Re: [libvirt] [PATCHv2 3/4] network: set macvtap/hostdev networks active if their state file exists

libvirt attempts to determine at startup time which networks are already active, and set their active flags. Previously it has done this by assuming that all networks are inactive, then setting the active flag if the network has a bridge device associated with it and that bridge device exists. This is not useful for macvtap and hostdev based networks, since they do not use a bridge device. Of course the reason that such a check had to be done was that the presence of a status file in the network "stateDir" couldn't be trusted as an indicator of whether or not a network was active. This was due to the network driver mistakenly using /var/lib/libvirt/network to store the status files, rather than /var/run/libvirt/network (similar to what is done by every other libvirt driver that stores status xml for its objects). The difference is that /var/run is cleared out when the host reboots, so you can be assured that the state file you are seeing isn't just left over from a previous boot of the host. Now that the network driver has been switched to using /var/run/libvirt/network for status, we can also modify it to assume that any network with an existing status file is by definition active - we do this when reading the status file. To fine tune the results, networkFindActiveConfigs() is changed to networkUpdateAllState(), and only sets active = 0 if the conditions for particular network types are *not* met. The result is that during the first run of libvirtd after the host boots, there are no status files, so no networks are active. Any time libvirtd is restarted, any network with a status file will be marked as active (unless the network uses a bridge device and that device for some reason doesn't exist). --- Changes from V1: * rename networkFindActiveConfigs() to networkUpdateAllState() (rather than networkFindInactiveConfigs() * undo the change in order of calling the above function vs. virNetworkReadAllConfigs(), just in case that would cause some undetected regression. * extricate the reading of pidfiles from the switch statement that behaves differently for different types of networks - those networks that don't use dnsmasq/radvd will not have any pidfiles for them anyway, so it becomes a NOP (and if a new network type that *does* use one of those processes is created, it will automatically work correctly here.) src/conf/network_conf.c | 1 + src/network/bridge_driver.c | 69 ++++++++++++++++++++++++++++++++------------- 2 files changed, 51 insertions(+), 19 deletions(-) diff --git a/src/conf/network_conf.c b/src/conf/network_conf.c index 56c4a09..69ad929 100644 --- a/src/conf/network_conf.c +++ b/src/conf/network_conf.c @@ -3060,6 +3060,7 @@ virNetworkLoadState(virNetworkObjListPtr nets, net->floor_sum = floor_sum_val; net->taint = taint; + net->active = 1; /* any network with a state file is by definition active */

cleanup: VIR_FREE(configFile); diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c index 57dfb2d..0c879b9 100644 --- a/src/network/bridge_driver.c +++ b/src/network/bridge_driver.c @@ -328,38 +328,69 @@ networkBridgeDummyNicName(const char *brname) return nicname; } +/* Update the internal status of all allegedly active networks + * according to external conditions on the host (i.e. anything that + * isn't stored directly in each network's state file). */ static void -networkFindActiveConfigs(virNetworkDriverStatePtr driver) +networkUpdateAllState(virNetworkDriverStatePtr driver) { size_t i; for (i = 0; i < driver->networks.count; i++) { virNetworkObjPtr obj = driver->networks.objs[i]; + if (!obj->active) + continue; + virNetworkObjLock(obj); - /* If bridge exists, then mark it active */ - if (obj->def->bridge && - virNetDevExists(obj->def->bridge) == 1) { - obj->active = 1; + switch (obj->def->forward.type) { + case VIR_NETWORK_FORWARD_NONE: + case VIR_NETWORK_FORWARD_NAT: + case VIR_NETWORK_FORWARD_ROUTE: + /* If bridge exists, then mark it active */ + if (!(obj->def->bridge && virNetDevExists(obj->def->bridge) == 1)) + obj->active = 0; + break;

- /* Try and read dnsmasq/radvd pids if any */ - if (obj->def->ips && (obj->def->nips > 0)) { - char *radvdpidbase; + case VIR_NETWORK_FORWARD_BRIDGE: + if (obj->def->bridge) { + if (virNetDevExists(obj->def->bridge) != 1) + obj->active = 0; + break; + } + /* intentionally drop through to common case for all + * macvtap networks (forward='bridge' with no bridge + * device defined is macvtap using its 'bridge' mode) + */ + case VIR_NETWORK_FORWARD_PRIVATE: + case VIR_NETWORK_FORWARD_VEPA: + case VIR_NETWORK_FORWARD_PASSTHROUGH: + /* so far no extra checks */ + break; - ignore_value(virPidFileReadIfAlive(driverState->pidDir, obj->def->name, - &obj->dnsmasqPid, - dnsmasqCapsGetBinaryPath(driver->dnsmasqCaps))); + case VIR_NETWORK_FORWARD_HOSTDEV: + /* so far no extra checks */ + break; + } - if (!(radvdpidbase = networkRadvdPidfileBasename(obj->def->name))) - goto cleanup; - ignore_value(virPidFileReadIfAlive(driverState->pidDir, radvdpidbase, - &obj->radvdPid, RADVD)); - VIR_FREE(radvdpidbase); - } + /* Try and read dnsmasq/radvd pids of active networks */ + if (obj->active && obj->def->ips && (obj->def->nips > 0)) { + char *radvdpidbase; + + ignore_value(virPidFileReadIfAlive(driverState->pidDir, + obj->def->name, + &obj->dnsmasqPid, + dnsmasqCapsGetBinaryPath(driver->dnsmasqCaps))); + radvdpidbase = networkRadvdPidfileBasename(obj->def->name); + if (!radvdpidbase) + break; + ignore_value(virPidFileReadIfAlive(driverState->pidDir, + radvdpidbase, + &obj->radvdPid, RADVD)); + VIR_FREE(radvdpidbase); } - cleanup: virNetworkObjUnlock(obj); } @@ -591,7 +622,7 @@ networkStateInitialize(bool privileged, driverState->networkAutostartDir) < 0) goto error; - networkFindActiveConfigs(driverState); + networkUpdateAllState(driverState); networkReloadFirewallRules(driverState); networkRefreshDaemons(driverState);