1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * This file contains the logic to work with MPEG Program-Specific Information.
4  * These are defined both in ISO/IEC 13818-1 (systems) and ETSI EN 300 468.
5  * PSI is carried in the form of table structures, and although each table might
6  * technically be broken into one or more sections, we do not do this here,
7  * hence 'table' and 'section' are interchangeable for vidtv.
8  *
9  * Copyright (C) 2020 Daniel W. S. Almeida
10  */
11 
12 #define pr_fmt(fmt) KBUILD_MODNAME ":%s, %d: " fmt, __func__, __LINE__
13 
14 #include <linux/bcd.h>
15 #include <linux/crc32.h>
16 #include <linux/kernel.h>
17 #include <linux/ktime.h>
18 #include <linux/printk.h>
19 #include <linux/ratelimit.h>
20 #include <linux/slab.h>
21 #include <linux/string.h>
22 #include <linux/string.h>
23 #include <linux/time.h>
24 #include <linux/types.h>
25 
26 #include "vidtv_common.h"
27 #include "vidtv_psi.h"
28 #include "vidtv_ts.h"
29 
30 #define CRC_SIZE_IN_BYTES 4
31 #define MAX_VERSION_NUM 32
32 #define INITIAL_CRC 0xffffffff
33 #define ISO_LANGUAGE_CODE_LEN 3
34 
35 static const u32 CRC_LUT[256] = {
36 	/* from libdvbv5 */
37 	0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b,
38 	0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61,
39 	0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd, 0x4c11db70, 0x48d0c6c7,
40 	0x4593e01e, 0x4152fda9, 0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75,
41 	0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3,
42 	0x709f7b7a, 0x745e66cd, 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
43 	0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 0xbe2b5b58, 0xbaea46ef,
44 	0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d,
45 	0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49, 0xc7361b4c, 0xc3f706fb,
46 	0xceb42022, 0xca753d95, 0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1,
47 	0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 0x34867077, 0x30476dc0,
48 	0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072,
49 	0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16, 0x018aeb13, 0x054bf6a4,
50 	0x0808d07d, 0x0cc9cdca, 0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde,
51 	0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02, 0x5e9f46bf, 0x5a5e5b08,
52 	0x571d7dd1, 0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
53 	0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b, 0xbb60adfc,
54 	0xb6238b25, 0xb2e29692, 0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6,
55 	0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a, 0xe0b41de7, 0xe4750050,
56 	0xe9362689, 0xedf73b3e, 0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2,
57 	0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34,
58 	0xdc3abded, 0xd8fba05a, 0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637,
59 	0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb, 0x4f040d56, 0x4bc510e1,
60 	0x46863638, 0x42472b8f, 0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53,
61 	0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5,
62 	0x3f9b762c, 0x3b5a6b9b, 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
63 	0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 0xf12f560e, 0xf5ee4bb9,
64 	0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b,
65 	0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f, 0xc423cd6a, 0xc0e2d0dd,
66 	0xcda1f604, 0xc960ebb3, 0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7,
67 	0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 0x9b3660c6, 0x9ff77d71,
68 	0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3,
69 	0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640, 0x4e8ee645, 0x4a4ffbf2,
70 	0x470cdd2b, 0x43cdc09c, 0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8,
71 	0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24, 0x119b4be9, 0x155a565e,
72 	0x18197087, 0x1cd86d30, 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
73 	0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d, 0x2056cd3a,
74 	0x2d15ebe3, 0x29d4f654, 0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0,
75 	0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c, 0xe3a1cbc1, 0xe760d676,
76 	0xea23f0af, 0xeee2ed18, 0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4,
77 	0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662,
78 	0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668,
79 	0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4
80 };
81 
dvb_crc32(u32 crc, u8 *data, u32 len)82 static u32 dvb_crc32(u32 crc, u8 *data, u32 len)
83 {
84 	/* from libdvbv5 */
85 	while (len--)
86 		crc = (crc << 8) ^ CRC_LUT[((crc >> 24) ^ *data++) & 0xff];
87 	return crc;
88 }
89 
vidtv_psi_update_version_num(struct vidtv_psi_table_header *h)90 static void vidtv_psi_update_version_num(struct vidtv_psi_table_header *h)
91 {
92 	h->version++;
93 }
94 
vidtv_psi_get_sec_len(struct vidtv_psi_table_header *h)95 static u16 vidtv_psi_get_sec_len(struct vidtv_psi_table_header *h)
96 {
97 	u16 mask;
98 	u16 ret;
99 
100 	mask = GENMASK(11, 0);
101 
102 	ret = be16_to_cpu(h->bitfield) & mask;
103 	return ret;
104 }
105 
vidtv_psi_get_pat_program_pid(struct vidtv_psi_table_pat_program *p)106 u16 vidtv_psi_get_pat_program_pid(struct vidtv_psi_table_pat_program *p)
107 {
108 	u16 mask;
109 	u16 ret;
110 
111 	mask = GENMASK(12, 0);
112 
113 	ret = be16_to_cpu(p->bitfield) & mask;
114 	return ret;
115 }
116 
vidtv_psi_pmt_stream_get_elem_pid(struct vidtv_psi_table_pmt_stream *s)117 u16 vidtv_psi_pmt_stream_get_elem_pid(struct vidtv_psi_table_pmt_stream *s)
118 {
119 	u16 mask;
120 	u16 ret;
121 
122 	mask = GENMASK(12, 0);
123 
124 	ret = be16_to_cpu(s->bitfield) & mask;
125 	return ret;
126 }
127 
vidtv_psi_set_desc_loop_len(__be16 *bitfield, u16 new_len, u8 desc_len_nbits)128 static void vidtv_psi_set_desc_loop_len(__be16 *bitfield, u16 new_len,
129 					u8 desc_len_nbits)
130 {
131 	__be16 new;
132 	u16 mask;
133 
134 	mask = GENMASK(15, desc_len_nbits);
135 
136 	new = cpu_to_be16((be16_to_cpu(*bitfield) & mask) | new_len);
137 	*bitfield = new;
138 }
139 
vidtv_psi_set_sec_len(struct vidtv_psi_table_header *h, u16 new_len)140 static void vidtv_psi_set_sec_len(struct vidtv_psi_table_header *h, u16 new_len)
141 {
142 	u16 old_len = vidtv_psi_get_sec_len(h);
143 	__be16 new;
144 	u16 mask;
145 
146 	mask = GENMASK(15, 13);
147 
148 	new = cpu_to_be16((be16_to_cpu(h->bitfield) & mask) | new_len);
149 
150 	if (old_len > MAX_SECTION_LEN)
151 		pr_warn_ratelimited("section length: %d > %d, old len was %d\n",
152 				    new_len,
153 				    MAX_SECTION_LEN,
154 				    old_len);
155 
156 	h->bitfield = new;
157 }
158 
159 /*
160  * Packetize PSI sections into TS packets:
161  * push a TS header (4bytes) every 184 bytes
162  * manage the continuity_counter
163  * add stuffing (i.e. padding bytes) after the CRC
164  */
vidtv_psi_ts_psi_write_into(struct psi_write_args *args)165 static u32 vidtv_psi_ts_psi_write_into(struct psi_write_args *args)
166 {
167 	struct vidtv_mpeg_ts ts_header = {
168 		.sync_byte = TS_SYNC_BYTE,
169 		.bitfield = cpu_to_be16((args->new_psi_section << 14) | args->pid),
170 		.scrambling = 0,
171 		.payload = 1,
172 		.adaptation_field = 0, /* no adaptation field */
173 	};
174 	u32 nbytes_past_boundary = (args->dest_offset % TS_PACKET_LEN);
175 	bool aligned = (nbytes_past_boundary == 0);
176 	u32 remaining_len = args->len;
177 	u32 payload_write_len = 0;
178 	u32 payload_offset = 0;
179 	u32 nbytes = 0;
180 
181 	if (!args->crc && !args->is_crc)
182 		pr_warn_ratelimited("Missing CRC for chunk\n");
183 
184 	if (args->crc)
185 		*args->crc = dvb_crc32(*args->crc, args->from, args->len);
186 
187 	if (args->new_psi_section && !aligned) {
188 		pr_warn_ratelimited("Cannot write a new PSI section in a misaligned buffer\n");
189 
190 		/* forcibly align and hope for the best */
191 		nbytes += vidtv_memset(args->dest_buf,
192 				       args->dest_offset + nbytes,
193 				       args->dest_buf_sz,
194 				       TS_FILL_BYTE,
195 				       TS_PACKET_LEN - nbytes_past_boundary);
196 	}
197 
198 	while (remaining_len) {
199 		nbytes_past_boundary = (args->dest_offset + nbytes) % TS_PACKET_LEN;
200 		aligned = (nbytes_past_boundary == 0);
201 
202 		if (aligned) {
203 			/* if at a packet boundary, write a new TS header */
204 			ts_header.continuity_counter = *args->continuity_counter;
205 
206 			nbytes += vidtv_memcpy(args->dest_buf,
207 					       args->dest_offset + nbytes,
208 					       args->dest_buf_sz,
209 					       &ts_header,
210 					       sizeof(ts_header));
211 			/*
212 			 * This will trigger a discontinuity if the buffer is full,
213 			 * effectively dropping the packet.
