From e3e8aabbcf65d37516bb97f9dc0f77df52f8cf55 Mon Sep 17 00:00:00 2001 From: Matt Holt Date: Wed, 28 Sep 2022 13:35:51 -0600 Subject: core: Refactor and improve listener logic (#5089) * core: Refactor, improve listener logic Deprecate: - caddy.Listen - caddy.ListenTimeout - caddy.ListenPacket Prefer caddy.NetworkAddress.Listen() instead. Change: - caddy.ListenQUIC (hopefully to remove later) - caddy.ListenerFunc signature (add context and ListenConfig) - Don't emit Alt-Svc header advertising h3 over HTTP/3 - Use quic.ListenEarly instead of quic.ListenEarlyAddr; this gives us more flexibility (e.g. possibility of HTTP/3 over UDS) but also introduces a new issue: https://github.com/lucas-clemente/quic-go/issues/3560#issuecomment-1258959608 - Unlink unix socket before and after use * Appease the linter * Keep ListenAll --- listeners.go | 626 ++++++++++++++++++++++++++++++++++++++++------------------- 1 file changed, 424 insertions(+), 202 deletions(-) (limited to 'listeners.go') diff --git a/listeners.go b/listeners.go index 6a23c61..aad6b69 100644 --- a/listeners.go +++ b/listeners.go @@ -19,230 +19,187 @@ import ( "crypto/tls" "errors" "fmt" + "io" "net" "net/netip" "os" "strconv" "strings" + "sync" "sync/atomic" "syscall" + "time" "github.com/lucas-clemente/quic-go" "github.com/lucas-clemente/quic-go/http3" "go.uber.org/zap" ) -// Listen is like net.Listen, except Caddy's listeners can overlap -// each other: multiple listeners may be created on the same socket -// at the same time. This is useful because during config changes, -// the new config is started while the old config is still running. -// When Caddy listeners are closed, the closing logic is virtualized -// so the underlying socket isn't actually closed until all uses of -// the socket have been finished. Always be sure to close listeners -// when you are done with them, just like normal listeners. -func Listen(network, addr string) (net.Listener, error) { - // a 0 timeout means Go uses its default - return ListenTimeout(network, addr, 0) -} - -// getListenerFromPlugin returns a listener on the given network and address -// if a plugin has registered the network name. It may return (nil, nil) if -// no plugin can provide a listener. -func getListenerFromPlugin(network, addr string) (net.Listener, error) { - network = strings.TrimSpace(strings.ToLower(network)) - - // get listener from plugin if network type is registered - if getListener, ok := networkTypes[network]; ok { - Log().Debug("getting listener from plugin", zap.String("network", network)) - return getListener(network, addr) - } - - return nil, nil +// NetworkAddress represents one or more network addresses. +// It contains the individual components for a parsed network +// address of the form accepted by ParseNetworkAddress(). +type NetworkAddress struct { + // Should be a network value accepted by Go's net package or + // by a plugin providing a listener for that network type. + Network string + + // The "main" part of the network address is the host, which + // often takes the form of a hostname, DNS name, IP address, + // or socket path. + Host string + + // For addresses that contain a port, ranges are given by + // [StartPort, EndPort]; i.e. for a single port, StartPort + // and EndPort are the same. For no port, they are 0. + StartPort uint + EndPort uint } -// ListenPacket returns a net.PacketConn suitable for use in a Caddy module. -// It is like Listen except for PacketConns. -// Always be sure to close the PacketConn when you are done. -func ListenPacket(network, addr string) (net.PacketConn, error) { - lnKey := listenerKey(network, addr) +// ListenAll calls Listen() for all addresses represented by this struct, i.e. all ports in the range. +// (If the address doesn't use ports or has 1 port only, then only 1 listener will be created.) +// It returns an error if any listener failed to bind, and closes any listeners opened up to that point. +// +// TODO: Experimental API: subject to change or removal. +func (na NetworkAddress) ListenAll(ctx context.Context, config net.ListenConfig) ([]any, error) { + var listeners []any + var err error + + // if one of the addresses has a failure, we need to close + // any that did open a socket to avoid leaking resources + defer func() { + if err == nil { + return + } + for _, ln := range listeners { + if cl, ok := ln.