116 lines
3.5 KiB
Go
116 lines
3.5 KiB
Go
package proxy
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import (
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"context"
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"fmt"
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"net"
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"sync/atomic"
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"github.com/hashicorp/boundary/internal/errors"
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"google.golang.org/protobuf/proto"
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)
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// GetEndpointDialer returns a ProxyDialer which, when Dial() is called
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// returns a net.Conn which reaches the provided endpoint.
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var GetEndpointDialer = directDialer
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// directDialer returns a ProxyDialer which tcp dials directly to the provided
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// endpoint.
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func directDialer(ctx context.Context, endpoint string, _ string, _ proto.Message, _ interface{}) (*ProxyDialer, error) {
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const op = "proxy.directDialer"
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if len(endpoint) == 0 {
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return nil, errors.New(ctx, errors.InvalidParameter, op, "endpoint is empty")
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}
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d, err := NewProxyDialer(ctx, func(opt ...Option) (net.Conn, error) {
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remoteConn, err := net.Dial("tcp", endpoint)
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if err != nil {
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return nil, errors.Wrap(ctx, err, op)
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}
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opts := GetOpts(opt...)
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if opts.WithPostConnectionHook != nil {
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opts.WithPostConnectionHook(remoteConn)
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}
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return remoteConn, nil
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})
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if err != nil {
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return nil, errors.Wrap(ctx, err, op)
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}
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return d, nil
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}
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// proxyAddr is a net.Addr with IP and port information for the endpoint being
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// proxied to.
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type proxyAddr struct {
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ip string
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port uint32
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}
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// Ip returns the ip address of the dialed endpoint
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func (p *proxyAddr) Ip() string {
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return p.ip
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}
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// Port returns the tcp port of the endpoint connected to
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func (p *proxyAddr) Port() uint32 {
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return p.port
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}
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// ProxyDialer dials downstream to eventually get to the target host.
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type ProxyDialer struct {
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dialFn func(...Option) (net.Conn, error)
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latestAddr atomic.Pointer[proxyAddr]
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}
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// Returns a new proxy dialer using the provided function to get the net.Conn.
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func NewProxyDialer(ctx context.Context, df func(...Option) (net.Conn, error)) (*ProxyDialer, error) {
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const op = "proxy.NewProxyDialer"
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if df == nil {
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return nil, errors.New(ctx, errors.InvalidParameter, op, "dialing function is nil")
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}
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return &ProxyDialer{
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dialFn: df,
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}, nil
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}
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// LastConnectionAddr returns the net.Addr of the last non nil net.Conn
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// returned from the Dial() call. Nil is returned if a non nil net.Conn has
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// never been returned from Dial().
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func (d *ProxyDialer) LastConnectionAddr() *proxyAddr {
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return d.latestAddr.Load()
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}
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// portAndIpGetter allows a dialing function to return a connection that can
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// provide it's ip address and port through the GetIp and GetPort methods
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// instead of providing directly a *net.TCPConn. This might be helpful if the
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// net.Conn embeds a protobuf message with Ip and Port fields for example.
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type portAndIpGetter interface {
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GetIp() string
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GetPort() uint32
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}
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// Dial uses the provided dial function to get a net.Conn and record its
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// net.Addr information. The returned net.Addr should contain the information
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// for the endpoint that is being proxied to.
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// All provided options (for example WithPostConnectionHook) are passed into the
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// dial function associated with this ProxyDialer.
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func (d *ProxyDialer) Dial(ctx context.Context, opt ...Option) (net.Conn, error) {
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const op = "proxy.(*ProxyDialer).Dial"
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c, err := d.dialFn(opt...)
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if err != nil {
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return nil, err
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}
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switch v := c.(type) {
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case *net.TCPConn:
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addr := v.RemoteAddr().(*net.TCPAddr)
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ip := addr.IP.String()
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port := uint32(addr.Port)
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d.latestAddr.Store(&proxyAddr{ip: ip, port: port})
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case portAndIpGetter:
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d.latestAddr.Store(&proxyAddr{ip: v.GetIp(), port: v.GetPort()})
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default:
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c.Close()
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return nil, errors.New(ctx, errors.Internal, op, fmt.Sprintf("connection type unexpected %T", v))
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}
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return c, nil
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}
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