mt.c

mt 是linux下得磁带机

/*	This file contains the source of the 'mt' program intended for
	Linux systems. The program supports the basic mt commands found
	in most Unix-like systems. In addition to this the program
	supports several commands designed for use with the Linux SCSI
	tape drive.

	Maintained by Kai M鋕isara (email [e-mail])
	Copyright by Kai M鋕isara, 1998 - 2005. The program may be distributed
	according to the GNU Public License

	Last Modified: Sun Aug 21 21:48:06 2005 by kai.makisara
*/

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/ioctl.h>

#include "mtio.h"

#ifndef DEFTAPE
#define DEFTAPE "/dev/tape"     /* default tape device */
#endif /* DEFTAPE */

#define VERSION "0.9b"

typedef int (* cmdfunc)(/* int, struct cmdef_tr *, int, char ** */);

typedef struct cmdef_tr {
    char *cmd_name;
    int cmd_code;
    cmdfunc cmd_function;
    int cmd_count_bits;
    unsigned char cmd_fdtype;
    unsigned char arg_cnt;
    int error_tests;
} cmdef_tr;

#define NO_FD      0
#define FD_RDONLY  1
#define FD_RDWR    2

#define NO_ARGS       0
#define ONE_ARG       1
#define TWO_ARGS      2
#define MULTIPLE_ARGS 255

#define DO_BOOLEANS    1002
#define SET_BOOLEANS   1003
#define CLEAR_BOOLEANS 1004

#define ET_ONLINE    1
#define ET_WPROT     2

static void usage(int);
static int do_standard(int, cmdef_tr *, int, char **);
static int do_drvbuffer(int, cmdef_tr *, int, char **);
static int do_options(int, cmdef_tr *, int, char **);
static int do_tell(int, cmdef_tr *, int, char **);
static int do_partseek(int, cmdef_tr *, int, char **);
static int do_status(int, cmdef_tr *, int, char **);
static int print_densities(int, cmdef_tr *, int, char **);
static int do_asf(int, cmdef_tr *, int, char **);
static void test_error(int, cmdef_tr *);

