SGSN: Implement network-initiated PDP CTX DEACT when GGSN restarts
If the GGSN restarts, its restart counter will increase. We can
detect that and accordingly release/delete all PDP contexts for
that GGSN.
diff --git a/openbsc/include/openbsc/gprs_gmm.h b/openbsc/include/openbsc/gprs_gmm.h
index b91b489..bd129ae 100644
--- a/openbsc/include/openbsc/gprs_gmm.h
+++ b/openbsc/include/openbsc/gprs_gmm.h
@@ -4,6 +4,7 @@
#include <osmocore/msgb.h>
#include <openbsc/gprs_sgsn.h>
+int gsm48_tx_gsm_deact_pdp_req(struct sgsn_pdp_ctx *pdp, uint8_t sm_cause);
int gsm48_tx_gsm_act_pdp_rej(struct sgsn_mm_ctx *mm, uint8_t tid,
uint8_t cause, uint8_t pco_len, uint8_t *pco_v);
int gsm48_tx_gsm_act_pdp_acc(struct sgsn_pdp_ctx *pdp);
diff --git a/openbsc/include/openbsc/gprs_sgsn.h b/openbsc/include/openbsc/gprs_sgsn.h
index b32c5cd..fb1b288 100644
--- a/openbsc/include/openbsc/gprs_sgsn.h
+++ b/openbsc/include/openbsc/gprs_sgsn.h
@@ -125,6 +125,10 @@
PDP_STATE_NONE,
PDP_STATE_CR_REQ,
PDP_STATE_CR_CONF,
+
+ /* 04.08 / Figure 6.2 / 6.1.2.2 */
+ PDP_STATE_INACT_PEND,
+ PDP_STATE_INACTIVE = PDP_STATE_NONE,
};
enum pdp_type {
@@ -162,6 +166,10 @@
uint32_t rx_gtp_snu;
//uint32_t charging_id;
int reordering_reqd;
+
+ struct timer_list timer;
+ unsigned int T; /* Txxxx number */
+ unsigned int num_T_exp; /* number of consecutive T expirations */
};
@@ -182,10 +190,12 @@
uint32_t id;
unsigned int gtp_version;
struct in_addr remote_addr;
+ int remote_restart_ctr;
struct gsn_t *gsn;
};
struct sgsn_ggsn_ctx *sgsn_ggsn_ctx_alloc(uint32_t id);
struct sgsn_ggsn_ctx *sgsn_ggsn_ctx_by_id(uint32_t id);
+struct sgsn_ggsn_ctx *sgsn_ggsn_ctx_by_addr(struct in_addr *addr);
struct sgsn_ggsn_ctx *sgsn_ggsn_ctx_find_alloc(uint32_t id);
struct apn_ctx {
@@ -202,4 +212,8 @@
uint32_t sgsn_alloc_ptmsi(void);
+/* High-level function to be called in case a GGSN has disappeared or
+ * ottherwise lost state (recovery procedure) */
+int drop_all_pdp_for_ggsn(struct sgsn_ggsn_ctx *ggsn);
+
#endif /* _GPRS_SGSN_H */
diff --git a/openbsc/src/gprs/gprs_gmm.c b/openbsc/src/gprs/gprs_gmm.c
index 158f577..ee6e366 100644
--- a/openbsc/src/gprs/gprs_gmm.c
+++ b/openbsc/src/gprs/gprs_gmm.c
@@ -67,6 +67,12 @@
#define GSM0408_T3314_SECS 44 /* force to STBY on expiry */
#define GSM0408_T3316_SECS 44
+/* Section 11.3 / Table 11.2d Timers of Session Management - network side */
+#define GSM0408_T3385_SECS 8 /* wait for ACT PDP CTX REQ */
+#define GSM0408_T3386_SECS 8 /* wait for MODIFY PDP CTX ACK */
