Re: [libvirt] [PATCH] interface: add virInterfaceGetXMLDesc() in udev

Added support for retrieving the XML defining a specific interface via the udev based backend to virInterface. Implement the following APIs for the udev based backend: * virInterfaceGetXMLDesc() Note: Does not support bond devices. --- src/interface/interface_backend_udev.c | 251 ++++++++++++++++++++++++++++++++ 1 files changed, 251 insertions(+), 0 deletions(-) diff --git a/src/interface/interface_backend_udev.c b/src/interface/interface_backend_udev.c index 1cb6dfe..370f64a 100644 --- a/src/interface/interface_backend_udev.c +++ b/src/interface/interface_backend_udev.c @@ -19,6 +19,8 @@ */ #include <config.h> +#include <errno.h> +#include <dirent.h> #include <libudev.h> #include "virterror_internal.h" @@ -489,6 +491,254 @@ err: return ret; } +/** + * Helper function for our use of scandir() + * + * @param entry - directory entry passed by scandir() + * + * @return 1 if we want to add it to scandir's list, 0 if not. + */ +static int +udevIfaceScanDirFilter(const struct dirent *entry) +{ + if (STREQ(entry->d_name, ".") || STREQ(entry->d_name, "..")) + return 0; + + return 1; +} + +/** + * Frees any memory allocated by udevIfaceGetIfaceDef() + * + * @param ifacedef - interface to free and cleanup + */ +static void +udevIfaceFreeIfaceDef(virInterfaceDef *ifacedef) +{ + if (!ifacedef) + return; + + if (ifacedef->type == VIR_INTERFACE_TYPE_BRIDGE) { + VIR_FREE(ifacedef->data.bridge.delay); + for (int i = 0; i < ifacedef->data.bridge.nbItf; i++) { + VIR_FREE(ifacedef->data.bridge.itf[i]);

+ } + VIR_FREE(ifacedef->data.bridge.itf); + } + + if (ifacedef->type == VIR_INTERFACE_TYPE_VLAN) { + VIR_FREE(ifacedef->data.vlan.devname); + } + + VIR_FREE(ifacedef->mac); + VIR_FREE(ifacedef->name); + + VIR_FREE(ifacedef); +} + + +static virInterfaceDef * ATTRIBUTE_NONNULL(1) +udevIfaceGetIfaceDef(struct udev *udev, char *name) +{ + struct udev_device *dev; + virInterfaceDef *ifacedef; + unsigned int mtu; + const char *mtu_str; + char *vlan_parent_dev = NULL; + struct dirent **member_list = NULL; + int member_count = 0; + + /* Allocate our interface definition structure */ + if (VIR_ALLOC(ifacedef) < 0) { + virReportOOMError(); + return NULL; + } + + /* Clear our structure and set safe defaults */ + memset(ifacedef, 0, sizeof(ifacedef));

+ ifacedef->startmode = VIR_INTERFACE_START_UNSPECIFIED; + ifacedef->type = VIR_INTERFACE_TYPE_ETHERNET; + ifacedef->name = strdup(name); + + if (!ifacedef->name) { + virReportOOMError(); + goto cleanup; + } + + /* Lookup the device we've been asked about */ + dev = udev_device_new_from_subsystem_sysname(udev, "net", name);

+ if (!dev) { + virReportError(VIR_ERR_NO_INTERFACE, + _("couldn't find interface named '%s'"), name); + goto cleanup; + } + + /* MAC address */ + ifacedef->mac = strdup(udev_device_get_sysattr_value(dev, "address"));

