xref: /freebsd/libexec/rbootd/rmpproto.c (revision a6fe717c2a876105123214c05176cd74106fb94b)
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: Utah Hdr: rmpproto.c 3.1 92/07/06
40  * Author: Jeff Forys, University of Utah CSS
41  */
42 
43 #include <sys/param.h>
44 #include <sys/time.h>
45 #include <netinet/in.h>
46 
47 #include <errno.h>
48 #include <fcntl.h>
49 #include <stdio.h>
50 #include <string.h>
51 #include <syslog.h>
52 #include <unistd.h>
53 #include "defs.h"
54 
55 /*
56 **  ProcessPacket -- determine packet type and do what's required.
57 **
58 **	An RMP BOOT packet has been received.  Look at the type field
59 **	and process Boot Requests, Read Requests, and Boot Complete
60 **	packets.  Any other type will be dropped with a warning msg.
61 **
62 **	Parameters:
63 **		rconn - the new connection
64 **		client - list of files available to this host
65 **
66 **	Returns:
67 **		Nothing.
68 **
69 **	Side Effects:
70 **		- If this is a valid boot request, it will be added to
71 **		  the linked list of outstanding requests (RmpConns).
72 **		- If this is a valid boot complete, its associated
73 **		  entry in RmpConns will be deleted.
74 **		- Also, unless we run out of memory, a reply will be
75 **		  sent to the host that sent the packet.
76 */
77 void
ProcessPacket(RMPCONN * rconn,CLIENT * client)78 ProcessPacket(RMPCONN *rconn, CLIENT *client)
79 {
80 	struct rmp_packet *rmp;
81 	RMPCONN *rconnout;
82 
83 	rmp = &rconn->rmp;		/* cache pointer to RMP packet */
84 
85 	switch(rmp->r_type) {		/* do what we came here to do */
86 		case RMP_BOOT_REQ:		/* boot request */
87 			if ((rconnout = NewConn(rconn)) == NULL)
88 				return;
89 
90 			/*
91 			 *  If the Session ID is 0xffff, this is a "probe"
92 			 *  packet and we do not want to add the connection
93 			 *  to the linked list of active connections.  There
94 			 *  are two types of probe packets, if the Sequence
95 			 *  Number is 0 they want to know our host name, o/w
96 			 *  they want the name of the file associated with
97 			 *  the number spec'd by the Sequence Number.
98 			 *
99 			 *  If this is an actual boot request, open the file
100 			 *  and send a reply.  If SendBootRepl() does not
101 			 *  return 0, add the connection to the linked list
102 			 *  of active connections, otherwise delete it since
103 			 *  an error was encountered.
104 			 */
105 			if (ntohs(rmp->r_brq.rmp_session) == RMP_PROBESID) {
106 				if (WORDZE(rmp->r_brq.rmp_seqno))
107 					(void) SendServerID(rconnout);
108 				else
109 					(void) SendFileNo(rmp, rconnout,
110 					                  client? client->files:
111 					                          BootFiles);
112 				FreeConn(rconnout);
113 			} else {
114 				if (SendBootRepl(rmp, rconnout,
115 				    client? client->files: BootFiles))
116 					AddConn(rconnout);
117 				else
118 					FreeConn(rconnout);
119 			}
120 			break;
121 
122 		case RMP_BOOT_REPL:		/* boot reply (not valid) */
123 			syslog(LOG_WARNING, "%s: sent a boot reply",
124 			       EnetStr(rconn));
125 			break;
126 
127 		case RMP_READ_REQ:		/* read request */
128 			/*
129 			 *  Send a portion of the boot file.
130 			 */
131 			(void) SendReadRepl(rconn);
132 			break;
133 
134 		case RMP_READ_REPL:		/* read reply (not valid) */
135 			syslog(LOG_WARNING, "%s: sent a read reply",
136 			       EnetStr(rconn));
137 			break;
138 
139 		case RMP_BOOT_DONE:		/* boot complete */
140 			/*
141 			 *  Remove the entry from the linked list of active
142 			 *  connections.
143 			 */
144 			(void) BootDone(rconn);
145 			break;
146 
147 		default:			/* unknown RMP packet type */
148 			syslog(LOG_WARNING, "%s: unknown packet type (%u)",
149 			       EnetStr(rconn), rmp->r_type);
150 	}
151 }
152 
153 /*
154 **  SendServerID -- send our host name to who ever requested it.
