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         char *tmp;
 186
 187         if (mmd->new_vss_status_flags & VSS_NOMORE)
 188                 mmd->new_vss_status_flags = VSS_NEXT;
 189         gettimeofday(&now, NULL);
 190         tv_add(&mmd->afd.afhi.eof_tv, &now, &eof_barrier);
 191         munmap(map, mmd->size);
 192         map = NULL;
 193         mmd->chunks_sent = 0;
 194         mmd->offset = 0;
 195         mmd->afd.afhi.seconds_total = 0;
 196         free(mmd->afd.afhi.chunk_table);
 197         mmd->afd.afhi.chunk_table = NULL;
 198         tmp  = make_message("%s:\n%s:\n%s:\n", status_item_list[SI_AUDIO_FILE_INFO],
 199                 status_item_list[SI_TAGINFO1], status_item_list[SI_TAGINFO2]);
 200         strncpy(mmd->afd.afhi.info_string, tmp, sizeof(mmd->afd.afhi.info_string));
 201         mmd->afd.afhi.info_string[sizeof(mmd->afd.afhi.info_string) - 1] = '\0';
 202         make_empty_status_items(mmd->afd.verbose_ls_output);
 203         free(tmp);
 204         mmd->mtime = 0;
 205         mmd->size = 0;
 206         mmd->events++;
 207 }
 208
 209 /**
 210  * Get the header of the current audio file.
 211  *
 212  * \param buf The length of the header is stored here.
 213  * \param len Points to a buffer containing the header on return.
 214  *
 215  * \sa afh_get_header.
 216  */
 217 void vss_get_header(char **buf, size_t *len)
 218 {
 219         afh_get_header(&mmd->afd.afhi, map, buf, len);
 220 }
 221
 222 /**
 223  * Get the list of all supported audio formats.
 224  *
 225  * \return Aa space separated list of all supported audio formats
 226  * It is not allocated at runtime, i.e. there is no need to free
 227  * the returned string in the caller.
 228  */
 229 const char *supported_audio_formats(void)
 230 {
 231         return SUPPORTED_AUDIO_FORMATS;
 232 }
 233
 234 /**
 235  * Get the chunk time of the current audio file.
 236  *
 237  * \return A pointer to a struct containing the chunk time, or NULL,
 238  * if currently no audio file is selected.
 239  */
 240 struct timeval *vss_chunk_time(void)
 241 {
 242         if (!map)
 243                 return NULL;
 244         return &mmd->afd.afhi.chunk_tv;
 245 }
 246
 247 /** The possible states of the afs socket. See \ref afs_socket. */
 248 enum afs_socket_status {
 249         /** Socket is inactive. */
 250         AFS_SOCKET_READY,
 251         /** Socket fd was included in the write fd set for select(). */
 252         AFS_SOCKET_CHECK_FOR_WRITE,
 253         /** vss wrote a request to the socket and waits for afs to reply. */
 254         AFS_SOCKET_AFD_PENDING
 255 };
 256
 257 static enum afs_socket_status afsss;
 258
 259 static int need_to_request_new_audio_file(void)
 260 {
 261         if (map) /* have audio file */
 262                 return 0;
 263         if (!vss_playing()) /* don't need one */
 264                 return 0;
 265         if (mmd->new_vss_status_flags & VSS_NOMORE)
 266                 return 0;
 267         if (afsss == AFS_SOCKET_AFD_PENDING) /* already requested one */
 268                 return 0;
 269         return 1;
 270 }
 271
 272 /**
 273  * Compute the timeout for para_server's main select-loop.
 274  *
 275  * This function gets called from para_server to determine the timeout value
 276  * for its main select loop.
 277  *
 278  * \param rfds The set of file descriptors to be checked for reading.
 279  * \param wfds The set of file descriptors to be checked for writing.
 280  * \param max_fileno The highest-numbered file descriptor.
 281  *
 282  * Before the timeout is computed, the current vss status flags are evaluated
 283  * and acted upon by calling appropriate functions from the lower layers.
 284  * Possible actions include
 285  *
 286  *      - request a new audio file from afs,
 287  *      - shutdown of all senders (stop/pause command),
 288  *      - reposition the stream (ff/jmp command).
 289  *
 290  * \return A pointer to a struct timeval containing the timeout for the next
 291  * chunk of data to be sent, or NULL if we're not sending right now.
