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, fmt: "%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(dev: 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(dev: 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(dev: 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(dev: 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(dev: ndev))
146 goto sysfs_failed;
147 if (ipoib_add_pkey_attr(dev: ndev))
148 goto sysfs_failed;
149 if (ipoib_add_umcast_attr(dev: ndev))
150 goto sysfs_failed;
151
152 if (device_create_file(device: &ndev->dev, entry: &dev_attr_parent))
153 goto sysfs_failed;
154 }
155
156 return 0;
157
158sysfs_failed:
159 unregister_netdevice(dev: 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(dev: pdev);
187
188 /* If you increase IFNAMSIZ, update snprintf below
189 * to allow longer names.
190 */
191 BUILD_BUG_ON(IFNAMSIZ != 16);
192 snprintf(buf: intf_name, size: sizeof(intf_name), fmt: "%.10s.%04x", ppriv->dev->name,
193 pkey);
194
195 ndev = ipoib_intf_alloc(hca: ppriv->ca, port: ppriv->port, format: intf_name);
196 if (IS_ERR(ptr: ndev)) {
197 result = PTR_ERR(ptr: ndev);
198 goto out;
199 }
200 priv = ipoib_priv(dev: ndev);
201
202 ndev->rtnl_link_ops = ipoib_get_link_ops();
203
204 result = __ipoib_vlan_add(ppriv, priv, pkey, type: IPOIB_LEGACY_CHILD);
205
206 if (result && ndev->reg_state == NETREG_UNINITIALIZED)
207 free_netdev(dev: 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(dev: 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(objp: 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(dev: pdev);
269
270 rc = -ENODEV;
271 netdev_lock(dev: 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(entry: &priv->list);
284 work->dev = priv->dev;
285 INIT_WORK(&work->work, ipoib_vlan_delete_task);
286 queue_work(wq: ipoib_workqueue, work: &work->work);
287
288 rc = 0;
289 break;
290 }
291 }
292
293out:
294 netdev_unlock(dev: ppriv->dev);
295 rtnl_unlock();
296
297 return rc;
298}
299

source code of linux/drivers/infiniband/ulp/ipoib/ipoib_vlan.c