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 the GPL v2 or later, see the file LICENSE in this tarball.
   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#include <sys/mount.h>
  17#include "libbb.h"
  18/* Must be after libbb.h: they need size_t */
  19#include "fix_u32.h"
  20#include <scsi/sg.h>
  21#include <scsi/scsi.h>
  22
  23/* various defines swiped from linux/cdrom.h */
  24#define CDROMCLOSETRAY            0x5319  /* pendant of CDROMEJECT  */
  25#define CDROMEJECT                0x5309  /* Ejects the cdrom media */
  26#define CDROM_DRIVE_STATUS        0x5326  /* Get tray position, etc. */
  27/* drive status possibilities returned by CDROM_DRIVE_STATUS ioctl */
  28#define CDS_TRAY_OPEN        2
  29
  30#define dev_fd 3
  31
  32/* Code taken from the original eject (http://eject.sourceforge.net/),
  33 * refactored it a bit for busybox (ne-bb@nicoerfurth.de) */
  34
  35static void eject_scsi(const char *dev)
  36{
  37        static const char sg_commands[3][6] = {
  38                { ALLOW_MEDIUM_REMOVAL, 0, 0, 0, 0, 0 },
  39                { START_STOP, 0, 0, 0, 1, 0 },
  40                { START_STOP, 0, 0, 0, 2, 0 }
  41        };
  42
  43        unsigned i;
  44        unsigned char sense_buffer[32];
  45        unsigned char inqBuff[2];
  46        sg_io_hdr_t io_hdr;
  47
  48        if ((ioctl(dev_fd, SG_GET_VERSION_NUM, &i) < 0) || (i < 30000))
  49                bb_error_msg_and_die("not a sg device or old sg driver");
  50
  51        memset(&io_hdr, 0, sizeof(sg_io_hdr_t));
  52        io_hdr.interface_id = 'S';
  53        io_hdr.cmd_len = 6;
  54        io_hdr.mx_sb_len = sizeof(sense_buffer);
  55        io_hdr.dxfer_direction = SG_DXFER_NONE;
  56        /* io_hdr.dxfer_len = 0; */
  57        io_hdr.dxferp = inqBuff;
  58        io_hdr.sbp = sense_buffer;
  59        io_hdr.timeout = 2000;
  60
  61        for (i = 0; i < 3; i++) {
  62                io_hdr.cmdp = (void *)sg_commands[i];
  63                ioctl_or_perror_and_die(dev_fd, SG_IO, (void *)&io_hdr, "%s", dev);
  64        }
  65
  66        /* force kernel to reread partition table when new disc is inserted */
  67        ioctl(dev_fd, BLKRRPART);
  68}
  69
  70#define FLAG_CLOSE  1
  71#define FLAG_SMART  2
  72#define FLAG_SCSI   4
  73
  74static void eject_cdrom(unsigned flags, const char *dev)
  75{
  76        int cmd = CDROMEJECT;
  77
  78        if (flags & FLAG_CLOSE
  79         || ((flags & FLAG_SMART) && ioctl(dev_fd, CDROM_DRIVE_STATUS) == CDS_TRAY_OPEN)
  80        ) {
  81                cmd = CDROMCLOSETRAY;
  82        }
  83
  84        ioctl_or_perror_and_die(dev_fd, cmd, NULL, "%s", dev);
  85}
  86
  87int eject_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  88int eject_main(int argc UNUSED_PARAM, char **argv)
  89{
  90        unsigned flags;
  91        const char *device;
  92
  93        opt_complementary = "?1:t--T:T--t";
  94        flags = getopt32(argv, "tT" IF_FEATURE_EJECT_SCSI("s"));
  95        device = argv[optind] ? argv[optind] : "/dev/cdrom";
  96
  97        /* We used to do "umount <device>" here, but it was buggy
  98           if something was mounted OVER cdrom and
  99           if cdrom is mounted many times.
 100
 101           This works equally well (or better):
 102           #!/bin/sh
 103           umount /dev/cdrom
 104           eject /dev/cdrom
 105        */
 106
 107        xmove_fd(xopen_nonblocking(device), dev_fd);
 108
 109        if (ENABLE_FEATURE_EJECT_SCSI && (flags & FLAG_SCSI))
 110                eject_scsi(device);
 111        else
 112                eject_cdrom(flags, device);
 113
 114        if (ENABLE_FEATURE_CLEAN_UP)
 115                close(dev_fd);
 116
 117        return EXIT_SUCCESS;
 118}
 119