drivers/infiniband/ulp/ipoib/ipoib_vlan.c

   1 /*
   2  * Copyright (c) 2004 Topspin Communications.  All rights reserved.
   3  *
   4  * This software is available to you under a choice of one of two
   5  * licenses.  You may choose to be licensed under the terms of the GNU
   6  * General Public License (GPL) Version 2, available from the file
   7  * COPYING in the main directory of this source tree, or the
   8  * OpenIB.org BSD license below:
   9  *
  10  *     Redistribution and use in source and binary forms, with or
  11  *     without modification, are permitted provided that the following
  12  *     conditions are met:
  13  *
  14  *      - Redistributions of source code must retain the above
  15  *        copyright notice, this list of conditions and the following
  16  *        disclaimer.
  17  *
  18  *      - Redistributions in binary form must reproduce the above
  19  *        copyright notice, this list of conditions and the following
  20  *        disclaimer in the documentation and/or other materials
  21  *        provided with the distribution.
  22  *
  23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  30  * SOFTWARE.
  31  */
  32
  33 #include <linux/module.h>
  34 #include <linux/sched/signal.h>
  35
  36 #include <linux/init.h>
  37 #include <linux/seq_file.h>
  38
  39 #include <linux/uaccess.h>
  40
  41 #include "ipoib.h"
  42
  43 static ssize_t show_parent(struct device *d, struct device_attribute *attr,
  44                            char *buf)
  45 {
  46         struct net_device *dev = to_net_dev(d);
  47         struct ipoib_dev_priv *priv = ipoib_priv(dev);
  48
  49         return sysfs_emit(buf, "%s\n", priv->parent->name);
  50 }
  51 static DEVICE_ATTR(parent, S_IRUGO, show_parent, NULL);
  52
  53 static bool is_child_unique(struct ipoib_dev_priv *ppriv,
  54                             struct ipoib_dev_priv *priv)
  55 {
  56         struct ipoib_dev_priv *tpriv;
  57
  58         ASSERT_RTNL();
  59
  60         /*
  61          * Since the legacy sysfs interface uses pkey for deletion it cannot
  62          * support more than one interface with the same pkey, it creates
  63          * ambiguity.  The RTNL interface deletes using the netdev so it does
  64          * not have a problem to support duplicated pkeys.
  65          */
  66         if (priv->child_type != IPOIB_LEGACY_CHILD)
  67                 return true;
  68
  69         /*
  70          * First ensure this isn't a duplicate. We check the parent device and
  71          * then all of the legacy child interfaces to make sure the Pkey
  72          * doesn't match.
  73          */
  74         if (ppriv->pkey == priv->pkey)
  75                 return false;
  76
  77         list_for_each_entry(tpriv, &ppriv->child_intfs, list) {
  78                 if (tpriv->pkey == priv->pkey &&
  79                     tpriv->child_type == IPOIB_LEGACY_CHILD)
  80                         return false;
  81         }
  82
  83         return true;
  84 }
  85
  86 /*
  87  * NOTE: If this function fails then the priv->dev will remain valid, however
  88  * priv will have been freed and must not be touched by caller in the error
  89  * case.
  90  *
  91  * If (ndev->reg_state == NETREG_UNINITIALIZED) then it is up to the caller to
  92  * free the net_device (just as rtnl_newlink does) otherwise the net_device
  93  * will be freed when the rtnl is unlocked.
  94  */
  95 int __ipoib_vlan_add(struct ipoib_dev_priv *ppriv, struct ipoib_dev_priv *priv,
  96                      u16 pkey, int type)
  97 {
  98         struct net_device *ndev = priv->dev;
  99         int result;
 100         struct rdma_netdev *rn = netdev_priv(ndev);
 101
 102         ASSERT_RTNL();
 103
 104         /*
 105          * We do not need to touch priv if register_netdevice fails, so just
 106          * always use this flow.
 107          */
 108         ndev->priv_destructor = ipoib_intf_free;
 109
 110         /*
 111          * Racing with unregister of the parent must be prevented by the
 112          * caller.
 113          */
 114         WARN_ON(ppriv->dev->reg_state != NETREG_REGISTERED);
 115
 116         if (pkey == 0 || pkey == 0x8000) {
 117                 result = -EINVAL;
 118                 goto out_early;
 119         }
 120
 121         rn->mtu = priv->mcast_mtu;
 122
 123         priv->parent = ppriv->dev;
 124         priv->pkey = pkey;
 125         priv->child_type = type;
 126
 127         if (!is_child_unique(ppriv, priv)) {
 128                 result = -ENOTUNIQ;
 129                 goto out_early;
 130         }
 131
 132         result = register_netdevice(ndev);
 133         if (result) {
 134                 ipoib_warn(priv, "failed to initialize; error %i", result);
 135
 136                 /*
 137                  * register_netdevice sometimes calls priv_destructor,
 138                  * sometimes not. Make sure it was done.
