gb: Fix RESET handling with changing NSEI
This modifies the NS stack's behavior to accept RESET and RESET_ACK
NSEI changes for NS-VC dynamically created by RESET messages from
BSSes. This feature is not used for NS-VC configured via VTY or NS-VC
to a SGSN.
Sponsored-by: On-Waves ehf
diff --git a/src/gb/gprs_ns.c b/src/gb/gprs_ns.c
index a597c2c..043a66c 100644
--- a/src/gb/gprs_ns.c
+++ b/src/gb/gprs_ns.c
@@ -114,7 +114,7 @@
{ "blocked", "NS-VC Block count " },
{ "dead", "NS-VC gone dead count " },
{ "replaced", "NS-VC replaced other count" },
- { "nsei-chg", "NS-VC changed NSEI " },
+ { "nsei-chg", "NS-VC changed NSEI count " },
{ "inv-nsvci", "NS-VCI was invalid count " },
{ "inv-nsei", "NSEI was invalid count " },
};
@@ -769,10 +769,8 @@
(*nsvc)->nsvci, (*nsvc)->nsvci_is_valid ? "" : "(invalid)",
nsei, nsvci, gprs_ns_cause_str(cause));
- if (!(*nsvc)->nsvci_is_valid) {
- /* It's a new uninitialised NS-VC, nothing to check here */
- } else if ((*nsvc)->nsvci != nsvci) {
- if ((*nsvc)->remote_end_is_sgsn) {
+ if ((*nsvc)->nsvci_is_valid && (*nsvc)->nsvci != nsvci) {
+ if ((*nsvc)->persistent || (*nsvc)->remote_end_is_sgsn) {
/* The incoming RESET doesn't match the NSVCI. Send an
* appropriate RESET_ACK and ignore the RESET.
* See 3GPP TS 08.16, 7.3.1, 2nd paragraph.
@@ -787,18 +785,25 @@
/* NS-VCI has changed */
gprs_nsvc_replace_if_found(nsvci, nsvc, &orig_nsvc);
+ }
- } else if ((*nsvc)->nsei != nsei) {
- /* The incoming RESET doesn't match the NSEI. Send an
- * appropriate RESET_ACK and ignore the RESET.
- * See 3GPP TS 08.16, 7.3.1, 3rd paragraph.
- */
- ns_osmo_signal_dispatch_mismatch(*nsvc, msg,
- NS_PDUT_RESET,
- NS_IE_NSEI);
- rate_ctr_inc(&(*nsvc)->ctrg->ctr[NS_CTR_INV_NSEI]);
- gprs_ns_tx_reset_ack(*nsvc);
- return 0;
+ if ((*nsvc)->nsvci_is_valid && (*nsvc)->nsei != nsei) {
+ if ((*nsvc)->persistent || (*nsvc)->remote_end_is_sgsn) {
+ /* The incoming RESET doesn't match the NSEI. Send an
+ * appropriate RESET_ACK and ignore the RESET.
+ * See 3GPP TS 08.16, 7.3.1, 3rd paragraph.
+ */
+ ns_osmo_signal_dispatch_mismatch(*nsvc, msg,
+ NS_PDUT_RESET,
+ NS_IE_NSEI);
+ rate_ctr_inc(&(*nsvc)->ctrg->ctr[NS_CTR_INV_NSEI]);
+ gprs_ns_tx_reset_ack(*nsvc);
+ return 0;
+ }
+
+ /* NSEI has changed */
+ rate_ctr_inc(&(*nsvc)->ctrg->ctr[NS_CTR_NSEI_CHG]);
+ (*nsvc)->nsei = nsei;
}
/* Mark NS-VC as blocked and alive */
@@ -885,7 +890,8 @@
int use_other_nsvc;
/* Only do this with BSS peers */
- use_other_nsvc = !(*nsvc)->remote_end_is_sgsn;
+ use_other_nsvc = !(*nsvc)->remote_end_is_sgsn &&
+ !(*nsvc)->persistent;
if (use_other_nsvc)
/* Update *nsvc to point to the right NSVC object */
@@ -916,17 +922,23 @@
gprs_ns_ll_copy(*nsvc, orig_nsvc);
gprs_ns_ll_clear(orig_nsvc);
} else if ((*nsvc)->nsei != nsei) {
- /* The incoming RESET_ACK doesn't match the NSEI.
- * See 3GPP TS 08.16, 7.3.1, 4th paragraph.
- */
- ns_osmo_signal_dispatch_mismatch(*nsvc, msg,
- NS_PDUT_RESET_ACK,
- NS_IE_NSEI);
- rate_ctr_inc(&(*nsvc)->ctrg->ctr[NS_CTR_INV_NSEI]);
- LOGP(DNS, LOGL_ERROR,
- "NS RESET ACK Unknown NSEI %d (NS-VCI=%u) from %s\n",
- nsei, nsvci, gprs_ns_ll_str(*nsvc));
- return -EINVAL;
+ if ((*nsvc)->persistent || (*nsvc)->remote_end_is_sgsn) {
+ /* The incoming RESET_ACK doesn't match the NSEI.
+ * See 3GPP TS 08.16, 7.3.1, 4th paragraph.
+ */
+ ns_osmo_signal_dispatch_mismatch(*nsvc, msg,
+ NS_PDUT_RESET_ACK,
+ NS_IE_NSEI);
+ rate_ctr_inc(&(*nsvc)->ctrg->ctr[NS_CTR_INV_NSEI]);
+ LOGP(DNS, LOGL_ERROR,
+ "NS RESET ACK Unknown NSEI %d (NS-VCI=%u) from %s\n",
+ nsei, nsvci, gprs_ns_ll_str(*nsvc));
+ return -EINVAL;
+ }
+
+ /* NSEI has changed */
+ rate_ctr_inc(&(*nsvc)->ctrg->ctr[NS_CTR_NSEI_CHG]);
+ (*nsvc)->nsei = nsei;
}
/* Mark NS-VC as blocked and alive */