[gprs] SGSN: Expect all Identifiers to be stored at highest level
We now expect the highest level (actual SGSN GMM code) to know
all identifiers for every element in the protocol stack, i.e.
TLLI, SAPI, BVCI and NSEI. The layer-inetrnal state is looked
up based on those identifiers.
The reason for this is to ensure only the highest level state
needs to be persistent, while everything else can be regenerated
dynamically (e.g. in a SGSN restart)
diff --git a/openbsc/src/gprs_bssgp.c b/openbsc/src/gprs_bssgp.c
index 330d8c8..6bba1af 100644
--- a/openbsc/src/gprs_bssgp.c
+++ b/openbsc/src/gprs_bssgp.c
@@ -255,7 +255,7 @@
}
/* Uplink unit-data */
-static int bssgp_rx_ul_ud(struct msgb *msg, u_int16_t bvci)
+static int bssgp_rx_ul_ud(struct msgb *msg)
{
struct bssgp_ud_hdr *budh = (struct bssgp_ud_hdr *) msgb_bssgph(msg);
int data_len = msgb_l3len(msg) - sizeof(*budh);
@@ -273,12 +273,14 @@
!TLVP_PRESENT(&tp, BSSGP_IE_LLC_PDU))
return -EIO;
+ /* FIXME: lookup bssgp_bts_ctx based on BVCI + NSEI */
+
msgb_llch(msg) = TLVP_VAL(&tp, BSSGP_IE_LLC_PDU);
return gprs_llc_rcvmsg(msg, &tp);
}
-static int bssgp_rx_suspend(struct msgb *msg, u_int16_t bvci)
+static int bssgp_rx_suspend(struct msgb *msg)
{
struct bssgp_normal_hdr *bgph =
(struct bssgp_normal_hdr *) msgb_bssgph(msg);
@@ -296,11 +298,11 @@
!TLVP_PRESENT(&tp, BSSGP_IE_ROUTEING_AREA))
return -EIO;
+ /* FIXME: pass the SUSPEND request to GMM */
/* SEND SUSPEND_ACK or SUSPEND_NACK */
- /* FIXME */
}
-static int bssgp_rx_resume(struct msgb *msg, u_int16_t bvci)
+static int bssgp_rx_resume(struct msgb *msg)
{
struct bssgp_normal_hdr *bgph =
(struct bssgp_normal_hdr *) msgb_bssgph(msg);
@@ -319,12 +321,11 @@
!TLVP_PRESENT(&tp, BSSGP_IE_SUSPEND_REF_NR))
return -EIO;
+ /* FIXME: pass the RESUME request to GMM */
/* SEND RESUME_ACK or RESUME_NACK */
- /* FIXME */
}
-static int bssgp_rx_fc_bvc(struct msgb *msg, struct tlv_parsed *tp,
- u_int16_t ns_bvci)
+static int bssgp_rx_fc_bvc(struct msgb *msg, struct tlv_parsed *tp)
{
DEBUGP(DGPRS, "BSSGP FC BVC\n");
@@ -336,22 +337,27 @@
!TLVP_PRESENT(tp, BSSGP_IE_R_DEFAULT_MS))
return bssgp_tx_status(BSSGP_CAUSE_MISSING_MAND_IE, NULL, msg);
+ /* FIXME: actually implement flow control */
+
/* Send FLOW_CONTROL_BVC_ACK */
return bssgp_tx_fc_bvc_ack(msgb_nsei(msg), *TLVP_VAL(tp, BSSGP_IE_TAG),
- ns_bvci);
+ msgb_bvci(msg));
}
/* We expect msgb_bssgph() to point to the BSSGP header */
-int gprs_bssgp_rcvmsg(struct msgb *msg, u_int16_t ns_bvci)
+int gprs_bssgp_rcvmsg(struct msgb *msg)
{
struct bssgp_normal_hdr *bgph =
(struct bssgp_normal_hdr *) msgb_bssgph(msg);
struct tlv_parsed tp;
- u_int8_t pdu_type = bgph->pdu_type;
+ uint8_t pdu_type = bgph->pdu_type;
int data_len = msgb_l3len(msg) - sizeof(*bgph);
- u_int16_t bvci;
+ uint16_t bvci; /* PTP BVCI */
+ uint16_t ns_bvci = msgb_bvci(msg);
int rc = 0;
+ /* Identifiers from DOWN: NSEI, BVCI (both in msg->cb) */
+
/* UNITDATA BSSGP headers have TLLI in front */
if (pdu_type != BSSGP_PDUT_UL_UNITDATA &&
pdu_type != BSSGP_PDUT_DL_UNITDATA)
