mirror of
https://github.com/tailscale/tailscale.git
synced 2024-11-29 21:15:39 +00:00
2968 lines
82 KiB
Go
2968 lines
82 KiB
Go
// Copyright (c) 2019 Tailscale Inc & AUTHORS All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// Package magicsock implements a socket that can change its communication path while
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// in use, actively searching for the best way to communicate.
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package magicsock
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import (
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"bufio"
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"context"
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crand "crypto/rand"
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"encoding/binary"
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"errors"
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"fmt"
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"hash/fnv"
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"math/rand"
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"net"
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"os"
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"reflect"
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"sort"
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"strconv"
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"strings"
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"sync"
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"sync/atomic"
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"syscall"
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"time"
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"github.com/golang/groupcache/lru"
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"github.com/tailscale/wireguard-go/conn"
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"github.com/tailscale/wireguard-go/device"
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"github.com/tailscale/wireguard-go/wgcfg"
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"go4.org/mem"
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"golang.org/x/crypto/nacl/box"
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"golang.org/x/time/rate"
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"inet.af/netaddr"
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"tailscale.com/control/controlclient"
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"tailscale.com/derp"
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"tailscale.com/derp/derphttp"
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"tailscale.com/disco"
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"tailscale.com/ipn/ipnstate"
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"tailscale.com/net/dnscache"
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"tailscale.com/net/interfaces"
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"tailscale.com/net/netcheck"
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"tailscale.com/net/netns"
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"tailscale.com/net/stun"
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"tailscale.com/syncs"
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"tailscale.com/tailcfg"
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"tailscale.com/types/key"
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"tailscale.com/types/logger"
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"tailscale.com/types/opt"
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"tailscale.com/types/structs"
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"tailscale.com/version"
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)
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// A Conn routes UDP packets and actively manages a list of its endpoints.
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// It implements wireguard/conn.Bind.
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type Conn struct {
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pconnPort uint16 // the preferred port from opts.Port; 0 means auto
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pconn4 *RebindingUDPConn
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pconn6 *RebindingUDPConn // non-nil if IPv6 available
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epFunc func(endpoints []string)
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logf logger.Logf
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sendLogLimit *rate.Limiter
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netChecker *netcheck.Client
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idleFunc func() time.Duration // nil means unknown
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// bufferedIPv4From and bufferedIPv4Packet are owned by
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// ReceiveIPv4, and used when both a DERP and IPv4 packet arrive
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// at the same time. It stores the IPv4 packet for use in the next call.
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bufferedIPv4From netaddr.IPPort // if non-zero, then bufferedIPv4Packet is valid
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bufferedIPv4Packet []byte // the received packet (reused, owned by ReceiveIPv4)
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connCtx context.Context // closed on Conn.Close
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connCtxCancel func() // closes connCtx
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// stunReceiveFunc holds the current STUN packet processing func.
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// Its Loaded value is always non-nil.
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stunReceiveFunc atomic.Value // of func(p []byte, fromAddr *net.UDPAddr)
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udpRecvCh chan udpReadResult
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derpRecvCh chan derpReadResult
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// ============================================================
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mu sync.Mutex // guards all following fields
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started bool // Start was called
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closed bool // Close was called
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endpointsUpdateWaiter *sync.Cond
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endpointsUpdateActive bool
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wantEndpointsUpdate string // true if non-empty; string is reason
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lastEndpoints []string
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peerSet map[key.Public]struct{}
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discoPrivate key.Private
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discoPublic tailcfg.DiscoKey // public of discoPrivate
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discoShort string // ShortString of discoPublic (to save logging work later)
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nodeOfDisco map[tailcfg.DiscoKey]*tailcfg.Node
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discoOfNode map[tailcfg.NodeKey]tailcfg.DiscoKey
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discoOfAddr map[netaddr.IPPort]tailcfg.DiscoKey // validated non-DERP paths only
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endpointOfDisco map[tailcfg.DiscoKey]*discoEndpoint
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sharedDiscoKey map[tailcfg.DiscoKey]*[32]byte // nacl/box precomputed key
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// addrsByUDP is a map of every remote ip:port to a priority
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// list of endpoint addresses for a peer.
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// The priority list is provided by wgengine configuration.
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//
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// Given a wgcfg describing:
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// machineA: 10.0.0.1:1, 10.0.0.2:2
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// machineB: 10.0.0.3:3
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// the addrsByUDP map contains:
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// 10.0.0.1:1 -> [10.0.0.1:1, 10.0.0.2:2]
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// 10.0.0.2:2 -> [10.0.0.1:1, 10.0.0.2:2]
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// 10.0.0.3:3 -> [10.0.0.3:3]
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addrsByUDP map[netaddr.IPPort]*AddrSet
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// addrsByKey maps from public keys (as seen by incoming DERP
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// packets) to its AddrSet (the same values as in addrsByUDP).
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addrsByKey map[key.Public]*AddrSet
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netInfoFunc func(*tailcfg.NetInfo) // nil until set
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netInfoLast *tailcfg.NetInfo
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derpMap *tailcfg.DERPMap // nil (or zero regions/nodes) means DERP is disabled
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netMap *controlclient.NetworkMap
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privateKey key.Private
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myDerp int // nearest DERP region ID; 0 means none/unknown
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derpStarted chan struct{} // closed on first connection to DERP; for tests
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activeDerp map[int]activeDerp // DERP regionID -> connection to a node in that region
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prevDerp map[int]*syncs.WaitGroupChan
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// derpRoute contains optional alternate routes to use as an
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// optimization instead of contacting a peer via their home
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// DERP connection. If they sent us a message on a different
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// DERP connection (which should really only be on our DERP
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// home connection, or what was once our home), then we
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// remember that route here to optimistically use instead of
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// creating a new DERP connection back to their home.
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derpRoute map[key.Public]derpRoute
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// peerLastDerp tracks which DERP node we last used to speak with a
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// peer. It's only used to quiet logging, so we only log on change.
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peerLastDerp map[key.Public]int
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// noV4 and noV6 are whether IPv4 and IPv6 are known to be
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// missing. They're only used to suppress log spam. The name
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// is named negatively because in early start-up, we don't yet
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// necessarily have a netcheck.Report and don't want to skip
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// logging.
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noV4, noV6 syncs.AtomicBool
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}
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// derpRoute is a route entry for a public key, saying that a certain
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// peer should be available at DERP node derpID, as long as the
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// current connection for that derpID is dc. (but dc should not be
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// used to write directly; it's owned by the read/write loops)
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type derpRoute struct {
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derpID int
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dc *derphttp.Client // don't use directly; see comment above
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}
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// removeDerpPeerRoute removes a DERP route entry previously added by addDerpPeerRoute.
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func (c *Conn) removeDerpPeerRoute(peer key.Public, derpID int, dc *derphttp.Client) {
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c.mu.Lock()
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defer c.mu.Unlock()
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r2 := derpRoute{derpID, dc}
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if r, ok := c.derpRoute[peer]; ok && r == r2 {
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delete(c.derpRoute, peer)
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}
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}
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// addDerpPeerRoute adds a DERP route entry, noting that peer was seen
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// on DERP node derpID, at least on the connection identified by dc.
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// See issue 150 for details.
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func (c *Conn) addDerpPeerRoute(peer key.Public, derpID int, dc *derphttp.Client) {
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c.mu.Lock()
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defer c.mu.Unlock()
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if c.derpRoute == nil {
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c.derpRoute = make(map[key.Public]derpRoute)
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}
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r := derpRoute{derpID, dc}
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c.derpRoute[peer] = r
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}
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// DerpMagicIP is a fake WireGuard endpoint IP address that means
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// to use DERP. When used, the port number of the WireGuard endpoint
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// is the DERP server number to use.
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//
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// Mnemonic: 3.3.40 are numbers above the keys D, E, R, P.
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const DerpMagicIP = "127.3.3.40"
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var derpMagicIP = net.ParseIP(DerpMagicIP).To4()
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var derpMagicIPAddr = netaddr.IPv4(127, 3, 3, 40)
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// activeDerp contains fields for an active DERP connection.
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type activeDerp struct {
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c *derphttp.Client
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cancel context.CancelFunc
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writeCh chan<- derpWriteRequest
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// lastWrite is the time of the last request for its write
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// channel (currently even if there was no write).
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// It is always non-nil and initialized to a non-zero Time[
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lastWrite *time.Time
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createTime time.Time
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}
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// DefaultPort is the default port to listen on.
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// The current default (zero) means to auto-select a random free port.
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const DefaultPort = 0
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var DisableSTUNForTesting bool
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// Options contains options for Listen.
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type Options struct {
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// Logf optionally provides a log function to use.
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// Must not be nil.
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Logf logger.Logf
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// Port is the port to listen on.
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// Zero means to pick one automatically.
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Port uint16
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// EndpointsFunc optionally provides a func to be called when
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// endpoints change. The called func does not own the slice.
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EndpointsFunc func(endpoint []string)
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// IdleFunc optionally provides a func to return how long
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// it's been since a TUN packet was sent or received.
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IdleFunc func() time.Duration
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}
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func (o *Options) logf() logger.Logf {
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if o.Logf == nil {
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panic("must provide magicsock.Options.logf")
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}
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return o.Logf
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}
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func (o *Options) endpointsFunc() func([]string) {
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if o == nil || o.EndpointsFunc == nil {
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return func([]string) {}
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}
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return o.EndpointsFunc
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}
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// newConn is the error-free, network-listening-side-effect-free based
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// of NewConn. Mostly for tests.
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func newConn() *Conn {
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c := &Conn{
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sendLogLimit: rate.NewLimiter(rate.Every(1*time.Minute), 1),
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addrsByUDP: make(map[netaddr.IPPort]*AddrSet),
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addrsByKey: make(map[key.Public]*AddrSet),
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derpRecvCh: make(chan derpReadResult),
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udpRecvCh: make(chan udpReadResult),
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derpStarted: make(chan struct{}),
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peerLastDerp: make(map[key.Public]int),
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endpointOfDisco: make(map[tailcfg.DiscoKey]*discoEndpoint),
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sharedDiscoKey: make(map[tailcfg.DiscoKey]*[32]byte),
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discoOfAddr: make(map[netaddr.IPPort]tailcfg.DiscoKey),
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}
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c.endpointsUpdateWaiter = sync.NewCond(&c.mu)
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return c
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}
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// NewConn creates a magic Conn listening on opts.Port.
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// As the set of possible endpoints for a Conn changes, the
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// callback opts.EndpointsFunc is called.
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//
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// It doesn't start doing anything until Start is called.
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func NewConn(opts Options) (*Conn, error) {
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c := newConn()
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c.pconnPort = opts.Port
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c.logf = opts.logf()
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c.epFunc = opts.endpointsFunc()
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c.idleFunc = opts.IdleFunc
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if err := c.initialBind(); err != nil {
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return nil, err
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}
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c.connCtx, c.connCtxCancel = context.WithCancel(context.Background())
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c.netChecker = &netcheck.Client{
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Logf: logger.WithPrefix(c.logf, "netcheck: "),
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GetSTUNConn4: func() netcheck.STUNConn { return c.pconn4 },
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}
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if c.pconn6 != nil {
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c.netChecker.GetSTUNConn6 = func() netcheck.STUNConn { return c.pconn6 }
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}
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c.ignoreSTUNPackets()
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return c, nil
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}
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func (c *Conn) Start() {
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c.mu.Lock()
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if c.started {
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panic("duplicate Start call")
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}
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c.started = true
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c.mu.Unlock()
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c.ReSTUN("initial")
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// We assume that LinkChange notifications are plumbed through well
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// on our mobile clients, so don't do the timer thing to save radio/battery/CPU/etc.
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if !version.IsMobile() {
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go c.periodicReSTUN()
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}
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go c.periodicDerpCleanup()
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}
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func (c *Conn) donec() <-chan struct{} { return c.connCtx.Done() }
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// ignoreSTUNPackets sets a STUN packet processing func that does nothing.
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func (c *Conn) ignoreSTUNPackets() {
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c.stunReceiveFunc.Store(func([]byte, netaddr.IPPort) {})
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}
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// c.mu must NOT be held.
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func (c *Conn) updateEndpoints(why string) {
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defer func() {
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c.mu.Lock()
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defer c.mu.Unlock()
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why := c.wantEndpointsUpdate
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c.wantEndpointsUpdate = ""
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if why != "" && !c.closed {
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go c.updateEndpoints(why)
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} else {
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c.endpointsUpdateActive = false
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c.endpointsUpdateWaiter.Broadcast()
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}
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}()
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c.logf("magicsock: starting endpoint update (%s)", why)
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endpoints, reasons, err := c.determineEndpoints(c.connCtx)
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if err != nil {
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c.logf("magicsock: endpoint update (%s) failed: %v", why, err)
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// TODO(crawshaw): are there any conditions under which
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// we should trigger a retry based on the error here?
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return
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}
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if c.setEndpoints(endpoints) {
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c.logEndpointChange(endpoints, reasons)
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c.epFunc(endpoints)
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}
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}
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// setEndpoints records the new endpoints, reporting whether they're changed.
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// It takes ownership of the slice.
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func (c *Conn) setEndpoints(endpoints []string) (changed bool) {
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c.mu.Lock()
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defer c.mu.Unlock()
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if stringsEqual(endpoints, c.lastEndpoints) {
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return false
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}
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c.lastEndpoints = endpoints
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return true
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}
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func (c *Conn) updateNetInfo(ctx context.Context) (*netcheck.Report, error) {
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c.mu.Lock()
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dm := c.derpMap
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c.mu.Unlock()
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if DisableSTUNForTesting || dm == nil {
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return new(netcheck.Report), nil
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}
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ctx, cancel := context.WithTimeout(ctx, 2*time.Second)
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defer cancel()
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c.stunReceiveFunc.Store(c.netChecker.ReceiveSTUNPacket)
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defer c.ignoreSTUNPackets()
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report, err := c.netChecker.GetReport(ctx, dm)
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if err != nil {
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return nil, err
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}
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c.noV4.Set(!report.IPv4)
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c.noV6.Set(!report.IPv6)
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ni := &tailcfg.NetInfo{
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DERPLatency: map[string]float64{},
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MappingVariesByDestIP: report.MappingVariesByDestIP,
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HairPinning: report.HairPinning,
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}
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for rid, d := range report.RegionV4Latency {
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ni.DERPLatency[fmt.Sprintf("%d-v4", rid)] = d.Seconds()
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}
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for rid, d := range report.RegionV6Latency {
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ni.DERPLatency[fmt.Sprintf("%d-v6", rid)] = d.Seconds()
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}
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ni.WorkingIPv6.Set(report.IPv6)
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ni.WorkingUDP.Set(report.UDP)
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ni.PreferredDERP = report.PreferredDERP
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if ni.PreferredDERP == 0 {
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// Perhaps UDP is blocked. Pick a deterministic but arbitrary
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// one.
