arexxd.c

   1 /*
   2  *      Linux Interfece for Arexx Data Loggers
   3  *
   4  *      (c) 2011-2012 Martin Mares <mj@ucw.cz>
   5  */
   6
   7 #include <stdio.h>
   8 #include <stdarg.h>
   9 #include <stdlib.h>
  10 #include <string.h>
  11 #include <unistd.h>
  12 #include <fcntl.h>
  13 #include <math.h>
  14 #include <time.h>
  15 #include <getopt.h>
  16 #include <syslog.h>
  17 #include <signal.h>
  18 #include <sys/stat.h>
  19 #include <libusb-1.0/libusb.h>
  20 #include <rrd.h>
  21
  22 #define DEFAULT_LOG_DIR "/var/log/arexxd"
  23
  24 typedef unsigned char byte;
  25 static libusb_context *usb_ctxt;
  26 static libusb_device_handle *devh;
  27
  28 static int use_syslog;
  29 static int debug_mode;
  30 static int debug_packets;
  31 static int debug_raw_data;
  32 static char *log_dir = DEFAULT_LOG_DIR;
  33
  34 static void die(char *fmt, ...)
  35 {
  36         va_list args;
  37         va_start(args, fmt);
  38         if (use_syslog)
  39                 vsyslog(LOG_CRIT, fmt, args);
  40         else {
  41                 vfprintf(stderr, fmt, args);
  42                 fprintf(stderr, "\n");
  43         }
  44         va_end(args);
  45         exit(1);
  46 }
  47
  48 static void log_error(char *fmt, ...)
  49 {
  50         va_list args;
  51         va_start(args, fmt);
  52         if (use_syslog)
  53                 vsyslog(LOG_ERR, fmt, args);
  54         else {
  55                 vfprintf(stderr, fmt, args);
  56                 fprintf(stderr, "\n");
  57         }
  58         va_end(args);
  59 }
  60
  61 static void log_info(char *fmt, ...)
  62 {
  63         va_list args;
  64         va_start(args, fmt);
  65         if (use_syslog)
  66                 vsyslog(LOG_INFO, fmt, args);
  67         else {
  68                 vfprintf(stderr, fmt, args);
  69                 fprintf(stderr, "\n");
  70         }
  71         va_end(args);
  72 }
  73
  74 static void log_pkt(char *fmt, ...)
  75 {
  76         if (!debug_packets)
  77                 return;
  78         va_list args;
  79         va_start(args, fmt);
  80         vprintf(fmt, args);
  81         va_end(args);
  82 }
  83
  84 /*** RRD interface ***/
  85
  86 #define MAX_ARGS 20
  87 #define MAX_ARG_SIZE 1024
  88
  89 static int arg_cnt;
  90 static char *arg_ptr[MAX_ARGS+1];
  91 static char arg_buf[MAX_ARG_SIZE];
  92 static int arg_pos;
  93
  94 static void arg_new(void)
  95 {
  96         arg_cnt = 1;
  97         arg_pos = 0;
  98         arg_ptr[0] = "rrdtool";
  99 }
 100
 101 static void arg_push(const char *fmt, ...)
 102 {
 103         if (arg_cnt >= MAX_ARGS)
 104                 die("MAX_ARGS exceeded");
 105         va_list va;
 106         va_start(va, fmt);
 107         int len = 1 + vsnprintf(arg_buf + arg_pos, MAX_ARG_SIZE - arg_pos, fmt, va);
 108         if (arg_pos + len > MAX_ARG_SIZE)
 109                 die("MAX_ARG_SIZE exceeded");
 110         arg_ptr[arg_cnt++] = arg_buf + arg_pos;
 111         arg_ptr[arg_cnt] = NULL;
 112         arg_pos += len;
 113 }
 114
 115 static void rrd_point(time_t t, const char *name, double val, char *unit)
 116 {
 117         char rr_name[256];
 118         snprintf(rr_name, sizeof(rr_name), "sensor-%s.rrd", name);
 119
 120         struct stat st;
 121         if (stat(rr_name, &st) < 0 || !st.st_size) {
 122                 // We have to create the RRD
 123                 log_info("Creating %s", rr_name);
 124                 arg_new();
 125                 arg_push(rr_name);
 126                 arg_push("--start");
 127                 arg_push("%d", (int) time(NULL) - 28*86400);
 128                 arg_push("--step");
 129                 arg_push("60");
 130                 if (!strcmp(unit, "%RH"))
 131                         arg_push("DS:rh:GAUGE:300:0:100");
 132                 else if (!strcmp(unit, "ppm"))
 133                         arg_push("DS:ppm:GAUGE:300:0:1000000");
 134                 else
 135                         arg_push("DS:temp:GAUGE:300:-200:200");
 136                 arg_push("RRA:AVERAGE:0.25:1:20160");           // Last 14 days with full resolution
 137                 arg_push("RRA:AVERAGE:0.25:60:88800");          // Last 10 years with 1h resolution
 138                 arg_push("RRA:MIN:0.25:60:88800");              // including minima and maxima
