libvirt/src/qemu/qemu_agent.c
Peter Krempa 56874f0191 qemu_agent: Remove obvious comments
Most APIs in libvirt report errors, thus no need to state that
explicitly.
2013-07-31 14:25:43 +02:00

1659 lines
46 KiB
C

/*
* qemu_agent.h: interaction with QEMU guest agent
*
* Copyright (C) 2006-2013 Red Hat, Inc.
* Copyright (C) 2006 Daniel P. Berrange
*
* 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: Daniel P. Berrange <berrange@redhat.com>
*/
#include <config.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <poll.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <sys/time.h>
#include "qemu_agent.h"
#include "viralloc.h"
#include "virlog.h"
#include "virerror.h"
#include "virjson.h"
#include "virfile.h"
#include "virprocess.h"
#include "virtime.h"
#include "virobject.h"
#include "virstring.h"
#define VIR_FROM_THIS VIR_FROM_QEMU
#define LINE_ENDING "\n"
#define DEBUG_IO 0
#define DEBUG_RAW_IO 0
/* When you are the first to uncomment this,
* don't forget to uncomment the corresponding
* part in qemuAgentIOProcessEvent as well.
*
static struct {
const char *type;
void (*handler)(qemuAgentPtr mon, virJSONValuePtr data);
} eventHandlers[] = {
};
*/
typedef struct _qemuAgentMessage qemuAgentMessage;
typedef qemuAgentMessage *qemuAgentMessagePtr;
struct _qemuAgentMessage {
char *txBuffer;
int txOffset;
int txLength;
/* Used by the JSON monitor to hold reply / error */
char *rxBuffer;
int rxLength;
void *rxObject;
/* True if rxBuffer / rxObject are ready, or a
* fatal error occurred on the monitor channel
*/
bool finished;
};
struct _qemuAgent {
virObjectLockable parent;
virCond notify;
int fd;
int watch;
bool connectPending;
virDomainObjPtr vm;
qemuAgentCallbacksPtr cb;
/* If there's a command being processed this will be
* non-NULL */
qemuAgentMessagePtr msg;
/* Buffer incoming data ready for Agent monitor
* code to process & find message boundaries */
size_t bufferOffset;
size_t bufferLength;
char *buffer;
/* If anything went wrong, this will be fed back
* the next monitor msg */
virError lastError;
/* Some guest agent commands don't return anything
* but fire up an event on qemu monitor instead.
* Take that as indication of successful completion */
qemuAgentEvent await_event;
};
static virClassPtr qemuAgentClass;
static void qemuAgentDispose(void *obj);
static int qemuAgentOnceInit(void)
{
if (!(qemuAgentClass = virClassNew(virClassForObjectLockable(),
"qemuAgent",
sizeof(qemuAgent),
qemuAgentDispose)))
return -1;
return 0;
}
VIR_ONCE_GLOBAL_INIT(qemuAgent)
#if DEBUG_RAW_IO
# include <c-ctype.h>
static char *
qemuAgentEscapeNonPrintable(const char *text)
{
size_t i;
virBuffer buf = VIR_BUFFER_INITIALIZER;
for (i = 0; text[i] != '\0'; i++) {
if (text[i] == '\\')
virBufferAddLit(&buf, "\\\\");
else if (c_isprint(text[i]) || text[i] == '\n' ||
(text[i] == '\r' && text[i+1] == '\n'))
virBufferAddChar(&buf, text[i]);
else
virBufferAsprintf(&buf, "\\x%02x", text[i]);
}
return virBufferContentAndReset(&buf);
}
#endif
static void qemuAgentDispose(void *obj)
{
qemuAgentPtr mon = obj;
VIR_DEBUG("mon=%p", mon);
if (mon->cb && mon->cb->destroy)
(mon->cb->destroy)(mon, mon->vm);
virCondDestroy(&mon->notify);
VIR_FREE(mon->buffer);
}
static int
qemuAgentOpenUnix(const char *monitor, pid_t cpid, bool *inProgress)
{
struct sockaddr_un addr;
int monfd;
int timeout = 3; /* In seconds */
int ret;
size_t i = 0;