+#define GSM0408_T3395_SECS 8 /* wait for DEACT PDP CTX ACK */
+#define GSM0408_T3397_SECS 8 /* wait for DEACT AA PDP CTX ACK */
+
extern struct sgsn_instance *sgsn;
/* Protocol related stuff, should go into libosmocore */
@@ -1092,6 +1098,25 @@
/* GPRS SESSION MANAGEMENT */
+static void pdpctx_timer_cb(void *_mm);
+
+static void pdpctx_timer_start(struct sgsn_pdp_ctx *pdp, unsigned int T,
+ unsigned int seconds)
+{
+ if (bsc_timer_pending(&pdp->timer))
+ LOGP(DMM, LOGL_ERROR, "Starting MM timer %u while old "
+ "timer %u pending\n", T, pdp->T);
+ pdp->T = T;
+ pdp->num_T_exp = 0;
+
+ /* FIXME: we should do this only once ? */
+ pdp->timer.data = pdp;
+ pdp->timer.cb = &pdpctx_timer_cb;
+
+ bsc_schedule_timer(&pdp->timer, seconds, 0);
+}
+
+
static void msgb_put_pdp_addr_ipv4(struct msgb *msg, uint32_t ipaddr)
{
uint8_t v[6];
@@ -1179,6 +1204,33 @@
return gsm48_gmm_sendmsg(msg, 0, mm);
}
+/* Section 9.5.8: Deactivate PDP Context Request */
+static int _gsm48_tx_gsm_deact_pdp_req(struct sgsn_mm_ctx *mm, uint8_t tid,
+ uint8_t sm_cause)
+{
+ struct msgb *msg = gsm48_msgb_alloc();
+ struct gsm48_hdr *gh;
+ uint8_t transaction_id = tid ^ 0x8; /* flip */
+
+ DEBUGP(DMM, "<- DEACTIVATE PDP CONTEXT REQ\n");
+
+ mmctx2msgid(msg, mm);
+
+ gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh));
+ gh->proto_discr = GSM48_PDISC_SM_GPRS | (transaction_id << 4);
+ gh->msg_type = GSM48_MT_GSM_DEACT_PDP_REQ;
+
+ msgb_v_put(msg, sm_cause);
+
+ return gsm48_gmm_sendmsg(msg, 0, mm);
+}
+int gsm48_tx_gsm_deact_pdp_req(struct sgsn_pdp_ctx *pdp, uint8_t sm_cause)
+{
+ pdpctx_timer_start(pdp, 3395, GSM0408_T3395_SECS);
+
+ return _gsm48_tx_gsm_deact_pdp_req(pdp->mm, pdp->ti, sm_cause);
+}
+
/* Section 9.5.9: Deactivate PDP Context Accept */
static int _gsm48_tx_gsm_deact_pdp_acc(struct sgsn_mm_ctx *mm, uint8_t tid)
{
@@ -1341,6 +1393,26 @@
return sgsn_delete_pdp_ctx(pdp);
}
+/* Section 9.5.9: Deactivate PDP Context Accept */
+static int gsm48_rx_gsm_deact_pdp_ack(struct sgsn_mm_ctx *mm, struct msgb *msg)
+{
+ struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_gmmh(msg);
+ uint8_t transaction_id = (gh->proto_discr >> 4);
+ struct sgsn_pdp_ctx *pdp;
+
+ DEBUGP(DMM, "-> DEACTIVATE PDP CONTEXT ACK\n");
+
+ pdp = sgsn_pdp_ctx_by_tid(mm, transaction_id);
+ if (!pdp) {
+ LOGP(DMM, LOGL_NOTICE, "Deactivate PDP Context Accept for "
+ "non-existing PDP Context (IMSI=%s, TI=%u)\n",
+ mm->imsi, transaction_id);
+ return 0;
+ }
+
