/* * File: pn_dev.c * * Phonet network device * * Copyright (C) 2008 Nokia Corporation. * * Contact: Remi Denis-Courmont <remi.denis-courmont@nokia.com> * Original author: Sakari Ailus <sakari.ailus@nokia.com> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * version 2 as published by the Free Software Foundation. * * 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. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA * 02110-1301 USA */ #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	*table[64];}; struct phonet_net {	struct phonet_device_list pndevs;	struct phonet_routes routes;}; static int phonet_net_id __read_mostly; static struct phonet_net *phonet_pernet(struct net *net){	BUG_ON(!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;	}	if (dev)		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_do_ioctl)		return -EOPNOTSUPP; 	ret = dev->netdev_ops->ndo_do_ioctl(dev, (struct ifreq *)&req,						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 (dev == pnn->routes.table[i]) {			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 *arg){	struct net_device *dev = arg; 	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_net_fops_create(net, "phonet", 0, &pn_sock_seq_fops))		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){	proc_net_remove(net, "phonet");} 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_net_fops_create(&init_net, "pnresource", 0, &pn_res_seq_fops);	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);	proc_net_remove(&init_net, "pnresource");} 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 (dev == routes->table[daddr])		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]);	if (dev)		dev_hold(dev);	rcu_read_unlock(); 	if (!dev)		dev = phonet_device_get(net); /* Default route */	return dev;}