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|
// SPDX-License-Identifier: GPL-2.0
/*
* This file contains the logic to work with MPEG Program-Specific Information.
* These are defined both in ISO/IEC 13818-1 (systems) and ETSI EN 300 468.
* PSI is carried in the form of table structures, and although each table might
* technically be broken into one or more sections, we do not do this here,
* hence 'table' and 'section' are interchangeable for vidtv.
*
* This code currently supports three tables: PAT, PMT and SDT. These are the
* bare minimum to get userspace to recognize our MPEG transport stream. It can
* be extended to support more PSI tables in the future.
*
* Copyright (C) 2020 Daniel W. S. Almeida
*/
#define pr_fmt(fmt) KBUILD_MODNAME ":%s, %d: " fmt, __func__, __LINE__
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/crc32.h>
#include <linux/string.h>
#include <linux/printk.h>
#include <linux/ratelimit.h>
#include <linux/string.h>
#include <asm/byteorder.h>
#include "vidtv_psi.h"
#include "vidtv_common.h"
#include "vidtv_ts.h"
#define CRC_SIZE_IN_BYTES 4
#define MAX_VERSION_NUM 32
static const u32 CRC_LUT[256] = {
/* from libdvbv5 */
0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b,
0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61,
0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd, 0x4c11db70, 0x48d0c6c7,
0x4593e01e, 0x4152fda9, 0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75,
0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3,
0x709f7b7a, 0x745e66cd, 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 0xbe2b5b58, 0xbaea46ef,
0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d,
0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49, 0xc7361b4c, 0xc3f706fb,
0xceb42022, 0xca753d95, 0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1,
0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 0x34867077, 0x30476dc0,
0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072,
0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16, 0x018aeb13, 0x054bf6a4,
0x0808d07d, 0x0cc9cdca, 0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde,
0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02, 0x5e9f46bf, 0x5a5e5b08,
0x571d7dd1, 0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b, 0xbb60adfc,
0xb6238b25, 0xb2e29692, 0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6,
0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a, 0xe0b41de7, 0xe4750050,
0xe9362689, 0xedf73b3e, 0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2,
0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34,
0xdc3abded, 0xd8fba05a, 0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637,
0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb, 0x4f040d56, 0x4bc510e1,
0x46863638, 0x42472b8f, 0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53,
0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5,
0x3f9b762c, 0x3b5a6b9b, 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 0xf12f560e, 0xf5ee4bb9,
0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b,
0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f, 0xc423cd6a, 0xc0e2d0dd,
0xcda1f604, 0xc960ebb3, 0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7,
0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 0x9b3660c6, 0x9ff77d71,
0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3,
0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640, 0x4e8ee645, 0x4a4ffbf2,
0x470cdd2b, 0x43cdc09c, 0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8,
0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24, 0x119b4be9, 0x155a565e,
0x18197087, 0x1cd86d30, 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d, 0x2056cd3a,
0x2d15ebe3, 0x29d4f654, 0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0,
0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c, 0xe3a1cbc1, 0xe760d676,
0xea23f0af, 0xeee2ed18, 0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4,
0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662,
0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668,
0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4
};
static inline u32 dvb_crc32(u32 crc, u8 *data, u32 len)
{
/* from libdvbv5 */
while (len--)
crc = (crc << 8) ^ CRC_LUT[((crc >> 24) ^ *data++) & 0xff];
