networkd-wait-online: track links

Rather than refetching the link information on ever event, we liston to
rtnl to track them. Much code stolen from resolved.

This will allow us to simplify the sd-network api and don't expose
information available over rtnl.

1 files changed, 304 insertions, 0 deletions

diff --git a/src/network/networkd-wait-online-manager.c b/src/network/networkd-wait-online-manager.c
new file mode 100644
index 0000000000..649a21c80c
--- /dev/null
+++ b/src/network/networkd-wait-online-manager.c
@@ -0,0 +1,304 @@
+/*-*- 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 <netinet/ether.h>
+#include <linux/if.h>
+
+#include "rtnl-util.h"
+
+#include "network-util.h"
+#include "network-internal.h"
+#include "networkd-wait-online-link.h"
+#include "networkd-wait-online.h"
+
+#include "util.h"
+
+bool manager_all_configured(Manager *m) {
+        Iterator i;
+        Link *l;
+        char **ifname;
+        bool one_ready = false;
+
+        /* wait for all the links given on the commandline to appear */
+        STRV_FOREACH(ifname, m->interfaces) {
+                l = hashmap_get(m->links_by_name, *ifname);
+                if (!l) {
+                        log_debug("still waiting for %s", *ifname);
+                        return false;
+                }
+        }
+
+        /* wait for all links networkd manages to be in admin state 'configured'
+           and at least one link to gain a carrier */
+        HASHMAP_FOREACH(l, m->links, i) {
+                if (!link_relevant(l)) {
+                        log_info("ignore irrelevant link: %s", l->ifname);
+                        continue;
+                }
+
+                if (!l->state) {
+                        log_debug("link %s has not yet been processed by udev",
+                                  l->ifname);
+                        return false;
+                }
+
+                if (streq(l->state, "configuring")) {
+                        log_debug("link %s is being processed by networkd",
+                                  l->ifname);
+                        return false;
+                }
+
+                if (l->operational_state &&
+                    STR_IN_SET(l->operational_state, "degraded", "routable"))
+                        /* we wait for at least one link to be ready,
+                           regardless of who manages it */
+                        one_ready = true;
+        }
+
+        return one_ready;
+}
+
+static int manager_process_link(sd_rtnl *rtnl, sd_rtnl_message *mm, void *userdata) {
+        Manager *m = userdata;
+        uint16_t type;
+        Link *l;
+        char *ifname;
+        int ifindex, r;
+
+        assert(rtnl);
+        assert(m);
+        assert(mm);
+
+        r = sd_rtnl_message_get_type(mm, &type);
+        if (r < 0)
+                goto fail;
+
+        r = sd_rtnl_message_link_get_ifindex(mm, &ifindex);
+        if (r < 0)
+                goto fail;
+
+        r = sd_rtnl_message_read_string(mm, IFLA_IFNAME, &ifname);
+        if (r < 0)
+                goto fail;
+
+        l = hashmap_get(m->links, INT_TO_PTR(ifindex));
+
+        switch (type) {
+
+        case RTM_NEWLINK:
+                if (!l) {
+                        log_debug("Found link %i", ifindex);
+
+                        r = link_new(m, &l, ifindex, ifname);
+                        if (r < 0)
+                                goto fail;
+
+                        r = link_update_monitor(l);
+                        if (r < 0)
+                                goto fail;
+                }
+
+                r = link_update_rtnl(l, mm);
+                if (r < 0)
+                        goto fail;
+
+                break;
+
+        case RTM_DELLINK:
+                if (l) {
+                        log_debug("Removing link %i", l->ifindex);
+                        link_free(l);
+                }
+
+                break;
+        }
+
+        return 0;
+
+fail:
+        log_warning("Failed to process RTNL link message: %s", strerror(-r));
+        return 0;
+}
+
+static int on_rtnl_event(sd_rtnl *rtnl, sd_rtnl_message *mm, void *userdata) {
+        Manager *m = userdata;
