lkml.org 
[lkml]   [2020]   [Apr]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[RFC, WIP, v3 4/6] media: vidtv: implement a PSI generator
Date
From: "Daniel W. S. Almeida" <dwlsalmeida@gmail.com>

PSI packets contain general information about a MPEG Transport Stream.
A PSI generator is needed so userspace apps can retrieve information
about the Transport Stream and eventually tune into a (dummy) channel.

Because the generator is implemented in a separate file, it can be
reused elsewhere in the media subsystem.

Currently this commit adds support for working with 3 PSI tables:
PAT, PMT and SDT.

Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
---
drivers/media/test_drivers/vidtv/Makefile | 4 +-
.../media/test_drivers/vidtv/vidtv_common.c | 44 +
.../media/test_drivers/vidtv/vidtv_common.h | 71 ++
drivers/media/test_drivers/vidtv/vidtv_psi.c | 960 ++++++++++++++++++
drivers/media/test_drivers/vidtv/vidtv_psi.h | 294 ++++++
5 files changed, 1372 insertions(+), 1 deletion(-)
create mode 100644 drivers/media/test_drivers/vidtv/vidtv_common.c
create mode 100644 drivers/media/test_drivers/vidtv/vidtv_common.h
create mode 100644 drivers/media/test_drivers/vidtv/vidtv_psi.c
create mode 100644 drivers/media/test_drivers/vidtv/vidtv_psi.h

diff --git a/drivers/media/test_drivers/vidtv/Makefile b/drivers/media/test_drivers/vidtv/Makefile
index 36ba00ddc0d1e..690420a7c904b 100644
--- a/drivers/media/test_drivers/vidtv/Makefile
+++ b/drivers/media/test_drivers/vidtv/Makefile
@@ -1,3 +1,5 @@
# SPDX-License-Identifier: GPL-2.0

-obj-$(CONFIG_DVB_VIDTV) += vidtv_tuner.o vidtv_demod.o
+vidtv_demod-objs := vidtv_common.o vidtv_psi.o
+
+obj-$(CONFIG_DVB_VIDTV) += vidtv_tuner.o vidtv_demod.o
diff --git a/drivers/media/test_drivers/vidtv/vidtv_common.c b/drivers/media/test_drivers/vidtv/vidtv_common.c
new file mode 100644
index 0000000000000..62713284e14d9
--- /dev/null
+++ b/drivers/media/test_drivers/vidtv/vidtv_common.c
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * The Virtual DTV test driver serves as a reference DVB driver and helps
+ * validate the existing APIs in the media subsystem. It can also aid
+ * developers working on userspace applications.
+ *
+ * Written by Daniel W. S. Almeida <dwlsalmeida@gmail.com>
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/printk.h>
+
+u32 vidtv_memcpy(void *to,
+ const void *from,
+ size_t len,
+ u32 offset,
+ u32 buf_sz)
+{
+ if (buf_sz && offset + len > buf_sz) {
+ pr_err("%s: overflow detected, skipping. Try increasing the buffer size",
+ __func__);
+ return 0;
+ }
+
+ memcpy(to, from, len);
+ return len;
+}
+
+u32 vidtv_memset(void *to,
+ int c,
+ size_t len,
+ u32 offset,
+ u32 buf_sz)
+{
+ if (buf_sz && offset + len > buf_sz) {
+ pr_err("%s: overflow detected, skipping. Try increasing the buffer size",
+ __func__);
+ return 0;
+ }
+
+ memset(to, c, len);
+ return len;
+}
diff --git a/drivers/media/test_drivers/vidtv/vidtv_common.h b/drivers/media/test_drivers/vidtv/vidtv_common.h
new file mode 100644
index 0000000000000..43269833ee866
--- /dev/null
+++ b/drivers/media/test_drivers/vidtv/vidtv_common.h
@@ -0,0 +1,71 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * The Virtual DTV test driver serves as a reference DVB driver and helps
+ * validate the existing APIs in the media subsystem. It can also aid
+ * developers working on userspace applications.
