1 files changed, 320 insertions, 0 deletions
diff --git a/src/libbsc/bsc_msc.c b/src/libbsc/bsc_msc.c
new file mode 100644
index 000000000..82a572dbe
--- /dev/null
+++ b/src/libbsc/bsc_msc.c
@@ -0,0 +1,320 @@
+/* Routines to talk to the MSC using the IPA Protocol */
+/*
+ * (C) 2010 by Holger Hans Peter Freyther <zecke@selfish.org>
+ * (C) 2010 by On-Waves
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <openbsc/bsc_msc.h>
+#include <openbsc/debug.h>
+#include <osmocom/abis/ipaccess.h>
+
+#include <osmocom/core/write_queue.h>
+#include <osmocom/core/talloc.h>
+
+#include <osmocom/gsm/tlv.h>
+
+#include <arpa/inet.h>
+#include <sys/socket.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+static void connection_loss(struct bsc_msc_connection *con)
+{
+	struct osmo_fd *fd;
+
+	fd = &con->write_queue.bfd;
+
+	if (con->pending_msg) {
+		LOGP(DMSC, LOGL_ERROR,
+		     "MSC(%s) dropping incomplete message.\n", con->name);
+		msgb_free(con->pending_msg);
+		con->pending_msg = NULL;
+	}
+
+	close(fd->fd);
+	fd->fd = -1;
+	fd->cb = osmo_wqueue_bfd_cb;
+	fd->when = 0;
+
+	con->is_connected = 0;
+	con->first_contact = 0;
+	con->connection_loss(con);
+}
+
+static void msc_con_timeout(void *_con)
+{
+	struct bsc_msc_connection *con = _con;
+
+	LOGP(DMSC, LOGL_ERROR,
+		"MSC(%s) Connection timeout.\n", con->name);
+	bsc_msc_lost(con);
+}
+
+/* called in the case of a non blocking connect */
+static int msc_connection_connect(struct osmo_fd *fd, unsigned int what)
+{
+	int rc;
+	int val;
+	struct bsc_msc_connection *con;
+	struct osmo_wqueue *queue;
+
+	socklen_t len = sizeof(val);
+
+	queue = container_of(fd, struct osmo_wqueue, bfd);
+	con = container_of(queue, struct bsc_msc_connection, write_queue);
+
+	if ((what & BSC_FD_WRITE) == 0) {
+		LOGP(DMSC, LOGL_ERROR,
+			"MSC(%s) Callback but not writable.\n", con->name);
+		return -1;
+	}
+
+	/* From here on we will either be connected or reconnect */
+	osmo_timer_del(&con->timeout_timer);
+
+	/* check the socket state */
+	rc = getsockopt(fd->fd, SOL_SOCKET, SO_ERROR, &val, &len);
+	if (rc != 0) {
+		LOGP(DMSC, LOGL_ERROR,
+			"getsockopt for the MSC(%s) socket failed.\n", con->name);
+		goto error;
+	}
+	if (val != 0) {
+		LOGP(DMSC, LOGL_ERROR,
+			"Not connected to the MSC(%s): %d\n",
+			con->name, val);
+		goto error;
+	}
+
+
+	/* go to full operation */
+	fd->cb = osmo_wqueue_bfd_cb;
+	fd->when = BSC_FD_READ | BSC_FD_EXCEPT;
+
+	con->is_connected = 1;
+	LOGP(DMSC, LOGL_NOTICE,
+		"(Re)Connected to the MSC(%s).\n", con->name);
+	if (con->connected)
+		con->connected(con);
+	return 0;
+
+error:
+	osmo_fd_unregister(fd);
+	connection_loss(con);
+	return -1;
+}
+static void setnonblocking(struct osmo_fd *fd)
+{
+	int flags;
+
+	flags = fcntl(fd->fd, F_GETFL);
+	if (flags < 0) {
+		perror("fcntl get failed");
+		close(fd->fd);
+		fd->fd = -1;
+		return;
+	}
+
+	flags |= O_NONBLOCK;
+	flags = fcntl(fd->fd, F_SETFL, flags);
+	if (flags < 0) {
+		perror("fcntl get failed");
+		close(fd->fd);
+		fd->fd = -1;
+		return;
+	}
+}
+
+int bsc_msc_connect(struct bsc_msc_connection *con)
+{
+	struct bsc_msc_dest *dest;
+	struct osmo_fd *fd;
+	struct sockaddr_in sin;
+	int on = 1, ret;
+
+	if (llist_empty(con->dests)) {
+		LOGP(DMSC, LOGL_ERROR,
+			"No MSC(%s) connections configured.\n",
+			con->name);
+		connection_loss(con);
+		return -1;
+	}
+
+	/* TODO: Why are we not using the libosmocore soecket
+	 * abstraction, or libosmo-netif? */
+
+	/* move to the next connection */
+	dest = (struct bsc_msc_dest *) con->dests->next;
+	llist_del(&dest->list);
+	llist_add_tail(&dest->list, con->dests);
+
+	LOGP(DMSC, LOGL_NOTICE,
+		"Attempting to connect MSC(%s) at %s:%d\n",
+		con->name, dest->ip, dest->port);
+
+	con->is_connected = 0;
+
+	msgb_free(con->pending_msg);
+	con->pending_msg = NULL;
+
