libvirt/src/util/virhook.c
Daniel P. Berrangé 6394cf9768 network: convert hook script to take a network port XML
When (un)plugging an interface into a network, the 'plugged'
and 'unplugged' operations are invoked in the hook script.

The data provided to the script contains the network XML, the
domain XML and the domain interface XML. When we strictly split the
drivers up this will no longer be possible and thus breakage is
unavoidable. The hook scripts are not considered to be covered by the
API guarantee so this is OK.

To avoid existing scripts taking the wrong action, the existing
operations are changed to 'port-created' and 'port-deleted'
instead. These will receive the network XML and the network port
XML.

Reviewed-by: Laine Stump <laine@laine.org>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2019-06-17 15:19:54 +01:00

328 lines
8.5 KiB
C

/*
* virhook.c: implementation of the synchronous hooks support
*
* Copyright (C) 2010-2014 Red Hat, Inc.
* Copyright (C) 2010 Daniel Veillard
*
* 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/>.
*/
#include <config.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <unistd.h>
#include "virerror.h"
#include "virhook.h"
#include "virutil.h"
#include "virlog.h"
#include "viralloc.h"
#include "virfile.h"
#include "configmake.h"
#include "vircommand.h"
#define VIR_FROM_THIS VIR_FROM_HOOK
VIR_LOG_INIT("util.hook");
#define LIBVIRT_HOOK_DIR SYSCONFDIR "/libvirt/hooks"
VIR_ENUM_DECL(virHookDriver);
VIR_ENUM_DECL(virHookDaemonOp);
VIR_ENUM_DECL(virHookSubop);
VIR_ENUM_DECL(virHookQemuOp);
VIR_ENUM_DECL(virHookLxcOp);
VIR_ENUM_DECL(virHookNetworkOp);
VIR_ENUM_DECL(virHookLibxlOp);
VIR_ENUM_IMPL(virHookDriver,
VIR_HOOK_DRIVER_LAST,
"daemon",
"qemu",
"lxc",
"network",
"libxl",
);
VIR_ENUM_IMPL(virHookDaemonOp,
VIR_HOOK_DAEMON_OP_LAST,
"start",
"shutdown",
"reload",
);
VIR_ENUM_IMPL(virHookSubop,
VIR_HOOK_SUBOP_LAST,
"-",
"begin",
"end",
);
VIR_ENUM_IMPL(virHookQemuOp,
VIR_HOOK_QEMU_OP_LAST,
"start",
"stopped",
"prepare",
"release",
"migrate",
"started",
"reconnect",
"attach",
"restore",
);
VIR_ENUM_IMPL(virHookLxcOp,
VIR_HOOK_LXC_OP_LAST,
"start",
"stopped",
"prepare",
"release",
"started",
"reconnect",
);
VIR_ENUM_IMPL(virHookNetworkOp,
VIR_HOOK_NETWORK_OP_LAST,
"start",
"started",
"stopped",
"port-created",
"port-deleted",
"updated",
);
VIR_ENUM_IMPL(virHookLibxlOp,
VIR_HOOK_LIBXL_OP_LAST,
"start",
"stopped",
"prepare",
"release",
"migrate",
"started",
"reconnect",
);
static int virHooksFound = -1;
/**
* virHookCheck:
* @driver: the driver name "daemon", "qemu", "lxc"...
*
* Check is there is an installed hook for the given driver, if this
* is the case register it. Then subsequent calls to virHookCall
* will call the hook if found.
*
* Returns 1 if found, 0 if not found, and -1 in case of error
*/
static int
virHookCheck(int no, const char *driver)
{
VIR_AUTOFREE(char *) path = NULL;
if (driver == NULL) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Invalid hook name for #%d"), no);
return -1;
}
if (virBuildPath(&path, LIBVIRT_HOOK_DIR, driver) < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Failed to build path for %s hook"),
driver);
return -1;
}
if (!virFileExists(path)) {
VIR_DEBUG("No hook script %s", path);
return 0;
}
if (!virFileIsExecutable(path)) {
VIR_WARN("Non-executable hook script %s", path);
return 0;
}
VIR_DEBUG("Found hook script %s", path);
return 1;
}
/*
* virHookInitialize:
*
* Initialize synchronous hooks support.
* Check is there is an installed hook for all the drivers
*
* Returns the number of hooks found or -1 in case of failure
*/
int
virHookInitialize(void)
{
size_t i;
int res, ret = 0;
