xref: /illumos-gate/usr/src/cmd/rmt/rmt.c (revision 533affcbc7fc4d0c8132976ea454aaa715fe2307)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*
27  *  Multi-process streaming 4.3bsd /etc/rmt server.
28  *  Has three locks (for stdin, stdout, and the tape)
29  *  that are passed by signals and received by sigpause().
30  */
31 
32 #include <stdio.h>
33 #include <locale.h>
34 #include <sys/types.h>
35 #include <errno.h>
36 #include <fcntl.h>
37 #include <string.h>
38 #include <signal.h>
39 #include <setjmp.h>
40 #include <sys/ioctl.h>
41 #include <sys/mtio.h>
42 #include <sys/wait.h>
43 #include <stdlib.h>
44 #include <unistd.h>
45 #include <sys/param.h>
46 
47 static sigset_t	cmdmask, maskall, newmask;
48 static sigset_t	sendmask, tapemask;
49 
50 static struct mtop mtop;
51 static struct mtget mtget;
52 static jmp_buf sjbuf;
53 
54 #define	RECV	SIGIO
55 #define	TAPE	SIGURG
56 #define	SEND	SIGALRM
57 #define	ERROR	SIGTERM
58 #define	OPEN	SIGUSR1
59 #define	CLOSE	SIGUSR2
60 
61 /*
62  * Support for Version 1 of the extended RMT protocol:
63  * Placing RMTIVERSION (-1) into the mt_op field of the ioctl ('I')
64  * request will return the current version of the RMT protocol that
65  * the server supports.  For servers that don't support Version 1,
66  * an error is returned and the client knows to only use Version 0
67  * (stock BSD) calls, which include mt_op values in the range of [0-7].
68  *
69  * Note: The RMTIVERSION request must be made in order for the extended
70  * protocol commands to be recognized.
71  */
72 #define	RMTIVERSION	-1
73 #define	RMT_VERSION	1
74 
75 /*
76  * These requests are made to the extended RMT protocol by specifying the
77  * new 'i' command of RMT Protocol Version 1.  They are intended to allow
78  * an intelligent client to communicate with both BSD and Solaris RMT
79  * servers heterogeneously.  The 'i' command taks an mtop structure as
80  * argument, exactly like the 'I' command does.
81  */
82 #define	RMTICACHE	0
83 #define	RMTINOCACHE	1
84 #define	RMTIRETEN	2
85 #define	RMTIERASE	3
86 #define	RMTIEOM		4
87 #define	RMTINBSF	5
88 
89 /*
90  * These requests are made to the extended RMT protocol by specifying the
91  * new 's' command of RMT Protocol Version 1.  They are intended to allow
92  * an intelligent client to obtain "mt status" information with both BSD
93  * and Solaris RMT servers heterogeneously.  They return the requested
94  * piece of the mtget structure as an ascii integer.  The request is made
95  * by sending the required character immediately after the 's' character
96  * without any trailing newline.  A single ascii integer is returned, else
97  * an error is returned.
98  */
99 #define	MTS_TYPE	'T'		/* mtget.mt_type */
100 #define	MTS_DSREG	'D'		/* mtget.mt_dsreg */
101 #define	MTS_ERREG	'E'		/* mtget.mt_erreg */
102 #define	MTS_RESID	'R'		/* mtget.mt_resid */
103 #define	MTS_FILENO	'F'		/* mtget.mt_fileno */
104 #define	MTS_BLKNO	'B'		/* mtget.mt_blkno */
105 #define	MTS_FLAGS	'f'		/* mtget.mt_flags */
106 #define	MTS_BF		'b'		/* mtget.mt_bf */
107 
108 #define	MAXCHILD 1
109 static pid_t	childpid[MAXCHILD];
110 static int	children;
111 
112 static int	tape = -1;
113 static size_t	maxrecsize = 0;
114 static char	*record;
115 
116 #define	SSIZE	64
117 static char	pos[SSIZE], op[SSIZE], mode[SSIZE], count[SSIZE];
118 static char	device[MAXPATHLEN];
119 
120 static FILE	*debug;
