Merge pull request #651 from Arceliar/search

Search
This commit is contained in:
Arceliar 2020-02-13 20:35:52 -06:00 committed by GitHub
commit a101fc0556
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
4 changed files with 80 additions and 64 deletions

View File

@ -131,7 +131,7 @@ func (c *Conn) search() error {
}
}
sinfo := c.core.router.searches.newIterSearch(c.nodeID, c.nodeMask, searchCompleted)
sinfo.continueSearch()
sinfo.startSearch()
} else {
err = errors.New("search already exists")
close(done)
@ -155,7 +155,7 @@ func (c *Conn) doSearch() {
sinfo = c.core.router.searches.newIterSearch(c.nodeID, c.nodeMask, searchCompleted)
c.core.log.Debugf("%s DHT search started: %p", c.String(), sinfo)
// Start the search
sinfo.continueSearch()
sinfo.startSearch()
}
}
c.core.router.Act(c.session, routerWork)

View File

@ -65,12 +65,15 @@ func (d *Dialer) DialContext(ctx context.Context, network, address string) (net.
// DialByNodeIDandMask opens a session to the given node based on raw
// NodeID parameters. If ctx is nil or has no timeout, then a default timeout of 6 seconds will apply, beginning *after* the search finishes.
func (d *Dialer) DialByNodeIDandMask(ctx context.Context, nodeID, nodeMask *crypto.NodeID) (net.Conn, error) {
startDial := time.Now()
conn := newConn(d.core, nodeID, nodeMask, nil)
if err := conn.search(); err != nil {
// TODO: make searches take a context, so they can be cancelled early
conn.Close()
return nil, err
}
endSearch := time.Now()
d.core.log.Debugln("Dial searched for:", nodeID, "in time:", endSearch.Sub(startDial))
conn.session.setConn(nil, conn)
var cancel context.CancelFunc
if ctx == nil {
@ -80,6 +83,9 @@ func (d *Dialer) DialByNodeIDandMask(ctx context.Context, nodeID, nodeMask *cryp
defer cancel()
select {
case <-conn.session.init:
endInit := time.Now()
d.core.log.Debugln("Dial initialized session for:", nodeID, "in time:", endInit.Sub(endSearch))
d.core.log.Debugln("Finished dial for:", nodeID, "in time:", endInit.Sub(startDial))
return conn, nil
case <-ctx.Done():
conn.Close()

