arexxd.c

   1 /*
   2  *      Linux Interfece for Arexx Data Loggers
   3  *
   4  *      (c) 2011 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 LOG_PATH "/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
  33 static void die(char *fmt, ...)
  34 {
  35         va_list args;
  36         va_start(args, fmt);
  37         if (use_syslog)
  38                 vsyslog(LOG_CRIT, fmt, args);
  39         else {
  40                 vfprintf(stderr, fmt, args);
  41                 fprintf(stderr, "\n");
  42         }
  43         va_end(args);
  44         exit(1);
  45 }
  46
  47 static void log_error(char *fmt, ...)
  48 {
  49         va_list args;
  50         va_start(args, fmt);
  51         if (use_syslog)
  52                 vsyslog(LOG_ERR, fmt, args);
  53         else {
  54                 vfprintf(stderr, fmt, args);
  55                 fprintf(stderr, "\n");
  56         }
  57         va_end(args);
  58 }
  59
  60 static void log_info(char *fmt, ...)
  61 {
  62         va_list args;
  63         va_start(args, fmt);
  64         if (use_syslog)
  65                 vsyslog(LOG_INFO, fmt, args);
  66         else {
  67                 vfprintf(stderr, fmt, args);
  68                 fprintf(stderr, "\n");
  69         }
  70         va_end(args);
  71 }
  72
  73 static void log_pkt(char *fmt, ...)
  74 {
  75         if (!debug_packets)
  76                 return;
  77         va_list args;
  78         va_start(args, fmt);
  79         vprintf(fmt, args);
  80         va_end(args);
  81 }
  82
  83 /*** RRD interface ***/
  84
  85 #define SLOT_SIZE 10                                    // 10 seconds per averaging slot
  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 void cooked_point(time_t t, int id, double val, char *unit, int q)
 162 {
 163         if (debug_raw_data) {
 164                 struct tm tm;
 165                 localtime_r(&t, &tm);
 166                 char tbuf[64];
 167                 strftime(tbuf, sizeof(tbuf), "%Y-%m-%d %H:%M:%S", &tm);
 168                 printf("== %s id=%d val=%.3f unit=%s q=%d\n", tbuf, id, val, unit, q);
 169         }
 170
 171         data_point_counter++;
 172         rrd_point(t, id, val, unit);
 173 }
 174
 175 static void raw_point(int t, int id, int raw, int q)
 176 {
 177         /*
 178          *  The binary blob provided by Arexx contains an embedded XML fragment
 179          *  with descriptions of all known sensor types. If you want to see it,
 180          *  grep the blob for "<deviceinfo>". The meanings of the parameters are
 181          *  as follows:
 182          *
 183          *      m1, m2          Device type matches if (raw_sensor_id & m1) == m2
 184          *      type            Unit measured by the sensor (1=Celsius, 2=RH%, 3=CO2 ppm)
 185          *      dm              User-visible sensor ID = raw_sensor_id & dm
 186          *      i               1 if the raw value is signed
 187          *      p[]             Coefficients of transformation polynomial (x^0 first)
 188          *      vLo, vUp        Upper and lower bound on the final value
 189          *      scale           Scaling function:
 190          *                              0 = identity (default)
 191          *                              1 = 10^x
 192          *                              2 = exp(x)
 193          *                              3 = (x < 0) ? 0 : log10(x)
 194          *                              4 = (x < 0) ? 0 : log(x)
 195          *
 196          *  The raw values are transformed this way:
 197          *      - sign-extend if signed
 198          *      - apply the transformation polynomial
 199          *      - apply the scaling function
 200          *      - drop if outside the interval [vLo,vUp]
 201          *
 202          *  This function applies the necessary transform for sensors we've
 203          *  seen in the wild. We deliberately ignore the "dm" parameter as we want
 204          *  to report different channels of a single sensor as multiple sensors.
