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 sprintf(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 can 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
 101         ASSERT_RTNL();
 102
 103         /*
 104          * Racing with unregister of the parent must be prevented by the
 105          * caller.
 106          */
 107         WARN_ON(ppriv->dev->reg_state != NETREG_REGISTERED);
 108
 109         if (pkey == 0 || pkey == 0x8000) {
 110                 result = -EINVAL;
 111                 goto out_early;
 112         }
 113
 114         priv->parent = ppriv->dev;
 115         priv->pkey = pkey;
 116         priv->child_type = type;
 117
 118         if (!is_child_unique(ppriv, priv)) {
 119                 result = -ENOTUNIQ;
 120                 goto out_early;
 121         }
 122
 123         /* We do not need to touch priv if register_netdevice fails */
 124         ndev->priv_destructor = ipoib_intf_free;
 125
 126         result = register_netdevice(ndev);
 127         if (result) {
 128                 ipoib_warn(priv, "failed to initialize; error %i", result);
 129
 130                 /*
 131                  * register_netdevice sometimes calls priv_destructor,
 132                  * sometimes not. Make sure it was done.
 133                  */
 134                 goto out_early;
 135         }
 136
 137         /* RTNL childs don't need proprietary sysfs entries */
 138         if (type == IPOIB_LEGACY_CHILD) {
 139                 if (ipoib_cm_add_mode_attr(ndev))
 140                         goto sysfs_failed;
 141                 if (ipoib_add_pkey_attr(ndev))
 142                         goto sysfs_failed;
 143                 if (ipoib_add_umcast_attr(ndev))
 144                         goto sysfs_failed;
 145
 146                 if (device_create_file(&ndev->dev, &dev_attr_parent))
 147                         goto sysfs_failed;
 148         }
 149
 150         return 0;
 151
 152 sysfs_failed:
 153         unregister_netdevice(priv->dev);
 154         return -ENOMEM;
 155
 156 out_early:
 157         if (ndev->priv_destructor)
 158                 ndev->priv_destructor(ndev);
 159         return result;
 160 }
 161
 162 int ipoib_vlan_add(struct net_device *pdev, unsigned short pkey)
 163 {
 164         struct ipoib_dev_priv *ppriv, *priv;
 165         char intf_name[IFNAMSIZ];
 166         struct net_device *ndev;
 167         int result;
 168
 169         if (!capable(CAP_NET_ADMIN))
 170                 return -EPERM;
 171
 172         if (!rtnl_trylock())
 173                 return restart_syscall();
 174
 175         if (pdev->reg_state != NETREG_REGISTERED) {
 176                 rtnl_unlock();
 177                 return -EPERM;
 178         }
 179
 180         ppriv = ipoib_priv(pdev);
 181
 182         snprintf(intf_name, sizeof(intf_name), "%s.%04x",
 183                  ppriv->dev->name, pkey);
 184
 185         priv = ipoib_intf_alloc(ppriv->ca, ppriv->port, intf_name);
 186         if (!priv) {
 187                 result = -ENOMEM;
 188                 goto out;
 189         }
 190         ndev = priv->dev;
 191
 192         result = __ipoib_vlan_add(ppriv, priv, pkey, IPOIB_LEGACY_CHILD);
 193
 194         if (result && ndev->reg_state == NETREG_UNINITIALIZED)
 195                 free_netdev(ndev);
 196
 197 out:
 198         rtnl_unlock();
 199
 200         return result;
 201 }
 202
 203 struct ipoib_vlan_delete_work {
 204         struct work_struct work;
 205         struct net_device *dev;
 206 };
 207
 208 /*
 209  * sysfs callbacks of a netdevice cannot obtain the rtnl lock as
 210  * unregister_netdev ultimately deletes the sysfs files while holding the rtnl
 211  * lock. This deadlocks the system.
 212  *
 213  * A callback can use rtnl_trylock to avoid the deadlock but it cannot call
 214  * unregister_netdev as that internally takes and releases the rtnl_lock.  So
 215  * instead we find the netdev to unregister and then do the actual unregister
 216  * from the global work queue where we can obtain the rtnl_lock safely.
 217  */
 218 static void ipoib_vlan_delete_task(struct work_struct *work)
 219 {
 220         struct ipoib_vlan_delete_work *pwork =
 221                 container_of(work, struct ipoib_vlan_delete_work, work);
 222         struct net_device *dev = pwork->dev;
 223
 224         rtnl_lock();
 225
 226         /* Unregistering tasks can race with another task or parent removal */
 227         if (dev->reg_state == NETREG_REGISTERED) {
 228                 struct ipoib_dev_priv *priv = ipoib_priv(dev);
 229                 struct ipoib_dev_priv *ppriv = ipoib_priv(priv->parent);
 230
 231                 ipoib_dbg(ppriv, "delete child vlan %s\n", dev->name);
 232                 unregister_netdevice(dev);
 233         }
 234
 235         rtnl_unlock();
 236
 237         kfree(pwork);
 238 }
 239
 240 int ipoib_vlan_delete(struct net_device *pdev, unsigned short pkey)
 241 {
 242         struct ipoib_dev_priv *ppriv, *priv, *tpriv;
 243         int rc;
 244
 245         if (!capable(CAP_NET_ADMIN))
 246                 return -EPERM;
 247
 248         if (!rtnl_trylock())
 249                 return restart_syscall();
 250
 251         if (pdev->reg_state != NETREG_REGISTERED) {
 252                 rtnl_unlock();
 253                 return -EPERM;
 254         }
 255
 256         ppriv = ipoib_priv(pdev);
 257
 258         rc = -ENODEV;
 259         list_for_each_entry_safe(priv, tpriv, &ppriv->child_intfs, list) {
 260                 if (priv->pkey == pkey &&
 261                     priv->child_type == IPOIB_LEGACY_CHILD) {
 262                         struct ipoib_vlan_delete_work *work;
 263
 264                         work = kmalloc(sizeof(*work), GFP_KERNEL);
 265                         if (!work) {
 266                                 rc = -ENOMEM;
 267                                 goto out;
 268                         }
 269
 270                         down_write(&ppriv->vlan_rwsem);
 271                         list_del_init(&priv->list);
 272                         up_write(&ppriv->vlan_rwsem);
 273                         work->dev = priv->dev;
 274                         INIT_WORK(&work->work, ipoib_vlan_delete_task);
 275                         queue_work(ipoib_workqueue, &work->work);
 276
 277                         rc = 0;
 278                         break;
 279                 }
 280         }
 281
 282 out:
 283         rtnl_unlock();
 284
 285         return rc;
 286 }