xref: /freebsd/libexec/rbootd/rmpproto.c (revision 2008043f386721d58158e37e0d7e50df8095942d)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1988, 1992 The University of Utah and the Center
5  *	for Software Science (CSS).
6  * Copyright (c) 1992, 1993
7  *	The Regents of the University of California.  All rights reserved.
8  *
9  * This code is derived from software contributed to Berkeley by
10  * the Center for Software Science of the University of Utah Computer
11  * Science Department.  CSS requests users of this software to return
12  * to css-dist@cs.utah.edu any improvements that they make and grant
13  * CSS redistribution rights.
14  *
15  * Redistribution and use in source and binary forms, with or without
16  * modification, are permitted provided that the following conditions
17  * are met:
18  * 1. Redistributions of source code must retain the above copyright
19  *    notice, this list of conditions and the following disclaimer.
20  * 2. Redistributions in binary form must reproduce the above copyright
21  *    notice, this list of conditions and the following disclaimer in the
22  *    documentation and/or other materials provided with the distribution.
23  * 3. 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  *	from: @(#)rmpproto.c	8.1 (Berkeley) 6/4/93
40  *
41  * From: Utah Hdr: rmpproto.c 3.1 92/07/06
42  * Author: Jeff Forys, University of Utah CSS
43  */
44 
45 #ifndef lint
46 #if 0
47 static const char sccsid[] = "@(#)rmpproto.c	8.1 (Berkeley) 6/4/93";
48 #endif
49 #endif /* not lint */
50 
51 #include <sys/param.h>
52 #include <sys/time.h>
53 #include <netinet/in.h>
54 
55 #include <errno.h>
56 #include <fcntl.h>
57 #include <stdio.h>
58 #include <string.h>
59 #include <syslog.h>
60 #include <unistd.h>
61 #include "defs.h"
62 
63 /*
64 **  ProcessPacket -- determine packet type and do what's required.
65 **
66 **	An RMP BOOT packet has been received.  Look at the type field
67 **	and process Boot Requests, Read Requests, and Boot Complete
68 **	packets.  Any other type will be dropped with a warning msg.
69 **
70 **	Parameters:
71 **		rconn - the new connection
72 **		client - list of files available to this host
73 **
74 **	Returns:
75 **		Nothing.
76 **
77 **	Side Effects:
78 **		- If this is a valid boot request, it will be added to
79 **		  the linked list of outstanding requests (RmpConns).
80 **		- If this is a valid boot complete, its associated
81 **		  entry in RmpConns will be deleted.
82 **		- Also, unless we run out of memory, a reply will be
83 **		  sent to the host that sent the packet.
84 */
85 void
86 ProcessPacket(RMPCONN *rconn, CLIENT *client)
87 {
88 	struct rmp_packet *rmp;
89 	RMPCONN *rconnout;
90 
91 	rmp = &rconn->rmp;		/* cache pointer to RMP packet */
92 
93 	switch(rmp->r_type) {		/* do what we came here to do */
94 		case RMP_BOOT_REQ:		/* boot request */
95 			if ((rconnout = NewConn(rconn)) == NULL)
96 				return;
97 
98 			/*
99 			 *  If the Session ID is 0xffff, this is a "probe"
100 			 *  packet and we do not want to add the connection
101 			 *  to the linked list of active connections.  There
102 			 *  are two types of probe packets, if the Sequence
103 			 *  Number is 0 they want to know our host name, o/w
104 			 *  they want the name of the file associated with
105 			 *  the number spec'd by the Sequence Number.
106 			 *
107 			 *  If this is an actual boot request, open the file
108 			 *  and send a reply.  If SendBootRepl() does not
109 			 *  return 0, add the connection to the linked list
110 			 *  of active connections, otherwise delete it since
111 			 *  an error was encountered.
112 			 */
113 			if (ntohs(rmp->r_brq.rmp_session) == RMP_PROBESID) {
114 				if (WORDZE(rmp->r_brq.rmp_seqno))
115 					(void) SendServerID(rconnout);
116 				else
117 					(void) SendFileNo(rmp, rconnout,
118 					                  client? client->files:
119 					                          BootFiles);
120 				FreeConn(rconnout);
121 			} else {
122 				if (SendBootRepl(rmp, rconnout,
123 				    client? client->files: BootFiles))
124 					AddConn(rconnout);
125 				else
126 					FreeConn(rconnout);
127 			}
128 			break;
129 
130 		case RMP_BOOT_REPL:		/* boot reply (not valid) */
131 			syslog(LOG_WARNING, "%s: sent a boot reply",
132 			       EnetStr(rconn));
133 			break;
134 
135 		case RMP_READ_REQ:		/* read request */
136 			/*
137 			 *  Send a portion of the boot file.
