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 1.5 2005/12/11 03:27:26 swildner 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(int sock, int flag)
  86 {
  87         struct iodesc *d;
  88         struct bootp *bp;
  89         struct {
  90                 u_char header[HEADER_SIZE];
  91                 struct bootp wbootp;
  92         } wbuf;
  93         struct {
  94                 u_char header[HEADER_SIZE];
  95                 struct bootp rbootp;
  96         } rbuf;
  97
  98 #ifdef BOOTP_DEBUG
  99         if (debug)
 100                 printf("bootp: socket=%d\n", sock);
 101 #endif
 102         if (!bot)
 103                 bot = getsecs();
 104
 105         if (!(d = socktodesc(sock))) {
 106                 printf("bootp: bad socket. %d\n", sock);
 107                 return;
 108         }
 109 #ifdef BOOTP_DEBUG
 110         if (debug)
 111                 printf("bootp: d=%lx\n", (long)d);
 112 #endif
 113
 114         bp = &wbuf.wbootp;
 115         bzero(bp, sizeof(*bp));
 116
 117         bp->bp_op = BOOTREQUEST;
 118         bp->bp_htype = 1;               /* 10Mb Ethernet (48 bits) */
 119         bp->bp_hlen = 6;
 120         bp->bp_xid = htonl(d->xid);
 121         MACPY(d->myea, bp->bp_chaddr);
 122         strncpy(bp->bp_file, bootfile, sizeof(bp->bp_file));
 123         bcopy(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048));
 124 #ifdef SUPPORT_DHCP
 125         bp->bp_vend[4] = TAG_DHCP_MSGTYPE;
 126         bp->bp_vend[5] = 1;
 127         bp->bp_vend[6] = DHCPDISCOVER;
 128
 129         /*
 130          * If we are booting from PXE, we want to send the string
 131          * 'PXEClient' to the DHCP server so you have the option of
 132          * only responding to PXE aware dhcp requests.
 133          */
 134         if (flag & BOOTP_PXE) {
 135                 bp->bp_vend[7] = TAG_CLASSID;
 136                 bp->bp_vend[8] = 9;
 137                 bcopy("PXEClient", &bp->bp_vend[9], 9);
 138                 bp->bp_vend[18] = TAG_END;
 139         } else
 140                 bp->bp_vend[7] = TAG_END;
 141 #else
 142         bp->bp_vend[4] = TAG_END;
 143 #endif
 144
 145         d->myip.s_addr = INADDR_ANY;
 146         d->myport = htons(IPPORT_BOOTPC);
 147         d->destip.s_addr = INADDR_BROADCAST;
 148         d->destport = htons(IPPORT_BOOTPS);
 149
 150 #ifdef SUPPORT_DHCP
 151         expected_dhcpmsgtype = DHCPOFFER;
 152         dhcp_ok = 0;
 153 #endif
 154
 155         if(sendrecv(d,
 156                     bootpsend, bp, sizeof(*bp),
 157                     bootprecv, &rbuf.rbootp, sizeof(rbuf.rbootp))
 158            == -1) {
 159             printf("bootp: no reply\n");
 160             return;
 161         }
 162
 163 #ifdef SUPPORT_DHCP
 164         if(dhcp_ok) {
 165                 u_int32_t leasetime;
 166                 bp->bp_vend[6] = DHCPREQUEST;
 167                 bp->bp_vend[7] = TAG_REQ_ADDR;
 168                 bp->bp_vend[8] = 4;
 169                 bcopy(&rbuf.rbootp.bp_yiaddr, &bp->bp_vend[9], 4);
 170                 bp->bp_vend[13] = TAG_SERVERID;
 171                 bp->bp_vend[14] = 4;
 172                 bcopy(&dhcp_serverip.s_addr, &bp->bp_vend[15], 4);
 173                 bp->bp_vend[19] = TAG_LEASETIME;
 174                 bp->bp_vend[20] = 4;
 175                 leasetime = htonl(300);
 176                 bcopy(&leasetime, &bp->bp_vend[21], 4);
 177                 if (flag & BOOTP_PXE) {
