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@noos.fr>, 1999-2000
   6  *      Stelian Pop <pop@noos.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 1.14 2001/04/27 15:22:47 stelian Exp $";
  45 #endif /* not linux */
  46
  47 /*
  48  * rmt
  49  */
  50 #include <config.h>
  51 #include <compatlfs.h>
  52 #include <sys/types.h>
  53 #include <sys/socket.h>
  54 #include <sys/mtio.h>
  55 #include <errno.h>
  56 #include <fcntl.h>
  57 #ifndef __linux__
  58 #include <sgtty.h>
  59 #endif
  60 #include <stdio.h>
  61 #include <stdlib.h>
  62 #include <string.h>
  63 #include <unistd.h>
  64
  65 int     tape = -1;
  66
  67 char    *record;
  68 int     maxrecsize = -1;
  69
  70 #define SSIZE   64
  71 char    device[SSIZE];
  72 char    count[SSIZE], filemode[SSIZE], pos[SSIZE], op[SSIZE];
  73
  74 char    resp[BUFSIZ];
  75
  76 FILE    *debug;
  77 #define DEBUG(f)        if (debug) fprintf(debug, f)
  78 #define DEBUG1(f,a)     if (debug) fprintf(debug, f, a)
  79 #define DEBUG2(f,a1,a2) if (debug) fprintf(debug, f, a1, a2)
  80
  81 char    *checkbuf __P((char *, int));
  82 void     error __P((int));
  83 void     getstring __P((char *));
  84
  85 int
  86 main(int argc, char *argv[])
  87 {
  88         int rval = 0;
  89         char c;
  90         int n, i, cc;
  91         unsigned long block = 0;
  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                 block = 0;
 122                 goto respond;
 123
 124         case 'C':
 125                 DEBUG1("rmtd: C  (%lu blocks)\n", block);
 126                 getstring(device);              /* discard */
 127                 if (close(tape) < 0)
 128                         goto ioerror;
 129                 tape = -1;
 130                 block = 0;
 131                 goto respond;
 132
 133         case 'L':
 134                 getstring(count);
 135                 getstring(pos);
 136                 DEBUG2("rmtd: L %s %s\n", count, pos);
 137                 rval = LSEEK(tape, (off_t)atol(count), atoi(pos));
 138                 if (rval < 0)
 139                         goto ioerror;
 140                 goto respond;
 141
 142         case 'W':
 143                 getstring(count);
 144                 n = atoi(count);
 145                 DEBUG2("rmtd: W %s (block = %lu)\n", count, block);
 146                 record = checkbuf(record, n);
 147                 for (i = 0; i < n; i += cc) {
 148                         cc = read(0, &record[i], n - i);
 149                         if (cc <= 0) {
 150                                 DEBUG("rmtd: premature eof\n");
 151                                 exit(2);
 152                         }
 153                 }
 154                 rval = write(tape, record, n);
 155                 if (rval < 0)
 156                         goto ioerror;
 157                 block += n >> 10;
 158                 goto respond;
 159
 160         case 'R':
 161                 getstring(count);
 162                 DEBUG2("rmtd: R %s (block %lu)\n", count, block);
 163                 n = atoi(count);
 164                 record = checkbuf(record, n);
 165                 rval = read(tape, record, n);
 166                 if (rval < 0)
 167                         goto ioerror;
 168                 (void)sprintf(resp, "A%d\n", rval);
 169                 (void)write(1, resp, strlen(resp));
 170                 (void)write(1, record, rval);
 171                 block += n >> 10;
 172                 goto top;
 173
 174         case 'I':
 175                 getstring(op);
 176                 getstring(count);
 177                 DEBUG2("rmtd: I %s %s\n", op, count);
 178                 { struct mtop mtop;
 179                   mtop.mt_op = atoi(op);
 180                   mtop.mt_count = atoi(count);
 181                   if (ioctl(tape, MTIOCTOP, (char *)&mtop) < 0)
 182                         goto ioerror;
 183                   rval = mtop.mt_count;
 184                 }
 185                 goto respond;
 186
 187         case 'S':               /* status */
 188                 DEBUG("rmtd: S\n");
 189                 { struct mtget mtget;
 190                   if (ioctl(tape, MTIOCGET, (char *)&mtget) < 0)
 191                         goto ioerror;
 192                   rval = sizeof (mtget);
 193                   (void)sprintf(resp, "A%d\n", rval);
 194                   (void)write(1, resp, strlen(resp));
 195                   (void)write(1, (char *)&mtget, sizeof (mtget));
 196                   goto top;
 197                 }
 198
 199         case 'V':               /* version */
 200                 getstring(op);
 201                 DEBUG1("rmtd: V %s\n", op);
 202                 rval = 2;
 203                 goto respond;
 204
 205         default:
 206                 DEBUG1("rmtd: garbage command %c\n", c);
 207                 exit(3);
 208         }
 209 respond:
 210         DEBUG1("rmtd: A %d\n", rval);
 211         (void)sprintf(resp, "A%d\n", rval);
 212         (void)write(1, resp, strlen(resp));
 213         goto top;
 214 ioerror:
 215         error(errno);
 216         goto top;
 217 }
 218
 219 void getstring(char *bp)
 220 {
 221         int i;
 222         char *cp = bp;
 223
 224         for (i = 0; i < SSIZE; i++) {
 225                 if (read(0, cp+i, 1) != 1)
 226                         exit(0);
 227                 if (cp[i] == '\n')
 228                         break;
 229         }
 230         cp[i] = '\0';
 231 }
 232
 233 char *
 234 checkbuf(char *record, int size)
 235 {
 236
 237         if (size <= maxrecsize)
 238                 return (record);
 239         if (record != 0)
 240                 free(record);
 241         record = malloc(size);
 242         if (record == 0) {
 243                 DEBUG("rmtd: cannot allocate buffer space\n");
 244                 exit(4);
 245         }
 246         maxrecsize = size;
 247         while (size > 1024 &&
 248                setsockopt(0, SOL_SOCKET, SO_RCVBUF, &size, sizeof (size)) < 0)
 249                 size -= 1024;
 250         return (record);
 251 }
 252
 253 void
 254 error(int num)
 255 {
 256
 257         DEBUG2("rmtd: E %d (%s)\n", num, strerror(num));
 258         (void)snprintf(resp, sizeof(resp), "E%d\n%s\n", num, strerror(num));
 259         (void)write(1, resp, strlen(resp));
 260 }