layer23: Initial integration of tun device

Use the new tundev API from libosmocore to create tun devices for each
configured (and enbled) APN.
No address nor routes are yet set on the tun devices because we still
lack GMM/SNDCP/LLC/RLCMAC layers to negotiate them.

A follow up patch will add some code to interact with the SNDCP layer.

Depends: libosmocore.git Change-Id I3463271666df1e85746fb7b06ec45a17024b8c53
Change-Id: I86cac406843157aa2e51727cf8ccac9804d7961d

1 files changed, 48 insertions, 1 deletions

diff --git a/src/host/layer23/src/common/apn.c b/src/host/layer23/src/common/apn.c
index f60053d9..169e30e9 100644
--- a/src/host/layer23/src/common/apn.c
+++ b/src/host/layer23/src/common/apn.c
@@ -18,13 +18,15 @@
 #include <stdint.h>
 #include <errno.h>
 #include <string.h>
-#include <arpa/inet.h>
+#include <netinet/ip.h>
+#include <netinet/ip6.h>
 
 #include <talloc.h>
 
 #include <osmocom/bb/common/logging.h>
 #include <osmocom/bb/common/apn.h>
 #include <osmocom/bb/common/ms.h>
+#include <osmocom/bb/common/l23_app.h>
 
 struct osmobb_apn *apn_alloc(struct osmocom_ms *ms, const char *name)
 {
@@ -38,6 +40,13 @@ struct osmobb_apn *apn_alloc(struct osmocom_ms *ms, const char *name)
 	apn->cfg.shutdown = true;
 	apn->cfg.tx_gpdu_seq = true;
 
+	apn->tun = osmo_tundev_alloc(apn, name);
+	if (!apn->tun) {
+		talloc_free(apn);
+		return NULL;
+	}
+	osmo_tundev_set_priv_data(apn->tun, apn);
+
 	apn->ms = ms;
 	llist_add_tail(&apn->list, &ms->gprs.apn_list);
 	return apn;
@@ -46,15 +55,53 @@ struct osmobb_apn *apn_alloc(struct osmocom_ms *ms, const char *name)
 void apn_free(struct osmobb_apn *apn)
 {
 	llist_del(&apn->list);
+	osmo_tundev_free(apn->tun);
 	talloc_free(apn);
 }
 
 int apn_start(struct osmobb_apn *apn)
 {
+	struct l23_app_info *app_info = l23_app_info();
+	int rc;
+
+	if (apn->started)
+		return 0;
+
+	LOGPAPN(LOGL_INFO, apn, "Opening TUN device %s\n", apn->cfg.dev_name);
+	/* Set TUN library callback. Must have been configured by the app: */
+	OSMO_ASSERT(app_info && app_info->tun_data_ind_cb);
+	osmo_tundev_set_data_ind_cb(apn->tun, app_info->tun_data_ind_cb);
+	osmo_tundev_set_dev_name(apn->tun, apn->cfg.dev_name);
+	osmo_tundev_set_netns_name(apn->tun, apn->cfg.dev_netns_name);
+
+	rc = osmo_tundev_open(apn->tun);
+	if (rc < 0) {
+		LOGPAPN(LOGL_ERROR, apn, "Failed to configure tun device\n");
+		return -1;
+	}
+
+	LOGPAPN(LOGL_INFO, apn, "Opened TUN device %s\n", osmo_tundev_get_dev_name(apn->tun));
+
+	/* TODO: set IP addresses on the tun device once we receive them from GGSN. See
+	   osmo-ggsn.git's apn_start() */
+
+	LOGPAPN(LOGL_NOTICE, apn, "Successfully started\n");
+	apn->started = true;
 	return 0;
 }
 
 int apn_stop(struct osmobb_apn *apn)
 {
+	LOGPAPN(LOGL_NOTICE, apn, "Stopping\n");
+
+	/* shutdown whatever old state might be left */
+	if (apn->tun) {
+		/* release tun device */
+		LOGPAPN(LOGL_INFO, apn, "Closing TUN device %s\n",
+			osmo_tundev_get_dev_name(apn->tun));
+		osmo_tundev_close(apn->tun);
+	}
+
+	apn->started = false;
 	return 0;
 }