core: add NMArpingManager

Add a new object which implements the logic for announcing IP
addresses and detecting duplicates using arping.

Based-on-patch-by: Jiří Klimeš <jklimes@redhat.com>

4 files changed, 512 insertions, 0 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index 7e85831035..d07fed6e2e 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -240,6 +240,8 @@ libNetworkManager_la_SOURCES = \
 	devices/nm-device.h \
 	devices/nm-lldp-listener.c \
 	devices/nm-lldp-listener.h \
+	devices/nm-arping-manager.c \
+	devices/nm-arping-manager.h \
 	devices/nm-device-ethernet-utils.c \
 	devices/nm-device-ethernet-utils.h \
 	devices/nm-device-factory.c \
diff --git a/src/devices/nm-arping-manager.c b/src/devices/nm-arping-manager.c
new file mode 100644
index 0000000000..a139c2cd44
--- /dev/null
+++ b/src/devices/nm-arping-manager.c
@@ -0,0 +1,453 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: t; c-basic-offset: 4 -*- */
+/* NetworkManager -- Network link manager
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * Copyright (C) 2015 Red Hat, Inc.
+ */
+
+#include "config.h"
+
+#include <netinet/in.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#include "nm-default.h"
+#include "nm-arping-manager.h"
+#include "nm-platform.h"
+#include "nm-utils.h"
+#include "NetworkManagerUtils.h"
+
+typedef enum {
+	STATE_INIT,
+	STATE_PROBING,
+	STATE_PROBE_DONE,
+	STATE_ANNOUNCING,
+} State;
+
+typedef struct {
+	int            ifindex;
+	State          state;
+	GHashTable    *addresses;
+	guint          completed;
+	guint          timer;
+	guint          round2_id;
+	void          *user_data;
+	GDestroyNotify user_data_destroy_func;
+} NMArpingManagerPrivate;
+
+typedef struct {
+	in_addr_t address;
+	GPid pid;
+	guint watch;
+	gboolean duplicate;
+	NMArpingManager *manager;
+} AddressInfo;
+
+enum {
+	PROBE_TERMINATED,
+	LAST_SIGNAL,
+};
+static guint signals[LAST_SIGNAL] = { 0 };
+
+G_DEFINE_TYPE (NMArpingManager, nm_arping_manager, G_TYPE_OBJECT)
+
+#define NM_ARPING_MANAGER_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), NM_TYPE_ARPING_MANAGER, NMArpingManagerPrivate))
+
+#define _NMLOG_DOMAIN         LOGD_IP4
+#define _NMLOG_PREFIX_NAME    "arping"
+#define _NMLOG(level, ...) \
+    G_STMT_START { \
+        char _sbuf[64]; \
+        \
+        nm_log ((level), _NMLOG_DOMAIN, \
+                "%s%s: " _NM_UTILS_MACRO_FIRST (__VA_ARGS__), \
+                _NMLOG_PREFIX_NAME, \
+                self ? nm_sprintf_buf (_sbuf, "[%p,%d]", \
+                                       self, \
+                                       NM_ARPING_MANAGER_GET_PRIVATE (self)->ifindex) : "" \
+                _NM_UTILS_MACRO_REST (__VA_ARGS__)); \
+    } G_STMT_END
+
+/**
+ * nm_arping_manager_add_address:
+ * @self: a #NMArpingManager
+ * @address: an IP address
+ *
+ * Add @address to the list of IP addresses to probe.
