xref: /freebsd/libexec/rbootd/rmpproto.c (revision 145992504973bd16cf3518af9ba5ce185fefa82a)
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   "$FreeBSD$";
53 #endif /* not lint */
54 
55 #include <sys/param.h>
56 #include <sys/time.h>
57 #include <netinet/in.h>
58 
59 #include <errno.h>
60 #include <fcntl.h>
61 #include <stdio.h>
62 #include <string.h>
63 #include <syslog.h>
64 #include <unistd.h>
65 #include "defs.h"
66 
67 /*
68 **  ProcessPacket -- determine packet type and do what's required.
69 **
70 **	An RMP BOOT packet has been received.  Look at the type field
71 **	and process Boot Requests, Read Requests, and Boot Complete
72 **	packets.  Any other type will be dropped with a warning msg.
73 **
74 **	Parameters:
75 **		rconn - the new connection
76 **		client - list of files available to this host
77 **
78 **	Returns:
79 **		Nothing.
80 **
81 **	Side Effects:
82 **		- If this is a valid boot request, it will be added to
83 **		  the linked list of outstanding requests (RmpConns).
84 **		- If this is a valid boot complete, its associated
85 **		  entry in RmpConns will be deleted.
86 **		- Also, unless we run out of memory, a reply will be
87 **		  sent to the host that sent the packet.
88 */
89 void
90 ProcessPacket(RMPCONN *rconn, CLIENT *client)
91 {
92 	struct rmp_packet *rmp;
93 	RMPCONN *rconnout;
94 
95 	rmp = &rconn->rmp;		/* cache pointer to RMP packet */
96 
97 	switch(rmp->r_type) {		/* do what we came here to do */
98 		case RMP_BOOT_REQ:		/* boot request */
99 			if ((rconnout = NewConn(rconn)) == NULL)
100 				return;
101 
102 			/*
103 			 *  If the Session ID is 0xffff, this is a "probe"
104 			 *  packet and we do not want to add the connection
105 			 *  to the linked list of active connections.  There
106 			 *  are two types of probe packets, if the Sequence
107 			 *  Number is 0 they want to know our host name, o/w
108 			 *  they want the name of the file associated with
109 			 *  the number spec'd by the Sequence Number.
110 			 *
111 			 *  If this is an actual boot request, open the file
112 			 *  and send a reply.  If SendBootRepl() does not
113 			 *  return 0, add the connection to the linked list
114 			 *  of active connections, otherwise delete it since
115 			 *  an error was encountered.
116 			 */
117 			if (ntohs(rmp->r_brq.rmp_session) == RMP_PROBESID) {
118 				if (WORDZE(rmp->r_brq.rmp_seqno))
119 					(void) SendServerID(rconnout);
120 				else
121 					(void) SendFileNo(rmp, rconnout,
122 					                  client? client->files:
123 					                          BootFiles);
124 				FreeConn(rconnout);
125 			} else {
126 				if (SendBootRepl(rmp, rconnout,
127 				    client? client->files: BootFiles))
128 					AddConn(rconnout);
129 				else
130 					FreeConn(rconnout);
131 			}
132 			break;
133 
134 		case RMP_BOOT_REPL:		/* boot reply (not valid) */
135 			syslog(LOG_WARNING, "%s: sent a boot reply",
136 			       EnetStr(rconn));
137 			break;
138 
139 		case RMP_READ_REQ:		/* read request */
140 			/*
141 			 *  Send a portion of the boot file.
142 			 */
143 			(void) SendReadRepl(rconn);
144 			break;
145 
146 		case RMP_READ_REPL:		/* read reply (not valid) */
147 			syslog(LOG_WARNING, "%s: sent a read reply",
148 			       EnetStr(rconn));
149 			break;
150 
151 		case RMP_BOOT_DONE:		/* boot complete */
152 			/*
153 			 *  Remove the entry from the linked list of active
154 			 *  connections.
155 			 */
156 			(void) BootDone(rconn);
157 			break;
158 
159 		default:			/* unknown RMP packet type */
160 			syslog(LOG_WARNING, "%s: unknown packet type (%u)",
161 			       EnetStr(rconn), rmp->r_type);
162 	}
163 }
164 
165 /*
166 **  SendServerID -- send our host name to who ever requested it.
