README
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tcpproxy
For library usage, see https://godoc.org/inet.af/tcpproxy/
For CLI usage, see https://github.com/inetaf/tcpproxy/blob/master/cmd/tlsrouter/README.md
Documentation
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Overview ¶
Package tcpproxy lets users build TCP proxies, optionally making routing decisions based on HTTP/1 Host headers and the SNI hostname in TLS connections.
Typical usage:
var p tcpproxy.Proxy
p.AddHTTPHostRoute(":80", "foo.com", tcpproxy.To("10.0.0.1:8081"))
p.AddHTTPHostRoute(":80", "bar.com", tcpproxy.To("10.0.0.2:8082"))
p.AddRoute(":80", tcpproxy.To("10.0.0.1:8081")) // fallback
p.AddSNIRoute(":443", "foo.com", tcpproxy.To("10.0.0.1:4431"))
p.AddSNIRoute(":443", "bar.com", tcpproxy.To("10.0.0.2:4432"))
p.AddRoute(":443", tcpproxy.To("10.0.0.1:4431")) // fallback
log.Fatal(p.Run())
Calling Run (or Start) on a proxy also starts all the necessary listeners.
For each accepted connection, the rules for that ipPort are matched, in order. If one matches (currently HTTP Host, SNI, or always), then the connection is handed to the target.
The two predefined Target implementations are:
1) DialProxy, proxying to another address (use the To func to return a DialProxy value),
2) TargetListener, making the matched connection available via a net.Listener.Accept call.
But Target is an interface, so you can also write your own.
Note that tcpproxy does not do any TLS encryption or decryption. It only (via DialProxy) copies bytes around. The SNI hostname in the TLS header is unencrypted, for better or worse.
This package makes no API stability promises. If you depend on it, vendor it.
Index ¶
- func UnderlyingConn(c net.Conn) net.Conn
- type Conn
- type DialProxy
- type Matcher
- type Proxy
- func (p *Proxy) AddHTTPHostMatchRoute(ipPort string, match Matcher, dest Target)
- func (p *Proxy) AddHTTPHostRoute(ipPort, httpHost string, dest Target)
- func (p *Proxy) AddRoute(ipPort string, dest Target)
- func (p *Proxy) AddSNIMatchRoute(ipPort string, matcher Matcher, dest Target)
- func (p *Proxy) AddSNIRoute(ipPort, sni string, dest Target)
- func (p *Proxy) AddSNIRouteFunc(ipPort string, fn SNITargetFunc)
- func (p *Proxy) Close() error
- func (p *Proxy) Run() error
- func (p *Proxy) Start() error
- func (p *Proxy) Wait() error
- type SNITargetFunc
- type Target
- type TargetListener
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
Types ¶
type Conn ¶
type Conn struct {
// HostName is the hostname field that was sent to the request router.
// In the case of TLS, this is the SNI header, in the case of HTTPHost
// route, it will be the host header. In the case of a fixed
// route, i.e. those created with AddRoute(), this will always be
// empty. This can be useful in the case where further routing decisions
// need to be made in the Target impementation.
HostName string
// Peeked are the bytes that have been read from Conn for the
// purposes of route matching, but have not yet been consumed
// by Read calls. It set to nil by Read when fully consumed.
Peeked []byte
// Conn is the underlying connection.
// It can be type asserted against *net.TCPConn or other types
// as needed. It should not be read from directly unless
// Peeked is nil.
net.Conn
}
Conn is an incoming connection that has had some bytes read from it to determine how to route the connection. The Read method stitches the peeked bytes and unread bytes back together.
type DialProxy ¶
type DialProxy struct {
// Addr is the TCP address to proxy to.
Addr string
// KeepAlivePeriod sets the period between TCP keep alives.
// If zero, a default is used. To disable, use a negative number.
// The keep-alive is used for both the client connection and
KeepAlivePeriod time.Duration
// DialTimeout optionally specifies a dial timeout.
// If zero, a default is used.
// If negative, the timeout is disabled.
DialTimeout time.Duration
// DialContext optionally specifies an alternate dial function
// for TCP targets. If nil, the standard
// net.Dialer.DialContext method is used.
DialContext func(ctx context.Context, network, address string) (net.Conn, error)
// OnDialError optionally specifies an alternate way to handle errors dialing Addr.
// If nil, the error is logged and src is closed.
// If non-nil, src is not closed automatically.
OnDialError func(src net.Conn, dstDialErr error)
// ProxyProtocolVersion optionally specifies the version of
// HAProxy's PROXY protocol to use. The PROXY protocol provides
// connection metadata to the DialProxy target, via a header
// inserted ahead of the client's traffic. The DialProxy target
// must explicitly support and expect the PROXY header; there is
// no graceful downgrade.