155 **
156 **	Parameters:
157 **		rconn - the reply packet to be formatted.
158 **
159 **	Returns:
160 **		1 on success, 0 on failure.
161 **
162 **	Side Effects:
163 **		none.
164 */
165 int
SendServerID(RMPCONN * rconn)166 SendServerID(RMPCONN *rconn)
167 {
168 	struct rmp_packet *rpl;
169 	char *src, *dst;
170 	u_int8_t *size;
171 
172 	rpl = &rconn->rmp;			/* cache ptr to RMP packet */
173 
174 	/*
175 	 *  Set up assorted fields in reply packet.
176 	 */
177 	rpl->r_brpl.rmp_type = RMP_BOOT_REPL;
178 	rpl->r_brpl.rmp_retcode = RMP_E_OKAY;
179 	ZEROWORD(rpl->r_brpl.rmp_seqno);
180 	rpl->r_brpl.rmp_session = 0;
181 	rpl->r_brpl.rmp_version = htons(RMP_VERSION);
182 
183 	size = &rpl->r_brpl.rmp_flnmsize;	/* ptr to length of host name */
184 
185 	/*
186 	 *  Copy our host name into the reply packet incrementing the
187 	 *  length as we go.  Stop at RMP_HOSTLEN or the first dot.
188 	 */
189 	src = MyHost;
190 	dst = (char *) &rpl->r_brpl.rmp_flnm;
191 	for (*size = 0; *size < RMP_HOSTLEN; (*size)++) {
192 		if (*src == '.' || *src == '\0')
193 			break;
194 		*dst++ = *src++;
195 	}
196 
197 	rconn->rmplen = RMPBOOTSIZE(*size);	/* set packet length */
198 
199 	return(SendPacket(rconn));		/* send packet */
200 }
201 
202 /*
203 **  SendFileNo -- send the name of a bootable file to the requester.
204 **
205 **	Parameters:
206 **		req - RMP BOOT packet containing the request.
207 **		rconn - the reply packet to be formatted.
208 **		filelist - list of files available to the requester.
209 **
210 **	Returns:
211 **		1 on success, 0 on failure.
212 **
213 **	Side Effects:
214 **		none.
215 */
216 int
SendFileNo(struct rmp_packet * req,RMPCONN * rconn,char * filelist[])217 SendFileNo(struct rmp_packet *req, RMPCONN *rconn, char *filelist[])
218 {
219 	struct rmp_packet *rpl;
220 	char *src, *dst;
221 	u_int8_t *size;
222 	int i;
223 
224 	GETWORD(req->r_brpl.rmp_seqno, i);	/* SeqNo is really FileNo */
225 	rpl = &rconn->rmp;			/* cache ptr to RMP packet */
226 
227 	/*
228 	 *  Set up assorted fields in reply packet.
229 	 */
230 	rpl->r_brpl.rmp_type = RMP_BOOT_REPL;
231 	PUTWORD(i, rpl->r_brpl.rmp_seqno);
232 	i--;
233 	rpl->r_brpl.rmp_session = 0;
234 	rpl->r_brpl.rmp_version = htons(RMP_VERSION);
235 
236 	size = &rpl->r_brpl.rmp_flnmsize;	/* ptr to length of filename */
237 	*size = 0;				/* init length to zero */
238 
239 	/*
240 	 *  Copy the file name into the reply packet incrementing the
241 	 *  length as we go.  Stop at end of string or when RMPBOOTDATA
242 	 *  characters have been copied.  Also, set return code to
243 	 *  indicate success or "no more files".
244 	 */
245 	if (i < C_MAXFILE && filelist[i] != NULL) {
246 		src = filelist[i];
247 		dst = (char *)&rpl->r_brpl.rmp_flnm;
248 		for (; *src && *size < RMPBOOTDATA; (*size)++) {
249 			if (*src == '\0')
250 				break;
251 			*dst++ = *src++;
252 		}
253 		rpl->r_brpl.rmp_retcode = RMP_E_OKAY;
254 	} else
255 		rpl->r_brpl.rmp_retcode = RMP_E_NODFLT;
256 
257 	rconn->rmplen = RMPBOOTSIZE(*size);	/* set packet length */
258 
259 	return(SendPacket(rconn));		/* send packet */
260 }
261 
262 /*
263 **  SendBootRepl -- open boot file and respond to boot request.
