networkd: introduce veth device support

This patch adds veth device support to networkd.

Example conf:

File: veth.netdev

[NetDev]
Name=veth-test
Kind=veth

[Peer]
Name=veth-peer

5 files changed, 144 insertions, 1 deletions

diff --git a/Makefile.am b/Makefile.am
index 5158bbc776..d2f2880c28 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -4269,6 +4269,7 @@ libsystemd_networkd_core_la_SOURCES = \
 	src/network/networkd-link.c \
 	src/network/networkd-netdev.c \
 	src/network/networkd-tunnel.c \
+	src/network/networkd-veth.c \
 	src/network/networkd-network.c \
 	src/network/networkd-address.c \
 	src/network/networkd-route.c \
diff --git a/src/network/networkd-netdev-gperf.gperf b/src/network/networkd-netdev-gperf.gperf
index 29889cd476..f39c922fd2 100644
--- a/src/network/networkd-netdev-gperf.gperf
+++ b/src/network/networkd-netdev-gperf.gperf
@@ -29,3 +29,4 @@ Tunnel.Local,            config_parse_tunnel_address,        0,
 Tunnel.Remote,           config_parse_tunnel_address,        0,                             offsetof(NetDev, tunnel_remote)
 Tunnel.TOS,              config_parse_unsigned,              0,                             offsetof(NetDev, tunnel_tos)
 Tunnel.TTL,              config_parse_unsigned,              0,                             offsetof(NetDev, tunnel_ttl)
+Peer.Name,               config_parse_ifname,                0,                             offsetof(NetDev, ifname_peer)
diff --git a/src/network/networkd-netdev.c b/src/network/networkd-netdev.c
index c54b0c10f2..472028c447 100644
--- a/src/network/networkd-netdev.c
+++ b/src/network/networkd-netdev.c
@@ -38,6 +38,7 @@ static const char* const netdev_kind_table[_NETDEV_KIND_MAX] = {
         [NETDEV_KIND_IPIP] = "ipip",
         [NETDEV_KIND_GRE] = "gre",
         [NETDEV_KIND_SIT] = "sit",
+        [NETDEV_KIND_VETH] = "veth",
 };
 
 DEFINE_STRING_TABLE_LOOKUP(netdev_kind, NetDevKind);
@@ -546,7 +547,7 @@ static int netdev_load_one(Manager *manager, const char *filename) {
         netdev->macvlan_mode = _NETDEV_MACVLAN_MODE_INVALID;
         netdev->vlanid = VLANID_MAX + 1;
 
-        r = config_parse(NULL, filename, file, "Match\0NetDev\0VLAN\0MACVLAN\0Tunnel\0",
+        r = config_parse(NULL, filename, file, "Match\0NetDev\0VLAN\0MACVLAN\0Tunnel\0Peer\0",
                          config_item_perf_lookup, (void*) network_netdev_gperf_lookup,
                          false, false, netdev);
         if (r < 0) {
@@ -598,6 +599,9 @@ static int netdev_load_one(Manager *manager, const char *filename) {
 
         LIST_HEAD_INIT(netdev->callbacks);
 
+        if(netdev->kind == NETDEV_KIND_VETH)
+                return netdev_create_veth(netdev, netdev_create_handler);
+
         if (netdev->kind != NETDEV_KIND_VLAN &&
             netdev->kind != NETDEV_KIND_MACVLAN &&
             netdev->kind != NETDEV_KIND_IPIP &&
diff --git a/src/network/networkd-veth.c b/src/network/networkd-veth.c
new file mode 100644
index 0000000000..1a5d880ac2
--- /dev/null
+++ b/src/network/networkd-veth.c
@@ -0,0 +1,134 @@
+/*-*- 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/veth.h>
+
+#include "sd-rtnl.h"
+#include "networkd.h"
+
+
+static int netdev_fill_veth_rtnl_message(NetDev *netdev, sd_rtnl_message *m) {
+        int r;
+
+        assert(netdev);
+        assert(m);
+
+        r = sd_rtnl_message_append_string(m, IFLA_IFNAME, netdev->ifname);
+        if (r < 0) {
+                log_error_netdev(netdev,
+                                 "Could not append IFLA_IFNAME, 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_open_container(m, VETH_INFO_PEER);
+        if (r < 0) {
+                log_error_netdev(netdev,
+                                 "Could not append IFLA_IPTUN_LINK attribute: %s",
+                                 strerror(-r));
+                return r;
+        }
+
+        if(netdev->ifname_peer) {
+                r = sd_rtnl_message_append_string(m, IFLA_IFNAME, netdev->ifname_peer);
+                if (r < 0) {
+                        log_error("Failed to add netlink interface name: %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_veth(NetDev *netdev, sd_rtnl_message_handler_t callback) {
+        _cleanup_rtnl_message_unref_ sd_rtnl_message *m = NULL;
+        int r;
+
+        assert(netdev);
+        assert(netdev->ifname);
+        assert(netdev->manager);
+        assert(netdev->manager->rtnl);
+
+        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;
+        }
+
+        if(netdev->kind != NETDEV_KIND_VETH)
+                return -ENOTSUP;
+
+        r = netdev_fill_veth_rtnl_message(netdev, m);
+        if(r < 0)
+                return r;
+
+        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 veth netdev: %s",
+                         netdev_kind_to_string(netdev->kind));
+
+        netdev->state = NETDEV_STATE_CREATING;
+
+        return 0;
+}
diff --git a/src/network/networkd.h b/src/network/networkd.h
index cfe24f5702..e504854761 100644
--- a/src/network/networkd.h
+++ b/src/network/networkd.h
@@ -71,6 +71,7 @@ typedef enum NetDevKind {
         NETDEV_KIND_IPIP,
         NETDEV_KIND_GRE,
         NETDEV_KIND_SIT,
+        NETDEV_KIND_VETH,
         _NETDEV_KIND_MAX,
         _NETDEV_KIND_INVALID = -1
 } NetDevKind;
@@ -98,6 +99,7 @@ struct NetDev {
 
         char *description;
         char *ifname;
+        char *ifname_peer;
         size_t mtu;
         NetDevKind kind;
 
@@ -310,6 +312,7 @@ int netdev_get(Manager *manager, const char *name, NetDev **ret);
 int netdev_set_ifindex(NetDev *netdev, sd_rtnl_message *newlink);
 int netdev_enslave(NetDev *netdev, Link *link, sd_rtnl_message_handler_t cb);
 int netdev_create_tunnel(Link *link, sd_rtnl_message_handler_t callback);
+int netdev_create_veth(NetDev *netdev, sd_rtnl_message_handler_t callback);
 
 const char *netdev_kind_to_string(NetDevKind d) _const_;
 NetDevKind netdev_kind_from_string(const char *d) _pure_;