// 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 #include #include #include #include #include #include #include #include #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++; } static inline u16 vidtv_psi_sdt_serv_get_desc_loop_len(struct vidtv_psi_table_sdt_service *s) { u16 mask; u16 ret; mask = GENMASK(11, 0); 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; mask = GENMASK(9, 0); 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; mask = GENMASK(9, 0); 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; mask = GENMASK(11, 0); 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; mask = GENMASK(12, 0); 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; mask = GENMASK(12, 0); 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; mask = GENMASK(15, desc_len_nbits); 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; mask = GENMASK(15, 13); 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); 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 = 0x1f; 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); 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 = 0x1f; 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); 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 = 0x1f; sdt->header.one2 = ONES; sdt->header.section_id = 0; sdt->header.last_section = 0; /* * FIXME: The network_id range from 0xFF01 to 0xFFFF is used to * indicate temporary private use. For now, let's use the first * value. * This can be changed to something more useful, when support for * NIT gets added */ sdt->network_id = cpu_to_be16(0xff01); 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 */ }