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  * $FreeBSD: src/lib/libstand/bootp.c,v 1.1.1.1.6.2 2000/09/20 18:37:25 ps Exp $
  41  * $DragonFly: src/lib/libstand/bootp.c,v 1.3 2004/08/20 00:43:00 joerg Exp $
  42  */
  43
  44 #include <sys/param.h>
  45 #include <netinet/in.h>
  46 #include <netinet/in_systm.h>
  47
  48 #include <string.h>
  49
  50 #define BOOTP_DEBUGxx
  51 #define SUPPORT_DHCP
  52
  53 #include "stand.h"
  54 #include "net.h"
  55 #include "netif.h"
  56 #include "bootp.h"
  57
  58
  59 struct in_addr servip;
  60
  61 static n_long   nmask, smask;
  62
  63 static time_t   bot;
  64
  65 static  char vm_rfc1048[4] = VM_RFC1048;
  66 #ifdef BOOTP_VEND_CMU
  67 static  char vm_cmu[4] = VM_CMU;
  68 #endif
  69
  70 /* Local forwards */
  71 static  ssize_t bootpsend(struct iodesc *, void *, size_t);
  72 static  ssize_t bootprecv(struct iodesc *, void *, size_t, time_t);
  73 static  int vend_rfc1048(u_char *, u_int);
  74 #ifdef BOOTP_VEND_CMU
  75 static  void vend_cmu(u_char *);
  76 #endif
  77
  78 #ifdef SUPPORT_DHCP
  79 static char expected_dhcpmsgtype = -1, dhcp_ok;
  80 struct in_addr dhcp_serverip;
  81 #endif
  82
  83 /* Fetch required bootp infomation */
  84 void
  85 bootp(sock, flag)
  86         int sock;
  87         int flag;
  88 {
  89         struct iodesc *d;
  90         register struct bootp *bp;
  91         struct {
  92                 u_char header[HEADER_SIZE];
  93                 struct bootp wbootp;
  94         } wbuf;
  95         struct {
  96                 u_char header[HEADER_SIZE];
  97                 struct bootp rbootp;
  98         } rbuf;
  99
 100 #ifdef BOOTP_DEBUG
 101         if (debug)
 102                 printf("bootp: socket=%d\n", sock);
 103 #endif
 104         if (!bot)
 105                 bot = getsecs();
 106
 107         if (!(d = socktodesc(sock))) {
 108                 printf("bootp: bad socket. %d\n", sock);
 109                 return;
 110         }
 111 #ifdef BOOTP_DEBUG
 112         if (debug)
 113                 printf("bootp: d=%lx\n", (long)d);
 114 #endif
 115
 116         bp = &wbuf.wbootp;
 117         bzero(bp, sizeof(*bp));
 118
 119         bp->bp_op = BOOTREQUEST;
 120         bp->bp_htype = 1;               /* 10Mb Ethernet (48 bits) */
 121         bp->bp_hlen = 6;
 122         bp->bp_xid = htonl(d->xid);
 123         MACPY(d->myea, bp->bp_chaddr);
 124         strncpy(bp->bp_file, bootfile, sizeof(bp->bp_file));
 125         bcopy(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048));
 126 #ifdef SUPPORT_DHCP
 127         bp->bp_vend[4] = TAG_DHCP_MSGTYPE;
 128         bp->bp_vend[5] = 1;
 129         bp->bp_vend[6] = DHCPDISCOVER;
 130
 131         /*
 132          * If we are booting from PXE, we want to send the string
 133          * 'PXEClient' to the DHCP server so you have the option of
 134          * only responding to PXE aware dhcp requests.
