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 <linux/proc_fs.h>
  31 #include <linux/if_arp.h>
  32 #include <net/sock.h>
  33 #include <net/netns/generic.h>
  34 #include <net/phonet/pn_dev.h>
  35
  36 struct phonet_net {
  37         struct phonet_device_list pndevs;
  38 };
  39
  40 int phonet_net_id;
  41
  42 struct phonet_device_list *phonet_device_list(struct net *net)
  43 {
  44         struct phonet_net *pnn = net_generic(net, phonet_net_id);
  45         return &pnn->pndevs;
  46 }
  47
  48 /* Allocate new Phonet device. */
  49 static struct phonet_device *__phonet_device_alloc(struct net_device *dev)
  50 {
  51         struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
  52         struct phonet_device *pnd = kmalloc(sizeof(*pnd), GFP_ATOMIC);
  53         if (pnd == NULL)
  54                 return NULL;
  55         pnd->netdev = dev;
  56         bitmap_zero(pnd->addrs, 64);
  57
  58         list_add(&pnd->list, &pndevs->list);
  59         return pnd;
  60 }
  61
  62 static struct phonet_device *__phonet_get(struct net_device *dev)
  63 {
  64         struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
  65         struct phonet_device *pnd;
  66
  67         list_for_each_entry(pnd, &pndevs->list, list) {
  68                 if (pnd->netdev == dev)
  69                         return pnd;
  70         }
  71         return NULL;
  72 }
  73
  74 static void phonet_device_destroy(struct net_device *dev)
  75 {
  76         struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
  77         struct phonet_device *pnd;
  78
  79         ASSERT_RTNL();
  80
  81         spin_lock_bh(&pndevs->lock);
  82         pnd = __phonet_get(dev);
  83         if (pnd)
  84                 list_del(&pnd->list);
  85         spin_unlock_bh(&pndevs->lock);
  86
  87         if (pnd) {
  88                 u8 addr;
  89
  90                 for (addr = find_first_bit(pnd->addrs, 64); addr < 64;
  91                         addr = find_next_bit(pnd->addrs, 64, 1+addr))
  92                         phonet_address_notify(RTM_DELADDR, dev, addr);
  93                 kfree(pnd);
  94         }
  95 }
  96
  97 struct net_device *phonet_device_get(struct net *net)
  98 {
  99         struct phonet_device_list *pndevs = phonet_device_list(net);
 100         struct phonet_device *pnd;
 101         struct net_device *dev = NULL;
 102
 103         spin_lock_bh(&pndevs->lock);
 104         list_for_each_entry(pnd, &pndevs->list, list) {
 105                 dev = pnd->netdev;
 106                 BUG_ON(!dev);
 107
 108                 if ((dev->reg_state == NETREG_REGISTERED) &&
 109                         ((pnd->netdev->flags & IFF_UP)) == IFF_UP)
 110                         break;
 111                 dev = NULL;
 112         }
 113         if (dev)
 114                 dev_hold(dev);
 115         spin_unlock_bh(&pndevs->lock);
 116         return dev;
 117 }
 118
 119 int phonet_address_add(struct net_device *dev, u8 addr)
 120 {
 121         struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
 122         struct phonet_device *pnd;
 123         int err = 0;
 124
 125         spin_lock_bh(&pndevs->lock);
 126         /* Find or create Phonet-specific device data */
 127         pnd = __phonet_get(dev);
 128         if (pnd == NULL)
 129                 pnd = __phonet_device_alloc(dev);
 130         if (unlikely(pnd == NULL))
 131                 err = -ENOMEM;
 132         else if (test_and_set_bit(addr >> 2, pnd->addrs))
 133                 err = -EEXIST;
 134         spin_unlock_bh(&pndevs->lock);
 135         return err;
 136 }
 137
 138 int phonet_address_del(struct net_device *dev, u8 addr)
 139 {
 140         struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
 141         struct phonet_device *pnd;
 142         int err = 0;
 143
 144         spin_lock_bh(&pndevs->lock);
 145         pnd = __phonet_get(dev);
 146         if (!pnd || !test_and_clear_bit(addr >> 2, pnd->addrs))
 147                 err = -EADDRNOTAVAIL;
 148         else if (bitmap_empty(pnd->addrs, 64)) {
 149                 list_del(&pnd->list);
 150                 kfree(pnd);
 151         }
 152         spin_unlock_bh(&pndevs->lock);
 153         return err;
 154 }
 155
 156 /* Gets a source address toward a destination, through a interface. */
 157 u8 phonet_address_get(struct net_device *dev, u8 addr)
 158 {
 159         struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev));
 160         struct phonet_device *pnd;
 161