return crc;
}
static void vidtv_psi_update_version_num(struct vidtv_psi_table_header *h)
{
++h->version;
if (h->version > MAX_VERSION_NUM)
h->version = 0;
}
static inline u16 vidtv_psi_sdt_serv_get_desc_loop_len(struct vidtv_psi_table_sdt_service *s)
{
u16 mask;
u16 ret;
#if defined(__BIG_ENDIAN)
mask = GENMASK(0, 11);
#else
mask = GENMASK(11, 0);
#endif
ret = be16_to_cpu(s->bitfield) & mask;
return ret;
}
static inline u16 vidtv_psi_pmt_stream_get_desc_loop_len(struct vidtv_psi_table_pmt_stream *s)
{
u16 mask;
u16 ret;
#if defined(__BIG_ENDIAN)
mask = GENMASK(0, 9);
#else
mask = GENMASK(9, 0);
#endif
ret = be16_to_cpu(s->bitfield2) & mask;
return ret;
}
static inline u16 vidtv_psi_pmt_get_desc_loop_len(struct vidtv_psi_table_pmt *p)
{
u16 mask;
u16 ret;
#if defined(__BIG_ENDIAN)
mask = GENMASK(0, 9);
#else
mask = GENMASK(9, 0);
#endif
ret = be16_to_cpu(p->bitfield2) & mask;
return ret;
}
static inline u16 vidtv_psi_get_sec_len(struct vidtv_psi_table_header *h)
{
u16 mask;
u16 ret;
#if defined(__BIG_ENDIAN)
mask = GENMASK(0, 11);
#else
mask = GENMASK(11, 0);
#endif
ret = be16_to_cpu(h->bitfield) & mask;
return ret;
}
inline u16 vidtv_psi_get_pat_program_pid(struct vidtv_psi_table_pat_program *p)
{
u16 mask;
u16 ret;
#if defined(__BIG_ENDIAN)
mask = GENMASK(0, 12);
#else
mask = GENMASK(12, 0);
#endif
ret = be16_to_cpu(p->bitfield) & mask;
return ret;
}
inline u16 vidtv_psi_pmt_stream_get_elem_pid(struct vidtv_psi_table_pmt_stream *s)
{
u16 mask;
u16 ret;
#if defined(__BIG_ENDIAN)
mask = GENMASK(0, 12);
#else
mask = GENMASK(12, 0);
#endif
ret = be16_to_cpu(s->bitfield) & mask;
return ret;
}
static inline void vidtv_psi_set_desc_loop_len(__be16 *bitfield, u16 new_len, u8 desc_len_nbits)
{
u16 mask;
__be16 new;
#if defined(__BIG_ENDIAN)
mask = GENMASK(desc_len_nbits, 15);
#else
mask = GENMASK(15, desc_len_nbits);
#endif
new = cpu_to_be16((be16_to_cpu(*bitfield) & mask) | new_len);
*bitfield = new;
}
static void vidtv_psi_set_sec_len(struct vidtv_psi_table_header *h, u16 new_len)
{
u16 old_len = vidtv_psi_get_sec_len(h);
__be16 new;
u16 mask;
#if defined(__BIG_ENDIAN)
mask = GENMASK(13, 15);
#else
mask = GENMASK(15, 13);
#endif
new = cpu_to_be16((be16_to_cpu(h->bitfield) & mask) | new_len);
if (old_len > MAX_SECTION_LEN)
pr_warn_ratelimited("section length: %d > %d, old len was %d\n",
new_len,
MAX_SECTION_LEN,
old_len);
h->bitfield = new;
}
static u32 vidtv_psi_ts_psi_write_into(struct psi_write_args args)
{
/*
* Packetize PSI sections into TS packets:
* push a TS header (4bytes) every 184 bytes
* manage the continuity_counter
* add stuffing (i.e. padding bytes) after the CRC
*/
u32 nbytes_past_boundary = (args.dest_offset % TS_PACKET_LEN);
bool aligned = (nbytes_past_boundary == 0);
struct vidtv_mpeg_ts ts_header = {};
/* number of bytes written by this function */
u32 nbytes = 0;
/* how much there is left to write */
u32 remaining_len = args.len;
/* how much we can be written in this packet */
u32 payload_write_len = 0;
/* where we are in the source */
u32 payload_offset = 0;
const u16 PAYLOAD_START = args.new_psi_section;
if (!args.crc && !args.is_crc)
pr_warn_ratelimited("Missing CRC for chunk\n");
if (args.crc)
*args.crc = dvb_crc32(*args.crc, args.from, args.len);
if (args.new_psi_section && !aligned) {
pr_warn_ratelimited("Cannot write a new PSI section in a misaligned buffer\n");
/* forcibly align and hope for the best */
nbytes += vidtv_memset(args.dest_buf,
args.dest_offset + nbytes,
args.dest_buf_sz,
TS_FILL_BYTE,
TS_PACKET_LEN - nbytes_past_boundary);
}
while (remaining_len) {
nbytes_past_boundary = (args.dest_offset + nbytes) % TS_PACKET_LEN;
aligned = (nbytes_past_boundary == 0);
if (aligned) {
/* if at a packet boundary, write a new TS header */
ts_header.sync_byte = TS_SYNC_BYTE;
ts_header.bitfield = cpu_to_be16((PAYLOAD_START << 14) | args.pid);
ts_header.scrambling = 0;
ts_header.continuity_counter = *args.continuity_counter;
ts_header.payload = 1;
/* no adaptation field */
ts_header.adaptation_field = 0;
/* copy the header */
nbytes += vidtv_memcpy(args.dest_buf,
args.dest_offset + nbytes,
args.dest_buf_sz,
&ts_header,
sizeof(ts_header));
/*
* This will trigger a discontinuity if the buffer is full,
* effectively dropping the packet.
