package hcs import ( "encoding/json" "io" "sync" "syscall" "time" "github.com/Microsoft/hcsshim/internal/guestrequest" "github.com/Microsoft/hcsshim/internal/interop" "github.com/Microsoft/hcsshim/internal/logfields" "github.com/sirupsen/logrus" ) // ContainerError is an error encountered in HCS type Process struct { handleLock sync.RWMutex handle hcsProcess processID int system *System cachedPipes *cachedPipes callbackNumber uintptr logctx logrus.Fields closedWaitOnce sync.Once waitBlock chan struct{} waitError error } func newProcess(process hcsProcess, processID int, computeSystem *System) *Process { return &Process{ handle: process, processID: processID, system: computeSystem, logctx: logrus.Fields{ logfields.ContainerID: computeSystem.ID(), logfields.ProcessID: processID, }, waitBlock: make(chan struct{}), } } type cachedPipes struct { stdIn syscall.Handle stdOut syscall.Handle stdErr syscall.Handle } type processModifyRequest struct { Operation string ConsoleSize *consoleSize `json:",omitempty"` CloseHandle *closeHandle `json:",omitempty"` } type consoleSize struct { Height uint16 Width uint16 } type closeHandle struct { Handle string } type ProcessStatus struct { ProcessID uint32 Exited bool ExitCode uint32 LastWaitResult int32 } const ( stdIn string = "StdIn" stdOut string = "StdOut" stdErr string = "StdErr" ) const ( modifyConsoleSize string = "ConsoleSize" modifyCloseHandle string = "CloseHandle" ) // Pid returns the process ID of the process within the container. func (process *Process) Pid() int { return process.processID } // SystemID returns the ID of the process's compute system. func (process *Process) SystemID() string { return process.system.ID() } func (process *Process) logOperationBegin(operation string) { logOperationBegin( process.logctx, operation+" - Begin Operation") } func (process *Process) logOperationEnd(operation string, err error) { var result string if err == nil { result = "Success" } else { result = "Error" } logOperationEnd( process.logctx, operation+" - End Operation - "+result, err) } // Signal signals the process with `options`. func (process *Process) Signal(options guestrequest.SignalProcessOptions) (err error) { process.handleLock.RLock() defer process.handleLock.RUnlock() operation := "hcsshim::Process::Signal" process.logOperationBegin(operation) defer func() { process.logOperationEnd(operation, err) }() if process.handle == 0 { return makeProcessError(process, operation, ErrAlreadyClosed, nil) } optionsb, err := json.Marshal(options) if err != nil { return err } optionsStr := string(optionsb) var resultp *uint16 syscallWatcher(process.logctx, func() { err = hcsSignalProcess(process.handle, optionsStr, &resultp) }) events := processHcsResult(resultp) if err != nil { return makeProcessError(process, operation, err, events) } return nil } // Kill signals the process to terminate but does not wait for it to finish terminating. func (process *Process) Kill() (err error) { process.handleLock.RLock() defer process.handleLock.RUnlock() operation := "hcsshim::Process::Kill" process.logOperationBegin(operation) defer func() { process.logOperationEnd(operation, err) }() if process.handle == 0 { return makeProcessError(process, operation, ErrAlreadyClosed, nil) } var resultp *uint16 syscallWatcher(process.logctx, func() { err = hcsTerminateProcess(process.handle, &resultp) }) events := processHcsResult(resultp) if err != nil { return makeProcessError(process, operation, err, events) } return nil } // waitBackground waits for the process exit notification. Once received sets // `process.waitError` (if any) and unblocks all `Wait` and `WaitTimeout` calls. // // This MUST be called exactly once per `process.handle` but `Wait` and // `WaitTimeout` are safe to call multiple times. func (process *Process) waitBackground() { process.waitError = waitForNotification(process.callbackNumber, hcsNotificationProcessExited, nil) process.closedWaitOnce.Do(func() { close(process.waitBlock) }) } // Wait