(io.Closer); ok { + cl.Close() + } + } + }() + + // an address can contain a port range, which represents multiple addresses; + // some addresses don't use ports at all and have a port range size of 1; + // whatever the case, iterate each address represented and bind a socket + for portOffset := uint(0); portOffset < na.PortRangeSize(); portOffset++ { + select { + case <-ctx.Done(): + return nil, ctx.Err() + default: + } - sharedPc, _, err := listenerPool.LoadOrNew(lnKey, func() (Destructor, error) { - pc, err := net.ListenPacket(network, addr) + // create (or reuse) the listener ourselves + var ln any + ln, err = na.Listen(ctx, portOffset, config) if err != nil { - // https://github.com/caddyserver/caddy/pull/4534 - if isUnixNetwork(network) && isListenBindAddressAlreadyInUseError(err) { - return nil, fmt.Errorf("%w: this can happen if Caddy was forcefully killed", err) - } return nil, err } - return &sharedPacketConn{PacketConn: pc, key: lnKey}, nil - }) - if err != nil { - return nil, err + listeners = append(listeners, ln) } - return &fakeClosePacketConn{sharedPacketConn: sharedPc.(*sharedPacketConn)}, nil + return listeners, nil } -// ListenQUIC returns a quic.EarlyListener suitable for use in a Caddy module. -// Note that the context passed to Accept is currently ignored, so using -// a context other than context.Background is meaningless. -// This API is EXPERIMENTAL and may change. -func ListenQUIC(addr string, tlsConf *tls.Config, activeRequests *int64) (quic.EarlyListener, error) { - lnKey := listenerKey("udp", addr) - - sharedEl, _, err := listenerPool.LoadOrNew(lnKey, func() (Destructor, error) { - el, err := quic.ListenAddrEarly(addr, http3.ConfigureTLSConfig(tlsConf), &quic.Config{ - RequireAddressValidation: func(clientAddr net.Addr) bool { - var highLoad bool - if activeRequests != nil { - highLoad = atomic.LoadInt64(activeRequests) > 1000 // TODO: make tunable? - } - return highLoad - }, - }) - if err != nil { - return nil, err - } - return &sharedQuicListener{EarlyListener: el, key: lnKey}, nil - }) - if err != nil { - return nil, err +// Listen is similar to net.Listen, with a few differences: +// +// Listen announces on the network address using the port calculated by adding +// portOffset to the start port. (For network types that do not use ports, the +// portOffset is ignored.) +// +// The provided ListenConfig is used to create the listener. Its Control function, +// if set, may be wrapped by an internally-used Control function. The provided +// context may be used to cancel long operations early. The context is not used +// to close the listener after it has been created. +// +// Caddy's listeners can overlap each other: multiple listeners may be created on +// the same socket at the same time. This is useful because during config changes, +// the new config is started while the old config is still running. How this is +// accomplished varies by platform and network type. For example, on Unix, SO_REUSEPORT +// is set except on Unix sockets, for which the file descriptor is duplicated and +// reused; on Windows, the close logic is virtualized using timeouts. Like normal +// listeners, be sure to Close() them when you are done. +// +// This method returns any