121 #define	DEBUG(f)		if (debug) (void) fprintf(debug, (f))
122 #define	DEBUG1(f, a)		if (debug) (void) fprintf(debug, (f), (a))
123 #define	DEBUG2(f, a, b)		if (debug) (void) fprintf(debug, (f), (a), (b))
124 #define	DEBUG3(f, a, b, c)	if (debug) \
125 				    (void) fprintf(debug, (f), (a), (b), (c))
126 
127 static char key;
128 
129 #ifdef __STDC__
130 static void respond(offset_t, int);
131 static void getstring(char *, size_t);
132 static void checkbuf(size_t);
133 #else
134 static void respond();
135 static void getstring();
136 static void checkbuf();
137 #endif
138 
139 static void
140 catch(int sig)
141 {
142 	switch (sig) {
143 	default:    return;
144 	case OPEN:  key = 'O';	break;
145 	case CLOSE: key = 'C';	break;
146 	case ERROR: key = 'E';	break;
147 	}
148 	(void) sigprocmask(SIG_SETMASK, &maskall, (sigset_t *)0);
149 	longjmp(sjbuf, 1);
150 }
151 
152 int
153 main(int argc, char *argv[])
154 {
155 	struct sigaction sa;
156 	pid_t parent = getpid(), next = parent;
157 	int saverr;
158 	offset_t rval;
159 	ssize_t cc;
160 	size_t n, i;
161 
162 	(void) setlocale(LC_ALL, "");
163 #if !defined(TEXT_DOMAIN)	/* Should be defined by cc -D */
164 #define	TEXT_DOMAIN "SYS_TEST"
165 #endif
166 	(void) textdomain(TEXT_DOMAIN);
167 
168 	if (argc > 1) {
169 		if ((debug = fopen(argv[1], "w")) == NULL)
170 			exit(1);
171 		setbuf(debug, NULL);
172 	}
173 	(void) sigemptyset(&maskall);
174 	(void) sigaddset(&maskall, RECV);
175 	(void) sigaddset(&maskall, OPEN);
176 	(void) sigaddset(&maskall, CLOSE);
177 	(void) sigaddset(&maskall, ERROR);
178 	(void) sigaddset(&maskall, TAPE);
179 	(void) sigaddset(&maskall, SEND);
180 
181 	tapemask = maskall;
182 	(void) sigdelset(&tapemask, TAPE);
183 
184 	sendmask = maskall;
185 	(void) sigdelset(&sendmask, SEND);
186 
187 	(void) sigemptyset(&cmdmask);
188 	(void) sigaddset(&cmdmask, TAPE);
189 	(void) sigaddset(&cmdmask, SEND);
190 
191 	(void) sigemptyset(&sa.sa_mask);
192 
193 	sa.sa_handler = catch;
194 	sa.sa_flags = SA_RESTART;
195 	(void) sigaction(RECV, &sa, (struct sigaction *)0);
196 	(void) sigaction(SEND, &sa, (struct sigaction *)0);
197 	(void) sigaction(TAPE, &sa, (struct sigaction *)0);
198 	(void) sigaction(OPEN, &sa, (struct sigaction *)0);
199 	(void) sigaction(CLOSE, &sa, (struct sigaction *)0);
200 	(void) sigaction(ERROR, &sa, (struct sigaction *)0);
201 
202 	(void) sigprocmask(SIG_SETMASK, &maskall, (sigset_t *)0);
203 
204 	(void) kill(parent, TAPE);
205 	(void) kill(parent, SEND);
206 
207 	while (read(0, &key, 1) == 1) {
208 		switch (key) {
209 		case 'L':		/* lseek */
210 			getstring(count, sizeof (count));
211 			getstring(pos, sizeof (pos));
212 			DEBUG2("rmtd: L %s %s\n", count, pos);
213 			(void) kill(next, RECV);
214 			(void) sigsuspend(&tapemask);
215 			rval = llseek(tape, atoll(count), atoi(pos));
216 			saverr = errno;
217 			(void) kill(next, TAPE);
218 			(void) sigsuspend(&sendmask);
219 			respond(rval, saverr);
220 			break;
221 
222 		case 'I':		/* ioctl */
223 		case 'i': {		/* extended version ioctl */
224 			int bad = 0;
225 
226 			getstring(op, sizeof (op));
227 			getstring(count, sizeof (count));
228 			DEBUG3("rmtd: %c %s %s\n", key, op, count);
229 			mtop.mt_op = atoi(op);
230 			mtop.mt_count = atoi(count);
231 			if (key == 'i') {
232 				/*
233 				 * Map the supported compatibility defines
234 				 * into real ioctl values.