264 **
265 **	Parameters:
266 **		req - RMP BOOT packet containing the request.
267 **		rconn - the reply packet to be formatted.
268 **		filelist - list of files available to the requester.
269 **
270 **	Returns:
271 **		1 on success, 0 on failure.
272 **
273 **	Side Effects:
274 **		none.
275 */
276 int
SendBootRepl(struct rmp_packet * req,RMPCONN * rconn,char * filelist[])277 SendBootRepl(struct rmp_packet *req, RMPCONN *rconn, char *filelist[])
278 {
279 	int retval;
280 	char *filename, filepath[RMPBOOTDATA+1];
281 	RMPCONN *oldconn;
282 	struct rmp_packet *rpl;
283 	char *src, *dst1, *dst2;
284 	u_int8_t i;
285 
286 	/*
287 	 *  If another connection already exists, delete it since we
288 	 *  are obviously starting again.
289 	 */
290 	if ((oldconn = FindConn(rconn)) != NULL) {
291 		syslog(LOG_WARNING, "%s: dropping existing connection",
292 		       EnetStr(oldconn));
293 		RemoveConn(oldconn);
294 	}
295 
296 	rpl = &rconn->rmp;			/* cache ptr to RMP packet */
297 
298 	/*
299 	 *  Set up assorted fields in reply packet.
300 	 */
301 	rpl->r_brpl.rmp_type = RMP_BOOT_REPL;
302 	COPYWORD(req->r_brq.rmp_seqno, rpl->r_brpl.rmp_seqno);
303 	rpl->r_brpl.rmp_session = htons(GenSessID());
304 	rpl->r_brpl.rmp_version = htons(RMP_VERSION);
305 	rpl->r_brpl.rmp_flnmsize = req->r_brq.rmp_flnmsize;
306 
307 	/*
308 	 *  Copy file name to `filepath' string, and into reply packet.
309 	 */
310 	src = &req->r_brq.rmp_flnm;
311 	dst1 = filepath;
312 	dst2 = &rpl->r_brpl.rmp_flnm;
313 	for (i = 0; i < req->r_brq.rmp_flnmsize; i++)
314 		*dst1++ = *dst2++ = *src++;
315 	*dst1 = '\0';
316 
317 	/*
318 	 *  If we are booting HP-UX machines, their secondary loader will
319 	 *  ask for files like "/hp-ux".  As a security measure, we do not
320 	 *  allow boot files to lay outside the boot directory (unless they
321 	 *  are purposely link'd out.  So, make `filename' become the path-
322 	 *  stripped file name and spoof the client into thinking that it
323 	 *  really got what it wanted.
324 	 */
325 	filename = strrchr(filepath,'/');
326 	filename = filename? filename + 1: filepath;
327 
328 	/*
329 	 *  Check that this is a valid boot file name.
330 	 */
331 	for (i = 0; i < C_MAXFILE && filelist[i] != NULL; i++)
332 		if (STREQN(filename, filelist[i]))
333 			goto match;
334 
335 	/*
336 	 *  Invalid boot file name, set error and send reply packet.
337 	 */
338 	rpl->r_brpl.rmp_retcode = RMP_E_NOFILE;
339 	retval = 0;
340 	goto sendpkt;
341 
342 match:
343 	/*
344 	 *  This is a valid boot file.  Open the file and save the file
345 	 *  descriptor associated with this connection and set success
346 	 *  indication.  If the file couldnt be opened, set error:
347 	 *  	"no such file or dir" - RMP_E_NOFILE
348 	 *	"file table overflow" - RMP_E_BUSY
349 	 *	"too many open files" - RMP_E_BUSY
350 	 *	anything else         - RMP_E_OPENFILE
351 	 */
352 	if ((rconn->bootfd = open(filename, O_RDONLY, 0600)) < 0) {
353 		rpl->r_brpl.rmp_retcode = (errno == ENOENT)? RMP_E_NOFILE:
354 			(errno == EMFILE || errno == ENFILE)? RMP_E_BUSY:
355 			RMP_E_OPENFILE;
356 		retval = 0;
357 	} else {
358 		rpl->r_brpl.rmp_retcode = RMP_E_OKAY;
359 		retval = 1;
360 	}
361 
362 sendpkt:
363 	syslog(LOG_INFO, "%s: request to boot %s (%s)",
364 	       EnetStr(rconn), filename, retval? "granted": "denied");
365 
366 	rconn->rmplen = RMPBOOTSIZE(rpl->r_brpl.rmp_flnmsize);
367 
368 	return (retval & SendPacket(rconn));
369 }
370 
371 /*
372 **  SendReadRepl -- send a portion of the boot file to the requester.
