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 19246:
 172                         *name = "catarium";
 173                         return val + 0.49;
 174                 case 12133:
 175                         *name = "balcony";
 176                         return val + 0.44;
 177                 default:
 178                         return val;
 179         }
 180 }
 181
 182 static void cooked_point(time_t t, int id, double val, char *unit, int q)
 183 {
 184         char namebuf[16];
 185         snprintf(namebuf, sizeof(namebuf), "%d", id);
 186         const char *name = namebuf;
 187
 188         double val2 = correct_point(id, val, &name);
 189
 190         if (debug_raw_data) {
 191                 struct tm tm;
 192                 localtime_r(&t, &tm);
 193                 char tbuf[64];
 194                 strftime(tbuf, sizeof(tbuf), "%Y-%m-%d %H:%M:%S", &tm);
 195                 printf("== %s id=%d name=%s val=%.3f val2=%.3f unit=%s q=%d\n", tbuf, id, name, val, val2, unit, q);
 196         }
 197
 198         data_point_counter++;
 199         rrd_point(t, name, val2, unit);
 200 }
 201
 202 static void raw_point(int t, int id, int raw, int q)
 203 {
 204         /*
 205          *  The binary blob provided by Arexx contains an embedded XML fragment
 206          *  with descriptions of all known sensor types. If you want to see it,
 207          *  grep the blob for "<deviceinfo>". The meanings of the parameters are
 208          *  as follows:
 209          *
 210          *      m1, m2          Device type matches if (raw_sensor_id & m1) == m2
 211          *      type            Unit measured by the sensor (1=Celsius, 2=RH%, 3=CO2 ppm)
 212          *      dm              User-visible sensor ID = raw_sensor_id & dm
 213          *      i               1 if the raw value is signed
 214          *      p[]             Coefficients of transformation polynomial (x^0 first)
 215          *      vLo, vUp        Upper and lower bound on the final value
 216          *      scale           Scaling function:
 217          *                              0 = identity (default)
 218          *                              1 = 10^x
 219          *                              2 = exp(x)
 220          *                              3 = (x < 0) ? 0 : log10(x)
 221          *                              4 = (x < 0) ? 0 : log(x)
 222          *
 223          *  The raw values are transformed this way:
 224          *      - sign-extend if signed
 225          *      - apply the transformation polynomial
 226          *      - apply the scaling function
 227          *      - drop if outside the interval [vLo,vUp]
 228          *
 229          *  This function applies the necessary transform for sensors we've
 230          *  seen in the wild. We deliberately ignore the "dm" parameter as we want
 231          *  to report different channels of a single sensor as multiple sensors.
 232          */
 233
 234         double z = raw;
 235         double hi, lo;
 236         char *unit;
 237         int idhi = id & 0xf000;
 238
 239         if (idhi == 0x1000) {
 240                 z = 0.02*z - 273.15;
 241                 lo = -200;
 242                 hi = 600;
 243                 unit = "C";
 244         } else if (idhi == 0x2000) {
 245                 if (raw >= 0x8000)
 246                         z -= 0x10000;
 247                 z /= 128;
 248                 lo = -60;
 249                 hi = 125;
 250                 unit = "C";
 251         } else if (idhi == 0x4000) {
 252                 if (!(id & 1)) {
 253                         z = z/100 - 39.6;
 254                         lo = -60;
 255                         hi = 125;
 256                         unit = "C";
 257                 } else {
 258                         z = -2.8e-6*z*z + 0.0405*z - 4;
 259                         lo = 0;
 260                         hi = 100.1;
 261                         unit = "%RH";
 262                 }
 263         } else if (idhi == 0x6000) {
 264                 if (!(id & 1)) {
 265                         if (raw >= 0x8000)
 266                                 z -= 0x10000;
 267                         z /= 128;
 268                         lo = -60;
 269                         hi = 125;
 270                         unit = "C";
 271                 } else {
