remove libasn1c dependency and use asn1c without libasn1c

TODO: re-introduce talloc integration for asn1 runtime

Change-Id: I2140509c5359727f304470249be2a726b9a8deb1
diff --git a/src/rspro/constr_CHOICE.c b/src/rspro/constr_CHOICE.c
new file mode 100644
index 0000000..18c24cd
--- /dev/null
+++ b/src/rspro/constr_CHOICE.c
@@ -0,0 +1,1272 @@
+/*
+ * Copyright (c) 2003, 2004, 2005, 2006, 2007 Lev Walkin <vlm@lionet.info>.
+ * All rights reserved.
+ * Redistribution and modifications are permitted subject to BSD license.
+ */
+#include <asn_internal.h>
+#include <constr_CHOICE.h>
+#include <per_opentype.h>
+
+/*
+ * Number of bytes left for this structure.
+ * (ctx->left) indicates the number of bytes _transferred_ for the structure.
+ * (size) contains the number of bytes in the buffer passed.
+ */
+#define	LEFT	((size<(size_t)ctx->left)?size:(size_t)ctx->left)
+
+/*
+ * If the subprocessor function returns with an indication that it wants
+ * more data, it may well be a fatal decoding problem, because the
+ * size is constrained by the <TLV>'s L, even if the buffer size allows
+ * reading more data.
+ * For example, consider the buffer containing the following TLVs:
+ * <T:5><L:1><V> <T:6>...
+ * The TLV length clearly indicates that one byte is expected in V, but
+ * if the V processor returns with "want more data" even if the buffer
+ * contains way more data than the V processor have seen.
+ */
+#define	SIZE_VIOLATION	(ctx->left >= 0 && (size_t)ctx->left <= size)
+
+/*
+ * This macro "eats" the part of the buffer which is definitely "consumed",
+ * i.e. was correctly converted into local representation or rightfully skipped.
+ */
+#undef	ADVANCE
+#define	ADVANCE(num_bytes)	do {		\
+		size_t num = num_bytes;		\
+		ptr = ((const char *)ptr) + num;\
+		size -= num;			\
+		if(ctx->left >= 0)		\
+			ctx->left -= num;	\
+		consumed_myself += num;		\
+	} while(0)
+
+/*
+ * Switch to the next phase of parsing.
+ */
+#undef	NEXT_PHASE
+#define	NEXT_PHASE(ctx)	do {			\
+		ctx->phase++;			\
+		ctx->step = 0;			\
+	} while(0)
+
+/*
+ * Return a standardized complex structure.
+ */
+#undef	RETURN
+#define	RETURN(_code)	do {			\
+		rval.code = _code;		\
+		rval.consumed = consumed_myself;\
+		return rval;			\
+	} while(0)
+
+/*
+ * See the definitions.
+ */
+static int _fetch_present_idx(const void *struct_ptr, int off, int size);
+static void _set_present_idx(void *sptr, int offset, int size, int pres);
+
+/*
+ * Tags are canonically sorted in the tag to member table.
+ */
+static int
+_search4tag(const void *ap, const void *bp) {
+	const asn_TYPE_tag2member_t *a = (const asn_TYPE_tag2member_t *)ap;
+	const asn_TYPE_tag2member_t *b = (const asn_TYPE_tag2member_t *)bp;
+
+	int a_class = BER_TAG_CLASS(a->el_tag);
+	int b_class = BER_TAG_CLASS(b->el_tag);
+
+	if(a_class == b_class) {
+		ber_tlv_tag_t a_value = BER_TAG_VALUE(a->el_tag);
+		ber_tlv_tag_t b_value = BER_TAG_VALUE(b->el_tag);
+
+		if(a_value == b_value)
+			return 0;
+		else if(a_value < b_value)
+			return -1;
+		else
+			return 1;
+	} else if(a_class < b_class) {
+		return -1;
+	} else {
+		return 1;
+	}
+}
+
+/*
+ * The decoder of the CHOICE type.
+ */
+asn_dec_rval_t
+CHOICE_decode_ber(asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td,
+	void **struct_ptr, const void *ptr, size_t size, int tag_mode) {
+	/*
+	 * Bring closer parts of structure description.
+	 */
+	asn_CHOICE_specifics_t *specs = (asn_CHOICE_specifics_t *)td->specifics;
+	asn_TYPE_member_t *elements = td->elements;
+
+	/*
+	 * Parts of the structure being constructed.
+	 */
+	void *st = *struct_ptr;	/* Target structure. */
+	asn_struct_ctx_t *ctx;	/* Decoder context */
+
+	ber_tlv_tag_t tlv_tag;	/* T from TLV */
+	ssize_t tag_len;	/* Length of TLV's T */
+	asn_dec_rval_t rval;	/* Return code from subparsers */
+
+	ssize_t consumed_myself = 0;	/* Consumed bytes from ptr */
+
+	ASN_DEBUG("Decoding %s as CHOICE", td->name);
+
+	/*
+	 * Create the target structure if it is not present already.
+	 */
+	if(st == 0) {
+		st = *struct_ptr = CALLOC(1, specs->struct_size);
+		if(st == 0) {
+			RETURN(RC_FAIL);
+		}
+	}
+
+	/*
+	 * Restore parsing context.
+	 */
+	ctx = (asn_struct_ctx_t *)((char *)st + specs->ctx_offset);
+	
+	/*
+	 * Start to parse where left previously
+	 */
+	switch(ctx->phase) {
+	case 0:
+		/*
+		 * PHASE 0.
+		 * Check that the set of tags associated with given structure
+		 * perfectly fits our expectations.