167 **
168 **	Parameters:
169 **		rconn - the reply packet to be formatted.
170 **
171 **	Returns:
172 **		1 on success, 0 on failure.
173 **
174 **	Side Effects:
175 **		none.
176 */
177 int
178 SendServerID(RMPCONN *rconn)
179 {
180 	struct rmp_packet *rpl;
181 	char *src, *dst;
182 	u_int8_t *size;
183 
184 	rpl = &rconn->rmp;			/* cache ptr to RMP packet */
185 
186 	/*
187 	 *  Set up assorted fields in reply packet.
188 	 */
189 	rpl->r_brpl.rmp_type = RMP_BOOT_REPL;
190 	rpl->r_brpl.rmp_retcode = RMP_E_OKAY;
191 	ZEROWORD(rpl->r_brpl.rmp_seqno);
192 	rpl->r_brpl.rmp_session = 0;
193 	rpl->r_brpl.rmp_version = htons(RMP_VERSION);
194 
195 	size = &rpl->r_brpl.rmp_flnmsize;	/* ptr to length of host name */
196 
197 	/*
198 	 *  Copy our host name into the reply packet incrementing the
199 	 *  length as we go.  Stop at RMP_HOSTLEN or the first dot.
200 	 */
201 	src = MyHost;
202 	dst = (char *) &rpl->r_brpl.rmp_flnm;
203 	for (*size = 0; *size < RMP_HOSTLEN; (*size)++) {
204 		if (*src == '.' || *src == '\0')
205 			break;
206 		*dst++ = *src++;
207 	}
208 
209 	rconn->rmplen = RMPBOOTSIZE(*size);	/* set packet length */
210 
211 	return(SendPacket(rconn));		/* send packet */
212 }
213 
214 /*
215 **  SendFileNo -- send the name of a bootable file to the requester.
216 **
217 **	Parameters:
218 **		req - RMP BOOT packet containing the request.
219 **		rconn - the reply packet to be formatted.
220 **		filelist - list of files available to the requester.
221 **
222 **	Returns:
223 **		1 on success, 0 on failure.
224 **
225 **	Side Effects:
226 **		none.
227 */
228 int
229 SendFileNo(struct rmp_packet *req, RMPCONN *rconn, char *filelist[])
230 {
231 	struct rmp_packet *rpl;
232 	char *src, *dst;
233 	u_int8_t *size;
234 	int i;
235 
236 	GETWORD(req->r_brpl.rmp_seqno, i);	/* SeqNo is really FileNo */
237 	rpl = &rconn->rmp;			/* cache ptr to RMP packet */
238 
239 	/*
240 	 *  Set up assorted fields in reply packet.
241 	 */
242 	rpl->r_brpl.rmp_type = RMP_BOOT_REPL;
243 	PUTWORD(i, rpl->r_brpl.rmp_seqno);
244 	i--;
245 	rpl->r_brpl.rmp_session = 0;
246 	rpl->r_brpl.rmp_version = htons(RMP_VERSION);
247 
248 	size = &rpl->r_brpl.rmp_flnmsize;	/* ptr to length of filename */
249 	*size = 0;				/* init length to zero */
250 
251 	/*
252 	 *  Copy the file name into the reply packet incrementing the
253 	 *  length as we go.  Stop at end of string or when RMPBOOTDATA
254 	 *  characters have been copied.  Also, set return code to
255 	 *  indicate success or "no more files".
256 	 */
257 	if (i < C_MAXFILE && filelist[i] != NULL) {
258 		src = filelist[i];
259 		dst = (char *)&rpl->r_brpl.rmp_flnm;
260 		for (; *src && *size < RMPBOOTDATA; (*size)++) {
261 			if (*src == '\0')
262 				break;
263 			*dst++ = *src++;
264 		}
265 		rpl->r_brpl.rmp_retcode = RMP_E_OKAY;
266 	} else
267 		rpl->r_brpl.rmp_retcode = RMP_E_NODFLT;
268 
269 	rconn->rmplen = RMPBOOTSIZE(*size);	/* set packet length */
270 
271 	return(SendPacket(rconn));		/* send packet */
272 }
273 
274 /*
275 **  SendBootRepl -- open boot file and respond to boot request.
