1/* $NetBSD: bootp.c,v 1.37 2009/07/10 12:16:31 roy 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/param.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 "bootp.h" 55 56struct in_addr servip; 57#ifdef SUPPORT_LINUX 58char linuxcmdline[256]; 59#ifndef TAG_LINUX_CMDLINE 60#define TAG_LINUX_CMDLINE 123 61#endif 62#endif 63 64static n_long nmask, smask; 65 66static satime_t bot; 67 68static char vm_rfc1048[4] = VM_RFC1048; 69#ifdef BOOTP_VEND_CMU 70static char vm_cmu[4] = VM_CMU; 71#endif 72 73/* Local forwards */ 74static ssize_t bootpsend(struct iodesc *, void *, size_t); 75static ssize_t bootprecv(struct iodesc *, void *, size_t, saseconds_t); 76static int vend_rfc1048(u_char *, u_int); 77#ifdef BOOTP_VEND_CMU 78static void vend_cmu(u_char *); 79#endif 80 81#ifdef SUPPORT_DHCP 82static char expected_dhcpmsgtype = -1, dhcp_ok; 83struct in_addr dhcp_serverip; 84#endif 85 86/* 87 * Boot programs can patch this at run-time to change the behavior 88 * of bootp/dhcp. 89 */ 90int bootp_flags; 91 92static void 93bootp_addvend(u_char *area) 94{ 95#ifdef SUPPORT_DHCP 96 char vci[64]; 97 int vcilen; 98 99 *area++ = TAG_PARAM_REQ; 100 *area++ = 6; 101 *area++ = TAG_SUBNET_MASK; 102 *area++ = TAG_GATEWAY; 103 *area++ = TAG_HOSTNAME; 104 *area++ = TAG_DOMAINNAME; 105 *area++ = TAG_ROOTPATH; 106 *area++ = TAG_SWAPSERVER; 107 108 /* Insert a NetBSD Vendor Class Identifier option. */ 109 sprintf(vci, "NetBSD:%s:libsa", MACHINE); 110 vcilen = strlen(vci); 111 *area++ = TAG_CLASSID; 112 *area++ = vcilen; 113 (void)memcpy(area, vci, vcilen); 114 area += vcilen; 115#endif 116 *area = TAG_END; 117} 118 119/* Fetch required bootp information */ 120void 121bootp(int sock) 122{ 123 struct iodesc *d; 124 struct bootp *bp; 125 struct { 126 u_char header[UDP_TOTAL_HEADER_SIZE]; 127 struct bootp wbootp; 128 } wbuf; 129 struct { 130 u_char header[UDP_TOTAL_HEADER_SIZE]; 131 struct bootp rbootp; 132 } rbuf; 133 unsigned int index; 134 135#ifdef BOOTP_DEBUG 136 if (debug) 137 printf("bootp: socket=%d\n", sock); 138#endif 139 if (!bot) 140 bot = getsecs(); 141 142 if (!(d = socktodesc(sock))) { 143 printf("bootp: bad socket. %d\n", sock); 144 return; 145 } 146#ifdef BOOTP_DEBUG 147 if (debug) 148 printf("bootp: d=%lx\n", (long)d); 149#endif 150 151 bp = &wbuf.wbootp; 152 (void)memset(bp, 0, sizeof(*bp)); 153 154 bp->bp_op = BOOTREQUEST; 155 bp->bp_htype = 1; /* 10Mb Ethernet (48 bits) */ 156 bp->bp_hlen = 6; 157 bp->bp_xid = htonl(d->xid); 158 MACPY(d->myea, bp->bp_chaddr); 159 (void)strncpy((char *)bp->bp_file, bootfile, sizeof(bp->bp_file)); 160 (void)memcpy(bp->bp_vend, vm_rfc1048, sizeof(vm_rfc1048)); 161 index = 4; 162#ifdef SUPPORT_DHCP 163 bp->bp_vend[index++] = TAG_DHCP_MSGTYPE; 164 bp->bp_vend[index++] = 1; 165 bp->bp_vend[index++] = DHCPDISCOVER; 166#endif 167 bootp_addvend(&bp->bp_vend[index]); 168 169 d->myip.s_addr = INADDR_ANY; 170 d->myport = htons(IPPORT_BOOTPC); 171 d->destip.s_addr = INADDR_BROADCAST; 172 d->destport = htons(IPPORT_BOOTPS); 173 174#ifdef SUPPORT_DHCP 175 expected_dhcpmsgtype = DHCPOFFER; 176 dhcp_ok = 0; 177#endif 178 179 if (sendrecv(d, 180 bootpsend, bp, sizeof(*bp), 181 bootprecv, &rbuf.rbootp, sizeof(rbuf.rbootp)) 182 == -1) { 183 printf("bootp: no