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ni.PreferredDERP = c.pickDERPFallback()
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}
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if !c.setNearestDERP(ni.PreferredDERP) {
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ni.PreferredDERP = 0
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}
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// TODO: set link type
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c.callNetInfoCallback(ni)
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return report, nil
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}
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var processStartUnixNano = time.Now().UnixNano()
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// pickDERPFallback returns a non-zero but deterministic DERP node to
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// connect to. This is only used if netcheck couldn't find the
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// nearest one (for instance, if UDP is blocked and thus STUN latency
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// checks aren't working).
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//
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// c.mu must NOT be held.
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func (c *Conn) pickDERPFallback() int {
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c.mu.Lock()
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defer c.mu.Unlock()
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if !c.wantDerpLocked() {
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return 0
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}
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ids := c.derpMap.RegionIDs()
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if len(ids) == 0 {
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// No DERP regions in non-nil map.
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return 0
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}
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// See where our peers are.
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var (
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peersOnDerp = map[int]int{}
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best int
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bestCount int
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)
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for _, as := range c.addrsByKey {
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if id := as.derpID(); id != 0 {
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peersOnDerp[id]++
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if v := peersOnDerp[id]; v > bestCount {
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bestCount = v
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best = id
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}
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}
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}
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// If we already had selected something in the past and it has
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// any peers, stay on it. If there are no peers, though, also
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// stay where we are.
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if c.myDerp != 0 && (best == 0 || peersOnDerp[c.myDerp] != 0) {
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return c.myDerp
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}
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// Otherwise pick wherever the most peers are.
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if best != 0 {
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return best
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}
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// Otherwise just pick something randomly.
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h := fnv.New64()
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h.Write([]byte(fmt.Sprintf("%p/%d", c, processStartUnixNano))) // arbitrary
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return ids[rand.New(rand.NewSource(int64(h.Sum64()))).Intn(len(ids))]
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}
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// callNetInfoCallback calls the NetInfo callback (if previously
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// registered with SetNetInfoCallback) if ni has substantially changed
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// since the last state.
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//
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// callNetInfoCallback takes ownership of ni.
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//
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// c.mu must NOT be held.
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func (c *Conn) callNetInfoCallback(ni *tailcfg.NetInfo) {
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c.mu.Lock()
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defer c.mu.Unlock()
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if ni.BasicallyEqual(c.netInfoLast) {
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return
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}
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c.netInfoLast = ni
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if c.netInfoFunc != nil {
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c.logf("magicsock: netInfo update: %+v", ni)
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go c.netInfoFunc(ni)
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}
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}
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|
|
func (c *Conn) SetNetInfoCallback(fn func(*tailcfg.NetInfo)) {
|
|
if fn == nil {
|
|
panic("nil NetInfoCallback")
|
|
}
|
|
c.mu.Lock()
|
|
last := c.netInfoLast
|
|
c.netInfoFunc = fn
|
|
c.mu.Unlock()
|
|
|
|
if last != nil {
|
|
fn(last)
|
|
}
|
|
}
|
|
|
|
// SetDiscoPrivateKey sets the discovery key.
|
|
func (c *Conn) SetDiscoPrivateKey(k key.Private) {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
if !c.discoPrivate.IsZero() && c.discoPrivate != k {
|
|
// TODO: support changing a key at runtime; need to
|
|
// clear a bunch of maps at least
|
|
panic("unsupported")
|
|
}
|
|
c.discoPrivate = k
|
|
c.discoPublic = tailcfg.DiscoKey(k.Public())
|
|
c.discoShort = c.discoPublic.ShortString()
|
|
c.logf("magicsock: set disco key = %v", c.discoShort)
|
|
}
|
|
|
|
// c.mu must NOT be held.
|
|
func (c *Conn) setNearestDERP(derpNum int) (wantDERP bool) {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
if !c.wantDerpLocked() {
|
|
c.myDerp = 0
|
|
return false
|
|
}
|
|
if derpNum == c.myDerp {
|
|
// No change.
|
|
return true
|
|
}
|
|
c.myDerp = derpNum
|
|
|
|
if c.privateKey.IsZero() {
|
|
// No private key yet, so DERP connections won't come up anyway.
|
|
// Return early rather than ultimately log a couple lines of noise.
|
|
return true
|
|
}
|
|
|
|
// On change, notify all currently connected DERP servers and
|
|
// start connecting to our home DERP if we are not already.
|
|
dr := c.derpMap.Regions[derpNum]
|
|
if dr == nil {
|
|
c.logf("[unexpected] magicsock: derpMap.Regions[%v] is nil", derpNum)
|
|
} else {
|
|
c.logf("magicsock: home is now derp-%v (%v)", derpNum, c.derpMap.Regions[derpNum].RegionCode)
|
|
}
|
|
for i, ad := range c.activeDerp {
|
|
go ad.c.NotePreferred(i == c.myDerp)
|
|
}
|
|
c.goDerpConnect(derpNum)
|
|
return true
|
|
}
|
|
|
|
// goDerpConnect starts a goroutine to start connecting to the given
|
|
// DERP node.
|
|
//
|
|
// c.mu may be held, but does not need to be.
|
|
func (c *Conn) goDerpConnect(node int) {
|
|
if node == 0 {
|
|
return
|
|
}
|
|
go c.derpWriteChanOfAddr(netaddr.IPPort{IP: derpMagicIPAddr, Port: uint16(node)}, key.Public{})
|
|
}
|
|
|
|
var debugOmitLocalAddresses, _ = strconv.ParseBool(os.Getenv("TS_DEBUG_OMIT_LOCAL_ADDRS"))
|
|
|
|
// determineEndpoints returns the machine's endpoint addresses. It
|
|
// does a STUN lookup (via netcheck) to determine its public address.
|
|
//
|
|
// c.mu must NOT be held.
|
|
func (c *Conn) determineEndpoints(ctx context.Context) (ipPorts []string, reasons map[string]string, err error) {
|
|
nr, err := c.updateNetInfo(ctx)
|
|
if err != nil {
|
|
c.logf("magicsock.Conn.determineEndpoints: updateNetInfo: %v", err)
|
|
return nil, nil, err
|
|
}
|
|
|
|
already := make(map[string]string) // endpoint -> how it was found
|
|
var eps []string // unique endpoints
|
|
|
|
addAddr := func(s, reason string) {
|
|
if debugOmitLocalAddresses && (reason == "localAddresses" || reason == "socket") {
|
|
return
|
|
}
|
|
if _, ok := already[s]; !ok {
|
|
already[s] = reason
|
|
eps = append(eps, s)
|
|
}
|
|
}
|
|
|
|
if nr.GlobalV4 != "" {
|
|
addAddr(nr.GlobalV4, "stun")
|
|
}
|
|
if nr.GlobalV6 != "" {
|
|
addAddr(nr.GlobalV6, "stun")
|
|
}
|
|
|
|
c.ignoreSTUNPackets()
|
|
|
|
if localAddr := c.pconn4.LocalAddr(); localAddr.IP.IsUnspecified() {
|
|
ips, loopback, err := interfaces.LocalAddresses()
|
|
if err != nil {
|
|
return nil, nil, err
|
|
}
|
|
reason := "localAddresses"
|
|
if len(ips) == 0 && len(eps) == 0 {
|
|
// Only include loopback addresses if we have no
|
|
// interfaces at all to use as endpoints and don't
|
|
// have a public IPv4 or IPv6 address. This allows
|
|
// for localhost testing when you're on a plane and
|
|
// offline, for example.
|
|
ips = loopback
|
|
reason = "loopback"
|
|
}
|
|
for _, ipStr := range ips {
|
|
addAddr(net.JoinHostPort(ipStr, fmt.Sprint(localAddr.Port)), reason)
|
|
}
|
|
} else {
|
|
// Our local endpoint is bound to a particular address.
|
|
// Do not offer addresses on other local interfaces.
|
|
addAddr(localAddr.String(), "socket")
|
|
}
|
|
|
|
// Note: the endpoints are intentionally returned in priority order,
|
|
// from "farthest but most reliable" to "closest but least
|
|
// reliable." Addresses returned from STUN should be globally
|
|
// addressable, but might go farther on the network than necessary.
|
|
// Local interface addresses might have lower latency, but not be
|
|
// globally addressable.
|
|
//
|
|
// The STUN address(es) are always first so that legacy wireguard
|
|
// can use eps[0] as its only known endpoint address (although that's
|
|
// obviously non-ideal).
|
|
return eps, already, nil
|
|
}
|
|
|
|
func stringsEqual(x, y []string) bool {
|
|
if len(x) != len(y) {
|
|
return false
|
|
}
|
|
for i := range x {
|
|
if x[i] != y[i] {
|
|
return false
|
|
}
|
|
}
|
|
return true
|
|
}
|
|
|
|
func (c *Conn) LocalPort() uint16 {
|
|
laddr := c.pconn4.LocalAddr()
|
|
return uint16(laddr.Port)
|
|
}
|
|
|
|
func shouldSprayPacket(b []byte) bool {
|
|
if len(b) < 4 {
|
|
return false
|
|
}
|
|
msgType := binary.LittleEndian.Uint32(b[:4])
|
|
switch msgType {
|
|
case device.MessageInitiationType,
|
|
device.MessageResponseType,
|
|
device.MessageCookieReplyType: // TODO: necessary?
|
|
return true
|
|
}
|
|
return false
|
|
}
|
|
|
|
var logPacketDests, _ = strconv.ParseBool(os.Getenv("TS_DEBUG_LOG_PACKET_DESTS"))
|
|
|
|
var logDisco, _ = strconv.ParseBool(os.Getenv("TS_DEBUG_DISCO"))
|
|
|
|
const sprayPeriod = 3 * time.Second
|
|
|
|
// appendDests appends to dsts the destinations that b should be
|
|
// written to in order to reach as. Some of the returned IPPorts may
|
|
// be fake addrs representing DERP servers.
|
|
//
|
|
// It also returns as's current roamAddr, if any.
|
|
func (as *AddrSet) appendDests(dsts []netaddr.IPPort, b []byte) (_ []netaddr.IPPort, roamAddr netaddr.IPPort) {
|
|
spray := shouldSprayPacket(b) // true for handshakes
|
|
now := as.timeNow()
|
|
|
|
as.mu.Lock()
|
|
defer as.mu.Unlock()
|
|
|
|
// Some internal invariant checks.
|
|
if len(as.addrs) != len(as.ipPorts) {
|
|
panic(fmt.Sprintf("lena %d != leni %d", len(as.addrs), len(as.ipPorts)))
|
|
}
|
|
if n1, n2 := as.roamAddr != nil, as.roamAddrStd != nil; n1 != n2 {
|
|
panic(fmt.Sprintf("roamnil %v != roamstdnil %v", n1, n2))
|
|
}
|
|
|
|
// Spray logic.
|
|
//
|
|
// After exchanging a handshake with a peer, we send some outbound
|
|
// packets to every endpoint of that peer. These packets are spaced out
|
|
// over several seconds to make sure that our peer has an opportunity to
|
|
// send its own spray packet to us before we are done spraying.
|
|
//
|
|
// Multiple packets are necessary because we have to both establish the
|
|
// NAT mappings between two peers *and use* the mappings to switch away
|
|
// from DERP to a higher-priority UDP endpoint.
|
|
const sprayFreq = 250 * time.Millisecond
|
|
if spray {
|
|
as.lastSpray = now
|
|
as.stopSpray = now.Add(sprayPeriod)
|
|
|
|
// Reset our favorite route on new handshakes so we
|
|
// can downgrade to a worse path if our better path
|
|
// goes away. (https://github.com/tailscale/tailscale/issues/92)
|
|
as.curAddr = -1
|
|
} else if now.Before(as.stopSpray) {
|
|
// We are in the spray window. If it has been sprayFreq since we
|
|
// last sprayed a packet, spray this packet.
|
|
if now.Sub(as.lastSpray) >= sprayFreq {
|
|
spray = true
|
|
as.lastSpray = now
|
|
}
|
|
}
|
|
|
|
// Pick our destination address(es).
|
|
switch {
|
|
case spray:
|
|
// This packet is being sprayed to all addresses.
|
|
for i := range as.ipPorts {
|
|
dsts = append(dsts, as.ipPorts[i])
|
|
}
|
|
if as.roamAddr != nil {
|
|
dsts = append(dsts, *as.roamAddr)
|
|
}
|
|
case as.roamAddr != nil:
|
|
// We have a roaming address, prefer it over other addrs.
|
|
// TODO(danderson): this is not correct, there's no reason
|
|
// roamAddr should be special like this.
|
|
dsts = append(dsts, *as.roamAddr)
|
|
case as.curAddr != -1:
|
|
if as.curAddr >= len(as.addrs) {
|
|
as.Logf("[unexpected] magicsock bug: as.curAddr >= len(as.addrs): %d >= %d", as.curAddr, len(as.addrs))
|
|
break
|
|
}
|
|
// No roaming addr, but we've seen packets from a known peer
|
|
// addr, so keep using that one.
|
|
dsts = append(dsts, as.ipPorts[as.curAddr])
|
|
default:
|
|
// We know nothing about how to reach this peer, and we're not
|
|
// spraying. Use the first address in the array, which will
|
|
// usually be a DERP address that guarantees connectivity.
|
|
if len(as.ipPorts) > 0 {
|
|
dsts = append(dsts, as.ipPorts[0])
|
|
}
|
|
}
|
|
|
|
if logPacketDests {
|
|
as.Logf("spray=%v; roam=%v; dests=%v", spray, as.roamAddr, dsts)
|
|
}
|
|
if as.roamAddr != nil {
|
|
roamAddr = *as.roamAddr
|
|
}
|
|
return dsts, roamAddr
|
|
}
|
|
|
|
var errNoDestinations = errors.New("magicsock: no destinations")
|
|
|
|
func (c *Conn) Send(b []byte, ep conn.Endpoint) error {
|
|
var as *AddrSet
|
|
switch v := ep.(type) {
|
|
default:
|
|
panic(fmt.Sprintf("[unexpected] Endpoint type %T", v))
|
|
case *discoEndpoint:
|
|
return v.send(b)
|
|
case *singleEndpoint:
|
|
addr := (*net.UDPAddr)(v)
|
|
if addr.IP.Equal(derpMagicIP) {
|
|
c.logf("magicsock: [unexpected] DERP BUG: attempting to send packet to DERP address %v", addr)
|
|
return nil
|
|
}
|
|
_, err := c.sendUDPStd(addr, b)
|
|
return err
|
|
case *AddrSet:
|
|
as = v
|
|
}
|
|
|
|
var addrBuf [8]netaddr.IPPort
|
|
dsts, roamAddr := as.appendDests(addrBuf[:0], b)
|
|
|
|
if len(dsts) == 0 {
|
|
return errNoDestinations
|
|
}
|
|
|
|
var success bool
|
|
var ret error
|
|
for _, addr := range dsts {
|
|
sent, err := c.sendAddr(addr, as.publicKey, b)
|
|
if sent {
|
|
success = true
|
|
} else if ret == nil {
|
|
ret = err
|
|
}
|
|
if err != nil && addr != roamAddr && c.sendLogLimit.Allow() {
|
|
if c.connCtx.Err() == nil { // don't log if we're closed
|
|
c.logf("magicsock: Conn.Send(%v): %v", addr, err)
|
|
}
|
|
}
|
|
}
|
|
if success {
|
|
return nil
|
|
}
|
|
return ret
|
|
}
|
|
|
|
var errConnClosed = errors.New("Conn closed")
|
|
|
|
var errDropDerpPacket = errors.New("too many DERP packets queued; dropping")
|
|
|
|
// sendUDP sends UDP packet b to ipp.
