From aaf34c63049ed8314fd222367cfbc1fa51813ca7 Mon Sep 17 00:00:00 2001 From: Arceliar Date: Sun, 25 Aug 2019 18:08:43 -0500 Subject: [PATCH] start migrating the TunAdapter to the actor model --- src/tuntap/conn.go | 5 +- src/tuntap/iface.go | 501 +++++++++++++++++++++++--------------------- src/tuntap/tun.go | 11 +- 3 files changed, 267 insertions(+), 250 deletions(-) diff --git a/src/tuntap/conn.go b/src/tuntap/conn.go index 3149091..cdb8c32 100644 --- a/src/tuntap/conn.go +++ b/src/tuntap/conn.go @@ -113,8 +113,7 @@ func (s *tunConn) _read(bs []byte) (err error) { util.PutBytes(bs) return } - // FIXME this send can block if the tuntap isn't running, which isn't really safe... - s.tun.send <- bs + s.tun.writer.writeFrom(s, bs) s.stillAlive() return } @@ -208,7 +207,7 @@ func (s *tunConn) _write(bs []byte) (err error) { Data: bs[:900], } if packet, err := CreateICMPv6(bs[8:24], bs[24:40], ipv6.ICMPTypePacketTooBig, 0, ptb); err == nil { - s.tun.send <- packet + s.tun.writer.writeFrom(s, packet) } } else { if e.Closed() { diff --git a/src/tuntap/iface.go b/src/tuntap/iface.go index e0693e5..3f92351 100644 --- a/src/tuntap/iface.go +++ b/src/tuntap/iface.go @@ -9,264 +9,279 @@ import ( "github.com/yggdrasil-network/yggdrasil-go/src/address" "github.com/yggdrasil-network/yggdrasil-go/src/crypto" "github.com/yggdrasil-network/yggdrasil-go/src/util" + + "github.com/Arceliar/phony" ) -func (tun *TunAdapter) writer() error { - var w int +type tunWriter struct { + phony.Inbox + tun *TunAdapter +} + +func (w *tunWriter) writeFrom(from phony.Actor, b []byte) { + w.RecvFrom(from, func() { + w._write(b) + }) +} + +// write is pretty loose with the memory safety rules, e.g. it assumes it can read w.tun.iface.IsTap() safely +func (w *tunWriter) _write(b []byte) { + var written int var err error - for { - b := <-tun.send - n := len(b) - if n == 0 { - continue - } - if tun.iface.IsTAP() { - sendndp := func(dstAddr address.Address) { - neigh, known := tun.icmpv6.getNeighbor(dstAddr) - known = known && (time.Since(neigh.lastsolicitation).Seconds() < 30) - if !known { - tun.icmpv6.Solicit(dstAddr) - } - } - peermac := net.HardwareAddr{0x00, 0x00, 0x00, 0x00, 0x00, 0x00} - var dstAddr address.Address - var peerknown bool - if b[0]&0xf0 == 0x40 { - dstAddr = tun.addr - } else if b[0]&0xf0 == 0x60 { - if !bytes.Equal(tun.addr[:16], dstAddr[:16]) && !bytes.Equal(tun.subnet[:8], dstAddr[:8]) { - dstAddr = tun.addr - } - } - if neighbor, ok := tun.icmpv6.getNeighbor(dstAddr); ok && neighbor.learned { - // If we've learned the MAC of a 300::/7 address, for example, or a CKR - // address, use the MAC address of that - peermac = neighbor.mac - peerknown = true - } else if neighbor, ok := tun.icmpv6.getNeighbor(tun.addr); ok && neighbor.learned { - // Otherwise send directly to the MAC address of the host if that's - // known instead - peermac = neighbor.mac - peerknown = true - } else { - // Nothing has been discovered, try to discover the destination - sendndp(tun.addr) - } - if peerknown { - var proto ethernet.Ethertype - switch { - case b[0]&0xf0 == 0x60: - proto = ethernet.IPv6 - case b[0]&0xf0 == 0x40: - proto = ethernet.IPv4 - } - var frame ethernet.Frame - frame.Prepare( - peermac[:6], // Destination MAC address - tun.icmpv6.mymac[:6], // Source MAC address - ethernet.NotTagged, // VLAN tagging - proto, // Ethertype - len(b)) // Payload length - copy(frame[tun_ETHER_HEADER_LENGTH:], b[:n]) - n += tun_ETHER_HEADER_LENGTH - w, err = tun.iface.Write(frame[:n]) - } else { - tun.log.Errorln("TUN/TAP iface write error: no peer MAC known for", net.IP(dstAddr[:]).String(), "- dropping packet") - } - } else { - w, err = tun.iface.Write(b[:n]) - util.PutBytes(b) - } - if err != nil { - if !tun.isOpen { - return err - } - tun.log.Errorln("TUN/TAP iface write error:", err) - continue - } - if w != n { - tun.log.Errorln("TUN/TAP