From a580407e11f89447bc40e505e305b6fcb6ab5e3f Mon Sep 17 00:00:00 2001
From: Pau Espin Pedrol <pespin@sysmocom.de>
Date: Mon, 1 Apr 2019 13:50:42 +0200
Subject: [PATCH] WIP: deetect net iface rename

---
 plugins/udevng.c | 84 +++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 83 insertions(+), 1 deletion(-)

diff --git a/plugins/udevng.c b/plugins/udevng.c
index 1a5bcb2b..5f85eb33 100644
--- a/plugins/udevng.c
+++ b/plugins/udevng.c
@@ -56,6 +56,7 @@ struct modem_info {
 	};
 	struct ofono_modem *modem;
 	const char *sysattr;
+	gboolean needs_update;
 };
 
 struct device_info {
@@ -1635,6 +1636,7 @@ static void add_device(const char *syspath, const char *devname,
 
 	modem->devices = g_slist_insert_sorted(modem->devices, info,
 							compare_device);
+	modem->needs_update = TRUE;
 }
 
 static struct {
@@ -1827,6 +1829,8 @@ static gboolean create_modem(gpointer key, gpointer value, gpointer user_data)
 	const char *syspath = key;
 	unsigned int i;
 
+	modem->needs_update = FALSE;
+
 	if (modem->modem != NULL)
 		return FALSE;
 
@@ -1914,6 +1918,81 @@ static gboolean check_modem_list(gpointer user_data)
 	return FALSE;
 }
 
+static void drop_old_device(gpointer key, gpointer value, gpointer user_data)
+{
+	const char *syspath = key;
+	struct modem_info *modem = value;
+	struct udev_device *device = user_data;
+	const char *devpath_old;
+	GSList *list;
+
+	devpath_old = udev_device_get_property_value(device, "DEVPATH_OLD");
+	if (!devpath_old)
+		return;
+
+	for (list = modem->devices; list; list = list->next) {
+		struct device_info *info = list->data;
+		struct udev_device *dev;
+
+		if (g_strcmp0(info->subsystem, "net") != 0)
+			continue;
+
+		if (g_strcmp0(info->devpath, devpath_old) != 0)
+			continue;
+
+		/* Drop no longer existing net iface device */
+		DBG("Dropping lost device %s", info->devpath);
+		modem->devices = g_slist_remove_link(modem->devices, list);
+		g_slist_free_1 (list);
+		device_info_free(info);
+		udev_device_unref(dev);
+		modem->needs_update = TRUE;
+	}
+}
+
+
+static void update_modem(gpointer key, gpointer value, gpointer user_data)
+{
+	const char *syspath = key;
+	struct modem_info *modem = value;
+	unsigned int i;
+
+	if (!modem->needs_update)
+		return;
+
+	DBG("Updating modem %s", syspath);
+
+	for (i = 0; driver_list[i].name; i++) {
+		if (g_str_equal(driver_list[i].name, modem->driver) == FALSE)
+			continue;
+		if (driver_list[i].setup(modem) == FALSE)
+			continue;
+	}
+}
+static void update_device(struct udev_device *device)
+{
+	const char *syspath;
+
+	syspath = udev_device_get_syspath(device);
+	if (syspath == NULL)
+		return;
+
+	DBG("%s", syspath);
+
+	/* We only care about net iface renames for now */
+	if (g_strcmp0(udev_device_get_subsystem(device), "net") != 0)
+		return;
+
+	/* Drop old device from modem */
+	g_hash_table_foreach(modem_list, drop_old_device, device);
+
+	/* Add new device to modem */
+	check_device(device);
+
+	/* Update modified modems */
+	g_hash_table_foreach(modem_list, update_modem, NULL);
+}
+
 static gboolean udev_event(GIOChannel *channel, GIOCondition cond,
 							gpointer user_data)
 {
@@ -1941,8 +2020,11 @@ static gboolean udev_event(GIOChannel *channel, GIOCondition cond,
 		check_device(device);
 
 		udev_delay = g_timeout_add_seconds(1, check_modem_list, NULL);
-	} else if (g_str_equal(action, "remove") == TRUE)
+	} else if (g_str_equal(action, "remove") == TRUE) {
 		remove_device(device);
+	} else if (g_str_equal(action, "move") == TRUE) {
+		update_device(device);
+	}
 
 	udev_device_unref(device);