 178                         bp->bp_vend[25] = TAG_CLASSID;
 179                         bp->bp_vend[26] = 9;
 180                         bcopy("PXEClient", &bp->bp_vend[27], 9);
 181                         bp->bp_vend[36] = TAG_END;
 182                 } else
 183                         bp->bp_vend[25] = TAG_END;
 184
 185                 expected_dhcpmsgtype = DHCPACK;
 186
 187                 if(sendrecv(d,
 188                             bootpsend, bp, sizeof(*bp),
 189                             bootprecv, &rbuf.rbootp, sizeof(rbuf.rbootp))
 190                    == -1) {
 191                         printf("DHCPREQUEST failed\n");
 192                         return;
 193                 }
 194         }
 195 #endif
 196
 197         myip = d->myip = rbuf.rbootp.bp_yiaddr;
 198         servip = rbuf.rbootp.bp_siaddr;
 199         if(rootip.s_addr == INADDR_ANY) rootip = servip;
 200         bcopy(rbuf.rbootp.bp_file, bootfile, sizeof(bootfile));
 201         bootfile[sizeof(bootfile) - 1] = '\0';
 202
 203         if (IN_CLASSA(ntohl(myip.s_addr)))
 204                 nmask = htonl(IN_CLASSA_NET);
 205         else if (IN_CLASSB(ntohl(myip.s_addr)))
 206                 nmask = htonl(IN_CLASSB_NET);
 207         else
 208                 nmask = htonl(IN_CLASSC_NET);
 209 #ifdef BOOTP_DEBUG
 210         if (debug)
 211                 printf("'native netmask' is %s\n", intoa(nmask));
 212 #endif
 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 is on a different net */
 233         if (!SAMENET(myip, rootip, netmask)) {
 234 #ifdef BOOTP_DEBUG
 235                 if (debug)
 236                         printf("need gateway for root ip\n");
 237 #endif
 238         }
 239
 240         /* Toss gateway if on a different net */
 241         if (!SAMENET(myip, gateip, netmask)) {
 242 #ifdef BOOTP_DEBUG
 243                 if (debug)
 244                         printf("gateway ip (%s) bad\n", inet_ntoa(gateip));
 245 #endif
 246                 gateip.s_addr = 0;
 247         }
 248
 249         /* Bump xid so next request will be unique. */
 250         ++d->xid;
 251 }
 252
 253 /* Transmit a bootp request */
 254 static ssize_t
 255 bootpsend(struct iodesc *d, void *pkt, size_t len)
 256 {
 257         struct bootp *bp;
 258
 259 #ifdef BOOTP_DEBUG
 260         if (debug)
 261                 printf("bootpsend: d=%lx called.\n", (long)d);
 262 #endif
 263
 264         bp = pkt;
 265         bp->bp_secs = htons((u_short)(getsecs() - bot));
 266
 267 #ifdef BOOTP_DEBUG
 268         if (debug)
 269                 printf("bootpsend: calling sendudp\n");
 270 #endif
 271
 272         return (sendudp(d, pkt, len));
 273 }
 274
 275 static ssize_t
 276 bootprecv(struct iodesc *d, void *pkt, size_t len, time_t tleft)
 277 {
 278         ssize_t n;
 279         struct bootp *bp;
 280
 281 #ifdef BOOTP_DEBUGx
 282         if (debug)
 283                 printf("bootp_recvoffer: called\n");
 284 #endif
 285
 286         n = readudp(d, pkt, len, tleft);
 287         if (n == -1 || n < sizeof(struct bootp) - BOOTP_VENDSIZE)
 288                 goto bad;
 289
 290         bp = (struct bootp *)pkt;
 291
 292 #ifdef BOOTP_DEBUG
 293         if (debug)
 294                 printf("bootprecv: checked.  bp = 0x%lx, n = %d\n",
 295                     (long)bp, (int)n);
 296 #endif
 297         if (bp->bp_xid != htonl(d->xid)) {
 298 #ifdef BOOTP_DEBUG
 299                 if (debug) {
