1 | /* $NetBSD: dtv_demux.c,v 1.6 2014/08/09 13:34:10 jmcneill Exp $ */ |
2 | |
3 | /*- |
4 | * Copyright (c) 2011 Jared D. McNeill <jmcneill@invisible.ca> |
5 | * All rights reserved. |
6 | * |
7 | * Redistribution and use in source and binary forms, with or without |
8 | * modification, are permitted provided that the following conditions |
9 | * are met: |
10 | * 1. Redistributions of source code must retain the above copyright |
11 | * notice, this list of conditions and the following disclaimer. |
12 | * 2. Redistributions in binary form must reproduce the above copyright |
13 | * notice, this list of conditions and the following disclaimer in the |
14 | * documentation and/or other materials provided with the distribution. |
15 | * 3. All advertising materials mentioning features or use of this software |
16 | * must display the following acknowledgement: |
17 | * This product includes software developed by Jared D. McNeill. |
18 | * 4. Neither the name of The NetBSD Foundation nor the names of its |
19 | * contributors may be used to endorse or promote products derived |
20 | * from this software without specific prior written permission. |
21 | * |
22 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS |
23 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
24 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
25 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS |
26 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
27 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
28 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
29 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
30 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
31 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
32 | * POSSIBILITY OF SUCH DAMAGE. |
33 | */ |
34 | |
35 | /* |
36 | * This file contains support for the /dev/dvb/adapter<n>/demux0 device. |
37 | * |
38 | * The demux device is implemented as a cloning device. Each instance can |
39 | * be in one of three modes: unconfigured (NONE), section filter (SECTION), |
40 | * or PID filter (PES). |
41 | * |
42 | * An instance in section filter mode extracts PSI sections based on a |
43 | * filter configured by the DMX_SET_FILTER ioctl. When an entire section is |
44 | * received, it is made available to userspace via read method. Data is fed |
45 | * into the section filter using the dtv_demux_write function. |
46 | * |
47 | * An instance in PID filter mode extracts TS packets that match the |
48 | * specified PID filter configured by the DMX_SET_PES_FILTER, DMX_ADD_PID, |
49 | * and DMX_REMOVE_PID ioctls. As this driver only implements the |
50 | * DMX_OUT_TS_TAP output, these TS packets are made available to userspace |
51 | * by calling read on the /dev/dvb/adapter<n>/dvr0 device. |
52 | */ |
53 | |
54 | #include <sys/cdefs.h> |
55 | __KERNEL_RCSID(0, "$NetBSD: dtv_demux.c,v 1.6 2014/08/09 13:34:10 jmcneill Exp $" ); |
56 | |
57 | #include <sys/param.h> |
58 | #include <sys/types.h> |
59 | #include <sys/conf.h> |
60 | #include <sys/kmem.h> |
61 | #include <sys/device.h> |
62 | #include <sys/select.h> |
63 | #include <sys/filedesc.h> |
64 | #include <sys/file.h> |
65 | #include <sys/poll.h> |
66 | #include <sys/vnode.h> |
67 | #include <sys/queue.h> |
68 | |
69 | #include <dev/dtv/dtvvar.h> |
70 | |
71 | static int dtv_demux_read(struct file *, off_t *, struct uio *, |
72 | kauth_cred_t, int); |
73 | static int dtv_demux_ioctl(struct file *, u_long, void *); |
74 | static int dtv_demux_poll(struct file *, int); |
75 | static int dtv_demux_close(struct file *); |
76 | |
