libexec/rbootd/rmpproto.c

   1 /*
   2  * Copyright (c) 1988, 1992 The University of Utah and the Center
   3  *      for Software Science (CSS).
   4  * Copyright (c) 1992, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * the Center for Software Science of the University of Utah Computer
   9  * Science Department.  CSS requests users of this software to return
  10  * to css-dist@cs.utah.edu any improvements that they make and grant
  11  * CSS redistribution rights.
  12  *
  13  * Redistribution and use in source and binary forms, with or without
  14  * modification, are permitted provided that the following conditions
  15  * are met:
  16  * 1. Redistributions of source code must retain the above copyright
  17  *    notice, this list of conditions and the following disclaimer.
  18  * 2. Redistributions in binary form must reproduce the above copyright
  19  *    notice, this list of conditions and the following disclaimer in the
  20  *    documentation and/or other materials provided with the distribution.
  21  * 3. Neither the name of the University nor the names of its contributors
  22  *    may be used to endorse or promote products derived from this software
  23  *    without specific prior written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  35  * SUCH DAMAGE.
  36  *
  37  *      from: @(#)rmpproto.c    8.1 (Berkeley) 6/4/93
  38  *
  39  * From: Utah Hdr: rmpproto.c 3.1 92/07/06
  40  * Author: Jeff Forys, University of Utah CSS
  41  *
  42  * @(#)rmpproto.c       8.1 (Berkeley) 6/4/93
  43  * $FreeBSD: src/libexec/rbootd/rmpproto.c,v 1.6.2.1 2001/02/18 02:54:11 kris Exp $
  44  */
  45
  46 #include <sys/param.h>
  47 #include <sys/time.h>
  48
  49 #include <errno.h>
  50 #include <fcntl.h>
  51 #include <stdio.h>
  52 #include <string.h>
  53 #include <syslog.h>
  54 #include <unistd.h>
  55 #include "defs.h"
  56
  57 /*
  58 **  ProcessPacket -- determine packet type and do what's required.
  59 **
  60 **      An RMP BOOT packet has been received.  Look at the type field
  61 **      and process Boot Requests, Read Requests, and Boot Complete
  62 **      packets.  Any other type will be dropped with a warning msg.
  63 **
  64 **      Parameters:
  65 **              rconn - the new connection
  66 **              client - list of files available to this host
  67 **
  68 **      Returns:
  69 **              Nothing.
  70 **
  71 **      Side Effects:
  72 **              - If this is a valid boot request, it will be added to
  73 **                the linked list of outstanding requests (RmpConns).
  74 **              - If this is a valid boot complete, its associated
  75 **                entry in RmpConns will be deleted.
  76 **              - Also, unless we run out of memory, a reply will be
  77 **                sent to the host that sent the packet.
  78 */
  79 void
  80 ProcessPacket(RMPCONN *rconn, CLIENT *client)
  81 {
  82         struct rmp_packet *rmp;
  83         RMPCONN *rconnout;
  84
  85         rmp = &rconn->rmp;              /* cache pointer to RMP packet */
  86
  87         switch(rmp->r_type) {           /* do what we came here to do */
  88                 case RMP_BOOT_REQ:              /* boot request */
  89                         if ((rconnout = NewConn(rconn)) == NULL)
  90                                 return;
  91
  92                         /*
  93                          *  If the Session ID is 0xffff, this is a "probe"
  94                          *  packet and we do not want to add the connection
  95                          *  to the linked list of active connections.  There
  96                          *  are two types of probe packets, if the Sequence
  97                          *  Number is 0 they want to know our host name, o/w
  98                          *  they want the name of the file associated with
  99                          *  the number spec'd by the Sequence Number.
 100                          *
 101                          *  If this is an actual boot request, open the file
 102                          *  and send a reply.  If SendBootRepl() does not
 103                          *  return 0, add the connection to the linked list
 104                          *  of active connections, otherwise delete it since
 105                          *  an error was encountered.
 106                          */
 107                         if (ntohs(rmp->r_brq.rmp_session) == RMP_PROBESID) {
 108                                 if (WORDZE(rmp->r_brq.rmp_seqno))
 109                                         (void) SendServerID(rconnout);
 110                                 else
 111                                         (void) SendFileNo(rmp, rconnout,
 112                                                           client? client->files:
 113                                                                   BootFiles);
 114                                 FreeConn(rconnout);
 115                         } else {
 116                                 if (SendBootRepl(rmp, rconnout,
 117                                     client? client->files: BootFiles))
 118                                         AddConn(rconnout);
 119                                 else
 120                                         FreeConn(rconnout);
 121                         }
 122                         break;
 123
 124                 case RMP_BOOT_REPL:             /* boot reply (not valid) */
 125                         syslog(LOG_WARNING, "%s: sent a boot reply",
 126                                EnetStr(rconn));
 127                         break;
 128
 129                 case RMP_READ_REQ:              /* read request */
 130                         /*
 131                          *  Send a portion of the boot file.
