vss.c

   1 /*
   2  * Copyright (C) 1997-2008 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file vss.c The virtual streaming system.
   8  *
   9  * This contains the audio streaming code of para_server which is independent
  10  * of the current audio format, audio file selector and of the activated
  11  * senders.
  12  */
  13
  14 #include <sys/mman.h> /* mmap */
  15 #include <sys/time.h> /* gettimeofday */
  16 #include <sys/types.h>
  17 #include <dirent.h>
  18
  19 #include "para.h"
  20 #include "error.h"
  21 #include "string.h"
  22 #include "afh.h"
  23 #include "afs.h"
  24 #include "server.h"
  25 #include "net.h"
  26 #include "server.cmdline.h"
  27 #include "vss.h"
  28 #include "send.h"
  29 #include "ipc.h"
  30 #include "fd.h"
  31
  32 static struct timeval announce_tv;
  33 static struct timeval data_send_barrier;
  34 static struct timeval eof_barrier;
  35 static struct timeval autoplay_barrier;
  36
  37 extern struct misc_meta_data *mmd;
  38 extern struct sender senders[];
  39
  40 static char *map;
  41
  42 /**
  43  * Check if vss status flag \a P (playing) is set.
  44  *
  45  * \return Greater than zero if playing, zero otherwise.
  46  *
  47  */
  48 unsigned int vss_playing(void)
  49 {
  50         return mmd->new_vss_status_flags & VSS_PLAYING;
  51 }
  52
  53 /**
  54  * Check if the \a N (next) status flag is set.
  55  *
  56  * \return Greater than zero if set, zero if not.
  57  *
  58  */
  59 unsigned int vss_next(void)
  60 {
  61         return mmd->new_vss_status_flags & VSS_NEXT;
  62 }
  63
  64 /**
  65  * Check if a reposition request is pending.
  66  *
  67  * \return Greater than zero if true, zero otherwise.
  68  *
  69  */
  70 unsigned int vss_repos(void)
  71 {
  72         return mmd->new_vss_status_flags & VSS_REPOS;
  73 }
  74
  75 /**
  76  * Check if the vss is currently paused.
  77  *
  78  * \return Greater than zero if paused, zero otherwise.
  79  *
  80  */
  81 unsigned int vss_paused(void)
  82 {
  83         return !(mmd->new_vss_status_flags & VSS_NEXT)
  84                 && !(mmd->new_vss_status_flags & VSS_PLAYING);
  85 }
  86
  87 /**
  88  * Check if the vss is currently stopped.
  89  *
  90  * \return Greater than zero if paused, zero otherwise.
  91  *
  92  */
  93 unsigned int vss_stopped(void)
  94 {
  95         return (mmd->new_vss_status_flags & VSS_NEXT)
  96                 && !(mmd->new_vss_status_flags & VSS_PLAYING);
  97 }
  98
  99 /**
 100  * Initialize the virtual streaming system.
 101  *
 102  * This also initializes all supported senders and starts streaming
 103  * if the --autoplay command line flag was given.
 104  */
 105 void vss_init(void)
 106 {
 107         int i;
 108         char *hn = para_hostname(), *home = para_homedir();
 109         long unsigned announce_time = conf.announce_time_arg > 0?
 110                         conf.announce_time_arg : 300,
 111                 autoplay_delay = conf.autoplay_delay_arg > 0?
