/*

 * Copyright (c) 1998,1999,2000

 *	Traakan, Inc., Los Altos, CA

 *	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 unmodified, 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.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.

 */

/*

 * Project:  NDMJOB

 * Ident:    $Id: $

 *

 * Description:

 *

 */

#include "ndmagents.h"

#ifndef NDMOS_OPTION_NO_TAPE_AGENT

int	simu_back_one (struct ndm_session *sess, int over_file_mark);

int	simu_forw_one (struct ndm_session *sess, int over_file_mark);

int	simu_flush_weof (struct ndm_session *sess);

#ifdef NDMOS_OPTION_TAPE_SIMULATOR

struct simu_gap {

	u_long		magic;

	u_long		rectype;

	u_long		prev_size;

	u_long		size;

};

#define SIMU_GAP_MAGIC		0x0BEEFEE0

#define SIMU_GAP_RT_(a,b,c,d) ((a<<0)+(b<<8)+(c<<16)+(d<<24))

#define SIMU_GAP_RT_BOT		SIMU_GAP_RT_('B','O','T','_')

#define SIMU_GAP_RT_DATA	SIMU_GAP_RT_('D','A','T','A')

#define SIMU_GAP_RT_FILE	SIMU_GAP_RT_('F','I','L','E')

#define SIMU_GAP_RT_EOT		SIMU_GAP_RT_('E','O','T','_')

/* send logical EOM with a bit less than 2 32k blocks left (due to SIMU_GAPs) */

#define TAPE_SIM_LOGICAL_EOM	32768*2

/* we sneak a peek at this global variable - probably not the best way, but

 * it works */

extern off_t o_tape_limit;

int

ndmos_tape_initialize (struct ndm_session *sess)

{

	struct ndm_tape_agent *	ta = &sess->tape_acb;

	ta->tape_fd = -1;

	NDMOS_MACRO_ZEROFILL (&ta->tape_state);

	ta->tape_state.error = NDMP9_DEV_NOT_OPEN_ERR;

	ta->tape_state.state = NDMP9_TAPE_STATE_IDLE;

	return 0;

}

static int

touch_tape_lockfile(char *drive_name)

{

    char *lockfile_name;

    int fd;

    lockfile_name = g_strdup_printf("%s.lck", drive_name);

    if ((fd = open(lockfile_name, O_CREAT|O_EXCL, 0666)) < 0) {

	g_free(lockfile_name);

	return -1;

    }

    close(fd);

    g_free(lockfile_name);

    return 0;

}

static void

unlink_tape_lockfile(char *drive_name)

{

    char *lockfile_name;

    lockfile_name = g_strdup_printf("%s.lck", drive_name);

    unlink(lockfile_name);

    g_free(lockfile_name);

}

ndmp9_error

ndmos_tape_open (struct ndm_session *sess, char *drive_name, int will_write)

{

	struct ndm_tape_agent *	ta = &sess->tape_acb;

	struct simu_gap		gap;

	struct stat		st;

	int			read_only, omode;

	int			rc, fd;

	char			*pos_symlink_name;

	char			pos_buf[32];

	off_t			pos = -1;

        if (ta->tape_fd >= 0) {

                ndma_send_logmsg(sess, NDMP9_LOG_ERROR, sess->plumb.control,

                         "device simulator is already open");

                return NDMP9_DEVICE_OPENED_ERR;

        }

	if (stat (drive_name, &st) < 0) {

		return NDMP9_NO_DEVICE_ERR;

	}

	read_only = (st.st_mode & 0222) == 0;

	if (!will_write) {

		omode = 0;

	} else {

		if (read_only)

			return NDMP9_WRITE_PROTECT_ERR;

		omode = 2;		/* ndmp_write means read/write */

	}

	if (touch_tape_lockfile(drive_name) < 0)

	    return NDMP9_DEVICE_BUSY_ERR;

	fd = open (drive_name, omode);

	if (fd < 0) {

		return NDMP9_PERMISSION_ERR;

