1 /* $OpenBSD: bootp.c,v 1.12 2006/02/06 17:37:28 jmc Exp $ */ 2 /* $NetBSD: bootp.c,v 1.10 1996/10/13 02:28:59 christos Exp $ */ 3 4 /* 5 * Copyright (c) 1992 Regents of the University of California. 6 * All rights reserved. 7 * 8 * This software was developed by the Computer Systems Engineering group 9 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 10 * contributed to Berkeley. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Lawrence Berkeley Laboratory and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#) Header: bootp.c,v 1.4 93/09/11 03:13:51 leres Exp (LBL) 41 */ 42 43 #include <sys/types.h> 44 #include <sys/socket.h> 45 #include <netinet/in.h> 46 #include <netinet/in_systm.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(struct iodesc *, void *, size_t); 62 static ssize_t bootprecv(struct iodesc *, void *, size_t, time_t); 63 static void vend_cmu(u_char *); 64 static void vend_rfc1048(u_char *, u_int); 65 66 /* Fetch required bootp information */ 67 void 68 bootp(int sock) 69 { 70 struct iodesc *d; 71 struct bootp *bp; 72 struct { 73 u_char header[HEADER_SIZE]; 74 struct bootp wbootp; 75 } wbuf; 76 struct { 77 u_char header[HEADER_SIZE]; 78 struct bootp rbootp; 79 } rbuf; 80 81 #ifdef BOOTP_DEBUG 82 if (debug) 83 printf("bootp: socket=%d\n", sock); 84 #endif 85 if (!bot) 86 bot = getsecs(); 87 88 if (!(d = socktodesc(sock))) { 89 printf("bootp: bad socket. %d\n", sock); 90 return; 91 } 92 #ifdef BOOTP_DEBUG 93 if (debug) 94 printf("bootp: d=%x\n", (u_int)d); 95 #endif 96 97 bp = &wbuf.wbootp; 98 bzero(bp, sizeof(*bp)); 99 100 bp->bp_op = BOOTREQUEST; 101 bp->bp_htype = HTYPE_ETHERNET; /* 10Mb Ethernet (48 bits) */ 102 bp->bp_hlen = 6; 103 bp->bp_xid = htonl(d->xid); 104 MACPY(d->myea, bp->bp_chaddr); 105 bzero(bp->bp_file, sizeof(bp->bp_file)); 106 bcopy(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048)); 107 108 d->myip = myip; 109 d->myport = htons(IPPORT_BOOTPC); 110 d->destip.s_addr = INADDR_BROADCAST; 111 d->destport = htons(IPPORT_BOOTPS); 112 113 (void)sendrecv(d, 114 bootpsend, bp, sizeof(*bp), 115 bootprecv, &rbuf.rbootp, sizeof(rbuf.rbootp)); 116 117 /* Bump xid so next request will be unique. */ 118 ++d->xid; 119 } 120 121 /* Transmit a bootp request */ 122 static ssize_t 123 bootpsend(struct iodesc *d, void *pkt, size_t len) 124 { 125 struct bootp *bp; 126 127 #ifdef BOOTP_DEBUG 128 if (debug) 129 printf("bootpsend: d=%x called.\n", (u_int)d); 130 #endif 131 132 bp = pkt; 133 bp->bp_secs = htons((u_short)(getsecs() - bot)); 134 135 #ifdef BOOTP_DEBUG 136 if (debug) 137 printf("bootpsend: calling sendudp\n"); 138 #endif 139 140 return (sendudp(d, pkt, len)); 141 } 142 143 /* Returns 0 if this is the packet we're waiting for else -1 (and errno == 0) */ 144 static ssize_t 145 bootprecv(struct iodesc *d, void *pkt, size_t len, time_t tleft) 146 { 147 ssize_t n; 148 struct bootp *bp; 149 150 #ifdef BOOTP_DEBUG 151 if (debug) 152 printf("bootprecv: called\n"); 153 #endif 154 155 n = readudp(d, pkt, len, tleft); 156 if (n < 0 || (size_t)n < sizeof(struct bootp)) 157 goto bad; 158 159 bp = (struct bootp *)pkt; 160 161 #ifdef BOOTP_DEBUG 162 if (debug) 163 printf("bootprecv: checked. bp = 0x%x, n = %d\n", 164 (unsigned)bp, n); 165 #endif 166 if (bp->bp_xid != htonl(d->xid)) { 167 #ifdef BOOTP_DEBUG 168 if (debug) { 169 printf("bootprecv: expected xid 0x%lx, got 0x%lx\n", 170 d->xid, ntohl(bp->bp_xid)); 171 } 172 #endif 173 goto bad; 174 } 175 176 #ifdef BOOTP_DEBUG 177 if (debug) 178 printf("bootprecv: got one!