 112                         conf.autoplay_delay_arg : 0;
 113         ms2tv(announce_time, &announce_tv);
 114         PARA_INFO_LOG("announce timeval: %lums\n", tv2ms(&announce_tv));
 115         for (i = 0; senders[i].name; i++) {
 116                 PARA_NOTICE_LOG("initializing %s sender\n", senders[i].name);
 117                 senders[i].init(&senders[i]);
 118         }
 119         free(hn);
 120         free(home);
 121         if (conf.autoplay_given) {
 122                 struct timeval now, tmp;
 123                 mmd->vss_status_flags |= VSS_PLAYING;
 124                 mmd->new_vss_status_flags |= VSS_PLAYING;
 125                 gettimeofday(&now, NULL);
 126                 ms2tv(autoplay_delay, &tmp);
 127                 tv_add(&now, &tmp, &autoplay_barrier);
 128         }
 129 }
 130
 131 static int chk_barrier(const char *bname, const struct timeval *now,
 132                 const struct timeval *barrier, struct timeval *diff,
 133                 int print_log)
 134 {
 135         long ms;
 136
 137         if (tv_diff(now, barrier, diff) > 0)
 138                 return 1;
 139         ms = tv2ms(diff);
 140         if (print_log && ms)
 141                 PARA_DEBUG_LOG("%s barrier: %lims left\n", bname, ms);
 142         return -1;
 143 }
 144
 145 static void vss_next_chunk_time(struct timeval *due)
 146 {
 147         struct timeval tmp;
 148
 149         tv_scale(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv, &tmp);
 150         tv_add(&tmp, &mmd->stream_start, due);
 151 }
 152
 153 /*
 154  * != NULL: timeout for next chunk
 155  * NULL: nothing to do
 156  */
 157 static struct timeval *vss_compute_timeout(void)
 158 {
 159         static struct timeval the_timeout;
 160         struct timeval now, next_chunk;
 161
 162         if (vss_next() && map) {
 163                 /* only sleep a bit, nec*/
 164                 the_timeout.tv_sec = 0;
 165                 the_timeout.tv_usec = 100;
 166                 return &the_timeout;
 167         }
 168         gettimeofday(&now, NULL);
 169         if (chk_barrier("autoplay_delay", &now, &autoplay_barrier,
 170                         &the_timeout, 1) < 0)
 171                 return &the_timeout;
 172         if (chk_barrier("eof", &now, &eof_barrier, &the_timeout, 1) < 0)
 173                 return &the_timeout;
 174         if (chk_barrier("data send", &now, &data_send_barrier,
 175                         &the_timeout, 1) < 0)
 176                 return &the_timeout;
 177         if (!vss_playing() || !map)
 178                 return NULL;
 179         vss_next_chunk_time(&next_chunk);
 180         if (chk_barrier("chunk", &now, &next_chunk, &the_timeout, 0) < 0)
 181                 return &the_timeout;
 182         /* chunk is due or bof */
 183         the_timeout.tv_sec = 0;
 184         the_timeout.tv_usec = 0;
 185         return &the_timeout;
 186 }
 187
 188 static void vss_eof(void)
 189 {
 190         struct timeval now;
 191         int i;
 192         char *tmp;
 193
 194         if (!map) {
 195                 for (i = 0; senders[i].name; i++)
 196                         senders[i].shutdown_clients();
 197                 return;
 198         }
 199         if (mmd->new_vss_status_flags & VSS_NOMORE)
 200                 mmd->new_vss_status_flags = VSS_NEXT;
 201         gettimeofday(&now, NULL);
 202         tv_add(&mmd->afd.afhi.eof_tv, &now, &eof_barrier);
 203         munmap(map, mmd->size);
 204         map = NULL;
 205         mmd->chunks_sent = 0;
 206         mmd->offset = 0;
 207         mmd->afd.afhi.seconds_total = 0;
 208         free(mmd->afd.afhi.chunk_table);
 209         mmd->afd.afhi.chunk_table = NULL;
 210         tmp  = make_message("%s:\n%s:\n%s:\n", status_item_list[SI_AUDIO_FILE_INFO],
 211                 status_item_list[SI_TAGINFO1], status_item_list[SI_TAGINFO2]);
 212         strncpy(mmd->afd.afhi.info_string, tmp, sizeof(mmd->afd.afhi.info_string));
 213         mmd->afd.afhi.info_string[sizeof(mmd->afd.afhi.info_string) - 1] = '\0';
 214         make_empty_status_items(mmd->afd.verbose_ls_output);
 215         free(tmp);
 216         mmd->mtime = 0;
 217         mmd->size = 0;
 218         mmd->events++;
 219 }
 220
 221 /**
 222  * Get the header of the current audio file.