+ *
+ * Written by Daniel W. S. Almeida <dwlsalmeida@gmail.com>
+ */
+
+#ifndef VIDTV_COMMON_H
+#define VIDTV_COMMON_H
+
+#include <linux/types.h>
+#include <media/dvb_frontend.h>
+
+#define CRC_SIZE_IN_BYTES 32
+#define TS_SYNC_BYTE 0x47
+#define TS_PACKET_LEN 188
+#define TS_PAYLOAD_LEN 184
+#define LAST_VALID_TS_PID 8191
+
+/* to be used by both PSI and ES */
+struct vidtv_mpeg_ts_adaption {
+ u8 length;
+ struct {
+ u8 extension:1;
+ u8 private_data:1;
+ u8 splicing_point:1;
+ u8 OPCR:1;
+ u8 PCR:1;
+ u8 priority:1;
+ u8 random_access:1;
+ u8 discontinued:1;
+ } __packed;
+ u8 data[];
+} __packed;
+
+/* to be used by both PSI and ES */
+struct vidtv_mpeg_ts {
+ u8 sync_byte;
+ union {
+ u16 bitfield;
+ struct {
+ u16 pid:13;
+ u16 priority:1;
+ u16 payload_start:1;
+ u16 tei:1;
+ } __packed;
+ } __packed;
+ struct {
+ u8 continuity_counter:4;
+ u8 payload:1;
+ u8 adaptation_field:1;
+ u8 scrambling:2;
+ } __packed;
+ struct vidtv_mpeg_ts_adaption adaption[];
+} __packed;
+
+u32 vidtv_memcpy(void *to,
+ const void *from,
+ size_t len,
+ u32 offset,
+ u32 buf_sz);
+
+u32 vidtv_memset(void *to,
+ int c,
+ size_t len,
+ u32 offset,
+ u32 buf_sz);
+
+#endif // VIDTV_COMMON_H
diff --git a/drivers/media/test_drivers/vidtv/vidtv_psi.c b/drivers/media/test_drivers/vidtv/vidtv_psi.c
new file mode 100644
index 0000000000000..70fc6289407a0
--- /dev/null
+++ b/drivers/media/test_drivers/vidtv/vidtv_psi.c
@@ -0,0 +1,960 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#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 "vidtv_common.h"
+#include "vidtv_psi.h"
+
+static u32 vidtv_psi_ts_psi_write_stuffing(void *to,
+ u32 len,
+ u32 offset,
+ u32 buf_sz)
+{
+ return vidtv_memset(to, 0xff, len, offset, buf_sz);
+}
+
+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 after the CRC
+ */
+
+ u32 nbytes_past_boundary = (args.offset % TS_PACKET_LEN);
+ bool aligned = nbytes_past_boundary == 0;
+ bool split = args.len > TS_PAYLOAD_LEN;
+ u32 payload_write_len = (split) ? TS_PAYLOAD_LEN : args.len;
+
+ struct psi_write_args new_args = {0};
+ struct vidtv_mpeg_ts ts_header = {0};
+
+ u32 nbytes = 0; /* number of bytes written by this function */
+ u32 temp;
+
+ if (args.new_psi_section && !aligned) {
+ /*
+ * must pad the buffer with the complement to get a
+ * multiple of 188
+ */
+ nbytes += vidtv_psi_ts_psi_write_stuffing(args.to +
+ args.offset +
+ nbytes,
+ TS_PACKET_LEN -
+ nbytes_past_boundary,
+ args.offset + nbytes,
+ args.buf_sz);
+
+ /*
+ * if we were not at a packet boundary, we are now after
+ * stuffing the buffer with 0xff
+ */
+ aligned = true;
+ }
+
+ if (aligned) {
+ /* if at a packet boundary, write a new TS header */
+ ts_header.sync_byte = TS_SYNC_BYTE;
+ ts_header.tei = 0;
+ ts_header.payload_start = 1;
+ ts_header.pid = args.pid;
+ ts_header.priority = 0;
+ ts_header.scrambling = 0; /* not scrambled */
+ ts_header.continuity_counter = *args.continuity_counter;
+ ts_header.payload_start = 0; /* no adaption for now */
+
+ /* copy the header minus the adaption pointer*/
+ nbytes += vidtv_memcpy(args.to + args.offset + nbytes,
+ &ts_header,
+ sizeof(ts_header),
+ args.offset + nbytes,
+ args.buf_sz);
+ }
+
+ if (args.new_psi_section) {
+ /* write the pointer_field in the first byte of the payload */
+ temp = vidtv_memset(args.to + args.offset + nbytes,
+ 0x0,
+ 1,
+ args.offset + nbytes,
+ args.buf_sz);
+ /* one byte was used by the pointer field*/
+ nbytes += temp;
+ payload_write_len -= temp;
+ }
+
+ /* write as much of the payload as we possibly can */
+ nbytes += vidtv_memcpy(args.to + args.offset + nbytes,
+ args.from,
+ payload_write_len,
+ args.offset + nbytes,
+ args.buf_sz);
+
+ if (split) {
+ /*
+ * next TS packet keeps the same PID, but increments the
+ * counter
+ */
+ ++(*args.continuity_counter);
+ /* 'nbytes' written from a total of 'len' requested*/
+ args.len -= nbytes;
+ /*
+ * recursively write the rest of the data until we do not
+ * need to split it anymore
+ */
+ memcpy(&new_args, &args, sizeof(struct psi_write_args));
+ new_args.from = args.from + nbytes;
+ new_args.offset = args.offset + nbytes;
+ new_args.new_psi_section = false;
+
+ nbytes += vidtv_psi_ts_psi_write_into(new_args);
+ }
+
+ /*
+ * as the CRC is last in the section, stuff the rest of the
+ * packet if there is any remaining space in there
+ */
+ if (args.is_crc)
+ nbytes += vidtv_psi_ts_psi_write_stuffing(args.to + nbytes,
+ TS_PAYLOAD_LEN -
+ nbytes,
+ args.offset + nbytes,
+ args.buf_sz);
+
+ 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;
+ u32 crc;
+ struct psi_write_args psi_args = {0};
+
+ crc = crc32(0, args.to, args.offset);
+
+ psi_args.to = args.to;
+ psi_args.from = &crc;
+ psi_args.len = CRC_SIZE_IN_BYTES;
+ psi_args.offset = args.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.buf_sz = args.buf_sz;
+
+ nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+
+ return nbytes;
+}
+
+struct vidtv_psi_desc *vidtv_psi_desc_init(struct vidtv_psi_desc *head,
+ u8 type,
+ u8 length)
+{
+ struct vidtv_psi_desc *desc;
+
+ /* alloc enough memory for the flexible array too */
+ desc = kzalloc(sizeof(*desc) + length, GFP_KERNEL);
+
+ desc->type = type;
+ desc->length = length;
+
+ if (head) {
+ while (head->next)
+ head = head->next;
+
+ head->next = desc;
+ }
+
+ return desc;
+}
+
+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;
+ kfree(tmp);
+ }
+}
+
+static u32
+vidtv_psi_desc_comp_len(struct vidtv_psi_desc *desc)
+{
+ u32 length = 0;
+
+ if (!desc)
+ return 0;
+
+ while (desc) {
+ length += desc->length;
+ desc = desc->next;
+ }
+
+ return length;
+}
+
+void vidtv_psi_desc_assign(struct vidtv_psi_desc **to,
+ struct vidtv_psi_desc *desc,
+ u16 *desc_length)
+{
+ /*
+ * This function transfers ownedship of desc.