type, as the implementations of listeners for various +// network types are not interchangeable. The type of listener returned is switched +// on the network type. Stream-based networks ("tcp", "unix", "unixpacket", etc.) +// return a net.Listener; datagram-based networks ("udp", "unixgram", etc.) return +// a net.PacketConn; and so forth. The actual concrete types are not guaranteed to +// be standard, exported types (wrapping is necessary to provide graceful reloads). +// +// Unix sockets will be unlinked before being created, to ensure we can bind to +// it even if the previous program using it exited uncleanly; it will also be +// unlinked upon a graceful exit (or when a new config does not use that socket). +// +// TODO: Experimental API: subject to change or removal. +func (na NetworkAddress) Listen(ctx context.Context, portOffset uint, config net.ListenConfig) (any, error) { + if na.IsUnixNetwork() { + unixSocketsMu.Lock() + defer unixSocketsMu.Unlock() } - ctx, cancel := context.WithCancel(context.Background()) - return &fakeCloseQuicListener{ - sharedQuicListener: sharedEl.(*sharedQuicListener), - context: ctx, - contextCancel: cancel, - }, nil -} + // check to see if plugin provides listener + if ln, err := getListenerFromPlugin(ctx, na.Network, na.JoinHostPort(portOffset), config); ln != nil || err != nil { + return ln, err + } -// ListenerUsage returns the current usage count of the given listener address. -func ListenerUsage(network, addr string) int { - count, _ := listenerPool.References(listenerKey(network, addr)) - return count + // create (or reuse) the listener ourselves + return na.listen(ctx, portOffset, config) } -func listenerKey(network, addr string) string { - return network + "/" + addr -} +func (na NetworkAddress) listen(ctx context.Context, portOffset uint, config net.ListenConfig) (any, error) { + var ln any + var err error -type fakeCloseQuicListener struct { - closed int32 // accessed atomically; belongs to this struct only - *sharedQuicListener // embedded, so we also become a quic.EarlyListener - context context.Context - contextCancel context.CancelFunc -} + address := na.JoinHostPort(portOffset) -// Currently Accept ignores the passed context, however a situation where -// someone would need a hotswappable QUIC-only (not http3, since it uses context.Background here) -// server on which Accept would be called with non-empty contexts -// (mind that the default net listeners' Accept doesn't take a context argument) -// sounds way too rare for us to sacrifice efficiency here. -func (fcql *fakeCloseQuicListener) Accept(_ context.Context) (quic.EarlyConnection, error) { - conn, err := fcql.sharedQuicListener.Accept(fcql.context) - if err == nil { - return conn, nil + // if this is a unix socket, see if we already have it open + if socket, err := reuseUnixSocket(na.Network, address); socket != nil || err != nil { + return socket, err } - // if the listener is "closed", return a fake closed error instead - if atomic.LoadInt32(&fcql.closed) == 1 && errors.Is(err, context.Canceled) { - return nil, fakeClosedErr(fcql) - } - return nil, err -} + lnKey := listenerKey(na.Network, address) -func (fcql *fakeCloseQuicListener) Close() error { - if atomic.CompareAndSwapInt32(&fcql.closed, 0, 1) { - fcql.contextCancel() - _, _ = listenerPool.Delete(fcql.sharedQuicListener.key) + switch na.Network { + case "tcp", "tcp4", "tcp6", "unix", "unixpacket": + ln, err = listenTCPOrUnix(ctx, lnKey, na.Network, address, config) + case "unixgram": + ln, err = config.ListenPacket(ctx, na.Network, address) + case "udp", "udp4", "udp6": + sharedPc, _, err := listenerPool.LoadOrNew(lnKey, func() (Destructor, error) { + pc, err := config.ListenPacket(ctx, na.Network, address) + if err != nil { + return nil, err + } + return &sharedPacketConn{PacketConn: pc, key: lnKey}, nil + }) + if err != nil { + return nil, err + } + ln = &fakeClosePacketConn{sharedPacketConn: sharedPc.