bootp.c revision 1.17
1 /* $NetBSD: bootp.c,v 1.17 1999/11/11 20:23:16 thorpej 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 "stand.h" 47 #include "net.h" 48 #include "netif.h" 49 #include "bootp.h" 50 51 struct in_addr servip; 52 #ifdef SUPPORT_LINUX 53 char linuxcmdline[256]; 54 #ifndef TAG_LINUX_CMDLINE 55 #define TAG_LINUX_CMDLINE 123 56 #endif 57 #endif 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) 181 rootip = servip; 182 bcopy(rbuf.rbootp.bp_file, bootfile, sizeof(bootfile)); 183 bootfile[sizeof(bootfile) - 1] = '\0'; 184 185 if (IN_CLASSA(myip.s_addr)) 186 nmask = IN_CLASSA_NET; 187 else if (IN_CLASSB(myip.s_addr)) 188 nmask = IN_CLASSB_NET; 189 else 190 nmask = IN_CLASSC_NET; 191 #ifdef BOOTP_DEBUG 192 if (debug) 193 printf("'native netmask' is %s\n", intoa(nmask)); 194 #endif 195 196 /* Check subnet mask against net mask; toss if bogus */ 197 if ((nmask & smask) != nmask) { 198 #ifdef BOOTP_DEBUG 199 if (debug) 200 printf("subnet mask (%s) bad\n", intoa(smask)); 201 #endif 202 smask = 0; 203 } 204 205 /* Get subnet (or natural net) mask */ 206 netmask = nmask; 207 if (smask) 208 netmask = smask; 209 #ifdef BOOTP_DEBUG 210 if (debug) 211 printf("mask: %s\n", intoa(netmask)); 212 #endif 213 214 /* We need a gateway if root is on a different net */ 215 if (!SAMENET(myip, rootip, netmask)) { 216 #ifdef BOOTP_DEBUG 217 if (debug) 218 printf("need gateway for root ip\n"); 219 #endif 220 } 221 222 /* Toss gateway if on a different net */ 223 if (!SAMENET(myip, gateip, netmask)) { 224 #ifdef BOOTP_DEBUG 225 if (debug) 226 printf("gateway ip (%s) bad\n", inet_ntoa(gateip)); 227 #endif 228 gateip.s_addr = 0; 229 } 230 231 /* Bump xid so next request will be unique. */ 232 ++d->xid; 233 } 234 235 /* Transmit a bootp request */ 236 static ssize_t 237 bootpsend(d, pkt, len) 238 register struct iodesc *d; 239 register void *pkt; 240 register size_t len; 241 { 242 register struct bootp *bp; 243 244 #ifdef BOOTP_DEBUG 245 if (debug) 246 printf("bootpsend: d=%lx called.\n", (long)d); 247 #endif 248 249 bp = pkt; 250 bp->bp_secs = htons((u_short)(getsecs() - bot)); 251 252 #ifdef BOOTP_DEBUG 253 if (debug) 254 printf("bootpsend: calling sendudp\n"); 255 #endif 256 257 return (sendudp(d, pkt, len)); 258 } 259 260 static ssize_t 261 bootprecv(d, pkt, len, tleft) 262 register struct iodesc *d; 263 register void *pkt; 264 register size_t len; 265 time_t tleft; 266 { 267 register ssize_t n; 268 register struct bootp *bp; 269 270 #ifdef BOOTP_DEBUGx 271 if (debug) 272 printf("bootp_recvoffer: called\n"); 273 #endif 274 275 n = readudp(d, pkt, len, tleft); 276 if (n == -1 || n < sizeof(struct bootp) - BOOTP_VENDSIZE) 277 goto bad; 278 279 bp = (struct bootp *)pkt; 280 281 #ifdef BOOTP_DEBUG 282 if (debug) 283 printf("bootprecv: checked. bp = 0x%lx, n = %d\n", 284 (long)bp, (int)n); 285 #endif 286 if (bp->bp_xid != htonl(d->xid)) { 287 #ifdef BOOTP_DEBUG 288 if (debug) { 289 printf("bootprecv: expected xid 0x%lx, got 0x%x\n", 290 d->xid, ntohl(bp->bp_xid)); 291 } 292 #endif 293 goto bad; 294 } 295 296 /* protect against bogus addresses sent by DHCP servers */ 297 if (bp->bp_yiaddr.s_addr == INADDR_ANY || 298 bp->bp_yiaddr.s_addr == INADDR_BROADCAST) 299 goto bad; 300 301 #ifdef BOOTP_DEBUG 302 if (debug) 303 printf("bootprecv: got one!\n"); 304 #endif 305 306 /* Suck out vendor info */ 307 if (bcmp(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048)) == 0) { 308 if (vend_rfc1048(bp->bp_vend, sizeof(bp->bp_vend)) != 0) 309 goto bad; 310 } 311 #ifdef BOOTP_VEND_CMU 312 else if (bcmp(vm_cmu, bp->bp_vend, sizeof(vm_cmu)) == 0) 313 vend_cmu(bp->bp_vend); 314 #endif 315 else 316 printf("bootprecv: unknown vendor 0x%lx\n", (long)bp->bp_vend); 317 318 return (n); 319 bad: 320 errno = 0; 321 return (-1); 322 } 323 324 static int 325 vend_rfc1048(cp, len) 326 register u_char *cp; 327 u_int len; 328 { 329 register u_char *ep; 330 register int size; 331 register u_char tag; 332 333 #ifdef BOOTP_DEBUG 334 if (debug) 335 printf("vend_rfc1048 bootp info. len=%d\n", len); 336 #endif 337 ep = cp + len; 338 339 /* Step over magic cookie */ 340 cp += sizeof(int); 341 342 while (cp < ep) { 343 tag = *cp++; 344 size = *cp++; 345 if (tag == TAG_END) 346 break; 347 348 if (tag == TAG_SUBNET_MASK) { 349 bcopy(cp, &smask, sizeof(smask)); 350 } 351 if (tag == TAG_GATEWAY) { 352 bcopy(cp, &gateip.s_addr, sizeof(gateip.s_addr)); 353 } 354 if (tag == TAG_SWAPSERVER) { 355 /* let it override bp_siaddr */ 356 bcopy(cp, &rootip.s_addr, sizeof(rootip.s_addr)); 357 } 358 if (tag == TAG_ROOTPATH) { 359 strncpy(rootpath, (char *)cp, sizeof(rootpath)); 360 rootpath[size] = '\0'; 361 } 362 if (tag == TAG_HOSTNAME) { 363 strncpy(hostname, (char *)cp, sizeof(hostname)); 364 hostname[size] = '\0'; 365 } 366 #ifdef SUPPORT_DHCP 367 if (tag == TAG_DHCP_MSGTYPE) { 368 if (*cp != expected_dhcpmsgtype) 369 return (-1); 370 dhcp_ok = 1; 371 } 372 if (tag == TAG_SERVERID) { 373 bcopy(cp, &dhcp_serverip.s_addr, 374 sizeof(dhcp_serverip.s_addr)); 375 } 376 #endif 377 #ifdef SUPPORT_LINUX 378 if (tag == TAG_LINUX_CMDLINE) { 379 strncpy(linuxcmdline, (char *)cp, sizeof(linuxcmdline)); 380 linuxcmdline[size] = '\0'; 381 } 382 #endif 383 cp += size; 384 } 385 return (0); 386 } 387 388 #ifdef BOOTP_VEND_CMU 389 static void 390 vend_cmu(cp) 391 u_char *cp; 392 { 393 register struct cmu_vend *vp; 394 395 #ifdef BOOTP_DEBUG 396 if (debug) 397 printf("vend_cmu bootp info.\n"); 398 #endif 399 vp = (struct cmu_vend *)cp; 400 401 if (vp->v_smask.s_addr != 0) { 402 smask = vp->v_smask.s_addr; 403 } 404 if (vp->v_dgate.s_addr != 0) { 405 gateip = vp->v_dgate; 406 } 407 } 408 #endif 409
Indexes created Tue Sep 30 11:09:46 GMT 2025