xref: /freebsd/libexec/rbootd/rmpproto.c (revision 380a989b3223d455375b4fae70fd0b9bdd43bafb)
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 
47 #ifndef lint
48 #if 0
49 static const char sccsid[] = "@(#)rmpproto.c	8.1 (Berkeley) 6/4/93";
50 #endif
51 static const char rcsid[] =
52 	"$Id: rmpproto.c,v 1.4 1997/11/24 07:33:41 charnier Exp $";
53 #endif /* not lint */
54 
55 #include <sys/param.h>
56 #include <sys/time.h>
57 
58 #include <errno.h>
59 #include <fcntl.h>
60 #include <stdio.h>
61 #include <string.h>
62 #include <syslog.h>
63 #include <unistd.h>
64 #include "defs.h"
65 
66 /*
67 **  ProcessPacket -- determine packet type and do what's required.
68 **
69 **	An RMP BOOT packet has been received.  Look at the type field
70 **	and process Boot Requests, Read Requests, and Boot Complete
71 **	packets.  Any other type will be dropped with a warning msg.
72 **
73 **	Parameters:
74 **		rconn - the new connection
75 **		client - list of files available to this host
76 **
77 **	Returns:
78 **		Nothing.
79 **
80 **	Side Effects:
81 **		- If this is a valid boot request, it will be added to
82 **		  the linked list of outstanding requests (RmpConns).
83 **		- If this is a valid boot complete, its associated
84 **		  entry in RmpConns will be deleted.
85 **		- Also, unless we run out of memory, a reply will be
86 **		  sent to the host that sent the packet.
87 */
88 void
89 ProcessPacket(rconn, client)
90 	RMPCONN *rconn;
91 	CLIENT *client;
92 {
93 	struct rmp_packet *rmp;
94 	RMPCONN *rconnout;
95 
96 	rmp = &rconn->rmp;		/* cache pointer to RMP packet */
97 
98 	switch(rmp->r_type) {		/* do what we came here to do */
99 		case RMP_BOOT_REQ:		/* boot request */
100 			if ((rconnout = NewConn(rconn)) == NULL)
101 				return;
102 
103 			/*
104 			 *  If the Session ID is 0xffff, this is a "probe"
105 			 *  packet and we do not want to add the connection
106 			 *  to the linked list of active connections.  There
107 			 *  are two types of probe packets, if the Sequence
108 			 *  Number is 0 they want to know our host name, o/w
109 			 *  they want the name of the file associated with
110 			 *  the number spec'd by the Sequence Number.
111 			 *
112 			 *  If this is an actual boot request, open the file
113 			 *  and send a reply.  If SendBootRepl() does not
114 			 *  return 0, add the connection to the linked list
115 			 *  of active connections, otherwise delete it since
116 			 *  an error was encountered.
117 			 */
118 			if (ntohs(rmp->r_brq.rmp_session) == RMP_PROBESID) {
119 				if (WORDZE(rmp->r_brq.rmp_seqno))
120 					(void) SendServerID(rconnout);
121 				else
122 					(void) SendFileNo(rmp, rconnout,
123 					                  client? client->files:
124 					                          BootFiles);
125 				FreeConn(rconnout);
126 			} else {
127 				if (SendBootRepl(rmp, rconnout,
128 				    client? client->files: BootFiles))
129 					AddConn(rconnout);
130 				else
131 					FreeConn(rconnout);
132 			}
133 			break;
134 
135 		case RMP_BOOT_REPL:		/* boot reply (not valid) */
136 			syslog(LOG_WARNING, "%s: sent a boot reply",
137 			       EnetStr(rconn));
138 			break;
139 
140 		case RMP_READ_REQ:		/* read request */
141 			/*
142 			 *  Send a portion of the boot file.
143 			 */
144 			(void) SendReadRepl(rconn);
145 			break;
146 
147 		case RMP_READ_REPL:		/* read reply (not valid) */
148 			syslog(LOG_WARNING, "%s: sent a read reply",
149 			       EnetStr(rconn));
150 			break;
151 
152 		case RMP_BOOT_DONE:		/* boot complete */
153 			/*
154 			 *  Remove the entry from the linked list of active
155 			 *  connections.