*/
vidtv_ts_inc_cc(args.continuity_counter);
}
/* write the pointer_field in the first byte of the payload */
if (args.new_psi_section)
nbytes += vidtv_memset(args.dest_buf,
args.dest_offset + nbytes,
args.dest_buf_sz,
0x0,
1);
/* write as much of the payload as possible */
nbytes_past_boundary = (args.dest_offset + nbytes) % TS_PACKET_LEN;
payload_write_len = min(TS_PACKET_LEN - nbytes_past_boundary, remaining_len);
nbytes += vidtv_memcpy(args.dest_buf,
args.dest_offset + nbytes,
args.dest_buf_sz,
args.from + payload_offset,
payload_write_len);
/* 'payload_write_len' written from a total of 'len' requested*/
remaining_len -= payload_write_len;
payload_offset += payload_write_len;
}
/*
* fill the rest of the packet if there is any remaining space unused
*/
nbytes_past_boundary = (args.dest_offset + nbytes) % TS_PACKET_LEN;
if (args.is_crc)
nbytes += vidtv_memset(args.dest_buf,
args.dest_offset + nbytes,
args.dest_buf_sz,
TS_FILL_BYTE,
TS_PACKET_LEN - nbytes_past_boundary);
return nbytes;
}
static u32 table_section_crc32_write_into(struct crc32_write_args args)
{
/* the CRC is the last entry in the section */
u32 nbytes = 0;
struct psi_write_args psi_args = {};
psi_args.dest_buf = args.dest_buf;
psi_args.from = &args.crc;
psi_args.len = CRC_SIZE_IN_BYTES;
psi_args.dest_offset = args.dest_offset;
psi_args.pid = args.pid;
psi_args.new_psi_section = false;
psi_args.continuity_counter = args.continuity_counter;
psi_args.is_crc = true;
psi_args.dest_buf_sz = args.dest_buf_sz;
nbytes += vidtv_psi_ts_psi_write_into(psi_args);
return nbytes;
}
struct vidtv_psi_desc_service *vidtv_psi_service_desc_init(struct vidtv_psi_desc *head,
enum service_type service_type,
char *service_name,
char *provider_name)
{
struct vidtv_psi_desc_service *desc;
u32 service_name_len = service_name ? strlen(service_name) : 0;
u32 provider_name_len = provider_name ? strlen(provider_name) : 0;
desc = kzalloc(sizeof(*desc), GFP_KERNEL);
desc->type = SERVICE_DESCRIPTOR;
desc->length = sizeof_field(struct vidtv_psi_desc_service, service_type)
+ sizeof_field(struct vidtv_psi_desc_service, provider_name_len)
+ provider_name_len
+ sizeof_field(struct vidtv_psi_desc_service, service_name_len)
+ service_name_len;
desc->service_type = service_type;
desc->service_name_len = service_name_len;
if (service_name && service_name_len)
desc->service_name = kstrdup(service_name, GFP_KERNEL);
desc->provider_name_len = provider_name_len;
if (provider_name && provider_name_len)
desc->provider_name = kstrdup(provider_name, GFP_KERNEL);
if (head) {
while (head->next)
head = head->next;
head->next = (struct vidtv_psi_desc *)desc;
}
return desc;
}
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)
{
struct vidtv_psi_desc_registration *desc;
desc = kzalloc(sizeof(*desc) + sizeof(format_id) + additional_info_len, GFP_KERNEL);
desc->type = REGISTRATION_DESCRIPTOR;
desc->length = sizeof_field(struct vidtv_psi_desc_registration, format_id)
+ additional_info_len;
desc->format_id = format_id;
if (additional_ident_info && additional_info_len)
memcpy(desc->additional_identification_info,
additional_ident_info,
additional_info_len);
if (head) {
while (head->next)
head = head->next;
head->next = (struct vidtv_psi_desc *)desc;
}
return desc;
}
struct vidtv_psi_desc *vidtv_psi_desc_clone(struct vidtv_psi_desc *desc)
{
struct vidtv_psi_desc *head = NULL;
struct vidtv_psi_desc *prev = NULL;
struct vidtv_psi_desc *curr = NULL;
struct vidtv_psi_desc_service *service;
while (desc) {
switch (desc->type) {
case SERVICE_DESCRIPTOR:
service = (struct vidtv_psi_desc_service *)desc;
curr = (struct vidtv_psi_desc *)
vidtv_psi_service_desc_init(head,
service->service_type,
service->service_name,
service->provider_name);
break;
case REGISTRATION_DESCRIPTOR:
default:
curr = kzalloc(sizeof(*desc) + desc->length, GFP_KERNEL);
memcpy(curr, desc, sizeof(*desc) + desc->length);
break;
}
if (curr)
curr->next = NULL;
if (!head)
head = curr;
if (prev)
prev->next = curr;
prev = curr;
desc = desc->next;
}
return head;
}
void vidtv_psi_desc_destroy(struct vidtv_psi_desc *desc)
{
struct vidtv_psi_desc *curr = desc;
struct vidtv_psi_desc *tmp = NULL;
while (curr) {
tmp = curr;
curr = curr->next;
switch (tmp->type) {
case SERVICE_DESCRIPTOR:
kfree(((struct vidtv_psi_desc_service *)tmp)->provider_name);