 223  *
 224  * \param header_len The length of the header is stored here.
 225  *
 226  * \return A pointer to a buffer containing the header, or NULL, if no audio
 227  * file is selected or if the current audio format does not need special header
 228  * treamtment.
 229  *
 230  */
 231 char *vss_get_header(size_t *header_len)
 232 {
 233         if (!map || !mmd->afd.afhi.header_len)
 234                 return NULL;
 235         *header_len = mmd->afd.afhi.header_len;
 236         return map + mmd->afd.afhi.header_offset;
 237 }
 238
 239 /**
 240  * Get the list of all supported audio formats.
 241  *
 242  * \return Aa space separated list of all supported audio formats
 243  * It is not allocated at runtime, i.e. there is no need to free
 244  * the returned string in the caller.
 245  */
 246 const char *supported_audio_formats(void)
 247 {
 248         return SUPPORTED_AUDIO_FORMATS;
 249 }
 250
 251 /**
 252  * Get the chunk time of the current audio file.
 253  *
 254  * \return A pointer to a struct containing the chunk time, or NULL,
 255  * if currently no audio file is selected.
 256  */
 257 struct timeval *vss_chunk_time(void)
 258 {
 259         if (!map)
 260                 return NULL;
 261         return &mmd->afd.afhi.chunk_tv;
 262 }
 263
 264 /** The possible states of the afs socket. See \ref afs_socket. */
 265 enum afs_socket_status {
 266         /** Socket is inactive. */
 267         AFS_SOCKET_READY,
 268         /** Socket fd was included in the write fd set for select(). */
 269         AFS_SOCKET_CHECK_FOR_WRITE,
 270         /** vss wrote a request to the socket and waits for afs to reply. */
 271         AFS_SOCKET_AFD_PENDING
 272 };
 273
 274 static enum afs_socket_status afsss;
 275
 276 /**
 277  * Compute the timeout for para_server's main select-loop.
 278  *
 279  * This function gets called from para_server to determine the timeout value
 280  * for its main select loop.
 281  *
 282  * \param rfds The set of file descriptors to be checked for reading.
 283  * \param wfds The set of file descriptors to be checked for writing.
 284  * \param max_fileno The highest-numbered file descriptor.
 285  *
 286  * Before the timeout is computed, the current vss status flags are evaluated
 287  * and acted upon by calling appropriate functions from the lower layers.
 288  * Possible actions include
 289  *
 290  *      - request a new audio file from afs,
 291  *      - shutdown of all senders (stop/pause command),
 292  *      - reposition the stream (ff/jmp command).
 293  *
 294  * \return A pointer to a struct timeval containing the timeout for the next
 295  * chunk of data to be sent, or NULL if we're not sending right now.
 296  */
 297 struct timeval *vss_preselect(fd_set *rfds, fd_set *wfds, int *max_fileno)
 298 {
 299         int i;
 300         struct timeval *tv;
 301
 302         para_fd_set(afs_socket, rfds, max_fileno);
 303         if (!map)
 304                 for (i = 0; senders[i].name; i++)
 305                         senders[i].shutdown_clients();
 306         else {
 307                 if (vss_next()) {
 308                         vss_eof();
 309                         return vss_compute_timeout();
 310                 }
 311         }
 312         if (vss_paused() || vss_repos()) {
 313                 for (i = 0; senders[i].name; i++)
 314                         senders[i].shutdown_clients();
 315                 if (map) {
 316                         struct timeval now;
 317                         gettimeofday(&now, NULL);
 318                         if (!vss_paused() || mmd->chunks_sent)
 319                                 tv_add(&mmd->afd.afhi.eof_tv, &now, &eof_barrier);
 320                         if (vss_repos())