(*sharedPacketConn)} } - return nil -} - -// fakeClosedErr returns an error value that is not temporary -// nor a timeout, suitable for making the caller think the -// listener is actually closed -func fakeClosedErr(l interface{ Addr() net.Addr }) error { - return &net.OpError{ - Op: "accept", - Net: l.Addr().Network(), - Addr: l.Addr(), - Err: errFakeClosed, + if strings.HasPrefix(na.Network, "ip") { + ln, err = config.ListenPacket(ctx, na.Network, address) } -} - -// ErrFakeClosed is the underlying error value returned by -// fakeCloseListener.Accept() after Close() has been called, -// indicating that it is pretending to be closed so that the -// server using it can terminate, while the underlying -// socket is actually left open. -var errFakeClosed = fmt.Errorf("listener 'closed' 😉") - -// fakeClosePacketConn is like fakeCloseListener, but for PacketConns. -type fakeClosePacketConn struct { - closed int32 // accessed atomically; belongs to this struct only - *sharedPacketConn // embedded, so we also become a net.PacketConn -} - -func (fcpc *fakeClosePacketConn) Close() error { - if atomic.CompareAndSwapInt32(&fcpc.closed, 0, 1) { - _, _ = listenerPool.Delete(fcpc.sharedPacketConn.key) + if err != nil { + return nil, err } - return nil -} - -// Supports QUIC implementation: https://github.com/caddyserver/caddy/issues/3998 -func (fcpc fakeClosePacketConn) SetReadBuffer(bytes int) error { - if conn, ok := fcpc.PacketConn.(interface{ SetReadBuffer(int) error }); ok { - return conn.SetReadBuffer(bytes) + if ln == nil { + return nil, fmt.Errorf("unsupported network type: %s", na.Network) } - return fmt.Errorf("SetReadBuffer() not implemented for %T", fcpc.PacketConn) -} -// Supports QUIC implementation: https://github.com/caddyserver/caddy/issues/3998 -func (fcpc fakeClosePacketConn) SyscallConn() (syscall.RawConn, error) { - if conn, ok := fcpc.PacketConn.(interface { - SyscallConn() (syscall.RawConn, error) - }); ok { - return conn.SyscallConn() + // if new listener is a unix socket, make sure we can reuse it later + // (we do our own "unlink on close" -- not required, but more tidy) + one := int32(1) + switch unix := ln.(type) { + case *net.UnixListener: + unix.SetUnlinkOnClose(false) + ln = &unixListener{unix, lnKey, &one} + unixSockets[lnKey] = ln.(*unixListener) + case *net.UnixConn: + ln = &unixConn{unix, address, lnKey, &one} + unixSockets[lnKey] = ln.(*unixConn) } - return nil, fmt.Errorf("SyscallConn() not implemented for %T", fcpc.PacketConn) -} - -// sharedQuicListener is like sharedListener, but for quic.EarlyListeners. -type sharedQuicListener struct { - quic.EarlyListener - key string -} - -// Destruct closes the underlying QUIC listener. -func (sql *sharedQuicListener) Destruct() error { - return sql.EarlyListener.Close() -} - -// sharedPacketConn is like sharedListener, but for net.PacketConns. -type sharedPacketConn struct { - net.PacketConn - key string -} - -// Destruct closes the underlying socket. -func (spc *sharedPacketConn) Destruct() error { - return spc.PacketConn.Close() -} -// NetworkAddress contains the individual components -// for a parsed network address of the form accepted -// by ParseNetworkAddress(). Network should be a -// network value accepted by Go's net package. Port -// ranges are given by [StartPort, EndPort]. -type NetworkAddress struct { - Network string - Host string - StartPort uint - EndPort uint + return ln, nil } // IsUnixNetwork returns true if na.Network is @@ -260,17 +217,27 @@ func (na NetworkAddress) JoinHostPort(offset uint) string { return net.JoinHostPort(na.Host, strconv.Itoa(int(na.StartPort+offset))) } +// Expand returns one NetworkAddress