	}

	pos_symlink_name = g_strdup_printf("%s.pos", drive_name);

	if (st.st_size == 0) {

		remove (pos_symlink_name);

		if (will_write) {

			gap.magic = SIMU_GAP_MAGIC;

			gap.rectype = SIMU_GAP_RT_BOT;

			gap.size = 0;

			gap.prev_size = 0;

			if (write (fd, &gap, sizeof gap) < (int)sizeof gap) {

			    close(fd);

			    return NDMP9_IO_ERR;

			}

			gap.rectype = SIMU_GAP_RT_EOT;

			if (write (fd, &gap, sizeof gap) < (int)sizeof gap) {

			    close(fd);

			    return NDMP9_IO_ERR;

			}

			lseek (fd, (off_t)0, 0);

		} else {

			goto skip_header_check;

		}

	}

	rc = read (fd, &gap, sizeof gap);

	if (rc != sizeof gap) {

		close (fd);

		return NDMP9_NO_TAPE_LOADED_ERR;

	}

#if 1

	if (gap.magic != SIMU_GAP_MAGIC) {

		close (fd);

		return NDMP9_IO_ERR;

	}

#else

	if (gap.magic != SIMU_GAP_MAGIC

	 || gap.rectype != SIMU_GAP_RT_BOT

	 || gap.size != 0) {

		close (fd);

		return NDMP9_IO_ERR;

	}

#endif

	rc = readlink (pos_symlink_name, pos_buf, sizeof pos_buf);

	if (rc > 0) {

		pos_buf[sizeof pos_buf - 1] = 0;

		if (rc < sizeof pos_buf)

		    pos_buf[rc] = 0;

		pos = strtol (pos_buf, 0, 0);

		lseek (fd, pos, 0);

		rc = read (fd, &gap, sizeof gap);

		if (rc == sizeof gap && gap.magic == SIMU_GAP_MAGIC) {

		} else {

			pos = sizeof gap;

		}

		lseek (fd, pos, 0);

	}

  skip_header_check:

	remove (pos_symlink_name);

	g_free(pos_symlink_name);

	ta->tape_fd = fd;

	NDMOS_API_BZERO (ta->drive_name, sizeof ta->drive_name);

	g_strlcpy (ta->drive_name, drive_name, sizeof ta->drive_name);

	bzero (&ta->tape_state, sizeof ta->tape_state);

	ta->tape_state.error = NDMP9_NO_ERR;

	ta->tape_state.state = NDMP9_TAPE_STATE_OPEN;

	ta->tape_state.open_mode =

		will_write ? NDMP9_TAPE_RDWR_MODE : NDMP9_TAPE_READ_MODE;

	ta->tape_state.file_num.valid = NDMP9_VALIDITY_VALID;

	ta->tape_state.soft_errors.valid = NDMP9_VALIDITY_VALID;

	ta->tape_state.block_size.valid = NDMP9_VALIDITY_VALID;

	ta->tape_state.blockno.valid = NDMP9_VALIDITY_VALID;

	ta->tape_state.total_space.valid = NDMP9_VALIDITY_INVALID;

	ta->tape_state.space_remain.valid = NDMP9_VALIDITY_INVALID;

	ta->sent_leom = 0;

	if (o_tape_limit) {

	    g_assert(o_tape_limit > st.st_size);

	    ta->tape_state.total_space.valid = NDMP9_VALIDITY_VALID;

	    ta->tape_state.total_space.value = o_tape_limit;

	    ta->tape_state.space_remain.valid = NDMP9_VALIDITY_VALID;

	    ta->tape_state.space_remain.value = o_tape_limit - st.st_size;

	}

	return NDMP9_NO_ERR;

}

ndmp9_error

ndmos_tape_close (struct ndm_session *sess)

{

	struct ndm_tape_agent *	ta = &sess->tape_acb;

	off_t			cur_pos;

	/* TODO this is not called on an EOF from the DMA, so the lockfile

	 * will remain, although the spec says the tape service should be

	 * automatically closed */

	if (ta->tape_fd < 0) {

		return NDMP9_DEV_NOT_OPEN_ERR;

	}

	simu_flush_weof(sess);

#if 0

	u_long			resid;

	ndmos_tape_mtio (sess, NDMP9_MTIO_REW, 1, &resid);