|
|
// See sendAddr's docs on the return value meanings.
|
|
func (c *Conn) sendUDP(ipp netaddr.IPPort, b []byte) (sent bool, err error) {
|
|
ua := ipp.UDPAddr()
|
|
defer netaddr.PutUDPAddr(ua)
|
|
return c.sendUDPStd(ua, b)
|
|
}
|
|
|
|
// sendUDP sends UDP packet b to addr.
|
|
// See sendAddr's docs on the return value meanings.
|
|
func (c *Conn) sendUDPStd(addr *net.UDPAddr, b []byte) (sent bool, err error) {
|
|
switch {
|
|
case addr.IP.To4() != nil:
|
|
_, err = c.pconn4.WriteTo(b, addr)
|
|
if err != nil && c.noV4.Get() {
|
|
return false, nil
|
|
}
|
|
case len(addr.IP) == net.IPv6len:
|
|
if c.pconn6 == nil {
|
|
// ignore IPv6 dest if we don't have an IPv6 address.
|
|
return false, nil
|
|
}
|
|
_, err = c.pconn6.WriteTo(b, addr)
|
|
if err != nil && c.noV6.Get() {
|
|
return false, nil
|
|
}
|
|
default:
|
|
panic("bogus sendUDPStd addr type")
|
|
}
|
|
return err == nil, err
|
|
}
|
|
|
|
// sendAddr sends packet b to addr, which is either a real UDP address
|
|
// or a fake UDP address representing a DERP server (see derpmap.go).
|
|
// The provided public key identifies the recipient.
|
|
//
|
|
// The returned err is whether there was an error writing when it
|
|
// should've worked.
|
|
// The returned sent is whether a packet went out at all.
|
|
// An example of when they might be different: sending to an
|
|
// IPv6 address when the local machine doesn't have IPv6 support
|
|
// returns (false, nil); it's not an error, but nothing was sent.
|
|
func (c *Conn) sendAddr(addr netaddr.IPPort, pubKey key.Public, b []byte) (sent bool, err error) {
|
|
if addr.IP != derpMagicIPAddr {
|
|
return c.sendUDP(addr, b)
|
|
}
|
|
|
|
ch := c.derpWriteChanOfAddr(addr, pubKey)
|
|
if ch == nil {
|
|
return false, nil
|
|
}
|
|
|
|
// TODO(bradfitz): this makes garbage for now; we could use a
|
|
// buffer pool later. Previously we passed ownership of this
|
|
// to derpWriteRequest and waited for derphttp.Client.Send to
|
|
// complete, but that's too slow while holding wireguard-go
|
|
// internal locks.
|
|
pkt := make([]byte, len(b))
|
|
copy(pkt, b)
|
|
|
|
select {
|
|
case <-c.donec():
|
|
return false, errConnClosed
|
|
case ch <- derpWriteRequest{addr, pubKey, pkt}:
|
|
return true, nil
|
|
default:
|
|
// Too many writes queued. Drop packet.
|
|
return false, errDropDerpPacket
|
|
}
|
|
}
|
|
|
|
// bufferedDerpWritesBeforeDrop is how many packets writes can be
|
|
// queued up the DERP client to write on the wire before we start
|
|
// dropping.
|
|
//
|
|
// TODO: this is currently arbitrary. Figure out something better?
|
|
const bufferedDerpWritesBeforeDrop = 32
|
|
|
|
// debugUseDerpRoute temporarily (2020-03-22) controls whether DERP
|
|
// reverse routing is enabled (Issue 150). It will become always true
|
|
// later.
|
|
var debugUseDerpRoute, _ = strconv.ParseBool(os.Getenv("TS_DEBUG_ENABLE_DERP_ROUTE"))
|
|
|
|
// derpWriteChanOfAddr returns a DERP client for fake UDP addresses that
|
|
// represent DERP servers, creating them as necessary. For real UDP
|
|
// addresses, it returns nil.
|
|
//
|
|
// If peer is non-zero, it can be used to find an active reverse
|
|
// path, without using addr.
|
|
func (c *Conn) derpWriteChanOfAddr(addr netaddr.IPPort, peer key.Public) chan<- derpWriteRequest {
|
|
if addr.IP != derpMagicIPAddr {
|
|
return nil
|
|
}
|
|
regionID := int(addr.Port)
|
|
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
if !c.wantDerpLocked() || c.closed {
|
|
return nil
|
|
}
|
|
if c.privateKey.IsZero() {
|
|
c.logf("magicsock: DERP lookup of %v with no private key; ignoring", addr)
|
|
return nil
|
|
}
|
|
|
|
// See if we have a connection open to that DERP node ID
|
|
// first. If so, might as well use it. (It's a little
|
|
// arbitrary whether we use this one vs. the reverse route
|
|
// below when we have both.)
|
|
ad, ok := c.activeDerp[regionID]
|
|
if ok {
|
|
*ad.lastWrite = time.Now()
|
|
c.setPeerLastDerpLocked(peer, regionID, regionID)
|
|
return ad.writeCh
|
|
}
|
|
|
|
// If we don't have an open connection to the peer's home DERP
|
|
// node, see if we have an open connection to a DERP node
|
|
// where we'd heard from that peer already. For instance,
|
|
// perhaps peer's home is Frankfurt, but they dialed our home DERP
|
|
// node in SF to reach us, so we can reply to them using our
|
|
// SF connection rather than dialing Frankfurt. (Issue 150)
|
|
if !peer.IsZero() && debugUseDerpRoute {
|
|
if r, ok := c.derpRoute[peer]; ok {
|
|
if ad, ok := c.activeDerp[r.derpID]; ok && ad.c == r.dc {
|
|
c.setPeerLastDerpLocked(peer, r.derpID, regionID)
|
|
*ad.lastWrite = time.Now()
|
|
return ad.writeCh
|
|
}
|
|
}
|
|
}
|
|
|
|
why := "home-keep-alive"
|
|
if !peer.IsZero() {
|
|
why = peerShort(peer)
|
|
}
|
|
c.logf("magicsock: adding connection to derp-%v for %v", regionID, why)
|
|
|
|
firstDerp := false
|
|
if c.activeDerp == nil {
|
|
firstDerp = true
|
|
c.activeDerp = make(map[int]activeDerp)
|
|
c.prevDerp = make(map[int]*syncs.WaitGroupChan)
|
|
}
|
|
if c.derpMap == nil || c.derpMap.Regions[regionID] == nil {
|
|
return nil
|
|
}
|
|
|
|
// Note that derphttp.NewClient does not dial the server
|
|
// so it is safe to do under the mu lock.
|
|
dc := derphttp.NewRegionClient(c.privateKey, c.logf, func() *tailcfg.DERPRegion {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
if c.derpMap == nil {
|
|
return nil
|
|
}
|
|
return c.derpMap.Regions[regionID]
|
|
})
|
|
|
|
dc.NotePreferred(c.myDerp == regionID)
|
|
dc.DNSCache = dnscache.Get()
|
|
|
|
ctx, cancel := context.WithCancel(c.connCtx)
|
|
ch := make(chan derpWriteRequest, bufferedDerpWritesBeforeDrop)
|
|
|
|
ad.c = dc
|
|
ad.writeCh = ch
|
|
ad.cancel = cancel
|
|
ad.lastWrite = new(time.Time)
|
|
*ad.lastWrite = time.Now()
|
|
ad.createTime = time.Now()
|
|
c.activeDerp[regionID] = ad
|
|
c.logActiveDerpLocked()
|
|
c.setPeerLastDerpLocked(peer, regionID, regionID)
|
|
|
|
// Build a startGate for the derp reader+writer
|
|
// goroutines, so they don't start running until any
|
|
// previous generation is closed.
|
|
startGate := syncs.ClosedChan()
|
|
if prev := c.prevDerp[regionID]; prev != nil {
|
|
startGate = prev.DoneChan()
|
|
}
|
|
// And register a WaitGroup(Chan) for this generation.
|
|
wg := syncs.NewWaitGroupChan()
|
|
wg.Add(2)
|
|
c.prevDerp[regionID] = wg
|
|
|
|
if firstDerp {
|
|
startGate = c.derpStarted
|
|
go func() {
|
|
dc.Connect(ctx)
|
|
close(c.derpStarted)
|
|
}()
|
|
}
|
|
|
|
go c.runDerpReader(ctx, addr, dc, wg, startGate)
|
|
go c.runDerpWriter(ctx, dc, ch, wg, startGate)
|
|
|
|
return ad.writeCh
|
|
}
|
|
|
|
// setPeerLastDerpLocked notes that peer is now being written to via
|
|
// the provided DERP regionID, and that the peer advertises a DERP
|
|
// home region ID of homeID.
|
|
//
|
|
// If there's any change, it logs.
|
|
//
|
|
// c.mu must be held.
|
|
func (c *Conn) setPeerLastDerpLocked(peer key.Public, regionID, homeID int) {
|
|
if peer.IsZero() {
|
|
return
|
|
}
|
|
old := c.peerLastDerp[peer]
|
|
if old == regionID {
|
|
return
|
|
}
|
|
c.peerLastDerp[peer] = regionID
|
|
|
|
var newDesc string
|
|
switch {
|
|
case regionID == homeID && regionID == c.myDerp:
|
|
newDesc = "shared home"
|
|
case regionID == homeID:
|
|
newDesc = "their home"
|
|
case regionID == c.myDerp:
|
|
newDesc = "our home"
|
|
case regionID != homeID:
|
|
newDesc = "alt"
|
|
}
|
|
if old == 0 {
|
|
c.logf("magicsock: derp route for %s set to derp-%d (%s)", peerShort(peer), regionID, newDesc)
|
|
} else {
|
|
c.logf("magicsock: derp route for %s changed from derp-%d => derp-%d (%s)", peerShort(peer), old, regionID, newDesc)
|
|
}
|
|
}
|
|
|
|
// derpReadResult is the type sent by runDerpClient to ReceiveIPv4
|
|
// when a DERP packet is available.
|
|
//
|
|
// Notably, it doesn't include the derp.ReceivedPacket because we
|
|
// don't want to give the receiver access to the aliased []byte. To
|
|
// get at the packet contents they need to call copyBuf to copy it
|
|
// out, which also releases the buffer.
|
|
type derpReadResult struct {
|
|
regionID int
|
|
n int // length of data received
|
|
src key.Public // may be zero until server deployment if v2+
|
|
// copyBuf is called to copy the data to dst. It returns how
|
|
// much data was copied, which will be n if dst is large
|
|
// enough. copyBuf can only be called once.
|
|
copyBuf func(dst []byte) int
|
|
}
|
|
|
|
var logDerpVerbose, _ = strconv.ParseBool(os.Getenv("DEBUG_DERP_VERBOSE"))
|
|
|
|
// runDerpReader runs in a goroutine for the life of a DERP
|
|
// connection, handling received packets.
|
|
func (c *Conn) runDerpReader(ctx context.Context, derpFakeAddr netaddr.IPPort, dc *derphttp.Client, wg *syncs.WaitGroupChan, startGate <-chan struct{}) {
|
|
defer wg.Decr()
|
|
defer dc.Close()
|
|
|
|
select {
|
|
case <-startGate:
|
|
case <-ctx.Done():
|
|
return
|
|
}
|
|
|
|
didCopy := make(chan struct{}, 1)
|
|
regionID := int(derpFakeAddr.Port)
|
|
res := derpReadResult{regionID: regionID}
|
|
var pkt derp.ReceivedPacket
|
|
res.copyBuf = func(dst []byte) int {
|
|
n := copy(dst, pkt.Data)
|
|
didCopy <- struct{}{}
|
|
return n
|
|
}
|
|
|
|
// peerPresent is the set of senders we know are present on this
|
|
// connection, based on messages we've received from the server.
|
|
peerPresent := map[key.Public]bool{}
|
|
|
|
for {
|
|
msg, err := dc.Recv()
|
|
if err == derphttp.ErrClientClosed {
|
|
return
|
|
}
|
|
if err != nil {
|
|
// Forget that all these peers have routes.
|
|
for peer := range peerPresent {
|
|
delete(peerPresent, peer)
|
|
c.removeDerpPeerRoute(peer, regionID, dc)
|
|
}
|
|
select {
|
|
case <-ctx.Done():
|
|
return
|
|
default:
|
|
}
|
|
c.ReSTUN("derp-close")
|
|
c.logf("magicsock: [%p] derp.Recv(derp-%d): %v", dc, regionID, err)
|
|
time.Sleep(250 * time.Millisecond)
|
|
continue
|
|
}
|
|
switch m := msg.(type) {
|
|
case derp.ReceivedPacket:
|
|
pkt = m
|
|
res.n = len(m.Data)
|
|
res.src = m.Source
|
|
if logDerpVerbose {
|
|
c.logf("magicsock: got derp-%v packet: %q", regionID, m.Data)
|
|
}
|
|
// If this is a new sender we hadn't seen before, remember it and
|
|
// register a route for this peer.
|
|
if _, ok := peerPresent[m.Source]; !ok {
|
|
peerPresent[m.Source] = true
|
|
c.addDerpPeerRoute(m.Source, regionID, dc)
|
|
}
|
|
default:
|
|
// Ignore.
|
|
// TODO: handle endpoint notification messages.
|
|
continue
|
|
}
|
|
select {
|
|
case <-ctx.Done():
|
|
return
|
|
case c.derpRecvCh <- res:
|
|
<-didCopy
|
|
}
|
|
}
|
|
}
|
|
|
|
type derpWriteRequest struct {
|
|
addr netaddr.IPPort
|
|
pubKey key.Public
|
|
b []byte // copied; ownership passed to receiver
|
|
}
|
|
|
|
// runDerpWriter runs in a goroutine for the life of a DERP
|
|
// connection, handling received packets.
