net/phonet/pn_dev.c

   1 /*
   2  * File: pn_dev.c
   3  *
   4  * Phonet network device
   5  *
   6  * Copyright (C) 2008 Nokia Corporation.
   7  *
   8  * Contact: Remi Denis-Courmont <remi.denis-courmont@nokia.com>
   9  * Original author: Sakari Ailus <sakari.ailus@nokia.com>
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * version 2 as published by the Free Software Foundation.
  14  *
  15  * This program is distributed in the hope that it will be useful, but
  16  * WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  23  * 02110-1301 USA
  24  */
  25
  26 #include <linux/kernel.h>
  27 #include <linux/net.h>
  28 #include <linux/netdevice.h>
  29 #include <linux/phonet.h>
  30 #include <net/sock.h>
  31 #include <net/netns/generic.h>
  32 #include <net/phonet/pn_dev.h>
  33
  34 struct phonet_net {
  35         struct phonet_device_list pndevs;
  36 };
  37
  38 int phonet_net_id;
  39
  40 struct phonet_device_list *phonet_device_list(struct net *net)
  41 {
  42         struct phonet_net *pnn = net_generic(net, phonet_net_id);
  43         return &pnn->pndevs;
  44 }
  45
  46 /* Allocate new Phonet device. */
  47 static struct phonet_device *__phonet_device_alloc(struct net_device *dev)
  48 {
  49         struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
  50         struct phonet_device *pnd = kmalloc(sizeof(*pnd), GFP_ATOMIC);
  51         if (pnd == NULL)
  52                 return NULL;
  53         pnd->netdev = dev;
  54         bitmap_zero(pnd->addrs, 64);
  55
  56         list_add(&pnd->list, &pndevs->list);
  57         return pnd;
  58 }
  59
  60 static struct phonet_device *__phonet_get(struct net_device *dev)
  61 {
  62         struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
  63         struct phonet_device *pnd;
  64
  65         list_for_each_entry(pnd, &pndevs->list, list) {
  66                 if (pnd->netdev == dev)
  67                         return pnd;
  68         }
  69         return NULL;
  70 }
  71
  72 static void phonet_device_destroy(struct net_device *dev)
  73 {
  74         struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
  75         struct phonet_device *pnd;
  76
  77         ASSERT_RTNL();
  78
  79         spin_lock_bh(&pndevs->lock);
  80         pnd = __phonet_get(dev);
  81         if (pnd)
  82                 list_del(&pnd->list);
  83         spin_unlock_bh(&pndevs->lock);
  84
  85         if (pnd) {
  86                 u8 addr;
  87
  88                 for (addr = find_first_bit(pnd->addrs, 64); addr < 64;
  89                         addr = find_next_bit(pnd->addrs, 64, 1+addr))
  90                         phonet_address_notify(RTM_DELADDR, dev, addr);
  91                 kfree(pnd);
  92         }
  93 }
  94
  95 struct net_device *phonet_device_get(struct net *net)
  96 {
  97         struct phonet_device_list *pndevs = phonet_device_list(net);
  98         struct phonet_device *pnd;
  99         struct net_device *dev = NULL;
 100
 101         spin_lock_bh(&pndevs->lock);
 102         list_for_each_entry(pnd, &pndevs->list, list) {
 103                 dev = pnd->netdev;
 104                 BUG_ON(!dev);
 105
 106                 if ((dev->reg_state == NETREG_REGISTERED) &&
 107                         ((pnd->netdev->flags & IFF_UP)) == IFF_UP)
 108                         break;
 109                 dev = NULL;
 110         }
 111         if (dev)
 112                 dev_hold(dev);
 113         spin_unlock_bh(&pndevs->lock);
 114         return dev;
 115 }
 116
 117 int phonet_address_add(struct net_device *dev, u8 addr)
 118 {
 119         struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
 120         struct phonet_device *pnd;
 121         int err = 0;
 122
 123         spin_lock_bh(&pndevs->lock);
 124         /* Find or create Phonet-specific device data */
 125         pnd = __phonet_get(dev);
 126         if (pnd == NULL)
 127                 pnd = __phonet_device_alloc(dev);
 128         if (unlikely(pnd == NULL))
 129                 err = -ENOMEM;
 130         else if (test_and_set_bit(addr >> 2, pnd->addrs))
 131                 err = -EEXIST;
 132         spin_unlock_bh(&pndevs->lock);
 133         return err;
 134 }
 135
 136 int phonet_address_del(struct net_device *dev, u8 addr)
 137 {
