1#!/bin/sh -e
2
3# This script is run if an optical drive lacks a rule for persistent naming.
4#
5# It adds symlinks for optical drives based on the device class determined
6# by cdrom_id and used ID_PATH to identify the device.
7#
8# (C) 2006 Marco d'Itri <md@Linux.IT>
9#
10# This program is free software; you can redistribute it and/or modify it
11# under the terms of the GNU General Public License as published by the
12# Free Software Foundation version 2 of the License.
13
14RULES_FILE="/etc/udev/rules.d/70-persistent-cd.rules"
15
16. /lib/udev/rule_generator.functions
17
18find_next_available() {
19	raw_find_next_available "$(find_all_rules 'SYMLINK+=' $1)"
20}
21
22write_rule() {
23	local match="$1"
24	local link="$2"
25	local comment="$3"
26
27	{
28	if [ "$PRINT_HEADER" ]; then
29		PRINT_HEADER=
30		echo "# This file was automatically generated by the $0"
31		echo "# program, probably run by the cd-aliases-generator.rules rules file."
32		echo "#"
33		echo "# You can modify it, as long as you keep each rule on a single line"
34		echo "# and set the \$GENERATED variable."
35		echo ""
36	fi
37
38	[ "$comment" ] && echo "# $comment"
39	echo "$match, SYMLINK+=\"$link\", ENV{GENERATED}=\"1\""
40	} >> $RULES_FILE
41	SYMLINKS="$SYMLINKS $link"
42}
43
44if [ -z "$DEVPATH" ]; then
45	echo "Missing \$DEVPATH." >&2
46	exit 1
47fi
48if [ -z "$ID_CDROM" ]; then
49	echo "$DEVPATH is not a CD reader." >&2
50	exit 1
51fi
52
53if [ "$1" ]; then
54	METHOD="$1"
55else
56	case "$ID_BUS" in
57		usb|ieee1394)
58		METHOD='by-id'
59		;;
60
61		*)
62		METHOD='by-path'
63		;;
64	esac
65fi
66
67case "$METHOD" in
68	by-path)
69	if [ -z "$ID_PATH" ]; then
70		echo "$DEVPATH not supported by path_id. by-id may work." >&2
71		exit 1
72	fi
73	RULE="ENV{ID_PATH}==\"$ID_PATH\""
74	;;
75
76	by-id)
77	if [ "$ID_SERIAL" ]; then
78		RULE="ENV{ID_SERIAL}==\"$ID_SERIAL\""
79	elif [ "$ID_MODEL" -a "$ID_REVISION" ]; then
80		RULE="ENV{ID_MODEL}==\"$ID_MODEL\", ENV{ID_REVISION}==\"$ID_REVISION\""
81	else
82		echo "$DEVPATH not supported by ata_id. by-path may work." >&2
83		exit 1
84	fi
85	;;
86
87	*)
88	echo "Invalid argument (must be either by-path or by-id)." >&2
89	exit 1
90	;;
91esac
92
93# Prevent concurrent processes from modifying the file at the same time.
94lock_rules_file
95
96# Check if the rules file is writeable.
97choose_rules_file
98
99link_num=$(find_next_available 'cdrom[0-9]*')
100
101match="ENV{ID_CDROM}==\"?*\", $RULE"
102
103comment="$ID_MODEL ($ID_PATH)"
104
105	write_rule "$match" "cdrom$link_num" "$comment"
106[ "$ID_CDROM_CD_R" -o "$ID_CDROM_CD_RW" ] && \
107	write_rule "$match" "cdrw$link_num"
108[ "$ID_CDROM_DVD" ] && \
109	write_rule "$match" "dvd$link_num"
110[ "$ID_CDROM_DVD_R" -o "$ID_CDROM_DVD_RW" -o "$ID_CDROM_DVD_RAM" ] && \
111	write_rule "$match" "dvdrw$link_num"
112
113unlock_rules_file
114
115echo $SYMLINKS
116
117exit 0
118
119