rmt/rmt.c

   1 /*
   2  *      Ported to Linux's Second Extended File System as part of the
   3  *      dump and restore backup suit
   4  *      Remy Card <card@Linux.EU.Org>, 1994-1997
   5  *      Stelian Pop <pop@cybercable.fr>, 1999
   6  */
   7
   8 /*
   9  * Copyright (c) 1983, 1993
  10  *      The Regents of the University of California.  All rights reserved.
  11  *
  12  * Redistribution and use in source and binary forms, with or without
  13  * modification, are permitted provided that the following conditions
  14  * are met:
  15  * 1. Redistributions of source code must retain the above copyright
  16  *    notice, this list of conditions and the following disclaimer.
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  * 3. All advertising materials mentioning features or use of this software
  21  *    must display the following acknowledgement:
  22  *      This product includes software developed by the University of
  23  *      California, Berkeley and its contributors.
  24  * 4. Neither the name of the University nor the names of its contributors
  25  *    may be used to endorse or promote products derived from this software
  26  *    without specific prior written permission.
  27  *
  28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  38  * SUCH DAMAGE.
  39  */
  40
  41 #ifndef lint
  42 static const char rcsid[] =
  43         "$Id: rmt.c,v 1.6 1999/10/13 09:57:22 stelian Exp $";
  44 #endif /* not linux */
  45
  46 /*
  47  * rmt
  48  */
  49 #include <sys/types.h>
  50 #include <sys/socket.h>
  51 #include <sys/mtio.h>
  52 #include <errno.h>
  53 #include <fcntl.h>
  54 #include <sgtty.h>
  55 #include <stdio.h>
  56 #include <stdlib.h>
  57 #include <string.h>
  58 #include <unistd.h>
  59
  60 #ifdef __linux__
  61 #include <linux/ext2_fs.h>
  62 #include <ext2fs/ext2fs.h>
  63 #include <bsdcompat.h>
  64 #endif
  65
  66 int     tape = -1;
  67
  68 char    *record;
  69 int     maxrecsize = -1;
  70
  71 #define SSIZE   64
  72 char    device[SSIZE];
  73 char    count[SSIZE], filemode[SSIZE], pos[SSIZE], op[SSIZE];
  74
  75 char    resp[BUFSIZ];
  76
  77 FILE    *debug;
  78 #define DEBUG(f)        if (debug) fprintf(debug, f)
  79 #define DEBUG1(f,a)     if (debug) fprintf(debug, f, a)
  80 #define DEBUG2(f,a1,a2) if (debug) fprintf(debug, f, a1, a2)
  81
  82 char    *checkbuf __P((char *, int));
  83 void     error __P((int));
  84 void     getstring __P((char *));
  85
  86 int
  87 main(int argc, char *argv[])
  88 {
  89         int rval = 0;
  90         char c;
  91         int n, i, cc;
  92
  93         argc--, argv++;
  94         if (argc > 0) {
  95                 debug = fopen(*argv, "w");
  96                 if (debug == 0)
  97                         exit(1);
  98                 (void)setbuf(debug, (char *)0);
  99         }
 100 top:
 101         errno = 0;
 102         rval = 0;
 103         if (read(0, &c, 1) != 1)
 104                 exit(0);
 105         switch (c) {
 106
 107         case 'O':
 108                 if (tape >= 0)
 109                         (void) close(tape);
 110                 getstring(device);
 111                 getstring(filemode);
 112                 DEBUG2("rmtd: O %s %s\n", device, filemode);
 113                 /*
 114                  * XXX the rmt protocol does not provide a means to
 115                  * specify the permission bits; allow rw for everyone,
 116                  * as modified by the users umask
 117                  */
 118                 tape = open(device, atoi(filemode), 0666);
 119                 if (tape < 0)
 120                         goto ioerror;
 121                 goto respond;
 122
 123         case 'C':
 124                 DEBUG("rmtd: C\n");
 125                 getstring(device);              /* discard */
 126                 if (close(tape) < 0)
 127                         goto ioerror;
 128                 tape = -1;
 129                 goto respond;
 130
 131         case 'L':
 132                 getstring(count);
 133                 getstring(pos);
 134                 DEBUG2("rmtd: L %s %s\n", count, pos);
 135                 rval = lseek(tape, (off_t)atol(count), atoi(pos));