@@ -360,7 +366,7 @@
switch (pdu_type) {
case BSSGP_PDUT_UL_UNITDATA:
/* some LLC data from the MS */
- rc = bssgp_rx_ul_ud(msg, ns_bvci);
+ rc = bssgp_rx_ul_ud(msg);
break;
case BSSGP_PDUT_RA_CAPABILITY:
/* BSS requests RA capability or IMSI */
@@ -370,32 +376,36 @@
case BSSGP_PDUT_RADIO_STATUS:
DEBUGP(DGPRS, "BSSGP RADIO STATUS\n");
/* BSS informs us of some exception */
+ /* FIXME: notify GMM */
break;
case BSSGP_PDUT_SUSPEND:
/* MS wants to suspend */
- rc = bssgp_rx_suspend(msg, ns_bvci);
+ rc = bssgp_rx_suspend(msg);
break;
case BSSGP_PDUT_RESUME:
/* MS wants to resume */
- rc = bssgp_rx_resume(msg, ns_bvci);
+ rc = bssgp_rx_resume(msg);
break;
case BSSGP_PDUT_FLUSH_LL:
/* BSS informs MS has moved to one cell to other cell */
DEBUGP(DGPRS, "BSSGP FLUSH LL\n");
+ /* FIXME: notify GMM */
/* Send FLUSH_LL_ACK */
break;
case BSSGP_PDUT_LLC_DISCARD:
/* BSS informs that some LLC PDU's have been discarded */
DEBUGP(DGPRS, "BSSGP LLC DISCARDED\n");
+ /* FIXME: notify GMM */
break;
case BSSGP_PDUT_FLOW_CONTROL_BVC:
/* BSS informs us of available bandwidth in Gb interface */
- rc = bssgp_rx_fc_bvc(msg, &tp, ns_bvci);
+ rc = bssgp_rx_fc_bvc(msg, &tp);
break;
case BSSGP_PDUT_FLOW_CONTROL_MS:
/* BSS informs us of available bandwidth to one MS */
DEBUGP(DGPRS, "BSSGP FC MS\n");
- /* Send FLOW_CONTROL_MS_ACK */
+ /* FIXME: actually implement flow control */
+ /* FIXME: Send FLOW_CONTROL_MS_ACK */
break;
case BSSGP_PDUT_BVC_BLOCK:
/* BSS tells us that BVC shall be blocked */
@@ -431,6 +441,7 @@
break;
case BSSGP_PDUT_STATUS:
/* Some exception has occurred */
+ /* FIXME: notify GMM */
case BSSGP_PDUT_DOWNLOAD_BSS_PFC:
case BSSGP_PDUT_CREATE_BSS_PFC_ACK:
case BSSGP_PDUT_CREATE_BSS_PFC_NACK:
@@ -469,8 +480,8 @@
}
/* Entry function from upper level (LLC), asking us to transmit a BSSGP PDU
- * to a remote MS (identified by TLLI) at a BTS identified by its RAC and CID */
-int gprs_bssgp_tx_dl_ud(struct msgb *msg, const struct gprs_ra_id *raid, uint16_t cid)
+ * to a remote MS (identified by TLLI) at a BTS identified by its BVCI and NSEI */
+int gprs_bssgp_tx_dl_ud(struct msgb *msg)
{
struct bssgp_bts_ctx *bctx;
struct bssgp_ud_hdr *budh;
@@ -479,8 +490,19 @@
u_int16_t pdu_lifetime = 1000; /* centi-seconds */
u_int8_t qos_profile_default[3] = { 0x00, 0x00, 0x21 };
u_int16_t msg_len = msg->len;
+ uint16_t bvci = msgb_bvci(msg);
+ uint16_t nsei = msgb_nsei(msg);
- bctx = btsctx_by_raid_cid(raid, cid);
+ /* Identifiers from UP: TLLI, BVCI, NSEI (all in msgb->cb) */
+ if (bvci < 2) {
+ LOGP(DGPRS, LOGL_ERROR, "Cannot send DL-UD to BVCI %u\n",
+ bvci);
+ return -EINVAL;
+ }
+
+ bctx = btsctx_by_bvci_nsei(bvci, nsei);
+ if (!bctx)
+ bctx = btsctx_alloc(bvci, nsei);
if (msg->len > TVLV_MAX_ONEBYTE)
llc_pdu_tlv_hdr_len += 1;
@@ -508,8 +530,7 @@
budh->tlli = htonl(msgb_tlli(msg));
budh->pdu_type = BSSGP_PDUT_DL_UNITDATA;
- msgb_nsei(msg) = bctx->nsei;
- msgb_bvci(msg) = bctx->bvci;
+ /* Identifiers down: BVCI, NSEI (in msgb->cb) */
return gprs_ns_sendmsg(bssgp_nsi, msg);
}