373 **
374 **	Parameters:
375 **		rconn - the reply packet to be formatted.
376 **
377 **	Returns:
378 **		1 on success, 0 on failure.
379 **
380 **	Side Effects:
381 **		none.
382 */
383 int
SendReadRepl(RMPCONN * rconn)384 SendReadRepl(RMPCONN *rconn)
385 {
386 	int retval = 0;
387 	RMPCONN *oldconn;
388 	struct rmp_packet *rpl, *req;
389 	int size = 0;
390 	int madeconn = 0;
391 
392 	/*
393 	 *  Find the old connection.  If one doesn't exist, create one only
394 	 *  to return the error code.
395 	 */
396 	if ((oldconn = FindConn(rconn)) == NULL) {
397 		if ((oldconn = NewConn(rconn)) == NULL)
398 			return(0);
399 		syslog(LOG_ERR, "SendReadRepl: no active connection (%s)",
400 		       EnetStr(rconn));
401 		madeconn++;
402 	}
403 
404 	req = &rconn->rmp;		/* cache ptr to request packet */
405 	rpl = &oldconn->rmp;		/* cache ptr to reply packet */
406 
407 	if (madeconn) {			/* no active connection above; abort */
408 		rpl->r_rrpl.rmp_retcode = RMP_E_ABORT;
409 		retval = 1;
410 		goto sendpkt;
411 	}
412 
413 	/*
414 	 *  Make sure Session ID's match.
415 	 */
416 	if (ntohs(req->r_rrq.rmp_session) !=
417 	    ((rpl->r_type == RMP_BOOT_REPL)? ntohs(rpl->r_brpl.rmp_session):
418 	                                     ntohs(rpl->r_rrpl.rmp_session))) {
419 		syslog(LOG_ERR, "SendReadRepl: bad session id (%s)",
420 		       EnetStr(rconn));
421 		rpl->r_rrpl.rmp_retcode = RMP_E_BADSID;
422 		retval = 1;
423 		goto sendpkt;
424 	}
425 
426 	/*
427 	 *  If the requester asks for more data than we can fit,
428 	 *  silently clamp the request size down to RMPREADDATA.
429 	 *
430 	 *  N.B. I do not know if this is "legal", however it seems
431 	 *  to work.  This is necessary for bpfwrite() on machines
432 	 *  with MCLBYTES less than 1514.
433 	 */
434 	if (ntohs(req->r_rrq.rmp_size) > RMPREADDATA)
435 		req->r_rrq.rmp_size = htons(RMPREADDATA);
436 
437 	/*
438 	 *  Position read head on file according to info in request packet.
439 	 */
440 	GETWORD(req->r_rrq.rmp_offset, size);
441 	if (lseek(oldconn->bootfd, (off_t)size, SEEK_SET) < 0) {
442 		syslog(LOG_ERR, "SendReadRepl: lseek: %m (%s)",
443 		       EnetStr(rconn));
444 		rpl->r_rrpl.rmp_retcode = RMP_E_ABORT;
445 		retval = 1;
446 		goto sendpkt;
447 	}
448 
449 	/*
450 	 *  Read data directly into reply packet.
451 	 */
452 	if ((size = read(oldconn->bootfd, &rpl->r_rrpl.rmp_data,
453 	                 (int) ntohs(req->r_rrq.rmp_size))) <= 0) {
454 		if (size < 0) {
455 			syslog(LOG_ERR, "SendReadRepl: read: %m (%s)",
456 			       EnetStr(rconn));
457 			rpl->r_rrpl.rmp_retcode = RMP_E_ABORT;
458 		} else {
459 			rpl->r_rrpl.rmp_retcode = RMP_E_EOF;
460 		}
461 		retval = 1;
462 		goto sendpkt;
463 	}
464 
465 	/*
466 	 *  Set success indication.
