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. All advertising materials mentioning features or use of this software
  22  *    must display the following acknowledgement:
  23  *      This product includes software developed by the University of
  24  *      California, Berkeley and its contributors.
  25  * 4. Neither the name of the University nor the names of its contributors
  26  *    may be used to endorse or promote products derived from this software
  27  *    without specific prior written permission.
  28  *
  29  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  30  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  31  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  32  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  33  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  34  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  35  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  36  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  37  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  38  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  39  * SUCH DAMAGE.
  40  *
  41  *      from: @(#)rmpproto.c    8.1 (Berkeley) 6/4/93
  42  *
  43  * From: Utah Hdr: rmpproto.c 3.1 92/07/06
  44  * Author: Jeff Forys, University of Utah CSS
  45  *
  46  * @(#)rmpproto.c       8.1 (Berkeley) 6/4/93
  47  * $FreeBSD: src/libexec/rbootd/rmpproto.c,v 1.6.2.1 2001/02/18 02:54:11 kris Exp $
  48  * $DragonFly: src/libexec/rbootd/rmpproto.c,v 1.2 2003/06/17 04:27:07 dillon Exp $
  49  */
  50
  51 #include <sys/param.h>
  52 #include <sys/time.h>
  53
  54 #include <errno.h>
  55 #include <fcntl.h>
  56 #include <stdio.h>
  57 #include <string.h>
  58 #include <syslog.h>
  59 #include <unistd.h>
  60 #include "defs.h"
  61
  62 /*
  63 **  ProcessPacket -- determine packet type and do what's required.
  64 **
  65 **      An RMP BOOT packet has been received.  Look at the type field
  66 **      and process Boot Requests, Read Requests, and Boot Complete
  67 **      packets.  Any other type will be dropped with a warning msg.
  68 **
  69 **      Parameters:
  70 **              rconn - the new connection
  71 **              client - list of files available to this host
  72 **
  73 **      Returns:
  74 **              Nothing.
  75 **
  76 **      Side Effects:
  77 **              - If this is a valid boot request, it will be added to
  78 **                the linked list of outstanding requests (RmpConns).
  79 **              - If this is a valid boot complete, its associated
  80 **                entry in RmpConns will be deleted.
  81 **              - Also, unless we run out of memory, a reply will be
  82 **                sent to the host that sent the packet.
  83 */
  84 void
  85 ProcessPacket(rconn, client)
  86         RMPCONN *rconn;
  87         CLIENT *client;
  88 {
  89         struct rmp_packet *rmp;
  90         RMPCONN *rconnout;
  91
  92         rmp = &rconn->rmp;              /* cache pointer to RMP packet */
  93
  94         switch(rmp->r_type) {           /* do what we came here to do */
  95                 case RMP_BOOT_REQ:              /* boot request */
  96                         if ((rconnout = NewConn(rconn)) == NULL)
  97                                 return;
  98
  99                         /*
 100                          *  If the Session ID is 0xffff, this is a "probe"
 101                          *  packet and we do not want to add the connection
 102                          *  to the linked list of active connections.  There
 103                          *  are two types of probe packets, if the Sequence
 104                          *  Number is 0 they want to know our host name, o/w
 105                          *  they want the name of the file associated with
 106                          *  the number spec'd by the Sequence Number.
 107                          *
 108                          *  If this is an actual boot request, open the file
 109                          *  and send a reply.  If SendBootRepl() does not
 110                          *  return 0, add the connection to the linked list
 111                          *  of active connections, otherwise delete it since
 112                          *  an error was encountered.
 113                          */
 114                         if (ntohs(rmp->r_brq.rmp_session) == RMP_PROBESID) {
 115                                 if (WORDZE(rmp->r_brq.rmp_seqno))
 116                                         (void) SendServerID(rconnout);
 117                                 else
 118                                         (void) SendFileNo(rmp, rconnout,
 119                                                           client? client->files:
 120                                                                   BootFiles);
 121                                 FreeConn(rconnout);
 122                         } else {
 123                                 if (SendBootRepl(rmp, rconnout,
 124                                     client? client->files: BootFiles))
 125                                         AddConn(rconnout);
 126                                 else
 127                                         FreeConn(rconnout);
 128                         }
 129                         break;
 130
 131                 case RMP_BOOT_REPL:             /* boot reply (not valid) */
 132                         syslog(LOG_WARNING, "%s: sent a boot reply",
 133                                EnetStr(rconn));
 134                         break;
 135
 136                 case RMP_READ_REQ:              /* read request */
 137                         /*
 138                          *  Send a portion of the boot file.
