lynxis lazus submitted this change.
GMM: split parsing of a RA Update Request in a separate file
gprs_gmm.c is huge. Further split the general validation
and parsing of the message into an own function.
Change-Id: I413da1b6b4b7c0c4781393acd8564661bc74ce2d
---
M include/osmocom/sgsn/gprs_gmm_util.h
M src/sgsn/gprs_gmm.c
M src/sgsn/gprs_gmm_util.c
3 files changed, 104 insertions(+), 44 deletions(-)
diff --git a/include/osmocom/sgsn/gprs_gmm_util.h b/include/osmocom/sgsn/gprs_gmm_util.h
index be89c35..c136cce 100644
--- a/include/osmocom/sgsn/gprs_gmm_util.h
+++ b/include/osmocom/sgsn/gprs_gmm_util.h
@@ -1,5 +1,25 @@
#pragma once
+#include <stdbool.h>
+#include <stdint.h>
+
+#include <osmocom/gsm/gsm23003.h>
#include <osmocom/gsm/tlv.h>
+struct msgb;
+
extern const struct tlv_definition gsm48_gmm_ie_tlvdef;
+
+/* 9.4.14 RAU Request */
+struct gprs_gmm_ra_upd_req {
+ uint8_t skip_ind; /* 10.3.1 */
+ uint8_t update_type; /* 10.5.5.18 */
+ bool follow_up_req; /* 10.5.5.18 */
+ uint8_t cksq; /* 10.5.1.2 */
+ struct osmo_routing_area_id old_rai; /* 10.5.5.15 */
+ uint8_t *ms_radio_cap; /* 10.5.5.12a */
+ uint8_t ms_radio_cap_len;
+ struct tlv_parsed tlv;
+};
+
+int gprs_gmm_parse_ra_upd_req(struct msgb *msg, struct gprs_gmm_ra_upd_req *rau_req);
diff --git a/src/sgsn/gprs_gmm.c b/src/sgsn/gprs_gmm.c
index 324c6bf..6122421 100644
--- a/src/sgsn/gprs_gmm.c
+++ b/src/sgsn/gprs_gmm.c
@@ -1594,52 +1594,30 @@
#ifndef PTMSI_ALLOC
struct sgsn_signal_data sig_data;
#endif
- struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_gmmh(msg);
- uint8_t *cur = gh->data;
- uint8_t ms_ra_acc_cap_len;
- struct osmo_routing_area_id old_ra_id;
- struct tlv_parsed tp;
- uint8_t upd_type;
enum gsm48_gmm_cause reject_cause = GMM_CAUSE_PROTO_ERR_UNSPEC;
+ struct gprs_gmm_ra_upd_req req;
int rc;
+ rc = gprs_gmm_parse_ra_upd_req(msg, &req);
+ if (rc) {
+ reject_cause = rc;
+ goto rejected;
+ }
+
/* TODO: In iu mode - handle follow-on request.
* The follow-on request can be signaled in an Attach Request on IuPS.
* This means the MS/UE asks to keep the PS connection open for further requests
* after the Attach Request succeed.
* The SGSN can decide if it close the connection or not. Both are spec conform. */
- /* Update Type 10.5.5.18 */
- upd_type = *cur++ & 0x07;
-
rate_ctr_inc(rate_ctr_group_get_ctr(sgsn->rate_ctrs, CTR_GPRS_ROUTING_AREA_REQUEST));
LOGMMCTXP(LOGL_INFO, mmctx, "-> GMM RA UPDATE REQUEST type=\"%s\"\n",
- get_value_string(gprs_upd_t_strs, upd_type));
+ get_value_string(gprs_upd_t_strs, req.update_type));
- /* Old routing area identification 10.5.5.15 */
- osmo_routing_area_id_decode(&old_ra_id, cur, msgb_l3len(msg) - (cur - msgb_gmmh(msg)));
- cur += 6;
-
- /* MS Radio Access Capability 10.5.5.12a */
- ms_ra_acc_cap_len = *cur++;
- if (ms_ra_acc_cap_len > 52) {
- LOGMMCTXP(LOGL_ERROR, mmctx,
- "Rejecting GMM RA Update Request: MS Radio Access Capability too long"
- " (ms_ra_acc_cap_len = %u > 52)\n", ms_ra_acc_cap_len);