156 			 */
157 			(void) BootDone(rconn);
158 			break;
159 
160 		default:			/* unknown RMP packet type */
161 			syslog(LOG_WARNING, "%s: unknown packet type (%u)",
162 			       EnetStr(rconn), rmp->r_type);
163 	}
164 }
165 
166 /*
167 **  SendServerID -- send our host name to who ever requested it.
168 **
169 **	Parameters:
170 **		rconn - the reply packet to be formatted.
171 **
172 **	Returns:
173 **		1 on success, 0 on failure.
174 **
175 **	Side Effects:
176 **		none.
177 */
178 int
179 SendServerID(rconn)
180 	RMPCONN *rconn;
181 {
182 	struct rmp_packet *rpl;
183 	char *src, *dst;
184 	u_int8_t *size;
185 
186 	rpl = &rconn->rmp;			/* cache ptr to RMP packet */
187 
188 	/*
189 	 *  Set up assorted fields in reply packet.
190 	 */
191 	rpl->r_brpl.rmp_type = RMP_BOOT_REPL;
192 	rpl->r_brpl.rmp_retcode = RMP_E_OKAY;
193 	ZEROWORD(rpl->r_brpl.rmp_seqno);
194 	rpl->r_brpl.rmp_session = 0;
195 	rpl->r_brpl.rmp_version = htons(RMP_VERSION);
196 
197 	size = &rpl->r_brpl.rmp_flnmsize;	/* ptr to length of host name */
198 
199 	/*
200 	 *  Copy our host name into the reply packet incrementing the
201 	 *  length as we go.  Stop at RMP_HOSTLEN or the first dot.
202 	 */
203 	src = MyHost;
204 	dst = (char *) &rpl->r_brpl.rmp_flnm;
205 	for (*size = 0; *size < RMP_HOSTLEN; (*size)++) {
206 		if (*src == '.' || *src == '\0')
207 			break;
208 		*dst++ = *src++;
209 	}
210 
211 	rconn->rmplen = RMPBOOTSIZE(*size);	/* set packet length */
212 
213 	return(SendPacket(rconn));		/* send packet */
214 }
215 
216 /*
217 **  SendFileNo -- send the name of a bootable file to the requester.
218 **
219 **	Parameters:
220 **		req - RMP BOOT packet containing the request.
221 **		rconn - the reply packet to be formatted.
222 **		filelist - list of files available to the requester.
223 **
224 **	Returns:
225 **		1 on success, 0 on failure.
226 **
227 **	Side Effects:
228 **		none.
229 */
230 int
231 SendFileNo(req, rconn, filelist)
232 	struct rmp_packet *req;
233 	RMPCONN *rconn;
234 	char *filelist[];
235 {
236 	struct rmp_packet *rpl;
237 	char *src, *dst;
238 	u_int8_t *size;
239 	int i;
240 
241 	GETWORD(req->r_brpl.rmp_seqno, i);	/* SeqNo is really FileNo */
242 	rpl = &rconn->rmp;			/* cache ptr to RMP packet */
243 
244 	/*
245 	 *  Set up assorted fields in reply packet.
246 	 */
247 	rpl->r_brpl.rmp_type = RMP_BOOT_REPL;
248 	PUTWORD(i, rpl->r_brpl.rmp_seqno);
249 	i--;
250 	rpl->r_brpl.rmp_session = 0;
251 	rpl->r_brpl.rmp_version = htons(RMP_VERSION);
252 
253 	size = &rpl->r_brpl.rmp_flnmsize;	/* ptr to length of filename */
254 	*size = 0;				/* init length to zero */
255 
256 	/*
257 	 *  Copy the file name into the reply packet incrementing the
258 	 *  length as we go.  Stop at end of string or when RMPBOOTDATA
259 	 *  characters have been copied.  Also, set return code to
260 	 *  indicate success or "no more files".
261 	 */
262 	if (i < C_MAXFILE && filelist[i] != NULL) {
263 		src = filelist[i];
264 		dst = (char *)&rpl->r_brpl.rmp_flnm;
265 		for (; *src && *size < RMPBOOTDATA; (*size)++) {
266 			if (*src == '\0')
267 				break;
268 			*dst++ = *src++;
269 		}
270 		rpl->r_brpl.rmp_retcode = RMP_E_OKAY;
271 	} else
272 		rpl->r_brpl.rmp_retcode = RMP_E_NODFLT;
273 
274 	rconn->rmplen = RMPBOOTSIZE(*size);	/* set packet length */
275 
276 	return(SendPacket(rconn));		/* send packet */
277 }
278 
279 /*
280 **  SendBootRepl -- open boot file and respond to boot request.
