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. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  *
  35  * @(#) Header: bootp.c,v 1.4 93/09/11 03:13:51 leres Exp  (LBL)
  36  * $FreeBSD: src/lib/libstand/bootp.c,v 1.1.1.1.6.2 2000/09/20 18:37:25 ps Exp $
  37  * $DragonFly: src/lib/libstand/bootp.c,v 1.5 2005/12/11 02:27:26 swildner Exp $
  38  */
  39
  40 #include <sys/param.h>
  41 #include <netinet/in.h>
  42 #include <netinet/in_systm.h>
  43
  44 #include <string.h>
  45
  46 #define BOOTP_DEBUGxx
  47 #define SUPPORT_DHCP
  48
  49 #include "stand.h"
  50 #include "net.h"
  51 #include "netif.h"
  52 #include "bootp.h"
  53
  54
  55 struct in_addr servip;
  56
  57 static n_long   nmask, smask;
  58
  59 static time_t   bot;
  60
  61 static  char vm_rfc1048[4] = VM_RFC1048;
  62 #ifdef BOOTP_VEND_CMU
  63 static  char vm_cmu[4] = VM_CMU;
  64 #endif
  65
  66 /* Local forwards */
  67 static  ssize_t bootpsend(struct iodesc *, void *, size_t);
  68 static  ssize_t bootprecv(struct iodesc *, void *, size_t, time_t);
  69 static  int vend_rfc1048(u_char *, u_int);
  70 #ifdef BOOTP_VEND_CMU
  71 static  void vend_cmu(u_char *);
  72 #endif
  73
  74 #ifdef SUPPORT_DHCP
  75 static char expected_dhcpmsgtype = -1, dhcp_ok;
  76 struct in_addr dhcp_serverip;
  77 #endif
  78
  79 /* Fetch required bootp infomation */
  80 void
  81 bootp(int sock, int flag)
  82 {
  83         struct iodesc *d;
  84         struct bootp *bp;
  85         struct {
  86                 u_char header[HEADER_SIZE];
  87                 struct bootp wbootp;
  88         } wbuf;
  89         struct {
  90                 u_char header[HEADER_SIZE];
  91                 struct bootp rbootp;
  92         } rbuf;
  93
  94 #ifdef BOOTP_DEBUG
  95         if (debug)
  96                 printf("bootp: socket=%d\n", sock);
  97 #endif
  98         if (!bot)
  99                 bot = getsecs();
 100
 101         if (!(d = socktodesc(sock))) {
 102                 printf("bootp: bad socket. %d\n", sock);
 103                 return;
 104         }
 105 #ifdef BOOTP_DEBUG
 106         if (debug)
 107                 printf("bootp: d=%lx\n", (long)d);
 108 #endif
 109
 110         bp = &wbuf.wbootp;
 111         bzero(bp, sizeof(*bp));
 112
 113         bp->bp_op = BOOTREQUEST;
 114         bp->bp_htype = 1;               /* 10Mb Ethernet (48 bits) */
 115         bp->bp_hlen = 6;
 116         bp->bp_xid = htonl(d->xid);
 117         MACPY(d->myea, bp->bp_chaddr);
 118         strncpy(bp->bp_file, bootfile, sizeof(bp->bp_file));
 119         bcopy(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048));
 120 #ifdef SUPPORT_DHCP
 121         bp->bp_vend[4] = TAG_DHCP_MSGTYPE;
 122         bp->bp_vend[5] = 1;
 123         bp->bp_vend[6] = DHCPDISCOVER;
 124
 125         /*
 126          * If we are booting from PXE, we want to send the string
 127          * 'PXEClient' to the DHCP server so you have the option of
 128          * only responding to PXE aware dhcp requests.
