From c3bba7f8c61ee98265bcffef8ee86e22aa89bbe9 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Wed, 28 Mar 2012 11:02:38 +0000 Subject: [PATCH] add trelay, a trivial ethernet relay which allows pseudo-bridging ad-hoc or client mode devices over vlans to other hosts SVN-Revision: 31122 --- package/trelay/Makefile | 51 ++++++ package/trelay/files/trelay.config | 4 + package/trelay/files/trelay.hotplug | 5 + package/trelay/files/trelay.init | 32 ++++ package/trelay/src/Makefile | 1 + package/trelay/src/trelay.c | 272 ++++++++++++++++++++++++++++ 6 files changed, 365 insertions(+) create mode 100644 package/trelay/Makefile create mode 100644 package/trelay/files/trelay.config create mode 100644 package/trelay/files/trelay.hotplug create mode 100644 package/trelay/files/trelay.init create mode 100644 package/trelay/src/Makefile create mode 100644 package/trelay/src/trelay.c diff --git a/package/trelay/Makefile b/package/trelay/Makefile new file mode 100644 index 0000000000..cbe0f045cf --- /dev/null +++ b/package/trelay/Makefile @@ -0,0 +1,51 @@ +# +# Copyright (C) 2012 OpenWrt.org +# +# This is free software, licensed under the GNU General Public License v2. +# See /LICENSE for more information. +# + +include $(TOPDIR)/rules.mk +include $(INCLUDE_DIR)/kernel.mk + +PKG_NAME:=trelay +PKG_VERSION:=0.1 +PKG_RELEASE:=1 + +include $(INCLUDE_DIR)/package.mk + +define KernelPackage/trelay + SUBMENU:=Network Support + TITLE:=Trivial Ethernet Relay + DEPENDS:=@!LINUX_2_6_30 @!LINUX_2_6_31 @!LINUX_2_6_32 + FILES:=$(PKG_BUILD_DIR)/trelay.ko + AUTOLOAD:=$(call AutoLoad,50,trelay) +endef + +define KernelPackage/trelay/description +trelay relays ethernet packets between two devices (similar to a bridge), but +without any MAC address checks. This makes it possible to bridge client mode +or ad-hoc mode wifi devices to ethernet VLANs, assuming the remote end uses +the same source MAC address as the device that packets are supposed to exit +from. +endef + +include $(INCLUDE_DIR)/kernel-defaults.mk + +define Build/Prepare + mkdir -p $(PKG_BUILD_DIR) + cp src/Makefile src/trelay.c $(PKG_BUILD_DIR)/ +endef + +define Build/Compile + $(MAKE) $(KERNEL_MAKEOPTS) SUBDIRS="$(PKG_BUILD_DIR)" modules +endef + +define KernelPackage/trelay/install + $(INSTALL_DIR) $(1)/etc/hotplug.d/net $(1)/etc/init.d $(1)/etc/config + $(INSTALL_DATA) ./files/trelay.hotplug $(1)/etc/hotplug.d/net/50-trelay + $(INSTALL_BIN) ./files/trelay.init $(1)/etc/init.d/trelay + $(INSTALL_DATA) ./files/trelay.config $(1)/etc/config/trelay +endef + +$(eval $(call KernelPackage,trelay)) diff --git a/package/trelay/files/trelay.config b/package/trelay/files/trelay.config new file mode 100644 index 0000000000..eb05013056 --- /dev/null +++ b/package/trelay/files/trelay.config @@ -0,0 +1,4 @@ +config trelay + option enabled 0 + option dev1 eth0 + option dev2 wlan0 diff --git a/package/trelay/files/trelay.hotplug b/package/trelay/files/trelay.hotplug new file mode 100644 index 0000000000..31f7378406 --- /dev/null +++ b/package/trelay/files/trelay.hotplug @@ -0,0 +1,5 @@ +case "$ACTION" in + add|register) + [ -f /var/run/trelay.active ] && /etc/init.d/trelay start + ;; +esac diff --git a/package/trelay/files/trelay.init b/package/trelay/files/trelay.init new file mode 100644 index 0000000000..c812e12c69 --- /dev/null +++ b/package/trelay/files/trelay.init @@ -0,0 +1,32 @@ +#!/bin/sh /etc/rc.common +START=80 + +check_relay() { + local cfg="$1" + + config_get_bool enabled "$cfg" enabled 1 + [ "$enabled" -gt 0 ] || return + + config_get dev1 "$cfg" dev1 + config_get dev2 "$cfg" dev2 + + [ -d "/sys/kernel/debug/trelay/${dev1}-${dev2}" ] && return + [ -d "/sys/class/net/${dev1}" -a -d "/sys/class/net/${dev2}" ] || return + + ifconfig "$dev1" up + ifconfig "$dev2" up + echo "${dev1}-${dev2},${dev1},${dev2}" > /sys/kernel/debug/trelay/add +} + +start() { + config_load trelay + config_foreach check_relay trelay + touch /var/run/trelay.active +} + +stop() { + rm -f /var/run/trelay.active + for relay in /sys/kernel/debug/trelay/*; do + [ -d "$relay" ] && echo > "$relay/remove" + done +} diff --git a/package/trelay/src/Makefile b/package/trelay/src/Makefile new file mode 100644 index 0000000000..e6bde8969b --- /dev/null +++ b/package/trelay/src/Makefile @@ -0,0 +1 @@ +obj-m := trelay.o diff --git a/package/trelay/src/trelay.c b/package/trelay/src/trelay.c new file mode 100644 index 0000000000..8fa4374c06 --- /dev/null +++ b/package/trelay/src/trelay.c @@ -0,0 +1,272 @@ +/* + * trelay.c: Trivial Ethernet Relay + * + * Copyright (C) 2012 Felix Fietkau + * + * 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 +#include +#include +#include +#include +#include + +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"); -- 2.25.1