--- /dev/null
+/*
+ * Copyright (c) 2017 Lev Walkin <vlm@lionet.info>.
+ * All rights reserved.
+ * Redistribution and modifications are permitted subject to BSD license.
+ */
+#include <asn_internal.h>
+#include <asn_codecs_prim.h>
+
+/*
+ * Local internal type passed around as an argument.
+ */
+struct xdp_arg_s {
+ const asn_TYPE_descriptor_t *type_descriptor;
+ void *struct_key;
+ xer_primitive_body_decoder_f *prim_body_decoder;
+ int decoded_something;
+ int want_more;
+};
+
+/*
+ * Since some kinds of primitive values can be encoded using value-specific
+ * tags (<MINUS-INFINITY>, <enum-element>, etc), the primitive decoder must
+ * be supplied with such tags to parse them as needed.
+ */
+static int
+xer_decode__unexpected_tag(void *key, const void *chunk_buf, size_t chunk_size) {
+ struct xdp_arg_s *arg = (struct xdp_arg_s *)key;
+ enum xer_pbd_rval bret;
+
+ /*
+ * The chunk_buf is guaranteed to start at '<'.
+ */
+ assert(chunk_size && ((const char *)chunk_buf)[0] == 0x3c);
+
+ /*
+ * Decoding was performed once already. Prohibit doing it again.
+ */
+ if(arg->decoded_something)
+ return -1;
+
+ bret = arg->prim_body_decoder(arg->type_descriptor,
+ arg->struct_key, chunk_buf,
+ chunk_size);
+ switch(bret) {
+ case XPBD_SYSTEM_FAILURE:
+ case XPBD_DECODER_LIMIT:
+ case XPBD_BROKEN_ENCODING:
+ break;
+ case XPBD_BODY_CONSUMED:
+ /* Tag decoded successfully */
+ arg->decoded_something = 1;
+ /* Fall through */
+ case XPBD_NOT_BODY_IGNORE: /* Safe to proceed further */
+ return 0;
+ }
+
+ return -1;
+}
+
+static ssize_t
+xer_decode__primitive_body(void *key, const void *chunk_buf, size_t chunk_size, int have_more) {
+ struct xdp_arg_s *arg = (struct xdp_arg_s *)key;
+ enum xer_pbd_rval bret;
+ size_t lead_wsp_size;
+
+ if(arg->decoded_something) {
+ if(xer_whitespace_span(chunk_buf, chunk_size) == chunk_size) {
+ /*
+ * Example:
+ * "<INTEGER>123<!--/--> </INTEGER>"
+ * ^- chunk_buf position.
+ */
+ return chunk_size;
+ }
+ /*
+ * Decoding was done once already. Prohibit doing it again.
+ */
+ return -1;
+ }
+
+ if(!have_more) {
+ /*
+ * If we've received something like "1", we can't really
+ * tell whether it is really `1` or `123`, until we know
+ * that there is no more data coming.
+ * The have_more argument will be set to 1 once something
+ * like this is available to the caller of this callback:
+ * "1<tag_start..."
+ */
+ arg->want_more = 1;
+ return -1;
+ }
+
+ lead_wsp_size = xer_whitespace_span(chunk_buf, chunk_size);
+ chunk_buf = (chunk_buf == NULL)? NULL : ((const char *)chunk_buf + lead_wsp_size);
+ chunk_size -= lead_wsp_size;
+
+ bret = arg->prim_body_decoder(arg->type_descriptor,
+ arg->struct_key, chunk_buf,
+ chunk_size);
+ switch(bret) {
+ case XPBD_SYSTEM_FAILURE:
+ case XPBD_DECODER_LIMIT:
+ case XPBD_BROKEN_ENCODING:
+ break;
+ case XPBD_BODY_CONSUMED:
+ /* Tag decoded successfully */
+ arg->decoded_something = 1;
+ /* Fall through */
+ case XPBD_NOT_BODY_IGNORE: /* Safe to proceed further */
+ return lead_wsp_size + chunk_size;
+ }
+
+ return -1;
+}
+
+asn_dec_rval_t
+xer_decode_primitive(const asn_codec_ctx_t *opt_codec_ctx,
+ const asn_TYPE_descriptor_t *td, void **sptr,
+ size_t struct_size, const char *opt_mname,
+ const void *buf_ptr, size_t size,
+ xer_primitive_body_decoder_f *prim_body_decoder) {
+ const char *xml_tag = opt_mname ? opt_mname : td->xml_tag;
+ asn_struct_ctx_t s_ctx;
+ struct xdp_arg_s s_arg;
+ asn_dec_rval_t rc;
+
+ /*
+ * Create the structure if does not exist.
+ */
+ if(!*sptr) {
+ *sptr = CALLOC(1, struct_size);
+ if(!*sptr) ASN__DECODE_FAILED;
+ }
+
+ memset(&s_ctx, 0, sizeof(s_ctx));
+ s_arg.type_descriptor = td;
+ s_arg.struct_key = *sptr;
+ s_arg.prim_body_decoder = prim_body_decoder;
+ s_arg.decoded_something = 0;
+ s_arg.want_more = 0;
+
+ rc = xer_decode_general(opt_codec_ctx, &s_ctx, &s_arg,
+ xml_tag, buf_ptr, size,
+ xer_decode__unexpected_tag,
+ xer_decode__primitive_body);
+ switch(rc.code) {
+ case RC_OK:
+ if(!s_arg.decoded_something) {
+ char ch;
+ ASN_DEBUG("Primitive body is not recognized, "
+ "supplying empty one");
+ /*
+ * Decoding opportunity has come and gone.
+ * Where's the result?
+ * Try to feed with empty body, see if it eats it.
+ */
+ if(prim_body_decoder(s_arg.type_descriptor,
+ s_arg.struct_key, &ch, 0)
+ != XPBD_BODY_CONSUMED) {
+ /*
+ * This decoder does not like empty stuff.
+ */
+ ASN__DECODE_FAILED;
+ }
+ }
+ break;
+ case RC_WMORE:
+ /*
+ * Redo the whole thing later.
+ * We don't have a context to save intermediate parsing state.
+ */
+ rc.consumed = 0;
+ break;
+ case RC_FAIL:
+ rc.consumed = 0;
+ if(s_arg.want_more)
+ rc.code = RC_WMORE;
+ else
+ ASN__DECODE_FAILED;
+ break;
+ }
+ return rc;
+}
Code Review / sim / e2-interface.git / blobdiff