1 /* $OpenBSD: rmt.c,v 1.20 2016/08/14 18:34:48 guenther Exp $ */ 2 3 /* 4 * Copyright (c) 1983 Regents of the University of California. 5 * 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/file.h> 38 #include <sys/stat.h> 39 #include <sys/ioctl.h> 40 #include <sys/mtio.h> 41 #include <unistd.h> 42 #include <stdio.h> 43 #include <stdlib.h> 44 #include <err.h> 45 #include <errno.h> 46 #include <string.h> 47 #include <limits.h> 48 49 int tape = -1; 50 51 char *record; 52 int maxrecsize = -1; 53 54 #define STRSIZE 64 55 char device[PATH_MAX]; 56 char lastdevice[PATH_MAX] = ""; 57 char count[STRSIZE], mode[STRSIZE], pos[STRSIZE], op[STRSIZE]; 58 59 char resp[BUFSIZ]; 60 61 FILE *debug; 62 #define DEBUG(f) if (debug) fprintf(debug, f) 63 #define DEBUG1(f,a) if (debug) fprintf(debug, f, a) 64 #define DEBUG2(f,a1,a2) if (debug) fprintf(debug, f, a1, a2) 65 66 char *checkbuf(char *, int); 67 void getstring(char *, int); 68 void error(int); 69 __dead void usage(void); 70 71 int 72 main(int argc, char *argv[]) 73 { 74 off_t orval; 75 int rval; 76 char c; 77 int n, i, cc; 78 int ch, rflag = 0, wflag = 0; 79 int f, acc; 80 mode_t m; 81 char *dir = NULL; 82 char *devp; 83 size_t dirlen; 84 85 if (pledge("stdio rpath wpath cpath inet", NULL) == -1) 86 err(1, "pledge"); 87 88 while ((ch = getopt(argc, argv, "d:rw")) != -1) { 89 switch (ch) { 90 case 'd': 91 dir = optarg; 92 if (*dir != '/') 93 errx(1, "directory must be absolute"); 94 break; 95 case 'r': 96 rflag = 1; 97 break; 98 case 'w': 99 wflag = 1; 100 break; 101 default: 102 usage(); 103 /* NOTREACHED */ 104 } 105 } 106 argc -= optind; 107 argv += optind; 108 109 if (rflag && wflag) 110 usage(); 111 112 if (argc > 0) { 113 debug = fopen(*argv, "w"); 114 if (debug == 0) 115 err(1, "cannot open debug file"); 116 setvbuf(debug, NULL, _IONBF, 0); 117 } 118 119 if (dir) { 120 if (chdir(dir) != 0) 121 err(1, "chdir"); 122 dirlen = strlen(dir); 123 } 124 125 top: 126 errno = 0; 127 rval = 0; 128 if (read(STDIN_FILENO, &c, 1) != 1) 129 exit(0); 130 switch (c) { 131 132 case 'O': 133 if (tape >= 0) 134 (void) close(tape); 135 getstring(device, sizeof(device)); 136 getstring(mode, sizeof(mode)); 137 DEBUG2("rmtd: O %s %s\n", device, mode); 138 139 devp = device; 140 f = atoi(mode); 141 m = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH; 142 acc = f & O_ACCMODE; 143 if (dir) { 144 /* Strip away valid directory prefix. */ 145 if (strncmp(dir, devp, dirlen) == 0 && 146 (devp[dirlen - 1] == '/' || 147 devp[dirlen] == '/')) { 148 devp += dirlen; 149 while (*devp == '/') 150 devp++; 151 } 152 /* Don't allow directory traversal. */ 153 if (strchr(devp, '/')) { 154 errno = EACCES; 155 goto ioerror; 156 } 157 f |= O_NOFOLLOW; 158 } 159 if (rflag) { 160 /* 161 * Only allow readonly open and ignore file 162 * creation requests. 163 */ 164 if (acc != O_RDONLY) { 165 errno = EPERM; 166 goto ioerror; 167 } 168 f &= ~O_CREAT; 169 } else if (wflag) { 170 /* 171 * Require, and force creation of, a nonexistant file, 172 * unless we are reopening the last opened file again, 173 * in which case it is opened read-only. 174 */ 175 if (strcmp(devp, lastdevice) != 0) { 176 /* 177 * Disallow read-only open since that would 178 * only result in an empty file. 179 */ 180 if (acc == O_RDONLY) { 181 errno = EPERM; 182 goto ioerror; 183 } 184 f |= O_CREAT | O_EXCL; 185 } else { 186 acc = O_RDONLY; 187 } 188 /* Create readonly file */ 189 m = S_IRUSR|S_IRGRP|S_IROTH; 190 } 191 /* Apply new