1
0
Fork 0
mirror of https://github.com/moby/moby.git synced 2022-11-09 12:21:53 -05:00
moby--moby/client/hijack.go
Daniel Nephin d32ffb72b7 Refactor client/request
Signed-off-by: Daniel Nephin <dnephin@docker.com>
2016-10-31 17:36:49 -04:00

177 lines
5.2 KiB
Go

package client
import (
"crypto/tls"
"errors"
"fmt"
"net"
"net/http"
"net/http/httputil"
"net/url"
"strings"
"time"
"github.com/docker/docker/api/types"
"github.com/docker/docker/pkg/tlsconfig"
"github.com/docker/go-connections/sockets"
"golang.org/x/net/context"
)
// tlsClientCon holds tls information and a dialed connection.
type tlsClientCon struct {
*tls.Conn
rawConn net.Conn
}
func (c *tlsClientCon) CloseWrite() error {
// Go standard tls.Conn doesn't provide the CloseWrite() method so we do it
// on its underlying connection.
if conn, ok := c.rawConn.(types.CloseWriter); ok {
return conn.CloseWrite()
}
return nil
}
// postHijacked sends a POST request and hijacks the connection.
func (cli *Client) postHijacked(ctx context.Context, path string, query url.Values, body interface{}, headers map[string][]string) (types.HijackedResponse, error) {
bodyEncoded, err := encodeData(body)
if err != nil {
return types.HijackedResponse{}, err
}
apiPath := cli.getAPIPath(path, query)
req, err := http.NewRequest("POST", apiPath, bodyEncoded)
if err != nil {
return types.HijackedResponse{}, err
}
req = cli.addHeaders(req, headers)
req.Host = cli.addr
req.Header.Set("Connection", "Upgrade")
req.Header.Set("Upgrade", "tcp")
conn, err := dial(cli.proto, cli.addr, resolveTLSConfig(cli.client.Transport))
if err != nil {
if strings.Contains(err.Error(), "connection refused") {
return types.HijackedResponse{}, fmt.Errorf("Cannot connect to the Docker daemon. Is 'docker daemon' running on this host?")
}
return types.HijackedResponse{}, err
}
// When we set up a TCP connection for hijack, there could be long periods
// of inactivity (a long running command with no output) that in certain
// network setups may cause ECONNTIMEOUT, leaving the client in an unknown
// state. Setting TCP KeepAlive on the socket connection will prohibit
// ECONNTIMEOUT unless the socket connection truly is broken
if tcpConn, ok := conn.(*net.TCPConn); ok {
tcpConn.SetKeepAlive(true)
tcpConn.SetKeepAlivePeriod(30 * time.Second)
}
clientconn := httputil.NewClientConn(conn, nil)
defer clientconn.Close()
// Server hijacks the connection, error 'connection closed' expected
_, err = clientconn.Do(req)
rwc, br := clientconn.Hijack()
return types.HijackedResponse{Conn: rwc, Reader: br}, err
}
func tlsDial(network, addr string, config *tls.Config) (net.Conn, error) {
return tlsDialWithDialer(new(net.Dialer), network, addr, config)
}
// We need to copy Go's implementation of tls.Dial (pkg/cryptor/tls/tls.go) in
// order to return our custom tlsClientCon struct which holds both the tls.Conn
// object _and_ its underlying raw connection. The rationale for this is that
// we need to be able to close the write end of the connection when attaching,
// which tls.Conn does not provide.
func tlsDialWithDialer(dialer *net.Dialer, network, addr string, config *tls.Config) (net.Conn, error) {
// We want the Timeout and Deadline values from dialer to cover the
// whole process: TCP connection and TLS handshake. This means that we
// also need to start our own timers now.
timeout := dialer.Timeout
if !dialer.Deadline.IsZero() {
deadlineTimeout := dialer.Deadline.Sub(time.Now())
if timeout == 0 || deadlineTimeout < timeout {
timeout = deadlineTimeout
}
}
var errChannel chan error
if timeout != 0 {
errChannel = make(chan error, 2)
time.AfterFunc(timeout, func() {
errChannel <- errors.New("")
})
}
proxyDialer, err := sockets.DialerFromEnvironment(dialer)
if err != nil {
return nil, err
}
rawConn, err := proxyDialer.Dial(network, addr)
if err != nil {
return nil, err
}
// When we set up a TCP connection for hijack, there could be long periods
// of inactivity (a long running command with no output) that in certain
// network setups may cause ECONNTIMEOUT, leaving the client in an unknown
// state. Setting TCP KeepAlive on the socket connection will prohibit
// ECONNTIMEOUT unless the socket connection truly is broken
if tcpConn, ok := rawConn.(*net.TCPConn); ok {
tcpConn.SetKeepAlive(true)
tcpConn.SetKeepAlivePeriod(30 * time.Second)
}
colonPos := strings.LastIndex(addr, ":")
if colonPos == -1 {
colonPos = len(addr)
}
hostname := addr[:colonPos]
// If no ServerName is set, infer the ServerName
// from the hostname we're connecting to.
if config.ServerName == "" {
// Make a copy to avoid polluting argument or default.
config = tlsconfig.Clone(config)
config.ServerName = hostname
}
conn := tls.Client(rawConn, config)
if timeout == 0 {
err = conn.Handshake()
} else {
go func() {
errChannel <- conn.Handshake()
}()
err = <-errChannel
}
if err != nil {
rawConn.Close()
return nil, err
}
// This is Docker difference with standard's crypto/tls package: returned a
// wrapper which holds both the TLS and raw connections.
return &tlsClientCon{conn, rawConn}, nil
}
func dial(proto, addr string, tlsConfig *tls.Config) (net.Conn, error) {
if tlsConfig != nil && proto != "unix" && proto != "npipe" {
// Notice this isn't Go standard's tls.Dial function
return tlsDial(proto, addr, tlsConfig)
}
if proto == "npipe" {
return sockets.DialPipe(addr, 32*time.Second)
}
return net.Dial(proto, addr)
}