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C:/proj/src/ethernut/nut/eboot/dhcp.c

00001 /*
00002  * Copyright (C) 2001-2002 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. All advertising materials mentioning features or use of this
00014  *    software must display the following acknowledgement:
00015  *
00016  *    This product includes software developed by egnite Software GmbH
00017  *    and its contributors.
00018  *
00019  * THIS SOFTWARE IS PROVIDED BY EGNITE SOFTWARE GMBH AND CONTRIBUTORS
00020  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
00021  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
00022  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL EGNITE
00023  * SOFTWARE GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
00024  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
00025  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
00026  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
00027  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
00028  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
00029  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
00030  * SUCH DAMAGE.
00031  *
00032  * For additional information see http://www.ethernut.de/
00033  *
00034  * -
00035  * Portions Copyright (c) 1983, 1993 by
00036  *  The Regents of the University of California.  All rights reserved.
00037  *
00038  * Redistribution and use in source and binary forms, with or without
00039  * modification, are permitted provided that the following conditions
00040  * are met:
00041  * 1. Redistributions of source code must retain the above copyright
00042  *    notice, this list of conditions and the following disclaimer.
00043  * 2. Redistributions in binary form must reproduce the above copyright
00044  *    notice, this list of conditions and the following disclaimer in the
00045  *    documentation and/or other materials provided with the distribution.
00046  * 3. All advertising materials mentioning features or use of this software
00047  *    must display the following acknowledgement:
00048  *  This product includes software developed by the University of
00049  *  California, Berkeley and its contributors.
00050  * 4. Neither the name of the University nor the names of its contributors
00051  *    may be used to endorse or promote products derived from this software
00052  *    without specific prior written permission.
00053  *
00054  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
00055  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
00056  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
00057  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
00058  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
00059  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
00060  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
00061  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
00062  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
00063  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
00064  * SUCH DAMAGE.
00065  * -
00066  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
00067  *
00068  * Permission to use, copy, modify, and distribute this software for any
00069  * purpose with or without fee is hereby granted, provided that the above
00070  * copyright notice and this permission notice appear in all copies, and that
00071  * the name of Digital Equipment Corporation not be used in advertising or
00072  * publicity pertaining to distribution of the document or software without
00073  * specific, written prior permission.
00074  * 
00075  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
00076  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
00077  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
00078  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
00079  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
00080  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
00081  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
00082  * SOFTWARE.
00083  */
00084 
00085 /*
00086  * $Log: dhcp.c,v $
00087  * Revision 1.1  2002/08/01 17:34:29  harald
00088  * First check in
00089  *
00090  */
00091 
00092 #include <string.h>
00093 
00094 #include "eboot.h"
00095 #include "ip.h"
00096 #include "dhcp.h"
00097 
00098 /*!
00099  * \addtogroup xgDhcp
00100  */
00101 /*@{*/
00102 
00103 static u_char cookie[4] = { 0x63, 0x82, 0x53, 0x63 };
00104 
00105 /*!
00106  * \brief Initialize the global send frame for DHCP requests.
00107  *
00108  * \return Size of the frame.
00109  */
00110 u_short DhcpFrameInit(void)
00111 {
00112     u_short i;
00113     BOOTPHDR *bp = &sframe.u.bootp;
00114     u_char *op = bp->bp_options;
00115 
00116     for(i = 0; i < sizeof(BOOTFRAME); i++)
00117         *((u_char *)&sframe + i) = 0;
00118 
00119     bp->bp_op = 1;
00120     bp->bp_xid = 0x04030201;
00121     bp->bp_htype = 1;
00122     bp->bp_hlen = sizeof(mac);
00123     for(i = 0; i < 6; i++)
00124         bp->bp_chaddr[i] = mac[i];
00125     for(i = 0; i < 4; i++)
00126         *op++ = cookie[i];
00127 
00128     *op++ = DHCPOPT_MSGTYPE;
00129     *op++ = 1;
00130     *op++ = DHCP_DISCOVER;
00131 
00132     *op++ = DHCPOPT_END;
00133 
00134     return sizeof(BOOTPHDR) - sizeof(sframe.u.bootp.bp_options) + 8;
00135 }
00136 
00137 u_short DhcpRequestFrame(void)
00138 {
00139     BOOTPHDR *bp = &sframe.u.bootp;
00140     u_char *op = &bp->bp_options[6];
00141 
00142     *op++ = DHCP_REQUEST;
00143 
00144     *op++ = DHCPOPT_REQUESTIP;
00145     *op++ = 4;
00146     *op++ = (u_char)rframe.u.bootp.bp_yiaddr;
00147     *op++ = (u_char)(rframe.u.bootp.bp_yiaddr >> 8);
00148     *op++ = (u_char)(rframe.u.bootp.bp_yiaddr >> 16);
00149     *op++ = (u_char)(rframe.u.bootp.bp_yiaddr >> 24);
00150 
00151     *op++ = DHCPOPT_SID;
00152     *op++ = 4;
00153     *op++ = (u_char)sid;
00154     *op++ = (u_char)(sid >> 8);
00155     *op++ = (u_char)(sid >> 16);
00156     *op++ = (u_char)(sid >> 24);
00157 
00158     *op++ = DHCPOPT_END;
00159 
00160     return sizeof(BOOTPHDR) - sizeof(sframe.u.bootp.bp_options) + 20;
00161 }
00162 
00163 /*!
