miracled: friendly-name support for local links

The friendly-name is used as name for local links. Default to a random
string and try to read the local hostname during startup.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>

src/miracled-dbus.c

@@ -303,7 +303,15 @@ static int link_dbus_set_name(sd_bus *bus,
 			      void *data,
 			      sd_bus_error *err)
 {
-	return -EACCES;
+	struct link *l = data;
+	int r;
+	const char *name;
+
+	r = sd_bus_message_read(value, "s", &name);
+	if (r < 0)
+		return r;
+
+	return link_set_friendly_name(l, name);
 }
 
 static const sd_bus_vtable link_dbus_vtable[] = {

src/miracled-link.c

@@ -152,6 +152,10 @@ static int link_wifi_init(struct link *l)
 	r = wifi_open(l->w, path);
 	free(path);
 
+	if (r < 0)
+		return r;
+
+	r = wifi_set_name(l->w, l->friendly_name);
 	if (r < 0)
 		return r;
 
@@ -212,7 +216,7 @@ int link_new(struct manager *m,
 		goto error;
 	}
 
-	l->friendly_name = strdup("");
+	l->friendly_name = strdup(m->friendly_name);
 	if (!l->friendly_name) {
 		r = log_ENOMEM();
 		goto error;
@@ -270,3 +274,33 @@ void link_free(struct link *l)
 	free(l->interface);
 	free(l);
 }
+
+int link_set_friendly_name(struct link *l, const char *name)
+{
+	char *dup;
+	int r;
+
+	if (!l || !name)
+		return log_EINVAL();
+
+	dup = strdup(name);
+	if (!dup)
+		return log_ENOMEM();
+
+	r = 0;
+	switch (l->type) {
+	case LINK_WIFI:
+		r = wifi_set_name(l->w, name);
+		break;
+	}
+
+	if (r < 0) {
+		free(dup);
+		return r;
+	}
+
+	free(l->friendly_name);
+	l->friendly_name = dup;
+
+	return 0;
+}

src/miracled-wifi.c

@@ -804,6 +804,14 @@ int wifi_set_discoverable(struct wifi *w, bool on)
 	return 0;
 }
 
+int wifi_set_name(struct wifi *w, const char *name)
+{
+	if (!w || !wifi_is_open(w) || !name || !*name)
+		return log_EINVAL();
+
+	return wifi_requestf_ok(w, "SET device_name %s", name);
+}
+
 struct wifi_dev *wifi_get_devs(struct wifi *w)
 {
 	if (!w || shl_dlist_empty(&w->devs))

src/miracled-wifi.h

@@ -101,6 +101,7 @@ int wifi_open(struct wifi *w, const char *wpa_path);
 void wifi_close(struct wifi *w);
 
 int wifi_set_discoverable(struct wifi *w, bool on);
+int wifi_set_name(struct wifi *w, const char *name);
 
 struct wifi_dev *wifi_get_devs(struct wifi *w);
 struct wifi_dev *wifi_dev_next(struct wifi_dev *d);

src/miracled.c

@@ -35,6 +35,7 @@
 #include <systemd/sd-bus.h>
 #include <systemd/sd-daemon.h>
 #include <systemd/sd-event.h>
+#include <time.h>
 #include <unistd.h>
 #include "miracled.h"
 #include "shl_htable.h"
@@ -112,11 +113,13 @@ static void manager_free(struct manager *m)
 		sd_event_source_unref(m->sigs[i]);
 	sd_bus_unref(m->bus);
 	sd_event_unref(m->event);
+	free(m->friendly_name);
 	free(m);
 }
 
 static int manager_new(struct manager **out)
 {
+	char buf[64] = { };
 	struct manager *m;
 	static const int sigs[] = {
 		SIGINT, SIGTERM, SIGQUIT, SIGHUP, SIGPIPE, SIGCHLD, 0
@@ -132,6 +135,13 @@ static int manager_new(struct manager **out)
 	shl_htable_init_str(&m->links);
 	shl_htable_init_str(&m->peers);
 
+	snprintf(buf, sizeof(buf) - 1, "unknown-%u", rand());
+	m->friendly_name = strdup(buf);
+	if (!m->friendly_name) {
+		r = log_ENOMEM();
+		goto error;
+	}
+
 	r = sd_event_default(&m->event);
 	if (r < 0) {
 		log_vERR(r);
@@ -184,8 +194,58 @@ error:
 	return r;
 }
 
+static void manager_read_name(struct manager *m)
+{
+	_cleanup_sd_bus_error_ sd_bus_error err = SD_BUS_ERROR_NULL;
+	_cleanup_sd_bus_message_ sd_bus_message *rep = NULL;
+	const char *name;
+	char *str;
+	int r;
+
+	r = sd_bus_call_method(m->bus,
+			       "org.freedesktop.hostname1",
+			       "/org/freedesktop/hostname1",
+			       "org.freedesktop.DBus.Properties",
+			       "Get",
+			       &err,
+			       &rep,
+			       "ss", "org.freedesktop.hostname1", "Hostname");
+	if (r < 0) {
+		return;
+	}
+
+	r = sd_bus_message_enter_container(rep, 'v', "s");
+	if (r < 0)
+		goto error;
+
+	r = sd_bus_message_read(rep, "s", &name);
+	if (r < 0)
+		goto error;
+
+	if (!name || !*name) {
+		log_warning("no hostname set on systemd.hostname1, using: %s",
+			    m->friendly_name);
+		return;
+	}
+
+	str = strdup(name);
+	if (!str)
+		return log_vENOMEM();
+
+	free(m->friendly_name);
+	m->friendly_name = str;
+	log_debug("friendly-name from local hostname: %s", str);
+
+	return;
+
+error:
+	log_warning("cannot read hostname from systemd.hostname1: %s",
+		    bus_error_message(&err, r));
+}
+
 static int manager_run(struct manager *m)
 {
+	manager_read_name(m);
 	return sd_event_loop(m->event);
 }
 
@@ -257,6 +317,8 @@ int main(int argc, char **argv)
 	struct manager *m = NULL;
 	int r;
 
+	srand(time(NULL));
+
 	r = parse_argv(argc, argv);
 	if (r < 0)
 		return EXIT_FAILURE;

src/miracled.h

@@ -101,6 +101,8 @@ int link_new(struct manager *m,
 	     struct link **out);
 void link_free(struct link *l);
 
+int link_set_friendly_name(struct link *l, const char *name);
+
 /* manager */
 
 struct manager {
@@ -114,6 +116,8 @@ struct manager {
 	size_t peer_cnt;
 	struct shl_htable links;
 	struct shl_htable peers;
+
+	char *friendly_name;
 };
 
 #define MANAGER_FIRST_LINK(_m) \