networkd: introduce vxcan netdev. (#7150)

Similar to the virtual ethernet driver veth, vxcan implements a
local CAN traffic tunnel between two virtual CAN network devices.
When creating a vxcan, two vxcan devices are created as pair
When one end receives the packet it appears on its pair and vice
versa. The vxcan can be used for cross namespace communication.

diff --git a/src/basic/missing.h b/src/basic/missing.h
index 63eacbb1714020fbd2b59cfe0f83adbc48f6f1be..4830a9723ca5fe4776294d69a42ffd11364b1ae1 100644 (file)
--- a/src/basic/missing.h
+++ b/src/basic/missing.h
@@ -960,6 +960,10 @@ struct input_mask {
 #define IFLA_VRF_TABLE 1
 #endif
 
+#if !HAVE_VXCAN_INFO_PEER
+#define VXCAN_INFO_PEER 1
+#endif
+
 #if !HAVE_NDA_IFINDEX
 #define NDA_UNSPEC 0
 #define NDA_DST 1

diff --git a/src/network/netdev/vxcan.c b/src/network/netdev/vxcan.c
new file mode 100644 (file)
index 0000000..e8a71d6
--- /dev/null
+++ b/src/network/netdev/vxcan.c
@@ -0,0 +1,89 @@
+/***
+  This file is part of elogind.
+
+  Copyright 2017 Susant Sahani
+
+  elogind is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  elogind 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
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with elogind; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include "netdev/vxcan.h"
+#include "missing.h"
+
+static int netdev_vxcan_fill_message_create(NetDev *netdev, Link *link, sd_netlink_message *m) {
+        VxCan *v;
+        int r;
+
+        assert(netdev);
+        assert(!link);
+        assert(m);
+
+        v = VXCAN(netdev);
+
+        assert(v);
+
+        r = sd_netlink_message_open_container(m, VXCAN_INFO_PEER);
+        if (r < 0)
+                return log_netdev_error_errno(netdev, r, "Could not append VXCAN_INFO_PEER attribute: %m");
+
+        if (v->ifname_peer) {
+                r = sd_netlink_message_append_string(m, IFLA_IFNAME, v->ifname_peer);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to add vxcan netlink interface peer name: %m");
+        }
+
+        r = sd_netlink_message_close_container(m);
+        if (r < 0)
+                return log_netdev_error_errno(netdev, r, "Could not append VXCAN_INFO_PEER attribute: %m");
+
+        return r;
+}
+
+static int netdev_vxcan_verify(NetDev *netdev, const char *filename) {
+        VxCan *v;
+
+        assert(netdev);
+        assert(filename);
+
+        v = VXCAN(netdev);
+
+        assert(v);
+
+        if (!v->ifname_peer) {
+                log_warning("VxCan NetDev without peer name configured in %s. Ignoring", filename);
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
+static void vxcan_done(NetDev *n) {
+        VxCan *v;
+
+        assert(n);
+
+        v = VXCAN(n);
+
+        assert(v);
+
+        free(v->ifname_peer);
+}
+
+const NetDevVTable vxcan_vtable = {
+        .object_size = sizeof(VxCan),
+        .sections = "Match\0NetDev\0VXCAN\0",
+        .done = vxcan_done,
+        .fill_message_create = netdev_vxcan_fill_message_create,
+        .create_type = NETDEV_CREATE_INDEPENDENT,
+        .config_verify = netdev_vxcan_verify,
+};