1 files changed, 419 insertions, 0 deletions

diff --git a/net/phonet/pn_dev.c b/net/phonet/pn_dev.c
new file mode 100644
index 000000000..cde671d29
--- /dev/null
+++ b/net/phonet/pn_dev.c
@@ -0,0 +1,419 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * File: pn_dev.c
+ *
+ * Phonet network device
+ *
+ * Copyright (C) 2008 Nokia Corporation.
+ *
+ * Authors: Sakari Ailus <sakari.ailus@nokia.com>
+ *          Rémi Denis-Courmont
+ */
+
+#include <linux/kernel.h>
+#include <linux/net.h>
+#include <linux/slab.h>
+#include <linux/netdevice.h>
+#include <linux/phonet.h>
+#include <linux/proc_fs.h>
+#include <linux/if_arp.h>
+#include <net/sock.h>
+#include <net/netns/generic.h>
+#include <net/phonet/pn_dev.h>
+
+struct phonet_routes {
+	struct mutex		lock;
+	struct net_device __rcu	*table[64];
+};
+
+struct phonet_net {
+	struct phonet_device_list pndevs;
+	struct phonet_routes routes;
+};
+
+static unsigned int phonet_net_id __read_mostly;
+
+static struct phonet_net *phonet_pernet(struct net *net)
+{
+	return net_generic(net, phonet_net_id);
+}
+
+struct phonet_device_list *phonet_device_list(struct net *net)
+{
+	struct phonet_net *pnn = phonet_pernet(net);
+	return &pnn->pndevs;
+}
+
+/* Allocate new Phonet device. */
+static struct phonet_device *__phonet_device_alloc(struct net_device *dev)
+{
+	struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
+	struct phonet_device *pnd = kmalloc(sizeof(*pnd), GFP_ATOMIC);
+	if (pnd == NULL)
+		return NULL;
+	pnd->netdev = dev;
+	bitmap_zero(pnd->addrs, 64);
+
+	BUG_ON(!mutex_is_locked(&pndevs->lock));
+	list_add_rcu(&pnd->list, &pndevs->list);
+	return pnd;
+}
+
+static struct phonet_device *__phonet_get(struct net_device *dev)
+{
+	struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
+	struct phonet_device *pnd;
+
+	BUG_ON(!mutex_is_locked(&pndevs->lock));
+	list_for_each_entry(pnd, &pndevs->list, list) {
+		if (pnd->netdev == dev)
+			return pnd;
+	}
+	return NULL;
+}
+
+static struct phonet_device *__phonet_get_rcu(struct net_device *dev)
+{
+	struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
+	struct phonet_device *pnd;
+
+	list_for_each_entry_rcu(pnd, &pndevs->list, list) {
+		if (pnd->netdev == dev)
+			return pnd;
+	}
+	return NULL;
+}
+
+static void phonet_device_destroy(struct net_device *dev)
+{
+	struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
+	struct phonet_device *pnd;
+
+	ASSERT_RTNL();
+
+	mutex_lock(&pndevs->lock);
+	pnd = __phonet_get(dev);
+	if (pnd)
+		list_del_rcu(&pnd->list);
+	mutex_unlock(&pndevs->lock);
+
+	if (pnd) {
+		u8 addr;
+
+		for_each_set_bit(addr, pnd->addrs, 64)
+			phonet_address_notify(RTM_DELADDR, dev, addr);
+		kfree(pnd);
+	}
+}
+
+struct net_device *phonet_device_get(struct net *net)
+{
+	struct phonet_device_list *pndevs = phonet_device_list(net);
+	struct phonet_device *pnd;
+	struct net_device *dev = NULL;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(pnd, &pndevs->list, list) {
+		dev = pnd->netdev;
+		BUG_ON(!dev);
+
+		if ((dev->reg_state == NETREG_REGISTERED) &&
+			((pnd->netdev->flags & IFF_UP)) == IFF_UP)
+			break;
+		dev = NULL;
+	}
+	dev_hold(dev);
+	rcu_read_unlock();
+	return dev;
+}
+
+int phonet_address_add(struct net_device *dev, u8 addr)
+{
+	struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
+	struct phonet_device *pnd;
+	int err = 0;
+
+	mutex_lock(&pndevs->lock);
+	/* Find or create Phonet-specific device data */
