[GPRS] Include IMSI and DRX params in BSSGP DL-UD

When we send a downlink unit-data request via BSSGP, there is a lot
of information that needs to be copied from the mm context, such as
the IMSI, DRX parametes, MS radio access parameters, ...

This is a quite strange layering violation, since we now need to pass
a pointer to the MM ctx from GMM through LLC into BSSGP :(

3 files changed, 56 insertions, 14 deletions

diff --git a/openbsc/src/gprs/gprs_bssgp.c b/openbsc/src/gprs/gprs_bssgp.c
index f3ce8a9fe..58ade4d21 100644
--- a/openbsc/src/gprs/gprs_bssgp.c
+++ b/openbsc/src/gprs/gprs_bssgp.c
@@ -39,6 +39,7 @@
 #include <openbsc/gprs_bssgp.h>
 #include <openbsc/gprs_llc.h>
 #include <openbsc/gprs_ns.h>
+#include <openbsc/gprs_sgsn.h>
 
 void *bssgp_tall_ctx = NULL;
 
@@ -685,7 +686,7 @@ int gprs_bssgp_rcvmsg(struct msgb *msg)
 
 /* 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 BVCI and NSEI */
-int gprs_bssgp_tx_dl_ud(struct msgb *msg)
+int gprs_bssgp_tx_dl_ud(struct msgb *msg, struct sgsn_mm_ctx *mmctx)
 {
 	struct bssgp_bvc_ctx *bctx;
 	struct bssgp_ud_hdr *budh;
@@ -696,6 +697,7 @@ int gprs_bssgp_tx_dl_ud(struct msgb *msg)
 	uint16_t msg_len = msg->len;
 	uint16_t bvci = msgb_bvci(msg);
 	uint16_t nsei = msgb_nsei(msg);
+	uint16_t drx_params;
 
 	/* Identifiers from UP: TLLI, BVCI, NSEI (all in msgb->cb) */
 	if (bvci <= BVCI_PTM ) {
@@ -724,7 +726,37 @@ int gprs_bssgp_tx_dl_ud(struct msgb *msg)
 		llc_pdu_tlv[1] |= 0x80;
 	}
 
-	/* FIXME: optional elements */
+	/* FIXME: optional elements: Alignment, UTRAN CCO, LSA, PFI */
+
+	if (mmctx) {
+		/* Old TLLI to help BSS map from old->new */
+#if 0
+		if (mmctx->tlli_old)
+			msgb_tvlv_push(msg, BSSGP_IE_TLLI, 4, htonl(*tlli_old));
+#endif
+
+		/* IMSI */
+		if (strlen(mmctx->imsi)) {
+			uint8_t mi[10];
+			int imsi_len = gsm48_generate_mid_from_imsi(mi, mmctx->imsi);
+			if (imsi_len > 2)
+				msgb_tvlv_push(msg, BSSGP_IE_IMSI,
+							imsi_len-2, mi+2);
+		}
+
+		/* DRX parameters */
+		drx_params = htons(mmctx->drx_parms);
+		msgb_tvlv_push(msg, BSSGP_IE_DRX_PARAMS, 2,
+				(uint8_t *) &drx_params);
+
+		/* FIXME: Priority */
+
+		/* MS Radio Access Capability */
+		if (mmctx->ms_radio_access_capa.len)
+			msgb_tvlv_push(msg, BSSGP_IE_MS_RADIO_ACCESS_CAP,
+					mmctx->ms_radio_access_capa.len,
+					mmctx->ms_radio_access_capa.buf);
+	}
 
 	/* prepend the pdu lifetime */
 	pdu_lifetime = htons(pdu_lifetime);
diff --git a/openbsc/src/gprs/gprs_gmm.c b/openbsc/src/gprs/gprs_gmm.c
index 3a6db62b7..95473281f 100644
--- a/openbsc/src/gprs/gprs_gmm.c
+++ b/openbsc/src/gprs/gprs_gmm.c
@@ -184,7 +184,7 @@ static int gsm48_gmm_sendmsg(struct msgb *msg, int command,
 		rate_ctr_inc(&mm->ctrg->ctr[GMM_CTR_PKTS_SIG_OUT]);
 
 	/* caller needs to provide TLLI, BVCI and NSEI */
-	return gprs_llc_tx_ui(msg, GPRS_SAPI_GMM, command);
+	return gprs_llc_tx_ui(msg, GPRS_SAPI_GMM, command, mm);
 }
 
 /* copy identifiers from old message to new message, this
@@ -278,7 +278,7 @@ static int gsm48_tx_gmm_att_ack(struct sgsn_mm_ctx *mm)
 	/* Optional: MS-identity (combined attach) */
 	/* Optional: GMM cause (partial attach result for combined attach) */
 
-	return gsm48_gmm_sendmsg(msg, 0, NULL);
+	return gsm48_gmm_sendmsg(msg, 0, mm);
 }
 
 /* Chapter 9.4.5: Attach reject */
@@ -325,7 +325,7 @@ static int gsm48_tx_gmm_det_ack(struct sgsn_mm_ctx *mm, uint8_t force_stby)
 	gh->msg_type = GSM48_MT_GMM_DETACH_ACK;
 	gh->data[0] = force_stby;
 
-	return gsm48_gmm_sendmsg(msg, 0, NULL);
+	return gsm48_gmm_sendmsg(msg, 0, mm);
 }
 
