87 lines
2.1 KiB
Go
87 lines
2.1 KiB
Go
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package core
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import (
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"errors"
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"golang.org/x/net/context"
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"log"
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"net"
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"strings"
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"time"
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)
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// XXX on failures, decide how long to wait before trying again
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// XXX limit and queue global attempts?
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// XXX circ/stream/fetch monitoring
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type OnionConnector struct {
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Network *Network
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NeverGiveUp bool
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AttemptCount int
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}
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// Attempt to connect to 'address', which must be a .onion address and port,
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// using the Network from this OnionConnector instance.
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//
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// If NeverGiveUp is set, failed connections will be retried automatically,
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// with appropriate backoff periods, and an error is only returned in fatal
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// situations. The backoff is defined by AttemptCount on the OnionConnector
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// instance -- it is not reset after Connect returns.
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//
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// If the Network is not ready, this function will wait and monitor the
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// Network's status.
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//
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// Context can be used to set a timeout, deadline, or cancel function for
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// the connection attempt.
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func (oc *OnionConnector) Connect(address string, c context.Context) (net.Conn, error) {
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if oc.Network == nil {
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return nil, errors.New("No network configured for connector")
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}
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host, _, err := net.SplitHostPort(address)
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if err != nil || !strings.HasSuffix(host, ".onion") {
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return nil, errors.New("Invalid address")
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}
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options := &net.Dialer{
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Cancel: c.Done(),
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Timeout: 0, // XXX should use timeout
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}
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for {
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// XXX This waits to know SOCKS info, but does not wait for connection
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// ready state; should it?
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proxy, err := oc.Network.WaitForProxyDialer(options, c)
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if err != nil {
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return nil, err
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}
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conn, err := proxy.Dial("tcp", address)
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if err != nil {
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if c.Err() != nil {
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return nil, c.Err()
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}
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if !oc.NeverGiveUp {
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return nil, err
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}
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log.Printf("Connection attempt to %s failed: %s", address, err)
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if err := oc.Backoff(c); err != nil {
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return nil, err
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}
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continue
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}
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return conn, nil
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}
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}
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func (oc *OnionConnector) Backoff(c context.Context) error {
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oc.AttemptCount++
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// XXX This should actually do backoff and be less dumb
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waitCtx, finish := context.WithTimeout(c, 10*time.Second)
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defer finish()
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<-waitCtx.Done()
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return c.Err()
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}
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