random_seed revision 1.4 
1#!/bin/sh
2#
3# $NetBSD: random_seed,v 1.4 2012/12/14 18:42:25 apb Exp $
4#
5
6# PROVIDE: random_seed
7# REQUIRE: mountcritlocal
8# BEFORE: securelevel
9# BEFORE: bootconf
10# KEYWORD: shutdown
11#
12# The "BEFORE: securelevel" is a real dependency, in that
13# this script won't work if run after the securelevel is changed.
14#
15# The "BEFORE: bootconf" is intended to cause this to
16# be the first script that runs after mountcritlocal.
17
18$_rc_subr_loaded . /etc/rc.subr
19
20name="random_seed"
21rcvar=$name
22start_cmd="random_load"
23stop_cmd="random_save"
24
25random_file=${random_file:-/var/db/entropy-file}
26
27fs_safe()
28{
29	#
30	# Enforce that the file's on a local filesystem.
31	# Include only the types we can actually write.
32	#
33	fstype=$(df -G "$1" |
34		while read line ; do
35		    set -- $line
36		    if [ "$2" = "fstype" ]; then echo "$1" ; break ; fi
37		done )
38	case $fstype in
39	    ffs)
40		return 0
41		;;
42	    lfs)
43		return 0
44		;;
45	    ext2fs)
46		return 0;
47		;;
48	    msdos)
49		return 0;
50		;;
51	    v7fs)
52		return 0;
53		;;
54	 esac
55	 return 1
56}
57
58random_load()
59{
60	if [ -f $random_file ]; then
61
62		if ! fs_safe "${random_file}"; then
63			return 1
64		fi
65
66		set -- $(ls -ldn "${random_file}")
67		st_mode="$1" # should be "-rw-------"
68		st_uid="$3"  # should be "0" for root
69
70		# The file must be owned by root,
71		if [ "$st_uid" != "0" ]; then
72			return 1
73		fi
74		# and root read/write only.
75		if [ "$st_mode" != "-rw-------" ]; then
76			return 1
77		fi
78
79		if rndctl -L "${random_file}"; then
80			echo "Loaded entropy from disk."
81		fi
82		
83	fi
84}
85
86random_save()
87{
88	oum=$(umask)
89	umask 077
90
91	rm -Pf "${random_file}"
92
93	if ! fs_safe "${random_file}"; then
94		return 1
95	fi
96
97	if rndctl -S "${random_file}"; then
98		echo "Saved entropy to disk."
99	fi
100}
101
102
103load_rc_config $name
104run_rc_command "$1"
105