xref: /freebsd/usr.sbin/rmt/rmt.c (revision f5463265955b829775bbb32e1fd0bc11dafc36ce)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1983, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 /*
33  * rmt
34  */
35 #include <sys/types.h>
36 #include <sys/socket.h>
37 #include <sys/mtio.h>
38 #include <errno.h>
39 #include <fcntl.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <unistd.h>
44 
45 static int	tape = -1;
46 
47 static char	*record;
48 static int	maxrecsize = -1;
49 
50 #define	SSIZE	64
51 static char	device[SSIZE];
52 static char	count[SSIZE], mode[SSIZE], pos[SSIZE], op[SSIZE];
53 
54 static char	resp[BUFSIZ];
55 
56 static FILE	*debug;
57 #define	DEBUG(f)	if (debug) fprintf(debug, f)
58 #define	DEBUG1(f,a)	if (debug) fprintf(debug, f, a)
59 #define	DEBUG2(f,a1,a2)	if (debug) fprintf(debug, f, a1, a2)
60 
61 static char	*checkbuf(char *, int);
62 static void	 error(int);
63 static void	 getstring(char *);
64 
65 int
66 main(int argc, char **argv)
67 {
68 	int rval;
69 	char c;
70 	int n, i, cc;
71 
72 	argc--, argv++;
73 	if (argc > 0) {
74 		debug = fopen(*argv, "w");
75 		if (debug == NULL) {
76 			DEBUG1("rmtd: error to open %s\n", *argv);
77 			exit(1);
78 		}
79 		(void)setbuf(debug, (char *)0);
80 	}
81 top:
82 	errno = 0;
83 	rval = 0;
84 	if (read(STDIN_FILENO, &c, 1) != 1)
85 		exit(0);
86 	switch (c) {
87 
88 	case 'O':
89 		if (tape >= 0)
90 			(void) close(tape);
91 		getstring(device);
92 		getstring(mode);
93 		DEBUG2("rmtd: O %s %s\n", device, mode);
94 		/*
95 		 * XXX the rmt protocol does not provide a means to
96 		 * specify the permission bits; allow rw for everyone,
97 		 * as modified by the users umask
98 		 */
99 		tape = open(device, atoi(mode), 0666);
100 		if (tape < 0)
101 			goto ioerror;
102 		goto respond;
103 
104 	case 'C':
105 		DEBUG("rmtd: C\n");
106 		getstring(device);		/* discard */
107 		if (close(tape) < 0)
108 			goto ioerror;
109 		tape = -1;
110 		goto respond;
111 
112 	case 'L':
113 		getstring(count);
114 		getstring(pos);
115 		DEBUG2("rmtd: L %s %s\n", count, pos);
116 		rval = lseek(tape, (off_t)strtoll(count, NULL, 10), atoi(pos));
117 		if (rval < 0)
118 			goto ioerror;
119 		goto respond;
120 
121 	case 'W':
122 		getstring(count);
123 		n = atoi(count);
124 		DEBUG1("rmtd: W %s\n", count);
125 		record = checkbuf(record, n);
126 		for (i = 0; i < n; i += cc) {
127 			cc = read(STDIN_FILENO, &record[i], n - i);
128 			if (cc <= 0) {
129 				DEBUG("rmtd: premature eof\n");
130 				exit(2);
131 			}
132 		}
133 		rval = write(tape, record, n);
134 		if (rval < 0)
135 			goto ioerror;
136 		goto respond;
137 
138 	case 'R':
139 		getstring(count);
140 		DEBUG1("rmtd: R %s\n", count);
141 		n = atoi(count);
142 		record = checkbuf(record, n);
143 		rval = read(tape, record, n);
144 		if (rval < 0)
145 			goto ioerror;
146 		(void)sprintf(resp, "A%d\n", rval);
147 		(void)write(STDOUT_FILENO, resp, strlen(resp));
148 		(void)write(STDOUT_FILENO, record, rval);
149 		goto top;
150 
151 	case 'I':
152 		getstring(op);
153 		getstring(count);
154 		DEBUG2("rmtd: I %s %s\n", op, count);
155 		{ struct mtop mtop;
156 		  mtop.mt_op = atoi(op);
157 		  mtop.mt_count = atoi(count);
158 		  if (ioctl(tape, MTIOCTOP, (char *)&mtop) < 0)
159 			goto ioerror;
160 		  rval = mtop.mt_count;
161 		}
162 		goto respond;
163 
164 	case 'S':		/* status */
165 		DEBUG("rmtd: S\n");
166 		{ struct mtget mtget;
167 		  if (ioctl(tape, MTIOCGET, (char *)&mtget) < 0)
168 			goto ioerror;
169 		  rval = sizeof (mtget);
170 		  if (rval > 24)	/* original mtget structure size */
171 			rval = 24;
172 		  (void)sprintf(resp, "A%d\n", rval);
173 		  (void)write(STDOUT_FILENO, resp, strlen(resp));
174 		  (void)write(STDOUT_FILENO, (char *)&mtget, rval);
175 		  goto top;
176 		}
177 
178         case 'V':               /* version */
179                 getstring(op);
180                 DEBUG1("rmtd: V %s\n", op);
181                 rval = 2;
182                 goto respond;
183 
184 	default:
185 		DEBUG1("rmtd: garbage command %c\n", c);
186 		exit(3);
187 	}
188 respond:
189 	DEBUG1("rmtd: A %d\n", rval);
190 	(void)sprintf(resp, "A%d\n", rval);
191 	(void)write(STDOUT_FILENO, resp, strlen(resp));
192 	goto top;
193 ioerror:
194 	error(errno);
195 	goto top;
196 }
197 
198 void
199 getstring(char *bp)
200 {
201 	int i;
202 	char *cp = bp;
203 
204 	for (i = 0; i < SSIZE; i++) {
205 		if (read(STDIN_FILENO, cp+i, 1) != 1)
206 			exit(0);
207 		if (cp[i] == '\n')
208 			break;
209 	}
210 	cp[i] = '\0';
211 }
212 
213 static char *
214 checkbuf(char *rec, int size)
215 {
216 
217 	if (size <= maxrecsize)
218 		return (rec);
219 	if (rec != NULL)
220 		free(rec);
221 	rec = malloc(size);
222 	if (rec == NULL) {
223 		DEBUG("rmtd: cannot allocate buffer space\n");
224 		exit(4);
225 	}
226 	maxrecsize = size;
227 	while (size > 1024 &&
228 	       setsockopt(0, SOL_SOCKET, SO_RCVBUF, &size, sizeof (size)) < 0)
229 		size -= 1024;
230 	return (rec);
231 }
232 
233 static void
234 error(int num)
235 {
236 
237 	DEBUG2("rmtd: E %d (%s)\n", num, strerror(num));
238 	(void)snprintf(resp, sizeof(resp), "E%d\n%s\n", num, strerror(num));
239 	(void)write(STDOUT_FILENO, resp, strlen(resp));
240 }
241