static cmdef_tr cmds[] = {
    { "weof",		MTWEOF,	  do_standard, 0, FD_RDWR,   ONE_ARG,
    ET_ONLINE | ET_WPROT },
    { "wset",		MTWSM,	  do_standard, 0, FD_RDWR,   ONE_ARG,
    ET_ONLINE | ET_WPROT },
    { "eof",		MTWEOF,	  do_standard, 0, FD_RDWR, ONE_ARG,
    ET_ONLINE },
    { "fsf",		MTFSF,	  do_standard, 0, FD_RDONLY, ONE_ARG,
    ET_ONLINE },
    { "fsfm",		MTFSFM,	  do_standard, 0, FD_RDONLY, ONE_ARG,
    ET_ONLINE },
    { "bsf",		MTBSF,	  do_standard, 0, FD_RDONLY, ONE_ARG,
    ET_ONLINE },
    { "bsfm",		MTBSFM,	  do_standard, 0, FD_RDONLY, ONE_ARG,
    ET_ONLINE },
    { "fsr",		MTFSR,	  do_standard, 0, FD_RDONLY, ONE_ARG,
    ET_ONLINE },
    { "bsr",		MTBSR,	  do_standard, 0, FD_RDONLY, ONE_ARG,
    ET_ONLINE },
    { "fss",		MTFSS,	  do_standard, 0, FD_RDONLY, ONE_ARG,
    ET_ONLINE },
    { "bss",		MTBSS,	  do_standard, 0, FD_RDONLY, ONE_ARG,
    ET_ONLINE },
    { "rewind",		MTREW,	  do_standard, 0, FD_RDONLY, NO_ARGS,
    ET_ONLINE },
    { "offline",	MTOFFL,	  do_standard, 0, FD_RDONLY, NO_ARGS,
    ET_ONLINE },
    { "rewoffl",	MTOFFL,	  do_standard, 0, FD_RDONLY, NO_ARGS,
    ET_ONLINE },
    { "eject",		MTOFFL,	  do_standard, 0, FD_RDONLY, NO_ARGS,
    ET_ONLINE },
    { "retension",	MTRETEN,  do_standard, 0, FD_RDONLY, NO_ARGS,
    ET_ONLINE },
    { "eod",		MTEOM,	  do_standard, 0, FD_RDONLY, NO_ARGS,
    ET_ONLINE },
    { "seod",		MTEOM,	  do_standard, 0, FD_RDONLY, NO_ARGS,
    ET_ONLINE },
    { "seek",		MTSEEK,   do_standard, 0, FD_RDONLY, ONE_ARG,
    ET_ONLINE },
    { "tell",		MTTELL,	  do_tell,     0, FD_RDONLY, NO_ARGS,
    ET_ONLINE },
    { "status",		MTNOP,	  do_status,   0, FD_RDONLY, NO_ARGS,
    0 },
    { "erase",		MTERASE,  do_standard, 0, FD_RDWR,   ONE_ARG,
    ET_ONLINE },
    { "setblk",		MTSETBLK, do_standard, 0, FD_RDONLY, ONE_ARG,
    0 },
    { "lock",		MTLOCK,   do_standard, 0, FD_RDONLY, NO_ARGS,
    ET_ONLINE },
    { "unlock", 	MTUNLOCK, do_standard, 0, FD_RDONLY, NO_ARGS,
    ET_ONLINE },
    { "load",		MTLOAD,	  do_standard, 0, FD_RDONLY, ONE_ARG,
    0 },
    { "compression",	MTCOMPRESSION,  do_standard,  0, FD_RDONLY, ONE_ARG,
    0 },
    { "setdensity",	MTSETDENSITY,   do_standard,  0, FD_RDONLY, ONE_ARG,
    0 },
    { "drvbuffer",	MTSETDRVBUFFER, do_drvbuffer, 0, FD_RDONLY, ONE_ARG,
    0 },
    { "stwrthreshold",	MTSETDRVBUFFER, do_drvbuffer, MT_ST_WRITE_THRESHOLD,
      FD_RDONLY, ONE_ARG, 0},
    { "stoptions",	DO_BOOLEANS,    do_options,   0, FD_RDONLY,
      MULTIPLE_ARGS, 0},
    { "stsetoptions",   SET_BOOLEANS,   do_options,   0, FD_RDONLY,
      MULTIPLE_ARGS, 0},
    { "stclearoptions", CLEAR_BOOLEANS, do_options,   0, FD_RDONLY,
      MULTIPLE_ARGS, 0},
    { "defblksize",	MTSETDRVBUFFER, do_drvbuffer, MT_ST_DEF_BLKSIZE,
      FD_RDONLY, ONE_ARG, 0},
    { "defdensity",	MTSETDRVBUFFER, do_drvbuffer, MT_ST_DEF_DENSITY,
      FD_RDONLY, ONE_ARG, 0},
    { "defdrvbuffer",	MTSETDRVBUFFER, do_drvbuffer, MT_ST_DEF_DRVBUFFER,
      FD_RDONLY, ONE_ARG, 0},
    { "defcompression", MTSETDRVBUFFER, do_drvbuffer, MT_ST_DEF_COMPRESSION,
      FD_RDONLY, ONE_ARG, 0},
    { "stsetcln",	MTSETDRVBUFFER, do_drvbuffer, MT_ST_SET_CLN,
      FD_RDONLY, ONE_ARG, 0},
    { "sttimeout",	MTSETDRVBUFFER, do_drvbuffer, MT_ST_SET_TIMEOUT,
      FD_RDONLY, ONE_ARG, 0},
    { "stlongtimeout",	MTSETDRVBUFFER, do_drvbuffer, MT_ST_SET_LONG_TIMEOUT,
      FD_RDONLY, ONE_ARG, 0},
    { "densities",	0, print_densities,     0, NO_FD,     NO_ARGS,
    0 },
    { "setpartition",	MTSETPART, do_standard, 0, FD_RDONLY, ONE_ARG,
    ET_ONLINE },
    { "mkpartition",	MTMKPART,  do_standard, 0, FD_RDWR,   ONE_ARG,
    ET_ONLINE },
    { "partseek",	0,         do_partseek, 0, FD_RDONLY, TWO_ARGS,
    ET_ONLINE },
    { "asf",		0,         do_asf, MTREW,  FD_RDONLY, ONE_ARG,
    ET_ONLINE },
    { NULL, 0, 0, 0 }
};


