OpenWrt – Blame information for rev 4
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Rev | Author | Line No. | Line |
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4 | office | 1 | /* |
2 | * trelay.c: Trivial Ethernet Relay |
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3 | * |
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4 | * Copyright (C) 2012 Felix Fietkau <nbd@nbd.name> |
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5 | * |
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6 | * This program is free software; you can redistribute it and/or |
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7 | * modify it under the terms of the GNU General Public License |
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8 | * as published by the Free Software Foundation; either version 2 |
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9 | * of the License, or (at your option) any later version. |
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10 | * |
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11 | * This program is distributed in the hope that it will be useful, |
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12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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14 | * GNU General Public License for more details. |
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15 | */ |
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16 | #include <linux/module.h> |
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17 | #include <linux/list.h> |
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18 | #include <linux/mutex.h> |
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19 | #include <linux/netdevice.h> |
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20 | #include <linux/rtnetlink.h> |
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21 | #include <linux/debugfs.h> |
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22 | |||
23 | static LIST_HEAD(trelay_devs); |
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24 | static struct dentry *debugfs_dir; |
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25 | |||
26 | struct trelay { |
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27 | struct list_head list; |
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28 | struct net_device *dev1, *dev2; |
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29 | struct dentry *debugfs; |
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30 | char name[]; |
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31 | }; |
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32 | |||
33 | rx_handler_result_t trelay_handle_frame(struct sk_buff **pskb) |
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34 | { |
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35 | struct net_device *dev; |
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36 | struct sk_buff *skb = *pskb; |
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37 | |||
38 | dev = rcu_dereference(skb->dev->rx_handler_data); |
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39 | if (!dev) |
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40 | return RX_HANDLER_PASS; |
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41 | |||
42 | if (skb->protocol == htons(ETH_P_PAE)) |
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43 | return RX_HANDLER_PASS; |
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44 | |||
45 | skb_push(skb, ETH_HLEN); |
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46 | skb->dev = dev; |
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47 | skb_forward_csum(skb); |
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48 | dev_queue_xmit(skb); |
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49 | |||
50 | return RX_HANDLER_CONSUMED; |
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51 | } |
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52 | |||
53 | static int trelay_open(struct inode *inode, struct file *file) |
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54 | { |
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55 | file->private_data = inode->i_private; |
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56 | return 0; |
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57 | } |
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58 | |||
59 | static int trelay_do_remove(struct trelay *tr) |
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60 | { |
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61 | list_del(&tr->list); |
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62 | |||
63 | dev_put(tr->dev1); |
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64 | dev_put(tr->dev2); |
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65 | |||
66 | netdev_rx_handler_unregister(tr->dev1); |
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67 | netdev_rx_handler_unregister(tr->dev2); |
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68 | |||
69 | debugfs_remove_recursive(tr->debugfs); |
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70 | kfree(tr); |
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71 | |||
72 | return 0; |
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73 | } |
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74 | |||
75 | static struct trelay *trelay_find(struct net_device *dev) |
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76 | { |
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77 | struct trelay *tr; |
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78 | |||
79 | list_for_each_entry(tr, &trelay_devs, list) { |
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80 | if (tr->dev1 == dev || tr->dev2 == dev) |
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81 | return tr; |
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82 | } |
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83 | return NULL; |
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84 | } |
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85 | |||
86 | static int tr_device_event(struct notifier_block *unused, unsigned long event, |
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87 | void *ptr) |
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88 | { |
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89 | struct net_device *dev = ptr; |
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90 | struct trelay *tr; |
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91 | |||
92 | if (event != NETDEV_UNREGISTER) |
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93 | goto out; |
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94 | |||
95 | tr = trelay_find(dev); |
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96 | if (!tr) |
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97 | goto out; |
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98 | |||
99 | trelay_do_remove(tr); |
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100 | |||
101 | out: |
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102 | return NOTIFY_DONE; |
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103 | } |
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104 | |||
105 | static ssize_t trelay_remove_write(struct file *file, const char __user *ubuf, |
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106 | size_t count, loff_t *ppos) |
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107 | { |
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108 | struct trelay *tr = file->private_data; |
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109 | int ret; |
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110 | |||
111 | rtnl_lock(); |
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112 | ret = trelay_do_remove(tr); |
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113 | rtnl_unlock(); |
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114 | |||
115 | if (ret < 0) |
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116 | return ret; |
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117 | |||
118 | return count; |
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119 | } |
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120 | |||
121 | static const struct file_operations fops_remove = { |
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122 | .owner = THIS_MODULE, |
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123 | .open = trelay_open, |
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124 | .write = trelay_remove_write, |
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125 | .llseek = default_llseek, |
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126 | }; |
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127 | |||
128 | |||
129 | static int trelay_do_add(char *name, char *devn1, char *devn2) |
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130 | { |
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131 | struct net_device *dev1, *dev2; |
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132 | struct trelay *tr, *tr1; |
