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, 151 insertions, 0 deletions

diff --git a/src/asn1c/per_encoder.c b/src/asn1c/per_encoder.c
new file mode 100644
index 0000000..e76ef74
--- /dev/null
+++ b/src/asn1c/per_encoder.c
@@ -0,0 +1,151 @@
+#include <asn_application.h>
+#include <asn_internal.h>
+#include <per_encoder.h>
+
+static asn_enc_rval_t uper_encode_internal(asn_TYPE_descriptor_t *td, asn_per_constraints_t *, void *sptr, asn_app_consume_bytes_f *cb, void *app_key);
+
+asn_enc_rval_t
+uper_encode(asn_TYPE_descriptor_t *td, void *sptr, asn_app_consume_bytes_f *cb, void *app_key) {
+	return uper_encode_internal(td, 0, sptr, cb, app_key);
+}
+
+/*
+ * Argument type and callback necessary for uper_encode_to_buffer().
+ */
+typedef struct enc_to_buf_arg {
+	void *buffer;
+	size_t left;
+} enc_to_buf_arg;
+static int encode_to_buffer_cb(const void *buffer, size_t size, void *key) {
+	enc_to_buf_arg *arg = (enc_to_buf_arg *)key;
+
+	if(arg->left < size)
+		return -1;	/* Data exceeds the available buffer size */
+
+	memcpy(arg->buffer, buffer, size);
+	arg->buffer = ((char *)arg->buffer) + size;
+	arg->left -= size;
+
+	return 0;
+}
+
+asn_enc_rval_t
+uper_encode_to_buffer(asn_TYPE_descriptor_t *td, void *sptr, void *buffer, size_t buffer_size) {
+	enc_to_buf_arg key;
+
+	key.buffer = buffer;
+	key.left = buffer_size;
+
+	if(td) ASN_DEBUG("Encoding \"%s\" using UNALIGNED PER", td->name);
+
+	return uper_encode_internal(td, 0, sptr, encode_to_buffer_cb, &key);
+}
+
+typedef struct enc_dyn_arg {
+	void *buffer;
+	size_t length;
+	size_t allocated;
+} enc_dyn_arg;
+static int
+encode_dyn_cb(const void *buffer, size_t size, void *key) {
+	enc_dyn_arg *arg = key;
+	if(arg->length + size >= arg->allocated) {
+		void *p;
+		arg->allocated = arg->allocated ? (arg->allocated << 2) : size;
+		p = REALLOC(arg->buffer, arg->allocated);
+		if(!p) {
+			FREEMEM(arg->buffer);
+			memset(arg, 0, sizeof(*arg));
+			return -1;
+		}
+		arg->buffer = p;
+	}
+	memcpy(((char *)arg->buffer) + arg->length, buffer, size);
+	arg->length += size;
+	return 0;
+}
+ssize_t
+uper_encode_to_new_buffer(asn_TYPE_descriptor_t *td, asn_per_constraints_t *constraints, void *sptr, void **buffer_r) {
+	asn_enc_rval_t er;
+	enc_dyn_arg key;
+
+	memset(&key, 0, sizeof(key));
+
+	er = uper_encode_internal(td, constraints, sptr, encode_dyn_cb, &key);
+	switch(er.encoded) {
+	case -1:
+		FREEMEM(key.buffer);
+		return -1;
+	case 0:
+		FREEMEM(key.buffer);
+		key.buffer = MALLOC(1);
+		if(key.buffer) {
+			*(char *)key.buffer = '\0';
+			*buffer_r = key.buffer;
+			return 1;
+		} else {
+			return -1;
+		}
+	default:
+		*buffer_r = key.buffer;
+		ASN_DEBUG("Complete encoded in %ld bits", (long)er.encoded);
+		return ((er.encoded + 7) >> 3);
+	}
+}
+
+/*
+ * Internally useful functions.
+ */
+
+/* Flush partially filled buffer */
+static int
+_uper_encode_flush_outp(asn_per_outp_t *po) {
+	uint8_t *buf;
+
+	if(po->nboff == 0 && po->buffer == po->tmpspace)
+		return 0;
+
+	buf = po->buffer + (po->nboff >> 3);
+	/* Make sure we account for the last, partially filled */
+	if(po->nboff & 0x07) {
+		buf[0] &= 0xff << (8 - (po->nboff & 0x07));
+		buf++;
+	}
+
+	return po->outper(po->tmpspace, buf - po->tmpspace, po->op_key);
+}
+
+static asn_enc_rval_t
+uper_encode_internal(asn_TYPE_descriptor_t *td, asn_per_constraints_t *constraints, void *sptr, asn_app_consume_bytes_f *cb, void *app_key) {
+	asn_per_outp_t po;
+	asn_enc_rval_t er;
+
+	/*
+	 * Invoke type-specific encoder.
+	 */
+	if(!td || !td->uper_encoder)
+		_ASN_ENCODE_FAILED;	/* PER is not compiled in */
+
+	po.buffer = po.tmpspace;
+	po.nboff = 0;
+	po.nbits = 8 * sizeof(po.tmpspace);
+	po.outper = cb;
+	po.op_key = app_key;
+	po.flushed_bytes = 0;
+
+	er = td->uper_encoder(td, constraints, sptr, &po);
+	if(er.encoded != -1) {
+		size_t bits_to_flush;
+
+		bits_to_flush = ((po.buffer - po.tmpspace) << 3) + po.nboff;
+
+		/* Set number of bits encoded to a firm value */
+		er.encoded = (po.flushed_bytes << 3) + bits_to_flush;
+
+		if(_uper_encode_flush_outp(&po))
+			_ASN_ENCODE_FAILED;
+	}
+
+	return er;
+}
+