/* $NetBSD: dtv_demux.c,v 1.11 2020/05/30 13:15:10 jdolecek Exp $ */ /*- * Copyright (c) 2011 Jared D. McNeill * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by Jared D. McNeill. * 4. Neither the name of The NetBSD Foundation nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ /* * This file contains support for the /dev/dvb/adapter/demux0 device. * * The demux device is implemented as a cloning device. Each instance can * be in one of three modes: unconfigured (NONE), section filter (SECTION), * or PID filter (PES). * * An instance in section filter mode extracts PSI sections based on a * filter configured by the DMX_SET_FILTER ioctl. When an entire section is * received, it is made available to userspace via read method. Data is fed * into the section filter using the dtv_demux_write function. * * An instance in PID filter mode extracts TS packets that match the * specified PID filter configured by the DMX_SET_PES_FILTER, DMX_ADD_PID, * and DMX_REMOVE_PID ioctls. As this driver only implements the * DMX_OUT_TS_TAP output, these TS packets are made available to userspace * by calling read on the /dev/dvb/adapter/dvr0 device. */ #include __KERNEL_RCSID(0, "$NetBSD: dtv_demux.c,v 1.11 2020/05/30 13:15:10 jdolecek Exp $"); #include #include #include #include #include #include #include #include #include #include #include #include static int dtv_demux_read(struct file *, off_t *, struct uio *, kauth_cred_t, int); static int dtv_demux_ioctl(struct file *, u_long, void *); static int dtv_demux_poll(struct file *, int); static int dtv_demux_close(struct file *); static const struct fileops dtv_demux_fileops = { .fo_name = "dtv_demux", .fo_read = dtv_demux_read, .fo_write = fbadop_write, .fo_ioctl = dtv_demux_ioctl, .fo_fcntl = fnullop_fcntl, .fo_poll = dtv_demux_poll, .fo_stat = fbadop_stat, .fo_close = dtv_demux_close, .fo_kqfilter = fnullop_kqfilter, .fo_restart = fnullop_restart, }; static uint32_t crc_table[256] = { 0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b, 0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61, 0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd, 0x4c11db70, 0x48d0c6c7, 0x4593e01e, 0x4152fda9, 0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75, 0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3, 0x709f7b7a, 0x745e66cd, 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039, 0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 0xbe2b5b58, 0xbaea46ef, 0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d, 0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49, 0xc7361b4c, 0xc3f706fb, 0xceb42022, 0xca753d95, 0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1, 0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 0x34867077, 0x30476dc0, 0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072, 0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16, 0x018aeb13, 0x054bf6a4, 0x0808d07d, 0x0cc9cdca, 0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde, 0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02, 0x5e9f46bf, 0x5a5e5b08, 0x571d7dd1, 0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba, 0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b, 0xbb60adfc, 0xb6238b25, 0xb2e29692, 0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6, 0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a, 0xe0b41de7, 0xe4750050, 0xe9362689, 0xedf73b3e, 0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2, 0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34, 0xdc3abded, 0xd8fba05a, 0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637, 0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb, 0x4f040d56, 0x4bc510e1, 0x46863638, 0x42472b8f, 0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53, 0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5, 0x3f9b762c, 0x3b5a6b9b, 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff, 0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 0xf12f560e, 0xf5ee4bb9, 0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b, 0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f, 0xc423cd6a, 0xc0e2d0dd, 0xcda1f604, 0xc960ebb3, 0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7, 0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 0x9b3660c6, 0x9ff77d71, 0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3, 0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640, 0x4e8ee645, 0x4a4ffbf2, 0x470cdd2b, 0x43cdc09c, 0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8, 