77 | static const struct fileops dtv_demux_fileops = { |
78 | .fo_read = dtv_demux_read, |
79 | .fo_write = fbadop_write, |
80 | .fo_ioctl = dtv_demux_ioctl, |
81 | .fo_fcntl = fnullop_fcntl, |
82 | .fo_poll = dtv_demux_poll, |
83 | .fo_stat = fbadop_stat, |
84 | .fo_close = dtv_demux_close, |
85 | .fo_kqfilter = fnullop_kqfilter, |
86 | .fo_restart = fnullop_restart, |
87 | }; |
88 | |
89 | static uint32_t crc_table[256] = { |
90 | 0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9, |
91 | 0x130476dc, 0x17c56b6b, 0x1a864db2, 0x1e475005, |
92 | 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61, |
93 | 0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd, |
94 | 0x4c11db70, 0x48d0c6c7, 0x4593e01e, 0x4152fda9, |
95 | 0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75, |
96 | 0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011, |
97 | 0x791d4014, 0x7ddc5da3, 0x709f7b7a, 0x745e66cd, |
98 | 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039, |
99 | 0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, |
100 | 0xbe2b5b58, 0xbaea46ef, 0xb7a96036, 0xb3687d81, |
101 | 0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d, |
102 | 0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49, |
103 | 0xc7361b4c, 0xc3f706fb, 0xceb42022, 0xca753d95, |
104 | 0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1, |
105 | 0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, |
106 | 0x34867077, 0x30476dc0, 0x3d044b19, 0x39c556ae, |
107 | 0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072, |
108 | 0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16, |
109 | 0x018aeb13, 0x054bf6a4, 0x0808d07d, 0x0cc9cdca, |
110 | 0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde, |
111 | 0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02, |
112 | 0x5e9f46bf, 0x5a5e5b08, 0x571d7dd1, 0x53dc6066, |
113 | 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba, |
114 | 0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, |
115 | 0xbfa1b04b, 0xbb60adfc, 0xb6238b25, 0xb2e29692, |
116 | 0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6, |
117 | 0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a, |
118 | 0xe0b41de7, 0xe4750050, 0xe9362689, 0xedf73b3e, |
119 | 0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2, |
120 | 0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686, |
121 | 0xd5b88683, 0xd1799b34, 0xdc3abded, 0xd8fba05a, |
122 | 0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637, |
123 | 0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb, |
124 | 0x4f040d56, 0x4bc510e1, 0x46863638, 0x42472b8f, |
125 | 0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53, |
126 | 0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47, |
127 | 0x36194d42, 0x32d850f5, 0x3f9b762c, 0x3b5a6b9b, |
128 | 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff, |
129 | 0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, |
130 | 0xf12f560e, 0xf5ee4bb9, 0xf8ad6d60, 0xfc6c70d7, |
131 | 0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b, |
132 | 0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f, |
133 | 0xc423cd6a, 0xc0e2d0dd, 0xcda1f604, 0xc960ebb3, |
134 | 0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7, |
135 | 0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, |
136 | 0x9b3660c6, 0x9ff77d71, 0x92b45ba8, 0x9675461f, |
137 | 0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3, |
138 | 0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640, |
139 | 0x4e8ee645, 0x4a4ffbf2, 0x470cdd2b, 0x43cdc09c, |
140 | 0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8, |
