networkd: add a basic network daemon

This daemon listens for and configures network devices tagged with
'systemd-networkd'. By default, no devices are tagged so this daemon
can safely run in parallel with existing network daemons/scripts.

Networks are configured in /etc/systemd/network/*.network. The first .network
file that matches a given link is applied. The matching logic is similar to
the one for .link files, but additionally supports matching on interface name.

The mid-term aim is to provide an alternative to ad-hoc scripts currently used
in initrd's and for wired setups that don't change much (e.g., as seen on
servers/and some embedded systems).

Currently, static addresses and a gateway can be configured.

Example .network file:

[Match]
Name=wlp2s0

[Network]
Description=My Network
Gateway=192.168.1.1
Address=192.168.1.23/24
Address=fe80::9aee:94ff:fe3f:c618/64

1 files changed, 210 insertions, 0 deletions

diff --git a/src/network/networkd-manager.c b/src/network/networkd-manager.c
new file mode 100644
index 0000000000..6a57a80147
--- /dev/null
+++ b/src/network/networkd-manager.c
@@ -0,0 +1,210 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2013 Tom Gundersen <teg@jklm.no>
+
+  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 "path-util.h"
+#include "networkd.h"
+#include "libudev-private.h"
+
+int manager_new(Manager **ret) {
+        _cleanup_manager_free_ Manager *m = NULL;
+        int r;
+
+        m = new0(Manager, 1);
+        if (!m)
+                return -ENOMEM;
+
+        r = sd_event_new(&m->event);
+        if (r < 0)
+                return r;
+
+        r = sd_rtnl_open(0, &m->rtnl);
+        if (r < 0)
+                return r;
+
+        m->udev = udev_new();
+        if (!m->udev)
+                return -ENOMEM;
+
+        m->udev_monitor = udev_monitor_new_from_netlink(m->udev, "udev");
+        if (!m->udev_monitor)
+                return -ENOMEM;
+
+        m->links = hashmap_new(uint64_hash_func, uint64_compare_func);
+        if (!m->links)
+                return -ENOMEM;
+
+        LIST_HEAD_INIT(m->networks);
+
+        m->network_dirs = strv_new("/etc/systemd/network/",
+                        "/run/systemd/network/",
+                        "/usr/lib/systemd/network",
+#ifdef HAVE_SPLIT_USER
+                        "/lib/systemd/network",
+#endif
+                        NULL);
+        if (!m->network_dirs)
+                return -ENOMEM;
+
+        if (!path_strv_canonicalize_uniq(m->network_dirs))
+                return -ENOMEM;
+
+        *ret = m;
+        m = NULL;
+
+        return 0;
+}
+
+void manager_free(Manager *m) {
+        udev_monitor_unref(m->udev_monitor);
+        udev_unref(m->udev);
+        sd_event_source_unref(m->udev_event_source);
+        sd_event_unref(m->event);
+        hashmap_free(m->links);
+        strv_free(m->network_dirs);
+        sd_rtnl_unref(m->rtnl);
+
+        free(m);
+}
+
+static int manager_process_link(Manager *m, struct udev_device *device) {
+        Link *link;
+        int r;
+
+        if (streq_ptr(udev_device_get_action(device), "remove")) {
+                uint64_t ifindex;
+
+                ifindex = udev_device_get_ifindex(device);
+                link = hashmap_get(m->links, &ifindex);
+                if (!link)
+                        return 0;
+
+                link_free(link);
+        } else {
+                r = link_add(m, device);
+                if (r < 0) {
+                        log_error("Could not handle link %s: %s",
+                                        udev_device_get_sysname(device),
+                                        strerror(-r));
+                }
+        }
+
+        return 0;
+}
+
+int manager_udev_enumerate_links(Manager *m) {
+        struct udev_list_entry *item = NULL, *first = NULL;
+        struct udev_enumerate *e;
+        int r;
+
+        assert(m);
+
+        e = udev_enumerate_new(m->udev);
+        if (!e) {
+                r = -ENOMEM;
+                goto finish;
+        }
+
+        r = udev_enumerate_add_match_subsystem(e, "net");
+        if (r < 0)
+                goto finish;
+
+        r = udev_enumerate_add_match_tag(e, "systemd-networkd");
+        if (r < 0)
+                goto finish;
+
+        r = udev_enumerate_scan_devices(e);
+        if (r < 0)
+                goto finish;
+
+        first = udev_enumerate_get_list_entry(e);
+        udev_list_entry_foreach(item, first) {
+                struct udev_device *d;
+                int k;
+
+                d = udev_device_new_from_syspath(m->udev, udev_list_entry_get_name(item));
+                if (!d) {
+                        r = -ENOMEM;
+                        goto finish;
+                }
+
+                k = manager_process_link(m, d);
+                udev_device_unref(d);
+
+                if (k < 0)
+                        r = k;
+        }
+
+finish:
+        if (e)
+                udev_enumerate_unref(e);
+
+        return r;
+}
+
+static int manager_dispatch_link_udev(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
+        Manager *m = userdata;
+        struct udev_monitor *monitor = m->udev_monitor;
+        struct udev_device *device;
+        int r;
+
+        device = udev_monitor_receive_device(monitor);
+        if (!device)
+                return -ENOMEM;
+
+        r = manager_process_link(m, device);
+        if (r < 0)
+                return r;
+
+        udev_device_unref(device);
+
+        return 0;
+}
+
+int manager_udev_listen(Manager *m) {
+        int r;
+
+        r = udev_monitor_filter_add_match_subsystem_devtype(m->udev_monitor, "net", NULL);
+        if (r < 0) {
+                log_error("Could not add udev monitor filter: %s", strerror(-r));
+                return r;
+        }
+
+        r = udev_monitor_filter_add_match_tag(m->udev_monitor, "systemd-networkd");
+        if (r < 0) {
+                log_error("Could not add udev monitor filter: %s", strerror(-r));
+                return r;
+        }
+
+        r = udev_monitor_enable_receiving(m->udev_monitor);
+        if (r < 0) {
+                log_error("Could not enable udev monitor");
+                return r;
+        }
+
+        r = sd_event_add_io(m->event,
+                        udev_monitor_get_fd(m->udev_monitor),
+                        EPOLLIN, manager_dispatch_link_udev,
+                        m, &m->udev_event_source);
+        if (r < 0)
+                return r;
+
+        return 0;
+}