nat: Attempt to have a single BSC write method

This method currently prepends the IPA header and sends
the data. In the future we might be able to use SCTP for
it.

We have to remove the IPA header from the static messages
for that to work.

This code is untested.

1 files changed, 19 insertions, 19 deletions

diff --git a/openbsc/src/nat/bsc_nat.c b/openbsc/src/nat/bsc_nat.c
index f44cb139f..e521516d8 100644
--- a/openbsc/src/nat/bsc_nat.c
+++ b/openbsc/src/nat/bsc_nat.c
@@ -58,7 +58,7 @@ static struct bsc_fd bsc_listen;
 
 
 static struct bsc_nat *nat;
-static void bsc_send_data(struct bsc_connection *bsc, const u_int8_t *data, unsigned int length);
+static void bsc_send_data(struct bsc_connection *bsc, const u_int8_t *data, unsigned int length, int);
 static void remove_bsc_connection(struct bsc_connection *connection);
 static void msc_send_reset(struct bsc_msc_connection *con);
 
@@ -93,28 +93,27 @@ int gsm0408_rcvmsg(struct msgb *msg, u_int8_t link_id)
 static void send_reset_ack(struct bsc_connection *bsc)
 {
 	static const u_int8_t gsm_reset_ack[] = {
-		0x00, 0x13, 0xfd,
 		0x09, 0x00, 0x03, 0x07, 0x0b, 0x04, 0x43, 0x01,
 		0x00, 0xfe, 0x04, 0x43, 0x5c, 0x00, 0xfe, 0x03,
 		0x00, 0x01, 0x31,
 	};
 
-	bsc_send_data(bsc, gsm_reset_ack, sizeof(gsm_reset_ack));
+	bsc_send_data(bsc, gsm_reset_ack, sizeof(gsm_reset_ack), IPAC_PROTO_SCCP);
 }
 
 static void send_id_ack(struct bsc_connection *bsc)
 {
 	static const u_int8_t id_ack[] = {
-		0, 1, IPAC_PROTO_IPACCESS, IPAC_MSGT_ID_ACK
+		IPAC_MSGT_ID_ACK
 	};
 
-	bsc_send_data(bsc, id_ack, sizeof(id_ack));
+	bsc_send_data(bsc, id_ack, sizeof(id_ack), IPAC_PROTO_IPACCESS);
 }
 
 static void send_id_req(struct bsc_connection *bsc)
 {
 	static const u_int8_t id_req[] = {
-		0, 17, IPAC_PROTO_IPACCESS, IPAC_MSGT_ID_GET,
+		IPAC_MSGT_ID_GET,
 		0x01, IPAC_IDTAG_UNIT,
 		0x01, IPAC_IDTAG_MACADDR,
 		0x01, IPAC_IDTAG_LOCATION1,
@@ -125,7 +124,7 @@ static void send_id_req(struct bsc_connection *bsc)
 		0x01, IPAC_IDTAG_SERNR,
 	};
 
-	bsc_send_data(bsc, id_req, sizeof(id_req));
+	bsc_send_data(bsc, id_req, sizeof(id_req), IPAC_PROTO_IPACCESS);
 }
 
 static void nat_send_rlsd(struct sccp_connections *conn)
@@ -180,27 +179,25 @@ static void initialize_msc_if_needed()
 /*
  * Currently we are lacking refcounting so we need to copy each message.
  */
-static void bsc_send_data(struct bsc_connection *bsc, const u_int8_t *data, unsigned int length)
+static void bsc_send_data(struct bsc_connection *bsc, const u_int8_t *data, unsigned int length, int proto)
 {
 	struct msgb *msg;
 
-	if (length > 4096) {
+	if (length > 4096 - 128) {
 		LOGP(DINP, LOGL_ERROR, "Can not send message of that size.\n");
 		return;
 	}
 
-	msg = msgb_alloc(4096, "to-bsc");
+	msg = msgb_alloc_headroom(4096, 128, "to-bsc");
 	if (!msg) {
 		LOGP(DINP, LOGL_ERROR, "Failed to allocate memory for BSC msg.\n");
 		return;
 	}
 
-	msgb_put(msg, length);
+	msg->l2h = msgb_put(msg, length);
 	memcpy(msg->data, data, length);
-	if (write_queue_enqueue(&bsc->write_queue, msg) != 0) {
-		LOGP(DINP, LOGL_ERROR, "Failed to enqueue the write.\n");
-		msgb_free(msg);
-	}
+
+	bsc_write(bsc, msg, proto);
 }
 
 static int forward_sccp_to_bts(struct msgb *msg)
@@ -208,6 +205,7 @@ static int forward_sccp_to_bts(struct msgb *msg)
 	struct sccp_connections *con;
 	struct bsc_connection *bsc;
 	struct bsc_nat_parsed *parsed;
+	int proto;
 
 	/* filter, drop, patch the message? */
 	parsed = bsc_nat_parse(msg);
@@ -219,8 +217,10 @@ static int forward_sccp_to_bts(struct msgb *msg)
 	if (bsc_nat_filter_ipa(DIR_BSC, msg, parsed))
 		goto exit;
 
+	proto = parsed->ipa_proto;
+
 	/* Route and modify the SCCP packet */
-	if (parsed->ipa_proto == IPAC_PROTO_SCCP) {
+	if (proto == IPAC_PROTO_SCCP) {
 		switch (parsed->sccp_type) {
 		case SCCP_MSG_TYPE_UDT:
 			/* forward UDT messages to every BSC */
@@ -266,7 +266,7 @@ static int forward_sccp_to_bts(struct msgb *msg)
 		return -1;
 	}
 
-	bsc_send_data(con->bsc, msg->data, msg->len);
+	bsc_send_data(con->bsc, msg->l2h, msgb_l2len(msg), proto);
 	return 0;
 
 send_to_all:
@@ -278,7 +278,7 @@ send_to_all:
 	if (parsed->ipa_proto == IPAC_PROTO_SCCP && parsed->gsm_type == BSS_MAP_MSG_PAGING) {
 		bsc = bsc_nat_find_bsc(nat, msg);
 		if (bsc)
-			bsc_send_data(bsc, msg->data, msg->len);
+			bsc_send_data(bsc, msg->l2h, msgb_l2len(msg), parsed->ipa_proto);
 		else
 			LOGP(DNAT, LOGL_ERROR, "Could not determine BSC for paging.\n");
 
@@ -289,7 +289,7 @@ send_to_all:
 		if (!bsc->authenticated)
 			continue;
 
-		bsc_send_data(bsc, msg->data, msg->len);
+		bsc_send_data(bsc, msg->l2h, msgb_l2len(msg), parsed->ipa_proto);
 	}
 
 exit: