bootp.c revision 1.14
1 /* $NetBSD: bootp.c,v 1.14 1998/02/16 11:10:54 drochner 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 #ifdef _STANDALONE 47 #include <lib/libkern/libkern.h> 48 #else 49 #include <string.h> 50 #endif 51 52 #include "stand.h" 53 #include "net.h" 54 #include "netif.h" 55 #include "bootp.h" 56 57 struct in_addr servip; 58 59 static n_long nmask, smask; 60 61 static time_t bot; 62 63 static char vm_rfc1048[4] = VM_RFC1048; 64 #ifdef BOOTP_VEND_CMU 65 static char vm_cmu[4] = VM_CMU; 66 #endif 67 68 /* Local forwards */ 69 static ssize_t bootpsend __P((struct iodesc *, void *, size_t)); 70 static ssize_t bootprecv __P((struct iodesc *, void *, size_t, time_t)); 71 static int vend_rfc1048 __P((u_char *, u_int)); 72 #ifdef BOOTP_VEND_CMU 73 static void vend_cmu __P((u_char *)); 74 #endif 75 76 #ifdef SUPPORT_DHCP 77 static char expected_dhcpmsgtype = -1, dhcp_ok; 78 struct in_addr dhcp_serverip; 79 #endif 80 81 /* Fetch required bootp infomation */ 82 void 83 bootp(sock) 84 int sock; 85 { 86 struct iodesc *d; 87 register struct bootp *bp; 88 struct { 89 u_char header[HEADER_SIZE]; 90 struct bootp wbootp; 91 } wbuf; 92 struct { 93 u_char header[HEADER_SIZE]; 94 struct bootp rbootp; 95 } rbuf; 96 97 #ifdef BOOTP_DEBUG 98 if (debug) 99 printf("bootp: socket=%d\n", sock); 100 #endif 101 if (!bot) 102 bot = getsecs(); 103 104 if (!(d = socktodesc(sock))) { 105 printf("bootp: bad socket. %d\n", sock); 106 return; 107 } 108 #ifdef BOOTP_DEBUG 109 if (debug) 110 printf("bootp: d=%lx\n", (long)d); 111 #endif 112 113 bp = &wbuf.wbootp; 114 bzero(bp, sizeof(*bp)); 115 116 bp->bp_op = BOOTREQUEST; 117 bp->bp_htype = 1; /* 10Mb Ethernet (48 bits) */ 118 bp->bp_hlen = 6; 119 bp->bp_xid = htonl(d->xid); 120 MACPY(d->myea, bp->bp_chaddr); 121 strncpy(bp->bp_file, bootfile, sizeof(bp->bp_file)); 122 bcopy(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048)); 123 #ifdef SUPPORT_DHCP 124 bp->bp_vend[4] = TAG_DHCP_MSGTYPE; 125 bp->bp_vend[5] = 1; 126 bp->bp_vend[6] = DHCPDISCOVER; 127 bp->bp_vend[7] = TAG_END; 128 #else 129 bp->bp_vend[4] = TAG_END; 130 #endif 131 132 d->myip.s_addr = INADDR_ANY; 133 d->myport = htons(IPPORT_BOOTPC); 134 d->destip.s_addr = INADDR_BROADCAST; 135 d->destport = htons(IPPORT_BOOTPS); 136 137 #ifdef SUPPORT_DHCP 138 expected_dhcpmsgtype = DHCPOFFER; 139 dhcp_ok = 0; 140 #endif 141 142 if(sendrecv(d, 143 bootpsend, bp, sizeof(*bp), 144 bootprecv, &rbuf.rbootp, sizeof(rbuf.rbootp)) 145 == -1) { 146 printf("bootp: no reply\n"); 147 return; 148 } 149 150 #ifdef SUPPORT_DHCP 151 if(dhcp_ok) { 152 u_int32_t leasetime; 153 bp->bp_vend[6] = DHCPREQUEST; 154 bp->bp_vend[7] = TAG_REQ_ADDR; 155 bp->bp_vend[8] = 4; 156 bcopy(&rbuf.rbootp.bp_yiaddr, &bp->bp_vend[9], 4); 157 