141 | 0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24, |
142 | 0x119b4be9, 0x155a565e, 0x18197087, 0x1cd86d30, |
143 | 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec, |
144 | 0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, |
145 | 0x2497d08d, 0x2056cd3a, 0x2d15ebe3, 0x29d4f654, |
146 | 0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0, |
147 | 0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c, |
148 | 0xe3a1cbc1, 0xe760d676, 0xea23f0af, 0xeee2ed18, |
149 | 0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4, |
150 | 0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0, |
151 | 0x9abc8bd5, 0x9e7d9662, 0x933eb0bb, 0x97ffad0c, |
152 | 0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668, |
153 | 0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4 |
154 | }; |
155 | |
156 | /* ISO/IEC 13818-1 Annex A "CRC Decoder Model" */ |
157 | static uint32_t |
158 | dtv_demux_crc32(uint8_t *buf, int len) |
159 | { |
160 | const uint32_t *crc_tab = crc_table; |
161 | uint32_t CRC = 0xffffffff; |
162 | int i; |
163 | |
164 | for (i = 0; i < len; i++) |
165 | CRC = (CRC << 8) ^ crc_tab[((CRC >> 24) ^ *buf++) & 0xff]; |
166 | |
167 | return CRC; |
168 | } |
169 | |
170 | /* |
171 | * Start running the demux. |
172 | */ |
173 | static int |
174 | dtv_demux_start(struct dtv_demux *demux) |
175 | { |
176 | struct dtv_softc *sc = demux->dd_sc; |
177 | int error = 0; |
178 | bool dostart = false; |
179 | |
180 | /* |
181 | * If the demux is not running, mark it as running and update the |
182 | * global demux run counter. |
183 | */ |
184 | mutex_enter(&sc->sc_lock); |
185 | KASSERT(sc->sc_demux_runcnt >= 0); |
186 | if (demux->dd_running == false) { |
187 | sc->sc_demux_runcnt++; |
188 | demux->dd_running = true; |
189 | /* If this is the first demux running, trigger device start */ |
190 | dostart = sc->sc_demux_runcnt == 1; |
191 | } |
192 | mutex_exit(&sc->sc_lock); |
193 | |
194 | if (dostart) { |
195 | /* Setup receive buffers and trigger device start */ |
196 | error = dtv_buffer_setup(sc); |
197 | if (error == 0) |
198 | error = dtv_device_start_transfer(sc); |
199 | } |
200 | |
201 | /* |
202 | * If something went wrong, restore the run counter and mark this |
203 | * demux instance as halted. |
204 | */ |
205 | if (error) { |
206 | mutex_enter(&sc->sc_lock); |
207 | sc->sc_demux_runcnt--; |
208 | demux->dd_running = false; |
209 | mutex_exit(&sc->sc_lock); |
210 | } |
211 | |
212 | return error; |
213 | } |
214 | |
215 | /* |
216 | * Stop running the demux. |
217 | */ |
218 | static int |
219 | dtv_demux_stop(struct dtv_demux *demux) |
220 | { |
221 | struct dtv_softc *sc = demux->dd_sc; |
222 | int error = 0; |
223 | bool dostop = false; |
224 | |
225 | /* |
226 | * If the demux is running, mark it as halted and update the |
227 | * global demux run counter. |
228 | */ |
229 | mutex_enter(&sc->sc_lock); |
230 | if (demux->dd_running == true) { |
231 | KASSERT(sc->sc_demux_runcnt > 0); |
232 | demux->dd_running = false; |
233 | sc->sc_demux_runcnt--; |
234 | /* If this was the last demux running, trigger device stop */ |
235 | dostop = sc->sc_demux_runcnt == 0; |
236 | } |
237 | mutex_exit(&sc->sc_lock); |
238 | |
239 | if (dostop) { |
240 | /* Trigger device stop */ |
241 | error = dtv_device_stop_transfer(sc); |
242 | } |
243 | |
244 | /* |
245 | * If something went wrong, restore the run counter and mark this |
246 | * demux instance as running. |
247 | */ |
248 | if (error) { |
249 | mutex_enter(&sc->sc_lock); |
250 | sc->sc_demux_runcnt++; |
251 | demux->dd_running = true; |
252 | mutex_exit(&sc->sc_lock); |
253 | } |
254 | |