 139                          */
 140                         (void) SendReadRepl(rconn);
 141                         break;
 142
 143                 case RMP_READ_REPL:             /* read reply (not valid) */
 144                         syslog(LOG_WARNING, "%s: sent a read reply",
 145                                EnetStr(rconn));
 146                         break;
 147
 148                 case RMP_BOOT_DONE:             /* boot complete */
 149                         /*
 150                          *  Remove the entry from the linked list of active
 151                          *  connections.
 152                          */
 153                         (void) BootDone(rconn);
 154                         break;
 155
 156                 default:                        /* unknown RMP packet type */
 157                         syslog(LOG_WARNING, "%s: unknown packet type (%u)",
 158                                EnetStr(rconn), rmp->r_type);
 159         }
 160 }
 161
 162 /*
 163 **  SendServerID -- send our host name to who ever requested it.
 164 **
 165 **      Parameters:
 166 **              rconn - the reply packet to be formatted.
 167 **
 168 **      Returns:
 169 **              1 on success, 0 on failure.
 170 **
 171 **      Side Effects:
 172 **              none.
 173 */
 174 int
 175 SendServerID(rconn)
 176         RMPCONN *rconn;
 177 {
 178         struct rmp_packet *rpl;
 179         char *src, *dst;
 180         u_int8_t *size;
 181
 182         rpl = &rconn->rmp;                      /* cache ptr to RMP packet */
 183
 184         /*
 185          *  Set up assorted fields in reply packet.
 186          */
 187         rpl->r_brpl.rmp_type = RMP_BOOT_REPL;
 188         rpl->r_brpl.rmp_retcode = RMP_E_OKAY;
 189         ZEROWORD(rpl->r_brpl.rmp_seqno);
 190         rpl->r_brpl.rmp_session = 0;
 191         rpl->r_brpl.rmp_version = htons(RMP_VERSION);
 192
 193         size = &rpl->r_brpl.rmp_flnmsize;       /* ptr to length of host name */
 194
 195         /*
 196          *  Copy our host name into the reply packet incrementing the
 197          *  length as we go.  Stop at RMP_HOSTLEN or the first dot.
 198          */
 199         src = MyHost;
 200         dst = (char *) &rpl->r_brpl.rmp_flnm;
 201         for (*size = 0; *size < RMP_HOSTLEN; (*size)++) {
 202                 if (*src == '.' || *src == '\0')
 203                         break;
 204                 *dst++ = *src++;
 205         }
 206
 207         rconn->rmplen = RMPBOOTSIZE(*size);     /* set packet length */
 208
 209         return(SendPacket(rconn));              /* send packet */
 210 }
 211
 212 /*
 213 **  SendFileNo -- send the name of a bootable file to the requester.
 214 **
 215 **      Parameters:
 216 **              req - RMP BOOT packet containing the request.
 217 **              rconn - the reply packet to be formatted.
 218 **              filelist - list of files available to the requester.
 219 **
 220 **      Returns:
 221 **              1 on success, 0 on failure.
 222 **
 223 **      Side Effects:
 224 **              none.
 225 */
 226 int
 227 SendFileNo(req, rconn, filelist)
 228         struct rmp_packet *req;
 229         RMPCONN *rconn;
 230         char *filelist[];
 231 {
 232         struct rmp_packet *rpl;
 233         char *src, *dst;
 234         u_int8_t *size;
 235         int i;
 236
 237         GETWORD(req->r_brpl.rmp_seqno, i);      /* SeqNo is really FileNo */
 238         rpl = &rconn->rmp;                      /* cache ptr to RMP packet */
 239
 240         /*
 241          *  Set up assorted fields in reply packet.
 242          */
 243         rpl->r_brpl.rmp_type = RMP_BOOT_REPL;
 244         PUTWORD(i, rpl->r_brpl.rmp_seqno);
 245         i--;
 246         rpl->r_brpl.rmp_session = 0;
 247         rpl->r_brpl.rmp_version = htons(RMP_VERSION);
 248
 249         size = &rpl->r_brpl.rmp_flnmsize;       /* ptr to length of filename */
 250         *size = 0;                              /* init length to zero */
 251
 252         /*
 253          *  Copy the file name into the reply packet incrementing the
 254          *  length as we go.  Stop at end of string or when RMPBOOTDATA
 255          *  characters have been copied.  Also, set return code to
 256          *  indicate success or "no more files".
