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>, 1999-2000
   6  *      Stelian Pop <pop@cybercable.fr> - Alcôve <www.alcove.fr>, 2000
   7  */
   8
   9 /*
  10  * Copyright (c) 1983, 1993
  11  *      The Regents of the University of California.  All rights reserved.
  12  *
  13  * Redistribution and use in source and binary forms, with or without
  14  * modification, are permitted provided that the following conditions
  15  * are met:
  16  * 1. Redistributions of source code must retain the above copyright
  17  *    notice, this list of conditions and the following disclaimer.
  18  * 2. Redistributions in binary form must reproduce the above copyright
  19  *    notice, this list of conditions and the following disclaimer in the
  20  *    documentation and/or other materials provided with the distribution.
  21  * 3. All advertising materials mentioning features or use of this software
  22  *    must display the following acknowledgement:
  23  *      This product includes software developed by the University of
  24  *      California, Berkeley and its contributors.
  25  * 4. Neither the name of the University nor the names of its contributors
  26  *    may be used to endorse or promote products derived from this software
  27  *    without specific prior written permission.
  28  *
  29  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  30  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  31  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  32  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  33  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  34  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  35  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  36  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  37  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  38  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  39  * SUCH DAMAGE.
  40  */
  41
  42 #ifndef lint
  43 static const char rcsid[] =
  44         "$Id: rmt.c,v 1.10 2000/11/10 14:51:42 stelian Exp $";
  45 #endif /* not linux */
  46
  47 /*
  48  * rmt
  49  */
  50 #include <sys/types.h>
  51 #include <sys/socket.h>
  52 #include <sys/mtio.h>
  53 #include <errno.h>
  54 #include <fcntl.h>
  55 #ifndef __linux__
  56 #include <sgtty.h>
  57 #endif
  58 #include <stdio.h>
  59 #include <stdlib.h>
  60 #include <string.h>
  61 #include <unistd.h>
  62
  63 int     tape = -1;
  64
  65 char    *record;
  66 int     maxrecsize = -1;
  67
  68 #define SSIZE   64
  69 char    device[SSIZE];
  70 char    count[SSIZE], filemode[SSIZE], pos[SSIZE], op[SSIZE];
  71
  72 char    resp[BUFSIZ];
  73
  74 FILE    *debug;
  75 #define DEBUG(f)        if (debug) fprintf(debug, f)
  76 #define DEBUG1(f,a)     if (debug) fprintf(debug, f, a)
  77 #define DEBUG2(f,a1,a2) if (debug) fprintf(debug, f, a1, a2)
  78
  79 char    *checkbuf __P((char *, int));
  80 void     error __P((int));
  81 void     getstring __P((char *));
  82
  83 int
  84 main(int argc, char *argv[])
  85 {
  86         int rval = 0;
  87         char c;
  88         int n, i, cc;
  89
  90         argc--, argv++;
  91         if (argc > 0) {
  92                 debug = fopen(*argv, "w");
  93                 if (debug == 0)
  94                         exit(1);
  95                 (void)setbuf(debug, (char *)0);
  96         }
  97 top:
  98         errno = 0;
  99         rval = 0;
 100         if (read(0, &c, 1) != 1)
 101                 exit(0);
 102         switch (c) {
 103
 104         case 'O':
 105                 if (tape >= 0)
 106                         (void) close(tape);
 107                 getstring(device);
 108                 getstring(filemode);
 109                 DEBUG2("rmtd: O %s %s\n", device, filemode);
 110                 /*
 111                  * XXX the rmt protocol does not provide a means to
 112                  * specify the permission bits; allow rw for everyone,
 113                  * as modified by the users umask
 114                  */
 115                 tape = open(device, atoi(filemode), 0666);
 116                 if (tape < 0)
 117                         goto ioerror;
 118                 goto respond;
 119
 120         case 'C':
 121                 DEBUG("rmtd: C\n");
 122                 getstring(device);              /* discard */
 123                 if (close(tape) < 0)
 124                         goto ioerror;
 125                 tape = -1;
