internal/socket: update zoneCache on cache misses to cover appearing interfaces
Updates golang/go#28535
Change-Id: Id653b21b4d893cc8b6b9a74b129d1ce9b7e26a9f
Reviewed-on: https://go-review.googlesource.com/c/147739
Reviewed-by: Mikio Hara <mikioh.public.networking@gmail.com>
Run-TryBot: Mikio Hara <mikioh.public.networking@gmail.com>
diff --git a/internal/socket/sys_posix.go b/internal/socket/sys_posix.go
index dc130c2..646cc2d 100644
--- a/internal/socket/sys_posix.go
+++ b/internal/socket/sys_posix.go
@@ -121,18 +121,21 @@
toName: make(map[int]string),
}
-func (zc *ipv6ZoneCache) update(ift []net.Interface) {
+// update refreshes the network interface information if the cache was last
+// updated more than 1 minute ago, or if force is set. It returns whether the
+// cache was updated.
+func (zc *ipv6ZoneCache) update(ift []net.Interface, force bool) (updated bool) {
zc.Lock()
defer zc.Unlock()
now := time.Now()
- if zc.lastFetched.After(now.Add(-60 * time.Second)) {
- return
+ if !force && zc.lastFetched.After(now.Add(-60*time.Second)) {
+ return false
}
zc.lastFetched = now
if len(ift) == 0 {
var err error
if ift, err = net.Interfaces(); err != nil {
- return
+ return false
}
}
zc.toIndex = make(map[string]int, len(ift))
@@ -143,13 +146,22 @@
zc.toName[ifi.Index] = ifi.Name
}
}
+ return true
}
func (zc *ipv6ZoneCache) name(zone int) string {
- zoneCache.update(nil)
+ updated := zoneCache.update(nil, false)
zoneCache.RLock()
- defer zoneCache.RUnlock()
name, ok := zoneCache.toName[zone]
+ zoneCache.RUnlock()
+ if !ok {
+ if !updated {
+ zoneCache.update(nil, true)
+ zoneCache.RLock()
+ name, ok = zoneCache.toName[zone]
+ zoneCache.RUnlock()
+ }
+ }
if !ok {
name = strconv.Itoa(zone)
}
@@ -157,10 +169,18 @@
}
func (zc *ipv6ZoneCache) index(zone string) int {
- zoneCache.update(nil)
+ updated := zoneCache.update(nil, false)
zoneCache.RLock()
- defer zoneCache.RUnlock()
index, ok := zoneCache.toIndex[zone]
+ zoneCache.RUnlock()
+ if !ok {
+ if !updated {
+ zoneCache.update(nil, true)
+ zoneCache.RLock()
+ index, ok = zoneCache.toIndex[zone]
+ zoneCache.RUnlock()
+ }
+ }
if !ok {
index, _ = strconv.Atoi(zone)
}
