read.c

使用libscsi做的一系列cdrom操作工具程序。包含cdwrite,cdflush,cdda三个程序

#include <scsi/da.h>
#include <scsi/all.h>
#include <scsi/taxm.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include "cdda.h"

struct {
    struct sc_mode_header6 h;
    struct sc_mode_block_descriptor b;
    struct sc_mode_taxm_speed s;
} mode_bdesc = {
    { 0, 0, 0, 1 },
    { 0x82, 0, 0, 0, 0, 0, 0x9, 0x30 },
#if SC_BIGENDIAN
    { 0, SC_MODE_TAXM_SPEED, 1, SC_TAXM_QUAD, SC_TAXM_QUAD }
#else
    { SC_MODE_TAXM_SPEED, 0, 1, SC_TAXM_QUAD, SC_TAXM_QUAD }
#endif
};



int
do_read(enum mode mode, SCSI *fd, FILE *fout,
	u_long start, u_long end, int nblocks)
{
    char s[80];
    u_char *buf;
    u_long i, n;
    u_long len = sizeof(struct sc_mode_header6)
	+ sizeof(struct sc_mode_block_descriptor) + 3;
	

    if ((buf=(u_char *)sc_alloc(2352*nblocks)) == NULL) {
	fprintf(stderr, "%s: malloc failure\n", prg);
	return -1;
    }

    switch (mode) {
    case m_hp:
	mode_bdesc.b.dcode = 0;
	len -= 3;
	/* FALLTHROUGH */
    case m_toshiba:
	if (sc_mode_select6(fd, 1, 0,
			    len, (u_char *)&mode_bdesc) < 0) {
	    sc_fstatus(fd, stderr, prg, "mode-select6", 3);
	    sc_free(buf);
	    return -1;
	}
	break;

    case m_yamaha:
	break;
	
    default:
	fprintf(stderr, "%s: unknown mode selected: %d\n",
		prg, mode);
	sc_free(buf);
	return -1;
    }

    for (i=start; i<end; i+=n/2352) {
	if (mode != m_yamaha) {
	    if ((n=sc_da_read10(fd, i, (u_short)
				((i+nblocks < end) ? nblocks : end-i),
				2352*nblocks, buf)) < 0) {
		sprintf(s, "read10(%0xlx)", i);
		sc_fstatus(fd, stderr, prg, s, 3);
		sc_free(buf);
		return -1;
	    }
	}
	else {
	    if ((n=sc_cdr102_read_cdda(fd, 0, i, (u_long)
				((i+nblocks < end) ? nblocks : end-i),
				2352*nblocks, buf)) < 0) {
		sprintf(s, "read-cdda(%0xlx)", i);
		sc_fstatus(fd, stderr, prg, s, 3);
		sc_free(buf);
		return -1;
	    }
	}

	if (fwrite(buf, 1, n, fout) != n) {
	    fprintf(stderr, "%s: write error: %s\n",
		    prg, strerror(errno));
	    sc_free(buf);
	    return -1;
	}
    }

    sc_free(buf);
    return 0;
}