+	fd = &con->write_queue.bfd;
+	fd->fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
+	fd->priv_nr = 1;
+
+	if (fd->fd < 0) {
+		perror("Creating TCP socket failed");
+		return fd->fd;
+	}
+
+	/* make it non blocking */
+	setnonblocking(fd);
+
+	/* set the socket priority */
+	ret = setsockopt(fd->fd, IPPROTO_IP, IP_TOS,
+			 &dest->dscp, sizeof(dest->dscp));
+	if (ret != 0)
+		LOGP(DMSC, LOGL_ERROR,
+			"Failed to set DSCP to %d on MSC(%s). %s\n",
+			dest->dscp, con->name, strerror(errno));
+
+	memset(&sin, 0, sizeof(sin));
+	sin.sin_family = AF_INET;
+	sin.sin_port = htons(dest->port);
+	inet_aton(dest->ip, &sin.sin_addr);
+
+	ret = setsockopt(fd->fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
+	if (ret != 0)
+		LOGP(DMSC, LOGL_ERROR,
+		     "Failed to set SO_REUSEADDR socket option\n");
+	ret = connect(fd->fd, (struct sockaddr *) &sin, sizeof(sin));
+
+	if (ret == -1 && errno == EINPROGRESS) {
+		LOGP(DMSC, LOGL_ERROR,
+			"MSC(%s) Connection in progress\n", con->name);
+		fd->when = BSC_FD_WRITE;
+		fd->cb = msc_connection_connect;
+		osmo_timer_setup(&con->timeout_timer, msc_con_timeout, con);
+		osmo_timer_schedule(&con->timeout_timer, 20, 0);
+	} else if (ret < 0) {
+		perror("Connection failed");
+		connection_loss(con);
+		return ret;
+	} else {
+		fd->when = BSC_FD_READ | BSC_FD_EXCEPT;
+		fd->cb = osmo_wqueue_bfd_cb;
+		con->is_connected = 1;
+		if (con->connected)
+			con->connected(con);
+	}
+
+	ret = osmo_fd_register(fd);
+	if (ret < 0) {
+		perror("Registering the fd failed");
+		close(fd->fd);
+		return ret;
+	}
+
+	return ret;
+}
+
+struct bsc_msc_connection *bsc_msc_create(void *ctx, struct llist_head *dests)
+{
+	struct bsc_msc_connection *con;
+
+	con = talloc_zero(NULL, struct bsc_msc_connection);
+	if (!con) {
+		LOGP(DMSC, LOGL_FATAL, "Failed to create the MSC connection.\n");
+		return NULL;
+	}
+
+	con->dests = dests;
+	con->write_queue.bfd.fd = -1;
+	con->name = "";
+	osmo_wqueue_init(&con->write_queue, 100);
+	return con;
+}
+
+void bsc_msc_lost(struct bsc_msc_connection *con)
+{
+	osmo_wqueue_clear(&con->write_queue);
+	osmo_timer_del(&con->timeout_timer);
+	osmo_timer_del(&con->reconnect_timer);
+
+	if (con->write_queue.bfd.fd >= 0)
+		osmo_fd_unregister(&con->write_queue.bfd);
+	connection_loss(con);
+}
+
+static void reconnect_msc(void *_msc)
+{
+	struct bsc_msc_connection *con = _msc;
+
+	LOGP(DMSC, LOGL_NOTICE,
+		"Attempting to reconnect to the MSC(%s).\n", con->name);
+	bsc_msc_connect(con);
+}
+
+void bsc_msc_schedule_connect(struct bsc_msc_connection *con)
+{
+	LOGP(DMSC, LOGL_NOTICE,
+		"Attempting to reconnect to the MSC(%s)\n", con->name);
+	osmo_timer_setup(&con->reconnect_timer, reconnect_msc, con);
+	osmo_timer_schedule(&con->reconnect_timer, 5, 0);
+}
+
+struct msgb *bsc_msc_id_get_resp(int fixed, const char *token, const uint8_t *res, int len)
+{
+	struct msgb *msg;
+
+	if (!token) {
+		LOGP(DMSC, LOGL_ERROR, "No token specified.\n");
+		return NULL;
+	}
+
+	msg = msgb_alloc_headroom(4096, 128, "id resp");
+	if (!msg) {
+		LOGP(DMSC, LOGL_ERROR, "Failed to create the message.\n");
+		return NULL;
+	}
+
+	/*
+	 * The situation is bizarre. The encoding doesn't follow the
+	 * TLV structure. It is more like a LV and old versions had
+	 * it wrong but we want new versions to old servers so we
+	 * introduce the quirk here.
+	 */
+	msg->l2h = msgb_v_put(msg, IPAC_MSGT_ID_RESP);
+	if (fixed) {
+		msgb_put_u8(msg, 0);
+		msgb_put_u8(msg, strlen(token) + 2);
+		msgb_tv_fixed_put(msg, IPAC_IDTAG_UNITNAME, strlen(token) + 1, (uint8_t *) token);
+		if (len > 0) {
+			msgb_put_u8(msg, 0);
+			msgb_put_u8(msg, len + 1);
+			msgb_tv_fixed_put(msg, 0x24, len, res);
+		}
+	} else {
+		msgb_l16tv_put(msg, strlen(token) + 1,
+			IPAC_IDTAG_UNITNAME, (uint8_t *) token);
+	}
+
+	return msg;
+}