libvirt/src/libvirt-qemu.c

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/*
* libvirt-qemu.c: Interfaces for the libvirt library to handle qemu-specific
* APIs.
*
* Copyright (C) 2010-2014 Red Hat, Inc.
*
* 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: Chris Lalancette <clalance@redhat.com>
*/
#include <config.h>
#include "virerror.h"
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#include "virlog.h"
#include "viruuid.h"
#include "datatypes.h"
#define VIR_FROM_THIS VIR_FROM_NONE
/**
* virDomainQemuMonitorCommand:
* @domain: a domain object
* @cmd: the qemu monitor command string
* @result: a string returned by @cmd
* @flags: bitwise-or of supported virDomainQemuMonitorCommandFlags
*
* This API is QEMU specific, so it will only work with hypervisor
* connections to the QEMU driver.
*
* Send an arbitrary monitor command @cmd to @domain through the
* qemu monitor. There are several requirements to safely and
* successfully use this API:
*
* - A @cmd that queries state without making any modifications is safe
* - A @cmd that alters state that is also tracked by libvirt is unsafe,
* and may cause libvirtd to crash
* - A @cmd that alters state not tracked by the current version of
* libvirt is possible as a means to test new qemu features before
* they have support in libvirt, but no guarantees are made to safety
*
* If VIR_DOMAIN_QEMU_MONITOR_COMMAND_HMP is set, the command is
* considered to be a human monitor command and libvirt will automatically
* convert it into QMP if needed. In that case the @result will also
* be converted back from QMP.
*
* If successful, @result will be filled with the string output of the
* @cmd, and the caller must free this string.
*
* Returns 0 in case of success, -1 in case of failure
*
*/
int
virDomainQemuMonitorCommand(virDomainPtr domain, const char *cmd,
char **result, unsigned int flags)
{
virConnectPtr conn;
VIR_DOMAIN_DEBUG(domain, "cmd=%s, result=%p, flags=%x",
cmd, result, flags);
virResetLastError();
virCheckDomainReturn(domain, -1);
conn = domain->conn;
virCheckNonNullArgGoto(result, error);
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virCheckReadOnlyGoto(conn->flags, error);
if (conn->driver->domainQemuMonitorCommand) {
int ret;
ret = conn->driver->domainQemuMonitorCommand(domain, cmd, result,
flags);
if (ret < 0)
goto error;
return ret;
}
maint: improve VIR_ERR_NO_SUPPORT usage We weren't very consistent in our use of VIR_ERR_NO_SUPPORT; many users just passed __FUNCTION__ on, while others passed "%s" to silence over-eager compilers that warn about __FUNCTION__ not containing any %. It's nicer to route all these uses through a single macro, so that if we ever need to change the reporting, we can do it in one place. I verified that 'virsh -c test:///default qemu-monitor-command test foo' gives the same error message before and after this patch: error: this function is not supported by the connection driver: virDomainQemuMonitorCommand Note that in libvirt.c, we were inconsistent on whether virDomain* API used virLibConnError() (with VIR_FROM_NONE) or virLibDomainError() (with VIR_FROM_DOMAIN); this patch unifies these errors to all use VIR_FROM_NONE, on the grounds that it is unlikely that a caller learning that a call is unimplemented can do anything in particular with extra knowledge of which error domain it belongs to. One particular change to note is virDomainOpenGraphics which was trying to fail with VIR_ERR_NO_SUPPORT after a failed VIR_DRV_SUPPORTS_FEATURE check; all other places that fail a feature check report VIR_ERR_ARGUMENT_UNSUPPORTED. * src/util/virerror.h (virReportUnsupportedError): New macro. * src/libvirt-qemu.c: Use new macro. * src/libvirt-lxc.c: Likewise. * src/lxc/lxc_driver.c: Likewise. * src/security/security_manager.c: Likewise. * src/util/virinitctl.c: Likewise. * src/libvirt.c: Likewise. (virDomainOpenGraphics): Use correct error for unsupported feature. Signed-off-by: Eric Blake <eblake@redhat.com>
