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130 lines
2.6 KiB
130 lines
2.6 KiB
/*
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* section and descriptor parser
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*
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* Copyright (C) 2005 Kenneth Aafloy (kenneth@linuxtv.org)
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
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*/
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#ifndef _UCSI_DESCRIPTOR_H
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#define _UCSI_DESCRIPTOR_H 1
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#ifdef __cplusplus
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extern "C"
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{
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#endif
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#include <libucsi/endianops.h>
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#include <stdint.h>
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#include <stdlib.h>
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/**
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* Generic descriptor header.
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*/
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struct descriptor {
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uint8_t tag;
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uint8_t len;
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} __ucsi_packed;
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/**
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* Retreive pointer to the next descriptor structure.
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*
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* @param buf The buffer of descriptors.
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* @param len Size of the buffer.
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* @param pos Current descriptor.
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* @return Pointer to next descriptor, or NULL if there are none.
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*/
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static inline struct descriptor *
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next_descriptor(uint8_t * buf, size_t len, struct descriptor * pos)
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{
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uint8_t* next;
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if (pos == NULL)
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return NULL;
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next = (uint8_t*) pos + 2 + pos->len;
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if (next >= buf + len)
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return NULL;
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return (struct descriptor *) next;
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}
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/**
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* The unknown descriptor.
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*/
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struct unknown_descriptor {
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struct descriptor d;
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/* uint8_t data [] */
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} __ucsi_packed;
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/**
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* Retrieve pointer to the unknown descriptor's data field.
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*
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* @param d The descriptor.
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* @return Pointer to the data field.
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*/
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static inline uint8_t *
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unknown_descriptor_data(struct unknown_descriptor *d)
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{
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return (uint8_t *) d + sizeof(struct unknown_descriptor);
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}
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/**
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* Retrieve size of unknown descriptor's data field.
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*
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* @param d The descriptor.
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* @return Size of data field in bytes.
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*/
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static inline int
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unknown_descriptor_data_size(struct unknown_descriptor *d)
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{
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return d->d.len;
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}
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/******************************** PRIVATE CODE ********************************/
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static inline int verify_descriptors(uint8_t * buf, size_t len)
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{
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size_t pos = 0;
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while (pos < len) {
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if ((pos + 2) > len)
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return -1;
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pos += 2 + buf[pos+1];
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}
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if (pos != len)
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return -1;
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return 0;
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}
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#ifdef __cplusplus
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}
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#endif
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#endif
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