This is the source code to the config driver. This driver is a hypervisor driver that does not support any domain operations. The sole purpose of this driver is to allow access to various bits of configuration information, such as secret or network definitions, from the initialization and auto-start routines of other drivers. This is the first step toward breaking the circular dependencies present in QEMU and the Storage driver, in addition to preventing future cases. Signed-off-by: Adam Walters <adam(a)pandorasboxen.com&gt; --- src/config/config_driver.c | 237 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 237 insertions(+) create mode 100644 src/config/config_driver.c diff --git a/src/config/config_driver.c b/src/config/config_driver.c new file mode 100644 index 0000000..a057300 --- /dev/null +++ b/src/config/config_driver.c @@ -0,0 +1,237 @@ +/* + * config_driver.c: core driver methods for accessing configs + * + * Copyright (C) 2013 Adam Walters + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library. If not, see + * <http://www.gnu.org/licenses/>;. + * + * Author: Adam Walters <adam(a)pandorasboxen.com&gt; + */ +#include <config.h> +#include <string.h> + +#include "internal.h" +#include "datatypes.h" +#include "driver.h" +#include "virlog.h" +#include "viralloc.h" +#include "virerror.h" +#include "virstring.h" +#include "viraccessapicheck.h" +#include "nodeinfo.h" +#include "config_driver.h" + +#define VIR_FROM_THIS VIR_FROM_CONFIG + +virConfigDriverPtr config_driver = NULL; + +static int configStateCleanup(void) { + if (config_driver == NULL) + return -1; + + virObjectUnref(config_driver->closeCallbacks); + + virSysinfoDefFree(config_driver->hostsysinfo); + + virMutexDestroy(&config_driver->lock); + VIR_FREE(config_driver); + + return 0; +} + +static int configStateInitialize(bool privileged, + virStateInhibitCallback callback ATTRIBUTE_UNUSED, + void *opaque ATTRIBUTE_UNUSED) +{ + if (!privileged) { + VIR_INFO("Not running privileged, disabling driver"); + return 0; + } + + if (VIR_ALLOC(config_driver) < 0) + return -1; + + if (virMutexInit(&config_driver->lock) < 0) { + VIR_ERROR(_("cannot initialize mutex")); + VIR_FREE(config_driver); + return -1; + } + + config_driver->hostsysinfo = virSysinfoRead(); + + if (!(config_driver->closeCallbacks = virCloseCallbacksNew())) + goto cleanup; + + return 0; + +cleanup: + configStateCleanup(); + return -1; +} + +static int configStateReload(void) { + return 0; +} + +static virDrvOpenStatus configConnectOpen(virConnectPtr conn, + virConnectAuthPtr auth ATTRIBUTE_UNUSED, + unsigned int flags) +{ + virDrvOpenStatus ret = VIR_DRV_OPEN_ERROR; + virCheckFlags(VIR_CONNECT_RO, VIR_DRV_OPEN_ERROR); + + if (conn->uri != NULL) { + /* If URI isn't 'config', decline the connection */ + if (conn->uri->scheme == NULL || + STRNEQ(conn->uri->scheme, "config")) { + ret = VIR_DRV_OPEN_DECLINED; + goto cleanup; + } + + /* Allow remote driver to deal with URIs with hostname set */ + if (conn->uri->server != NULL) { + ret = VIR_DRV_OPEN_DECLINED; + goto cleanup; + } + + if (config_driver == NULL) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("config state driver is not active")); + goto cleanup; + } + } else { + ret = VIR_DRV_OPEN_DECLINED; + goto cleanup; + } + + if (virConnectOpenEnsureACL(conn) < 0) + goto cleanup; + + conn->privateData = config_driver; + + ret = VIR_DRV_OPEN_SUCCESS; +cleanup: + return ret; +} + +static int configConnectClose(virConnectPtr conn ATTRIBUTE_UNUSED) +{ + /* Cleanup callbacks on config_driver */ + /* Set conn->privateData to NULL */ + return 0; +} + +static int +configConnectSupportsFeature(virConnectPtr conn, int feature ATTRIBUTE_UNUSED) +{ + if (virConnectSupportsFeatureEnsureACL(conn) < 0) + return -1; + + return 0; +} + +static const char *configConnectGetType(virConnectPtr conn ATTRIBUTE_UNUSED) { + if (virConnectGetTypeEnsureACL(conn) < 0) + return NULL; + + return "config"; +} + +static int configConnectIsSecure(virConnectPtr conn ATTRIBUTE_UNUSED) +{ + return 1; +} + +static int configConnectIsEncrypted(virConnectPtr conn ATTRIBUTE_UNUSED) +{ + return 0; +} + +static char *configConnectGetHostname(virConnectPtr conn) +{ + if (virConnectGetHostnameEnsureACL(conn) < 0) + return NULL; + + return virGetHostname(); +} + +static char * +configConnectGetSysinfo(virConnectPtr conn, unsigned int flags) +{ + virConfigDriverPtr driver = conn->privateData; + virBuffer buf = VIR_BUFFER_INITIALIZER; + + virCheckFlags(0, NULL); + + if (virConnectGetSysinfoEnsureACL(conn) < 0) + return NULL; + + if (!driver->hostsysinfo) { + return NULL; + } + + if (virSysinfoFormat(&buf, driver->hostsysinfo) < 0) + return NULL; + + if (virBufferError(&buf)) { + virReportOOMError(); + return NULL; + } + + return virBufferContentAndReset(&buf); +} + +static int +configNodeGetInfo(virConnectPtr conn, + virNodeInfoPtr nodeinfo) +{ + if (virNodeGetInfoEnsureACL(conn) < 0) + return -1; + + return nodeGetInfo(nodeinfo); +} + +static int configConnectIsAlive(virConnectPtr conn ATTRIBUTE_UNUSED) +{ + return 1; +} + +static virDriver configDriver = { + .name = "config", + .connectOpen = configConnectOpen, /* 0.2.0 */ + .connectClose = configConnectClose, /* 0.2.0 */ + .connectSupportsFeature = configConnectSupportsFeature, /* 0.5.0 */ + .connectGetType = configConnectGetType, /* 0.2.0 */ + .connectGetHostname = configConnectGetHostname, /* 0.3.3 */ + .connectGetSysinfo = configConnectGetSysinfo, /* 0.8.8 */ + .nodeGetInfo = configNodeGetInfo, /* 0.2.0 */ + .connectIsEncrypted = configConnectIsEncrypted, /* 0.7.3 */ + .connectIsSecure = configConnectIsSecure, /* 0.7.3 */ + .connectIsAlive = configConnectIsAlive, /* 0.9.8 */ +}; + + +static virStateDriver configStateDriver = { + .name = "config", + .stateInitialize = configStateInitialize, + .stateCleanup = configStateCleanup, + .stateReload = configStateReload, +}; + +int configRegister(void) { + virRegisterDriver(&configDriver); + virRegisterStateDriver(&configStateDriver); + return 0; +} -- 1.8.5.2