static struct densities {
    int code;
    char *name;
} density_tbl[] = {
    {0x00, "default"},
    {0x01, "NRZI (800 bpi)"},
    {0x02, "PE (1600 bpi)"},
    {0x03, "GCR (6250 bpi)"},
    {0x04, "QIC-11"},
    {0x05, "QIC-45/60 (GCR, 8000 bpi)"},
    {0x06, "PE (3200 bpi)"},
    {0x07, "IMFM (6400 bpi)"},
    {0x08, "GCR (8000 bpi)"},
    {0x09, "GCR (37871 bpi)"},
    {0x0a, "MFM (6667 bpi)"},
    {0x0b, "PE (1600 bpi)"},
    {0x0c, "GCR (12960 bpi)"},
    {0x0d, "GCR (25380 bpi)"},
    {0x0f, "QIC-120 (GCR 10000 bpi)"},
    {0x10, "QIC-150/250 (GCR 10000 bpi)"},
    {0x11, "QIC-320/525 (GCR 16000 bpi)"},
    {0x12, "QIC-1350 (RLL 51667 bpi)"},
    {0x13, "DDS (61000 bpi)"},
    {0x14, "EXB-8200 (RLL 43245 bpi)"},
    {0x15, "EXB-8500 or QIC-1000"},
    {0x16, "MFM 10000 bpi"},
    {0x17, "MFM 42500 bpi"},
    {0x18, "TZ86"},
    {0x19, "DLT 10GB"},
    {0x1a, "DLT 20GB"},
    {0x1b, "DLT 35GB"},
    {0x1c, "QIC-385M"},
    {0x1d, "QIC-410M"},
    {0x1e, "QIC-1000C"},
    {0x1f, "QIC-2100C"},
    {0x20, "QIC-6GB"},
    {0x21, "QIC-20GB"},
    {0x22, "QIC-2GB"},
    {0x23, "QIC-875"},
    {0x24, "DDS-2"},
    {0x25, "DDS-3"},
    {0x26, "DDS-4 or QIC-4GB"},
    {0x27, "Exabyte Mammoth"},
    {0x28, "Exabyte Mammoth-2"},
    {0x29, "QIC-3080MC"},
    {0x30, "AIT-1 or MLR3"},
    {0x31, "AIT-2"},
    {0x32, "AIT-3"},
    {0x33, "SLR6"},
    {0x34, "SLR100"},
    {0x40, "DLT1 40 GB, or Ultrium"},
    {0x41, "DLT 40GB, or Ultrium2"},
    {0x42, "LTO-2"},
    {0x45, "QIC-3095-MC (TR-4)"},
    {0x47, "TR-5"},
    {0x80, "DLT 15GB uncomp. or Ecrix"},
    {0x81, "DLT 15GB compressed"},
    {0x82, "DLT 20GB uncompressed"},
    {0x83, "DLT 20GB compressed"},
    {0x84, "DLT 35GB uncompressed"},
    {0x85, "DLT 35GB compressed"},
    {0x86, "DLT1 40 GB uncompressed"},
    {0x87, "DLT1 40 GB compressed"},
    {0x88, "DLT 40GB uncompressed"},
    {0x89, "DLT 40GB compressed"},
    {0x8c, "EXB-8505 compressed"},
    {0x90, "SDLT110 uncompr/EXB-8205 compr"},
    {0x91, "SDLT110 compressed"},
    {0x92, "SDLT160 uncompressed"},
    {0x93, "SDLT160 comprssed"}
};