+ * Start by cleaning the old data
+ */
+ if (*to)
+ vidtv_psi_desc_destroy(*to);
+
+ *desc_length = vidtv_psi_desc_comp_len(desc);
+ *to = desc; /* reassign pointer */
+}
+
+static u32 vidtv_psi_desc_write_into(struct desc_write_args args)
+{
+ u32 nbytes = 0; /* the number of bytes written by this function */
+ struct psi_write_args psi_args = {0};
+
+ psi_args.to = args.to;
+ psi_args.from = args.desc;
+ psi_args.len = sizeof_field(struct vidtv_psi_desc, type) +
+ sizeof_field(struct vidtv_psi_desc, length);
+ psi_args.offset = args.offset;
+ 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.buf_sz = args.buf_sz;
+
+ nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+
+ /* move 'from' pointer to point to u8 data[] */
+ psi_args.from = args.desc + nbytes + sizeof(struct vidtv_psi_desc *);
+ psi_args.len = args.desc->length;
+ psi_args.offset = args.offset + nbytes;
+
+ nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+
+ 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 = {0};
+
+ psi_args.to = args.to;
+ psi_args.from = args.h;
+ psi_args.len = sizeof(struct vidtv_psi_table_header);
+ psi_args.offset = args.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.buf_sz = args.buf_sz;
+
+ nbytes += vidtv_psi_ts_psi_write_into(psi_args);
+
+ return nbytes;
+}
+
+static u16
+vidtv_psi_pat_table_comp_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;
+
+ WARN_ON(length > PAT_MAX_SECTION_LEN);
+ return length;
+}
+
+static u16
+vidtv_psi_pmt_table_comp_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;
+
+ /* from immediately after 'section_length' until 'program_info_length'*/
+ length += PMT_LEN_UNTIL_PROGRAM_INFO_LENGTH;
+
+ /* do not fail if 'desc_length' has not been computed yet */
+ length += vidtv_psi_desc_comp_len(pmt->descriptor);
+ length += pmt->desc_length;
+
+ 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 *);
+
+ length += vidtv_psi_desc_comp_len(s->descriptor);
+ s = s->next;
+ }
+
+ length += CRC_SIZE_IN_BYTES;
+
+ WARN_ON(length > PMT_MAX_SECTION_LEN);
+ return length;
+}
+
+static u16
+vidtv_psi_sdt_table_comp_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;
+
+ /*
+ * 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_pmt_stream) -
+ sizeof(struct vidtv_psi_desc *) -
+ sizeof(struct vidtv_psi_table_pmt_stream *);
+ /* do not fail if 'desc_length' has not been computed yet */
+ length += vidtv_psi_desc_comp_len(s->descriptor);
+
+ s = s->next;
+ }
+
+ length += CRC_SIZE_IN_BYTES;
+
+ WARN_ON(length > SDT_MAX_SECTION_LEN);
+ return length;
+}
+
+struct vidtv_psi_table_pat_program*
+vidtv_psi_pat_program_init(struct vidtv_psi_table_pat_program *head,
+ u16 service_id,
+ u16 pid)
+{
+ struct vidtv_psi_table_pat_program *program;
+
+ program = kzalloc(sizeof(*program), GFP_KERNEL);
+
+ program->service_id = service_id;
+ program->pid = pid; /* pid for the PMT section in the TS */
+ program->next = NULL;
+ program->reserved = 0x7;
+
+ 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;
+ struct vidtv_psi_table_pat_program *temp = pat->program;
+
+ while (program) {
+ ++program_count;
+ program = program->next;
+ }
+
+ pat->programs = program_count;
+ pat->program = p;
+
+ /* Recompute section length */
+ pat->header.section_length = vidtv_psi_pat_table_comp_sec_len(pat);
+
+ /* do not break userspace: reassign if the new size is too big */
+ if (pat->header.section_length > PAT_MAX_SECTION_LEN)
+ vidtv_psi_pat_program_assign(pat, temp);
+ else
+ vidtv_psi_pat_program_destroy(temp);
+}
+
+void vidtv_psi_pat_table_init(struct vidtv_psi_table_pat *pat,
+ bool update_version_num,
+ u16 transport_stream_id)
+{
+ static u8 pat_version;
+
+ pat->header.table_id = 0x0;
+ pat->header.syntax = 0x1;
+ pat->header.zero = 0x0;
+ pat->header.one = 0x03;
+
+ pat->header.id = transport_stream_id; /* transport stream ID, at will */
+ pat->header.current_next = 0x1;
+
+ /* ETSI 300 468: indicates changes in the TS described by this table*/
+ if (update_version_num)
+ ++pat_version;
+
+ pat->header.version = pat_version;
+