 139                 arg_push("RRA:MAX:0.25:60:88800");
 140                 rrd_create(arg_cnt, arg_ptr);
 141                 if (rrd_test_error()) {
 142                         log_error("rrd_create on %s failed: %s", rr_name, rrd_get_error());
 143                         return;
 144                 }
 145         }
 146
 147         arg_new();
 148         arg_push(rr_name);
 149         arg_push("%d:%f", t, val);
 150         rrd_update(arg_cnt, arg_ptr);
 151         if (rrd_test_error())
 152                 log_error("rrd_update on %s failed: %s", rr_name, rrd_get_error());
 153 }
 154
 155 /*** Transforms ***/
 156
 157 #define TIME_OFFSET 946681200           // Timestamp of 2000-01-01 00:00:00
 158
 159 static int data_point_counter;          // Since last log message
 160
 161 static double correct_point(int id, double val, const char **name)
 162 {
 163         /*
 164          *  Manually calculated corrections and renames for my sensors.
 165          *  Replace with your formulae.
 166          */
 167         switch (id) {
 168                 case 10415:
 169                         *name = "ursarium";
 170                         return val - 0.93;
 171                 case 10707:
 172                         *name = "balcony";
 173                         return val - 0.71;
 174                 case 19246:
 175                         *name = "catarium";
 176                         return val + 0.49;
 177                 case 19247:
 178                         *name = "catarium-rh";
 179                         return val;
 180                 case 12133:
 181                         *name = "outside";
 182                         return val + 0.44;
 183                 default:
 184                         return val;
 185         }
 186 }
 187
 188 static void cooked_point(time_t t, int id, double val, char *unit, int q)
 189 {
 190         char namebuf[16];
 191         snprintf(namebuf, sizeof(namebuf), "%d", id);
 192         const char *name = namebuf;
 193
 194         double val2 = correct_point(id, val, &name);
 195
 196         if (debug_raw_data) {
 197                 struct tm tm;
 198                 localtime_r(&t, &tm);
 199                 char tbuf[64];
 200                 strftime(tbuf, sizeof(tbuf), "%Y-%m-%d %H:%M:%S", &tm);
 201                 printf("== %s id=%d name=%s val=%.3f val2=%.3f unit=%s q=%d\n", tbuf, id, name, val, val2, unit, q);
 202         }
 203
 204         data_point_counter++;
 205         rrd_point(t, name, val2, unit);
 206 }
 207
 208 static void raw_point(int t, int id, int raw, int q)
 209 {
 210         /*
 211          *  The binary blob provided by Arexx contains an embedded XML fragment
 212          *  with descriptions of all known sensor types. If you want to see it,
 213          *  grep the blob for "<deviceinfo>". The meanings of the parameters are
 214          *  as follows:
 215          *
 216          *      m1, m2          Device type matches if (raw_sensor_id & m1) == m2
 217          *      type            Unit measured by the sensor (1=Celsius, 2=RH%, 3=CO2 ppm)
 218          *      dm              User-visible sensor ID = raw_sensor_id & dm
 219          *      i               1 if the raw value is signed
 220          *      p[]             Coefficients of transformation polynomial (x^0 first)
 221          *      vLo, vUp        Upper and lower bound on the final value
 222          *      scale           Scaling function:
 223          *                              0 = identity (default)
 224          *                              1 = 10^x
 225          *                              2 = exp(x)
 226          *                              3 = (x < 0) ? 0 : log10(x)
 227          *                              4 = (x < 0) ? 0 : log(x)
 228          *
 229          *  The raw values are transformed this way:
 230          *      - sign-extend if signed
 231          *      - apply the transformation polynomial
 232          *      - apply the scaling function
 233          *      - drop if outside the interval [vLo,vUp]
 234          *
 235          *  This function applies the necessary transform for sensors we've
 236          *  seen in the wild. We deliberately ignore the "dm" parameter as we want
 237          *  to report different channels of a single sensor as multiple sensors.