+
+ * Returns: %TRUE on success, %FALSE if the address was already in the list
+ */
+gboolean
+nm_arping_manager_add_address (NMArpingManager *self, in_addr_t address)
+{
+	NMArpingManagerPrivate *priv;
+	AddressInfo *info;
+
+	g_return_val_if_fail (NM_IS_ARPING_MANAGER (self), FALSE);
+	priv = NM_ARPING_MANAGER_GET_PRIVATE (self);
+	g_return_val_if_fail (priv->state == STATE_INIT, FALSE);
+
+	if (g_hash_table_lookup (priv->addresses, GUINT_TO_POINTER (address))) {
+		_LOGD ("address already exists");
+		return FALSE;
+	}
+
+	info = g_new0 (AddressInfo, 1);
+	info->address = address;
+	info->manager = g_object_ref (self);
+
+	g_hash_table_insert (priv->addresses, GUINT_TO_POINTER (address), info);
+
+	return TRUE;
+}
+
+static void
+arping_notify_probe_terminated (NMArpingManager *self)
+{
+	NMArpingManagerPrivate *priv = NM_ARPING_MANAGER_GET_PRIVATE (self);
+
+	g_signal_emit (self, signals[PROBE_TERMINATED], 0, priv->user_data);
+	if (priv->user_data_destroy_func)
+		g_clear_pointer (&priv->user_data, priv->user_data_destroy_func);
+}
+
+static void
+arping_watch_cb (GPid pid, gint status, gpointer user_data)
+{
+	AddressInfo *info = user_data;
+	NMArpingManager *self = info->manager;
+	NMArpingManagerPrivate *priv = NM_ARPING_MANAGER_GET_PRIVATE (self);
+	const char *addr;
+
+	info->pid = 0;
+	info->watch = 0;
+	addr = nm_utils_inet4_ntop (info->address, NULL);
+
+	if (WIFEXITED (status)) {
+		if (WEXITSTATUS (status) != 0) {
+			_LOGD ("%s already used in the %s network",
+			       addr, nm_platform_link_get_name (NM_PLATFORM_GET, priv->ifindex));
+			info->duplicate = TRUE;
+		} else
+			_LOGD ("DAD succeeded for %s", addr);
+	} else {
+		_LOGD ("stopped unexpectedly with status %d for %s", status, addr);
+	}
+
+	if (++priv->completed == g_hash_table_size (priv->addresses)) {
+		priv->state = STATE_PROBE_DONE;
+		nm_clear_g_source (&priv->timer);
+		arping_notify_probe_terminated (self);
+	}
+}
+
+static gboolean
+arping_timeout_cb (gpointer user_data)
+{
+	NMArpingManager *self = user_data;
+	NMArpingManagerPrivate *priv = NM_ARPING_MANAGER_GET_PRIVATE (self);
+	GHashTableIter iter;
+	AddressInfo *info;
+
+	priv->timer = 0;
+
+	g_hash_table_iter_init (&iter, priv->addresses);
+	while (g_hash_table_iter_next (&iter, NULL, (gpointer *) &info)) {
+		nm_clear_g_source (&info->watch);
+		if (info->pid) {
+			_LOGD ("DAD timed out for %s",
+			       nm_utils_inet4_ntop (info->address, NULL));
+			nm_utils_kill_child_async (info->pid, SIGTERM, LOGD_IP4,
+			                           "arping", 1000, NULL, NULL);
+			info->pid = 0;
+		}
+	}
+
+	priv->state = STATE_PROBE_DONE;
+	arping_notify_probe_terminated (self);
+
+	return G_SOURCE_REMOVE;
+}
+
+/**
+ * nm_arping_manager_start_probe:
+ * @self: a #NMArpingManager
+ * @timeout: maximum probe duration in milliseconds
+ * @user_data: pointer to user data to be passed back to signal handler
+ * @user_data_destroy_func: function to destroy @user_data
+ * @error: location to store error, or %NULL
+ *
+ * Start probing IP addresses for duplicates; when the probe terminates a
+ * PROBE_TERMINATED signal is emitted with @user_data as argument, then
+ * @user_data is released using @user_data_destroy. When @self is destroyed or
+ * reset, @user_data_destroy_func will be called on @user_data if the signal was
+ * not emitted.
