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bootp.c revision 1.8
      1 /*	$NetBSD: bootp.c,v 1.8 1996/09/26 23:22:01 cgd Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1992 Regents of the University of California.
      5  * All rights reserved.
      6  *
      7  * This software was developed by the Computer Systems Engineering group
      8  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
      9  * contributed to Berkeley.
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  * 2. Redistributions in binary form must reproduce the above copyright
     17  *    notice, this list of conditions and the following disclaimer in the
     18  *    documentation and/or other materials provided with the distribution.
     19  * 3. All advertising materials mentioning features or use of this software
     20  *    must display the following acknowledgement:
     21  *	This product includes software developed by the University of
     22  *	California, Lawrence Berkeley Laboratory and its contributors.
     23  * 4. Neither the name of the University nor the names of its contributors
     24  *    may be used to endorse or promote products derived from this software
     25  *    without specific prior written permission.
     26  *
     27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     37  * SUCH DAMAGE.
     38  *
     39  * @(#) Header: bootp.c,v 1.4 93/09/11 03:13:51 leres Exp  (LBL)
     40  */
     41 
     42 #include <sys/types.h>
     43 #include <netinet/in.h>
     44 #include <netinet/in_systm.h>
     45 
     46 #include <string.h>
     47 
     48 #include "stand.h"
     49 #include "net.h"
     50 #include "netif.h"
     51 #include "bootp.h"
     52 
     53 static n_long	nmask, smask;
     54 
     55 static time_t	bot;
     56 
     57 static	char vm_rfc1048[4] = VM_RFC1048;
     58 static	char vm_cmu[4] = VM_CMU;
     59 
     60 /* Local forwards */
     61 static	ssize_t bootpsend __P((struct iodesc *, void *, size_t));
     62 static	ssize_t bootprecv __P((struct iodesc *, void *, size_t, time_t));
     63 static	void vend_cmu __P((u_char *));
     64 static	void vend_rfc1048 __P((u_char *, u_int));
     65 
     66 /* Fetch required bootp infomation */
     67 void
     68 bootp(sock)
     69 	int sock;
     70 {
     71 	struct iodesc *d;
     72 	register struct bootp *bp;
     73 	struct {
     74 		u_char header[HEADER_SIZE];
     75 		struct bootp wbootp;
     76 	} wbuf;
     77 	struct {
     78 		u_char header[HEADER_SIZE];
     79 		struct bootp rbootp;
     80 	} rbuf;
     81 
     82 #ifdef BOOTP_DEBUG
     83  	if (debug)
     84 		printf("bootp: socket=%d\n", sock);
     85 #endif
     86 	if (!bot)
     87 		bot = getsecs();
     88 
     89 	if (!(d = socktodesc(sock))) {
     90 		printf("bootp: bad socket. %d\n", sock);
     91 		return;
     92 	}
     93 #ifdef BOOTP_DEBUG
     94  	if (debug)
     95 		printf("bootp: d=%x\n", (u_int)d);
     96 #endif
     97 
     98 	bp = &wbuf.wbootp;
     99 	bzero(bp, sizeof(*bp));
    100 
    101 	bp->bp_op = BOOTREQUEST;
    102 	bp->bp_htype = 1;		/* 10Mb Ethernet (48 bits) */
    103 	bp->bp_hlen = 6;
    104 	bp->bp_xid = htonl(d->xid);
    105 	MACPY(d->myea, bp->bp_chaddr);
    106 	bzero(bp->bp_file, sizeof(bp->bp_file));
    107 	bcopy(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048));
