Commit 924fa031 authored by Lev Walkin's avatar Lev Walkin
Browse files

proper way of handling duplicate tags when bsearching

parent 38abe79f
......@@ -78,9 +78,15 @@ _t2e_cmp(const void *ap, const void *bp) {
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)
if(a_value == b_value) {
if(a->el_no < b->el_no)
return -1;
/*
* Important: we do not check
* for a->el_no being greater than b->el_no!
*/
return 0;
else if(a_value < b_value)
} else if(a_value < b_value)
return -1;
else
return 1;
......@@ -232,9 +238,10 @@ SEQUENCE_decode_ber(asn1_TYPE_descriptor_t *sd,
if(opt_edx_end > specs->elements_count)
opt_edx_end = specs->elements_count; /* Cap */
else if(opt_edx_end - edx > 5) {
/* Limit the scope of linear search */
/* Limit the scope of linear search... */
opt_edx_end = edx + 5;
use_bsearch = 1;
/* ... and resort to bsearch() */
}
for(n = edx; n < opt_edx_end; n++) {
if(BER_TAGS_EQUAL(tlv_tag, elements[n].tag)) {
......@@ -259,21 +266,29 @@ SEQUENCE_decode_ber(asn1_TYPE_descriptor_t *sd,
asn1_TYPE_tag2member_t *t2m;
asn1_TYPE_tag2member_t key;
key.el_tag = tlv_tag;
key.el_no = edx;
t2m = bsearch(&key, specs->tag2el, specs->tag2el_count,
sizeof(specs->tag2el[0]), _t2e_cmp);
if(t2m && t2m->el_no >= edx) {
if(t2m) {
asn1_TYPE_tag2member_t *best = 0;
asn1_TYPE_tag2member_t *t2m_f, *t2m_l;
int edx_max = edx + elements[edx].optional;
/*
* Rewind to the first element with that tag,
* `cause bsearch() does not guarantee order.
*/
while(t2m > specs->tag2el
&& BER_TAGS_EQUAL(tlv_tag,
t2m[-1].el_tag)
&& t2m[-1].el_no >= edx)
t2m++;
edx = t2m->el_no;
ctx->step = 1 + 2 * edx;
goto microphase2;
t2m_f = t2m + t2m->toff_first;
t2m_l = t2m + t2m->toff_last;
for(t2m = t2m_f; t2m <= t2m_l; t2m++) {
if(t2m->el_no > edx_max) break;
if(t2m->el_no < edx) continue;
best = t2m;
}
if(best) {
edx = best->el_no;
ctx->step = 1 + 2 * edx;
goto microphase2;
}
}
n = opt_edx_end;
}
......
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