waits for the process to exit. If the process has already exited returns // the pervious error (if any). func (process *Process) Wait() (err error) { operation := "hcsshim::Process::Wait" process.logOperationBegin(operation) defer func() { process.logOperationEnd(operation, err) }() <-process.waitBlock if process.waitError != nil { return makeProcessError(process, operation, err, nil) } return nil } // WaitTimeout waits for the process to exit or the duration to elapse. If the // process has already exited returns the pervious error (if any). If a timeout // occurs returns `ErrTimeout`. func (process *Process) WaitTimeout(timeout time.Duration) (err error) { operation := "hcssshim::Process::WaitTimeout" process.logOperationBegin(operation) defer func() { process.logOperationEnd(operation, err) }() select { case <-process.waitBlock: if process.waitError != nil { return makeProcessError(process, operation, process.waitError, nil) } return nil case <-time.After(timeout): return makeProcessError(process, operation, ErrTimeout, nil) } } // ResizeConsole resizes the console of the process. func (process *Process) ResizeConsole(width, height uint16) (err error) { process.handleLock.RLock() defer process.handleLock.RUnlock() operation := "hcsshim::Process::ResizeConsole" process.logOperationBegin(operation) defer func() { process.logOperationEnd(operation, err) }() if process.handle == 0 { return makeProcessError(process, operation, ErrAlreadyClosed, nil) } modifyRequest := processModifyRequest{ Operation: modifyConsoleSize, ConsoleSize: &consoleSize{ Height: height, Width: width, }, } modifyRequestb, err := json.Marshal(modifyRequest) if err != nil { return err } modifyRequestStr := string(modifyRequestb) var resultp *uint16 err = hcsModifyProcess(process.handle, modifyRequestStr, &resultp) events := processHcsResult(resultp) if err != nil { return makeProcessError(process, operation, err, events) } return nil } func (process *Process) Properties() (_ *ProcessStatus, err error) { process.handleLock.RLock() defer process.handleLock.RUnlock() operation := "hcsshim::Process::Properties" process.logOperationBegin(operation) defer func() { process.logOperationEnd(operation, err) }() if process.handle == 0 { return nil, makeProcessError(process, operation, ErrAlreadyClosed, nil) } var ( resultp *uint16 propertiesp *uint16 ) syscallWatcher(process.logctx, func() { err = hcsGetProcessProperties(process.handle, &propertiesp, &resultp) }) events := processHcsResult(resultp) if err != nil { return nil, makeProcessError(process, operation, err, events) } if propertiesp == nil { return nil, ErrUnexpectedValue } propertiesRaw := interop.ConvertAndFreeCoTaskMemBytes(propertiesp) properties := &ProcessStatus{} if err := json.Unmarshal(propertiesRaw, properties); err != nil { return nil, makeProcessError(process, operation, err, nil) } return properties, nil } // ExitCode returns the exit code of the process. The process must have // already terminated. func (process *Process) ExitCode() (_ int, err error) { operation := "hcsshim::Process::ExitCode" process.logOperationBegin(operation) defer func() { process.logOperationEnd(operation, err) }() properties, err := process.Properties() if err != nil { return -1, makeProcessError(process, operation, err, nil) } if properties.Exited == false { return -1, makeProcessError(process, operation, ErrInvalidProcessState, nil) } if properties.LastWaitResult != 0 { logrus.WithFields(logrus.Fields{ logfields.ContainerID: process.SystemID(), logfields.ProcessID: process.processID, "wait-result": properties.LastWaitResult, }).Warn("hcsshim::Process::ExitCode - Non-zero last wait result") return -1, nil } return int(properties.ExitCode), nil } // Stdio returns the stdin, stdout, and stderr pipes, respectively. Closing // these pipes does not close the underlying pipes; it should be possible to // call this multiple times to get multiple interfaces. func (process *Process) Stdio() (_ io.WriteCloser, _ io.ReadCloser, _ io.ReadCloser, err error) { process.handleLock.RLock() defer process.handleLock.RUnlock() operation := "hcsshim::Process::Stdio" process.logOperationBegin(operation) defer func() { process.logOperationEnd(operation, err) }() if process.handle == 0 { return nil, nil, nil, makeProcessError(process, operation, ErrAlreadyClosed, nil) } var stdIn, stdOut, stdErr syscall.Handle if process.cachedPipes == nil { var ( processInfo hcsProcessInformation resultp *uint16 ) err = hcsGetProcessInfo(process.handle, &processInfo, &resultp) events := processHcsResult(resultp) if err != nil { return nil, nil, nil, makeProcessError(process, operation, err, events) } stdIn, stdOut, stdErr = processInfo.StdInput, processInfo.StdOutput, processInfo.StdError } else { // Use cached pipes stdIn, stdOut, stdErr = process.cachedPipes.stdIn, process.cachedPipes.stdOut, process.cachedPipes.stdErr // Invalidate the cache process.cachedPipes = nil } pipes, err := makeOpenFiles([]syscall.Handle{stdIn, stdOut, stdErr}) if err != nil { return nil, nil, nil, makeProcessError(process, operation, err, nil) } return pipes[0], pipes[1], pipes[2], nil } // CloseStdin closes the write side of the stdin pipe so that the process is // notified on the read side that there is no more data in stdin. func (process *Process) CloseStdin() (err error) { process.handleLock.RLock() defer process.handleLock.RUnlock() operation := "hcsshim::Process::CloseStdin" process.logOperationBegin(operation) defer func() { process.logOperationEnd(operation, err) }() if process.handle == 0 { return makeProcessError(process, operation, ErrAlreadyClosed, nil) } modifyRequest := processModifyRequest{ Operation: modifyCloseHandle, CloseHandle: &closeHandle{ Handle: stdIn, }, } modifyRequestb, err := json.Marshal(modifyRequest) if err != nil { return err } modifyRequestStr := string(modifyRequestb) var resultp *uint16 err = hcsModifyProcess(process.handle, modifyRequestStr, &resultp) events := processHcsResult(resultp) if err != nil { return makeProcessError(process, operation, err, events) } return nil } // Close cleans up any state associated with the process but does not kill // or wait on it. func (process *Process) Close() (err error) { process.handleLock.Lock() defer process.handleLock.Unlock() operation := "hcsshim::Process::Close" process.logOperationBegin(operation) defer func() { process.logOperationEnd(operation, err) }() // Don't double free this if process.handle == 0 { return nil } if err = process.unregisterCallback(); err != nil { return makeProcessError(process, operation, err, nil) } if err = hcsCloseProcess(process.handle); err != nil { return makeProcessError(process, operation, err, nil) } process.handle = 0 process.closedWaitOnce.Do(func() { close(process.waitBlock) }) return nil } func (process *Process) registerCallback() error { context := ¬ifcationWatcherContext{ channels: newChannels(), } callbackMapLock.Lock() callbackNumber := nextCallback nextCallback++ callbackMap[callbackNumber] = context callbackMapLock.Unlock() var callbackHandle hcsCallback err := hcsRegisterProcessCallback(process.handle, notificationWatcherCallback, callbackNumber, &callbackHandle) if err != nil { return err } context.handle = callbackHandle process.callbackNumber = callbackNumber return nil } func (process *Process) unregisterCallback() error { callbackNumber := process.callbackNumber callbackMapLock.RLock() context := callbackMap[callbackNumber] callbackMapLock.RUnlock() if context == nil { return nil } handle := context.handle if handle == 0 { return nil } // hcsUnregisterProcessCallback has its own syncronization // to wait for all callbacks to complete. We must NOT hold the callbackMapLock. err := hcsUnregisterProcessCallback(handle) if err != nil { return err } closeChannels(context.channels) callbackMapLock.Lock() delete(callbackMap, callbackNumber) callbackMapLock.Unlock() handle = 0 return nil }