214 			 */
215 			vidtv_ts_inc_cc(args->continuity_counter);
216 		}
217 
218 		/* write the pointer_field in the first byte of the payload */
219 		if (args->new_psi_section)
220 			nbytes += vidtv_memset(args->dest_buf,
221 					       args->dest_offset + nbytes,
222 					       args->dest_buf_sz,
223 					       0x0,
224 					       1);
225 
226 		/* write as much of the payload as possible */
227 		nbytes_past_boundary = (args->dest_offset + nbytes) % TS_PACKET_LEN;
228 		payload_write_len = min(TS_PACKET_LEN - nbytes_past_boundary, remaining_len);
229 
230 		nbytes += vidtv_memcpy(args->dest_buf,
231 				       args->dest_offset + nbytes,
232 				       args->dest_buf_sz,
233 				       args->from + payload_offset,
234 				       payload_write_len);
235 
236 		/* 'payload_write_len' written from a total of 'len' requested*/
237 		remaining_len -= payload_write_len;
238 		payload_offset += payload_write_len;
239 	}
240 
241 	/*
242 	 * fill the rest of the packet if there is any remaining space unused
243 	 */
244 
245 	nbytes_past_boundary = (args->dest_offset + nbytes) % TS_PACKET_LEN;
246 
247 	if (args->is_crc)
248 		nbytes += vidtv_memset(args->dest_buf,
249 				       args->dest_offset + nbytes,
250 				       args->dest_buf_sz,
251 				       TS_FILL_BYTE,
252 				       TS_PACKET_LEN - nbytes_past_boundary);
253 
254 	return nbytes;
255 }
256 
table_section_crc32_write_into(struct crc32_write_args *args)257 static u32 table_section_crc32_write_into(struct crc32_write_args *args)
258 {
259 	struct psi_write_args psi_args = {
260 		.dest_buf           = args->dest_buf,
261 		.from               = &args->crc,
262 		.len                = CRC_SIZE_IN_BYTES,
263 		.dest_offset        = args->dest_offset,
264 		.pid                = args->pid,
265 		.new_psi_section    = false,
266 		.continuity_counter = args->continuity_counter,
267 		.is_crc             = true,
268 		.dest_buf_sz        = args->dest_buf_sz,
269 	};
270 
271 	/* the CRC is the last entry in the section */
272 
273 	return vidtv_psi_ts_psi_write_into(&psi_args);
274 }
275 
vidtv_psi_desc_chain(struct vidtv_psi_desc *head, struct vidtv_psi_desc *desc)276 static void vidtv_psi_desc_chain(struct vidtv_psi_desc *head, struct vidtv_psi_desc *desc)
277 {
278 	if (head) {
279 		while (head->next)
280 			head = head->next;
281 
282 		head->next = desc;
283 	}
284 }
285 
vidtv_psi_service_desc_init(struct vidtv_psi_desc *head, enum service_type service_type, char *service_name, char *provider_name)286 struct vidtv_psi_desc_service *vidtv_psi_service_desc_init(struct vidtv_psi_desc *head,
287 							   enum service_type service_type,
288 							   char *service_name,
289 							   char *provider_name)
290 {
291 	struct vidtv_psi_desc_service *desc;
292 	u32 service_name_len = service_name ? strlen(service_name) : 0;
293 	u32 provider_name_len = provider_name ? strlen(provider_name) : 0;
294 
295 	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
296 	if (!desc)
297 		return NULL;
298 
299 	desc->type = SERVICE_DESCRIPTOR;
300 
301 	desc->length = sizeof_field(struct vidtv_psi_desc_service, service_type)
302 		       + sizeof_field(struct vidtv_psi_desc_service, provider_name_len)
303 		       + provider_name_len
304 		       + sizeof_field(struct vidtv_psi_desc_service, service_name_len)
305 		       + service_name_len;
306 
307 	desc->service_type = service_type;
308 
309 	desc->service_name_len = service_name_len;
310 
311 	if (service_name && service_name_len) {
312 		desc->service_name = kstrdup(service_name, GFP_KERNEL);
313 		if (!desc->service_name)
314 			goto free_desc;
315 	}
316 
317 	desc->provider_name_len = provider_name_len;
318 
319 	if (provider_name && provider_name_len) {
320 		desc->provider_name = kstrdup(provider_name, GFP_KERNEL);
321 		if (!desc->provider_name)
322 			goto free_desc_service_name;
323 	}
324 
325 	vidtv_psi_desc_chain(head, (struct vidtv_psi_desc *)desc);
326 	return desc;
327 
328 free_desc_service_name:
329 	if (service_name && service_name_len)
330 		kfree(desc->service_name);
331 free_desc:
332 	kfree(desc);
333 	return NULL;
334 }
335 
336 struct vidtv_psi_desc_registration
vidtv_psi_registration_desc_init(struct vidtv_psi_desc *head, __be32 format_id, u8 *additional_ident_info, u32 additional_info_len)337 *vidtv_psi_registration_desc_init(struct vidtv_psi_desc *head,
338 				  __be32 format_id,
339 				  u8 *additional_ident_info,
340 				  u32 additional_info_len)
341 {
342 	struct vidtv_psi_desc_registration *desc;
343 
344 	desc = kzalloc(sizeof(*desc) + sizeof(format_id) + additional_info_len, GFP_KERNEL);
345 	if (!desc)
346 		return NULL;
347 
348 	desc->type = REGISTRATION_DESCRIPTOR;
349 
350 	desc->length = sizeof_field(struct vidtv_psi_desc_registration, format_id)
351 		       + additional_info_len;
352 
353 	desc->format_id = format_id;
354 
355 	if (additional_ident_info && additional_info_len)
356 		memcpy(desc->additional_identification_info,
357 		       additional_ident_info,
358 		       additional_info_len);
359 
360 	vidtv_psi_desc_chain(head, (struct vidtv_psi_desc *)desc);
361 	return desc;
362 }
363 
364 struct vidtv_psi_desc_network_name
vidtv_psi_network_name_desc_init(struct vidtv_psi_desc *head, char *network_name)365 *vidtv_psi_network_name_desc_init(struct vidtv_psi_desc *head, char *network_name)
366 {
367 	u32 network_name_len = network_name ? strlen(network_name) : 0;
368 	struct vidtv_psi_desc_network_name *desc;
369 
370 	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
371 	if (!desc)
372 		return NULL;
373 
374 	desc->type = NETWORK_NAME_DESCRIPTOR;
375 
376 	desc->length = network_name_len;
377 
378 	if (network_name && network_name_len) {
379 		desc->network_name = kstrdup(network_name, GFP_KERNEL);
380 		if (!desc->network_name) {
381 			kfree(desc);
382 			return NULL;
383 		}
384 	}
385 
386 	vidtv_psi_desc_chain(head, (struct vidtv_psi_desc *)desc);
387 	return desc;
388 }
389 
390 struct vidtv_psi_desc_service_list
vidtv_psi_service_list_desc_init(struct vidtv_psi_desc *head, struct vidtv_psi_desc_service_list_entry *entry)391 *vidtv_psi_service_list_desc_init(struct vidtv_psi_desc *head,
392 				  struct vidtv_psi_desc_service_list_entry *entry)
393 {
394 	struct vidtv_psi_desc_service_list_entry *curr_e = NULL;
395 	struct vidtv_psi_desc_service_list_entry *head_e = NULL;
396 	struct vidtv_psi_desc_service_list_entry *prev_e = NULL;
397 	struct vidtv_psi_desc_service_list *desc;
398 	u16 length = 0;
399 
400 	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
401 	if (!desc)
402 		return NULL;
403 
404 	desc->type = SERVICE_LIST_DESCRIPTOR;
405 
406 	while (entry) {
407 		curr_e = kzalloc(sizeof(*curr_e), GFP_KERNEL);
408 		if (!curr_e) {
409 			while (head_e) {
410 				curr_e = head_e;
411 				head_e = head_e->next;
412 				kfree(curr_e);
413 			}
414 			kfree(desc);
415 			return NULL;
416 		}
417 
418 		curr_e->service_id = entry->service_id;
419 		curr_e->service_type = entry->service_type;
420 
421 		length += sizeof(struct vidtv_psi_desc_service_list_entry) -
422 			  sizeof(struct vidtv_psi_desc_service_list_entry *);
423 
424 		if (!head_e)
425 			head_e = curr_e;
426 		if (prev_e)
427 			prev_e->next = curr_e;
428 
429 		prev_e = curr_e;
430 		entry = entry->next;
431 	}
432 
433 	desc->length = length;
434 	desc->service_list = head_e;
435 
436 	vidtv_psi_desc_chain(head, (struct vidtv_psi_desc *)desc);
437 	return desc;
438 }
439 
440 struct vidtv_psi_desc_short_event
vidtv_psi_short_event_desc_init(struct vidtv_psi_desc *head, char *iso_language_code, char *event_name, char *text)441 *vidtv_psi_short_event_desc_init(struct vidtv_psi_desc *head,
442 				 char *iso_language_code,
443 				 char *event_name,
444 				 char *text)
445 {
446 	u32 iso_len =  iso_language_code ? strlen(iso_language_code) : 0;
447 	u32 event_name_len = event_name ? strlen(event_name) : 0;
448 	struct vidtv_psi_desc_short_event *desc;
449 	u32 text_len =  text ? strlen(text) : 0;
450 
451 	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
452 	if (!desc)
453 		return NULL;
454 
455 	desc->type = SHORT_EVENT_DESCRIPTOR;
456 
457 	desc->length = ISO_LANGUAGE_CODE_LEN +
458 		       sizeof_field(struct vidtv_psi_desc_short_event, event_name_len) +
459 		       event_name_len +
460 		       sizeof_field(struct vidtv_psi_desc_short_event, text_len) +
461 		       text_len;
462 
463 	desc->event_name_len = event_name_len;
464 	desc->text_len = text_len;
465 
466 	if (iso_len != ISO_LANGUAGE_CODE_LEN)
467 		iso_language_code = "eng";
468 
469 	desc->iso_language_code = kstrdup(iso_language_code, GFP_KERNEL);
470 	if (!desc->iso_language_code)
471 		goto free_desc;
472 
473 	if (event_name && event_name_len) {
474 		desc->event_name = kstrdup(event_name, GFP_KERNEL);
475 		if (!desc->event_name)
476 			goto free_desc_language_code;
477 	}
478 
479 	if (text && text_len) {
480 		desc->text = kstrdup(text, GFP_KERNEL);
481 		if (!desc->text)
482 			goto free_desc_event_name;
483 	}
484 
485 	vidtv_psi_desc_chain(head, (struct vidtv_psi_desc *)desc);
486 	return desc;
487 
488 free_desc_event_name:
489 	if (event_name && event_name_len)
490 		kfree(desc->event_name);
491 free_desc_language_code:
492 	kfree(desc->iso_language_code);
493 free_desc:
494 	kfree(desc);