+ return sgsn_delete_pdp_ctx(pdp);
+}
+
static int gsm48_rx_gsm_status(struct sgsn_mm_ctx *ctx, struct msgb *msg)
{
struct gsm48_hdr *gh = msgb_l3(msg);
@@ -1351,6 +1423,30 @@
return 0;
}
+static void pdpctx_timer_cb(void *_pdp)
+{
+ struct sgsn_pdp_ctx *pdp = _pdp;
+
+ pdp->num_T_exp++;
+
+ switch (pdp->T) {
+ case 3395: /* waiting for PDP CTX DEACT ACK */
+ if (pdp->num_T_exp >= 4) {
+ LOGP(DMM, LOGL_NOTICE, "T3395 expired >= 5 times\n");
+ pdp->state = PDP_STATE_INACTIVE;
+ sgsn_delete_pdp_ctx(pdp);
+ break;
+ }
+ gsm48_tx_gsm_deact_pdp_req(pdp, GSM_CAUSE_NET_FAIL);
+ bsc_schedule_timer(&pdp->timer, GSM0408_T3395_SECS, 0);
+ break;
+ default:
+ LOGP(DMM, LOGL_ERROR, "timer expired in unknown mode %u\n",
+ pdp->T);
+ }
+}
+
+
/* GPRS Session Management */
static int gsm0408_rcv_gsm(struct sgsn_mm_ctx *mmctx, struct msgb *msg,
struct gprs_llc_llme *llme)
@@ -1373,6 +1469,9 @@
case GSM48_MT_GSM_DEACT_PDP_REQ:
rc = gsm48_rx_gsm_deact_pdp_req(mmctx, msg);
break;
+ case GSM48_MT_GSM_DEACT_PDP_ACK:
+ rc = gsm48_rx_gsm_deact_pdp_ack(mmctx, msg);
+ break;
case GSM48_MT_GSM_STATUS:
rc = gsm48_rx_gsm_status(mmctx, msg);
break;
diff --git a/openbsc/src/gprs/gprs_sgsn.c b/openbsc/src/gprs/gprs_sgsn.c
index 48a00b8..f558003 100644
--- a/openbsc/src/gprs/gprs_sgsn.c
+++ b/openbsc/src/gprs/gprs_sgsn.c
@@ -32,6 +32,8 @@
#include <openbsc/gprs_ns.h>
#include <openbsc/gprs_bssgp.h>
#include <openbsc/sgsn.h>
+#include <openbsc/gsm_04_08_gprs.h>
+#include <openbsc/gprs_gmm.h>
extern struct sgsn_instance *sgsn;
@@ -240,6 +242,7 @@
ggc->id = id;
ggc->gtp_version = 1;
+ ggc->remote_restart_ctr = -1;
/* if we are called from config file parse, this gsn doesn't exist yet */
ggc->gsn = sgsn->gsn;
llist_add(&ggc->list, &sgsn_ggsn_ctxts);
@@ -258,6 +261,18 @@
return NULL;
}
+struct sgsn_ggsn_ctx *sgsn_ggsn_ctx_by_addr(struct in_addr *addr)
+{
+ struct sgsn_ggsn_ctx *ggc;
+
+ llist_for_each_entry(ggc, &sgsn_ggsn_ctxts, list) {
+ if (!memcmp(addr, &ggc->remote_addr, sizeof(*addr)))
+ return ggc;
+ }
+ return NULL;
+}
+
+
struct sgsn_ggsn_ctx *sgsn_ggsn_ctx_find_alloc(uint32_t id)
{
struct sgsn_ggsn_ctx *ggc;
@@ -320,3 +335,35 @@
return ptmsi;
}
+
+static void drop_one_pdp(struct sgsn_pdp_ctx *pdp)
+{
+ if (pdp->mm->mm_state == GMM_REGISTERED_NORMAL)
+ gsm48_tx_gsm_deact_pdp_req(pdp, GSM_CAUSE_NET_FAIL);
+ else {
+ /* FIXME: GPRS paging in case MS is SUSPENDED */
+ LOGP(DGPRS, LOGL_NOTICE, "Hard-dropping PDP ctx due to GGSN "
+ "recovery\n");