+	pnd = __phonet_get(dev);
+	if (pnd == NULL)
+		pnd = __phonet_device_alloc(dev);
+	if (unlikely(pnd == NULL))
+		err = -ENOMEM;
+	else if (test_and_set_bit(addr >> 2, pnd->addrs))
+		err = -EEXIST;
+	mutex_unlock(&pndevs->lock);
+	return err;
+}
+
+int phonet_address_del(struct net_device *dev, u8 addr)
+{
+	struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
+	struct phonet_device *pnd;
+	int err = 0;
+
+	mutex_lock(&pndevs->lock);
+	pnd = __phonet_get(dev);
+	if (!pnd || !test_and_clear_bit(addr >> 2, pnd->addrs)) {
+		err = -EADDRNOTAVAIL;
+		pnd = NULL;
+	} else if (bitmap_empty(pnd->addrs, 64))
+		list_del_rcu(&pnd->list);
+	else
+		pnd = NULL;
+	mutex_unlock(&pndevs->lock);
+
+	if (pnd)
+		kfree_rcu(pnd, rcu);
+
+	return err;
+}
+
+/* Gets a source address toward a destination, through a interface. */
+u8 phonet_address_get(struct net_device *dev, u8 daddr)
+{
+	struct phonet_device *pnd;
+	u8 saddr;
+
+	rcu_read_lock();
+	pnd = __phonet_get_rcu(dev);
+	if (pnd) {
+		BUG_ON(bitmap_empty(pnd->addrs, 64));
+
+		/* Use same source address as destination, if possible */
+		if (test_bit(daddr >> 2, pnd->addrs))
+			saddr = daddr;
+		else
+			saddr = find_first_bit(pnd->addrs, 64) << 2;
+	} else
+		saddr = PN_NO_ADDR;
+	rcu_read_unlock();
+
+	if (saddr == PN_NO_ADDR) {
+		/* Fallback to another device */
+		struct net_device *def_dev;
+
+		def_dev = phonet_device_get(dev_net(dev));
+		if (def_dev) {
+			if (def_dev != dev)
+				saddr = phonet_address_get(def_dev, daddr);
+			dev_put(def_dev);
+		}
+	}
+	return saddr;
+}
+
+int phonet_address_lookup(struct net *net, u8 addr)
+{
+	struct phonet_device_list *pndevs = phonet_device_list(net);
+	struct phonet_device *pnd;
+	int err = -EADDRNOTAVAIL;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(pnd, &pndevs->list, list) {
+		/* Don't allow unregistering devices! */
+		if ((pnd->netdev->reg_state != NETREG_REGISTERED) ||
+				((pnd->netdev->flags & IFF_UP)) != IFF_UP)
+			continue;
+
+		if (test_bit(addr >> 2, pnd->addrs)) {
+			err = 0;
+			goto found;
+		}
+	}
+found:
+	rcu_read_unlock();
+	return err;
+}
+
+/* automatically configure a Phonet device, if supported */
+static int phonet_device_autoconf(struct net_device *dev)
+{
+	struct if_phonet_req req;
+	int ret;
+
+	if (!dev->netdev_ops->ndo_siocdevprivate)
+		return -EOPNOTSUPP;
+
+	ret = dev->netdev_ops->ndo_siocdevprivate(dev, (struct ifreq *)&req,
+						  NULL, SIOCPNGAUTOCONF);
+	if (ret < 0)
+		return ret;
+
+	ASSERT_RTNL();
+	ret = phonet_address_add(dev, req.ifr_phonet_autoconf.device);
+	if (ret)
+		return ret;
+	phonet_address_notify(RTM_NEWADDR, dev,
+				req.ifr_phonet_autoconf.device);
+	return 0;
+}
+
+static void phonet_route_autodel(struct net_device *dev)
+{
+	struct phonet_net *pnn = phonet_pernet(dev_net(dev));
+	unsigned int i;
+	DECLARE_BITMAP(deleted, 64);
+
+	/* Remove left-over Phonet routes */
+	bitmap_zero(deleted, 64);
+	mutex_lock(&pnn->routes.lock);
+	for (i = 0; i < 64; i++)
+		if (rcu_access_pointer(pnn->routes.table[i]) == dev) {
+			RCU_INIT_POINTER(pnn->routes.table[i], NULL);
+			set_bit(i, deleted);
+		}
+	mutex_unlock(&pnn->routes.lock);
+
+	if (bitmap_empty(deleted, 64))
+		return; /* short-circuit RCU */
+	synchronize_rcu();
+	for_each_set_bit(i, deleted, 64) {
+		rtm_phonet_notify(RTM_DELROUTE, dev, i);
+		dev_put(dev);
+	}
+}
+
+/* notify Phonet of device events */
+static int phonet_device_notify(struct notifier_block *me, unsigned long what,