 238          */
 239
 240         double z = raw;
 241         double hi, lo;
 242         char *unit;
 243         int idhi = id & 0xf000;
 244
 245         if (idhi == 0x1000) {
 246                 z = 0.02*z - 273.15;
 247                 lo = -200;
 248                 hi = 600;
 249                 unit = "C";
 250         } else if (idhi == 0x2000) {
 251                 if (raw >= 0x8000)
 252                         z -= 0x10000;
 253                 z /= 128;
 254                 lo = -60;
 255                 hi = 125;
 256                 unit = "C";
 257         } else if (idhi == 0x4000) {
 258                 if (!(id & 1)) {
 259                         z = z/100 - 39.6;
 260                         lo = -60;
 261                         hi = 125;
 262                         unit = "C";
 263                 } else {
 264                         z = -2.8e-6*z*z + 0.0405*z - 4;
 265                         lo = 0;
 266                         hi = 100.1;
 267                         unit = "%RH";
 268                 }
 269         } else if (idhi == 0x6000) {
 270                 if (!(id & 1)) {
 271                         if (raw >= 0x8000)
 272                                 z -= 0x10000;
 273                         z /= 128;
 274                         lo = -60;
 275                         hi = 125;
 276                         unit = "C";
 277                 } else {
 278                         z = -3.8123e-11*z;
 279                         z = (z + 1.9184e-7) * z;
 280                         z = (z - 1.0998e-3) * z;
 281                         z += 6.56;
 282                         z = pow(10, z);
 283                         lo = 0;
 284                         hi = 1e6;
 285                         unit = "ppm";
 286                 }
 287         } else {
 288                 log_error("Unknown sensor type 0x%04x", id);
 289                 return;
 290         }
 291
 292         if (z < lo || z > hi) {
 293                 log_error("Sensor %d: value %f out of range", id, z);
 294                 return;
 295         }
 296
 297         cooked_point(t + TIME_OFFSET, id, z, unit, q);
 298 }
 299
 300 /*** USB interface ***/
 301
 302 static int find_device(void)
 303 {
 304         libusb_device **devlist;
 305         ssize_t devn = libusb_get_device_list(usb_ctxt, &devlist);
 306         if (devn < 0) {
 307                 log_error("Cannot enumerate USB devices: error %d", (int) devn);
 308                 return 0;
 309         }
 310
 311         for (ssize_t i=0; i<devn; i++) {
 312                 struct libusb_device_descriptor desc;
 313                 libusb_device *dev = devlist[i];
 314                 if (!libusb_get_device_descriptor(dev, &desc)) {
 315                         if (desc.idVendor == 0x0451 && desc.idProduct == 0x3211) {
 316                                 log_info("Arexx data logger found at usb%d.%d", libusb_get_bus_number(dev), libusb_get_device_address(dev));
 317                                 int err;
 318                                 if (err = libusb_open(dev, &devh)) {
 319                                         log_error("libusb_open() failed: error %d", err);
 320                                         goto failed;
 321                                 }
 322                                 if (err = libusb_claim_interface(devh, 0)) {
 323                                         log_error("libusb_claim_interface() failed: error %d", err);
 324                                         libusb_close(devh);
 325                                         goto failed;
 326                                 }
 327                                 libusb_free_device_list(devlist, 1);
 328                                 return 1;
 329                         }
 330                 }
 331         }
 332
 333 failed:
 334         libusb_free_device_list(devlist, 1);
 335         return 0;
 336 }
 337
 338 static void release_device(void)
 339 {
 340         libusb_close(devh);
 341         devh = NULL;
 342 }
 343
 344 static void dump_packet(byte *pkt)
 345 {
 346         for (int i=0; i<64; i++) {
 347                 if (!(i % 16))
 348                         log_pkt("\t%02x:", i);
 349                 log_pkt(" %02x", pkt[i]);
 350                 if (i % 16 == 15)
