1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Vidtv serves as a reference DVB driver and helps validate the existing APIs
4 * in the media subsystem. It can also aid developers working on userspace
5 * applications.
6 *
7 * This file contains the code for a 'channel' abstraction.
8 *
9 * When vidtv boots, it will create some hardcoded channels.
10 * Their services will be concatenated to populate the SDT.
11 * Their programs will be concatenated to populate the PAT
12 * Their events will be concatenated to populate the EIT
13 * For each program in the PAT, a PMT section will be created
14 * The PMT section for a channel will be assigned its streams.
15 * Every stream will have its corresponding encoder polled to produce TS packets
16 * These packets may be interleaved by the mux and then delivered to the bridge
17 *
18 *
19 * Copyright (C) 2020 Daniel W. S. Almeida
20 */
21
22#include <linux/dev_printk.h>
23#include <linux/ratelimit.h>
24#include <linux/slab.h>
25#include <linux/types.h>
26
27#include "vidtv_channel.h"
28#include "vidtv_common.h"
29#include "vidtv_encoder.h"
30#include "vidtv_mux.h"
31#include "vidtv_psi.h"
32#include "vidtv_s302m.h"
33
34static void vidtv_channel_encoder_destroy(struct vidtv_encoder *e)
35{
36	struct vidtv_encoder *tmp = NULL;
37	struct vidtv_encoder *curr = e;
38
39	while (curr) {
40		/* forward the call to the derived type */
41		tmp = curr;
42		curr = curr->next;
43		tmp->destroy(tmp);
44	}
45}
46
47#define ENCODING_ISO8859_15 "\x0b"
48#define TS_NIT_PID	0x10
49
50/*
51 * init an audio only channel with a s302m encoder
52 */
53struct vidtv_channel
54*vidtv_channel_s302m_init(struct vidtv_channel *head, u16 transport_stream_id)
55{
56	const __be32 s302m_fid              = cpu_to_be32(VIDTV_S302M_FORMAT_IDENTIFIER);
57	char *event_text = ENCODING_ISO8859_15 "Bagatelle No. 25 in A minor for solo piano, also known as F\xfcr Elise, composed by Ludwig van Beethoven";
58	char *event_name = ENCODING_ISO8859_15 "Ludwig van Beethoven: F\xfcr Elise";
59	struct vidtv_s302m_encoder_init_args encoder_args = {};
60	char *iso_language_code = ENCODING_ISO8859_15 "eng";
61	char *provider = ENCODING_ISO8859_15 "LinuxTV.org";
62	char *name = ENCODING_ISO8859_15 "Beethoven";
63	const u16 s302m_es_pid              = 0x111; /* packet id for the ES */
64	const u16 s302m_program_pid         = 0x101; /* packet id for PMT*/
65	const u16 s302m_service_id          = 0x880;
66	const u16 s302m_program_num         = 0x880;
67	const u16 s302m_beethoven_event_id  = 1;
68	struct vidtv_channel *s302m;
69
70	s302m = kzalloc(sizeof(*s302m), GFP_KERNEL);
71	if (!s302m)
72		return NULL;
73
74	s302m->name = kstrdup(name, GFP_KERNEL);
75	if (!s302m->name)
76		goto free_s302m;
77
78	s302m->service = vidtv_psi_sdt_service_init(NULL, s302m_service_id, false, true);
79	if (!s302m->service)
80		goto free_name;
81
82	s302m->service->descriptor = (struct vidtv_psi_desc *)
83				     vidtv_psi_service_desc_init(NULL,
84								 DIGITAL_RADIO_SOUND_SERVICE,
85								 name,
86								 provider);
87	if (!s302m->service->descriptor)
88		goto free_service;
89
90	s302m->transport_stream_id = transport_stream_id;
91
92	s302m->program = vidtv_psi_pat_program_init(NULL,
93						    s302m_service_id,
94						    s302m_program_pid);
95	if (!s302m->program)
96		goto free_service;
97
98	s302m->program_num = s302m_program_num;
99
100	s302m->streams = vidtv_psi_pmt_stream_init(NULL,
101						   STREAM_PRIVATE_DATA,
102						   s302m_es_pid);
103	if (!s302m->streams)
104		goto free_program;
105
106	s302m->streams->descriptor = (struct vidtv_psi_desc *)
107				     vidtv_psi_registration_desc_init(NULL,
108								      s302m_fid,
109								      NULL,
110								      0);
111	if (!s302m->streams->descriptor)