kfree(((struct vidtv_psi_desc_service *)tmp)->service_name);
break;
case REGISTRATION_DESCRIPTOR:
/* nothing to do */
break;
default:
pr_warn_ratelimited("Possible leak: not handling descriptor type %d\n",
tmp->type);
break;
}
kfree(tmp);
}
}
static u16
vidtv_psi_desc_comp_loop_len(struct vidtv_psi_desc *desc)
{
u32 length = 0;
if (!desc)
return 0;
while (desc) {
length += sizeof_field(struct vidtv_psi_desc, type);
length += sizeof_field(struct vidtv_psi_desc, length);
length += desc->length; /* from 'length' field until the end of the descriptor */
desc = desc->next;
}
return length;
}
void vidtv_psi_desc_assign(struct vidtv_psi_desc **to,
struct vidtv_psi_desc *desc)
{
if (desc == *to)
return;
if (*to)
vidtv_psi_desc_destroy(*to);
*to = desc;
}
void vidtv_pmt_desc_assign(struct vidtv_psi_table_pmt *pmt,
struct vidtv_psi_desc **to,
struct vidtv_psi_desc *desc)
{
vidtv_psi_desc_assign(to, desc);
vidtv_psi_pmt_table_update_sec_len(pmt);
if (vidtv_psi_get_sec_len(&pmt->header) > MAX_SECTION_LEN)
vidtv_psi_desc_assign(to, NULL);
vidtv_psi_update_version_num(&pmt->header);
}
void vidtv_sdt_desc_assign(struct vidtv_psi_table_sdt *sdt,
struct vidtv_psi_desc **to,
struct vidtv_psi_desc *desc)
{
vidtv_psi_desc_assign(to, desc);
vidtv_psi_sdt_table_update_sec_len(sdt);
if (vidtv_psi_get_sec_len(&sdt->header) > MAX_SECTION_LEN)
vidtv_psi_desc_assign(to, NULL);
vidtv_psi_update_version_num(&sdt->header);
}
static u32 vidtv_psi_desc_write_into(struct desc_write_args args)
{
/* the number of bytes written by this function */
u32 nbytes = 0;
struct psi_write_args psi_args = {};
psi_args.dest_buf = args.dest_buf;
psi_args.from = &args.desc->type;
psi_args.len = sizeof_field(struct vidtv_psi_desc, type) +
sizeof_field(struct vidtv_psi_desc, length);
psi_args.dest_offset = args.dest_offset + nbytes;
psi_args.pid = args.pid;
psi_args.new_psi_section = false;
psi_args.continuity_counter = args.continuity_counter;
psi_args.is_crc = false;
psi_args.dest_buf_sz = args.dest_buf_sz;
psi_args.crc = args.crc;
nbytes += vidtv_psi_ts_psi_write_into(psi_args);
switch (args.desc->type) {
case SERVICE_DESCRIPTOR:
psi_args.dest_offset = args.dest_offset + nbytes;
psi_args.len = sizeof_field(struct vidtv_psi_desc_service, service_type) +
sizeof_field(struct vidtv_psi_desc_service, provider_name_len);
psi_args.from = &((struct vidtv_psi_desc_service *)args.desc)->service_type;
nbytes += vidtv_psi_ts_psi_write_into(psi_args);
psi_args.dest_offset = args.dest_offset + nbytes;
psi_args.len = ((struct vidtv_psi_desc_service *)args.desc)->provider_name_len;
psi_args.from = ((struct vidtv_psi_desc_service *)args.desc)->provider_name;
nbytes += vidtv_psi_ts_psi_write_into(psi_args);
psi_args.dest_offset = args.dest_offset + nbytes;
psi_args.len = sizeof_field(struct vidtv_psi_desc_service, service_name_len);
psi_args.from = &((struct vidtv_psi_desc_service *)args.desc)->service_name_len;
nbytes += vidtv_psi_ts_psi_write_into(psi_args);
psi_args.dest_offset = args.dest_offset + nbytes;
psi_args.len = ((struct vidtv_psi_desc_service *)args.desc)->service_name_len;
psi_args.from = ((struct vidtv_psi_desc_service *)args.desc)->service_name;
nbytes += vidtv_psi_ts_psi_write_into(psi_args);
break;
case REGISTRATION_DESCRIPTOR:
default:
psi_args.dest_offset = args.dest_offset + nbytes;
psi_args.len = args.desc->length;
psi_args.from = &args.desc->data;
nbytes += vidtv_psi_ts_psi_write_into(psi_args);
break;
}
return nbytes;
}
static u32
vidtv_psi_table_header_write_into(struct header_write_args args)
{
/* the number of bytes written by this function */
u32 nbytes = 0;
struct psi_write_args psi_args = {};
psi_args.dest_buf = args.dest_buf;
psi_args.from = args.h;
psi_args.len = sizeof(struct vidtv_psi_table_header);
psi_args.dest_offset = args.dest_offset;
psi_args.pid = args.pid;
psi_args.new_psi_section = true;
psi_args.continuity_counter = args.continuity_counter;
psi_args.is_crc = false;
psi_args.dest_buf_sz = args.dest_buf_sz;
psi_args.crc = args.crc;
nbytes += vidtv_psi_ts_psi_write_into(psi_args);
return nbytes;
}
void
vidtv_psi_pat_table_update_sec_len(struct vidtv_psi_table_pat *pat)
{
/* see ISO/IEC 13818-1 : 2000 p.43 */
u16 length = 0;
u32 i;
/* from immediately after 'section_length' until 'last_section_number'*/