+ pat->header.one2 = 0x03;
+ pat->header.section_id = 0x0;
+ pat->header.last_section = 0x0;
+
+ pat->programs = 0;
+
+ pat->header.section_length = vidtv_psi_pat_table_comp_sec_len(pat);
+}
+
+u32 vidtv_psi_pat_write_into(char *buf,
+ u32 offset,
+ struct vidtv_psi_table_pat *pat,
+ u32 buf_sz)
+{
+ u32 nbytes = 0; /* the number of bytes written by this function */
+ u8 continuity_counter = 0;
+ const u16 pat_pid = pat->header.table_id; /* always 0x0 */
+
+ struct vidtv_psi_table_pat_program *p = pat->program;
+ struct header_write_args h_args = {0};
+ struct psi_write_args args = {0};
+ struct crc32_write_args c_args = {0};
+
+ h_args.to = buf;
+ h_args.offset = offset;
+ h_args.h = &pat->header;
+ h_args.pid = pat_pid;
+ h_args.continuity_counter = &continuity_counter;
+ h_args.buf_sz = buf_sz;
+
+ nbytes += vidtv_psi_table_header_write_into(h_args);
+
+ args.to = buf;
+ args.from = pat + sizeof(struct vidtv_psi_table_header),
+ args.len = sizeof(pat->programs);
+ args.offset = offset + nbytes;
+ args.pid = pat_pid;
+ args.new_psi_section = false;
+ args.continuity_counter = &continuity_counter;
+ args.is_crc = false;
+ args.buf_sz = buf_sz;
+
+ nbytes += vidtv_psi_ts_psi_write_into(args);
+
+ while (p) {
+ args.from = p;
+ /* skip the pointer */
+ args. len = sizeof(*p) -
+ sizeof(struct vidtv_psi_table_pat_program *);
+ args.offset = offset + nbytes;
+
+ nbytes += vidtv_psi_ts_psi_write_into(args);
+ p = p->next;
+ }
+
+ c_args.to = buf;
+ c_args.offset = offset + nbytes;
+ c_args.pid = pat_pid;
+ c_args.continuity_counter = &continuity_counter;
+ c_args.buf_sz = buf_sz;
+
+ 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);
+}
+
+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;
+
+ stream = kzalloc(sizeof(*stream), GFP_KERNEL);
+
+ stream->type = stream_type;
+ stream->elementary_pid = es_pid;
+ stream->reserved = 0x07;
+
+ stream->desc_length = vidtv_psi_desc_comp_len(stream->descriptor);
+
+ stream->zero = 0x0;
+ stream->reserved2 = 0x0f;
+
+ 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;
+ 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 */
+ struct vidtv_psi_table_pmt_stream *stream = s;
+ struct vidtv_psi_desc *desc = s->descriptor;
+ struct vidtv_psi_table_pmt_stream *temp = pmt->stream;
+
+ while (stream)
+ stream = stream->next;
+
+ while (desc)
+ desc = desc->next;
+
+ pmt->stream = s;
+ /* Recompute section length */
+ pmt->header.section_length = vidtv_psi_pmt_table_comp_sec_len(pmt);
+
+ /* do not break userspace: reassign if the new size is too big */
+ if (pmt->header.section_length > PMT_MAX_SECTION_LEN)
+ vidtv_psi_pmt_stream_assign(pmt, temp);
+ else
+ vidtv_psi_pmt_stream_destroy(temp);
+}
+
+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 pat->program->pid;
+
+ return LAST_VALID_TS_PID + 1; /* not found */
+}
+
+void vidtv_psi_pmt_table_init(struct vidtv_psi_table_pmt *pmt,
+ bool update_version_num,
+ u16 program_number,
+ u16 pcr_pid)
+{
+ static u8 pmt_version;
+
+ pmt->header.table_id = 0x2;
+ pmt->header.syntax = 0x1;
+ pmt->header.zero = 0x0;
+ pmt->header.one = 0x3;
+
+ pmt->header.id = program_number;
+ pmt->header.current_next = 0x1;
+
+ /* ETSI 300 468: indicates changes in the TS described by this table*/
+ if (update_version_num)
+ ++pmt_version;
+
+ pmt->header.version = pmt_version;
+
+ pmt->header.one2 = 0x3;
+ pmt->header.section_id = 0;
+ pmt->header.last_section = 0;
+
+ pmt->pcr_pid = (pcr_pid) ? pcr_pid : 0x1fff;
+ pmt->reserved2 = 0x03;
+
+ pmt->reserved3 = 0x0f;
+ pmt->zero3 = 0x0;
+
+ pmt->desc_length = vidtv_psi_desc_comp_len(pmt->descriptor);
+
+ pmt->header.section_length = vidtv_psi_pmt_table_comp_sec_len(pmt);
+}
+
+u32 vidtv_psi_pmt_write_into(char *buf,
+ u32 offset,
+ struct vidtv_psi_table_pmt *pmt,
+ u16 pid,
+ u32 buf_sz)
+{
+ u32 nbytes = 0; /* the number of bytes written by this function */
+ u8 continuity_counter = 0;
+ struct vidtv_psi_desc *table_descriptor = pmt->descriptor;
+ struct vidtv_psi_table_pmt_stream *stream = pmt->stream;
+ struct vidtv_psi_desc *stream_descriptor = (stream) ?