#endif

	cur_pos = lseek (ta->tape_fd, (off_t)0, 1);

	if (cur_pos != -1) {

		char		*pos_symlink_name;

		char		pos_buf[32];

		pos_symlink_name = g_strdup_printf("%s.pos", ta->drive_name);

		sprintf (pos_buf, "%ld", (long) cur_pos);

		if (symlink (pos_buf, pos_symlink_name) < 0) {

		    ; /* ignore error during close */

		}

		g_free(pos_symlink_name);

	}

	close (ta->tape_fd);

	ta->tape_fd = -1;

	unlink_tape_lockfile(ta->drive_name);

	ndmos_tape_initialize (sess);

	return NDMP9_NO_ERR;

}

void

ndmos_tape_sync_state (struct ndm_session *sess)

{

	struct ndm_tape_agent *	ta = &sess->tape_acb;

	if (ta->tape_fd < 0) {

		ta->tape_state.error = NDMP9_DEV_NOT_OPEN_ERR;

		ta->tape_state.state = NDMP9_TAPE_STATE_IDLE;

		ta->tape_state.file_num.valid = NDMP9_VALIDITY_INVALID;

		ta->tape_state.soft_errors.valid = NDMP9_VALIDITY_INVALID;

		ta->tape_state.block_size.valid = NDMP9_VALIDITY_INVALID;

		ta->tape_state.blockno.valid = NDMP9_VALIDITY_INVALID;

	} else {

		ta->tape_state.error = NDMP9_NO_ERR;

		if (ta->mover_state.state == NDMP9_MOVER_STATE_ACTIVE)

			ta->tape_state.state = NDMP9_TAPE_STATE_MOVER;

		else

			ta->tape_state.state = NDMP9_TAPE_STATE_OPEN;

		ta->tape_state.file_num.valid = NDMP9_VALIDITY_VALID;

		ta->tape_state.soft_errors.valid = NDMP9_VALIDITY_VALID;

		ta->tape_state.block_size.valid = NDMP9_VALIDITY_VALID;

		ta->tape_state.blockno.valid = NDMP9_VALIDITY_VALID;

	}

	return;

}

int

simu_back_one (struct ndm_session *sess, int over_file_mark)

{

	struct ndm_tape_agent *	ta = &sess->tape_acb;

	struct simu_gap		gap;

	off_t			cur_pos;

	off_t			new_pos;

	int			rc;

	cur_pos = lseek (ta->tape_fd, (off_t)0, 1);

	rc = read (ta->tape_fd, &gap, sizeof gap);

	if (rc != sizeof gap || gap.magic != SIMU_GAP_MAGIC)

		goto bail_out;

	new_pos = cur_pos;

	new_pos -= sizeof gap + gap.prev_size;

	ta->sent_leom = 0;

	/*

	 * This is the new position. We need to update simu_prev_gap.

	 */

	lseek (ta->tape_fd, new_pos, 0);

	rc = read (ta->tape_fd, &gap, sizeof gap);

	if (rc != sizeof gap || gap.magic != SIMU_GAP_MAGIC)

		goto bail_out;

	switch (gap.rectype) {

	case SIMU_GAP_RT_BOT:

		/* can't actually back up to this, but update stuff */

		ta->tape_state.file_num.value = 0;

		ta->tape_state.blockno.value = 0;

		/* cur_pos is now just right */

		return 0;		/* can't back up */

	case SIMU_GAP_RT_EOT:

		/* this just isn't suppose to happen */

		goto bail_out;

	case SIMU_GAP_RT_DATA:

		/* this is always OK */

		if (ta->tape_state.blockno.value > 0)

			ta->tape_state.blockno.value--;

		lseek (ta->tape_fd, new_pos, 0);

		return SIMU_GAP_RT_DATA;

	case SIMU_GAP_RT_FILE:

		ta->tape_state.blockno.value = 0;

		if (!over_file_mark) {

			lseek (ta->tape_fd, cur_pos, 0);

			return 0;

		}

		if (ta->tape_state.file_num.value > 0)

			ta->tape_state.file_num.value--;

		lseek (ta->tape_fd, new_pos, 0);

		return SIMU_GAP_RT_FILE;

	default:

		/* this just isn't suppose to happen */

		goto bail_out;

