lib/libstand/bootp.c

   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/cdefs.h>
  43 __FBSDID("$FreeBSD$");
  44
  45 #include <sys/types.h>
  46 #include <netinet/in.h>
  47 #include <netinet/in_systm.h>
  48
  49 #include <string.h>
  50
  51 #define BOOTP_DEBUGxx
  52 #define SUPPORT_DHCP
  53
  54 #include "stand.h"
  55 #include "net.h"
  56 #include "netif.h"
  57 #include "bootp.h"
  58
  59
  60 struct in_addr servip;
  61
  62 static n_long   nmask, smask;
  63
  64 static time_t   bot;
  65
  66 static  char vm_rfc1048[4] = VM_RFC1048;
  67 #ifdef BOOTP_VEND_CMU
  68 static  char vm_cmu[4] = VM_CMU;
  69 #endif
  70
  71 /* Local forwards */
  72 static  ssize_t bootpsend(struct iodesc *, void *, size_t);
  73 static  ssize_t bootprecv(struct iodesc *, void *, size_t, time_t);
  74 static  int vend_rfc1048(u_char *, u_int);
  75 #ifdef BOOTP_VEND_CMU
  76 static  void vend_cmu(u_char *);
  77 #endif
  78
  79 #ifdef SUPPORT_DHCP
  80 static char expected_dhcpmsgtype = -1, dhcp_ok;
  81 struct in_addr dhcp_serverip;
  82 #endif
  83
  84 /* Fetch required bootp infomation */
  85 void
  86 bootp(sock, flag)
  87         int sock;
  88         int flag;
  89 {
  90         struct iodesc *d;
  91         struct bootp *bp;
  92         struct {
  93                 u_char header[HEADER_SIZE];
  94                 struct bootp wbootp;
  95         } wbuf;
  96         struct {
  97                 u_char header[HEADER_SIZE];
  98                 struct bootp rbootp;
  99         } rbuf;
 100
 101 #ifdef BOOTP_DEBUG
 102         if (debug)
 103                 printf("bootp: socket=%d\n", sock);
 104 #endif
 105         if (!bot)
 106                 bot = getsecs();
 107
 108         if (!(d = socktodesc(sock))) {
 109                 printf("bootp: bad socket. %d\n", sock);
 110                 return;
 111         }
 112 #ifdef BOOTP_DEBUG
 113         if (debug)
 114                 printf("bootp: d=%lx\n", (long)d);
 115 #endif
 116
 117         bp = &wbuf.wbootp;
 118         bzero(bp, sizeof(*bp));
 119
 120         bp->bp_op = BOOTREQUEST;
 121         bp->bp_htype = 1;               /* 10Mb Ethernet (48 bits) */
 122         bp->bp_hlen = 6;
 123         bp->bp_xid = htonl(d->xid);
 124         MACPY(d->myea, bp->bp_chaddr);
 125         strncpy(bp->bp_file, bootfile, sizeof(bp->bp_file));
 126         bcopy(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048));
 127 #ifdef SUPPORT_DHCP
 128         bp->bp_vend[4] = TAG_DHCP_MSGTYPE;
 129         bp->bp_vend[5] = 1;
 130         bp->bp_vend[6] = DHCPDISCOVER;
 131
 132         /*
 133          * If we are booting from PXE, we want to send the string
 134          * 'PXEClient' to the DHCP server so you have the option of
 135          * only responding to PXE aware dhcp requests.
