--- /dev/null
+/*
+ * Copyright (c) 2017 Lev Walkin <vlm@lionet.info>.
+ * All rights reserved.
+ * Redistribution and modifications are permitted subject to BSD license.
+ */
+#ifndef ASN_DISABLE_OER_SUPPORT
+
+#include <asn_internal.h>
+#include <constr_CHOICE.h>
+#include <errno.h>
+
+/*
+ * Return a standardized complex structure.
+ */
+#undef RETURN
+#define RETURN(_code) \
+ do { \
+ asn_dec_rval_t rval; \
+ rval.code = _code; \
+ rval.consumed = consumed_myself; \
+ return rval; \
+ } while(0)
+
+#undef ADVANCE
+#define ADVANCE(num_bytes) \
+ do { \
+ size_t num = num_bytes; \
+ ptr = ((const char *)ptr) + num; \
+ size -= 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)
+#undef SET_PHASE
+#define SET_PHASE(ctx, value) \
+ do { \
+ ctx->phase = value; \
+ ctx->step = 0; \
+ } while(0)
+
+/*
+ * 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;
+ }
+}
+
+/*
+ * X.696 (08/2015) #8.7 Encoding of tags
+ */
+static ssize_t
+oer_fetch_tag(const void *ptr, size_t size, ber_tlv_tag_t *tag_r) {
+ ber_tlv_tag_t val;
+ ber_tlv_tag_t tclass;
+ size_t skipped;
+
+ if(size == 0)
+ return 0;
+
+ val = *(const uint8_t *)ptr;
+ tclass = (val >> 6);
+ if((val & 0x3F) != 0x3F) {
+ /* #8.7.1 */
+ *tag_r = ((val & 0x3F) << 2) | tclass;
+ return 1;
+ }
+
+ /*
+ * Each octet contains 7 bits of useful information.
+ * The MSB is 0 if it is the last octet of the tag.
+ */
+ for(val = 0, ptr = ((const char *)ptr) + 1, skipped = 2; skipped <= size;
+ ptr = ((const char *)ptr) + 1, skipped++) {
+ unsigned int oct = *(const uint8_t *)ptr;
+ if(oct & 0x80) {
+ val = (val << 7) | (oct & 0x7F);
+ /*
+ * Make sure there are at least 9 bits spare
+ * at the MS side of a value.
+ */
+ if(val >> ((8 * sizeof(val)) - 9)) {
+ /*
+ * We would not be able to accomodate
+ * any more tag bits.
+ */
+ return -1;
+ }
+ } else {
+ val = (val << 7) | oct;
+ *tag_r = (val << 2) | tclass;
+ return skipped;
+ }
+ }
+
+ return 0; /* Want more */
+}
+
+asn_dec_rval_t
+CHOICE_decode_oer(const asn_codec_ctx_t *opt_codec_ctx,
+ const asn_TYPE_descriptor_t *td,
+ const asn_oer_constraints_t *constraints, void **struct_ptr,
+ const void *ptr, size_t size) {
+ /*
+ * Bring closer parts of structure description.
+ */
+ const asn_CHOICE_specifics_t *specs =
+ (const 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 */
+
+ ssize_t consumed_myself = 0; /* Consumed bytes from ptr */
+
+ (void)constraints;
+
+ 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);
+ switch(ctx->phase) {
+ case 0: {
+ /*
+ * Discover the tag.
+ */
+ ber_tlv_tag_t tlv_tag; /* T from TLV */
+ ssize_t tag_len; /* Length of TLV's T */
+
+ tag_len = oer_fetch_tag(ptr, size, &tlv_tag);
+ switch(tag_len) {
+ case 0:
+ ASN__DECODE_STARVED;
+ case -1:
+ ASN__DECODE_FAILED;
+ }
+
+ do {
+ const asn_TYPE_tag2member_t *t2m;
+ asn_TYPE_tag2member_t key = {0, 0, 0, 0};
+ 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 open type extension */
+ ASN_DEBUG(
+ "Not implemented skipping open type extension for tag %s",
+ ber_tlv_tag_string(tlv_tag));
+ RETURN(RC_FAIL);
+ }
+ } while(0);
+
+
+ ADVANCE(tag_len);
+ }
+ /* Fall through */
+ case 1: {
+ asn_TYPE_member_t *elm = &elements[ctx->step]; /* CHOICE's element */
+ void *memb_ptr; /* Pointer to the member */
+ void **memb_ptr2; /* Pointer to that pointer */
+ asn_dec_rval_t rval;
+
+ /*
+ * 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 */
+ (void)CHOICE_variant_set_presence(td, st, ctx->step + 1);