	}

  bail_out:

	lseek (ta->tape_fd, cur_pos, 0);

	return -1;

}

int

simu_forw_one (struct ndm_session *sess, int over_file_mark)

{

	struct ndm_tape_agent *	ta = &sess->tape_acb;

	struct simu_gap		gap;

	off_t			cur_pos;

	off_t			new_pos;

	int			rc;

	cur_pos = lseek (ta->tape_fd, (off_t)0, 1);

	rc = read (ta->tape_fd, &gap, sizeof gap);

	if (rc != sizeof gap || gap.magic != SIMU_GAP_MAGIC)

		goto bail_out;

	ta->sent_leom = 0;

	new_pos = cur_pos;

	new_pos += gap.size + sizeof gap;

	switch (gap.rectype) {

	case SIMU_GAP_RT_BOT:

		/* this just isn't suppose to happen */

		goto bail_out;

	case SIMU_GAP_RT_EOT:

		lseek (ta->tape_fd, cur_pos, 0);

		return 0;	/* can't go forward */

	case SIMU_GAP_RT_DATA:

		/* this is always OK */

		ta->tape_state.blockno.value++;

		lseek (ta->tape_fd, new_pos, 0);

		return SIMU_GAP_RT_DATA;

	case SIMU_GAP_RT_FILE:

		if (!over_file_mark) {

			lseek (ta->tape_fd, cur_pos, 0);

			return 0;

		}

		ta->tape_state.blockno.value = 0;

		ta->tape_state.file_num.value++;

		/* cur_pos is just right */

		return SIMU_GAP_RT_FILE;

	default:

		/* this just isn't suppose to happen */

		goto bail_out;

	}

  bail_out:

	lseek (ta->tape_fd, cur_pos, 0);

	return -1;

}

int

simu_flush_weof (struct ndm_session *sess)

{

	struct ndm_tape_agent *	ta = &sess->tape_acb;

	if (ta->weof_on_close) {

		/* best effort */

		ndmos_tape_wfm (sess);

	}

	return 0;

}

ndmp9_error

ndmos_tape_mtio (struct ndm_session *sess,

  ndmp9_tape_mtio_op op, u_long count, u_long *resid)

{

	struct ndm_tape_agent *	ta = &sess->tape_acb;

	int			rc;

	*resid = count;

	if (ta->tape_fd < 0) {

		return NDMP9_DEV_NOT_OPEN_ERR;

	}

	/* audit for valid op and for tape mode */

	switch (op) {

	case NDMP9_MTIO_FSF:

		while (*resid > 0) {

			simu_flush_weof(sess);

			rc = simu_forw_one (sess, 1);

			if (rc < 0)

				return NDMP9_IO_ERR;

			if (rc == 0)

				break;

			if (rc == SIMU_GAP_RT_FILE)

				*resid -= 1;

		}

		break;

	case NDMP9_MTIO_BSF:

		while (*resid > 0) {

			simu_flush_weof(sess);

			rc = simu_back_one (sess, 1);

			if (rc < 0)

				return NDMP9_IO_ERR;

			if (rc == 0)

				break;

			if (rc == SIMU_GAP_RT_FILE)

				*resid -= 1;

		}

		break;

	case NDMP9_MTIO_FSR:

		while (*resid > 0) {

			simu_flush_weof(sess);

			rc = simu_forw_one (sess, 0);

			if (rc < 0)

				return NDMP9_IO_ERR;

			if (rc == 0)

				break;

			*resid -= 1;

		}

		break;

	case NDMP9_MTIO_BSR:

		while (*resid > 0) {

			simu_flush_weof(sess);

			rc = simu_back_one (sess, 0);

			if (rc < 0)

				return NDMP9_IO_ERR;

			if (rc == 0)

				break;

			*resid -= 1;

		}

		break;

	case NDMP9_MTIO_REW:

		simu_flush_weof(sess);

		*resid = 0;

		ta->tape_state.file_num.value = 0;

		ta->tape_state.blockno.value = 0;

		lseek (ta->tape_fd, (off_t)(sizeof (struct simu_gap)), 0);

		break;

	case NDMP9_MTIO_OFF:

		simu_flush_weof(sess);