 132                          */
 133                         (void) SendReadRepl(rconn);
 134                         break;
 135
 136                 case RMP_READ_REPL:             /* read reply (not valid) */
 137                         syslog(LOG_WARNING, "%s: sent a read reply",
 138                                EnetStr(rconn));
 139                         break;
 140
 141                 case RMP_BOOT_DONE:             /* boot complete */
 142                         /*
 143                          *  Remove the entry from the linked list of active
 144                          *  connections.
 145                          */
 146                         (void) BootDone(rconn);
 147                         break;
 148
 149                 default:                        /* unknown RMP packet type */
 150                         syslog(LOG_WARNING, "%s: unknown packet type (%u)",
 151                                EnetStr(rconn), rmp->r_type);
 152         }
 153 }
 154
 155 /*
 156 **  SendServerID -- send our host name to who ever requested it.
 157 **
 158 **      Parameters:
 159 **              rconn - the reply packet to be formatted.
 160 **
 161 **      Returns:
 162 **              1 on success, 0 on failure.
 163 **
 164 **      Side Effects:
 165 **              none.
 166 */
 167 int
 168 SendServerID(RMPCONN *rconn)
 169 {
 170         struct rmp_packet *rpl;
 171         char *src, *dst;
 172         u_int8_t *size;
 173
 174         rpl = &rconn->rmp;                      /* cache ptr to RMP packet */
 175
 176         /*
 177          *  Set up assorted fields in reply packet.
 178          */
 179         rpl->r_brpl.rmp_type = RMP_BOOT_REPL;
 180         rpl->r_brpl.rmp_retcode = RMP_E_OKAY;
 181         ZEROWORD(rpl->r_brpl.rmp_seqno);
 182         rpl->r_brpl.rmp_session = 0;
 183         rpl->r_brpl.rmp_version = htons(RMP_VERSION);
 184
 185         size = &rpl->r_brpl.rmp_flnmsize;       /* ptr to length of host name */
 186
 187         /*
 188          *  Copy our host name into the reply packet incrementing the
 189          *  length as we go.  Stop at RMP_HOSTLEN or the first dot.
 190          */
 191         src = MyHost;
 192         dst = (char *) &rpl->r_brpl.rmp_flnm;
 193         for (*size = 0; *size < RMP_HOSTLEN; (*size)++) {
 194                 if (*src == '.' || *src == '\0')
 195                         break;
 196                 *dst++ = *src++;
 197         }
 198
 199         rconn->rmplen = RMPBOOTSIZE(*size);     /* set packet length */
 200
 201         return(SendPacket(rconn));              /* send packet */
 202 }
 203
 204 /*
 205 **  SendFileNo -- send the name of a bootable file to the requester.
 206 **
 207 **      Parameters:
 208 **              req - RMP BOOT packet containing the request.
 209 **              rconn - the reply packet to be formatted.
 210 **              filelist - list of files available to the requester.
 211 **
 212 **      Returns:
 213 **              1 on success, 0 on failure.
 214 **
 215 **      Side Effects:
 216 **              none.
 217 */
 218 int
 219 SendFileNo(struct rmp_packet *req, RMPCONN *rconn, char *filelist[])
 220 {
 221         struct rmp_packet *rpl;
 222         char *src, *dst;
 223         u_int8_t *size;
 224         int i;
 225
 226         GETWORD(req->r_brpl.rmp_seqno, i);      /* SeqNo is really FileNo */
 227         rpl = &rconn->rmp;                      /* cache ptr to RMP packet */
 228
 229         /*
 230          *  Set up assorted fields in reply packet.
 231          */
 232         rpl->r_brpl.rmp_type = RMP_BOOT_REPL;
 233         PUTWORD(i, rpl->r_brpl.rmp_seqno);
 234         i--;
 235         rpl->r_brpl.rmp_session = 0;
 236         rpl->r_brpl.rmp_version = htons(RMP_VERSION);
 237
 238         size = &rpl->r_brpl.rmp_flnmsize;       /* ptr to length of filename */
 239         *size = 0;                              /* init length to zero */
 240
 241         /*
 242          *  Copy the file name into the reply packet incrementing the
 243          *  length as we go.  Stop at end of string or when RMPBOOTDATA
 244          *  characters have been copied.  Also, set return code to
 245          *  indicate success or "no more files".
