/
dial.go
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/
dial.go
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package conn
import (
"fmt"
"math/rand"
"strings"
ma "github.com/ipfs/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-multiaddr"
manet "github.com/ipfs/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-multiaddr-net"
context "github.com/ipfs/go-ipfs/Godeps/_workspace/src/golang.org/x/net/context"
lgbl "github.com/ipfs/go-ipfs/util/eventlog/loggables"
ci "github.com/ipfs/go-ipfs/p2p/crypto"
addrutil "github.com/ipfs/go-ipfs/p2p/net/swarm/addr"
transport "github.com/ipfs/go-ipfs/p2p/net/transport"
peer "github.com/ipfs/go-ipfs/p2p/peer"
)
type WrapFunc func(transport.Conn) transport.Conn
func NewDialer(p peer.ID, pk ci.PrivKey, wrap WrapFunc) *Dialer {
return &Dialer{
LocalPeer: p,
PrivateKey: pk,
Wrapper: wrap,
}
}
// String returns the string rep of d.
func (d *Dialer) String() string {
return fmt.Sprintf("<Dialer %s ...>", d.LocalPeer)
}
// Dial connects to a peer over a particular address
// Ensures raddr is part of peer.Addresses()
// Example: d.DialAddr(ctx, peer.Addresses()[0], peer)
func (d *Dialer) Dial(ctx context.Context, raddr ma.Multiaddr, remote peer.ID) (Conn, error) {
logdial := lgbl.Dial("conn", d.LocalPeer, remote, nil, raddr)
logdial["encrypted"] = (d.PrivateKey != nil) // log wether this will be an encrypted dial or not.
defer log.EventBegin(ctx, "connDial", logdial).Done()
var connOut Conn
var errOut error
done := make(chan struct{})
// do it async to ensure we respect don contexteone
go func() {
defer func() {
select {
case done <- struct{}{}:
case <-ctx.Done():
}
}()
maconn, err := d.rawConnDial(ctx, raddr, remote)
if err != nil {
errOut = err
return
}
if d.Wrapper != nil {
maconn = d.Wrapper(maconn)
}
c, err := newSingleConn(ctx, d.LocalPeer, remote, maconn)
if err != nil {
maconn.Close()
errOut = err
return
}
if d.PrivateKey == nil || EncryptConnections == false {
log.Warning("dialer %s dialing INSECURELY %s at %s!", d, remote, raddr)
connOut = c
return
}
c2, err := newSecureConn(ctx, d.PrivateKey, c)
if err != nil {
errOut = err
c.Close()
return
}
connOut = c2
}()
select {
case <-ctx.Done():
logdial["error"] = ctx.Err()
logdial["dial"] = "failure"
return nil, ctx.Err()
case <-done:
// whew, finished.
}
if errOut != nil {
logdial["error"] = errOut
logdial["dial"] = "failure"
return nil, errOut
}
logdial["dial"] = "success"
return connOut, nil
}
func (d *Dialer) AddDialer(pd transport.Dialer) {
d.Dialers = append(d.Dialers, pd)
}
// returns dialer that can dial the given address
func (d *Dialer) subDialerForAddr(raddr ma.Multiaddr) transport.Dialer {
for _, pd := range d.Dialers {
if pd.Matches(raddr) {
return pd
}
}
return nil
}
// rawConnDial dials the underlying net.Conn + manet.Conns
func (d *Dialer) rawConnDial(ctx context.Context, raddr ma.Multiaddr, remote peer.ID) (transport.Conn, error) {
if strings.HasPrefix(raddr.String(), "/ip4/0.0.0.0") {
log.Event(ctx, "connDialZeroAddr", lgbl.Dial("conn", d.LocalPeer, remote, nil, raddr))
return nil, fmt.Errorf("Attempted to connect to zero address: %s", raddr)
}
sd := d.subDialerForAddr(raddr)
if sd == nil {
return nil, fmt.Errorf("no dialer for %s", raddr)
}
return sd.Dial(raddr)
}
func pickLocalAddr(laddrs []ma.Multiaddr, raddr ma.Multiaddr) (laddr ma.Multiaddr) {
if len(laddrs) < 1 {
return nil
}
// make sure that we ONLY use local addrs that match the remote addr.
laddrs = manet.AddrMatch(raddr, laddrs)
if len(laddrs) < 1 {
return nil
}
// make sure that we ONLY use local addrs that CAN dial the remote addr.
// filter out all the local addrs that aren't capable
raddrIPLayer := ma.Split(raddr)[0]
raddrIsLoopback := manet.IsIPLoopback(raddrIPLayer)
raddrIsLinkLocal := manet.IsIP6LinkLocal(raddrIPLayer)
laddrs = addrutil.FilterAddrs(laddrs, func(a ma.Multiaddr) bool {
laddrIPLayer := ma.Split(a)[0]
laddrIsLoopback := manet.IsIPLoopback(laddrIPLayer)
laddrIsLinkLocal := manet.IsIP6LinkLocal(laddrIPLayer)
if laddrIsLoopback { // our loopback addrs can only dial loopbacks.
return raddrIsLoopback
}
if laddrIsLinkLocal {
return raddrIsLinkLocal // out linklocal addrs can only dial link locals.
}
return true
})
// TODO pick with a good heuristic
// we use a random one for now to prevent bad addresses from making nodes unreachable
// with a random selection, multiple tries may work.
return laddrs[rand.Intn(len(laddrs))]
}
// MultiaddrProtocolsMatch returns whether two multiaddrs match in protocol stacks.
func MultiaddrProtocolsMatch(a, b ma.Multiaddr) bool {
ap := a.Protocols()
bp := b.Protocols()
if len(ap) != len(bp) {
return false
}
for i, api := range ap {
if api.Code != bp[i].Code {
return false
}
}
return true
}
// MultiaddrNetMatch returns the first Multiaddr found to match network.
func MultiaddrNetMatch(tgt ma.Multiaddr, srcs []ma.Multiaddr) ma.Multiaddr {
for _, a := range srcs {
if MultiaddrProtocolsMatch(tgt, a) {
return a
}
}
return nil
}