khenaidoo | 59ce9dd | 2019-11-11 13:05:32 -0500 | [diff] [blame] | 1 | // Copyright 2015 The etcd Authors |
| 2 | // |
| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | // you may not use this file except in compliance with the License. |
| 5 | // You may obtain a copy of the License at |
| 6 | // |
| 7 | // http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | // |
| 9 | // Unless required by applicable law or agreed to in writing, software |
| 10 | // distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | // See the License for the specific language governing permissions and |
| 13 | // limitations under the License. |
| 14 | |
| 15 | package transport |
| 16 | |
| 17 | import ( |
| 18 | "crypto/tls" |
| 19 | "fmt" |
| 20 | "net" |
| 21 | "time" |
| 22 | ) |
| 23 | |
| 24 | type keepAliveConn interface { |
| 25 | SetKeepAlive(bool) error |
| 26 | SetKeepAlivePeriod(d time.Duration) error |
| 27 | } |
| 28 | |
| 29 | // NewKeepAliveListener returns a listener that listens on the given address. |
| 30 | // Be careful when wrap around KeepAliveListener with another Listener if TLSInfo is not nil. |
| 31 | // Some pkgs (like go/http) might expect Listener to return TLSConn type to start TLS handshake. |
| 32 | // http://tldp.org/HOWTO/TCP-Keepalive-HOWTO/overview.html |
| 33 | func NewKeepAliveListener(l net.Listener, scheme string, tlscfg *tls.Config) (net.Listener, error) { |
| 34 | if scheme == "https" { |
| 35 | if tlscfg == nil { |
| 36 | return nil, fmt.Errorf("cannot listen on TLS for given listener: KeyFile and CertFile are not presented") |
| 37 | } |
| 38 | return newTLSKeepaliveListener(l, tlscfg), nil |
| 39 | } |
| 40 | |
| 41 | return &keepaliveListener{ |
| 42 | Listener: l, |
| 43 | }, nil |
| 44 | } |
| 45 | |
| 46 | type keepaliveListener struct{ net.Listener } |
| 47 | |
| 48 | func (kln *keepaliveListener) Accept() (net.Conn, error) { |
| 49 | c, err := kln.Listener.Accept() |
| 50 | if err != nil { |
| 51 | return nil, err |
| 52 | } |
| 53 | kac := c.(keepAliveConn) |
| 54 | // detection time: tcp_keepalive_time + tcp_keepalive_probes + tcp_keepalive_intvl |
| 55 | // default on linux: 30 + 8 * 30 |
| 56 | // default on osx: 30 + 8 * 75 |
| 57 | kac.SetKeepAlive(true) |
| 58 | kac.SetKeepAlivePeriod(30 * time.Second) |
| 59 | return c, nil |
| 60 | } |
| 61 | |
| 62 | // A tlsKeepaliveListener implements a network listener (net.Listener) for TLS connections. |
| 63 | type tlsKeepaliveListener struct { |
| 64 | net.Listener |
| 65 | config *tls.Config |
| 66 | } |
| 67 | |
| 68 | // Accept waits for and returns the next incoming TLS connection. |
| 69 | // The returned connection c is a *tls.Conn. |
| 70 | func (l *tlsKeepaliveListener) Accept() (c net.Conn, err error) { |
| 71 | c, err = l.Listener.Accept() |
| 72 | if err != nil { |
| 73 | return |
| 74 | } |
| 75 | kac := c.(keepAliveConn) |
| 76 | // detection time: tcp_keepalive_time + tcp_keepalive_probes + tcp_keepalive_intvl |
| 77 | // default on linux: 30 + 8 * 30 |
| 78 | // default on osx: 30 + 8 * 75 |
| 79 | kac.SetKeepAlive(true) |
| 80 | kac.SetKeepAlivePeriod(30 * time.Second) |
| 81 | c = tls.Server(c, l.config) |
| 82 | return c, nil |
| 83 | } |
| 84 | |
| 85 | // NewListener creates a Listener which accepts connections from an inner |
| 86 | // Listener and wraps each connection with Server. |
| 87 | // The configuration config must be non-nil and must have |
| 88 | // at least one certificate. |
| 89 | func newTLSKeepaliveListener(inner net.Listener, config *tls.Config) net.Listener { |
| 90 | l := &tlsKeepaliveListener{} |
| 91 | l.Listener = inner |
| 92 | l.config = config |
| 93 | return l |
| 94 | } |