Use a compiler to marshall/unmarshall the sessions

This way changes are easier, all is needed is to change the session.asn1
file to add or remove elements, and different session types can also be
supported at the same time.

1 files changed, 365 insertions, 0 deletions

diff --git a/src/asn1c/xer_decoder.c b/src/asn1c/xer_decoder.c
new file mode 100644
index 0000000..cb4b5f8
--- /dev/null
+++ b/src/asn1c/xer_decoder.c
@@ -0,0 +1,365 @@
+/*
+ * Copyright (c) 2004, 2005 Lev Walkin <vlm@lionet.info>. All rights reserved.
+ * Redistribution and modifications are permitted subject to BSD license.
+ */
+#include <asn_application.h>
+#include <asn_internal.h>
+#include <xer_support.h>		/* XER/XML parsing support */
+
+
+/*
+ * Decode the XER encoding of a given type.
+ */
+asn_dec_rval_t
+xer_decode(asn_codec_ctx_t *opt_codec_ctx, asn_TYPE_descriptor_t *td,
+		void **struct_ptr, const void *buffer, size_t size) {
+	asn_codec_ctx_t s_codec_ctx;
+
+	/*
+	 * 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;
+	}
+
+	/*
+	 * Invoke type-specific decoder.
+	 */
+	return td->xer_decoder(opt_codec_ctx, td, struct_ptr, 0, buffer, size);
+}
+
+
+
+struct xer__cb_arg {
+	pxml_chunk_type_e	chunk_type;
+	size_t			chunk_size;
+	const void		*chunk_buf;
+	int callback_not_invoked;
+};
+
+static int
+xer__token_cb(pxml_chunk_type_e type, const void *_chunk_data, size_t _chunk_size, void *key) {
+	struct xer__cb_arg *arg = (struct xer__cb_arg *)key;
+	arg->chunk_type = type;
+	arg->chunk_size = _chunk_size;
+	arg->chunk_buf = _chunk_data;
+	arg->callback_not_invoked = 0;
+	return -1;	/* Terminate the XML parsing */
+}
+
+/*
+ * Fetch the next token from the XER/XML stream.
+ */
+ssize_t
+xer_next_token(int *stateContext, const void *buffer, size_t size, pxer_chunk_type_e *ch_type) {
+	struct xer__cb_arg arg;
+	int new_stateContext = *stateContext;
+	ssize_t ret;
+
+	arg.callback_not_invoked = 1;
+	ret = pxml_parse(&new_stateContext, buffer, size, xer__token_cb, &arg);
+	if(ret < 0) return -1;
+	if(arg.callback_not_invoked) {
+		assert(ret == 0);	/* No data was consumed */
+		return 0;		/* Try again with more data */
+	} else {
+		assert(arg.chunk_size);
+		assert(arg.chunk_buf == buffer);
+	}
+
+	/*
+	 * Translate the XML chunk types into more convenient ones.
+	 */
+	switch(arg.chunk_type) {
+	case PXML_TEXT:
+		*ch_type = PXER_TEXT;
+		break;
+	case PXML_TAG: return 0;	/* Want more */
+	case PXML_TAG_END:
+		*ch_type = PXER_TAG;
+		break;
+	case PXML_COMMENT:
+	case PXML_COMMENT_END:
+		*ch_type = PXER_COMMENT;
+		break;
+	}
+
+	*stateContext = new_stateContext;
+	return arg.chunk_size;
+}
+
+#define	CSLASH	0x2f	/* '/' */
+#define	LANGLE	0x3c	/* '<' */
+#define	RANGLE	0x3e	/* '>' */
+
+xer_check_tag_e
+xer_check_tag(const void *buf_ptr, int size, const char *need_tag) {
+	const char *buf = (const char *)buf_ptr;
+	const char *end;
+	xer_check_tag_e ct = XCT_OPENING;
+
+	if(size < 2 || buf[0] != LANGLE || buf[size-1] != RANGLE) {
+		if(size >= 2)
+			ASN_DEBUG("Broken XML tag: \"%c...%c\"",
+			buf[0], buf[size - 1]);
+		return XCT_BROKEN;
+	}
+
+	/*
+	 * Determine the tag class.