495 	return NULL;
496 }
497 
vidtv_psi_desc_clone(struct vidtv_psi_desc *desc)498 struct vidtv_psi_desc *vidtv_psi_desc_clone(struct vidtv_psi_desc *desc)
499 {
500 	struct vidtv_psi_desc_network_name *desc_network_name;
501 	struct vidtv_psi_desc_service_list *desc_service_list;
502 	struct vidtv_psi_desc_short_event  *desc_short_event;
503 	struct vidtv_psi_desc_service *service;
504 	struct vidtv_psi_desc *head = NULL;
505 	struct vidtv_psi_desc *prev = NULL;
506 	struct vidtv_psi_desc *curr = NULL;
507 
508 	while (desc) {
509 		switch (desc->type) {
510 		case SERVICE_DESCRIPTOR:
511 			service = (struct vidtv_psi_desc_service *)desc;
512 			curr = (struct vidtv_psi_desc *)
513 			       vidtv_psi_service_desc_init(head,
514 							   service->service_type,
515 							   service->service_name,
516 							   service->provider_name);
517 		break;
518 
519 		case NETWORK_NAME_DESCRIPTOR:
520 			desc_network_name = (struct vidtv_psi_desc_network_name *)desc;
521 			curr = (struct vidtv_psi_desc *)
522 			       vidtv_psi_network_name_desc_init(head,
523 								desc_network_name->network_name);
524 		break;
525 
526 		case SERVICE_LIST_DESCRIPTOR:
527 			desc_service_list = (struct vidtv_psi_desc_service_list *)desc;
528 			curr = (struct vidtv_psi_desc *)
529 			       vidtv_psi_service_list_desc_init(head,
530 								desc_service_list->service_list);
531 		break;
532 
533 		case SHORT_EVENT_DESCRIPTOR:
534 			desc_short_event = (struct vidtv_psi_desc_short_event *)desc;
535 			curr = (struct vidtv_psi_desc *)
536 			       vidtv_psi_short_event_desc_init(head,
537 							       desc_short_event->iso_language_code,
538 							       desc_short_event->event_name,
539 							       desc_short_event->text);
540 		break;
541 
542 		case REGISTRATION_DESCRIPTOR:
543 		default:
544 			curr = kzalloc(sizeof(*desc) + desc->length, GFP_KERNEL);
545 			if (!curr)
546 				return NULL;
547 			memcpy(curr, desc, sizeof(*desc) + desc->length);
548 		}
549 
550 		if (!curr)
551 			return NULL;
552 
553 		curr->next = NULL;
554 		if (!head)
555 			head = curr;
556 		if (prev)
557 			prev->next = curr;
558 
559 		prev = curr;
560 		desc = desc->next;
561 	}
562 
563 	return head;
564 }
565 
vidtv_psi_desc_destroy(struct vidtv_psi_desc *desc)566 void vidtv_psi_desc_destroy(struct vidtv_psi_desc *desc)
567 {
568 	struct vidtv_psi_desc_service_list_entry *sl_entry_tmp = NULL;
569 	struct vidtv_psi_desc_service_list_entry *sl_entry = NULL;
570 	struct vidtv_psi_desc *curr = desc;
571 	struct vidtv_psi_desc *tmp  = NULL;
572 
573 	while (curr) {
574 		tmp  = curr;
575 		curr = curr->next;
576 
577 		switch (tmp->type) {
578 		case SERVICE_DESCRIPTOR:
579 			kfree(((struct vidtv_psi_desc_service *)tmp)->provider_name);
580 			kfree(((struct vidtv_psi_desc_service *)tmp)->service_name);
581 
582 			break;
583 		case REGISTRATION_DESCRIPTOR:
584 			/* nothing to do */
585 			break;
586 
587 		case NETWORK_NAME_DESCRIPTOR:
588 			kfree(((struct vidtv_psi_desc_network_name *)tmp)->network_name);
589 			break;
590 
591 		case SERVICE_LIST_DESCRIPTOR:
592 			sl_entry = ((struct vidtv_psi_desc_service_list *)tmp)->service_list;
593 			while (sl_entry) {
594 				sl_entry_tmp = sl_entry;
595 				sl_entry = sl_entry->next;
596 				kfree(sl_entry_tmp);
597 			}
598 			break;
599 
600 		case SHORT_EVENT_DESCRIPTOR:
601 			kfree(((struct vidtv_psi_desc_short_event *)tmp)->iso_language_code);
602 			kfree(((struct vidtv_psi_desc_short_event *)tmp)->event_name);
603 			kfree(((struct vidtv_psi_desc_short_event *)tmp)->text);
604 		break;
605 
606 		default:
607 			pr_warn_ratelimited("Possible leak: not handling descriptor type %d\n",
608 					    tmp->type);
609 			break;
610 		}
611 
612 		kfree(tmp);
613 	}
614 }
615 
616 static u16
vidtv_psi_desc_comp_loop_len(struct vidtv_psi_desc *desc)617 vidtv_psi_desc_comp_loop_len(struct vidtv_psi_desc *desc)
618 {
619 	u32 length = 0;
620 
621 	if (!desc)
622 		return 0;
623 
624 	while (desc) {
625 		length += sizeof_field(struct vidtv_psi_desc, type);
626 		length += sizeof_field(struct vidtv_psi_desc, length);
627 		length += desc->length; /* from 'length' field until the end of the descriptor */
628 		desc    = desc->next;
629 	}
630 
631 	return length;
632 }
633 
vidtv_psi_desc_assign(struct vidtv_psi_desc **to, struct vidtv_psi_desc *desc)634 void vidtv_psi_desc_assign(struct vidtv_psi_desc **to,
635 			   struct vidtv_psi_desc *desc)
636 {
637 	if (desc == *to)
638 		return;
639 
640 	if (*to)
641 		vidtv_psi_desc_destroy(*to);
642 
643 	*to = desc;
644 }
645 
vidtv_pmt_desc_assign(struct vidtv_psi_table_pmt *pmt, struct vidtv_psi_desc **to, struct vidtv_psi_desc *desc)646 void vidtv_pmt_desc_assign(struct vidtv_psi_table_pmt *pmt,
647 			   struct vidtv_psi_desc **to,
648 			   struct vidtv_psi_desc *desc)
649 {
650 	vidtv_psi_desc_assign(to, desc);
651 	vidtv_psi_pmt_table_update_sec_len(pmt);
652 
653 	if (vidtv_psi_get_sec_len(&pmt->header) > MAX_SECTION_LEN)
654 		vidtv_psi_desc_assign(to, NULL);
655 
656 	vidtv_psi_update_version_num(&pmt->header);
657 }
658 
vidtv_sdt_desc_assign(struct vidtv_psi_table_sdt *sdt, struct vidtv_psi_desc **to, struct vidtv_psi_desc *desc)659 void vidtv_sdt_desc_assign(struct vidtv_psi_table_sdt *sdt,
660 			   struct vidtv_psi_desc **to,
661 			   struct vidtv_psi_desc *desc)
662 {
663 	vidtv_psi_desc_assign(to, desc);
664 	vidtv_psi_sdt_table_update_sec_len(sdt);
665 
666 	if (vidtv_psi_get_sec_len(&sdt->header) > MAX_SECTION_LEN)
667 		vidtv_psi_desc_assign(to, NULL);
668 
669 	vidtv_psi_update_version_num(&sdt->header);
670 }
671 
vidtv_psi_desc_write_into(struct desc_write_args *args)672 static u32 vidtv_psi_desc_write_into(struct desc_write_args *args)
673 {
674 	struct psi_write_args psi_args = {
675 		.dest_buf           = args->dest_buf,
676 		.from               = &args->desc->type,
677 		.pid                = args->pid,
678 		.new_psi_section    = false,
679 		.continuity_counter = args->continuity_counter,
680 		.is_crc             = false,
681 		.dest_buf_sz        = args->dest_buf_sz,
682 		.crc                = args->crc,
683 		.len		    = sizeof_field(struct vidtv_psi_desc, type) +
684 				      sizeof_field(struct vidtv_psi_desc, length),
685 	};
686 	struct vidtv_psi_desc_service_list_entry *serv_list_entry = NULL;
687 	u32 nbytes = 0;
688 
689 	psi_args.dest_offset        = args->dest_offset + nbytes;
690 
691 	nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
692 
693 	switch (args->desc->type) {
694 	case SERVICE_DESCRIPTOR:
695 		psi_args.dest_offset = args->dest_offset + nbytes;
696 		psi_args.len = sizeof_field(struct vidtv_psi_desc_service, service_type) +
697 			       sizeof_field(struct vidtv_psi_desc_service, provider_name_len);
698 		psi_args.from = &((struct vidtv_psi_desc_service *)args->desc)->service_type;
699 
700 		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
701 
702 		psi_args.dest_offset = args->dest_offset + nbytes;
703 		psi_args.len = ((struct vidtv_psi_desc_service *)args->desc)->provider_name_len;
704 		psi_args.from = ((struct vidtv_psi_desc_service *)args->desc)->provider_name;
705 
706 		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
707 
708 		psi_args.dest_offset = args->dest_offset + nbytes;
709 		psi_args.len = sizeof_field(struct vidtv_psi_desc_service, service_name_len);
710 		psi_args.from = &((struct vidtv_psi_desc_service *)args->desc)->service_name_len;
711 
712 		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
713 
714 		psi_args.dest_offset = args->dest_offset + nbytes;
715 		psi_args.len = ((struct vidtv_psi_desc_service *)args->desc)->service_name_len;
716 		psi_args.from = ((struct vidtv_psi_desc_service *)args->desc)->service_name;
717 
718 		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
719 		break;
720 
721 	case NETWORK_NAME_DESCRIPTOR:
722 		psi_args.dest_offset = args->dest_offset + nbytes;
723 		psi_args.len = args->desc->length;
724 		psi_args.from = ((struct vidtv_psi_desc_network_name *)args->desc)->network_name;
725 
726 		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
727 		break;
728 
729 	case SERVICE_LIST_DESCRIPTOR:
730 		serv_list_entry = ((struct vidtv_psi_desc_service_list *)args->desc)->service_list;
731 		while (serv_list_entry) {
732 			psi_args.dest_offset = args->dest_offset + nbytes;
733 			psi_args.len = sizeof(struct vidtv_psi_desc_service_list_entry) -
734 				       sizeof(struct vidtv_psi_desc_service_list_entry *);
735 			psi_args.from = serv_list_entry;
736 
737 			nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
738 
739 			serv_list_entry = serv_list_entry->next;
740 		}
741 		break;
742 
743 	case SHORT_EVENT_DESCRIPTOR:
744 		psi_args.dest_offset = args->dest_offset + nbytes;
745 		psi_args.len = ISO_LANGUAGE_CODE_LEN;
746 		psi_args.from = ((struct vidtv_psi_desc_short_event *)
747 				  args->desc)->iso_language_code;
748 
749 		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
750 
751 		psi_args.dest_offset = args->dest_offset + nbytes;
752 		psi_args.len = sizeof_field(struct vidtv_psi_desc_short_event, event_name_len);
753 		psi_args.from = &((struct vidtv_psi_desc_short_event *)
754 				  args->desc)->event_name_len;
755 
756 		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
757 
