networkd: introduce ipip tunnel

This patch enables basic ipip tunnel support.
It works with kernel module ipip

example conf:

file: ipip.netdev

[NetDev]
Name=ipip-tun
Kind=ipip
MTUBytes=1480

[Tunnel]
Local=192.168.223.238
Remote=192.169.224.239
TTL=64

file: ipip.network

[Match]
Name=em1

[Network]
Tunnel=ipip-tun

[tomegun:
         - drop unused variable
         - take ref when enslaving]

1 files changed, 192 insertions, 0 deletions

diff --git a/src/network/networkd-tunnel.c b/src/network/networkd-tunnel.c
new file mode 100644
index 0000000000..49a4975522
--- /dev/null
+++ b/src/network/networkd-tunnel.c
@@ -0,0 +1,192 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+    This file is part of systemd.
+
+    Copyright 2014 Susant Sahani <susant@redhat.com>
+
+    systemd 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.
+
+    systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <netinet/ether.h>
+#include <arpa/inet.h>
+#include <net/if.h>
+#include <linux/ip.h>
+#include <linux/if_tunnel.h>
+#include <libkmod.h>
+
+#include "sd-rtnl.h"
+#include "networkd.h"
+#include "network-internal.h"
+#include "util.h"
+
+
+static int netdev_fill_ipip_rtnl_message(Link *link, sd_rtnl_message *m) {
+        NetDev *netdev;
+        int r;
+
+        assert(link);
+        assert(link->network);
+        assert(link->network->tunnel);
+        assert(m);
+
+        netdev = link->network->tunnel;
+
+        r = sd_rtnl_message_append_string(m, IFLA_IFNAME, netdev->name);
+        if (r < 0) {
+                log_error_netdev(netdev,
+                                 "Could not append IFLA_IFNAME, attribute: %s",
+                                 strerror(-r));
+                return r;
+        }
+
+        if(netdev->mtu) {
+                r = sd_rtnl_message_append_u32(m, IFLA_MTU, netdev->mtu);
+                if (r < 0) {
+                        log_error_netdev(netdev,
+                                         "Could not append IFLA_MTU attribute: %s",
+                                         strerror(-r));
+                        return r;
+                }
+        }
+
+        r = sd_rtnl_message_open_container(m, IFLA_LINKINFO);
+        if (r < 0) {
+                log_error_netdev(netdev,
+                                 "Could not append IFLA_LINKINFO attribute: %s",
+                                 strerror(-r));
+                return r;
+        }
+
+        r = sd_rtnl_message_open_container_union(m, IFLA_INFO_DATA,
+                                                 netdev_kind_to_string(netdev->kind));
+        if (r < 0) {
+                log_error_netdev(netdev,
+                                 "Could not append IFLA_INFO_DATA attribute: %s",
+                                 strerror(-r));
+                return r;
+        }
+
+        r = sd_rtnl_message_append_u32(m, IFLA_IPTUN_LINK, link->ifindex);
+        if (r < 0) {
+                log_error_netdev(netdev,
+                                 "Could not append IFLA_IPTUN_LINK attribute: %s",
+                                 strerror(-r));
+                return r;
+        }
+
+        r = sd_rtnl_message_append_in_addr(m, IFLA_IPTUN_LOCAL, &netdev->tunnel_local);
+        if (r < 0) {
+                log_error_netdev(netdev,
+                                 "Could not append IFLA_IPTUN_LOCAL attribute: %s",
+                                 strerror(-r));
+                return r;
+        }
+
+        r = sd_rtnl_message_append_in_addr(m, IFLA_IPTUN_REMOTE, &netdev->tunnel_remote);
+        if (r < 0) {
+                log_error_netdev(netdev,
+                                 "Could not append IFLA_IPTUN_REMOTE attribute: %s",
+                                 strerror(-r));
+                return r;
+        }
+
+        r = sd_rtnl_message_close_container(m);
+        if (r < 0) {
+                log_error_netdev(netdev,
+                                 "Could not append IFLA_INFO_DATA attribute: %s",
+                                 strerror(-r));
+                return r;
+        }
+
+        r = sd_rtnl_message_close_container(m);
+        if (r < 0) {
+                log_error_netdev(netdev,
+                                 "Could not append IFLA_LINKINFO attribute: %s",
+                                 strerror(-r));
+                return r;
+        }
+
+        return r;
+}
+
+int netdev_create_tunnel(Link *link, sd_rtnl_message_handler_t callback) {
+        _cleanup_rtnl_message_unref_ sd_rtnl_message *m = NULL;
+        NetDev *netdev;
+        int r;
+
+        assert(link);
+        assert(link->network);
+        assert(link->network->tunnel);
+
+        netdev = link->network->tunnel;
+
+        assert(netdev);
+        assert(netdev->name);
+        assert(netdev->manager);
+        assert(netdev->manager->rtnl);
+        assert(netdev->manager->kmod_ctx);
+
+        /* Load kernel module first */
+        switch(netdev->kind) {
+        case NETDEV_KIND_IPIP:
+        case NETDEV_KIND_GRE:
+        case NETDEV_KIND_SIT:
+                r = load_module(netdev->manager->kmod_ctx,
+                                netdev_kind_to_string(netdev->kind));
+                if (r < 0) {
+                        log_error_netdev(netdev,
+                                         "Could not load Kernel module: %s . Ignoring",
+                                         netdev_kind_to_string(netdev->kind));
+                        return r;
+                }
+                break;
+        default:
+                return -ENOTSUP;
+        }
+
+        r = sd_rtnl_message_new_link(netdev->manager->rtnl, &m, RTM_NEWLINK, 0);
+        if (r < 0) {
+                log_error_netdev(netdev,
+                                 "Could not allocate RTM_NEWLINK message: %s",
+                                 strerror(-r));
+                return r;
+        }
+
+        switch(netdev->kind) {
+        case NETDEV_KIND_IPIP:
+                r = netdev_fill_ipip_rtnl_message(link, m);
+                if(r < 0)
+                        return r;
+                break;
+        case NETDEV_KIND_GRE:
+        case NETDEV_KIND_SIT:
+        default:
+                return -ENOTSUP;
+        }
+
+        r = sd_rtnl_call_async(netdev->manager->rtnl, m, callback, netdev, 0, NULL);
+        if (r < 0) {
+                log_error_netdev(netdev,
+                                 "Could not send rtnetlink message: %s", strerror(-r));
+                return r;
+        }
+
+        log_debug_netdev(netdev, "Creating tunnel netdev: %s",
+                         netdev_kind_to_string(netdev->kind));
+
+        netdev->state = NETDEV_STATE_CREATING;
+
+        return 0;
+}