sys/lib/libsa/bootp.c

   1 /*      $NetBSD: bootp.c,v 1.38 2011/05/11 16:23:40 zoltan 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/param.h>
  43 #include <netinet/in.h>
  44 #include <netinet/in_systm.h>
  45
  46 #ifdef _STANDALONE
  47 #include <lib/libkern/libkern.h>
  48 #else
  49 #include <string.h>
  50 #endif
  51
  52 #include "stand.h"
  53 #include "net.h"
  54 #include "bootp.h"
  55
  56 struct in_addr servip;
  57 #ifdef SUPPORT_LINUX
  58 char linuxcmdline[256];
  59 #ifndef TAG_LINUX_CMDLINE
  60 #define TAG_LINUX_CMDLINE 123
  61 #endif
  62 #endif
  63
  64 static n_long   nmask, smask;
  65
  66 static satime_t bot;
  67
  68 static  char vm_rfc1048[4] = VM_RFC1048;
  69 #ifdef BOOTP_VEND_CMU
  70 static  char vm_cmu[4] = VM_CMU;
  71 #endif
  72
  73 /* Local forwards */
  74 static  ssize_t bootpsend(struct iodesc *, void *, size_t);
  75 static  ssize_t bootprecv(struct iodesc *, void *, size_t, saseconds_t);
  76 static  int vend_rfc1048(u_char *, u_int);
  77 #ifdef BOOTP_VEND_CMU
  78 static  void vend_cmu(u_char *);
  79 #endif
  80
  81 #ifdef SUPPORT_DHCP
  82 static char expected_dhcpmsgtype = -1, dhcp_ok;
  83 struct in_addr dhcp_serverip;
  84 #endif
  85
  86 /*
  87  * Boot programs can patch this at run-time to change the behavior
  88  * of bootp/dhcp.
  89  */
  90 int bootp_flags;
  91
  92 static void
  93 bootp_addvend(u_char *area)
  94 {
  95 #ifdef SUPPORT_DHCP
  96         char vci[64];
  97         int vcilen;
  98
  99         *area++ = TAG_PARAM_REQ;
 100         *area++ = 6;
 101         *area++ = TAG_SUBNET_MASK;
 102         *area++ = TAG_GATEWAY;
 103         *area++ = TAG_HOSTNAME;
 104         *area++ = TAG_DOMAINNAME;
 105         *area++ = TAG_ROOTPATH;
 106         *area++ = TAG_SWAPSERVER;
 107
 108         /* Insert a NetBSD Vendor Class Identifier option. */
 109         sprintf(vci, "NetBSD:%s:libsa", MACHINE);
 110         vcilen = strlen(vci);
 111         *area++ = TAG_CLASSID;
 112         *area++ = vcilen;
 113         (void)memcpy(area, vci, vcilen);
 114         area += vcilen;
 115 #endif
 116         *area = TAG_END;
 117 }
 118
 119 /* Fetch required bootp information */
 120 void
 121 bootp(int sock)
 122 {
 123         struct iodesc *d;
 124         struct bootp *bp;
 125         struct {
 126                 u_char header[UDP_TOTAL_HEADER_SIZE];
 127                 struct bootp wbootp;
 128         } wbuf;
 129         struct {
 130                 u_char header[UDP_TOTAL_HEADER_SIZE];
 131                 struct bootp rbootp;
 132         } rbuf;
 133         unsigned int index;
 134
 135 #ifdef BOOTP_DEBUG
 136         if (debug)
 137                 printf("bootp: socket=%d\n", sock);
 138 #endif
 139         if (!bot)
 140                 bot = getsecs();
 141
 142         if (!(d = socktodesc(sock))) {
 143                 printf("bootp: bad socket. %d\n", sock);
 144                 return;
 145         }
 146 #ifdef BOOTP_DEBUG
 147         if (debug)
 148                 printf("bootp: d=%lx\n", (long)d);
 149 #endif
 150
 151         bp = &wbuf.wbootp;
 152         (void)memset(bp, 0, sizeof(*bp));
 153
 154         bp->bp_op = BOOTREQUEST;
 155         bp->bp_htype = 1;               /* 10Mb Ethernet (48 bits) */
 156         bp->bp_hlen = 6;
 157         bp->bp_xid = htonl(d->xid);
 158         MACPY(d->myea, bp->bp_chaddr);
