Fixed decoding of hexadecimal LAI components

libosmocore has changed its LAI decoding from hex to decimal. This caused
wrong decoding of MCC and MNC. In order to provide required hex
transcoding, special hex encoding and decoding function are added to
mobile/sysinfo.c.

6 files changed, 44 insertions, 27 deletions

diff --git a/src/host/layer23/include/osmocom/bb/common/sysinfo.h b/src/host/layer23/include/osmocom/bb/common/sysinfo.h
index 5d3ed596..f843f271 100644
--- a/src/host/layer23/include/osmocom/bb/common/sysinfo.h
+++ b/src/host/layer23/include/osmocom/bb/common/sysinfo.h
@@ -154,5 +154,9 @@ int gsm48_decode_sysinfo6(struct gsm48_sysinfo *s,
 int gsm48_decode_mobile_alloc(struct gsm_sysinfo_freq *freq,
 	uint8_t *ma, uint8_t len, uint16_t *hopping, uint8_t *hopp_len,
 	int si4);
+int gsm48_encode_lai_hex(struct gsm48_loc_area_id *lai, uint16_t mcc,
+	uint16_t mnc, uint16_t lac);
+int gsm48_decode_lai_hex(struct gsm48_loc_area_id *lai, uint16_t *mcc,
+	uint16_t *mnc, uint16_t *lac);
 
 #endif /* _SYSINFO_H */
diff --git a/src/host/layer23/include/osmocom/bb/mobile/gsm48_rr.h b/src/host/layer23/include/osmocom/bb/mobile/gsm48_rr.h
index b7280fb4..38ac3611 100644
--- a/src/host/layer23/include/osmocom/bb/mobile/gsm48_rr.h
+++ b/src/host/layer23/include/osmocom/bb/mobile/gsm48_rr.h
@@ -195,10 +195,6 @@ int gsm48_rsl_dequeue(struct osmocom_ms *ms);
 int gsm48_rr_downmsg(struct osmocom_ms *ms, struct msgb *msg);
 struct msgb *gsm48_l3_msgb_alloc(void);
 struct msgb *gsm48_rr_msgb_alloc(int msg_type);
-int gsm48_decode_lai(struct gsm48_loc_area_id *lai, uint16_t *mcc,
-	uint16_t *mnc, uint16_t *lac);
-int gsm48_encode_lai(struct gsm48_loc_area_id *lai, uint16_t mcc,
-	uint16_t mnc, uint16_t lac);
 int gsm48_rr_enc_cm2(struct osmocom_ms *ms, struct gsm48_classmark2 *cm,
 	uint16_t arfcn);
 int gsm48_rr_tx_rand_acc(struct osmocom_ms *ms, struct msgb *msg);
diff --git a/src/host/layer23/src/common/sysinfo.c b/src/host/layer23/src/common/sysinfo.c
index 8f82c289..2816c266 100644
--- a/src/host/layer23/src/common/sysinfo.c
+++ b/src/host/layer23/src/common/sysinfo.c
@@ -687,7 +687,7 @@ int gsm48_decode_sysinfo3(struct gsm48_sysinfo *s,
 	/* Cell Identity */
 	s->cell_id = ntohs(si->cell_identity);
 	/* LAI */
-	gsm48_decode_lai(&si->lai, &s->mcc, &s->mnc, &s->lac);
+	gsm48_decode_lai_hex(&si->lai, &s->mcc, &s->mnc, &s->lac);
 	/* Control Channel Description */
 	gsm48_decode_ccd(s, &si->control_channel_desc);
 	/* Cell Options (BCCH) */
@@ -720,7 +720,7 @@ int gsm48_decode_sysinfo4(struct gsm48_sysinfo *s,
 	memcpy(s->si4_msg, si, MIN(len, sizeof(s->si4_msg)));
 