 257          */
 258         if (i < C_MAXFILE && filelist[i] != NULL) {
 259                 src = filelist[i];
 260                 dst = (char *)&rpl->r_brpl.rmp_flnm;
 261                 for (; *src && *size < RMPBOOTDATA; (*size)++) {
 262                         if (*src == '\0')
 263                                 break;
 264                         *dst++ = *src++;
 265                 }
 266                 rpl->r_brpl.rmp_retcode = RMP_E_OKAY;
 267         } else
 268                 rpl->r_brpl.rmp_retcode = RMP_E_NODFLT;
 269
 270         rconn->rmplen = RMPBOOTSIZE(*size);     /* set packet length */
 271
 272         return(SendPacket(rconn));              /* send packet */
 273 }
 274
 275 /*
 276 **  SendBootRepl -- open boot file and respond to boot request.
 277 **
 278 **      Parameters:
 279 **              req - RMP BOOT packet containing the request.
 280 **              rconn - the reply packet to be formatted.
 281 **              filelist - list of files available to the requester.
 282 **
 283 **      Returns:
 284 **              1 on success, 0 on failure.
 285 **
 286 **      Side Effects:
 287 **              none.
 288 */
 289 int
 290 SendBootRepl(req, rconn, filelist)
 291         struct rmp_packet *req;
 292         RMPCONN *rconn;
 293         char *filelist[];
 294 {
 295         int retval;
 296         char *filename, filepath[RMPBOOTDATA+1];
 297         RMPCONN *oldconn;
 298         struct rmp_packet *rpl;
 299         char *src, *dst1, *dst2;
 300         u_int8_t i;
 301
 302         /*
 303          *  If another connection already exists, delete it since we
 304          *  are obviously starting again.
 305          */
 306         if ((oldconn = FindConn(rconn)) != NULL) {
 307                 syslog(LOG_WARNING, "%s: dropping existing connection",
 308                        EnetStr(oldconn));
 309                 RemoveConn(oldconn);
 310         }
 311
 312         rpl = &rconn->rmp;                      /* cache ptr to RMP packet */
 313
 314         /*
 315          *  Set up assorted fields in reply packet.
 316          */
 317         rpl->r_brpl.rmp_type = RMP_BOOT_REPL;
 318         COPYWORD(req->r_brq.rmp_seqno, rpl->r_brpl.rmp_seqno);
 319         rpl->r_brpl.rmp_session = htons(GenSessID());
 320         rpl->r_brpl.rmp_version = htons(RMP_VERSION);
 321         rpl->r_brpl.rmp_flnmsize = req->r_brq.rmp_flnmsize;
 322
 323         /*
 324          *  Copy file name to `filepath' string, and into reply packet.
 325          */
 326         src = &req->r_brq.rmp_flnm;
 327         dst1 = filepath;
 328         dst2 = &rpl->r_brpl.rmp_flnm;
 329         for (i = 0; i < req->r_brq.rmp_flnmsize; i++)
 330                 *dst1++ = *dst2++ = *src++;
 331         *dst1 = '\0';
 332
 333         /*
 334          *  If we are booting HP-UX machines, their secondary loader will
 335          *  ask for files like "/hp-ux".  As a security measure, we do not
 336          *  allow boot files to lay outside the boot directory (unless they
 337          *  are purposely link'd out.  So, make `filename' become the path-
 338          *  stripped file name and spoof the client into thinking that it
 339          *  really got what it wanted.
 340          */
 341         filename = (filename = strrchr(filepath,'/'))? ++filename: filepath;
 342
 343         /*
 344          *  Check that this is a valid boot file name.
 345          */
 346         for (i = 0; i < C_MAXFILE && filelist[i] != NULL; i++)
 347                 if (STREQN(filename, filelist[i]))
 348                         goto match;
 349
 350         /*
 351          *  Invalid boot file name, set error and send reply packet.