2013-12-20 01:38:59 +00:00
virReportUnsupportedError();
error:
virDispatchError(conn);
return -1;
}
/**
* virDomainQemuAttach:
* @conn: pointer to a hypervisor connection
build: use correct type for pid and similar types No thanks to 64-bit windows, with 64-bit pid_t, we have to avoid constructs like 'int pid'. Our API in libvirt-qemu cannot be changed without breaking ABI; but then again, libvirt-qemu can only be used on systems that support UNIX sockets, which rules out Windows (even if qemu could be compiled there) - so for all points on the call chain that interact with this API decision, we require a different variable name to make it clear that we audited the use for safety. Adding a syntax-check rule only solves half the battle; anywhere that uses printf on a pid_t still needs to be converted, but that will be a separate patch. * cfg.mk (sc_correct_id_types): New syntax check. * src/libvirt-qemu.c (virDomainQemuAttach): Document why we didn't use pid_t for pid, and validate for overflow. * include/libvirt/libvirt-qemu.h (virDomainQemuAttach): Tweak name for syntax check. * src/vmware/vmware_conf.c (vmwareExtractPid): Likewise. * src/driver.h (virDrvDomainQemuAttach): Likewise. * tools/virsh.c (cmdQemuAttach): Likewise. * src/remote/qemu_protocol.x (qemu_domain_attach_args): Likewise. * src/qemu_protocol-structs (qemu_domain_attach_args): Likewise. * src/util/cgroup.c (virCgroupPidCode, virCgroupKillInternal): Likewise. * src/qemu/qemu_command.c(qemuParseProcFileStrings): Likewise. (qemuParseCommandLinePid): Use pid_t for pid. * daemon/libvirtd.c (daemonForkIntoBackground): Likewise. * src/conf/domain_conf.h (_virDomainObj): Likewise. * src/probes.d (rpc_socket_new): Likewise. * src/qemu/qemu_command.h (qemuParseCommandLinePid): Likewise. * src/qemu/qemu_driver.c (qemudGetProcessInfo, qemuDomainAttach): Likewise. * src/qemu/qemu_process.c (qemuProcessAttach): Likewise. * src/qemu/qemu_process.h (qemuProcessAttach): Likewise. * src/uml/uml_driver.c (umlGetProcessInfo): Likewise. * src/util/virnetdev.h (virNetDevSetNamespace): Likewise. * src/util/virnetdev.c (virNetDevSetNamespace): Likewise. * tests/testutils.c (virtTestCaptureProgramOutput): Likewise. * src/conf/storage_conf.h (_virStoragePerms): Use mode_t, uid_t, and gid_t rather than int. * src/security/security_dac.c (virSecurityDACSetOwnership): Likewise. * src/conf/storage_conf.c (virStorageDefParsePerms): Avoid compiler warning.
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* @pid_value: the UNIX process ID of the external QEMU process
* @flags: optional flags, currently unused
*
* This API is QEMU specific, so it will only work with hypervisor
* connections to the QEMU driver.
*
* This API will attach to an externally launched QEMU process
* identified by @pid. There are several requirements to successfully
* attach to an external QEMU process:
*
* - It must have been started with a monitor socket using the UNIX
* domain socket protocol.
* - No device hotplug/unplug, or other configuration changes can
* have been made via the monitor since it started.