 205          */
 206
 207         double z = raw;
 208         double hi, lo;
 209         char *unit;
 210         int idhi = id & 0xf000;
 211
 212         if (idhi == 0x1000) {
 213                 z = 0.02*z - 273.15;
 214                 lo = -200;
 215                 hi = 600;
 216                 unit = "C";
 217         } else if (idhi == 0x2000) {
 218                 if (raw >= 0x8000)
 219                         z -= 0x10000;
 220                 z /= 128;
 221                 lo = -60;
 222                 hi = 125;
 223                 unit = "C";
 224         } else if (idhi == 0x4000) {
 225                 if (!(id & 1)) {
 226                         z = z/100 - 39.6;
 227                         lo = -60;
 228                         hi = 125;
 229                         unit = "C";
 230                 } else {
 231                         z = -2.8e-6*z*z + 0.0405*z - 4;
 232                         lo = 0;
 233                         hi = 100.1;
 234                         unit = "%RH";
 235                 }
 236         } else if (idhi == 0x6000) {
 237                 if (!(id & 1)) {
 238                         if (raw >= 0x8000)
 239                                 z -= 0x10000;
 240                         z /= 128;
 241                         lo = -60;
 242                         hi = 125;
 243                         unit = "C";
 244                 } else {
 245                         z = -3.8123e-11*z;
 246                         z = (z + 1.9184e-7) * z;
 247                         z = (z - 1.0998e-3) * z;
 248                         z += 6.56;
 249                         z = pow(10, z);
 250                         lo = 0;
 251                         hi = 1e6;
 252                         unit = "ppm";
 253                 }
 254         } else {
 255                 log_error("Unknown sensor type 0x%04x", id);
 256                 return;
 257         }
 258
 259         if (z < lo || z > hi) {
 260                 log_error("Sensor %d: value %f out of range", id, z);
 261                 return;
 262         }
 263
 264         cooked_point(t + TIME_OFFSET, id, z, unit, q);
 265 }
 266
 267 /*** USB interface ***/
 268
 269 static int find_device(void)
 270 {
 271         libusb_device **devlist;
 272         ssize_t devn = libusb_get_device_list(usb_ctxt, &devlist);
 273         if (devn < 0) {
 274                 log_error("Cannot enumerate USB devices: error %d", (int) devn);
 275                 return 0;
 276         }
 277
 278         for (ssize_t i=0; i<devn; i++) {
 279                 struct libusb_device_descriptor desc;
 280                 libusb_device *dev = devlist[i];
 281                 if (!libusb_get_device_descriptor(dev, &desc)) {
 282                         if (desc.idVendor == 0x0451 && desc.idProduct == 0x3211) {
 283                                 log_info("Arexx data logger found at usb%d.%d", libusb_get_bus_number(dev), libusb_get_device_address(dev));
 284                                 int err;
 285                                 if (err = libusb_open(dev, &devh)) {
 286                                         log_error("libusb_open() failed: error %d", err);
 287                                         goto failed;
 288                                 }
 289                                 if (err = libusb_claim_interface(devh, 0)) {
 290                                         log_error("libusb_claim_interface() failed: error %d", err);
 291                                         libusb_close(devh);
 292                                         goto failed;
 293                                 }
 294                                 libusb_free_device_list(devlist, 1);
 295                                 return 1;
 296                         }
 297                 }
 298         }
 299
 300 failed:
 301         libusb_free_device_list(devlist, 1);
 302         return 0;
 303 }
 304
 305 static void release_device(void)
 306 {
 307         libusb_close(devh);
 308         devh = NULL;
 309 }
 310
 311 static void dump_packet(byte *pkt)
 312 {
 313         for (int i=0; i<64; i++) {
 314                 if (!(i % 16))
 315                         log_pkt("\t%02x:", i);
 316                 log_pkt(" %02x", pkt[i]);
 317                 if (i % 16 == 15)
