[libvirt] [PATCH 2/2] interface: add udev based backend for virInterface

Add a read-only udev based backend for virInterface. Useful for distros that do not have netcf support yet. Multiple libvirt based utilities use a HAL based fallback when virInterface is not available which is less than ideal. This implements: * virConnectNumOfInterfaces() * virConnectListInterfaces() * virConnectNumOfDefinedInterfaces() * virConnectListDefinedInterfaces() * virConnectInterfaceLookupByName() * virConnectInterfaceLookupByMACString() Signed-off-by: Doug Goldstein <cardoe(a)cardoe.com&gt; --- configure.ac | 10 +- src/Makefile.am | 12 +- src/interface/interface_backend_udev.c | 377 ++++++++++++++++++++++++++++++++ 3 files changed, 395 insertions(+), 4 deletions(-) create mode 100644 src/interface/interface_backend_udev.c diff --git a/configure.ac b/configure.ac index fd546fc..c2ad8e2 100644 --- a/configure.ac +++ b/configure.ac @@ -2822,11 +2822,15 @@ if test "$with_interface:$with_netcf" = "check:yes" ; then fi if test "$with_interface:$with_netcf" = "check:no" ; then - with_interface=no + if test "$with_udev" = "yes" ; then + with_interface=yes + else + with_interface=no + fi fi -if test "$with_interface:$with_netcf" = "yes:no" ; then - AC_MSG_ERROR([Requested the Interface driver without netcf support]) +if test "$with_interface:$with_netcf:$with_udev" = "yes:no:no" ; then + AC_MSG_ERROR([Requested the Interface driver without netcf or udev support]) fi if test "$with_interface" = "yes" ; then diff --git a/src/Makefile.am b/src/Makefile.am index 72c4d6c..7143ae0 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -553,11 +553,16 @@ INTERFACE_DRIVER_SOURCES = if WITH_INTERFACE INTERFACE_DRIVER_SOURCES += \ interface/interface_driver.h -endif if WITH_NETCF INTERFACE_DRIVER_SOURCES += \ interface/interface_backend_netcf.c +else +if HAVE_UDEV +INTERFACE_DRIVER_SOURCES += \ + interface/interface_backend_udev.c +endif +endif endif SECRET_DRIVER_SOURCES = \ @@ -1040,6 +1045,11 @@ libvirt_driver_interface_la_LIBADD = if WITH_NETCF libvirt_driver_interface_la_CFLAGS += $(NETCF_CFLAGS) libvirt_driver_interface_la_LIBADD += $(NETCF_LIBS) +else +if HAVE_UDEV +libvirt_driver_interface_la_CFLAGS += $(UDEV_CFLAGS) +libvirt_driver_interface_la_LIBADD += $(UDEV_LIBS) +endif endif if WITH_DRIVER_MODULES libvirt_driver_interface_la_LIBADD += ../gnulib/lib/libgnu.la diff --git a/src/interface/interface_backend_udev.c b/src/interface/interface_backend_udev.c new file mode 100644 index 0000000..b1a4be3 --- /dev/null +++ b/src/interface/interface_backend_udev.c @@ -0,0 +1,377 @@ + +#include <config.h> + +#include <libudev.h> + +#include "virterror_internal.h" +#include "datatypes.h" +#include "interface_driver.h" +#include "interface_conf.h" +#include "memory.h" + +#define VIR_FROM_THIS VIR_FROM_INTERFACE + +struct udev_iface_driver { + struct udev *udev; +}; + +enum udev_status { UDEV_IFACE_ACTIVE, UDEV_IFACE_INACTIVE, UDEV_IFACE_ALL }; + +static struct udev_enumerate * +udevIfaceGetDevices(struct udev *udev, enum udev_status status) +{ + struct udev_enumerate *enumerate; + + /* Check input params for sanity */ + if (!udev) + return NULL; + + /* Create a new enumeration to create a list */ + enumerate = udev_enumerate_new(udev); + + if (!enumerate) + return NULL; + + /* Enumerate all network subsystem devices */ + udev_enumerate_add_match_subsystem(enumerate, "net"); + + /* Ignore devices that are part of a bridge */ + udev_enumerate_add_nomatch_sysattr(enumerate, "brport/state", NULL); + + /* State of the device */ + switch (status) { + case UDEV_IFACE_ACTIVE: + udev_enumerate_add_match_sysattr(enumerate, "operstate", "up"); + break; + + case UDEV_IFACE_INACTIVE: + udev_enumerate_add_match_sysattr(enumerate, "operstate", "down"); + break; + + case UDEV_IFACE_ALL: + break; + } + + /* We don't want to see the TUN devices that QEMU creates for other gets + * running on this machine. By saying nomatch NULL, we just are getting + * devices without the tun_flags sysattr. + */ + udev_enumerate_add_nomatch_sysattr(enumerate, "tun_flags", NULL); + + return enumerate; +} + +static virDrvOpenStatus +udevIfaceOpenInterface(virConnectPtr conn, + virConnectAuthPtr auth ATTRIBUTE_UNUSED, + unsigned int flags ATTRIBUTE_UNUSED) +{ + struct udev_iface_driver *driverState = NULL; + + if (VIR_ALLOC(driverState) < 0) { + virReportOOMError(); + goto err; + } + + driverState->udev = udev_new(); + if (!driverState->udev) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("failed to create udev context")); + goto err; + } + + conn->interfacePrivateData = driverState; + + return VIR_DRV_OPEN_SUCCESS; + +err: + VIR_FREE(driverState); + + return VIR_DRV_OPEN_ERROR; +} + +static int +udevIfaceCloseInterface(virConnectPtr conn) +{ + struct udev_iface_driver *driverState; + + if (conn->interfacePrivateData != NULL) { + driverState = conn->interfacePrivateData; + + udev_unref(driverState->udev); + + VIR_FREE(driverState); + } + + conn->interfacePrivateData = NULL; + return 0; +} + +static int +udevIfaceNumOfInterfaces(virConnectPtr conn) +{ + struct udev_iface_driver *driverState = conn->interfacePrivateData; + struct udev *udev = udev_ref(driverState->udev); + struct udev_enumerate *enumerate = NULL; + struct udev_list_entry *devices; + struct udev_list_entry *dev_entry; + int count = 0; + + enumerate = udevIfaceGetDevices(udev, UDEV_IFACE_ACTIVE); + + if (!enumerate) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("failed to get number of active interfaces on host")); + return -1; + } + + /* Do the scan to load up the enumeration */ + udev_enumerate_scan_devices(enumerate); + + /* Get a list we can walk */ + devices = udev_enumerate_get_list_entry(enumerate); + + /* For each item so we can count */ + udev_list_entry_foreach(dev_entry, devices) { + count++; + } + + udev_enumerate_unref(enumerate); + + udev_unref(udev); + + return count; +} + +static int +udevIfaceListInterfaces(virConnectPtr conn, char **const names, int names_len) +{ + struct udev_iface_driver *driverState = conn->interfacePrivateData; + struct udev *udev = udev_ref(driverState->udev); + struct udev_enumerate *enumerate = NULL; + struct udev_list_entry *devices; + struct udev_list_entry *dev_entry; + int count = 0; + + enumerate = udevIfaceGetDevices(udev, UDEV_IFACE_ACTIVE); + + if (!enumerate) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("failed to get list of active interfaces on host")); + return -1; + } + + /* Do the scan to load up the enumeration */ + udev_enumerate_scan_devices(enumerate); + + /* Get a list we can walk */ + devices = udev_enumerate_get_list_entry(enumerate); + + /* For each item so we can count */ + udev_list_entry_foreach(dev_entry, devices) { + struct udev_device *dev; + const char *path; + + path = udev_list_entry_get_name(dev_entry); + dev = udev_device_new_from_syspath(udev, path); + names[count] = strdup(udev_device_get_sysname(dev)); + udev_device_unref(dev); + + count++; + if (count > names_len) + break; + } + + udev_enumerate_unref(enumerate); + + udev_unref(udev); + + return count; +} + +static int +udevIfaceNumOfDefinedInterfaces(virConnectPtr conn) +{ + struct udev_iface_driver *driverState = conn->interfacePrivateData; + struct udev *udev = udev_ref(driverState->udev); + struct udev_enumerate *enumerate = NULL; + struct udev_list_entry *devices; + struct udev_list_entry *dev_entry; + int count = 0; + + enumerate = udevIfaceGetDevices(udev, UDEV_IFACE_INACTIVE); + + if (!enumerate) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("failed to get number of defined interfaces on host")); + return -1; + } + + /* Do the scan to load up the enumeration */ + udev_enumerate_scan_devices(enumerate); + + /* Get a list we can walk */ + devices = udev_enumerate_get_list_entry(enumerate); + + /* For each item so we can count */ + udev_list_entry_foreach(dev_entry, devices) { + count++; + } + + udev_enumerate_unref(enumerate); + + udev_unref(udev); + + return count; +} + +static int +udevIfaceListDefinedInterfaces(virConnectPtr conn, + char **const