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133 | int ret; |
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134 | |||
135 | tr = kzalloc(sizeof(*tr) + strlen(name) + 1, GFP_KERNEL); |
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136 | if (!tr) |
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137 | return -ENOMEM; |
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138 | |||
139 | rtnl_lock(); |
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140 | rcu_read_lock(); |
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141 | |||
142 | ret = -EEXIST; |
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143 | list_for_each_entry(tr1, &trelay_devs, list) { |
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144 | if (!strcmp(tr1->name, name)) |
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145 | goto out; |
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146 | } |
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147 | |||
148 | ret = -ENOENT; |
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149 | dev1 = dev_get_by_name_rcu(&init_net, devn1); |
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150 | dev2 = dev_get_by_name_rcu(&init_net, devn2); |
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151 | if (!dev1 || !dev2) |
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152 | goto out; |
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153 | |||
154 | ret = netdev_rx_handler_register(dev1, trelay_handle_frame, dev2); |
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155 | if (ret < 0) |
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156 | goto out; |
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157 | |||
158 | ret = netdev_rx_handler_register(dev2, trelay_handle_frame, dev1); |
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159 | if (ret < 0) { |
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160 | netdev_rx_handler_unregister(dev1); |
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161 | goto out; |
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162 | } |
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163 | |||
164 | dev_hold(dev1); |
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165 | dev_hold(dev2); |
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166 | |||
167 | strcpy(tr->name, name); |
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168 | tr->dev1 = dev1; |
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169 | tr->dev2 = dev2; |
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170 | list_add_tail(&tr->list, &trelay_devs); |
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171 | |||
172 | tr->debugfs = debugfs_create_dir(name, debugfs_dir); |
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173 | debugfs_create_file("remove", S_IWUSR, tr->debugfs, tr, &fops_remove); |
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174 | ret = 0; |
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175 | |||
176 | out: |
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177 | rcu_read_unlock(); |
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178 | rtnl_unlock(); |
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179 | if (ret < 0) |
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180 | kfree(tr); |
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181 | |||
182 | return ret; |
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183 | } |
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184 | |||
185 | static ssize_t trelay_add_write(struct file *file, const char __user *ubuf, |
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186 | size_t count, loff_t *ppos) |
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187 | { |
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188 | char buf[256]; |
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189 | char *dev1, *dev2, *tmp; |
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190 | ssize_t len, ret; |
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191 | |||
192 | len = min(count, sizeof(buf) - 1); |
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193 | if (copy_from_user(buf, ubuf, len)) |
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194 | return -EFAULT; |
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195 | |||
196 | buf[len] = 0; |
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197 | |||
198 | if ((tmp = strchr(buf, '\n'))) |
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199 | *tmp = 0; |
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200 | |||
201 | dev1 = strchr(buf, ','); |
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202 | if (!dev1) |
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203 | return -EINVAL; |
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204 | |||
205 | *(dev1++) = 0; |
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206 | |||
207 | dev2 = strchr(dev1, ','); |
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208 | if (!dev2) |
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209 | return -EINVAL; |
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210 | |||
211 | *(dev2++) = 0; |
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212 | if (strchr(dev2, ',')) |
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213 | return -EINVAL; |
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214 | |||
215 | if (!strlen(buf) || !strlen(dev1) || !strlen(dev2)) |
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216 | return -EINVAL; |
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217 | |||
218 | ret = trelay_do_add(buf, dev1, dev2); |
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219 | if (ret < 0) |
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220 | return ret; |
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221 | |||
222 | return count; |
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223 | } |
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224 | |||
225 | static const struct file_operations fops_add = { |
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226 | .owner = THIS_MODULE, |
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227 | .write = trelay_add_write, |
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228 | .llseek = default_llseek, |
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229 | }; |
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230 | |||
231 | static struct notifier_block tr_dev_notifier = { |
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232 | .notifier_call = tr_device_event |
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233 | }; |
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234 | |||
235 | static int __init trelay_init(void) |
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236 | { |
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237 | int ret; |
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238 | |||
239 | debugfs_dir = debugfs_create_dir("trelay", NULL); |
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240 | if (!debugfs_dir) |
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241 | return -ENOMEM; |
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242 | |||
243 | debugfs_create_file("add", S_IWUSR, debugfs_dir, NULL, &fops_add); |
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244 | |||
245 | ret = register_netdevice_notifier(&tr_dev_notifier); |
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246 | if (ret < 0) |
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247 | goto error; |
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248 | |||
249 | return 0; |
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250 | |||
251 | error: |
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252 | debugfs_remove_recursive(debugfs_dir); |
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253 | return ret; |
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254 | } |
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255 | |||
256 | static void __exit trelay_exit(void) |
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257 | { |
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258 | struct trelay *tr, *tmp; |
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259 | |||
260 | unregister_netdevice_notifier(&tr_dev_notifier); |
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261 | |||
262 | rtnl_lock(); |
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263 | list_for_each_entry_safe(tr, tmp, &trelay_devs, list) |
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264 | trelay_do_remove(tr); |
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265 | rtnl_unlock(); |
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266 | |||
267 | debugfs_remove_recursive(debugfs_dir); |
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268 | } |
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269 | |||
270 | module_init(trelay_init); |
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271 | module_exit(trelay_exit); |
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272 | MODULE_LICENSE("GPL"); |