ranap_rab_ass: add function to check if RAB is in ReleaseList

A RANAP RAB-AssignmentRelease may contain a ReleaseList. In order to
detect that a RAB is about to be released we need to be able to check if
the RAB we are dealing with is contained in such a ReleaseList.

Change-Id: I5b67cc2d35d11de7a09e66c181a1fdd5a58c75bb
Related: OS#5152
This commit is contained in:
Philipp Maier 2022-02-15 11:20:52 +01:00
parent efe4850e75
commit f5742a3bed
4 changed files with 103 additions and 0 deletions

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@ -15,4 +15,5 @@ int ranap_rab_ass_req_ies_replace_inet_addr(RANAP_RAB_AssignmentRequestIEs_t *ie
int ranap_rab_ass_resp_ies_replace_inet_addr(RANAP_RAB_AssignmentResponseIEs_t *ies, struct osmo_sockaddr *addr,
uint8_t rab_id);
bool ranap_rab_ass_req_ies_check_release(RANAP_RAB_AssignmentRequestIEs_t *ies, uint8_t rab_id);
bool ranap_rab_ass_resp_ies_check_failure(RANAP_RAB_AssignmentResponseIEs_t *ies, uint8_t rab_id);

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@ -135,6 +135,23 @@ static RANAP_ProtocolIE_FieldPair_t *prot_ie_field_pair_from_ass_req_ies(const R
return protocol_ie_field_pair;
}
/* Pick the indexed item from the RAB release-list list and return a pointer to it */
static RANAP_IE_t *release_item_from_ass_req_ies(const RANAP_RAB_AssignmentRequestIEs_t *ies, unsigned int index)
{
/* Make sure we indeed deal with a setup-or-modify list */
if (!(ies->presenceMask & RAB_ASSIGNMENTREQUESTIES_RANAP_RAB_RELEASELIST_PRESENT)) {
RANAP_DEBUG
("Decoding failed, the RANAP RAB AssignmentRequest did not contain a release list!\n");
return NULL;
}
/* Detect the end of the list */
if (index >= ies->raB_ReleaseList.raB_ReleaseList_ies.list.count)
return NULL;
return ies->raB_ReleaseList.raB_ReleaseList_ies.list.array[index];
}
/* Pick the indexed item from the RAB setup-or-modified list and return a pointer to it */
static RANAP_IE_t *setup_or_modif_item_from_rab_ass_resp(const RANAP_RAB_AssignmentResponseIEs_t *ies,
unsigned int index)
@ -261,6 +278,41 @@ static int decode_rab_smditms_from_req_ies(RANAP_RAB_SetupOrModifyItemFirst_t *i
}
}
static int decode_rab_relitms_from_req_ies(RANAP_RAB_ReleaseItemIEs_t *items_ies,
RANAP_RAB_AssignmentRequestIEs_t *ies, uint8_t rab_id)
{
RANAP_IE_t *release_list_ie;
RANAP_RAB_ReleaseItem_t *rab_release_item;
int rc;
uint8_t rab_id_decoded;
unsigned int index = 0;
while (1) {
release_list_ie = release_item_from_ass_req_ies(ies, index);
if (!release_list_ie)
return -EINVAL;
if (release_list_ie->id != RANAP_ProtocolIE_ID_id_RAB_ReleaseItem) {
RANAP_DEBUG("Decoding failed, the protocol IE is not of type RANAP RAB ReleaseItem!\n");
return -EINVAL;
}
rc = ranap_decode_rab_releaseitemies_fromlist(items_ies, &release_list_ie->value);
if (rc < 0)
return -EINVAL;
rab_release_item = &items_ies->raB_ReleaseItem;
/* The RAB-ID is defined as a bitstring with a size of 8 (1 byte),
* See also RANAP-IEs.asn, RAB-ID ::= BIT STRING (SIZE (8)) */
rab_id_decoded = rab_release_item->rAB_ID.buf[0];
if (rab_id_decoded == rab_id)
return index;
ASN_STRUCT_FREE_CONTENTS_ONLY(asn_DEF_RANAP_RAB_ReleaseItem, items_ies);
index++;
}
}
/*! Extract IP address and port from RANAP_RAB_AssignmentRequestIEs.
* \ptmap[out] addr user provided memory to store extracted RTP stream IP-Address and port number.
* \ptmap[out] rab_id pointer to store RAB-ID (optional, can be NULL).
@ -546,3 +598,25 @@ bool ranap_rab_ass_resp_ies_check_failure(RANAP_RAB_AssignmentResponseIEs_t *ies
return result;
}
/*! Check if a specific RAB is present in an RAB-ReleaseList inside RANAP_RAB_AssignmentRequestIEs.
* \ptmap[in] ies user provided memory with RANAP_RAB_AssignmentRequestIEs.
* \ptmap[in] rab_id expected rab id to look for.
* \returns true when RAB is intended for release; false otherwise */
bool ranap_rab_ass_req_ies_check_release(RANAP_RAB_AssignmentRequestIEs_t *ies, uint8_t rab_id)
{
RANAP_RAB_ReleaseItemIEs_t _rab_release_items_ies;
RANAP_RAB_ReleaseItemIEs_t *rab_release_items_ies = &_rab_release_items_ies;
int rc;
bool result = true;
/* If we can get a rlease list item for the specified RAB ID, then we know that the
* MSC intends to release the specified RAB */
rc = decode_rab_relitms_from_req_ies(rab_release_items_ies, ies, rab_id);
if (rc < 0)
result = false;
ASN_STRUCT_FREE_CONTENTS_ONLY(asn_DEF_RANAP_RAB_ReleaseItem, rab_release_items_ies);
return result;
}