 321                                 tv_add(&now, &announce_tv, &data_send_barrier);
 322                 }
 323                 mmd->chunks_sent = 0;
 324         }
 325         if (vss_repos()) {
 326                 mmd->new_vss_status_flags &= ~(VSS_REPOS);
 327                 mmd->current_chunk = mmd->repos_request;
 328         }
 329         tv = vss_compute_timeout();
 330         if (tv)
 331                 return tv;
 332         if (!map && vss_playing() &&
 333                         !(mmd->new_vss_status_flags & VSS_NOMORE)) {
 334                 if (afsss == AFS_SOCKET_READY ||
 335                                 afsss == AFS_SOCKET_CHECK_FOR_WRITE) {
 336                         PARA_DEBUG_LOG("ready and playing, but no audio file\n");
 337                         para_fd_set(afs_socket, wfds, max_fileno);
 338                         afsss = AFS_SOCKET_CHECK_FOR_WRITE;
 339                 }
 340         }
 341         return tv;
 342 }
 343
 344 static int recv_afs_msg(int *fd, uint32_t *code, uint32_t *data)
 345 {
 346         char control[255], buf[8];
 347         struct msghdr msg = {.msg_iov = NULL};
 348         struct cmsghdr *cmsg;
 349         struct iovec iov;
 350         int ret = 0;
 351
 352         *fd = -1;
 353         iov.iov_base = buf;
 354         iov.iov_len = sizeof(buf);
 355         msg.msg_iov = &iov;
 356         msg.msg_iovlen = 1;
 357         msg.msg_control = control;
 358         msg.msg_controllen = sizeof(control);
 359         memset(buf, 0, sizeof(buf));
 360         ret = recvmsg(afs_socket, &msg, 0);
 361         if (ret < 0)
 362                 return -ERRNO_TO_PARA_ERROR(errno);
 363         afsss = AFS_SOCKET_READY;
 364         if (iov.iov_len != sizeof(buf))
 365                 return -E_SHORT_AFS_READ;
 366         *code = *(uint32_t*)buf;
 367         *data =  *(uint32_t*)(buf + 4);
 368         for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
 369                 if (cmsg->cmsg_level != SOL_SOCKET
 370                         || cmsg->cmsg_type != SCM_RIGHTS)
 371                 continue;
 372                 if ((cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int) != 1)
 373                 continue;
 374                 *fd = *(int *)CMSG_DATA(cmsg);
 375         }
 376         return 1;
 377 }
 378
 379 static void recv_afs_result(void)
 380 {
 381         int ret, passed_fd, shmid;
 382         uint32_t afs_code = 0, afs_data = 0;
 383         struct stat statbuf;
 384         struct timeval now;
 385
 386         ret = recv_afs_msg(&passed_fd, &afs_code, &afs_data);
 387         if (ret < 0)
 388                 goto err;
 389         PARA_DEBUG_LOG("fd: %d, code: %u, shmid: %u\n", passed_fd, afs_code,
 390                 afs_data);
 391         ret = -E_NOFD;
 392         if (afs_code != NEXT_AUDIO_FILE)
 393                 goto err;
 394         if (passed_fd < 0)
 395                 goto err;
 396         shmid = afs_data;
 397         ret = load_afd(shmid, &mmd->afd);
 398         if (ret < 0)
 399                 goto err;
 400         shm_destroy(shmid);
 401         ret = fstat(passed_fd, &statbuf);
 402         if (ret < 0) {
 403                 PARA_ERROR_LOG("fstat error:\n");
 404                 ret = -ERRNO_TO_PARA_ERROR(errno);
 405                 goto err;
 406         }
 407         mmd->size = statbuf.st_size;
 408         mmd->mtime = statbuf.st_mtime;
 409         map = para_mmap(mmd->size, PROT_READ, MAP_PRIVATE,
 410                 passed_fd, 0);
 411         close(passed_fd);
 412         mmd->chunks_sent = 0;
 413         mmd->current_chunk = 0;
 414         mmd->offset = 0;
 415         mmd->events++;
 416         mmd->num_played++;
 417         mmd->new_vss_status_flags &= (~VSS_NEXT);
