// 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 {	spinlock_t		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_obj(*pnd, GFP_ATOMIC);	if (pnd == NULL)		return NULL;	pnd->netdev = dev;	bitmap_zero(pnd->addrs, 64); 	lockdep_assert_held(&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; 	lockdep_assert_held(&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(); 	spin_lock(&pndevs->lock); 	pnd = __phonet_get(dev);	if (pnd)		list_del_rcu(&pnd->list); 	spin_unlock(&pndevs->lock); 	if (pnd) {		struct net *net = dev_net(dev);		u32 ifindex = dev->ifindex;		u8 addr; 		for_each_set_bit(addr, pnd->addrs, 64)			phonet_address_notify(net, RTM_DELADDR, ifindex, addr); 		kfree_rcu(pnd, rcu);	}} 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; 	spin_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; 	spin_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; 	spin_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; 	spin_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(dev_net(dev), RTM_NEWADDR, dev->ifindex,			      req.ifr_phonet_autoconf.device);	return 0;} static void phonet_route_autodel(struct net_device *dev){	struct net *net = dev_net(dev);	DECLARE_BITMAP(deleted, 64);	u32 ifindex = dev->ifindex;	struct phonet_net *pnn;	unsigned int i; 	pnn = phonet_pernet(net); 	/* Remove left-over Phonet routes */	bitmap_zero(deleted, 64); 	spin_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);		}	}	spin_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(net, RTM_DELROUTE, ifindex, 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);	spin_lock_init(&pnn->pndevs.lock);	spin_lock_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; 	err = register_pernet_subsys(&phonet_net_ops);	if (err)		return err; 	if (!proc_create_net("pnresource", 0, init_net.proc_net,			     &pn_res_seq_ops, sizeof(struct seq_net_private))) {		err = -ENOMEM;		goto err_pernet;	} 	err = register_netdevice_notifier(&phonet_device_notifier);	if (err)		goto err_proc; 	err = phonet_netlink_register();	if (err)		goto err_notifier; 	return 0; err_notifier:	unregister_netdevice_notifier(&phonet_device_notifier);err_proc:	remove_proc_entry("pnresource", init_net.proc_net);err_pernet:	unregister_pernet_subsys(&phonet_net_ops);	return err;} void phonet_device_exit(void){	rtnl_unregister_all(PF_PHONET);	unregister_netdevice_notifier(&phonet_device_notifier);	remove_proc_entry("pnresource", init_net.proc_net);	unregister_pernet_subsys(&phonet_net_ops);} 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; 	spin_lock(&routes->lock);	if (routes->table[daddr] == NULL) {		rcu_assign_pointer(routes->table[daddr], dev);		dev_hold(dev);		err = 0;	}	spin_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; 	spin_lock(&routes->lock);	if (rcu_access_pointer(routes->table[daddr]) == dev)		RCU_INIT_POINTER(routes->table[daddr], NULL);	else		dev = NULL;	spin_unlock(&routes->lock); 	if (!dev)		return -ENOENT; 	/* Note : our caller must call synchronize_rcu() and 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;}