jackwsmeter.c

   1 /*
   2  * jackwsmeter - jack meter over websockets
   3  *
   4  * Copyright (C) 2014 Frederic Peters <fpeters@0d.be>
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License as
   8  * published by the Free Software Foundation; either version 2 of the
   9  * License, or (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public
  17  * License along with this program; if not, see
  18  * <http://www.gnu.org/licenses/>.
  19  */
  20
  21 /*
  22  * based on code,
  23  * from the libwebsockets test server: LGPL 2.1
  24  *   Copyright (C) 2010-2011 Andy Green <andy@warmcat.com>
  25  * from jackmeter, GPL 2+
  26  *   Copyright (C) 2005  Nicholas J. Humfrey
  27  */
  28
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <unistd.h>
  32 #include <getopt.h>
  33 #include <string.h>
  34 #include <sys/time.h>
  35 #include <assert.h>
  36 #include <syslog.h>
  37 #include <math.h>
  38
  39 #include <signal.h>
  40
  41 #include <libwebsockets.h>
  42
  43 #include <jack/jack.h>
  44
  45 int max_poll_elements;
  46
  47 struct pollfd *pollfds;
  48 int *fd_lookup;
  49 int count_pollfds;
  50 int num_meters = 0;
  51
  52 int force_exit = 0;
  53
  54 #define MAX_METERS 20
  55
  56 float bias = 1.0f;
  57 float peaks[MAX_METERS];
  58 float sent_peaks[MAX_METERS];
  59
  60 jack_port_t *input_ports[MAX_METERS];
  61 jack_client_t *client = NULL;
  62
  63
  64 /* Read and reset the recent peak sample */
  65 static void read_peaks()
  66 {
  67         memcpy(sent_peaks, peaks, sizeof(peaks));
  68         memset(peaks, 0, sizeof(peaks));
  69 }
  70
  71
  72 /* this protocol server (always the first one) just knows how to do HTTP */
  73
  74 static int callback_http(struct libwebsocket_context *context,
  75                 struct libwebsocket *wsi,
  76                 enum libwebsocket_callback_reasons reason, void *user,
  77                                                            void *in, size_t len)
  78 {
  79         int m;
  80         char *html_filepath;
  81 #ifdef LWS_13
  82         struct libwebsocket_pollargs *pa = (struct libwebsocket_pollargs *)in;
  83 #else
  84         int fd = (int)(long)user;
  85 #endif
  86
  87         switch (reason) {
  88         case LWS_CALLBACK_HTTP:
  89                 html_filepath = malloc(strlen(DATADIR "/jackwsmeter.html") + 1);
  90                 strcpy(html_filepath, DATADIR "jackwsmeter.html\n\n");
  91                 if (access(html_filepath, F_OK) != 0) {
  92                         /* it doesn't exist in the system directory, fall back
  93                          * on the current directory. */
  94                         strcpy(html_filepath, "jackwsmeter.html");
  95                 }
  96 #ifdef LWS_13
  97                 if (libwebsockets_serve_http_file(context, wsi, html_filepath, "text/html", NULL)) {
  98 #else
  99                 if (libwebsockets_serve_http_file(context, wsi, html_filepath, "text/html")) {
 100 #endif
 101                         free(html_filepath);
 102                         return 1; /* through completion or error, close the socket */
 103                 }
 104                 free(html_filepath);
 105
 106                 break;
 107
 108         case LWS_CALLBACK_HTTP_FILE_COMPLETION:
 109                 return 1;
 110
 111         case LWS_CALLBACK_ADD_POLL_FD:
 112
 113                 if (count_pollfds >= max_poll_elements) {
 114                         lwsl_err("LWS_CALLBACK_ADD_POLL_FD: too many sockets to track\n");
 115                         return 1;
 116                 }
 117
 118 #ifdef LWS_13
 119                 fd_lookup[pa->fd] = count_pollfds;
 120                 pollfds[count_pollfds].fd = pa->fd;
 121                 pollfds[count_pollfds].events = pa->events;
 122 #else
 123                 fd_lookup[fd] = count_pollfds;
 124                 pollfds[count_pollfds].fd = fd;
 125                 pollfds[count_pollfds].events = (int)(long)len;
 126 #endif
 127                 pollfds[count_pollfds++].revents = 0;
