diff options
Diffstat (limited to 'package/kernel/trelay/src/trelay.c')
| -rw-r--r-- | package/kernel/trelay/src/trelay.c | 272 |
1 files changed, 272 insertions, 0 deletions
diff --git a/package/kernel/trelay/src/trelay.c b/package/kernel/trelay/src/trelay.c new file mode 100644 index 0000000000..8fa4374c06 --- /dev/null +++ b/package/kernel/trelay/src/trelay.c @@ -0,0 +1,272 @@ +/* + * trelay.c: Trivial Ethernet Relay + * + * Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ +#include <linux/module.h> +#include <linux/list.h> +#include <linux/mutex.h> +#include <linux/netdevice.h> +#include <linux/rtnetlink.h> +#include <linux/debugfs.h> + +static LIST_HEAD(trelay_devs); +static struct dentry *debugfs_dir; + +struct trelay { + struct list_head list; + struct net_device *dev1, *dev2; + struct dentry *debugfs; + char name[]; +}; + +rx_handler_result_t trelay_handle_frame(struct sk_buff **pskb) +{ + struct net_device *dev; + struct sk_buff *skb = *pskb; + + dev = rcu_dereference(skb->dev->rx_handler_data); + if (!dev) + return RX_HANDLER_PASS; + + if (skb->protocol == htons(ETH_P_PAE)) + return RX_HANDLER_PASS; + + skb_push(skb, ETH_HLEN); + skb->dev = dev; + skb_forward_csum(skb); + dev_queue_xmit(skb); + + return RX_HANDLER_CONSUMED; +} + +static int trelay_open(struct inode *inode, struct file *file) +{ + file->private_data = inode->i_private; + return 0; +} + +static int trelay_do_remove(struct trelay *tr) +{ + list_del(&tr->list); + + dev_put(tr->dev1); + dev_put(tr->dev2); + + netdev_rx_handler_unregister(tr->dev1); + netdev_rx_handler_unregister(tr->dev2); + + debugfs_remove_recursive(tr->debugfs); + kfree(tr); + + return 0; +} + +static struct trelay *trelay_find(struct net_device *dev) +{ + struct trelay *tr; + + list_for_each_entry(tr, &trelay_devs, list) { + if (tr->dev1 == dev || tr->dev2 == dev) + return tr; + } + return NULL; +} + +static int tr_device_event(struct notifier_block *unused, unsigned long event, + void *ptr) +{ + struct net_device *dev = ptr; + struct trelay *tr; + + if (event != NETDEV_UNREGISTER) + goto out; + + tr = trelay_find(dev); + if (!tr) + goto out; + + trelay_do_remove(tr); + +out: + return NOTIFY_DONE; +} + +static ssize_t trelay_remove_write(struct file *file, const char __user *ubuf, + size_t count, loff_t *ppos) +{ + struct trelay *tr = file->private_data; + int ret; + + rtnl_lock(); + ret = trelay_do_remove(tr); + rtnl_unlock(); + + if (ret < 0) + return ret; + + return count; +} + +static const struct file_operations fops_remove = { + .owner = THIS_MODULE, + .open = trelay_open, + .write = trelay_remove_write, + .llseek = default_llseek, +}; + + +static int trelay_do_add(char *name, char *devn1, char *devn2) +{ + struct net_device *dev1, *dev2; + struct trelay *tr, *tr1; + int ret; + + tr = kzalloc(sizeof(*tr) + strlen(name) + 1, GFP_KERNEL); + if (!tr) + return -ENOMEM; + + rtnl_lock(); + rcu_read_lock(); + + ret = -EEXIST; + list_for_each_entry(tr1, &trelay_devs, list) { + if (!strcmp(tr1->name, name)) + goto out; + } + + ret = -ENOENT; + dev1 = dev_get_by_name_rcu(&init_net, devn1); + dev2 = dev_get_by_name_rcu(&init_net, devn2); + if (!dev1 || !dev2) + goto out; + + ret = netdev_rx_handler_register(dev1, trelay_handle_frame, dev2); + if (ret < 0) + goto out; + + ret = netdev_rx_handler_register(dev2, trelay_handle_frame, dev1); + if (ret < 0) { + netdev_rx_handler_unregister(dev1); + goto out; + } + + dev_hold(dev1); + dev_hold(dev2); + + strcpy(tr->name, name); + tr->dev1 = dev1; + tr->dev2 = dev2; + list_add_tail(&tr->list, &trelay_devs); + + tr->debugfs = debugfs_create_dir(name, debugfs_dir); + debugfs_create_file("remove", S_IWUSR, tr->debugfs, tr, &fops_remove); + ret = 0; + +out: + rcu_read_unlock(); + rtnl_unlock(); + if (ret < 0) + kfree(tr); + + return ret; +} + +static ssize_t trelay_add_write(struct file *file, const char __user *ubuf, + size_t count, loff_t *ppos) +{ + char buf[256]; + char *dev1, *dev2, *tmp; + ssize_t len, ret; + + len = min(count, sizeof(buf) - 1); + if (copy_from_user(buf, ubuf, len)) + return -EFAULT; + + buf[len] = 0; + + if ((tmp = strchr(buf, '\n'))) + *tmp = 0; + + dev1 = strchr(buf, ','); + if (!dev1) + return -EINVAL; + + *(dev1++) = 0; + + dev2 = strchr(dev1, ','); + if (!dev2) + return -EINVAL; + + *(dev2++) = 0; + if (strchr(dev2, ',')) + return -EINVAL; + + if (!strlen(buf) || !strlen(dev1) || !strlen(dev2)) + return -EINVAL; + + ret = trelay_do_add(buf, dev1, dev2); + if (ret < 0) + return ret; + + return count; +} + +static const struct file_operations fops_add = { + .owner = THIS_MODULE, + .write = trelay_add_write, + .llseek = default_llseek, +}; + +static struct notifier_block tr_dev_notifier = { + .notifier_call = tr_device_event +}; + +static int __init trelay_init(void) +{ + int ret; + + debugfs_dir = debugfs_create_dir("trelay", NULL); + if (!debugfs_dir) + return -ENOMEM; + + debugfs_create_file("add", S_IWUSR, debugfs_dir, NULL, &fops_add); + + ret = register_netdevice_notifier(&tr_dev_notifier); + if (ret < 0) + goto error; + + return 0; + +error: + debugfs_remove_recursive(debugfs_dir); + return ret; +} + +static void __exit trelay_exit(void) +{ + struct trelay *tr, *tmp; + + unregister_netdevice_notifier(&tr_dev_notifier); + + rtnl_lock(); + list_for_each_entry_safe(tr, tmp, &trelay_devs, list) + trelay_do_remove(tr); + rtnl_unlock(); + + debugfs_remove_recursive(debugfs_dir); +} + +module_init(trelay_init); +module_exit(trelay_exit); +MODULE_LICENSE("GPL"); |