ipin.c

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00001 /*
00002  * Copyright (C) 2001-2007 by egnite Software GmbH. All rights reserved.
00003  *
00004  * Redistribution and use in source and binary forms, with or without
00005  * modification, are permitted provided that the following conditions
00006  * are met:
00007  *
00008  * 1. Redistributions of source code must retain the above copyright
00009  *    notice, this list of conditions and the following disclaimer.
00010  * 2. Redistributions in binary form must reproduce the above copyright
00011  *    notice, this list of conditions and the following disclaimer in the
00012  *    documentation and/or other materials provided with the distribution.
00013  * 3. Neither the name of the copyright holders nor the names of
00014  *    contributors may be used to endorse or promote products derived
00015  *    from this software without specific prior written permission.
00016  *
00017  * THIS SOFTWARE IS PROVIDED BY EGNITE SOFTWARE GMBH AND CONTRIBUTORS
00018  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
00019  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
00020  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL EGNITE
00021  * SOFTWARE GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
00022  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
00023  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
00024  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
00025  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
00026  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
00027  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
00028  * SUCH DAMAGE.
00029  *
00030  * For additional information see http://www.ethernut.de/
00031  *
00032  * -
00033  * Portions Copyright (C) 2000 David J. Hudson <dave@humbug.demon.co.uk>
00034  *
00035  * This file is distributed in the hope that it will be useful, but WITHOUT
00036  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
00037  * FITNESS FOR A PARTICULAR PURPOSE.
00038  *
00039  * You can redistribute this file and/or modify it under the terms of the GNU
00040  * General Public License (GPL) as published by the Free Software Foundation;
00041  * either version 2 of the License, or (at your discretion) any later version.
00042  * See the accompanying file "copying-gpl.txt" for more details.
00043  *
00044  * As a special exception to the GPL, permission is granted for additional
00045  * uses of the text contained in this file.  See the accompanying file
00046  * "copying-liquorice.txt" for details.
00047  * -
00048  * Portions Copyright (c) 1983, 1993 by
00049  *  The Regents of the University of California.  All rights reserved.
00050  *
00051  * Redistribution and use in source and binary forms, with or without
00052  * modification, are permitted provided that the following conditions
00053  * are met:
00054  * 1. Redistributions of source code must retain the above copyright
00055  *    notice, this list of conditions and the following disclaimer.
00056  * 2. Redistributions in binary form must reproduce the above copyright
00057  *    notice, this list of conditions and the following disclaimer in the
00058  *    documentation and/or other materials provided with the distribution.
00059  * 3. Neither the name of the University nor the names of its contributors
00060  *    may be used to endorse or promote products derived from this software
00061  *    without specific prior written permission.
00062  *
00063  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
00064  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
00065  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
00066  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
00067  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
00068  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
00069  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
00070  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
00071  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
00072  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
00073  * SUCH DAMAGE.
00074  * -
00075  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
00076  *
00077  * Permission to use, copy, modify, and distribute this software for any
00078  * purpose with or without fee is hereby granted, provided that the above
00079  * copyright notice and this permission notice appear in all copies, and that
00080  * the name of Digital Equipment Corporation not be used in advertising or
00081  * publicity pertaining to distribution of the document or software without
00082  * specific, written prior permission.
00083  * 
00084  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
00085  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
00086  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
00087  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
00088  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
00089  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
00090  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
00091  * SOFTWARE.
00092  */
00093 
00094 /*
00095  * $Log: ipin.c,v $
00096  * Revision 1.11  2007/07/09 16:20:19  olereinhardt
00097  * 2007-07-09  Ole Reinhardt <ole.reinhardt@embedded-it.de>
00098  *         * net/Makefile: Commented in igmp_in.c and igmp_out.c again
00099  *         * net/ipin.c: igmp support reenabled
00100  *
00101  * Revision 1.10  2007/07/09 15:59:00  olereinhardt
00102  * 2007-07-09  Ole Reinhardt <ole.reinhardt@embedded-it.de>
00103  *  * ipin.c: commented out igmp support as long as it does not compile
00104  *
00105  * Revision 1.9  2007/05/02 11:18:32  haraldkipp
00106  * IGMP support added. Incomplete.
00107  *
00108  * Revision 1.8  2007/03/23 12:43:50  haraldkipp
00109  * ARP method wasn't actually disabled by default. Fixed.
00110  *
00111  * Revision 1.7  2006/09/05 12:35:39  haraldkipp
00112  * DHCP servers may probe an IP/MAC relationship by sending an
00113  * ICMP request. This triggered the Nut/Net ARP method and
00114  * terminated the DHCP client, leaving the system with default
00115  * configurations of the network mask (255.255.255.0) and
00116  * default gateway (none). The rarely used ARP method is now
00117  * disabled by default.
00118  *
00119  * Revision 1.6  2006/07/10 17:46:59  haraldkipp
00120  * Now really like Jan suggested to fix it.
00121  *
00122  * Revision 1.5  2006/07/10 08:49:47  haraldkipp
00123  * Do not respond to broadcasts with unknown protocols. Many thanks to Jan.
00124  *
00125  * Revision 1.4  2005/06/05 16:48:26  haraldkipp
00126  * Additional parameter enables NutUdpInput() to avoid responding to UDP
00127  * broadcasts with ICMP unreachable messages. Fixes bug #1215192.
00128  *
00129  * Revision 1.3  2004/12/16 18:48:50  haraldkipp
00130  * Added Damian Slee's IP filter function.
00131  *
00132  * Revision 1.2  2004/02/02 18:59:25  drsung
00133  * Some more ICMP support added.