+ if (!ifacedef) { + virReportOOMError(); + goto cleanup; + } + + /* MTU */ + mtu_str = udev_device_get_sysattr_value(dev, "mtu"); + if (virStrToLong_ui(mtu_str, NULL, 10, &mtu) < 0) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Could not parse MTU value '%s'"), mtu_str); + goto cleanup; + } + ifacedef->mtu = mtu; + + /* Number of IP protocols this interface has assigned */ + /* XXX: Do we want a netlink query or a call out to ip or leave it? */ + ifacedef->nprotos = 0; + ifacedef->protos = NULL; + + /* Check if its a VLAN since we can have a VLAN of any of the + * other devices */ + vlan_parent_dev = strrchr(name, '.'); + if (vlan_parent_dev) { + /* Found the VLAN dot */ + char *vid; + + vlan_parent_dev = strdup(name); + if (!vlan_parent_dev) { + virReportOOMError(); + goto cleanup; + } + + /* Find the DEVICE.VID separator again */ + vid = strrchr(vlan_parent_dev, '.'); + if (!vid) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("failed to find the VID for the VLAN device '%s'"), + name); + goto cleanup; + } + + /* Replace the dot with a NULL so we can have the device and VID */ + vid[0] = '\0'; + vid++; + + /* Set our type to VLAN */ + ifacedef->type = VIR_INTERFACE_TYPE_VLAN; + + /* Set the VLAN specifics */ + ifacedef->data.vlan.tag = vid; + ifacedef->data.vlan.devname = vlan_parent_dev; + } else if (STREQ_NULLABLE(udev_device_get_devtype(dev), "bridge")) { + /* Check if its a bridge device */ + char *member_path; + const char *stp_str; + int stp; + + /* Set our type to Bridge */ + ifacedef->type = VIR_INTERFACE_TYPE_BRIDGE; + + /* Bridge specifics */ + ifacedef->data.bridge.delay = + strdup(udev_device_get_sysattr_value(dev, "bridge/forward_delay")); + if (!ifacedef->data.bridge.delay) { + virReportOOMError(); + goto cleanup; + } + + stp_str = udev_device_get_sysattr_value(dev, "bridge/stp_state"); + if (virStrToLong_i(stp_str, NULL, 10, &stp) < 0) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Could not parse STP state '%s'"), stp_str); + goto cleanup; + } + ifacedef->data.bridge.stp = stp; + + /* Members of the bridge */ + virAsprintf(&member_path, "%s/%s", + udev_device_get_syspath(dev), "brif"); + if (!member_path) { + virReportOOMError(); + goto cleanup; + } + + /* Get each member of the bridge */ + member_count = scandir(member_path, &member_list, + udevIfaceScanDirFilter, alphasort); + + /* Don't need the path anymore */ + VIR_FREE(member_path); + + if (member_count < 0) { + virReportSystemError(errno, + _("Could not get members of bridge '%s'"), + name); + goto cleanup; + } + + /* Allocate our list of member devices */ + if (VIR_ALLOC_N(ifacedef->data.bridge.itf, member_count) < 0) { + virReportOOMError(); + goto cleanup; + } + ifacedef->data.bridge.nbItf = member_count; + + for (int i= 0; i < member_count; i++) { + ifacedef->data.bridge.itf[i] = + udevIfaceGetIfaceDef(udev, member_list[i]->d_name); + VIR_FREE(member_list[i]); + } + + VIR_FREE(member_list); + + } else { + /* Set our type to ethernet */ + ifacedef->type = VIR_INTERFACE_TYPE_ETHERNET; + } + + return ifacedef; + +cleanup: + for (int i = 0; i < member_count; i++) { + VIR_FREE(member_list[i]); + } + VIR_FREE(member_list); + + udevIfaceFreeIfaceDef(ifacedef); + + return NULL; +} + +static char * +udevIfaceGetXMLDesc(virInterfacePtr ifinfo, + unsigned int flags) +{ + struct udev_iface_driver *driverState = ifinfo->conn->interfacePrivateData; + struct udev *udev = udev_ref(driverState->udev); + virInterfaceDef *ifacedef; + char *xmlstr = NULL; + + virCheckFlags(VIR_INTERFACE_XML_INACTIVE, NULL); + + /* Recursively build up the interface XML based on the requested + * interface name + */ + ifacedef = udevIfaceGetIfaceDef(udev, ifinfo->name); + + /* We've already printed by it happened */ + if (!ifacedef) + goto err; + + /* Convert our interface to XML */ + xmlstr = virInterfaceDefFormat(ifacedef); + + /* Recursively free our interface structures and free the children too */ + udevIfaceFreeIfaceDef(ifacedef); + +err: + /* decrement our udev ptr */ + udev_unref(udev); + + return xmlstr; +} + static int udevIfaceIsActive(virInterfacePtr ifinfo) { @@ -529,6 +779,7 @@ static virInterfaceDriver udevIfaceDriver = { .listAllInterfaces = udevIfaceListAllInterfaces, /* 0.10.3 */ .interfaceLookupByName = udevIfaceLookupByName, /* 0.10.3 */ .interfaceLookupByMACString = udevIfaceLookupByMACString, /* 0.10.3 */ + .interfaceGetXMLDesc = udevIfaceGetXMLDesc, /* 0.10.3 */ .interfaceIsActive = udevIfaceIsActive, /* 0.10.3 */ };