138 			 */
139 			(void) SendReadRepl(rconn);
140 			break;
141 
142 		case RMP_READ_REPL:		/* read reply (not valid) */
143 			syslog(LOG_WARNING, "%s: sent a read reply",
144 			       EnetStr(rconn));
145 			break;
146 
147 		case RMP_BOOT_DONE:		/* boot complete */
148 			/*
149 			 *  Remove the entry from the linked list of active
150 			 *  connections.
151 			 */
152 			(void) BootDone(rconn);
153 			break;
154 
155 		default:			/* unknown RMP packet type */
156 			syslog(LOG_WARNING, "%s: unknown packet type (%u)",
157 			       EnetStr(rconn), rmp->r_type);
158 	}
159 }
160 
161 /*
162 **  SendServerID -- send our host name to who ever requested it.
163 **
164 **	Parameters:
165 **		rconn - the reply packet to be formatted.
166 **
167 **	Returns:
168 **		1 on success, 0 on failure.
169 **
170 **	Side Effects:
171 **		none.
172 */
173 int
174 SendServerID(RMPCONN *rconn)
175 {
176 	struct rmp_packet *rpl;
177 	char *src, *dst;
178 	u_int8_t *size;
179 
180 	rpl = &rconn->rmp;			/* cache ptr to RMP packet */
181 
182 	/*
183 	 *  Set up assorted fields in reply packet.
184 	 */
185 	rpl->r_brpl.rmp_type = RMP_BOOT_REPL;
186 	rpl->r_brpl.rmp_retcode = RMP_E_OKAY;
187 	ZEROWORD(rpl->r_brpl.rmp_seqno);
188 	rpl->r_brpl.rmp_session = 0;
189 	rpl->r_brpl.rmp_version = htons(RMP_VERSION);
190 
191 	size = &rpl->r_brpl.rmp_flnmsize;	/* ptr to length of host name */
192 
193 	/*
194 	 *  Copy our host name into the reply packet incrementing the
195 	 *  length as we go.  Stop at RMP_HOSTLEN or the first dot.
196 	 */
197 	src = MyHost;
198 	dst = (char *) &rpl->r_brpl.rmp_flnm;
199 	for (*size = 0; *size < RMP_HOSTLEN; (*size)++) {
200 		if (*src == '.' || *src == '\0')
201 			break;
202 		*dst++ = *src++;
203 	}
204 
205 	rconn->rmplen = RMPBOOTSIZE(*size);	/* set packet length */
206 
207 	return(SendPacket(rconn));		/* send packet */
208 }
209 
210 /*
211 **  SendFileNo -- send the name of a bootable file to the requester.
212 **
213 **	Parameters:
214 **		req - RMP BOOT packet containing the request.
215 **		rconn - the reply packet to be formatted.
216 **		filelist - list of files available to the requester.
217 **
218 **	Returns:
219 **		1 on success, 0 on failure.
220 **
221 **	Side Effects:
222 **		none.
223 */
224 int
225 SendFileNo(struct rmp_packet *req, RMPCONN *rconn, char *filelist[])
226 {
227 	struct rmp_packet *rpl;
228 	char *src, *dst;
229 	u_int8_t *size;
230 	int i;
231 
232 	GETWORD(req->r_brpl.rmp_seqno, i);	/* SeqNo is really FileNo */
233 	rpl = &rconn->rmp;			/* cache ptr to RMP packet */
234 
235 	/*
236 	 *  Set up assorted fields in reply packet.
237 	 */
238 	rpl->r_brpl.rmp_type = RMP_BOOT_REPL;
239 	PUTWORD(i, rpl->r_brpl.rmp_seqno);
240 	i--;
241 	rpl->r_brpl.rmp_session = 0;
242 	rpl->r_brpl.rmp_version = htons(RMP_VERSION);
243 
244 	size = &rpl->r_brpl.rmp_flnmsize;	/* ptr to length of filename */
245 	*size = 0;				/* init length to zero */
246 
247 	/*
248 	 *  Copy the file name into the reply packet incrementing the
249 	 *  length as we go.  Stop at end of string or when RMPBOOTDATA
250 	 *  characters have been copied.  Also, set return code to
251 	 *  indicate success or "no more files".