* - The '-name' and '-uuid' arguments should have been set (not
* mandatory, but strongly recommended)
*
build: use correct type for pid and similar types No thanks to 64-bit windows, with 64-bit pid_t, we have to avoid constructs like 'int pid'. Our API in libvirt-qemu cannot be changed without breaking ABI; but then again, libvirt-qemu can only be used on systems that support UNIX sockets, which rules out Windows (even if qemu could be compiled there) - so for all points on the call chain that interact with this API decision, we require a different variable name to make it clear that we audited the use for safety. Adding a syntax-check rule only solves half the battle; anywhere that uses printf on a pid_t still needs to be converted, but that will be a separate patch. * cfg.mk (sc_correct_id_types): New syntax check. * src/libvirt-qemu.c (virDomainQemuAttach): Document why we didn't use pid_t for pid, and validate for overflow. * include/libvirt/libvirt-qemu.h (virDomainQemuAttach): Tweak name for syntax check. * src/vmware/vmware_conf.c (vmwareExtractPid): Likewise. * src/driver.h (virDrvDomainQemuAttach): Likewise. * tools/virsh.c (cmdQemuAttach): Likewise. * src/remote/qemu_protocol.x (qemu_domain_attach_args): Likewise. * src/qemu_protocol-structs (qemu_domain_attach_args): Likewise. * src/util/cgroup.c (virCgroupPidCode, virCgroupKillInternal): Likewise. * src/qemu/qemu_command.c(qemuParseProcFileStrings): Likewise. (qemuParseCommandLinePid): Use pid_t for pid. * daemon/libvirtd.c (daemonForkIntoBackground): Likewise. * src/conf/domain_conf.h (_virDomainObj): Likewise. * src/probes.d (rpc_socket_new): Likewise. * src/qemu/qemu_command.h (qemuParseCommandLinePid): Likewise. * src/qemu/qemu_driver.c (qemudGetProcessInfo, qemuDomainAttach): Likewise. * src/qemu/qemu_process.c (qemuProcessAttach): Likewise. * src/qemu/qemu_process.h (qemuProcessAttach): Likewise. * src/uml/uml_driver.c (umlGetProcessInfo): Likewise. * src/util/virnetdev.h (virNetDevSetNamespace): Likewise. * src/util/virnetdev.c (virNetDevSetNamespace): Likewise. * tests/testutils.c (virtTestCaptureProgramOutput): Likewise. * src/conf/storage_conf.h (_virStoragePerms): Use mode_t, uid_t, and gid_t rather than int. * src/security/security_dac.c (virSecurityDACSetOwnership): Likewise. * src/conf/storage_conf.c (virStorageDefParsePerms): Avoid compiler warning.
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* To date, the only platforms we know of where pid_t is larger than
* unsigned int (64-bit Windows) also lack UNIX sockets, so the choice
* of @pid_value as an unsigned int should not present any difficulties.
*
* If successful, then the guest will appear in the list of running
* domains for this connection, and other APIs should operate
* normally (provided the above requirements were honored).
*
* Returns a new domain object on success, NULL otherwise
*/
virDomainPtr
virDomainQemuAttach(virConnectPtr conn,
build: use correct type for pid and similar types No thanks to 64-bit windows, with 64-bit pid_t, we have to avoid constructs like 'int pid'. Our API in libvirt-qemu cannot be changed without breaking ABI; but then again, libvirt-qemu can only be used on systems that support UNIX sockets, which rules out Windows (even if qemu could be compiled there) - so for all points on the call chain that interact with this API decision, we require a different variable name to make it clear that we audited the use for safety. Adding a syntax-check rule only solves half the battle; anywhere that uses printf on a pid_t still needs to be converted, but that will be a separate patch. * cfg.mk (sc_correct_id_types): New syntax check. * src/libvirt-qemu.c (virDomainQemuAttach): Document why we didn't use pid_t for pid, and validate for overflow. * include/libvirt/libvirt-qemu.h (virDomainQemuAttach): Tweak name for syntax check. * src/vmware/vmware_conf.c (vmwareExtractPid): Likewise. * src/driver.h (virDrvDomainQemuAttach): Likewise. * tools/virsh.c (cmdQemuAttach): Likewise. * src/remote/qemu_protocol.x (qemu_domain_attach_args): Likewise. * src/qemu_protocol-structs (qemu_domain_attach_args): Likewise. * src/util/cgroup.c (virCgroupPidCode, virCgroupKillInternal): Likewise. * src/qemu/qemu_command.c(qemuParseProcFileStrings): Likewise. (qemuParseCommandLinePid): Use pid_t for pid. * daemon/libvirtd.c (daemonForkIntoBackground): Likewise. * src/conf/domain_conf.h (_virDomainObj): Likewise. * src/probes.d (rpc_socket_new): Likewise. * src/qemu/qemu_command.h (qemuParseCommandLinePid): Likewise. * src/qemu/qemu_driver.c (qemudGetProcessInfo, qemuDomainAttach): Likewise. * src/qemu/qemu_process.c (qemuProcessAttach): Likewise. * src/qemu/qemu_process.h (qemuProcessAttach): Likewise. * src/uml/uml_driver.c (umlGetProcessInfo): Likewise. * src/util/virnetdev.h (virNetDevSetNamespace): Likewise. * src/util/virnetdev.c (virNetDevSetNamespace): Likewise. * tests/testutils.c (virtTestCaptureProgramOutput): Likewise. * src/conf/storage_conf.h (_virStoragePerms): Use mode_t, uid_t, and gid_t rather than int. * src/security/security_dac.c (virSecurityDACSetOwnership): Likewise. * src/conf/storage_conf.c (virStorageDefParsePerms): Avoid compiler warning.
