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