*inProgress = false;
if ((monfd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) {
virReportSystemError(errno,
"%s", _("failed to create socket"));
return -1;
}
if (virSetNonBlock(monfd) < 0) {
virReportSystemError(errno, "%s",
_("Unable to put monitor "
"into non-blocking mode"));
goto error;
}
if (virSetCloseExec(monfd) < 0) {
virReportSystemError(errno, "%s",
_("Unable to set monitor "
"close-on-exec flag"));
goto error;
}
memset(&addr, 0, sizeof(addr));
addr.sun_family = AF_UNIX;
if (virStrcpyStatic(addr.sun_path, monitor) == NULL) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Agent path %s too big for destination"), monitor);
goto error;
}
do {
ret = connect(monfd, (struct sockaddr *) &addr, sizeof(addr));
if (ret == 0)
break;
if ((errno == ENOENT || errno == ECONNREFUSED) &&
virProcessKill(cpid, 0) == 0) {
/* ENOENT : Socket may not have shown up yet
* ECONNREFUSED : Leftover socket hasn't been removed yet */
continue;
}
if ((errno == EINPROGRESS) ||
(errno == EAGAIN)) {
VIR_DEBUG("Connection attempt continuing in background");
*inProgress = true;
ret = 0;
break;
}
virReportSystemError(errno, "%s",
_("failed to connect to monitor socket"));
goto error;
} while ((++i <= timeout*5) && (usleep(.2 * 1000000) <= 0));
if (ret != 0) {
virReportSystemError(errno, "%s",
_("monitor socket did not show up"));
goto error;
}
return monfd;
error:
VIR_FORCE_CLOSE(monfd);
return -1;
}
static int
qemuAgentOpenPty(const char *monitor)
{
int monfd;
if ((monfd = open(monitor, O_RDWR | O_NONBLOCK)) < 0) {
virReportSystemError(errno,
_("Unable to open monitor path %s"), monitor);
return -1;
}
if (virSetCloseExec(monfd) < 0) {
virReportSystemError(errno, "%s",
_("Unable to set monitor close-on-exec flag"));
goto error;
}
return monfd;
error:
VIR_FORCE_CLOSE(monfd);
return -1;
}
static int
qemuAgentIOProcessEvent(qemuAgentPtr mon,
virJSONValuePtr obj)
{
const char *type;
VIR_DEBUG("mon=%p obj=%p", mon, obj);
type = virJSONValueObjectGetString(obj, "event");
if (!type) {
VIR_WARN("missing event type in message");
errno = EINVAL;
return -1;
}
/*
for (i = 0; i < ARRAY_CARDINALITY(eventHandlers); i++) {
if (STREQ(eventHandlers[i].type, type)) {
virJSONValuePtr data = virJSONValueObjectGet(obj, "data");
VIR_DEBUG("handle %s handler=%p data=%p", type,
eventHandlers[i].handler, data);
(eventHandlers[i].handler)(mon, data);
break;
}
}
*/
return 0;
}
static int
qemuAgentIOProcessLine(qemuAgentPtr mon,
const char *line,
qemuAgentMessagePtr msg)
{
virJSONValuePtr obj = NULL;
int ret = -1;
unsigned long long id;
VIR_DEBUG("Line [%s]", line);
if (!(obj = virJSONValueFromString(line)))
goto cleanup;
if (obj->type != VIR_JSON_TYPE_OBJECT) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Parsed JSON reply '%s' isn't an object"), line);
goto cleanup;
}
if (virJSONValueObjectHasKey(obj, "QMP") == 1) {
ret = 0;
} else if (virJSONValueObjectHasKey(obj, "event") == 1) {
ret = qemuAgentIOProcessEvent(mon, obj);
} else if (virJSONValueObjectHasKey(obj, "error") == 1 ||
virJSONValueObjectHasKey(obj, "return") == 1) {
if (msg) {
msg->rxObject = obj;
msg->finished = 1;
obj = NULL;
ret = 0;
} else {
/* If we've received something like:
* {"return": 1234}
* it is likely that somebody started GA
* which is now processing our previous
* guest-sync commands. Check if this is
* the case and don't report an error but
* return silently.