 129          */
 130         if (flag & BOOTP_PXE) {
 131                 bp->bp_vend[7] = TAG_CLASSID;
 132                 bp->bp_vend[8] = 9;
 133                 bcopy("PXEClient", &bp->bp_vend[9], 9);
 134                 bp->bp_vend[18] = TAG_END;
 135         } else
 136                 bp->bp_vend[7] = TAG_END;
 137 #else
 138         bp->bp_vend[4] = TAG_END;
 139 #endif
 140
 141         d->myip.s_addr = INADDR_ANY;
 142         d->myport = htons(IPPORT_BOOTPC);
 143         d->destip.s_addr = INADDR_BROADCAST;
 144         d->destport = htons(IPPORT_BOOTPS);
 145
 146 #ifdef SUPPORT_DHCP
 147         expected_dhcpmsgtype = DHCPOFFER;
 148         dhcp_ok = 0;
 149 #endif
 150
 151         if(sendrecv(d,
 152                     bootpsend, bp, sizeof(*bp),
 153                     bootprecv, &rbuf.rbootp, sizeof(rbuf.rbootp))
 154            == -1) {
 155             printf("bootp: no reply\n");
 156             return;
 157         }
 158
 159 #ifdef SUPPORT_DHCP
 160         if(dhcp_ok) {
 161                 u_int32_t leasetime;
 162                 bp->bp_vend[6] = DHCPREQUEST;
 163                 bp->bp_vend[7] = TAG_REQ_ADDR;
 164                 bp->bp_vend[8] = 4;
 165                 bcopy(&rbuf.rbootp.bp_yiaddr, &bp->bp_vend[9], 4);
 166                 bp->bp_vend[13] = TAG_SERVERID;
 167                 bp->bp_vend[14] = 4;
 168                 bcopy(&dhcp_serverip.s_addr, &bp->bp_vend[15], 4);
 169                 bp->bp_vend[19] = TAG_LEASETIME;
 170                 bp->bp_vend[20] = 4;
 171                 leasetime = htonl(300);
 172                 bcopy(&leasetime, &bp->bp_vend[21], 4);
 173                 if (flag & BOOTP_PXE) {
 174                         bp->bp_vend[25] = TAG_CLASSID;
 175                         bp->bp_vend[26] = 9;
 176                         bcopy("PXEClient", &bp->bp_vend[27], 9);
 177                         bp->bp_vend[36] = TAG_END;
 178                 } else
 179                         bp->bp_vend[25] = TAG_END;
 180
 181                 expected_dhcpmsgtype = DHCPACK;
 182
 183                 if(sendrecv(d,
 184                             bootpsend, bp, sizeof(*bp),
 185                             bootprecv, &rbuf.rbootp, sizeof(rbuf.rbootp))
 186                    == -1) {
 187                         printf("DHCPREQUEST failed\n");
 188                         return;
 189                 }
 190         }
 191 #endif
 192
 193         myip = d->myip = rbuf.rbootp.bp_yiaddr;
 194         servip = rbuf.rbootp.bp_siaddr;
 195         if(rootip.s_addr == INADDR_ANY) rootip = servip;
 196         bcopy(rbuf.rbootp.bp_file, bootfile, sizeof(bootfile));
 197         bootfile[sizeof(bootfile) - 1] = '\0';
 198
 199         if (IN_CLASSA(ntohl(myip.s_addr)))
 200                 nmask = htonl(IN_CLASSA_NET);
 201         else if (IN_CLASSB(ntohl(myip.s_addr)))
 202                 nmask = htonl(IN_CLASSB_NET);
 203         else
 204                 nmask = htonl(IN_CLASSC_NET);
 205 #ifdef BOOTP_DEBUG
 206         if (debug)
 207                 printf("'native netmask' is %s\n", intoa(nmask));
 208 #endif
 209
 210         /* Check subnet mask against net mask; toss if bogus */
 211         if ((nmask & smask) != nmask) {
 212 #ifdef BOOTP_DEBUG
 213                 if (debug)
 214                         printf("subnet mask (%s) bad\n", intoa(smask));
 215 #endif
 216                 smask = 0;
 217         }
 218
 219         /* Get subnet (or natural net) mask */
 220         netmask = nmask;
 221         if (smask)
 222                 netmask = smask;
 223 #ifdef BOOTP_DEBUG
 224         if (debug)
 225                 printf("mask: %s\n", intoa(netmask));
 226 #endif
 227
 228         /* We need a gateway if root is on a different net */
 229         if (!SAMENET(myip, rootip, netmask)) {
 230 #ifdef BOOTP_DEBUG
 231                 if (debug)
 232                         printf("need gateway for root ip\n");
 233 #endif
 234         }
 235
 236         /* Toss gateway if on a different net */
 237         if (!SAMENET(myip, gateip, netmask)) {
 238 #ifdef BOOTP_DEBUG
 239                 if (debug)
 240                         printf("gateway ip (%s) bad\n", inet_ntoa(gateip));
 241 #endif
 242                 gateip.s_addr = 0;
 243         }
 244
 245         /* Bump xid so next request will be unique. */
 246         ++d->xid;
 247 }
 248
 249 /* Transmit a bootp request */
 250 static ssize_t
 251 bootpsend(struct iodesc *d, void *pkt, size_t len)
 252 {
 253         struct bootp *bp;
 254
 255 #ifdef BOOTP_DEBUG
 256         if (debug)
