summaryrefslogtreecommitdiffhomepage
path: root/util-linux/eject.c
blob: 6c30facd2624a2def33319b35c2b931db4e6691f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
/* vi: set sw=4 ts=4: */
/*
 * eject implementation for busybox
 *
 * Copyright (C) 2004  Peter Willis <psyphreak@phreaker.net>
 * Copyright (C) 2005  Tito Ragusa <farmatito@tiscali.it>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */

/*
 * This is a simple hack of eject based on something Erik posted in #uclibc.
 * Most of the dirty work blatantly ripped off from cat.c =)
 */
//config:config EJECT
//config:	bool "eject (4.1 kb)"
//config:	default y
//config:	select PLATFORM_LINUX
//config:	help
//config:	Used to eject cdroms. (defaults to /dev/cdrom)
//config:
//config:config FEATURE_EJECT_SCSI
//config:	bool "SCSI support"
//config:	default y
//config:	depends on EJECT
//config:	help
//config:	Add the -s option to eject, this allows to eject SCSI-Devices and
//config:	usb-storage devices.

//applet:IF_EJECT(APPLET(eject, BB_DIR_USR_BIN, BB_SUID_DROP))

//kbuild:lib-$(CONFIG_EJECT) += eject.o

//usage:#define eject_trivial_usage
//usage:       "[-t] [-T] [DEVICE]"
//usage:#define eject_full_usage "\n\n"
//usage:       "Eject DEVICE or default /dev/cdrom\n"
//usage:	IF_FEATURE_EJECT_SCSI(
//usage:     "\n	-s	SCSI device"
//usage:	)
//usage:     "\n	-t	Close tray"
//usage:     "\n	-T	Open/close tray (toggle)"

#include <sys/mount.h>
#include "libbb.h"
#if ENABLE_FEATURE_EJECT_SCSI
/* Must be after libbb.h: they need size_t */
# include "fix_u32.h"
# include <scsi/sg.h>
# include <scsi/scsi.h>
#endif

#define dev_fd 3

/* Code taken from the original eject (http://eject.sourceforge.net/),
 * refactored it a bit for busybox (ne-bb@nicoerfurth.de) */

#if ENABLE_FEATURE_EJECT_SCSI
static void eject_scsi(const char *dev)
{
	static const char sg_commands[3][6] ALIGN1 = {
		{ ALLOW_MEDIUM_REMOVAL, 0, 0, 0, 0, 0 },
		{ START_STOP, 0, 0, 0, 1, 0 },
		{ START_STOP, 0, 0, 0, 2, 0 }
	};

	unsigned i;
	unsigned char sense_buffer[32];
	unsigned char inqBuff[2];
	sg_io_hdr_t io_hdr;

	if ((ioctl(dev_fd, SG_GET_VERSION_NUM, &i) < 0) || (i < 30000))
		bb_error_msg_and_die("not a sg device or old sg driver");

	memset(&io_hdr, 0, sizeof(sg_io_hdr_t));
	io_hdr.interface_id = 'S';
	io_hdr.cmd_len = 6;
	io_hdr.mx_sb_len = sizeof(sense_buffer);
	io_hdr.dxfer_direction = SG_DXFER_NONE;
	/* io_hdr.dxfer_len = 0; */
	io_hdr.dxferp = inqBuff;
	io_hdr.sbp = sense_buffer;
	io_hdr.timeout = 2000;

	for (i = 0; i < 3; i++) {
		io_hdr.cmdp = (void *)sg_commands[i];
		ioctl_or_perror_and_die(dev_fd, SG_IO, (void *)&io_hdr, "%s", dev);
	}

	/* force kernel to reread partition table when new disc is inserted */
	ioctl(dev_fd, BLKRRPART);
}
#else
# define eject_scsi(dev) ((void)0)
#endif

/* various defines swiped from linux/cdrom.h */
#define CDROMCLOSETRAY            0x5319  /* pendant of CDROMEJECT  */
#define CDROMEJECT                0x5309  /* Ejects the cdrom media */
#define CDROM_DRIVE_STATUS        0x5326  /* Get tray position, etc. */
/* drive status possibilities returned by CDROM_DRIVE_STATUS ioctl */
#define CDS_TRAY_OPEN        2

#define FLAG_CLOSE  1
#define FLAG_SMART  2
#define FLAG_SCSI   4

static void eject_cdrom(unsigned flags, const char *dev)
{
	int cmd = CDROMEJECT;

	if (flags & FLAG_CLOSE
	 || ((flags & FLAG_SMART) && ioctl(dev_fd, CDROM_DRIVE_STATUS) == CDS_TRAY_OPEN)
	) {
		cmd = CDROMCLOSETRAY;
	}

	ioctl_or_perror_and_die(dev_fd, cmd, NULL, "%s", dev);
}

int eject_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int eject_main(int argc UNUSED_PARAM, char **argv)
{
	unsigned flags;
	const char *device;

	flags = getopt32(argv, "^" "tT"IF_FEATURE_EJECT_SCSI("s")
			"\0" "?1:t--T:T--t"
	);
	device = argv[optind] ? argv[optind] : "/dev/cdrom";

	/* We used to do "umount <device>" here, but it was buggy
	   if something was mounted OVER cdrom and
	   if cdrom is mounted many times.

	   This works equally well (or better):
	   #!/bin/sh
	   umount /dev/cdrom
	   eject /dev/cdrom
	*/

	xmove_fd(xopen_nonblocking(device), dev_fd);

	if (ENABLE_FEATURE_EJECT_SCSI && (flags & FLAG_SCSI))
		eject_scsi(device);
	else
		eject_cdrom(flags, device);

	if (ENABLE_FEATURE_CLEAN_UP)
		close(dev_fd);

	return EXIT_SUCCESS;
}