 136                 if (rval < 0)
 137                         goto ioerror;
 138                 goto respond;
 139
 140         case 'W':
 141                 getstring(count);
 142                 n = atoi(count);
 143                 DEBUG1("rmtd: W %s\n", count);
 144                 record = checkbuf(record, n);
 145                 for (i = 0; i < n; i += cc) {
 146                         cc = read(0, &record[i], n - i);
 147                         if (cc <= 0) {
 148                                 DEBUG("rmtd: premature eof\n");
 149                                 exit(2);
 150                         }
 151                 }
 152                 rval = write(tape, record, n);
 153                 if (rval < 0)
 154                         goto ioerror;
 155                 goto respond;
 156
 157         case 'R':
 158                 getstring(count);
 159                 DEBUG1("rmtd: R %s\n", count);
 160                 n = atoi(count);
 161                 record = checkbuf(record, n);
 162                 rval = read(tape, record, n);
 163                 if (rval < 0)
 164                         goto ioerror;
 165                 (void)sprintf(resp, "A%d\n", rval);
 166                 (void)write(1, resp, strlen(resp));
 167                 (void)write(1, record, rval);
 168                 goto top;
 169
 170         case 'I':
 171                 getstring(op);
 172                 getstring(count);
 173                 DEBUG2("rmtd: I %s %s\n", op, count);
 174                 { struct mtop mtop;
 175                   mtop.mt_op = atoi(op);
 176                   mtop.mt_count = atoi(count);
 177                   if (ioctl(tape, MTIOCTOP, (char *)&mtop) < 0)
 178                         goto ioerror;
 179                   rval = mtop.mt_count;
 180                 }
 181                 goto respond;
 182
 183         case 'S':               /* status */
 184                 DEBUG("rmtd: S\n");
 185                 { struct mtget mtget;
 186                   if (ioctl(tape, MTIOCGET, (char *)&mtget) < 0)
 187                         goto ioerror;
 188                   rval = sizeof (mtget);
 189                   (void)sprintf(resp, "A%d\n", rval);
 190                   (void)write(1, resp, strlen(resp));
 191                   (void)write(1, (char *)&mtget, sizeof (mtget));
 192                   goto top;
 193                 }
 194
 195         case 'V':               /* version */
 196                 getstring(op);
 197                 DEBUG1("rmtd: V %s\n", op);
 198                 rval = 2;
 199                 goto respond;
 200
 201         default:
 202                 DEBUG1("rmtd: garbage command %c\n", c);
 203                 exit(3);
 204         }
 205 respond:
 206         DEBUG1("rmtd: A %d\n", rval);
 207         (void)sprintf(resp, "A%d\n", rval);
 208         (void)write(1, resp, strlen(resp));
 209         goto top;
 210 ioerror:
 211         error(errno);
 212         goto top;
 213 }
 214
 215 void getstring(char *bp)
 216 {
 217         int i;
 218         char *cp = bp;
 219
 220         for (i = 0; i < SSIZE; i++) {
 221                 if (read(0, cp+i, 1) != 1)
 222                         exit(0);
 223                 if (cp[i] == '\n')
 224                         break;
 225         }
 226         cp[i] = '\0';
 227 }
 228
 229 char *
 230 checkbuf(char *record, int size)
 231 {
 232
 233         if (size <= maxrecsize)
 234                 return (record);
 235         if (record != 0)
 236                 free(record);
 237         record = malloc(size);
 238         if (record == 0) {
 239                 DEBUG("rmtd: cannot allocate buffer space\n");
 240                 exit(4);
 241         }
 242         maxrecsize = size;
 243         while (size > 1024 &&
 244                setsockopt(0, SOL_SOCKET, SO_RCVBUF, &size, sizeof (size)) < 0)
 245                 size -= 1024;
 246         return (record);
 247 }
 248
 249 void
 250 error(int num)
 251 {
 252
 253         DEBUG2("rmtd: E %d (%s)\n", num, strerror(num));
 254         (void)snprintf(resp, sizeof(resp), "E%d\n%s\n", num, strerror(num));
 255         (void)write(1, resp, strlen(resp));
 256 }