Port to CMake, get rid of os_int.h.

[stg.git] / libs / smux / per_decoder.c

diff --git a/libs/smux/per_decoder.c b/libs/smux/per_decoder.c
new file mode 100644 (file)
index 0000000..16dee36
--- /dev/null
+++ b/libs/smux/per_decoder.c
@@ -0,0 +1,55 @@
+#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;
+}
+