loopif.c

00001 /**
00002  * @file
00003  * Loop Interface
00004  *
00005  */
00006 
00007 /*
00008  * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
00009  * All rights reserved. 
00010  * 
00011  * Redistribution and use in source and binary forms, with or without modification, 
00012  * are permitted provided that the following conditions are met:
00013  *
00014  * 1. Redistributions of source code must retain the above copyright notice,
00015  *    this list of conditions and the following disclaimer.
00016  * 2. Redistributions in binary form must reproduce the above copyright notice,
00017  *    this list of conditions and the following disclaimer in the documentation
00018  *    and/or other materials provided with the distribution.
00019  * 3. The name of the author may not be used to endorse or promote products
00020  *    derived from this software without specific prior written permission. 
00021  *
00022  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 
00023  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
00024  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 
00025  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
00026  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 
00027  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
00028  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
00029  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 
00030  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
00031  * OF SUCH DAMAGE.
00032  *
00033  * This file is part of the lwIP TCP/IP stack.
00034  * 
00035  * Author: Adam Dunkels <adam@sics.se>
00036  *
00037  */
00038 #include "lwip/opt.h"
00039 
00040 #if LWIP_HAVE_LOOPIF
00041 
00042 #include "netif/loopif.h"
00043 #include "lwip/snmp.h"
00044 
00045 /**
00046  * Initialize a lwip network interface structure for a loopback interface
00047  *
00048  * @param netif the lwip network interface structure for this loopif
00049  * @return ERR_OK if the loopif is initialized
00050  *         ERR_MEM if private data couldn't be allocated
00051  */
00052 err_t
00053 loopif_init(struct netif *netif)
00054 {
00055   /* initialize the snmp variables and counters inside the struct netif
00056    * ifSpeed: no assumption can be made!
00057    */
00058   NETIF_INIT_SNMP(netif, snmp_ifType_softwareLoopback, 0);
00059 
00060   netif->name[0] = 'l';
00061   netif->name[1] = 'o';
00062   netif->output = netif_loop_output;
00063   return ERR_OK;
00064 }
00065 
00066 #endif /* LWIP_HAVE_LOOPIF */