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