*/
if (virJSONValueObjectGetNumberUlong(obj, "return", &id) == 0) {
VIR_DEBUG("Ignoring delayed reply to guest-sync: %llu", id);
ret = 0;
goto cleanup;
}
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Unexpected JSON reply '%s'"), line);
}
} else {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Unknown JSON reply '%s'"), line);
}
cleanup:
virJSONValueFree(obj);
return ret;
}
static int qemuAgentIOProcessData(qemuAgentPtr mon,
char *data,
size_t len,
qemuAgentMessagePtr msg)
{
int used = 0;
size_t i = 0;
#if DEBUG_IO
# if DEBUG_RAW_IO
char *str1 = qemuAgentEscapeNonPrintable(data);
VIR_ERROR("[%s]", str1);
VIR_FREE(str1);
# else
VIR_DEBUG("Data %zu bytes [%s]", len, data);
# endif
#endif
while (used < len) {
char *nl = strstr(data + used, LINE_ENDING);
if (nl) {
int got = nl - (data + used);
for (i = 0; i < strlen(LINE_ENDING); i++)
data[used + got + i] = '\0';
if (qemuAgentIOProcessLine(mon, data + used, msg) < 0) {
return -1;
}
used += got + strlen(LINE_ENDING);
} else {
break;
}
}
VIR_DEBUG("Total used %d bytes out of %zd available in buffer", used, len);
return used;
}
/* This method processes data that has been received
* from the monitor. Looking for async events and
* replies/errors.
*/
static int
qemuAgentIOProcess(qemuAgentPtr mon)
{
int len;
qemuAgentMessagePtr msg = NULL;
/* See if there's a message ready for reply; that is,
* one that has completed writing all its data.
*/
if (mon->msg && mon->msg->txOffset == mon->msg->txLength)
msg = mon->msg;
#if DEBUG_IO
# if DEBUG_RAW_IO
char *str1 = qemuAgentEscapeNonPrintable(msg ? msg->txBuffer : "");
char *str2 = qemuAgentEscapeNonPrintable(mon->buffer);
VIR_ERROR(_("Process %zu %p %p [[[%s]]][[[%s]]]"),
mon->bufferOffset, mon->msg, msg, str1, str2);
VIR_FREE(str1);
VIR_FREE(str2);
# else
VIR_DEBUG("Process %zu", mon->bufferOffset);
# endif
#endif
len = qemuAgentIOProcessData(mon,
mon->buffer, mon->bufferOffset,
msg);
if (len < 0)
return -1;
if (len < mon->bufferOffset) {
memmove(mon->buffer, mon->buffer + len, mon->bufferOffset - len);
mon->bufferOffset -= len;
} else {
VIR_FREE(mon->buffer);
mon->bufferOffset = mon->bufferLength = 0;
}
#if DEBUG_IO
VIR_DEBUG("Process done %zu used %d", mon->bufferOffset, len);
#endif
if (msg && msg->finished)
virCondBroadcast(&mon->notify);
return len;
}
static int
qemuAgentIOConnect(qemuAgentPtr mon)
{
int optval;
socklen_t optlen;
VIR_DEBUG("Checking on background connection status");
mon->connectPending = false;
optlen = sizeof(optval);
if (getsockopt(mon->fd, SOL_SOCKET, SO_ERROR,
&optval, &optlen) < 0) {
virReportSystemError(errno, "%s",
_("Cannot check socket connection status"));
return -1;
}
if (optval != 0) {
virReportSystemError(optval, "%s",
_("Cannot connect to agent socket"));
return -1;
}
VIR_DEBUG("Agent is now connected");
return 0;
}
/*
* Called when the monitor is able to write data
* Call this function while holding the monitor lock.
