Merge pull request #1036 from yggdrasil-network/neil/linktweaks

Tweak link state locking, add comments, listener priority, other fixes
This commit is contained in:
Neil 2023-05-21 00:06:43 +01:00 committed by GitHub
commit 52709696a5
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2 changed files with 150 additions and 100 deletions

View File

@ -9,7 +9,6 @@ import (
"time"
"github.com/Arceliar/ironwood/network"
"github.com/Arceliar/phony"
"github.com/yggdrasil-network/yggdrasil-go/src/address"
)
@ -76,19 +75,19 @@ func (c *Core) GetPeers() []PeerInfo {
for info, state := range c.links._links {
var peerinfo PeerInfo
var conn net.Conn
phony.Block(state, func() {
peerinfo.URI = info.uri
peerinfo.LastError = state._err
peerinfo.LastErrorTime = state._errtime
if c := state._conn; c != nil {
conn = c
peerinfo.Up = true
peerinfo.Inbound = info.linkType == linkTypeIncoming
peerinfo.RXBytes = c.rx
peerinfo.TXBytes = c.tx
peerinfo.Uptime = time.Since(c.up)
}
})
state.RLock()
peerinfo.URI = info.uri
peerinfo.LastError = state._err
peerinfo.LastErrorTime = state._errtime
if c := state._conn; c != nil {
conn = c
peerinfo.Up = true
peerinfo.Inbound = state.linkType == linkTypeIncoming
peerinfo.RXBytes = c.rx
peerinfo.TXBytes = c.tx
peerinfo.Uptime = time.Since(c.up)
}
state.RUnlock()
if p, ok := conns[conn]; ok {
peerinfo.Key = p.Key
peerinfo.Root = p.Root