for each port in the port range. +// +// This is EXPERIMENTAL and subject to change or removal. func (na NetworkAddress) Expand() []NetworkAddress { size := na.PortRangeSize() addrs := make([]NetworkAddress, size) for portOffset := uint(0); portOffset < size; portOffset++ { - na2 := na - na2.StartPort, na2.EndPort = na.StartPort+portOffset, na.StartPort+portOffset - addrs[portOffset] = na2 + addrs[portOffset] = na.At(portOffset) } return addrs } +// At returns a NetworkAddress with a port range of just 1 +// at the given port offset; i.e. a NetworkAddress that +// represents precisely 1 address only. +func (na NetworkAddress) At(portOffset uint) NetworkAddress { + na2 := na + na2.StartPort, na2.EndPort = na.StartPort+portOffset, na.StartPort+portOffset + return na2 +} + // PortRangeSize returns how many ports are in // pa's port range. Port ranges are inclusive, // so the size is the difference of start and @@ -326,20 +293,6 @@ func isUnixNetwork(netw string) bool { return netw == "unix" || netw == "unixgram" || netw == "unixpacket" } -func isListenBindAddressAlreadyInUseError(err error) bool { - switch networkOperationError := err.(type) { - case *net.OpError: - switch syscallError := networkOperationError.Err.(type) { - case *os.SyscallError: - if syscallError.Syscall == "bind" { - return true - } - } - } - - return false -} - // ParseNetworkAddress parses addr into its individual // components. The input string is expected to be of // the form "network/host:port-range" where any part is @@ -439,6 +392,209 @@ func JoinNetworkAddress(network, host, port string) string { return a } +// DEPRECATED: Use NetworkAddress.Listen instead. This function will likely be changed or removed in the future. +func Listen(network, addr string) (net.Listener, error) { + // a 0 timeout means Go uses its default + return ListenTimeout(network, addr, 0) +} + +// DEPRECATED: Use NetworkAddress.Listen instead. This function will likely be changed or removed in the future. +func ListenTimeout(network, addr string, keepalivePeriod time.Duration) (net.Listener, error) { + netAddr, err := ParseNetworkAddress(JoinNetworkAddress(network, addr, "")) + if err != nil { + return nil, err + } + + ln, err := netAddr.Listen(context.TODO(), 0, net.ListenConfig{KeepAlive: keepalivePeriod}) + if err != nil { + return nil, err + } + + return ln.(net.Listener), nil +} + +// DEPRECATED: Use NetworkAddress.Listen instead. This function will likely be changed or removed in the future. +func ListenPacket(network, addr string) (net.PacketConn, error) { + netAddr, err := ParseNetworkAddress(JoinNetworkAddress(network, addr, "")) + if err != nil { + return nil, err + } + + ln, err := netAddr.Listen(context.TODO(), 0, net.ListenConfig{}) + if err != nil { + return nil, err + } + + return ln.(net.PacketConn), nil +} + +// ListenQUIC returns a quic.EarlyListener suitable for use in a Caddy module. +// The network will be transformed into a QUIC-compatible type (if unix, then +// unixgram will be used; otherwise, udp will be used). +// +// NOTE: This API is EXPERIMENTAL and may be changed or removed. +// +// TODO: See if we can find a more elegant solution closer to the new NetworkAddress.Listen API. +func ListenQUIC(ln net.PacketConn, tlsConf *tls.Config, activeRequests *int64) (quic.EarlyListener, error) { + lnKey := listenerKey(ln.LocalAddr().Network(), ln.LocalAddr().String()) + + sharedEarlyListener, _, err := listenerPool.LoadOrNew(lnKey, func() (Destructor, error) { + earlyLn, err := quic.ListenEarly(ln, http3.ConfigureTLSConfig(tlsConf), &quic.Config{ + RequireAddressValidation: func(clientAddr net.Addr) bool { + var highLoad bool + if activeRequests != nil { + highLoad = atomic.LoadInt64(activeRequests) > 1000 // TODO: make tunable? + } + return highLoad + }, + }) + if err != nil { + return nil, err + } + + return &sharedQuicListener{EarlyListener: earlyLn, key: lnKey}, nil + }) + if err != nil { + return nil, err + } + + // TODO: to serve QUIC over a unix socket, currently we need to hold onto + // the underlying net.PacketConn (which we wrap as unixConn to keep count + // of closes) because closing the quic.EarlyListener doesn't actually close + // the underlying PacketConn, but we need to for unix sockets since we dup + // the file descriptor and thus need to close the original; track issue: + // https://github.com/lucas-clemente/quic-go/issues/3560#issuecomment-1258959608 + var unix *unixConn + if uc, ok := ln.(*unixConn); ok { + unix = uc + } + + ctx, cancel := context.WithCancel(context.Background()) + return &fakeCloseQuicListener{ + sharedQuicListener: sharedEarlyListener.(*sharedQuicListener), + uc: unix, + context: ctx, + contextCancel: cancel, + }, nil +} + +// ListenerUsage returns the current usage count of the given listener address. +func ListenerUsage(network, addr string) int { + count, _ := listenerPool.References(listenerKey(network, addr)) + return count +} + +// sharedQuicListener is like sharedListener, but for quic.EarlyListeners. +type sharedQuicListener struct { + quic.EarlyListener + key string +} + +// Destruct closes the underlying QUIC listener. +func (sql *sharedQuicListener) Destruct() error { + return sql.EarlyListener.Close() +} + +// sharedPacketConn is like sharedListener, but for net.PacketConns. +type sharedPacketConn struct { + net.PacketConn + key string +} + +// Destruct closes the underlying socket. +func (spc *sharedPacketConn) Destruct() error { + return spc.PacketConn.Close() +} + +// fakeClosedErr returns an error value that is not temporary +// nor a timeout, suitable for making the caller think the +// listener is actually closed +func fakeClosedErr(l interface{ Addr() net.Addr }) error { + return &net.OpError{ + Op: "accept", + Net: l.Addr().Network(), + Addr: l.Addr(), + Err: errFakeClosed, + } +} + +// errFakeClosed is the underlying error value returned by +// fakeCloseListener.Accept() after Close() has been called, +// indicating that it is pretending to be closed so that the +// server using it can terminate, while the underlying +// socket is actually left open. +var errFakeClosed = fmt.Errorf("listener 'closed' 😉") + +// fakeClosePacketConn is like fakeCloseListener, but for PacketConns. +type fakeClosePacketConn struct { + closed int32 // accessed atomically; belongs to this struct only + *sharedPacketConn // embedded, so we also become a net.PacketConn +} + +func (fcpc *fakeClosePacketConn) Close() error { + if atomic.CompareAndSwapInt32(&fcpc.closed, 0, 1) { + _, _ = listenerPool.Delete(fcpc.sharedPacketConn.key) + } + return nil +} + +// Supports QUIC implementation: https://github.com/caddyserver/caddy/issues/3998 +func (fcpc fakeClosePacketConn) SetReadBuffer(bytes int) error { + if conn, ok := fcpc.PacketConn.(interface{ SetReadBuffer(int) error }); ok { + return conn.SetReadBuffer(bytes) + } + return fmt.Errorf("SetReadBuffer() not implemented for %T", fcpc.PacketConn) +} + +// Supports QUIC implementation: https://github.com/caddyserver/caddy/issues/3998 +func (fcpc fakeClosePacketConn) SyscallConn() (syscall.RawConn, error) { + if conn, ok := fcpc.PacketConn.