252 	 */
253 	if (i < C_MAXFILE && filelist[i] != NULL) {
254 		src = filelist[i];
255 		dst = (char *)&rpl->r_brpl.rmp_flnm;
256 		for (; *src && *size < RMPBOOTDATA; (*size)++) {
257 			if (*src == '\0')
258 				break;
259 			*dst++ = *src++;
260 		}
261 		rpl->r_brpl.rmp_retcode = RMP_E_OKAY;
262 	} else
263 		rpl->r_brpl.rmp_retcode = RMP_E_NODFLT;
264 
265 	rconn->rmplen = RMPBOOTSIZE(*size);	/* set packet length */
266 
267 	return(SendPacket(rconn));		/* send packet */
268 }
269 
270 /*
271 **  SendBootRepl -- open boot file and respond to boot request.
272 **
273 **	Parameters:
274 **		req - RMP BOOT packet containing the request.
275 **		rconn - the reply packet to be formatted.
276 **		filelist - list of files available to the requester.
277 **
278 **	Returns:
279 **		1 on success, 0 on failure.
280 **
281 **	Side Effects:
282 **		none.
283 */
284 int
285 SendBootRepl(struct rmp_packet *req, RMPCONN *rconn, char *filelist[])
286 {
287 	int retval;
288 	char *filename, filepath[RMPBOOTDATA+1];
289 	RMPCONN *oldconn;
290 	struct rmp_packet *rpl;
291 	char *src, *dst1, *dst2;
292 	u_int8_t i;
293 
294 	/*
295 	 *  If another connection already exists, delete it since we
296 	 *  are obviously starting again.
297 	 */
298 	if ((oldconn = FindConn(rconn)) != NULL) {
299 		syslog(LOG_WARNING, "%s: dropping existing connection",
300 		       EnetStr(oldconn));
301 		RemoveConn(oldconn);
302 	}
303 
304 	rpl = &rconn->rmp;			/* cache ptr to RMP packet */
305 
306 	/*
307 	 *  Set up assorted fields in reply packet.
308 	 */
309 	rpl->r_brpl.rmp_type = RMP_BOOT_REPL;
310 	COPYWORD(req->r_brq.rmp_seqno, rpl->r_brpl.rmp_seqno);
311 	rpl->r_brpl.rmp_session = htons(GenSessID());
312 	rpl->r_brpl.rmp_version = htons(RMP_VERSION);
313 	rpl->r_brpl.rmp_flnmsize = req->r_brq.rmp_flnmsize;
314 
315 	/*
316 	 *  Copy file name to `filepath' string, and into reply packet.
317 	 */
318 	src = &req->r_brq.rmp_flnm;
319 	dst1 = filepath;
320 	dst2 = &rpl->r_brpl.rmp_flnm;
321 	for (i = 0; i < req->r_brq.rmp_flnmsize; i++)
322 		*dst1++ = *dst2++ = *src++;
323 	*dst1 = '\0';
324 
325 	/*
326 	 *  If we are booting HP-UX machines, their secondary loader will
327 	 *  ask for files like "/hp-ux".  As a security measure, we do not
328 	 *  allow boot files to lay outside the boot directory (unless they
329 	 *  are purposely link'd out.  So, make `filename' become the path-
330 	 *  stripped file name and spoof the client into thinking that it
331 	 *  really got what it wanted.
332 	 */
333 	filename = strrchr(filepath,'/');
334 	filename = filename? filename + 1: filepath;
335 
336 	/*
337 	 *  Check that this is a valid boot file name.
338 	 */
339 	for (i = 0; i < C_MAXFILE && filelist[i] != NULL; i++)
340 		if (STREQN(filename, filelist[i]))
341 			goto match;
342 
343 	/*
344 	 *  Invalid boot file name, set error and send reply packet.