276 **
277 **	Parameters:
278 **		req - RMP BOOT packet containing the request.
279 **		rconn - the reply packet to be formatted.
280 **		filelist - list of files available to the requester.
281 **
282 **	Returns:
283 **		1 on success, 0 on failure.
284 **
285 **	Side Effects:
286 **		none.
287 */
288 int
289 SendBootRepl(struct rmp_packet *req, RMPCONN *rconn, char *filelist[])
290 {
291 	int retval;
292 	char *filename, filepath[RMPBOOTDATA+1];
293 	RMPCONN *oldconn;
294 	struct rmp_packet *rpl;
295 	char *src, *dst1, *dst2;
296 	u_int8_t i;
297 
298 	/*
299 	 *  If another connection already exists, delete it since we
300 	 *  are obviously starting again.
301 	 */
302 	if ((oldconn = FindConn(rconn)) != NULL) {
303 		syslog(LOG_WARNING, "%s: dropping existing connection",
304 		       EnetStr(oldconn));
305 		RemoveConn(oldconn);
306 	}
307 
308 	rpl = &rconn->rmp;			/* cache ptr to RMP packet */
309 
310 	/*
311 	 *  Set up assorted fields in reply packet.
312 	 */
313 	rpl->r_brpl.rmp_type = RMP_BOOT_REPL;
314 	COPYWORD(req->r_brq.rmp_seqno, rpl->r_brpl.rmp_seqno);
315 	rpl->r_brpl.rmp_session = htons(GenSessID());
316 	rpl->r_brpl.rmp_version = htons(RMP_VERSION);
317 	rpl->r_brpl.rmp_flnmsize = req->r_brq.rmp_flnmsize;
318 
319 	/*
320 	 *  Copy file name to `filepath' string, and into reply packet.
321 	 */
322 	src = &req->r_brq.rmp_flnm;
323 	dst1 = filepath;
324 	dst2 = &rpl->r_brpl.rmp_flnm;
325 	for (i = 0; i < req->r_brq.rmp_flnmsize; i++)
326 		*dst1++ = *dst2++ = *src++;
327 	*dst1 = '\0';
328 
329 	/*
330 	 *  If we are booting HP-UX machines, their secondary loader will
331 	 *  ask for files like "/hp-ux".  As a security measure, we do not
332 	 *  allow boot files to lay outside the boot directory (unless they
333 	 *  are purposely link'd out.  So, make `filename' become the path-
334 	 *  stripped file name and spoof the client into thinking that it
335 	 *  really got what it wanted.
336 	 */
337 	filename = (filename = strrchr(filepath,'/'))? ++filename: filepath;
338 
339 	/*
340 	 *  Check that this is a valid boot file name.
341 	 */
342 	for (i = 0; i < C_MAXFILE && filelist[i] != NULL; i++)
343 		if (STREQN(filename, filelist[i]))
344 			goto match;
345 
346 	/*
347 	 *  Invalid boot file name, set error and send reply packet.
348 	 */
349 	rpl->r_brpl.rmp_retcode = RMP_E_NOFILE;
350 	retval = 0;
351 	goto sendpkt;
352 
353 match:
354 	/*
355 	 *  This is a valid boot file.  Open the file and save the file
356 	 *  descriptor associated with this connection and set success
357 	 *  indication.  If the file couldnt be opened, set error:
358 	 *  	"no such file or dir" - RMP_E_NOFILE
359 	 *	"file table overflow" - RMP_E_BUSY
360 	 *	"too many open files" - RMP_E_BUSY
361 	 *	anything else         - RMP_E_OPENFILE
362 	 */
363 	if ((rconn->bootfd = open(filename, O_RDONLY, 0600)) < 0) {
364 		rpl->r_brpl.rmp_retcode = (errno == ENOENT)? RMP_E_NOFILE:
365 			(errno == EMFILE || errno == ENFILE)? RMP_E_BUSY:
366 			RMP_E_OPENFILE;
367 		retval = 0;
368 	} else {
369 		rpl->r_brpl.rmp_retcode = RMP_E_OKAY;
370 		retval = 1;
371 	}
372 
373 sendpkt:
374 	syslog(LOG_INFO, "%s: request to boot %s (%s)",
375 	       EnetStr(rconn), filename, retval? "granted": "denied");
376 
377 	rconn->rmplen = RMPBOOTSIZE(rpl->r_brpl.rmp_flnmsize);
378 
379 	return (retval & SendPacket(rconn));
380 }
381 
382 /*
383 **  SendReadRepl -- send a portion of the boot file to the requester.