|
|
func (c *Conn) runDerpWriter(ctx context.Context, dc *derphttp.Client, ch <-chan derpWriteRequest, wg *syncs.WaitGroupChan, startGate <-chan struct{}) {
|
|
defer wg.Decr()
|
|
select {
|
|
case <-startGate:
|
|
case <-ctx.Done():
|
|
return
|
|
}
|
|
|
|
for {
|
|
select {
|
|
case <-ctx.Done():
|
|
return
|
|
case wr := <-ch:
|
|
err := dc.Send(wr.pubKey, wr.b)
|
|
if err != nil {
|
|
c.logf("magicsock: derp.Send(%v): %v", wr.addr, err)
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// findEndpoint maps from a UDP address to a WireGuard endpoint, for
|
|
// ReceiveIPv4/ReceiveIPv6.
|
|
// The provided addr and ipp must match.
|
|
//
|
|
// TODO(bradfitz): add a fast path that returns nil here for normal
|
|
// wireguard-go transport packets; IIRC wireguard-go only uses this
|
|
// Endpoint for the relatively rare non-data packets.
|
|
func (c *Conn) findEndpoint(ipp netaddr.IPPort, addr *net.UDPAddr) conn.Endpoint {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
|
|
// See if they have a discoEndpoint, for a set of peers
|
|
// both supporting active discovery.
|
|
if dk, ok := c.discoOfAddr[ipp]; ok {
|
|
if ep, ok := c.endpointOfDisco[dk]; ok {
|
|
return ep
|
|
}
|
|
}
|
|
|
|
// Pre-disco: look up their AddrSet.
|
|
if as, ok := c.addrsByUDP[ipp]; ok {
|
|
return as
|
|
}
|
|
|
|
// Pre-disco: the peer that sent this packet has roamed beyond
|
|
// the knowledge provided by the control server. If the
|
|
// packet is valid wireguard will call UpdateDst on the
|
|
// original endpoint using this addr.
|
|
return (*singleEndpoint)(addr)
|
|
}
|
|
|
|
type udpReadResult struct {
|
|
_ structs.Incomparable
|
|
n int
|
|
err error
|
|
addr *net.UDPAddr
|
|
ipp netaddr.IPPort
|
|
}
|
|
|
|
// aLongTimeAgo is a non-zero time, far in the past, used for
|
|
// immediate cancellation of network operations.
|
|
var aLongTimeAgo = time.Unix(233431200, 0)
|
|
|
|
// awaitUDP4 reads a single IPv4 UDP packet (or an error) and sends it
|
|
// to c.udpRecvCh, skipping over (but handling) any STUN replies.
|
|
func (c *Conn) awaitUDP4(b []byte) {
|
|
for {
|
|
n, pAddr, err := c.pconn4.ReadFrom(b)
|
|
if err != nil {
|
|
select {
|
|
case c.udpRecvCh <- udpReadResult{err: err}:
|
|
case <-c.donec():
|
|
}
|
|
return
|
|
}
|
|
addr := pAddr.(*net.UDPAddr)
|
|
ipp, ok := c.pconn4.ippCache.IPPort(addr)
|
|
if !ok {
|
|
continue
|
|
}
|
|
if stun.Is(b[:n]) {
|
|
c.stunReceiveFunc.Load().(func([]byte, netaddr.IPPort))(b[:n], ipp)
|
|
continue
|
|
}
|
|
if c.handleDiscoMessage(b[:n], ipp) {
|
|
continue
|
|
}
|
|
|
|
select {
|
|
case c.udpRecvCh <- udpReadResult{n: n, addr: addr, ipp: ipp}:
|
|
case <-c.donec():
|
|
}
|
|
return
|
|
}
|
|
}
|
|
|
|
// wgRecvAddr returns the net.UDPAddr we tell wireguard-go the address
|
|
// from which we received a packet for an endpoint.
|
|
//
|
|
// ipp is required. addr can be optionally provided.
|
|
func wgRecvAddr(e conn.Endpoint, ipp netaddr.IPPort, addr *net.UDPAddr) *net.UDPAddr {
|
|
if ipp == (netaddr.IPPort{}) {
|
|
panic("zero ipp")
|
|
}
|
|
if de, ok := e.(*discoEndpoint); ok {
|
|
return de.fakeWGAddrStd
|
|
}
|
|
if addr != nil {
|
|
return addr
|
|
}
|
|
return ipp.UDPAddr()
|
|
}
|
|
|
|
func (c *Conn) ReceiveIPv4(b []byte) (n int, ep conn.Endpoint, addr *net.UDPAddr, err error) {
|
|
Top:
|
|
// First, process any buffered packet from earlier.
|
|
if from := c.bufferedIPv4From; from != (netaddr.IPPort{}) {
|
|
c.bufferedIPv4From = netaddr.IPPort{}
|
|
addr = from.UDPAddr()
|
|
ep := c.findEndpoint(from, addr)
|
|
return copy(b, c.bufferedIPv4Packet), ep, wgRecvAddr(ep, from, addr), nil
|
|
}
|
|
|
|
go c.awaitUDP4(b)
|
|
|
|
// Once the above goroutine has started, it owns b until it writes
|
|
// to udpRecvCh. The code below must not access b until it's
|
|
// completed a successful receive on udpRecvCh.
|
|
|
|
var addrSet *AddrSet
|
|
var discoEp *discoEndpoint
|
|
var ipp netaddr.IPPort
|
|
|
|
select {
|
|
case dm := <-c.derpRecvCh:
|
|
// Cancel the pconn read goroutine
|
|
c.pconn4.SetReadDeadline(aLongTimeAgo)
|
|
// Wait for the UDP-reading goroutine to be done, since it's currently
|
|
// the owner of the b []byte buffer:
|
|
select {
|
|
case um := <-c.udpRecvCh:
|
|
if um.err != nil {
|
|
// The normal case. The SetReadDeadline interrupted
|
|
// the read and we get an error which we now ignore.
|
|
} else {
|
|
// The pconn.ReadFrom succeeded and was about to send,
|
|
// but DERP sent first. So now we have both ready.
|
|
// Save the UDP packet away for use by the next
|
|
// ReceiveIPv4 call.
|
|
c.bufferedIPv4From = um.ipp
|
|
c.bufferedIPv4Packet = append(c.bufferedIPv4Packet[:0], b[:um.n]...)
|
|
}
|
|
c.pconn4.SetReadDeadline(time.Time{})
|
|
case <-c.donec():
|
|
return 0, nil, nil, errors.New("Conn closed")
|
|
}
|
|
var regionID int
|
|
n, regionID = dm.n, dm.regionID
|
|
ncopy := dm.copyBuf(b)
|
|
if ncopy != n {
|
|
err = fmt.Errorf("received DERP packet of length %d that's too big for WireGuard ReceiveIPv4 buf size %d", n, ncopy)
|
|
c.logf("magicsock: %v", err)
|
|
return 0, nil, nil, err
|
|
}
|
|
|
|
ipp = netaddr.IPPort{IP: derpMagicIPAddr, Port: uint16(regionID)}
|
|
if c.handleDiscoMessage(b[:n], ipp) {
|
|
goto Top
|
|
}
|
|
|
|
c.mu.Lock()
|
|
if dk, ok := c.discoOfNode[tailcfg.NodeKey(dm.src)]; ok {
|
|
discoEp = c.endpointOfDisco[dk]
|
|
}
|
|
if discoEp == nil {
|
|
addrSet = c.addrsByKey[dm.src]
|
|
}
|
|
c.mu.Unlock()
|
|
|
|
if addrSet == nil && discoEp == nil {
|
|
key := wgcfg.Key(dm.src)
|
|
c.logf("magicsock: DERP packet from unknown key: %s", key.ShortString())
|
|
}
|
|
|
|
case um := <-c.udpRecvCh:
|
|
if um.err != nil {
|
|
return 0, nil, nil, err
|
|
}
|
|
n, addr, ipp = um.n, um.addr, um.ipp
|
|
|
|
case <-c.donec():
|
|
// Socket has been shut down. All the producers of packets
|
|
// respond to the context cancellation and go away, so we have
|
|
// to also unblock and return an error, to inform wireguard-go
|
|
// that this socket has gone away.
|
|
//
|
|
// Specifically, wireguard-go depends on its bind.Conn having
|
|
// the standard socket behavior, which is that a Close()
|
|
// unblocks any concurrent Read()s. wireguard-go itself calls
|
|
// Clos() on magicsock, and expects ReceiveIPv4 to unblock
|
|
// with an error so it can clean up.
|
|
return 0, nil, nil, errors.New("socket closed")
|
|
}
|
|
|
|
if addrSet != nil {
|
|
ep = addrSet
|
|
} else if discoEp != nil {
|
|
ep = discoEp
|
|
} else {
|
|
ep = c.findEndpoint(ipp, addr)
|
|
}
|
|
return n, ep, wgRecvAddr(ep, ipp, addr), nil
|
|
}
|
|
|
|
func (c *Conn) ReceiveIPv6(b []byte) (int, conn.Endpoint, *net.UDPAddr, error) {
|
|
if c.pconn6 == nil {
|
|
return 0, nil, nil, syscall.EAFNOSUPPORT
|
|
}
|
|
for {
|
|
n, pAddr, err := c.pconn6.ReadFrom(b)
|
|
if err != nil {
|
|
return 0, nil, nil, err
|
|
}
|
|
addr := pAddr.(*net.UDPAddr)
|
|
ipp, ok := c.pconn6.ippCache.IPPort(addr)
|
|
if !ok {
|
|
continue
|
|
}
|
|
if stun.Is(b[:n]) {
|
|
c.stunReceiveFunc.Load().(func([]byte, netaddr.IPPort))(b[:n], ipp)
|
|
continue
|
|
}
|
|
if c.handleDiscoMessage(b[:n], ipp) {
|
|
continue
|
|
}
|
|
|
|
ep := c.findEndpoint(ipp, addr)
|
|
return n, ep, wgRecvAddr(ep, ipp, addr), nil
|
|
}
|
|
}
|
|
|
|
func (c *Conn) sendDiscoMessage(dst netaddr.IPPort, dstKey key.Public, dstDisco tailcfg.DiscoKey, m disco.Message) (sent bool, err error) {
|
|
c.mu.Lock()
|
|
var nonce [disco.NonceLen]byte
|
|
if _, err := crand.Read(nonce[:]); err != nil {
|
|
panic(err) // worth dying for
|
|
}
|
|
pkt := make([]byte, 0, 512) // TODO: size it correctly? pool? if it matters.
|
|
pkt = append(pkt, disco.Magic...)
|
|
pkt = append(pkt, c.discoPublic[:]...)
|
|
pkt = append(pkt, nonce[:]...)
|
|
sharedKey := c.sharedDiscoKeyLocked(dstDisco)
|
|
c.mu.Unlock()
|
|
|
|
pkt = box.SealAfterPrecomputation(pkt, m.AppendMarshal(nil), &nonce, sharedKey)
|
|
sent, err = c.sendAddr(dst, dstKey, pkt)
|
|
if sent {
|
|
c.logf("magicsock: disco: %v->%v (%v, %v): %v", c.discoShort, dstDisco.ShortString(), dstKey.ShortString(), derpStr(dst.String()), disco.MessageSummary(m))
|
|
} else if err == nil {
|
|
// Can't send. (e.g. no IPv6 locally)
|
|
} else {
|
|
c.logf("magicsock: disco: failed to send %T to %v: %v", m, dst, err)
|
|
}
|
|
return sent, err
|
|
}
|
|
|
|
// handleDiscoMessage reports whether msg was a Tailscale inter-node discovery message
|
|
// that was handled.
|
|
//
|
|
// A discovery message has the form:
|
|
//
|
|
// * magic [6]byte
|
|
// * senderDiscoPubKey [32]byte
|
|
// * nonce [24]byte
|
|
// * naclbox of payload (see tailscale.com/disco package for inner payload format)
|
|
//
|
|
// For messages received over DERP, the addr will be derpMagicIP (with
|
|
// port being the region)
|
|
func (c *Conn) handleDiscoMessage(msg []byte, src netaddr.IPPort) bool {
|
|
const headerLen = len(disco.Magic) + len(tailcfg.DiscoKey{}) + disco.NonceLen
|
|
if len(msg) < headerLen || string(msg[:len(disco.Magic)]) != disco.Magic {
|
|
return false
|
|
}
|
|
var sender tailcfg.DiscoKey
|
|
copy(sender[:], msg[len(disco.Magic):])
|
|
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
|
|
if logDisco {
|
|
c.logf("magicsock: disco: got disco-looking frame from %v", sender.ShortString())
|
|
}
|
|
if c.discoPrivate.IsZero() {
|
|
if logDisco {
|
|
c.logf("magicsock: disco: ignoring disco-looking frame, no local key")
|
|
}
|
|
return false
|
|
}
|
|
|
|
de, ok := c.endpointOfDisco[sender]
|
|
if !ok {
|
|
if logDisco {
|
|
c.logf("magicsock: disco: ignoring disco-looking frame, don't know about %v", sender.ShortString())
|
|
}
|
|
// Returning false keeps passing it down, to WireGuard.
|
|
// WireGuard will almost surely reject it, but give it a chance.
|
|
return false
|
|
}
|
|
|
|
// First, do we even know (and thus care) about this sender? If not,
|
|
// don't bother decrypting it.
|
|
|
|
var nonce [disco.NonceLen]byte
|
|
copy(nonce[:], msg[len(disco.Magic)+len(key.Public{}):])
|
|
sealedBox := msg[headerLen:]
|
|
payload, ok := box.OpenAfterPrecomputation(nil, sealedBox, &nonce, c.sharedDiscoKeyLocked(sender))
|
|
if !ok {
|
|
// This might be have been intended for a previous
|
|
// disco key. When we restart we get a new disco key
|
|
// and old packets might've still been in flight (or
|
|
// scheduled). This is particularly the case for LANs
|
|
// or non-NATed endpoints.
|
|
// Don't log in normal case. Pass on to wireguard, in case
|
|
// it's actually a a wireguard packet (super unlikely,
|
|
// but).
|
|
if logDisco {
|
|
c.logf("magicsock: disco: failed to open naclbox from %v (wrong rcpt?)", sender)
|
|
}
|
|
// TODO(bradfitz): add some counter for this that logs rarely
|
|
return false
|
|
}
|
|
|
|
dm, err := disco.Parse(payload)
|
|
if logDisco {
|
|
c.logf("magicsock: disco: disco.Parse = %T, %v", dm, err)
|
|
}
|
|
if err != nil {
|
|
// Couldn't parse it, but it was inside a correctly
|
|
// signed box, so just ignore it, assuming it's from a
|
|
// newer version of Tailscale that we don't
|
|
// understand. Not even worth logging about, lest it
|
|
// be too spammy for old clients.