 272                         z = -3.8123e-11*z;
 273                         z = (z + 1.9184e-7) * z;
 274                         z = (z - 1.0998e-3) * z;
 275                         z += 6.56;
 276                         z = pow(10, z);
 277                         lo = 0;
 278                         hi = 1e6;
 279                         unit = "ppm";
 280                 }
 281         } else {
 282                 log_error("Unknown sensor type 0x%04x", id);
 283                 return;
 284         }
 285
 286         if (z < lo || z > hi) {
 287                 log_error("Sensor %d: value %f out of range", id, z);
 288                 return;
 289         }
 290
 291         cooked_point(t + TIME_OFFSET, id, z, unit, q);
 292 }
 293
 294 /*** USB interface ***/
 295
 296 static int find_device(void)
 297 {
 298         libusb_device **devlist;
 299         ssize_t devn = libusb_get_device_list(usb_ctxt, &devlist);
 300         if (devn < 0) {
 301                 log_error("Cannot enumerate USB devices: error %d", (int) devn);
 302                 return 0;
 303         }
 304
 305         for (ssize_t i=0; i<devn; i++) {
 306                 struct libusb_device_descriptor desc;
 307                 libusb_device *dev = devlist[i];
 308                 if (!libusb_get_device_descriptor(dev, &desc)) {
 309                         if (desc.idVendor == 0x0451 && desc.idProduct == 0x3211) {
 310                                 log_info("Arexx data logger found at usb%d.%d", libusb_get_bus_number(dev), libusb_get_device_address(dev));
 311                                 int err;
 312                                 if (err = libusb_open(dev, &devh)) {
 313                                         log_error("libusb_open() failed: error %d", err);
 314                                         goto failed;
 315                                 }
 316                                 if (err = libusb_claim_interface(devh, 0)) {
 317                                         log_error("libusb_claim_interface() failed: error %d", err);
 318                                         libusb_close(devh);
 319                                         goto failed;
 320                                 }
 321                                 libusb_free_device_list(devlist, 1);
 322                                 return 1;
 323                         }
 324                 }
 325         }
 326
 327 failed:
 328         libusb_free_device_list(devlist, 1);
 329         return 0;
 330 }
 331
 332 static void release_device(void)
 333 {
 334         libusb_close(devh);
 335         devh = NULL;
 336 }
 337
 338 static void dump_packet(byte *pkt)
 339 {
 340         for (int i=0; i<64; i++) {
 341                 if (!(i % 16))
 342                         log_pkt("\t%02x:", i);
 343                 log_pkt(" %02x", pkt[i]);
 344                 if (i % 16 == 15)
 345                         log_pkt("\n");
 346         }
 347 }
 348
 349 static int send_and_receive(byte *req, byte *reply)
 350 {
 351         if (debug_packets) {
 352                 time_t t = time(NULL);
 353                 struct tm tm;
 354                 localtime_r(&t, &tm);
 355
 356                 char tbuf[64];
 357                 strftime(tbuf, sizeof(tbuf), "%Y-%m-%d %H:%M:%S", &tm);
 358                 log_pkt("## %s\n", tbuf);
 359         }
 360
 361         int err, transferred;
 362         if (err = libusb_bulk_transfer(devh, 0x01, req, 64, &transferred, 200)) {
 363                 if (err == LIBUSB_ERROR_TIMEOUT) {
 364                         log_pkt(">> xmit timed out\n");
 365                         return 0;
 366                 }
 367                 log_pkt(">> xmit error %d\n", err);
 368                 log_error("Transmit error: %d", err);
 369                 return err;
 370         }
 371         if (debug_packets) {
 372                 log_pkt(">> xmit %d bytes\n", transferred);
 373                 dump_packet(req);
 374         }
 375         if (err = libusb_bulk_transfer(devh, 0x81, reply, 64, &transferred, 200)) {
 376                 if (err == LIBUSB_ERROR_TIMEOUT) {
 377                         log_pkt("<< recv timed out\n");
 378                         return 0;
 379                 }
 380                 log_pkt("<< recv error %d\n", err);
 381                 log_error("Receive error: %d", err);