+		 */
+
+		if(tag_mode || td->tags_count) {
+			rval = ber_check_tags(opt_codec_ctx, td, ctx, ptr, size,
+				tag_mode, -1, &ctx->left, 0);
+			if(rval.code != RC_OK) {
+				ASN_DEBUG("%s tagging check failed: %d",
+					td->name, rval.code);
+				return rval;
+			}
+
+			if(ctx->left >= 0) {
+				/* ?Substracted below! */
+				ctx->left += rval.consumed;
+			}
+			ADVANCE(rval.consumed);
+		} else {
+			ctx->left = -1;
+		}
+
+		NEXT_PHASE(ctx);
+
+		ASN_DEBUG("Structure consumes %ld bytes, buffer %ld",
+			(long)ctx->left, (long)size);
+
+		/* Fall through */
+	case 1:
+		/*
+		 * Fetch the T from TLV.
+		 */
+		tag_len = ber_fetch_tag(ptr, LEFT, &tlv_tag);
+		ASN_DEBUG("In %s CHOICE tag length %d", td->name, (int)tag_len);
+		switch(tag_len) {
+		case 0: if(!SIZE_VIOLATION) RETURN(RC_WMORE);
+			/* Fall through */
+		case -1: RETURN(RC_FAIL);
+		}
+
+		do {
+			const asn_TYPE_tag2member_t *t2m;
+			asn_TYPE_tag2member_t key;
+
+			key.el_tag = tlv_tag;
+			t2m = (const asn_TYPE_tag2member_t *)bsearch(&key,
+					specs->tag2el, specs->tag2el_count,
+					sizeof(specs->tag2el[0]), _search4tag);
+			if(t2m) {
+				/*
+				 * Found the element corresponding to the tag.
+				 */
+				NEXT_PHASE(ctx);
+				ctx->step = t2m->el_no;
+				break;
+			} else if(specs->ext_start == -1) {
+				ASN_DEBUG("Unexpected tag %s "
+					"in non-extensible CHOICE %s",
+					ber_tlv_tag_string(tlv_tag), td->name);
+				RETURN(RC_FAIL);
+			} else {
+				/* Skip this tag */
+				ssize_t skip;
+
+				ASN_DEBUG("Skipping unknown tag %s",
+					ber_tlv_tag_string(tlv_tag));
+
+				skip = ber_skip_length(opt_codec_ctx,
+					BER_TLV_CONSTRUCTED(ptr),
+					(const char *)ptr + tag_len,
+					LEFT - tag_len);
+
+				switch(skip) {
+				case 0: if(!SIZE_VIOLATION) RETURN(RC_WMORE);
+					/* Fall through */
+				case -1: RETURN(RC_FAIL);
+				}
+
+				ADVANCE(skip + tag_len);
+				RETURN(RC_OK);
+			}
+		} while(0);
+
+	case 2:
+		/*
+		 * PHASE 2.
+		 * Read in the element.
+		 */
+	    do {
+		asn_TYPE_member_t *elm;/* CHOICE's element */
+		void *memb_ptr;		/* Pointer to the member */
+		void **memb_ptr2;	/* Pointer to that pointer */
+
+		elm = &elements[ctx->step];
+
+		/*
+		 * Compute the position of the member inside a structure,
+		 * and also a type of containment (it may be contained
+		 * as pointer or using inline inclusion).
+		 */
+		if(elm->flags & ATF_POINTER) {
+			/* Member is a pointer to another structure */
+			memb_ptr2 = (void **)((char *)st + elm->memb_offset);
+		} else {
+			/*
+			 * A pointer to a pointer
+			 * holding the start of the structure
+			 */
+			memb_ptr = (char *)st + elm->memb_offset;
+			memb_ptr2 = &memb_ptr;
+		}
+		/* Set presence to be able to free it properly at any time */
+		_set_present_idx(st, specs->pres_offset,
+				specs->pres_size, ctx->step + 1);
+		/*
+		 * Invoke the member fetch routine according to member's type
+		 */
+		rval = elm->type->ber_decoder(opt_codec_ctx, elm->type,
+				memb_ptr2, ptr, LEFT, elm->tag_mode);
+		switch(rval.code) {
+		case RC_OK:
+			break;
+		case RC_WMORE: /* More data expected */
+			if(!SIZE_VIOLATION) {
+				ADVANCE(rval.consumed);
+				RETURN(RC_WMORE);
+			}
+			RETURN(RC_FAIL);
+		case RC_FAIL: /* Fatal error */
+			RETURN(rval.code);
+		} /* switch(rval) */
+		
+		ADVANCE(rval.consumed);
+	  } while(0);
+
+		NEXT_PHASE(ctx);
+
+		/* Fall through */
+	case 3:
+		ASN_DEBUG("CHOICE %s Leftover: %ld, size = %ld, tm=%d, tc=%d",
+			td->name, (long)ctx->left, (long)size,
+			tag_mode, td->tags_count);
+
+		if(ctx->left > 0) {
+			/*
+			 * The type must be fully decoded
+			 * by the CHOICE member-specific decoder.
+			 */
+			RETURN(RC_FAIL);
+		}
+
+		if(ctx->left == -1
+		&& !(tag_mode || td->tags_count)) {
+			/*
+			 * This is an untagged CHOICE.
+			 * It doesn't contain nothing
+			 * except for the member itself, including all its tags.
+			 * The decoding is completed.
+			 */
+			NEXT_PHASE(ctx);
+			break;
+		}
+
+		/*
+		 * Read in the "end of data chunks"'s.
+		 */
+		while(ctx->left < 0) {
+			ssize_t tl;
+
+			tl = ber_fetch_tag(ptr, LEFT, &tlv_tag);
+			switch(tl) {
+			case 0: if(!SIZE_VIOLATION) RETURN(RC_WMORE);
+				/* Fall through */
+			case -1: RETURN(RC_FAIL);
+			}
+
+			/*
+			 * Expected <0><0>...
+			 */
+			if(((const uint8_t *)ptr)[0] == 0) {
+				if(LEFT < 2) {
+					if(SIZE_VIOLATION)
+						RETURN(RC_FAIL);
+					else
+						RETURN(RC_WMORE);
+				} else if(((const uint8_t *)ptr)[1] == 0) {
+					/*
+					 * Correctly finished with <0><0>.