758 		psi_args.dest_offset = args->dest_offset + nbytes;
759 		psi_args.len = ((struct vidtv_psi_desc_short_event *)args->desc)->event_name_len;
760 		psi_args.from = ((struct vidtv_psi_desc_short_event *)args->desc)->event_name;
761 
762 		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
763 
764 		psi_args.dest_offset = args->dest_offset + nbytes;
765 		psi_args.len = sizeof_field(struct vidtv_psi_desc_short_event, text_len);
766 		psi_args.from = &((struct vidtv_psi_desc_short_event *)args->desc)->text_len;
767 
768 		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
769 
770 		psi_args.dest_offset = args->dest_offset + nbytes;
771 		psi_args.len = ((struct vidtv_psi_desc_short_event *)args->desc)->text_len;
772 		psi_args.from = ((struct vidtv_psi_desc_short_event *)args->desc)->text;
773 
774 		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
775 
776 		break;
777 
778 	case REGISTRATION_DESCRIPTOR:
779 	default:
780 		psi_args.dest_offset = args->dest_offset + nbytes;
781 		psi_args.len = args->desc->length;
782 		psi_args.from = &args->desc->data;
783 
784 		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
785 		break;
786 	}
787 
788 	return nbytes;
789 }
790 
791 static u32
vidtv_psi_table_header_write_into(struct header_write_args *args)792 vidtv_psi_table_header_write_into(struct header_write_args *args)
793 {
794 	struct psi_write_args psi_args = {
795 		.dest_buf           = args->dest_buf,
796 		.from               = args->h,
797 		.len                = sizeof(struct vidtv_psi_table_header),
798 		.dest_offset        = args->dest_offset,
799 		.pid                = args->pid,
800 		.new_psi_section    = true,
801 		.continuity_counter = args->continuity_counter,
802 		.is_crc             = false,
803 		.dest_buf_sz        = args->dest_buf_sz,
804 		.crc                = args->crc,
805 	};
806 
807 	return vidtv_psi_ts_psi_write_into(&psi_args);
808 }
809 
810 void
vidtv_psi_pat_table_update_sec_len(struct vidtv_psi_table_pat *pat)811 vidtv_psi_pat_table_update_sec_len(struct vidtv_psi_table_pat *pat)
812 {
813 	u16 length = 0;
814 	u32 i;
815 
816 	/* see ISO/IEC 13818-1 : 2000 p.43 */
817 
818 	/* from immediately after 'section_length' until 'last_section_number'*/
819 	length += PAT_LEN_UNTIL_LAST_SECTION_NUMBER;
820 
821 	/* do not count the pointer */
822 	for (i = 0; i < pat->num_pat; ++i)
823 		length += sizeof(struct vidtv_psi_table_pat_program) -
824 			  sizeof(struct vidtv_psi_table_pat_program *);
825 
826 	length += CRC_SIZE_IN_BYTES;
827 
828 	vidtv_psi_set_sec_len(&pat->header, length);
829 }
830 
vidtv_psi_pmt_table_update_sec_len(struct vidtv_psi_table_pmt *pmt)831 void vidtv_psi_pmt_table_update_sec_len(struct vidtv_psi_table_pmt *pmt)
832 {
833 	struct vidtv_psi_table_pmt_stream *s = pmt->stream;
834 	u16 desc_loop_len;
835 	u16 length = 0;
836 
837 	/* see ISO/IEC 13818-1 : 2000 p.46 */
838 
839 	/* from immediately after 'section_length' until 'program_info_length'*/
840 	length += PMT_LEN_UNTIL_PROGRAM_INFO_LENGTH;
841 
842 	desc_loop_len = vidtv_psi_desc_comp_loop_len(pmt->descriptor);
843 	vidtv_psi_set_desc_loop_len(&pmt->bitfield2, desc_loop_len, 10);
844 
845 	length += desc_loop_len;
846 
847 	while (s) {
848 		/* skip both pointers at the end */
849 		length += sizeof(struct vidtv_psi_table_pmt_stream) -
850 			  sizeof(struct vidtv_psi_desc *) -
851 			  sizeof(struct vidtv_psi_table_pmt_stream *);
852 
853 		desc_loop_len = vidtv_psi_desc_comp_loop_len(s->descriptor);
854 		vidtv_psi_set_desc_loop_len(&s->bitfield2, desc_loop_len, 10);
855 
856 		length += desc_loop_len;
857 
858 		s = s->next;
859 	}
860 
861 	length += CRC_SIZE_IN_BYTES;
862 
863 	vidtv_psi_set_sec_len(&pmt->header, length);
864 }
865 
vidtv_psi_sdt_table_update_sec_len(struct vidtv_psi_table_sdt *sdt)866 void vidtv_psi_sdt_table_update_sec_len(struct vidtv_psi_table_sdt *sdt)
867 {
868 	struct vidtv_psi_table_sdt_service *s = sdt->service;
869 	u16 desc_loop_len;
870 	u16 length = 0;
871 
872 	/* see ETSI EN 300 468 V 1.10.1 p.24 */
873 
874 	/*
875 	 * from immediately after 'section_length' until
876 	 * 'reserved_for_future_use'
877 	 */
878 	length += SDT_LEN_UNTIL_RESERVED_FOR_FUTURE_USE;
879 
880 	while (s) {
881 		/* skip both pointers at the end */
882 		length += sizeof(struct vidtv_psi_table_sdt_service) -
883 			  sizeof(struct vidtv_psi_desc *) -
884 			  sizeof(struct vidtv_psi_table_sdt_service *);
885 
886 		desc_loop_len = vidtv_psi_desc_comp_loop_len(s->descriptor);
887 		vidtv_psi_set_desc_loop_len(&s->bitfield, desc_loop_len, 12);
888 
889 		length += desc_loop_len;
890 
891 		s = s->next;
892 	}
893 
894 	length += CRC_SIZE_IN_BYTES;
895 	vidtv_psi_set_sec_len(&sdt->header, length);
896 }
897 
898 struct vidtv_psi_table_pat_program*
vidtv_psi_pat_program_init(struct vidtv_psi_table_pat_program *head, u16 service_id, u16 program_map_pid)899 vidtv_psi_pat_program_init(struct vidtv_psi_table_pat_program *head,
900 			   u16 service_id,
901 			   u16 program_map_pid)
902 {
903 	struct vidtv_psi_table_pat_program *program;
904 	const u16 RESERVED = 0x07;
905 
906 	program = kzalloc(sizeof(*program), GFP_KERNEL);
907 	if (!program)
908 		return NULL;
909 
910 	program->service_id = cpu_to_be16(service_id);
911 
912 	/* pid for the PMT section in the TS */
913 	program->bitfield = cpu_to_be16((RESERVED << 13) | program_map_pid);
914 	program->next = NULL;
915 
916 	if (head) {
917 		while (head->next)
918 			head = head->next;
919 
920 		head->next = program;
921 	}
922 
923 	return program;
924 }
925 
926 void
vidtv_psi_pat_program_destroy(struct vidtv_psi_table_pat_program *p)927 vidtv_psi_pat_program_destroy(struct vidtv_psi_table_pat_program *p)
928 {
929 	struct vidtv_psi_table_pat_program *tmp  = NULL;
930 	struct vidtv_psi_table_pat_program *curr = p;
931 
932 	while (curr) {
933 		tmp  = curr;
934 		curr = curr->next;
935 		kfree(tmp);
936 	}
937 }
938 
939 /* This function transfers ownership of p to the table */
940 void
vidtv_psi_pat_program_assign(struct vidtv_psi_table_pat *pat, struct vidtv_psi_table_pat_program *p)941 vidtv_psi_pat_program_assign(struct vidtv_psi_table_pat *pat,
942 			     struct vidtv_psi_table_pat_program *p)
943 {
944 	struct vidtv_psi_table_pat_program *program;
945 	u16 program_count;
946 
947 	do {
948 		program_count = 0;
949 		program = p;
950 
951 		if (p == pat->program)
952 			return;
953 
954 		while (program) {
955 			++program_count;
956 			program = program->next;
957 		}
958 
959 		pat->num_pat = program_count;
960 		pat->program  = p;
961 
962 		/* Recompute section length */
963 		vidtv_psi_pat_table_update_sec_len(pat);
964 
965 		p = NULL;
966 	} while (vidtv_psi_get_sec_len(&pat->header) > MAX_SECTION_LEN);
967 
968 	vidtv_psi_update_version_num(&pat->header);
969 }
970 
vidtv_psi_pat_table_init(u16 transport_stream_id)971 struct vidtv_psi_table_pat *vidtv_psi_pat_table_init(u16 transport_stream_id)
972 {
973 	struct vidtv_psi_table_pat *pat;
974 	const u16 SYNTAX = 0x1;
975 	const u16 ZERO = 0x0;
976 	const u16 ONES = 0x03;
977 
978 	pat = kzalloc(sizeof(*pat), GFP_KERNEL);
979 	if (!pat)
980 		return NULL;
981 
982 	pat->header.table_id = 0x0;
983 
984 	pat->header.bitfield = cpu_to_be16((SYNTAX << 15) | (ZERO << 14) | (ONES << 12));
985 	pat->header.id           = cpu_to_be16(transport_stream_id);
986 	pat->header.current_next = 0x1;
987 
988 	pat->header.version = 0x1f;
989 
990 	pat->header.one2         = 0x03;
991 	pat->header.section_id   = 0x0;
992 	pat->header.last_section = 0x0;
993 
994 	vidtv_psi_pat_table_update_sec_len(pat);
995 
996 	return pat;
997 }
998 
vidtv_psi_pat_write_into(struct vidtv_psi_pat_write_args *args)999 u32 vidtv_psi_pat_write_into(struct vidtv_psi_pat_write_args *args)
1000 {
1001 	struct vidtv_psi_table_pat_program *p = args->pat->program;
1002 	struct header_write_args h_args       = {
1003 		.dest_buf           = args->buf,
1004 		.dest_offset        = args->offset,
1005 		.pid                = VIDTV_PAT_PID,
1006 		.h                  = &args->pat->header,
1007 		.continuity_counter = args->continuity_counter,
1008 		.dest_buf_sz        = args->buf_sz,
1009 	};
1010 	struct psi_write_args psi_args        = {
1011 		.dest_buf           = args->buf,
1012 		.pid                = VIDTV_PAT_PID,
1013 		.new_psi_section    = false,
1014 		.continuity_counter = args->continuity_counter,
1015 		.is_crc             = false,
1016 		.dest_buf_sz        = args->buf_sz,
1017 	};
1018 	struct crc32_write_args c_args        = {
1019 		.dest_buf           = args->buf,
1020 		.pid                = VIDTV_PAT_PID,
1021 		.dest_buf_sz        = args->buf_sz,
1022 	};
1023 	u32 crc = INITIAL_CRC;
1024 	u32 nbytes = 0;
1025 
1026 	vidtv_psi_pat_table_update_sec_len(args->pat);
1027 
1028 	h_args.crc = &crc;
1029 
1030 	nbytes += vidtv_psi_table_header_write_into(&h_args);
1031 
1032 	/* note that the field 'u16 programs' is not really part of the PAT */
1033 
1034 	psi_args.crc = &crc;
1035 
1036 	while (p) {
1037 		/* copy the PAT programs */
1038 		psi_args.from = p;
1039 		/* skip the pointer */
1040 		psi_args.len = sizeof(*p) -
1041 			       sizeof(struct vidtv_psi_table_pat_program *);
1042 		psi_args.dest_offset = args->offset + nbytes;
1043 		psi_args.continuity_counter = args->continuity_counter;