View File

@ -46,23 +46,19 @@ type linkProtocol interface {
// linkInfo is used as a map key
type linkInfo struct {
uri string // Peering URI in complete form
sintf string // Peering source interface (i.e. from InterfacePeers)
linkType linkType // Type of link, i.e. outbound/inbound, persistent/ephemeral
uri string // Peering URI in complete form
sintf string // Peering source interface (i.e. from InterfacePeers)
}
// link tracks the state of a connection, either persistent or non-persistent
type link struct {
phony.Inbox
ctx context.Context //
cancel context.CancelFunc //
kick chan struct{} // Attempt to reconnect now, if backing off
info linkInfo //
linkProto string // Protocol carrier of link, e.g. TCP, AWDL
_conn *linkConn // Connected link, if any, nil if not connected
_err error // Last error on the connection, if any
_errtime time.Time // Last time an error occured
kick chan struct{} // Attempt to reconnect now, if backing off
linkType linkType // Type of link, i.e. outbound/inbound, persistent/ephemeral
linkProto string // Protocol carrier of link, e.g. TCP, AWDL
sync.RWMutex // Protects the below
_conn *linkConn // Connected link, if any, nil if not connected
_err error // Last error on the connection, if any
_errtime time.Time // Last time an error occured
}
type linkOptions struct {
@ -125,16 +121,6 @@ func (l *links) shutdown() {
})
}
func (l *links) isConnectedTo(info linkInfo) bool {
l.RLock()
link, ok := l._links[info]
l.RUnlock()
if !ok {
return false
}
return link._conn != nil
}
type linkError string
func (e linkError) Error() string { return string(e) }
@ -149,30 +135,8 @@ func (l *links) add(u *url.URL, sintf string, linkType linkType) error {
// have an open peering to this peer.
lu := urlForLinkInfo(*u)
info := linkInfo{
uri: lu.String(),
sintf: sintf,
linkType: linkType,
}
l.RLock()
state, ok := l._links[info]
l.RUnlock()
if ok && state != nil {
select {
case state.kick <- struct{}{}:
default:
}
return ErrLinkAlreadyConfigured
}
// Create the link entry. This will contain the connection
// in progress (if any), any error details and a context that
// lets the link be cancelled later.
ctx, cancel := context.WithCancel(l.core.ctx)
state = &link{
info: info,
linkProto: strings.ToUpper(u.Scheme),
ctx: ctx,
cancel: cancel,
uri: lu.String(),
sintf: sintf,
}
// Collect together the link options, these are global options
@ -198,9 +162,31 @@ func (l *links) add(u *url.URL, sintf string, linkType linkType) error {
options.priority = uint8(pi)
}
// Store the state of the link, try to connect and then run
// the handler.
// If we think we're already connected to this peer, load up
// the existing peer state. Try to kick the peer if possible,
// which will cause an immediate connection attempt if it is
// backing off for some reason.
l.Lock()
state, ok := l._links[info]
if ok && state != nil {
select {
case state.kick <- struct{}{}:
default:
}
l.Unlock()
return ErrLinkAlreadyConfigured
}
// Create the link entry. This will contain the connection
// in progress (if any), any error details and a context that
// lets the link be cancelled later.
state = &link{
linkType: linkType,
linkProto: strings.ToUpper(u.Scheme),
kick: make(chan struct{}),
}
// Store the state of the link so that it can be queried later.
l._links[info] = state
l.Unlock()
@ -223,7 +209,7 @@ func (l *links) add(u *url.URL, sintf string, linkType linkType) error {
return true
case <-state.kick:
return true
case <-ctx.Done():
case <-l.core.ctx.Done():
return false
}
}
@ -238,44 +224,75 @@ func (l *links) add(u *url.URL, sintf string, linkType linkType) error {
defer l.Unlock()
delete(l._links, info)
}()
// This loop will run each and every time we want to attempt
// a connection to this peer.
for {
conn, err := l.connect(u, info, options)
if err != nil {
if linkType == linkTypePersistent {
phony.Block(state, func() {
state._err = err
state._errtime = time.Now()
})
// If the link is a persistent configured peering,
// store information about the connection error so
// that we can report it through the admin socket.
state.Lock()
state._conn = nil
state._err = err
state._errtime = time.Now()
state.Unlock()
// Back off for a bit. If true is returned here, we
// can continue onto the next loop iteration to try
// the next connection.
if backoffNow() {
continue
} else {
return
}
} else {
// Ephemeral and incoming connections don't remain
// after a connection failure, so exit out of the
// loop and clean up the link entry.
break
}
}
// The linkConn wrapper allows us to track the number of
// bytes written to and read from this connection without
// the help of ironwood.
lc := &linkConn{
Conn: conn,
up: time.Now(),
}
phony.Block(state, func() {