 246          */
 247         if (i < C_MAXFILE && filelist[i] != NULL) {
 248                 src = filelist[i];
 249                 dst = (char *)&rpl->r_brpl.rmp_flnm;
 250                 for (; *src && *size < RMPBOOTDATA; (*size)++) {
 251                         if (*src == '\0')
 252                                 break;
 253                         *dst++ = *src++;
 254                 }
 255                 rpl->r_brpl.rmp_retcode = RMP_E_OKAY;
 256         } else
 257                 rpl->r_brpl.rmp_retcode = RMP_E_NODFLT;
 258
 259         rconn->rmplen = RMPBOOTSIZE(*size);     /* set packet length */
 260
 261         return(SendPacket(rconn));              /* send packet */
 262 }
 263
 264 /*
 265 **  SendBootRepl -- open boot file and respond to boot request.
 266 **
 267 **      Parameters:
 268 **              req - RMP BOOT packet containing the request.
 269 **              rconn - the reply packet to be formatted.
 270 **              filelist - list of files available to the requester.
 271 **
 272 **      Returns:
 273 **              1 on success, 0 on failure.
 274 **
 275 **      Side Effects:
 276 **              none.
 277 */
 278 int
 279 SendBootRepl(struct rmp_packet *req, RMPCONN *rconn, char *filelist[])
 280 {
 281         int retval;
 282         char *filename, filepath[RMPBOOTDATA+1];
 283         RMPCONN *oldconn;
 284         struct rmp_packet *rpl;
 285         char *src, *dst1, *dst2;
 286         u_int8_t i;
 287
 288         /*
 289          *  If another connection already exists, delete it since we
 290          *  are obviously starting again.
 291          */
 292         if ((oldconn = FindConn(rconn)) != NULL) {
 293                 syslog(LOG_WARNING, "%s: dropping existing connection",
 294                        EnetStr(oldconn));
 295                 RemoveConn(oldconn);
 296         }
 297
 298         rpl = &rconn->rmp;                      /* cache ptr to RMP packet */
 299
 300         /*
 301          *  Set up assorted fields in reply packet.
 302          */
 303         rpl->r_brpl.rmp_type = RMP_BOOT_REPL;
 304         COPYWORD(req->r_brq.rmp_seqno, rpl->r_brpl.rmp_seqno);
 305         rpl->r_brpl.rmp_session = htons(GenSessID());
 306         rpl->r_brpl.rmp_version = htons(RMP_VERSION);
 307         rpl->r_brpl.rmp_flnmsize = req->r_brq.rmp_flnmsize;
 308
 309         /*
 310          *  Copy file name to `filepath' string, and into reply packet.
 311          */
 312         src = &req->r_brq.rmp_flnm;
 313         dst1 = filepath;
 314         dst2 = &rpl->r_brpl.rmp_flnm;
 315         for (i = 0; i < req->r_brq.rmp_flnmsize; i++)
 316                 *dst1++ = *dst2++ = *src++;
 317         *dst1 = '\0';
 318
 319         /*
 320          *  If we are booting HP-UX machines, their secondary loader will
 321          *  ask for files like "/hp-ux".  As a security measure, we do not
 322          *  allow boot files to lay outside the boot directory (unless they
 323          *  are purposely link'd out.  So, make `filename' become the path-
 324          *  stripped file name and spoof the client into thinking that it
 325          *  really got what it wanted.
 326          */
 327         if ((filename = strrchr(filepath, '/')) != NULL)
 328                 filename++;
 329         else
 330                 filename = filepath;
 331
 332         /*
 333          *  Check that this is a valid boot file name.
 334          */
 335         for (i = 0; i < C_MAXFILE && filelist[i] != NULL; i++)
 336                 if (STREQN(filename, filelist[i]))
 337                         goto match;
 338
 339         /*
 340          *  Invalid boot file name, set error and send reply packet.