reply\n"); 184 return; 185 } 186 187#ifdef SUPPORT_DHCP 188 if (dhcp_ok) { 189 u_int32_t leasetime; 190 index = 6; 191 bp->bp_vend[index++] = DHCPREQUEST; 192 bp->bp_vend[index++] = TAG_REQ_ADDR; 193 bp->bp_vend[index++] = 4; 194 (void)memcpy(&bp->bp_vend[9], &rbuf.rbootp.bp_yiaddr, 4); 195 index += 4; 196 bp->bp_vend[index++] = TAG_SERVERID; 197 bp->bp_vend[index++] = 4; 198 (void)memcpy(&bp->bp_vend[index], &dhcp_serverip.s_addr, 4); 199 index += 4; 200 bp->bp_vend[index++] = TAG_LEASETIME; 201 bp->bp_vend[index++] = 4; 202 leasetime = htonl(300); 203 (void)memcpy(&bp->bp_vend[index], &leasetime, 4); 204 index += 4; 205 bootp_addvend(&bp->bp_vend[index]); 206 207 expected_dhcpmsgtype = DHCPACK; 208 209 if (sendrecv(d, 210 bootpsend, bp, sizeof(*bp), 211 bootprecv, &rbuf.rbootp, sizeof(rbuf.rbootp)) 212 == -1) { 213 printf("DHCPREQUEST failed\n"); 214 return; 215 } 216 } 217#endif 218 219 myip = d->myip = rbuf.rbootp.bp_yiaddr; 220 servip = rbuf.rbootp.bp_siaddr; 221 if (rootip.s_addr == INADDR_ANY) 222 rootip = servip; 223 (void)memcpy(bootfile, rbuf.rbootp.bp_file, sizeof(bootfile)); 224 bootfile[sizeof(bootfile) - 1] = '\0'; 225 226 if (IN_CLASSA(myip.s_addr)) 227 nmask = IN_CLASSA_NET; 228 else if (IN_CLASSB(myip.s_addr)) 229 nmask = IN_CLASSB_NET; 230 else 231 nmask = IN_CLASSC_NET; 232#ifdef BOOTP_DEBUG 233 if (debug) 234 printf("'native netmask' is %s\n", intoa(nmask)); 235#endif 236 237 /* Get subnet (or natural net) mask */ 238 netmask = nmask; 239 if (smask) 240 netmask = smask; 241#ifdef BOOTP_DEBUG 242 if (debug) 243 printf("mask: %s\n", intoa(netmask)); 244#endif 245 246 /* We need a gateway if root is on a different net */ 247 if (!SAMENET(myip, rootip, netmask)) { 248#ifdef BOOTP_DEBUG 249 if (debug) 250 printf("need gateway for root ip\n"); 251#endif 252 } 253 254 /* Toss gateway if on a different net */ 255 if (!SAMENET(myip, gateip, netmask)) { 256#ifdef BOOTP_DEBUG 257 if (debug) 258 printf("gateway ip (%s) bad\n", inet_ntoa(gateip)); 259#endif 260 gateip.s_addr = 0; 261 } 262 263#ifdef BOOTP_DEBUG 264 if (debug) { 265 printf("client addr: %s\n", inet_ntoa(myip)); 266 if (smask) 267 printf("subnet mask: %s\n", intoa(smask)); 268 if (gateip.s_addr != 0) 269 printf("net gateway: %s\n", inet_ntoa(gateip)); 270 printf("server addr: %s\n", inet_ntoa(rootip)); 271 if (rootpath[0] != '\0') 272 printf("server path: %s\n", rootpath); 273 if (bootfile[0] != '\0') 274 printf("file name: %s\n", bootfile); 275 } 276#endif 277 278 /* Bump xid so next request will be unique. */ 279 ++d->xid; 280} 281 282/* Transmit a bootp request */ 283static ssize_t 284bootpsend(struct iodesc *d, void *pkt, size_t len) 285{ 286 struct bootp *bp; 287 288#ifdef BOOTP_DEBUG 289 if (debug) 290 printf("bootpsend: d=%lx called.