+ pmt->stream->descriptor :
+ NULL;
+
+ struct header_write_args h_args = {0};
+ struct psi_write_args args = {0};
+ struct desc_write_args d_args = {0};
+ struct crc32_write_args c_args = {0};
+
+ h_args.to = buf;
+ h_args.offset = offset;
+ h_args.h = &pmt->header;
+ h_args.pid = pid;
+ h_args.continuity_counter = &continuity_counter;
+ h_args.buf_sz = buf_sz;
+
+ nbytes += vidtv_psi_table_header_write_into(h_args);
+
+ args.to = buf;
+ args.from = pmt + sizeof(struct vidtv_psi_table_header);
+ args.len = sizeof_field(struct vidtv_psi_table_pmt, bitfield) +
+ sizeof_field(struct vidtv_psi_table_pmt, bitfield2);
+ args.offset = offset + nbytes;
+ args.pid = pid;
+ args.new_psi_section = false;
+ args.continuity_counter = &continuity_counter;
+ args.is_crc = false;
+ args.buf_sz = buf_sz;
+
+ nbytes += vidtv_psi_ts_psi_write_into(args);
+
+ while (table_descriptor) {
+ d_args.to = buf;
+ d_args.offset = offset + nbytes;
+ d_args.desc = table_descriptor;
+ d_args.pid = pid;
+ d_args.continuity_counter = &continuity_counter;
+ d_args.buf_sz = buf_sz;
+
+ nbytes += vidtv_psi_desc_write_into(d_args);
+
+ table_descriptor = table_descriptor->next;
+ }
+
+ while (stream) {
+ args.from = stream;
+ 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);
+ args.offset = offset + nbytes;
+
+ nbytes += vidtv_psi_ts_psi_write_into(args);
+
+ while (stream_descriptor) {
+ d_args.desc = stream_descriptor;
+ d_args.offset = offset + nbytes;
+ nbytes += vidtv_psi_desc_write_into(d_args);
+
+ stream_descriptor = stream_descriptor->next;
+ }
+
+ stream = stream->next;
+ }
+
+ c_args.to = buf;
+ c_args.offset = offset + nbytes;
+ c_args.pid = pid;
+ c_args.continuity_counter = &continuity_counter;
+ c_args.buf_sz = buf_sz;
+
+ nbytes += table_section_crc32_write_into(c_args);
+
+ return nbytes;
+}
+
+void vidtv_psi_pmt_table_destroy(struct vidtv_psi_table_pmt *pmt)
+{
+ struct vidtv_psi_desc *curr_desc = pmt->descriptor;
+ struct vidtv_psi_desc *tmp_desc = NULL;
+
+ while (curr_desc) {
+ tmp_desc = curr_desc;
+ curr_desc = curr_desc->next;
+ vidtv_psi_desc_destroy(tmp_desc);
+ kfree(tmp_desc);
+ }
+
+ vidtv_psi_pmt_stream_destroy(pmt->stream);
+}
+
+void vidtv_psi_sdt_table_init(struct vidtv_psi_table_sdt *sdt,
+ bool update_version_num,
+ u16 transport_stream_id)
+{
+ static u8 sdt_version;
+
+ sdt->header.table_id = 0x42;
+
+ sdt->header.one = 0x3;
+ sdt->header.zero = 0x1;
+ /*
+ * The PAT, PMT, and CAT all set this to 0.
+ * Other tables set this to 1.
+ */
+ sdt->header.syntax = 0x1;
+
+ /*
+ * 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 = transport_stream_id;
+ sdt->header.current_next = 0x1;
+
+ /* ETSI 300 468: indicates changes in the TS described by this table*/
+ if (update_version_num)
+ ++sdt_version;
+
+ sdt->header.version = sdt_version;
+
+ sdt->header.one2 = 0x3;
+ sdt->header.section_id = 0;
+ sdt->header.last_section = 0;
+
+ sdt->network_id = transport_stream_id;
+ sdt->reserved = 0xff;
+
+ sdt->header.section_length = vidtv_psi_sdt_table_comp_sec_len(sdt);
+}
+
+u32 vidtv_psi_sdt_write_into(char *buf,
+ u32 offset,
+ struct vidtv_psi_table_sdt *sdt,
+ u32 buf_sz)
+{
+ u32 nbytes = 0; /* the number of bytes written */
+ u16 sdt_pid = 0x11; /* see ETSI EN 300 468 v1.15.1 p. 11 */
+ u8 continuity_counter = 0;
+
+ struct vidtv_psi_table_sdt_service *service = sdt->service;
+ struct vidtv_psi_desc *service_desc = (sdt->service) ?
