commit 9436eba46455f8f0d0db7109959d7779e980fe9f Author: David Fifield david@bamsoftware.com Date: Thu Apr 18 22:54:06 2019 -0600

Factor out a startProcesses function, kill processes in main. --- meek-client-torbrowser/meek-client-torbrowser.go | 98 +++++++++++++++--------- 1 file changed, 60 insertions(+), 38 deletions(-)

diff --git a/meek-client-torbrowser/meek-client-torbrowser.go b/meek-client-torbrowser/meek-client-torbrowser.go index 16f0ebc..ce79193 100644 --- a/meek-client-torbrowser/meek-client-torbrowser.go +++ b/meek-client-torbrowser/meek-client-torbrowser.go @@ -315,6 +315,53 @@ func runMeekClient(helperAddr string, meekClientCommandLine []string) (cmd *exec return cmd, nil }

+// Run firefox and meek-client and return the processes. When err is nil, both +// processes were started successfully. If err is non-nil, one or both processes +// may have failed to start. If a process did not start, its corresponding +// return value will be nil. The caller is responsible for terminating whatever +// processes were started, whether or not err is nil. +func startProcesses(sigChan <-chan os.Signal, meekClientCommandLine []string) (firefoxCmd *exec.Cmd, meekClientCmd *exec.Cmd, err error) { + // Start firefox. + var stdout io.Reader + firefoxCmd, stdout, err = runFirefox() + if err != nil { + firefoxCmd = nil + err = fmt.Errorf("error running firefox: %v", err) + return + } + + // Find out the helper's listening address. + addrChan := make(chan string) + errChan := make(chan error) + go func() { + addr, err := grepHelperAddr(stdout) + if err == nil { + addrChan <- addr + } else { + errChan <- err + } + }() + var helperAddr string + select { + case sig := <-sigChan: + err = fmt.Errorf("received signal %v before starting meek-client", sig) + return + case err = <-errChan: + err = fmt.Errorf("error looking for helper address: %v", err) + return + case helperAddr = <-addrChan: + } + + // Start meek-client with the helper address. + meekClientCmd, err = runMeekClient(helperAddr, meekClientCommandLine) + if err != nil { + meekClientCmd = nil + err = fmt.Errorf("error running meek-client: %v", err) + return + } + return +} + func main() { var logFilename string

@@ -361,48 +408,23 @@ func main() { }() }

- // Start firefox. - firefoxCmd, stdout, err := runFirefox() - if err != nil { - log.Print(err) - return - } - defer logKill(firefoxCmd.Process) - - // Find out the helper's listening address. - addrChan := make(chan string) - errChan := make(chan error) - go func() { - addr, err := grepHelperAddr(stdout) - if err == nil { - addrChan <- addr - } else { - errChan <- err - } - }() - var helperAddr string - select { - case sig := <-sigChan: + firefoxCmd, meekClientCmd, err := startProcesses(sigChan, meekClientCommandLine) + if err == nil { + // Both processes started successfully. Now let them run until + // we are instructed to stop. + sig := <-sigChan log.Printf("sig %s", sig) - return - case err = <-errChan: + logSignal(meekClientCmd.Process, sig) + } else { + // Otherwise don't wait, go ahead and terminate whatever + // processes were started. log.Print(err) - return - case helperAddr = <-addrChan: }

- // Start meek-client with the helper address. - meekClientCmd, err := runMeekClient(helperAddr, meekClientCommandLine) - if err != nil { - log.Print(err) - return + if firefoxCmd != nil { + logKill(firefoxCmd.Process) } - defer logKill(meekClientCmd.Process) - - sig := <-sigChan - log.Printf("sig %s", sig) - err = logSignal(meekClientCmd.Process, sig) - if err != nil { - log.Print(err) + if meekClientCmd != nil { + logKill(firefoxCmd.Process) } }