/lib/udev/tbtacl is in thunderbolt-tools 0.9.3-3.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
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 | #!/bin/sh
################################################################################
# Thunderbolt(TM) tbtacl tool
# This code is distributed under the following BSD-style license:
#
# Copyright(c) 2017 Intel Corporation.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
# * Neither the name of Intel Corporation nor the names of its contributors
# may be used to endorse or promote products derived from this software
# without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
################################################################################
log="logger -t tbtacl $$:"
$log args: $*
acltree=/var/lib/thunderbolt/acl
write_helper=/lib/udev/tbtacl-write
action=$1
device=/sys$2
debug() {
$log $*
}
die() {
debug $*
exit 1
}
# The main function to authorize a specific device. The parameter it expects is
# the full sysfs path to the device. Then, if the device is found in ACL, it
# authorizes it.
authorize() {
# TOCTOU protection: chdir so if an attacker replaces the device between
# the read of unique_id and the write of authorized, the write will fail
cd $1 || { debug "can't access" $1 ; return 1 ; }
$log authorizing $1
uuid=$( cat unique_id )
[ -n "$uuid" ] || { debug -p err no UUID; return 1 ; } # Exit if UUID read failed
[ -e $acltree/$uuid ] || { debug not in ACL ; return 1 ; } # Exit if UUID isn't in ACL
if [ $sl -eq 2 ]; then
# Exit if device doesn't support SL2 or key is empty
[ -e key ] || { debug "device doesn't support SL2"; return 1 ; }
[ -e $acltree/$uuid/key ] || { debug no key found ; return 1 ; }
cat $acltree/$uuid/key > key
$log key found
fi
$write_helper $sl authorized
err=$?
if $( which errno ); then
errstr=$( errno $err | cut -d' ' -f1 )
fi
$log authorization result: $err $errstr
case "$err" in
126|129) # ENOKEY or EKEYREJECTED
rm -f $acltree/$uuid/key
debug invalid key removed, reapprove
udevadm trigger -c change $1 # Not needed if GUI watchs $acltree/$uuid/key
;;
esac
}
# Find the domain and extract the current SL
domain=$device
while [ -n "$domain" ] && [ $domain != '/' ]; do
basename $domain | grep -Fq "domain" && break
domain=$( dirname $domain )
done
sl=$( cat $domain/security )
case "$sl" in
user) sl=1
;;
secure) sl=2
;;
*) die SL is $sl, leaving...
;;
esac
case "$action" in
# New device attached, go to authorize it
add) authorize $device
;;
# The device got authorized, let's try to authorize again the devices
# behind it
change) list=$device/*/authorized
# Stop if no substitution was done (no relevant childs found)
echo $list | grep -Fvq '*' || die no childs found
for i in $list ; do
i=$( dirname $i )
[ -e $i/uevent ] || continue
if grep -Fxq 'DEVTYPE=thunderbolt_device' $i/uevent; then
authorize $i
fi
done
;;
*) die unhandled action: $action
;;
esac
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