+				void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+
+	switch (what) {
+	case NETDEV_REGISTER:
+		if (dev->type == ARPHRD_PHONET)
+			phonet_device_autoconf(dev);
+		break;
+	case NETDEV_UNREGISTER:
+		phonet_device_destroy(dev);
+		phonet_route_autodel(dev);
+		break;
+	}
+	return 0;
+
+}
+
+static struct notifier_block phonet_device_notifier = {
+	.notifier_call = phonet_device_notify,
+	.priority = 0,
+};
+
+/* Per-namespace Phonet devices handling */
+static int __net_init phonet_init_net(struct net *net)
+{
+	struct phonet_net *pnn = phonet_pernet(net);
+
+	if (!proc_create_net("phonet", 0, net->proc_net, &pn_sock_seq_ops,
+			sizeof(struct seq_net_private)))
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&pnn->pndevs.list);
+	mutex_init(&pnn->pndevs.lock);
+	mutex_init(&pnn->routes.lock);
+	return 0;
+}
+
+static void __net_exit phonet_exit_net(struct net *net)
+{
+	struct phonet_net *pnn = phonet_pernet(net);
+
+	remove_proc_entry("phonet", net->proc_net);
+	WARN_ON_ONCE(!list_empty(&pnn->pndevs.list));
+}
+
+static struct pernet_operations phonet_net_ops = {
+	.init = phonet_init_net,
+	.exit = phonet_exit_net,
+	.id   = &phonet_net_id,
+	.size = sizeof(struct phonet_net),
+};
+
+/* Initialize Phonet devices list */
+int __init phonet_device_init(void)
+{
+	int err = register_pernet_subsys(&phonet_net_ops);
+	if (err)
+		return err;
+
+	proc_create_net("pnresource", 0, init_net.proc_net, &pn_res_seq_ops,
+			sizeof(struct seq_net_private));
+	register_netdevice_notifier(&phonet_device_notifier);
+	err = phonet_netlink_register();
+	if (err)
+		phonet_device_exit();
+	return err;
+}
+
+void phonet_device_exit(void)
+{
+	rtnl_unregister_all(PF_PHONET);
+	unregister_netdevice_notifier(&phonet_device_notifier);
+	unregister_pernet_subsys(&phonet_net_ops);
+	remove_proc_entry("pnresource", init_net.proc_net);
+}
+
+int phonet_route_add(struct net_device *dev, u8 daddr)
+{
+	struct phonet_net *pnn = phonet_pernet(dev_net(dev));
+	struct phonet_routes *routes = &pnn->routes;
+	int err = -EEXIST;
+
+	daddr = daddr >> 2;
+	mutex_lock(&routes->lock);
+	if (routes->table[daddr] == NULL) {
+		rcu_assign_pointer(routes->table[daddr], dev);
+		dev_hold(dev);
+		err = 0;
+	}
+	mutex_unlock(&routes->lock);
+	return err;
+}
+
+int phonet_route_del(struct net_device *dev, u8 daddr)
+{
+	struct phonet_net *pnn = phonet_pernet(dev_net(dev));
+	struct phonet_routes *routes = &pnn->routes;
+
+	daddr = daddr >> 2;
+	mutex_lock(&routes->lock);
+	if (rcu_access_pointer(routes->table[daddr]) == dev)
+		RCU_INIT_POINTER(routes->table[daddr], NULL);
+	else
+		dev = NULL;
+	mutex_unlock(&routes->lock);
+
+	if (!dev)
+		return -ENOENT;
+	synchronize_rcu();
+	dev_put(dev);
+	return 0;
+}
+
+struct net_device *phonet_route_get_rcu(struct net *net, u8 daddr)
+{
+	struct phonet_net *pnn = phonet_pernet(net);
+	struct phonet_routes *routes = &pnn->routes;
+	struct net_device *dev;
+
+	daddr >>= 2;
+	dev = rcu_dereference(routes->table[daddr]);
+	return dev;
+}
+
+struct net_device *phonet_route_output(struct net *net, u8 daddr)
+{
+	struct phonet_net *pnn = phonet_pernet(net);
+	struct phonet_routes *routes = &pnn->routes;
+	struct net_device *dev;
+
+	daddr >>= 2;
+	rcu_read_lock();
+	dev = rcu_dereference(routes->table[daddr]);
+	dev_hold(dev);
+	rcu_read_unlock();
+
+	if (!dev)
+		dev = phonet_device_get(net); /* Default route */
+	return dev;
+}