 159         (void)strncpy((char *)bp->bp_file, bootfile, sizeof(bp->bp_file));
 160         (void)memcpy(bp->bp_vend, vm_rfc1048, sizeof(vm_rfc1048));
 161         index = 4;
 162 #ifdef SUPPORT_DHCP
 163         bp->bp_vend[index++] = TAG_DHCP_MSGTYPE;
 164         bp->bp_vend[index++] = 1;
 165         bp->bp_vend[index++] = DHCPDISCOVER;
 166 #endif
 167         bootp_addvend(&bp->bp_vend[index]);
 168
 169         d->myip.s_addr = INADDR_ANY;
 170         d->myport = htons(IPPORT_BOOTPC);
 171         d->destip.s_addr = INADDR_BROADCAST;
 172         d->destport = htons(IPPORT_BOOTPS);
 173
 174 #ifdef SUPPORT_DHCP
 175         expected_dhcpmsgtype = DHCPOFFER;
 176         dhcp_ok = 0;
 177 #endif
 178
 179         if (sendrecv(d,
 180                     bootpsend, bp, sizeof(*bp),
 181                     bootprecv, &rbuf.rbootp, sizeof(rbuf.rbootp))
 182            == -1) {
 183                 printf("bootp: no reply\n");
 184                 return;
 185         }
 186
 187 #ifdef SUPPORT_DHCP
 188         if (dhcp_ok) {
 189                 u_int32_t leasetime;
 190                 index = 6;
 191                 bp->bp_vend[index++] = DHCPREQUEST;
 192                 bp->bp_vend[index++] = TAG_REQ_ADDR;
 193                 bp->bp_vend[index++] = 4;
 194                 (void)memcpy(&bp->bp_vend[9], &rbuf.rbootp.bp_yiaddr, 4);
 195                 index += 4;
 196                 bp->bp_vend[index++] = TAG_SERVERID;
 197                 bp->bp_vend[index++] = 4;
 198                 (void)memcpy(&bp->bp_vend[index], &dhcp_serverip.s_addr, 4);
 199                 index += 4;
 200                 bp->bp_vend[index++] = TAG_LEASETIME;
 201                 bp->bp_vend[index++] = 4;
 202                 leasetime = htonl(300);
 203                 (void)memcpy(&bp->bp_vend[index], &leasetime, 4);
 204                 index += 4;
 205                 bootp_addvend(&bp->bp_vend[index]);
 206
 207                 expected_dhcpmsgtype = DHCPACK;
 208
 209                 if (sendrecv(d,
 210                             bootpsend, bp, sizeof(*bp),
 211                             bootprecv, &rbuf.rbootp, sizeof(rbuf.rbootp))
 212                    == -1) {
 213                         printf("DHCPREQUEST failed\n");
 214                         return;
 215                 }
 216         }
 217 #endif
 218
 219         myip = d->myip = rbuf.rbootp.bp_yiaddr;
 220         servip = rbuf.rbootp.bp_siaddr;
 221         if (rootip.s_addr == INADDR_ANY)
 222                 rootip = servip;
 223         (void)memcpy(bootfile, rbuf.rbootp.bp_file, sizeof(bootfile));
 224         bootfile[sizeof(bootfile) - 1] = '\0';
 225
 226         if (IN_CLASSA(myip.s_addr))
 227                 nmask = IN_CLASSA_NET;
 228         else if (IN_CLASSB(myip.s_addr))
 229                 nmask = IN_CLASSB_NET;
 230         else
 231                 nmask = IN_CLASSC_NET;
 232 #ifdef BOOTP_DEBUG
 233         if (debug)
 234                 printf("'native netmask' is %s\n", intoa(nmask));
 235 #endif
 236
 237         /* Get subnet (or natural net) mask */
 238         netmask = nmask;
 239         if (smask)
 240                 netmask = smask;
 241 #ifdef BOOTP_DEBUG
 242         if (debug)
 243                 printf("mask: %s\n", intoa(netmask));
 244 #endif
 245
 246         /* We need a gateway if root is on a different net */
 247         if (!SAMENET(myip, rootip, netmask)) {