2012-02-10 23:08:11 +00:00
unsigned int pid_value,
unsigned int flags)
{
build: use correct type for pid and similar types No thanks to 64-bit windows, with 64-bit pid_t, we have to avoid constructs like 'int pid'. Our API in libvirt-qemu cannot be changed without breaking ABI; but then again, libvirt-qemu can only be used on systems that support UNIX sockets, which rules out Windows (even if qemu could be compiled there) - so for all points on the call chain that interact with this API decision, we require a different variable name to make it clear that we audited the use for safety. Adding a syntax-check rule only solves half the battle; anywhere that uses printf on a pid_t still needs to be converted, but that will be a separate patch. * cfg.mk (sc_correct_id_types): New syntax check. * src/libvirt-qemu.c (virDomainQemuAttach): Document why we didn't use pid_t for pid, and validate for overflow. * include/libvirt/libvirt-qemu.h (virDomainQemuAttach): Tweak name for syntax check. * src/vmware/vmware_conf.c (vmwareExtractPid): Likewise. * src/driver.h (virDrvDomainQemuAttach): Likewise. * tools/virsh.c (cmdQemuAttach): Likewise. * src/remote/qemu_protocol.x (qemu_domain_attach_args): Likewise. * src/qemu_protocol-structs (qemu_domain_attach_args): Likewise. * src/util/cgroup.c (virCgroupPidCode, virCgroupKillInternal): Likewise. * src/qemu/qemu_command.c(qemuParseProcFileStrings): Likewise. (qemuParseCommandLinePid): Use pid_t for pid. * daemon/libvirtd.c (daemonForkIntoBackground): Likewise. * src/conf/domain_conf.h (_virDomainObj): Likewise. * src/probes.d (rpc_socket_new): Likewise. * src/qemu/qemu_command.h (qemuParseCommandLinePid): Likewise. * src/qemu/qemu_driver.c (qemudGetProcessInfo, qemuDomainAttach): Likewise. * src/qemu/qemu_process.c (qemuProcessAttach): Likewise. * src/qemu/qemu_process.h (qemuProcessAttach): Likewise. * src/uml/uml_driver.c (umlGetProcessInfo): Likewise. * src/util/virnetdev.h (virNetDevSetNamespace): Likewise. * src/util/virnetdev.c (virNetDevSetNamespace): Likewise. * tests/testutils.c (virtTestCaptureProgramOutput): Likewise. * src/conf/storage_conf.h (_virStoragePerms): Use mode_t, uid_t, and gid_t rather than int. * src/security/security_dac.c (virSecurityDACSetOwnership): Likewise. * src/conf/storage_conf.c (virStorageDefParsePerms): Avoid compiler warning.
2012-02-10 23:08:11 +00:00
pid_t pid = pid_value;
VIR_DEBUG("conn=%p, pid=%u, flags=%x", conn, pid_value, flags);
virResetLastError();
virCheckConnectReturn(conn, NULL);
virCheckPositiveArgGoto(pid_value, error);
if (pid != pid_value) {
virReportInvalidArg(pid_value,
_("pid_value in %s is too large"),
__FUNCTION__);
goto error;
}
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virCheckReadOnlyGoto(conn->flags, error);
if (conn->driver->domainQemuAttach) {
virDomainPtr ret;
ret = conn->driver->domainQemuAttach(conn, pid_value, flags);
if (!ret)
goto error;
return ret;
}
maint: improve VIR_ERR_NO_SUPPORT usage We weren't very consistent in our use of VIR_ERR_NO_SUPPORT; many users just passed __FUNCTION__ on, while others passed "%s" to silence over-eager compilers that warn about __FUNCTION__ not containing any %. It's nicer to route all these uses through a single macro, so that if we ever need to change the reporting, we can do it in one place. I verified that 'virsh -c test:///default qemu-monitor-command test foo' gives the same error message before and after this patch: error: this function is not supported by the connection driver: virDomainQemuMonitorCommand Note that in libvirt.c, we were inconsistent on whether virDomain* API used virLibConnError() (with VIR_FROM_NONE) or virLibDomainError() (with VIR_FROM_DOMAIN); this patch unifies these errors to all use VIR_FROM_NONE, on the grounds that it is unlikely that a caller learning that a call is unimplemented can do anything in particular with extra knowledge of which error domain it belongs to. One particular change to note is virDomainOpenGraphics which was trying to fail with VIR_ERR_NO_SUPPORT after a failed VIR_DRV_SUPPORTS_FEATURE check; all other places that fail a feature check report VIR_ERR_ARGUMENT_UNSUPPORTED. * src/util/virerror.h (virReportUnsupportedError): New macro. * src/libvirt-qemu.c: Use new macro. * src/libvirt-lxc.c: Likewise. * src/lxc/lxc_driver.c: Likewise. * src/security/security_manager.c: Likewise. * src/util/virinitctl.c: Likewise. * src/libvirt.c: Likewise. (virDomainOpenGraphics): Use correct error for unsupported feature. Signed-off-by: Eric Blake <eblake@redhat.com>
2013-12-20 01:38:59 +00:00
virReportUnsupportedError();
error:
virDispatchError(conn);
return NULL;
}
/**
* virDomainQemuAgentCommand:
* @domain: a domain object
* @cmd: the guest agent command string
* @timeout: timeout seconds
* @flags: execution flags
*
* Execute an arbitrary Guest Agent command.
