X-Git-Url: https://gerrit.o-ran-sc.org/r/gitweb?p=sim%2Fe2-interface.git;a=blobdiff_plain;f=e2sim%2Fasn1c%2Faper_decoder.c;fp=e2sim%2Fasn1c%2Faper_decoder.c;h=0637b6a5a7bd3a80a8adc205146d399019f09503;hp=0000000000000000000000000000000000000000;hb=f5900596513e4359fc839ba361da085674e90b68;hpb=215d350dbe06a4c7ee370815f26128a7f7e160cb

diff --git a/e2sim/asn1c/aper_decoder.c b/e2sim/asn1c/aper_decoder.c
new file mode 100644
index 0000000..0637b6a
--- /dev/null
+++ b/e2sim/asn1c/aper_decoder.c
@@ -0,0 +1,91 @@
+#include <asn_application.h>
+#include <asn_internal.h>
+#include <aper_decoder.h>
+
+asn_dec_rval_t
+aper_decode_complete(const asn_codec_ctx_t *opt_codec_ctx,
+                     const asn_TYPE_descriptor_t *td, void **sptr,
+                     const void *buffer, size_t size) {
+	asn_dec_rval_t rval;
+
+	rval = aper_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(((const 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
+aper_decode(const asn_codec_ctx_t *opt_codec_ctx,
+            const 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->op->aper_decoder)
+		ASN__DECODE_FAILED;	/* PER is not compiled in */
+	rval = td->op->aper_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 %zu, counted %zu",
+				  rval.consumed, pd.moved);
+		assert(rval.consumed == pd.moved);
+	} else {
+		/* PER codec is not a restartable */
+		rval.consumed = 0;
+	}
+	return rval;
+}