 135          */
 136         if (flag & BOOTP_PXE) {
 137                 bp->bp_vend[7] = TAG_CLASSID;
 138                 bp->bp_vend[8] = 9;
 139                 bcopy("PXEClient", &bp->bp_vend[9], 9);
 140                 bp->bp_vend[18] = TAG_END;
 141         } else
 142                 bp->bp_vend[7] = TAG_END;
 143 #else
 144         bp->bp_vend[4] = TAG_END;
 145 #endif
 146
 147         d->myip.s_addr = INADDR_ANY;
 148         d->myport = htons(IPPORT_BOOTPC);
 149         d->destip.s_addr = INADDR_BROADCAST;
 150         d->destport = htons(IPPORT_BOOTPS);
 151
 152 #ifdef SUPPORT_DHCP
 153         expected_dhcpmsgtype = DHCPOFFER;
 154         dhcp_ok = 0;
 155 #endif
 156
 157         if(sendrecv(d,
 158                     bootpsend, bp, sizeof(*bp),
 159                     bootprecv, &rbuf.rbootp, sizeof(rbuf.rbootp))
 160            == -1) {
 161             printf("bootp: no reply\n");
 162             return;
 163         }
 164
 165 #ifdef SUPPORT_DHCP
 166         if(dhcp_ok) {
 167                 u_int32_t leasetime;
 168                 bp->bp_vend[6] = DHCPREQUEST;
 169                 bp->bp_vend[7] = TAG_REQ_ADDR;
 170                 bp->bp_vend[8] = 4;
 171                 bcopy(&rbuf.rbootp.bp_yiaddr, &bp->bp_vend[9], 4);
 172                 bp->bp_vend[13] = TAG_SERVERID;
 173                 bp->bp_vend[14] = 4;
 174                 bcopy(&dhcp_serverip.s_addr, &bp->bp_vend[15], 4);
 175                 bp->bp_vend[19] = TAG_LEASETIME;
 176                 bp->bp_vend[20] = 4;
 177                 leasetime = htonl(300);
 178                 bcopy(&leasetime, &bp->bp_vend[21], 4);
 179                 if (flag & BOOTP_PXE) {
 180                         bp->bp_vend[25] = TAG_CLASSID;
 181                         bp->bp_vend[26] = 9;
 182                         bcopy("PXEClient", &bp->bp_vend[27], 9);
 183                         bp->bp_vend[36] = TAG_END;
 184                 } else
 185                         bp->bp_vend[25] = TAG_END;
 186
 187                 expected_dhcpmsgtype = DHCPACK;
 188
 189                 if(sendrecv(d,
 190                             bootpsend, bp, sizeof(*bp),
 191                             bootprecv, &rbuf.rbootp, sizeof(rbuf.rbootp))
 192                    == -1) {
 193                         printf("DHCPREQUEST failed\n");
 194                         return;
 195                 }
 196         }
 197 #endif
 198
 199         myip = d->myip = rbuf.rbootp.bp_yiaddr;
 200         servip = rbuf.rbootp.bp_siaddr;
 201         if(rootip.s_addr == INADDR_ANY) rootip = servip;
 202         bcopy(rbuf.rbootp.bp_file, bootfile, sizeof(bootfile));
 203         bootfile[sizeof(bootfile) - 1] = '\0';
 204
 205         if (IN_CLASSA(ntohl(myip.s_addr)))
 206                 nmask = htonl(IN_CLASSA_NET);
 207         else if (IN_CLASSB(ntohl(myip.s_addr)))
 208                 nmask = htonl(IN_CLASSB_NET);
 209         else
 210                 nmask = htonl(IN_CLASSC_NET);
 211 #ifdef BOOTP_DEBUG
 212         if (debug)
 213                 printf("'native netmask' is %s\n", intoa(nmask));
 214 #endif
 215
 216         /* Check subnet mask against net mask; toss if bogus */
 217         if ((nmask & smask) != nmask) {
 218 #ifdef BOOTP_DEBUG
 219                 if (debug)
 220                         printf("subnet mask (%s) bad\n", intoa(smask));
 221 #endif
 222                 smask = 0;
 223         }
 224
 225         /* Get subnet (or natural net) mask */
 226         netmask = nmask;
 227         if (smask)
 228                 netmask = smask;
 229 #ifdef BOOTP_DEBUG
 230         if (debug)
 231                 printf("mask: %s\n", intoa(netmask));
 232 #endif
 233
 234         /* We need a gateway if root is on a different net */
 235         if (!SAMENET(myip, rootip, netmask)) {
 236 #ifdef BOOTP_DEBUG
 237                 if (debug)
 238                         printf("need gateway for root ip\n");
 239 #endif
 240         }
 241
 242         /* Toss gateway if on a different net */
 243         if (!SAMENET(myip, gateip, netmask)) {
 244 #ifdef BOOTP_DEBUG
 245                 if (debug)
 246                         printf("gateway ip (%s) bad\n", inet_ntoa(gateip));
 247 #endif
 248                 gateip.s_addr = 0;
 249         }
 250
 251         /* Bump xid so next request will be unique. */
 252         ++d->xid;
 253 }
 254
 255 /* Transmit a bootp request */
 256 static ssize_t
 257 bootpsend(d, pkt, len)
 258         register struct iodesc *d;
 259         register void *pkt;
 260         register size_t len;
 261 {
 262         register struct bootp *bp;
 263
 264 #ifdef BOOTP_DEBUG
 265         if (debug)
 266                 printf("bootpsend: d=%lx called.\n", (long)d);