+ sgsn_pdp_ctx_free(pdp);
+ }
+}
+
+/* High-level function to be called in case a GGSN has disappeared or
+ * ottherwise lost state (recovery procedure) */
+int drop_all_pdp_for_ggsn(struct sgsn_ggsn_ctx *ggsn)
+{
+ struct sgsn_mm_ctx *mm;
+ int num = 0;
+
+ llist_for_each_entry(mm, &sgsn_mm_ctxts, list) {
+ struct sgsn_pdp_ctx *pdp;
+ llist_for_each_entry(pdp, &mm->pdp_list, list) {
+ if (pdp->ggsn == ggsn) {
+ drop_one_pdp(pdp);
+ num++;
+ }
+ }
+ }
+
+ return num;
+}
diff --git a/openbsc/src/gprs/sgsn_libgtp.c b/openbsc/src/gprs/sgsn_libgtp.c
index 5278e4d..e5defe7 100644
--- a/openbsc/src/gprs/sgsn_libgtp.c
+++ b/openbsc/src/gprs/sgsn_libgtp.c
@@ -325,15 +325,38 @@
}
/* Confirmation of an GTP ECHO request */
-static int echo_conf(int recovery)
+static int echo_conf(struct pdp_t *pdp, void *cbp, int recovery)
{
if (recovery < 0) {
DEBUGP(DGPRS, "GTP Echo Request timed out\n");
/* FIXME: if version == 1, retry with version 0 */
} else {
DEBUGP(DGPRS, "GTP Rx Echo Response\n");
- /* FIXME: check if recovery counter has incremented and
- * release all PDP context (if it has) */
+ }
+ return 0;
+}
+
+/* Any message received by GGSN contains a recovery IE */
+static int cb_recovery(struct sockaddr_in *peer, uint8_t recovery)
+{
+ struct sgsn_ggsn_ctx *ggsn;
+
+ ggsn = sgsn_ggsn_ctx_by_addr(&peer->sin_addr);
+ if (!ggsn) {
+ DEBUGP(DGPRS, "Received Recovery IE for unknown GGSN\n");
+ return -EINVAL;
+ }
+
+ if (ggsn->remote_restart_ctr == -1) {
+ /* First received ECHO RESPONSE, note the restart ctr */
+ ggsn->remote_restart_ctr = recovery;
+ } else if (ggsn->remote_restart_ctr != recovery) {
+ /* counter has changed (GGSN restart): release all PDP */
+ LOGP(DGPRS, LOGL_NOTICE, "GGSN recovery (%u->%u), "
+ "releasing all PDP contexts\n",
+ ggsn->remote_restart_ctr, recovery);
+ ggsn->remote_restart_ctr = recovery;
+ drop_all_pdp_for_ggsn(ggsn);
}
return 0;
}
@@ -351,7 +374,7 @@
switch (type) {
case GTP_ECHO_REQ:
/* libgtp hands us the RECOVERY number instead of a cause */
- return echo_conf(cause);
+ return echo_conf(pdp, cbp, cause);
case GTP_CREATE_PDP_REQ:
return create_pdp_conf(pdp, cbp, cause);
case GTP_DELETE_PDP_REQ:
@@ -579,6 +602,7 @@
/* Register callbackcs with libgtp */
gtp_set_cb_delete_context(gsn, cb_delete_context);
gtp_set_cb_conf(gsn, cb_conf);
+ gtp_set_cb_recovery(gsn, cb_recovery);
gtp_set_cb_data_ind(gsn, cb_data_ind);
gtp_set_cb_unsup_ind(gsn, cb_unsup_ind);
gtp_set_cb_extheader_ind(gsn, cb_extheader_ind);