- reject_cause = GMM_CAUSE_PROTO_ERR_UNSPEC;
- goto rejected;
- }
- cur += ms_ra_acc_cap_len;
-
- /* Optional: Old P-TMSI Signature, Requested READY timer, TMSI Status,
- * DRX parameter, MS network capability */
- tlv_parse(&tp, &gsm48_gmm_ie_tlvdef, cur,
- (msg->data + msg->len) - cur, 0, 0);
-
- switch (upd_type) {
+ switch (req.update_type) {
case GPRS_UPD_T_RA_LA:
case GPRS_UPD_T_RA_LA_IMSI_ATT:
- LOGMMCTXP(LOGL_NOTICE, mmctx, "Update type %i unsupported in Mode III, is your SI13 corrupt?\n", upd_type);
+ LOGMMCTXP(LOGL_NOTICE, mmctx, "Update type %d unsupported in Mode III, is your SI13 corrupt?\n", req.update_type);
reject_cause = GMM_CAUSE_PROTO_ERR_UNSPEC;
goto rejected;
case GPRS_UPD_T_RA:
@@ -1658,13 +1636,13 @@
/* Look-up the MM context based on old RA-ID and TLLI */
if (!MSG_IU_UE_CTX(msg)) {
/* Gb */
- mmctx = sgsn_mm_ctx_by_tlli_and_ptmsi(msgb_tlli(msg), &old_ra_id);
- } else if (TLVP_PRESENT(&tp, GSM48_IE_GMM_ALLOC_PTMSI)) {
+ mmctx = sgsn_mm_ctx_by_tlli_and_ptmsi(msgb_tlli(msg), &req.old_rai);
+ } else if (TLVP_PRESENT(&req.tlv, GSM48_IE_GMM_ALLOC_PTMSI)) {
#ifdef BUILD_IU
/* In Iu mode search only for ptmsi */
struct osmo_mobile_identity mi;
- if (osmo_mobile_identity_decode(&mi, TLVP_VAL(&tp, GSM48_IE_GMM_ALLOC_PTMSI),
- TLVP_LEN(&tp, GSM48_IE_GMM_ALLOC_PTMSI), false)
+ if (osmo_mobile_identity_decode(&mi, TLVP_VAL(&req.tlv, GSM48_IE_GMM_ALLOC_PTMSI),
+ TLVP_LEN(&req.tlv, GSM48_IE_GMM_ALLOC_PTMSI), false)
|| mi.type != GSM_MI_TYPE_TMSI) {
LOGIUP(MSG_IU_UE_CTX(msg), LOGL_ERROR, "Cannot decode P-TMSI\n");
goto rejected;
@@ -1692,7 +1670,7 @@
osmo_fsm_inst_dispatch(mmctx->gmm_fsm, E_GMM_COMMON_PROC_INIT_REQ, NULL);
}
- } else if (osmo_rai_cmp(&mmctx->ra, &old_ra_id) ||
+ } else if (osmo_rai_cmp(&mmctx->ra, &req.old_rai) ||
mmctx->gmm_fsm->state == ST_GMM_DEREGISTERED)
{
/* We've received either a RAU for a MS which isn't registered
@@ -1707,11 +1685,11 @@
if (mmctx->gmm_fsm->state == ST_GMM_DEREGISTERED)
LOGMMCTXP(LOGL_INFO, mmctx,
"Rejecting RAU - GMM state is deregistered. Old RA: %s New RA: %s\n",
- osmo_rai_name2(&old_ra_id), new_ra);
+ osmo_rai_name2(&req.old_rai), new_ra);
else
LOGMMCTXP(LOGL_INFO, mmctx,
"Rejecting RAU - Old RA doesn't match MM. Old RA: %s New RA: %s\n",
- osmo_rai_name2(&old_ra_id), new_ra);
+ osmo_rai_name2(&req.old_rai), new_ra);
reject_cause = GMM_CAUSE_IMPL_DETACHED;
goto rejected;
@@ -1732,7 +1710,7 @@
mmctx = sgsn_mm_ctx_by_llme(llme);
if (mmctx) {
char old_ra_id_name[32];
- osmo_rai_name2_buf(old_ra_id_name, sizeof(old_ra_id_name), &old_ra_id);
+ osmo_rai_name2_buf(old_ra_id_name, sizeof(old_ra_id_name), &req.old_rai);
LOGMMCTXP(LOGL_NOTICE, mmctx,
"Rx RA Update Request with unexpected TLLI=%08x Old RA=%s (expected Old RA: %s)!\n",
msgb_tlli(msg), old_ra_id_name, osmo_rai_name2(&mmctx->ra));
@@ -1764,8 +1742,8 @@
mmctx->gb.tlli = msgb_tlli(msg);
}
/* Update the MM context with the new DRX params */
- if (TLVP_PRESENT(&tp, GSM48_IE_GMM_DRX_PARAM))
- memcpy(&mmctx->drx_parms, TLVP_VAL(&tp, GSM48_IE_GMM_DRX_PARAM), sizeof(mmctx->drx_parms));