 138         struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
 139         struct phonet_device *pnd;
 140         int err = 0;
 141
 142         spin_lock_bh(&pndevs->lock);
 143         pnd = __phonet_get(dev);
 144         if (!pnd || !test_and_clear_bit(addr >> 2, pnd->addrs))
 145                 err = -EADDRNOTAVAIL;
 146         else if (bitmap_empty(pnd->addrs, 64)) {
 147                 list_del(&pnd->list);
 148                 kfree(pnd);
 149         }
 150         spin_unlock_bh(&pndevs->lock);
 151         return err;
 152 }
 153
 154 /* Gets a source address toward a destination, through a interface. */
 155 u8 phonet_address_get(struct net_device *dev, u8 addr)
 156 {
 157         struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
 158         struct phonet_device *pnd;
 159
 160         spin_lock_bh(&pndevs->lock);
 161         pnd = __phonet_get(dev);
 162         if (pnd) {
 163                 BUG_ON(bitmap_empty(pnd->addrs, 64));
 164
 165                 /* Use same source address as destination, if possible */
 166                 if (!test_bit(addr >> 2, pnd->addrs))
 167                         addr = find_first_bit(pnd->addrs, 64) << 2;
 168         } else
 169                 addr = PN_NO_ADDR;
 170         spin_unlock_bh(&pndevs->lock);
 171         return addr;
 172 }
 173
 174 int phonet_address_lookup(struct net *net, u8 addr)
 175 {
 176         struct phonet_device_list *pndevs = phonet_device_list(net);
 177         struct phonet_device *pnd;
 178         int err = -EADDRNOTAVAIL;
 179
 180         spin_lock_bh(&pndevs->lock);
 181         list_for_each_entry(pnd, &pndevs->list, list) {
 182                 /* Don't allow unregistering devices! */
 183                 if ((pnd->netdev->reg_state != NETREG_REGISTERED) ||
 184                                 ((pnd->netdev->flags & IFF_UP)) != IFF_UP)
 185                         continue;
 186
 187                 if (test_bit(addr >> 2, pnd->addrs)) {
 188                         err = 0;
 189                         goto found;
 190                 }
 191         }
 192 found:
 193         spin_unlock_bh(&pndevs->lock);
 194         return err;
 195 }
 196
 197 /* notify Phonet of device events */
 198 static int phonet_device_notify(struct notifier_block *me, unsigned long what,
 199                                 void *arg)
 200 {
 201         struct net_device *dev = arg;
 202
 203         if (what == NETDEV_UNREGISTER)
 204                 phonet_device_destroy(dev);
 205         return 0;
 206
 207 }
 208
 209 static struct notifier_block phonet_device_notifier = {
 210         .notifier_call = phonet_device_notify,
 211         .priority = 0,
 212 };
 213
 214 /* Per-namespace Phonet devices handling */
 215 static int phonet_init_net(struct net *net)
 216 {
 217         struct phonet_net *pnn = kmalloc(sizeof(*pnn), GFP_KERNEL);
 218         if (!pnn)
 219                 return -ENOMEM;
 220
 221         INIT_LIST_HEAD(&pnn->pndevs.list);
 222         spin_lock_init(&pnn->pndevs.lock);
 223         net_assign_generic(net, phonet_net_id, pnn);
 224         return 0;
 225 }
 226
 227 static void phonet_exit_net(struct net *net)
 228 {
 229         struct phonet_net *pnn = net_generic(net, phonet_net_id);
 230         struct net_device *dev;
 231
 232         rtnl_lock();
 233         for_each_netdev(net, dev)
 234                 phonet_device_destroy(dev);
 235         rtnl_unlock();
 236         kfree(pnn);
 237 }
 238
 239 static struct pernet_operations phonet_net_ops = {
 240         .init = phonet_init_net,
 241         .exit = phonet_exit_net,
 242 };
 243
 244 /* Initialize Phonet devices list */
 245 int __init phonet_device_init(void)
 246 {
 247         int err = register_pernet_gen_device(&phonet_net_id, &phonet_net_ops);
 248         if (err)
 249                 return err;
 250
 251         register_netdevice_notifier(&phonet_device_notifier);
 252         err = phonet_netlink_register();
 253         if (err)
 254                 phonet_device_exit();
 255         return err;
 256 }
 257
 258 void phonet_device_exit(void)
 259 {
 260         rtnl_unregister_all(PF_PHONET);
 261         unregister_netdevice_notifier(&phonet_device_notifier);
 262         unregister_pernet_gen_device(phonet_net_id, &phonet_net_ops);
 263 }