0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24, 0x119b4be9, 0x155a565e, 0x18197087, 0x1cd86d30, 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec, 0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d, 0x2056cd3a, 0x2d15ebe3, 0x29d4f654, 0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0, 0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c, 0xe3a1cbc1, 0xe760d676, 0xea23f0af, 0xeee2ed18, 0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4, 0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662, 0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668, 0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4 }; /* ISO/IEC 13818-1 Annex A "CRC Decoder Model" */ static uint32_t dtv_demux_crc32(uint8_t *buf, int len) { const uint32_t *crc_tab = crc_table; uint32_t CRC = 0xffffffff; int i; for (i = 0; i < len; i++) CRC = (CRC << 8) ^ crc_tab[((CRC >> 24) ^ *buf++) & 0xff]; return CRC; } /* * Start running the demux. */ static int dtv_demux_start(struct dtv_demux *demux) { struct dtv_softc *sc = demux->dd_sc; int error = 0; bool dostart = false; /* * If the demux is not running, mark it as running and update the * global demux run counter. */ mutex_enter(&sc->sc_lock); KASSERT(sc->sc_demux_runcnt >= 0); if (demux->dd_running == false) { sc->sc_demux_runcnt++; demux->dd_running = true; /* If this is the first demux running, trigger device start */ dostart = sc->sc_demux_runcnt == 1; } mutex_exit(&sc->sc_lock); if (dostart) { /* Setup receive buffers and trigger device start */ error = dtv_buffer_setup(sc); if (error == 0) error = dtv_device_start_transfer(sc); } /* * If something went wrong, restore the run counter and mark this * demux instance as halted. */ if (error) { mutex_enter(&sc->sc_lock); sc->sc_demux_runcnt--; demux->dd_running = false; mutex_exit(&sc->sc_lock); } return error; } /* * Stop running the demux. */ static int dtv_demux_stop(struct dtv_demux *demux) { struct dtv_softc *sc = demux->dd_sc; int error = 0; bool dostop = false; /* * If the demux is running, mark it as halted and update the * global demux run counter. */ mutex_enter(&sc->sc_lock); if (demux->dd_running == true) { KASSERT(sc->sc_demux_runcnt > 0); demux->dd_running = false; sc->sc_demux_runcnt--; /* If this was the last demux running, trigger device stop */ dostop = sc->sc_demux_runcnt == 0; } mutex_exit(&sc->sc_lock); if (dostop) { /* Trigger device stop */ error = dtv_device_stop_transfer(sc); } /* * If something went wrong, restore the run counter and mark this * demux instance as running. */ if (error) { mutex_enter(&sc->sc_lock); sc->sc_demux_runcnt++; demux->dd_running = true; mutex_exit(&sc->sc_lock); } return error; } /* * Put the demux into PID filter mode and update the PID filter table. */ static int dtv_demux_set_pidfilter(struct dtv_demux *demux, uint16_t pid, bool onoff) { struct dtv_softc *sc = demux->dd_sc; /* * TS PID is 13 bits; demux device uses special PID 0x2000 to mean * "all PIDs". Verify that the requested PID is in range. */ if (pid > 0x2000) return EINVAL; /* Set demux mode */ demux->dd_mode = DTV_DEMUX_MODE_PES; /* * If requesting "all PIDs", set the on/off flag for all PIDs in * the PID map, otherwise set the on/off flag for the requested * PID. */ if (pid == 0x2000) { memset(sc->sc_ts.ts_pidfilter, onoff ? 0xff : 0, sizeof(sc->sc_ts.ts_pidfilter)); } else { sc->sc_ts.ts_pidfilter[pid] = onoff; } return 0; } /* * Open a new instance of the demux cloning device. */ int dtv_demux_open(struct dtv_softc *sc, int flags, int mode, lwp_t *l) { struct file *fp; struct dtv_demux *demux; int error, fd; /* Allocate private storage */ demux = kmem_zalloc(sizeof(*demux), KM_SLEEP); demux->dd_sc = sc; /* Default operation mode is unconfigured */ demux->dd_mode = DTV_DEMUX_MODE_NONE; selinit(&demux->dd_sel); mutex_init(&demux->dd_lock, MUTEX_DEFAULT, IPL_SCHED); cv_init(&demux->dd_section_cv, "dtvsec"); error = fd_allocfile(&fp, &fd); if (error) { kmem_free(demux, sizeof(*demux)); return error; } /* Add the demux to the list of demux instances */ mutex_enter(&sc->sc_demux_lock); TAILQ_INSERT_TAIL(&sc->sc_demux_list, demux, dd_entries); mutex_exit(&sc->sc_demux_lock); return fd_clone(fp, fd, flags, &dtv_demux_fileops, demux); } /* * Close the instance of the demux cloning device. */ int dtv_demux_close(struct file *fp) { struct dtv_demux *demux = fp->f_data; struct dtv_softc *sc; int error; if (demux == NULL) return ENXIO; fp->f_data = NULL; sc = demux->dd_sc; /* If the demux is