    108 
    109 	d->myip = myip;
    110 	d->myport = htons(IPPORT_BOOTPC);
    111 	d->destip.s_addr = INADDR_BROADCAST;
    112 	d->destport = htons(IPPORT_BOOTPS);
    113 
    114 	(void)sendrecv(d,
    115 	    bootpsend, bp, sizeof(*bp),
    116 	    bootprecv, &rbuf.rbootp, sizeof(rbuf.rbootp));
    117 
    118 	/* Bump xid so next request will be unique. */
    119 	++d->xid;
    120 }
    121 
    122 /* Transmit a bootp request */
    123 static ssize_t
    124 bootpsend(d, pkt, len)
    125 	register struct iodesc *d;
    126 	register void *pkt;
    127 	register size_t len;
    128 {
    129 	register struct bootp *bp;
    130 
    131 #ifdef BOOTP_DEBUG
    132 	if (debug)
    133 		printf("bootpsend: d=%x called.\n", (u_int)d);
    134 #endif
    135 
    136 	bp = pkt;
    137 	bp->bp_secs = htons((u_short)(getsecs() - bot));
    138 
    139 #ifdef BOOTP_DEBUG
    140 	if (debug)
    141 		printf("bootpsend: calling sendudp\n");
    142 #endif
    143 
    144 	return (sendudp(d, pkt, len));
    145 }
    146 
    147 /* Returns 0 if this is the packet we're waiting for else -1 (and errno == 0) */
    148 static ssize_t
    149 bootprecv(d, pkt, len, tleft)
    150 	register struct iodesc *d;
    151 	register void *pkt;
    152 	register size_t len;
    153 	time_t tleft;
    154 {
    155 	register ssize_t n;
    156 	register struct bootp *bp;
    157 
    158 #ifdef BOOTP_DEBUG
    159 	if (debug)
    160 		printf("bootprecv: called\n");
    161 #endif
    162 
    163 	n = readudp(d, pkt, len, tleft);
    164 	if (n == -1 || n < sizeof(struct bootp))
    165 		goto bad;
    166 
    167 	bp = (struct bootp *)pkt;
    168 
    169 #ifdef BOOTP_DEBUG
    170 	if (debug)
    171 		printf("bootprecv: checked.  bp = 0x%x, n = %d\n",
    172 		    (unsigned)bp, n);
    173 #endif
    174 	if (bp->bp_xid != htonl(d->xid)) {
    175 #ifdef BOOTP_DEBUG
    176 		if (debug) {
    177 			printf("bootprecv: expected xid 0x%x, got 0x%x\n",
    178 			    d->xid, ntohl(bp->bp_xid));
    179 		}
    180 #endif
    181 		goto bad;
    182 	}
    183 
    184 #ifdef BOOTP_DEBUG
    185 	if (debug)
    186 		printf("bootprecv: got one!\n");
    187 #endif
    188 
    189 	/* Pick up our ip address (and natural netmask) */
    190 	myip = d->myip = bp->bp_yiaddr;
    191 #ifdef BOOTP_DEBUG
    192 	if (debug)
    193 		printf("our ip address is %s\n", inet_ntoa(d->myip));
    194 #endif
    195 	if (IN_CLASSA(d->myip.s_addr))
    196 		nmask = IN_CLASSA_NET;
    197 	else if (IN_CLASSB(d->myip.s_addr))
    198 		nmask = IN_CLASSB_NET;
    199 	else
    200 		nmask = IN_CLASSC_NET;
    201 #ifdef BOOTP_DEBUG
    202 	if (debug)
    203 		printf("'native netmask' is %s\n", intoa(nmask));
    204 #endif
    205 
    206 	/* Pick up root or swap server address and file spec. */
    207 	if (bp->bp_siaddr.s_addr != 0)
    208 		rootip = bp->bp_siaddr;
    209 	if (bp->bp_file[0] != '\0') {
    210 		strncpy(bootfile, (char *)bp->bp_file, sizeof(bootfile));
    211 		bootfile[sizeof(bootfile) - 1] = '\0';
    212 	}
    213 
    214 	/* Suck out vendor info */
    215 	if (bcmp(vm_cmu, bp->bp_vend, sizeof(vm_cmu)) == 0)
    216 		vend_cmu(bp->bp_vend);
    217 	else if (bcmp(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048)) == 0)
    218 		vend_rfc1048(bp->bp_vend, sizeof(bp->bp_vend));