+					 */
+					ADVANCE(2);
+					ctx->left++;
+					continue;
+				}
+			} else {
+				ASN_DEBUG("Unexpected continuation in %s",
+					td->name);
+				RETURN(RC_FAIL);
+			}
+
+			/* UNREACHABLE */
+		}
+
+		NEXT_PHASE(ctx);
+	case 4:
+		/* No meaningful work here */
+		break;
+	}
+	
+	RETURN(RC_OK);
+}
+
+asn_enc_rval_t
+CHOICE_encode_der(asn_TYPE_descriptor_t *td, void *sptr,
+		int tag_mode, ber_tlv_tag_t tag,
+		asn_app_consume_bytes_f *cb, void *app_key) {
+	asn_CHOICE_specifics_t *specs = (asn_CHOICE_specifics_t *)td->specifics;
+	asn_TYPE_member_t *elm;	/* CHOICE element */
+	asn_enc_rval_t erval;
+	void *memb_ptr;
+	size_t computed_size = 0;
+	int present;
+
+	if(!sptr) _ASN_ENCODE_FAILED;
+
+	ASN_DEBUG("%s %s as CHOICE",
+		cb?"Encoding":"Estimating", td->name);
+
+	present = _fetch_present_idx(sptr,
+		specs->pres_offset, specs->pres_size);
+
+	/*
+	 * If the structure was not initialized, it cannot be encoded:
+	 * can't deduce what to encode in the choice type.
+	 */
+	if(present <= 0 || present > td->elements_count) {
+		if(present == 0 && td->elements_count == 0) {
+			/* The CHOICE is empty?! */
+			erval.encoded = 0;
+			_ASN_ENCODED_OK(erval);
+		}
+		_ASN_ENCODE_FAILED;
+	}
+
+	/*
+	 * Seek over the present member of the structure.
+	 */
+	elm = &td->elements[present-1];
+	if(elm->flags & ATF_POINTER) {
+		memb_ptr = *(void **)((char *)sptr + elm->memb_offset);
+		if(memb_ptr == 0) {
+			if(elm->optional) {
+				erval.encoded = 0;
+				_ASN_ENCODED_OK(erval);
+			}
+			/* Mandatory element absent */
+			_ASN_ENCODE_FAILED;
+		}
+	} else {
+		memb_ptr = (void *)((char *)sptr + elm->memb_offset);
+	}
+
+	/*
+	 * If the CHOICE itself is tagged EXPLICIT:
+	 * T ::= [2] EXPLICIT CHOICE { ... }
+	 * Then emit the appropriate tags.
+	 */
+	if(tag_mode == 1 || td->tags_count) {
+		/*
+		 * For this, we need to pre-compute the member.
+		 */
+		ssize_t ret;
+
+		/* Encode member with its tag */
+		erval = elm->type->der_encoder(elm->type, memb_ptr,
+			elm->tag_mode, elm->tag, 0, 0);
+		if(erval.encoded == -1)
+			return erval;
+
+		/* Encode CHOICE with parent or my own tag */
+		ret = der_write_tags(td, erval.encoded, tag_mode, 1, tag,
+			cb, app_key);
+		if(ret == -1)
+			_ASN_ENCODE_FAILED;
+		computed_size += ret;
+	}
+
+	/*
+	 * Encode the single underlying member.
+	 */
+	erval = elm->type->der_encoder(elm->type, memb_ptr,
+		elm->tag_mode, elm->tag, cb, app_key);
+	if(erval.encoded == -1)
+		return erval;
+
+	ASN_DEBUG("Encoded CHOICE member in %ld bytes (+%ld)",
+		(long)erval.encoded, (long)computed_size);
+
+	erval.encoded += computed_size;
+
+	return erval;
+}
+
+ber_tlv_tag_t
+CHOICE_outmost_tag(const asn_TYPE_descriptor_t *td, const void *ptr, int tag_mode, ber_tlv_tag_t tag) {
+	asn_CHOICE_specifics_t *specs = (asn_CHOICE_specifics_t *)td->specifics;
+	int present;
+
+	assert(tag_mode == 0); (void)tag_mode;
+	assert(tag == 0); (void)tag;
+
+	/*
+	 * Figure out which CHOICE element is encoded.
+	 */
+	present = _fetch_present_idx(ptr, specs->pres_offset, specs->pres_size);
+
+	if(present > 0 || present <= td->elements_count) {
+		const asn_TYPE_member_t *elm = &td->elements[present-1];
+		const void *memb_ptr;
+
+		if(elm->flags & ATF_POINTER) {
+			memb_ptr = *(const void * const *)
+					((const char *)ptr + elm->memb_offset);
+		} else {
+			memb_ptr = (const void *)
+					((const char *)ptr + elm->memb_offset);
+		}
+
+		return asn_TYPE_outmost_tag(elm->type, memb_ptr,
+			elm->tag_mode, elm->tag);
+	} else {
+		return (ber_tlv_tag_t)-1;
+	}
+}
+
+int
+CHOICE_constraint(asn_TYPE_descriptor_t *td, const void *sptr,
+		asn_app_constraint_failed_f *ctfailcb, void *app_key) {
+	asn_CHOICE_specifics_t *specs = (asn_CHOICE_specifics_t *)td->specifics;
+	int present;
+
+	if(!sptr) {
+		_ASN_CTFAIL(app_key, td, sptr,
+			"%s: value not given (%s:%d)",
+			td->name, __FILE__, __LINE__);
+		return -1;
+	}
+
+	/*
+	 * Figure out which CHOICE element is encoded.