 341          */
 342         rpl->r_brpl.rmp_retcode = RMP_E_NOFILE;
 343         retval = 0;
 344         goto sendpkt;
 345
 346 match:
 347         /*
 348          *  This is a valid boot file.  Open the file and save the file
 349          *  descriptor associated with this connection and set success
 350          *  indication.  If the file couldnt be opened, set error:
 351          *      "no such file or dir" - RMP_E_NOFILE
 352          *      "file table overflow" - RMP_E_BUSY
 353          *      "too many open files" - RMP_E_BUSY
 354          *      anything else         - RMP_E_OPENFILE
 355          */
 356         if ((rconn->bootfd = open(filename, O_RDONLY, 0600)) < 0) {
 357                 rpl->r_brpl.rmp_retcode = (errno == ENOENT)? RMP_E_NOFILE:
 358                         (errno == EMFILE || errno == ENFILE)? RMP_E_BUSY:
 359                         RMP_E_OPENFILE;
 360                 retval = 0;
 361         } else {
 362                 rpl->r_brpl.rmp_retcode = RMP_E_OKAY;
 363                 retval = 1;
 364         }
 365
 366 sendpkt:
 367         syslog(LOG_INFO, "%s: request to boot %s (%s)",
 368                EnetStr(rconn), filename, retval? "granted": "denied");
 369
 370         rconn->rmplen = RMPBOOTSIZE(rpl->r_brpl.rmp_flnmsize);
 371
 372         return (retval & SendPacket(rconn));
 373 }
 374
 375 /*
 376 **  SendReadRepl -- send a portion of the boot file to the requester.
 377 **
 378 **      Parameters:
 379 **              rconn - the reply packet to be formatted.
 380 **
 381 **      Returns:
 382 **              1 on success, 0 on failure.
 383 **
 384 **      Side Effects:
 385 **              none.
 386 */
 387 int
 388 SendReadRepl(RMPCONN *rconn)
 389 {
 390         int retval = 0;
 391         RMPCONN *oldconn;
 392         struct rmp_packet *rpl, *req;
 393         int size = 0;
 394         int madeconn = 0;
 395
 396         /*
 397          *  Find the old connection.  If one doesnt exist, create one only
 398          *  to return the error code.
 399          */
 400         if ((oldconn = FindConn(rconn)) == NULL) {
 401                 if ((oldconn = NewConn(rconn)) == NULL)
 402                         return(0);
 403                 syslog(LOG_ERR, "SendReadRepl: no active connection (%s)",
 404                        EnetStr(rconn));
 405                 madeconn++;
 406         }
 407
 408         req = &rconn->rmp;              /* cache ptr to request packet */
 409         rpl = &oldconn->rmp;            /* cache ptr to reply packet */
 410
 411         if (madeconn) {                 /* no active connection above; abort */
 412                 rpl->r_rrpl.rmp_retcode = RMP_E_ABORT;
 413                 retval = 1;
 414                 goto sendpkt;
 415         }
 416
 417         /*
 418          *  Make sure Session ID's match.
 419          */
 420         if (ntohs(req->r_rrq.rmp_session) !=
 421             ((rpl->r_type == RMP_BOOT_REPL)? ntohs(rpl->r_brpl.rmp_session):
 422                                              ntohs(rpl->r_rrpl.rmp_session))) {
 423                 syslog(LOG_ERR, "SendReadRepl: bad session id (%s)",
 424                        EnetStr(rconn));
 425                 rpl->r_rrpl.rmp_retcode = RMP_E_BADSID;
 426                 retval = 1;
 427                 goto sendpkt;
 428         }
 429
 430         /*
 431          *  If the requester asks for more data than we can fit,
 432          *  silently clamp the request size down to RMPREADDATA.
 433          *
 434          *  N.B. I do not know if this is "legal", however it seems
 435          *  to work.  This is necessary for bpfwrite() on machines
 436          *  with MCLBYTES less than 1514.
 437          */
 438         if (ntohs(req->r_rrq.rmp_size) > RMPREADDATA)
 439                 req->r_rrq.rmp_size = htons(RMPREADDATA);
 440
 441         /*
 442          *  Position read head on file according to info in request packet.
 443          */
 444         GETWORD(req->r_rrq.rmp_offset, size);
 445         if (lseek(oldconn->bootfd, (off_t)size, SEEK_SET) < 0) {
 446                 syslog(LOG_ERR, "SendReadRepl: lseek: %m (%s)",
 447                        EnetStr(rconn));
 448                 rpl->r_rrpl.rmp_retcode = RMP_E_ABORT;
 449                 retval = 1;
 450                 goto sendpkt;
 451         }
 452
 453         /*
 454          *  Read data directly into reply packet.