1044 
1045 		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
1046 
1047 		p = p->next;
1048 	}
1049 
1050 	c_args.dest_offset        = args->offset + nbytes;
1051 	c_args.continuity_counter = args->continuity_counter;
1052 	c_args.crc                = cpu_to_be32(crc);
1053 
1054 	/* Write the CRC32 at the end */
1055 	nbytes += table_section_crc32_write_into(&c_args);
1056 
1057 	return nbytes;
1058 }
1059 
1060 void
vidtv_psi_pat_table_destroy(struct vidtv_psi_table_pat *p)1061 vidtv_psi_pat_table_destroy(struct vidtv_psi_table_pat *p)
1062 {
1063 	vidtv_psi_pat_program_destroy(p->program);
1064 	kfree(p);
1065 }
1066 
1067 struct vidtv_psi_table_pmt_stream*
vidtv_psi_pmt_stream_init(struct vidtv_psi_table_pmt_stream *head, enum vidtv_psi_stream_types stream_type, u16 es_pid)1068 vidtv_psi_pmt_stream_init(struct vidtv_psi_table_pmt_stream *head,
1069 			  enum vidtv_psi_stream_types stream_type,
1070 			  u16 es_pid)
1071 {
1072 	struct vidtv_psi_table_pmt_stream *stream;
1073 	const u16 RESERVED1 = 0x07;
1074 	const u16 RESERVED2 = 0x0f;
1075 	const u16 ZERO = 0x0;
1076 	u16 desc_loop_len;
1077 
1078 	stream = kzalloc(sizeof(*stream), GFP_KERNEL);
1079 	if (!stream)
1080 		return NULL;
1081 
1082 	stream->type = stream_type;
1083 
1084 	stream->bitfield = cpu_to_be16((RESERVED1 << 13) | es_pid);
1085 
1086 	desc_loop_len = vidtv_psi_desc_comp_loop_len(stream->descriptor);
1087 
1088 	stream->bitfield2 = cpu_to_be16((RESERVED2 << 12) |
1089 					(ZERO << 10)      |
1090 					desc_loop_len);
1091 	stream->next = NULL;
1092 
1093 	if (head) {
1094 		while (head->next)
1095 			head = head->next;
1096 
1097 		head->next = stream;
1098 	}
1099 
1100 	return stream;
1101 }
1102 
vidtv_psi_pmt_stream_destroy(struct vidtv_psi_table_pmt_stream *s)1103 void vidtv_psi_pmt_stream_destroy(struct vidtv_psi_table_pmt_stream *s)
1104 {
1105 	struct vidtv_psi_table_pmt_stream *tmp_stream  = NULL;
1106 	struct vidtv_psi_table_pmt_stream *curr_stream = s;
1107 
1108 	while (curr_stream) {
1109 		tmp_stream  = curr_stream;
1110 		curr_stream = curr_stream->next;
1111 		vidtv_psi_desc_destroy(tmp_stream->descriptor);
1112 		kfree(tmp_stream);
1113 	}
1114 }
1115 
vidtv_psi_pmt_stream_assign(struct vidtv_psi_table_pmt *pmt, struct vidtv_psi_table_pmt_stream *s)1116 void vidtv_psi_pmt_stream_assign(struct vidtv_psi_table_pmt *pmt,
1117 				 struct vidtv_psi_table_pmt_stream *s)
1118 {
1119 	do {
1120 		/* This function transfers ownership of s to the table */
1121 		if (s == pmt->stream)
1122 			return;
1123 
1124 		pmt->stream = s;
1125 		vidtv_psi_pmt_table_update_sec_len(pmt);
1126 
1127 		s = NULL;
1128 	} while (vidtv_psi_get_sec_len(&pmt->header) > MAX_SECTION_LEN);
1129 
1130 	vidtv_psi_update_version_num(&pmt->header);
1131 }
1132 
vidtv_psi_pmt_get_pid(struct vidtv_psi_table_pmt *section, struct vidtv_psi_table_pat *pat)1133 u16 vidtv_psi_pmt_get_pid(struct vidtv_psi_table_pmt *section,
1134 			  struct vidtv_psi_table_pat *pat)
1135 {
1136 	struct vidtv_psi_table_pat_program *program = pat->program;
1137 
1138 	/*
1139 	 * service_id is the same as program_number in the
1140 	 * corresponding program_map_section
1141 	 * see ETSI EN 300 468 v1.15.1 p. 24
1142 	 */
1143 	while (program) {
1144 		if (program->service_id == section->header.id)
1145 			return vidtv_psi_get_pat_program_pid(program);
1146 
1147 		program = program->next;
1148 	}
1149 
1150 	return TS_LAST_VALID_PID + 1; /* not found */
1151 }
1152 
vidtv_psi_pmt_table_init(u16 program_number, u16 pcr_pid)1153 struct vidtv_psi_table_pmt *vidtv_psi_pmt_table_init(u16 program_number,
1154 						     u16 pcr_pid)
1155 {
1156 	struct vidtv_psi_table_pmt *pmt;
1157 	const u16 RESERVED1 = 0x07;
1158 	const u16 RESERVED2 = 0x0f;
1159 	const u16 SYNTAX = 0x1;
1160 	const u16 ONES = 0x03;
1161 	const u16 ZERO = 0x0;
1162 	u16 desc_loop_len;
1163 
1164 	pmt = kzalloc(sizeof(*pmt), GFP_KERNEL);
1165 	if (!pmt)
1166 		return NULL;
1167 
1168 	if (!pcr_pid)
1169 		pcr_pid = 0x1fff;
1170 
1171 	pmt->header.table_id = 0x2;
1172 
1173 	pmt->header.bitfield = cpu_to_be16((SYNTAX << 15) | (ZERO << 14) | (ONES << 12));
1174 
1175 	pmt->header.id = cpu_to_be16(program_number);
1176 	pmt->header.current_next = 0x1;
1177 
1178 	pmt->header.version = 0x1f;
1179 
1180 	pmt->header.one2 = ONES;
1181 	pmt->header.section_id   = 0;
1182 	pmt->header.last_section = 0;
1183 
1184 	pmt->bitfield = cpu_to_be16((RESERVED1 << 13) | pcr_pid);
1185 
1186 	desc_loop_len = vidtv_psi_desc_comp_loop_len(pmt->descriptor);
1187 
1188 	pmt->bitfield2 = cpu_to_be16((RESERVED2 << 12) |
1189 				     (ZERO << 10)      |
1190 				     desc_loop_len);
1191 
1192 	vidtv_psi_pmt_table_update_sec_len(pmt);
1193 
1194 	return pmt;
1195 }
1196 
vidtv_psi_pmt_write_into(struct vidtv_psi_pmt_write_args *args)1197 u32 vidtv_psi_pmt_write_into(struct vidtv_psi_pmt_write_args *args)
1198 {
1199 	struct vidtv_psi_desc *table_descriptor   = args->pmt->descriptor;
1200 	struct vidtv_psi_table_pmt_stream *stream = args->pmt->stream;
1201 	struct vidtv_psi_desc *stream_descriptor;
1202 	u32 crc = INITIAL_CRC;
1203 	u32 nbytes = 0;
1204 	struct header_write_args h_args = {
1205 		.dest_buf           = args->buf,
1206 		.dest_offset        = args->offset,
1207 		.h                  = &args->pmt->header,
1208 		.pid                = args->pid,
1209 		.continuity_counter = args->continuity_counter,
1210 		.dest_buf_sz        = args->buf_sz,
1211 	};
1212 	struct psi_write_args psi_args  = {
1213 		.dest_buf = args->buf,
1214 		.from     = &args->pmt->bitfield,
1215 		.len      = sizeof_field(struct vidtv_psi_table_pmt, bitfield) +
1216 			    sizeof_field(struct vidtv_psi_table_pmt, bitfield2),
1217 		.pid                = args->pid,
1218 		.new_psi_section    = false,
1219 		.is_crc             = false,
1220 		.dest_buf_sz        = args->buf_sz,
1221 		.crc                = &crc,
1222 	};
1223 	struct desc_write_args d_args   = {
1224 		.dest_buf           = args->buf,
1225 		.desc               = table_descriptor,
1226 		.pid                = args->pid,
1227 		.dest_buf_sz        = args->buf_sz,
1228 	};
1229 	struct crc32_write_args c_args  = {
1230 		.dest_buf           = args->buf,
1231 		.pid                = args->pid,
1232 		.dest_buf_sz        = args->buf_sz,
1233 	};
1234 
1235 	vidtv_psi_pmt_table_update_sec_len(args->pmt);
1236 
1237 	h_args.crc                = &crc;
1238 
1239 	nbytes += vidtv_psi_table_header_write_into(&h_args);
1240 
1241 	/* write the two bitfields */
1242 	psi_args.dest_offset        = args->offset + nbytes;
1243 	psi_args.continuity_counter = args->continuity_counter;
1244 	nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
1245 
1246 	while (table_descriptor) {
1247 		/* write the descriptors, if any */
1248 		d_args.dest_offset        = args->offset + nbytes;
1249 		d_args.continuity_counter = args->continuity_counter;
1250 		d_args.crc                = &crc;
1251 
1252 		nbytes += vidtv_psi_desc_write_into(&d_args);
1253 
1254 		table_descriptor = table_descriptor->next;
1255 	}
1256 
1257 	psi_args.len += sizeof_field(struct vidtv_psi_table_pmt_stream, type);
1258 	while (stream) {
1259 		/* write the streams, if any */
1260 		psi_args.from = stream;
1261 		psi_args.dest_offset = args->offset + nbytes;
1262 		psi_args.continuity_counter = args->continuity_counter;
1263 
1264 		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
1265 
1266 		stream_descriptor = stream->descriptor;
1267 
1268 		while (stream_descriptor) {
1269 			/* write the stream descriptors, if any */
1270 			d_args.dest_offset        = args->offset + nbytes;
1271 			d_args.desc               = stream_descriptor;
1272 			d_args.continuity_counter = args->continuity_counter;
1273 			d_args.crc                = &crc;
1274 
1275 			nbytes += vidtv_psi_desc_write_into(&d_args);
1276 
1277 			stream_descriptor = stream_descriptor->next;
1278 		}
1279 
1280 		stream = stream->next;
1281 	}
1282 
1283 	c_args.dest_offset        = args->offset + nbytes;
1284 	c_args.crc                = cpu_to_be32(crc);
1285 	c_args.continuity_counter = args->continuity_counter;
1286 
1287 	/* Write the CRC32 at the end */
1288 	nbytes += table_section_crc32_write_into(&c_args);
1289 
1290 	return nbytes;
1291 }
1292 
vidtv_psi_pmt_table_destroy(struct vidtv_psi_table_pmt *pmt)1293 void vidtv_psi_pmt_table_destroy(struct vidtv_psi_table_pmt *pmt)
1294 {
1295 	vidtv_psi_desc_destroy(pmt->descriptor);
1296 	vidtv_psi_pmt_stream_destroy(pmt->stream);
1297 	kfree(pmt);
1298 }
1299 
vidtv_psi_sdt_table_init(u16 network_id, u16 transport_stream_id)1300 struct vidtv_psi_table_sdt *vidtv_psi_sdt_table_init(u16 network_id,
1301 						     u16 transport_stream_id)
1302 {
1303 	struct vidtv_psi_table_sdt *sdt;
1304 	const u16 RESERVED = 0xff;
1305 	const u16 SYNTAX = 0x1;
1306 	const u16 ONES = 0x03;
1307 	const u16 ONE = 0x1;
1308 
1309 	sdt  = kzalloc(sizeof(*sdt), GFP_KERNEL);
1310 	if (!sdt)
1311 		return NULL;
1312 
1313 	sdt->header.table_id = 0x42;
1314 	sdt->header.bitfield = cpu_to_be16((SYNTAX << 15) | (ONE << 14) | (ONES << 12));
1315 
1316 	/*
1317 	 * This is a 16-bit field which serves as a label for identification
1318 	 * of the TS, about which the SDT informs, from any other multiplex
1319 	 * within the delivery system.