384 **
385 **	Parameters:
386 **		rconn - the reply packet to be formatted.
387 **
388 **	Returns:
389 **		1 on success, 0 on failure.
390 **
391 **	Side Effects:
392 **		none.
393 */
394 int
395 SendReadRepl(RMPCONN *rconn)
396 {
397 	int retval = 0;
398 	RMPCONN *oldconn;
399 	struct rmp_packet *rpl, *req;
400 	int size = 0;
401 	int madeconn = 0;
402 
403 	/*
404 	 *  Find the old connection.  If one doesn't exist, create one only
405 	 *  to return the error code.
406 	 */
407 	if ((oldconn = FindConn(rconn)) == NULL) {
408 		if ((oldconn = NewConn(rconn)) == NULL)
409 			return(0);
410 		syslog(LOG_ERR, "SendReadRepl: no active connection (%s)",
411 		       EnetStr(rconn));
412 		madeconn++;
413 	}
414 
415 	req = &rconn->rmp;		/* cache ptr to request packet */
416 	rpl = &oldconn->rmp;		/* cache ptr to reply packet */
417 
418 	if (madeconn) {			/* no active connection above; abort */
419 		rpl->r_rrpl.rmp_retcode = RMP_E_ABORT;
420 		retval = 1;
421 		goto sendpkt;
422 	}
423 
424 	/*
425 	 *  Make sure Session ID's match.
426 	 */
427 	if (ntohs(req->r_rrq.rmp_session) !=
428 	    ((rpl->r_type == RMP_BOOT_REPL)? ntohs(rpl->r_brpl.rmp_session):
429 	                                     ntohs(rpl->r_rrpl.rmp_session))) {
430 		syslog(LOG_ERR, "SendReadRepl: bad session id (%s)",
431 		       EnetStr(rconn));
432 		rpl->r_rrpl.rmp_retcode = RMP_E_BADSID;
433 		retval = 1;
434 		goto sendpkt;
435 	}
436 
437 	/*
438 	 *  If the requester asks for more data than we can fit,
439 	 *  silently clamp the request size down to RMPREADDATA.
440 	 *
441 	 *  N.B. I do not know if this is "legal", however it seems
442 	 *  to work.  This is necessary for bpfwrite() on machines
443 	 *  with MCLBYTES less than 1514.
444 	 */
445 	if (ntohs(req->r_rrq.rmp_size) > RMPREADDATA)
446 		req->r_rrq.rmp_size = htons(RMPREADDATA);
447 
448 	/*
449 	 *  Position read head on file according to info in request packet.
450 	 */
451 	GETWORD(req->r_rrq.rmp_offset, size);
452 	if (lseek(oldconn->bootfd, (off_t)size, SEEK_SET) < 0) {
453 		syslog(LOG_ERR, "SendReadRepl: lseek: %m (%s)",
454 		       EnetStr(rconn));
455 		rpl->r_rrpl.rmp_retcode = RMP_E_ABORT;
456 		retval = 1;
457 		goto sendpkt;
458 	}
459 
460 	/*
461 	 *  Read data directly into reply packet.
462 	 */
463 	if ((size = read(oldconn->bootfd, &rpl->r_rrpl.rmp_data,
464 	                 (int) ntohs(req->r_rrq.rmp_size))) <= 0) {
465 		if (size < 0) {
466 			syslog(LOG_ERR, "SendReadRepl: read: %m (%s)",
467 			       EnetStr(rconn));
468 			rpl->r_rrpl.rmp_retcode = RMP_E_ABORT;
469 		} else {
470 			rpl->r_rrpl.rmp_retcode = RMP_E_EOF;
471 		}
472 		retval = 1;
473 		goto sendpkt;
474 	}
475 
476 	/*
477 	 *  Set success indication.