 382                 return err;
 383         }
 384         if (debug_packets)
 385                 log_pkt("<< recv %d bytes\n", transferred);
 386         while (transferred < 64)
 387                 reply[transferred++] = 0xff;
 388         if (debug_packets)
 389                 dump_packet(reply);
 390         return 1;
 391 }
 392
 393 static unsigned int get_be16(byte *p)
 394 {
 395         return p[1] | (p[0] << 8);
 396 }
 397
 398 static unsigned int get_le16(byte *p)
 399 {
 400         return p[0] | (p[1] << 8);
 401 }
 402
 403 static unsigned int get_le32(byte *p)
 404 {
 405         return get_le16(p) | (get_le16(p+2) << 16);
 406 }
 407
 408 static void put_le16(byte *p, unsigned int x)
 409 {
 410         p[0] = x;
 411         p[1] = x >> 8;
 412 }
 413
 414 static void put_le32(byte *p, unsigned int x)
 415 {
 416         put_le16(p, x);
 417         put_le16(p+2, x>>16);
 418 }
 419
 420 static int parse_packet(byte *reply)
 421 {
 422         if (reply[0]) {
 423                 log_error("Unknown packet type %02x", reply[0]);
 424                 return 0;
 425         }
 426
 427         int pos = 1;
 428         int points = 0;
 429         while (pos < 64) {
 430                 byte *p = reply + pos;
 431                 int len = p[0];
 432                 if (!len || len == 0xff)
 433                         break;
 434                 if (len < 9 || len > 10) {
 435                         log_error("Unknown tuple length %02x", len);
 436                         break;
 437                 }
 438                 if (pos + len > 64) {
 439                         log_error("Tuple truncated");
 440                         break;
 441                 }
 442                 int id = get_le16(p+1);
 443                 int raw = get_be16(p+3);
 444                 int t = get_le32(p+5);
 445                 int q = (len > 9) ? p[9] : -1;
 446                 if (debug_raw_data) {
 447                         printf("... %02x: id=%d raw=%d t=%d", len, id, raw, t);
 448                         if (len > 9)
 449                                 printf(" q=%d", q);
 450                         printf("\n");
 451                 }
 452                 raw_point(t, id, raw, q);
 453                 pos += len;
 454                 points++;
 455         }
 456
 457         return points;
 458 }
 459
 460 static void set_clock(void)
 461 {
 462         byte req[64], reply[64];
 463         memset(req, 0, 64);
 464         req[0] = 4;
 465         time_t t = time(NULL);
 466         put_le32(req+1, t-TIME_OFFSET);
 467         send_and_receive(req, reply);
 468
 469 #if 0
 470         /*
 471          *  Original software also sends a packet with type 3 and the timestamp,
 472          *  but it does not make any sense, especially as they ignore the sensor
 473          *  readings in the answer.
 474          */
 475         req[0] = 3;
 476         send_and_receive(req, reply);
 477         parse_packet(reply);
 478 #endif
 479 }
 480
 481 /*** Main ***/
 482
 483 static volatile sig_atomic_t want_shutdown;
 484
 485 static void sigterm_handler(int sig __attribute__((unused)))
 486 {
 487         want_shutdown = 1;
 488 }
 489
 490 static const struct option long_options[] = {
 491         { "debug",              0, NULL, 'd' },
 492         { "log-dir",            1, NULL, 'l' },
 493         { "debug-packets",      0, NULL, 'p' },
 494         { "debug-raw",          0, NULL, 'r' },
 495         { NULL,                 0, NULL, 0 },
 496 };
 497
 498 static void usage(void)
 499 {
 500         fprintf(stderr, "\n\
 501 Usage: arexxd <options>\n\
 502 \n\
 503 Options:\n\
 504 -d, --debug             Debug mode (no chdir, no fork, no syslog)\n\
 505 -l, --log-dir=<dir>     Directory where all received data should be stored\n\
 506 -p, --debug-packets     Log all packets sent and received\n\
 507 -r, --debug-raw         Log conversion from raw values\n\
 508 ");
 509         exit(1);
 510 }
 511
 512 int main(int argc, char **argv)
 513 {
 514         int opt;
 515         while ((opt = getopt_long(argc, argv, "dl:pr", long_options, NULL)) >= 0)
 516                 switch (opt) {
 517                         case 'd':
 518                                 debug_mode++;
 519                                 break;
 520                         case 'l':