+ sdt->service->descriptor :
+ NULL;
+
+ struct header_write_args h_args = {0};
+ struct psi_write_args args = {0};
+ struct desc_write_args d_args = {0};
+ struct crc32_write_args c_args = {0};
+
+ h_args.to = buf;
+ h_args.offset = offset;
+ h_args.h = &sdt->header;
+ h_args.pid = sdt_pid;
+ h_args.continuity_counter = &continuity_counter;
+ h_args.buf_sz = buf_sz;
+
+ nbytes += vidtv_psi_table_header_write_into(h_args);
+
+ args.to = buf;
+ args.from = sdt + sizeof(struct vidtv_psi_table_header);
+ args.len = sizeof_field(struct vidtv_psi_table_sdt, network_id) +
+ sizeof_field(struct vidtv_psi_table_sdt, reserved);
+ args.offset = offset + nbytes;
+ args.pid = sdt_pid;
+ args.new_psi_section = false;
+ args.continuity_counter = &continuity_counter;
+ args.is_crc = false;
+ args.buf_sz = buf_sz;
+
+ /* copy u16 network_id + u8 reserved)*/
+ nbytes += vidtv_psi_ts_psi_write_into(args);
+
+ while (service) {
+ args.from = service;
+ /* skip both pointers at the end */
+ args.len = sizeof(struct vidtv_psi_table_sdt_service) -
+ sizeof(struct vidtv_psi_desc *) -
+ sizeof(struct vidtv_psi_table_sdt_service *);
+ args.offset = offset + nbytes;
+
+ nbytes += vidtv_psi_ts_psi_write_into(args);
+
+ while (service_desc) {
+ d_args.to = buf;
+ d_args.offset = offset + nbytes;
+ d_args.desc = service_desc;
+ d_args.pid = sdt_pid;
+ d_args.continuity_counter = &continuity_counter;
+ d_args.buf_sz = buf_sz;
+
+ nbytes += vidtv_psi_desc_write_into(d_args);
+
+ service_desc = service_desc->next;
+ }
+
+ service = service->next;
+ }
+
+ c_args.to = buf;
+ c_args.offset = offset + nbytes;
+ c_args.pid = sdt_pid;
+ c_args.continuity_counter = &continuity_counter;
+ c_args.buf_sz = buf_sz;
+
+ nbytes += table_section_crc32_write_into(c_args);
+
+ return nbytes;
+}
+
+void vidtv_psi_sdt_table_destroy(struct vidtv_psi_table_sdt *sdt)
+{
+ struct vidtv_psi_table_sdt_service *curr_service = sdt->service;
+ struct vidtv_psi_table_sdt_service *tmp_service = NULL;
+ struct vidtv_psi_desc *curr_desc = (sdt->service) ?
+ sdt->service->descriptor : NULL;
+ struct vidtv_psi_desc *tmp_desc = NULL;
+
+ while (curr_service) {
+ curr_desc = curr_service->descriptor;
+
+ while (curr_desc) {
+ /* clear all descriptors for the service */
+ tmp_desc = curr_desc;
+ curr_desc = curr_desc->next;
+ vidtv_psi_desc_destroy(tmp_desc);
+ kfree(tmp_desc);
+ }
+
+ /* then clear the current service */
+ tmp_service = curr_service;
+ curr_service = curr_service->next;
+ kfree(tmp_service);
+ }
+}
+
+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 = service_id;
+ service->EIT_schedule = 0x0; /* TODO */
+ service->EIT_present_following = 0x0; /* TODO */
+ service->reserved = 0x3f; /* all bits on */
+ service->free_CA_mode = 0x0; /* not scrambled */
+ service->running_status = RUNNING;
+
+ 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;
+ kfree(tmp);
+ }
+}
+
+void
+vidtv_psi_sdt_service_assign(struct vidtv_psi_table_sdt *sdt,
+ struct vidtv_psi_table_sdt_service *service)
+{
+ struct vidtv_psi_table_sdt_service *temp = sdt->service;
+
+ sdt->service = service;
+
+ sdt->header.section_length = vidtv_psi_sdt_table_comp_sec_len(sdt);
+
+ /* do not break userspace: reassign if the new size is too big */
+ if (sdt->header.section_length > SDT_MAX_SECTION_LEN)
+ vidtv_psi_sdt_service_assign(sdt, temp);
+ else
+ vidtv_psi_sdt_service_destroy(temp);
+}
+
+void
+vidtv_psi_pmt_create_sec_for_each_pat_entry(struct vidtv_psi_table_pat *pat,
+ struct vidtv_psi_table_pmt *sec)
+
+{
+ /*
+ * PMTs contain information about programs. For each program,
+ * there is one PMT
+ */