 248 #ifdef BOOTP_DEBUG
 249                 if (debug)
 250                         printf("need gateway for root ip\n");
 251 #endif
 252         }
 253
 254         /* Toss gateway if on a different net */
 255         if (!SAMENET(myip, gateip, netmask)) {
 256 #ifdef BOOTP_DEBUG
 257                 if (debug)
 258                         printf("gateway ip (%s) bad\n", inet_ntoa(gateip));
 259 #endif
 260                 gateip.s_addr = 0;
 261         }
 262
 263 #ifdef BOOTP_DEBUG
 264         if (debug) {
 265                 printf("client addr: %s\n", inet_ntoa(myip));
 266                 if (smask)
 267                         printf("subnet mask: %s\n", intoa(smask));
 268                 if (gateip.s_addr != 0)
 269                         printf("net gateway: %s\n", inet_ntoa(gateip));
 270                 printf("server addr: %s\n", inet_ntoa(rootip));
 271                 if (rootpath[0] != '\0')
 272                         printf("server path: %s\n", rootpath);
 273                 if (bootfile[0] != '\0')
 274                         printf("file name: %s\n", bootfile);
 275         }
 276 #endif
 277
 278         /* Bump xid so next request will be unique. */
 279         ++d->xid;
 280 }
 281
 282 /* Transmit a bootp request */
 283 static ssize_t
 284 bootpsend(struct iodesc *d, void *pkt, size_t len)
 285 {
 286         struct bootp *bp;
 287
 288 #ifdef BOOTP_DEBUG
 289         if (debug)
 290                 printf("bootpsend: d=%lx called.\n", (long)d);
 291 #endif
 292
 293         bp = pkt;
 294         bp->bp_secs = htons((u_short)(getsecs() - bot));
 295
 296 #ifdef BOOTP_DEBUG
 297         if (debug)
 298                 printf("bootpsend: calling sendudp\n");
 299 #endif
 300
 301         return sendudp(d, pkt, len);
 302 }
 303
 304 static ssize_t
 305 bootprecv(struct iodesc *d, void *pkt, size_t len, saseconds_t tleft)
 306 {
 307         ssize_t n;
 308         struct bootp *bp;
 309
 310 #ifdef BOOTP_DEBUGx
 311         if (debug)
 312                 printf("bootp_recvoffer: called\n");
 313 #endif
 314
 315         n = readudp(d, pkt, len, tleft);
 316         if (n == -1 || (size_t)n < sizeof(struct bootp) - BOOTP_VENDSIZE)
 317                 goto bad;
 318
 319         bp = (struct bootp *)pkt;
 320
 321 #ifdef BOOTP_DEBUG
 322         if (debug)
 323                 printf("bootprecv: checked.  bp = 0x%lx, n = %d\n",
 324                     (long)bp, (int)n);
 325 #endif
 326         if (bp->bp_xid != htonl(d->xid)) {
 327 #ifdef BOOTP_DEBUG
 328                 if (debug) {
 329                         printf("bootprecv: expected xid 0x%lx, got 0x%x\n",
 330                             d->xid, ntohl(bp->bp_xid));
 331                 }
 332 #endif
 333                 goto bad;
 334         }
 335
 336         /* protect against bogus addresses sent by DHCP servers */
 337         if (bp->bp_yiaddr.s_addr == INADDR_ANY ||
 338             bp->bp_yiaddr.s_addr == INADDR_BROADCAST)
 339                 goto bad;
 340
 341 #ifdef BOOTP_DEBUG
 342         if (debug)
 343                 printf("bootprecv: got one!\n");
 344 #endif
 345
 346         /* Suck out vendor info */
 347         if (memcmp(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048)) == 0) {
 348                 if (vend_rfc1048(bp->bp_vend, sizeof(bp->bp_vend)) != 0)
 349                         goto bad;
 350         }
 351 #ifdef BOOTP_VEND_CMU