 	/* LAI */
-	gsm48_decode_lai(&si->lai, &s->mcc, &s->mnc, &s->lac);
+	gsm48_decode_lai_hex(&si->lai, &s->mcc, &s->mnc, &s->lac);
 	/* Cell Selection Parameters */
 	gsm48_decode_cell_sel_param(s, &si->cell_sel_par);
 	/* RACH Control Parameter */
@@ -829,7 +829,7 @@ int gsm48_decode_sysinfo6(struct gsm48_sysinfo *s,
 			"read.\n");
 	s->cell_id = ntohs(si->cell_identity);
 	/* LAI */
-	gsm48_decode_lai(&si->lai, &s->mcc, &s->mnc, &s->lac);
+	gsm48_decode_lai_hex(&si->lai, &s->mcc, &s->mnc, &s->lac);
 	/* Cell Options (SACCH) */
 	gsm48_decode_cellopt_sacch(s, &si->cell_options);
 	/* NCC Permitted */
@@ -843,3 +843,28 @@ int gsm48_decode_sysinfo6(struct gsm48_sysinfo *s,
 	return 0;
 }
 
+int gsm48_encode_lai_hex(struct gsm48_loc_area_id *lai, uint16_t mcc,
+	uint16_t mnc, uint16_t lac)
+{
+	lai->digits[0] = (mcc >> 8) | (mcc & 0xf0);
+	lai->digits[1] = (mcc & 0x0f) | (mnc << 4);
+	lai->digits[2] = (mnc >> 8) | (mnc & 0xf0);
+	lai->lac = htons(lac);
+
+	return 0;
+}
+
+ int gsm48_decode_lai_hex(struct gsm48_loc_area_id *lai, uint16_t *mcc,
+       	uint16_t *mnc, uint16_t *lac)
+{
+	*mcc = ((lai->digits[0] & 0x0f) << 8)
+		| (lai->digits[0] & 0xf0)
+		| (lai->digits[1] & 0x0f);
+	*mnc = ((lai->digits[2] & 0x0f) << 8)
+		| (lai->digits[2] & 0xf0)
+		| ((lai->digits[1] & 0xf0) >> 4);
+	*lac = ntohs(lai->lac);
+			        
+	return 0;
+}
+
diff --git a/src/host/layer23/src/mobile/gsm48_mm.c b/src/host/layer23/src/mobile/gsm48_mm.c
index a8f699d2..331cfe3b 100644
--- a/src/host/layer23/src/mobile/gsm48_mm.c
+++ b/src/host/layer23/src/mobile/gsm48_mm.c
@@ -1577,7 +1577,7 @@ static int gsm48_mm_rx_tmsi_realloc_cmd(struct osmocom_ms *ms, struct msgb *msg)
 		return -EINVAL;
 	}
 	/* LAI */
-	gsm48_decode_lai(lai, &subscr->mcc, &subscr->mnc, &subscr->lac);
+	gsm48_decode_lai_hex(lai, &subscr->mcc, &subscr->mnc, &subscr->lac);
 	/* MI */
 	mi = gh->data + sizeof(struct gsm48_loc_area_id);
 	mi_type = mi[1] & GSM_MI_TYPE_MASK;
@@ -2349,7 +2349,7 @@ static int gsm48_mm_tx_loc_upd_req(struct osmocom_ms *ms)
 	 *
 	 * NOTE: The TMSI is only valid within a LAI!
 	 */
-	gsm48_encode_lai(&nlu->lai, subscr->mcc, subscr->mnc, subscr->lac);
+	gsm48_encode_lai_hex(&nlu->lai, subscr->mcc, subscr->mnc, subscr->lac);
 	LOGP(DMM, LOGL_INFO, " using LAI (mcc %s mnc %s " "lac 0x%04x)\n",
 		gsm_print_mcc(subscr->mcc),
 		gsm_print_mnc(subscr->mnc), subscr->lac);
@@ -2419,7 +2419,7 @@ static int gsm48_mm_rx_loc_upd_acc(struct osmocom_ms *ms, struct msgb *msg)
 	stop_mm_t3212(mm); /* 4.4.2 */
 
 	/* LAI */
-	gsm48_decode_lai(lai, &subscr->mcc, &subscr->mnc, &subscr->lac);
+	gsm48_decode_lai_hex(lai, &subscr->mcc, &subscr->mnc, &subscr->lac);
 
 	/* stop location update timer */
 	stop_mm_t3210(mm);
diff --git a/src/host/layer23/src/mobile/gsm48_rr.c b/src/host/layer23/src/mobile/gsm48_rr.c
index b6083afe..bc244699 100644
--- a/src/host/layer23/src/mobile/gsm48_rr.c
+++ b/src/host/layer23/src/mobile/gsm48_rr.c
@@ -98,17 +98,6 @@ static int gsm48_rr_rel_cnf(struct osmocom_ms *ms, struct msgb *msg);
 
