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 /*
  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  * $Id: rmt.c,v 1.5 1999/10/11 13:31:14 stelian Exp $
  42  */
  43
  44 /*
  45  * rmt
  46  */
  47 #include <sys/types.h>
  48 #include <sys/socket.h>
  49 #include <sys/mtio.h>
  50 #include <errno.h>
  51 #include <fcntl.h>
  52 #include <sgtty.h>
  53 #include <stdio.h>
  54 #include <stdlib.h>
  55 #include <string.h>
  56 #include <unistd.h>
  57
  58 #ifdef __linux__
  59 #include <linux/ext2_fs.h>
  60 #include <ext2fs/ext2fs.h>
  61 #include <bsdcompat.h>
  62 #endif
  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
  91         argc--, argv++;
  92         if (argc > 0) {
  93                 debug = fopen(*argv, "w");
  94                 if (debug == 0)
  95                         exit(1);
  96                 (void)setbuf(debug, (char *)0);
  97         }
  98 top:
  99         errno = 0;
 100         rval = 0;
 101         if (read(0, &c, 1) != 1)
 102                 exit(0);
 103         switch (c) {
 104
 105         case 'O':
 106                 if (tape >= 0)
 107                         (void) close(tape);
 108                 getstring(device);
 109                 getstring(filemode);
 110                 DEBUG2("rmtd: O %s %s\n", device, filemode);
 111                 /*
 112                  * XXX the rmt protocol does not provide a means to
 113                  * specify the permission bits; allow rw for everyone,
 114                  * as modified by the users umask
 115                  */
 116                 tape = open(device, atoi(filemode), 0666);
 117                 if (tape < 0)
 118                         goto ioerror;
 119                 goto respond;
 120
 121         case 'C':
 122                 DEBUG("rmtd: C\n");
 123                 getstring(device);              /* discard */
 124                 if (close(tape) < 0)
 125                         goto ioerror;
 126                 tape = -1;
 127                 goto respond;
 128
 129         case 'L':
 130                 getstring(count);
 131                 getstring(pos);
 132                 DEBUG2("rmtd: L %s %s\n", count, pos);
 133                 rval = lseek(tape, (off_t)atol(count), atoi(pos));
 134                 if (rval < 0)
 135                         goto ioerror;
 136                 goto respond;
 137
 138         case 'W':
 139                 getstring(count);
 140                 n = atoi(count);
 141                 DEBUG1("rmtd: W %s\n", count);
 142                 record = checkbuf(record, n);
 143                 for (i = 0; i < n; i += cc) {
 144                         cc = read(0, &record[i], n - i);
 145                         if (cc <= 0) {
 146                                 DEBUG("rmtd: premature eof\n");
 147                                 exit(2);
 148                         }
 149                 }
 150                 rval = write(tape, record, n);
 151                 if (rval < 0)
 152                         goto ioerror;
 153                 goto respond;
 154
 155         case 'R':
 156                 getstring(count);
 157                 DEBUG1("rmtd: R %s\n", count);
 158                 n = atoi(count);
 159                 record = checkbuf(record, n);
 160                 rval = read(tape, record, n);
 161                 if (rval < 0)
 162                         goto ioerror;
 163                 (void)sprintf(resp, "A%d\n", rval);
 164                 (void)write(1, resp, strlen(resp));
 165                 (void)write(1, record, rval);
 166                 goto top;
 167
 168         case 'I':
 169                 getstring(op);
 170                 getstring(count);
 171                 DEBUG2("rmtd: I %s %s\n", op, count);
 172                 { struct mtop mtop;
 173                   mtop.mt_op = atoi(op);
 174                   mtop.mt_count = atoi(count);
 175                   if (ioctl(tape, MTIOCTOP, (char *)&mtop) < 0)
 176                         goto ioerror;
 177                   rval = mtop.mt_count;
 178                 }
 179                 goto respond;
 180
 181         case 'S':               /* status */
 182                 DEBUG("rmtd: S\n");
 183                 { struct mtget mtget;
 184                   if (ioctl(tape, MTIOCGET, (char *)&mtget) < 0)
 185                         goto ioerror;
 186                   rval = sizeof (mtget);
 187                   (void)sprintf(resp, "A%d\n", rval);
 188                   (void)write(1, resp, strlen(resp));
 189                   (void)write(1, (char *)&mtget, sizeof (mtget));
 190                   goto top;
 191                 }
 192
 193         case 'V':               /* version */
 194                 getstring(op);
 195                 DEBUG1("rmtd: V %s\n", op);
 196                 rval = 2;
 197                 goto respond;
 198
 199         default:
 200                 DEBUG1("rmtd: garbage command %c\n", c);
 201                 exit(3);
 202         }
 203 respond:
 204         DEBUG1("rmtd: A %d\n", rval);
 205         (void)sprintf(resp, "A%d\n", rval);
 206         (void)write(1, resp, strlen(resp));
 207         goto top;
 208 ioerror:
 209         error(errno);
 210         goto top;
 211 }
 212
 213 void getstring(char *bp)
 214 {
 215         int i;
 216         char *cp = bp;
 217
 218         for (i = 0; i < SSIZE; i++) {
 219                 if (read(0, cp+i, 1) != 1)
 220                         exit(0);
 221                 if (cp[i] == '\n')
 222                         break;
 223         }
 224         cp[i] = '\0';
 225 }
 226
 227 char *
 228 checkbuf(char *record, int size)
 229 {
 230
 231         if (size <= maxrecsize)
 232                 return (record);
 233         if (record != 0)
 234                 free(record);
 235         record = malloc(size);
 236         if (record == 0) {
 237                 DEBUG("rmtd: cannot allocate buffer space\n");
 238                 exit(4);
 239         }
 240         maxrecsize = size;
 241         while (size > 1024 &&
 242                setsockopt(0, SOL_SOCKET, SO_RCVBUF, &size, sizeof (size)) < 0)
 243                 size -= 1024;
 244         return (record);
 245 }
 246
 247 void
 248 error(int num)
 249 {
 250
 251         DEBUG2("rmtd: E %d (%s)\n", num, strerror(num));
 252         (void)snprintf(resp, sizeof(resp), "E%d\n%s\n", num, strerror(num));
 253         (void)write(1, resp, strlen(resp));
 254 }