1320 	 */
1321 	sdt->header.id = cpu_to_be16(transport_stream_id);
1322 	sdt->header.current_next = ONE;
1323 
1324 	sdt->header.version = 0x1f;
1325 
1326 	sdt->header.one2  = ONES;
1327 	sdt->header.section_id   = 0;
1328 	sdt->header.last_section = 0;
1329 
1330 	/*
1331 	 * FIXME: The network_id range from 0xFF01 to 0xFFFF is used to
1332 	 * indicate temporary private use. For now, let's use the first
1333 	 * value.
1334 	 * This can be changed to something more useful, when support for
1335 	 * NIT gets added
1336 	 */
1337 	sdt->network_id = cpu_to_be16(network_id);
1338 	sdt->reserved = RESERVED;
1339 
1340 	vidtv_psi_sdt_table_update_sec_len(sdt);
1341 
1342 	return sdt;
1343 }
1344 
vidtv_psi_sdt_write_into(struct vidtv_psi_sdt_write_args *args)1345 u32 vidtv_psi_sdt_write_into(struct vidtv_psi_sdt_write_args *args)
1346 {
1347 	struct header_write_args h_args = {
1348 		.dest_buf           = args->buf,
1349 		.dest_offset        = args->offset,
1350 		.h                  = &args->sdt->header,
1351 		.pid                = VIDTV_SDT_PID,
1352 		.dest_buf_sz        = args->buf_sz,
1353 	};
1354 	struct psi_write_args psi_args  = {
1355 		.dest_buf = args->buf,
1356 		.len = sizeof_field(struct vidtv_psi_table_sdt, network_id) +
1357 		       sizeof_field(struct vidtv_psi_table_sdt, reserved),
1358 		.pid                = VIDTV_SDT_PID,
1359 		.new_psi_section    = false,
1360 		.is_crc             = false,
1361 		.dest_buf_sz        = args->buf_sz,
1362 	};
1363 	struct desc_write_args d_args   = {
1364 		.dest_buf           = args->buf,
1365 		.pid                = VIDTV_SDT_PID,
1366 		.dest_buf_sz        = args->buf_sz,
1367 	};
1368 	struct crc32_write_args c_args  = {
1369 		.dest_buf           = args->buf,
1370 		.pid                = VIDTV_SDT_PID,
1371 		.dest_buf_sz        = args->buf_sz,
1372 	};
1373 	struct vidtv_psi_table_sdt_service *service = args->sdt->service;
1374 	struct vidtv_psi_desc *service_desc;
1375 	u32 nbytes  = 0;
1376 	u32 crc = INITIAL_CRC;
1377 
1378 	/* see ETSI EN 300 468 v1.15.1 p. 11 */
1379 
1380 	vidtv_psi_sdt_table_update_sec_len(args->sdt);
1381 
1382 	h_args.continuity_counter = args->continuity_counter;
1383 	h_args.crc                = &crc;
1384 
1385 	nbytes += vidtv_psi_table_header_write_into(&h_args);
1386 
1387 	psi_args.from               = &args->sdt->network_id;
1388 	psi_args.dest_offset        = args->offset + nbytes;
1389 	psi_args.continuity_counter = args->continuity_counter;
1390 	psi_args.crc                = &crc;
1391 
1392 	/* copy u16 network_id + u8 reserved)*/
1393 	nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
1394 
1395 	/* skip both pointers at the end */
1396 	psi_args.len = sizeof(struct vidtv_psi_table_sdt_service) -
1397 		       sizeof(struct vidtv_psi_desc *) -
1398 		       sizeof(struct vidtv_psi_table_sdt_service *);
1399 
1400 	while (service) {
1401 		/* copy the services, if any */
1402 		psi_args.from = service;
1403 		psi_args.dest_offset = args->offset + nbytes;
1404 		psi_args.continuity_counter = args->continuity_counter;
1405 
1406 		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
1407 
1408 		service_desc = service->descriptor;
1409 
1410 		while (service_desc) {
1411 			/* copy the service descriptors, if any */
1412 			d_args.dest_offset        = args->offset + nbytes;
1413 			d_args.desc               = service_desc;
1414 			d_args.continuity_counter = args->continuity_counter;
1415 			d_args.crc                = &crc;
1416 
1417 			nbytes += vidtv_psi_desc_write_into(&d_args);
1418 
1419 			service_desc = service_desc->next;
1420 		}
1421 
1422 		service = service->next;
1423 	}
1424 
1425 	c_args.dest_offset        = args->offset + nbytes;
1426 	c_args.crc                = cpu_to_be32(crc);
1427 	c_args.continuity_counter = args->continuity_counter;
1428 
1429 	/* Write the CRC at the end */
1430 	nbytes += table_section_crc32_write_into(&c_args);
1431 
1432 	return nbytes;
1433 }
1434 
vidtv_psi_sdt_table_destroy(struct vidtv_psi_table_sdt *sdt)1435 void vidtv_psi_sdt_table_destroy(struct vidtv_psi_table_sdt *sdt)
1436 {
1437 	vidtv_psi_sdt_service_destroy(sdt->service);
1438 	kfree(sdt);
1439 }
1440 
1441 struct vidtv_psi_table_sdt_service
vidtv_psi_sdt_service_init(struct vidtv_psi_table_sdt_service *head, u16 service_id, bool eit_schedule, bool eit_present_following)1442 *vidtv_psi_sdt_service_init(struct vidtv_psi_table_sdt_service *head,
1443 			    u16 service_id,
1444 			    bool eit_schedule,
1445 			    bool eit_present_following)
1446 {
1447 	struct vidtv_psi_table_sdt_service *service;
1448 
1449 	service = kzalloc(sizeof(*service), GFP_KERNEL);
1450 	if (!service)
1451 		return NULL;
1452 
1453 	/*
1454 	 * ETSI 300 468: this is a 16bit field which serves as a label to
1455 	 * identify this service from any other service within the TS.
1456 	 * The service id is the same as the program number in the
1457 	 * corresponding program_map_section
1458 	 */
1459 	service->service_id            = cpu_to_be16(service_id);
1460 	service->EIT_schedule          = eit_schedule;
1461 	service->EIT_present_following = eit_present_following;
1462 	service->reserved              = 0x3f;
1463 
1464 	service->bitfield = cpu_to_be16(RUNNING << 13);
1465 
1466 	if (head) {
1467 		while (head->next)
1468 			head = head->next;
1469 
1470 		head->next = service;
1471 	}
1472 
1473 	return service;
1474 }
1475 
1476 void
vidtv_psi_sdt_service_destroy(struct vidtv_psi_table_sdt_service *service)1477 vidtv_psi_sdt_service_destroy(struct vidtv_psi_table_sdt_service *service)
1478 {
1479 	struct vidtv_psi_table_sdt_service *curr = service;
1480 	struct vidtv_psi_table_sdt_service *tmp  = NULL;
1481 
1482 	while (curr) {
1483 		tmp  = curr;
1484 		curr = curr->next;
1485 		vidtv_psi_desc_destroy(tmp->descriptor);
1486 		kfree(tmp);
1487 	}
1488 }
1489 
1490 void
vidtv_psi_sdt_service_assign(struct vidtv_psi_table_sdt *sdt, struct vidtv_psi_table_sdt_service *service)1491 vidtv_psi_sdt_service_assign(struct vidtv_psi_table_sdt *sdt,
1492 			     struct vidtv_psi_table_sdt_service *service)
1493 {
1494 	do {
1495 		if (service == sdt->service)
1496 			return;
1497 
1498 		sdt->service = service;
1499 
1500 		/* recompute section length */
1501 		vidtv_psi_sdt_table_update_sec_len(sdt);
1502 
1503 		service = NULL;
1504 	} while (vidtv_psi_get_sec_len(&sdt->header) > MAX_SECTION_LEN);
1505 
1506 	vidtv_psi_update_version_num(&sdt->header);
1507 }
1508 
1509 /*
1510  * PMTs contain information about programs. For each program,
1511  * there is one PMT section. This function will create a section
1512  * for each program found in the PAT
1513  */
1514 struct vidtv_psi_table_pmt**
vidtv_psi_pmt_create_sec_for_each_pat_entry(struct vidtv_psi_table_pat *pat, u16 pcr_pid)1515 vidtv_psi_pmt_create_sec_for_each_pat_entry(struct vidtv_psi_table_pat *pat,
1516 					    u16 pcr_pid)
1517 
1518 {
1519 	struct vidtv_psi_table_pat_program *program;
1520 	struct vidtv_psi_table_pmt **pmt_secs;
1521 	u32 i = 0, num_pmt = 0;
1522 
1523 	/*
1524 	 * The number of PMT entries is the number of PAT entries
1525 	 * that contain service_id. That exclude special tables, like NIT
1526 	 */
1527 	program = pat->program;
1528 	while (program) {
1529 		if (program->service_id)
1530 			num_pmt++;
1531 		program = program->next;
1532 	}
1533 
1534 	pmt_secs = kcalloc(num_pmt,
1535 			   sizeof(struct vidtv_psi_table_pmt *),
1536 			   GFP_KERNEL);
1537 	if (!pmt_secs)
1538 		return NULL;
1539 
1540 	for (program = pat->program; program; program = program->next) {
1541 		if (!program->service_id)
1542 			continue;
1543 		pmt_secs[i] = vidtv_psi_pmt_table_init(be16_to_cpu(program->service_id),
1544 						       pcr_pid);
1545 
1546 		if (!pmt_secs[i]) {
1547 			while (i > 0) {
1548 				i--;
1549 				vidtv_psi_pmt_table_destroy(pmt_secs[i]);
1550 			}
1551 			return NULL;
1552 		}
1553 		i++;
1554 	}
1555 	pat->num_pmt = num_pmt;
1556 
1557 	return pmt_secs;
1558 }
1559 
1560 /* find the PMT section associated with 'program_num' */
1561 struct vidtv_psi_table_pmt
vidtv_psi_find_pmt_sec(struct vidtv_psi_table_pmt **pmt_sections, u16 nsections, u16 program_num)1562 *vidtv_psi_find_pmt_sec(struct vidtv_psi_table_pmt **pmt_sections,
1563 			u16 nsections,
1564 			u16 program_num)
1565 {
1566 	struct vidtv_psi_table_pmt *sec = NULL;
1567 	u32 i;
1568 
1569 	for (i = 0; i < nsections; ++i) {