255 | return error; |
256 | } |
257 | |
258 | /* |
259 | * Put the demux into PID filter mode and update the PID filter table. |
260 | */ |
261 | static int |
262 | dtv_demux_set_pidfilter(struct dtv_demux *demux, uint16_t pid, bool onoff) |
263 | { |
264 | struct dtv_softc *sc = demux->dd_sc; |
265 | |
266 | /* |
267 | * TS PID is 13 bits; demux device uses special PID 0x2000 to mean |
268 | * "all PIDs". Verify that the requested PID is in range. |
269 | */ |
270 | if (pid > 0x2000) |
271 | return EINVAL; |
272 | |
273 | /* Set demux mode */ |
274 | demux->dd_mode = DTV_DEMUX_MODE_PES; |
275 | /* |
276 | * If requesting "all PIDs", set the on/off flag for all PIDs in |
277 | * the PID map, otherwise set the on/off flag for the requested |
278 | * PID. |
279 | */ |
280 | if (pid == 0x2000) { |
281 | memset(sc->sc_ts.ts_pidfilter, onoff, |
282 | sizeof(sc->sc_ts.ts_pidfilter)); |
283 | } else { |
284 | sc->sc_ts.ts_pidfilter[pid] = onoff; |
285 | } |
286 | |
287 | return 0; |
288 | } |
289 | |
290 | /* |
291 | * Open a new instance of the demux cloning device. |
292 | */ |
293 | int |
294 | dtv_demux_open(struct dtv_softc *sc, int flags, int mode, lwp_t *l) |
295 | { |
296 | struct file *fp; |
297 | struct dtv_demux *demux; |
298 | int error, fd; |
299 | |
300 | /* Allocate private storage */ |
301 | demux = kmem_zalloc(sizeof(*demux), KM_SLEEP); |
302 | if (demux == NULL) |
303 | return ENOMEM; |
304 | demux->dd_sc = sc; |
305 | /* Default operation mode is unconfigured */ |
306 | demux->dd_mode = DTV_DEMUX_MODE_NONE; |
307 | selinit(&demux->dd_sel); |
308 | mutex_init(&demux->dd_lock, MUTEX_DEFAULT, IPL_SCHED); |
309 | cv_init(&demux->dd_section_cv, "dtvsec" ); |
310 | |
311 | error = fd_allocfile(&fp, &fd); |
312 | if (error) { |
313 | kmem_free(demux, sizeof(*demux)); |
314 | return error; |
315 | } |
316 | |
317 | /* Add the demux to the list of demux instances */ |
318 | mutex_enter(&sc->sc_demux_lock); |
319 | TAILQ_INSERT_TAIL(&sc->sc_demux_list, demux, dd_entries); |
320 | mutex_exit(&sc->sc_demux_lock); |
321 | |
322 | return fd_clone(fp, fd, flags, &dtv_demux_fileops, demux); |
323 | } |
324 | |
325 | /* |
326 | * Close the instance of the demux cloning device. |
327 | */ |
328 | int |
329 | dtv_demux_close(struct file *fp) |
330 | { |
331 | struct dtv_demux *demux = fp->f_data; |
332 | struct dtv_softc *sc; |
333 | int error; |
334 | |
335 | if (demux == NULL) |
336 | return ENXIO; |
337 | |
338 | fp->f_data = NULL; |
339 | |
340 | sc = demux->dd_sc; |
341 | |
342 | /* If the demux is still running, stop it */ |
343 | if (demux->dd_running) { |
344 | error = dtv_demux_stop(demux); |
345 | if (error) |
346 | return error; |
347 | } |
348 | |
349 | /* Remove the demux from the list of demux instances */ |
350 | mutex_enter(&sc->sc_demux_lock); |
351 | TAILQ_REMOVE(&sc->sc_demux_list, demux, dd_entries); |
352 | mutex_exit(&sc->sc_demux_lock); |
353 | |
354 | mutex_destroy(&demux->dd_lock); |
355 | cv_destroy(&demux->dd_section_cv); |
356 | kmem_free(demux, sizeof(*demux)); |
357 | |
358 | /* Update the global device open count */ |
359 | dtv_common_close(sc); |
360 | |
361 | return 0; |
362 | } |
363 | |
364 | /* |
365 | * Handle demux ioctl requests |
366 | */ |
367 | static int |
368 | dtv_demux_ioctl(struct file *fp, u_long cmd, void *data) |
369 | { |
370 | struct dtv_demux *demux = fp->f_data; |
371 | struct dmx_pes_filter_params *pesfilt; |
372 | struct dmx_sct_filter_params *sctfilt; |
373 | uint16_t pid; |
374 | int error; |
375 | |
376 | if (demux == NULL) |
377 | return ENXIO; |
378 | |
379 | switch (cmd) { |
380 | case DMX_START: |