length += PAT_LEN_UNTIL_LAST_SECTION_NUMBER;
/* do not count the pointer */
for (i = 0; i < pat->programs; ++i)
length += sizeof(struct vidtv_psi_table_pat_program) -
sizeof(struct vidtv_psi_table_pat_program *);
length += CRC_SIZE_IN_BYTES;
vidtv_psi_set_sec_len(&pat->header, length);
}
void vidtv_psi_pmt_table_update_sec_len(struct vidtv_psi_table_pmt *pmt)
{
/* see ISO/IEC 13818-1 : 2000 p.46 */
u16 length = 0;
struct vidtv_psi_table_pmt_stream *s = pmt->stream;
u16 desc_loop_len;
/* from immediately after 'section_length' until 'program_info_length'*/
length += PMT_LEN_UNTIL_PROGRAM_INFO_LENGTH;
desc_loop_len = vidtv_psi_desc_comp_loop_len(pmt->descriptor);
vidtv_psi_set_desc_loop_len(&pmt->bitfield2, desc_loop_len, 10);
length += desc_loop_len;
while (s) {
/* skip both pointers at the end */
length += sizeof(struct vidtv_psi_table_pmt_stream) -
sizeof(struct vidtv_psi_desc *) -
sizeof(struct vidtv_psi_table_pmt_stream *);
desc_loop_len = vidtv_psi_desc_comp_loop_len(s->descriptor);
vidtv_psi_set_desc_loop_len(&s->bitfield2, desc_loop_len, 10);
length += desc_loop_len;
s = s->next;
}
length += CRC_SIZE_IN_BYTES;
vidtv_psi_set_sec_len(&pmt->header, length);
}
void vidtv_psi_sdt_table_update_sec_len(struct vidtv_psi_table_sdt *sdt)
{
/* see ETSI EN 300 468 V 1.10.1 p.24 */
u16 length = 0;
struct vidtv_psi_table_sdt_service *s = sdt->service;
u16 desc_loop_len;
/*
* from immediately after 'section_length' until
* 'reserved_for_future_use'
*/
length += SDT_LEN_UNTIL_RESERVED_FOR_FUTURE_USE;
while (s) {
/* skip both pointers at the end */
length += sizeof(struct vidtv_psi_table_sdt_service) -
sizeof(struct vidtv_psi_desc *) -
sizeof(struct vidtv_psi_table_sdt_service *);
desc_loop_len = vidtv_psi_desc_comp_loop_len(s->descriptor);
vidtv_psi_set_desc_loop_len(&s->bitfield, desc_loop_len, 12);
length += desc_loop_len;
s = s->next;
}
length += CRC_SIZE_IN_BYTES;
vidtv_psi_set_sec_len(&sdt->header, length);
}
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)
{
struct vidtv_psi_table_pat_program *program;
const u16 RESERVED = 0x07;
program = kzalloc(sizeof(*program), GFP_KERNEL);
program->service_id = cpu_to_be16(service_id);
/* pid for the PMT section in the TS */
program->bitfield = cpu_to_be16((RESERVED << 13) | program_map_pid);
program->next = NULL;
if (head) {
while (head->next)
head = head->next;
head->next = program;
}
return program;
}
void
vidtv_psi_pat_program_destroy(struct vidtv_psi_table_pat_program *p)
{
struct vidtv_psi_table_pat_program *curr = p;
struct vidtv_psi_table_pat_program *tmp = NULL;
while (curr) {
tmp = curr;
curr = curr->next;
kfree(tmp);
}
}
void
vidtv_psi_pat_program_assign(struct vidtv_psi_table_pat *pat,
struct vidtv_psi_table_pat_program *p)
{
/* This function transfers ownership of p to the table */
u16 program_count = 0;
struct vidtv_psi_table_pat_program *program = p;
if (p == pat->program)
return;
while (program) {
++program_count;
program = program->next;
}
pat->programs = program_count;
pat->program = p;
/* Recompute section length */
vidtv_psi_pat_table_update_sec_len(pat);
if (vidtv_psi_get_sec_len(&pat->header) > MAX_SECTION_LEN)
vidtv_psi_pat_program_assign(pat, NULL);
vidtv_psi_update_version_num(&pat->header);
}
struct vidtv_psi_table_pat *vidtv_psi_pat_table_init(u16 transport_stream_id)
{
struct vidtv_psi_table_pat *pat = kzalloc(sizeof(*pat), GFP_KERNEL);
static u8 pat_version;
const u16 SYNTAX = 0x1;
const u16 ZERO = 0x0;
const u16 ONES = 0x03;
pat->header.table_id = 0x0;
pat->header.bitfield = cpu_to_be16((SYNTAX << 15) | (ZERO << 14) | (ONES << 12));
pat->header.id = cpu_to_be16(transport_stream_id);
pat->header.current_next = 0x1;
pat->header.version = pat_version;
pat->header.one2 = 0x03;
pat->header.section_id = 0x0;
pat->header.last_section = 0x0;
pat->programs = 0;
vidtv_psi_pat_table_update_sec_len(pat);
return pat;
}
u32 vidtv_psi_pat_write_into(struct vidtv_psi_pat_write_args args)
{
/* the number of bytes written by this function */
u32 nbytes = 0;
const u16 pat_pid = VIDTV_PAT_PID;
u32 crc = 0xffffffff;
struct vidtv_psi_table_pat_program *p = args.pat->program;
struct header_write_args h_args = {};
struct psi_write_args psi_args = {};
struct crc32_write_args c_args = {};
vidtv_psi_pat_table_update_sec_len(args.pat);
h_args.dest_buf = args.buf;
