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 1.8 1999/11/21 02:24:47 tiniou 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 #ifndef __linux__
  55 #include <sgtty.h>
  56 #endif
  57 #include <stdio.h>
  58 #include <stdlib.h>
  59 #include <string.h>
  60 #include <unistd.h>
  61
  62 int     tape = -1;
  63
  64 char    *record;
  65 int     maxrecsize = -1;
  66
  67 #define SSIZE   64
  68 char    device[SSIZE];
  69 char    count[SSIZE], filemode[SSIZE], pos[SSIZE], op[SSIZE];
  70
  71 char    resp[BUFSIZ];
  72
  73 FILE    *debug;
  74 #define DEBUG(f)        if (debug) fprintf(debug, f)
  75 #define DEBUG1(f,a)     if (debug) fprintf(debug, f, a)
  76 #define DEBUG2(f,a1,a2) if (debug) fprintf(debug, f, a1, a2)
  77
  78 char    *checkbuf __P((char *, int));
  79 void     error __P((int));
  80 void     getstring __P((char *));
  81
  82 int
  83 main(int argc, char *argv[])
  84 {
  85         int rval = 0;
  86         char c;
  87         int n, i, cc;
  88
  89         argc--, argv++;
  90         if (argc > 0) {
  91                 debug = fopen(*argv, "w");
  92                 if (debug == 0)
  93                         exit(1);
  94                 (void)setbuf(debug, (char *)0);
  95         }
  96 top:
  97         errno = 0;
  98         rval = 0;
  99         if (read(0, &c, 1) != 1)
 100                 exit(0);
 101         switch (c) {
 102
 103         case 'O':
 104                 if (tape >= 0)
 105                         (void) close(tape);
 106                 getstring(device);
 107                 getstring(filemode);
 108                 DEBUG2("rmtd: O %s %s\n", device, filemode);
 109                 /*
 110                  * XXX the rmt protocol does not provide a means to
 111                  * specify the permission bits; allow rw for everyone,
 112                  * as modified by the users umask
 113                  */
 114                 tape = open(device, atoi(filemode), 0666);
 115                 if (tape < 0)
 116                         goto ioerror;
 117                 goto respond;
 118
 119         case 'C':
 120                 DEBUG("rmtd: C\n");
 121                 getstring(device);              /* discard */
 122                 if (close(tape) < 0)
 123                         goto ioerror;
 124                 tape = -1;
 125                 goto respond;
 126
 127         case 'L':
 128                 getstring(count);
 129                 getstring(pos);
 130                 DEBUG2("rmtd: L %s %s\n", count, pos);
 131                 rval = lseek(tape, (off_t)atol(count), atoi(pos));
 132                 if (rval < 0)
 133                         goto ioerror;
 134                 goto respond;
 135
 136         case 'W':
 137                 getstring(count);
 138                 n = atoi(count);
 139                 DEBUG1("rmtd: W %s\n", count);
 140                 record = checkbuf(record, n);
 141                 for (i = 0; i < n; i += cc) {
 142                         cc = read(0, &record[i], n - i);
 143                         if (cc <= 0) {
 144                                 DEBUG("rmtd: premature eof\n");
 145                                 exit(2);
 146                         }
 147                 }
 148                 rval = write(tape, record, n);
 149                 if (rval < 0)
 150                         goto ioerror;
 151                 goto respond;
 152
 153         case 'R':
 154                 getstring(count);
 155                 DEBUG1("rmtd: R %s\n", count);
 156                 n = atoi(count);
 157                 record = checkbuf(record, n);
 158                 rval = read(tape, record, n);
 159                 if (rval < 0)
 160                         goto ioerror;
 161                 (void)sprintf(resp, "A%d\n", rval);
 162                 (void)write(1, resp, strlen(resp));
 163                 (void)write(1, record, rval);
 164                 goto top;
 165
 166         case 'I':
 167                 getstring(op);
 168                 getstring(count);
 169                 DEBUG2("rmtd: I %s %s\n", op, count);
 170                 { struct mtop mtop;
 171                   mtop.mt_op = atoi(op);
 172                   mtop.mt_count = atoi(count);
 173                   if (ioctl(tape, MTIOCTOP, (char *)&mtop) < 0)
 174                         goto ioerror;
 175                   rval = mtop.mt_count;
 176                 }
 177                 goto respond;
 178
 179         case 'S':               /* status */
 180                 DEBUG("rmtd: S\n");
 181                 { struct mtget mtget;
 182                   if (ioctl(tape, MTIOCGET, (char *)&mtget) < 0)
 183                         goto ioerror;
 184                   rval = sizeof (mtget);
 185                   (void)sprintf(resp, "A%d\n", rval);
 186                   (void)write(1, resp, strlen(resp));
 187                   (void)write(1, (char *)&mtget, sizeof (mtget));
 188                   goto top;
 189                 }
 190
 191         case 'V':               /* version */
 192                 getstring(op);
 193                 DEBUG1("rmtd: V %s\n", op);
 194                 rval = 2;
 195                 goto respond;
 196
 197         default:
 198                 DEBUG1("rmtd: garbage command %c\n", c);
 199                 exit(3);
 200         }
 201 respond:
 202         DEBUG1("rmtd: A %d\n", rval);
 203         (void)sprintf(resp, "A%d\n", rval);
 204         (void)write(1, resp, strlen(resp));
 205         goto top;
 206 ioerror:
 207         error(errno);
 208         goto top;
 209 }
 210
 211 void getstring(char *bp)
 212 {
 213         int i;
 214         char *cp = bp;
 215
 216         for (i = 0; i < SSIZE; i++) {
 217                 if (read(0, cp+i, 1) != 1)
 218                         exit(0);
 219                 if (cp[i] == '\n')
 220                         break;
 221         }
 222         cp[i] = '\0';
 223 }
 224
 225 char *
 226 checkbuf(char *record, int size)
 227 {
 228
 229         if (size <= maxrecsize)
 230                 return (record);
 231         if (record != 0)
 232                 free(record);
 233         record = malloc(size);
 234         if (record == 0) {
 235                 DEBUG("rmtd: cannot allocate buffer space\n");
 236                 exit(4);
 237         }
 238         maxrecsize = size;
 239         while (size > 1024 &&
 240                setsockopt(0, SOL_SOCKET, SO_RCVBUF, &size, sizeof (size)) < 0)
 241                 size -= 1024;
 242         return (record);
 243 }
 244
 245 void
 246 error(int num)
 247 {
 248
 249         DEBUG2("rmtd: E %d (%s)\n", num, strerror(num));
 250         (void)snprintf(resp, sizeof(resp), "E%d\n%s\n", num, strerror(num));
 251         (void)write(1, resp, strlen(resp));
 252 }