235 				 */
236 				switch (mtop.mt_op) {
237 				case RMTICACHE:
238 				case RMTINOCACHE:	/* not support on Sun */
239 					bad = 1;
240 					break;
241 				case RMTIRETEN:
242 					mtop.mt_op = MTRETEN;
243 					break;
244 				case RMTIERASE:
245 					mtop.mt_op = MTERASE;
246 					break;
247 				case RMTIEOM:
248 					mtop.mt_op = MTEOM;
249 					break;
250 				case RMTINBSF:
251 					mtop.mt_op = MTNBSF;
252 					break;
253 				default:
254 					bad = 1;
255 					break;
256 				}
257 			}
258 			if (bad) {
259 				respond(-1LL, EINVAL);
260 			} else {
261 				(void) kill(next, RECV);
262 				(void) sigsuspend(&tapemask);
263 				if (mtop.mt_op == RMTIVERSION) {
264 					mtop.mt_count = RMT_VERSION;
265 					rval = (offset_t)mtop.mt_count;
266 				} else {
267 					rval = (offset_t)ioctl(tape, MTIOCTOP,
268 					    (char *)&mtop);
269 				}
270 				saverr = errno;
271 				(void) kill(next, TAPE);
272 				(void) sigsuspend(&sendmask);
273 				respond(rval < 0 ?
274 				    rval : (offset_t)mtop.mt_count,
275 				    saverr);
276 			}
277 			break;
278 		}
279 
280 		case 'S':		/* status */
281 		case 's': {		/* extended status */
282 			char skey;
283 
284 			DEBUG1("rmtd: %c\n", key);
285 			if (key == 's') {
286 				if (read(0, &skey, 1) != 1)
287 					continue;
288 			}
289 			(void) kill(next, RECV);
290 			(void) sigsuspend(&tapemask);
291 			errno = 0;
292 			rval = (offset_t)ioctl(tape, MTIOCGET, (char *)&mtget);
293 			saverr = errno;
294 			(void) kill(next, TAPE);
295 			(void) sigsuspend(&sendmask);
296 			if (rval < 0)
297 				respond(rval, saverr);
298 			else {
299 				if (key == 's') {	/* extended status */
300 					DEBUG1("rmtd: s%c\n", key);
301 					switch (skey) {
302 					case MTS_TYPE:
303 						respond(
304 						    (offset_t)mtget.mt_type,
305 						    saverr);
306 						break;
307 					case MTS_DSREG:
308 						respond(
309 						    (offset_t)mtget.mt_dsreg,
310 						    saverr);
311 						break;
312 					case MTS_ERREG:
313 						respond(
314 						    (offset_t)mtget.mt_erreg,
315 						    saverr);
316 						break;
317 					case MTS_RESID:
318 						respond(
319 						    (offset_t)mtget.mt_resid,
320 						    saverr);
321 						break;
322 					case MTS_FILENO:
323 						respond(
324 						    (offset_t)mtget.mt_fileno,
325 						    saverr);
326 						break;
327 					case MTS_BLKNO:
328 						respond(
329 						    (offset_t)mtget.mt_blkno,
330 						    saverr);
331 						break;
332 					case MTS_FLAGS:
333 						respond(
334 						    (offset_t)mtget.mt_flags,
335 						    saverr);
336 						break;
337 					case MTS_BF:
338 						respond((offset_t)mtget.mt_bf,
339 						    saverr);
340 						break;
341 					default:
342 						respond(-1LL, EINVAL);
343 						break;
344 					}
345 				} else {
346 					respond((offset_t)sizeof (mtget),
347 					    saverr);
348 					(void) write(1, (char *)&mtget,
349 					    sizeof (mtget));
350 				}
351 			}
352 			break;
353 		}
354 
355 		case 'W':
356 			getstring(count, sizeof (count));
357 			n = (size_t)atol(count);
358 			checkbuf(n);
359 			DEBUG1("rmtd: W %s\n", count);
360 #ifdef lint
361 			cc = 0;
362 #endif
363 			for (i = 0; i < n; i += (size_t)cc) {
364 				cc = read(0, &record[i], n - i);
365 				if (cc <= 0) {
366 					DEBUG1(gettext("%s: premature eof\n"),
367 						"rmtd");
368 					exit(2);
369 				}
370 			}
371 			(void) kill(next, RECV);
372 			(void) sigsuspend(&tapemask);
373 			rval = (offset_t)write(tape, record, n);
374 			saverr = errno;
375 			(void) kill(next, TAPE);
376 			(void) sigsuspend(&sendmask);
377 			respond(rval, saverr);