 300                         printf("bootprecv: expected xid 0x%lx, got 0x%x\n",
 301                             d->xid, ntohl(bp->bp_xid));
 302                 }
 303 #endif
 304                 goto bad;
 305         }
 306
 307 #ifdef BOOTP_DEBUG
 308         if (debug)
 309                 printf("bootprecv: got one!\n");
 310 #endif
 311
 312         /* Suck out vendor info */
 313         if (bcmp(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048)) == 0) {
 314                 if(vend_rfc1048(bp->bp_vend, sizeof(bp->bp_vend)) != 0)
 315                     goto bad;
 316         }
 317 #ifdef BOOTP_VEND_CMU
 318         else if (bcmp(vm_cmu, bp->bp_vend, sizeof(vm_cmu)) == 0)
 319                 vend_cmu(bp->bp_vend);
 320 #endif
 321         else
 322                 printf("bootprecv: unknown vendor 0x%lx\n", (long)bp->bp_vend);
 323
 324         return(n);
 325 bad:
 326         errno = 0;
 327         return (-1);
 328 }
 329
 330 static int
 331 vend_rfc1048(u_char *cp, u_int len)
 332 {
 333         u_char *ep;
 334         int size;
 335         u_char tag;
 336
 337 #ifdef BOOTP_DEBUG
 338         if (debug)
 339                 printf("vend_rfc1048 bootp info. len=%d\n", len);
 340 #endif
 341         ep = cp + len;
 342
 343         /* Step over magic cookie */
 344         cp += sizeof(int);
 345
 346         while (cp < ep) {
 347                 tag = *cp++;
 348                 size = *cp++;
 349                 if (tag == TAG_END)
 350                         break;
 351
 352                 if (tag == TAG_SUBNET_MASK) {
 353                         bcopy(cp, &smask, sizeof(smask));
 354                 }
 355                 if (tag == TAG_GATEWAY) {
 356                         bcopy(cp, &gateip.s_addr, sizeof(gateip.s_addr));
 357                 }
 358                 if (tag == TAG_SWAPSERVER) {
 359                         /* let it override bp_siaddr */
 360                         bcopy(cp, &rootip.s_addr, sizeof(swapip.s_addr));
 361                 }
 362                 if (tag == TAG_ROOTPATH) {
 363                         strncpy(rootpath, (char *)cp, sizeof(rootpath));
 364                         rootpath[size] = '\0';
 365                 }
 366                 if (tag == TAG_HOSTNAME) {
 367                         strncpy(hostname, (char *)cp, sizeof(hostname));
 368                         hostname[size] = '\0';
 369                 }
 370 #ifdef SUPPORT_DHCP
 371                 if (tag == TAG_DHCP_MSGTYPE) {
 372                         if(*cp != expected_dhcpmsgtype)
 373                             return(-1);
 374                         dhcp_ok = 1;
 375                 }
 376                 if (tag == TAG_SERVERID) {
 377                         bcopy(cp, &dhcp_serverip.s_addr,
 378                               sizeof(dhcp_serverip.s_addr));
 379                 }
 380 #endif
 381                 cp += size;
 382         }
 383         return(0);
 384 }
 385
 386 #ifdef BOOTP_VEND_CMU
 387 static void
 388 vend_cmu(u_char *cp)
 389 {
 390         struct cmu_vend *vp;
 391
 392 #ifdef BOOTP_DEBUG
 393         if (debug)
 394                 printf("vend_cmu bootp info.\n");
 395 #endif
 396         vp = (struct cmu_vend *)cp;
 397
 398         if (vp->v_smask.s_addr != 0) {
 399                 smask = vp->v_smask.s_addr;
 400         }
 401         if (vp->v_dgate.s_addr != 0) {
 402                 gateip = vp->v_dgate;
 403         }
 404 }
 405 #endif