diff mbox

[2/2] GSM 04.08 message types: fix use of bitmasks

Message ID 1457648540-3481-2-git-send-email-nhofmeyr@sysmocom.de
State Changes Requested
Headers show

Commit Message

Neels Hofmeyr March 10, 2016, 10:22 p.m. UTC 
According to spec, the bitmasks for message types apply only for MM and CC
messages. However, various code used the bitmask even though no MM or CC
messages are involved:

bsc_msg_filter.c:
bsc_msg_filter_initial(): use bitmasked msg_type_mm for MM messages, use
unmasked msg_type for RR.

osmo_bsc_filter.c:
bsc_find_msc() and
bsc_scan_bts_msg(): use msg_type_mm for MM, unmasked for RR.

bsc_nat_rewrite.c:
bsc_nat_rewrite_msg(): use msg_type_cc for CC, unmasked for SMS.

bsc_ussd.c: don't mask, no MM nor CC involved.
---
 openbsc/src/libfilter/bsc_msg_filter.c     |  9 +++++----
 openbsc/src/osmo-bsc/osmo_bsc_filter.c     | 11 +++++++----
 openbsc/src/osmo-bsc_nat/bsc_nat_rewrite.c |  7 ++++---
 openbsc/src/osmo-bsc_nat/bsc_ussd.c        |  2 +-
 4 files changed, 17 insertions(+), 12 deletions(-)
diff mbox

Patch

diff --git a/openbsc/src/libfilter/bsc_msg_filter.c b/openbsc/src/libfilter/bsc_msg_filter.c
index 25674e1..581bba1 100644
--- a/openbsc/src/libfilter/bsc_msg_filter.c
+++ b/openbsc/src/libfilter/bsc_msg_filter.c
@@ -332,7 +332,7 @@  int bsc_msg_filter_initial(struct gsm48_hdr *hdr48, size_t hdr48_len,
 			char **imsi, struct bsc_filter_reject_cause *cause)
 {
 	int ret = 0;
-	uint8_t msg_type, proto;
+	uint8_t msg_type, msg_type_mm, proto;
 
 	*con_type = FLT_CON_TYPE_NONE;
 	cause->cm_reject_cause = GSM48_REJECT_PLMN_NOT_ALLOWED;
@@ -340,14 +340,15 @@  int bsc_msg_filter_initial(struct gsm48_hdr *hdr48, size_t hdr48_len,
 	*imsi = NULL;
 
 	proto = hdr48->proto_discr & GSM48_PDISC_MASK;
-	msg_type = hdr48->msg_type & GSM48_MT_MM_MSG_TYPE_MASK;
+	msg_type = hdr48->msg_type;
+	msg_type_mm = msg_type & GSM48_MT_MM_MSG_TYPE_MASK;
 	if (proto == GSM48_PDISC_MM &&
-	    msg_type == GSM48_MT_MM_LOC_UPD_REQUEST) {
+	    msg_type_mm == GSM48_MT_MM_LOC_UPD_REQUEST) {
 		*con_type = FLT_CON_TYPE_LU;
 		ret = _cr_check_loc_upd(req->ctx, &hdr48->data[0],
 					hdr48_len - sizeof(*hdr48), imsi);
 	} else if (proto == GSM48_PDISC_MM &&
-		  msg_type == GSM48_MT_MM_CM_SERV_REQ) {
+		   msg_type_mm == GSM48_MT_MM_CM_SERV_REQ) {
 		*con_type = FLT_CON_TYPE_CM_SERV_REQ;
 		ret = _cr_check_cm_serv_req(req->ctx, &hdr48->data[0],
 					     hdr48_len - sizeof(*hdr48),
diff --git a/openbsc/src/osmo-bsc/osmo_bsc_filter.c b/openbsc/src/osmo-bsc/osmo_bsc_filter.c
index e1e948b..017db57 100644
--- a/openbsc/src/osmo-bsc/osmo_bsc_filter.c
+++ b/openbsc/src/osmo-bsc/osmo_bsc_filter.c
@@ -128,6 +128,7 @@  struct osmo_msc_data *bsc_find_msc(struct gsm_subscriber_connection *conn,
 	struct gsm48_hdr *gh;
 	int8_t pdisc;
 	uint8_t mtype;
+	uint8_t mtype_mm;
 	struct osmo_bsc_data *bsc;
 	struct osmo_msc_data *msc, *pag_msc;
 	struct gsm_subscriber *subscr;
@@ -142,7 +143,8 @@  struct osmo_msc_data *bsc_find_msc(struct gsm_subscriber_connection *conn,
 
 	gh = msgb_l3(msg);
 	pdisc = gh->proto_discr & GSM48_PDISC_MASK;
-	mtype = gh->msg_type & GSM48_MT_MM_MSG_TYPE_MASK;
+	mtype = gh->msg_type;
+	mtype_mm = mtype & GSM48_MT_MM_MSG_TYPE_MASK;
 