// If zero, no PROXY header is sent. Currently, version 1 is supported.
ProxyProtocolVersion int
}
DialProxy implements Target by dialing a new connection to Addr and then proxying data back and forth.
The To func is a shorthand way of creating a DialProxy.
func To ¶
To is shorthand way of writing &tcpproxy.DialProxy{Addr: addr}.
type Matcher ¶
Matcher reports whether hostname matches the Matcher's criteria.
type Proxy ¶
type Proxy struct {
// ListenFunc optionally specifies an alternate listen
// function. If nil, net.Dial is used.
// The provided net is always "tcp".
ListenFunc func(net, laddr string) (net.Listener, error)
// contains filtered or unexported fields
}
Proxy is a proxy. Its zero value is a valid proxy that does nothing. Call methods to add routes before calling Start or Run.
The order that routes are added in matters; each is matched in the order registered.
func (*Proxy) AddHTTPHostMatchRoute ¶
AddHTTPHostMatchRoute appends a route to the ipPort listener that routes to dest if the incoming HTTP/1.x Host header name is accepted by matcher. If it doesn't match, rule processing continues for any additional routes on ipPort.
The ipPort is any valid net.Listen TCP address.
func (*Proxy) AddHTTPHostRoute ¶
AddHTTPHostRoute appends a route to the ipPort listener that routes to dest if the incoming HTTP/1.x Host header name is httpHost. If it doesn't match, rule processing continues for any additional routes on ipPort.
The ipPort is any valid net.Listen TCP address.
func (*Proxy) AddRoute ¶
AddRoute appends an always-matching route to the ipPort listener, directing any connection to dest.
This is generally used as either the only rule (for simple TCP proxies), or as the final fallback rule for an ipPort.
The ipPort is any valid net.Listen TCP address.
func (*Proxy) AddSNIMatchRoute ¶
AddSNIMatchRoute appends a route to the ipPort listener that routes to dest if the incoming TLS SNI server name is accepted by matcher. If it doesn't match, rule processing continues for any additional routes on ipPort.
The ipPort is any valid net.Listen TCP address.
func (*Proxy) AddSNIRoute ¶
AddSNIRoute appends a route to the ipPort listener that routes to dest if the incoming TLS SNI server name is sni. If it doesn't match, rule processing continues for any additional routes on ipPort.
The ipPort is any valid net.Listen TCP address.
func (*Proxy) AddSNIRouteFunc ¶
func (p *Proxy) AddSNIRouteFunc(ipPort string, fn SNITargetFunc)
AddSNIRouteFunc adds a route to ipPort that matches an SNI request and calls fn to map its nap to a target.
func (*Proxy) Close ¶
Close closes all the proxy's self-opened listeners.
func (*Proxy) Run ¶
Run is calls Start, and then Wait.
It blocks until there's an error. The return value is always non-nil.
func (*Proxy) Start ¶
Start creates a TCP listener for each unique ipPort from the previously created routes and starts the proxy. It returns any error from starting listeners.
If it returns a non-nil error, any successfully opened listeners are closed.
type SNITargetFunc ¶
SNITargetFunc is the func callback used by Proxy.AddSNIRouteFunc.
type Target ¶
type Target interface {
// HandleConn is called when an incoming connection is
// matched. After the call to HandleConn, the tcpproxy
// package never touches the conn again. Implementations are
// responsible for closing the connection when needed.
//
// The concrete type of conn will be of type *Conn if any
// bytes have been consumed for the purposes of route
// matching.
HandleConn(net.Conn)
}
Target is what an incoming matched connection is sent to.
type TargetListener ¶
type TargetListener struct {
Address string // Address is the string reported by TargetListener.Addr().String().
// contains filtered or unexported fields
}
TargetListener implements both net.Listener and Target. Matched Targets become accepted connections.
func (*TargetListener) Accept ¶
func (tl *TargetListener) Accept() (net.Conn, error)
Accept implements the Accept method in the net.Listener interface.
func (*TargetListener) Addr ¶
func (tl *TargetListener) Addr() net.Addr
Addr returns the listener's Address field as a net.Addr.
func (*TargetListener) Close ¶
func (tl *TargetListener) Close() error
Close stops listening for new connections. All new connections routed to this listener will be closed. Already accepted connections are not closed.
func (*TargetListener) HandleConn ¶
func (tl *TargetListener) HandleConn(c net.Conn)
HandleConn implements the Target interface. It blocks until tl is closed or another goroutine has called Accept and received c.
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