
    uint8_t old_counter = counter;
    counter = v;
    if (((old_counter+1) & ((1 << cnt_size) -1)) != v) {
      counter_fail += 1;
      if (counter_fail > 1) {
        INFO("0x%X COUNTER FAIL %d -- %d vs %d\n", address, counter_fail, old_counter, (int)v);
      }
      if (counter_fail >= MAX_BAD_COUNTER) {
        return false;
      }
    } else if (counter_fail > 0) {
      counter_fail--;
    }
    return true;
  }

};


class CANParser {
 public:
  CANParser(int abus, const std::string& dbc_name,
            const std::vector<MessageParseOptions> &options,
            const std::vector<SignalParseOptions> &sigoptions,
            bool sendcan, const std::string& tcp_addr, int timeout=-1)
    : bus(abus) {
    // connect to can on 8006
    context = zmq_ctx_new();

    if (tcp_addr.length() > 0) {
      subscriber = zmq_socket(context, ZMQ_SUB);
      zmq_setsockopt(subscriber, ZMQ_SUBSCRIBE, "", 0);
      zmq_setsockopt(subscriber, ZMQ_RCVTIMEO, &timeout, sizeof(int));

      std::string tcp_addr_str;

      if (sendcan) {
        tcp_addr_str = "tcp://" + tcp_addr + ":8017";
      } else {
        tcp_addr_str = "tcp://" + tcp_addr + ":8006";
      }
      const char *tcp_addr_char = tcp_addr_str.c_str();

      zmq_connect(subscriber, tcp_addr_char);

      // drain sendcan to delete any stale messages from previous runs
      zmq_msg_t msgDrain;
      zmq_msg_init(&msgDrain);
      int err = 0;
      while(err >= 0) {
        err = zmq_msg_recv(&msgDrain, subscriber, ZMQ_DONTWAIT);
      }
    } else {
      subscriber = NULL;
    }

    dbc = dbc_lookup(dbc_name);
    assert(dbc);
    init_crc_lookup_tables();

    for (const auto& op : options) {
      MessageState state = {
        .address = op.address,
        // .check_frequency = op.check_frequency,
      };

      // msg is not valid if a message isn't received for 10 consecutive steps
      if (op.check_frequency > 0) {
        state.check_threshold = (1000000000ULL / op.check_frequency) * 10;
      }


      const Msg* msg = NULL;
      for (int i=0; i<dbc->num_msgs; i++) {
        if (dbc->msgs[i].address == op.address) {
          msg = &dbc->msgs[i];
          break;
        }
      }
      if (!msg) {
        fprintf(stderr, "CANParser: could not find message 0x%X in dnc %s\n", op.address, dbc_name.c_str());
        assert(false);
      }

      state.size = msg->size;

      // track checksums and counters for this message
      for (int i=0; i<msg->num_sigs; i++) {
        const Signal *sig = &msg->sigs[i];
        if (sig->type != SignalType::DEFAULT) {
          state.parse_sigs.push_back(*sig);
          state.vals.push_back(0);
        }
      }

      // track requested signals for this message
      for (const auto& sigop : sigoptions) {
        if (sigop.address != op.address) continue;

        for (int i=0; i<msg->num_sigs; i++) {
          const Signal *sig = &msg->sigs[i];
          if (strcmp(sig->name, sigop.name) == 0
              && sig->type == SignalType::DEFAULT) {
            state.parse_sigs.push_back(*sig);
            state.vals.push_back(sigop.default_value);
            break;
          }
        }

      }

      message_states[state.address] = state;
    }
  }

  void UpdateCans(uint64_t sec, const capnp::List<cereal::CanData>::Reader& cans) {
      int msg_count = cans.size();
      uint64_t p;

      DEBUG("got %d messages\n", msg_count);

      // parse the messages
      for (int i = 0; i < msg_count; i++) {
        auto cmsg = cans[i];
        if (cmsg.getSrc() != bus) {
          // DEBUG("skip %d: wrong bus\n", cmsg.getAddress());
          continue;
        }
        auto state_it = message_states.find(cmsg.getAddress());
        if (state_it == message_states.end()) {
          // DEBUG("skip %d: not specified\n", cmsg.getAddress());
          continue;
        }

        if (cmsg.getDat().size() > 8) continue; //shouldnt ever happen
        uint8_t dat[8] = {0};
        memcpy(dat, cmsg.getDat().begin(), cmsg.getDat().size());

        // Assumes all signals in the message are of the same type (little or big endian)
        // TODO: allow signals within the same message to have different endianess
        auto& sig = message_states[cmsg.getAddress()].parse_sigs[0];
        if (sig.is_little_endian) {
            p = read_u64_le(dat);
        } else {
            p = read_u64_be(dat);
        }