 418         gettimeofday(&now, NULL);
 419         tv_add(&now, &announce_tv, &data_send_barrier);
 420         return;
 421 err:
 422         if (passed_fd >= 0)
 423                 close(passed_fd);
 424         PARA_ERROR_LOG("%s\n", para_strerror(-ret));
 425         mmd->new_vss_status_flags = VSS_NEXT;
 426 }
 427
 428 void vss_post_select(fd_set *rfds, fd_set *wfds)
 429 {
 430         int ret;
 431
 432         if (FD_ISSET(afs_socket, rfds))
 433                 recv_afs_result();
 434         if (afsss != AFS_SOCKET_CHECK_FOR_WRITE || !FD_ISSET(afs_socket, wfds))
 435                 return;
 436         PARA_NOTICE_LOG("requesting new fd from afs\n");
 437         ret = send_buffer(afs_socket, "new");
 438         afsss = AFS_SOCKET_AFD_PENDING;
 439 }
 440
 441 static void get_chunk(long unsigned chunk_num, char **buf, size_t *len)
 442 {
 443         size_t pos = mmd->afd.afhi.chunk_table[chunk_num];
 444         *buf = map + pos;
 445         *len = mmd->afd.afhi.chunk_table[chunk_num + 1] - pos;
 446 }
 447
 448 /**
 449  * Get the data of the given chunk.
 450  *
 451  * \param chunk_num The number of the desired chunk.
 452  * \param buf Chunk data.
 453  * \param len Chunk length in bytes.
 454  *
 455  * \return Standard.
 456  */
 457 int vss_get_chunk(long unsigned chunk_num, char **buf, size_t *len)
 458 {
 459         if (!map || !vss_playing())
 460                 return -E_CHUNK;
 461         if (chunk_num >= mmd->afd.afhi.chunks_total)
 462                 return -E_CHUNK;
 463         get_chunk(chunk_num, buf, len);
 464         return 1;
 465 }
 466
 467 /**
 468  * Main sending function.
 469  *
 470  * This function gets called from para_server as soon as the next chunk of data
 471  * should be pushed out. It obtains a pointer to the data to be sent out as
 472  * well as its length from mmd->afd.afhi. This information is then passed to
 473  * each supported sender's send() function which is supposed to send out the data
 474  * to all connected clients.
 475  */
 476 void vss_send_chunk(void)
 477 {
 478         int i;
 479         struct timeval now, due;
 480         char *buf;
 481         size_t len;
 482
 483         if (!map || !vss_playing())
 484                 return;
 485         gettimeofday(&now, NULL);
 486         vss_next_chunk_time(&due);
 487         if (tv_diff(&due, &now, NULL) > 0)
 488                 return;
 489         if (chk_barrier("eof", &now, &eof_barrier, &due, 1) < 0)
 490                 return;
 491         if (chk_barrier("data send", &now, &data_send_barrier,
 492                         &due, 1) < 0)
 493                 return;
 494         mmd->new_vss_status_flags &= ~VSS_REPOS;
 495         if (mmd->current_chunk >= mmd->afd.afhi.chunks_total) { /* eof */
 496                 mmd->new_vss_status_flags |= VSS_NEXT;
 497                 return vss_eof();
 498         }
 499         /*
 500          * We call the send function also in case of empty chunks as they
 501          * might have still some data queued which can be sent in this case.
 502          */
 503         if (!mmd->chunks_sent) {
 504                 struct timeval tmp;
 505                 gettimeofday(&mmd->stream_start, NULL);
 506                 tv_scale(mmd->current_chunk, &mmd->afd.afhi.chunk_tv, &tmp);
 507                 mmd->offset = tv2ms(&tmp);
 508                 mmd->events++;
 509         }
 510         get_chunk(mmd->current_chunk, &buf, &len);
 511         for (i = 0; senders[i].name; i++)
 512                 senders[i].send(mmd->current_chunk, mmd->chunks_sent, buf, len);
 513         mmd->new_vss_status_flags |= VSS_PLAYING;
 514         mmd->chunks_sent++;
 515         mmd->current_chunk++;
 516 }