Peter, Thank you for the feedback on my patches, and sorry for the delay. I was away all weekend, since it was a holiday weekend (definitely a plus, having my day job in education). I figured it would be a bit spammy to reply to each individual message, but I did read each of them, and will be working to implement the suggestions tonight and/or tomorrow night. On Mon, Jan 20, 2014 at 10:34 AM, Peter Krempa <pkrempa(a)redhat.com&gt; wrote: I apologize for the long lines. I had forgotten about reading the log messages in a standard terminal, as I mostly read those in a web interface. As for denying unprivileged connections, I'm honestly not sure if it would be useful. All this driver does is grant access to definitions of networks, storage pools, secrets, etc. I just ensured that this driver is loaded very early in the load order, and has zero external dependencies. I suppose that I made an assumption that the privileged variable indicated a privileged connection, but thinking about it more, I suppose it could also mean running privileged in the OS. I simply disabled the driver if unprivileged so that I would not leak any privileged information to an unprivileged connection by accident. If that isn't a concern (either I misunderstood the meaning of the privileged variable, or the code wouldn't leak information), I can certainly drop those lines to allow the driver when unprivileged. As I've mentioned before, I am not intimately familiar with the libvirt code, so I tend to err on the side of caution. I hadn't forgotten about the API version comment, but when I wrote the patches, I simply had no idea when version would be next. Never know if there will be a minor version increment instead of the standard micro. Since it was more of an RFC-type patch, I didn't even have an idea of a timeframe for submission, since I thought there might be more discussion prior to looking at pulling a change of this type into the code.

On 12/21/13 05:03, Adam Walters wrote: This patch will need to be squashed into the patch that actually introduces the syntax-check error. Libvirt's policy is that after each patch the tree must be buildable and pass "make check" and " make syntax-check". Peter

On 12/21/13 05:03, Adam Walters wrote: This patch definitely needs to go after the makefile change, otherwise the tree won't be buildable after this patch. Also you may want to squash it with the makefile changes. Also the configure script contains a section outputting the config summary at the bottom of configure.ac where you need to add a corresponding entry for the new driver. Peter