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