1 files changed, 77 insertions, 0 deletions
diff --git a/skeletons/ber_decoder.h b/skeletons/ber_decoder.h
new file mode 100644
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--- /dev/null
+++ b/skeletons/ber_decoder.h
@@ -0,0 +1,77 @@
+/*-
+ * Copyright (c) 2003, 2004 Lev Walkin <vlm@lionet.info>. All rights reserved.
+ * Redistribution and modifications are permitted subject to BSD license.
+ */
+#ifndef	_BER_DECODER_H_
+#define	_BER_DECODER_H_
+
+#include <constr_TYPE.h>
+
+struct asn1_TYPE_descriptor_s;	/* Forward declaration */
+
+/*
+ * This structure describes the return value common across the
+ * various BER decoders.
+ * 
+ * Please note that the number of consumed bytes is ALWAYS meaningful,
+ * even if code!=RC_OK. This is so to indicate the number of successfully
+ * decoded bytes, hence provide a possibility, to fail with more diagnostics
+ * (i.e., print the offending remainder of the buffer).
+ */
+typedef struct ber_dec_rval_s {
+	enum {
+		RC_OK,		/* Decoded successfully */
+		RC_WMORE,	/* More data expected, call again */
+		RC_FAIL,	/* Failure to decode data */
+	} code;
+
+	size_t consumed;	/* Number of bytes consumed */
+} ber_dec_rval_t;
+
+/*
+ * A context for decoding BER across buffer boundaries.
+ */
+typedef struct ber_dec_ctx_s {
+	int phase;	/* Decoding phase */
+	int step;	/* Elementary step of a phase */
+	ber_tlv_len_t left;	/* Number of bytes left, -1 for indefinite */
+	void *ptr;	/* Decoder-specific stuff */
+} ber_dec_ctx_t;
+
+/*
+ * The BER decoder of any type.
+ * This function may be invoked directly from the application.
+ */
+ber_dec_rval_t ber_decode(struct asn1_TYPE_descriptor_s *type_descriptor,
+	void **struct_ptr,	/* Pointer to a target structure's pointer */
+	void *buffer,		/* Data to be decoded */
+	size_t size		/* Size of that buffer */
+	);
+
+/*
+ * Type of generic function which decodes the byte stream into the structure.
+ */
+typedef ber_dec_rval_t (ber_type_decoder_f)(
+		struct asn1_TYPE_descriptor_s *type_descriptor,
+		void **type_structure, void *buf_ptr, size_t size,
+		int tag_mode);
+
+/*******************************
+ * INTERNALLY USEFUL FUNCTIONS *
+ *******************************/
+
+/*
+ * Check that all tags correspond to the type definition (as given in head).
+ * On return, last_length would contain either a non-negative length of the
+ * value part of the last TLV, or the negative number of expected
+ * "end of content" sequences. The number may only be negative if the
+ * head->last_tag_form is non-zero.
+ */
+ber_dec_rval_t ber_check_tags(struct asn1_TYPE_descriptor_s *type_dsc,
+		ber_dec_ctx_t *ctx,	/* saved context */
+		void *ptr, size_t size,
+		int tag_mode,		/* {-1,0,1}: IMPLICIT, no, EXPLICIT */
+		ber_tlv_len_t *last_length,
+		int *opt_tlv_form);
+
+#endif	/* _BER_DECODER_H_ */