 128                 break;
 129
 130         case LWS_CALLBACK_DEL_POLL_FD:
 131                 if (!--count_pollfds)
 132                         break;
 133 #ifdef LWS_13
 134                 m = fd_lookup[pa->fd];
 135 #else
 136                 m = fd_lookup[fd];
 137 #endif
 138                 /* have the last guy take up the vacant slot */
 139                 pollfds[m] = pollfds[count_pollfds];
 140                 fd_lookup[pollfds[count_pollfds].fd] = m;
 141                 break;
 142
 143 #ifdef LWS_13
 144         case LWS_CALLBACK_CHANGE_MODE_POLL_FD:
 145                 pollfds[fd_lookup[pa->fd]].events = pa->events;
 146                 break;
 147 #else
 148         case LWS_CALLBACK_SET_MODE_POLL_FD:
 149                 pollfds[fd_lookup[fd]].events |= (int)(long)len;
 150                 break;
 151
 152         case LWS_CALLBACK_CLEAR_MODE_POLL_FD:
 153                 pollfds[fd_lookup[fd]].events &= ~(int)(long)len;
 154                 break;
 155 #endif
 156
 157         default:
 158                 break;
 159         }
 160
 161         return 0;
 162 }
 163
 164 static int
 165 callback_meter(struct libwebsocket_context *context,
 166                 struct libwebsocket *wsi,
 167                 enum libwebsocket_callback_reasons reason,
 168                 void *user, void *in, size_t len)
 169 {
 170         int n;
 171         int i;
 172         float db;
 173         char one_peak[100];
 174         char buf[LWS_SEND_BUFFER_PRE_PADDING + 512 + LWS_SEND_BUFFER_POST_PADDING];
 175         char *p = &buf[LWS_SEND_BUFFER_PRE_PADDING];
 176
 177         switch (reason) {
 178
 179         case LWS_CALLBACK_ESTABLISHED:
 180                 break;
 181
 182         case LWS_CALLBACK_SERVER_WRITEABLE:
 183                 p[0] = '\0';
 184                 for (i=0; i<num_meters; i++) {
 185                         db = 20.0f * log10f(sent_peaks[i] * bias);
 186                         snprintf(one_peak, 100, "%f ", db);
 187                         strcat((char*)p, one_peak);
 188                 }
 189                 n = strlen(p);
 190                 p[n-1] = '\0'; /* remove trailing space */
 191
 192                 n = libwebsocket_write(wsi, (unsigned char*)p, n, LWS_WRITE_TEXT);
 193                 if (n < 0) {
 194                         lwsl_err("ERROR %d writing to socket\n", n);
 195                         return 1;
 196                 }
 197                 break;
 198
 199         default:
 200                 break;
 201         }
 202
 203         return 0;
 204 }
 205
 206 /* list of supported protocols and callbacks */
 207
 208 static struct libwebsocket_protocols protocols[] = {
 209         /* first protocol must always be HTTP handler */
 210
 211         {
 212                 "http-only",            /* name */
 213                 callback_http,          /* callback */
 214                 0,                      /* per_session_data_size */
 215                 0,                      /* max frame size / rx buffer */
 216         },
 217         {
 218                 "jack-wsmeter-protocol",
 219                 callback_meter,
 220                 0,
 221                 0,
 222         },
 223         { NULL, NULL, 0, 0 } /* terminator */
 224 };
 225
 226 void sighandler(int sig)
 227 {
 228         force_exit = 1;
 229 }
 230
 231 static struct option options[] = {
 232         { "help",       no_argument,            NULL, 'h' },
 233         { "debug",      required_argument,      NULL, 'd' },
 234         { "port",       required_argument,      NULL, 'p' },
 235         { "ssl-cert",   required_argument,      NULL, 'E' },
 236         { "ssl-key",    required_argument,      NULL, 'k' },
 237         { "interface",  required_argument,      NULL, 'i' },
 238 #ifndef LWS_NO_DAEMONIZE
 239         { "daemonize",  no_argument,            NULL, 'D' },
 240 #endif
 241         { "name",       required_argument,      NULL, 'n' },
 242         { NULL, 0, 0, 0 }
 243 };
 244
 245
 246 /* Callback called by JACK when audio is available.