|
|
// TODO(bradfitz): add some counter for this that logs rarely
|
|
return true
|
|
}
|
|
|
|
switch dm := dm.(type) {
|
|
case *disco.Ping:
|
|
c.handlePingLocked(dm, de, src)
|
|
case *disco.Pong:
|
|
de.handlePongConnLocked(dm, src)
|
|
case disco.CallMeMaybe:
|
|
if src.IP != derpMagicIPAddr {
|
|
// CallMeMaybe messages should only come via DERP.
|
|
c.logf("[unexpected] CallMeMaybe packets should only come via DERP")
|
|
return true
|
|
}
|
|
go de.handleCallMeMaybe()
|
|
}
|
|
|
|
return true
|
|
}
|
|
|
|
func (c *Conn) handlePingLocked(dm *disco.Ping, de *discoEndpoint, src netaddr.IPPort) {
|
|
c.logf("magicsock: disco: %v<-%v (%v, %v) ping tx=%x", c.discoShort, de.discoKey.ShortString(), de.publicKey.ShortString(), src, dm.TxID)
|
|
|
|
// Remember this this route if not present.
|
|
c.setAddrToDiscoLocked(src, de.discoKey, nil)
|
|
|
|
go de.sendDiscoMessage(src, &disco.Pong{
|
|
TxID: dm.TxID,
|
|
Src: src,
|
|
})
|
|
}
|
|
|
|
// setAddrToDiscoLocked records that newk is at src.
|
|
//
|
|
// c.mu must be held.
|
|
//
|
|
// If the caller already has a discoEndpoint mutex held as well, it
|
|
// can be passed in as alreadyLocked so it won't be re-acquired during
|
|
// any lazy cleanup of the mapping.
|
|
func (c *Conn) setAddrToDiscoLocked(src netaddr.IPPort, newk tailcfg.DiscoKey, alreadyLocked *discoEndpoint) {
|
|
oldk, ok := c.discoOfAddr[src]
|
|
if ok && oldk == newk {
|
|
return
|
|
}
|
|
if ok {
|
|
c.logf("magicsock: disco: changing mapping of %v from %x=>%x", src, oldk.ShortString(), newk.ShortString())
|
|
} else {
|
|
c.logf("magicsock: disco: adding mapping of %v to %v", src, newk.ShortString())
|
|
}
|
|
c.discoOfAddr[src] = newk
|
|
if !ok {
|
|
c.cleanDiscoOfAddrLocked(alreadyLocked)
|
|
}
|
|
}
|
|
|
|
// cleanDiscoOfAddrLocked lazily checks a few entries in c.discoOfAddr
|
|
// and deletes them if they're stale. It has no pointers in it so we
|
|
// don't go through the effort of keeping it aggressively
|
|
// pruned. Instead, we lazily clean it whenever it grows.
|
|
//
|
|
// c.mu must be held.
|
|
//
|
|
// If the caller already has a discoEndpoint mutex held as well, it
|
|
// can be passed in as alreadyLocked so it won't be re-acquired.
|
|
func (c *Conn) cleanDiscoOfAddrLocked(alreadyLocked *discoEndpoint) {
|
|
// If it's small enough, don't worry about it.
|
|
if len(c.discoOfAddr) < 16 {
|
|
return
|
|
}
|
|
|
|
const checkEntries = 5 // per one unit of growth
|
|
|
|
// Take advantage of Go's random map iteration to check & clean
|
|
// a few entries.
|
|
n := 0
|
|
for ipp, dk := range c.discoOfAddr {
|
|
n++
|
|
if n > checkEntries {
|
|
return
|
|
}
|
|
de, ok := c.endpointOfDisco[dk]
|
|
if !ok {
|
|
// This discokey isn't even known anymore. Clean.
|
|
delete(c.discoOfAddr, ipp)
|
|
continue
|
|
}
|
|
if de != alreadyLocked {
|
|
de.mu.Lock()
|
|
}
|
|
if _, ok := de.endpointState[ipp]; !ok {
|
|
// The discoEndpoint no longer knows about that endpoint.
|
|
// It must've changed. Clean.
|
|
delete(c.discoOfAddr, ipp)
|
|
}
|
|
if de != alreadyLocked {
|
|
de.mu.Unlock()
|
|
}
|
|
}
|
|
}
|
|
|
|
func (c *Conn) sharedDiscoKeyLocked(k tailcfg.DiscoKey) *[32]byte {
|
|
if v, ok := c.sharedDiscoKey[k]; ok {
|
|
return v
|
|
}
|
|
shared := new([32]byte)
|
|
box.Precompute(shared, key.Public(k).B32(), c.discoPrivate.B32())
|
|
c.sharedDiscoKey[k] = shared
|
|
return shared
|
|
}
|
|
|
|
// SetPrivateKey sets the connection's private key.
|
|
//
|
|
// This is only used to be able prove our identity when connecting to
|
|
// DERP servers.
|
|
//
|
|
// If the private key changes, any DERP connections are torn down &
|
|
// recreated when needed.
|
|
func (c *Conn) SetPrivateKey(privateKey wgcfg.PrivateKey) error {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
|
|
oldKey, newKey := c.privateKey, key.Private(privateKey)
|
|
if newKey == oldKey {
|
|
return nil
|
|
}
|
|
c.privateKey = newKey
|
|
|
|
if oldKey.IsZero() {
|
|
c.logf("magicsock: SetPrivateKey called (init)")
|
|
go c.ReSTUN("set-private-key")
|
|
} else {
|
|
c.logf("magicsock: SetPrivateKey called (changed")
|
|
}
|
|
c.closeAllDerpLocked("new-private-key")
|
|
|
|
// Key changed. Close existing DERP connections and reconnect to home.
|
|
if c.myDerp != 0 {
|
|
c.logf("magicsock: private key changed, reconnecting to home derp-%d", c.myDerp)
|
|
c.goDerpConnect(c.myDerp)
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// UpdatePeers is called when the set of WireGuard peers changes. It
|
|
// then removes any state for old peers.
|
|
//
|
|
// The caller passes ownership of newPeers map to UpdatePeers.
|
|
func (c *Conn) UpdatePeers(newPeers map[key.Public]struct{}) {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
|
|
oldPeers := c.peerSet
|
|
c.peerSet = newPeers
|
|
|
|
// Clean up any key.Public-keyed maps for peers that no longer
|
|
// exist.
|
|
for peer := range oldPeers {
|
|
if _, ok := newPeers[peer]; !ok {
|
|
delete(c.addrsByKey, peer)
|
|
delete(c.derpRoute, peer)
|
|
delete(c.peerLastDerp, peer)
|
|
}
|
|
}
|
|
|
|
if len(oldPeers) == 0 && len(newPeers) > 0 {
|
|
go c.ReSTUN("non-zero-peers")
|
|
}
|
|
}
|
|
|
|
// SetDERPMap controls which (if any) DERP servers are used.
|
|
// A nil value means to disable DERP; it's disabled by default.
|
|
func (c *Conn) SetDERPMap(dm *tailcfg.DERPMap) {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
|
|
if reflect.DeepEqual(dm, c.derpMap) {
|
|
return
|
|
}
|
|
|
|
c.derpMap = dm
|
|
if dm == nil {
|
|
c.closeAllDerpLocked("derp-disabled")
|
|
return
|
|
}
|
|
|
|
go c.ReSTUN("derp-map-update")
|
|
}
|
|
|
|
// SetNetworkMap is called when the control client gets a new network
|
|
// map from the control server.
|
|
//
|
|
// It should not use the DERPMap field of NetworkMap; that's
|
|
// conditionally sent to SetDERPMap instead.
|
|
func (c *Conn) SetNetworkMap(nm *controlclient.NetworkMap) {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
|
|
if reflect.DeepEqual(nm, c.netMap) {
|
|
return
|
|
}
|
|
|
|
numDisco := 0
|
|
for _, n := range nm.Peers {
|
|
if n.DiscoKey.IsZero() {
|
|
continue
|
|
}
|
|
numDisco++
|
|
if ep, ok := c.endpointOfDisco[n.DiscoKey]; ok {
|
|
ep.updateFromNode(n)
|
|
}
|
|
}
|
|
|
|
c.logf("magicsock: got updated network map; %d peers (%d with discokey)", len(nm.Peers), numDisco)
|
|
c.netMap = nm
|
|
|
|
// Build and/or update node<->disco maps, only reallocating if
|
|
// the set of discokeys changed.
|
|
for pass := 1; pass <= 2; pass++ {
|
|
if c.nodeOfDisco == nil || pass == 2 {
|
|
c.nodeOfDisco = map[tailcfg.DiscoKey]*tailcfg.Node{}
|
|
c.discoOfNode = map[tailcfg.NodeKey]tailcfg.DiscoKey{}
|
|
}
|
|
for _, n := range nm.Peers {
|
|
if !n.DiscoKey.IsZero() {
|
|
c.nodeOfDisco[n.DiscoKey] = n
|
|
if old, ok := c.discoOfNode[n.Key]; ok && old != n.DiscoKey {
|
|
c.logf("magicsock: node %s changed discovery key from %x to %x", n.Key.ShortString(), old[:8], n.DiscoKey[:8])
|
|
// TODO: reset AddrSet states, reset wireguard session key, etc.
|
|
}
|
|
c.discoOfNode[n.Key] = n.DiscoKey
|
|
}
|
|
}
|
|
if len(c.nodeOfDisco) == numDisco && len(c.discoOfNode) == numDisco {
|
|
break
|
|
}
|
|
}
|
|
|
|
// Clean c.endpointOfDisco for discovery keys that are no longer present.
|
|
for dk, de := range c.endpointOfDisco {
|
|
if _, ok := c.nodeOfDisco[dk]; !ok {
|
|
de.cleanup()
|
|
delete(c.endpointOfDisco, dk)
|
|
delete(c.sharedDiscoKey, dk)
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
func (c *Conn) wantDerpLocked() bool { return c.derpMap != nil }
|
|
|
|
// c.mu must be held.
|
|
func (c *Conn) closeAllDerpLocked(why string) {
|
|
if len(c.activeDerp) == 0 {
|
|
return // without the useless log statement
|
|
}
|
|
for i := range c.activeDerp {
|
|
c.closeDerpLocked(i, why)
|
|
}
|
|
c.logActiveDerpLocked()
|
|
}
|
|
|
|
// c.mu must be held.
|
|
// It is the responsibility of the caller to call logActiveDerpLocked after any set of closes.
|
|
func (c *Conn) closeDerpLocked(node int, why string) {
|
|
if ad, ok := c.activeDerp[node]; ok {
|
|
c.logf("magicsock: closing connection to derp-%v (%v), age %v", node, why, time.Since(ad.createTime).Round(time.Second))
|
|
go ad.c.Close()
|
|
ad.cancel()
|
|
delete(c.activeDerp, node)
|
|
}
|
|
}
|
|
|
|
// c.mu must be held.
|
|
func (c *Conn) logActiveDerpLocked() {
|
|
now := time.Now()
|
|
c.logf("magicsock: %v active derp conns%s", len(c.activeDerp), logger.ArgWriter(func(buf *bufio.Writer) {
|
|
if len(c.activeDerp) == 0 {
|
|
return
|
|
}
|
|
buf.WriteString(":")
|
|
c.foreachActiveDerpSortedLocked(func(node int, ad activeDerp) {
|
|
fmt.Fprintf(buf, " derp-%d=cr%v,wr%v", node, simpleDur(now.Sub(ad.createTime)), simpleDur(now.Sub(*ad.lastWrite)))
|
|
})
|
|
}))
|
|
}
|
|
|
|
func (c *Conn) logEndpointChange(endpoints []string, reasons map[string]string) {
|
|
c.logf("magicsock: endpoints changed: %s", logger.ArgWriter(func(buf *bufio.Writer) {
|
|
for i, ep := range endpoints {
|
|
if i > 0 {
|
|
buf.WriteString(", ")
|
|
}
|
|
fmt.Fprintf(buf, "%s (%s)", ep, reasons[ep])
|
|
}
|
|
}))
|
|
}
|
|
|
|
// c.mu must be held.
|
|
func (c *Conn) foreachActiveDerpSortedLocked(fn func(regionID int, ad activeDerp)) {
|
|
if len(c.activeDerp) < 2 {
|
|
for id, ad := range c.activeDerp {
|
|
fn(id, ad)
|
|
}
|
|
return
|
|
}
|
|
ids := make([]int, 0, len(c.activeDerp))
|
|
for id := range c.activeDerp {
|
|
ids = append(ids, id)
|
|
}
|
|
sort.Ints(ids)
|
|
for _, id := range ids {
|
|
fn(id, c.activeDerp[id])
|
|
}
|
|
}
|
|
|
|
func (c *Conn) cleanStaleDerp() {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
const inactivityTime = 60 * time.Second
|
|
tooOld := time.Now().Add(-inactivityTime)
|
|
dirty := false
|
|
for i, ad := range c.activeDerp {
|
|
if i == c.myDerp {
|
|
continue
|
|
}
|
|
if ad.lastWrite.Before(tooOld) {
|
|
c.closeDerpLocked(i, "idle")
|
|
dirty = true
|
|
}
|
|
}
|
|
if dirty {
|
|
c.logActiveDerpLocked()
|
|
}
|
|
}
|
|
|
|
// DERPs reports the number of active DERP connections.
|
|
func (c *Conn) DERPs() int {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
|
|
return len(c.activeDerp)
|
|
}
|
|
|
|
func (c *Conn) SetMark(value uint32) error { return nil }
|
|
func (c *Conn) LastMark() uint32 { return 0 }
|
|
|
|
// Close closes the connection.
|
|
//
|
|
// Only the first close does anything. Any later closes return nil.
|
|
func (c *Conn) Close() error {
|
|
c.mu.Lock()
|
|
if c.closed {
|
|
c.mu.Unlock()
|
|
return nil
|
|
}
|
|
defer c.mu.Unlock()
|
|
|
|
c.closed = true
|
|
c.connCtxCancel()
|
|
c.closeAllDerpLocked("conn-close")
|
|
if c.pconn6 != nil {
|
|
c.pconn6.Close()
|
|
}
|
|
err := c.pconn4.Close()
|
|
// Wait on endpoints updating right at the end, once everything is
|
|
// already closed. We want everything else in the Conn to be
|
|
// consistently in the closed state before we release mu to wait
|
|
// on the endpoint updater.
|
|
for c.endpointsUpdateActive {
|
|
c.endpointsUpdateWaiter.Wait()
|
|
}
|
|
return err
|
|
}
|
|
|
|
var debugReSTUNStopOnIdle, _ = strconv.ParseBool(os.Getenv("TS_DEBUG_RESTUN_STOP_ON_IDLE"))
|
|
|
|
func maxIdleBeforeSTUNShutdown() time.Duration {
|
|
if debugReSTUNStopOnIdle {
|
|
return time.Minute
|
|
}
|
|
return 5 * time.Minute
|
|
}
|
|
|
|
func (c *Conn) shouldDoPeriodicReSTUN() bool {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
if len(c.peerSet) == 0 {
|
|
// No peers, so not worth doing.