 292  */
 293 struct timeval *vss_preselect(fd_set *rfds, fd_set *wfds, int *max_fileno)
 294 {
 295         int i;
 296         struct timeval now;
 297
 298         if (!map || vss_next() || vss_paused() || vss_repos())
 299                 for (i = 0; senders[i].name; i++)
 300                         senders[i].shutdown_clients();
 301         if (vss_next())
 302                 vss_eof();
 303         else if (vss_paused()) {
 304                 if (mmd->chunks_sent) {
 305                         gettimeofday(&now, NULL);
 306                         tv_add(&mmd->afd.afhi.eof_tv, &now, &eof_barrier);
 307                 }
 308                 mmd->chunks_sent = 0;
 309         } else if (vss_repos()) {
 310                 gettimeofday(&now, NULL);
 311                 tv_add(&now, &announce_tv, &data_send_barrier);
 312                 tv_add(&mmd->afd.afhi.eof_tv, &now, &eof_barrier);
 313                 mmd->chunks_sent = 0;
 314                 mmd->current_chunk = mmd->repos_request;
 315                 mmd->new_vss_status_flags &= ~VSS_REPOS;
 316         }
 317
 318         if (need_to_request_new_audio_file()) {
 319                 PARA_DEBUG_LOG("ready and playing, but no audio file\n");
 320                 para_fd_set(afs_socket, wfds, max_fileno);
 321                 afsss = AFS_SOCKET_CHECK_FOR_WRITE;
 322         } else
 323                 para_fd_set(afs_socket, rfds, max_fileno);
 324         for (i = 0; senders[i].name; i++) {
 325                 if (!senders[i].pre_select)
 326                         continue;
 327                 senders[i].pre_select(max_fileno, rfds, wfds);
 328         }
 329         return vss_compute_timeout();
 330 }
 331
 332 static int recv_afs_msg(int *fd, uint32_t *code, uint32_t *data)
 333 {
 334         char control[255], buf[8];
 335         struct msghdr msg = {.msg_iov = NULL};
 336         struct cmsghdr *cmsg;
 337         struct iovec iov;
 338         int ret = 0;
 339
 340         *fd = -1;
 341         iov.iov_base = buf;
 342         iov.iov_len = sizeof(buf);
 343         msg.msg_iov = &iov;
 344         msg.msg_iovlen = 1;
 345         msg.msg_control = control;
 346         msg.msg_controllen = sizeof(control);
 347         memset(buf, 0, sizeof(buf));
 348         ret = recvmsg(afs_socket, &msg, 0);
 349         if (ret < 0)
 350                 return -ERRNO_TO_PARA_ERROR(errno);
 351         afsss = AFS_SOCKET_READY;
 352         if (iov.iov_len != sizeof(buf))
 353                 return -E_AFS_SHORT_READ;
 354         *code = *(uint32_t*)buf;
 355         *data =  *(uint32_t*)(buf + 4);
 356         for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
 357                 if (cmsg->cmsg_level != SOL_SOCKET
 358                         || cmsg->cmsg_type != SCM_RIGHTS)
 359                 continue;
 360                 if ((cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int) != 1)
 361                 continue;
 362                 *fd = *(int *)CMSG_DATA(cmsg);
 363         }
 364         return 1;
 365 }
 366
 367 static void recv_afs_result(void)
 368 {
 369         int ret, passed_fd, shmid;
 370         uint32_t afs_code = 0, afs_data = 0;
 371         struct stat statbuf;
 372         struct timeval now;
 373
 374         mmd->afd.afhi.chunk_table = NULL;
 375         ret = recv_afs_msg(&passed_fd, &afs_code, &afs_data);
 376         if (ret < 0)
 377                 goto err;
 378         PARA_DEBUG_LOG("fd: %d, code: %u, shmid: %u\n", passed_fd, afs_code,
 379                 afs_data);
 380         ret = -E_NOFD;
 381         if (afs_code != NEXT_AUDIO_FILE)
 382                 goto err;
 383         if (passed_fd < 0)
 384                 goto err;
 385         shmid = afs_data;
 386         ret = load_afd(shmid, &mmd->afd);
 387         if (ret < 0)
 388                 goto err;
 389         shm_destroy(shmid);
 390         ret = fstat(passed_fd, &statbuf);
 391         if (ret < 0) {
 392                 PARA_ERROR_LOG("fstat error:\n");
 393                 ret = -ERRNO_TO_PARA_ERROR(errno);
 394                 goto err;
 395         }
 396         mmd->size = statbuf.st_size;
 397         mmd->mtime = statbuf.st_mtime;
 398         map = para_mmap(mmd->size, PROT_READ, MAP_PRIVATE,