281 **
282 **	Parameters:
283 **		req - RMP BOOT packet containing the request.
284 **		rconn - the reply packet to be formatted.
285 **		filelist - list of files available to the requester.
286 **
287 **	Returns:
288 **		1 on success, 0 on failure.
289 **
290 **	Side Effects:
291 **		none.
292 */
293 int
294 SendBootRepl(req, rconn, filelist)
295 	struct rmp_packet *req;
296 	RMPCONN *rconn;
297 	char *filelist[];
298 {
299 	int retval;
300 	char *filename, filepath[RMPBOOTDATA+1];
301 	RMPCONN *oldconn;
302 	struct rmp_packet *rpl;
303 	char *src, *dst1, *dst2;
304 	u_int8_t i;
305 
306 	/*
307 	 *  If another connection already exists, delete it since we
308 	 *  are obviously starting again.
309 	 */
310 	if ((oldconn = FindConn(rconn)) != NULL) {
311 		syslog(LOG_WARNING, "%s: dropping existing connection",
312 		       EnetStr(oldconn));
313 		RemoveConn(oldconn);
314 	}
315 
316 	rpl = &rconn->rmp;			/* cache ptr to RMP packet */
317 
318 	/*
319 	 *  Set up assorted fields in reply packet.
320 	 */
321 	rpl->r_brpl.rmp_type = RMP_BOOT_REPL;
322 	COPYWORD(req->r_brq.rmp_seqno, rpl->r_brpl.rmp_seqno);
323 	rpl->r_brpl.rmp_session = htons(GenSessID());
324 	rpl->r_brpl.rmp_version = htons(RMP_VERSION);
325 	rpl->r_brpl.rmp_flnmsize = req->r_brq.rmp_flnmsize;
326 
327 	/*
328 	 *  Copy file name to `filepath' string, and into reply packet.
329 	 */
330 	src = &req->r_brq.rmp_flnm;
331 	dst1 = filepath;
332 	dst2 = &rpl->r_brpl.rmp_flnm;
333 	for (i = 0; i < req->r_brq.rmp_flnmsize; i++)
334 		*dst1++ = *dst2++ = *src++;
335 	*dst1 = '\0';
336 
337 	/*
338 	 *  If we are booting HP-UX machines, their secondary loader will
339 	 *  ask for files like "/hp-ux".  As a security measure, we do not
340 	 *  allow boot files to lay outside the boot directory (unless they
341 	 *  are purposely link'd out.  So, make `filename' become the path-
342 	 *  stripped file name and spoof the client into thinking that it
343 	 *  really got what it wanted.
344 	 */
345 	filename = (filename = strrchr(filepath,'/'))? ++filename: filepath;
346 
347 	/*
348 	 *  Check that this is a valid boot file name.
349 	 */
350 	for (i = 0; i < C_MAXFILE && filelist[i] != NULL; i++)
351 		if (STREQN(filename, filelist[i]))
352 			goto match;
353 
354 	/*
355 	 *  Invalid boot file name, set error and send reply packet.
356 	 */
357 	rpl->r_brpl.rmp_retcode = RMP_E_NOFILE;
358 	retval = 0;
359 	goto sendpkt;
360 
361 match:
362 	/*
363 	 *  This is a valid boot file.  Open the file and save the file
364 	 *  descriptor associated with this connection and set success
365 	 *  indication.  If the file couldnt be opened, set error:
366 	 *  	"no such file or dir" - RMP_E_NOFILE
367 	 *	"file table overflow" - RMP_E_BUSY
368 	 *	"too many open files" - RMP_E_BUSY
369 	 *	anything else         - RMP_E_OPENFILE
370 	 */
371 	if ((rconn->bootfd = open(filename, O_RDONLY, 0600)) < 0) {
372 		rpl->r_brpl.rmp_retcode = (errno == ENOENT)? RMP_E_NOFILE:
373 			(errno == EMFILE || errno == ENFILE)? RMP_E_BUSY:
374 			RMP_E_OPENFILE;
375 		retval = 0;
376 	} else {
377 		rpl->r_brpl.rmp_retcode = RMP_E_OKAY;
378 		retval = 1;
379 	}
380 
381 sendpkt:
382 	syslog(LOG_INFO, "%s: request to boot %s (%s)",
383 	       EnetStr(rconn), filename, retval? "granted": "denied");
384 
385 	rconn->rmplen = RMPBOOTSIZE(rpl->r_brpl.rmp_flnmsize);
386 
387 	return (retval & SendPacket(rconn));
388 }
389 
390 /*
391 **  SendReadRepl -- send a portion of the boot file to the requester.
