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
43static 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}
51static DEVICE_ATTR(parent, S_IRUGO, show_parent, NULL);
52
53static 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 */
95int __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
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	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
205out:
206	rtnl_unlock();
207
208	return result;
209}
210
211struct 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 */
226static 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
248int 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
290out:
291	rtnl_unlock();
292
293	return rc;
294}
295