View File

@ -22,9 +22,6 @@ import (
"github.com/yggdrasil-network/yggdrasil-go/src/crypto"
)
// This defines the maximum number of dhtInfo that we keep track of for nodes to query in an ongoing search.
const search_MAX_SEARCH_SIZE = 16
// This defines the time after which we time out a search (so it can restart).
const search_RETRY_TIME = 3 * time.Second
const search_STEP_TIME = 100 * time.Millisecond
@ -36,7 +33,6 @@ type searchInfo struct {
dest crypto.NodeID
mask crypto.NodeID
time time.Time
toVisit []*dhtInfo
visited crypto.NodeID // Closest address visited so far
callback func(*sessionInfo, error)
// TODO context.Context for timeout and cancellation
@ -79,57 +75,26 @@ func (s *searches) createSearch(dest *crypto.NodeID, mask *crypto.NodeID, callba
// If there is, it adds the response info to the search and triggers a new search step.
// If there's no ongoing search, or we if the dhtRes finished the search (it was from the target node), then don't do anything more.
func (sinfo *searchInfo) handleDHTRes(res *dhtRes) {
old := sinfo.visited
if res != nil {
sinfo.recv++
if sinfo.checkDHTRes(res) {
return // Search finished successfully
}
// Add results to the search
sinfo.addToSearch(res)
}
if res == nil || sinfo.visited != old {
// Continue the search
sinfo.doSearchStep()
}
}
// Adds the information from a dhtRes to an ongoing search.
// Info about a node that has already been visited is not re-added to the search.
func (sinfo *searchInfo) addToSearch(res *dhtRes) {
// Add to search
for _, info := range res.Infos {
sinfo.toVisit = append(sinfo.toVisit, info)
}
// Sort
sort.SliceStable(sinfo.toVisit, func(i, j int) bool {
// Should return true if i is closer to the destination than j
return dht_ordered(&sinfo.dest, sinfo.toVisit[i].getNodeID(), sinfo.toVisit[j].getNodeID())
})
// Remove anything too far away
for idx, info := range sinfo.toVisit {
if *info.getNodeID() == sinfo.visited || !dht_ordered(&sinfo.dest, info.getNodeID(), &sinfo.visited) {
sinfo.toVisit = sinfo.toVisit[:idx]
break
// Use results to start an additional search thread
infos := append([]*dhtInfo(nil), res.Infos...)
infos = sinfo.getAllowedInfos(infos)
if len(infos) > 0 {
sinfo.continueSearch(infos)
}
}
}
// If there are no nodes left toVisit, then this cleans up the search.
// If there has been no response in too long, then this cleans up the search.
// Otherwise, it pops the closest node to the destination (in keyspace) off of the toVisit list and sends a dht ping.
func (sinfo *searchInfo) doSearchStep() {
if len(sinfo.toVisit) == 0 {
if time.Since(sinfo.time) > search_RETRY_TIME {
// Dead end and no response in too long, do cleanup
delete(sinfo.searches.searches, sinfo.dest)
sinfo.callback(nil, errors.New("search reached dead end"))
}
return
}
func (sinfo *searchInfo) doSearchStep(infos []*dhtInfo) {
if len(infos) > 0 {
// Send to the next search target
if len(sinfo.toVisit) > 0 {
next := sinfo.toVisit[0]
sinfo.toVisit = sinfo.toVisit[1:]
next := infos[0]
rq := dhtReqKey{next.key, sinfo.dest}
sinfo.searches.router.dht.addCallback(&rq, sinfo.handleDHTRes)
sinfo.searches.router.dht.ping(next, &sinfo.dest)
@ -137,13 +102,29 @@ func (sinfo *searchInfo) doSearchStep() {
}
}
// If we've recently sent a ping for this search, do nothing.
// Otherwise, doSearchStep and schedule another continueSearch to happen after search_RETRY_TIME.
func (sinfo *searchInfo) continueSearch() {
sinfo.doSearchStep()
// In case the search dies, try to spawn another thread later
// Note that this will spawn multiple parallel searches as time passes
// Any that die aren't restarted, but a new one will start later
// Get a list of search targets that are close enough to the destination to try
// Requires an initial list as input
func (sinfo *searchInfo) getAllowedInfos(infos []*dhtInfo) []*dhtInfo {
sort.SliceStable(infos, func(i, j int) bool {
// Should return true if i is closer to the destination than j
return dht_ordered(&sinfo.dest, infos[i].getNodeID(), infos[j].getNodeID())
})
// Remove anything too far away to be useful
for idx, info := range infos {