 352          */
 353         rpl->r_brpl.rmp_retcode = RMP_E_NOFILE;
 354         retval = 0;
 355         goto sendpkt;
 356
 357 match:
 358         /*
 359          *  This is a valid boot file.  Open the file and save the file
 360          *  descriptor associated with this connection and set success
 361          *  indication.  If the file couldnt be opened, set error:
 362          *      "no such file or dir" - RMP_E_NOFILE
 363          *      "file table overflow" - RMP_E_BUSY
 364          *      "too many open files" - RMP_E_BUSY
 365          *      anything else         - RMP_E_OPENFILE
 366          */
 367         if ((rconn->bootfd = open(filename, O_RDONLY, 0600)) < 0) {
 368                 rpl->r_brpl.rmp_retcode = (errno == ENOENT)? RMP_E_NOFILE:
 369                         (errno == EMFILE || errno == ENFILE)? RMP_E_BUSY:
 370                         RMP_E_OPENFILE;
 371                 retval = 0;
 372         } else {
 373                 rpl->r_brpl.rmp_retcode = RMP_E_OKAY;
 374                 retval = 1;
 375         }
 376
 377 sendpkt:
 378         syslog(LOG_INFO, "%s: request to boot %s (%s)",
 379                EnetStr(rconn), filename, retval? "granted": "denied");
 380
 381         rconn->rmplen = RMPBOOTSIZE(rpl->r_brpl.rmp_flnmsize);
 382
 383         return (retval & SendPacket(rconn));
 384 }
 385
 386 /*
 387 **  SendReadRepl -- send a portion of the boot file to the requester.
 388 **
 389 **      Parameters:
 390 **              rconn - the reply packet to be formatted.
 391 **
 392 **      Returns:
 393 **              1 on success, 0 on failure.
 394 **
 395 **      Side Effects:
 396 **              none.
 397 */
 398 int
 399 SendReadRepl(rconn)
 400         RMPCONN *rconn;
 401 {
 402         int retval = 0;
 403         RMPCONN *oldconn;
 404         struct rmp_packet *rpl, *req;
 405         int size = 0;
 406         int madeconn = 0;
 407
 408         /*
 409          *  Find the old connection.  If one doesnt exist, create one only
 410          *  to return the error code.
 411          */
 412         if ((oldconn = FindConn(rconn)) == NULL) {
 413                 if ((oldconn = NewConn(rconn)) == NULL)
 414                         return(0);
 415                 syslog(LOG_ERR, "SendReadRepl: no active connection (%s)",
 416                        EnetStr(rconn));
 417                 madeconn++;
 418         }
 419
 420         req = &rconn->rmp;              /* cache ptr to request packet */
 421         rpl = &oldconn->rmp;            /* cache ptr to reply packet */
 422
 423         if (madeconn) {                 /* no active connection above; abort */
 424                 rpl->r_rrpl.rmp_retcode = RMP_E_ABORT;
 425                 retval = 1;
 426                 goto sendpkt;
 427         }
 428
 429         /*
 430          *  Make sure Session ID's match.
 431          */
 432         if (ntohs(req->r_rrq.rmp_session) !=
 433             ((rpl->r_type == RMP_BOOT_REPL)? ntohs(rpl->r_brpl.rmp_session):
 434                                              ntohs(rpl->r_rrpl.rmp_session))) {
 435                 syslog(LOG_ERR, "SendReadRepl: bad session id (%s)",
 436                        EnetStr(rconn));
 437                 rpl->r_rrpl.rmp_retcode = RMP_E_BADSID;
 438                 retval = 1;
 439                 goto sendpkt;
 440         }
 441
 442         /*
 443          *  If the requester asks for more data than we can fit,
 444          *  silently clamp the request size down to RMPREADDATA.
 445          *
 446          *  N.B. I do not know if this is "legal", however it seems
 447          *  to work.  This is necessary for bpfwrite() on machines
 448          *  with MCLBYTES less than 1514.
 449          */
 450         if (ntohs(req->r_rrq.rmp_size) > RMPREADDATA)
 451                 req->r_rrq.rmp_size = htons(RMPREADDATA);
 452
 453         /*
 454          *  Position read head on file according to info in request packet.
 455          */
 456         GETWORD(req->r_rrq.rmp_offset, size);
 457         if (lseek(oldconn->bootfd, (off_t)size, SEEK_SET) < 0) {
 458                 syslog(LOG_ERR, "SendReadRepl: lseek: %m (%s)",
 459                        EnetStr(rconn));
 460                 rpl->r_rrpl.rmp_retcode = RMP_E_ABORT;
 461                 retval = 1;
 462                 goto sendpkt;
 463         }
 464
 465         /*
 466          *  Read data directly into reply packet.