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@ -295,6 +295,31 @@ void test_ranap_rab_ass_resp_ies_check_failure(void)
ranap_cn_rx_co_free(&message);
}
void test_ranap_rab_ass_req_ies_check_release(void)
{
int rc;
ranap_message message;
bool rab_release_req;
uint8_t testvec[] = {
0x00, 0x00, 0x00, 0x11, 0x00, 0x00, 0x01, 0x00,
0x29, 0x40, 0x0a, 0x00, 0x00, 0x01, 0x00, 0x28,
0x40, 0x03, 0x05, 0xd0, 0x00
};
rc = ranap_ran_rx_co_decode(talloc_asn1_ctx, &message, testvec, sizeof(testvec));
OSMO_ASSERT(rc == 0);
rab_release_req =
ranap_rab_ass_req_ies_check_release(&message.msg.raB_AssignmentRequestIEs, 23);
printf("ranap_rab_ass_req_ies_check_release rab_release_req=%u (RAB ID 23)\n", rab_release_req);
rab_release_req =
ranap_rab_ass_req_ies_check_release(&message.msg.raB_AssignmentRequestIEs, 44);
printf("ranap_rab_ass_req_ies_check_release rab_release_req=%u (RAB ID 44, which is not in the message)\n", rab_release_req);
ranap_ran_rx_co_free(&message);
}
static const struct log_info_cat log_cat[] = {
[DRANAP] = {
.name = "RANAP", .loglevel = LOGL_DEBUG, .enabled = 1,
@ -356,6 +381,7 @@ int main(int argc, char **argv)
test_ranap_rab_ass_req_replace_inet_addr();
test_ranap_rab_ass_resp_replace_inet_addr();
test_ranap_rab_ass_resp_ies_check_failure();
test_ranap_rab_ass_req_ies_check_release();
test_cleanup();
return 0;

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@ -16,3 +16,5 @@ ranap_rab_ass_resp_replace_inet_addr rc=0
after: addr=1.2.3.4, port=1234
ranap_rab_ass_resp_ies_check_failure rab_failed_at_hnb=1 (RAB ID 23)
ranap_rab_ass_resp_ies_check_failure rab_failed_at_hnb=0 (RAB ID 44, which is not in the message)
ranap_rab_ass_req_ies_check_release rab_release_req=1 (RAB ID 23)
ranap_rab_ass_req_ies_check_release rab_release_req=0 (RAB ID 44, which is not in the message)