345 	 */
346 	rpl->r_brpl.rmp_retcode = RMP_E_NOFILE;
347 	retval = 0;
348 	goto sendpkt;
349 
350 match:
351 	/*
352 	 *  This is a valid boot file.  Open the file and save the file
353 	 *  descriptor associated with this connection and set success
354 	 *  indication.  If the file couldnt be opened, set error:
355 	 *  	"no such file or dir" - RMP_E_NOFILE
356 	 *	"file table overflow" - RMP_E_BUSY
357 	 *	"too many open files" - RMP_E_BUSY
358 	 *	anything else         - RMP_E_OPENFILE
359 	 */
360 	if ((rconn->bootfd = open(filename, O_RDONLY, 0600)) < 0) {
361 		rpl->r_brpl.rmp_retcode = (errno == ENOENT)? RMP_E_NOFILE:
362 			(errno == EMFILE || errno == ENFILE)? RMP_E_BUSY:
363 			RMP_E_OPENFILE;
364 		retval = 0;
365 	} else {
366 		rpl->r_brpl.rmp_retcode = RMP_E_OKAY;
367 		retval = 1;
368 	}
369 
370 sendpkt:
371 	syslog(LOG_INFO, "%s: request to boot %s (%s)",
372 	       EnetStr(rconn), filename, retval? "granted": "denied");
373 
374 	rconn->rmplen = RMPBOOTSIZE(rpl->r_brpl.rmp_flnmsize);
375 
376 	return (retval & SendPacket(rconn));
377 }
378 
379 /*
380 **  SendReadRepl -- send a portion of the boot file to the requester.
381 **
382 **	Parameters:
383 **		rconn - the reply packet to be formatted.
384 **
385 **	Returns:
386 **		1 on success, 0 on failure.
387 **
388 **	Side Effects:
389 **		none.
390 */
391 int
392 SendReadRepl(RMPCONN *rconn)
393 {
394 	int retval = 0;
395 	RMPCONN *oldconn;
396 	struct rmp_packet *rpl, *req;
397 	int size = 0;
398 	int madeconn = 0;
399 
400 	/*
401 	 *  Find the old connection.  If one doesn't exist, create one only
402 	 *  to return the error code.
403 	 */
404 	if ((oldconn = FindConn(rconn)) == NULL) {
405 		if ((oldconn = NewConn(rconn)) == NULL)
406 			return(0);
407 		syslog(LOG_ERR, "SendReadRepl: no active connection (%s)",
408 		       EnetStr(rconn));
409 		madeconn++;
410 	}
411 
412 	req = &rconn->rmp;		/* cache ptr to request packet */
413 	rpl = &oldconn->rmp;		/* cache ptr to reply packet */
414 
415 	if (madeconn) {			/* no active connection above; abort */
416 		rpl->r_rrpl.rmp_retcode = RMP_E_ABORT;
417 		retval = 1;
418 		goto sendpkt;
419 	}
420 
421 	/*
422 	 *  Make sure Session ID's match.
423 	 */
424 	if (ntohs(req->r_rrq.rmp_session) !=
425 	    ((rpl->r_type == RMP_BOOT_REPL)? ntohs(rpl->r_brpl.rmp_session):
426 	                                     ntohs(rpl->r_rrpl.rmp_session))) {
427 		syslog(LOG_ERR, "SendReadRepl: bad session id (%s)",
428 		       EnetStr(rconn));
429 		rpl->r_rrpl.rmp_retcode = RMP_E_BADSID;
430 		retval = 1;
431 		goto sendpkt;
432 	}
433 
434 	/*
435 	 *  If the requester asks for more data than we can fit,
436 	 *  silently clamp the request size down to RMPREADDATA.
437 	 *
438 	 *  N.B. I do not know if this is "legal", however it seems
439 	 *  to work.  This is necessary for bpfwrite() on machines
440 	 *  with MCLBYTES less than 1514.
441 	 */
442 	if (ntohs(req->r_rrq.rmp_size) > RMPREADDATA)
443 		req->r_rrq.rmp_size = htons(RMPREADDATA);
444 
445 	/*
446 	 *  Position read head on file according to info in request packet.
447 	 */
448 	GETWORD(req->r_rrq.rmp_offset, size);
449 	if (lseek(oldconn->bootfd, (off_t)size, SEEK_SET) < 0) {
450 		syslog(LOG_ERR, "SendReadRepl: lseek: %m (%s)",
451 		       EnetStr(rconn));
452 		rpl->r_rrpl.rmp_retcode = RMP_E_ABORT;
453 		retval = 1;
454 		goto sendpkt;
455 	}
456 
457 	/*
458 	 *  Read data directly into reply packet.