1570 		sec = pmt_sections[i];
1571 		if (be16_to_cpu(sec->header.id) == program_num)
1572 			return sec;
1573 	}
1574 
1575 	return NULL; /* not found */
1576 }
1577 
vidtv_psi_nit_table_update_sec_len(struct vidtv_psi_table_nit *nit)1578 static void vidtv_psi_nit_table_update_sec_len(struct vidtv_psi_table_nit *nit)
1579 {
1580 	u16 length = 0;
1581 	struct vidtv_psi_table_transport *t = nit->transport;
1582 	u16 desc_loop_len;
1583 	u16 transport_loop_len = 0;
1584 
1585 	/*
1586 	 * from immediately after 'section_length' until
1587 	 * 'network_descriptor_length'
1588 	 */
1589 	length += NIT_LEN_UNTIL_NETWORK_DESCRIPTOR_LEN;
1590 
1591 	desc_loop_len = vidtv_psi_desc_comp_loop_len(nit->descriptor);
1592 	vidtv_psi_set_desc_loop_len(&nit->bitfield, desc_loop_len, 12);
1593 
1594 	length += desc_loop_len;
1595 
1596 	length += sizeof_field(struct vidtv_psi_table_nit, bitfield2);
1597 
1598 	while (t) {
1599 		/* skip both pointers at the end */
1600 		transport_loop_len += sizeof(struct vidtv_psi_table_transport) -
1601 				      sizeof(struct vidtv_psi_desc *) -
1602 				      sizeof(struct vidtv_psi_table_transport *);
1603 
1604 		length += transport_loop_len;
1605 
1606 		desc_loop_len = vidtv_psi_desc_comp_loop_len(t->descriptor);
1607 		vidtv_psi_set_desc_loop_len(&t->bitfield, desc_loop_len, 12);
1608 
1609 		length += desc_loop_len;
1610 
1611 		t = t->next;
1612 	}
1613 
1614 	// Actually sets the transport stream loop len, maybe rename this function later
1615 	vidtv_psi_set_desc_loop_len(&nit->bitfield2, transport_loop_len, 12);
1616 	length += CRC_SIZE_IN_BYTES;
1617 
1618 	vidtv_psi_set_sec_len(&nit->header, length);
1619 }
1620 
1621 struct vidtv_psi_table_nit
vidtv_psi_nit_table_init(u16 network_id, u16 transport_stream_id, char *network_name, struct vidtv_psi_desc_service_list_entry *service_list)1622 *vidtv_psi_nit_table_init(u16 network_id,
1623 			  u16 transport_stream_id,
1624 			  char *network_name,
1625 			  struct vidtv_psi_desc_service_list_entry *service_list)
1626 {
1627 	struct vidtv_psi_table_transport *transport;
1628 	struct vidtv_psi_table_nit *nit;
1629 	const u16 SYNTAX = 0x1;
1630 	const u16 ONES = 0x03;
1631 	const u16 ONE = 0x1;
1632 
1633 	nit = kzalloc(sizeof(*nit), GFP_KERNEL);
1634 	if (!nit)
1635 		return NULL;
1636 
1637 	transport = kzalloc(sizeof(*transport), GFP_KERNEL);
1638 	if (!transport)
1639 		goto free_nit;
1640 
1641 	nit->header.table_id = 0x40; // ACTUAL_NETWORK
1642 
1643 	nit->header.bitfield = cpu_to_be16((SYNTAX << 15) | (ONE << 14) | (ONES << 12));
1644 
1645 	nit->header.id = cpu_to_be16(network_id);
1646 	nit->header.current_next = ONE;
1647 
1648 	nit->header.version = 0x1f;
1649 
1650 	nit->header.one2  = ONES;
1651 	nit->header.section_id   = 0;
1652 	nit->header.last_section = 0;
1653 
1654 	nit->bitfield = cpu_to_be16(0xf);
1655 	nit->bitfield2 = cpu_to_be16(0xf);
1656 
1657 	nit->descriptor = (struct vidtv_psi_desc *)
1658 			  vidtv_psi_network_name_desc_init(NULL, network_name);
1659 	if (!nit->descriptor)
1660 		goto free_transport;
1661 
1662 	transport->transport_id = cpu_to_be16(transport_stream_id);
1663 	transport->network_id = cpu_to_be16(network_id);
1664 	transport->bitfield = cpu_to_be16(0xf);
1665 	transport->descriptor = (struct vidtv_psi_desc *)
1666 				vidtv_psi_service_list_desc_init(NULL, service_list);
1667 	if (!transport->descriptor)
1668 		goto free_nit_desc;
1669 
1670 	nit->transport = transport;
1671 
1672 	vidtv_psi_nit_table_update_sec_len(nit);
1673 
1674 	return nit;
1675 
1676 free_nit_desc:
1677 	vidtv_psi_desc_destroy((struct vidtv_psi_desc *)nit->descriptor);
1678 
1679 free_transport:
1680 	kfree(transport);
1681 free_nit:
1682 	kfree(nit);
1683 	return NULL;
1684 }
1685 
vidtv_psi_nit_write_into(struct vidtv_psi_nit_write_args *args)1686 u32 vidtv_psi_nit_write_into(struct vidtv_psi_nit_write_args *args)
1687 {
1688 	struct header_write_args h_args = {
1689 		.dest_buf           = args->buf,
1690 		.dest_offset        = args->offset,
1691 		.h                  = &args->nit->header,
1692 		.pid                = VIDTV_NIT_PID,
1693 		.dest_buf_sz        = args->buf_sz,
1694 	};
1695 	struct psi_write_args psi_args  = {
1696 		.dest_buf           = args->buf,
1697 		.from               = &args->nit->bitfield,
1698 		.len                = sizeof_field(struct vidtv_psi_table_nit, bitfield),
1699 		.pid                = VIDTV_NIT_PID,
1700 		.new_psi_section    = false,
1701 		.is_crc             = false,
1702 		.dest_buf_sz        = args->buf_sz,
1703 	};
1704 	struct desc_write_args d_args   = {
1705 		.dest_buf           = args->buf,
1706 		.pid                = VIDTV_NIT_PID,
1707 		.dest_buf_sz        = args->buf_sz,
1708 	};
1709 	struct crc32_write_args c_args  = {
1710 		.dest_buf           = args->buf,
1711 		.pid                = VIDTV_NIT_PID,
1712 		.dest_buf_sz        = args->buf_sz,
1713 	};
1714 	struct vidtv_psi_desc *table_descriptor     = args->nit->descriptor;
1715 	struct vidtv_psi_table_transport *transport = args->nit->transport;
1716 	struct vidtv_psi_desc *transport_descriptor;
1717 	u32 crc = INITIAL_CRC;
1718 	u32 nbytes = 0;
1719 
1720 	vidtv_psi_nit_table_update_sec_len(args->nit);
1721 
1722 	h_args.continuity_counter = args->continuity_counter;
1723 	h_args.crc                = &crc;
1724 
1725 	nbytes += vidtv_psi_table_header_write_into(&h_args);
1726 
1727 	/* write the bitfield */
1728 
1729 	psi_args.dest_offset        = args->offset + nbytes;
1730 	psi_args.continuity_counter = args->continuity_counter;
1731 	psi_args.crc                = &crc;
1732 
1733 	nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
1734 
1735 	while (table_descriptor) {
1736 		/* write the descriptors, if any */
1737 		d_args.dest_offset        = args->offset + nbytes;
1738 		d_args.desc               = table_descriptor;
1739 		d_args.continuity_counter = args->continuity_counter;
1740 		d_args.crc                = &crc;
1741 
1742 		nbytes += vidtv_psi_desc_write_into(&d_args);
1743 
1744 		table_descriptor = table_descriptor->next;
1745 	}
1746 
1747 	/* write the second bitfield */
1748 	psi_args.from = &args->nit->bitfield2;
1749 	psi_args.len = sizeof_field(struct vidtv_psi_table_nit, bitfield2);
1750 	psi_args.dest_offset = args->offset + nbytes;
1751 
1752 	nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
1753 
1754 	psi_args.len  = sizeof_field(struct vidtv_psi_table_transport, transport_id) +
1755 			sizeof_field(struct vidtv_psi_table_transport, network_id)   +
1756 			sizeof_field(struct vidtv_psi_table_transport, bitfield);
1757 	while (transport) {
1758 		/* write the transport sections, if any */
1759 		psi_args.from = transport;
1760 		psi_args.dest_offset = args->offset + nbytes;
1761 
1762 		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
1763 
1764 		transport_descriptor = transport->descriptor;
1765 
1766 		while (transport_descriptor) {
1767 			/* write the transport descriptors, if any */
1768 			d_args.dest_offset        = args->offset + nbytes;
1769 			d_args.desc               = transport_descriptor;
1770 			d_args.continuity_counter = args->continuity_counter;
1771 			d_args.crc                = &crc;
1772 
1773 			nbytes += vidtv_psi_desc_write_into(&d_args);
1774 
1775 			transport_descriptor = transport_descriptor->next;
1776 		}
1777 
1778 		transport = transport->next;
1779 	}
1780 
1781 	c_args.dest_offset        = args->offset + nbytes;
1782 	c_args.crc                = cpu_to_be32(crc);
1783 	c_args.continuity_counter = args->continuity_counter;
1784 
1785 	/* Write the CRC32 at the end */
1786 	nbytes += table_section_crc32_write_into(&c_args);
1787 
1788 	return nbytes;
1789 }
1790 
vidtv_psi_transport_destroy(struct vidtv_psi_table_transport *t)1791 static void vidtv_psi_transport_destroy(struct vidtv_psi_table_transport *t)
1792 {
1793 	struct vidtv_psi_table_transport *tmp_t  = NULL;
1794 	struct vidtv_psi_table_transport *curr_t = t;
1795 
1796 	while (curr_t) {
1797 		tmp_t  = curr_t;
1798 		curr_t = curr_t->next;
1799 		vidtv_psi_desc_destroy(tmp_t->descriptor);
1800 		kfree(tmp_t);
1801 	}
1802 }
1803 
vidtv_psi_nit_table_destroy(struct vidtv_psi_table_nit *nit)1804 void vidtv_psi_nit_table_destroy(struct vidtv_psi_table_nit *nit)
1805 {
1806 	vidtv_psi_desc_destroy(nit->descriptor);
1807 	vidtv_psi_transport_destroy(nit->transport);
1808 	kfree(nit);
1809 }
1810 
