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authorMatt Holt <[email protected]>2022-09-28 13:35:51 -0600
committerGitHub <[email protected]>2022-09-28 13:35:51 -0600
commite3e8aabbcf65d37516bb97f9dc0f77df52f8cf55 (patch)
treea7f50b045ab2b526d0f1dc83f9a8adbd502f5d14 /listeners.go
parentd0556929a4a574ea67be4c1ca2a2741b0f7a52c2 (diff)
downloadcaddy-e3e8aabbcf65d37516bb97f9dc0f77df52f8cf55.tar.gz
caddy-e3e8aabbcf65d37516bb97f9dc0f77df52f8cf55.zip
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
Diffstat (limited to 'listeners.go')
-rw-r--r--listeners.go626
1 files changed, 424 insertions, 202 deletions
diff --git a/listeners.go b/listeners.go
index 6a23c61a1..aad6b691c 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{}