+ struct vidtv_psi_table_pat_program *program = pat->program;
+ u32 i = 0;
+
+ while (program) {
+ vidtv_psi_pmt_table_init(&sec[i],
+ false,
+ sec[i].header.id,
+ 0);
+
+ ++i;
+ program = program->next;
+ }
+}
diff --git a/drivers/media/test_drivers/vidtv/vidtv_psi.h b/drivers/media/test_drivers/vidtv/vidtv_psi.h
new file mode 100644
index 0000000000000..0336934b3aba2
--- /dev/null
+++ b/drivers/media/test_drivers/vidtv/vidtv_psi.h
@@ -0,0 +1,294 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef VIDTV_PSI_H
+#define VIDTV_PSI_H
+
+#include <linux/types.h>
+
+/*
+ * all section lengths start immediately after the 'section_length' field
+ * see ISO/IEC 13818-1 : 2000 and ETSI EN 300 468 V 1.10.1 for
+ * reference
+ */
+#define PAT_LEN_UNTIL_LAST_SECTION_NUMBER 5
+#define PAT_MAX_SECTION_LEN 1021
+#define PMT_LEN_UNTIL_PROGRAM_INFO_LENGTH 9
+#define PMT_MAX_SECTION_LEN 1021
+#define SDT_LEN_UNTIL_RESERVED_FOR_FUTURE_USE 8
+#define SDT_MAX_SECTION_LEN 1021
+
+enum vidtv_psi_descriptors {
+ SERVICE_DESCRIPTOR = 0x48,
+};
+
+enum vidtv_psi_stream_types {
+ ISO_IEC_13818_3_AUDIO = 0x4,
+};
+
+struct vidtv_psi_desc {
+ u8 type;
+ u8 length;
+ struct vidtv_psi_desc *next;
+ u8 data[];
+} __packed;
+
+struct vidtv_psi_desc_service {
+ u8 type;
+ u8 length;
+ struct dvb_desc *next;
+
+ u8 service_type;
+ char *name;
+ char *name_emph;
+ char *provider;
+ char *provider_emph;
+} __packed;
+
+struct vidtv_psi_table_header {
+ u8 table_id;
+ union {
+ u16 bitfield;
+ struct {
+ u16 section_length:12;
+ u8 one:2;
+ u8 zero:1;
+ u8 syntax:1;
+ } __packed;
+ } __packed;
+ u16 id; /* TS ID */
+ u8 current_next:1;
+ u8 version:5;
+ u8 one2:2;
+
+ u8 section_id; /* section_number */
+ u8 last_section; /* last_section_number */
+} __packed;
+
+struct vidtv_psi_table_pat_program {
+ u16 service_id;
+ union {
+ u16 bitfield;
+ struct {
+ u16 pid:13;
+ u8 reserved:3;
+ } __packed;
+ } __packed;
+ struct vidtv_psi_table_pat_program *next;
+} __packed;
+
+struct vidtv_psi_table_pat {
+ struct vidtv_psi_table_header header;
+ u16 programs;
+ struct vidtv_psi_table_pat_program *program;
+} __packed;
+
+struct vidtv_psi_table_sdt_service {
+ u16 service_id;
+ u8 EIT_present_following:1;
+ u8 EIT_schedule:1;
+ u8 reserved:6;
+ union {
+ u16 bitfield;
+ struct {
+ u16 desc_length:12;
+ u16 free_CA_mode:1;
+ u16 running_status:3;
+ } __packed;
+ } __packed;
+ struct vidtv_psi_desc *descriptor;
+ struct vidtv_psi_table_sdt_service *next;
+} __packed;
+
+struct vidtv_psi_table_sdt {
+ struct vidtv_psi_table_header header;
+ u16 network_id;
+ u8 reserved;
+ struct vidtv_psi_table_sdt_service *service;
+} __packed;
+
+enum service_running_status {
+ RUNNING,
+};
+
+enum service_type {
+ /* see ETSI EN 300 468 v1.15.1 p. 77 */
+ DIGITAL_TELEVISION_SERVICE = 0x1,
+};
+
+struct vidtv_psi_table_pmt_stream {
+ u8 type;
+ union {
+ u16 bitfield;
+ struct {
+ u16 elementary_pid:13;
+ u16 reserved:3;
+ } __packed;
+ } __packed;
+ union {
+ u16 bitfield2;
+ struct {
+ u16 desc_length:10;
+ u16 zero:2;
+ u16 reserved2:4;
+ } __packed;
+ } __packed;
+ struct vidtv_psi_desc *descriptor;
+ struct vidtv_psi_table_pmt_stream *next;
+} __packed;
+
+struct vidtv_psi_table_pmt {
+ struct vidtv_psi_table_header header;
+ union {
+ u16 bitfield;
+ struct {
+ u16 pcr_pid:13;
+ u16 reserved2:3;
+ } __packed;
+ } __packed;
+
+ union {
+ u16 bitfield2;
+ struct {
+ u16 desc_length:10;
+ u16 zero3:2;
+ u16 reserved3:4;
+ } __packed;
+ } __packed;
+ struct vidtv_psi_desc *descriptor;
+ struct vidtv_psi_table_pmt_stream *stream;
+} __packed;
+
+struct psi_write_args {
+ void *to;