|
|
return false
|
|
}
|
|
// If it turns out this optimization was a mistake, we can
|
|
// override it from the control server without waiting for a
|
|
// new software rollout:
|
|
if c.netMap != nil && c.netMap.Debug != nil && c.netMap.Debug.ForceBackgroundSTUN && !debugReSTUNStopOnIdle {
|
|
return true
|
|
}
|
|
if f := c.idleFunc; f != nil {
|
|
idleFor := f()
|
|
if debugReSTUNStopOnIdle {
|
|
c.logf("magicsock: periodicReSTUN: idle for %v", idleFor.Round(time.Second))
|
|
}
|
|
if idleFor > maxIdleBeforeSTUNShutdown() {
|
|
if debugReSTUNStopOnIdle || version.IsMobile() { // TODO: make this unconditional later
|
|
return false
|
|
}
|
|
}
|
|
}
|
|
return true
|
|
}
|
|
|
|
func (c *Conn) periodicReSTUN() {
|
|
prand := rand.New(rand.NewSource(time.Now().UnixNano()))
|
|
dur := func() time.Duration {
|
|
// Just under 30s, a common UDP NAT timeout (Linux at least)
|
|
return time.Duration(20+prand.Intn(7)) * time.Second
|
|
}
|
|
timer := time.NewTimer(dur())
|
|
defer timer.Stop()
|
|
var lastIdleState opt.Bool
|
|
for {
|
|
select {
|
|
case <-c.donec():
|
|
return
|
|
case <-timer.C:
|
|
doReSTUN := c.shouldDoPeriodicReSTUN()
|
|
if !lastIdleState.EqualBool(doReSTUN) {
|
|
if doReSTUN {
|
|
c.logf("magicsock: periodicReSTUN enabled")
|
|
} else {
|
|
c.logf("magicsock: periodicReSTUN disabled due to inactivity")
|
|
}
|
|
lastIdleState.Set(doReSTUN)
|
|
}
|
|
if doReSTUN {
|
|
c.ReSTUN("periodic")
|
|
}
|
|
timer.Reset(dur())
|
|
}
|
|
}
|
|
}
|
|
|
|
func (c *Conn) periodicDerpCleanup() {
|
|
ticker := time.NewTicker(15 * time.Second) // arbitrary
|
|
defer ticker.Stop()
|
|
for {
|
|
select {
|
|
case <-c.donec():
|
|
return
|
|
case <-ticker.C:
|
|
c.cleanStaleDerp()
|
|
}
|
|
}
|
|
}
|
|
|
|
// ReSTUN triggers an address discovery.
|
|
// The provided why string is for debug logging only.
|
|
func (c *Conn) ReSTUN(why string) {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
if !c.started {
|
|
panic("call to ReSTUN before Start")
|
|
}
|
|
if c.closed {
|
|
// raced with a shutdown.
|
|
return
|
|
}
|
|
|
|
if c.endpointsUpdateActive {
|
|
if c.wantEndpointsUpdate != why {
|
|
c.logf("magicsock: ReSTUN: endpoint update active, need another later (%q)", why)
|
|
c.wantEndpointsUpdate = why
|
|
}
|
|
} else {
|
|
c.endpointsUpdateActive = true
|
|
go c.updateEndpoints(why)
|
|
}
|
|
}
|
|
|
|
func (c *Conn) initialBind() error {
|
|
if err := c.bind1(&c.pconn4, "udp4"); err != nil {
|
|
return err
|
|
}
|
|
if err := c.bind1(&c.pconn6, "udp6"); err != nil {
|
|
c.logf("magicsock: ignoring IPv6 bind failure: %v", err)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (c *Conn) bind1(ruc **RebindingUDPConn, which string) error {
|
|
host := ""
|
|
if v, _ := strconv.ParseBool(os.Getenv("IN_TS_TEST")); v {
|
|
host = "127.0.0.1"
|
|
}
|
|
var pc net.PacketConn
|
|
var err error
|
|
listenCtx := context.Background() // unused without DNS name to resolve
|
|
if c.pconnPort == 0 && DefaultPort != 0 {
|
|
pc, err = netns.Listener().ListenPacket(listenCtx, which, fmt.Sprintf("%s:%d", host, DefaultPort))
|
|
if err != nil {
|
|
c.logf("magicsock: bind: default port %s/%v unavailable; picking random", which, DefaultPort)
|
|
}
|
|
}
|
|
if pc == nil {
|
|
pc, err = netns.Listener().ListenPacket(listenCtx, which, fmt.Sprintf("%s:%d", host, c.pconnPort))
|
|
}
|
|
if err != nil {
|
|
c.logf("magicsock: bind(%s/%v): %v", which, c.pconnPort, err)
|
|
return fmt.Errorf("magicsock: bind: %s/%d: %v", which, c.pconnPort, err)
|
|
}
|
|
if *ruc == nil {
|
|
*ruc = new(RebindingUDPConn)
|
|
}
|
|
(*ruc).Reset(pc.(*net.UDPConn))
|
|
return nil
|
|
}
|
|
|
|
// Rebind closes and re-binds the UDP sockets.
|
|
// It should be followed by a call to ReSTUN.
|
|
func (c *Conn) Rebind() {
|
|
host := ""
|
|
if v, _ := strconv.ParseBool(os.Getenv("IN_TS_TEST")); v {
|
|
host = "127.0.0.1"
|
|
}
|
|
listenCtx := context.Background() // unused without DNS name to resolve
|
|
if c.pconnPort != 0 {
|
|
c.pconn4.mu.Lock()
|
|
if err := c.pconn4.pconn.Close(); err != nil {
|
|
c.logf("magicsock: link change close failed: %v", err)
|
|
}
|
|
packetConn, err := netns.Listener().ListenPacket(listenCtx, "udp4", fmt.Sprintf("%s:%d", host, c.pconnPort))
|
|
if err == nil {
|
|
c.logf("magicsock: link change rebound port: %d", c.pconnPort)
|
|
c.pconn4.pconn = packetConn.(*net.UDPConn)
|
|
c.pconn4.mu.Unlock()
|
|
return
|
|
}
|
|
c.logf("magicsock: link change unable to bind fixed port %d: %v, falling back to random port", c.pconnPort, err)
|
|
c.pconn4.mu.Unlock()
|
|
}
|
|
c.logf("magicsock: link change, binding new port")
|
|
packetConn, err := netns.Listener().ListenPacket(listenCtx, "udp4", host+":0")
|
|
if err != nil {
|
|
c.logf("magicsock: link change failed to bind new port: %v", err)
|
|
return
|
|
}
|
|
c.pconn4.Reset(packetConn.(*net.UDPConn))
|
|
|
|
c.mu.Lock()
|
|
c.closeAllDerpLocked("rebind")
|
|
c.mu.Unlock()
|
|
c.goDerpConnect(c.myDerp)
|
|
c.resetAddrSetStates()
|
|
}
|
|
|
|
// resetAddrSetStates resets the preferred address for all peers and
|
|
// re-enables spraying.
|
|
// This is called when connectivity changes enough that we no longer
|
|
// trust the old routes.
|
|
func (c *Conn) resetAddrSetStates() {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
for _, as := range c.addrsByKey {
|
|
as.curAddr = -1
|
|
as.stopSpray = as.timeNow().Add(sprayPeriod)
|
|
}
|
|
for _, de := range c.endpointOfDisco {
|
|
de.noteConnectivityChange()
|
|
}
|
|
}
|
|
|
|
// AddrSet is a set of UDP addresses that implements wireguard/conn.Endpoint.
|
|
//
|
|
// This is the legacy endpoint for peers that don't support discovery;
|
|
// it predates discoEndpoint.
|
|
type AddrSet struct {
|
|
publicKey key.Public // peer public key used for DERP communication
|
|
|
|
// addrs is an ordered priority list provided by wgengine,
|
|
// sorted from expensive+slow+reliable at the begnining to
|
|
// fast+cheap at the end. More concretely, it's typically:
|
|
//
|
|
// [DERP fakeip:node, Global IP:port, LAN ip:port]
|
|
//
|
|
// But there could be multiple or none of each.
|
|
addrs []net.UDPAddr
|
|
ipPorts []netaddr.IPPort // same as addrs, in different form
|
|
|
|
// clock, if non-nil, is used in tests instead of time.Now.
|
|
clock func() time.Time
|
|
Logf logger.Logf // must not be nil
|
|
|
|
mu sync.Mutex // guards following fields
|
|
|
|
// roamAddr is non-nil if/when we receive a correctly signed
|
|
// WireGuard packet from an unexpected address. If so, we
|
|
// remember it and send responses there in the future, but
|
|
// this should hopefully never be used (or at least used
|
|
// rarely) in the case that all the components of Tailscale
|
|
// are correctly learning/sharing the network map details.
|
|
roamAddr *netaddr.IPPort
|
|
roamAddrStd *net.UDPAddr
|
|
|
|
// curAddr is an index into addrs of the highest-priority
|
|
// address a valid packet has been received from so far.
|
|
// If no valid packet from addrs has been received, curAddr is -1.
|
|
curAddr int
|
|
|
|
// stopSpray is the time after which we stop spraying packets.
|
|
stopSpray time.Time
|
|
|
|
// lastSpray is the last time we sprayed a packet.
|
|
lastSpray time.Time
|
|
|
|
// loggedLogPriMask is a bit field of that tracks whether
|
|
// we've already logged about receiving a packet from a low
|
|
// priority ("low-pri") address when we already have curAddr
|
|
// set to a better one. This is only to suppress some
|
|
// redundant logs.
|
|
loggedLogPriMask uint32
|
|
}
|
|
|
|
// derpID returns this AddrSet's home DERP node, or 0 if none is found.
|
|
func (as *AddrSet) derpID() int {
|
|
for _, ua := range as.addrs {
|
|
if ua.IP.Equal(derpMagicIP) {
|
|
return ua.Port
|
|
}
|
|
}
|
|
return 0
|
|
}
|
|
|
|
func (as *AddrSet) timeNow() time.Time {
|
|
if as.clock != nil {
|
|
return as.clock()
|
|
}
|
|
return time.Now()
|
|
}
|
|
|
|
var noAddr, _ = netaddr.FromStdAddr(net.ParseIP("127.127.127.127"), 127, "")
|
|
|
|
func (a *AddrSet) dst() netaddr.IPPort {
|
|
a.mu.Lock()
|
|
defer a.mu.Unlock()
|
|
|
|
if a.roamAddr != nil {
|
|
return *a.roamAddr
|
|
}
|
|
if len(a.addrs) == 0 {
|
|
return noAddr
|
|
}
|
|
i := a.curAddr
|
|
if i == -1 {
|
|
i = 0
|
|
}
|
|
return a.ipPorts[i]
|
|
}
|
|
|
|
// packUDPAddr packs a UDPAddr in the form wanted by WireGuard.
|
|
func packUDPAddr(ua *net.UDPAddr) []byte {
|
|
ip := ua.IP.To4()
|
|
if ip == nil {
|
|
ip = ua.IP
|
|
}
|
|
b := make([]byte, 0, len(ip)+2)
|
|
b = append(b, ip...)
|
|
b = append(b, byte(ua.Port))
|
|
b = append(b, byte(ua.Port>>8))
|
|
return b
|
|
}
|
|
|
|
// packIPPort packs an IPPort into the form wanted by WireGuard.
|
|
func packIPPort(ua netaddr.IPPort) []byte {
|
|
ip := ua.IP.Unmap()
|
|
a := ip.As16()
|
|
ipb := a[:]
|
|
if ip.Is4() {
|
|
ipb = ipb[12:]
|
|
}
|
|
b := make([]byte, 0, len(ipb)+2)
|
|
b = append(b, ipb...)
|
|
b = append(b, byte(ua.Port))
|
|
b = append(b, byte(ua.Port>>8))
|
|
return b
|
|
}
|
|
|
|
func (a *AddrSet) DstToBytes() []byte {
|
|
return packIPPort(a.dst())
|
|
}
|
|
func (a *AddrSet) DstToString() string {
|
|
dst := a.dst()
|
|
return dst.String()
|
|
}
|
|
func (a *AddrSet) DstIP() net.IP {
|
|
return a.dst().IP.IPAddr().IP // TODO: add netaddr accessor to cut an alloc here?
|
|
}
|
|
func (a *AddrSet) SrcIP() net.IP { return nil }
|
|
func (a *AddrSet) SrcToString() string { return "" }
|
|
func (a *AddrSet) ClearSrc() {}
|
|
|
|
func (a *AddrSet) UpdateDst(new *net.UDPAddr) error {
|
|
if new.IP.Equal(derpMagicIP) {
|
|
// Never consider DERP addresses as a viable candidate for
|
|
// either curAddr or roamAddr. It's only ever a last resort
|
|
// choice, never a preferred choice.
|
|
// This is a hot path for established connections.
|
|
return nil
|
|
}
|
|
|
|
a.mu.Lock()
|
|
defer a.mu.Unlock()
|
|
|
|
if a.roamAddrStd != nil && equalUDPAddr(new, a.roamAddrStd) {
|
|
// Packet from the current roaming address, no logging.
|
|
// This is a hot path for established connections.
|
|
return nil
|
|
}
|
|
if a.roamAddr == nil && a.curAddr >= 0 && equalUDPAddr(new, &a.addrs[a.curAddr]) {
|
|
// Packet from current-priority address, no logging.
|
|
// This is a hot path for established connections.
