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
154
155
156
157
158
159
160
161
|
#!/bin/sh
# Copyright (c) 2012 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
# Version = @@VERSION@@
NAME=org.chromium.chromoting
CONFIG_DIR=/Library/PrivilegedHelperTools
HOST_EXE=$CONFIG_DIR/$NAME.me2me_host.app/Contents/MacOS/remoting_me2me_host
PLIST_FILE=$CONFIG_DIR/$NAME.me2me_host.app/Contents/Info.plist
ENABLED_FILE=$CONFIG_DIR/$NAME.me2me_enabled
CONFIG_FILE=$CONFIG_DIR/$NAME.json
PREF_PANE_BUNDLE=/Library/PreferencePanes/$NAME.prefPane
# The exit code returned by 'wait' when a process is terminated by SIGTERM.
SIGTERM_EXIT_CODE=143
# Range of exit codes returned by the host to indicate that a permanent error
# has occurred and that the host should not be restarted. Please, keep these
# constants in sync with remoting/host/host_exit_codes.h.
MIN_PERMANENT_ERROR_EXIT_CODE=100
MAX_PERMANENT_ERROR_EXIT_CODE=105
# Constants controlling the host process relaunch throttling.
MINIMUM_RELAUNCH_INTERVAL=60
MAXIMUM_HOST_FAILURES=10
# Exit code 126 is defined by Posix to mean "Command found, but not
# executable", and is returned if the process cannot be launched due to
# parental control.
PERMISSION_DENIED_PARENTAL_CONTROL=126
HOST_PID=0
SIGNAL_WAS_TRAPPED=0
# This script works as a proxy between launchd and the host. Signals of
# interest to the host must be forwarded.
SIGNAL_LIST="SIGHUP SIGINT SIGQUIT SIGILL SIGTRAP SIGABRT SIGEMT \
SIGFPE SIGKILL SIGBUS SIGSEGV SIGSYS SIGPIPE SIGALRM SIGTERM SIGURG \
SIGSTOP SIGTSTP SIGCONT SIGCHLD SIGTTIN SIGTTOU SIGIO SIGXCPU SIGXFSZ \
SIGVTALRM SIGPROF SIGWINCH SIGINFO SIGUSR1 SIGUSR2"
handle_signal() {
SIGNAL_WAS_TRAPPED=1
}
run_host() {
local host_failure_count=0
local host_start_time=0
while true; do
if [[ ! -f "$ENABLED_FILE" ]]; then
echo "Daemon is disabled."
exit 0
fi
# If this is not the first time the host has run, make sure we don't
# relaunch it too soon.
if [[ "$host_start_time" -gt 0 ]]; then
local host_lifetime=$(($(date +%s) - $host_start_time))
echo "Host ran for ${host_lifetime}s"
if [[ "$host_lifetime" -lt "$MINIMUM_RELAUNCH_INTERVAL" ]]; then
# If the host didn't run for very long, assume it crashed. Relaunch only
# after a suitable delay and increase the failure count.
host_failure_count=$(($host_failure_count + 1))
echo "Host failure count $host_failure_count/$MAXIMUM_HOST_FAILURES"
if [[ "$host_failure_count" -ge "$MAXIMUM_HOST_FAILURES" ]]; then
echo "Too many host failures. Giving up."
exit 1
fi
local relaunch_in=$(($MINIMUM_RELAUNCH_INTERVAL - $host_lifetime))
echo "Relaunching in ${relaunch_in}s"
sleep "$relaunch_in"
else
# If the host ran for long enough, reset the crash counter.
host_failure_count=0
fi
fi
# Execute the host asynchronously and forward signals to it.
trap "handle_signal" $SIGNAL_LIST
host_start_time=$(date +%s)
"$HOST_EXE" --host-config="$CONFIG_FILE" &
HOST_PID="$!"
# Wait for the host to return and process its exit code.
while true; do
wait "$HOST_PID"
EXIT_CODE="$?"
if [[ $SIGNAL_WAS_TRAPPED -eq 1 ]]; then
# 'wait' returned as the result of a trapped signal and the exit code is
# the signal that was trapped + 128. Forward the signal to the host.
SIGNAL_WAS_TRAPPED=0
local SIGNAL=$(($EXIT_CODE - 128))
echo "Forwarding signal $SIGNAL to host"
kill -$SIGNAL "$HOST_PID"
elif [[ "$EXIT_CODE" -eq "0" ||
"$EXIT_CODE" -eq "$SIGTERM_EXIT_CODE" ||
"$EXIT_CODE" -eq "$PERMISSION_DENIED_PARENTAL_CONTROL" ||
("$EXIT_CODE" -ge "$MIN_PERMANENT_ERROR_EXIT_CODE" && \
"$EXIT_CODE" -le "$MAX_PERMANENT_ERROR_EXIT_CODE") ]]; then
echo "Host returned permanent exit code $EXIT_CODE at ""$(date)"""
if [[ "$EXIT_CODE" -eq 101 ]]; then
# Exit code 101 is "hostID deleted", which indicates that the host
# was taken off-line remotely. To prevent the host being restarted
# when the login context changes, try to delete the "enabled" file.
# Since this requires root privileges, this is only possible when
# this script is launched in the "login" context. In the "aqua"
# context, just exit and try again next time.
echo "Host id deleted - disabling"
rm -f "$ENABLED_FILE" 2>/dev/null
fi
exit "$EXIT_CODE"
else
# Ignore non-permanent error-code and launch host again. Stop handling
# signals temporarily in case the script has to sleep to throttle host
# relaunches. While throttling, there is no host process to which to
# forward the signal, so the default behaviour should be restored.
echo "Host returned non-permanent exit code $EXIT_CODE at ""$(date)"""
trap - $SIGNAL_LIST
HOST_PID=0
break
fi
done
done
}
if [[ "$1" = "--disable" ]]; then
# This script is executed from base::mac::ExecuteWithPrivilegesAndWait(),
# which requires the child process to write its PID to stdout before
# anythine else. See base/mac/authorization_util.h for details.
echo $$
rm -f "$ENABLED_FILE"
elif [[ "$1" = "--enable" ]]; then
echo $$
# Ensure the config file is private whilst being written.
rm -f "$CONFIG_FILE"
umask 0077
cat > "$CONFIG_FILE"
# Ensure the config is readable by the user registering the host.
chmod +a "$USER:allow:read" "$CONFIG_FILE"
touch "$ENABLED_FILE"
elif [[ "$1" = "--save-config" ]]; then
echo $$
cat > "$CONFIG_FILE"
elif [[ "$1" = "--host-version" ]]; then
/usr/libexec/PlistBuddy -c "Print CFBundleVersion" "$PLIST_FILE"
elif [[ "$1" = "--relaunch-prefpane" ]]; then
# Wait for the parent (System Preferences applet) to die, by reading from
# stdin until the pipe is broken.
cat 2>/dev/null || true
open "$PREF_PANE_BUNDLE"
elif [[ "$1" = "--run-from-launchd" ]]; then
echo Host started for user $USER at $"$(date)"
run_host
else
echo $$
exit 1
fi
|
