[libvirt] RFC: Introduce API to return configuration/state paths of the network driver

Currently, there is no API which returns configuration/state paths of the network driver. Although it is a private implementation of the network driver, I don't see any harm in making the locations public because although the locations might change, there will always be a location for these files. There is a need for this API to implement method 2 of the "API to query ip addresses of a given domain", refer: http://www.mail-archive.com/libvir-list@redhat.com/msg79793.html . It is required to parse the leases file generated by dnsmasq. So, this API will be used by the qemu driver, but it can also be made public, so that, if a user wants to know get some information from a configuration file, he can get the location from libvirt and analyze it on his own. Right now, there is an alternate way to get the info: by using networkDnsmasqLeaseFileNameDefault, defined in /src/network/bridge_driver.c Since this function is static, it is part of the private implementation and not visible outside. To make it public, the following hack is possible: diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c index a7ff602..7274861 100644 --- a/src/network/bridge_driver.c +++ b/src/network/bridge_driver.c @@ -124,7 +124,7 @@ static int networkUnplugBandwidth(virNetworkObjPtr net, static struct network_driver *driverState = NULL; -static char * +char * networkDnsmasqLeaseFileNameDefault(const char *netname) { char *leasefile; diff --git a/src/network/bridge_driver.h b/src/network/bridge_driver.h index 50258b5..40e3990 100644 --- a/src/network/bridge_driver.h +++ b/src/network/bridge_driver.h @@ -49,6 +49,8 @@ int networkDnsmasqConfContents(virNetworkObjPtr network, char **configstr, dnsmasqContext *dctx, dnsmasqCapsPtr caps); +char * networkDnsmasqLeaseFileNameDefault(const char *netname) + ATTRIBUTE_NONNULL(1); # else /* Define no-op replacements that don't drag in any link dependencies. */ # define networkAllocateActualDevice(iface) 0 @@ -57,6 +59,7 @@ int networkDnsmasqConfContents(virNetworkObjPtr network, # define networkGetNetworkAddress(netname, netaddr) (-2) # define networkDnsmasqConfContents(network, pidfile, configstr, \ dctx, caps) 0 +# define networkDnsmasqLeaseFileNameDefault(netname) 0 # endif typedef char *(*networkDnsmasqLeaseFileNameFunc)(const char *netname); Similar hack has been used so that networkAllocateActualDevice() can be called from qemu_command.c. Although the above method works, we want to have a formal API and not leave things like a hack. /* * @conn: connection object * @params: array to populate on output * @nparams: number of parameters that will be filled * @flags: not supported, user should pass 0 for now * return 0 on success -1 otherwise * Valid parameter field names: * VIR_NETWORK_CONFIG_DIR, VIR_NETWORK_AUTOSTART_DIR, VIR_STATE_DIR, * VIR_PID_DIR, VIR_DNSMASQ_STATE_DIR, VIR_RADVD_STATE_DIR * All the above will of the type VIR_TYPED_PARAM_STRING */ int virNetworkGetConfigFileName(virConnectPtr conn, virTypedParameterPtr params, int nparams, unsigned int flags) Nehal J. Wani UG3, BTech CS+MS(CL) IIIT-Hyderabad http://commandlinewani.blogspot.com