|
|
return nil
|
|
}
|
|
|
|
newa, ok := netaddr.FromStdAddr(new.IP, new.Port, new.Zone)
|
|
if !ok {
|
|
return nil
|
|
}
|
|
|
|
index := -1
|
|
for i := range a.addrs {
|
|
if equalUDPAddr(new, &a.addrs[i]) {
|
|
index = i
|
|
break
|
|
}
|
|
}
|
|
|
|
publicKey := wgcfg.Key(a.publicKey)
|
|
pk := publicKey.ShortString()
|
|
old := "<none>"
|
|
if a.curAddr >= 0 {
|
|
old = a.addrs[a.curAddr].String()
|
|
}
|
|
|
|
switch {
|
|
case index == -1:
|
|
if a.roamAddr == nil {
|
|
a.Logf("magicsock: rx %s from roaming address %s, set as new priority", pk, new)
|
|
} else {
|
|
a.Logf("magicsock: rx %s from roaming address %s, replaces roaming address %s", pk, new, a.roamAddr)
|
|
}
|
|
a.roamAddr = &newa
|
|
a.roamAddrStd = new
|
|
|
|
case a.roamAddr != nil:
|
|
a.Logf("magicsock: rx %s from known %s (%d), replaces roaming address %s", pk, new, index, a.roamAddr)
|
|
a.roamAddr = nil
|
|
a.roamAddrStd = nil
|
|
a.curAddr = index
|
|
a.loggedLogPriMask = 0
|
|
|
|
case a.curAddr == -1:
|
|
a.Logf("magicsock: rx %s from %s (%d/%d), set as new priority", pk, new, index, len(a.addrs))
|
|
a.curAddr = index
|
|
a.loggedLogPriMask = 0
|
|
|
|
case index < a.curAddr:
|
|
if 1 <= index && index <= 32 && (a.loggedLogPriMask&1<<(index-1)) == 0 {
|
|
a.Logf("magicsock: rx %s from low-pri %s (%d), keeping current %s (%d)", pk, new, index, old, a.curAddr)
|
|
a.loggedLogPriMask |= 1 << (index - 1)
|
|
}
|
|
|
|
default: // index > a.curAddr
|
|
a.Logf("magicsock: rx %s from %s (%d/%d), replaces old priority %s", pk, new, index, len(a.addrs), old)
|
|
a.curAddr = index
|
|
a.loggedLogPriMask = 0
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
func equalUDPAddr(x, y *net.UDPAddr) bool {
|
|
return x.Port == y.Port && x.IP.Equal(y.IP)
|
|
}
|
|
|
|
func (a *AddrSet) String() string {
|
|
a.mu.Lock()
|
|
defer a.mu.Unlock()
|
|
|
|
buf := new(strings.Builder)
|
|
buf.WriteByte('[')
|
|
if a.roamAddr != nil {
|
|
buf.WriteString("roam:")
|
|
sbPrintAddr(buf, *a.roamAddrStd)
|
|
}
|
|
for i, addr := range a.addrs {
|
|
if i > 0 || a.roamAddr != nil {
|
|
buf.WriteString(", ")
|
|
}
|
|
sbPrintAddr(buf, addr)
|
|
if a.curAddr == i {
|
|
buf.WriteByte('*')
|
|
}
|
|
}
|
|
buf.WriteByte(']')
|
|
|
|
return buf.String()
|
|
}
|
|
|
|
func (a *AddrSet) Addrs() []wgcfg.Endpoint {
|
|
var eps []wgcfg.Endpoint
|
|
for _, addr := range a.addrs {
|
|
eps = append(eps, wgcfg.Endpoint{
|
|
Host: addr.IP.String(),
|
|
Port: uint16(addr.Port),
|
|
})
|
|
}
|
|
|
|
a.mu.Lock()
|
|
defer a.mu.Unlock()
|
|
if a.roamAddr != nil {
|
|
eps = append(eps, wgcfg.Endpoint{
|
|
Host: a.roamAddr.IP.String(),
|
|
Port: uint16(a.roamAddr.Port),
|
|
})
|
|
}
|
|
return eps
|
|
}
|
|
|
|
// CreateBind is called by WireGuard to create a UDP binding.
|
|
func (c *Conn) CreateBind(uint16) (conn.Bind, uint16, error) {
|
|
return c, c.LocalPort(), nil
|
|
}
|
|
|
|
// CreateEndpoint is called by WireGuard to connect to an endpoint.
|
|
//
|
|
// The key is the public key of the peer and addrs is either:
|
|
//
|
|
// 1) a comma-separated list of UDP ip:ports (the the peer doesn't have a discovery key)
|
|
// 2) "<hex-discovery-key>.disco.tailscale:12345", a magic value that means the peer
|
|
// is running code that supports active discovery, so CreateEndpoint returns
|
|
// a discoEndpoint.
|
|
//
|
|
|
|
func (c *Conn) CreateEndpoint(pubKey [32]byte, addrs string) (conn.Endpoint, error) {
|
|
pk := key.Public(pubKey)
|
|
c.logf("magicsock: CreateEndpoint: key=%s: %s", pk.ShortString(), derpStr(addrs))
|
|
|
|
if strings.HasSuffix(addrs, controlclient.EndpointDiscoSuffix) {
|
|
discoHex := strings.TrimSuffix(addrs, controlclient.EndpointDiscoSuffix)
|
|
discoKey, err := key.NewPublicFromHexMem(mem.S(discoHex))
|
|
if err != nil {
|
|
return nil, fmt.Errorf("magicsock: invalid discokey endpoint %q for %v: %w", addrs, pk.ShortString(), err)
|
|
}
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
de := &discoEndpoint{
|
|
c: c,
|
|
publicKey: pk, // peer public key (for WireGuard + DERP)
|
|
discoKey: tailcfg.DiscoKey(discoKey), // for discovery mesages
|
|
wgEndpointHostPort: addrs,
|
|
sentPing: map[stun.TxID]sentPing{},
|
|
endpointState: map[netaddr.IPPort]*endpointState{},
|
|
timers: map[*time.Timer]bool{},
|
|
}
|
|
de.initFakeUDPAddr()
|
|
de.updateFromNode(c.nodeOfDisco[de.discoKey])
|
|
c.endpointOfDisco[de.discoKey] = de
|
|
return de, nil
|
|
}
|
|
|
|
a := &AddrSet{
|
|
Logf: c.logf,
|
|
publicKey: pk,
|
|
curAddr: -1,
|
|
}
|
|
|
|
if addrs != "" {
|
|
for _, ep := range strings.Split(addrs, ",") {
|
|
ipp, err := netaddr.ParseIPPort(ep)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("bogus address %q", ep)
|
|
}
|
|
a.ipPorts = append(a.ipPorts, ipp)
|
|
a.addrs = append(a.addrs, *ipp.UDPAddr())
|
|
}
|
|
}
|
|
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
|
|
// If this endpoint is being updated, remember its old set of
|
|
// endpoints so we can remove any (from c.addrsByUDP) that are
|
|
// not in the new set.
|
|
var oldIPP []netaddr.IPPort
|
|
if preva, ok := c.addrsByKey[pk]; ok {
|
|
oldIPP = preva.ipPorts
|
|
}
|
|
c.addrsByKey[pk] = a
|
|
|
|
// Add entries to c.addrsByUDP.
|
|
for _, ipp := range a.ipPorts {
|
|
if ipp.IP == derpMagicIPAddr {
|
|
continue
|
|
}
|
|
c.addrsByUDP[ipp] = a
|
|
}
|
|
|
|
// Remove previous c.addrsByUDP entries that are no longer in the new set.
|
|
for _, ipp := range oldIPP {
|
|
if ipp.IP != derpMagicIPAddr && c.addrsByUDP[ipp] != a {
|
|
delete(c.addrsByUDP, ipp)
|
|
}
|
|
}
|
|
|
|
return a, nil
|
|
}
|
|
|
|
// singleEndpoint is a wireguard-go/conn.Endpoint used for "roaming
|
|
// addressed" in releases of Tailscale that predate discovery
|
|
// messages. New peers use discoEndpoint.
|
|
type singleEndpoint net.UDPAddr
|
|
|
|
func (e *singleEndpoint) ClearSrc() {}
|
|
func (e *singleEndpoint) DstIP() net.IP { return (*net.UDPAddr)(e).IP }
|
|
func (e *singleEndpoint) SrcIP() net.IP { return nil }
|
|
func (e *singleEndpoint) SrcToString() string { return "" }
|
|
func (e *singleEndpoint) DstToString() string { return (*net.UDPAddr)(e).String() }
|
|
func (e *singleEndpoint) DstToBytes() []byte { return packUDPAddr((*net.UDPAddr)(e)) }
|
|
func (e *singleEndpoint) UpdateDst(dst *net.UDPAddr) error {
|
|
return fmt.Errorf("magicsock.singleEndpoint(%s).UpdateDst(%s): should never be called", (*net.UDPAddr)(e), dst)
|
|
}
|
|
func (e *singleEndpoint) Addrs() []wgcfg.Endpoint {
|
|
return []wgcfg.Endpoint{{
|
|
Host: e.IP.String(),
|
|
Port: uint16(e.Port),
|
|
}}
|
|
}
|
|
|
|
// RebindingUDPConn is a UDP socket that can be re-bound.
|
|
// Unix has no notion of re-binding a socket, so we swap it out for a new one.
|
|
type RebindingUDPConn struct {
|
|
// ippCache is a cache from UDPAddr => netaddr.IPPort. It's not safe for concurrent use.
|
|
// This is used by ReceiveIPv6 and awaitUDP4 (called from ReceiveIPv4).
|
|
ippCache ippCache
|
|
|
|
mu sync.Mutex
|
|
pconn *net.UDPConn
|
|
}
|
|
|
|
func (c *RebindingUDPConn) Reset(pconn *net.UDPConn) {
|
|
c.mu.Lock()
|
|
old := c.pconn
|
|
c.pconn = pconn
|
|
c.mu.Unlock()
|
|
|
|
if old != nil {
|
|
old.Close()
|
|
}
|
|
}
|
|
|
|
func (c *RebindingUDPConn) ReadFrom(b []byte) (int, net.Addr, error) {
|
|
for {
|
|
c.mu.Lock()
|
|
pconn := c.pconn
|
|
c.mu.Unlock()
|
|
|
|
n, addr, err := pconn.ReadFrom(b)
|
|
if err != nil {
|
|
c.mu.Lock()
|
|
pconn2 := c.pconn
|
|
c.mu.Unlock()
|
|
|
|
if pconn != pconn2 {
|
|
continue
|
|
}
|
|
}
|
|
return n, addr, err
|
|
}
|
|
}
|
|
|
|
func (c *RebindingUDPConn) LocalAddr() *net.UDPAddr {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
return c.pconn.LocalAddr().(*net.UDPAddr)
|
|
}
|
|
|
|
func (c *RebindingUDPConn) Close() error {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
return c.pconn.Close()
|
|
}
|
|
|
|
func (c *RebindingUDPConn) SetReadDeadline(t time.Time) {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
c.pconn.SetReadDeadline(t)
|
|
}
|
|
|
|
func (c *RebindingUDPConn) WriteToUDP(b []byte, addr *net.UDPAddr) (int, error) {
|
|
for {
|
|
c.mu.Lock()
|
|
pconn := c.pconn
|
|
c.mu.Unlock()
|
|
|
|
n, err := pconn.WriteToUDP(b, addr)
|
|
if err != nil {
|
|
c.mu.Lock()
|
|
pconn2 := c.pconn
|
|
c.mu.Unlock()
|
|
|
|
if pconn != pconn2 {
|
|
continue
|
|
}
|
|
}
|
|
return n, err
|
|
}
|
|
}
|
|
|
|
func (c *RebindingUDPConn) WriteTo(b []byte, addr net.Addr) (int, error) {
|
|
for {
|
|
c.mu.Lock()
|
|
pconn := c.pconn
|
|
c.mu.Unlock()
|
|
|
|
n, err := pconn.WriteTo(b, addr)
|
|
if err != nil {
|
|
c.mu.Lock()
|
|
pconn2 := c.pconn
|
|
c.mu.Unlock()
|
|
|
|
if pconn != pconn2 {
|
|
continue
|
|
}
|
|
}
|
|
return n, err
|
|
}
|
|
}
|
|
|
|
// simpleDur rounds d such that it stringifies to something short.
|
|
func simpleDur(d time.Duration) time.Duration {
|
|
if d < time.Second {
|
|
return d.Round(time.Millisecond)
|
|
}
|
|
if d < time.Minute {
|
|
return d.Round(time.Second)
|
|
}
|
|
return d.Round(time.Minute)
|
|
}
|
|
|
|
func peerShort(k key.Public) string {
|
|
k2 := wgcfg.Key(k)
|
|
return k2.ShortString()
|
|
}
|
|
|
|
func sbPrintAddr(sb *strings.Builder, a net.UDPAddr) {
|
|
is6 := a.IP.To4() == nil
|
|
if is6 {
|
|
sb.WriteByte('[')
|
|
}
|
|
fmt.Fprintf(sb, "%s", a.IP)
|
|
if is6 {
|
|
sb.WriteByte(']')
|
|
}
|
|
fmt.Fprintf(sb, ":%d", a.Port)
|
|
}
|
|
|
|
func (c *Conn) UpdateStatus(sb *ipnstate.StatusBuilder) {
|
|
c.mu.Lock()
|
|
defer c.mu.Unlock()
|
|
|
|
for k, as := range c.addrsByKey {
|
|
ps := &ipnstate.PeerStatus{
|
|
InMagicSock: true,
|
|
}
|
|
for i, ua := range as.addrs {
|
|
uaStr := udpAddrDebugString(ua)
|
|
ps.Addrs = append(ps.Addrs, uaStr)
|
|
if as.curAddr == i {
|
|
ps.CurAddr = uaStr
|
|
}
|
|
}
|
|
if as.roamAddr != nil {
|
|
ps.CurAddr = udpAddrDebugString(*as.roamAddrStd)
|
|
}
|
|
sb.AddPeer(k, ps)
|
|
}
|
|
|
|
c.foreachActiveDerpSortedLocked(func(node int, ad activeDerp) {
|
|
// TODO(bradfitz): add to ipnstate.StatusBuilder
|
|
//f("<li><b>derp-%v</b>: cr%v,wr%v</li>", node, simpleDur(now.Sub(ad.createTime)), simpleDur(now.Sub(*ad.lastWrite)))
|
|
})
|
|
}
|
|
|
|
func udpAddrDebugString(ua net.UDPAddr) string {
|
|
if ua.IP.Equal(derpMagicIP) {
|
|
return fmt.Sprintf("derp-%d", ua.Port)
|
|
}
|
|
return ua.String()
|
|
}
|
|
|
|
// discoEndpoint is a wireguard/conn.Endpoint for new-style peers that
|
|
// advertise a DiscoKey and participate in active discovery.
|
|
type discoEndpoint struct {
|
|
// These fields are initialized once and never modified.
|
|
c *Conn
|
|
publicKey key.Public // peer public key (for WireGuard + DERP)
|
|
discoKey tailcfg.DiscoKey // for discovery mesages
|
|
fakeWGAddr netaddr.IPPort // the UDP address we tell wireguard-go we're using
|
|
fakeWGAddrStd *net.UDPAddr // the *net.UDPAddr form of fakeWGAddr
|
|
wgEndpointHostPort string // string from CreateEndpoint: "<hex-discovery-key>.disco.tailscale:12345"
|
|
|
|
// mu protects all following fields.
|
|
mu sync.Mutex // Lock ordering: Conn.mu, then discoEndpoint.mu
|
|
|
|
lastSend time.Time // last time there was outgoing packets sent to this peer (from wireguard-go)
|
|
derpAddr netaddr.IPPort // fallback/bootstrap path, if non-zero (non-zero for well-behaved clients)
|
|
|
|
bestAddr netaddr.IPPort // best non-DERP path; zero if none
|
|
bestAddrLatency time.Duration
|
|
bestAddrAt time.Time // time best address re-confirmed
|
|
trustBestAddrUntil time.Time // time when bestAddr expires
|
|
sentPing map[stun.TxID]sentPing
|
|
endpointState map[netaddr.IPPort]*endpointState
|
|
|
|
// timers are all outstanding timers. They're all stopped on
|
|
// cleanup if the discovery endpoint is removed from the
|
|
// network map.
