/* loopback.c
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*
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* Copyright (C) 2002 Ulrich Marx <marx@kammer.uni-hannover.de>
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* extended by Jose Carlos Billalabeitia and Jan Kiszka
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/printk.h>
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/netdevice.h>
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#include <rtnet_port.h>
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#include <stack_mgr.h>
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MODULE_AUTHOR("Maintainer: Jan Kiszka <Jan.Kiszka@web.de>");
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MODULE_DESCRIPTION("RTnet loopback driver");
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MODULE_LICENSE("GPL");
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static struct rtnet_device *rt_loopback_dev;
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/***
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* rt_loopback_open
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* @rtdev
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*/
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static int rt_loopback_open(struct rtnet_device *rtdev)
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{
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rt_stack_connect(rtdev, &STACK_manager);
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rtnetif_start_queue(rtdev);
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return 0;
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}
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/***
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* rt_loopback_close
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* @rtdev
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*/
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static int rt_loopback_close(struct rtnet_device *rtdev)
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{
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rtnetif_stop_queue(rtdev);
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rt_stack_disconnect(rtdev);
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return 0;
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}
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/***
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* rt_loopback_xmit - begin packet transmission
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* @skb: packet to be sent
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* @dev: network device to which packet is sent
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*
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*/
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static int rt_loopback_xmit(struct rtskb *rtskb, struct rtnet_device *rtdev)
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{
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/* write transmission stamp - in case any protocol ever gets the idea to
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ask the lookback device for this service... */
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if (rtskb->xmit_stamp)
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*rtskb->xmit_stamp =
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cpu_to_be64(rtdm_clock_read() + *rtskb->xmit_stamp);
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/* make sure that critical fields are re-intialised */
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rtskb->chain_end = rtskb;
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/* parse the Ethernet header as usual */
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rtskb->protocol = rt_eth_type_trans(rtskb, rtdev);
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rt_stack_deliver(rtskb);
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return 0;
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}
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/***
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* loopback_init
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*/
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static int __init loopback_init(void)
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{
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int err;
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struct rtnet_device *rtdev;
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pr_info("initializing loopback interface...\n");
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if ((rtdev = rt_alloc_etherdev(0, 1)) == NULL)
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return -ENODEV;
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rt_rtdev_connect(rtdev, &RTDEV_manager);
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strcpy(rtdev->name, "rtlo");
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rtdev->vers = RTDEV_VERS_2_0;
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rtdev->open = &rt_loopback_open;
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rtdev->stop = &rt_loopback_close;
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rtdev->hard_start_xmit = &rt_loopback_xmit;
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rtdev->flags |= IFF_LOOPBACK;
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rtdev->flags &= ~IFF_BROADCAST;
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rtdev->features |= NETIF_F_LLTX;
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if ((err = rt_register_rtnetdev(rtdev)) != 0) {
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rtdev_free(rtdev);
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return err;
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}
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rt_loopback_dev = rtdev;
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return 0;
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}
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/***
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* loopback_cleanup
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*/
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static void __exit loopback_cleanup(void)
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{
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struct rtnet_device *rtdev = rt_loopback_dev;
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pr_info("removing loopback interface...\n");
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rt_unregister_rtnetdev(rtdev);
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rt_rtdev_disconnect(rtdev);
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rtdev_free(rtdev);
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}
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module_init(loopback_init);
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module_exit(loopback_cleanup);
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