+	 */
+	if(buf[1] == CSLASH) {
+		buf += 2;	/* advance past "</" */
+		size -= 3;	/* strip "</" and ">" */
+		ct = XCT_CLOSING;
+		if(size > 0 && buf[size-1] == CSLASH)
+			return XCT_BROKEN;	/* </abc/> */
+	} else {
+		buf++;		/* advance past "<" */
+		size -= 2;	/* strip "<" and ">" */
+		if(size > 0 && buf[size-1] == CSLASH) {
+			ct = XCT_BOTH;
+			size--;	/* One more, for "/" */
+		}
+	}
+
+	/* Sometimes we don't care about the tag */
+	if(!need_tag || !*need_tag)
+		return (xer_check_tag_e)(XCT__UNK__MASK | ct);
+
+	/*
+	 * Determine the tag name.
+	 */
+	for(end = buf + size; buf < end; buf++, need_tag++) {
+		int b = *buf, n = *need_tag;
+		if(b != n) {
+			if(n == 0) {
+				switch(b) {
+				case 0x09: case 0x0a: case 0x0c: case 0x0d:
+				case 0x20:
+					/* "<abc def/>": whitespace is normal */
+					return ct;
+				}
+			}
+			return (xer_check_tag_e)(XCT__UNK__MASK | ct);
+		}
+		if(b == 0)
+			return XCT_BROKEN;	/* Embedded 0 in buf?! */
+	}
+	if(*need_tag)
+		return (xer_check_tag_e)(XCT__UNK__MASK | ct);
+
+	return ct;
+}
+
+
+#undef	ADVANCE
+#define	ADVANCE(num_bytes)	do {				\
+		size_t num = (num_bytes);			\
+		buf_ptr = ((const char *)buf_ptr) + num;	\
+		size -= num;					\
+		consumed_myself += num;				\
+	} while(0)
+
+#undef	RETURN
+#define	RETURN(_code)	do {					\
+		rval.code = _code;				\
+		rval.consumed = consumed_myself;		\
+		if(rval.code != RC_OK)				\
+			ASN_DEBUG("Failed with %d", rval.code);	\
+		return rval;					\
+	} while(0)
+
+#define	XER_GOT_BODY(chunk_buf, chunk_size, size)	do {	\
+		ssize_t converted_size = body_receiver		\
+			(struct_key, chunk_buf, chunk_size,	\
+				(size_t)chunk_size < size);	\
+		if(converted_size == -1) RETURN(RC_FAIL);	\
+		if(converted_size == 0				\
+			&& size == (size_t)chunk_size)		\
+			RETURN(RC_WMORE);			\
+		chunk_size = converted_size;			\
+	} while(0)
+#define	XER_GOT_EMPTY()	do {					\
+	if(body_receiver(struct_key, 0, 0, size > 0) == -1)	\
+			RETURN(RC_FAIL);			\
+	} while(0)
+
+/*
+ * Generalized function for decoding the primitive values.
+ */
+asn_dec_rval_t
+xer_decode_general(asn_codec_ctx_t *opt_codec_ctx,
+	asn_struct_ctx_t *ctx,	/* Type decoder context */
+	void *struct_key,
+	const char *xml_tag,	/* Expected XML tag */
+	const void *buf_ptr, size_t size,
+	int (*opt_unexpected_tag_decoder)
+		(void *struct_key, const void *chunk_buf, size_t chunk_size),
+	ssize_t (*body_receiver)
+		(void *struct_key, const void *chunk_buf, size_t chunk_size,
+			int have_more)
+	) {
+
+	asn_dec_rval_t rval;
+	ssize_t consumed_myself = 0;
+
+	(void)opt_codec_ctx;
+
+	/*
+	 * Phases of XER/XML processing:
+	 * Phase 0: Check that the opening tag matches our expectations.
+	 * Phase 1: Processing body and reacting on closing tag.