access mode. */ 192 f = (f & ~O_ACCMODE) | acc; 193 194 tape = open(devp, f, m); 195 if (tape == -1) 196 goto ioerror; 197 (void)strlcpy(lastdevice, devp, sizeof(lastdevice)); 198 goto respond; 199 200 case 'C': 201 DEBUG("rmtd: C\n"); 202 getstring(device, sizeof(device)); /* discard */ 203 if (close(tape) == -1) 204 goto ioerror; 205 tape = -1; 206 goto respond; 207 208 case 'L': 209 getstring(count, sizeof(count)); 210 getstring(pos, sizeof(pos)); 211 DEBUG2("rmtd: L %s %s\n", count, pos); 212 orval = lseek(tape, strtoll(count, NULL, 0), atoi(pos)); 213 if (orval == -1) 214 goto ioerror; 215 goto respond; 216 217 case 'W': 218 getstring(count, sizeof(count)); 219 n = atoi(count); 220 DEBUG1("rmtd: W %s\n", count); 221 record = checkbuf(record, n); 222 for (i = 0; i < n; i += cc) { 223 cc = read(STDIN_FILENO, &record[i], n - i); 224 if (cc <= 0) { 225 DEBUG("rmtd: premature eof\n"); 226 exit(2); 227 } 228 } 229 rval = write(tape, record, n); 230 if (rval < 0) 231 goto ioerror; 232 goto respond; 233 234 case 'R': 235 getstring(count, sizeof(count)); 236 DEBUG1("rmtd: R %s\n", count); 237 n = atoi(count); 238 record = checkbuf(record, n); 239 rval = read(tape, record, n); 240 if (rval < 0) 241 goto ioerror; 242 (void) snprintf(resp, sizeof resp, "A%d\n", rval); 243 (void) write(STDOUT_FILENO, resp, strlen(resp)); 244 (void) write(STDOUT_FILENO, record, rval); 245 goto top; 246 247 case 'I': 248 getstring(op, sizeof(op)); 249 getstring(count, sizeof(count)); 250 DEBUG2("rmtd: I %s %s\n", op, count); 251 { struct mtop mtop; 252 mtop.mt_op = atoi(op); 253 mtop.mt_count = atoi(count); 254 if (ioctl(tape, MTIOCTOP, (char *)&mtop) == -1) 255 goto ioerror; 256 rval = mtop.mt_count; 257 } 258 goto respond; 259 260 case 'S': /* status */ 261 DEBUG("rmtd: S\n"); 262 { struct mtget mtget; 263 if (ioctl(tape, MTIOCGET, (char *)&mtget) == -1) 264 goto ioerror; 265 rval = sizeof (mtget); 266 (void) snprintf(resp, sizeof resp, "A%d\n", rval); 267 (void) write(STDOUT_FILENO, resp, strlen(resp)); 268 (void) write(STDOUT_FILENO, (char *)&mtget, sizeof (mtget)); 269 goto top; 270 } 271 272 default: 273 DEBUG1("rmtd: garbage command %c\n", c); 274 exit(3); 275 } 276 respond: 277 DEBUG1("rmtd: A %d\n", rval); 278 (void) snprintf(resp, sizeof resp, "A%d\n", rval); 279 (void) write(STDOUT_FILENO, resp, strlen(resp)); 280 goto top; 281 ioerror: 282 error(errno); 283 goto top; 284 } 285 286 void 287 getstring(char *bp, int size) 288 { 289 char *cp = bp; 290 char *ep = bp + size - 1; 291 292 do { 293 if (read(STDIN_FILENO, cp, 1) != 1) 294 exit(0); 295 } while (*cp != '\n' && ++cp < ep); 296 *cp = '\0'; 297 } 298 299 char * 300 checkbuf(char *record, int size) 301 { 302 if (size <= maxrecsize) 303 return (record); 304 if (record != 0) 305 free(record); 306 record = malloc(size); 307 if (record == 0) { 308 DEBUG("rmtd: cannot allocate buffer space\n"); 309 exit(4); 310 } 311 maxrecsize = size; 312 while (size > 1024 && 313 setsockopt(0, SOL_SOCKET, SO_RCVBUF, &size, sizeof (size)) == -1) 314 size -= 1024; 315 return (record); 316 } 317 318 void 319 error(int num) 320 { 321 322 DEBUG2("rmtd: E %d (%s)\n", num, strerror(num)); 323 (void) snprintf(resp, sizeof (resp), "E%d\n%s\n", num, strerror(num)); 324 (void) write(STDOUT_FILENO, resp, strlen(resp)); 325 } 326 327 __dead void 328 usage(void) 329 { 330 extern char *__progname; 331 332 (void)fprintf(stderr, "usage: %s [-r | -w] [-d directory]\n", 333 __progname); 334 exit(1); 335 } 336