00134  *
00135  * Revision 1.1.1.1  2003/05/09 14:41:32  haraldkipp
00136  * Initial using 3.2.1
00137  *
00138  * Revision 1.16  2003/05/06 18:14:18  harald
00139  * Allow incoming DHCP telegrams, even if not broadcasted
00140  *
00141  * Revision 1.15  2003/03/31 12:26:05  harald
00142  * Accept masks with all bits set
00143  *
00144  * Revision 1.14  2003/02/04 18:14:57  harald
00145  * Version 3 released
00146  *
00147  * Revision 1.13  2002/06/26 17:29:36  harald
00148  * First pre-release with 2.4 stack
00149  *
00150  */
00151 
00152 #include <cfg/ip.h>
00153 
00154 #include <net/route.h>
00155 #include <netinet/in.h>
00156 #include <netinet/ip.h>
00157 #include <netinet/icmp.h>
00158 #include <netinet/ip_icmp.h>
00159 #include <netinet/igmp.h>
00160 #include <netinet/udp.h>
00161 #include <sys/socket.h>
00162 #include <arpa/inet.h>
00163 
00168 
00169 static NutIpFilterFunc NutIpFilter;
00170 
00184 void NutIpSetInputFilter(NutIpFilterFunc callbackFunc)
00185 {
00186     NutIpFilter = callbackFunc;
00187 }
00188 
00202 void NutIpInput(NUTDEVICE * dev, NETBUF * nb)
00203 {
00204     IPHDR *ip;
00205     u_short ip_hdrlen;
00206     u_long dst;
00207     ureg_t bcast;
00208     IFNET *nif;
00209 
00210     ip = nb->nb_nw.vp;
00211 
00212     /*
00213      * Silently discard datagrams of different IP version as well as
00214      * fragmented or filtered datagrams.
00215      */
00216     if (ip->ip_v != IPVERSION ||        /* Version check. */
00217         (ntohs(ip->ip_off) & (IP_MF | IP_OFFMASK)) != 0 ||      /* Fragmentation. */
00218         (NutIpFilter && NutIpFilter(ip->ip_src))) {     /* Filter. */
00219         NutNetBufFree(nb);
00220         return;
00221     }
00222 
00223     /*
00224      * IP header length is given in 32-bit fields. Calculate the size in
00225      * bytes and make sure that the header we know will fit in.
00226      */
00227     ip_hdrlen = ip->ip_hl * 4;
00228     if (ip_hdrlen < sizeof(IPHDR)) {
00229         NutNetBufFree(nb);
00230         return;
00231     }
00232 
00233     /*
00234      * No checksum calculation on incoming datagrams!
00235      */
00236 
00237     /*
00238      * Check for broadcast.
00239      */
00240     dst = ip->ip_dst;
00241     nif = dev->dev_icb;
00242 
00243     if (dst == INADDR_BROADCAST || 
00244         (nif->if_local_ip && nif->if_mask != INADDR_BROADCAST && (dst | nif->if_mask) == INADDR_BROADCAST)) {
00245         bcast = 1;
00246     }
00247 
00248     /*
00249      * Check for multicast.
00250      */
00251     else if (IN_MULTICAST(dst)) {
00252         MCASTENTRY *mca;
00253 
00254         for (mca = nif->if_mcast; mca; mca = mca->mca_next) {
00255             if (dst == mca->mca_ip) {
00256                 break;
00257             }
00258         }
00259         if (mca == NULL) {
00260             NutNetBufFree(nb);
00261             return;
00262         }
00263         bcast = 2;
00264     }
00265 
00266     /*
00267      * Packet is unicast.
00268      */
00269     else {
00270         bcast = 0;
00271 
00272 #ifdef NUTIPCONF_ICMP_ARPMETHOD
00273         /*
00274          * Silently discard datagrams for other destinations.
00275          * However, if we haven't got an IP address yet, we
00276          * allow ICMP datagrams to support dynamic IP ARP method,
00277          * if this option had been enabled.
00278          */
00279         if (nif->if_local_ip == 0 && ip->ip_p == IPPROTO_ICMP && (dst & 0xff000000) != 0xff000000 && (dst & 0xff000000) != 0) {
00280             NutNetIfSetup(dev, dst, 0, 0);
00281         }
00282 #endif
00283         if (nif->if_local_ip && (dst == 0 || dst != nif->if_local_ip)) {
00284             NutNetBufFree(nb);
00285             return;
00286         }
00287     }
00288 
00289     nb->nb_nw.sz = ip_hdrlen;
00290     nb->nb_tp.vp = ((u_char *) ip) + (ip_hdrlen);
00291     nb->nb_tp.sz = htons(ip->ip_len) - (ip_hdrlen);
00292 
00293     switch (ip->ip_p) {
00294     case IPPROTO_ICMP:
00295         NutIcmpInput(dev, nb);
00296         break;
00297     case IPPROTO_UDP:
00298         NutUdpInput(nb, bcast);
00299         break;
00300     case IPPROTO_TCP:
00301         /*
00302          * Silently discard TCP broadcasts.
00303          */
00304         if (bcast)
00305             NutNetBufFree(nb);
00306         else
00307             NutTcpInput(nb);
00308         break;
00309     case IPPROTO_IGMP:
00310         NutIgmpInput(dev, nb);
00311         break;
00312     default:
00313         /* Unkown protocol, send ICMP destination (protocol)
00314          * unreachable message.
00315          */
00316         if (bcast || !NutIcmpResponse(ICMP_UNREACH, ICMP_UNREACH_PROTOCOL, 0, nb))
00317             NutNetBufFree(nb);
00318         break;
00319     }
00320 }
00321 

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