bp->bp_vend[13] = TAG_SERVERID; 158 bp->bp_vend[14] = 4; 159 bcopy(&dhcp_serverip.s_addr, &bp->bp_vend[15], 4); 160 bp->bp_vend[19] = TAG_LEASETIME; 161 bp->bp_vend[20] = 4; 162 leasetime = htonl(300); 163 bcopy(&leasetime, &bp->bp_vend[21], 4); 164 bp->bp_vend[25] = TAG_END; 165 166 expected_dhcpmsgtype = DHCPACK; 167 168 if(sendrecv(d, 169 bootpsend, bp, sizeof(*bp), 170 bootprecv, &rbuf.rbootp, sizeof(rbuf.rbootp)) 171 == -1) { 172 printf("DHCPREQUEST failed\n"); 173 return; 174 } 175 } 176 #endif 177 178 myip = d->myip = rbuf.rbootp.bp_yiaddr; 179 servip = rbuf.rbootp.bp_siaddr; 180 if(rootip.s_addr == INADDR_ANY) rootip = servip; 181 bcopy(rbuf.rbootp.bp_file, bootfile, sizeof(bootfile)); 182 bootfile[sizeof(bootfile) - 1] = '\0'; 183 184 if (IN_CLASSA(myip.s_addr)) 185 nmask = IN_CLASSA_NET; 186 else if (IN_CLASSB(myip.s_addr)) 187 nmask = IN_CLASSB_NET; 188 else 189 nmask = IN_CLASSC_NET; 190 #ifdef BOOTP_DEBUG 191 if (debug) 192 printf("'native netmask' is %s\n", intoa(nmask)); 193 #endif 194 195 /* Check subnet mask against net mask; toss if bogus */ 196 if ((nmask & smask) != nmask) { 197 #ifdef BOOTP_DEBUG 198 if (debug) 199 printf("subnet mask (%s) bad\n", intoa(smask)); 200 #endif 201 smask = 0; 202 } 203 204 /* Get subnet (or natural net) mask */ 205 netmask = nmask; 206 if (smask) 207 netmask = smask; 208 #ifdef BOOTP_DEBUG 209 if (debug) 210 printf("mask: %s\n", intoa(netmask)); 211 #endif 212 213 /* We need a gateway if root is on a different net */ 214 if (!SAMENET(myip, rootip, netmask)) { 215 #ifdef BOOTP_DEBUG 216 if (debug) 217 printf("need gateway for root ip\n"); 218 #endif 219 } 220 221 /* Toss gateway if on a different net */ 222 if (!SAMENET(myip, gateip, netmask)) { 223 #ifdef BOOTP_DEBUG 224 if (debug) 225 printf("gateway ip (%s) bad\n", inet_ntoa(gateip)); 226 #endif 227 gateip.s_addr = 0; 228 } 229 230 /* Bump xid so next request will be unique. */ 231 ++d->xid; 232 } 233 234 /* Transmit a bootp request */ 235 static ssize_t 236 bootpsend(d, pkt, len) 237 register struct iodesc *d; 238 register void *pkt; 239 register size_t len; 240 { 241 register struct bootp *bp; 242 243 #ifdef BOOTP_DEBUG 244 if (debug) 245 printf("bootpsend: d=%lx called.\n", (long)d); 246 #endif 247 248 bp = pkt; 249 bp->bp_secs = htons((u_short)(getsecs() - bot)); 250 251 #ifdef BOOTP_DEBUG 252 if (debug) 253 printf("bootpsend: calling sendudp\n"); 254 #endif 255 256 return (sendudp(d, pkt, len)); 257 } 258 259 static ssize_t 260 bootprecv(d, pkt, len, tleft) 261 register struct iodesc *d; 262 register void *pkt; 263 register size_t len; 264 time_t tleft; 265 { 266 register ssize_t n; 267 register struct bootp *bp; 268 269 #ifdef BOOTP_DEBUGx 270 if (debug) 271 printf("bootp_recvoffer: called\n"); 272 #endif 273 274 n = readudp(d, pkt, len, tleft); 275 if (n == -1 || n < sizeof(struct bootp) - BOOTP_VENDSIZE) 276 goto bad; 277 278 bp = (struct bootp *)pkt; 279 280 #ifdef BOOTP_DEBUG 281 if (debug) 282 printf("bootprecv: checked. bp = 0x%lx, n = %d\n", 283 (long)bp, (int)n); 284 #endif 285 if (bp->bp_xid != htonl(d->xid)) { 286 #ifdef BOOTP_DEBUG 287 if (debug) { 288 printf("bootprecv: expected xid 0x%lx, got 0x%x\n", 289 d->xid, ntohl(bp->bp_xid)); 290 } 291 #endif 292 goto bad; 293 } 294 295 #ifdef BOOTP_DEBUG 296 if (debug) 297 printf("bootprecv: got one!\n"); 298 #endif 299 300 /* Suck out vendor info */ 301 if (bcmp(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048)) == 0) { 302 if(vend_rfc1048(bp->bp_vend, sizeof(bp->bp_vend)) != 0) 303 goto bad; 304 } 305 #ifdef BOOTP_VEND_CMU 306 else if (bcmp(vm_cmu, bp->bp_vend, sizeof(vm_cmu)) == 0) 307 vend_cmu(bp->bp_vend); 308 #endif 309 else 310 printf("bootprecv: unknown vendor 0x%lx\n", (long)bp->bp_vend); 311 312 return(n); 313 bad: 314 errno = 0; 315 return (-1); 316 } 317 318 static int 319 vend_rfc1048(cp, len) 320 register u_char *cp; 321 u_int len; 322 { 323 register u_char *ep; 324 register int size; 325 register u_char tag; 326 327 #ifdef BOOTP_DEBUG 328 if (debug) 329 printf("vend_rfc1048 bootp info. len=%d\n", len); 330 #endif 331 ep = cp + len; 332 333 /* Step over magic cookie */ 334 cp += sizeof(int); 335 336 while (cp < ep) { 337 tag = *cp++; 338 size = *cp++; 339 if (tag == TAG_END) 340 break; 341 342 if (tag == TAG_SUBNET_MASK) { 343 bcopy(cp, &smask, sizeof(smask)); 344 } 345 if (tag == TAG_GATEWAY) { 346 bcopy(cp, &gateip.s_addr, sizeof(gateip.s_addr)); 347 } 348 if (tag == TAG_SWAPSERVER) { 349 /* let it override bp_siaddr */ 350 bcopy(cp, &rootip.s_addr, sizeof(swapip.s_addr)); 351 } 352 if (tag == TAG_ROOTPATH) { 353 strncpy(rootpath, (char *)cp, sizeof(rootpath)); 354 rootpath[size] = '\0'; 355 } 356 if (tag == TAG_HOSTNAME) { 357 strncpy(hostname, (char *)cp, sizeof(hostname)); 358 hostname[size] = '\0'; 359 } 360 #ifdef SUPPORT_DHCP 361 if (tag == TAG_DHCP_MSGTYPE) { 362 if(*cp != expected_dhcpmsgtype) 363 return(-1); 364 dhcp_ok = 1; 365 } 366 if (tag == TAG_SERVERID) { 367 bcopy(cp, &dhcp_serverip.s_addr, 368 sizeof(dhcp_serverip.s_addr)); 369 } 370 #endif 371 cp += size; 372 } 373 return(0); 374 } 375 376 #ifdef BOOTP_VEND_CMU 377 static void 378 vend_cmu(cp) 379 u_char *cp; 380 { 381 register struct cmu_vend *vp; 382 383 #ifdef BOOTP_DEBUG 384 if (debug) 385 printf("vend_cmu bootp info.\n"); 386 #endif 387 vp = (struct cmu_vend *)cp; 388 389 if (vp->v_smask.s_addr != 0) { 390 smask = vp->v_smask.s_addr; 391 } 392 if (vp->v_dgate.s_addr != 0) { 393 gateip = vp->v_dgate; 394 } 395 } 396 #endif 397
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