392 **
393 **	Parameters:
394 **		rconn - the reply packet to be formatted.
395 **
396 **	Returns:
397 **		1 on success, 0 on failure.
398 **
399 **	Side Effects:
400 **		none.
401 */
402 int
403 SendReadRepl(rconn)
404 	RMPCONN *rconn;
405 {
406 	int retval = 0;
407 	RMPCONN *oldconn;
408 	struct rmp_packet *rpl, *req;
409 	int size = 0;
410 	int madeconn = 0;
411 
412 	/*
413 	 *  Find the old connection.  If one doesnt exist, create one only
414 	 *  to return the error code.
415 	 */
416 	if ((oldconn = FindConn(rconn)) == NULL) {
417 		if ((oldconn = NewConn(rconn)) == NULL)
418 			return(0);
419 		syslog(LOG_ERR, "SendReadRepl: no active connection (%s)",
420 		       EnetStr(rconn));
421 		madeconn++;
422 	}
423 
424 	req = &rconn->rmp;		/* cache ptr to request packet */
425 	rpl = &oldconn->rmp;		/* cache ptr to reply packet */
426 
427 	if (madeconn) {			/* no active connection above; abort */
428 		rpl->r_rrpl.rmp_retcode = RMP_E_ABORT;
429 		retval = 1;
430 		goto sendpkt;
431 	}
432 
433 	/*
434 	 *  Make sure Session ID's match.
435 	 */
436 	if (ntohs(req->r_rrq.rmp_session) !=
437 	    ((rpl->r_type == RMP_BOOT_REPL)? ntohs(rpl->r_brpl.rmp_session):
438 	                                     ntohs(rpl->r_rrpl.rmp_session))) {
439 		syslog(LOG_ERR, "SendReadRepl: bad session id (%s)",
440 		       EnetStr(rconn));
441 		rpl->r_rrpl.rmp_retcode = RMP_E_BADSID;
442 		retval = 1;
443 		goto sendpkt;
444 	}
445 
446 	/*
447 	 *  If the requester asks for more data than we can fit,
448 	 *  silently clamp the request size down to RMPREADDATA.
449 	 *
450 	 *  N.B. I do not know if this is "legal", however it seems
451 	 *  to work.  This is necessary for bpfwrite() on machines
452 	 *  with MCLBYTES less than 1514.
453 	 */
454 	if (ntohs(req->r_rrq.rmp_size) > RMPREADDATA)
455 		req->r_rrq.rmp_size = htons(RMPREADDATA);
456 
457 	/*
458 	 *  Position read head on file according to info in request packet.
459 	 */
460 	GETWORD(req->r_rrq.rmp_offset, size);
461 	if (lseek(oldconn->bootfd, (off_t)size, L_SET) < 0) {
462 		syslog(LOG_ERR, "SendReadRepl: lseek: %m (%s)",
463 		       EnetStr(rconn));
464 		rpl->r_rrpl.rmp_retcode = RMP_E_ABORT;
465 		retval = 1;
466 		goto sendpkt;
467 	}
468 
469 	/*
470 	 *  Read data directly into reply packet.
471 	 */
472 	if ((size = read(oldconn->bootfd, &rpl->r_rrpl.rmp_data,
473 	                 (int) ntohs(req->r_rrq.rmp_size))) <= 0) {
474 		if (size < 0) {
475 			syslog(LOG_ERR, "SendReadRepl: read: %m (%s)",
476 			       EnetStr(rconn));
477 			rpl->r_rrpl.rmp_retcode = RMP_E_ABORT;
478 		} else {
479 			rpl->r_rrpl.rmp_retcode = RMP_E_EOF;
480 		}
481 		retval = 1;
482 		goto sendpkt;
483 	}
484 
485 	/*
486 	 *  Set success indication.