h_args.dest_offset = args.offset;
h_args.h = &args.pat->header;
h_args.pid = pat_pid;
h_args.continuity_counter = args.continuity_counter;
h_args.dest_buf_sz = args.buf_sz;
h_args.crc = &crc;
nbytes += vidtv_psi_table_header_write_into(h_args);
/* note that the field 'u16 programs' is not really part of the PAT */
psi_args.dest_buf = args.buf;
psi_args.pid = pat_pid;
psi_args.new_psi_section = false;
psi_args.continuity_counter = args.continuity_counter;
psi_args.is_crc = false;
psi_args.dest_buf_sz = args.buf_sz;
psi_args.crc = &crc;
while (p) {
/* copy the PAT programs */
psi_args.from = p;
/* skip the pointer */
psi_args.len = sizeof(*p) -
sizeof(struct vidtv_psi_table_pat_program *);
psi_args.dest_offset = args.offset + nbytes;
nbytes += vidtv_psi_ts_psi_write_into(psi_args);
p = p->next;
}
c_args.dest_buf = args.buf;
c_args.dest_offset = args.offset + nbytes;
c_args.crc = cpu_to_be32(crc);
c_args.pid = pat_pid;
c_args.continuity_counter = args.continuity_counter;
c_args.dest_buf_sz = args.buf_sz;
/* Write the CRC32 at the end */
nbytes += table_section_crc32_write_into(c_args);
return nbytes;
}
void
vidtv_psi_pat_table_destroy(struct vidtv_psi_table_pat *p)
{
vidtv_psi_pat_program_destroy(p->program);
kfree(p);
}
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)
{
struct vidtv_psi_table_pmt_stream *stream;
const u16 RESERVED1 = 0x07;
const u16 RESERVED2 = 0x0f;
const u16 ZERO = 0x0;
u16 desc_loop_len;
stream = kzalloc(sizeof(*stream), GFP_KERNEL);
stream->type = stream_type;
stream->bitfield = cpu_to_be16((RESERVED1 << 13) | es_pid);
desc_loop_len = vidtv_psi_desc_comp_loop_len(stream->descriptor);
stream->bitfield2 = cpu_to_be16((RESERVED2 << 12) |
(ZERO << 10) |
desc_loop_len);
stream->next = NULL;
if (head) {
while (head->next)
head = head->next;
head->next = stream;
}
return stream;
}
void vidtv_psi_pmt_stream_destroy(struct vidtv_psi_table_pmt_stream *s)
{
struct vidtv_psi_table_pmt_stream *curr_stream = s;
struct vidtv_psi_table_pmt_stream *tmp_stream = NULL;
while (curr_stream) {
tmp_stream = curr_stream;
curr_stream = curr_stream->next;
vidtv_psi_desc_destroy(tmp_stream->descriptor);
kfree(tmp_stream);
}
}
void vidtv_psi_pmt_stream_assign(struct vidtv_psi_table_pmt *pmt,
struct vidtv_psi_table_pmt_stream *s)
{
/* This function transfers ownership of s to the table */
if (s == pmt->stream)
return;
pmt->stream = s;
vidtv_psi_pmt_table_update_sec_len(pmt);
if (vidtv_psi_get_sec_len(&pmt->header) > MAX_SECTION_LEN)
vidtv_psi_pmt_stream_assign(pmt, NULL);
vidtv_psi_update_version_num(&pmt->header);
}
u16 vidtv_psi_pmt_get_pid(struct vidtv_psi_table_pmt *section,
struct vidtv_psi_table_pat *pat)
{
struct vidtv_psi_table_pat_program *program = pat->program;
/*
* service_id is the same as program_number in the
* corresponding program_map_section
* see ETSI EN 300 468 v1.15.1 p. 24
*/
while (program) {
if (program->service_id == section->header.id)
return vidtv_psi_get_pat_program_pid(program);
program = program->next;
}
return TS_LAST_VALID_PID + 1; /* not found */
}
struct vidtv_psi_table_pmt *vidtv_psi_pmt_table_init(u16 program_number,
u16 pcr_pid)
{
struct vidtv_psi_table_pmt *pmt = kzalloc(sizeof(*pmt), GFP_KERNEL);
static u8 pmt_version;
const u16 SYNTAX = 0x1;
const u16 ZERO = 0x0;
const u16 ONES = 0x03;
const u16 RESERVED1 = 0x07;
const u16 RESERVED2 = 0x0f;
u16 desc_loop_len;
if (!pcr_pid)
pcr_pid = 0x1fff;
pmt->header.table_id = 0x2;
pmt->header.bitfield = cpu_to_be16((SYNTAX << 15) | (ZERO << 14) | (ONES << 12));
pmt->header.id = cpu_to_be16(program_number);
pmt->header.current_next = 0x1;
pmt->header.version = pmt_version;
pmt->header.one2 = ONES;
pmt->header.section_id = 0;
pmt->header.last_section = 0;
pmt->bitfield = cpu_to_be16((RESERVED1 << 13) | pcr_pid);
desc_loop_len = vidtv_psi_desc_comp_loop_len(pmt->descriptor);
pmt->bitfield2 = cpu_to_be16((RESERVED2 << 12) |
(ZERO << 10) |
desc_loop_len);
vidtv_psi_pmt_table_update_sec_len(pmt);
return pmt;
}
u32 vidtv_psi_pmt_write_into(struct vidtv_psi_pmt_write_args args)
{
/* the number of bytes written by this function */
u32 nbytes = 0;
u32 crc = 0xffffffff;
struct vidtv_psi_desc *table_descriptor = args.pmt->descriptor;
struct vidtv_psi_table_pmt_stream *stream = args.pmt->stream;
struct vidtv_psi_desc *stream_descriptor = (stream) ?