+	 */
+	present = _fetch_present_idx(sptr, specs->pres_offset,specs->pres_size);
+	if(present > 0 && present <= td->elements_count) {
+		asn_TYPE_member_t *elm = &td->elements[present-1];
+		const void *memb_ptr;
+
+		if(elm->flags & ATF_POINTER) {
+			memb_ptr = *(const void * const *)((const char *)sptr + elm->memb_offset);
+			if(!memb_ptr) {
+				if(elm->optional)
+					return 0;
+				_ASN_CTFAIL(app_key, td, sptr,
+					"%s: mandatory CHOICE element %s absent (%s:%d)",
+					td->name, elm->name, __FILE__, __LINE__);
+				return -1;
+			}
+		} else {
+			memb_ptr = (const void *)((const char *)sptr + elm->memb_offset);
+		}
+
+		if(elm->memb_constraints) {
+			return elm->memb_constraints(elm->type, memb_ptr,
+				ctfailcb, app_key);
+		} else {
+			int ret = elm->type->check_constraints(elm->type,
+					memb_ptr, ctfailcb, app_key);
+			/*
+			 * Cannot inherit it eralier:
+			 * need to make sure we get the updated version.
+			 */
+			elm->memb_constraints = elm->type->check_constraints;
+			return ret;
+		}
+	} else {
+		_ASN_CTFAIL(app_key, td, sptr,
+			"%s: no CHOICE element given (%s:%d)",
+			td->name, __FILE__, __LINE__);
+		return -1;
+	}
+}
+
+#undef	XER_ADVANCE
+#define	XER_ADVANCE(num_bytes)	do {			\
+		size_t num = num_bytes;			\
+		buf_ptr = (const void *)(((const char *)buf_ptr) + num); \
+		size -= num;				\
+		consumed_myself += num;			\
+	} while(0)
+
+/*
+ * Decode the XER (XML) data.
+ */
+asn_dec_rval_t
+CHOICE_decode_xer(asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td,
+	void **struct_ptr, const char *opt_mname,
+		const void *buf_ptr, size_t size) {
+	/*
+	 * Bring closer parts of structure description.
+	 */
+	asn_CHOICE_specifics_t *specs = (asn_CHOICE_specifics_t *)td->specifics;
+	const char *xml_tag = opt_mname ? opt_mname : td->xml_tag;
+
+	/*
+	 * Parts of the structure being constructed.
+	 */
+	void *st = *struct_ptr;	/* Target structure. */
+	asn_struct_ctx_t *ctx;	/* Decoder context */
+
+	asn_dec_rval_t rval;		/* Return value of a decoder */
+	ssize_t consumed_myself = 0;	/* Consumed bytes from ptr */
+	int edx;			/* Element index */
+
+	/*
+	 * Create the target structure if it is not present already.
+	 */
+	if(st == 0) {
+		st = *struct_ptr = CALLOC(1, specs->struct_size);
+		if(st == 0) RETURN(RC_FAIL);
+	}
+
+	/*
+	 * Restore parsing context.
+	 */
+	ctx = (asn_struct_ctx_t *)((char *)st + specs->ctx_offset);
+	if(ctx->phase == 0 && !*xml_tag)
+		ctx->phase = 1;	/* Skip the outer tag checking phase */
+
+	/*
+	 * Phases of XER/XML processing:
+	 * Phase 0: Check that the opening tag matches our expectations.
+	 * Phase 1: Processing body and reacting on closing tag.
+	 * Phase 2: Processing inner type.
+	 * Phase 3: Only waiting for closing tag.
+	 * Phase 4: Skipping unknown extensions.
+	 * Phase 5: PHASED OUT
+	 */
+	for(edx = ctx->step; ctx->phase <= 4;) {
+		pxer_chunk_type_e ch_type;	/* XER chunk type */
+		ssize_t ch_size;		/* Chunk size */
+		xer_check_tag_e tcv;		/* Tag check value */
+		asn_TYPE_member_t *elm;
+
+		/*
+		 * Go inside the member.
+		 */
+		if(ctx->phase == 2) {
+			asn_dec_rval_t tmprval;
+			void *memb_ptr;		/* Pointer to the member */
+			void **memb_ptr2;	/* Pointer to that pointer */
+
+			elm = &td->elements[edx];
+
+			if(elm->flags & ATF_POINTER) {
+				/* Member is a pointer to another structure */
+				memb_ptr2 = (void **)((char *)st
+					+ elm->memb_offset);
+			} else {
+				memb_ptr = (char *)st + elm->memb_offset;
+				memb_ptr2 = &memb_ptr;
+			}
+
+			/* Start/Continue decoding the inner member */
+			tmprval = elm->type->xer_decoder(opt_codec_ctx,
+					elm->type, memb_ptr2, elm->name,
+					buf_ptr, size);
+			XER_ADVANCE(tmprval.consumed);
+			ASN_DEBUG("XER/CHOICE: itdf: [%s] code=%d",
+				elm->type->name, tmprval.code);
+			if(tmprval.code != RC_OK)
+				RETURN(tmprval.code);
+			assert(_fetch_present_idx(st,
+				specs->pres_offset, specs->pres_size) == 0);
+			/* Record what we've got */
+			_set_present_idx(st,
+				specs->pres_offset, specs->pres_size, edx + 1);
+			ctx->phase = 3;
+			/* Fall through */
+		}
+
+		/* No need to wait for closing tag; special mode. */
+		if(ctx->phase == 3 && !*xml_tag) {
+			ctx->phase = 5;	/* Phase out */
+			RETURN(RC_OK);
+		}
+
+		/*
+		 * Get the next part of the XML stream.