 521                                 log_dir = optarg;
 522                                 break;
 523                         case 'p':
 524                                 debug_packets++;
 525                                 break;
 526                         case 'r':
 527                                 debug_raw_data++;
 528                                 break;
 529                         default:
 530                                 usage();
 531                 }
 532         if (optind < argc)
 533                 usage();
 534
 535         int err;
 536         if (err = libusb_init(&usb_ctxt))
 537                 die("Cannot initialize libusb: error %d", err);
 538         // libusb_set_debug(usb_ctxt, 3);
 539
 540         if (!debug_mode) {
 541                 if (chdir(log_dir) < 0)
 542                         die("Cannot change directory to %s: %m", log_dir);
 543                 if (debug_packets || debug_raw_data) {
 544                         close(1);
 545                         if (open("debug", O_WRONLY | O_CREAT | O_APPEND, 0666) < 0)
 546                                 die("Cannot open debug log: %m");
 547                         setlinebuf(stdout);
 548                 }
 549                 openlog("arexxd", LOG_NDELAY, LOG_DAEMON);
 550                 pid_t pid = fork();
 551                 if (pid < 0)
 552                         die("fork() failed: %m");
 553                 if (pid)
 554                         return 0;
 555                 setsid();
 556                 use_syslog = 1;
 557         }
 558
 559         struct sigaction sa = { .sa_handler = sigterm_handler };
 560         sigaction(SIGTERM, &sa, NULL);
 561         sigaction(SIGINT, &sa, NULL);
 562
 563         sigset_t term_sigs;
 564         sigemptyset(&term_sigs);
 565         sigaddset(&term_sigs, SIGTERM);
 566         sigaddset(&term_sigs, SIGINT);
 567         sigprocmask(SIG_BLOCK, &term_sigs, NULL);
 568
 569         int inited = 0;
 570         while (!want_shutdown) {
 571                 if (!find_device()) {
 572                         if (!inited) {
 573                                 inited = 1;
 574                                 log_error("Data logger not connected, waiting until it appears");
 575                         }
 576                         sleep(30);
 577                         continue;
 578                 }
 579                 log_info("Listening");
 580
 581                 time_t last_sync = 0;
 582                 time_t last_show = 0;
 583                 int want_stats = 0;
 584                 int want_sleep = 0;
 585                 data_point_counter = 0;
 586                 while (!want_shutdown) {
 587                         time_t now = time(NULL);
 588                         if (now > last_sync + 900) {
 589                                 log_info("Synchronizing data logger time");
 590                                 set_clock();
 591                                 last_sync = now;
 592                         }
 593                         if (want_stats && now > last_show + 300) {
 594                                 log_info("Stats: received %d data points", data_point_counter);
 595                                 data_point_counter = 0;
 596                                 last_show = now;
 597                         }
 598
 599                         byte req[64], reply[64];
 600                         memset(req, 0, sizeof(req));
 601                         req[0] = 3;
 602                         err = send_and_receive(req, reply);
 603                         if (err < 0)
 604                                 break;
 605                         want_sleep = 1;
 606                         if (err > 0 && parse_packet(reply))
 607                                 want_sleep = 0;
 608                         sigprocmask(SIG_UNBLOCK, &term_sigs, NULL);
 609                         if (want_sleep) {
 610                                 sleep(4);
 611                                 want_stats = 1;
 612                         }
 613                         sigprocmask(SIG_BLOCK, &term_sigs, NULL);
 614                 }
 615
 616                 log_info("Disconnecting data logger");
 617                 release_device();
 618                 inited = 0;
 619         }
 620
 621         log_info("Terminated");
 622         return 0;
 623 }