+ *
+ * Returns: %TRUE on success, %FALSE on failure
+ */
+gboolean
+nm_arping_manager_start_probe (NMArpingManager *self, guint timeout, void *user_data,
+                               GDestroyNotify user_data_destroy_func, GError **error)
+{
+	const char *argv[] = { NULL, "-D", "-q", "-I", NULL, "-c", NULL, "-w", NULL, NULL, NULL };
+	NMArpingManagerPrivate *priv;
+	GHashTableIter iter;
+	AddressInfo *info;
+	gs_free char *timeout_str = NULL;
+
+	g_return_val_if_fail (NM_IS_ARPING_MANAGER (self), FALSE);
+	g_return_val_if_fail (!error || !*error, FALSE);
+	g_return_val_if_fail (timeout, FALSE);
+
+	priv = NM_ARPING_MANAGER_GET_PRIVATE (self);
+	g_return_val_if_fail (priv->state == STATE_INIT, FALSE);
+
+	argv[4] = nm_platform_link_get_name (NM_PLATFORM_GET, priv->ifindex);
+	g_return_val_if_fail (argv[4], FALSE);
+
+	priv->completed = 0;
+	priv->user_data = user_data;
+	priv->user_data_destroy_func = user_data_destroy_func;
+
+	argv[0] = nm_utils_find_helper ("arping", NULL, NULL);
+	if (!argv[0]) {
+		g_set_error_literal (error, NM_DEVICE_ERROR, NM_DEVICE_ERROR_FAILED,
+		                     "arping could not be found");
+		return FALSE;
+	}
+
+	timeout_str = g_strdup_printf ("%u", timeout / 1000 + 2);
+	argv[6] = timeout_str;
+	argv[8] = timeout_str;
+
+	g_hash_table_iter_init (&iter, priv->addresses);
+
+	while (g_hash_table_iter_next (&iter, NULL, (gpointer *) &info)) {
+		gs_free char *tmp_str = NULL;
+		gboolean success;
+
+		argv[9] = nm_utils_inet4_ntop (info->address, NULL);
+		_LOGD ("run %s", (tmp_str = g_strjoinv (" ", (char **) argv)));
+
+		success = g_spawn_async (NULL, (char **) argv, NULL,
+		                         G_SPAWN_STDOUT_TO_DEV_NULL |
+		                         G_SPAWN_STDERR_TO_DEV_NULL |
+		                         G_SPAWN_DO_NOT_REAP_CHILD,
+		                         NULL, NULL, &info->pid, NULL);
+
+		info->watch = g_child_watch_add (info->pid, arping_watch_cb, info);
+	}
+
+	priv->timer = g_timeout_add (timeout, arping_timeout_cb, self);
+	priv->state = STATE_PROBING;
+
+	return TRUE;
+}
+
+/**
+ * nm_arping_manager_reset:
+ * @self: a #NMArpingManager
+ *
+ * Stop any operation in progress and reset @self to the initial state.
+ */
+void
+nm_arping_manager_reset (NMArpingManager *self)
+{
+	NMArpingManagerPrivate *priv;
+
+	g_return_if_fail (NM_IS_ARPING_MANAGER (self));
+	priv = NM_ARPING_MANAGER_GET_PRIVATE (self);
+
+	nm_clear_g_source (&priv->timer);
+	nm_clear_g_source (&priv->round2_id);
+	g_hash_table_remove_all (priv->addresses);
+
+	if (priv->user_data_destroy_func && priv->user_data)
+		priv->user_data_destroy_func (priv->user_data);
+
+	priv->user_data_destroy_func = NULL;
+	priv->user_data = NULL;
+	priv->state = STATE_INIT;
+}
+
+/**
+ * nm_arping_manager_check_address:
+ * @self: a #NMArpingManager
+ * @address: an IP address
+ *
+ * Check if an IP address is duplicate. @address must have been added with
+ * nm_arping_manager_add_address().
