asn1/per_support.h

   1 /*
   2  * Copyright (c) 2005, 2006, 2007 Lev Walkin <vlm@lionet.info>.
   3  * All rights reserved.
   4  * Redistribution and modifications are permitted subject to BSD license.
   5  */
   6 #ifndef _PER_SUPPORT_H_
   7 #define _PER_SUPPORT_H_
   8
   9 #include <asn_system.h>         /* Platform-specific types */
  10
  11 #ifdef __cplusplus
  12 extern "C" {
  13 #endif
  14
  15 /*
  16  * Pre-computed PER constraints.
  17  */
  18 typedef struct asn_per_constraint_s {
  19         enum asn_per_constraint_flags {
  20                 APC_UNCONSTRAINED       = 0x0,  /* No PER visible constraints */
  21                 APC_SEMI_CONSTRAINED    = 0x1,  /* Constrained at "lb" */
  22                 APC_CONSTRAINED         = 0x2,  /* Fully constrained */
  23                 APC_EXTENSIBLE          = 0x4   /* May have extension */
  24         } flags;
  25         int  range_bits;                /* Full number of bits in the range */
  26         int  effective_bits;            /* Effective bits */
  27         long lower_bound;               /* "lb" value */
  28         long upper_bound;               /* "ub" value */
  29 } asn_per_constraint_t;
  30 typedef struct asn_per_constraints_s {
  31         asn_per_constraint_t value;
  32         asn_per_constraint_t size;
  33         int (*value2code)(unsigned int value);
  34         int (*code2value)(unsigned int code);
  35 } asn_per_constraints_t;
  36
  37 /*
  38  * This structure describes a position inside an incoming PER bit stream.
  39  */
  40 typedef struct asn_per_data_s {
  41   const uint8_t *buffer;  /* Pointer to the octet stream */
  42          size_t  nboff;   /* Bit offset to the meaningful bit */
  43          size_t  nbits;   /* Number of bits in the stream */
  44          size_t  moved;   /* Number of bits moved through this bit stream */
  45   int (*refill)(struct asn_per_data_s *);
  46   void *refill_key;
  47 } asn_per_data_t;
  48
  49 /*
  50  * Extract a small number of bits (<= 31) from the specified PER data pointer.
  51  * This function returns -1 if the specified number of bits could not be
  52  * extracted due to EOD or other conditions.
  53  */
  54 int32_t per_get_few_bits(asn_per_data_t *per_data, int get_nbits);
  55
  56 /* Undo the immediately preceeding "get_few_bits" operation */
  57 void per_get_undo(asn_per_data_t *per_data, int get_nbits);
  58
  59 /*
  60  * Extract a large number of bits from the specified PER data pointer.
  61  * This function returns -1 if the specified number of bits could not be
  62  * extracted due to EOD or other conditions.
  63  */
  64 int per_get_many_bits(asn_per_data_t *pd, uint8_t *dst, int right_align,
  65                         int get_nbits);
  66
  67 /*
  68  * Get the length "n" from the Unaligned PER stream.
  69  */
  70 ssize_t uper_get_length(asn_per_data_t *pd,
  71                         int effective_bound_bits,
  72                         int *repeat);
  73
  74 /*
  75  * Get the normally small length "n".
  76  */
  77 ssize_t uper_get_nslength(asn_per_data_t *pd);
  78
  79 /*
  80  * Get the normally small non-negative whole number.
  81  */
  82 ssize_t uper_get_nsnnwn(asn_per_data_t *pd);
  83
  84 /* Non-thread-safe debugging function, don't use it */
  85 char *per_data_string(asn_per_data_t *pd);
  86
  87 /*
  88  * This structure supports forming PER output.
  89  */
  90 typedef struct asn_per_outp_s {
  91         uint8_t *buffer;        /* Pointer into the (tmpspace) */
  92         size_t nboff;           /* Bit offset to the meaningful bit */
  93         size_t nbits;           /* Number of bits left in (tmpspace) */
  94         uint8_t tmpspace[32];   /* Preliminary storage to hold data */
  95         int (*outper)(const void *data, size_t size, void *op_key);
  96         void *op_key;           /* Key for (outper) data callback */
  97         size_t flushed_bytes;   /* Bytes already flushed through (outper) */
  98 } asn_per_outp_t;
  99
 100 /* Output a small number of bits (<= 31) */
 101 int per_put_few_bits(asn_per_outp_t *per_data, uint32_t bits, int obits);
 102
 103 /* Output a large number of bits */
 104 int per_put_many_bits(asn_per_outp_t *po, const uint8_t *src, int put_nbits);
 105
 106 /*
 107  * Put the length "n" to the Unaligned PER stream.
 108  * This function returns the number of units which may be flushed
 109  * in the next units saving iteration.
 110  */
 111 ssize_t uper_put_length(asn_per_outp_t *po, size_t whole_length);
 112
 113 /*
 114  * Put the normally small length "n" to the Unaligned PER stream.
 115  * Returns 0 or -1.
 116  */
 117 int uper_put_nslength(asn_per_outp_t *po, size_t length);
 118
 119 /*
 120  * Put the normally small non-negative whole number.
 121  */
 122 int uper_put_nsnnwn(asn_per_outp_t *po, int n);
 123
 124 #ifdef __cplusplus
 125 }
 126 #endif
 127
 128 #endif  /* _PER_SUPPORT_H_ */