*
* Issue @cmd to the guest agent running in @domain.
* @timeout must be -2, -1, 0 or positive.
* VIR_DOMAIN_QEMU_AGENT_COMMAND_BLOCK(-2): meaning to block forever waiting for
* a result.
* VIR_DOMAIN_QEMU_AGENT_COMMAND_DEFAULT(-1): use default timeout value.
* VIR_DOMAIN_QEMU_AGENT_COMMAND_NOWAIT(0): does not wait.
* positive value: wait for @timeout seconds
*
* Returns strings if success, NULL in failure.
*/
char *
virDomainQemuAgentCommand(virDomainPtr domain,
const char *cmd,
int timeout,
unsigned int flags)
{
virConnectPtr conn;
char *ret;
VIR_DOMAIN_DEBUG(domain, "cmd=%s, timeout=%d, flags=%x",
cmd, timeout, flags);
virResetLastError();
virCheckDomainReturn(domain, NULL);
conn = domain->conn;
2013-12-20 14:02:49 +00:00
virCheckReadOnlyGoto(conn->flags, error);
if (conn->driver->domainQemuAgentCommand) {
ret = conn->driver->domainQemuAgentCommand(domain, cmd,
timeout, flags);
if (!ret)
goto error;
return ret;
}
maint: improve VIR_ERR_NO_SUPPORT usage We weren't very consistent in our use of VIR_ERR_NO_SUPPORT; many users just passed __FUNCTION__ on, while others passed "%s" to silence over-eager compilers that warn about __FUNCTION__ not containing any %. It's nicer to route all these uses through a single macro, so that if we ever need to change the reporting, we can do it in one place. I verified that 'virsh -c test:///default qemu-monitor-command test foo' gives the same error message before and after this patch: error: this function is not supported by the connection driver: virDomainQemuMonitorCommand Note that in libvirt.c, we were inconsistent on whether virDomain* API used virLibConnError() (with VIR_FROM_NONE) or virLibDomainError() (with VIR_FROM_DOMAIN); this patch unifies these errors to all use VIR_FROM_NONE, on the grounds that it is unlikely that a caller learning that a call is unimplemented can do anything in particular with extra knowledge of which error domain it belongs to. One particular change to note is virDomainOpenGraphics which was trying to fail with VIR_ERR_NO_SUPPORT after a failed VIR_DRV_SUPPORTS_FEATURE check; all other places that fail a feature check report VIR_ERR_ARGUMENT_UNSUPPORTED. * src/util/virerror.h (virReportUnsupportedError): New macro. * src/libvirt-qemu.c: Use new macro. * src/libvirt-lxc.c: Likewise. * src/lxc/lxc_driver.c: Likewise. * src/security/security_manager.c: Likewise. * src/util/virinitctl.c: Likewise. * src/libvirt.c: Likewise. (virDomainOpenGraphics): Use correct error for unsupported feature. Signed-off-by: Eric Blake <eblake@redhat.com>
2013-12-20 01:38:59 +00:00
virReportUnsupportedError();
error:
virDispatchError(conn);
return NULL;
}