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authorHarald Welte <laforge@gnumonks.org>2016-04-30 17:31:33 +0200
committerHarald Welte <laforge@gnumonks.org>2016-04-30 17:39:04 +0200
commitc867ddeb3027b3d84f2df73ebd44f9fe9fad7184 (patch)
tree251d2247d870654e48be40ccaff30cd30b1adb31 /src
parentf3c3049e754cb288911169333966881a9c4dee8c (diff)
fix APER encoding of integer (backport from openairinterface)
The number of bytes used by an APER encoded integer depends on its actually encoded value, not on the maximum value that could be possibly encoded. The old code would e.g. always use 24 bits if the maximum encoded value would require 24 bits. To give an example RANAP MaxBitrate (INTEER 1 .. 16000000) value 64000 was previously encoded as "80 00 f9 ff", while it is now the correct representation "40 f9 ff". Thanks to Dieter Spaar for detecting this problem in the Osmo-IUH generated RANAP output, and thanks to openairinterface for fixing the bug in their code (sadly not contributed to upstream asn1c, though).
Diffstat (limited to 'src')
-rw-r--r--src/INTEGER.c27
1 files changed, 22 insertions, 5 deletions
diff --git a/src/INTEGER.c b/src/INTEGER.c
index 9ba14bc..eef89f5 100644
--- a/src/INTEGER.c
+++ b/src/INTEGER.c
@@ -995,18 +995,35 @@ INTEGER_encode_aper(asn_TYPE_descriptor_t *td,
} else {
/* TODO: extend to >64 bits */
int64_t v64 = v;
- int i;
+ int i, j;
+ int max_range_bytes = (ct->range_bits >> 3) +
+ (((ct->range_bits % 8) > 0) ? 1 : 0);
+
+ for (i = 1; ; i++) {
+ int upper = 1 << i;
+ if (upper >= max_range_bytes)
+ break;
+ }
+
+ for (j = sizeof(int64_t) -1; j != 0; j--) {
+ uint8_t val;
+ val = v64 >> (j * 8);
+ if (val != 0)
+ break;
+ }
- /* Putting length - 1 in the minimum number of bits ex: 5 = 3bits */
- if (per_put_few_bits(po, st->size - 1, (ct->range_bits >> 3)-1))
+ /* Putting length in the minimum number of bits ex: 5 = 3bits */
+ if (per_put_few_bits(po, j, i))
_ASN_ENCODE_FAILED;
// Consume the bits to align on octet
if (aper_put_align(po) < 0)
_ASN_ENCODE_FAILED;
+
/* Put the value */
- for (i = 0; i < st->size; i++) {
- if(per_put_few_bits(po, (v64 >> (8 * (st->size - i - 1))) & 0xff, 8)) _ASN_ENCODE_FAILED;
+ for (i = 0; i <= j; i++) {
+ if(per_put_few_bits(po, (v64 >> (8 * (j - i))) & 0xff, 8))
+ _ASN_ENCODE_FAILED;
}
}
_ASN_ENCODED_OK(er);