 351                         log_pkt("\n");
 352         }
 353 }
 354
 355 static int send_and_receive(byte *req, byte *reply)
 356 {
 357         if (debug_packets) {
 358                 time_t t = time(NULL);
 359                 struct tm tm;
 360                 localtime_r(&t, &tm);
 361
 362                 char tbuf[64];
 363                 strftime(tbuf, sizeof(tbuf), "%Y-%m-%d %H:%M:%S", &tm);
 364                 log_pkt("## %s\n", tbuf);
 365         }
 366
 367         int err, transferred;
 368         if (err = libusb_bulk_transfer(devh, 0x01, req, 64, &transferred, 200)) {
 369                 if (err == LIBUSB_ERROR_TIMEOUT) {
 370                         log_pkt(">> xmit timed out\n");
 371                         return 0;
 372                 }
 373                 log_pkt(">> xmit error %d\n", err);
 374                 log_error("Transmit error: %d", err);
 375                 return err;
 376         }
 377         if (debug_packets) {
 378                 log_pkt(">> xmit %d bytes\n", transferred);
 379                 dump_packet(req);
 380         }
 381         if (err = libusb_bulk_transfer(devh, 0x81, reply, 64, &transferred, 200)) {
 382                 if (err == LIBUSB_ERROR_TIMEOUT) {
 383                         log_pkt("<< recv timed out\n");
 384                         return 0;
 385                 }
 386                 log_pkt("<< recv error %d\n", err);
 387                 log_error("Receive error: %d", err);
 388                 return err;
 389         }
 390         if (debug_packets)
 391                 log_pkt("<< recv %d bytes\n", transferred);
 392         while (transferred < 64)
 393                 reply[transferred++] = 0xff;
 394         if (debug_packets)
 395                 dump_packet(reply);
 396         return 1;
 397 }
 398
 399 static unsigned int get_be16(byte *p)
 400 {
 401         return p[1] | (p[0] << 8);
 402 }
 403
 404 static unsigned int get_le16(byte *p)
 405 {
 406         return p[0] | (p[1] << 8);
 407 }
 408
 409 static unsigned int get_le32(byte *p)
 410 {
 411         return get_le16(p) | (get_le16(p+2) << 16);
 412 }
 413
 414 static void put_le16(byte *p, unsigned int x)
 415 {
 416         p[0] = x;
 417         p[1] = x >> 8;
 418 }
 419
 420 static void put_le32(byte *p, unsigned int x)
 421 {
 422         put_le16(p, x);
 423         put_le16(p+2, x>>16);
 424 }
 425
 426 static int parse_packet(byte *reply)
 427 {
 428         if (reply[0]) {
 429                 log_error("Unknown packet type %02x", reply[0]);
 430                 return 0;
 431         }
 432
 433         int pos = 1;
 434         int points = 0;
 435         while (pos < 64) {
 436                 byte *p = reply + pos;
 437                 int len = p[0];
 438                 if (!len || len == 0xff)
 439                         break;
 440                 if (len < 9 || len > 10) {
 441                         log_error("Unknown tuple length %02x", len);
 442                         break;
 443                 }
 444                 if (pos + len > 64) {
 445                         log_error("Tuple truncated");
 446                         break;
 447                 }
 448                 int id = get_le16(p+1);
 449                 int raw = get_be16(p+3);
 450                 int t = get_le32(p+5);
 451                 int q = (len > 9) ? p[9] : -1;
 452                 if (debug_raw_data) {
 453                         printf("... %02x: id=%d raw=%d t=%d", len, id, raw, t);
 454                         if (len > 9)
 455                                 printf(" q=%d", q);
 456                         printf("\n");
 457                 }
 458                 raw_point(t, id, raw, q);
 459                 pos += len;
 460                 points++;
 461         }
 462
 463         return points;
 464 }
 465
 466 static void set_clock(void)
 467 {
 468         byte req[64], reply[64];
 469         memset(req, 0, 64);
 470         req[0] = 4;
 471         time_t t = time(NULL);
 472         put_le32(req+1, t-TIME_OFFSET);
 473         send_and_receive(req, reply);
 474
 475 #if 0
 476         /*
 477          *  Original software also sends a packet with type 3 and the timestamp,
 478          *  but it does not make any sense, especially as they ignore the sensor
 479          *  readings in the answer.
