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