		/* Hmmm. */

		break;

	case NDMP9_MTIO_EOF:		/* should be "WFM" write-file-mark */

		if (!NDMTA_TAPE_IS_WRITABLE(ta)) {

			return NDMP9_PERMISSION_ERR;

		}

		while (*resid > 0) {

			ndmp9_error	err;

			err = ndmos_tape_wfm (sess);

			if (err != NDMP9_NO_ERR)

				return err;

			*resid -= 1;

		}

		break;

	default:

		return NDMP9_ILLEGAL_ARGS_ERR;

	}

	return NDMP9_NO_ERR;

}

ndmp9_error

ndmos_tape_write (struct ndm_session *sess,

  char *buf, u_long count, u_long *done_count)

{

	struct ndm_tape_agent *	ta = &sess->tape_acb;

	int			rc;

	struct simu_gap		gap;

	off_t			cur_pos;

	ndmp9_error		err;

	u_long			prev_size;

	if (ta->tape_fd < 0) {

		return NDMP9_DEV_NOT_OPEN_ERR;

	}

	if (!NDMTA_TAPE_IS_WRITABLE(ta)) {

		return NDMP9_PERMISSION_ERR;

	}

	if (count == 0) {

		/*

		 * NDMPv4 clarification -- a tape read or write with

		 * a count==0 is a no-op. This is undoubtedly influenced

		 * by the SCSI Sequential Access specification which

		 * says much the same thing.

		 */

		*done_count = 0;

		return NDMP9_NO_ERR;

	}

	cur_pos = lseek (ta->tape_fd, (off_t)0, 1);

	if (o_tape_limit) {

	    /* if cur_pos is past LEOM, but we haven't sent NDMP9_EOM_ERR yet,

	     * then do so now */

	    if (!ta->sent_leom && cur_pos > o_tape_limit - TAPE_SIM_LOGICAL_EOM) {

		ta->sent_leom = 1;

		return NDMP9_EOM_ERR;

	    }

	    /* if this write will put us over PEOM, then send NDMP9_IO_ERR */

	    if ((off_t)(cur_pos + sizeof gap + count) > o_tape_limit) {

		return NDMP9_IO_ERR;

	    }

	}

	rc = read (ta->tape_fd, &gap, sizeof gap);

	if (rc != sizeof gap

	 || gap.magic != SIMU_GAP_MAGIC) {

		lseek (ta->tape_fd, cur_pos, 0);

		return NDMP9_IO_ERR;

	}

	prev_size = gap.prev_size;

	gap.magic = SIMU_GAP_MAGIC;

	gap.rectype = SIMU_GAP_RT_DATA;

	gap.prev_size = prev_size;

	gap.size = count;

	lseek (ta->tape_fd, cur_pos, 0);

	if (write (ta->tape_fd, &gap, sizeof gap) == sizeof gap

	 && (u_long)write (ta->tape_fd, buf, count) == count) {

		cur_pos += count + sizeof gap;

		prev_size = count;

		ta->tape_state.blockno.value++;

		*done_count = count;

		err = NDMP9_NO_ERR;

	} else {

		err = NDMP9_IO_ERR;

	}

	if (ftruncate (ta->tape_fd, cur_pos) < 0)

	    return NDMP9_IO_ERR;

	lseek (ta->tape_fd, cur_pos, 0);

	gap.rectype = SIMU_GAP_RT_EOT;

	gap.size = 0;

	gap.prev_size = prev_size;

	if (write (ta->tape_fd, &gap, sizeof gap) < (int)sizeof gap)

	    return NDMP9_IO_ERR;

	lseek (ta->tape_fd, cur_pos, 0);

	if (o_tape_limit) {

	    ta->tape_state.space_remain.value = o_tape_limit - cur_pos;

	}

	ta->weof_on_close = 1;

	return err;

}

ndmp9_error

ndmos_tape_wfm (struct ndm_session *sess)

{

	struct ndm_tape_agent *	ta = &sess->tape_acb;

	int			rc;

	struct simu_gap		gap;

	off_t			cur_pos;

	ndmp9_error		err;

	u_long			prev_size;

	ta->weof_on_close = 0;

	if (ta->tape_fd < 0) {

		return NDMP9_DEV_NOT_OPEN_ERR;