if !dht_ordered(&sinfo.dest, info.getNodeID(), &sinfo.visited) {
infos = infos[:idx]
break
}
}
return infos
}
// Run doSearchStep and schedule another continueSearch to happen after search_RETRY_TIME.
// Must not be called with an empty list of infos
func (sinfo *searchInfo) continueSearch(infos []*dhtInfo) {
sinfo.doSearchStep(infos)
infos = infos[1:] // Remove the node we just tried
// In case there's no response, try the next node in infos later
time.AfterFunc(search_STEP_TIME, func() {
sinfo.searches.router.Act(nil, func() {
// FIXME this keeps the search alive forever if not for the searches map, fix that
@ -151,20 +132,51 @@ func (sinfo *searchInfo) continueSearch() {
if newSearchInfo != sinfo {
return
}
sinfo.continueSearch()
// Get good infos here instead of at the top, to make sure we can always start things off with a continueSearch call to ourself
infos = sinfo.getAllowedInfos(infos)
if len(infos) > 0 {
sinfo.continueSearch(infos)
}
})
})
}
// Initially start a search
func (sinfo *searchInfo) startSearch() {
loc := sinfo.searches.router.core.switchTable.getLocator()
var infos []*dhtInfo
infos = append(infos, &dhtInfo{
key: sinfo.searches.router.core.boxPub,
coords: loc.getCoords(),
})
// Start the search by asking ourself, useful if we're the destination
sinfo.continueSearch(infos)
// Start a timer to clean up the search if everything times out
var cleanupFunc func()
cleanupFunc = func() {
sinfo.searches.router.Act(nil, func() {
// FIXME this keeps the search alive forever if not for the searches map, fix that
newSearchInfo := sinfo.searches.searches[sinfo.dest]
if newSearchInfo != sinfo {
return
}
elapsed := time.Since(sinfo.time)
if elapsed > search_RETRY_TIME {
// cleanup
delete(sinfo.searches.searches, sinfo.dest)
sinfo.callback(nil, errors.New("search reached dead end"))
return
}
time.AfterFunc(search_RETRY_TIME-elapsed, cleanupFunc)
})
}
time.AfterFunc(search_RETRY_TIME, cleanupFunc)
}
// Calls create search, and initializes the iterative search parts of the struct before returning it.
func (s *searches) newIterSearch(dest *crypto.NodeID, mask *crypto.NodeID, callback func(*sessionInfo, error)) *searchInfo {
sinfo := s.createSearch(dest, mask, callback)
sinfo.visited = s.router.dht.nodeID
loc := s.router.core.switchTable.getLocator()
sinfo.toVisit = append(sinfo.toVisit, &dhtInfo{
key: s.router.core.boxPub,
coords: loc.getCoords(),
}) // Start the search by asking ourself, useful if we're the destination
return sinfo
}
@ -175,7 +187,7 @@ func (sinfo *searchInfo) checkDHTRes(res *dhtRes) bool {
from := dhtInfo{key: res.Key, coords: res.Coords}
if *from.getNodeID() != sinfo.visited && dht_ordered(&sinfo.dest, from.getNodeID(), &sinfo.visited) {
// Closer to the destination, so update visited
sinfo.searches.router.core.log.Debugln("Updating search:", sinfo.dest, *from.getNodeID(), sinfo.send, sinfo.recv)
sinfo.searches.router.core.log.Debugln("Updating search:", &sinfo.dest, from.getNodeID(), sinfo.send, sinfo.recv)
sinfo.visited = *from.getNodeID()
sinfo.time = time.Now()
}
@ -202,7 +214,7 @@ func (sinfo *searchInfo) checkDHTRes(res *dhtRes) bool {
}
// Cleanup
if _, isIn := sinfo.searches.searches[sinfo.dest]; isIn {
sinfo.searches.router.core.log.Debugln("Finished search:", sinfo.dest, sinfo.send, sinfo.recv)
sinfo.searches.router.core.log.Debugln("Finished search:", &sinfo.dest, sinfo.send, sinfo.recv)
delete(sinfo.searches.searches, res.Dest)
}
}

View File

@ -43,7 +43,6 @@ type sessionInfo struct {
time time.Time // Time we last received a packet
mtuTime time.Time // time myMTU was last changed
pingTime time.Time // time the first ping was sent since the last received packet
pingSend time.Time // time the last ping was sent
coords []byte // coords of destination
reset bool // reset if coords change
tstamp int64 // ATOMIC - tstamp from their last session ping, replay attack mitigation
@ -197,7 +196,6 @@ func (ss *sessions) createSession(theirPermKey *crypto.BoxPubKey) *sessionInfo {
sinfo.time = now
sinfo.mtuTime = now
sinfo.pingTime = now
sinfo.pingSend = now
sinfo.init = make(chan struct{})
sinfo.cancel = util.NewCancellation()
higher := false