112		goto free_streams;
113
114	encoder_args.es_pid = s302m_es_pid;
115
116	s302m->encoders = vidtv_s302m_encoder_init(encoder_args);
117	if (!s302m->encoders)
118		goto free_streams;
119
120	s302m->events = vidtv_psi_eit_event_init(NULL, s302m_beethoven_event_id);
121	if (!s302m->events)
122		goto free_encoders;
123	s302m->events->descriptor = (struct vidtv_psi_desc *)
124				    vidtv_psi_short_event_desc_init(NULL,
125								    iso_language_code,
126								    event_name,
127								    event_text);
128	if (!s302m->events->descriptor)
129		goto free_events;
130
131	if (head) {
132		while (head->next)
133			head = head->next;
134
135		head->next = s302m;
136	}
137
138	return s302m;
139
140free_events:
141	vidtv_psi_eit_event_destroy(s302m->events);
142free_encoders:
143	vidtv_s302m_encoder_destroy(s302m->encoders);
144free_streams:
145	vidtv_psi_pmt_stream_destroy(s302m->streams);
146free_program:
147	vidtv_psi_pat_program_destroy(s302m->program);
148free_service:
149	vidtv_psi_sdt_service_destroy(s302m->service);
150free_name:
151	kfree(s302m->name);
152free_s302m:
153	kfree(s302m);
154
155	return NULL;
156}
157
158static struct vidtv_psi_table_eit_event
159*vidtv_channel_eit_event_cat_into_new(struct vidtv_mux *m)
160{
161	/* Concatenate the events */
162	const struct vidtv_channel *cur_chnl = m->channels;
163	struct vidtv_psi_table_eit_event *curr = NULL;
164	struct vidtv_psi_table_eit_event *head = NULL;
165	struct vidtv_psi_table_eit_event *tail = NULL;
166	struct vidtv_psi_desc *desc = NULL;
167	u16 event_id;
168
169	if (!cur_chnl)
170		return NULL;
171
172	while (cur_chnl) {
173		curr = cur_chnl->events;
174
175		if (!curr)
176			dev_warn_ratelimited(m->dev,
177					     "No events found for channel %s\n",
178					     cur_chnl->name);
179
180		while (curr) {
181			event_id = be16_to_cpu(curr->event_id);
182			tail = vidtv_psi_eit_event_init(tail, event_id);
183			if (!tail) {
184				vidtv_psi_eit_event_destroy(head);
185				return NULL;
186			}
187
188			desc = vidtv_psi_desc_clone(curr->descriptor);
189			vidtv_psi_desc_assign(&tail->descriptor, desc);
190
191			if (!head)
192				head = tail;
193
194			curr = curr->next;
195		}
196
197		cur_chnl = cur_chnl->next;
198	}
199
200	return head;
201}
202
203static struct vidtv_psi_table_sdt_service
204*vidtv_channel_sdt_serv_cat_into_new(struct vidtv_mux *m)
205{
206	/* Concatenate the services */
207	const struct vidtv_channel *cur_chnl = m->channels;
208
209	struct vidtv_psi_table_sdt_service *curr = NULL;
210	struct vidtv_psi_table_sdt_service *head = NULL;
211	struct vidtv_psi_table_sdt_service *tail = NULL;
212
213	struct vidtv_psi_desc *desc = NULL;
214	u16 service_id;
215
216	if (!cur_chnl)
217		return NULL;
218
219	while (cur_chnl) {
220		curr = cur_chnl->service;
221
222		if (!curr)
223			dev_warn_ratelimited(m->dev,
224					     "No services found for channel %s\n",
225					     cur_chnl->name);
226
227		while (curr) {
228			service_id = be16_to_cpu(curr->service_id);
229			tail = vidtv_psi_sdt_service_init(tail,
230							  service_id,
231							  curr->EIT_schedule,
232							  curr->EIT_present_following);
233			if (!tail)
234				goto free;
235
236			desc = vidtv_psi_desc_clone(curr->descriptor);
237			if (!desc)
238				goto free_tail;
239			vidtv_psi_desc_assign(&tail->descriptor, desc);
240
241			if (!head)
242				head = tail;
243
244			curr = curr->next;
245		}
246
247		cur_chnl = cur_chnl->next;
248	}
249
250	return head;
251
252free_tail:
253	vidtv_psi_sdt_service_destroy(tail);
254free:
255	vidtv_psi_sdt_service_destroy(head);
256	return NULL;
257}
258
259static struct vidtv_psi_table_pat_program*
260vidtv_channel_pat_prog_cat_into_new(struct vidtv_mux *m)
261{
262	/* Concatenate the programs */
263	const struct vidtv_channel *cur_chnl = m->channels;