+ *
+ * Returns: %TRUE if the address is not duplicate, %FALSE otherwise
+ */
+gboolean
+nm_arping_manager_check_address (NMArpingManager *self, in_addr_t address)
+{
+	NMArpingManagerPrivate *priv;
+	AddressInfo *info;
+
+	g_return_val_if_fail (NM_IS_ARPING_MANAGER (self), FALSE);
+	priv = NM_ARPING_MANAGER_GET_PRIVATE (self);
+	g_return_val_if_fail (   priv->state == STATE_INIT
+	                      || priv->state == STATE_PROBE_DONE, FALSE);
+
+	info = g_hash_table_lookup (priv->addresses, GUINT_TO_POINTER (address));
+	g_return_val_if_fail (info, FALSE);
+
+	return !info->duplicate;
+}
+
+static void
+send_announcements (NMArpingManager *self, const char *mode_arg)
+{
+	NMArpingManagerPrivate *priv = NM_ARPING_MANAGER_GET_PRIVATE (self);
+	const char *argv[] = { NULL, mode_arg, "-q", "-I", NULL, "-c", "1", NULL, NULL };
+	int ip_arg = G_N_ELEMENTS (argv) - 2;
+	GError *error = NULL;
+	GHashTableIter iter;
+	AddressInfo *info;
+
+	argv[4] = nm_platform_link_get_name (NM_PLATFORM_GET, priv->ifindex);
+	g_return_if_fail (argv[4]);
+
+	argv[0] = nm_utils_find_helper ("arping", NULL, NULL);
+	if (!argv[0]) {
+		_LOGW ("arping could not be found; no ARPs will be sent");
+		return;
+	}
+
+	g_hash_table_iter_init (&iter, priv->addresses);
+
+	while (g_hash_table_iter_next (&iter, NULL, (gpointer *) &info)) {
+		gs_free char *tmp_str = NULL;
+		gboolean success;
+
+		if (info->duplicate)
+			continue;
+
+		argv[ip_arg] = nm_utils_inet4_ntop (info->address, NULL);
+		_LOGD ("run %s", (tmp_str = g_strjoinv (" ", (char **) argv)));
+
+		success = g_spawn_async (NULL, (char **) argv, NULL,
+		                         G_SPAWN_STDOUT_TO_DEV_NULL |
+		                         G_SPAWN_STDERR_TO_DEV_NULL,
+		                         NULL, NULL, NULL, &error);
+		if (!success) {
+			_LOGW ("could not send ARP for address %s: %s", argv[ip_arg],
+			       error->message);
+			g_clear_error (&error);
+		}
+	}
+}
+
+static gboolean
+arp_announce_round2 (gpointer self)
+{
+	NMArpingManagerPrivate *priv = NM_ARPING_MANAGER_GET_PRIVATE (self);
+
+	priv->round2_id = 0;
+	send_announcements (self, "-U");
+	priv->state = STATE_INIT;
+	g_hash_table_remove_all (priv->addresses);
+
+	return G_SOURCE_REMOVE;
+}
+
+/**
+ * nm_arping_manager_announce_addresses:
+ * @self: a #NMArpingManager
+ *
+ * Start announcing addresses.
+ */
+void
+nm_arping_manager_announce_addresses (NMArpingManager *self)
+{
+	NMArpingManagerPrivate *priv = NM_ARPING_MANAGER_GET_PRIVATE (self);
+
+	g_return_if_fail (   priv->state == STATE_INIT
+	                  || priv->state == STATE_PROBE_DONE);
+
+	send_announcements (self, "-A");
+	nm_clear_g_source (&priv->round2_id);
+	priv->round2_id = g_timeout_add_seconds (2, arp_announce_round2, self);
+	priv->state = STATE_ANNOUNCING;
+}
+
+static void
+destroy_address_info (gpointer data)
+{
+	AddressInfo *info = (AddressInfo *) data;
+
+	nm_clear_g_source (&info->watch);
+
+	if (info->pid) {
+		nm_utils_kill_child_async (info->pid, SIGTERM, LOGD_IP4, "arping",
+		                           1000, NULL, NULL);
+	}
+
+	g_object_unref (info->manager);
+	g_free (info);
+}
+
+static void
+dispose (GObject *object)
+{
+	NMArpingManager *self = NM_ARPING_MANAGER (object);
+	NMArpingManagerPrivate *priv = NM_ARPING_MANAGER_GET_PRIVATE (self);
+
+	nm_clear_g_source (&priv->timer);
+	nm_clear_g_source (&priv->round2_id);
+	g_clear_pointer (&priv->addresses, g_hash_table_destroy);
+
+	G_OBJECT_CLASS (nm_arping_manager_parent_class)->dispose (object);
+}
+
+static void
+nm_arping_manager_init (NMArpingManager *self)
+{
+	NMArpingManagerPrivate *priv = NM_ARPING_MANAGER_GET_PRIVATE (self);
+