still running, stop it */ if (demux->dd_running) { error = dtv_demux_stop(demux); if (error) return error; } /* Remove the demux from the list of demux instances */ mutex_enter(&sc->sc_demux_lock); TAILQ_REMOVE(&sc->sc_demux_list, demux, dd_entries); mutex_exit(&sc->sc_demux_lock); mutex_destroy(&demux->dd_lock); cv_destroy(&demux->dd_section_cv); kmem_free(demux, sizeof(*demux)); /* Update the global device open count */ dtv_common_close(sc); return 0; } /* * Handle demux ioctl requests */ static int dtv_demux_ioctl(struct file *fp, u_long cmd, void *data) { struct dtv_demux *demux = fp->f_data; struct dmx_pes_filter_params *pesfilt; struct dmx_sct_filter_params *sctfilt; uint16_t pid; int error; if (demux == NULL) return ENXIO; switch (cmd) { case DMX_START: return dtv_demux_start(demux); case DMX_STOP: return dtv_demux_stop(demux); case DMX_SET_BUFFER_SIZE: /* * The demux driver doesn't support configurable buffer sizes, * but software relies on this command succeeding. */ return 0; case DMX_SET_FILTER: sctfilt = data; /* Verify that the requested PID is in range. */ if (sctfilt->pid >= 0x2000) return EINVAL; /* * Update section filter parameters, reset read/write ptrs, * clear section count and overflow flag, and set the * demux instance mode to section filter. */ demux->dd_secfilt.params = *sctfilt; demux->dd_secfilt.rp = demux->dd_secfilt.wp = 0; demux->dd_secfilt.nsections = 0; demux->dd_secfilt.overflow = false; demux->dd_mode = DTV_DEMUX_MODE_SECTION; /* * If the DMX_IMMEDIATE_START flag is present in the request, * start running the demux immediately (no need for a * subsequent DMX_START ioctl). */ if (sctfilt->flags & DMX_IMMEDIATE_START) { error = dtv_demux_start(demux); if (error) return error; } return 0; case DMX_SET_PES_FILTER: pesfilt = data; /* The driver only supports input from the frontend */ if (pesfilt->input != DMX_IN_FRONTEND) return EINVAL; /* * The driver only supports output to the TS TAP in PID * filter mode. */ if (pesfilt->output != DMX_OUT_TS_TAP) return EINVAL; /* Update PID filter table */ error = dtv_demux_set_pidfilter(demux, pesfilt->pid, true); if (error) return error; /* * If the DMX_IMMEDIATE_START flag is present in the request, * start running the demux immediately (no need for a * subsequent DMX_START ioctl). */ if (pesfilt->flags & DMX_IMMEDIATE_START) { error = dtv_demux_start(demux); if (error) return error; } return 0; case DMX_ADD_PID: pid = *(uint16_t *)data; return dtv_demux_set_pidfilter(demux, pid, true); case DMX_REMOVE_PID: pid = *(uint16_t *)data; return dtv_demux_set_pidfilter(demux, pid, false); default: return EINVAL; } } /* * Test for I/O readiness */ static int dtv_demux_poll(struct file *fp, int events) { struct dtv_demux *demux = fp->f_data; int revents = 0; if (demux == NULL) return POLLERR; /* * If the demux instance is in section filter mode, wait for an * entire section to become ready. */ mutex_enter(&demux->dd_lock); if (demux->dd_mode == DTV_DEMUX_MODE_SECTION && demux->dd_secfilt.nsections > 0) { revents |= POLLIN; } else { selrecord(curlwp, &demux->dd_sel); } mutex_exit(&demux->dd_lock); return revents; } /* * Read from the demux instance */ static int dtv_demux_read(struct file *fp, off_t *offp, struct uio *uio, kauth_cred_t cred, int flags) { struct dtv_demux *demux = fp->f_data; struct dtv_ts_section *sec; int error; if (demux == NULL) return ENXIO; /* Only support read if the instance is in section filter mode */ if (demux->dd_mode != DTV_DEMUX_MODE_SECTION) return EIO; sec = kmem_alloc(sizeof(*sec), KM_SLEEP); /* Wait for a complete PSI section */ mutex_enter(&demux->dd_lock); while (demux->dd_secfilt.nsections == 0) { if (flags & IO_NDELAY) { mutex_exit(&demux->dd_lock); /* No data available */ error = EWOULDBLOCK; goto out; } error = cv_wait_sig(&demux->dd_section_cv, &demux->dd_lock); if (error) { mutex_exit(&demux->dd_lock); goto out; } } /* Copy the completed PSI section */ *sec = demux->dd_secfilt.section[demux->dd_secfilt.rp]; /* Update read pointer */ demux->dd_secfilt.rp++; if (demux->dd_secfilt.rp >= __arraycount(demux->dd_secfilt.section)) demux->dd_secfilt.rp = 0; /* Update section count */ demux->dd_secfilt.nsections--; mutex_exit(&demux->dd_lock); /* * If the filter parameters specify the DMX_ONESHOT flag, stop * the demux after one PSI section is received. */ if (demux->dd_secfilt.params.flags & DMX_ONESHOT) dtv_demux_stop(demux); /* * Copy the PSI section to userspace. If the receiving buffer is * too small, the