vidtv_psi_eit_table_update_sec_len(struct vidtv_psi_table_eit *eit)1811 void vidtv_psi_eit_table_update_sec_len(struct vidtv_psi_table_eit *eit)
1812 {
1813 	struct vidtv_psi_table_eit_event *e = eit->event;
1814 	u16 desc_loop_len;
1815 	u16 length = 0;
1816 
1817 	/*
1818 	 * from immediately after 'section_length' until
1819 	 * 'last_table_id'
1820 	 */
1821 	length += EIT_LEN_UNTIL_LAST_TABLE_ID;
1822 
1823 	while (e) {
1824 		/* skip both pointers at the end */
1825 		length += sizeof(struct vidtv_psi_table_eit_event) -
1826 			  sizeof(struct vidtv_psi_desc *) -
1827 			  sizeof(struct vidtv_psi_table_eit_event *);
1828 
1829 		desc_loop_len = vidtv_psi_desc_comp_loop_len(e->descriptor);
1830 		vidtv_psi_set_desc_loop_len(&e->bitfield, desc_loop_len, 12);
1831 
1832 		length += desc_loop_len;
1833 
1834 		e = e->next;
1835 	}
1836 
1837 	length += CRC_SIZE_IN_BYTES;
1838 
1839 	vidtv_psi_set_sec_len(&eit->header, length);
1840 }
1841 
vidtv_psi_eit_event_assign(struct vidtv_psi_table_eit *eit, struct vidtv_psi_table_eit_event *e)1842 void vidtv_psi_eit_event_assign(struct vidtv_psi_table_eit *eit,
1843 				struct vidtv_psi_table_eit_event *e)
1844 {
1845 	do {
1846 		if (e == eit->event)
1847 			return;
1848 
1849 		eit->event = e;
1850 		vidtv_psi_eit_table_update_sec_len(eit);
1851 
1852 		e = NULL;
1853 	} while (vidtv_psi_get_sec_len(&eit->header) > EIT_MAX_SECTION_LEN);
1854 
1855 	vidtv_psi_update_version_num(&eit->header);
1856 }
1857 
1858 struct vidtv_psi_table_eit
vidtv_psi_eit_table_init(u16 network_id, u16 transport_stream_id, __be16 service_id)1859 *vidtv_psi_eit_table_init(u16 network_id,
1860 			  u16 transport_stream_id,
1861 			  __be16 service_id)
1862 {
1863 	struct vidtv_psi_table_eit *eit;
1864 	const u16 SYNTAX = 0x1;
1865 	const u16 ONE = 0x1;
1866 	const u16 ONES = 0x03;
1867 
1868 	eit = kzalloc(sizeof(*eit), GFP_KERNEL);
1869 	if (!eit)
1870 		return NULL;
1871 
1872 	eit->header.table_id = 0x4e; //actual_transport_stream: present/following
1873 
1874 	eit->header.bitfield = cpu_to_be16((SYNTAX << 15) | (ONE << 14) | (ONES << 12));
1875 
1876 	eit->header.id = service_id;
1877 	eit->header.current_next = ONE;
1878 
1879 	eit->header.version = 0x1f;
1880 
1881 	eit->header.one2  = ONES;
1882 	eit->header.section_id   = 0;
1883 	eit->header.last_section = 0;
1884 
1885 	eit->transport_id = cpu_to_be16(transport_stream_id);
1886 	eit->network_id = cpu_to_be16(network_id);
1887 
1888 	eit->last_segment = eit->header.last_section; /* not implemented */
1889 	eit->last_table_id = eit->header.table_id; /* not implemented */
1890 
1891 	vidtv_psi_eit_table_update_sec_len(eit);
1892 
1893 	return eit;
1894 }
1895 
vidtv_psi_eit_write_into(struct vidtv_psi_eit_write_args *args)1896 u32 vidtv_psi_eit_write_into(struct vidtv_psi_eit_write_args *args)
1897 {
1898 	struct header_write_args h_args = {
1899 		.dest_buf        = args->buf,
1900 		.dest_offset     = args->offset,
1901 		.h               = &args->eit->header,
1902 		.pid             = VIDTV_EIT_PID,
1903 		.dest_buf_sz     = args->buf_sz,
1904 	};
1905 	struct psi_write_args psi_args  = {
1906 		.dest_buf        = args->buf,
1907 		.len             = sizeof_field(struct vidtv_psi_table_eit, transport_id) +
1908 				   sizeof_field(struct vidtv_psi_table_eit, network_id)   +
1909 				   sizeof_field(struct vidtv_psi_table_eit, last_segment) +
1910 				   sizeof_field(struct vidtv_psi_table_eit, last_table_id),
1911 		.pid             = VIDTV_EIT_PID,
1912 		.new_psi_section = false,
1913 		.is_crc          = false,
1914 		.dest_buf_sz     = args->buf_sz,
1915 	};
1916 	struct desc_write_args d_args   = {
1917 		.dest_buf           = args->buf,
1918 		.pid                = VIDTV_EIT_PID,
1919 		.dest_buf_sz        = args->buf_sz,
1920 	};
1921 	struct crc32_write_args c_args  = {
1922 		.dest_buf           = args->buf,
1923 		.pid                = VIDTV_EIT_PID,
1924 		.dest_buf_sz        = args->buf_sz,
1925 	};
1926 	struct vidtv_psi_table_eit_event *event = args->eit->event;
1927 	struct vidtv_psi_desc *event_descriptor;
1928 	u32 crc = INITIAL_CRC;
1929 	u32 nbytes  = 0;
1930 
1931 	vidtv_psi_eit_table_update_sec_len(args->eit);
1932 
1933 	h_args.continuity_counter = args->continuity_counter;
1934 	h_args.crc                = &crc;
1935 
1936 	nbytes += vidtv_psi_table_header_write_into(&h_args);
1937 
1938 	psi_args.from               = &args->eit->transport_id;
1939 	psi_args.dest_offset        = args->offset + nbytes;
1940 	psi_args.continuity_counter = args->continuity_counter;
1941 	psi_args.crc                = &crc;
1942 
1943 	nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
1944 
1945 	/* skip both pointers at the end */
1946 	psi_args.len = sizeof(struct vidtv_psi_table_eit_event) -
1947 		       sizeof(struct vidtv_psi_desc *) -
1948 		       sizeof(struct vidtv_psi_table_eit_event *);
1949 	while (event) {
1950 		/* copy the events, if any */
1951 		psi_args.from = event;
1952 		psi_args.dest_offset = args->offset + nbytes;
1953 
1954 		nbytes += vidtv_psi_ts_psi_write_into(&psi_args);
1955 
1956 		event_descriptor = event->descriptor;
1957 
1958 		while (event_descriptor) {
1959 			/* copy the event descriptors, if any */
1960 			d_args.dest_offset        = args->offset + nbytes;
1961 			d_args.desc               = event_descriptor;
1962 			d_args.continuity_counter = args->continuity_counter;
1963 			d_args.crc                = &crc;
1964 
1965 			nbytes += vidtv_psi_desc_write_into(&d_args);
1966 
1967 			event_descriptor = event_descriptor->next;
1968 		}
1969 
1970 		event = event->next;
1971 	}
1972 
1973 	c_args.dest_offset        = args->offset + nbytes;
1974 	c_args.crc                = cpu_to_be32(crc);
1975 	c_args.continuity_counter = args->continuity_counter;
1976 
1977 	/* Write the CRC at the end */
1978 	nbytes += table_section_crc32_write_into(&c_args);
1979 
1980 	return nbytes;
1981 }
1982 
1983 struct vidtv_psi_table_eit_event
vidtv_psi_eit_event_init(struct vidtv_psi_table_eit_event *head, u16 event_id)1984 *vidtv_psi_eit_event_init(struct vidtv_psi_table_eit_event *head, u16 event_id)
1985 {
1986 	const u8 DURATION[] = {0x23, 0x59, 0x59}; /* BCD encoded */
1987 	struct vidtv_psi_table_eit_event *e;
1988 	struct timespec64 ts;
1989 	struct tm time;
1990 	int mjd, l;
1991 	__be16 mjd_be;
1992 
1993 	e = kzalloc(sizeof(*e), GFP_KERNEL);
1994 	if (!e)
1995 		return NULL;
1996 
1997 	e->event_id = cpu_to_be16(event_id);
1998 
1999 	ts = ktime_to_timespec64(ktime_get_real());
2000 	time64_to_tm(ts.tv_sec, 0, &time);
2001 
2002 	/* Convert date to Modified Julian Date - per EN 300 468 Annex C */
2003 	if (time.tm_mon < 2)
2004 		l = 1;
2005 	else
2006 		l = 0;
2007 
2008 	mjd = 14956 + time.tm_mday;
2009 	mjd += (time.tm_year - l) * 36525 / 100;
2010 	mjd += (time.tm_mon + 2 + l * 12) * 306001 / 10000;
2011 	mjd_be = cpu_to_be16(mjd);
2012 
2013 	/*
2014 	 * Store MJD and hour/min/sec to the event.
2015 	 *
2016 	 * Let's make the event to start on a full hour
2017 	 */
2018 	memcpy(e->start_time, &mjd_be, sizeof(mjd_be));
2019 	e->start_time[2] = bin2bcd(time.tm_hour);
2020 	e->start_time[3] = 0;
2021 	e->start_time[4] = 0;
2022 
2023 	/*
2024 	 * TODO: for now, the event will last for a day. Should be
2025 	 * enough for testing purposes, but if one runs the driver
2026 	 * for more than that, the current event will become invalid.
2027 	 * So, we need a better code here in order to change the start
2028 	 * time once the event expires.
2029 	 */
2030 	memcpy(e->duration, DURATION, sizeof(e->duration));
2031 
2032 	e->bitfield = cpu_to_be16(RUNNING << 13);
2033 
2034 	if (head) {
2035 		while (head->next)
2036 			head = head->next;
2037 
2038 		head->next = e;
2039 	}
2040 
2041 	return e;
2042 }
2043 
vidtv_psi_eit_event_destroy(struct vidtv_psi_table_eit_event *e)2044 void vidtv_psi_eit_event_destroy(struct vidtv_psi_table_eit_event *e)
2045 {
2046 	struct vidtv_psi_table_eit_event *tmp_e  = NULL;
2047 	struct vidtv_psi_table_eit_event *curr_e = e;
2048 
2049 	while (curr_e) {
2050 		tmp_e  = curr_e;
2051 		curr_e = curr_e->next;
2052 		vidtv_psi_desc_destroy(tmp_e->descriptor);
2053 		kfree(tmp_e);
2054 	}
2055 }
2056 
vidtv_psi_eit_table_destroy(struct vidtv_psi_table_eit *eit)2057 void vidtv_psi_eit_table_destroy(struct vidtv_psi_table_eit *eit)
2058 {
2059 	vidtv_psi_eit_event_destroy(eit->event);
2060 	kfree(eit);
2061 }
2062