diff --git a/resolver/api.go b/resolver/api.go index a31b19a1..72703462 100644 --- a/resolver/api.go +++ b/resolver/api.go @@ -12,7 +12,7 @@ func registerAPI() error { Path: "dns/clear", Write: api.PermitUser, BelongsTo: module, - ActionFunc: clearNameCache, + ActionFunc: clearNameCacheHandler, Name: "Clear cached DNS records", Description: "Deletes all saved DNS records from the database.", }); err != nil { diff --git a/resolver/namerecord.go b/resolver/namerecord.go index 8e4841f2..e3db05e0 100644 --- a/resolver/namerecord.go +++ b/resolver/namerecord.go @@ -1,6 +1,7 @@ package resolver import ( + "context" "errors" "fmt" "sync" @@ -129,13 +130,18 @@ func (nameRecord *NameRecord) Save() error { return recordDatabase.PutNew(nameRecord) } -// clearNameCache clears all dns caches from the database. -func clearNameCache(ar *api.Request) (msg string, err error) { +// clearNameCacheHandler is an API handler that clears all dns caches from the database. +func clearNameCacheHandler(ar *api.Request) (msg string, err error) { log.Info("resolver: user requested dns cache clearing via action") + return clearNameCache(ar.Context()) +} + +// clearNameCache clears all dns caches from the database. +func clearNameCache(ctx context.Context) (msg string, err error) { recordDatabase.FlushCache() recordDatabase.ClearCache() - n, err := recordDatabase.Purge(ar.Context(), query.New(nameRecordsKeyPrefix)) + n, err := recordDatabase.Purge(ctx, query.New(nameRecordsKeyPrefix)) if err != nil { return "", err } diff --git a/resolver/resolvers.go b/resolver/resolvers.go index 0f7eaa16..4360d836 100644 --- a/resolver/resolvers.go +++ b/resolver/resolvers.go @@ -1,6 +1,7 @@ package resolver import ( + "context" "fmt" "net" "net/url" @@ -34,12 +35,13 @@ const ( ) var ( - globalResolvers []*Resolver // all (global) resolvers - localResolvers []*Resolver // all resolvers that are in site-local or link-local IP ranges - systemResolvers []*Resolver // all resolvers that were assigned by the system - localScopes []*Scope // list of scopes with a list of local resolvers that can resolve the scope - activeResolvers map[string]*Resolver // lookup map of all resolvers - resolversLock sync.RWMutex + globalResolvers []*Resolver // all (global) resolvers + localResolvers []*Resolver // all resolvers that are in site-local or link-local IP ranges + systemResolvers []*Resolver // all resolvers that were assigned by the system + localScopes []*Scope // list of scopes with a list of local resolvers that can resolve the scope + activeResolvers map[string]*Resolver // lookup map of all resolvers + currentResolverConfig []string // current active resolver config, to detect changes + resolversLock sync.RWMutex ) func indexOfScope(domain string, list []*Scope) int { @@ -285,8 +287,20 @@ func loadResolvers() { // Resolve module error about missing resolvers. module.Resolve(missingResolversErrorID) + // Check if settings were changed and clear name cache when they did. + newResolverConfig := configuredNameServers() + if len(currentResolverConfig) > 0 && + !utils.StringSliceEqual(currentResolverConfig, newResolverConfig) { + module.StartWorker("clear dns cache", func(ctx context.Context) error { + log.Info("resolver: clearing dns cache due to changed resolver config") + _, err := clearNameCache(ctx) + return err + }) + } + currentResolverConfig = newResolverConfig + newResolvers := append( - getConfiguredResolvers(configuredNameServers()), + getConfiguredResolvers(newResolverConfig), getSystemResolvers()..., )