 162         spin_lock_bh(&pndevs->lock);
 163         pnd = __phonet_get(dev);
 164         if (pnd) {
 165                 BUG_ON(bitmap_empty(pnd->addrs, 64));
 166
 167                 /* Use same source address as destination, if possible */
 168                 if (!test_bit(addr >> 2, pnd->addrs))
 169                         addr = find_first_bit(pnd->addrs, 64) << 2;
 170         } else
 171                 addr = PN_NO_ADDR;
 172         spin_unlock_bh(&pndevs->lock);
 173         return addr;
 174 }
 175
 176 int phonet_address_lookup(struct net *net, u8 addr)
 177 {
 178         struct phonet_device_list *pndevs = phonet_device_list(net);
 179         struct phonet_device *pnd;
 180         int err = -EADDRNOTAVAIL;
 181
 182         spin_lock_bh(&pndevs->lock);
 183         list_for_each_entry(pnd, &pndevs->list, list) {
 184                 /* Don't allow unregistering devices! */
 185                 if ((pnd->netdev->reg_state != NETREG_REGISTERED) ||
 186                                 ((pnd->netdev->flags & IFF_UP)) != IFF_UP)
 187                         continue;
 188
 189                 if (test_bit(addr >> 2, pnd->addrs)) {
 190                         err = 0;
 191                         goto found;
 192                 }
 193         }
 194 found:
 195         spin_unlock_bh(&pndevs->lock);
 196         return err;
 197 }
 198
 199 /* automatically configure a Phonet device, if supported */
 200 static int phonet_device_autoconf(struct net_device *dev)
 201 {
 202         struct if_phonet_req req;
 203         int ret;
 204
 205         if (!dev->netdev_ops->ndo_do_ioctl)
 206                 return -EOPNOTSUPP;
 207
 208         ret = dev->netdev_ops->ndo_do_ioctl(dev, (struct ifreq *)&req,
 209                                                 SIOCPNGAUTOCONF);
 210         if (ret < 0)
 211                 return ret;
 212         return phonet_address_add(dev, req.ifr_phonet_autoconf.device);
 213 }
 214
 215 /* notify Phonet of device events */
 216 static int phonet_device_notify(struct notifier_block *me, unsigned long what,
 217                                 void *arg)
 218 {
 219         struct net_device *dev = arg;
 220
 221         switch (what) {
 222         case NETDEV_REGISTER:
 223                 if (dev->type == ARPHRD_PHONET)
 224                         phonet_device_autoconf(dev);
 225                 break;
 226         case NETDEV_UNREGISTER:
 227                 phonet_device_destroy(dev);
 228                 break;
 229         }
 230         return 0;
 231
 232 }
 233
 234 static struct notifier_block phonet_device_notifier = {
 235         .notifier_call = phonet_device_notify,
 236         .priority = 0,
 237 };
 238
 239 /* Per-namespace Phonet devices handling */
 240 static int phonet_init_net(struct net *net)
 241 {
 242         struct phonet_net *pnn = kmalloc(sizeof(*pnn), GFP_KERNEL);
 243         if (!pnn)
 244                 return -ENOMEM;
 245
 246         if (!proc_net_fops_create(net, "phonet", 0, &pn_sock_seq_fops)) {
 247                 kfree(pnn);
 248                 return -ENOMEM;
 249         }
 250
 251         INIT_LIST_HEAD(&pnn->pndevs.list);
 252         spin_lock_init(&pnn->pndevs.lock);
 253         net_assign_generic(net, phonet_net_id, pnn);
 254         return 0;
 255 }
 256
 257 static void phonet_exit_net(struct net *net)
 258 {
 259         struct phonet_net *pnn = net_generic(net, phonet_net_id);
 260         struct net_device *dev;
 261
 262         rtnl_lock();
 263         for_each_netdev(net, dev)
 264                 phonet_device_destroy(dev);
 265         rtnl_unlock();
 266
 267         proc_net_remove(net, "phonet");
 268         kfree(pnn);
 269 }
 270
 271 static struct pernet_operations phonet_net_ops = {
 272         .init = phonet_init_net,
 273         .exit = phonet_exit_net,
 274 };
 275
 276 /* Initialize Phonet devices list */
 277 int __init phonet_device_init(void)
 278 {
 279         int err = register_pernet_gen_device(&phonet_net_id, &phonet_net_ops);
 280         if (err)
 281                 return err;
 282
 283         register_netdevice_notifier(&phonet_device_notifier);
 284         err = phonet_netlink_register();
 285         if (err)
 286                 phonet_device_exit();
 287         return err;
 288 }
 289
 290 void phonet_device_exit(void)
 291 {
 292         rtnl_unregister_all(PF_PHONET);
 293         unregister_netdevice_notifier(&phonet_device_notifier);
 294         unregister_pernet_gen_device(phonet_net_id, &phonet_net_ops);
 295 }