    219 	else
    220 		printf("bootprecv: unknown vendor 0x%lx\n", (long)bp->bp_vend);
    221 
    222 	/* Check subnet mask against net mask; toss if bogus */
    223 	if ((nmask & smask) != nmask) {
    224 #ifdef BOOTP_DEBUG
    225 		if (debug)
    226 			printf("subnet mask (%s) bad\n", intoa(smask));
    227 #endif
    228 		smask = 0;
    229 	}
    230 
    231 	/* Get subnet (or natural net) mask */
    232 	netmask = nmask;
    233 	if (smask)
    234 		netmask = smask;
    235 #ifdef BOOTP_DEBUG
    236 	if (debug)
    237 		printf("mask: %s\n", intoa(netmask));
    238 #endif
    239 
    240 	/* We need a gateway if root or swap is on a different net */
    241 	if (!SAMENET(d->myip, rootip, netmask)) {
    242 #ifdef BOOTP_DEBUG
    243 		if (debug)
    244 			printf("need gateway for root ip\n");
    245 #endif
    246 	}
    247 
    248 	if (!SAMENET(d->myip, swapip, netmask)) {
    249 #ifdef BOOTP_DEBUG
    250 		if (debug)
    251 			printf("need gateway for swap ip\n");
    252 #endif
    253 	}
    254 
    255 	/* Toss gateway if on a different net */
    256 	if (!SAMENET(d->myip, gateip, netmask)) {
    257 #ifdef BOOTP_DEBUG
    258 		if (debug)
    259 			printf("gateway ip (%s) bad\n", inet_ntoa(gateip));
    260 #endif
    261 		gateip.s_addr = 0;
    262 	}
    263 
    264 	return (n);
    265 
    266 bad:
    267 	errno = 0;
    268 	return (-1);
    269 }
    270 
    271 static void
    272 vend_cmu(cp)
    273 	u_char *cp;
    274 {
    275 	register struct cmu_vend *vp;
    276 
    277 #ifdef BOOTP_DEBUG
    278 	if (debug)
    279 		printf("vend_cmu bootp info.\n");
    280 #endif
    281 	vp = (struct cmu_vend *)cp;
    282 
    283 	if (vp->v_smask.s_addr != 0) {
    284 		smask = vp->v_smask.s_addr;
    285 	}
    286 	if (vp->v_dgate.s_addr != 0) {
    287 		gateip = vp->v_dgate;
    288 	}
    289 }
    290 
    291 static void
    292 vend_rfc1048(cp, len)
    293 	register u_char *cp;
    294 	u_int len;
    295 {
    296 	register u_char *ep;
    297 	register int size;
    298 	register u_char tag;
    299 
    300 #ifdef BOOTP_DEBUG
    301 	if (debug)
    302 		printf("vend_rfc1048 bootp info. len=%d\n", len);
    303 #endif
    304 	ep = cp + len;
    305 
    306 	/* Step over magic cookie */
    307 	cp += sizeof(int);
    308 
    309 	while (cp < ep) {
    310 		tag = *cp++;
    311 		size = *cp++;
    312 		if (tag == TAG_END)
    313 			break;
    314 
    315 		if (tag == TAG_SUBNET_MASK) {
    316 			bcopy(cp, &smask, sizeof(smask));
    317 		}
    318 		if (tag == TAG_GATEWAY) {
    319 			bcopy(cp, &gateip.s_addr, sizeof(gateip.s_addr));
    320 		}
    321 		if (tag == TAG_SWAPSERVER) {
    322 			bcopy(cp, &swapip.s_addr, sizeof(swapip.s_addr));
    323 		}
    324 		if (tag == TAG_DOMAIN_SERVER) {
    325 			bcopy(cp, &nameip.s_addr, sizeof(nameip.s_addr));
    326 		}
    327 		if (tag == TAG_ROOTPATH) {
    328 			strncpy(rootpath, (char *)cp, sizeof(rootpath));
    329 			rootpath[size] = '\0';
    330 		}
    331 		if (tag == TAG_HOSTNAME) {
    332 			strncpy(hostname, (char *)cp, sizeof(hostname));
    333 			hostname[size] = '\0';
    334 		}
    335 		if (tag == TAG_DOMAINNAME) {
    336 			strncpy(domainname, (char *)cp, sizeof(domainname));
    337 			domainname[size] = '\0';
    338 		}
    339 		cp += size;
    340 	}
    341 }
    342