From 85b7374491e842c44bec3ce5ec800794cae10295 Mon Sep 17 00:00:00 2001 From: Valentin Rothberg Date: Wed, 12 Feb 2020 11:10:55 +0100 Subject: add pkg/signal Add pkg/signal to deal with parts of signal processing and translating signals from string to numeric representations. The code has been copied from docker/docker (and attributed with the copyright) but been reduced to only what libpod needs (on Linux). Signed-off-by: Valentin Rothberg --- pkg/signal/signal_linux.go | 127 +++++++++++++++++++++++++++++++++++++++ pkg/signal/signal_unsupported.go | 28 +++++++++ 2 files changed, 155 insertions(+) create mode 100644 pkg/signal/signal_linux.go create mode 100644 pkg/signal/signal_unsupported.go (limited to 'pkg/signal') diff --git a/pkg/signal/signal_linux.go b/pkg/signal/signal_linux.go new file mode 100644 index 000000000..3d549898f --- /dev/null +++ b/pkg/signal/signal_linux.go @@ -0,0 +1,127 @@ +// +build linux + +// Signal handling for Linux only. +package signal + +// Copyright 2013-2018 Docker, Inc. + +// NOTE: this package has originally been copied from github.com/docker/docker. + +import ( + "fmt" + "os" + "os/signal" + "strconv" + "strings" + "syscall" + + "golang.org/x/sys/unix" +) + +const ( + sigrtmin = 34 + sigrtmax = 64 + + SIGWINCH = syscall.SIGWINCH // For cross-compilation with Windows +) + +// signalMap is a map of Linux signals. +var signalMap = map[string]syscall.Signal{ + "ABRT": unix.SIGABRT, + "ALRM": unix.SIGALRM, + "BUS": unix.SIGBUS, + "CHLD": unix.SIGCHLD, + "CLD": unix.SIGCLD, + "CONT": unix.SIGCONT, + "FPE": unix.SIGFPE, + "HUP": unix.SIGHUP, + "ILL": unix.SIGILL, + "INT": unix.SIGINT, + "IO": unix.SIGIO, + "IOT": unix.SIGIOT, + "KILL": unix.SIGKILL, + "PIPE": unix.SIGPIPE, + "POLL": unix.SIGPOLL, + "PROF": unix.SIGPROF, + "PWR": unix.SIGPWR, + "QUIT": unix.SIGQUIT, + "SEGV": unix.SIGSEGV, + "STKFLT": unix.SIGSTKFLT, + "STOP": unix.SIGSTOP, + "SYS": unix.SIGSYS, + "TERM": unix.SIGTERM, + "TRAP": unix.SIGTRAP, + "TSTP": unix.SIGTSTP, + "TTIN": unix.SIGTTIN, + "TTOU": unix.SIGTTOU, + "URG": unix.SIGURG, + "USR1": unix.SIGUSR1, + "USR2": unix.SIGUSR2, + "VTALRM": unix.SIGVTALRM, + "WINCH": unix.SIGWINCH, + "XCPU": unix.SIGXCPU, + "XFSZ": unix.SIGXFSZ, + "RTMIN": sigrtmin, + "RTMIN+1": sigrtmin + 1, + "RTMIN+2": sigrtmin + 2, + "RTMIN+3": sigrtmin + 3, + "RTMIN+4": sigrtmin + 4, + "RTMIN+5": sigrtmin + 5, + "RTMIN+6": sigrtmin + 6, + "RTMIN+7": sigrtmin + 7, + "RTMIN+8": sigrtmin + 8, + "RTMIN+9": sigrtmin + 9, + "RTMIN+10": sigrtmin + 10, + "RTMIN+11": sigrtmin + 11, + "RTMIN+12": sigrtmin + 12, + "RTMIN+13": sigrtmin + 13, + "RTMIN+14": sigrtmin + 14, + "RTMIN+15": sigrtmin + 15, + "RTMAX-14": sigrtmax - 14, + "RTMAX-13": sigrtmax - 13, + "RTMAX-12": sigrtmax - 12, + "RTMAX-11": sigrtmax - 11, + "RTMAX-10": sigrtmax - 10, + "RTMAX-9": sigrtmax - 9, + "RTMAX-8": sigrtmax - 8, + "RTMAX-7": sigrtmax - 7, + "RTMAX-6": sigrtmax - 6, + "RTMAX-5": sigrtmax - 5, + "RTMAX-4": sigrtmax - 4, + "RTMAX-3": sigrtmax - 3, + "RTMAX-2": sigrtmax - 2, + "RTMAX-1": sigrtmax - 1, + "RTMAX": sigrtmax, +} + +// ParseSignal translates a string to a valid syscall signal. +// It returns an error if the signal map doesn't include the given signal. +func ParseSignal(rawSignal string) (syscall.Signal, error) { + s, err := strconv.Atoi(rawSignal) + if err == nil { + if s == 0 { + return -1, fmt.Errorf("invalid signal: %s", rawSignal) + } + return syscall.Signal(s), nil + } + signal, ok := signalMap[strings.TrimPrefix(strings.ToUpper(rawSignal), "SIG")] + if !ok { + return -1, fmt.Errorf("invalid signal: %s", rawSignal) + } + return signal, nil +} + +// CatchAll catches all signals and relays them to the specified channel. +func CatchAll(sigc chan os.Signal) { + var handledSigs []os.Signal + for _, s := range signalMap { + handledSigs = append(handledSigs, s) + } + signal.Notify(sigc, handledSigs...) +} + +// StopCatch stops catching the signals and closes the specified channel. +func StopCatch(sigc chan os.Signal) { + signal.Stop(sigc) + close(sigc) +} diff --git a/pkg/signal/signal_unsupported.go b/pkg/signal/signal_unsupported.go new file mode 100644 index 000000000..0a92a5b3a --- /dev/null +++ b/pkg/signal/signal_unsupported.go @@ -0,0 +1,28 @@ +// +build !linux + +// Signal handling for Linux only. +package signal + +import ( + "fmt" + "os" + "syscall" +) + +const SIGWINCH = syscall.Signal(0xff) + +// ParseSignal translates a string to a valid syscall signal. +// It returns an error if the signal map doesn't include the given signal. +func ParseSignal(rawSignal string) (syscall.Signal, error) { + return 0, fmt.Errorf("unsupported on non-linux platforms") +} + +// CatchAll catches all signals and relays them to the specified channel. +func CatchAll(sigc chan os.Signal) { + panic("Unsupported on non-linux platforms") +} + +// StopCatch stops catching the signals and closes the specified channel. +func StopCatch(sigc chan os.Signal) { + panic("Unsupported on non-linux platforms") +} -- cgit v1.2.3-54-g00ecf