 318                         log_pkt("\n");
 319         }
 320 }
 321
 322 static int send_and_receive(byte *req, byte *reply)
 323 {
 324         if (debug_packets) {
 325                 time_t t = time(NULL);
 326                 struct tm tm;
 327                 localtime_r(&t, &tm);
 328
 329                 char tbuf[64];
 330                 strftime(tbuf, sizeof(tbuf), "%Y-%m-%d %H:%M:%S", &tm);
 331                 log_pkt("## %s\n", tbuf);
 332         }
 333
 334         int err, transferred;
 335         if (err = libusb_bulk_transfer(devh, 0x01, req, 64, &transferred, 200)) {
 336                 if (err == LIBUSB_ERROR_TIMEOUT) {
 337                         log_pkt(">> xmit timed out\n");
 338                         return 0;
 339                 }
 340                 log_pkt(">> xmit error %d\n", err);
 341                 log_error("Transmit error: %d", err);
 342                 return err;
 343         }
 344         if (debug_packets) {
 345                 log_pkt(">> xmit %d bytes\n", transferred);
 346                 dump_packet(req);
 347         }
 348         if (err = libusb_bulk_transfer(devh, 0x81, reply, 64, &transferred, 200)) {
 349                 if (err == LIBUSB_ERROR_TIMEOUT) {
 350                         log_pkt("<< recv timed out\n");
 351                         return 0;
 352                 }
 353                 log_pkt("<< recv error %d\n", err);
 354                 log_error("Receive error: %d", err);
 355                 return err;
 356         }
 357         if (debug_packets)
 358                 log_pkt("<< recv %d bytes\n", transferred);
 359         while (transferred < 64)
 360                 reply[transferred++] = 0xff;
 361         if (debug_packets)
 362                 dump_packet(reply);
 363         return 1;
 364 }
 365
 366 static unsigned int get_be16(byte *p)
 367 {
 368         return p[1] | (p[0] << 8);
 369 }
 370
 371 static unsigned int get_le16(byte *p)
 372 {
 373         return p[0] | (p[1] << 8);
 374 }
 375
 376 static unsigned int get_le32(byte *p)
 377 {
 378         return get_le16(p) | (get_le16(p+2) << 16);
 379 }
 380
 381 static void put_le16(byte *p, unsigned int x)
 382 {
 383         p[0] = x;
 384         p[1] = x >> 8;
 385 }
 386
 387 static void put_le32(byte *p, unsigned int x)
 388 {
 389         put_le16(p, x);
 390         put_le16(p+2, x>>16);
 391 }
 392
 393 static int parse_packet(byte *reply)
 394 {
 395         if (reply[0]) {
 396                 log_error("Unknown packet type %02x", reply[0]);
 397                 return 0;
 398         }
 399
 400         int pos = 1;
 401         int points = 0;
 402         while (pos < 64) {
 403                 byte *p = reply + pos;
 404                 int len = p[0];
 405                 if (!len || len == 0xff)
 406                         break;
 407                 if (len < 9 || len > 10) {
 408                         log_error("Unknown tuple length %02x", len);
 409                         break;
 410                 }
 411                 if (pos + len > 64) {
 412                         log_error("Tuple truncated");
 413                         break;
 414                 }
 415                 int id = get_le16(p+1);
 416                 int raw = get_be16(p+3);
 417                 int t = get_le32(p+5);
 418                 int q = (len > 9) ? p[9] : -1;
 419                 if (debug_raw_data) {
 420                         printf("... %02x: id=%d raw=%d t=%d", len, id, raw, t);
 421                         if (len > 9)
 422                                 printf(" q=%d", q);
 423                         printf("\n");
 424                 }
 425                 raw_point(t, id, raw, q);
 426                 pos += len;
 427                 points++;
 428         }
 429
 430         return points;
 431 }
 432
 433 static void set_clock(void)
 434 {
 435         byte req[64], reply[64];
 436         memset(req, 0, 64);
 437         req[0] = 4;
 438         time_t t = time(NULL);
 439         put_le32(req+1, t-TIME_OFFSET);
 440         send_and_receive(req, reply);
 441
 442 #if 0
 443         /*
 444          *  Original software also sends a packet with type 3 and the timestamp,
 445          *  but it does not make any sense, especially as they ignore the sensor
 446          *  readings in the answer.