virHooksFound = 0;
for (i = 0; i < VIR_HOOK_DRIVER_LAST; i++) {
res = virHookCheck(i, virHookDriverTypeToString(i));
if (res < 0)
return -1;
if (res == 1) {
virHooksFound |= (1 << i);
ret++;
}
}
return ret;
}
/**
* virHookPresent:
* @driver: the driver number (from virHookDriver enum)
*
* Check if a hook exists for the given driver, this is needed
* to avoid unnecessary work if the hook is not present
*
* Returns 1 if present, 0 otherwise
*/
int
virHookPresent(int driver)
{
if ((driver < VIR_HOOK_DRIVER_DAEMON) ||
(driver >= VIR_HOOK_DRIVER_LAST))
return 0;
if (virHooksFound == -1)
return 0;
if ((virHooksFound & (1 << driver)) == 0)
return 0;
return 1;
}
/**
* virHookCall:
* @driver: the driver number (from virHookDriver enum)
* @id: an id for the object '-' if non available for example on daemon hooks
* @op: the operation on the id e.g. VIR_HOOK_QEMU_OP_START
* @sub_op: a sub_operation, currently unused
* @extra: optional string information
* @input: extra input given to the script on stdin
* @output: optional address of variable to store malloced result buffer
*
* Implement a hook call, where the external script for the driver is
* called with the given information. This is a synchronous call, we wait for
* execution completion. If @output is non-NULL, *output is guaranteed to be
* allocated after successful virHookCall, and is best-effort allocated after
* failed virHookCall; the caller is responsible for freeing *output.
*
* Returns: 0 if the execution succeeded, 1 if the script was not found or
* invalid parameters, and -1 if script returned an error
*/
int
virHookCall(int driver,
const char *id,
int op,
int sub_op,
const char *extra,
const char *input,
char **output)
{
int ret;
VIR_AUTOFREE(char *) path = NULL;
VIR_AUTOPTR(virCommand) cmd = NULL;
const char *drvstr;
const char *opstr;
const char *subopstr;
if (output)
*output = NULL;
if ((driver < VIR_HOOK_DRIVER_DAEMON) ||
(driver >= VIR_HOOK_DRIVER_LAST))
return 1;
/*
* We cache the availability of the script to minimize impact at
* runtime if no script is defined, this is being reset on SIGHUP
*/
if ((virHooksFound == -1) ||
((driver == VIR_HOOK_DRIVER_DAEMON) &&
(op == VIR_HOOK_DAEMON_OP_RELOAD ||
op == VIR_HOOK_DAEMON_OP_SHUTDOWN)))
virHookInitialize();
if ((virHooksFound & (1 << driver)) == 0)
return 1;
drvstr = virHookDriverTypeToString(driver);
opstr = NULL;
switch (driver) {
case VIR_HOOK_DRIVER_DAEMON:
opstr = virHookDaemonOpTypeToString(op);
break;
case VIR_HOOK_DRIVER_QEMU:
opstr = virHookQemuOpTypeToString(op);
break;
case VIR_HOOK_DRIVER_LXC:
opstr = virHookLxcOpTypeToString(op);
break;
case VIR_HOOK_DRIVER_LIBXL:
opstr = virHookLibxlOpTypeToString(op);
break;
case VIR_HOOK_DRIVER_NETWORK:
opstr = virHookNetworkOpTypeToString(op);
}
if (opstr == NULL) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Hook for %s, failed to find operation #%d"),
drvstr, op);
return 1;
}
subopstr = virHookSubopTypeToString(sub_op);
if (subopstr == NULL)
subopstr = "-";
if (extra == NULL)
extra = "-";
if (virBuildPath(&path, LIBVIRT_HOOK_DIR, drvstr) < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Failed to build path for %s hook"),
drvstr);
return -1;
}
VIR_DEBUG("Calling hook opstr=%s subopstr=%s extra=%s",
opstr, subopstr, extra);
cmd = virCommandNewArgList(path, id, opstr, subopstr, extra, NULL);
virCommandAddEnvPassCommon(cmd);
if (input)
virCommandSetInputBuffer(cmd, input);
if (output)
virCommandSetOutputBuffer(cmd, output);
ret = virCommandRun(cmd, NULL);
if (ret < 0) {
/* Convert INTERNAL_ERROR into known error. */
virReportError(VIR_ERR_HOOK_SCRIPT_FAILED, "%s",
virGetLastErrorMessage());
}
return ret;
}