diff options
Diffstat (limited to 'mDNSResponder/mDNSMacOSX/mDNSMacOSX.c')
| -rw-r--r-- | mDNSResponder/mDNSMacOSX/mDNSMacOSX.c | 32 |
1 files changed, 18 insertions, 14 deletions
diff --git a/mDNSResponder/mDNSMacOSX/mDNSMacOSX.c b/mDNSResponder/mDNSMacOSX/mDNSMacOSX.c index c33c1663..d8697fae 100644 --- a/mDNSResponder/mDNSMacOSX/mDNSMacOSX.c +++ b/mDNSResponder/mDNSMacOSX/mDNSMacOSX.c @@ -1835,7 +1835,7 @@ mDNSlocal int mDNSPlatformGetSocktFd(void *sockCxt, mDNSTransport_Type transType } } -mDNSexport void mDNSPlatformSetSocktOpt(void *sockCxt, mDNSTransport_Type transType, mDNSAddr_Type addrType, DNSQuestion *q) +mDNSexport void mDNSPlatformSetSocktOpt(void *sockCxt, mDNSTransport_Type transType, mDNSAddr_Type addrType, const DNSQuestion *q) { int sockfd; char unenc_name[MAX_ESCAPED_DOMAIN_NAME]; @@ -6966,7 +6966,19 @@ mDNSexport mDNSBool mDNSPlatformSetDNSConfig(mDNS *const m, mDNSBool setservers, else { LogInfo("mDNSPlatformSetDNSConfig: config->n_resolver = %d, generation %llu, last %llu", config->n_resolver, config->generation, m->p->LastConfigGeneration); - if (m->p->LastConfigGeneration == config->generation) + + // For every network change, the search domain list is updated. + // This update is done without regard for generation number because it is + // not an expensive update and it keeps the search domain list in sync (even when + // a network change occurs, while currently processing a network + // change). + // + // For every DNS configuration change, the DNS server list is updated. + // This update is NOT done every network change because it may involve + // updating cache entries which worst-case is expensive. Setting the generation + // per DNS server list change keeps the list in sync with configd. + + if (setservers && m->p->LastConfigGeneration == config->generation) { LogInfo("mDNSPlatformSetDNSConfig: generation number %llu same, not processing", config->generation); dns_configuration_free(config); @@ -6992,21 +7004,13 @@ mDNSexport mDNSBool mDNSPlatformSetDNSConfig(mDNS *const m, mDNSBool setservers, ConfigResolvers(m, config, kScopeServiceID, setsearch, setservers, &sdc, resolverGroupID); - // Acking provides a hint that we processed this current configuration and - // we will use that from now on, assuming we don't get another one immediately - // after we return from here. + // Acking provides a hint to other processes that the current DNS configuration has completed + // its update. When configd receives the ack, it publishes a notification. + // Applications monitoring the notification then know when to re-issue their DNS queries + // after a network change occurs. if (ackConfig) { // Note: We have to set the generation number here when we are acking. - // For every DNS configuration change, we do the following: - // - // 1) Copy dns configuration, handle search domains change - // 2) Copy dns configuration, handle dns server change - // - // If we update the generation number at step (1), we won't process the - // DNS servers the second time because generation number would be the same. - // As we ack only when we process dns servers, we set the generation number - // during acking. m->p->LastConfigGeneration = config->generation; LogInfo("mDNSPlatformSetDNSConfig: Acking configuration setservers %d, setsearch %d", setservers, setsearch); AckConfigd(m, config); |