 /* Transmit Chapter 9.4.12 Identity Request */
@@ -344,7 +344,7 @@ static int gsm48_tx_gmm_id_req(struct sgsn_mm_ctx *mm, uint8_t id_type)
 	/* 10.5.5.9 ID type 2 + identity type and 10.5.5.7 'force to standby' IE */
 	gh->data[0] = id_type & 0xf;
 
-	return gsm48_gmm_sendmsg(msg, 0, NULL);
+	return gsm48_gmm_sendmsg(msg, 0, mm);
 }
 
 /* Check if we can already authorize a subscriber */
@@ -419,8 +419,8 @@ static int gsm48_rx_gmm_id_resp(struct sgsn_mm_ctx *ctx, struct msgb *msg)
 static int gsm48_rx_gmm_att_req(struct sgsn_mm_ctx *mmctx, struct msgb *msg)
 {
 	struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_gmmh(msg);
-	uint8_t *cur = gh->data, *msnc, *mi, *old_ra_info;
-	uint8_t msnc_len, att_type, mi_len, mi_type;
+	uint8_t *cur = gh->data, *msnc, *mi, *old_ra_info, *ms_ra_acc_cap;
+	uint8_t msnc_len, att_type, mi_len, mi_type, ms_ra_acc_cap_len;
 	uint16_t drx_par;
 	uint32_t tmsi;
 	char mi_string[GSM48_MI_SIZE];
@@ -447,8 +447,8 @@ static int gsm48_rx_gmm_att_req(struct sgsn_mm_ctx *mmctx, struct msgb *msg)
 	att_type = *cur++ & 0x0f;
 
 	/* DRX parameter 10.5.5.6 */
-	drx_par = *cur++;
-	drx_par |= *cur++ << 8;
+	drx_par = *cur++ << 8;
+	drx_par |= *cur++;
 
 	/* Mobile Identity (P-TMSI or IMSI) 10.5.1.4 */
 	mi_len = *cur++;
@@ -468,6 +468,8 @@ static int gsm48_rx_gmm_att_req(struct sgsn_mm_ctx *mmctx, struct msgb *msg)
 	cur += 6;
 
 	/* MS Radio Access Capability 10.5.5.12a */
+	ms_ra_acc_cap_len = *cur++;
+	ms_ra_acc_cap = cur;
 
 	/* Optional: Old P-TMSI Signature, Requested READY timer, TMSI Status */
 
@@ -509,6 +511,13 @@ static int gsm48_rx_gmm_att_req(struct sgsn_mm_ctx *mmctx, struct msgb *msg)
 	/* Update MM Context with currient RA and Cell ID */
 	ctx->ra = ra_id;
 	ctx->cell_id = cid;
+	/* Update MM Context with other data */
+	ctx->drx_parms = drx_par;
+	ctx->ms_radio_access_capa.len = ms_ra_acc_cap_len;
+	memcpy(ctx->ms_radio_access_capa.buf, ms_ra_acc_cap, ms_ra_acc_cap_len);
+	ctx->ms_network_capa.len = msnc_len;
+	memcpy(ctx->ms_network_capa.buf, msnc, msnc_len);
+
 #ifdef PTMSI_ALLOC
 	/* Allocate a new P-TMSI (+ P-TMSI signature) */
 	ctx->p_tmsi_old = ctx->p_tmsi;
@@ -587,7 +596,7 @@ static int gsm48_tx_gmm_ra_upd_ack(struct sgsn_mm_ctx *mm)
 #endif
 
 	/* Option: MS ID, ... */
-	return gsm48_gmm_sendmsg(msg, 0, NULL);
+	return gsm48_gmm_sendmsg(msg, 0, mm);
 }
 
 /* Chapter 9.4.17: Routing area update reject */
diff --git a/openbsc/src/gprs/gprs_llc.c b/openbsc/src/gprs/gprs_llc.c
index 68d7d7654..c13f45f07 100644
--- a/openbsc/src/gprs/gprs_llc.c
+++ b/openbsc/src/gprs/gprs_llc.c
@@ -197,7 +197,7 @@ int gprs_llc_tx_u(struct msgb *msg, uint8_t sapi, int command,
 	/* Identifiers passed down: (BVCI, NSEI) */
 
 	/* Send BSSGP-DL-UNITDATA.req */
-	return gprs_bssgp_tx_dl_ud(msg);
+	return gprs_bssgp_tx_dl_ud(msg, NULL);
 }
 
 /* Send XID response to LLE */
@@ -212,7 +212,8 @@ static int gprs_llc_tx_xid(struct gprs_llc_lle *lle, struct msgb *msg)
 }
 
 /* Transmit a UI frame over the given SAPI */
-int gprs_llc_tx_ui(struct msgb *msg, uint8_t sapi, int command)
+int gprs_llc_tx_ui(struct msgb *msg, uint8_t sapi, int command,
+		   void *mmctx)
 {
 	struct gprs_llc_lle *lle;
 	uint8_t *fcs, *llch;
@@ -261,7 +262,7 @@ int gprs_llc_tx_ui(struct msgb *msg, uint8_t sapi, int command)
 	/* Identifiers passed down: (BVCI, NSEI) */
 
 	/* Send BSSGP-DL-UNITDATA.req */
-	return gprs_bssgp_tx_dl_ud(msg);
+	return gprs_bssgp_tx_dl_ud(msg, mmctx);
 }
 
 static void gprs_llc_hdr_dump(struct gprs_llc_hdr_parsed *gph)