*/
static int
qemuAgentIOWrite(qemuAgentPtr mon)
{
int done;
/* If no active message, or fully transmitted, then no-op */
if (!mon->msg || mon->msg->txOffset == mon->msg->txLength)
return 0;
done = safewrite(mon->fd,
mon->msg->txBuffer + mon->msg->txOffset,
mon->msg->txLength - mon->msg->txOffset);
if (done < 0) {
if (errno == EAGAIN)
return 0;
virReportSystemError(errno, "%s",
_("Unable to write to monitor"));
return -1;
}
mon->msg->txOffset += done;
return done;
}
/*
* Called when the monitor has incoming data to read
* Call this function while holding the monitor lock.
*
* Returns -1 on error, or number of bytes read
*/
static int
qemuAgentIORead(qemuAgentPtr mon)
{
size_t avail = mon->bufferLength - mon->bufferOffset;
int ret = 0;
if (avail < 1024) {
if (VIR_REALLOC_N(mon->buffer,
mon->bufferLength + 1024) < 0)
return -1;
mon->bufferLength += 1024;
avail += 1024;
}
/* Read as much as we can get into our buffer,
until we block on EAGAIN, or hit EOF */
while (avail > 1) {
int got;
got = read(mon->fd,
mon->buffer + mon->bufferOffset,
avail - 1);
if (got < 0) {
if (errno == EAGAIN)
break;
virReportSystemError(errno, "%s",
_("Unable to read from monitor"));
ret = -1;
break;
}
if (got == 0)
break;
ret += got;
avail -= got;
mon->bufferOffset += got;
mon->buffer[mon->bufferOffset] = '\0';
}
#if DEBUG_IO
VIR_DEBUG("Now read %zu bytes of data", mon->bufferOffset);
#endif
return ret;
}
static void qemuAgentUpdateWatch(qemuAgentPtr mon)
{
int events =
VIR_EVENT_HANDLE_HANGUP |
VIR_EVENT_HANDLE_ERROR;
if (mon->lastError.code == VIR_ERR_OK) {
events |= VIR_EVENT_HANDLE_READABLE;
if (mon->msg && mon->msg->txOffset < mon->msg->txLength)
events |= VIR_EVENT_HANDLE_WRITABLE;
}
virEventUpdateHandle(mon->watch, events);
}
static void
qemuAgentIO(int watch, int fd, int events, void *opaque) {
qemuAgentPtr mon = opaque;
bool error = false;
bool eof = false;
virObjectRef(mon);
/* lock access to the monitor and protect fd */
virObjectLock(mon);
#if DEBUG_IO
VIR_DEBUG("Agent %p I/O on watch %d fd %d events %d", mon, watch, fd, events);
#endif
if (mon->fd != fd || mon->watch != watch) {
if (events & (VIR_EVENT_HANDLE_HANGUP | VIR_EVENT_HANDLE_ERROR))
eof = true;
virReportError(VIR_ERR_INTERNAL_ERROR,
_("event from unexpected fd %d!=%d / watch %d!=%d"),
mon->fd, fd, mon->watch, watch);
error = true;
} else if (mon->lastError.code != VIR_ERR_OK) {
if (events & (VIR_EVENT_HANDLE_HANGUP | VIR_EVENT_HANDLE_ERROR))
eof = true;
error = true;
} else {
if (events & VIR_EVENT_HANDLE_WRITABLE) {
if (mon->connectPending) {
if (qemuAgentIOConnect(mon) < 0)
error = true;
} else {
if (qemuAgentIOWrite(mon) < 0)
error = true;
}
events &= ~VIR_EVENT_HANDLE_WRITABLE;
}
if (!error &&
events & VIR_EVENT_HANDLE_READABLE) {
int got = qemuAgentIORead(mon);
events &= ~VIR_EVENT_HANDLE_READABLE;
if (got < 0) {
error = true;
} else if (got == 0) {
eof = true;
} else {
/* Ignore hangup/error events if we read some data, to
* give time for that data to be consumed */
events = 0;
if (qemuAgentIOProcess(mon) < 0)
error = true;
}
}
if (!error &&
events & VIR_EVENT_HANDLE_HANGUP) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("End of file from monitor"));
eof = true;
events &= ~VIR_EVENT_HANDLE_HANGUP;
}
if (!error && !eof &&
events & VIR_EVENT_HANDLE_ERROR) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("Invalid file descriptor while waiting for monitor"));