        DEBUG("  proc %X: %llx\n", cmsg.getAddress(), p);

        state_it->second.parse(sec, cmsg.getBusTime(), p);
      }
  }

  void UpdateValid(uint64_t sec) {
    can_valid = true;
    for (const auto& kv : message_states) {
      const auto& state = kv.second;
      if (state.check_threshold > 0 && (sec - state.seen) > state.check_threshold) {
        if (state.seen > 0) {
          DEBUG("%X TIMEOUT\n", state.address);
        }
        can_valid = false;
      }
    }
  }

  void update_string(std::string data) {
    // format for board, make copy due to alignment issues, will be freed on out of scope
    auto amsg = kj::heapArray<capnp::word>((data.length() / sizeof(capnp::word)) + 1);
    memcpy(amsg.begin(), data.data(), data.length());

    // extract the messages
    capnp::FlatArrayMessageReader cmsg(amsg);
    cereal::Event::Reader event = cmsg.getRoot<cereal::Event>();

    last_sec = event.getLogMonoTime();

    auto cans = event.getCan();
    UpdateCans(last_sec, cans);

    UpdateValid(last_sec);
  }

  int update(uint64_t sec, bool wait) {
    int err;
    int result = 0;

    // recv from can
    zmq_msg_t msg;
    zmq_msg_init(&msg);

    // multiple recv is fine
    bool first = wait;
    while (subscriber != NULL) {
      if (first) {
        err = zmq_msg_recv(&msg, subscriber, 0);
        first = false;

        // When we timeout on the first message, return error
        if (err < 0){
          result = -1;
        }
      } else {
        err = zmq_msg_recv(&msg, subscriber, ZMQ_DONTWAIT);
      }
      if (err < 0) break;

      // format for board, make copy due to alignment issues, will be freed on out of scope
      auto amsg = kj::heapArray<capnp::word>((zmq_msg_size(&msg) / sizeof(capnp::word)) + 1);
      memcpy(amsg.begin(), zmq_msg_data(&msg), zmq_msg_size(&msg));

      // extract the messages
      capnp::FlatArrayMessageReader cmsg(amsg);
      cereal::Event::Reader event = cmsg.getRoot<cereal::Event>();

      auto cans = event.getCan();
      UpdateCans(sec, cans);
    }

    last_sec = sec;
    UpdateValid(sec);
    zmq_msg_close(&msg);
    return result;
  }

  std::vector<SignalValue> query_latest() {
    std::vector<SignalValue> ret;

    for (const auto& kv : message_states) {
      const auto& state = kv.second;
      if (last_sec != 0 && state.seen != last_sec) continue;

      for (int i=0; i<state.parse_sigs.size(); i++) {
        const Signal &sig = state.parse_sigs[i];
        ret.push_back((SignalValue){
          .address = state.address,
          .ts = state.ts,
          .name = sig.name,
          .value = state.vals[i],
        });
      }
    }

    return ret;
  }

  bool can_valid = false;
  uint64_t last_sec = 0;

 private:
  const int bus;
  // zmq vars
  void *context = NULL;
  void *subscriber = NULL;

  const DBC *dbc = NULL;
  std::unordered_map<uint32_t, MessageState> message_states;
};

}

extern "C" {

void* can_init(int bus, const char* dbc_name,
               size_t num_message_options, const MessageParseOptions* message_options,
               size_t num_signal_options, const SignalParseOptions* signal_options,
               bool sendcan, const char* tcp_addr, int timeout) {
  CANParser* ret = new CANParser(bus, std::string(dbc_name),
                                 (message_options ? std::vector<MessageParseOptions>(message_options, message_options+num_message_options)
                                  : std::vector<MessageParseOptions>{}),
                                 (signal_options ? std::vector<SignalParseOptions>(signal_options, signal_options+num_signal_options)
                                  : std::vector<SignalParseOptions>{}), sendcan, std::string(tcp_addr), timeout);
  return (void*)ret;
}

void* can_init_with_vectors(int bus, const char* dbc_name,
               std::vector<MessageParseOptions> message_options,
               std::vector<SignalParseOptions> signal_options,
               bool sendcan, const char* tcp_addr, int timeout) {
  CANParser* ret = new CANParser(bus, std::string(dbc_name),
                                 message_options,
                                 signal_options,
                                 sendcan, std::string(tcp_addr), timeout);
  return (void*)ret;
}

