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/sched/signal.h>
 34
 35#include <linux/init.h>
 36#include <linux/seq_file.h>
 37
 38#include <linux/uaccess.h>
 39
 40#include "ipoib.h"
 41
 42static ssize_t parent_show(struct device *d, struct device_attribute *attr,
 43			   char *buf)
 44{
 45	struct net_device *dev = to_net_dev(d);
 46	struct ipoib_dev_priv *priv = ipoib_priv(dev);
 47
 48	return sysfs_emit(buf, "%s\n", priv->parent->name);
 49}
 50static DEVICE_ATTR_RO(parent);
 51
 52static bool is_child_unique(struct ipoib_dev_priv *ppriv,
 53			    struct ipoib_dev_priv *priv)
 54{
 55	struct ipoib_dev_priv *tpriv;
 56	bool result = true;
 57
 58	/*
 59	 * Since the legacy sysfs interface uses pkey for deletion it cannot
 60	 * support more than one interface with the same pkey, it creates
 61	 * ambiguity.  The RTNL interface deletes using the netdev so it does
 62	 * not have a problem to support duplicated pkeys.
 63	 */
 64	if (priv->child_type != IPOIB_LEGACY_CHILD)
 65		return true;
 66
 67	/*
 68	 * First ensure this isn't a duplicate. We check the parent device and
 69	 * then all of the legacy child interfaces to make sure the Pkey
 70	 * doesn't match.
 71	 */
 72	if (ppriv->pkey == priv->pkey)
 73		return false;
 74
 75	netdev_lock(ppriv->dev);
 76	list_for_each_entry(tpriv, &ppriv->child_intfs, list) {
 77		if (tpriv->pkey == priv->pkey &&
 78		    tpriv->child_type == IPOIB_LEGACY_CHILD) {
 79			result = false;
 80			break;
 81		}
 82	}
 83	netdev_unlock(ppriv->dev);
 84
 85	return result;
 86}
 87
 88/*
 89 * NOTE: If this function fails then the priv->dev will remain valid, however
 90 * priv will have been freed and must not be touched by caller in the error
 91 * case.
 92 *
 93 * If (ndev->reg_state == NETREG_UNINITIALIZED) then it is up to the caller to
 94 * free the net_device (just as rtnl_newlink does) otherwise the net_device
 95 * will be freed when the rtnl is unlocked.
 96 */
 97int __ipoib_vlan_add(struct ipoib_dev_priv *ppriv, struct ipoib_dev_priv *priv,
 98		     u16 pkey, int type)
 99{
100	struct net_device *ndev = priv->dev;
101	int result;
102	struct rdma_netdev *rn = netdev_priv(ndev);
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
158sysfs_failed:
159	unregister_netdevice(priv->dev);
160	return -ENOMEM;
161
162out_early:
163	if (ndev->priv_destructor)
164		ndev->priv_destructor(ndev);
165	return result;
166}
167
168int 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	/* If you increase IFNAMSIZ, update snprintf below
189	 * to allow longer names.
190	 */
191	BUILD_BUG_ON(IFNAMSIZ != 16);
192	snprintf(intf_name, sizeof(intf_name), "%.10s.%04x", ppriv->dev->name,
193		 pkey);
194
195	ndev = ipoib_intf_alloc(ppriv->ca, ppriv->port, intf_name);
196	if (IS_ERR(ndev)) {
197		result = PTR_ERR(ndev);
198		goto out;
199	}
200	priv = ipoib_priv(ndev);
201
202	ndev->rtnl_link_ops = ipoib_get_link_ops();
203
204	result = __ipoib_vlan_add(ppriv, priv, pkey, IPOIB_LEGACY_CHILD);
205
206	if (result && ndev->reg_state == NETREG_UNINITIALIZED)
207		free_netdev(ndev);
208
209out:
210	rtnl_unlock();
211
212	return result;
213}
214
215struct ipoib_vlan_delete_work {
216	struct work_struct work;
217	struct net_device *dev;
218};
219
220/*
221 * sysfs callbacks of a netdevice cannot obtain the rtnl lock as
222 * unregister_netdev ultimately deletes the sysfs files while holding the rtnl
223 * lock. This deadlocks the system.
224 *
225 * A callback can use rtnl_trylock to avoid the deadlock but it cannot call
226 * unregister_netdev as that internally takes and releases the rtnl_lock.  So
227 * instead we find the netdev to unregister and then do the actual unregister
228 * from the global work queue where we can obtain the rtnl_lock safely.
229 */
230static void ipoib_vlan_delete_task(struct work_struct *work)
231{
232	struct ipoib_vlan_delete_work *pwork =
233		container_of(work, struct ipoib_vlan_delete_work, work);
234	struct net_device *dev = pwork->dev;
235
236	rtnl_lock();
237
238	/* Unregistering tasks can race with another task or parent removal */
239	if (dev->reg_state == NETREG_REGISTERED) {
240		struct ipoib_dev_priv *priv = ipoib_priv(dev);
241		struct ipoib_dev_priv *ppriv = ipoib_priv(priv->parent);
242
243		ipoib_dbg(ppriv, "delete child vlan %s\n", dev->name);
244		unregister_netdevice(dev);
245	}
246
247	rtnl_unlock();
248
249	kfree(pwork);
250}
251
252int ipoib_vlan_delete(struct net_device *pdev, unsigned short pkey)
253{
254	struct ipoib_dev_priv *ppriv, *priv, *tpriv;
255	int rc;
256
257	if (!capable(CAP_NET_ADMIN))
258		return -EPERM;
259
260	if (!rtnl_trylock())
261		return restart_syscall();
262
263	if (pdev->reg_state != NETREG_REGISTERED) {
264		rtnl_unlock();
265		return -EPERM;
266	}
267
268	ppriv = ipoib_priv(pdev);
269
270	rc = -ENODEV;
271	netdev_lock(ppriv->dev);
272	list_for_each_entry_safe(priv, tpriv, &ppriv->child_intfs, list) {
273		if (priv->pkey == pkey &&
274		    priv->child_type == IPOIB_LEGACY_CHILD) {
275			struct ipoib_vlan_delete_work *work;
276
277			work = kmalloc(sizeof(*work), GFP_KERNEL);
278			if (!work) {
279				rc = -ENOMEM;
280				goto out;
281			}
282
283			list_del_init(&priv->list);
284			work->dev = priv->dev;
285			INIT_WORK(&work->work, ipoib_vlan_delete_task);
286			queue_work(ipoib_workqueue, &work->work);
287
288			rc = 0;
289			break;
290		}
291	}
292
293out:
294	netdev_unlock(ppriv->dev);
295	rtnl_unlock();
296
297	return rc;
298}