(interface { + SyscallConn() (syscall.RawConn, error) + }); ok { + return conn.SyscallConn() + } + return nil, fmt.Errorf("SyscallConn() not implemented for %T", fcpc.PacketConn) +} + +type fakeCloseQuicListener struct { + closed int32 // accessed atomically; belongs to this struct only + *sharedQuicListener // embedded, so we also become a quic.EarlyListener + uc *unixConn // underlying unix socket, if UDS + context context.Context + contextCancel context.CancelFunc +} + +// Currently Accept ignores the passed context, however a situation where +// someone would need a hotswappable QUIC-only (not http3, since it uses context.Background here) +// server on which Accept would be called with non-empty contexts +// (mind that the default net listeners' Accept doesn't take a context argument) +// sounds way too rare for us to sacrifice efficiency here. +func (fcql *fakeCloseQuicListener) Accept(_ context.Context) (quic.EarlyConnection, error) { + conn, err := fcql.sharedQuicListener.Accept(fcql.context) + if err == nil { + return conn, nil + } + + // if the listener is "closed", return a fake closed error instead + if atomic.LoadInt32(&fcql.closed) == 1 && errors.Is(err, context.Canceled) { + return nil, fakeClosedErr(fcql) + } + return nil, err +} + +func (fcql *fakeCloseQuicListener) Close() error { + if atomic.CompareAndSwapInt32(&fcql.closed, 0, 1) { + fcql.contextCancel() + _, _ = listenerPool.Delete(fcql.sharedQuicListener.key) + if fcql.uc != nil { + // unix sockets need to be closed ourselves because we dup() the file + // descriptor when we reuse them, so this avoids a resource leak + fcql.uc.Close() + } + } + return nil +} + // RegisterNetwork registers a network type with Caddy so that if a listener is // created for that network type, getListener will be invoked to get the listener. // This should be called during init() and will panic if the network type is standard @@ -460,11 +616,77 @@ func RegisterNetwork(network string, getListener ListenerFunc) { networkTypes[network] = getListener } +type unixListener struct { + *net.UnixListener + mapKey string + count *int32 // accessed atomically +} + +func (uln *unixListener) Close() error { + newCount := atomic.AddInt32(uln.count, -1) + if newCount == 0 { + defer func() { + addr := uln.Addr().String() + unixSocketsMu.Lock() + delete(unixSockets, uln.mapKey) + unixSocketsMu.Unlock() + _ = syscall.Unlink(addr) + }() + } + return uln.UnixListener.Close() +} + +type unixConn struct { + *net.UnixConn + filename string + mapKey string + count *int32 // accessed atomically +} + +func (uc *unixConn) Close() error { + newCount := atomic.AddInt32(uc.count, -1) + if newCount == 0 { + defer func() { + unixSocketsMu.Lock() + delete(unixSockets, uc.mapKey) + unixSocketsMu.Unlock() + _ = syscall.Unlink(uc.filename) + }() + } + return uc.UnixConn.Close() +} + +// unixSockets keeps track of the currently-active unix sockets +// so we can transfer their FDs gracefully during reloads. +var ( + unixSockets = make(map[string]interface { + File() (*os.File, error) + }) + unixSocketsMu sync.Mutex +) + +// getListenerFromPlugin returns a listener on the given network and address +// if a plugin has registered the network name. It may return (nil, nil) if +// no plugin can provide a listener. +func getListenerFromPlugin(ctx context.Context, network, addr string, config net.ListenConfig) (any, error) { + // get listener from plugin if network type is registered + if getListener, ok := networkTypes[network]; ok { + Log().Debug("getting listener from plugin", zap.String("network", network)) + return getListener(ctx, network, addr, config) + } + + return nil, nil +} + +func listenerKey(network, addr string) string { + return network + "/" + addr +} + // ListenerFunc is a function that can return a listener given a network and address. // The listeners must be capable of overlapping: with Caddy, new configs are loaded // before old ones are unloaded, so listeners may overlap briefly if the configs // both need the same listener. EXPERIMENTAL and subject to change. -type ListenerFunc func(network, addr string) (net.Listener, error) +type ListenerFunc func(ctx context.Context, network, addr string, cfg net.ListenConfig) (any, error) var networkTypes = map[string]ListenerFunc{} -- cgit v1.2.3