X-Git-Url: https://git.stg.codes/stg.git/blobdiff_plain/8c6fa3fbaccc22127280bf77a48fab5a3ee0716e..46b0747592074017ff0ea4b33d4a7194235886e5:/libs/smux/include/stg/per_support.h diff --git a/libs/smux/include/stg/per_support.h b/libs/smux/include/stg/per_support.h new file mode 100644 index 00000000..420bb83c --- /dev/null +++ b/libs/smux/include/stg/per_support.h @@ -0,0 +1,105 @@ +/* + * Copyright (c) 2005, 2006 Lev Walkin . All rights reserved. + * Redistribution and modifications are permitted subject to BSD license. + */ +#ifndef _PER_SUPPORT_H_ +#define _PER_SUPPORT_H_ + +#include /* Platform-specific types */ + +#ifdef __cplusplus +extern "C" { +#endif + +/* + * Pre-computed PER constraints. + */ +typedef struct asn_per_constraint_s { + enum asn_per_constraint_flags { + APC_UNCONSTRAINED = 0x0, /* No PER visible constraints */ + APC_SEMI_CONSTRAINED = 0x1, /* Constrained at "lb" */ + APC_CONSTRAINED = 0x2, /* Fully constrained */ + APC_EXTENSIBLE = 0x4 /* May have extension */ + } flags; + int range_bits; /* Full number of bits in the range */ + int effective_bits; /* Effective bits */ + long lower_bound; /* "lb" value */ + long upper_bound; /* "ub" value */ +} asn_per_constraint_t; +typedef struct asn_per_constraints_s { + asn_per_constraint_t value; + asn_per_constraint_t size; +} asn_per_constraints_t; + +/* + * This structure describes a position inside an incoming PER bit stream. + */ +typedef struct asn_per_data_s { + const uint8_t *buffer; /* Pointer to the octet stream */ + size_t nboff; /* Bit offset to the meaningful bit */ + size_t nbits; /* Number of bits in the stream */ +} asn_per_data_t; + +/* + * Extract a small number of bits (<= 31) from the specified PER data pointer. + * This function returns -1 if the specified number of bits could not be + * extracted due to EOD or other conditions. + */ +int32_t per_get_few_bits(asn_per_data_t *per_data, int get_nbits); + +/* + * Extract a large number of bits from the specified PER data pointer. + * This function returns -1 if the specified number of bits could not be + * extracted due to EOD or other conditions. + */ +int per_get_many_bits(asn_per_data_t *pd, uint8_t *dst, int right_align, + int get_nbits); + +/* + * Get the length "n" from the Unaligned PER stream. + */ +ssize_t uper_get_length(asn_per_data_t *pd, + int effective_bound_bits, + int *repeat); + +/* + * Get the normally small non-negative whole number. + */ +ssize_t uper_get_nsnnwn(asn_per_data_t *pd); + +/* + * This structure supports forming PER output. + */ +typedef struct asn_per_outp_s { + uint8_t *buffer; /* Pointer into the (tmpspace) */ + size_t nboff; /* Bit offset to the meaningful bit */ + size_t nbits; /* Number of bits left in (tmpspace) */ + uint8_t tmpspace[32]; /* Preliminary storage to hold data */ + int (*outper)(const void *data, size_t size, void *op_key); + void *op_key; /* Key for (outper) data callback */ + size_t flushed_bytes; /* Bytes already flushed through (outper) */ +} asn_per_outp_t; + +/* Output a small number of bits (<= 31) */ +int per_put_few_bits(asn_per_outp_t *per_data, uint32_t bits, int obits); + +/* Output a large number of bits */ +int per_put_many_bits(asn_per_outp_t *po, const uint8_t *src, int put_nbits); + +/* + * Put the length "n" to the Unaligned PER stream. + * This function returns the number of units which may be flushed + * in the next units saving iteration. + */ +ssize_t uper_put_length(asn_per_outp_t *po, size_t whole_length); + +/* + * Put the normally small non-negative whole number. + */ +int uper_put_nsnnwn(asn_per_outp_t *po, int n); + +#ifdef __cplusplus +} +#endif + +#endif /* _PER_SUPPORT_H_ */