 399                 passed_fd, 0);
 400         close(passed_fd);
 401         mmd->chunks_sent = 0;
 402         mmd->current_chunk = 0;
 403         mmd->offset = 0;
 404         mmd->events++;
 405         mmd->num_played++;
 406         mmd->new_vss_status_flags &= (~VSS_NEXT);
 407         gettimeofday(&now, NULL);
 408         tv_add(&now, &announce_tv, &data_send_barrier);
 409         return;
 410 err:
 411         free(mmd->afd.afhi.chunk_table);
 412         if (passed_fd >= 0)
 413                 close(passed_fd);
 414         PARA_ERROR_LOG("%s\n", para_strerror(-ret));
 415         mmd->new_vss_status_flags = VSS_NEXT;
 416 }
 417
 418 void vss_post_select(fd_set *rfds, fd_set *wfds)
 419 {
 420         int ret, i;
 421
 422         if (afsss != AFS_SOCKET_CHECK_FOR_WRITE) {
 423                 if (FD_ISSET(afs_socket, rfds))
 424                         recv_afs_result();
 425         } else if (FD_ISSET(afs_socket, wfds)) {
 426                 PARA_NOTICE_LOG("requesting new fd from afs\n");
 427                 ret = send_buffer(afs_socket, "new");
 428                 afsss = AFS_SOCKET_AFD_PENDING;
 429         }
 430         for (i = 0; senders[i].name; i++) {
 431                 if (!senders[i].post_select)
 432                         continue;
 433                 senders[i].post_select(rfds, wfds);
 434         }
 435         vss_send_chunk();
 436 }
 437
 438 /**
 439  * Get the data of the given chunk.
 440  *
 441  * \param chunk_num The number of the desired chunk.
 442  * \param buf Chunk data.
 443  * \param len Chunk length in bytes.
 444  *
 445  * \return Standard.
 446  */
 447 int vss_get_chunk(long unsigned chunk_num, char **buf, size_t *len)
 448 {
 449         if (!map || !vss_playing())
 450                 return -E_CHUNK;
 451         if (chunk_num >= mmd->afd.afhi.chunks_total)
 452                 return -E_CHUNK;
 453         afh_get_chunk(chunk_num, &mmd->afd.afhi, map, buf, len);
 454         return 1;
 455 }
 456
 457 /**
 458  * Main sending function.
 459  *
 460  * This function gets called from para_server as soon as the next chunk of data
 461  * should be pushed out. It obtains a pointer to the data to be sent out as
 462  * well as its length from mmd->afd.afhi. This information is then passed to
 463  * each supported sender's send() function which is supposed to send out the data
 464  * to all connected clients.
 465  */
 466 void vss_send_chunk(void)
 467 {
 468         int i;
 469         struct timeval now, due;
 470         char *buf;
 471         size_t len;
 472
 473         if (!map || !vss_playing())
 474                 return;
 475         gettimeofday(&now, NULL);
 476         compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
 477                 &mmd->stream_start, &due);
 478         if (tv_diff(&due, &now, NULL) > 0)
 479                 return;
 480         if (chk_barrier("eof", &now, &eof_barrier, &due, 1) < 0)
 481                 return;
 482         if (chk_barrier("data send", &now, &data_send_barrier,
 483                         &due, 1) < 0)
 484                 return;
 485         mmd->new_vss_status_flags &= ~VSS_REPOS;
 486         if (mmd->current_chunk >= mmd->afd.afhi.chunks_total) { /* eof */
 487                 mmd->new_vss_status_flags |= VSS_NEXT;
 488                 return;
 489         }
 490         /*
 491          * We call the send function also in case of empty chunks as they
 492          * might have still some data queued which can be sent in this case.
 493          */
 494         if (!mmd->chunks_sent) {
 495                 struct timeval tmp;
 496                 gettimeofday(&mmd->stream_start, NULL);
 497                 tv_scale(mmd->current_chunk, &mmd->afd.afhi.chunk_tv, &tmp);
 498                 mmd->offset = tv2ms(&tmp);
 499                 mmd->events++;
 500         }
 501         afh_get_chunk(mmd->current_chunk, &mmd->afd.afhi, map, &buf, &len);
 502         for (i = 0; senders[i].name; i++)
 503                 senders[i].send(mmd->current_chunk, mmd->chunks_sent, buf, len);
 504         mmd->new_vss_status_flags |= VSS_PLAYING;
 505         mmd->chunks_sent++;
 506         mmd->current_chunk++;
 507 }