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 1.13 2001/03/28 12:59:49 stelian Exp $";
  45 #endif /* not linux */
  46
  47 /*
  48  * rmt
  49  */
  50 #include <config.h>
  51 #include <sys/types.h>
  52 #include <sys/socket.h>
  53 #include <sys/mtio.h>
  54 #include <errno.h>
  55 #include <fcntl.h>
  56 #ifndef __linux__
  57 #include <sgtty.h>
  58 #endif
  59 #include <stdio.h>
  60 #include <stdlib.h>
  61 #include <string.h>
  62 #include <unistd.h>
  63
  64 int     tape = -1;
  65
  66 char    *record;
  67 int     maxrecsize = -1;
  68
  69 #define SSIZE   64
  70 char    device[SSIZE];
  71 char    count[SSIZE], filemode[SSIZE], pos[SSIZE], op[SSIZE];
  72
  73 char    resp[BUFSIZ];
  74
  75 FILE    *debug;
  76 #define DEBUG(f)        if (debug) fprintf(debug, f)
  77 #define DEBUG1(f,a)     if (debug) fprintf(debug, f, a)
  78 #define DEBUG2(f,a1,a2) if (debug) fprintf(debug, f, a1, a2)
  79
  80 char    *checkbuf __P((char *, int));
  81 void     error __P((int));
  82 void     getstring __P((char *));
  83
  84 int
  85 main(int argc, char *argv[])
  86 {
  87         int rval = 0;
  88         char c;
  89         int n, i, cc;
  90         unsigned long block = 0;
  91
  92         argc--, argv++;
  93         if (argc > 0) {
  94                 debug = fopen(*argv, "w");
  95                 if (debug == 0)
  96                         exit(1);
  97                 (void)setbuf(debug, (char *)0);
  98         }
  99 top:
 100         errno = 0;
 101         rval = 0;
 102         if (read(0, &c, 1) != 1)
 103                 exit(0);
 104         switch (c) {
 105
 106         case 'O':
 107                 if (tape >= 0)
 108                         (void) close(tape);
 109                 getstring(device);
 110                 getstring(filemode);
 111                 DEBUG2("rmtd: O %s %s\n", device, filemode);
 112                 /*
 113                  * XXX the rmt protocol does not provide a means to
 114                  * specify the permission bits; allow rw for everyone,
 115                  * as modified by the users umask
 116                  */
 117                 tape = open(device, atoi(filemode), 0666);
 118                 if (tape < 0)
 119                         goto ioerror;
 120                 block = 0;
 121                 goto respond;
 122
 123         case 'C':
 124                 DEBUG1("rmtd: C  (%lu blocks)\n", block);
 125                 getstring(device);              /* discard */
 126                 if (close(tape) < 0)
 127                         goto ioerror;
 128                 tape = -1;
 129                 block = 0;
 130                 goto respond;
 131
 132         case 'L':
 133                 getstring(count);
 134                 getstring(pos);
 135                 DEBUG2("rmtd: L %s %s\n", count, pos);
 136                 rval = lseek(tape, (off_t)atol(count), atoi(pos));
 137                 if (rval < 0)
 138                         goto ioerror;
 139                 goto respond;
 140
 141         case 'W':
 142                 getstring(count);
 143                 n = atoi(count);
 144                 DEBUG2("rmtd: W %s (block = %lu)\n", count, block);
 145                 record = checkbuf(record, n);
 146                 for (i = 0; i < n; i += cc) {
 147                         cc = read(0, &record[i], n - i);
 148                         if (cc <= 0) {
 149                                 DEBUG("rmtd: premature eof\n");
 150                                 exit(2);
 151                         }
 152                 }
 153                 rval = write(tape, record, n);
 154                 if (rval < 0)
 155                         goto ioerror;
 156                 block += n >> 10;
 157                 goto respond;
 158
 159         case 'R':
 160                 getstring(count);
 161                 DEBUG2("rmtd: R %s (block %lu)\n", count, block);
 162                 n = atoi(count);
 163                 record = checkbuf(record, n);
 164                 rval = read(tape, record, n);
 165                 if (rval < 0)
 166                         goto ioerror;
 167                 (void)sprintf(resp, "A%d\n", rval);
 168                 (void)write(1, resp, strlen(resp));
 169                 (void)write(1, record, rval);
 170                 block += n >> 10;
 171                 goto top;
 172
 173         case 'I':
 174                 getstring(op);
 175                 getstring(count);
 176                 DEBUG2("rmtd: I %s %s\n", op, count);
 177                 { struct mtop mtop;
 178                   mtop.mt_op = atoi(op);
 179                   mtop.mt_count = atoi(count);
 180                   if (ioctl(tape, MTIOCTOP, (char *)&mtop) < 0)
 181                         goto ioerror;
 182                   rval = mtop.mt_count;
 183                 }
 184                 goto respond;
 185
 186         case 'S':               /* status */
 187                 DEBUG("rmtd: S\n");
 188                 { struct mtget mtget;
 189                   if (ioctl(tape, MTIOCGET, (char *)&mtget) < 0)
 190                         goto ioerror;
 191                   rval = sizeof (mtget);
 192                   (void)sprintf(resp, "A%d\n", rval);
 193                   (void)write(1, resp, strlen(resp));
 194                   (void)write(1, (char *)&mtget, sizeof (mtget));
 195                   goto top;
 196                 }
 197
 198         case 'V':               /* version */
 199                 getstring(op);
 200                 DEBUG1("rmtd: V %s\n", op);
 201                 rval = 2;
 202                 goto respond;
 203
 204         default:
 205                 DEBUG1("rmtd: garbage command %c\n", c);
 206                 exit(3);
 207         }
 208 respond:
 209         DEBUG1("rmtd: A %d\n", rval);
 210         (void)sprintf(resp, "A%d\n", rval);
 211         (void)write(1, resp, strlen(resp));
 212         goto top;
 213 ioerror:
 214         error(errno);
 215         goto top;
 216 }
 217
 218 void getstring(char *bp)
 219 {
 220         int i;
 221         char *cp = bp;
 222
 223         for (i = 0; i < SSIZE; i++) {
 224                 if (read(0, cp+i, 1) != 1)
 225                         exit(0);
 226                 if (cp[i] == '\n')
 227                         break;
 228         }
 229         cp[i] = '\0';
 230 }
 231
 232 char *
 233 checkbuf(char *record, int size)
 234 {
 235
 236         if (size <= maxrecsize)
 237                 return (record);
 238         if (record != 0)
 239                 free(record);
 240         record = malloc(size);
 241         if (record == 0) {
 242                 DEBUG("rmtd: cannot allocate buffer space\n");
 243                 exit(4);
 244         }
 245         maxrecsize = size;
 246         while (size > 1024 &&
 247                setsockopt(0, SOL_SOCKET, SO_RCVBUF, &size, sizeof (size)) < 0)
 248                 size -= 1024;
 249         return (record);
 250 }
 251
 252 void
 253 error(int num)
 254 {
 255
 256         DEBUG2("rmtd: E %d (%s)\n", num, strerror(num));
 257         (void)snprintf(resp, sizeof(resp), "E%d\n%s\n", num, strerror(num));
 258         (void)write(1, resp, strlen(resp));
 259 }