[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_llc.c b/openbsc/src/gprs/gprs_llc.c
index c13f45f..26730d4 100644
--- a/openbsc/src/gprs/gprs_llc.c
+++ b/openbsc/src/gprs/gprs_llc.c
@@ -30,39 +30,57 @@
#include <openbsc/gsm_data.h>
#include <openbsc/debug.h>
+#include <openbsc/gprs_sgsn.h>
+#include <openbsc/gprs_gmm.h>
#include <openbsc/gprs_bssgp.h>
#include <openbsc/gprs_llc.h>
#include <openbsc/crc24.h>
-LLIST_HEAD(gprs_llc_lles);
+LLIST_HEAD(gprs_llc_llmes);
void *llc_tall_ctx;
/* lookup LLC Entity based on DLCI (TLLI+SAPI tuple) */
static struct gprs_llc_lle *lle_by_tlli_sapi(uint32_t tlli, uint32_t sapi)
{
- struct gprs_llc_lle *lle;
+ struct gprs_llc_llme *llme;
- llist_for_each_entry(lle, &gprs_llc_lles, list) {
- if (lle->tlli == tlli && lle->sapi == sapi)
- return lle;
+ llist_for_each_entry(llme, &gprs_llc_llmes, list) {
+ if (llme->tlli == tlli || llme->old_tlli == tlli)
+ return &llme->lle[sapi];
}
return NULL;
}
-static struct gprs_llc_lle *lle_alloc(uint32_t tlli, uint32_t sapi)
+static void lle_init(struct gprs_llc_llme *llme, uint32_t sapi)
{
- struct gprs_llc_lle *lle;
+ struct gprs_llc_lle *lle = &llme->lle[sapi];
- lle = talloc_zero(llc_tall_ctx, struct gprs_llc_lle);
- if (!lle)
+ lle->llme = llme;
+ lle->sapi = sapi;
+ lle->state = GPRS_LLES_UNASSIGNED;
+
+ /* FIXME: Initialize according to parameters from SAPI9 */
+
+}
+
+static struct gprs_llc_llme *llme_alloc(uint32_t tlli)
+{
+ struct gprs_llc_llme *llme;
+ uint32_t i;
+
+ llme = talloc_zero(llc_tall_ctx, struct gprs_llc_llme);
+ if (!llme)
return NULL;
- lle->tlli = tlli;
- lle->sapi = sapi;
- lle->state = GPRS_LLS_UNASSIGNED;
- llist_add(&lle->list, &gprs_llc_lles);
+ llme->tlli = tlli;
+ llme->state = GPRS_LLMS_UNASSIGNED;
- return lle;
+ for (i = 0; i < ARRAY_SIZE(llme->lle); i++)
+ lle_init(llme, i);
+
+ llist_add(&llme->list, &gprs_llc_llmes);
+
+ return llme;
}
enum gprs_llc_cmd {
@@ -134,16 +152,16 @@
if (lle->retrans_ctr >= lle->n200) {
/* FIXME: LLGM-STATUS-IND, LL-RELEASE-IND/CNF */
- lle->state = GPRS_LLS_ASSIGNED_ADM;
+ lle->state = GPRS_LLES_ASSIGNED_ADM;
}
switch (lle->state) {
- case GPRS_LLS_LOCAL_EST:
+ case GPRS_LLES_LOCAL_EST:
/* FIXME: retransmit SABM */
/* FIXME: re-start T200 */
lle->retrans_ctr++;
break;
- case GPRS_LLS_LOCAL_REL:
+ case GPRS_LLES_LOCAL_REL:
/* FIXME: retransmit DISC */
/* FIXME: re-start T200 */
lle->retrans_ctr++;
@@ -204,9 +222,9 @@
static int gprs_llc_tx_xid(struct gprs_llc_lle *lle, struct msgb *msg)
{
/* copy identifiers from LLE to ensure lower layers can route */
- msgb_tlli(msg) = lle->tlli;
- msgb_bvci(msg) = lle->bvci;
- msgb_nsei(msg) = lle->nsei;
+ msgb_tlli(msg) = lle->llme->tlli;
+ msgb_bvci(msg) = lle->llme->bvci;
+ msgb_nsei(msg) = lle->llme->nsei;
return gprs_llc_tx_u(msg, lle->sapi, 0, GPRS_LLC_U_XID, 1);
}
@@ -225,11 +243,14 @@
/* look-up or create the LL Entity for this (TLLI, SAPI) tuple */
lle = lle_by_tlli_sapi(msgb_tlli(msg), sapi);
- if (!lle)
- lle = lle_alloc(msgb_tlli(msg), sapi);
+ if (!lle) {
+ struct gprs_llc_llme *llme;
+ llme = llme_alloc(msgb_tlli(msg));
+ lle = &llme->lle[sapi];
+ }
/* Update LLE's (BVCI, NSEI) tuple */
- lle->bvci = msgb_bvci(msg);
- lle->nsei = msgb_nsei(msg);
+ lle->llme->bvci = msgb_bvci(msg);
+ lle->llme->nsei = msgb_nsei(msg);
/* Increment V(U) */
nu = lle->vu_send;
@@ -285,26 +306,26 @@
switch (gph->cmd) {
case GPRS_LLC_SABM: /* Section 6.4.1.1 */
lle->v_sent = lle->v_ack = lle->v_recv = 0;
- if (lle->state == GPRS_LLS_ASSIGNED_ADM) {
+ if (lle->state == GPRS_LLES_ASSIGNED_ADM) {
/* start re-establishment (8.7.1) */
}
- lle->state = GPRS_LLS_REMOTE_EST;
+ lle->state = GPRS_LLES_REMOTE_EST;
/* FIXME: Send UA */