#define NBR_DENSITIES (sizeof(density_tbl) / sizeof(struct densities))

static struct booleans {
    char *name;
    unsigned long bitmask;
    char *expl;
} boolean_tbl[] = {
    {"buffer-writes", MT_ST_BUFFER_WRITES, "buffered writes"},
    {"async-writes",  MT_ST_ASYNC_WRITES,  "asynchronous writes"},
    {"read-ahead",    MT_ST_READ_AHEAD,    "read-ahead for fixed block size"},
    {"debug",         MT_ST_DEBUGGING,     "debugging (if compiled into driver)"},
    {"two-fms",       MT_ST_TWO_FM,        "write two filemarks when file closed"},
    {"fast-eod",      MT_ST_FAST_MTEOM, "space directly to eod (and lose file number)"},
    {"auto-lock",     MT_ST_AUTO_LOCK,     "automatically lock/unlock drive door"},
    {"def-writes",    MT_ST_DEF_WRITES,    "the block size and density are for writes"},
    {"can-bsr",       MT_ST_CAN_BSR,       "drive can space backwards well"},
    {"no-blklimits",  MT_ST_NO_BLKLIMS,    "drive doesn't support read block limits"},
    {"can-partitions",MT_ST_CAN_PARTITIONS,"drive can handle partitioned tapes"},
    {"scsi2logical",  MT_ST_SCSI2LOGICAL,  "logical block addresses used with SCSI-2"},
    {"no-wait",       MT_ST_NOWAIT,        "immediate mode for rewind, etc."},
#ifdef MT_ST_SYSV
    {"sysv",	      MT_ST_SYSV,	   "enable the SystemV semantics"},
#endif
    {"cleaning",      MT_ST_SET_CLN,	   "set the cleaning bit location and mask"},
    {NULL, 0}};

static char *tape_name;   /* The tape name for messages */


	int
main(int argc, char **argv)
{
    int mtfd, cmd_code, i, argn, len, oflags;
    char *cmdstr;
    cmdef_tr *comp, *comp2;

    for (argn=1; argn < argc; argn++)
	if (*argv[argn] == '-')
	    switch (*(argv[argn] + 1)) {
	    case 'f':
	    case 't':
		argn += 1;
		if (argn >= argc) {
		    usage(0);
		    exit(1);
		}
		tape_name = argv[argn];
		break;
	    case 'h':
		usage(1);
		exit(0);
		break;
	    case 'v':
		printf("mt-st v. %s\n", VERSION);
		exit(0);
		break;
	    case '-':
		if (*(argv[argn] + 1) == '-' &&
		    *(argv[argn] + 2) == 'v') {
		    printf("mt-st v. %s\n", VERSION);
		    exit(0);
		}
		/* Fall through */
	    default:
		usage(0);
		exit(1);
	}
	else
	    break;

    if (tape_name == NULL && (tape_name = getenv("TAPE")) == NULL)
	tape_name = DEFTAPE;
       
    if (argn >= argc ) {
	usage(0);
	exit(1);
    }
    cmdstr = argv[argn++];

    len = strlen(cmdstr);
    for (comp = cmds; comp->cmd_name != NULL; comp++)
	if (strncmp(cmdstr, comp->cmd_name, len) == 0)
	    break;
    if (comp->cmd_name == NULL) {
	fprintf(stderr, "mt: unknown command \"%s\"\n", cmdstr);
	usage(1);
	exit(1);
    }
    if (len != strlen(comp->cmd_name)) {
	for (comp2 = comp + 1; comp2->cmd_name != NULL; comp2++)
	    if (strncmp(cmdstr, comp2->cmd_name, len) == 0)
		break;
	if (comp2->cmd_name != NULL) {
	    fprintf(stderr, "mt: ambiguous command \"%s\"\n", cmdstr);
	    usage(1);
	    exit(1);
	}
    }
    if (comp->arg_cnt != MULTIPLE_ARGS && comp->arg_cnt < argc - argn) {
	fprintf(stderr, "mt: too many arguments for the command '%s'.\n",
		comp->cmd_name);
	exit(1);
    }
    cmd_code = comp->cmd_code;

    if (comp->cmd_fdtype != NO_FD) {
	oflags = comp->cmd_fdtype == FD_RDONLY ? O_RDONLY : O_RDWR;
	if ((comp->error_tests & ET_ONLINE) == 0)
	    oflags |= O_NONBLOCK;
	if ((mtfd = open(tape_name, oflags)) < 0) {
	    perror(tape_name);
	    exit(1);
	}
    }
    else
	mtfd = (-1);

    if (comp->cmd_function != NULL) {
	i = comp->cmd_function(mtfd, comp, argc - argn,
			       (argc - argn > 0 ? argv + argn : NULL));