+        int r;
+
+        r = manager_process_link(rtnl, mm, m);
+        if (r < 0)
+                return r;
+
+        if (manager_all_configured(m))
+                sd_event_exit(m->event, 0);
+
+        return 1;
+}
+
+static int manager_rtnl_listen(Manager *m) {
+        _cleanup_rtnl_message_unref_ sd_rtnl_message *req = NULL, *reply = NULL;
+        sd_rtnl_message *i;
+        int r;
+
+        assert(m);
+
+        /* First, subscibe to interfaces coming and going */
+        r = sd_rtnl_open(&m->rtnl, 3, RTNLGRP_LINK, RTNLGRP_IPV4_IFADDR, RTNLGRP_IPV6_IFADDR);
+        if (r < 0)
+                return r;
+
+        r = sd_rtnl_attach_event(m->rtnl, m->event, 0);
+        if (r < 0)
+                return r;
+
+        r = sd_rtnl_add_match(m->rtnl, RTM_NEWLINK, on_rtnl_event, m);
+        if (r < 0)
+                return r;
+
+        r = sd_rtnl_add_match(m->rtnl, RTM_DELLINK, on_rtnl_event, m);
+        if (r < 0)
+                return r;
+
+        /* Then, enumerate all links */
+        r = sd_rtnl_message_new_link(m->rtnl, &req, RTM_GETLINK, 0);
+        if (r < 0)
+                return r;
+
+        r = sd_rtnl_message_request_dump(req, true);
+        if (r < 0)
+                return r;
+
+        r = sd_rtnl_call(m->rtnl, req, 0, &reply);
+        if (r < 0)
+                return r;
+
+        for (i = reply; i; i = sd_rtnl_message_next(i)) {
+                r = manager_process_link(m->rtnl, i, m);
+                if (r < 0)
+                        return r;
+        }
+
+        return r;
+}
+
+static int on_network_event(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+        Manager *m = userdata;
+        Iterator i;
+        Link *l;
+        int r;
+
+        assert(m);
+
+        sd_network_monitor_flush(m->network_monitor);
+
+        HASHMAP_FOREACH(l, m->links, i) {
+                r = link_update_monitor(l);
+                if (r < 0)
+                        log_warning("Failed to update monitor information for %i: %s", l->ifindex, strerror(-r));
+        }
+
+        if (manager_all_configured(m))
+                sd_event_exit(m->event, 0);
+
+        return 0;
+}
+
+static int manager_network_monitor_listen(Manager *m) {
+        int r, fd, events;
+
+        assert(m);
+
+        r = sd_network_monitor_new(&m->network_monitor, NULL);
+        if (r < 0)
+                return r;
+
+        fd = sd_network_monitor_get_fd(m->network_monitor);
+        if (fd < 0)
+                return fd;
+
+        events = sd_network_monitor_get_events(m->network_monitor);
+        if (events < 0)
+                return events;
+
+        r = sd_event_add_io(m->event, &m->network_monitor_event_source,
+                            fd, events, &on_network_event, m);
+        if (r < 0)
+                return r;
+
+        return 0;
+}
+
+int manager_new(Manager **ret, char **interfaces) {
+        _cleanup_(manager_freep) Manager *m = NULL;
+        int r;
+
+        assert(ret);
+
+        m = new0(Manager, 1);
+        if (!m)
+                return -ENOMEM;
+
+        m->interfaces = interfaces;
+
+        r = sd_event_default(&m->event);
+        if (r < 0)
+                return r;
+
+        sd_event_add_signal(m->event, NULL, SIGTERM, NULL,  NULL);
+        sd_event_add_signal(m->event, NULL, SIGINT, NULL, NULL);
+
+        sd_event_set_watchdog(m->event, true);
+
+        r = manager_network_monitor_listen(m);
+        if (r < 0)
+                return r;
+
+        r = manager_rtnl_listen(m);
+        if (r < 0)
+                return r;
+
+        *ret = m;
+        m = NULL;
+
+        return 0;
+}
+
+void manager_free(Manager *m) {
+        Link *l;
+
+        if (!m)
+                return;
+
+        while ((l = hashmap_first(m->links)))
+               link_free(l);
+        hashmap_free(m->links);
+        hashmap_free(m->links_by_name);
+
+        sd_event_source_unref(m->network_monitor_event_source);
+        sd_network_monitor_unref(m->network_monitor);
+
+        sd_event_source_unref(m->rtnl_event_source);
+        sd_rtnl_unref(m->rtnl);
+
+        sd_event_unref(m->event);
+        free(m);
+
+        return;
+}