names, + int names_len) +{ + struct udev_iface_driver *driverState = conn->interfacePrivateData; + struct udev *udev = udev_ref(driverState->udev); + struct udev_enumerate *enumerate = NULL; + struct udev_list_entry *devices; + struct udev_list_entry *dev_entry; + int count = 0; + + enumerate = udevIfaceGetDevices(udev, UDEV_IFACE_INACTIVE); + + if (!enumerate) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("failed to get list of defined interfaces on host")); + return -1; + } + + /* Do the scan to load up the enumeration */ + udev_enumerate_scan_devices(enumerate); + + /* Get a list we can walk */ + devices = udev_enumerate_get_list_entry(enumerate); + + /* For each item so we can count */ + udev_list_entry_foreach(dev_entry, devices) { + struct udev_device *dev; + const char *path; + + path = udev_list_entry_get_name(dev_entry); + dev = udev_device_new_from_syspath(udev, path); + names[count] = strdup(udev_device_get_sysname(dev)); + udev_device_unref(dev); + + count++; + if (count > names_len) + break; + } + + udev_enumerate_unref(enumerate); + + udev_unref(udev); + + return count; +} + +static virInterfacePtr +udevIfaceLookupByName(virConnectPtr conn, const char *name) +{ + struct udev_iface_driver *driverState = conn->interfacePrivateData; + struct udev *udev = udev_ref(driverState->udev); + struct udev_device *dev; + const char *macaddr; + virInterfacePtr ret; + + /* get a device reference based on the device name */ + dev = udev_device_new_from_subsystem_sysname(udev, "net", name); + if (!dev) { + virReportError(VIR_ERR_NO_INTERFACE, + _("couldn't find interface named '%s'"), + name); + return NULL; + } + + macaddr = udev_device_get_sysattr_value(dev, "address"); + ret = virGetInterface(conn, name, macaddr); + udev_device_unref(dev); + + udev_unref(udev); + + return ret; +} + +static virInterfacePtr +udevIfaceLookupByMACString(virConnectPtr conn, const char *macstr) +{ + struct udev_iface_driver *driverState = conn->interfacePrivateData; + struct udev *udev = udev_ref(driverState->udev); + struct udev_enumerate *enumerate = NULL; + struct udev_list_entry *dev_entry; + struct udev_device *dev; + const char *name; + virInterfacePtr ret; + + enumerate = udevIfaceGetDevices(udev, UDEV_IFACE_ALL); + + if (!enumerate) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("failed to lookup interface with MAC address '%s'"), + macstr); + return NULL; + } + + /* Match on MAC */ + udev_enumerate_add_match_sysattr(enumerate, "address", macstr); + + /* Do the scan to load up the enumeration */ + udev_enumerate_scan_devices(enumerate); + + /* Get a list we can walk */ + dev_entry = udev_enumerate_get_list_entry(enumerate); + + /* Check that we got something back */ + if (!dev_entry) { + virReportError(VIR_ERR_NO_INTERFACE, + _("couldn't find interface with MAC address '%s'"), + macstr); + return NULL; + } + + /* Check that we didn't get multiple items back */ + if (udev_list_entry_get_next(dev_entry)) { + virReportError(VIR_ERR_MULTIPLE_INTERFACES, + _("the MAC address '%s' matches multiple interfaces"), + macstr); + return NULL; + } + + dev = udev_device_new_from_syspath(udev, udev_list_entry_get_name(dev_entry)); + name = udev_device_get_sysname(dev); + ret = virGetInterface(conn, name, macstr); + udev_device_unref(dev); + + udev_enumerate_unref(enumerate); + + udev_unref(udev); + + return ret; +} +static virInterfaceDriver udevIfaceDriver = { + "Interface", + .open = udevIfaceOpenInterface, + .close = udevIfaceCloseInterface, + .numOfInterfaces = udevIfaceNumOfInterfaces, + .listInterfaces = udevIfaceListInterfaces, + .numOfDefinedInterfaces = udevIfaceNumOfDefinedInterfaces, + .listDefinedInterfaces = udevIfaceListDefinedInterfaces, + .interfaceLookupByName = udevIfaceLookupByName, + .interfaceLookupByMACString = udevIfaceLookupByMACString, +}; + +int +interfaceRegister(void) { + if (virRegisterInterfaceDriver(&udevIfaceDriver) < 0) + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("failed to register udev interface driver")); + return 0; +} -- 1.7.8.6