467 	 */
468 	rpl->r_rrpl.rmp_retcode = RMP_E_OKAY;
469 
470 sendpkt:
471 	/*
472 	 *  Set up assorted fields in reply packet.
473 	 */
474 	rpl->r_rrpl.rmp_type = RMP_READ_REPL;
475 	COPYWORD(req->r_rrq.rmp_offset, rpl->r_rrpl.rmp_offset);
476 	rpl->r_rrpl.rmp_session = req->r_rrq.rmp_session;
477 
478 	oldconn->rmplen = RMPREADSIZE(size);	/* set size of packet */
479 
480 	retval &= SendPacket(oldconn);		/* send packet */
481 
482 	if (madeconn)				/* clean up after ourself */
483 		FreeConn(oldconn);
484 
485 	return (retval);
486 }
487 
488 /*
489 **  BootDone -- free up memory allocated for a connection.
490 **
491 **	Parameters:
492 **		rconn - incoming boot complete packet.
493 **
494 **	Returns:
495 **		1 on success, 0 on failure.
496 **
497 **	Side Effects:
498 **		none.
499 */
500 int
BootDone(RMPCONN * rconn)501 BootDone(RMPCONN *rconn)
502 {
503 	RMPCONN *oldconn;
504 	struct rmp_packet *rpl;
505 
506 	/*
507 	 *  If we can't find the connection, ignore the request.
508 	 */
509 	if ((oldconn = FindConn(rconn)) == NULL) {
510 		syslog(LOG_ERR, "BootDone: no existing connection (%s)",
511 		       EnetStr(rconn));
512 		return(0);
513 	}
514 
515 	rpl = &oldconn->rmp;			/* cache ptr to RMP packet */
516 
517 	/*
518 	 *  Make sure Session ID's match.
519 	 */
520 	if (ntohs(rconn->rmp.r_rrq.rmp_session) !=
521 	    ((rpl->r_type == RMP_BOOT_REPL)? ntohs(rpl->r_brpl.rmp_session):
522 	                                    ntohs(rpl->r_rrpl.rmp_session))) {
523 		syslog(LOG_ERR, "BootDone: bad session id (%s)",
524 		       EnetStr(rconn));
525 		return(0);
526 	}
527 
528 	RemoveConn(oldconn);			/* remove connection */
529 
530 	syslog(LOG_INFO, "%s: boot complete", EnetStr(rconn));
531 
532 	return(1);
533 }
534 
535 /*
536 **  SendPacket -- send an RMP packet to a remote host.
537 **
538 **	Parameters:
539 **		rconn - packet to be sent.
540 **
541 **	Returns:
542 **		1 on success, 0 on failure.
543 **
544 **	Side Effects:
545 **		none.
546 */
547 int
SendPacket(RMPCONN * rconn)548 SendPacket(RMPCONN *rconn)
549 {
550 	/*
551 	 *  Set Ethernet Destination address to Source (BPF and the enet
552 	 *  driver will take care of getting our source address set).
553 	 */
554 	memmove((char *)&rconn->rmp.hp_hdr.daddr[0],
555 	        (char *)&rconn->rmp.hp_hdr.saddr[0], RMP_ADDRLEN);
556 	rconn->rmp.hp_hdr.len = htons(rconn->rmplen - sizeof(struct hp_hdr));
557 
558 	/*
559 	 *  Reverse 802.2/HP Extended Source & Destination Access Pts.
560 	 */
561 	rconn->rmp.hp_llc.dxsap = htons(HPEXT_SXSAP);
562 	rconn->rmp.hp_llc.sxsap = htons(HPEXT_DXSAP);
563 
564 	/*
565 	 *  Last time this connection was active.
566 	 */
567 	(void)gettimeofday(&rconn->tstamp, NULL);
568 
569 	if (DbgFp != NULL)			/* display packet */
570 		DispPkt(rconn,DIR_SENT);
571 
572 	/*
573 	 *  Send RMP packet to remote host.
574 	 */
575 	return(BpfWrite(rconn));
576 }
577