int can_update(void* can, uint64_t sec, bool wait) {
  CANParser* cp = (CANParser*)can;
  return cp->update(sec, wait);
}

void can_update_string(void *can, const char* dat, int len) {
  CANParser* cp = (CANParser*)can;
  cp->update_string(std::string(dat, len));
}

size_t can_query_latest(void* can, bool *out_can_valid, size_t out_values_size, SignalValue* out_values) {
  CANParser* cp = (CANParser*)can;

  if (out_can_valid) {
    *out_can_valid = cp->can_valid;
  }

  const std::vector<SignalValue> values = cp->query_latest();
  if (out_values) {
    std::copy(values.begin(), values.begin()+std::min(out_values_size, values.size()), out_values);
  }
  return values.size();
};

void can_query_latest_vector(void* can, bool *out_can_valid, std::vector<SignalValue> &values) {
  CANParser* cp = (CANParser*)can;
  if (out_can_valid) {
    *out_can_valid = cp->can_valid;
  }
  values = cp->query_latest();
};

}

#ifdef TEST

int main(int argc, char** argv) {
  CANParser cp(0, "honda_civic_touring_2016_can",
    std::vector<MessageParseOptions>{
      // address, check_frequency
      {0x14a, 100},
      {0x158, 100},
      {0x17c, 100},
      {0x191, 100},
      {0x1a4, 50},
      {0x326, 10},
      {0x1b0, 50},
      {0x1d0, 50},
      {0x305, 10},
      {0x324, 10},
      {0x405, 3},
      {0x18f, 0},
      {0x130, 0},
      {0x296, 0},
      {0x30c, 0},
    },
    std::vector<SignalParseOptions>{
      //  sig_name, sig_address, default
      {0x158, "XMISSION_SPEED", 0},
      {0x1d0, "WHEEL_SPEED_FL", 0},
      {0x1d0, "WHEEL_SPEED_FR", 0},
      {0x1d0, "WHEEL_SPEED_RL", 0},
      {0x14a, "STEER_ANGLE", 0},
      {0x18f, "STEER_TORQUE_SENSOR", 0},
      {0x191, "GEAR", 0},
      {0x1b0, "WHEELS_MOVING", 1},
      {0x405, "DOOR_OPEN_FL", 1},
      {0x405, "DOOR_OPEN_FR", 1},
      {0x405, "DOOR_OPEN_RL", 1},
      {0x405, "DOOR_OPEN_RR", 1},
      {0x324, "CRUISE_SPEED_PCM", 0},
      {0x305, "SEATBELT_DRIVER_LAMP", 1},
      {0x305, "SEATBELT_DRIVER_LATCHED", 0},
      {0x17c, "BRAKE_PRESSED", 0},
      {0x130, "CAR_GAS", 0},
      {0x296, "CRUISE_BUTTONS", 0},
      {0x1a4, "ESP_DISABLED", 1},
      {0x30c, "HUD_LEAD", 0},
      {0x1a4, "USER_BRAKE", 0},
      {0x18f, "STEER_STATUS", 5},
      {0x1d0, "WHEEL_SPEED_RR", 0},
      {0x1b0, "BRAKE_ERROR_1", 1},
      {0x1b0, "BRAKE_ERROR_2", 1},
      {0x191, "GEAR_SHIFTER", 0},
      {0x326, "MAIN_ON", 0},
      {0x17c, "ACC_STATUS", 0},
      {0x17c, "PEDAL_GAS", 0},
      {0x296, "CRUISE_SETTING", 0},
      {0x326, "LEFT_BLINKER", 0},
      {0x326, "RIGHT_BLINKER", 0},
      {0x324, "COUNTER", 0},
      {0x17c, "ENGINE_RPM", 0},
    });



  const std::string log_fn = "dats.bin";

  int log_fd = open(log_fn.c_str(), O_RDONLY, 0);
  assert(log_fd >= 0);

  off_t log_size = lseek(log_fd, 0, SEEK_END);
  lseek(log_fd, 0, SEEK_SET);

  void* log_data = mmap(NULL, log_size, PROT_READ, MAP_PRIVATE, log_fd, 0);
  assert(log_data);

  auto words = kj::arrayPtr((const capnp::word*)log_data, log_size/sizeof(capnp::word));
  while (words.size() > 0) {
    capnp::FlatArrayMessageReader reader(words);

    auto evt = reader.getRoot<cereal::Event>();
    auto cans = evt.getCan();

    cp.UpdateCans(0, cans);

    words = kj::arrayPtr(reader.getEnd(), words.end());
  }

  munmap(log_data, log_size);

  close(log_fd);

  return 0;
}

#endif