+ if (TLVP_PRESENT(&req.tlv, GSM48_IE_GMM_DRX_PARAM))
+ memcpy(&mmctx->drx_parms, TLVP_VAL(&req.tlv, GSM48_IE_GMM_DRX_PARAM), sizeof(mmctx->drx_parms));
/* FIXME: Update the MM context with the MS radio acc capabilities */
/* FIXME: Update the MM context with the MS network capabilities */
@@ -1798,8 +1776,8 @@
/* Look at PDP Context Status IE and see if MS's view of
* activated/deactivated NSAPIs agrees with our view */
- if (TLVP_PRESENT(&tp, GSM48_IE_GMM_PDP_CTX_STATUS)) {
- const uint8_t *pdp_status = TLVP_VAL(&tp, GSM48_IE_GMM_PDP_CTX_STATUS);
+ if (TLVP_PRESENT(&req.tlv, GSM48_IE_GMM_PDP_CTX_STATUS)) {
+ const uint8_t *pdp_status = TLVP_VAL(&req.tlv, GSM48_IE_GMM_PDP_CTX_STATUS);
process_ms_ctx_status(mmctx, pdp_status);
}
diff --git a/src/sgsn/gprs_gmm_util.c b/src/sgsn/gprs_gmm_util.c
index 1248e93..0cf730f 100644
--- a/src/sgsn/gprs_gmm_util.c
+++ b/src/sgsn/gprs_gmm_util.c
@@ -23,10 +23,14 @@
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+#include <osmocom/core/msgb.h>
+#include <osmocom/gprs/gprs_msgb.h>
#include <osmocom/gsm/gsm48.h>
#include <osmocom/gsm/protocol/gsm_04_08_gprs.h>
#include <osmocom/gsm/tlv.h>
+#include <osmocom/sgsn/gprs_gmm_util.h>
+
const struct tlv_definition gsm48_gmm_ie_tlvdef = {
.def = {
[GSM48_IE_GMM_CIPH_CKSN] = { TLV_TYPE_SINGLE_TV, 1 },
@@ -47,3 +51,61 @@
},
};
+/*! Parse 24.008 9.4.14 RAU Request
+ * \param[in] msg l3 pointers must point to gmm.
+ * \param[out] rau_req parsed RA update request
+ * \returns 0 on success or GMM cause
+ */
+int gprs_gmm_parse_ra_upd_req(struct msgb *msg, struct gprs_gmm_ra_upd_req *rau_req)
+{
+ uint8_t *cur, len;
+ size_t mandatory_fields_len;
+ struct gsm48_hdr *gh;
+ int ret;
+
+ OSMO_ASSERT(msg);
+ OSMO_ASSERT(rau_req);
+
+ memset(rau_req, 0, sizeof(struct gprs_gmm_ra_upd_req));
+
+ /* all mandatory fields + variable length MS Radio Cap (min value) */
+ if (msgb_l3len(msg) < 16)
+ return GMM_CAUSE_PROTO_ERR_UNSPEC;
+
+ gh = (struct gsm48_hdr *) msgb_gmmh(msg);
+ cur = gh->data;
+
+ rau_req->skip_ind = gh->proto_discr >> 4;
+
+ /* V: Update Type 10.5.5.18 */
+ rau_req->update_type = *cur & 0x07;
+ rau_req->follow_up_req = !!(*cur & 0x08);
+ /* V: GPRS Ciphering Key Sequence 10.5.1.2 */
+ rau_req->cksq = *cur >> 4;
+ cur++;
+
+ /* V: Old routing area identification 10.5.5.15 */
+ osmo_routing_area_id_decode(&rau_req->old_rai, cur, 6);
+ cur += 6;
+
+ /* LV: MS radio cap 10.5.5.12a */
+ len = *cur++;
+ if (msgb_l3len(msg) < (len + (cur - msgb_gmmh(msg))))
+ return GMM_CAUSE_PROTO_ERR_UNSPEC;
+
+ rau_req->ms_radio_cap = cur;
+ rau_req->ms_radio_cap_len = len;
+ cur += len;
+
+ mandatory_fields_len = (cur - msgb_gmmh(msg));
+ if (msgb_l3len(msg) == mandatory_fields_len)
+ return 0;
+
+ ret = tlv_parse(&rau_req->tlv, &gsm48_gmm_ie_tlvdef,
+ cur, msgb_l3len(msg) - mandatory_fields_len, 0, 0);
+
+ if (ret < 0)
+ return GMM_CAUSE_COND_IE_ERR;
+
+ return 0;
+}
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