 247    Stores value of peak sample */
 248 static int process_peak(jack_nframes_t nframes, void *arg)
 249 {
 250         unsigned int i, port;
 251
 252         for (port = 0; port < num_meters; port++) {
 253                 jack_default_audio_sample_t *in;
 254
 255                 /* just incase the port isn't registered yet */
 256                 if (input_ports[port] == 0) {
 257                         break;
 258                 }
 259
 260                 in = (jack_default_audio_sample_t *) jack_port_get_buffer(input_ports[port], nframes);
 261
 262                 for (i = 0; i < nframes; i++) {
 263                         const float s = fabs(in[i]);
 264                         if (s > peaks[port]) {
 265                                 peaks[port] = s;
 266                         }
 267                 }
 268         }
 269
 270         return 0;
 271 }
 272
 273
 274 /* Close down JACK when exiting */
 275 static void cleanup()
 276 {
 277         const char **all_ports;
 278         unsigned int i, j;
 279
 280         lwsl_debug("cleanup()\n");
 281
 282         for (i=0; i<num_meters; i++) {
 283                 all_ports = jack_port_get_all_connections(client, input_ports[i]);
 284
 285                 for (j=0; all_ports && all_ports[j]; j++) {
 286                         jack_disconnect(client, all_ports[j], jack_port_name(input_ports[i]));
 287                 }
 288         }
 289
 290         /* Leave the jack graph */
 291         jack_client_close(client);
 292
 293         closelog();
 294 }
 295
 296
 297 int main(int argc, char **argv)
 298 {
 299         int n = 0;
 300         struct libwebsocket_context *context;
 301         int opts = 0;
 302         char interface_name[128] = "";
 303         char jack_name[128] = "wsmeter";
 304         const char *iface = NULL;
 305         int syslog_options = LOG_PID | LOG_PERROR;
 306         unsigned int oldus = 0;
 307         struct lws_context_creation_info info;
 308
 309         int debug_level = 7;
 310 #ifndef LWS_NO_DAEMONIZE
 311         int daemonize = 0;
 312 #endif
 313
 314         jack_status_t status;
 315
 316         memset(&info, 0, sizeof info);
 317         info.port = 7681;
 318
 319         while (n >= 0) {
 320                 n = getopt_long(argc, argv, "ci:hsp:d:Dn:", options, NULL);
 321                 if (n < 0)
 322                         continue;
 323                 switch (n) {
 324 #ifndef LWS_NO_DAEMONIZE
 325                 case 'D':
 326                         daemonize = 1;
 327                         syslog_options &= ~LOG_PERROR;
 328                         break;
 329 #endif
 330                 case 'd':
 331                         debug_level = atoi(optarg);
 332                         break;
 333                 case 'E':
 334                         info.ssl_cert_filepath = strdup(optarg);
 335                         break;
 336                 case 'k':
 337                         info.ssl_private_key_filepath = strdup(optarg);
 338                         break;
 339                 case 'p':
 340                         info.port = atoi(optarg);
 341                         break;
 342                 case 'i':
 343                         strncpy(interface_name, optarg, sizeof interface_name);
 344                         interface_name[(sizeof interface_name) - 1] = '\0';
 345                         iface = interface_name;
 346                         break;
 347                 case 'n':
 348                         strncpy(jack_name, optarg, sizeof jack_name);
 349                         jack_name[(sizeof jack_name) - 1] = '\0';
 350                         break;
 351                 case 'h':
 352                         fprintf(stderr, "Usage: jackwsserver "
 353                                         "[--port=<p>] [--ssl-cert FILEPATH] [--ssl-key FILEPATH] "
 354                                         "[-d <log bitfield>] <port>+\n");
 355                         exit(1);
 356                 }
 357         }
 358
 359 #if !defined(LWS_NO_DAEMONIZE)
 360         /*
 361          * normally lock path would be /var/lock/jwsm or similar, to
 362          * simplify getting started without having to take care about
 363          * permissions or running as root, set to /tmp/.jwsm-lock
 364          */
 365         if (daemonize && lws_daemonize("/tmp/.jwsm-lock")) {
 366                 fprintf(stderr, "Failed to daemonize\n");
 367                 return 1;
 368         }
 369 #endif
 370
 371         signal(SIGINT, sighandler);
 372
 373         /* we will only try to log things according to our debug_level */
 374         setlogmask(LOG_UPTO (LOG_DEBUG));
 375         openlog("jackwsmeter", syslog_options, LOG_DAEMON);
 376
 377         /* tell the library what debug level to emit and to send it to syslog */