 136          */
 137         if (flag & BOOTP_PXE) {
 138                 bp->bp_vend[7] = TAG_CLASSID;
 139                 bp->bp_vend[8] = 9;
 140                 bcopy("PXEClient", &bp->bp_vend[9], 9);
 141                 bp->bp_vend[18] = TAG_END;
 142         } else
 143                 bp->bp_vend[7] = TAG_END;
 144 #else
 145         bp->bp_vend[4] = TAG_END;
 146 #endif
 147
 148         d->myip.s_addr = INADDR_ANY;
 149         d->myport = htons(IPPORT_BOOTPC);
 150         d->destip.s_addr = INADDR_BROADCAST;
 151         d->destport = htons(IPPORT_BOOTPS);
 152
 153 #ifdef SUPPORT_DHCP
 154         expected_dhcpmsgtype = DHCPOFFER;
 155         dhcp_ok = 0;
 156 #endif
 157
 158         if(sendrecv(d,
 159                     bootpsend, bp, sizeof(*bp),
 160                     bootprecv, &rbuf.rbootp, sizeof(rbuf.rbootp))
 161            == -1) {
 162             printf("bootp: no reply\n");
 163             return;
 164         }
 165
 166 #ifdef SUPPORT_DHCP
 167         if(dhcp_ok) {
 168                 u_int32_t leasetime;
 169                 bp->bp_vend[6] = DHCPREQUEST;
 170                 bp->bp_vend[7] = TAG_REQ_ADDR;
 171                 bp->bp_vend[8] = 4;
 172                 bcopy(&rbuf.rbootp.bp_yiaddr, &bp->bp_vend[9], 4);
 173                 bp->bp_vend[13] = TAG_SERVERID;
 174                 bp->bp_vend[14] = 4;
 175                 bcopy(&dhcp_serverip.s_addr, &bp->bp_vend[15], 4);
 176                 bp->bp_vend[19] = TAG_LEASETIME;
 177                 bp->bp_vend[20] = 4;
 178                 leasetime = htonl(300);
 179                 bcopy(&leasetime, &bp->bp_vend[21], 4);
 180                 if (flag & BOOTP_PXE) {
 181                         bp->bp_vend[25] = TAG_CLASSID;
 182                         bp->bp_vend[26] = 9;
 183                         bcopy("PXEClient", &bp->bp_vend[27], 9);
 184                         bp->bp_vend[36] = TAG_END;
 185                 } else
 186                         bp->bp_vend[25] = TAG_END;
 187
 188                 expected_dhcpmsgtype = DHCPACK;
 189
 190                 if(sendrecv(d,
 191                             bootpsend, bp, sizeof(*bp),
 192                             bootprecv, &rbuf.rbootp, sizeof(rbuf.rbootp))
 193                    == -1) {
 194                         printf("DHCPREQUEST failed\n");
 195                         return;
 196                 }
 197         }
 198 #endif
 199
 200         myip = d->myip = rbuf.rbootp.bp_yiaddr;
 201         servip = rbuf.rbootp.bp_siaddr;
 202         if(rootip.s_addr == INADDR_ANY) rootip = servip;
 203         bcopy(rbuf.rbootp.bp_file, bootfile, sizeof(bootfile));
 204         bootfile[sizeof(bootfile) - 1] = '\0';
 205
 206         if (IN_CLASSA(ntohl(myip.s_addr)))
 207                 nmask = htonl(IN_CLASSA_NET);
 208         else if (IN_CLASSB(ntohl(myip.s_addr)))
 209                 nmask = htonl(IN_CLASSB_NET);
 210         else
 211                 nmask = htonl(IN_CLASSC_NET);
 212 #ifdef BOOTP_DEBUG
 213         if (debug)
 214                 printf("'native netmask' is %s\n", intoa(nmask));
 215 #endif
 216
 217         /* Check subnet mask against net mask; toss if bogus */
 218         if ((nmask & smask) != nmask) {
 219 #ifdef BOOTP_DEBUG
 220                 if (debug)
 221                         printf("subnet mask (%s) bad\n", intoa(smask));
 222 #endif
 223                 smask = 0;
 224         }
 225
 226         /* Get subnet (or natural net) mask */
 227         netmask = nmask;
 228         if (smask)
 229                 netmask = smask;
 230 #ifdef BOOTP_DEBUG
 231         if (debug)
 232                 printf("mask: %s\n", intoa(netmask));
 233 #endif
 234
 235         /* We need a gateway if root is on a different net */
 236         if (!SAMENET(myip, rootip, netmask)) {
 237 #ifdef BOOTP_DEBUG
 238                 if (debug)
 239                         printf("need gateway for root ip\n");
 240 #endif
 241         }
 242
 243         /* Toss gateway if on a different net */
 244         if (!SAMENET(myip, gateip, netmask)) {
 245 #ifdef BOOTP_DEBUG
 246                 if (debug)
 247                         printf("gateway ip (%s) bad\n", inet_ntoa(gateip));
 248 #endif
 249                 gateip.s_addr = 0;
 250         }
 251
 252         /* Bump xid so next request will be unique. */
 253         ++d->xid;
 254 }
 255
 256 /* Transmit a bootp request */
 257 static ssize_t
 258 bootpsend(d, pkt, len)
 259         struct iodesc *d;
 260         void *pkt;
 261         size_t len;
 262 {
 263         struct bootp *bp;
 264
 265 #ifdef BOOTP_DEBUG
 266         if (debug)
