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Diffstat (limited to 'lib/libucsi/descriptor.h')
-rw-r--r-- | lib/libucsi/descriptor.h | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/lib/libucsi/descriptor.h b/lib/libucsi/descriptor.h new file mode 100644 index 0000000..606e45d --- /dev/null +++ b/lib/libucsi/descriptor.h @@ -0,0 +1,129 @@ +/* + * section and descriptor parser + * + * Copyright (C) 2005 Kenneth Aafloy (kenneth@linuxtv.org) + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA + */ + +#ifndef _UCSI_DESCRIPTOR_H +#define _UCSI_DESCRIPTOR_H 1 + +#ifdef __cplusplus +extern "C" +{ +#endif + +#include <libucsi/endianops.h> +#include <stdint.h> +#include <stdlib.h> + +/** + * Generic descriptor header. + */ +struct descriptor { + uint8_t tag; + uint8_t len; +} __ucsi_packed; + +/** + * Retreive pointer to the next descriptor structure. + * + * @param buf The buffer of descriptors. + * @param len Size of the buffer. + * @param pos Current descriptor. + * @return Pointer to next descriptor, or NULL if there are none. + */ +static inline struct descriptor * + next_descriptor(uint8_t * buf, size_t len, struct descriptor * pos) +{ + uint8_t* next; + + if (pos == NULL) + return NULL; + + next = (uint8_t*) pos + 2 + pos->len; + if (next >= buf + len) + return NULL; + + return (struct descriptor *) next; +} + + +/** + * The unknown descriptor. + */ +struct unknown_descriptor { + struct descriptor d; + + /* uint8_t data [] */ +} __ucsi_packed; + +/** + * Retrieve pointer to the unknown descriptor's data field. + * + * @param d The descriptor. + * @return Pointer to the data field. + */ +static inline uint8_t * + unknown_descriptor_data(struct unknown_descriptor *d) +{ + return (uint8_t *) d + sizeof(struct unknown_descriptor); +} + +/** + * Retrieve size of unknown descriptor's data field. + * + * @param d The descriptor. + * @return Size of data field in bytes. + */ +static inline int + unknown_descriptor_data_size(struct unknown_descriptor *d) +{ + return d->d.len; +} + + + + + + + + + + +/******************************** PRIVATE CODE ********************************/ +static inline int verify_descriptors(uint8_t * buf, size_t len) +{ + size_t pos = 0; + + while (pos < len) { + if ((pos + 2) > len) + return -1; + + pos += 2 + buf[pos+1]; + } + + if (pos != len) + return -1; + + return 0; +} + +#ifdef __cplusplus +} +#endif + +#endif |