+		 */
+		ch_size = xer_next_token(&ctx->context, buf_ptr, size, &ch_type);
+		switch(ch_size) {
+		case -1: RETURN(RC_FAIL);
+		case 0:  RETURN(RC_WMORE);
+		default:
+			switch(ch_type) {
+			case PXER_COMMENT:	/* Got XML comment */
+			case PXER_TEXT:		/* Ignore free-standing text */
+				XER_ADVANCE(ch_size);	/* Skip silently */
+				continue;
+			case PXER_TAG:
+				break;	/* Check the rest down there */
+			}
+		}
+
+		tcv = xer_check_tag(buf_ptr, ch_size, xml_tag);
+		ASN_DEBUG("XER/CHOICE checked [%c%c%c%c] vs [%s], tcv=%d",
+			ch_size>0?((const uint8_t *)buf_ptr)[0]:'?',
+			ch_size>1?((const uint8_t *)buf_ptr)[1]:'?',
+			ch_size>2?((const uint8_t *)buf_ptr)[2]:'?',
+			ch_size>3?((const uint8_t *)buf_ptr)[3]:'?',
+		xml_tag, tcv);
+
+		/* Skip the extensions section */
+		if(ctx->phase == 4) {
+			ASN_DEBUG("skip_unknown(%d, %ld)",
+				tcv, (long)ctx->left);
+			switch(xer_skip_unknown(tcv, &ctx->left)) {
+			case -1:
+				ctx->phase = 5;
+				RETURN(RC_FAIL);
+				continue;
+			case 1:
+				ctx->phase = 3;
+				/* Fall through */
+			case 0:
+				XER_ADVANCE(ch_size);
+				continue;
+			case 2:
+				ctx->phase = 3;
+				break;
+			}
+		}
+
+		switch(tcv) {
+		case XCT_BOTH:
+			break;	/* No CHOICE? */
+		case XCT_CLOSING:
+			if(ctx->phase != 3)
+				break;
+			XER_ADVANCE(ch_size);
+			ctx->phase = 5;	/* Phase out */
+			RETURN(RC_OK);
+		case XCT_OPENING:
+			if(ctx->phase == 0) {
+				XER_ADVANCE(ch_size);
+				ctx->phase = 1;	/* Processing body phase */
+				continue;
+			}
+			/* Fall through */
+		case XCT_UNKNOWN_OP:
+		case XCT_UNKNOWN_BO:
+
+			if(ctx->phase != 1)
+				break;	/* Really unexpected */
+
+			/*
+			 * Search which inner member corresponds to this tag.
+			 */
+			for(edx = 0; edx < td->elements_count; edx++) {
+				elm = &td->elements[edx];
+				tcv = xer_check_tag(buf_ptr,ch_size,elm->name);
+				switch(tcv) {
+				case XCT_BOTH:
+				case XCT_OPENING:
+					/*
+					 * Process this member.
+					 */
+					ctx->step = edx;
+					ctx->phase = 2;
+					break;
+				case XCT_UNKNOWN_OP:
+				case XCT_UNKNOWN_BO:
+					continue;
+				default:
+					edx = td->elements_count;
+					break;	/* Phase out */
+				}
+				break;
+			}
+			if(edx != td->elements_count)
+				continue;
+
+			/* It is expected extension */
+			if(specs->ext_start != -1) {
+				ASN_DEBUG("Got anticipated extension");
+				/*
+				 * Check for (XCT_BOTH or XCT_UNKNOWN_BO)
+				 * By using a mask. Only record a pure
+				 * <opening> tags.
+				 */
+				if(tcv & XCT_CLOSING) {
+					/* Found </extension> without body */
+					ctx->phase = 3; /* Terminating */
+				} else {
+					ctx->left = 1;
+					ctx->phase = 4; /* Skip ...'s */
+				}
+				XER_ADVANCE(ch_size);
+				continue;
+			}
+
+			/* Fall through */
+		default:
+			break;
+		}
+
+		ASN_DEBUG("Unexpected XML tag [%c%c%c%c] in CHOICE [%s]"
+			" (ph=%d, tag=%s)",
+			ch_size>0?((const uint8_t *)buf_ptr)[0]:'?',
+			ch_size>1?((const uint8_t *)buf_ptr)[1]:'?',
+			ch_size>2?((const uint8_t *)buf_ptr)[2]:'?',
+			ch_size>3?((const uint8_t *)buf_ptr)[3]:'?',
+			td->name, ctx->phase, xml_tag);
+		break;
+	}
+
+	ctx->phase = 5;	/* Phase out, just in case */
+	RETURN(RC_FAIL);
+}
+
+
+asn_enc_rval_t
+CHOICE_encode_xer(asn_TYPE_descriptor_t *td, void *sptr,
+	int ilevel, enum xer_encoder_flags_e flags,
+		asn_app_consume_bytes_f *cb, void *app_key) {
+	asn_CHOICE_specifics_t *specs=(asn_CHOICE_specifics_t *)td->specifics;
+	asn_enc_rval_t er;
+	int present;
+
+	if(!sptr)
+		_ASN_ENCODE_FAILED;
+
+	/*
+	 * Figure out which CHOICE element is encoded.
+	 */
+	present = _fetch_present_idx(sptr, specs->pres_offset,specs->pres_size);
+
+	if(present <= 0 || present > td->elements_count) {
+		_ASN_ENCODE_FAILED;
+	}  else {
+		asn_enc_rval_t tmper;
+		asn_TYPE_member_t *elm = &td->elements[present-1];
+		void *memb_ptr;
+		const char *mname = elm->name;
+		unsigned int mlen = strlen(mname);
+
+		if(elm->flags & ATF_POINTER) {
+			memb_ptr = *(void **)((char *)sptr + elm->memb_offset);
+			if(!memb_ptr) _ASN_ENCODE_FAILED;
+		} else {
+			memb_ptr = (void *)((char *)sptr + elm->memb_offset);
+		}
+
+		er.encoded = 0;
+
+                if(!(flags & XER_F_CANONICAL)) _i_ASN_TEXT_INDENT(1, ilevel);
+		_ASN_CALLBACK3("<", 1, mname, mlen, ">", 1);
+
+		tmper = elm->type->xer_encoder(elm->type, memb_ptr,
+				ilevel + 1, flags, cb, app_key);
+		if(tmper.encoded == -1) return tmper;
+
+		_ASN_CALLBACK3("</", 2, mname, mlen, ">", 1);
+
+		er.encoded += 5 + (2 * mlen) + tmper.encoded;
+	}
+
+	if(!(flags & XER_F_CANONICAL)) _i_ASN_TEXT_INDENT(1, ilevel - 1);
+
+	_ASN_ENCODED_OK(er);
+cb_failed:
+	_ASN_ENCODE_FAILED;
+}
+
+asn_dec_rval_t
+CHOICE_decode_uper(asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td,
+	asn_per_constraints_t *constraints, void **sptr, asn_per_data_t *pd) {
+	asn_CHOICE_specifics_t *specs = (asn_CHOICE_specifics_t *)td->specifics;
+	asn_dec_rval_t rv;
+	asn_per_constraint_t *ct;
+	asn_TYPE_member_t *elm;	/* CHOICE's element */
+	void *memb_ptr;
+	void **memb_ptr2;
+	void *st = *sptr;
+	int value;
+
+	if(_ASN_STACK_OVERFLOW_CHECK(opt_codec_ctx))
+		_ASN_DECODE_FAILED;
+
+	/*
+	 * Create the target structure if it is not present already.
