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
parent_show(struct device * d,struct device_attribute * attr,char * buf)42 static 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 }
50 static DEVICE_ATTR_RO(parent);
51
is_child_unique(struct ipoib_dev_priv * ppriv,struct ipoib_dev_priv * priv)52 static bool is_child_unique(struct ipoib_dev_priv *ppriv,
53 struct ipoib_dev_priv *priv)
54 {
55 struct ipoib_dev_priv *tpriv;
56
57 ASSERT_RTNL();
58
59 /*
60 * Since the legacy sysfs interface uses pkey for deletion it cannot
61 * support more than one interface with the same pkey, it creates
62 * ambiguity. The RTNL interface deletes using the netdev so it does
63 * not have a problem to support duplicated pkeys.
64 */
65 if (priv->child_type != IPOIB_LEGACY_CHILD)
66 return true;
67
68 /*
69 * First ensure this isn't a duplicate. We check the parent device and
70 * then all of the legacy child interfaces to make sure the Pkey
71 * doesn't match.
72 */
73 if (ppriv->pkey == priv->pkey)
74 return false;
75
76 list_for_each_entry(tpriv, &ppriv->child_intfs, list) {
77 if (tpriv->pkey == priv->pkey &&
78 tpriv->child_type == IPOIB_LEGACY_CHILD)
79 return false;
80 }
81
82 return true;
83 }
84
85 /*
86 * NOTE: If this function fails then the priv->dev will remain valid, however
87 * priv will have been freed and must not be touched by caller in the error
88 * case.
89 *
90 * If (ndev->reg_state == NETREG_UNINITIALIZED) then it is up to the caller to
91 * free the net_device (just as rtnl_newlink does) otherwise the net_device
92 * will be freed when the rtnl is unlocked.
93 */
__ipoib_vlan_add(struct ipoib_dev_priv * ppriv,struct ipoib_dev_priv * priv,u16 pkey,int type)94 int __ipoib_vlan_add(struct ipoib_dev_priv *ppriv, struct ipoib_dev_priv *priv,
95 u16 pkey, int type)
96 {
97 struct net_device *ndev = priv->dev;
98 int result;
99 struct rdma_netdev *rn = netdev_priv(ndev);
100
101 ASSERT_RTNL();
102
103 /*
104 * We do not need to touch priv if register_netdevice fails, so just
105 * always use this flow.
106 */
107 ndev->priv_destructor = ipoib_intf_free;
108
109 /*
110 * Racing with unregister of the parent must be prevented by the
111 * caller.
112 */
113 WARN_ON(ppriv->dev->reg_state != NETREG_REGISTERED);
114
115 if (pkey == 0 || pkey == 0x8000) {
116 result = -EINVAL;
117 goto out_early;
118 }
119
120 rn->mtu = priv->mcast_mtu;
121
122 priv->parent = ppriv->dev;
123 priv->pkey = pkey;
124 priv->child_type = type;
125
126 if (!is_child_unique(ppriv, priv)) {
127 result = -ENOTUNIQ;
128 goto out_early;
129 }
130
131 result = register_netdevice(ndev);
132 if (result) {
133 ipoib_warn(priv, "failed to initialize; error %i", result);
134
135 /*
136 * register_netdevice sometimes calls priv_destructor,
137 * sometimes not. Make sure it was done.
138 */
139 goto out_early;
140 }
141
142 /* RTNL childs don't need proprietary sysfs entries */
143 if (type == IPOIB_LEGACY_CHILD) {
144 if (ipoib_cm_add_mode_attr(ndev))
145 goto sysfs_failed;
146 if (ipoib_add_pkey_attr(ndev))
147 goto sysfs_failed;
148 if (ipoib_add_umcast_attr(ndev))
149 goto sysfs_failed;
150
151 if (device_create_file(&ndev->dev, &dev_attr_parent))
152 goto sysfs_failed;
153 }
154
155 return 0;
156
157 sysfs_failed:
158 unregister_netdevice(priv->dev);
159 return -ENOMEM;
160
161 out_early:
162 if (ndev->priv_destructor)
163 ndev->priv_destructor(ndev);
164 return result;
165 }
166
ipoib_vlan_add(struct net_device * pdev,unsigned short pkey)167 int ipoib_vlan_add(struct net_device *pdev, unsigned short pkey)
168 {
169 struct ipoib_dev_priv *ppriv, *priv;
170 char intf_name[IFNAMSIZ];
171 struct net_device *ndev;
172 int result;
173
174 if (!capable(CAP_NET_ADMIN))
175 return -EPERM;
176
177 if (!rtnl_trylock())
178 return restart_syscall();
179
180 if (pdev->reg_state != NETREG_REGISTERED) {
181 rtnl_unlock();
182 return -EPERM;
183 }
184
185 ppriv = ipoib_priv(pdev);
186
187 /* If you increase IFNAMSIZ, update snprintf below
188 * to allow longer names.