+	 */
+	if(ctx->phase > 1) RETURN(RC_FAIL);
+	for(;;) {
+		pxer_chunk_type_e ch_type;	/* XER chunk type */
+		ssize_t ch_size;		/* Chunk size */
+		xer_check_tag_e tcv;		/* Tag check value */
+
+		/*
+		 * 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 */
+				ADVANCE(ch_size);	/* Skip silently */
+				continue;
+			case PXER_TEXT:
+				if(ctx->phase == 0) {
+					/*
+					 * We have to ignore whitespace here,
+					 * but in order to be forward compatible
+					 * with EXTENDED-XER (EMBED-VALUES, #25)
+					 * any text is just ignored here.
+					 */
+				} else {
+					XER_GOT_BODY(buf_ptr, ch_size, size);
+				}
+				ADVANCE(ch_size);
+				continue;
+			case PXER_TAG:
+				break;	/* Check the rest down there */
+			}
+		}
+
+		assert(ch_type == PXER_TAG && size);
+
+		tcv = xer_check_tag(buf_ptr, ch_size, xml_tag);
+		/*
+		 * Phase 0:
+		 * 	Expecting the opening tag
+		 * 	for the type being processed.
+		 * Phase 1:
+		 * 	Waiting for the closing XML tag.
+		 */
+		switch(tcv) {
+		case XCT_BOTH:
+			if(ctx->phase) break;
+			/* Finished decoding of an empty element */
+			XER_GOT_EMPTY();
+			ADVANCE(ch_size);
+			ctx->phase = 2;	/* Phase out */
+			RETURN(RC_OK);
+		case XCT_OPENING:
+			if(ctx->phase) break;
+			ADVANCE(ch_size);
+			ctx->phase = 1;	/* Processing body phase */
+			continue;
+		case XCT_CLOSING:
+			if(!ctx->phase) break;
+			ADVANCE(ch_size);
+			ctx->phase = 2;	/* Phase out */
+			RETURN(RC_OK);
+		case XCT_UNKNOWN_BO:
+			/*
+			 * Certain tags in the body may be expected.
+			 */
+			if(opt_unexpected_tag_decoder
+			&& opt_unexpected_tag_decoder(struct_key,
+					buf_ptr, ch_size) >= 0) {
+				/* Tag's processed fine */
+				ADVANCE(ch_size);
+				if(!ctx->phase) {
+					/* We are not expecting
+					 * the closing tag anymore. */
+					ctx->phase = 2;	/* Phase out */
+					RETURN(RC_OK);
+				}
+				continue;
+			}
+			/* Fall through */
+		default:
+			break;		/* Unexpected tag */
+		}
+
+		ASN_DEBUG("Unexpected XML tag (expected \"%s\")", xml_tag);
+		break;	/* Dark and mysterious things have just happened */
+	}
+
+	RETURN(RC_FAIL);
+}
+
+
+size_t
+xer_whitespace_span(const void *chunk_buf, size_t chunk_size) {
+	const char *p = (const char *)chunk_buf;
+	const char *pend = p + chunk_size;
+
+	for(; p < pend; p++) {
+		switch(*p) {
+		/* X.693, #8.1.4
+		 * HORISONTAL TAB (9)
+		 * LINE FEED (10) 
+		 * CARRIAGE RETURN (13) 
+		 * SPACE (32)
+		 */
+		case 0x09: case 0x0a: case 0x0d: case 0x20:
+			continue;
+		default:
+			break;
+		}
+		break;
+	}
+	return (p - (const char *)chunk_buf);
+}
+
+/*
+ * This is a vastly simplified, non-validating XML tree skipper.
+ */
+int
+xer_skip_unknown(xer_check_tag_e tcv, ber_tlv_len_t *depth) {
+	assert(*depth > 0);
+	switch(tcv) {
+	case XCT_BOTH:
+	case XCT_UNKNOWN_BO:
+		/* These negate each other. */
+		return 0;
+	case XCT_OPENING:
+	case XCT_UNKNOWN_OP:
+		++(*depth);
+		return 0;
+	case XCT_CLOSING:
+	case XCT_UNKNOWN_CL:
+		if(--(*depth) == 0)
+			return (tcv == XCT_CLOSING) ? 2 : 1;
+		return 0;
+	default:
+		return -1;
+	}
+}