381 lines
11 KiB
C
381 lines
11 KiB
C
/*
|
|
* 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 */
|