189 */
190 BUILD_BUG_ON(IFNAMSIZ != 16);
191 snprintf(intf_name, sizeof(intf_name), "%.10s.%04x", ppriv->dev->name,
192 pkey);
193
194 ndev = ipoib_intf_alloc(ppriv->ca, ppriv->port, intf_name);
195 if (IS_ERR(ndev)) {
196 result = PTR_ERR(ndev);
197 goto out;
198 }
199 priv = ipoib_priv(ndev);
200
201 ndev->rtnl_link_ops = ipoib_get_link_ops();
202
203 result = __ipoib_vlan_add(ppriv, priv, pkey, IPOIB_LEGACY_CHILD);
204
205 if (result && ndev->reg_state == NETREG_UNINITIALIZED)
206 free_netdev(ndev);
207
208 out:
209 rtnl_unlock();
210
211 return result;
212 }
213
214 struct ipoib_vlan_delete_work {
215 struct work_struct work;
216 struct net_device *dev;
217 };
218
219 /*
220 * sysfs callbacks of a netdevice cannot obtain the rtnl lock as
221 * unregister_netdev ultimately deletes the sysfs files while holding the rtnl
222 * lock. This deadlocks the system.
223 *
224 * A callback can use rtnl_trylock to avoid the deadlock but it cannot call
225 * unregister_netdev as that internally takes and releases the rtnl_lock. So
226 * instead we find the netdev to unregister and then do the actual unregister
227 * from the global work queue where we can obtain the rtnl_lock safely.
228 */
ipoib_vlan_delete_task(struct work_struct * work)229 static void ipoib_vlan_delete_task(struct work_struct *work)
230 {
231 struct ipoib_vlan_delete_work *pwork =
232 container_of(work, struct ipoib_vlan_delete_work, work);
233 struct net_device *dev = pwork->dev;
234
235 rtnl_lock();
236
237 /* Unregistering tasks can race with another task or parent removal */
238 if (dev->reg_state == NETREG_REGISTERED) {
239 struct ipoib_dev_priv *priv = ipoib_priv(dev);
240 struct ipoib_dev_priv *ppriv = ipoib_priv(priv->parent);
241
242 ipoib_dbg(ppriv, "delete child vlan %s\n", dev->name);
243 unregister_netdevice(dev);
244 }
245
246 rtnl_unlock();
247
248 kfree(pwork);
249 }
250
ipoib_vlan_delete(struct net_device * pdev,unsigned short pkey)251 int ipoib_vlan_delete(struct net_device *pdev, unsigned short pkey)
252 {
253 struct ipoib_dev_priv *ppriv, *priv, *tpriv;
254 int rc;
255
256 if (!capable(CAP_NET_ADMIN))
257 return -EPERM;
258
259 if (!rtnl_trylock())
260 return restart_syscall();
261
262 if (pdev->reg_state != NETREG_REGISTERED) {
263 rtnl_unlock();
264 return -EPERM;
265 }
266
267 ppriv = ipoib_priv(pdev);
268
269 rc = -ENODEV;
270 list_for_each_entry_safe(priv, tpriv, &ppriv->child_intfs, list) {
271 if (priv->pkey == pkey &&
272 priv->child_type == IPOIB_LEGACY_CHILD) {
273 struct ipoib_vlan_delete_work *work;
274
275 work = kmalloc(sizeof(*work), GFP_KERNEL);
276 if (!work) {
277 rc = -ENOMEM;
278 goto out;
279 }
280
281 down_write(&ppriv->vlan_rwsem);
282 list_del_init(&priv->list);
283 up_write(&ppriv->vlan_rwsem);
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
293 out:
294 rtnl_unlock();
295
296 return rc;
297 }
298