 455          */
 456         if ((size = read(oldconn->bootfd, &rpl->r_rrpl.rmp_data,
 457                          (int) ntohs(req->r_rrq.rmp_size))) <= 0) {
 458                 if (size < 0) {
 459                         syslog(LOG_ERR, "SendReadRepl: read: %m (%s)",
 460                                EnetStr(rconn));
 461                         rpl->r_rrpl.rmp_retcode = RMP_E_ABORT;
 462                 } else {
 463                         rpl->r_rrpl.rmp_retcode = RMP_E_EOF;
 464                 }
 465                 retval = 1;
 466                 goto sendpkt;
 467         }
 468
 469         /*
 470          *  Set success indication.
 471          */
 472         rpl->r_rrpl.rmp_retcode = RMP_E_OKAY;
 473
 474 sendpkt:
 475         /*
 476          *  Set up assorted fields in reply packet.
 477          */
 478         rpl->r_rrpl.rmp_type = RMP_READ_REPL;
 479         COPYWORD(req->r_rrq.rmp_offset, rpl->r_rrpl.rmp_offset);
 480         rpl->r_rrpl.rmp_session = req->r_rrq.rmp_session;
 481
 482         oldconn->rmplen = RMPREADSIZE(size);    /* set size of packet */
 483
 484         retval &= SendPacket(oldconn);          /* send packet */
 485
 486         if (madeconn)                           /* clean up after ourself */
 487                 FreeConn(oldconn);
 488
 489         return (retval);
 490 }
 491
 492 /*
 493 **  BootDone -- free up memory allocated for a connection.
 494 **
 495 **      Parameters:
 496 **              rconn - incoming boot complete packet.
 497 **
 498 **      Returns:
 499 **              1 on success, 0 on failure.
 500 **
 501 **      Side Effects:
 502 **              none.
 503 */
 504 int
 505 BootDone(RMPCONN *rconn)
 506 {
 507         RMPCONN *oldconn;
 508         struct rmp_packet *rpl;
 509
 510         /*
 511          *  If we cant find the connection, ignore the request.
 512          */
 513         if ((oldconn = FindConn(rconn)) == NULL) {
 514                 syslog(LOG_ERR, "BootDone: no existing connection (%s)",
 515                        EnetStr(rconn));
 516                 return(0);
 517         }
 518
 519         rpl = &oldconn->rmp;                    /* cache ptr to RMP packet */
 520
 521         /*
 522          *  Make sure Session ID's match.
 523          */
 524         if (ntohs(rconn->rmp.r_rrq.rmp_session) !=
 525             ((rpl->r_type == RMP_BOOT_REPL)? ntohs(rpl->r_brpl.rmp_session):
 526                                             ntohs(rpl->r_rrpl.rmp_session))) {
 527                 syslog(LOG_ERR, "BootDone: bad session id (%s)",
 528                        EnetStr(rconn));
 529                 return(0);
 530         }
 531
 532         RemoveConn(oldconn);                    /* remove connection */
 533
 534         syslog(LOG_INFO, "%s: boot complete", EnetStr(rconn));
 535
 536         return(1);
 537 }
 538
 539 /*
 540 **  SendPacket -- send an RMP packet to a remote host.
 541 **
 542 **      Parameters:
 543 **              rconn - packet to be sent.
 544 **
 545 **      Returns:
 546 **              1 on success, 0 on failure.
 547 **
 548 **      Side Effects:
 549 **              none.
 550 */
 551 int
 552 SendPacket(RMPCONN *rconn)
 553 {
 554         /*
 555          *  Set Ethernet Destination address to Source (BPF and the enet
 556          *  driver will take care of getting our source address set).
 557          */
 558         memmove((char *)&rconn->rmp.hp_hdr.daddr[0],
 559                 (char *)&rconn->rmp.hp_hdr.saddr[0], RMP_ADDRLEN);
 560         rconn->rmp.hp_hdr.len = htons(rconn->rmplen - sizeof(struct hp_hdr));
 561
 562         /*
 563          *  Reverse 802.2/HP Extended Source & Destination Access Pts.
 564          */
 565         rconn->rmp.hp_llc.dxsap = htons(HPEXT_SXSAP);
 566         rconn->rmp.hp_llc.sxsap = htons(HPEXT_DXSAP);
 567
 568         /*
 569          *  Last time this connection was active.
 570          */
 571         (void) gettimeofday(&rconn->tstamp, NULL);
 572
 573         if (DbgFp != NULL)                      /* display packet */
 574                 DispPkt(rconn,DIR_SENT);
 575
 576         /*
 577          *  Send RMP packet to remote host.
 578          */
 579         return(BpfWrite(rconn));
 580 }