264	struct vidtv_psi_table_pat_program *curr = NULL;
265	struct vidtv_psi_table_pat_program *head = NULL;
266	struct vidtv_psi_table_pat_program *tail = NULL;
267	u16 serv_id;
268	u16 pid;
269
270	if (!cur_chnl)
271		return NULL;
272
273	while (cur_chnl) {
274		curr = cur_chnl->program;
275
276		if (!curr)
277			dev_warn_ratelimited(m->dev,
278					     "No programs found for channel %s\n",
279					     cur_chnl->name);
280
281		while (curr) {
282			serv_id = be16_to_cpu(curr->service_id);
283			pid = vidtv_psi_get_pat_program_pid(curr);
284			tail = vidtv_psi_pat_program_init(tail,
285							  serv_id,
286							  pid);
287			if (!tail) {
288				vidtv_psi_pat_program_destroy(head);
289				return NULL;
290			}
291
292			if (!head)
293				head = tail;
294
295			curr = curr->next;
296		}
297
298		cur_chnl = cur_chnl->next;
299	}
300	/* Add the NIT table */
301	vidtv_psi_pat_program_init(tail, 0, TS_NIT_PID);
302
303	return head;
304}
305
306/*
307 * Match channels to their respective PMT sections, then assign the
308 * streams
309 */
310static void
311vidtv_channel_pmt_match_sections(struct vidtv_channel *channels,
312				 struct vidtv_psi_table_pmt **sections,
313				 u32 nsections)
314{
315	struct vidtv_psi_table_pmt *curr_section = NULL;
316	struct vidtv_psi_table_pmt_stream *head = NULL;
317	struct vidtv_psi_table_pmt_stream *tail = NULL;
318	struct vidtv_psi_table_pmt_stream *s = NULL;
319	struct vidtv_channel *cur_chnl = channels;
320	struct vidtv_psi_desc *desc = NULL;
321	u16 e_pid; /* elementary stream pid */
322	u16 curr_id;
323	u32 j;
324
325	while (cur_chnl) {
326		for (j = 0; j < nsections; ++j) {
327			curr_section = sections[j];
328
329			if (!curr_section)
330				continue;
331
332			curr_id = be16_to_cpu(curr_section->header.id);
333
334			/* we got a match */
335			if (curr_id == cur_chnl->program_num) {
336				s = cur_chnl->streams;
337
338				/* clone the streams for the PMT */
339				while (s) {
340					e_pid = vidtv_psi_pmt_stream_get_elem_pid(s);
341					tail = vidtv_psi_pmt_stream_init(tail,
342									 s->type,
343									 e_pid);
344
345					if (!head)
346						head = tail;
347
348					desc = vidtv_psi_desc_clone(s->descriptor);
349					vidtv_psi_desc_assign(&tail->descriptor,
350							      desc);
351
352					s = s->next;
353				}
354
355				vidtv_psi_pmt_stream_assign(curr_section, head);
356				break;
357			}
358		}
359
360		cur_chnl = cur_chnl->next;
361	}
362}
363
364static void
365vidtv_channel_destroy_service_list(struct vidtv_psi_desc_service_list_entry *e)
366{
367	struct vidtv_psi_desc_service_list_entry *tmp;
368
369	while (e) {
370		tmp = e;
371		e = e->next;
372		kfree(tmp);
373	}
374}
375
376static struct vidtv_psi_desc_service_list_entry
377*vidtv_channel_build_service_list(struct vidtv_psi_table_sdt_service *s)
378{
379	struct vidtv_psi_desc_service_list_entry *curr_e = NULL;
380	struct vidtv_psi_desc_service_list_entry *head_e = NULL;
381	struct vidtv_psi_desc_service_list_entry *prev_e = NULL;
382	struct vidtv_psi_desc *desc = s->descriptor;
383	struct vidtv_psi_desc_service *s_desc;
384
385	while (s) {
386		while (desc) {
387			if (s->descriptor->type != SERVICE_DESCRIPTOR)
388				goto next_desc;
389
390			s_desc = (struct vidtv_psi_desc_service *)desc;
391
392			curr_e = kzalloc(sizeof(*curr_e), GFP_KERNEL);
393			if (!curr_e) {
394				vidtv_channel_destroy_service_list(head_e);
395				return NULL;
396			}
397
398			curr_e->service_id = s->service_id;
399			curr_e->service_type = s_desc->service_type;
400
401			if (!head_e)
402				head_e = curr_e;
403			if (prev_e)
404				prev_e->next = curr_e;
405
406			prev_e = curr_e;
407
408next_desc:
409			desc = desc->next;
410		}
411		s = s->next;
412	}
413	return head_e;
414}
415