378 			break;
379 
380 		case 'R':
381 			getstring(count, sizeof (count));
382 			n = (size_t)atol(count);
383 			checkbuf(n);
384 			DEBUG1("rmtd: R %s\n", count);
385 			(void) kill(next, RECV);
386 			(void) sigsuspend(&tapemask);
387 			rval = (offset_t)read(tape, record, n);
388 			saverr = errno;
389 			(void) kill(next, TAPE);
390 			(void) sigsuspend(&sendmask);
391 			respond(rval, saverr);
392 			(void) write(1, record, (size_t)rval);
393 			break;
394 
395 		default:
396 			DEBUG2(gettext("%s: garbage command '%c'\n"),
397 				"rmtd", key);
398 			/*FALLTHROUGH*/
399 
400 		case 'C':
401 		case 'O':
402 			/* rendezvous back into a single process */
403 			if (setjmp(sjbuf) == 0 || getpid() != parent) {
404 				(void) sigsuspend(&tapemask);
405 				(void) sigsuspend(&sendmask);
406 				(void) kill(parent, key == 'O' ? OPEN :
407 					key == 'C' ? CLOSE : ERROR);
408 				(void) sigemptyset(&newmask);
409 				(void) sigsuspend(&newmask);
410 			}
411 			while (children > 0) {
412 				(void) kill(childpid[--children], SIGKILL);
413 				while (wait(NULL) != childpid[children])
414 					;
415 			}
416 			next = parent;
417 			if (key == 'C') {
418 				getstring(device, sizeof (device));
419 				DEBUG1("rmtd: C %s\n", device);
420 				rval = (offset_t)close(tape);
421 				respond(rval, errno);
422 				(void) kill(parent, TAPE);
423 				(void) kill(parent, SEND);
424 				continue;
425 			}
426 			if (key != 'O') 		/* garbage command */
427 				exit(3);
428 			(void) close(tape);
429 			getstring(device, sizeof (device));
430 			getstring(mode, sizeof (mode));
431 			DEBUG2("rmtd: O %s %s\n", device, mode);
432 			/*
433 			 * Due to incompatibilities in the
434 			 * assignment of mode bits between
435 			 * BSD and System V, we strip all
436 			 * but the read/write bits.  However,
437 			 * we also want to handle things larger
438 			 * than 2GB, so we also force O_LARGEFILE.
439 			 */
440 			tape = open(device, O_LARGEFILE |
441 			    (atoi(mode) & (O_RDONLY|O_WRONLY|O_RDWR)));
442 			respond((offset_t)tape, errno);
443 			if (tape >= 0)			/* fork off */
444 				while (children < MAXCHILD &&
445 					(childpid[children] = fork()) > 0)
446 						next = childpid[children++];
447 			if (next == parent) {
448 				(void) kill(parent, RECV);
449 				(void) kill(parent, TAPE);
450 				(void) kill(parent, SEND);
451 			}
452 			(void) sigsuspend(&cmdmask);
453 			continue;
454 		}
455 		(void) kill(next, SEND);
456 		(void) sigsuspend(&cmdmask);
457 	}
458 	(void) kill(next, RECV);
459 	return (0);
460 }
461 
462 static void
463 respond(offset_t rval, int Errno)
464 {
465 	char resp[SSIZE];
466 	char *errstr = strerror(Errno);
467 
468 	if (rval < 0) {
469 		(void) snprintf(resp, SSIZE, "E%d\n%s\n", Errno, errstr);
470 		DEBUG2("rmtd: E %d (%s)\n", Errno, errstr);
471 	} else {
472 		(void) snprintf(resp, SSIZE, "A%lld\n", rval);
473 		DEBUG1("rmtd: A %lld\n", rval);
474 	}
475 	resp[SSIZE - 1] = '\0';
476 	(void) write(1, resp, (int)strlen(resp));
477 }
478 
479 static void
480 getstring(char *cp, size_t size)
481 {
482 	char *limit = cp + size - 1;
483 
484 	cp--;			/* nullify first increment */
485 	do {
486 		cp++;
487 		if (read(0, cp, 1) != 1)
488 			exit(0);
489 	} while ((*cp != '\n') && (cp < limit));
490 	*cp = '\0';
491 }
492 
493 static void
494 checkbuf(size_t size)
495 {
496 	if (size <= maxrecsize)
497 		return;
498 	if (record != 0)
499 		free(record);
500 	if ((record = malloc(size)) == NULL) {
501 		DEBUG2(gettext("%s: cannot allocate %ld-byte buffer\n"),
502 		    size, "rmtd");
503 		exit(4);
504 	}
505 	maxrecsize = size;
506 }
507