459 	 */
460 	if ((size = read(oldconn->bootfd, &rpl->r_rrpl.rmp_data,
461 	                 (int) ntohs(req->r_rrq.rmp_size))) <= 0) {
462 		if (size < 0) {
463 			syslog(LOG_ERR, "SendReadRepl: read: %m (%s)",
464 			       EnetStr(rconn));
465 			rpl->r_rrpl.rmp_retcode = RMP_E_ABORT;
466 		} else {
467 			rpl->r_rrpl.rmp_retcode = RMP_E_EOF;
468 		}
469 		retval = 1;
470 		goto sendpkt;
471 	}
472 
473 	/*
474 	 *  Set success indication.
475 	 */
476 	rpl->r_rrpl.rmp_retcode = RMP_E_OKAY;
477 
478 sendpkt:
479 	/*
480 	 *  Set up assorted fields in reply packet.
481 	 */
482 	rpl->r_rrpl.rmp_type = RMP_READ_REPL;
483 	COPYWORD(req->r_rrq.rmp_offset, rpl->r_rrpl.rmp_offset);
484 	rpl->r_rrpl.rmp_session = req->r_rrq.rmp_session;
485 
486 	oldconn->rmplen = RMPREADSIZE(size);	/* set size of packet */
487 
488 	retval &= SendPacket(oldconn);		/* send packet */
489 
490 	if (madeconn)				/* clean up after ourself */
491 		FreeConn(oldconn);
492 
493 	return (retval);
494 }
495 
496 /*
497 **  BootDone -- free up memory allocated for a connection.
498 **
499 **	Parameters:
500 **		rconn - incoming boot complete packet.
501 **
502 **	Returns:
503 **		1 on success, 0 on failure.
504 **
505 **	Side Effects:
506 **		none.
507 */
508 int
509 BootDone(RMPCONN *rconn)
510 {
511 	RMPCONN *oldconn;
512 	struct rmp_packet *rpl;
513 
514 	/*
515 	 *  If we can't find the connection, ignore the request.
516 	 */
517 	if ((oldconn = FindConn(rconn)) == NULL) {
518 		syslog(LOG_ERR, "BootDone: no existing connection (%s)",
519 		       EnetStr(rconn));
520 		return(0);
521 	}
522 
523 	rpl = &oldconn->rmp;			/* cache ptr to RMP packet */
524 
525 	/*
526 	 *  Make sure Session ID's match.
527 	 */
528 	if (ntohs(rconn->rmp.r_rrq.rmp_session) !=
529 	    ((rpl->r_type == RMP_BOOT_REPL)? ntohs(rpl->r_brpl.rmp_session):
530 	                                    ntohs(rpl->r_rrpl.rmp_session))) {
531 		syslog(LOG_ERR, "BootDone: bad session id (%s)",
532 		       EnetStr(rconn));
533 		return(0);
534 	}
535 
536 	RemoveConn(oldconn);			/* remove connection */
537 
538 	syslog(LOG_INFO, "%s: boot complete", EnetStr(rconn));
539 
540 	return(1);
541 }
542 
543 /*
544 **  SendPacket -- send an RMP packet to a remote host.
545 **
546 **	Parameters:
547 **		rconn - packet to be sent.
548 **
549 **	Returns:
550 **		1 on success, 0 on failure.
551 **
552 **	Side Effects:
553 **		none.
554 */
555 int
556 SendPacket(RMPCONN *rconn)
557 {
558 	/*
559 	 *  Set Ethernet Destination address to Source (BPF and the enet
560 	 *  driver will take care of getting our source address set).
561 	 */
562 	memmove((char *)&rconn->rmp.hp_hdr.daddr[0],
563 	        (char *)&rconn->rmp.hp_hdr.saddr[0], RMP_ADDRLEN);
564 	rconn->rmp.hp_hdr.len = htons(rconn->rmplen - sizeof(struct hp_hdr));
565 
566 	/*
567 	 *  Reverse 802.2/HP Extended Source & Destination Access Pts.
568 	 */
569 	rconn->rmp.hp_llc.dxsap = htons(HPEXT_SXSAP);
570 	rconn->rmp.hp_llc.sxsap = htons(HPEXT_DXSAP);
571 
572 	/*
573 	 *  Last time this connection was active.
574 	 */
575 	(void)gettimeofday(&rconn->tstamp, NULL);
576 
577 	if (DbgFp != NULL)			/* display packet */
578 		DispPkt(rconn,DIR_SENT);
579 
580 	/*
581 	 *  Send RMP packet to remote host.
582 	 */
583 	return(BpfWrite(rconn));
584 }
585