\n", (long)d); 291#endif 292 293 bp = pkt; 294 bp->bp_secs = htons((u_short)(getsecs() - bot)); 295 296#ifdef BOOTP_DEBUG 297 if (debug) 298 printf("bootpsend: calling sendudp\n"); 299#endif 300 301 return sendudp(d, pkt, len); 302} 303 304static ssize_t 305bootprecv(struct iodesc *d, void *pkt, size_t len, saseconds_t tleft) 306{ 307 ssize_t n; 308 struct bootp *bp; 309 310#ifdef BOOTP_DEBUGx 311 if (debug) 312 printf("bootp_recvoffer: called\n"); 313#endif 314 315 n = readudp(d, pkt, len, tleft); 316 if (n == -1 || (size_t)n < sizeof(struct bootp) - BOOTP_VENDSIZE) 317 goto bad; 318 319 bp = (struct bootp *)pkt; 320 321#ifdef BOOTP_DEBUG 322 if (debug) 323 printf("bootprecv: checked. bp = 0x%lx, n = %d\n", 324 (long)bp, (int)n); 325#endif 326 if (bp->bp_xid != htonl(d->xid)) { 327#ifdef BOOTP_DEBUG 328 if (debug) { 329 printf("bootprecv: expected xid 0x%lx, got 0x%x\n", 330 d->xid, ntohl(bp->bp_xid)); 331 } 332#endif 333 goto bad; 334 } 335 336 /* protect against bogus addresses sent by DHCP servers */ 337 if (bp->bp_yiaddr.s_addr == INADDR_ANY || 338 bp->bp_yiaddr.s_addr == INADDR_BROADCAST) 339 goto bad; 340 341#ifdef BOOTP_DEBUG 342 if (debug) 343 printf("bootprecv: got one!\n"); 344#endif 345 346 /* Suck out vendor info */ 347 if (memcmp(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048)) == 0) { 348 if (vend_rfc1048(bp->bp_vend, sizeof(bp->bp_vend)) != 0) 349 goto bad; 350 } 351#ifdef BOOTP_VEND_CMU 352 else if (memcmp(vm_cmu, bp->bp_vend, sizeof(vm_cmu)) == 0) 353 vend_cmu(bp->bp_vend); 354#endif 355 else 356 printf("bootprecv: unknown vendor 0x%lx\n", (long)bp->bp_vend); 357 358 return n; 359bad: 360 errno = 0; 361 return -1; 362} 363 364static int 365vend_rfc1048(u_char *cp, u_int len) 366{ 367 u_char *ep; 368 int size; 369 u_char tag; 370 371#ifdef BOOTP_DEBUG 372 if (debug) 373 printf("vend_rfc1048 bootp info. len=%d\n", len); 374#endif 375 ep = cp + len; 376 377 /* Step over magic cookie */ 378 cp += sizeof(int); 379 380 while (cp < ep) { 381 tag = *cp++; 382 size = *cp++; 383 if (tag == TAG_END) 384 break; 385 386 if (tag == TAG_SUBNET_MASK && size >= sizeof(smask)) { 387 (void)memcpy(&smask, cp, sizeof(smask)); 388 } 389 if (tag == TAG_GATEWAY && size >= sizeof(gateip.s_addr)) { 390 (void)memcpy(&gateip.s_addr, cp, sizeof(gateip.s_addr)); 391 } 392 if (tag == TAG_SWAPSERVER && size >= sizeof(rootip.s_addr)) { 393 /* let it override bp_siaddr */ 394 (void)memcpy(&rootip.s_addr, cp, sizeof(rootip.s_addr)); 395 } 396 if (tag == TAG_ROOTPATH && size < sizeof(rootpath)) { 397 strncpy(rootpath, (char *)cp, sizeof(rootpath)); 398 rootpath[size] = '\0'; 399 } 400 if (tag == TAG_HOSTNAME && size < sizeof(hostname)) { 401 strncpy(hostname, (char *)cp, sizeof(hostname)); 402 hostname[size] = '\0'; 403 } 404#ifdef SUPPORT_DHCP 405 if (tag == TAG_DHCP_MSGTYPE) { 406 if (*cp != expected_dhcpmsgtype) 407 return -1; 408 dhcp_ok = 1; 409 } 410 if (tag == TAG_SERVERID && 411 size >= sizeof(dhcp_serverip.s_addr)) 412 { 413 (void)memcpy(&dhcp_serverip.s_addr, cp, 414 sizeof(dhcp_serverip.s_addr)); 415 } 416#endif 417#ifdef SUPPORT_LINUX 418 if (tag == TAG_LINUX_CMDLINE && size < sizeof(linuxcmdline)) { 419 strncpy(linuxcmdline, (char *)cp, sizeof(linuxcmdline)); 420 linuxcmdline[size] = '\0'; 421 } 422#endif 423 cp += size; 424 } 425 return 0; 426} 427 428#ifdef BOOTP_VEND_CMU 429static void 430vend_cmu(u_char *cp) 431{ 432 struct cmu_vend *vp; 433 434#ifdef BOOTP_DEBUG 435 if (debug) 436 printf("vend_cmu bootp info.\n"); 437#endif 438 vp = (struct cmu_vend *)cp; 439 440 if (vp->v_smask.s_addr != 0) { 441 smask = vp->v_smask.s_addr; 442 } 443 if (vp->v_dgate.s_addr != 0) { 444 gateip = vp->v_dgate; 445 } 446} 447#endif 448