[GPRS] Major LLC / TLLI handling fixes
* separate the LLME and LLE state in the LLC layer
* introduce gprs_llgmm_assign() function for LLGMM-ASSIGN.req primitive
* change QoS profile to match 'real' SGSN
* Update the new TLLI when assigning a P-TMSI
The result now is that the LLC layer is notified of TLLI changes, which in turn
means it doesn't allocate a new LLE structure every TLLI change, which again
in turn means that the UI frame sequence number does not reset to zero.
As a result, MS should no longer ignore frames based on wrong UI sequence number.
diff --git a/openbsc/src/gprs/gprs_gmm.c b/openbsc/src/gprs/gprs_gmm.c
index 5492b16..ed9f403 100644
--- a/openbsc/src/gprs/gprs_gmm.c
+++ b/openbsc/src/gprs/gprs_gmm.c
@@ -416,7 +416,8 @@
}
/* Section 9.4.1 Attach request */
-static int gsm48_rx_gmm_att_req(struct sgsn_mm_ctx *mmctx, struct msgb *msg)
+static int gsm48_rx_gmm_att_req(struct sgsn_mm_ctx *ctx, struct msgb *msg,
+ struct gprs_llc_llme *llme)
{
struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_gmmh(msg);
uint8_t *cur = gh->data, *msnc, *mi, *old_ra_info, *ms_ra_acc_cap;
@@ -426,7 +427,6 @@
char mi_string[GSM48_MI_SIZE];
struct gprs_ra_id ra_id;
uint16_t cid;
- struct sgsn_mm_ctx *ctx;
DEBUGP(DMM, "-> GMM ATTACH REQUEST ");
@@ -476,7 +476,8 @@
switch (mi_type) {
case GSM_MI_TYPE_IMSI:
/* Try to find MM context based on IMSI */
- ctx = sgsn_mm_ctx_by_imsi(mi_string);
+ if (!ctx)
+ ctx = sgsn_mm_ctx_by_imsi(mi_string);
if (!ctx) {
#if 0
return gsm48_tx_gmm_att_rej(msg, GMM_CAUSE_IMSI_UNKNOWN);
@@ -489,19 +490,22 @@
#endif
}
ctx->tlli = msgb_tlli(msg);
+ ctx->llme = llme;
msgid2mmctx(ctx, msg);
break;
case GSM_MI_TYPE_TMSI:
memcpy(&tmsi, mi+1, 4);
tmsi = ntohl(tmsi);
/* Try to find MM context based on P-TMSI */
- ctx = sgsn_mm_ctx_by_ptmsi(tmsi);
+ if (!ctx)
+ ctx = sgsn_mm_ctx_by_ptmsi(tmsi);
if (!ctx) {
ctx = sgsn_mm_ctx_alloc(msgb_tlli(msg), &ra_id);
- ctx->tlli = msgb_tlli(msg);
- msgid2mmctx(ctx, msg);
+ ctx->p_tmsi = tmsi;
}
- ctx->p_tmsi = tmsi;
+ ctx->tlli = msgb_tlli(msg);
+ ctx->llme = llme;
+ msgid2mmctx(ctx, msg);
break;
default:
LOGP(DMM, LOGL_NOTICE, "Rejecting ATTACH REQUEST with "
@@ -519,14 +523,18 @@
memcpy(ctx->ms_network_capa.buf, msnc, msnc_len);
#ifdef PTMSI_ALLOC
- /* Allocate a new P-TMSI (+ P-TMSI signature) */
+ /* Allocate a new P-TMSI (+ P-TMSI signature) and update TLLI */
ctx->p_tmsi_old = ctx->p_tmsi;
ctx->p_tmsi = sgsn_alloc_ptmsi();
#endif
- /* FIXME: update the TLLI with the new local TLLI based on the P-TMSI */
+ /* Even if there is no P-TMSI allocated, the MS will switch from
+ * foreign TLLI to local TLLI */
+ ctx->tlli_new = gprs_tmsi2tlli(ctx->p_tmsi, TLLI_LOCAL);
+
+ /* Inform LLC layer about new TLLI but keep old active */
+ gprs_llgmm_assign(ctx->llme, ctx->tlli, ctx->tlli_new, 0, NULL);
DEBUGPC(DMM, "\n");
-
return ctx ? gsm48_gmm_authorize(ctx, GMM_T3350_MODE_ATT) : 0;
err_inval:
@@ -620,12 +628,14 @@
}
/* Chapter 9.4.14: Routing area update request */
-static int gsm48_rx_gmm_ra_upd_req(struct sgsn_mm_ctx *mmctx, struct msgb *msg)
+static int gsm48_rx_gmm_ra_upd_req(struct sgsn_mm_ctx *mmctx, struct msgb *msg,
+ struct gprs_llc_llme *llme)
{
struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_gmmh(msg);
uint8_t *cur = gh->data;
struct gprs_ra_id old_ra_id;
uint8_t upd_type;
+ int rc;
/* Update Type 10.5.5.18 */
upd_type = *cur++ & 0x0f;
@@ -678,7 +688,14 @@
mmctx->t3350_mode = GMM_T3350_MODE_RAU;