+	 */
+	if(!st) {
+		st = *sptr = CALLOC(1, specs->struct_size);
+		if(!st) _ASN_DECODE_FAILED;
+	}
+
+	if(constraints) ct = &constraints->value;
+	else if(td->per_constraints) ct = &td->per_constraints->value;
+	else ct = 0;
+
+	if(ct && ct->flags & APC_EXTENSIBLE) {
+		value = per_get_few_bits(pd, 1);
+		if(value < 0) _ASN_DECODE_STARVED;
+		if(value) ct = 0;	/* Not restricted */
+	}
+
+	if(ct && ct->range_bits >= 0) {
+		value = per_get_few_bits(pd, ct->range_bits);
+		if(value < 0) _ASN_DECODE_STARVED;
+		ASN_DEBUG("CHOICE %s got index %d in range %d",
+			td->name, value, ct->range_bits);
+		if(value > ct->upper_bound)
+			_ASN_DECODE_FAILED;
+	} else {
+		if(specs->ext_start == -1)
+			_ASN_DECODE_FAILED;
+		value = uper_get_nsnnwn(pd);
+		if(value < 0) _ASN_DECODE_STARVED;
+		value += specs->ext_start;
+		if(value >= td->elements_count)
+			_ASN_DECODE_FAILED;
+	}
+
+	/* Adjust if canonical order is different from natural order */
+	if(specs->canonical_order)
+		value = specs->canonical_order[value];
+
+	/* Set presence to be able to free it later */
+	_set_present_idx(st, specs->pres_offset, specs->pres_size, value + 1);
+
+	elm = &td->elements[value];
+	if(elm->flags & ATF_POINTER) {
+		/* Member is a pointer to another structure */
+		memb_ptr2 = (void **)((char *)st + elm->memb_offset);
+	} else {
+		memb_ptr = (char *)st + elm->memb_offset;
+		memb_ptr2 = &memb_ptr;
+	}
+	ASN_DEBUG("Discovered CHOICE %s encodes %s", td->name, elm->name);
+
+	if(ct && ct->range_bits >= 0) {
+		rv = elm->type->uper_decoder(opt_codec_ctx, elm->type,
+			elm->per_constraints, memb_ptr2, pd);
+	} else {
+		rv = uper_open_type_get(opt_codec_ctx, elm->type,
+			elm->per_constraints, memb_ptr2, pd);
+	}
+
+	if(rv.code != RC_OK)
+		ASN_DEBUG("Failed to decode %s in %s (CHOICE) %d",
+			elm->name, td->name, rv.code);
+	return rv;
+}
+
+asn_dec_rval_t
+CHOICE_decode_aper(asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td,
+	asn_per_constraints_t *constraints, void **sptr, asn_per_data_t *pd) {
+	asn_CHOICE_specifics_t *specs = (asn_CHOICE_specifics_t *)td->specifics;
+	asn_dec_rval_t rv;
+	asn_per_constraint_t *ct;
+	asn_TYPE_member_t *elm;	/* CHOICE's element */
+	void *memb_ptr;
+	void **memb_ptr2;
+	void *st = *sptr;
+	int value;
+
+	if(_ASN_STACK_OVERFLOW_CHECK(opt_codec_ctx))
+		_ASN_DECODE_FAILED;
+
+	/*
+	 * Create the target structure if it is not present already.