+ void *from;
+ size_t len; /* how much to write */
+ u32 offset; /* where to start writing in the buffer */
+ u16 pid; /* TS packet ID */
+ bool new_psi_section; /* set when starting a table section */
+ u8 *continuity_counter; /* TS: incremented when section gets split */
+ bool is_crc; /* set when writing the CRC at the end */
+ u32 buf_sz; /* protect against overflow when this field is not zero */
+};
+
+struct desc_write_args {
+ void *to;
+ u32 offset;
+ struct vidtv_psi_desc *desc;
+ u16 pid;
+ u8 *continuity_counter;
+ u32 buf_sz; /* protect against overflow when this field is not zero */
+};
+
+struct crc32_write_args {
+ void *to;
+ u32 offset;
+ u16 pid;
+ u8 *continuity_counter;
+ u32 buf_sz; /* protect against overflow when this field is not zero */
+};
+
+struct header_write_args {
+ void *to;
+ u32 offset;
+ struct vidtv_psi_table_header *h;
+ u16 pid;
+ u8 *continuity_counter;
+ u32 buf_sz; /* protect against overflow when this field is not zero */
+};
+
+struct vidtv_psi_desc *vidtv_psi_desc_init(struct vidtv_psi_desc *head,
+ u8 type,
+ u8 length);
+
+void vidtv_psi_pat_table_init(struct vidtv_psi_table_pat *pat,
+ bool update_version_num,
+ u16 transport_stream_id);
+
+struct vidtv_psi_table_pat_program*
+vidtv_psi_pat_program_init(struct vidtv_psi_table_pat_program *head,
+ u16 service_id,
+ u16 pid);
+
+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);
+
+void vidtv_psi_pmt_table_init(struct vidtv_psi_table_pmt *pmt,
+ bool update_version_num,
+ u16 program_number,
+ u16 pcr_pid);
+
+void
+vidtv_psi_sdt_table_init(struct vidtv_psi_table_sdt *sdt,
+ bool update_version_num,
+ u16 transport_stream_id);
+
+struct vidtv_psi_table_sdt_service*
+vidtv_psi_sdt_service_init(struct vidtv_psi_table_sdt_service *head,
+ u16 service_id);
+
+void
+vidtv_psi_desc_destroy(struct vidtv_psi_desc *desc);
+
+void
+vidtv_psi_pat_program_destroy(struct vidtv_psi_table_pat_program *p);
+
+void
+vidtv_psi_pat_table_destroy(struct vidtv_psi_table_pat *p);
+
+void
+vidtv_psi_pmt_stream_destroy(struct vidtv_psi_table_pmt_stream *s);
+
+void
+vidtv_psi_pmt_table_destroy(struct vidtv_psi_table_pmt *pmt);
+
+void
+vidtv_psi_sdt_table_destroy(struct vidtv_psi_table_sdt *sdt);
+
+void
+vidtv_psi_sdt_service_destroy(struct vidtv_psi_table_sdt_service *service);
+
+void
+vidtv_psi_desc_destroy(struct vidtv_psi_desc *desc);
+
+void
+vidtv_psi_pat_program_destroy(struct vidtv_psi_table_pat_program *p);
+
+void
+vidtv_psi_sdt_service_assign(struct vidtv_psi_table_sdt *sdt,
+ struct vidtv_psi_table_sdt_service *service);
+
+void vidtv_psi_desc_assign(struct vidtv_psi_desc **to,
+ struct vidtv_psi_desc *desc,
+ u16 *desc_length);
+
+void vidtv_psi_pat_program_assign(struct vidtv_psi_table_pat *pat,
+ struct vidtv_psi_table_pat_program *p);
+
+void vidtv_psi_pmt_stream_assign(struct vidtv_psi_table_pmt *pmt,
+ struct vidtv_psi_table_pmt_stream *s);
+void
+vidtv_psi_pmt_create_sec_for_each_pat_entry(struct vidtv_psi_table_pat *pat,
+ struct vidtv_psi_table_pmt *sec);
+
+u16 vidtv_psi_pmt_get_pid(struct vidtv_psi_table_pmt *section,
+ struct vidtv_psi_table_pat *pat);
+
+u32 vidtv_psi_pat_write_into(char *buf,
+ u32 offset,
+ struct vidtv_psi_table_pat *pat,
+ u32 buf_sz);
+
+u32 vidtv_psi_sdt_write_into(char *buf,
+ u32 offset,
+ struct vidtv_psi_table_sdt *sdt,
+ u32 buf_sz);
+
+u32 vidtv_psi_pmt_write_into(char *buf,
+ u32 offset,
+ struct vidtv_psi_table_pmt *pmt,
+ u16 pid,
+ u32 buf_sz);
+
+#endif // VIDTV_PSI_H
--
2.26.0
\
 
 \ /
  Last update: 2020-04-07 01:22    [W:0.415 / U:0.068 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site