/* * 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; }; 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 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; }