+	 */
+	if(!st) {
+		st = *sptr = CALLOC(1, specs->struct_size);
+		if(!st) _ASN_DECODE_FAILED;
+	}
+
+	if(constraints) ct = &constraints->value;
+	else if(td->per_constraints) ct = &td->per_constraints->value;
+	else ct = 0;
+
+	if(ct && ct->flags & APC_EXTENSIBLE) {
+		value = per_get_few_bits(pd, 1);
+		if(value < 0) _ASN_DECODE_STARVED;
+		if(value) ct = 0;	/* Not restricted */
+	}
+
+	if(ct && ct->range_bits >= 0) {
+		value = per_get_few_bits(pd, ct->range_bits);
+		if(value < 0) _ASN_DECODE_STARVED;
+		ASN_DEBUG("CHOICE %s got index %d in range %d",
+			td->name, value, ct->range_bits);
+		if(value > ct->upper_bound)
+			_ASN_DECODE_FAILED;
+	} else {
+		if(specs->ext_start == -1)
+			_ASN_DECODE_FAILED;
+		value = uper_get_nsnnwn(pd);
+		if(value < 0) _ASN_DECODE_STARVED;
+		value += specs->ext_start;
+		if(value >= td->elements_count)
+			_ASN_DECODE_FAILED;
+	}
+
+	/* Adjust if canonical order is different from natural order */
+	if(specs->canonical_order)
+		value = specs->canonical_order[value];
+
+	/* Set presence to be able to free it later */
+	_set_present_idx(st, specs->pres_offset, specs->pres_size, value + 1);
+
+	elm = &td->elements[value];
+	if(elm->flags & ATF_POINTER) {
+		/* Member is a pointer to another structure */
+		memb_ptr2 = (void **)((char *)st + elm->memb_offset);
+	} else {
+		memb_ptr = (char *)st + elm->memb_offset;
+		memb_ptr2 = &memb_ptr;
+	}
+	ASN_DEBUG("Discovered CHOICE %s encodes %s", td->name, elm->name);
+
+	if(ct && ct->range_bits >= 0) {
+		rv = elm->type->aper_decoder(opt_codec_ctx, elm->type,
+			elm->per_constraints, memb_ptr2, pd);
+	} else {
+		rv = uper_open_type_get(opt_codec_ctx, elm->type,
+			elm->per_constraints, memb_ptr2, pd);
+	}
+
+	if(rv.code != RC_OK)
+		ASN_DEBUG("Failed to decode %s in %s (CHOICE) %d",
+			elm->name, td->name, rv.code);
+	return rv;
+}
+
+asn_enc_rval_t
+CHOICE_encode_uper(asn_TYPE_descriptor_t *td,
+	asn_per_constraints_t *constraints, void *sptr, asn_per_outp_t *po) {
+	asn_CHOICE_specifics_t *specs = (asn_CHOICE_specifics_t *)td->specifics;
+	asn_TYPE_member_t *elm;	/* CHOICE's element */
+	asn_per_constraint_t *ct;
+	void *memb_ptr;
+	int present;
+	int present_enc;
+
+	if(!sptr) _ASN_ENCODE_FAILED;
+
+        ASN_DEBUG("Encoding %s as CHOICE using UPER", td->name);
+
+	if(constraints) ct = &constraints->value;
+	else if(td->per_constraints) ct = &td->per_constraints->value;
+	else ct = 0;
+
+	present = _fetch_present_idx(sptr,
+		specs->pres_offset, specs->pres_size);
+
+	/*
+	 * If the structure was not initialized properly, it cannot be encoded:
+	 * can't deduce what to encode in the choice type.
+	 */
+	if(present <= 0 || present > td->elements_count)
+		_ASN_ENCODE_FAILED;
+	else
+		present--;
+
+	ASN_DEBUG("Encoding %s CHOICE element %d", td->name, present);
+
+	/* Adjust if canonical order is different from natural order */
+	if(specs->canonical_order)
+		present_enc = specs->canonical_order[present];
+	else
+		present_enc = present;
+
+	if(ct && ct->range_bits >= 0) {
+		if(present_enc < ct->lower_bound
+		|| present_enc > ct->upper_bound) {
+			if(ct->flags & APC_EXTENSIBLE) {
+				if(per_put_few_bits(po, 1, 1))
+					_ASN_ENCODE_FAILED;
+			} else {
+				_ASN_ENCODE_FAILED;
+			}
+			ct = 0;
+		}
+	}
+	if(ct && ct->flags & APC_EXTENSIBLE)
+		if(per_put_few_bits(po, 0, 1))
+			_ASN_ENCODE_FAILED;
+
+	elm = &td->elements[present];
+	if(elm->flags & ATF_POINTER) {
+		/* Member is a pointer to another structure */
+		memb_ptr = *(void **)((char *)sptr + elm->memb_offset);
+		if(!memb_ptr) _ASN_ENCODE_FAILED;
+	} else {
+		memb_ptr = (char *)sptr + elm->memb_offset;
+	}
+
+	if(ct && ct->range_bits >= 0) {
+		if(per_put_few_bits(po, present_enc, ct->range_bits))
+			_ASN_ENCODE_FAILED;
+
+		return elm->type->uper_encoder(elm->type, elm->per_constraints,
+			memb_ptr, po);
+	} else {
+		asn_enc_rval_t rval;
+		if(specs->ext_start == -1)
+			_ASN_ENCODE_FAILED;
+		if(uper_put_nsnnwn(po, present_enc - specs->ext_start))
+			_ASN_ENCODE_FAILED;
+		if(uper_open_type_put(elm->type, elm->per_constraints,
+			memb_ptr, po))
+			_ASN_ENCODE_FAILED;
+		rval.encoded = 0;
+		_ASN_ENCODED_OK(rval);
+	}
+}
+
+asn_enc_rval_t
+CHOICE_encode_aper(asn_TYPE_descriptor_t *td,
+				   asn_per_constraints_t *constraints, void *sptr, asn_per_outp_t *po) {
+	asn_CHOICE_specifics_t *specs = (asn_CHOICE_specifics_t *)td->specifics;
+	asn_TYPE_member_t *elm; /* CHOICE's element */
+	asn_per_constraint_t *ct;
+	void *memb_ptr;
+	int present;
+
+	if(!sptr) _ASN_ENCODE_FAILED;
+
+	ASN_DEBUG("Encoding %s as CHOICE using ALIGNED PER", td->name);
+
+	if(constraints) ct = &constraints->value;
+	else if(td->per_constraints) ct = &td->per_constraints->value;
+	else ct = 0;
+
+	present = _fetch_present_idx(sptr,
+								 specs->pres_offset, specs->pres_size);
+
+	/*
+	 * If the structure was not initialized properly, it cannot be encoded:
+	 * can't deduce what to encode in the choice type.