 480          */
 481         req[0] = 3;
 482         send_and_receive(req, reply);
 483         parse_packet(reply);
 484 #endif
 485 }
 486
 487 /*** Main ***/
 488
 489 static volatile sig_atomic_t want_shutdown;
 490
 491 static void sigterm_handler(int sig __attribute__((unused)))
 492 {
 493         want_shutdown = 1;
 494 }
 495
 496 static const struct option long_options[] = {
 497         { "debug",              0, NULL, 'd' },
 498         { "log-dir",            1, NULL, 'l' },
 499         { "debug-packets",      0, NULL, 'p' },
 500         { "debug-raw",          0, NULL, 'r' },
 501         { NULL,                 0, NULL, 0 },
 502 };
 503
 504 static void usage(void)
 505 {
 506         fprintf(stderr, "\n\
 507 Usage: arexxd <options>\n\
 508 \n\
 509 Options:\n\
 510 -d, --debug             Debug mode (no chdir, no fork, no syslog)\n\
 511 -l, --log-dir=<dir>     Directory where all received data should be stored\n\
 512 -p, --debug-packets     Log all packets sent and received\n\
 513 -r, --debug-raw         Log conversion from raw values\n\
 514 ");
 515         exit(1);
 516 }
 517
 518 int main(int argc, char **argv)
 519 {
 520         int opt;
 521         while ((opt = getopt_long(argc, argv, "dl:pr", long_options, NULL)) >= 0)
 522                 switch (opt) {
 523                         case 'd':
 524                                 debug_mode++;
 525                                 break;
 526                         case 'l':
 527                                 log_dir = optarg;
 528                                 break;
 529                         case 'p':
 530                                 debug_packets++;
 531                                 break;
 532                         case 'r':
 533                                 debug_raw_data++;
 534                                 break;
 535                         default:
 536                                 usage();
 537                 }
 538         if (optind < argc)
 539                 usage();
 540
 541         int err;
 542         if (err = libusb_init(&usb_ctxt))
 543                 die("Cannot initialize libusb: error %d", err);
 544         // libusb_set_debug(usb_ctxt, 3);
 545
 546         if (!debug_mode) {
 547                 if (chdir(log_dir) < 0)
 548                         die("Cannot change directory to %s: %m", log_dir);
 549                 if (debug_packets || debug_raw_data) {
 550                         close(1);
 551                         if (open("debug", O_WRONLY | O_CREAT | O_APPEND, 0666) < 0)
 552                                 die("Cannot open debug log: %m");
 553                         setlinebuf(stdout);
 554                 }
 555                 openlog("arexxd", LOG_NDELAY, LOG_DAEMON);
 556                 pid_t pid = fork();
 557                 if (pid < 0)
 558                         die("fork() failed: %m");
 559                 if (pid)
 560                         return 0;
 561                 setsid();
 562                 use_syslog = 1;
 563         }
 564
 565         struct sigaction sa = { .sa_handler = sigterm_handler };
 566         sigaction(SIGTERM, &sa, NULL);
 567         sigaction(SIGINT, &sa, NULL);
 568
 569         sigset_t term_sigs;
 570         sigemptyset(&term_sigs);
 571         sigaddset(&term_sigs, SIGTERM);
 572         sigaddset(&term_sigs, SIGINT);
 573         sigprocmask(SIG_BLOCK, &term_sigs, NULL);
 574
 575         int inited = 0;
 576         while (!want_shutdown) {
 577                 if (!find_device()) {
 578                         if (!inited) {
 579                                 inited = 1;
 580                                 log_error("Data logger not connected, waiting until it appears");
 581                         }
 582                         sleep(30);
 583                         continue;
 584                 }
 585                 log_info("Listening");
 586
 587                 time_t last_sync = 0;
 588                 time_t last_show = 0;
 589                 int want_stats = 0;
 590                 int want_sleep = 0;
 591                 data_point_counter = 0;
 592                 while (!want_shutdown) {
 593                         time_t now = time(NULL);
 594                         if (now > last_sync + 900) {
 595                                 log_info("Synchronizing data logger time");
 596                                 set_clock();
 597                                 last_sync = now;
 598                         }
 599                         if (want_stats && now > last_show + 300) {
 600                                 log_info("Stats: received %d data points", data_point_counter);
 601                                 data_point_counter = 0;
 602                                 last_show = now;
 603                         }
 604
 605                         byte req[64], reply[64];
 606                         memset(req, 0, sizeof(req));
 607                         req[0] = 3;
 608                         err = send_and_receive(req, reply);
 609                         if (err < 0)
 610                                 break;
 611                         want_sleep = 1;
 612                         if (err > 0 && parse_packet(reply))
 613                                 want_sleep = 0;
 614                         sigprocmask(SIG_UNBLOCK, &term_sigs, NULL);
 615                         if (want_sleep) {
 616                                 sleep(4);
 617                                 want_stats = 1;
 618                         }
 619                         sigprocmask(SIG_BLOCK, &term_sigs, NULL);
 620                 }
 621
 622                 log_info("Disconnecting data logger");
 623                 release_device();
 624                 inited = 0;
 625         }
 626
 627         log_info("Terminated");
 628         return 0;
 629 }