mmctx_timer_start(mmctx, 3350, GSM0408_T3350_SECS);
#endif
+ /* Even if there is no P-TMSI allocated, the MS will switch from
+ * foreign TLLI to local TLLI */
+ mmctx->tlli_new = gprs_tmsi2tlli(mmctx->p_tmsi, TLLI_LOCAL);
+ /* Inform LLC layer about new TLLI but keep old active */
+ gprs_llgmm_assign(mmctx->llme, mmctx->tlli, mmctx->tlli_new, 0, NULL);
+
+ /* Send RA UPDATE ACCEPT */
return gsm48_tx_gmm_ra_upd_ack(mmctx);
}
@@ -693,11 +710,14 @@
}
/* GPRS Mobility Management */
-static int gsm0408_rcv_gmm(struct sgsn_mm_ctx *mmctx, struct msgb *msg)
+static int gsm0408_rcv_gmm(struct sgsn_mm_ctx *mmctx, struct msgb *msg,
+ struct gprs_llc_llme *llme)
{
struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_gmmh(msg);
int rc;
+ /* MMCTX can be NULL when called */
+
if (!mmctx &&
gh->msg_type != GSM48_MT_GMM_ATTACH_REQ &&
gh->msg_type != GSM48_MT_GMM_RA_UPD_REQ) {
@@ -706,13 +726,12 @@
return -EINVAL;
}
-
switch (gh->msg_type) {
case GSM48_MT_GMM_RA_UPD_REQ:
- rc = gsm48_rx_gmm_ra_upd_req(mmctx, msg);
+ rc = gsm48_rx_gmm_ra_upd_req(mmctx, msg, llme);
break;
case GSM48_MT_GMM_ATTACH_REQ:
- rc = gsm48_rx_gmm_att_req(mmctx, msg);
+ rc = gsm48_rx_gmm_att_req(mmctx, msg, llme);
break;
case GSM48_MT_GMM_ID_RESP:
rc = gsm48_rx_gmm_id_resp(mmctx, msg);
@@ -728,17 +747,26 @@
DEBUGP(DMM, "-> ATTACH COMPLETE\n");
mmctx_timer_stop(mmctx, 3350);
mmctx->p_tmsi_old = 0;
+ /* Unassign the old TLLI */
+ mmctx->tlli = mmctx->tlli_new;
+ //gprs_llgmm_assign(mmctx->llme, 0xffffffff, mmctx->tlli_new, 0, NULL);
break;
case GSM48_MT_GMM_RA_UPD_COMPL:
/* only in case SGSN offered new P-TMSI */
DEBUGP(DMM, "-> ROUTEING AREA UPDATE COMPLETE\n");
mmctx_timer_stop(mmctx, 3350);
mmctx->p_tmsi_old = 0;
+ /* Unassign the old TLLI */
+ mmctx->tlli = mmctx->tlli_new;
+ //gprs_llgmm_assign(mmctx->llme, 0xffffffff, mmctx->tlli_new, 0, NULL);
break;
case GSM48_MT_GMM_PTMSI_REALL_COMPL:
DEBUGP(DMM, "-> PTMSI REALLLICATION COMPLETE\n");
mmctx_timer_stop(mmctx, 3350);
mmctx->p_tmsi_old = 0;
+ /* Unassign the old TLLI */
+ mmctx->tlli = mmctx->tlli_new;
+ //gprs_llgmm_assign(mmctx->llme, 0xffffffff, mmctx->tlli_new, 0, NULL);
break;
case GSM48_MT_GMM_AUTH_CIPH_RESP:
DEBUGP(DMM, "Unimplemented GSM 04.08 GMM msg type 0x%02x\n",
@@ -1044,11 +1072,14 @@
}
/* GPRS Session Management */
-static int gsm0408_rcv_gsm(struct sgsn_mm_ctx *mmctx, struct msgb *msg)
+static int gsm0408_rcv_gsm(struct sgsn_mm_ctx *mmctx, struct msgb *msg,
+ struct gprs_llc_llme *llme)
{
struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_gmmh(msg);
int rc;
+ /* MMCTX can be NULL when called */
+
if (!mmctx) {
LOGP(DMM, LOGL_NOTICE, "Cannot handle SM for unknown MM CTX\n");
/* FIXME: return SM / MM STATUS */
@@ -1084,7 +1115,7 @@
}
/* Main entry point for incoming 04.08 GPRS messages */
-int gsm0408_gprs_rcvmsg(struct msgb *msg)
+int gsm0408_gprs_rcvmsg(struct msgb *msg, struct gprs_llc_llme *llme)
{
struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_gmmh(msg);
uint8_t pdisc = gh->proto_discr & 0x0f;
@@ -1097,16 +1128,17 @@
if (mmctx) {
msgid2mmctx(mmctx, msg);
rate_ctr_inc(&mmctx->ctrg->ctr[GMM_CTR_PKTS_SIG_IN]);
+ mmctx->llme = llme;
}
/* MMCTX can be NULL */
switch (pdisc) {
case GSM48_PDISC_MM_GPRS:
- rc = gsm0408_rcv_gmm(mmctx, msg);
+ rc = gsm0408_rcv_gmm(mmctx, msg, llme);
break;
case GSM48_PDISC_SM_GPRS:
- rc = gsm0408_rcv_gsm(mmctx, msg);
+ rc = gsm0408_rcv_gsm(mmctx, msg, llme);
break;
default:
DEBUGP(DMM, "Unknown GSM 04.08 discriminator 0x%02x\n",