|
|
timers map[*time.Timer]bool
|
|
}
|
|
|
|
type endpointState struct {
|
|
lastPing time.Time
|
|
// TODO: lastPong time.Time
|
|
index int // index in nodecfg.Node.Endpoints
|
|
}
|
|
|
|
type sentPing struct {
|
|
to netaddr.IPPort
|
|
at time.Time
|
|
timer *time.Timer // timeout timer
|
|
}
|
|
|
|
// initFakeUDPAddr populates fakeWGAddr with a globally unique fake UDPAddr.
|
|
// The current implementation just uses the pointer value of de jammed into an IPv6
|
|
// address, but it could also be, say, a counter.
|
|
func (de *discoEndpoint) initFakeUDPAddr() {
|
|
var addr [16]byte
|
|
addr[0] = 0xfd
|
|
addr[1] = 0x00
|
|
binary.BigEndian.PutUint64(addr[2:], uint64(reflect.ValueOf(de).Pointer()))
|
|
de.fakeWGAddr = netaddr.IPPort{
|
|
IP: netaddr.IPFrom16(addr),
|
|
Port: 12345,
|
|
}
|
|
de.fakeWGAddrStd = de.fakeWGAddr.UDPAddr()
|
|
}
|
|
|
|
func (de *discoEndpoint) Addrs() []wgcfg.Endpoint {
|
|
// This has to be the same string that was passed to
|
|
// CreateEndpoint, otherwise Reconfig will end up recreating
|
|
// Endpoints and losing state over time.
|
|
host, portStr, err := net.SplitHostPort(de.wgEndpointHostPort)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
port, err := strconv.ParseUint(portStr, 10, 16)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
return []wgcfg.Endpoint{{host, uint16(port)}}
|
|
}
|
|
|
|
func (de *discoEndpoint) ClearSrc() {}
|
|
func (de *discoEndpoint) SrcToString() string { panic("unused") } // unused by wireguard-go
|
|
func (de *discoEndpoint) SrcIP() net.IP { panic("unused") } // unused by wireguard-go
|
|
func (de *discoEndpoint) DstToString() string { return de.wgEndpointHostPort }
|
|
func (de *discoEndpoint) DstIP() net.IP { panic("unused") }
|
|
func (de *discoEndpoint) DstToBytes() []byte { return packIPPort(de.fakeWGAddr) }
|
|
func (de *discoEndpoint) UpdateDst(addr *net.UDPAddr) error {
|
|
// This is called ~per packet (and requiring a mutex acquisition inside wireguard-go).
|
|
// TODO(bradfitz): make that cheaper and/or remove it. We don't need it.
|
|
return nil
|
|
}
|
|
|
|
func (de *discoEndpoint) send(b []byte) error {
|
|
now := time.Now()
|
|
|
|
de.mu.Lock()
|
|
de.lastSend = now
|
|
derpAddr := de.derpAddr
|
|
haveDerp := !derpAddr.IsZero()
|
|
bestAddr := de.bestAddr
|
|
bestOld := now.After(de.trustBestAddrUntil)
|
|
if bestAddr.IsZero() || bestOld {
|
|
de.sendPingsLocked(now, true)
|
|
}
|
|
de.mu.Unlock()
|
|
|
|
var didDerp bool
|
|
if bestAddr.IsZero() {
|
|
if !haveDerp {
|
|
return errors.New("no DERP addr")
|
|
}
|
|
bestAddr = derpAddr
|
|
} else if bestOld && haveDerp {
|
|
// We have a bestAddr, but it hasn't been confirmed in a while,
|
|
// so let's not entirely trust it and also send via DERP.
|
|
didDerp, _ = de.c.sendAddr(derpAddr, de.publicKey, b)
|
|
}
|
|
|
|
_, err := de.c.sendAddr(bestAddr, de.publicKey, b)
|
|
if didDerp {
|
|
return nil
|
|
}
|
|
return err
|
|
}
|
|
|
|
// newTimerLocked creates a new AfterFunc(d, f) and returns it after
|
|
// registering it with de.timers.
|
|
//
|
|
// The timer will unregister itself from de.timers after it fires and after f runs.
|
|
func (de *discoEndpoint) newTimerLocked(d time.Duration, f func()) *time.Timer {
|
|
var t *time.Timer
|
|
t = time.AfterFunc(d, func() {
|
|
f()
|
|
|
|
de.mu.Lock()
|
|
delete(de.timers, t)
|
|
de.mu.Unlock()
|
|
})
|
|
de.timers[t] = true
|
|
return t
|
|
}
|
|
|
|
// forgetPing is called by a timer when a ping either fails to send or
|
|
// has taken too long to get a pong reply.
|
|
func (de *discoEndpoint) forgetPing(txid stun.TxID) {
|
|
de.mu.Lock()
|
|
defer de.mu.Unlock()
|
|
if sp, ok := de.sentPing[txid]; ok {
|
|
// Stop the timer for the case where sendPing failed to write to UDP.
|
|
// In the case of a timer already having fired, this is a no-op:
|
|
sp.timer.Stop()
|
|
delete(de.sentPing, txid)
|
|
delete(de.timers, sp.timer)
|
|
}
|
|
}
|
|
|
|
// sendPing sends a ping with the provided txid to ep.
|
|
// The caller should've already been recorded the ping in sentPing
|
|
// and set up the timer.
|
|
func (de *discoEndpoint) sendPing(ep netaddr.IPPort, txid stun.TxID) {
|
|
sent, _ := de.sendDiscoMessage(ep, &disco.Ping{TxID: [12]byte(txid)})
|
|
if !sent {
|
|
de.forgetPing(txid)
|
|
}
|
|
}
|
|
|
|
func (de *discoEndpoint) sendPingsLocked(now time.Time, sendCallMeMaybe bool) {
|
|
sent := false
|
|
for ep, st := range de.endpointState {
|
|
ep := ep
|
|
if !st.lastPing.IsZero() && now.Sub(st.lastPing) < 5*time.Second {
|
|
continue
|
|
}
|
|
st.lastPing = now
|
|
|
|
txid := stun.NewTxID()
|
|
t := de.newTimerLocked(5*time.Second, func() {
|
|
de.c.logf("magicsock: disco: timeout waiting for pong %x from %v (%v, %v)", txid, ep, de.publicKey.ShortString(), de.discoKey.ShortString())
|
|
de.forgetPing(txid)
|
|
})
|
|
de.sentPing[txid] = sentPing{
|
|
to: ep,
|
|
at: now,
|
|
timer: t,
|
|
}
|
|
sent = true
|
|
go de.sendPing(ep, txid)
|
|
}
|
|
derpAddr := de.derpAddr
|
|
if sent && sendCallMeMaybe && !derpAddr.IsZero() {
|
|
// In just a bit of a time (for goroutines above to schedule and run),
|
|
// send a message to peer via DERP informing them that we've sent
|
|
// so our firewall ports are probably open and now would be a good time
|
|
// for them to connect.
|
|
time.AfterFunc(5*time.Millisecond, func() {
|
|
de.sendDiscoMessage(derpAddr, disco.CallMeMaybe{})
|
|
})
|
|
}
|
|
}
|
|
|
|
func (de *discoEndpoint) sendDiscoMessage(dst netaddr.IPPort, dm disco.Message) (sent bool, err error) {
|
|
return de.c.sendDiscoMessage(dst, de.publicKey, de.discoKey, dm)
|
|
}
|
|
|
|
func (de *discoEndpoint) updateFromNode(n *tailcfg.Node) {
|
|
if n == nil {
|
|
// TODO: log, error, count? if this even happens.
|
|
return
|
|
}
|
|
de.mu.Lock()
|
|
defer de.mu.Unlock()
|
|
|
|
if n.DERP == "" {
|
|
de.derpAddr = netaddr.IPPort{}
|
|
} else {
|
|
de.derpAddr, _ = netaddr.ParseIPPort(n.DERP)
|
|
}
|
|
|
|
for _, st := range de.endpointState {
|
|
st.index = -1 // assume deleted until updated in next loop
|
|
}
|
|
for i, epStr := range n.Endpoints {
|
|
ipp, err := netaddr.ParseIPPort(epStr)
|
|
if err != nil {
|
|
de.c.logf("magicsock: bogus netmap endpoint %q", epStr)
|
|
continue
|
|
}
|
|
if st, ok := de.endpointState[ipp]; ok {
|
|
st.index = i
|
|
} else {
|
|
de.endpointState[ipp] = &endpointState{index: i}
|
|
}
|
|
}
|
|
// Now delete anything that wasn't updated.
|
|
for ipp, st := range de.endpointState {
|
|
if st.index == -1 {
|
|
delete(de.endpointState, ipp)
|
|
if de.bestAddr == ipp {
|
|
de.bestAddr = netaddr.IPPort{}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// noteConnectivityChange is called when connectivity changes enough
|
|
// that we should question our earlier assumptions about which paths
|
|
// work.
|
|
func (de *discoEndpoint) noteConnectivityChange() {
|
|
de.mu.Lock()
|
|
defer de.mu.Unlock()
|
|
|
|
de.trustBestAddrUntil = time.Time{}
|
|
}
|
|
|
|
// handlePongConnLocked handles a Pong message (a reply to an earlier ping).
|
|
// It should be called with the Conn.mu held.
|
|
func (de *discoEndpoint) handlePongConnLocked(m *disco.Pong, src netaddr.IPPort) {
|
|
de.mu.Lock()
|
|
defer de.mu.Unlock()
|
|
|
|
if src.IP == derpMagicIPAddr {
|
|
// We might support pinging a node via DERP in the
|
|
// future to see if it's still there, but we don't
|
|
// yet. We shouldn't ever get here, but bail out early
|
|
// in case we do in the future. (In which case, hi!,
|
|
// you'll be modifying this code.)
|
|
return
|
|
}
|
|
|
|
sp, ok := de.sentPing[m.TxID]
|
|
if !ok {
|
|
// This is not a pong for a ping we sent. Ignore.
|
|
return
|
|
}
|
|
delete(de.sentPing, m.TxID)
|
|
|
|
de.c.setAddrToDiscoLocked(src, de.discoKey, de)
|
|
|
|
now := time.Now()
|
|
delay := now.Sub(sp.at)
|
|
de.c.logf("magicsock: disco: %v<-%v (%v, %v) pong tx=%x latency=%v", de.c.discoShort, de.discoKey.ShortString(), de.publicKey.ShortString(), src, m.TxID, delay.Round(time.Millisecond))
|
|
|
|
// Expire our best address if we haven't heard from it in awhile.
|
|
tooOld := now.Add(-15 * time.Second)
|
|
if !de.bestAddr.IsZero() && de.bestAddrAt.Before(tooOld) {
|
|
de.bestAddr = netaddr.IPPort{}
|
|
}
|
|
|
|
// Promote this pong response to our current best address if it's lower latency.
|
|
// TODO(bradfitz): decide how latency vs. preference order affects decision
|
|
if de.bestAddr.IsZero() || delay < de.bestAddrLatency {
|
|
if de.bestAddr != sp.to {
|
|
de.c.logf("magicsock: disco: node %v %v now using %v", de.publicKey.ShortString(), de.discoKey.ShortString(), sp.to)
|
|
de.bestAddr = sp.to
|
|
}
|
|
}
|
|
if src == de.bestAddr {
|
|
de.bestAddrLatency = delay
|
|
de.bestAddrAt = now
|
|
de.trustBestAddrUntil = now.Add(5 * time.Second)
|
|
}
|
|
}
|
|
|
|
// handleCallMeMaybe handles a CallMeMaybe discovery message via
|
|
// DERP. The contract for use of this message is that the peer has
|
|
// already sent to us via UDP, so their stateful firewall should be
|
|
// open. Now we can Ping back and make it through.
|
|
func (de *discoEndpoint) handleCallMeMaybe() {
|
|
de.mu.Lock()
|
|
defer de.mu.Unlock()
|
|
|
|
// Zero out all the lastPing times to force sendPingsLocked to send new ones,
|
|
// even if it's been less than 5 seconds ago.
|
|
for _, st := range de.endpointState {
|
|
st.lastPing = time.Time{}
|
|
}
|
|
de.sendPingsLocked(time.Now(), false)
|
|
}
|
|
|
|
// cleanup is called when a discovery endpoint is no longer present in the NetworkMap.
|
|
// This is where we can do cleanup such as closing goroutines or canceling timers.
|
|
func (de *discoEndpoint) cleanup() {
|
|
de.mu.Lock()
|
|
defer de.mu.Unlock()
|
|
|
|
de.c.logf("magicsock: doing cleanup for discovery key %x", de.discoKey[:])
|
|
|
|
// TODO: real work later, when there's stuff to do
|
|
for t := range de.timers {
|
|
t.Stop()
|
|
delete(de.timers, t)
|
|
}
|
|
}
|
|
|
|
// ippCache is a cache of *net.UDPAddr => netaddr.IPPort mappings.
|
|
//
|
|
// It's not safe for concurrent use.
|
|
type ippCache struct {
|
|
c *lru.Cache
|
|
}
|
|
|
|
// IPPort is a caching wrapper around netaddr.FromStdAddr.
|
|
//
|
|
// It is not safe for concurrent use.
|
|
func (ic *ippCache) IPPort(u *net.UDPAddr) (netaddr.IPPort, bool) {
|
|
if u == nil || len(u.IP) > 16 {
|
|
return netaddr.IPPort{}, false
|
|
}
|
|
if ic.c == nil {
|
|
ic.c = lru.New(64) // arbitrary
|
|
}
|
|
|
|
key := ippCacheKey{ipLen: uint8(len(u.IP)), port: uint16(u.Port), zone: u.Zone}
|
|
copy(key.ip[:], u.IP[:])
|
|
|
|
if v, ok := ic.c.Get(key); ok {
|
|
return v.(netaddr.IPPort), true
|
|
}
|
|
ipp, ok := netaddr.FromStdAddr(u.IP, u.Port, u.Zone)
|
|
if ok {
|
|
ic.c.Add(key, ipp)
|
|
}
|
|
return ipp, ok
|
|
}
|
|
|
|
// ippCacheKey is the cache key type used by ippCache.IPPort.
|
|
// It must be comparable, being used as a map key in the lru package.
|
|
type ippCacheKey struct {
|
|
ip [16]byte
|
|
port uint16
|
|
ipLen uint8 // bytes in ip that are valid; rest are zero
|
|
zone string
|
|
}
|
|
|
|
// derpStr replaces DERP IPs in s with "derp-".
|
|
func derpStr(s string) string { return strings.ReplaceAll(s, "127.3.3.40:", "derp-") }
|