 	/*
 	 * We are asked to select a MSC here but they are not equal. We
@@ -152,7 +154,7 @@  struct osmo_msc_data *bsc_find_msc(struct gsm_subscriber_connection *conn,
 	 */
 	if (pdisc == GSM48_PDISC_RR && mtype == GSM48_MT_RR_PAG_RESP)
 		goto paging;
-	else if (pdisc == GSM48_PDISC_MM && mtype == GSM48_MT_MM_CM_SERV_REQ) {
+	else if (pdisc == GSM48_PDISC_MM && mtype_mm == GSM48_MT_MM_CM_SERV_REQ) {
 		is_emerg = is_cm_service_for_emerg(msg);
 		goto round_robin;
 	} else
@@ -213,10 +215,11 @@  int bsc_scan_bts_msg(struct gsm_subscriber_connection *conn, struct msgb *msg)
 {
 	struct gsm48_hdr *gh = msgb_l3(msg);
 	uint8_t pdisc = gh->proto_discr & 0x0f;
-	uint8_t mtype = gh->msg_type & GSM48_MT_MM_MSG_TYPE_MASK;
+	uint8_t mtype = gh->msg_type;
+	uint8_t mtype_mm = mtype & GSM48_MT_MM_MSG_TYPE_MASK;
 
 	if (pdisc == GSM48_PDISC_MM) {
-		if (mtype == GSM48_MT_MM_LOC_UPD_REQUEST)
+		if (mtype_mm == GSM48_MT_MM_LOC_UPD_REQUEST)
 			handle_lu_request(conn, msg);
 	} else if (pdisc == GSM48_PDISC_RR) {
 		if (mtype == GSM48_MT_RR_PAG_RESP)
diff --git a/openbsc/src/osmo-bsc_nat/bsc_nat_rewrite.c b/openbsc/src/osmo-bsc_nat/bsc_nat_rewrite.c
index ce7dfb8..97d5e3d 100644
--- a/openbsc/src/osmo-bsc_nat/bsc_nat_rewrite.c
+++ b/openbsc/src/osmo-bsc_nat/bsc_nat_rewrite.c
@@ -576,7 +576,7 @@  struct msgb *bsc_nat_rewrite_msg(struct bsc_nat *nat, struct msgb *msg, struct b
 {
 	struct gsm48_hdr *hdr48;
 	uint32_t len;
-	uint8_t msg_type, proto;
+	uint8_t msg_type, msg_type_cc, proto;
 	struct msgb *new_msg = NULL, *sccp;
 	uint8_t link_id;
 
@@ -595,9 +595,10 @@  struct msgb *bsc_nat_rewrite_msg(struct bsc_nat *nat, struct msgb *msg, struct b
 
 	link_id = msg->l3h[1];
 	proto = hdr48->proto_discr & GSM48_PDISC_MASK;
-	msg_type = hdr48->msg_type & GSM48_MT_CC_MSG_TYPE_MASK;
+	msg_type = hdr48->msg_type;
+	msg_type_cc = msg_type & GSM48_MT_CC_MSG_TYPE_MASK;
 
-	if (proto == GSM48_PDISC_CC && msg_type == GSM48_MT_CC_SETUP)
+	if (proto == GSM48_PDISC_CC && msg_type_cc == GSM48_MT_CC_SETUP)
 		new_msg = rewrite_setup(nat, msg, parsed, imsi, hdr48, len);
 	else if (proto == GSM48_PDISC_SMS && msg_type == GSM411_MT_CP_DATA)
 		new_msg = rewrite_sms(nat, msg, parsed, imsi, hdr48, len);
diff --git a/openbsc/src/osmo-bsc_nat/bsc_ussd.c b/openbsc/src/osmo-bsc_nat/bsc_ussd.c
index 8954ac1..96d4a84 100644
--- a/openbsc/src/osmo-bsc_nat/bsc_ussd.c
+++ b/openbsc/src/osmo-bsc_nat/bsc_ussd.c
@@ -408,7 +408,7 @@  int bsc_ussd_check(struct nat_sccp_connection *con, struct bsc_nat_parsed *parse
 		return 0;
 
 	proto = hdr48->proto_discr & GSM48_PDISC_MASK;
-	msg_type = hdr48->msg_type & GSM48_MT_CC_MSG_TYPE_MASK;
+	msg_type = hdr48->msg_type;
 	ti = (hdr48->proto_discr & 0x70) >> 4;
 	if (proto != GSM48_PDISC_NC_SS)
 		return 0;