release/src/router/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
  45 static 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
  84 static 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
  97 int eject_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  98 int 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 }