381 | return dtv_demux_start(demux); |
382 | case DMX_STOP: |
383 | return dtv_demux_stop(demux); |
384 | case DMX_SET_BUFFER_SIZE: |
385 | /* |
386 | * The demux driver doesn't support configurable buffer sizes, |
387 | * but software relies on this command succeeding. |
388 | */ |
389 | return 0; |
390 | case DMX_SET_FILTER: |
391 | sctfilt = data; |
392 | |
393 | /* Verify that the requested PID is in range. */ |
394 | if (sctfilt->pid >= 0x2000) |
395 | return EINVAL; |
396 | |
397 | /* |
398 | * Update section filter parameters, reset read/write ptrs, |
399 | * clear section count and overflow flag, and set the |
400 | * demux instance mode to section filter. |
401 | */ |
402 | demux->dd_secfilt.params = *sctfilt; |
403 | demux->dd_secfilt.rp = demux->dd_secfilt.wp = 0; |
404 | demux->dd_secfilt.nsections = 0; |
405 | demux->dd_secfilt.overflow = false; |
406 | demux->dd_mode = DTV_DEMUX_MODE_SECTION; |
407 | |
408 | /* |
409 | * If the DMX_IMMEDIATE_START flag is present in the request, |
410 | * start running the demux immediately (no need for a |
411 | * subsequent DMX_START ioctl). |
412 | */ |
413 | if (sctfilt->flags & DMX_IMMEDIATE_START) { |
414 | error = dtv_demux_start(demux); |
415 | if (error) |
416 | return error; |
417 | } |
418 | |
419 | return 0; |
420 | case DMX_SET_PES_FILTER: |
421 | pesfilt = data; |
422 | |
423 | /* The driver only supports input from the frontend */ |
424 | if (pesfilt->input != DMX_IN_FRONTEND) |
425 | return EINVAL; |
426 | /* |
427 | * The driver only supports output to the TS TAP in PID |
428 | * filter mode. |
429 | */ |
430 | if (pesfilt->output != DMX_OUT_TS_TAP) |
431 | return EINVAL; |
432 | |
433 | /* Update PID filter table */ |
434 | error = dtv_demux_set_pidfilter(demux, pesfilt->pid, true); |
435 | if (error) |
436 | return error; |
437 | |
438 | /* |
439 | * If the DMX_IMMEDIATE_START flag is present in the request, |
440 | * start running the demux immediately (no need for a |
441 | * subsequent DMX_START ioctl). |
442 | */ |
443 | if (pesfilt->flags & DMX_IMMEDIATE_START) { |
444 | error = dtv_demux_start(demux); |
445 | if (error) |
446 | return error; |
447 | } |
448 | return 0; |
449 | case DMX_ADD_PID: |
450 | pid = *(uint16_t *)data; |
451 | return dtv_demux_set_pidfilter(demux, pid, true); |
452 | case DMX_REMOVE_PID: |
453 | pid = *(uint16_t *)data; |
454 | return dtv_demux_set_pidfilter(demux, pid, false); |
455 | default: |
456 | return EINVAL; |
457 | } |
458 | } |
459 | |
460 | /* |
461 | * Test for I/O readiness |
462 | */ |
463 | static int |
464 | dtv_demux_poll(struct file *fp, int events) |
465 | { |
466 | struct dtv_demux *demux = fp->f_data; |
467 | int revents = 0; |
468 | |
469 | if (demux == NULL) |
470 | return POLLERR; |
471 | |
472 | /* |
473 | * If the demux instance is in section filter mode, wait for an |
474 | * entire section to become ready. |
475 | */ |
476 | mutex_enter(&demux->dd_lock); |
477 | if (demux->dd_mode == DTV_DEMUX_MODE_SECTION && |
478 | demux->dd_secfilt.nsections > 0) { |
479 | revents |= POLLIN; |
480 | } else { |
481 | selrecord(curlwp, &demux->dd_sel); |
482 | } |
483 | mutex_exit(&demux->dd_lock); |
484 | |
485 | return revents; |
486 | } |
487 | |
488 | /* |
489 | * Read from the demux instance |
490 | */ |
491 | static int |
492 | dtv_demux_read(struct file *fp, off_t *offp, struct uio *uio, |
493 | kauth_cred_t cred, int flags) |
494 | { |
495 | struct dtv_demux *demux = fp->f_data; |
496 | struct dtv_ts_section sec; |
497 | int error; |
498 | |
499 | if (demux == NULL) |
500 | return ENXIO; |
501 | |