args.pmt->stream->descriptor :
NULL;
struct header_write_args h_args = {};
struct psi_write_args psi_args = {};
struct desc_write_args d_args = {};
struct crc32_write_args c_args = {};
vidtv_psi_pmt_table_update_sec_len(args.pmt);
h_args.dest_buf = args.buf;
h_args.dest_offset = args.offset;
h_args.h = &args.pmt->header;
h_args.pid = args.pid;
h_args.continuity_counter = args.continuity_counter;
h_args.dest_buf_sz = args.buf_sz;
h_args.crc = &crc;
nbytes += vidtv_psi_table_header_write_into(h_args);
/* write the two bitfields */
psi_args.dest_buf = args.buf;
psi_args.from = &args.pmt->bitfield;
psi_args.len = sizeof_field(struct vidtv_psi_table_pmt, bitfield) +
sizeof_field(struct vidtv_psi_table_pmt, bitfield2);
psi_args.dest_offset = args.offset + nbytes;
psi_args.pid = args.pid;
psi_args.new_psi_section = false;
psi_args.continuity_counter = args.continuity_counter;
psi_args.is_crc = false;
psi_args.dest_buf_sz = args.buf_sz;
psi_args.crc = &crc;
nbytes += vidtv_psi_ts_psi_write_into(psi_args);
while (table_descriptor) {
/* write the descriptors, if any */
d_args.dest_buf = args.buf;
d_args.dest_offset = args.offset + nbytes;
d_args.desc = table_descriptor;
d_args.pid = args.pid;
d_args.continuity_counter = args.continuity_counter;
d_args.dest_buf_sz = args.buf_sz;
d_args.crc = &crc;
nbytes += vidtv_psi_desc_write_into(d_args);
table_descriptor = table_descriptor->next;
}
while (stream) {
/* write the streams, if any */
psi_args.from = stream;
psi_args.len = sizeof_field(struct vidtv_psi_table_pmt_stream, type) +
sizeof_field(struct vidtv_psi_table_pmt_stream, bitfield) +
sizeof_field(struct vidtv_psi_table_pmt_stream, bitfield2);
psi_args.dest_offset = args.offset + nbytes;
nbytes += vidtv_psi_ts_psi_write_into(psi_args);
while (stream_descriptor) {
/* write the stream descriptors, if any */
d_args.dest_buf = args.buf;
d_args.dest_offset = args.offset + nbytes;
d_args.desc = stream_descriptor;
d_args.pid = args.pid;
d_args.continuity_counter = args.continuity_counter;
d_args.dest_buf_sz = args.buf_sz;
d_args.crc = &crc;
nbytes += vidtv_psi_desc_write_into(d_args);
stream_descriptor = stream_descriptor->next;
}
stream = stream->next;
}
c_args.dest_buf = args.buf;
c_args.dest_offset = args.offset + nbytes;
c_args.crc = cpu_to_be32(crc);
c_args.pid = args.pid;
c_args.continuity_counter = args.continuity_counter;
c_args.dest_buf_sz = args.buf_sz;
/* Write the CRC32 at the end */
nbytes += table_section_crc32_write_into(c_args);
return nbytes;
}
void vidtv_psi_pmt_table_destroy(struct vidtv_psi_table_pmt *pmt)
{
vidtv_psi_desc_destroy(pmt->descriptor);
vidtv_psi_pmt_stream_destroy(pmt->stream);
kfree(pmt);
}
struct vidtv_psi_table_sdt *vidtv_psi_sdt_table_init(u16 transport_stream_id)
{
struct vidtv_psi_table_sdt *sdt = kzalloc(sizeof(*sdt), GFP_KERNEL);
static u8 sdt_version;
const u16 SYNTAX = 0x1;
const u16 ONE = 0x1;
const u16 ONES = 0x03;
const u16 RESERVED = 0xff;
sdt->header.table_id = 0x42;
sdt->header.bitfield = cpu_to_be16((SYNTAX << 15) | (ONE << 14) | (ONES << 12));
/*
* This is a 16-bit field which serves as a label for identification
* of the TS, about which the SDT informs, from any other multiplex
* within the delivery system.
*/
sdt->header.id = cpu_to_be16(transport_stream_id);
sdt->header.current_next = ONE;
sdt->header.version = sdt_version;
sdt->header.one2 = ONES;
sdt->header.section_id = 0;
sdt->header.last_section = 0;
sdt->network_id = cpu_to_be16(transport_stream_id);
sdt->reserved = RESERVED;
vidtv_psi_sdt_table_update_sec_len(sdt);
return sdt;
}
u32 vidtv_psi_sdt_write_into(struct vidtv_psi_sdt_write_args args)
{
u32 nbytes = 0;
u16 sdt_pid = VIDTV_SDT_PID; /* see ETSI EN 300 468 v1.15.1 p. 11 */
u32 crc = 0xffffffff;
struct vidtv_psi_table_sdt_service *service = args.sdt->service;
struct vidtv_psi_desc *service_desc = (args.sdt->service) ?
