diff options
Diffstat (limited to 'obfs4proxy/termmon.go')
-rw-r--r-- | obfs4proxy/termmon.go | 135 |
1 files changed, 0 insertions, 135 deletions
diff --git a/obfs4proxy/termmon.go b/obfs4proxy/termmon.go deleted file mode 100644 index 86db190..0000000 --- a/obfs4proxy/termmon.go +++ /dev/null @@ -1,135 +0,0 @@ -/* - * Copyright (c) 2015, Yawning Angel <yawning at torproject dot org> - * All rights reserved. - * - * 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. - * - * 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 HOLDER 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. - */ - -package main - -import ( - "io" - "io/ioutil" - "os" - "os/signal" - "runtime" - "syscall" - "time" - - "git.torproject.org/pluggable-transports/obfs4.git/common/log" -) - -var termMonitorOSInit func(*termMonitor) error - -type termMonitor struct { - sigChan chan os.Signal - handlerChan chan int - numHandlers int -} - -func (m *termMonitor) onHandlerStart() { - m.handlerChan <- 1 -} - -func (m *termMonitor) onHandlerFinish() { - m.handlerChan <- -1 -} - -func (m *termMonitor) wait(termOnNoHandlers bool) os.Signal { - // Block until a signal has been received, or (optionally) the - // number of pending handlers has hit 0. In the case of the - // latter, treat it as if a SIGTERM has been received. - for { - select { - case n := <-m.handlerChan: - m.numHandlers += n - case sig := <-m.sigChan: - return sig - } - if termOnNoHandlers && m.numHandlers == 0 { - return syscall.SIGTERM - } - } -} - -func (m *termMonitor) termOnStdinClose() { - _, err := io.Copy(ioutil.Discard, os.Stdin) - - // io.Copy() will return a nil on EOF, since reaching EOF is - // expected behavior. No matter what, if this unblocks, assume - // that stdin is closed, and treat that as having received a - // SIGTERM. - log.Noticef("Stdin is closed or unreadable: %v", err) - m.sigChan <- syscall.SIGTERM -} - -func (m *termMonitor) termOnPPIDChange(ppid int) { - // Under most if not all U*IX systems, the parent PID will change - // to that of init once the parent dies. There are several notable - // exceptions (Slowlaris/Android), but the parent PID changes - // under those platforms as well. - // - // Naturally we lose if the parent has died by the time when the - // Getppid() call was issued in our parent, but, this is better - // than nothing. - const ppidPollInterval = 1 * time.Second - for ppid == os.Getppid() { - time.Sleep(ppidPollInterval) - } - - // Treat the parent PID changing as the same as having received - // a SIGTERM. - log.Noticef("Parent pid changed: %d (was %d)", os.Getppid(), ppid) - m.sigChan <- syscall.SIGTERM -} - -func newTermMonitor() (m *termMonitor) { - ppid := os.Getppid() - m = new(termMonitor) - m.sigChan = make(chan os.Signal) - m.handlerChan = make(chan int) - signal.Notify(m.sigChan, syscall.SIGINT, syscall.SIGTERM) - - // If tor supports feature #15435, we can use Stdin being closed as an - // indication that tor has died, or wants the PT to shutdown for any - // reason. - if ptShouldExitOnStdinClose() { - go m.termOnStdinClose() - } else { - // Instead of feature #15435, use various kludges and hacks: - // * Linux - Platform specific code that should always work. - // * Other U*IX - Somewhat generic code, that works unless the - // parent dies before the monitor is initialized. - if termMonitorOSInit != nil { - // Errors here are non-fatal, since it might still be - // possible to fall back to a generic implementation. - if err := termMonitorOSInit(m); err == nil { - return - } - } - if runtime.GOOS != "windows" { - go m.termOnPPIDChange(ppid) - } - } - return -} |