 #define MIN(a, b) ((a < b) ? a : b)
 
-int gsm48_encode_lai(struct gsm48_loc_area_id *lai, uint16_t mcc,
-	uint16_t mnc, uint16_t lac)
-{
-	lai->digits[0] = (mcc >> 8) | (mcc & 0xf0);
-	lai->digits[1] = (mcc & 0x0f) | (mnc << 4);
-	lai->digits[2] = (mnc >> 8) | (mnc & 0xf0);
-	lai->lac = htons(lac);
-
-	return 0;
-}
-
 /* decode "Power Command" (10.5.2.28) and (10.5.2.28a) */
 static int gsm48_decode_power_cmd_acc(struct gsm48_power_cmd *pc,
 	uint8_t *power_level, uint8_t *atc)
diff --git a/src/host/layer23/src/mobile/subscriber.c b/src/host/layer23/src/mobile/subscriber.c
index 8ebb1738..cefc8556 100644
--- a/src/host/layer23/src/mobile/subscriber.c
+++ b/src/host/layer23/src/mobile/subscriber.c
@@ -282,7 +282,8 @@ static int subscr_sim_loci(struct osmocom_ms *ms, uint8_t *data,
 	subscr->tmsi = ntohl(loci->tmsi);
 
 	/* LAI */
-	gsm48_decode_lai(&loci->lai, &subscr->mcc, &subscr->mnc, &subscr->lac);
+	gsm48_decode_lai_hex(&loci->lai, &subscr->mcc, &subscr->mnc,
+		&subscr->lac);
 
 	/* location update status */
 	switch (loci->lupd_status & 0x07) {
@@ -408,8 +409,8 @@ static int subscr_sim_plmnsel(struct osmocom_ms *ms, uint8_t *data,
 		lai[0] = data[0];
 		lai[1] = data[1];
 		lai[2] = data[2];
-		gsm48_decode_lai((struct gsm48_loc_area_id *)lai, &plmn->mcc,
-			&plmn->mnc, &dummy_lac);
+		gsm48_decode_lai_hex((struct gsm48_loc_area_id *)lai,
+			&plmn->mcc, &plmn->mnc, &dummy_lac);
 		llist_add_tail(&plmn->entry, &subscr->plmn_list);
 
 		LOGP(DMM, LOGL_INFO, "received PLMN selector (mcc=%s mnc=%s) "
@@ -512,8 +513,10 @@ static int subscr_sim_fplmn(struct osmocom_ms *ms, uint8_t *data,
 		lai[0] = data[0];
 		lai[1] = data[1];
 		lai[2] = data[2];
-		gsm48_decode_lai((struct gsm48_loc_area_id *)lai, &na->mcc,
+		gsm48_decode_lai_hex((struct gsm48_loc_area_id *)lai, &na->mcc,
 			&na->mnc, &dummy_lac);
+		LOGP(DMM, LOGL_INFO, "received Forbidden PLMN %s %s from SIM\n",
+			gsm_print_mcc(na->mcc), gsm_print_mnc(na->mnc));
 		na->cause = -1; /* must have a value, but SIM stores no cause */
 		llist_add_tail(&na->entry, &subscr->plmn_na);
 
@@ -821,7 +824,7 @@ static int subscr_write_plmn_na(struct osmocom_ms *ms)
 	nsh->file = 0x6f7b;
 	for (i = 0; i < 4; i++) {
 		if (nas[i]) {
-			gsm48_encode_lai((struct gsm48_loc_area_id *)lai,
+			gsm48_encode_lai_hex((struct gsm48_loc_area_id *)lai,
 			nas[i]->mcc, nas[i]->mnc, 0);
 			*data++ = lai[0];
 			*data++ = lai[1];
@@ -866,7 +869,7 @@ int gsm_subscr_write_loci(struct osmocom_ms *ms)
 	loci->tmsi = htonl(subscr->tmsi);
 
 	/* LAI */
-	gsm48_encode_lai(&loci->lai, subscr->mcc, subscr->mnc, subscr->lac);
+	gsm48_encode_lai_hex(&loci->lai, subscr->mcc, subscr->mnc, subscr->lac);
 
 	/* TMSI time */
 	loci->tmsi_time = 0xff;