args.sdt->service->descriptor :
NULL;
struct header_write_args h_args = {};
struct psi_write_args psi_args = {};
struct desc_write_args d_args = {};
struct crc32_write_args c_args = {};
vidtv_psi_sdt_table_update_sec_len(args.sdt);
h_args.dest_buf = args.buf;
h_args.dest_offset = args.offset;
h_args.h = &args.sdt->header;
h_args.pid = sdt_pid;
h_args.continuity_counter = args.continuity_counter;
h_args.dest_buf_sz = args.buf_sz;
h_args.crc = &crc;
nbytes += vidtv_psi_table_header_write_into(h_args);
psi_args.dest_buf = args.buf;
psi_args.from = &args.sdt->network_id;
psi_args.len = sizeof_field(struct vidtv_psi_table_sdt, network_id) +
sizeof_field(struct vidtv_psi_table_sdt, reserved);
psi_args.dest_offset = args.offset + nbytes;
psi_args.pid = sdt_pid;
psi_args.new_psi_section = false;
psi_args.continuity_counter = args.continuity_counter;
psi_args.is_crc = false;
psi_args.dest_buf_sz = args.buf_sz;
psi_args.crc = &crc;
/* copy u16 network_id + u8 reserved)*/
nbytes += vidtv_psi_ts_psi_write_into(psi_args);
while (service) {
/* copy the services, if any */
psi_args.from = service;
/* skip both pointers at the end */
psi_args.len = sizeof(struct vidtv_psi_table_sdt_service) -
sizeof(struct vidtv_psi_desc *) -
sizeof(struct vidtv_psi_table_sdt_service *);
psi_args.dest_offset = args.offset + nbytes;
nbytes += vidtv_psi_ts_psi_write_into(psi_args);
while (service_desc) {
/* copy the service descriptors, if any */
d_args.dest_buf = args.buf;
d_args.dest_offset = args.offset + nbytes;
d_args.desc = service_desc;
d_args.pid = sdt_pid;
d_args.continuity_counter = args.continuity_counter;
d_args.dest_buf_sz = args.buf_sz;
d_args.crc = &crc;
nbytes += vidtv_psi_desc_write_into(d_args);
service_desc = service_desc->next;
}
service = service->next;
}
c_args.dest_buf = args.buf;
c_args.dest_offset = args.offset + nbytes;
c_args.crc = cpu_to_be32(crc);
c_args.pid = sdt_pid;
c_args.continuity_counter = args.continuity_counter;
c_args.dest_buf_sz = args.buf_sz;
/* Write the CRC at the end */
nbytes += table_section_crc32_write_into(c_args);
return nbytes;
}
void vidtv_psi_sdt_table_destroy(struct vidtv_psi_table_sdt *sdt)
{
vidtv_psi_sdt_service_destroy(sdt->service);
kfree(sdt);
}
struct vidtv_psi_table_sdt_service
*vidtv_psi_sdt_service_init(struct vidtv_psi_table_sdt_service *head,
u16 service_id)
{
struct vidtv_psi_table_sdt_service *service;
service = kzalloc(sizeof(*service), GFP_KERNEL);
/*
* ETSI 300 468: this is a 16bit field which serves as a label to
* identify this service from any other service within the TS.
* The service id is the same as the program number in the
* corresponding program_map_section
*/
service->service_id = cpu_to_be16(service_id);
service->EIT_schedule = 0x0;
service->EIT_present_following = 0x0;
service->reserved = 0x3f;
service->bitfield = cpu_to_be16(RUNNING << 13);
if (head) {
while (head->next)
head = head->next;
head->next = service;
}
return service;
}
void
vidtv_psi_sdt_service_destroy(struct vidtv_psi_table_sdt_service *service)
{
struct vidtv_psi_table_sdt_service *curr = service;
struct vidtv_psi_table_sdt_service *tmp = NULL;
while (curr) {
tmp = curr;
curr = curr->next;
vidtv_psi_desc_destroy(tmp->descriptor);
kfree(tmp);
}
}
void
vidtv_psi_sdt_service_assign(struct vidtv_psi_table_sdt *sdt,
struct vidtv_psi_table_sdt_service *service)
{
if (service == sdt->service)
return;
sdt->service = service;
/* recompute section length */
vidtv_psi_sdt_table_update_sec_len(sdt);
if (vidtv_psi_get_sec_len(&sdt->header) > MAX_SECTION_LEN)
vidtv_psi_sdt_service_assign(sdt, NULL);
vidtv_psi_update_version_num(&sdt->header);
}
struct vidtv_psi_table_pmt**
vidtv_psi_pmt_create_sec_for_each_pat_entry(struct vidtv_psi_table_pat *pat, u16 pcr_pid)
{
/*
* PMTs contain information about programs. For each program,
* there is one PMT section. This function will create a section
* for each program found in the PAT
*/
struct vidtv_psi_table_pat_program *program = pat->program;
struct vidtv_psi_table_pmt **pmt_secs;
u32 i = 0;
/* a section for each program_id */
pmt_secs = kcalloc(pat->programs,
sizeof(struct vidtv_psi_table_pmt *),
GFP_KERNEL);
while (program) {
pmt_secs[i] = vidtv_psi_pmt_table_init(be16_to_cpu(program->service_id), pcr_pid);
++i;
program = program->next;
}
return pmt_secs;
}
struct vidtv_psi_table_pmt
*vidtv_psi_find_pmt_sec(struct vidtv_psi_table_pmt **pmt_sections,
u16 nsections,
u16 program_num)
{
/* find the PMT section associated with 'program_num' */
struct vidtv_psi_table_pmt *sec = NULL;
u32 i;
for (i = 0; i < nsections; ++i) {
sec = pmt_sections[i];
if (be16_to_cpu(sec->header.id) == program_num)
return sec;
}
return NULL; /* not found */
}
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