416int vidtv_channel_si_init(struct vidtv_mux *m)
417{
418	struct vidtv_psi_desc_service_list_entry *service_list = NULL;
419	struct vidtv_psi_table_pat_program *programs = NULL;
420	struct vidtv_psi_table_sdt_service *services = NULL;
421	struct vidtv_psi_table_eit_event *events = NULL;
422
423	m->si.pat = vidtv_psi_pat_table_init(m->transport_stream_id);
424	if (!m->si.pat)
425		return -ENOMEM;
426
427	m->si.sdt = vidtv_psi_sdt_table_init(m->network_id,
428					     m->transport_stream_id);
429	if (!m->si.sdt)
430		goto free_pat;
431
432	programs = vidtv_channel_pat_prog_cat_into_new(m);
433	if (!programs)
434		goto free_sdt;
435	services = vidtv_channel_sdt_serv_cat_into_new(m);
436	if (!services)
437		goto free_programs;
438
439	events = vidtv_channel_eit_event_cat_into_new(m);
440	if (!events)
441		goto free_services;
442
443	/* look for a service descriptor for every service */
444	service_list = vidtv_channel_build_service_list(services);
445	if (!service_list)
446		goto free_events;
447
448	/* use these descriptors to build the NIT */
449	m->si.nit = vidtv_psi_nit_table_init(m->network_id,
450					     m->transport_stream_id,
451					     m->network_name,
452					     service_list);
453	if (!m->si.nit)
454		goto free_service_list;
455
456	m->si.eit = vidtv_psi_eit_table_init(m->network_id,
457					     m->transport_stream_id,
458					     programs->service_id);
459	if (!m->si.eit)
460		goto free_nit;
461
462	/* assemble all programs and assign to PAT */
463	vidtv_psi_pat_program_assign(m->si.pat, programs);
464
465	/* assemble all services and assign to SDT */
466	vidtv_psi_sdt_service_assign(m->si.sdt, services);
467
468	/* assemble all events and assign to EIT */
469	vidtv_psi_eit_event_assign(m->si.eit, events);
470
471	m->si.pmt_secs = vidtv_psi_pmt_create_sec_for_each_pat_entry(m->si.pat,
472								     m->pcr_pid);
473	if (!m->si.pmt_secs)
474		goto free_eit;
475
476	vidtv_channel_pmt_match_sections(m->channels,
477					 m->si.pmt_secs,
478					 m->si.pat->num_pmt);
479
480	vidtv_channel_destroy_service_list(service_list);
481
482	return 0;
483
484free_eit:
485	vidtv_psi_eit_table_destroy(m->si.eit);
486free_nit:
487	vidtv_psi_nit_table_destroy(m->si.nit);
488free_service_list:
489	vidtv_channel_destroy_service_list(service_list);
490free_events:
491	vidtv_psi_eit_event_destroy(events);
492free_services:
493	vidtv_psi_sdt_service_destroy(services);
494free_programs:
495	vidtv_psi_pat_program_destroy(programs);
496free_sdt:
497	vidtv_psi_sdt_table_destroy(m->si.sdt);
498free_pat:
499	vidtv_psi_pat_table_destroy(m->si.pat);
500	return 0;
501}
502
503void vidtv_channel_si_destroy(struct vidtv_mux *m)
504{
505	u32 i;
506
507	for (i = 0; i < m->si.pat->num_pmt; ++i)
508		vidtv_psi_pmt_table_destroy(m->si.pmt_secs[i]);
509
510	vidtv_psi_pat_table_destroy(m->si.pat);
511
512	kfree(m->si.pmt_secs);
513	vidtv_psi_sdt_table_destroy(m->si.sdt);
514	vidtv_psi_nit_table_destroy(m->si.nit);
515	vidtv_psi_eit_table_destroy(m->si.eit);
516}
517
518int vidtv_channels_init(struct vidtv_mux *m)
519{
520	/* this is the place to add new 'channels' for vidtv */
521	m->channels = vidtv_channel_s302m_init(NULL, m->transport_stream_id);
522
523	if (!m->channels)
524		return -ENOMEM;
525
526	return 0;
527}
528
529void vidtv_channels_destroy(struct vidtv_mux *m)
530{
531	struct vidtv_channel *curr = m->channels;
532	struct vidtv_channel *tmp = NULL;
533
534	while (curr) {
535		kfree(curr->name);
536		vidtv_psi_sdt_service_destroy(curr->service);
537		vidtv_psi_pat_program_destroy(curr->program);
538		vidtv_psi_pmt_stream_destroy(curr->streams);
539		vidtv_channel_encoder_destroy(curr->encoders);
540		vidtv_psi_eit_event_destroy(curr->events);
541
542		tmp = curr;
543		curr = curr->next;
544		kfree(tmp);
545	}
546}
547