+
+ if(specs->ext_start >= 0 && specs->ext_start <= ctx->step) {
+ ssize_t got =
+ oer_open_type_get(opt_codec_ctx, elm->type,
+ elm->encoding_constraints.oer_constraints,
+ memb_ptr2, ptr, size);
+ if(got < 0) ASN__DECODE_FAILED;
+ if(got == 0) ASN__DECODE_STARVED;
+ rval.code = RC_OK;
+ rval.consumed = got;
+ } else {
+ rval = elm->type->op->oer_decoder(
+ opt_codec_ctx, elm->type,
+ elm->encoding_constraints.oer_constraints, memb_ptr2, ptr,
+ size);
+ }
+ rval.consumed += consumed_myself;
+ switch(rval.code) {
+ case RC_OK:
+ NEXT_PHASE(ctx);
+ case RC_WMORE:
+ break;
+ case RC_FAIL:
+ SET_PHASE(ctx, 3); /* => 3 */
+ }
+ return rval;
+ }
+ case 2:
+ /* Already decoded everything */
+ RETURN(RC_OK);
+ case 3:
+ /* Failed to decode, after all */
+ RETURN(RC_FAIL);
+ }
+
+ RETURN(RC_FAIL);
+}
+
+/*
+ * X.696 (08/2015) #8.7 Encoding of tags
+ */
+static ssize_t
+oer_put_tag(ber_tlv_tag_t tag, asn_app_consume_bytes_f *cb, void *app_key) {
+ uint8_t tclass = BER_TAG_CLASS(tag);
+ ber_tlv_tag_t tval = BER_TAG_VALUE(tag);
+
+ if(tval < 0x3F) {
+ uint8_t b = (uint8_t)((tclass << 6) | tval);
+ if(cb(&b, 1, app_key) < 0) {
+ return -1;
+ }
+ return 1;
+ } else {
+ uint8_t buf[1 + 2 * sizeof(tval)];
+ uint8_t *b = &buf[sizeof(buf)-1]; /* Last addressable */
+ size_t encoded;
+ for(; ; tval >>= 7) {
+ if(tval >> 7) {
+ *b-- = 0x80 | (tval & 0x7f);
+ } else {
+ *b-- = tval & 0x7f;
+ break;
+ }
+ }
+ *b = (uint8_t)((tclass << 6) | 0x3F);
+ encoded = sizeof(buf) - (b - buf);
+ if(cb(b, encoded, app_key) < 0) {
+ return -1;
+ }
+ return encoded;
+ }
+
+}
+
+/*
+ * Encode as Canonical OER.
+ */
+asn_enc_rval_t
+CHOICE_encode_oer(const asn_TYPE_descriptor_t *td,
+ const asn_oer_constraints_t *constraints, const void *sptr,
+ asn_app_consume_bytes_f *cb, void *app_key) {
+ const asn_CHOICE_specifics_t *specs =
+ (const asn_CHOICE_specifics_t *)td->specifics;
+ asn_TYPE_member_t *elm; /* CHOICE element */
+ unsigned present;
+ const void *memb_ptr;
+ ber_tlv_tag_t tag;
+ ssize_t tag_len;
+ asn_enc_rval_t er = {0, 0, 0};
+
+ (void)constraints;
+
+ if(!sptr) ASN__ENCODE_FAILED;
+
+ ASN_DEBUG("OER %s encoding as CHOICE", td->name);
+
+ present = CHOICE_variant_get_presence(td, sptr);
+ if(present == 0 || present > td->elements_count) {
+ ASN_DEBUG("CHOICE %s member is not selected", td->name);
+ ASN__ENCODE_FAILED;
+ }
+
+ elm = &td->elements[present-1];
+ if(elm->flags & ATF_POINTER) {
+ memb_ptr =
+ *(const void *const *)((const char *)sptr + elm->memb_offset);
+ if(memb_ptr == 0) {
+ /* Mandatory element absent */
+ ASN__ENCODE_FAILED;
+ }
+ } else {
+ memb_ptr = (const void *)((const char *)sptr + elm->memb_offset);
+ }
+
+ tag = asn_TYPE_outmost_tag(elm->type, memb_ptr, elm->tag_mode, elm->tag);
+ if(tag == 0) {
+ ASN__ENCODE_FAILED;
+ }
+
+ tag_len = oer_put_tag(tag, cb, app_key);
+ if(tag_len < 0) {
+ ASN__ENCODE_FAILED;
+ }
+
+ if(specs->ext_start >= 0 && (unsigned)specs->ext_start <= (present-1)) {
+ ssize_t encoded = oer_open_type_put(elm->type,
+ elm->encoding_constraints.oer_constraints,
+ memb_ptr, cb, app_key);
+ if(encoded < 0) ASN__ENCODE_FAILED;
+ er.encoded = tag_len + encoded;
+ } else {
+ er = elm->type->op->oer_encoder(
+ elm->type, elm->encoding_constraints.oer_constraints, memb_ptr, cb,
+ app_key);
+ if(er.encoded >= 0) er.encoded += tag_len;
+ }
+
+ return er;
+}
+
+#endif /* ASN_DISABLE_OER_SUPPORT */
git.stg.codes / stg.git / blobdiff