\n"); 179 #endif 180 181 /* Pick up our ip address (and natural netmask) */ 182 myip = d->myip = bp->bp_yiaddr; 183 #ifdef BOOTP_DEBUG 184 if (debug) 185 printf("our ip address is %s\n", inet_ntoa(d->myip)); 186 #endif 187 if (IN_CLASSA(d->myip.s_addr)) 188 nmask = IN_CLASSA_NET; 189 else if (IN_CLASSB(d->myip.s_addr)) 190 nmask = IN_CLASSB_NET; 191 else 192 nmask = IN_CLASSC_NET; 193 #ifdef BOOTP_DEBUG 194 if (debug) 195 printf("'native netmask' is %s\n", intoa(nmask)); 196 #endif 197 198 /* Pick up root or swap server address and file spec. */ 199 if (bp->bp_siaddr.s_addr != 0) 200 rootip = bp->bp_siaddr; 201 if (bp->bp_file[0] != '\0') { 202 strncpy(bootfile, (char *)bp->bp_file, sizeof(bootfile)); 203 bootfile[sizeof(bootfile) - 1] = '\0'; 204 } 205 206 /* Suck out vendor info */ 207 if (bcmp(vm_cmu, bp->bp_vend, sizeof(vm_cmu)) == 0) 208 vend_cmu(bp->bp_vend); 209 else if (bcmp(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048)) == 0) 210 vend_rfc1048(bp->bp_vend, sizeof(bp->bp_vend)); 211 else 212 printf("bootprecv: unknown vendor 0x%lx\n", (long)bp->bp_vend); 213 214 /* Check subnet mask against net mask; toss if bogus */ 215 if ((nmask & smask) != nmask) { 216 #ifdef BOOTP_DEBUG 217 if (debug) 218 printf("subnet mask (%s) bad\n", intoa(smask)); 219 #endif 220 smask = 0; 221 } 222 223 /* Get subnet (or natural net) mask */ 224 netmask = nmask; 225 if (smask) 226 netmask = smask; 227 #ifdef BOOTP_DEBUG 228 if (debug) 229 printf("mask: %s\n", intoa(netmask)); 230 #endif 231 232 /* We need a gateway if root or swap is on a different net */ 233 if (!SAMENET(d->myip, rootip, netmask)) { 234 #ifdef BOOTP_DEBUG 235 if (debug) 236 printf("need gateway for root ip\n"); 237 #endif 238 } 239 240 if (!SAMENET(d->myip, swapip, netmask)) { 241 #ifdef BOOTP_DEBUG 242 if (debug) 243 printf("need gateway for swap ip\n"); 244 #endif 245 } 246 247 /* Toss gateway if on a different net */ 248 if (!SAMENET(d->myip, gateip, netmask)) { 249 #ifdef BOOTP_DEBUG 250 if (debug) 251 printf("gateway ip (%s) bad\n", inet_ntoa(gateip)); 252 #endif 253 gateip.s_addr = 0; 254 } 255 256 return (n); 257 258 bad: 259 errno = 0; 260 return (-1); 261 } 262 263 static void 264 vend_cmu(u_char *cp) 265 { 266 struct cmu_vend *vp; 267 268 #ifdef BOOTP_DEBUG 269 if (debug) 270 printf("vend_cmu bootp info.\n"); 271 #endif 272 vp = (struct cmu_vend *)cp; 273 274 if (vp->v_smask.s_addr != 0) 275 smask = vp->v_smask.s_addr; 276 if (vp->v_dgate.s_addr != 0) 277 gateip = vp->v_dgate; 278 } 279 280 static void 281 vend_rfc1048(u_char *cp, u_int len) 282 { 283 u_char *ep; 284 int size; 285 u_char tag; 286 287 #ifdef BOOTP_DEBUG 288 if (debug) 289 printf("vend_rfc1048 bootp info. len=%d\n", len); 290 #endif 291 ep = cp + len; 292 293 /* Step over magic cookie */ 294 cp += sizeof(int); 295 296 while (cp < ep) { 297 tag = *cp++; 298 size = *cp++; 299 if (tag == TAG_END) 300 break; 301 302 if (tag == TAG_SUBNET_MASK) 303 bcopy(cp, &smask, sizeof(smask)); 304 if (tag == TAG_GATEWAY) 305 bcopy(cp, &gateip.s_addr, sizeof(gateip.s_addr)); 306 if (tag == TAG_SWAPSERVER) 307 bcopy(cp, &swapip.s_addr, sizeof(swapip.s_addr)); 308 if (tag == TAG_DOMAIN_SERVER) 309 bcopy(cp, &nameip.s_addr, sizeof(nameip.s_addr)); 310 if (tag == TAG_ROOTPATH) { 311 strncpy(rootpath, (char *)cp, sizeof(rootpath)); 312 rootpath[size] = '\0'; 313 } 314 if (tag == TAG_HOSTNAME) { 315 strncpy(hostname, (char *)cp, sizeof(hostname)); 316 hostname[size] = '\0'; 317 } 318 if (tag == TAG_DOMAINNAME) { 319 strncpy(domainname, (char *)cp, sizeof(domainname)); 320 domainname[size] = '\0'; 321 } 322 cp += size; 323 } 324 } 325