+	priv->addresses = g_hash_table_new_full (g_direct_hash, g_direct_equal,
+	                                         NULL, destroy_address_info);
+	priv->state = STATE_INIT;
+}
+
+NMArpingManager *
+nm_arping_manager_new (int ifindex)
+{
+	NMArpingManager *self;
+	NMArpingManagerPrivate *priv;
+
+	self = g_object_new (NM_TYPE_ARPING_MANAGER, NULL);
+	priv = NM_ARPING_MANAGER_GET_PRIVATE (self);
+	priv->ifindex = ifindex;
+
+	return self;
+}
+
+static void
+nm_arping_manager_class_init (NMArpingManagerClass *klass)
+{
+	GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+	g_type_class_add_private (klass, sizeof (NMArpingManagerPrivate));
+
+	object_class->dispose = dispose;
+
+	signals[PROBE_TERMINATED] =
+		g_signal_new (NM_ARPING_MANAGER_PROBE_TERMINATED,
+		              G_OBJECT_CLASS_TYPE (object_class),
+		              G_SIGNAL_RUN_FIRST,
+		              0, NULL, NULL,
+		              g_cclosure_marshal_VOID__POINTER,
+		              G_TYPE_NONE, 1, G_TYPE_POINTER);
+}
diff --git a/src/devices/nm-arping-manager.h b/src/devices/nm-arping-manager.h
new file mode 100644
index 0000000000..86b4458ebe
--- /dev/null
+++ b/src/devices/nm-arping-manager.h
@@ -0,0 +1,56 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: t; c-basic-offset: 4 -*- */
+/* NetworkManager -- Network link manager
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * Copyright (C) 2015 Red Hat, Inc.
+ */
+
+#ifndef __NM_ARPING_MANAGER__
+#define __NM_ARPING_MANAGER__
+
+#include <netinet/in.h>
+
+#include "nm-glib.h"
+#include "nm-types.h"
+
+G_BEGIN_DECLS
+
+#define NM_TYPE_ARPING_MANAGER            (nm_arping_manager_get_type ())
+#define NM_ARPING_MANAGER(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), NM_TYPE_ARPING_MANAGER, NMArpingManager))
+#define NM_ARPING_MANAGER_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass),  NM_TYPE_ARPING_MANAGER, NMArpingManagerClass))
+#define NM_IS_ARPING_MANAGER(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), NM_TYPE_ARPING_MANAGER))
+#define NM_IS_ARPING_MANAGER_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass),  NM_TYPE_ARPING_MANAGER))
+#define NM_ARPING_MANAGER_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj),  NM_TYPE_ARPING_MANAGER, NMArpingManagerClass))
+
+#define NM_ARPING_MANAGER_PROBE_TERMINATED  "probe-terminated"
+
+struct _NMArpingManager {
+	GObject parent;
+};
+
+typedef struct {
+	GObjectClass parent;
+} NMArpingManagerClass;
+
+GType nm_arping_manager_get_type (void);
+
+NMArpingManager *nm_arping_manager_new (int ifindex);
+gboolean nm_arping_manager_add_address (NMArpingManager *self, in_addr_t address);
+gboolean nm_arping_manager_start_probe (NMArpingManager *self, guint timeout, void *user_data,
+                                        GDestroyNotify user_data_destroy_func, GError **error);
+gboolean nm_arping_manager_check_address (NMArpingManager *self, in_addr_t address);
+void nm_arping_manager_announce_addresses (NMArpingManager *self);
+void nm_arping_manager_reset (NMArpingManager *self);
+
+G_END_DECLS
+
+#endif /* __NM_ARPING_MANAGER__ */
diff --git a/src/nm-types.h b/src/nm-types.h
index 7934fcbbed..0fda9216a7 100644
--- a/src/nm-types.h
+++ b/src/nm-types.h
@@ -35,6 +35,7 @@ typedef struct _NMAuthSubject        NMAuthSubject;
 typedef struct _NMBusManager         NMBusManager;
 typedef struct _NMConfig             NMConfig;
 typedef struct _NMConfigData         NMConfigData;
+typedef struct _NMArpingManager      NMArpingManager;
 typedef struct _NMConnectionProvider NMConnectionProvider;
 typedef struct _NMConnectivity       NMConnectivity;
 typedef struct _NMDefaultRouteManager NMDefaultRouteManager;