LXR busybox/miscutils/eject.c

   1/* vi: set sw=4 ts=4: */
   2/*
   3 * eject implementation for busybox
   4 *
   5 * Copyright (C) 2004  Peter Willis <psyphreak@phreaker.net>
   6 * Copyright (C) 2005  Tito Ragusa <farmatito@tiscali.it>
   7 *
   8 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   9 */
  10
  11/*
  12 * This is a simple hack of eject based on something Erik posted in #uclibc.
  13 * Most of the dirty work blatantly ripped off from cat.c =)
  14 */
  15
  16//usage:#define eject_trivial_usage
  17//usage:       "[-t] [-T] [DEVICE]"
  18//usage:#define eject_full_usage "\n\n"
  19//usage:       "Eject DEVICE or default /dev/cdrom\n"
  20//usage:        IF_FEATURE_EJECT_SCSI(
  21//usage:     "\n        -s      SCSI device"
  22//usage:        )
  23//usage:     "\n        -t      Close tray"
  24//usage:     "\n        -T      Open/close tray (toggle)"
  25
  26#include <sys/mount.h>
  27#include "libbb.h"
  28/* Must be after libbb.h: they need size_t */
  29#include "fix_u32.h"
  30#include <scsi/sg.h>
  31#include <scsi/scsi.h>
  32
  33/* various defines swiped from linux/cdrom.h */
  34#define CDROMCLOSETRAY            0x5319  /* pendant of CDROMEJECT  */
  35#define CDROMEJECT                0x5309  /* Ejects the cdrom media */
  36#define CDROM_DRIVE_STATUS        0x5326  /* Get tray position, etc. */
  37/* drive status possibilities returned by CDROM_DRIVE_STATUS ioctl */
  38#define CDS_TRAY_OPEN        2
  39
  40#define dev_fd 3
  41
  42/* Code taken from the original eject (http://eject.sourceforge.net/),
  43 * refactored it a bit for busybox (ne-bb@nicoerfurth.de) */
  44
  45static void eject_scsi(const char *dev)
  46{
  47        static const char sg_commands[3][6] = {
  48                { ALLOW_MEDIUM_REMOVAL, 0, 0, 0, 0, 0 },
  49                { START_STOP, 0, 0, 0, 1, 0 },
  50                { START_STOP, 0, 0, 0, 2, 0 }
  51        };
  52
  53        unsigned i;
  54        unsigned char sense_buffer[32];
  55        unsigned char inqBuff[2];
  56        sg_io_hdr_t io_hdr;
  57
  58        if ((ioctl(dev_fd, SG_GET_VERSION_NUM, &i) < 0) || (i < 30000))
  59                bb_error_msg_and_die("not a sg device or old sg driver");
  60
  61        memset(&io_hdr, 0, sizeof(sg_io_hdr_t));
  62        io_hdr.interface_id = 'S';
  63        io_hdr.cmd_len = 6;
  64        io_hdr.mx_sb_len = sizeof(sense_buffer);
  65        io_hdr.dxfer_direction = SG_DXFER_NONE;
  66        /* io_hdr.dxfer_len = 0; */
  67        io_hdr.dxferp = inqBuff;
  68        io_hdr.sbp = sense_buffer;
  69        io_hdr.timeout = 2000;
  70
  71        for (i = 0; i < 3; i++) {
  72                io_hdr.cmdp = (void *)sg_commands[i];
  73                ioctl_or_perror_and_die(dev_fd, SG_IO, (void *)&io_hdr, "%s", dev);
  74        }
  75
  76        /* force kernel to reread partition table when new disc is inserted */
  77        ioctl(dev_fd, BLKRRPART);
  78}
  79
  80#define FLAG_CLOSE  1
  81#define FLAG_SMART  2
  82#define FLAG_SCSI   4
  83
  84static void eject_cdrom(unsigned flags, const char *dev)
  85{
  86        int cmd = CDROMEJECT;
  87
  88        if (flags & FLAG_CLOSE
  89         || ((flags & FLAG_SMART) && ioctl(dev_fd, CDROM_DRIVE_STATUS) == CDS_TRAY_OPEN)
  90        ) {
  91                cmd = CDROMCLOSETRAY;
  92        }
  93
  94        ioctl_or_perror_and_die(dev_fd, cmd, NULL, "%s", dev);
  95}
  96
  97int eject_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  98int eject_main(int argc UNUSED_PARAM, char **argv)
  99{
 100        unsigned flags;
 101        const char *device;
 102
 103        opt_complementary = "?1:t--T:T--t";
 104        flags = getopt32(argv, "tT" IF_FEATURE_EJECT_SCSI("s"));
 105        device = argv[optind] ? argv[optind] : "/dev/cdrom";
 106
 107        /* We used to do "umount <device>" here, but it was buggy
 108           if something was mounted OVER cdrom and
 109           if cdrom is mounted many times.
 110
 111           This works equally well (or better):
 112           #!/bin/sh
 113           umount /dev/cdrom
 114           eject /dev/cdrom
 115        */
 116
 117        xmove_fd(xopen_nonblocking(device), dev_fd);
 118
 119        if (ENABLE_FEATURE_EJECT_SCSI && (flags & FLAG_SCSI))
 120                eject_scsi(device);
 121        else
 122                eject_cdrom(flags, device);
 123
 124        if (ENABLE_FEATURE_CLEAN_UP)
 125                close(dev_fd);
 126
 127        return EXIT_SUCCESS;
 128}
 129