 257                 printf("bootpsend: d=%lx called.\n", (long)d);
 258 #endif
 259
 260         bp = pkt;
 261         bp->bp_secs = htons((u_short)(getsecs() - bot));
 262
 263 #ifdef BOOTP_DEBUG
 264         if (debug)
 265                 printf("bootpsend: calling sendudp\n");
 266 #endif
 267
 268         return (sendudp(d, pkt, len));
 269 }
 270
 271 static ssize_t
 272 bootprecv(struct iodesc *d, void *pkt, size_t len, time_t tleft)
 273 {
 274         ssize_t n;
 275         struct bootp *bp;
 276
 277 #ifdef BOOTP_DEBUGx
 278         if (debug)
 279                 printf("bootp_recvoffer: called\n");
 280 #endif
 281
 282         n = readudp(d, pkt, len, tleft);
 283         if (n == -1 || n < sizeof(struct bootp) - BOOTP_VENDSIZE)
 284                 goto bad;
 285
 286         bp = (struct bootp *)pkt;
 287
 288 #ifdef BOOTP_DEBUG
 289         if (debug)
 290                 printf("bootprecv: checked.  bp = 0x%lx, n = %d\n",
 291                     (long)bp, (int)n);
 292 #endif
 293         if (bp->bp_xid != htonl(d->xid)) {
 294 #ifdef BOOTP_DEBUG
 295                 if (debug) {
 296                         printf("bootprecv: expected xid 0x%lx, got 0x%x\n",
 297                             d->xid, ntohl(bp->bp_xid));
 298                 }
 299 #endif
 300                 goto bad;
 301         }
 302
 303 #ifdef BOOTP_DEBUG
 304         if (debug)
 305                 printf("bootprecv: got one!\n");
 306 #endif
 307
 308         /* Suck out vendor info */
 309         if (bcmp(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048)) == 0) {
 310                 if(vend_rfc1048(bp->bp_vend, sizeof(bp->bp_vend)) != 0)
 311                     goto bad;
 312         }
 313 #ifdef BOOTP_VEND_CMU
 314         else if (bcmp(vm_cmu, bp->bp_vend, sizeof(vm_cmu)) == 0)
 315                 vend_cmu(bp->bp_vend);
 316 #endif
 317         else
 318                 printf("bootprecv: unknown vendor 0x%lx\n", (long)bp->bp_vend);
 319
 320         return(n);
 321 bad:
 322         errno = 0;
 323         return (-1);
 324 }
 325
 326 static int
 327 vend_rfc1048(u_char *cp, u_int len)
 328 {
 329         u_char *ep;
 330         int size;
 331         u_char tag;
 332
 333 #ifdef BOOTP_DEBUG
 334         if (debug)
 335                 printf("vend_rfc1048 bootp info. len=%d\n", len);
 336 #endif
 337         ep = cp + len;
 338
 339         /* Step over magic cookie */
 340         cp += sizeof(int);
 341
 342         while (cp < ep) {
 343                 tag = *cp++;
 344                 size = *cp++;
 345                 if (tag == TAG_END)
 346                         break;
 347
 348                 if (tag == TAG_SUBNET_MASK) {
 349                         bcopy(cp, &smask, sizeof(smask));
 350                 }
 351                 if (tag == TAG_GATEWAY) {
 352                         bcopy(cp, &gateip.s_addr, sizeof(gateip.s_addr));
 353                 }
 354                 if (tag == TAG_SWAPSERVER) {
 355                         /* let it override bp_siaddr */
 356                         bcopy(cp, &rootip.s_addr, sizeof(swapip.s_addr));
 357                 }
 358                 if (tag == TAG_ROOTPATH) {
 359                         strncpy(rootpath, (char *)cp, sizeof(rootpath));
 360                         rootpath[size] = '\0';
 361                 }
 362                 if (tag == TAG_HOSTNAME) {
 363                         strncpy(hostname, (char *)cp, sizeof(hostname));
 364                         hostname[size] = '\0';
 365                 }
 366 #ifdef SUPPORT_DHCP
 367                 if (tag == TAG_DHCP_MSGTYPE) {
 368                         if(*cp != expected_dhcpmsgtype)
 369                             return(-1);
 370                         dhcp_ok = 1;
 371                 }
 372                 if (tag == TAG_SERVERID) {
 373                         bcopy(cp, &dhcp_serverip.s_addr,
 374                               sizeof(dhcp_serverip.s_addr));
 375                 }
 376 #endif
 377                 cp += size;
 378         }
 379         return(0);
 380 }
 381
 382 #ifdef BOOTP_VEND_CMU
 383 static void
 384 vend_cmu(u_char *cp)
 385 {
 386         struct cmu_vend *vp;
 387
 388 #ifdef BOOTP_DEBUG
 389         if (debug)
 390                 printf("vend_cmu bootp info.\n");
 391 #endif
 392         vp = (struct cmu_vend *)cp;
 393
 394         if (vp->v_smask.s_addr != 0) {
 395                 smask = vp->v_smask.s_addr;
 396         }
 397         if (vp->v_dgate.s_addr != 0) {
 398                 gateip = vp->v_dgate;
 399         }
 400 }
 401 #endif