 352         else if (memcmp(vm_cmu, bp->bp_vend, sizeof(vm_cmu)) == 0)
 353                 vend_cmu(bp->bp_vend);
 354 #endif
 355         else
 356                 printf("bootprecv: unknown vendor 0x%lx\n", (long)bp->bp_vend);
 357
 358         return n;
 359 bad:
 360         errno = 0;
 361         return -1;
 362 }
 363
 364 static int
 365 vend_rfc1048(u_char *cp, u_int len)
 366 {
 367         u_char *ep;
 368         int size;
 369         u_char tag;
 370
 371 #ifdef BOOTP_DEBUG
 372         if (debug)
 373                 printf("vend_rfc1048 bootp info. len=%d\n", len);
 374 #endif
 375         ep = cp + len;
 376
 377         /* Step over magic cookie */
 378         cp += sizeof(int);
 379
 380         while (cp < ep) {
 381                 tag = *cp++;
 382                 size = *cp++;
 383                 if (tag == TAG_END)
 384                         break;
 385
 386                 if (tag == TAG_SUBNET_MASK && size >= sizeof(smask)) {
 387                         (void)memcpy(&smask, cp, sizeof(smask));
 388                 }
 389                 if (tag == TAG_GATEWAY && size >= sizeof(gateip.s_addr)) {
 390                         (void)memcpy(&gateip.s_addr, cp, sizeof(gateip.s_addr));
 391                 }
 392                 if (tag == TAG_SWAPSERVER && size >= sizeof(rootip.s_addr)) {
 393                         /* let it override bp_siaddr */
 394                         (void)memcpy(&rootip.s_addr, cp, sizeof(rootip.s_addr));
 395                 }
 396                 if (tag == TAG_ROOTPATH && size < sizeof(rootpath)) {
 397                         strncpy(rootpath, (char *)cp, sizeof(rootpath));
 398                         rootpath[size] = '\0';
 399                 }
 400                 if (tag == TAG_HOSTNAME && size < sizeof(hostname)) {
 401                         strncpy(hostname, (char *)cp, sizeof(hostname));
 402                         hostname[size] = '\0';
 403                 }
 404 #ifdef SUPPORT_DHCP
 405                 if (tag == TAG_DHCP_MSGTYPE) {
 406                         if (*cp != expected_dhcpmsgtype)
 407                                 return -1;
 408                         dhcp_ok = 1;
 409                 }
 410                 if (tag == TAG_SERVERID &&
 411                     size >= sizeof(dhcp_serverip.s_addr))
 412                 {
 413                         (void)memcpy(&dhcp_serverip.s_addr, cp,
 414                               sizeof(dhcp_serverip.s_addr));
 415                 }
 416 #endif
 417 #ifdef SUPPORT_LINUX
 418                 if (tag == TAG_LINUX_CMDLINE && size < sizeof(linuxcmdline)) {
 419                         strncpy(linuxcmdline, (char *)cp, sizeof(linuxcmdline));
 420                         linuxcmdline[size] = '\0';
 421                 }
 422 #endif
 423                 cp += size;
 424         }
 425         return 0;
 426 }
 427
 428 #ifdef BOOTP_VEND_CMU
 429 static void
 430 vend_cmu(u_char *cp)
 431 {
 432         struct cmu_vend *vp;
 433
 434 #ifdef BOOTP_DEBUG
 435         if (debug)
 436                 printf("vend_cmu bootp info.\n");
 437 #endif
 438         vp = (struct cmu_vend *)cp;
 439
 440         if (vp->v_smask.s_addr != 0) {
 441                 smask = vp->v_smask.s_addr;
 442         }
 443         if (vp->v_dgate.s_addr != 0) {
 444                 gateip = vp->v_dgate;
 445         }
 446 }
 447 #endif