502 | /* Only support read if the instance is in section filter mode */ |
503 | if (demux->dd_mode != DTV_DEMUX_MODE_SECTION) |
504 | return EIO; |
505 | |
506 | /* Wait for a complete PSI section */ |
507 | mutex_enter(&demux->dd_lock); |
508 | while (demux->dd_secfilt.nsections == 0) { |
509 | if (flags & IO_NDELAY) { |
510 | mutex_exit(&demux->dd_lock); |
511 | /* No data available */ |
512 | return EWOULDBLOCK; |
513 | } |
514 | error = cv_wait_sig(&demux->dd_section_cv, &demux->dd_lock); |
515 | if (error) { |
516 | mutex_exit(&demux->dd_lock); |
517 | return error; |
518 | } |
519 | } |
520 | /* Copy the completed PSI section */ |
521 | sec = demux->dd_secfilt.section[demux->dd_secfilt.rp]; |
522 | /* Update read pointer */ |
523 | demux->dd_secfilt.rp++; |
524 | if (demux->dd_secfilt.rp >= __arraycount(demux->dd_secfilt.section)) |
525 | demux->dd_secfilt.rp = 0; |
526 | /* Update section count */ |
527 | demux->dd_secfilt.nsections--; |
528 | mutex_exit(&demux->dd_lock); |
529 | |
530 | /* |
531 | * If the filter parameters specify the DMX_ONESHOT flag, stop |
532 | * the demux after one PSI section is received. |
533 | */ |
534 | if (demux->dd_secfilt.params.flags & DMX_ONESHOT) |
535 | dtv_demux_stop(demux); |
536 | |
537 | /* |
538 | * Copy the PSI section to userspace. If the receiving buffer is |
539 | * too small, the rest of the payload will be discarded. Although |
540 | * this behaviour differs from the Linux implementation, in practice |
541 | * it should not be an issue as PSI sections have a max size of 4KB |
542 | * (and callers will generally provide a big enough buffer). |
543 | */ |
544 | return uiomove(sec.sec_buf, sec.sec_length, uio); |
545 | } |
546 | |
547 | /* |
548 | * Verify the CRC of a PSI section. |
549 | */ |
550 | static bool |
551 | dtv_demux_check_crc(struct dtv_demux *demux, struct dtv_ts_section *sec) |
552 | { |
553 | uint32_t crc, sec_crc; |
554 | |
555 | /* |
556 | * If section_syntax_indicator is not set, the PSI section does |
557 | * not include a CRC field. |
558 | */ |
559 | if ((sec->sec_buf[1] & 0x80) == 0) |
560 | return false; |
561 | |
562 | sec_crc = be32dec(&sec->sec_buf[sec->sec_length - 4]); |
563 | crc = dtv_demux_crc32(&sec->sec_buf[0], sec->sec_length - 4); |
564 | |
565 | return crc == sec_crc; |
566 | } |
567 | |
568 | /* |
569 | * Process a single TS packet and extract PSI sections based on the |
570 | * instance's section filter. |
571 | */ |
572 | static int |
573 | dtv_demux_process(struct dtv_demux *demux, const uint8_t *tspkt, |
574 | size_t tspktlen) |
575 | { |
576 | struct dtv_ts_section *sec; |
577 | dmx_filter_t *dmxfilt = &demux->dd_secfilt.params.filter; |
578 | const uint8_t *p; |
579 | uint16_t section_length; |
580 | int brem, avail; |
581 | |
582 | KASSERT(tspktlen == TS_PKTLEN); |
583 | |
584 | /* If the demux instance is not running, ignore the packet */ |
585 | if (demux->dd_running == false) |
586 | return 0; |
587 | |
588 | /* |
589 | * If the demux instance is not in section filter mode, ignore |
590 | * the packet |
591 | */ |
592 | if (demux->dd_mode != DTV_DEMUX_MODE_SECTION) |
593 | return 0; |
594 | /* |
595 | * If the packet's TS PID does not match the section filter PID, |
596 | * ignore the packet |
597 | */ |
598 | if (TS_PID(tspkt) != demux->dd_secfilt.params.pid) |
599 | return 0; |
600 | /* |
601 | * If the TS packet does not contain a payload, ignore the packet |
602 | */ |
603 | if (TS_HAS_PAYLOAD(tspkt) == 0) |
604 | return 0; |
605 | |
606 | mutex_enter(&demux->dd_lock); |
607 | |
608 | /* If the section buffer is full, set the overflow flag and return */ |
