canghaiwuhen has uploaded this change for review. (
https://gerrit.osmocom.org/c/osmo-sgsn/+/41948?usp=email )
Change subject: Related: OS#6922 Modified to dynamically adjust the returned
QoS length to ensure compatibility with older modules.
......................................................................
Related: OS#6922 Modified to dynamically adjust the returned QoS length to
ensure compatibility with older modules.
Change-Id: I872d882de4ce186f644b1b3ab684963050709d4f
---
M include/osmocom/sgsn/pdpctx.h
M src/sgsn/gprs_sm.c
2 files changed, 15 insertions(+), 4 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/osmo-sgsn refs/changes/48/41948/1
diff --git a/include/osmocom/sgsn/pdpctx.h b/include/osmocom/sgsn/pdpctx.h
index c6a43de..ac84a18 100644
--- a/include/osmocom/sgsn/pdpctx.h
+++ b/include/osmocom/sgsn/pdpctx.h
@@ -65,6 +65,7 @@
uint16_t sapi; /* LLC */
uint8_t ti; /* transaction identifier */
int vplmn_allowed;
+ uint8_t req_qos_len; /* Original Requested QoS Length
(Air Interface) */
uint32_t qos_profile_subscr;
//uint32_t qos_profile_req;
//uint32_t qos_profile_neg;
diff --git a/src/sgsn/gprs_sm.c b/src/sgsn/gprs_sm.c
index 919dbf3..51ebdec 100644
--- a/src/sgsn/gprs_sm.c
+++ b/src/sgsn/gprs_sm.c
@@ -206,11 +206,20 @@
/* FIXME: copy QoS parameters from original request */
//msgb_lv_put(msg, pdp->lib->qos_neg.l, pdp->lib->qos_neg.v);
-// msgb_lv_put(msg, sizeof(default_qos), (uint8_t *)&default_qos);
- /* HACK: Force R97 QoS length (3 bytes) to avoid crashing legacy modems
- * which cannot handle R99 extensions (14 bytes). */
- msgb_lv_put(msg, 3, (uint8_t *)&default_qos);
+ /* ANTIGRAVITY PATCH: True Echo.
+ * Use the explicitly stored original Air Interface QoS length
(req_qos_len).
+ * Modern modules send 14+ bytes (R99) and expect full responses.
+ * SOLUTION: Reply with exactly the length they asked for.
+ * Special circumstances force R97 QoS length (3 bytes)
+ */
+ uint8_t qos_len = pdp->req_qos_len;
+ if (qos_len == 0)
+ qos_len = 3; // Safety fallback for R97
+ if (qos_len > sizeof(default_qos))
+ qos_len = sizeof(default_qos);
+
+ msgb_lv_put(msg, qos_len, (uint8_t *)&default_qos);
/* Radio priority 10.5.7.2 */
msgb_v_put(msg, pdp->lib->radio_pri);
@@ -328,6 +337,7 @@
pdp->sapi = req_llc_sapi;
pdp->ti = transaction_id;
pdp->destroy_ggsn = destroy_ggsn;
+ pdp->req_qos_len = tp->lv[OSMO_IE_GSM_REQ_QOS].len;
return 0;
}
--
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Gerrit-MessageType: newchange
Gerrit-Project: osmo-sgsn
Gerrit-Branch: master
Gerrit-Change-Id: I872d882de4ce186f644b1b3ab684963050709d4f
Gerrit-Change-Number: 41948
Gerrit-PatchSet: 1
Gerrit-Owner: canghaiwuhen <[email protected]>