 139                  */
 140                 goto out_early;
 141         }
 142
 143         /* RTNL childs don't need proprietary sysfs entries */
 144         if (type == IPOIB_LEGACY_CHILD) {
 145                 if (ipoib_cm_add_mode_attr(ndev))
 146                         goto sysfs_failed;
 147                 if (ipoib_add_pkey_attr(ndev))
 148                         goto sysfs_failed;
 149                 if (ipoib_add_umcast_attr(ndev))
 150                         goto sysfs_failed;
 151
 152                 if (device_create_file(&ndev->dev, &dev_attr_parent))
 153                         goto sysfs_failed;
 154         }
 155
 156         return 0;
 157
 158 sysfs_failed:
 159         unregister_netdevice(priv->dev);
 160         return -ENOMEM;
 161
 162 out_early:
 163         if (ndev->priv_destructor)
 164                 ndev->priv_destructor(ndev);
 165         return result;
 166 }
 167
 168 int ipoib_vlan_add(struct net_device *pdev, unsigned short pkey)
 169 {
 170         struct ipoib_dev_priv *ppriv, *priv;
 171         char intf_name[IFNAMSIZ];
 172         struct net_device *ndev;
 173         int result;
 174
 175         if (!capable(CAP_NET_ADMIN))
 176                 return -EPERM;
 177
 178         if (!rtnl_trylock())
 179                 return restart_syscall();
 180
 181         if (pdev->reg_state != NETREG_REGISTERED) {
 182                 rtnl_unlock();
 183                 return -EPERM;
 184         }
 185
 186         ppriv = ipoib_priv(pdev);
 187
 188         snprintf(intf_name, sizeof(intf_name), "%s.%04x",
 189                  ppriv->dev->name, pkey);
 190
 191         ndev = ipoib_intf_alloc(ppriv->ca, ppriv->port, intf_name);
 192         if (IS_ERR(ndev)) {
 193                 result = PTR_ERR(ndev);
 194                 goto out;
 195         }
 196         priv = ipoib_priv(ndev);
 197
 198         ndev->rtnl_link_ops = ipoib_get_link_ops();
 199
 200         result = __ipoib_vlan_add(ppriv, priv, pkey, IPOIB_LEGACY_CHILD);
 201
 202         if (result && ndev->reg_state == NETREG_UNINITIALIZED)
 203                 free_netdev(ndev);
 204
 205 out:
 206         rtnl_unlock();
 207
 208         return result;
 209 }
 210
 211 struct ipoib_vlan_delete_work {
 212         struct work_struct work;
 213         struct net_device *dev;
 214 };
 215
 216 /*
 217  * sysfs callbacks of a netdevice cannot obtain the rtnl lock as
 218  * unregister_netdev ultimately deletes the sysfs files while holding the rtnl
 219  * lock. This deadlocks the system.
 220  *
 221  * A callback can use rtnl_trylock to avoid the deadlock but it cannot call
 222  * unregister_netdev as that internally takes and releases the rtnl_lock.  So
 223  * instead we find the netdev to unregister and then do the actual unregister
 224  * from the global work queue where we can obtain the rtnl_lock safely.
 225  */
 226 static void ipoib_vlan_delete_task(struct work_struct *work)
 227 {
 228         struct ipoib_vlan_delete_work *pwork =
 229                 container_of(work, struct ipoib_vlan_delete_work, work);
 230         struct net_device *dev = pwork->dev;
 231
 232         rtnl_lock();
 233
 234         /* Unregistering tasks can race with another task or parent removal */
 235         if (dev->reg_state == NETREG_REGISTERED) {
 236                 struct ipoib_dev_priv *priv = ipoib_priv(dev);
 237                 struct ipoib_dev_priv *ppriv = ipoib_priv(priv->parent);
 238
 239                 ipoib_dbg(ppriv, "delete child vlan %s\n", dev->name);
 240                 unregister_netdevice(dev);
 241         }
 242
 243         rtnl_unlock();
 244
 245         kfree(pwork);
 246 }
 247
 248 int ipoib_vlan_delete(struct net_device *pdev, unsigned short pkey)
 249 {
 250         struct ipoib_dev_priv *ppriv, *priv, *tpriv;
 251         int rc;
 252
 253         if (!capable(CAP_NET_ADMIN))
 254                 return -EPERM;
 255
 256         if (!rtnl_trylock())
 257                 return restart_syscall();
 258
 259         if (pdev->reg_state != NETREG_REGISTERED) {
 260                 rtnl_unlock();
 261                 return -EPERM;
 262         }
 263
 264         ppriv = ipoib_priv(pdev);
 265
 266         rc = -ENODEV;
 267         list_for_each_entry_safe(priv, tpriv, &ppriv->child_intfs, list) {
 268                 if (priv->pkey == pkey &&
 269                     priv->child_type == IPOIB_LEGACY_CHILD) {
 270                         struct ipoib_vlan_delete_work *work;
 271
 272                         work = kmalloc(sizeof(*work), GFP_KERNEL);
 273                         if (!work) {
 274                                 rc = -ENOMEM;
 275                                 goto out;
 276                         }
 277
 278                         down_write(&ppriv->vlan_rwsem);
 279                         list_del_init(&priv->list);
 280                         up_write(&ppriv->vlan_rwsem);
 281                         work->dev = priv->dev;
 282                         INIT_WORK(&work->work, ipoib_vlan_delete_task);
 283                         queue_work(ipoib_workqueue, &work->work);
 284
 285                         rc = 0;
 286                         break;
 287                 }
 288         }
 289
 290 out:
 291         rtnl_unlock();
 292
 293         return rc;
 294 }