mirror of https://github.com/gnss-sdr/gnss-sdr
119 lines
3.3 KiB
C
119 lines
3.3 KiB
C
#include <asn_application.h>
|
|
#include <asn_internal.h>
|
|
#include <per_decoder.h>
|
|
|
|
/*
|
|
* Decode a "Production of a complete encoding", X.691#10.1.
|
|
* The complete encoding contains at least one byte, and is an integral
|
|
* multiple of 8 bytes.
|
|
*/
|
|
asn_dec_rval_t uper_decode_complete(asn_codec_ctx_t *opt_codec_ctx,
|
|
asn_TYPE_descriptor_t *td, void **sptr,
|
|
const void *buffer, size_t size)
|
|
{
|
|
asn_dec_rval_t rval;
|
|
|
|
rval = uper_decode(opt_codec_ctx, td, sptr, buffer, size, 0, 0);
|
|
if (rval.consumed)
|
|
{
|
|
/*
|
|
* We've always given 8-aligned data,
|
|
* so convert bits to integral bytes.
|
|
*/
|
|
rval.consumed += 7;
|
|
rval.consumed >>= 3;
|
|
}
|
|
else if (rval.code == RC_OK)
|
|
{
|
|
if (size)
|
|
{
|
|
if (((uint8_t *)buffer)[0] == 0)
|
|
{
|
|
rval.consumed = 1; /* 1 byte */
|
|
}
|
|
else
|
|
{
|
|
ASN_DEBUG("Expecting single zeroed byte");
|
|
rval.code = RC_FAIL;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Must contain at least 8 bits. */
|
|
rval.code = RC_WMORE;
|
|
}
|
|
}
|
|
|
|
return rval;
|
|
}
|
|
|
|
asn_dec_rval_t uper_decode(asn_codec_ctx_t *opt_codec_ctx,
|
|
asn_TYPE_descriptor_t *td, void **sptr,
|
|
const void *buffer, size_t size, int skip_bits,
|
|
int unused_bits)
|
|
{
|
|
asn_codec_ctx_t s_codec_ctx;
|
|
asn_dec_rval_t rval;
|
|
asn_per_data_t pd;
|
|
|
|
if (skip_bits < 0 || skip_bits > 7 || unused_bits < 0 || unused_bits > 7 ||
|
|
(unused_bits > 0 && !size))
|
|
{
|
|
_ASN_DECODE_FAILED;
|
|
}
|
|
|
|
/*
|
|
* Stack checker requires that the codec context
|
|
* must be allocated on the stack.
|
|
*/
|
|
if (opt_codec_ctx)
|
|
{
|
|
if (opt_codec_ctx->max_stack_size)
|
|
{
|
|
s_codec_ctx = *opt_codec_ctx;
|
|
opt_codec_ctx = &s_codec_ctx;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* If context is not given, be security-conscious anyway */
|
|
memset(&s_codec_ctx, 0, sizeof(s_codec_ctx));
|
|
s_codec_ctx.max_stack_size = _ASN_DEFAULT_STACK_MAX;
|
|
opt_codec_ctx = &s_codec_ctx;
|
|
}
|
|
|
|
/* Fill in the position indicator */
|
|
memset(&pd, 0, sizeof(pd));
|
|
pd.buffer = (const uint8_t *)buffer;
|
|
pd.nboff = skip_bits;
|
|
pd.nbits = 8 * size - unused_bits; /* 8 is CHAR_BIT from <limits.h> */
|
|
if (pd.nboff > pd.nbits)
|
|
{
|
|
_ASN_DECODE_FAILED;
|
|
}
|
|
|
|
/*
|
|
* Invoke type-specific decoder.
|
|
*/
|
|
if (!td->uper_decoder)
|
|
{
|
|
_ASN_DECODE_FAILED; /* PER is not compiled in */
|
|
}
|
|
rval = td->uper_decoder(opt_codec_ctx, td, 0, sptr, &pd);
|
|
if (rval.code == RC_OK)
|
|
{
|
|
/* Return the number of consumed bits */
|
|
rval.consumed = ((pd.buffer - (const uint8_t *)buffer) << 3) +
|
|
pd.nboff - skip_bits;
|
|
ASN_DEBUG("PER decoding consumed %d, counted %d", rval.consumed,
|
|
pd.moved);
|
|
assert(rval.consumed == pd.moved);
|
|
}
|
|
else
|
|
{
|
|
/* PER codec is not a restartable */
|
|
rval.consumed = 0;
|
|
}
|
|
return rval;
|
|
}
|