 267 #endif
 268
 269         bp = pkt;
 270         bp->bp_secs = htons((u_short)(getsecs() - bot));
 271
 272 #ifdef BOOTP_DEBUG
 273         if (debug)
 274                 printf("bootpsend: calling sendudp\n");
 275 #endif
 276
 277         return (sendudp(d, pkt, len));
 278 }
 279
 280 static ssize_t
 281 bootprecv(d, pkt, len, tleft)
 282 register struct iodesc *d;
 283 register void *pkt;
 284 register size_t len;
 285 time_t tleft;
 286 {
 287         register ssize_t n;
 288         register struct bootp *bp;
 289
 290 #ifdef BOOTP_DEBUGx
 291         if (debug)
 292                 printf("bootp_recvoffer: called\n");
 293 #endif
 294
 295         n = readudp(d, pkt, len, tleft);
 296         if (n == -1 || n < sizeof(struct bootp) - BOOTP_VENDSIZE)
 297                 goto bad;
 298
 299         bp = (struct bootp *)pkt;
 300
 301 #ifdef BOOTP_DEBUG
 302         if (debug)
 303                 printf("bootprecv: checked.  bp = 0x%lx, n = %d\n",
 304                     (long)bp, (int)n);
 305 #endif
 306         if (bp->bp_xid != htonl(d->xid)) {
 307 #ifdef BOOTP_DEBUG
 308                 if (debug) {
 309                         printf("bootprecv: expected xid 0x%lx, got 0x%x\n",
 310                             d->xid, ntohl(bp->bp_xid));
 311                 }
 312 #endif
 313                 goto bad;
 314         }
 315
 316 #ifdef BOOTP_DEBUG
 317         if (debug)
 318                 printf("bootprecv: got one!\n");
 319 #endif
 320
 321         /* Suck out vendor info */
 322         if (bcmp(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048)) == 0) {
 323                 if(vend_rfc1048(bp->bp_vend, sizeof(bp->bp_vend)) != 0)
 324                     goto bad;
 325         }
 326 #ifdef BOOTP_VEND_CMU
 327         else if (bcmp(vm_cmu, bp->bp_vend, sizeof(vm_cmu)) == 0)
 328                 vend_cmu(bp->bp_vend);
 329 #endif
 330         else
 331                 printf("bootprecv: unknown vendor 0x%lx\n", (long)bp->bp_vend);
 332
 333         return(n);
 334 bad:
 335         errno = 0;
 336         return (-1);
 337 }
 338
 339 static int
 340 vend_rfc1048(cp, len)
 341         register u_char *cp;
 342         u_int len;
 343 {
 344         register u_char *ep;
 345         register int size;
 346         register u_char tag;
 347
 348 #ifdef BOOTP_DEBUG
 349         if (debug)
 350                 printf("vend_rfc1048 bootp info. len=%d\n", len);
 351 #endif
 352         ep = cp + len;
 353
 354         /* Step over magic cookie */
 355         cp += sizeof(int);
 356
 357         while (cp < ep) {
 358                 tag = *cp++;
 359                 size = *cp++;
 360                 if (tag == TAG_END)
 361                         break;
 362
 363                 if (tag == TAG_SUBNET_MASK) {
 364                         bcopy(cp, &smask, sizeof(smask));
 365                 }
 366                 if (tag == TAG_GATEWAY) {
 367                         bcopy(cp, &gateip.s_addr, sizeof(gateip.s_addr));
 368                 }
 369                 if (tag == TAG_SWAPSERVER) {
 370                         /* let it override bp_siaddr */
 371                         bcopy(cp, &rootip.s_addr, sizeof(swapip.s_addr));
 372                 }
 373                 if (tag == TAG_ROOTPATH) {
 374                         strncpy(rootpath, (char *)cp, sizeof(rootpath));
 375                         rootpath[size] = '\0';
 376                 }
 377                 if (tag == TAG_HOSTNAME) {
 378                         strncpy(hostname, (char *)cp, sizeof(hostname));
 379                         hostname[size] = '\0';
 380                 }
 381 #ifdef SUPPORT_DHCP
 382                 if (tag == TAG_DHCP_MSGTYPE) {
 383                         if(*cp != expected_dhcpmsgtype)
 384                             return(-1);
 385                         dhcp_ok = 1;
 386                 }
 387                 if (tag == TAG_SERVERID) {
 388                         bcopy(cp, &dhcp_serverip.s_addr,
 389                               sizeof(dhcp_serverip.s_addr));
 390                 }
 391 #endif
 392                 cp += size;
 393         }
 394         return(0);
 395 }
 396
 397 #ifdef BOOTP_VEND_CMU
 398 static void
 399 vend_cmu(cp)
 400         u_char *cp;
 401 {
 402         register struct cmu_vend *vp;
 403
 404 #ifdef BOOTP_DEBUG
 405         if (debug)
 406                 printf("vend_cmu bootp info.\n");
 407 #endif
 408         vp = (struct cmu_vend *)cp;
 409
 410         if (vp->v_smask.s_addr != 0) {
 411                 smask = vp->v_smask.s_addr;
 412         }
 413         if (vp->v_dgate.s_addr != 0) {
 414                 gateip = vp->v_dgate;
 415         }
 416 }
 417 #endif