* Copyright (c) 1983, 1993

/* $NetBSD: rmt.c,v 1.17 2018/01/23 21:06:25 sevan Exp $ */

/*
* Copyright (c) 1983, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1983, 1993\
The Regents of the University of California. All rights reserved.");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)rmt.c 8.1 (Berkeley) 6/6/93";
#else
__RCSID("$NetBSD: rmt.c,v 1.17 2018/01/23 21:06:25 sevan Exp $");
#endif
#endif /* not lint */

/*
* rmt
*/
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/mtio.h>
#include <sys/socket.h>
#include <sys/stat.h>

#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

int tape = -1;

int maxrecsize = -1;

#define SSIZE 64
char device[SSIZE];
char count[SSIZE], mode[SSIZE], pos[SSIZE], op[SSIZE];

char resp[BUFSIZ];

FILE *debug;
#define DEBUG(f) if (debug) fprintf(debug, f)
#define DEBUG1(f,a) if (debug) fprintf(debug, f, a)
#define DEBUG2(f,a1,a2) if (debug) fprintf(debug, f, a1, a2)

char *checkbuf(char *, int);
void error(int);
void getstring(char *, size_t);

int
main(int argc, char *argv[])
{
char *record = NULL;
int rval;
char c;
int n, i, cc;

argc--, argv++;
if (argc > 0) {
debug = fopen(*argv, "w");
if (debug == 0)
exit(1);
(void)setbuf(debug, (char *)0);
}
top:
errno = 0;
rval = 0;
if (read(STDIN_FILENO, &c, 1) != 1)
exit(0);
switch (c) {

case 'O':
if (tape >= 0)
(void) close(tape);
getstring(device, sizeof(device));
getstring(mode, sizeof(mode));
DEBUG2("rmtd: O %s %s\n", device, mode);
tape = open(device, atoi(mode),
S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH);
if (tape < 0)
goto ioerror;
goto respond;

case 'C':
DEBUG("rmtd: C\n");
getstring(device, sizeof(device)); /* discard */
if (close(tape) < 0)
goto ioerror;
tape = -1;
goto respond;

case 'L':
getstring(count, sizeof(count));
getstring(pos, sizeof(pos));
DEBUG2("rmtd: L %s %s\n", count, pos);
rval = lseek(tape, (off_t)strtoll(count, NULL, 10), atoi(pos));
if (rval < 0)
goto ioerror;
goto respond;

case 'W':
getstring(count, sizeof(count));
n = atoi(count);
DEBUG1("rmtd: W %s\n", count);
record = checkbuf(record, n);
for (i = 0; i < n; i += cc) {
cc = read(STDIN_FILENO, &record[i], n - i);
if (cc <= 0) {
DEBUG("rmtd: premature eof\n");
exit(2);
}
}
rval = write(tape, record, n);
if (rval < 0)
goto ioerror;
goto respond;

case 'R':
getstring(count, sizeof(count));
DEBUG1("rmtd: R %s\n", count);
n = atoi(count);
record = checkbuf(record, n);
rval = read(tape, record, n);
if (rval < 0)
goto ioerror;
(void)snprintf(resp, sizeof(resp), "A%d\n", rval);
(void)write(STDOUT_FILENO, resp, strlen(resp));
(void)write(STDOUT_FILENO, record, rval);
goto top;

case 'I':
getstring(op, sizeof(op));
getstring(count, sizeof(count));
DEBUG2("rmtd: I %s %s\n", op, count);
{
struct mtop mtop;

mtop.mt_op = atoi(op);
mtop.mt_count = atoi(count);
if (ioctl(tape, MTIOCTOP, (char *)&mtop) < 0)
goto ioerror;
rval = mtop.mt_count;
}
goto respond;

case 'S': /* status */
DEBUG("rmtd: S\n");
{
struct mtget mtget;

if (ioctl(tape, MTIOCGET, (char *)&mtget) < 0)
goto ioerror;
rval = sizeof (mtget);
/* limit size to 'original' mtget size */
if (rval > 24)
rval = 24;
(void)snprintf(resp, sizeof(resp), "A%d\n", rval);
(void)write(STDOUT_FILENO, resp, strlen(resp));
(void)write(STDOUT_FILENO, (char *)&mtget, rval);
goto top;
}

default:
DEBUG1("rmtd: garbage command %c\n", c);
exit(3);
}
respond:
DEBUG1("rmtd: A %d\n", rval);
(void)snprintf(resp, sizeof(resp), "A%d\n", rval);
(void)write(STDOUT_FILENO, resp, strlen(resp));
goto top;
ioerror:
error(errno);
goto top;
}

void
getstring(char *bp, size_t size)
{
char *cp = bp;
char *ep = bp + size - 1;

do {
if (read(STDIN_FILENO, cp, 1) != 1)
exit(0);
} while (*cp != '\n' && ++cp < ep);
*cp = '\0';
}

char *
checkbuf(char *record, int size)
{

if (size <= maxrecsize)
return (record);
if (record != 0)
free(record);
record = malloc(size);
if (record == 0) {
DEBUG("rmtd: cannot allocate buffer space\n");
exit(4);
}
maxrecsize = size;
while (size > 1024 &&
setsockopt(0, SOL_SOCKET, SO_RCVBUF, &size, sizeof (size)) < 0)
size -= 1024;
return (record);
}

void
error(int num)
{

DEBUG2("rmtd: E %d (%s)\n", num, strerror(num));
(void)snprintf(resp, sizeof(resp), "E%d\n%s\n", num, strerror(num));
(void)write(STDOUT_FILENO, resp, strlen(resp));
}