+	 */
+	if(present <= 0 || present > td->elements_count)
+		_ASN_ENCODE_FAILED;
+	else
+		present--;
+
+	/* Adjust if canonical order is different from natural order */
+	if(specs->canonical_order)
+		present = specs->canonical_order[present];
+
+	ASN_DEBUG("Encoding %s CHOICE element %d", td->name, present);
+
+	if(ct && ct->range_bits >= 0) {
+		if(present < ct->lower_bound
+			|| present > ct->upper_bound) {
+			if(ct->flags & APC_EXTENSIBLE) {
+				if(per_put_few_bits(po, 1, 1))
+					_ASN_ENCODE_FAILED;
+			} else {
+				_ASN_ENCODE_FAILED;
+			}
+			ct = 0;
+			}
+	}
+	if(ct && ct->flags & APC_EXTENSIBLE) {
+		if(per_put_few_bits(po, 0, 1))
+			_ASN_ENCODE_FAILED;
+	}
+
+	elm = &td->elements[present];
+	if(elm->flags & ATF_POINTER) {
+		/* Member is a pointer to another structure */
+		memb_ptr = *(void **)((char *)sptr + elm->memb_offset);
+		if(!memb_ptr) _ASN_ENCODE_FAILED;
+	} else {
+		memb_ptr = (char *)sptr + elm->memb_offset;
+	}
+
+	if(ct && ct->range_bits >= 0) {
+		if(per_put_few_bits(po, present, ct->range_bits))
+			_ASN_ENCODE_FAILED;
+
+			return elm->type->aper_encoder(elm->type, elm->per_constraints,
+										   memb_ptr, po);
+	} else {
+		asn_enc_rval_t rval;
+		if(specs->ext_start == -1)
+			_ASN_ENCODE_FAILED;
+		if(aper_put_nsnnwn(po, ct->range_bits, present - specs->ext_start))
+			_ASN_ENCODE_FAILED;
+		if(aper_open_type_put(elm->type, elm->per_constraints,
+			memb_ptr, po))
+			_ASN_ENCODE_FAILED;
+		rval.encoded = 0;
+		_ASN_ENCODED_OK(rval);
+	}
+}
+
+int
+CHOICE_print(asn_TYPE_descriptor_t *td, const void *sptr, int ilevel,
+		asn_app_consume_bytes_f *cb, void *app_key) {
+	asn_CHOICE_specifics_t *specs = (asn_CHOICE_specifics_t *)td->specifics;
+	int present;
+
+	if(!sptr) return (cb("<absent>", 8, app_key) < 0) ? -1 : 0;
+
+	/*
+	 * Figure out which CHOICE element is encoded.
+	 */
+	present = _fetch_present_idx(sptr, specs->pres_offset,specs->pres_size);
+
+	/*
+	 * Print that element.
+	 */
+	if(present > 0 && present <= td->elements_count) {
+		asn_TYPE_member_t *elm = &td->elements[present-1];
+		const void *memb_ptr;
+
+		if(elm->flags & ATF_POINTER) {
+			memb_ptr = *(const void * const *)((const char *)sptr + elm->memb_offset);
+			if(!memb_ptr) return (cb("<absent>", 8, app_key) < 0) ? -1 : 0;
+		} else {
+			memb_ptr = (const void *)((const char *)sptr + elm->memb_offset);
+		}
+
+		/* Print member's name and stuff */
+		if(cb(elm->name, strlen(elm->name), app_key) < 0
+		|| cb(": ", 2, app_key) < 0)
+			return -1;
+
+		return elm->type->print_struct(elm->type, memb_ptr, ilevel,
+			cb, app_key);
+	} else {
+		return (cb("<absent>", 8, app_key) < 0) ? -1 : 0;
+	}
+}
+
+void
+CHOICE_free(asn_TYPE_descriptor_t *td, void *ptr, int contents_only) {
+	asn_CHOICE_specifics_t *specs = (asn_CHOICE_specifics_t *)td->specifics;
+	int present;
+
+	if(!td || !ptr)
+		return;
+
+	ASN_DEBUG("Freeing %s as CHOICE", td->name);
+
+	/*
+	 * Figure out which CHOICE element is encoded.
+	 */
+	present = _fetch_present_idx(ptr, specs->pres_offset, specs->pres_size);
+
+	/*
+	 * Free that element.
+	 */
+	if(present > 0 && present <= td->elements_count) {
+		asn_TYPE_member_t *elm = &td->elements[present-1];
+		void *memb_ptr;
+
+		if(elm->flags & ATF_POINTER) {
+			memb_ptr = *(void **)((char *)ptr + elm->memb_offset);
+			if(memb_ptr)
+				ASN_STRUCT_FREE(*elm->type, memb_ptr);
+		} else {
+			memb_ptr = (void *)((char *)ptr + elm->memb_offset);
+			ASN_STRUCT_FREE_CONTENTS_ONLY(*elm->type, memb_ptr);
+		}
+	}
+
+	if(!contents_only) {
+		FREEMEM(ptr);
+	}
+}
+
+
+/*
+ * The following functions functions offer protection against -fshort-enums,
+ * compatible with little- and big-endian machines.
+ * If assertion is triggered, either disable -fshort-enums, or add an entry
+ * here with the ->pres_size of your target stracture.
+ * Unless the target structure is packed, the ".present" member
+ * is guaranteed to be aligned properly. ASN.1 compiler itself does not
+ * produce packed code.
+ */
+static int
+_fetch_present_idx(const void *struct_ptr, int pres_offset, int pres_size) {
+	const void *present_ptr;
+	int present;
+
+	present_ptr = ((const char *)struct_ptr) + pres_offset;
+
+	switch(pres_size) {
+	case sizeof(int):	present =   *(const int *)present_ptr; break;
+	case sizeof(short):	present = *(const short *)present_ptr; break;
+	case sizeof(char):	present =  *(const char *)present_ptr; break;
+	default:
+		/* ANSI C mandates enum to be equivalent to integer */
+		assert(pres_size != sizeof(int));
+		return 0;	/* If not aborted, pass back safe value */
+	}
+
+	return present;
+}
+
+static void
+_set_present_idx(void *struct_ptr, int pres_offset, int pres_size, int present) {
+	void *present_ptr;
+	present_ptr = ((char *)struct_ptr) + pres_offset;
+
+	switch(pres_size) {
+	case sizeof(int):	*(int *)present_ptr   = present; break;
+	case sizeof(short):	*(short *)present_ptr = present; break;
+	case sizeof(char):	*(char *)present_ptr  = present; break;
+	default:
+		/* ANSI C mandates enum to be equivalent to integer */
+		assert(pres_size != sizeof(int));
+	}
+}