| #include <asn_application.h> |
| #include <asn_internal.h> |
| #include <per_decoder.h> |
| |
| 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 */ |
| 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; |
| } else { |
| /* PER codec is not a restartable */ |
| rval.consumed = 0; |
| } |
| return rval; |
| } |
| |