 447          */
 448         req[0] = 3;
 449         send_and_receive(req, reply);
 450         parse_packet(reply);
 451 #endif
 452 }
 453
 454 /*** Main ***/
 455
 456 static volatile sig_atomic_t want_shutdown;
 457
 458 static void sigterm_handler(int sig __attribute__((unused)))
 459 {
 460         want_shutdown = 1;
 461 }
 462
 463 static const struct option long_options[] = {
 464         { "debug",              0, NULL, 'd' },
 465         { "log-packets",        0, NULL, 'p' },
 466         { NULL,                 0, NULL, 0 },
 467 };
 468
 469 static void usage(void)
 470 {
 471         fprintf(stderr, "Usage: arexxd [--debug] [--log-packets]\n");
 472         exit(1);
 473 }
 474
 475 int main(int argc, char **argv)
 476 {
 477         int opt;
 478         while ((opt = getopt_long(argc, argv, "dp", long_options, NULL)) >= 0)
 479                 switch (opt) {
 480                         case 'd':
 481                                 debug_mode++;
 482                                 break;
 483                         case 'p':
 484                                 debug_packets++;
 485                                 debug_raw_data++;
 486                                 break;
 487                         default:
 488                                 usage();
 489                 }
 490         if (optind < argc)
 491                 usage();
 492
 493         int err;
 494         if (err = libusb_init(&usb_ctxt))
 495                 die("Cannot initialize libusb: error %d", err);
 496         // libusb_set_debug(usb_ctxt, 3);
 497
 498         if (!debug_mode) {
 499                 if (chdir(LOG_PATH) < 0)
 500                         die("Cannot change directory to %s: %m", LOG_PATH);
 501                 if (debug_packets || debug_raw_data) {
 502                         close(1);
 503                         if (open("debug", O_WRONLY | O_CREAT | O_APPEND, 0666) < 0)
 504                                 die("Cannot open debug log: %m");
 505                         setlinebuf(stdout);
 506                 }
 507                 openlog("arexxd", LOG_NDELAY, LOG_DAEMON);
 508                 pid_t pid = fork();
 509                 if (pid < 0)
 510                         die("fork() failed: %m");
 511                 if (pid)
 512                         return 0;
 513                 setsid();
 514                 use_syslog = 1;
 515         }
 516
 517         struct sigaction sa = { .sa_handler = sigterm_handler };
 518         sigaction(SIGTERM, &sa, NULL);
 519         sigaction(SIGINT, &sa, NULL);
 520
 521         sigset_t term_sigs;
 522         sigemptyset(&term_sigs);
 523         sigaddset(&term_sigs, SIGTERM);
 524         sigaddset(&term_sigs, SIGINT);
 525         sigprocmask(SIG_BLOCK, &term_sigs, NULL);
 526
 527         int inited = 0;
 528         while (!want_shutdown) {
 529                 if (!find_device()) {
 530                         if (!inited) {
 531                                 inited = 1;
 532                                 log_error("Data logger not connected, waiting until it appears");
 533                         }
 534                         sleep(30);
 535                         continue;
 536                 }
 537                 log_info("Listening");
 538
 539                 time_t last_sync = 0;
 540                 time_t last_show = 0;
 541                 int want_stats = 0;
 542                 int want_sleep = 0;
 543                 data_point_counter = 0;
 544                 while (!want_shutdown) {
 545                         time_t now = time(NULL);
 546                         if (now > last_sync + 900) {
 547                                 log_info("Synchronizing data logger time");
 548                                 set_clock();
 549                                 last_sync = now;
 550                         }
 551                         if (want_stats && now > last_show + 300) {
 552                                 log_info("Stats: received %d data points", data_point_counter);
 553                                 data_point_counter = 0;
 554                                 last_show = now;
 555                         }
 556
 557                         byte req[64], reply[64];
 558                         memset(req, 0, sizeof(req));
 559                         req[0] = 3;
 560                         err = send_and_receive(req, reply);
 561                         if (err < 0)
 562                                 break;
 563                         want_sleep = 1;
 564                         if (err > 0 && parse_packet(reply))
 565                                 want_sleep = 0;
 566                         want_stats = 1;
 567                         sigprocmask(SIG_UNBLOCK, &term_sigs, NULL);
 568                         sleep(4);
 569                         sigprocmask(SIG_BLOCK, &term_sigs, NULL);
 570                 }
 571
 572                 log_info("Disconnecting data logger");
 573                 release_device();
 574                 inited = 0;
 575         }
 576
 577         log_info("Terminated");
 578         return 0;
 579 }