- lle->state = GPRS_LLS_ABM;
+ lle->state = GPRS_LLES_ABM;
/* FIXME: process data */
break;
case GPRS_LLC_DISC: /* Section 6.4.1.2 */
/* FIXME: Send UA */
/* terminate ABM */
- lle->state = GPRS_LLS_ASSIGNED_ADM;
+ lle->state = GPRS_LLES_ASSIGNED_ADM;
break;
case GPRS_LLC_UA: /* Section 6.4.1.3 */
- if (lle->state == GPRS_LLS_LOCAL_EST)
- lle->state = GPRS_LLS_ABM;
+ if (lle->state == GPRS_LLES_LOCAL_EST)
+ lle->state = GPRS_LLES_ABM;
break;
case GPRS_LLC_DM: /* Section 6.4.1.4: ABM cannot be performed */
- if (lle->state == GPRS_LLS_LOCAL_EST)
- lle->state = GPRS_LLS_ASSIGNED_ADM;
+ if (lle->state == GPRS_LLES_LOCAL_EST)
+ lle->state = GPRS_LLES_ASSIGNED_ADM;
break;
case GPRS_LLC_FRMR: /* Section 6.4.1.5 */
break;
@@ -514,6 +535,18 @@
return -EIO;
}
+ switch (gprs_tlli_type(msgb_tlli(msg))) {
+ case TLLI_LOCAL:
+ case TLLI_FOREIGN:
+ case TLLI_RANDOM:
+ case TLLI_AUXILIARY:
+ break;
+ default:
+ LOGP(DLLC, LOGL_ERROR,
+ "Discarding frame with strange TLLI type\n");
+ break;
+ }
+
/* find the LLC Entity for this TLLI+SAPI tuple */
lle = lle_by_tlli_sapi(msgb_tlli(msg), llhp.sapi);
@@ -522,8 +555,10 @@
if (!lle) {
if (llhp.sapi == GPRS_SAPI_GMM &&
(llhp.cmd == GPRS_LLC_XID || llhp.cmd == GPRS_LLC_UI)) {
+ struct gprs_llc_llme *llme;
/* FIXME: don't use the TLLI but the 0xFFFF unassigned? */
- lle = lle_alloc(msgb_tlli(msg), llhp.sapi);
+ llme = llme_alloc(msgb_tlli(msg));
+ lle = &llme->lle[llhp.sapi];
} else {
LOGP(DLLC, LOGL_NOTICE,
"unknown TLLI/SAPI: Silently dropping\n");
@@ -532,8 +567,8 @@
}
/* Update LLE's (BVCI, NSEI) tuple */
- lle->bvci = msgb_bvci(msg);
- lle->nsei = msgb_nsei(msg);
+ lle->llme->bvci = msgb_bvci(msg);
+ lle->llme->nsei = msgb_nsei(msg);
/* Receive and Process the actual LLC frame */
rc = gprs_llc_hdr_rx(&llhp, lle);
@@ -546,7 +581,7 @@
switch (llhp.sapi) {
case GPRS_SAPI_GMM:
/* send LL_UNITDATA_IND to GMM */
- rc = gsm0408_gprs_rcvmsg(msg);
+ rc = gsm0408_gprs_rcvmsg(msg, lle->llme);
break;
case GPRS_SAPI_TOM2:
case GPRS_SAPI_TOM8:
@@ -567,3 +602,51 @@
return rc;
}
+
+/* 04.64 Chapter 7.2.1.1 LLGMM-ASSIGN */
+int gprs_llgmm_assign(struct gprs_llc_llme *llme,
+ uint32_t old_tlli, uint32_t new_tlli,
+ enum gprs_ciph_algo alg, const uint8_t *kc)
+{
+ unsigned int i;
+
+ if (old_tlli == 0xffffffff && new_tlli != 0xffffffff) {
+ /* TLLI Assignment 8.3.1 */
+ /* New TLLI shall be assigned and used when (re)transmitting LLC frames */
+ /* If old TLLI != 0xffffffff was assigned to LLME, then TLLI
+ * old is unassigned. Only TLLI new shall be accepted when
+ * received from peer. */
+
+ /* If TLLI old == 0xffffffff was assigned to LLME, then this is
+ * TLLI assignmemt according to 8.3.1 */
+ llme->old_tlli = 0;
+ llme->tlli = new_tlli;
+ llme->state = GPRS_LLMS_ASSIGNED;
+ /* 8.5.3.1 For all LLE's */
+ for (i = 0; i < ARRAY_SIZE(llme->lle); i++) {
+ struct gprs_llc_lle *l = &llme->lle[i];
+ l->vu_send = l->vu_recv = 0;
+ l->retrans_ctr = 0;
+ l->state = GPRS_LLES_ASSIGNED_ADM;
+ /* FIXME Set parameters according to table 9 */
+ }
+ } else if (old_tlli != 0xffffffff && new_tlli != 0xffffffff) {
+ /* TLLI Change 8.3.2 */
+ /* Both TLLI Old and TLLI New are assigned; use New when
+ * (re)transmitting. Accept toth Old and New on Rx */
+ llme->old_tlli = llme->tlli;
+ llme->tlli = new_tlli;
+ llme->state = GPRS_LLMS_ASSIGNED;
+ } else if (old_tlli != 0xffffffff && new_tlli == 0xffffffff) {
+ /* TLLI Unassignment 8.3.3) */
+ llme->tlli = llme->old_tlli = 0;
+ llme->state = GPRS_LLMS_UNASSIGNED;
+ for (i = 0; i < ARRAY_SIZE(llme->lle); i++) {
+ struct gprs_llc_lle *l = &llme->lle[i];
+ l->state = GPRS_LLES_UNASSIGNED;
+ }
+ } else
+ return -EINVAL;
+
+ return 0;
+}