rest of the payload will be discarded. Although * this behaviour differs from the Linux implementation, in practice * it should not be an issue as PSI sections have a max size of 4KB * (and callers will generally provide a big enough buffer). */ error = uiomove(sec->sec_buf, sec->sec_length, uio); out: kmem_free(sec, sizeof(*sec)); return error; } /* * Verify the CRC of a PSI section. */ static bool dtv_demux_check_crc(struct dtv_demux *demux, struct dtv_ts_section *sec) { uint32_t crc, sec_crc; /* * If section_syntax_indicator is not set, the PSI section does * not include a CRC field. */ if ((sec->sec_buf[1] & 0x80) == 0) return false; sec_crc = be32dec(&sec->sec_buf[sec->sec_length - 4]); crc = dtv_demux_crc32(&sec->sec_buf[0], sec->sec_length - 4); return crc == sec_crc; } /* * Process a single TS packet and extract PSI sections based on the * instance's section filter. */ static int dtv_demux_process(struct dtv_demux *demux, const uint8_t *tspkt, size_t tspktlen) { struct dtv_ts_section *sec; dmx_filter_t *dmxfilt = &demux->dd_secfilt.params.filter; const uint8_t *p; uint16_t section_length; int brem, avail; KASSERT(tspktlen == TS_PKTLEN); /* If the demux instance is not running, ignore the packet */ if (demux->dd_running == false) return 0; /* * If the demux instance is not in section filter mode, ignore * the packet */ if (demux->dd_mode != DTV_DEMUX_MODE_SECTION) return 0; /* * If the packet's TS PID does not match the section filter PID, * ignore the packet */ if (TS_PID(tspkt) != demux->dd_secfilt.params.pid) return 0; /* * If the TS packet does not contain a payload, ignore the packet */ if (TS_HAS_PAYLOAD(tspkt) == 0) return 0; mutex_enter(&demux->dd_lock); /* If the section buffer is full, set the overflow flag and return */ if (demux->dd_secfilt.nsections == __arraycount(demux->dd_secfilt.section)) { demux->dd_secfilt.overflow = true; goto done; } sec = &demux->dd_secfilt.section[demux->dd_secfilt.wp]; /* If we have no bytes in our buffer, wait for payload unit start */ if (sec->sec_bytesused == 0 && TS_HAS_PUSI(tspkt) == 0) goto done; /* find payload start */ p = tspkt + 4; if (TS_HAS_AF(tspkt)) { if (*p > 182) /* AF length with payload is between 0-182 */ goto done; p += (1 + *p); } if (TS_HAS_PUSI(tspkt)) { p += (1 + *p); } brem = tspktlen - (p - tspkt); if (TS_HAS_PUSI(tspkt)) { if (brem < 16) goto done; section_length = ((p[1] & 0xf) << 8) | p[2]; /* table_id filter */ if (dmxfilt->mask[0]) { if ((p[0] & dmxfilt->mask[0]) != dmxfilt->filter[0]) goto done; } /* table_id_ext filter */ if (dmxfilt->mask[1] && dmxfilt->mask[2]) { /* * table_id_ext is only valid if * section_syntax_indicator is set */ if (section_length < 2 || (p[1] & 0x80) == 0) goto done; if ((p[3] & dmxfilt->mask[1]) != dmxfilt->filter[1]) goto done; if ((p[4] & dmxfilt->mask[2]) != dmxfilt->filter[2]) goto done; } sec->sec_length = section_length + 3; /* maximum section length is 4KB */ if (sec->sec_length > sizeof(sec->sec_buf)) { sec->sec_bytesused = sec->sec_length = 0; goto done; } } /* If we have bytes pending and we see payload unit start, flush buf */ if (sec->sec_bytesused > 0 && TS_HAS_PUSI(tspkt)) sec->sec_bytesused = sec->sec_length = 0; /* Copy data into section buffer */ avail = uimin(sec->sec_length - sec->sec_bytesused, brem); if (avail < 0) goto done; memcpy(&sec->sec_buf[sec->sec_bytesused], p, avail); sec->sec_bytesused += avail; /* * If a complete section has been received, update section count * and notify readers. */ if (sec->sec_bytesused == sec->sec_length) { /* * If the DMX_CHECK_CRC flag was present in the DMX_SET_FILTER * parameters, verify the PSI section checksum. If the * checksum is invalid, discard the entire corrupt section. */ if ((demux->dd_secfilt.params.flags & DMX_CHECK_CRC) && dtv_demux_check_crc(demux, sec) == false) { /* discard section */ sec->sec_bytesused = sec->sec_length = 0; goto done; } demux->dd_secfilt.wp++; if (demux->dd_secfilt.wp >= __arraycount(demux->dd_secfilt.section)) demux->dd_secfilt.wp = 0; demux->dd_secfilt.nsections++; cv_broadcast(&demux->dd_section_cv); selnotify(&demux->dd_sel, 0, 0); } done: mutex_exit(&demux->dd_lock); return 0; } /* * Submit TS data to all demux instances */ void dtv_demux_write(struct dtv_softc *sc, const uint8_t *tspkt, size_t tspktlen) { struct dtv_demux *demux; mutex_enter(&sc->sc_demux_lock); TAILQ_FOREACH(demux, &sc->sc_demux_list, dd_entries) { dtv_demux_process(demux, tspkt, tspktlen); } mutex_exit(&sc->sc_demux_lock); }