 467          */
 468         if ((size = read(oldconn->bootfd, &rpl->r_rrpl.rmp_data,
 469                          (int) ntohs(req->r_rrq.rmp_size))) <= 0) {
 470                 if (size < 0) {
 471                         syslog(LOG_ERR, "SendReadRepl: read: %m (%s)",
 472                                EnetStr(rconn));
 473                         rpl->r_rrpl.rmp_retcode = RMP_E_ABORT;
 474                 } else {
 475                         rpl->r_rrpl.rmp_retcode = RMP_E_EOF;
 476                 }
 477                 retval = 1;
 478                 goto sendpkt;
 479         }
 480
 481         /*
 482          *  Set success indication.
 483          */
 484         rpl->r_rrpl.rmp_retcode = RMP_E_OKAY;
 485
 486 sendpkt:
 487         /*
 488          *  Set up assorted fields in reply packet.
 489          */
 490         rpl->r_rrpl.rmp_type = RMP_READ_REPL;
 491         COPYWORD(req->r_rrq.rmp_offset, rpl->r_rrpl.rmp_offset);
 492         rpl->r_rrpl.rmp_session = req->r_rrq.rmp_session;
 493
 494         oldconn->rmplen = RMPREADSIZE(size);    /* set size of packet */
 495
 496         retval &= SendPacket(oldconn);          /* send packet */
 497
 498         if (madeconn)                           /* clean up after ourself */
 499                 FreeConn(oldconn);
 500
 501         return (retval);
 502 }
 503
 504 /*
 505 **  BootDone -- free up memory allocated for a connection.
 506 **
 507 **      Parameters:
 508 **              rconn - incoming boot complete packet.
 509 **
 510 **      Returns:
 511 **              1 on success, 0 on failure.
 512 **
 513 **      Side Effects:
 514 **              none.
 515 */
 516 int
 517 BootDone(rconn)
 518         RMPCONN *rconn;
 519 {
 520         RMPCONN *oldconn;
 521         struct rmp_packet *rpl;
 522
 523         /*
 524          *  If we cant find the connection, ignore the request.
 525          */
 526         if ((oldconn = FindConn(rconn)) == NULL) {
 527                 syslog(LOG_ERR, "BootDone: no existing connection (%s)",
 528                        EnetStr(rconn));
 529                 return(0);
 530         }
 531
 532         rpl = &oldconn->rmp;                    /* cache ptr to RMP packet */
 533
 534         /*
 535          *  Make sure Session ID's match.
 536          */
 537         if (ntohs(rconn->rmp.r_rrq.rmp_session) !=
 538             ((rpl->r_type == RMP_BOOT_REPL)? ntohs(rpl->r_brpl.rmp_session):
 539                                             ntohs(rpl->r_rrpl.rmp_session))) {
 540                 syslog(LOG_ERR, "BootDone: bad session id (%s)",
 541                        EnetStr(rconn));
 542                 return(0);
 543         }
 544
 545         RemoveConn(oldconn);                    /* remove connection */
 546
 547         syslog(LOG_INFO, "%s: boot complete", EnetStr(rconn));
 548
 549         return(1);
 550 }
 551
 552 /*
 553 **  SendPacket -- send an RMP packet to a remote host.
 554 **
 555 **      Parameters:
 556 **              rconn - packet to be sent.
 557 **
 558 **      Returns:
 559 **              1 on success, 0 on failure.
 560 **
 561 **      Side Effects:
 562 **              none.
 563 */
 564 int
 565 SendPacket(rconn)
 566         RMPCONN *rconn;
 567 {
 568         /*
 569          *  Set Ethernet Destination address to Source (BPF and the enet
 570          *  driver will take care of getting our source address set).
 571          */
 572         memmove((char *)&rconn->rmp.hp_hdr.daddr[0],
 573                 (char *)&rconn->rmp.hp_hdr.saddr[0], RMP_ADDRLEN);
 574         rconn->rmp.hp_hdr.len = htons(rconn->rmplen - sizeof(struct hp_hdr));
 575
 576         /*
 577          *  Reverse 802.2/HP Extended Source & Destination Access Pts.
 578          */
 579         rconn->rmp.hp_llc.dxsap = htons(HPEXT_SXSAP);
 580         rconn->rmp.hp_llc.sxsap = htons(HPEXT_DXSAP);
 581
 582         /*
 583          *  Last time this connection was active.
 584          */
 585         (void) gettimeofday(&rconn->tstamp, (struct timezone *)0);
 586
 587         if (DbgFp != NULL)                      /* display packet */
 588                 DispPkt(rconn,DIR_SENT);
 589
 590         /*
 591          *  Send RMP packet to remote host.
 592          */
 593         return(BpfWrite(rconn));
 594 }