00164  * \brief Retrive the specified DCHP option.
00165  *
00166  * \param opt  Option to look for.
00167  * \param ptr  Pointer to the buffer that receives the option value.
00168  * \param size Size of the buffer.
00169  *
00170  * \return Size of the retrieved option value or zero,
00171  *         if the specified option couldn't be found.
00172  */
00173 u_char DhcpGetOption(u_char opt, void *ptr, u_char size)
00174 {
00175     register u_char *cp;
00176     u_char i;
00177 
00178     cp = rframe.u.bootp.bp_options + 4;
00179     for(;;) {
00180         if(*cp == DHCPOPT_PAD) {
00181             cp++;
00182             continue;
00183         }
00184         if(*cp == DHCPOPT_END)
00185             break;
00186         if(*cp == opt) {
00187             if(*(cp + 1) < size)
00188                 size = *(cp + 1);
00189             for(i = 0; i < size; i++)
00190                 *(((u_char *)ptr) + i) = *(cp + i + 2);
00191             return *(cp + 1);
00192         }
00193         cp++;
00194         cp += *cp;
00195         cp++;
00196     }
00197     return 0;
00198 }
00199 
00200 /*!
00201  * \brief Query any DHCP server on the local net.
00202  *
00203  * On success, this routine will fill some global
00204  * variables:
00205  *
00206  * - local_ip 
00207  * - server_ip
00208  * - bootfile
00209  * - netmask
00210  * - broadcast
00211  * - gateway
00212  * - dns
00213  * - sid
00214  * 
00215  * \return 0 on success, -1 otherwise.
00216  */
00217 int DhcpQuery(void)
00218 {
00219     u_char type;
00220     u_char retry;
00221     int rlen;
00222     int slen;
00223     u_char i;
00224     u_char *cp;
00225 
00226     /*
00227      * Discovery loop.
00228      */
00229     slen = DhcpFrameInit();
00230     for(rlen = retry = 0; rlen == 0 && retry < 10; retry++) {
00231         if(UdpOutput(INADDR_BROADCAST, DHCP_SERVERPORT, DHCP_CLIENTPORT, slen) < 0)
00232             return -1;
00233         if((rlen = UdpInput(DHCP_CLIENTPORT, 5000)) < 0) 
00234             break;
00235         if(rlen &&
00236            rframe.u.bootp.bp_xid == sframe.u.bootp.bp_xid &&
00237            DhcpGetOption(DHCPOPT_MSGTYPE, &type, 1) == 1 && 
00238            type == DHCP_OFFER)
00239                break;
00240         rlen = 0;
00241     }
00242     if(rlen == 0) {
00243         return -1;
00244     }
00245 
00246     DhcpGetOption(DHCPOPT_SID, &sid, 4);
00247 
00248     /*
00249      * Request loop.
00250      */
00251     slen = DhcpRequestFrame();
00252     for(rlen = retry = 0; rlen == 0 && retry < 10; retry++) {
00253         if(UdpOutput(INADDR_BROADCAST, DHCP_SERVERPORT, DHCP_CLIENTPORT, slen) < 0)
00254             return -1;
00255         if((rlen = UdpInput(DHCP_CLIENTPORT, 1000)) < 0)
00256             return -1;
00257         if(rlen &&
00258            rframe.u.bootp.bp_xid == sframe.u.bootp.bp_xid &&
00259            DhcpGetOption(DHCPOPT_MSGTYPE, &type, 1) == 1 && 
00260            type == DHCP_ACK) 
00261                 break;
00262         rlen = 0;
00263     }
00264     if(rlen == 0) {
00265         return -1;
00266     }
00267 
00268     local_ip = rframe.u.bootp.bp_yiaddr;
00269     server_ip = rframe.u.bootp.bp_siaddr;
00270     for(cp = rframe.u.bootp.bp_file, i = 0; *cp && i < sizeof(bootfile) - 1; cp++, i++)
00271         bootfile[i] = *cp;
00272     bootfile[i] = 0;
00273 
00274     DhcpGetOption(DHCPOPT_NETMASK, &netmask, 4);
00275     DhcpGetOption(DHCPOPT_BROADCAST, &broadcast, 4);
00276     DhcpGetOption(DHCPOPT_GATEWAY, &gateway, 4);
00277     DhcpGetOption(DHCPOPT_DNS, &dns, 4);
00278     DhcpGetOption(DHCPOPT_SID, &sid, 4);
00279 
00280     return 0;
00281 }
00282 
00283 /*@}*/

© 2002 by egnite Software GmbH - visit http://www.ethernut.de/