 267                 printf("bootpsend: d=%lx called.\n", (long)d);
 268 #endif
 269
 270         bp = pkt;
 271         bp->bp_secs = htons((u_short)(getsecs() - bot));
 272
 273 #ifdef BOOTP_DEBUG
 274         if (debug)
 275                 printf("bootpsend: calling sendudp\n");
 276 #endif
 277
 278         return (sendudp(d, pkt, len));
 279 }
 280
 281 static ssize_t
 282 bootprecv(d, pkt, len, tleft)
 283 struct iodesc *d;
 284 void *pkt;
 285 size_t len;
 286 time_t tleft;
 287 {
 288         ssize_t n;
 289         struct bootp *bp;
 290
 291 #ifdef BOOTP_DEBUGx
 292         if (debug)
 293                 printf("bootp_recvoffer: called\n");
 294 #endif
 295
 296         n = readudp(d, pkt, len, tleft);
 297         if (n == -1 || n < sizeof(struct bootp) - BOOTP_VENDSIZE)
 298                 goto bad;
 299
 300         bp = (struct bootp *)pkt;
 301
 302 #ifdef BOOTP_DEBUG
 303         if (debug)
 304                 printf("bootprecv: checked.  bp = 0x%lx, n = %d\n",
 305                     (long)bp, (int)n);
 306 #endif
 307         if (bp->bp_xid != htonl(d->xid)) {
 308 #ifdef BOOTP_DEBUG
 309                 if (debug) {
 310                         printf("bootprecv: expected xid 0x%lx, got 0x%x\n",
 311                             d->xid, ntohl(bp->bp_xid));
 312                 }
 313 #endif
 314                 goto bad;
 315         }
 316
 317 #ifdef BOOTP_DEBUG
 318         if (debug)
 319                 printf("bootprecv: got one!\n");
 320 #endif
 321
 322         /* Suck out vendor info */
 323         if (bcmp(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048)) == 0) {
 324                 if(vend_rfc1048(bp->bp_vend, sizeof(bp->bp_vend)) != 0)
 325                     goto bad;
 326         }
 327 #ifdef BOOTP_VEND_CMU
 328         else if (bcmp(vm_cmu, bp->bp_vend, sizeof(vm_cmu)) == 0)
 329                 vend_cmu(bp->bp_vend);
 330 #endif
 331         else
 332                 printf("bootprecv: unknown vendor 0x%lx\n", (long)bp->bp_vend);
 333
 334         return(n);
 335 bad:
 336         errno = 0;
 337         return (-1);
 338 }
 339
 340 static int
 341 vend_rfc1048(cp, len)
 342         u_char *cp;
 343         u_int len;
 344 {
 345         u_char *ep;
 346         int size;
 347         u_char tag;
 348
 349 #ifdef BOOTP_DEBUG
 350         if (debug)
 351                 printf("vend_rfc1048 bootp info. len=%d\n", len);
 352 #endif
 353         ep = cp + len;
 354
 355         /* Step over magic cookie */
 356         cp += sizeof(int);
 357
 358         while (cp < ep) {
 359                 tag = *cp++;
 360                 size = *cp++;
 361                 if (tag == TAG_END)
 362                         break;
 363
 364                 if (tag == TAG_SUBNET_MASK) {
 365                         bcopy(cp, &smask, sizeof(smask));
 366                 }
 367                 if (tag == TAG_GATEWAY) {
 368                         bcopy(cp, &gateip.s_addr, sizeof(gateip.s_addr));
 369                 }
 370                 if (tag == TAG_SWAPSERVER) {
 371                         /* let it override bp_siaddr */
 372                         bcopy(cp, &rootip.s_addr, sizeof(swapip.s_addr));
 373                 }
 374                 if (tag == TAG_ROOTPATH) {
 375                         strncpy(rootpath, (char *)cp, sizeof(rootpath));
 376                         rootpath[size] = '\0';
 377                 }
 378                 if (tag == TAG_HOSTNAME) {
 379                         strncpy(hostname, (char *)cp, sizeof(hostname));
 380                         hostname[size] = '\0';
 381                 }
 382 #ifdef SUPPORT_DHCP
 383                 if (tag == TAG_DHCP_MSGTYPE) {
 384                         if(*cp != expected_dhcpmsgtype)
 385                             return(-1);
 386                         dhcp_ok = 1;
 387                 }
 388                 if (tag == TAG_SERVERID) {
 389                         bcopy(cp, &dhcp_serverip.s_addr,
 390                               sizeof(dhcp_serverip.s_addr));
 391                 }
 392 #endif
 393                 cp += size;
 394         }
 395         return(0);
 396 }
 397
 398 #ifdef BOOTP_VEND_CMU
 399 static void
 400 vend_cmu(cp)
 401         u_char *cp;
 402 {
 403         struct cmu_vend *vp;
 404
 405 #ifdef BOOTP_DEBUG
 406         if (debug)
 407                 printf("vend_cmu bootp info.\n");
 408 #endif
 409         vp = (struct cmu_vend *)cp;
 410
 411         if (vp->v_smask.s_addr != 0) {
 412                 smask = vp->v_smask.s_addr;
 413         }
 414         if (vp->v_dgate.s_addr != 0) {
 415                 gateip = vp->v_dgate;
 416         }
 417 }
 418 #endif