609 | if (demux->dd_secfilt.nsections == |
610 | __arraycount(demux->dd_secfilt.section)) { |
611 | demux->dd_secfilt.overflow = true; |
612 | goto done; |
613 | } |
614 | sec = &demux->dd_secfilt.section[demux->dd_secfilt.wp]; |
615 | /* If we have no bytes in our buffer, wait for payload unit start */ |
616 | if (sec->sec_bytesused == 0 && TS_HAS_PUSI(tspkt) == 0) |
617 | goto done; |
618 | |
619 | /* find payload start */ |
620 | p = tspkt + 4; |
621 | if (TS_HAS_AF(tspkt)) { |
622 | if (*p > 182) /* AF length with payload is between 0-182 */ |
623 | goto done; |
624 | p += (1 + *p); |
625 | } |
626 | if (TS_HAS_PUSI(tspkt)) { |
627 | p += (1 + *p); |
628 | } |
629 | |
630 | brem = tspktlen - (p - tspkt); |
631 | |
632 | if (TS_HAS_PUSI(tspkt)) { |
633 | if (brem < 16) |
634 | goto done; |
635 | |
636 | section_length = ((p[1] & 0xf) << 8) | p[2]; |
637 | |
638 | /* table_id filter */ |
639 | if (dmxfilt->mask[0]) { |
640 | if ((p[0] & dmxfilt->mask[0]) != dmxfilt->filter[0]) |
641 | goto done; |
642 | } |
643 | /* table_id_ext filter */ |
644 | if (dmxfilt->mask[1] && dmxfilt->mask[2]) { |
645 | /* |
646 | * table_id_ext is only valid if |
647 | * section_syntax_indicator is set |
648 | */ |
649 | if (section_length < 2 || (p[1] & 0x80) == 0) |
650 | goto done; |
651 | if ((p[3] & dmxfilt->mask[1]) != dmxfilt->filter[1]) |
652 | goto done; |
653 | if ((p[4] & dmxfilt->mask[2]) != dmxfilt->filter[2]) |
654 | goto done; |
655 | } |
656 | |
657 | sec->sec_length = section_length + 3; |
658 | |
659 | /* maximum section length is 4KB */ |
660 | if (sec->sec_length > sizeof(sec->sec_buf)) { |
661 | sec->sec_bytesused = sec->sec_length = 0; |
662 | goto done; |
663 | } |
664 | |
665 | } |
666 | |
667 | /* If we have bytes pending and we see payload unit start, flush buf */ |
668 | if (sec->sec_bytesused > 0 && TS_HAS_PUSI(tspkt)) |
669 | sec->sec_bytesused = sec->sec_length = 0; |
670 | |
671 | /* Copy data into section buffer */ |
672 | avail = min(sec->sec_length - sec->sec_bytesused, brem); |
673 | if (avail < 0) |
674 | goto done; |
675 | memcpy(&sec->sec_buf[sec->sec_bytesused], p, avail); |
676 | sec->sec_bytesused += avail; |
677 | |
678 | /* |
679 | * If a complete section has been received, update section count |
680 | * and notify readers. |
681 | */ |
682 | if (sec->sec_bytesused == sec->sec_length) { |
683 | /* |
684 | * If the DMX_CHECK_CRC flag was present in the DMX_SET_FILTER |
685 | * parameters, verify the PSI section checksum. If the |
686 | * checksum is invalid, discard the entire corrupt section. |
687 | */ |
688 | if ((demux->dd_secfilt.params.flags & DMX_CHECK_CRC) && |
689 | dtv_demux_check_crc(demux, sec) == false) { |
690 | /* discard section */ |
691 | sec->sec_bytesused = sec->sec_length = 0; |
692 | goto done; |
693 | } |
694 | |
695 | demux->dd_secfilt.wp++; |
696 | if (demux->dd_secfilt.wp >= |
697 | __arraycount(demux->dd_secfilt.section)) |
698 | demux->dd_secfilt.wp = 0; |
699 | demux->dd_secfilt.nsections++; |
700 | cv_broadcast(&demux->dd_section_cv); |
701 | selnotify(&demux->dd_sel, 0, 0); |
702 | } |
703 | |
704 | done: |
705 | mutex_exit(&demux->dd_lock); |
706 | return 0; |
707 | } |
708 | |
709 | /* |
710 | * Submit TS data to all demux instances |
711 | */ |
712 | void |
713 | dtv_demux_write(struct dtv_softc *sc, const uint8_t *tspkt, size_t tspktlen) |
714 | { |
715 | struct dtv_demux *demux; |
716 | |
717 | mutex_enter(&sc->sc_demux_lock); |
718 | TAILQ_FOREACH(demux, &sc->sc_demux_list, dd_entries) { |
719 | dtv_demux_process(demux, tspkt, tspktlen); |
720 | } |
721 | mutex_exit(&sc->sc_demux_lock); |
722 | } |
723 | |