iface write mismatch:", w, "bytes written vs", n, "bytes given") - continue - } + n := len(b) + if n == 0 { + return } -} - -// Run in a separate goroutine by the reader -// Does all of the per-packet ICMP checks, passes packets to the right Conn worker -func (tun *TunAdapter) readerPacketHandler(ch chan []byte) { - for recvd := range ch { - // If it's a TAP adapter, update the buffer slice so that we no longer - // include the ethernet headers - offset := 0 - if tun.iface.IsTAP() { - // Set our offset to beyond the ethernet headers - offset = tun_ETHER_HEADER_LENGTH - // Check first of all that we can go beyond the ethernet headers - if len(recvd) <= offset { - continue + if w.tun.iface.IsTAP() { + sendndp := func(dstAddr address.Address) { + neigh, known := w.tun.icmpv6.getNeighbor(dstAddr) + known = known && (time.Since(neigh.lastsolicitation).Seconds() < 30) + if !known { + w.tun.icmpv6.Solicit(dstAddr) } } - // Offset the buffer from now on so that we can ignore ethernet frames if - // they are present - bs := recvd[offset:] - // If we detect an ICMP packet then hand it to the ICMPv6 module - if bs[6] == 58 { - // Found an ICMPv6 packet - we need to make sure to give ICMPv6 the full - // Ethernet frame rather than just the IPv6 packet as this is needed for - // NDP to work correctly - if err := tun.icmpv6.ParsePacket(recvd); err == nil { - // We acted on the packet in the ICMPv6 module so don't forward or do - // anything else with it - continue - } - } - if offset != 0 { - // Shift forward to avoid leaking bytes off the front of the slice when we eventually store it - bs = append(recvd[:0], bs...) - } - // From the IP header, work out what our source and destination addresses - // and node IDs are. We will need these in order to work out where to send - // the packet + peermac := net.HardwareAddr{0x00, 0x00, 0x00, 0x00, 0x00, 0x00} var dstAddr address.Address - var dstSnet address.Subnet - var addrlen int - n := len(bs) - // Check the IP protocol - if it doesn't match then we drop the packet and - // do nothing with it - if bs[0]&0xf0 == 0x60 { - // Check if we have a fully-sized IPv6 header - if len(bs) < 40 { - continue + var peerknown bool + if b[0]&0xf0 == 0x40 { + dstAddr = w.tun.addr + } else if b[0]&0xf0 == 0x60 { + if !bytes.Equal(w.tun.addr[:16], dstAddr[:16]) && !bytes.Equal(w.tun.subnet[:8], dstAddr[:8]) { + dstAddr = w.tun.addr } - // Check the packet size - if n-tun_IPv6_HEADER_LENGTH != 256*int(bs[4])+int(bs[5]) { - continue - } - // IPv6 address - addrlen = 16 - copy(dstAddr[:addrlen], bs[24:]) - copy(dstSnet[:addrlen/2], bs[24:]) - } else if bs[0]&0xf0 == 0x40 { - // Check if we have a fully-sized IPv4 header - if len(bs) < 20 { - continue - } - // Check the packet size - if n != 256*int(bs[2])+int(bs[3]) { - continue - } - // IPv4 address - addrlen = 4 - copy(dstAddr[:addrlen], bs[16:]) + } + if neighbor, ok := w.tun.icmpv6.getNeighbor(dstAddr); ok && neighbor.learned { + // If we've learned the MAC of a 300::/7 address, for example, or a CKR + // address, use the MAC address of that + peermac = neighbor.mac + peerknown = true + } else if neighbor, ok := w.tun.icmpv6.getNeighbor(w.tun.addr); ok && neighbor.learned { + // Otherwise send directly to the MAC address of the host if that's + // known instead + peermac = neighbor.mac + peerknown = true } else { - // Unknown address length or protocol, so drop the packet and ignore it - tun.log.Traceln("Unknown packet type, dropping") - continue + // Nothing has been discovered, try to discover the destination + sendndp(w.tun.addr) } - if tun.ckr.isEnabled() { - if addrlen != 16 || (!dstAddr.IsValid() && !dstSnet.IsValid()) { - if key, err := tun.ckr.getPublicKeyForAddress(dstAddr, addrlen); err == nil { - // A public key was found, get the node ID for the search - dstNodeID := crypto.GetNodeID(&key) - dstAddr = *address.AddrForNodeID(dstNodeID) - dstSnet = *address.SubnetForNodeID(dstNodeID) - addrlen = 16 - } + if peerknown { + var proto ethernet.Ethertype + switch { + case b[0]&0xf0 == 0x60: + proto = ethernet.IPv6 + case b[0]&0xf0 == 0x40: + proto = ethernet.IPv4 } + var frame ethernet.Frame + frame.Prepare( + peermac[:6], // Destination MAC address + w.tun.icmpv6.mymac[:6], // Source MAC address + ethernet.NotTagged, // VLAN tagging + proto, // Ethertype + len(b)) // Payload length + copy(frame[tun_ETHER_HEADER_LENGTH:], b[:n]) + n += tun_ETHER_HEADER_LENGTH + written, err = w.tun.iface.Write(frame[:n]) + } else { + w.tun.log.Errorln("TUN/TAP iface write error: no peer MAC known for", net.IP(dstAddr[:]).String(), "- dropping packet") } - if addrlen != 16 || (!dstAddr.IsValid() && !dstSnet.IsValid()) { - // Couldn't find this node's ygg IP - continue - } - // Do we have an active connection for this node address? - var dstNodeID, dstNodeIDMask *crypto.NodeID - tun.mutex.RLock() - session, isIn := tun.addrToConn[dstAddr] - if !isIn || session == nil { - session, isIn = tun.subnetToConn[dstSnet] - if !isIn || session == nil { - // Neither an address nor a subnet mapping matched, therefore populate - // the node ID and mask to commence a search - if dstAddr.IsValid() { - dstNodeID, dstNodeIDMask = dstAddr.GetNodeIDandMask() - } else { - dstNodeID, dstNodeIDMask = dstSnet.GetNodeIDandMask() - } - } - } - tun.mutex.RUnlock() - // If we don't have a connection then we should open one - if !isIn || session == nil { - // Check we haven't been given empty node ID, really this shouldn't ever - // happen but just to be sure... - if dstNodeID == nil || dstNodeIDMask == nil { - panic("Given empty dstNodeID and dstNodeIDMask - this shouldn't happen") - } - // Dial to the remote node - go func() { - // FIXME just spitting out a goroutine to do this is kind of ugly and means we drop packets until the dial finishes - tun.mutex.Lock() - _, known := tun.dials[*dstNodeID] - tun.dials[*dstNodeID] = append(tun.dials[*dstNodeID], bs) - for len(tun.dials[*dstNodeID]) > 32 { - util.PutBytes(tun.dials[*dstNodeID][0]) - tun.dials[*dstNodeID] = tun.dials[*dstNodeID][1:] - } - tun.mutex.Unlock() - if known { - return - } - var tc *tunConn - if conn, err := tun.dialer.DialByNodeIDandMask(dstNodeID, dstNodeIDMask); err == nil { - // We've been given a connection so prepare the session wrapper - if tc, err = tun.wrap(conn); err != nil { - // Something went wrong when storing the connection, typically that - // something already exists for this address or subnet - tun.log.Debugln("TUN/TAP iface wrap:", err) - } - } - tun.mutex.Lock() - packets := tun.dials[*dstNodeID] - delete(tun.dials, *dstNodeID) - tun.mutex.Unlock() - if tc != nil { - for _, packet := range packets { - p := packet // Possibly required because of how range - <-tc.SyncExec(func() { tc._write(p) }) - } - } - }() - // While the dial is going on we can't do much else - // continuing this iteration - skip to the next one - continue - } - // If we have a connection now, try writing to it - if isIn && session != nil { - <-session.SyncExec(func() { session._write(bs) }) + } else { + written, err = w.tun.iface.Write(b[:n]) + util.PutBytes(b) + } + if err != nil { + w.tun.mutex.Lock() + open := w.tun.isOpen + w.tun.mutex.Unlock() + if !open { + return } + w.tun.log.Errorln("TUN/TAP iface write error:", err) + } + if written != n { + w.tun.log.Errorln("TUN/TAP iface write mismatch:", written, "bytes written vs", n, "bytes given") } } -func (tun *TunAdapter) reader() error { - toWorker := make(chan []byte, 32) - defer close(toWorker) - go tun.readerPacketHandler(toWorker) - for { - // Get a slice to store the packet in - recvd := util.ResizeBytes(util.GetBytes(), 65535+tun_ETHER_HEADER_LENGTH) - // Wait for a packet to be delivered to us through the TUN/TAP adapter - n, err := tun.iface.Read(recvd) - if err != nil { - if !tun.isOpen { - return err - } - panic(err) - } - if n == 0 { - util.PutBytes(recvd) - continue - } - // Send the packet to the worker - toWorker <- recvd[:n] +type tunReader struct { + phony.Inbox + tun *TunAdapter +} + +func (r *tunReader) _read() { + // Get a slice to store the packet in + recvd := util.ResizeBytes(util.GetBytes(), 65535+tun_ETHER_HEADER_LENGTH) + // Wait for a packet to be delivered to us through the TUN/TAP adapter + n, err := r.tun.iface.Read(recvd) + if n == 0 { + util.PutBytes(recvd) + } else { + r.tun.handlePacketFrom(r, recvd[:n], err) + } + if err == nil { + // Now read again + r.RecvFrom(nil, r._read) + } +} + +func (tun *TunAdapter) handlePacketFrom(from phony.Actor, packet []byte, err error) { + tun.RecvFrom(from, func() { + tun._handlePacket(packet, err) + }) +} + +// does the work of reading a packet and sending it to the correct tunConn +func (tun *TunAdapter) _handlePacket(recvd []byte, err error) { + if err != nil { + tun.log.Errorln("TUN/TAP iface read error:", err) + return + } + // If it's a TAP adapter, update the buffer slice so that we no longer + // include the ethernet headers + offset := 0 + if tun.iface.IsTAP() { + // Set our offset to beyond the ethernet headers + offset = tun_ETHER_HEADER_LENGTH + // Check first of all that we can go beyond the ethernet headers + if len(recvd) <= offset { + return + } + } + // Offset the buffer from now on so that we can ignore ethernet frames if + // they are present + bs := recvd[offset:] + // If we detect an ICMP packet then hand it to the ICMPv6 module + if bs[6] == 58 { + // Found an ICMPv6 packet - we need to make sure to give ICMPv6 the full + // Ethernet frame rather than just the IPv6 packet as this is needed for + // NDP to work correctly + if err := tun.icmpv6.ParsePacket(recvd); err == nil { + // We acted on the packet in the ICMPv6 module so don't forward or do + // anything else with it + return + } + } + if offset != 0 { + // Shift forward to avoid leaking bytes off the front of the slice when we eventually store it + bs = append(recvd[:0], bs...) + } + // From the IP header, work out what our source and destination addresses + // and node IDs are. We will need these in order to work out where to send + // the packet + var dstAddr address.Address + var dstSnet address.Subnet + var addrlen int + n := len(bs) + // Check the IP protocol - if it doesn't match then we drop the packet and + // do nothing with it + if bs[0]&0xf0 == 0x60 { + // Check if we have a fully-sized IPv6 header + if len(bs) < 40 { + return + } + // Check the packet size + if n-tun_IPv6_HEADER_LENGTH != 256*int(bs[4])+int(bs[5]) { + return + } + // IPv6 address + addrlen = 16 + copy(dstAddr[:addrlen], bs[24:]) + copy(dstSnet[:addrlen/2], bs[24:]) + } else if bs[0]&0xf0 == 0x40 { + // Check if we have a fully-sized IPv4 header + if len(bs) < 20 { + return + } + // Check the packet size + if n != 256*int(bs[2])+int(bs[3]) { + return + } + // IPv4 address + addrlen = 4 + copy(dstAddr[:addrlen], bs[16:]) + } else { + // Unknown address length or protocol, so drop the packet and ignore it + tun.log.Traceln("Unknown packet type, dropping") + return + } + if tun.ckr.isEnabled() { + if addrlen != 16 || (!dstAddr.IsValid() && !dstSnet.IsValid()) { + if key, err := tun.ckr.getPublicKeyForAddress(dstAddr, addrlen); err == nil { + // A public key was found, get the node ID for the search + dstNodeID := crypto.GetNodeID(&key) + dstAddr = *address.AddrForNodeID(dstNodeID) + dstSnet = *address.SubnetForNodeID(dstNodeID) + addrlen = 16 + } + } + } + if addrlen != 16 || (!dstAddr.IsValid() && !dstSnet.IsValid()) { + // Couldn't find this node's ygg IP + return + } + // Do we have an active connection for this node address? + var dstNodeID, dstNodeIDMask *crypto.NodeID + tun.mutex.RLock() + session, isIn := tun.addrToConn[dstAddr] + if !isIn || session == nil { + session, isIn = tun.subnetToConn[dstSnet] + if !isIn || session == nil { + // Neither an address nor a subnet mapping matched, therefore populate + // the node ID and mask to commence a search + if dstAddr.IsValid() { + dstNodeID, dstNodeIDMask = dstAddr.GetNodeIDandMask() + } else { + dstNodeID, dstNodeIDMask = dstSnet.GetNodeIDandMask() + } + } + } + tun.mutex.RUnlock() + // If we don't have a connection then we should open one + if !isIn || session == nil { + // Check we haven't been given empty node ID, really this shouldn't ever + // happen but just to be sure... + if dstNodeID == nil || dstNodeIDMask == nil { + panic("Given empty dstNodeID and dstNodeIDMask - this shouldn't happen") + } + // Dial to the remote node + go func() { + // FIXME just spitting out a goroutine to do this is kind of ugly and means we drop packets until the dial finishes + tun.mutex.Lock() + _, known := tun.dials[*dstNodeID] + tun.dials[*dstNodeID] = append(tun.dials[*dstNodeID], bs) + for len(tun.dials[*dstNodeID]) > 32 { + util.PutBytes(tun.dials[*dstNodeID][0]) + tun.dials[*dstNodeID] = tun.dials[*dstNodeID][1:] + } + tun.mutex.Unlock() + if known { + return + } + var tc *tunConn + if conn, err := tun.dialer.DialByNodeIDandMask(dstNodeID, dstNodeIDMask); err == nil { + // We've been given a connection so prepare the session wrapper + if tc, err = tun.wrap(conn); err != nil { + // Something went wrong when storing the connection, typically that + // something already exists for this address or subnet + tun.log.Debugln("TUN/TAP iface wrap:", err) + } + } + tun.mutex.Lock() + packets := tun.dials[*dstNodeID] + delete(tun.dials, *dstNodeID) + tun.mutex.Unlock() + if tc != nil { + for _, packet := range packets { + p := packet // Possibly required because of how range + <-tc.SyncExec(func() { tc._write(p) }) + } + } + }() + // While the dial is going on we can't do much else + return + } + // If we have a connection now, try writing to it + if isIn && session != nil { + session.RecvFrom(tun, func() { session._write(bs) }) } } diff --git a/src/tuntap/tun.go b/src/tuntap/tun.go index d73384d..7bb3a59 100644 --- a/src/tuntap/tun.go +++ b/src/tuntap/tun.go @@ -15,6 +15,7 @@ import ( "net" "sync" + "github.com/Arceliar/phony" "github.com/gologme/log" "github.com/yggdrasil-network/water" @@ -33,6 +34,8 @@ const tun_ETHER_HEADER_LENGTH = 14 // you should pass this object to the yggdrasil.SetRouterAdapter() function // before calling yggdrasil.Start(). type TunAdapter struct { + writer tunWriter + reader tunReader config *config.NodeState log *log.Logger reconfigure chan chan error @@ -44,7 +47,7 @@ type TunAdapter struct { icmpv6 ICMPv6 mtu int iface *water.Interface - send chan []byte + phony.Inbox // Currently only used for _handlePacket from the reader, TODO: all the stuff that currently needs a mutex below mutex sync.RWMutex // Protects the below addrToConn map[address.Address]*tunConn subnetToConn map[address.Subnet]*tunConn @@ -114,6 +117,8 @@ func (tun *TunAdapter) Init(config *config.NodeState, log *log.Logger, listener tun.addrToConn = make(map[address.Address]*tunConn) tun.subnetToConn = make(map[address.Subnet]*tunConn) tun.dials = make(map[crypto.NodeID][][]byte) + tun.writer.tun = tun + tun.reader.tun = tun } // Start the setup process for the TUN/TAP adapter. If successful, starts the @@ -147,7 +152,6 @@ func (tun *TunAdapter) Start() error { } tun.mutex.Lock() tun.isOpen = true - tun.send = make(chan []byte, 32) // TODO: is this a sensible value? tun.reconfigure = make(chan chan error) tun.mutex.Unlock() go func() { @@ -157,8 +161,7 @@ func (tun *TunAdapter) Start() error { } }() go tun.handler() - go tun.reader() - go tun.writer() + tun.reader.RecvFrom(nil, tun.reader._read) // Start the reader tun.icmpv6.Init(tun) if iftapmode { go tun.icmpv6.Solicit(tun.addr)