487 	 */
488 	rpl->r_rrpl.rmp_retcode = RMP_E_OKAY;
489 
490 sendpkt:
491 	/*
492 	 *  Set up assorted fields in reply packet.
493 	 */
494 	rpl->r_rrpl.rmp_type = RMP_READ_REPL;
495 	COPYWORD(req->r_rrq.rmp_offset, rpl->r_rrpl.rmp_offset);
496 	rpl->r_rrpl.rmp_session = req->r_rrq.rmp_session;
497 
498 	oldconn->rmplen = RMPREADSIZE(size);	/* set size of packet */
499 
500 	retval &= SendPacket(oldconn);		/* send packet */
501 
502 	if (madeconn)				/* clean up after ourself */
503 		FreeConn(oldconn);
504 
505 	return (retval);
506 }
507 
508 /*
509 **  BootDone -- free up memory allocated for a connection.
510 **
511 **	Parameters:
512 **		rconn - incoming boot complete packet.
513 **
514 **	Returns:
515 **		1 on success, 0 on failure.
516 **
517 **	Side Effects:
518 **		none.
519 */
520 int
521 BootDone(rconn)
522 	RMPCONN *rconn;
523 {
524 	RMPCONN *oldconn;
525 	struct rmp_packet *rpl;
526 
527 	/*
528 	 *  If we cant find the connection, ignore the request.
529 	 */
530 	if ((oldconn = FindConn(rconn)) == NULL) {
531 		syslog(LOG_ERR, "BootDone: no existing connection (%s)",
532 		       EnetStr(rconn));
533 		return(0);
534 	}
535 
536 	rpl = &oldconn->rmp;			/* cache ptr to RMP packet */
537 
538 	/*
539 	 *  Make sure Session ID's match.
540 	 */
541 	if (ntohs(rconn->rmp.r_rrq.rmp_session) !=
542 	    ((rpl->r_type == RMP_BOOT_REPL)? ntohs(rpl->r_brpl.rmp_session):
543 	                                    ntohs(rpl->r_rrpl.rmp_session))) {
544 		syslog(LOG_ERR, "BootDone: bad session id (%s)",
545 		       EnetStr(rconn));
546 		return(0);
547 	}
548 
549 	RemoveConn(oldconn);			/* remove connection */
550 
551 	syslog(LOG_INFO, "%s: boot complete", EnetStr(rconn));
552 
553 	return(1);
554 }
555 
556 /*
557 **  SendPacket -- send an RMP packet to a remote host.
558 **
559 **	Parameters:
560 **		rconn - packet to be sent.
561 **
562 **	Returns:
563 **		1 on success, 0 on failure.
564 **
565 **	Side Effects:
566 **		none.
567 */
568 int
569 SendPacket(rconn)
570 	RMPCONN *rconn;
571 {
572 	/*
573 	 *  Set Ethernet Destination address to Source (BPF and the enet
574 	 *  driver will take care of getting our source address set).
575 	 */
576 	memmove((char *)&rconn->rmp.hp_hdr.daddr[0],
577 	        (char *)&rconn->rmp.hp_hdr.saddr[0], RMP_ADDRLEN);
578 	rconn->rmp.hp_hdr.len = htons(rconn->rmplen - sizeof(struct hp_hdr));
579 
580 	/*
581 	 *  Reverse 802.2/HP Extended Source & Destination Access Pts.
582 	 */
583 	rconn->rmp.hp_llc.dxsap = htons(HPEXT_SXSAP);
584 	rconn->rmp.hp_llc.sxsap = htons(HPEXT_DXSAP);
585 
586 	/*
587 	 *  Last time this connection was active.
588 	 */
589 	(void) gettimeofday(&rconn->tstamp, (struct timezone *)0);
590 
591 	if (DbgFp != NULL)			/* display packet */
592 		DispPkt(rconn,DIR_SENT);
593 
594 	/*
595 	 *  Send RMP packet to remote host.
596 	 */
597 	return(BpfWrite(rconn));
598 }
599