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 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 */ 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 * 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 priv->parent = ppriv->dev; 121 priv->pkey = pkey; 122 priv->child_type = type; 123 124 if (!is_child_unique(ppriv, priv)) { 125 result = -ENOTUNIQ; 126 goto out_early; 127 } 128 129 result = register_netdevice(ndev); 130 if (result) { 131 ipoib_warn(priv, "failed to initialize; error %i", result); 132 133 /* 134 * register_netdevice sometimes calls priv_destructor, 135 * sometimes not. Make sure it was done. 136 */ 137 goto out_early; 138 } 139 140 /* RTNL childs don't need proprietary sysfs entries */ 141 if (type == IPOIB_LEGACY_CHILD) { 142 if (ipoib_cm_add_mode_attr(ndev)) 143 goto sysfs_failed; 144 if (ipoib_add_pkey_attr(ndev)) 145 goto sysfs_failed; 146 if (ipoib_add_umcast_attr(ndev)) 147 goto sysfs_failed; 148 149 if (device_create_file(&ndev->dev, &dev_attr_parent)) 150 goto sysfs_failed; 151 } 152 153 return 0; 154 155 sysfs_failed: 156 unregister_netdevice(priv->dev); 157 return -ENOMEM; 158 159 out_early: 160 if (ndev->priv_destructor) 161 ndev->priv_destructor(ndev); 162 return result; 163 } 164 165 int ipoib_vlan_add(struct net_device *pdev, unsigned short pkey) 166 { 167 struct ipoib_dev_priv *ppriv, *priv; 168 char intf_name[IFNAMSIZ]; 169 struct net_device *ndev; 170 int result; 171 172 if (!capable(CAP_NET_ADMIN)) 173 return -EPERM; 174 175 if (!rtnl_trylock()) 176 return restart_syscall(); 177 178 if (pdev->reg_state != NETREG_REGISTERED) { 179 rtnl_unlock(); 180 return -EPERM; 181 } 182 183 ppriv = ipoib_priv(pdev); 184 185 snprintf(intf_name, sizeof(intf_name), "%s.%04x", 186 ppriv->dev->name, pkey); 187 188 ndev = ipoib_intf_alloc(ppriv->ca, ppriv->port, intf_name); 189 if (IS_ERR(ndev)) { 190 result = PTR_ERR(ndev); 191 goto out; 192 } 193 priv = ipoib_priv(ndev); 194 195 result = __ipoib_vlan_add(ppriv, priv, pkey, IPOIB_LEGACY_CHILD); 196 197 if (result && ndev->reg_state == NETREG_UNINITIALIZED) 198 free_netdev(ndev); 199 200 out: 201 rtnl_unlock(); 202 203 return result; 204 } 205 206 struct ipoib_vlan_delete_work { 207 struct work_struct work; 208 struct net_device *dev; 209 }; 210 211 /* 212 * sysfs callbacks of a netdevice cannot obtain the rtnl lock as 213 * unregister_netdev ultimately deletes the sysfs files while holding the rtnl 214 * lock. This deadlocks the system. 215 * 216 * A callback can use rtnl_trylock to avoid the deadlock but it cannot call 217 * unregister_netdev as that internally takes and releases the rtnl_lock. So 218 * instead we find the netdev to unregister and then do the actual unregister 219 * from the global work queue where we can obtain the rtnl_lock safely. 220 */ 221 static void ipoib_vlan_delete_task(struct work_struct *work) 222 { 223 struct ipoib_vlan_delete_work *pwork = 224 container_of(work, struct ipoib_vlan_delete_work, work); 225 struct net_device *dev = pwork->dev; 226 227 rtnl_lock(); 228 229 /* Unregistering tasks can race with another task or parent removal */ 230 if (dev->reg_state == NETREG_REGISTERED) { 231 struct ipoib_dev_priv *priv = ipoib_priv(dev); 232 struct ipoib_dev_priv *ppriv = ipoib_priv(priv->parent); 233 234 ipoib_dbg(ppriv, "delete child vlan %s\n", dev->name); 235 unregister_netdevice(dev); 236 } 237 238 rtnl_unlock(); 239 240 kfree(pwork); 241 } 242 243 int ipoib_vlan_delete(struct net_device *pdev, unsigned short pkey) 244 { 245 struct ipoib_dev_priv *ppriv, *priv, *tpriv; 246 int rc; 247 248 if (!capable(CAP_NET_ADMIN)) 249 return -EPERM; 250 251 if (!rtnl_trylock()) 252 return restart_syscall(); 253 254 if (pdev->reg_state != NETREG_REGISTERED) { 255 rtnl_unlock(); 256 return -EPERM; 257 } 258 259 ppriv = ipoib_priv(pdev); 260 261 rc = -ENODEV; 262 list_for_each_entry_safe(priv, tpriv, &ppriv->child_intfs, list) { 263 if (priv->pkey == pkey && 264 priv->child_type == IPOIB_LEGACY_CHILD) { 265 struct ipoib_vlan_delete_work *work; 266 267 work = kmalloc(sizeof(*work), GFP_KERNEL); 268 if (!work) { 269 rc = -ENOMEM; 270 goto out; 271 } 272 273 down_write(&ppriv->vlan_rwsem); 274 list_del_init(&priv->list); 275 up_write(&ppriv->vlan_rwsem); 276 work->dev = priv->dev; 277 INIT_WORK(&work->work, ipoib_vlan_delete_task); 278 queue_work(ipoib_workqueue, &work->work); 279 280 rc = 0; 281 break; 282 } 283 } 284 285 out: 286 rtnl_unlock(); 287 288 return rc; 289 } 290