478 	 */
479 	rpl->r_rrpl.rmp_retcode = RMP_E_OKAY;
480 
481 sendpkt:
482 	/*
483 	 *  Set up assorted fields in reply packet.
484 	 */
485 	rpl->r_rrpl.rmp_type = RMP_READ_REPL;
486 	COPYWORD(req->r_rrq.rmp_offset, rpl->r_rrpl.rmp_offset);
487 	rpl->r_rrpl.rmp_session = req->r_rrq.rmp_session;
488 
489 	oldconn->rmplen = RMPREADSIZE(size);	/* set size of packet */
490 
491 	retval &= SendPacket(oldconn);		/* send packet */
492 
493 	if (madeconn)				/* clean up after ourself */
494 		FreeConn(oldconn);
495 
496 	return (retval);
497 }
498 
499 /*
500 **  BootDone -- free up memory allocated for a connection.
501 **
502 **	Parameters:
503 **		rconn - incoming boot complete packet.
504 **
505 **	Returns:
506 **		1 on success, 0 on failure.
507 **
508 **	Side Effects:
509 **		none.
510 */
511 int
512 BootDone(RMPCONN *rconn)
513 {
514 	RMPCONN *oldconn;
515 	struct rmp_packet *rpl;
516 
517 	/*
518 	 *  If we can't find the connection, ignore the request.
519 	 */
520 	if ((oldconn = FindConn(rconn)) == NULL) {
521 		syslog(LOG_ERR, "BootDone: no existing connection (%s)",
522 		       EnetStr(rconn));
523 		return(0);
524 	}
525 
526 	rpl = &oldconn->rmp;			/* cache ptr to RMP packet */
527 
528 	/*
529 	 *  Make sure Session ID's match.
530 	 */
531 	if (ntohs(rconn->rmp.r_rrq.rmp_session) !=
532 	    ((rpl->r_type == RMP_BOOT_REPL)? ntohs(rpl->r_brpl.rmp_session):
533 	                                    ntohs(rpl->r_rrpl.rmp_session))) {
534 		syslog(LOG_ERR, "BootDone: bad session id (%s)",
535 		       EnetStr(rconn));
536 		return(0);
537 	}
538 
539 	RemoveConn(oldconn);			/* remove connection */
540 
541 	syslog(LOG_INFO, "%s: boot complete", EnetStr(rconn));
542 
543 	return(1);
544 }
545 
546 /*
547 **  SendPacket -- send an RMP packet to a remote host.
548 **
549 **	Parameters:
550 **		rconn - packet to be sent.
551 **
552 **	Returns:
553 **		1 on success, 0 on failure.
554 **
555 **	Side Effects:
556 **		none.
557 */
558 int
559 SendPacket(RMPCONN *rconn)
560 {
561 	/*
562 	 *  Set Ethernet Destination address to Source (BPF and the enet
563 	 *  driver will take care of getting our source address set).
564 	 */
565 	memmove((char *)&rconn->rmp.hp_hdr.daddr[0],
566 	        (char *)&rconn->rmp.hp_hdr.saddr[0], RMP_ADDRLEN);
567 	rconn->rmp.hp_hdr.len = htons(rconn->rmplen - sizeof(struct hp_hdr));
568 
569 	/*
570 	 *  Reverse 802.2/HP Extended Source & Destination Access Pts.
571 	 */
572 	rconn->rmp.hp_llc.dxsap = htons(HPEXT_SXSAP);
573 	rconn->rmp.hp_llc.sxsap = htons(HPEXT_DXSAP);
574 
575 	/*
576 	 *  Last time this connection was active.
577 	 */
578 	(void)gettimeofday(&rconn->tstamp, NULL);
579 
580 	if (DbgFp != NULL)			/* display packet */
581 		DispPkt(rconn,DIR_SENT);
582 
583 	/*
584 	 *  Send RMP packet to remote host.
585 	 */
586 	return(BpfWrite(rconn));
587 }
588