 378         lws_set_log_level(debug_level, lwsl_emit_syslog);
 379
 380         max_poll_elements = getdtablesize();
 381         pollfds = malloc(max_poll_elements * sizeof (struct pollfd));
 382         fd_lookup = malloc(max_poll_elements * sizeof (int));
 383         if (pollfds == NULL || fd_lookup == NULL) {
 384                 lwsl_err("Out of memory pollfds=%d\n", max_poll_elements);
 385                 return -1;
 386         }
 387
 388         info.iface = iface;
 389         info.protocols = protocols;
 390 #ifndef LWS_NO_EXTENSIONS
 391         info.extensions = libwebsocket_get_internal_extensions();
 392 #endif
 393         info.gid = -1;
 394         info.uid = -1;
 395         info.options = opts;
 396
 397         // Register with Jack
 398         if ((client = jack_client_open(jack_name, JackNullOption, &status)) == 0) {
 399                 lwsl_err("Failed to start jack client: %d\n", status);
 400                 exit(1);
 401         }
 402         lwsl_debug("Registering as '%s'.\n", jack_get_client_name(client));
 403
 404         // Register the cleanup function to be called when program exits
 405         atexit(cleanup);
 406
 407         // Register the peak signal callback
 408         jack_set_process_callback(client, process_peak, 0);
 409
 410
 411         if (jack_activate(client)) {
 412                 lwsl_err("Cannot activate client.\n");
 413                 exit(1);
 414         }
 415
 416         opts = optind;
 417         num_meters = 0;
 418         while (argv[opts]) {
 419                 char in_name[255];
 420                 jack_port_t *port;
 421                 // Create our input port
 422                 snprintf(in_name, 255, "in_%d", num_meters);
 423                 if (!(input_ports[num_meters] = jack_port_register(client, in_name,
 424                                                 JACK_DEFAULT_AUDIO_TYPE, JackPortIsInput, 0))) {
 425                         lwsl_err("Cannot register input port '%s'.\n", in_name);
 426                         exit(1);
 427                 }
 428
 429                 port = jack_port_by_name(client, argv[opts]);
 430                 if (port == NULL) {
 431                         lwsl_err("Can't find port '%s'\n", argv[opts]);
 432                 } else {
 433                         if (jack_connect(client, jack_port_name(port), jack_port_name(input_ports[num_meters]))) {
 434                                 lwsl_err("failed to connect to port '%s'\n", argv[opts]);
 435                                 exit(1);
 436                         }
 437                 }
 438                 num_meters += 1;
 439                 if (num_meters == MAX_METERS) {
 440                         lwsl_err("maximum number of meters (%d) reached.\n", MAX_METERS);
 441                         break;
 442                 }
 443                 opts++;
 444         }
 445
 446         if (num_meters == 0) {
 447                 lwsl_err("You must specify at least one port, aborting.");
 448                 exit(1);
 449         }
 450
 451         context = libwebsocket_create_context(&info);
 452         if (context == NULL) {
 453                 lwsl_err("libwebsocket init failed\n");
 454                 return -1;
 455         }
 456
 457         n = 0;
 458         while (n >= 0 && !force_exit) {
 459                 struct timeval tv;
 460
 461                 gettimeofday(&tv, NULL);
 462
 463                 read_peaks();
 464
 465                 /*
 466                  * This provokes the LWS_CALLBACK_SERVER_WRITEABLE for every
 467                  * live websocket connection as soon as it can take more packets
 468                  * (usually immediately)
 469                  */
 470
 471                 if (((unsigned int)tv.tv_usec - oldus) > 100000) {
 472                         libwebsocket_callback_on_writable_all_protocol(&protocols[1]);
 473                         oldus = tv.tv_usec;
 474                 }
 475
 476                 n = poll(pollfds, count_pollfds, 25);
 477                 if (n < 0)
 478                         continue;
 479
 480
 481                 if (n)
 482                         for (n = 0; n < count_pollfds; n++)
 483                                 if (pollfds[n].revents)
 484                                         if (libwebsocket_service_fd(context,
 485                                                                   &pollfds[n]) < 0)
 486                                                 goto done;
 487
 488
 489                 n = libwebsocket_service(context, 25);
 490         }
 491
 492 done:
 493         libwebsocket_context_destroy(context);
 494
 495         lwsl_notice("jackwsserver exited cleanly\n");
 496
 497         return 0;
 498 }