	}

	if (!NDMTA_TAPE_IS_WRITABLE(ta)) {

		return NDMP9_PERMISSION_ERR;

	}

	cur_pos = lseek (ta->tape_fd, (off_t)0, 1);

	if (o_tape_limit) {

	    /* note: filemarks *never* trigger NDMP9_EOM_ERR */

	    /* if this write will put us over PEOM, then send NDMP9_IO_ERR */

	    if ((off_t)(cur_pos + sizeof gap) > o_tape_limit) {

		return NDMP9_IO_ERR;

	    }

	}

	rc = read (ta->tape_fd, &gap, sizeof gap);

	if (rc != sizeof gap

	 || gap.magic != SIMU_GAP_MAGIC) {

		lseek (ta->tape_fd, cur_pos, 0);

		return NDMP9_IO_ERR;

	}

	prev_size = gap.prev_size;

	gap.magic = SIMU_GAP_MAGIC;

	gap.rectype = SIMU_GAP_RT_FILE;

	gap.prev_size = prev_size;

	gap.size = 0;

	lseek (ta->tape_fd, cur_pos, 0);

	if (write (ta->tape_fd, &gap, sizeof gap) == sizeof gap) {

		cur_pos += sizeof gap;

		prev_size = 0;

		ta->tape_state.file_num.value++;

		ta->tape_state.blockno.value = 0;

		err = NDMP9_NO_ERR;

	} else {

		err = NDMP9_IO_ERR;

	}

	if (ftruncate (ta->tape_fd, cur_pos) < 0)

	    return NDMP9_IO_ERR;

	lseek (ta->tape_fd, cur_pos, 0);

	gap.rectype = SIMU_GAP_RT_EOT;

	gap.size = 0;

	gap.prev_size = prev_size;

	if (write (ta->tape_fd, &gap, sizeof gap) < (int)sizeof gap)

		return NDMP9_IO_ERR;

	lseek (ta->tape_fd, cur_pos, 0);

	if (o_tape_limit) {

	    ta->tape_state.space_remain.value = o_tape_limit - cur_pos;

	}

	return err;

}

ndmp9_error

ndmos_tape_read (struct ndm_session *sess,

  char *buf, u_long count, u_long *done_count)

{

	struct ndm_tape_agent *	ta = &sess->tape_acb;

	int			rc;

	struct simu_gap		gap;

	off_t			cur_pos;

	if (ta->tape_fd < 0) {

		return NDMP9_DEV_NOT_OPEN_ERR;

	}

	if (count == 0) {

		/*

		 * NDMPv4 clarification -- a tape read or write with

		 * a count==0 is a no-op. This is undoubtedly influenced

		 * by the SCSI Sequential Access specification which

		 * says much the same thing.

		 */

		*done_count = 0;

		return NDMP9_NO_ERR;

	}

	cur_pos = lseek (ta->tape_fd, (off_t)0, 1);

	rc = read (ta->tape_fd, &gap, sizeof gap);

	if (rc != sizeof gap

	 || gap.magic != SIMU_GAP_MAGIC) {

		lseek (ta->tape_fd, cur_pos, 0);

		return NDMP9_IO_ERR;

	}

	if (gap.rectype == SIMU_GAP_RT_DATA) {

		unsigned	nb;

		nb = count;

		if (nb > gap.size)

			nb = gap.size;

		rc = read (ta->tape_fd, buf, nb);

		if (rc != (int)nb) {

			lseek (ta->tape_fd, cur_pos, 0);

			return NDMP9_IO_ERR;

		}

		if (gap.size != nb) {

			cur_pos += sizeof gap + gap.size;

			lseek (ta->tape_fd, cur_pos, 0);

		}

		ta->tape_state.blockno.value++;

		*done_count = nb;

	} else {

		/* all other record types are interpretted as EOF */

		lseek (ta->tape_fd, cur_pos, 0);

		*done_count = 0;

		return NDMP9_EOF_ERR;

	}

	return NDMP9_NO_ERR;

}

#endif /* NDMOS_OPTION_TAPE_SIMULATOR */

#endif /* !NDMOS_OPTION_NO_TAPE_AGENT */