state._conn = lc
state._err = nil
state._errtime = time.Time{}
})
if err = l.handler(&info, options, lc); err != nil && err != io.EOF {
// Update the link state with our newly wrapped connection.
// Clear the error state.
state.Lock()
state._conn = lc
state._err = nil
state._errtime = time.Time{}
state.Unlock()
// Give the connection to the handler. The handler will block
// for the lifetime of the connection.
if err = l.handler(linkType, options, lc); err != nil && err != io.EOF {
l.core.log.Debugf("Link %s error: %s\n", info.uri, err)
} else {
backoff = 0
}
_ = conn.Close()
phony.Block(state, func() {
state._conn = nil
if state._err = err; state._err != nil {
state._errtime = time.Now()
}
})
// The handler has stopped running so the connection is dead,
// try to close the underlying socket just in case and then
// update the link state.
_ = lc.Close()
state.Lock()
state._conn = nil
if state._err = err; state._err != nil {
state._errtime = time.Now()
}
state.Unlock()
// If the link is persistently configured, back off if needed
// and then try reconnecting. Otherwise, exit out.
if linkType == linkTypePersistent {
if backoffNow() {
continue
@ -314,6 +331,16 @@ func (l *links) listen(u *url.URL, sintf string) (*Listener, error) {
ctx: ctx,
Cancel: cancel,
}
var options linkOptions
if p := u.Query().Get("priority"); p != "" {
pi, err := strconv.ParseUint(p, 10, 8)
if err != nil {
return nil, ErrLinkPriorityInvalid
}
options.priority = uint8(pi)
}
go func() {
l.core.log.Printf("%s listener started on %s", strings.ToUpper(u.Scheme), listener.Addr())
defer l.core.log.Printf("%s listener stopped on %s", strings.ToUpper(u.Scheme), listener.Addr())
@ -324,41 +351,65 @@ func (l *links) listen(u *url.URL, sintf string) (*Listener, error) {
}
go func(conn net.Conn) {
defer conn.Close()
// In order to populate a somewhat sane looking connection
// URI in the admin socket, we need to replace the host in
// the listener URL with the remote address.
pu := *u
pu.Host = conn.RemoteAddr().String()
lu := urlForLinkInfo(pu)
info := linkInfo{
uri: lu.String(),
sintf: sintf,
linkType: linkTypeEphemeral, // TODO: should be incoming
uri: lu.String(),
sintf: sintf,
}
if l.isConnectedTo(info) {
// If there's an existing link state for this link, get it.
// If this node is already connected to us, just drop the
// connection. This prevents duplicate peerings.
l.Lock()
state, ok := l._links[info]
if ok && state != nil && state._conn != nil {
l.Unlock()
return
}
l.RLock()
state, ok := l._links[info]
l.RUnlock()
if !ok || state == nil {
state = &link{
info: info,
linkType: linkTypeIncoming,
linkProto: strings.ToUpper(u.Scheme),
kick: make(chan struct{}),
}
}
// The linkConn wrapper allows us to track the number of
// bytes written to and read from this connection without
// the help of ironwood.
lc := &linkConn{
Conn: conn,
up: time.Now(),
}
var options linkOptions
phony.Block(state, func() {
state._conn = lc
state._err = nil
state.linkProto = strings.ToUpper(u.Scheme)
})
l.Lock()
// Update the link state with our newly wrapped connection.
// Clear the error state.
state.Lock()
state._conn = lc
state._err = nil
state._errtime = time.Time{}
state.Unlock()
// Store the state of the link so that it can be queried later.
l._links[info] = state
l.Unlock()
if err = l.handler(&info, options, lc); err != nil && err != io.EOF {
// Give the connection to the handler. The handler will block
// for the lifetime of the connection.
if err = l.handler(linkTypeIncoming, options, lc); err != nil && err != io.EOF {
l.core.log.Debugf("Link %s error: %s\n", u.Host, err)
}
// The handler has stopped running so the connection is dead,
// try to close the underlying socket just in case and then
// drop the link state.
_ = lc.Close()
l.Lock()
delete(l._links, info)
l.Unlock()
@ -401,7 +452,7 @@ func (l *links) connect(u *url.URL, info linkInfo, options linkOptions) (net.Con
return dialer.dial(u, info, options)
}
func (l *links) handler(info *linkInfo, options linkOptions, conn net.Conn) error {
func (l *links) handler(linkType linkType, options linkOptions, conn net.Conn) error {
meta := version_getBaseMetadata()
meta.publicKey = l.core.public
metaBytes := meta.encode()
@ -453,12 +504,12 @@ func (l *links) handler(info *linkInfo, options linkOptions, conn net.Conn) erro
break
}
}
if info.linkType == linkTypeIncoming && !isallowed {
if linkType == linkTypeIncoming && !isallowed {
return fmt.Errorf("node public key %q is not in AllowedPublicKeys", hex.EncodeToString(meta.publicKey))
}
dir := "outbound"
if info.linkType == linkTypeIncoming {
if linkType == linkTypeIncoming {
dir = "inbound"
}
remoteAddr := net.IP(address.AddrForKey(meta.publicKey)[:]).String()