 126                 goto respond;
 127
 128         case 'L':
 129                 getstring(count);
 130                 getstring(pos);
 131                 DEBUG2("rmtd: L %s %s\n", count, pos);
 132                 rval = lseek(tape, (off_t)atol(count), atoi(pos));
 133                 if (rval < 0)
 134                         goto ioerror;
 135                 goto respond;
 136
 137         case 'W':
 138                 getstring(count);
 139                 n = atoi(count);
 140                 DEBUG1("rmtd: W %s\n", count);
 141                 record = checkbuf(record, n);
 142                 for (i = 0; i < n; i += cc) {
 143                         cc = read(0, &record[i], n - i);
 144                         if (cc <= 0) {
 145                                 DEBUG("rmtd: premature eof\n");
 146                                 exit(2);
 147                         }
 148                 }
 149                 rval = write(tape, record, n);
 150                 if (rval < 0)
 151                         goto ioerror;
 152                 goto respond;
 153
 154         case 'R':
 155                 getstring(count);
 156                 DEBUG1("rmtd: R %s\n", count);
 157                 n = atoi(count);
 158                 record = checkbuf(record, n);
 159                 rval = read(tape, record, n);
 160                 if (rval < 0)
 161                         goto ioerror;
 162                 (void)sprintf(resp, "A%d\n", rval);
 163                 (void)write(1, resp, strlen(resp));
 164                 (void)write(1, record, rval);
 165                 goto top;
 166
 167         case 'I':
 168                 getstring(op);
 169                 getstring(count);
 170                 DEBUG2("rmtd: I %s %s\n", op, count);
 171                 { struct mtop mtop;
 172                   mtop.mt_op = atoi(op);
 173                   mtop.mt_count = atoi(count);
 174                   if (ioctl(tape, MTIOCTOP, (char *)&mtop) < 0)
 175                         goto ioerror;
 176                   rval = mtop.mt_count;
 177                 }
 178                 goto respond;
 179
 180         case 'S':               /* status */
 181                 DEBUG("rmtd: S\n");
 182                 { struct mtget mtget;
 183                   if (ioctl(tape, MTIOCGET, (char *)&mtget) < 0)
 184                         goto ioerror;
 185                   rval = sizeof (mtget);
 186                   (void)sprintf(resp, "A%d\n", rval);
 187                   (void)write(1, resp, strlen(resp));
 188                   (void)write(1, (char *)&mtget, sizeof (mtget));
 189                   goto top;
 190                 }
 191
 192         case 'V':               /* version */
 193                 getstring(op);
 194                 DEBUG1("rmtd: V %s\n", op);
 195                 rval = 2;
 196                 goto respond;
 197
 198         default:
 199                 DEBUG1("rmtd: garbage command %c\n", c);
 200                 exit(3);
 201         }
 202 respond:
 203         DEBUG1("rmtd: A %d\n", rval);
 204         (void)sprintf(resp, "A%d\n", rval);
 205         (void)write(1, resp, strlen(resp));
 206         goto top;
 207 ioerror:
 208         error(errno);
 209         goto top;
 210 }
 211
 212 void getstring(char *bp)
 213 {
 214         int i;
 215         char *cp = bp;
 216
 217         for (i = 0; i < SSIZE; i++) {
 218                 if (read(0, cp+i, 1) != 1)
 219                         exit(0);
 220                 if (cp[i] == '\n')
 221                         break;
 222         }
 223         cp[i] = '\0';
 224 }
 225
 226 char *
 227 checkbuf(char *record, int size)
 228 {
 229
 230         if (size <= maxrecsize)
 231                 return (record);
 232         if (record != 0)
 233                 free(record);
 234         record = malloc(size);
 235         if (record == 0) {
 236                 DEBUG("rmtd: cannot allocate buffer space\n");
 237                 exit(4);
 238         }
 239         maxrecsize = size;
 240         while (size > 1024 &&
 241                setsockopt(0, SOL_SOCKET, SO_RCVBUF, &size, sizeof (size)) < 0)
 242                 size -= 1024;
 243         return (record);
 244 }
 245
 246 void
 247 error(int num)
 248 {
 249
 250         DEBUG2("rmtd: E %d (%s)\n", num, strerror(num));
 251         (void)snprintf(resp, sizeof(resp), "E%d\n%s\n", num, strerror(num));
 252         (void)write(1, resp, strlen(resp));
 253 }