eof = true;
events &= ~VIR_EVENT_HANDLE_ERROR;
}
if (!error && events) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Unhandled event %d for monitor fd %d"),
events, mon->fd);
error = true;
}
}
if (error || eof) {
if (mon->lastError.code != VIR_ERR_OK) {
/* Already have an error, so clear any new error */
virResetLastError();
} else {
virErrorPtr err = virGetLastError();
if (!err)
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("Error while processing monitor IO"));
virCopyLastError(&mon->lastError);
virResetLastError();
}
VIR_DEBUG("Error on monitor %s", NULLSTR(mon->lastError.message));
/* If IO process resulted in an error & we have a message,
* then wakeup that waiter */
if (mon->msg && !mon->msg->finished) {
mon->msg->finished = 1;
virCondSignal(&mon->notify);
}
}
qemuAgentUpdateWatch(mon);
/* We have to unlock to avoid deadlock against command thread,
* but is this safe ? I think it is, because the callback
* will try to acquire the virDomainObjPtr mutex next */
if (eof) {
void (*eofNotify)(qemuAgentPtr, virDomainObjPtr)
= mon->cb->eofNotify;
virDomainObjPtr vm = mon->vm;
/* Make sure anyone waiting wakes up now */
virCondSignal(&mon->notify);
virObjectUnlock(mon);
virObjectUnref(mon);
VIR_DEBUG("Triggering EOF callback");
(eofNotify)(mon, vm);
} else if (error) {
void (*errorNotify)(qemuAgentPtr, virDomainObjPtr)
= mon->cb->errorNotify;
virDomainObjPtr vm = mon->vm;
/* Make sure anyone waiting wakes up now */
virCondSignal(&mon->notify);
virObjectUnlock(mon);
virObjectUnref(mon);
VIR_DEBUG("Triggering error callback");
(errorNotify)(mon, vm);
} else {
virObjectUnlock(mon);
virObjectUnref(mon);
}
}
qemuAgentPtr
qemuAgentOpen(virDomainObjPtr vm,
virDomainChrSourceDefPtr config,
qemuAgentCallbacksPtr cb)
{
qemuAgentPtr mon;
if (!cb || !cb->eofNotify) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("EOF notify callback must be supplied"));
return NULL;
}
if (qemuAgentInitialize() < 0)
return NULL;
if (!(mon = virObjectLockableNew(qemuAgentClass)))
return NULL;
mon->fd = -1;
if (virCondInit(&mon->notify) < 0) {
virReportSystemError(errno, "%s",
_("cannot initialize monitor condition"));
virObjectUnref(mon);
return NULL;
}
mon->vm = vm;
mon->cb = cb;
switch (config->type) {
case VIR_DOMAIN_CHR_TYPE_UNIX:
mon->fd = qemuAgentOpenUnix(config->data.nix.path, vm->pid,
&mon->connectPending);
break;
case VIR_DOMAIN_CHR_TYPE_PTY:
mon->fd = qemuAgentOpenPty(config->data.file.path);
break;
default:
virReportError(VIR_ERR_INTERNAL_ERROR,
_("unable to handle monitor type: %s"),
virDomainChrTypeToString(config->type));
goto cleanup;
}
if (mon->fd == -1)
goto cleanup;
virObjectRef(mon);
if ((mon->watch = virEventAddHandle(mon->fd,
VIR_EVENT_HANDLE_HANGUP |
VIR_EVENT_HANDLE_ERROR |
VIR_EVENT_HANDLE_READABLE |
(mon->connectPending ?
VIR_EVENT_HANDLE_WRITABLE :
0),
qemuAgentIO,
mon,
virObjectFreeCallback)) < 0) {
virObjectUnref(mon);
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("unable to register monitor events"));
goto cleanup;
}
VIR_DEBUG("New mon %p fd =%d watch=%d", mon, mon->fd, mon->watch);
return mon;
cleanup:
/* We don't want the 'destroy' callback invoked during
* cleanup from construction failure, because that can
* give a double-unref on virDomainObjPtr in the caller,
* so kill the callbacks now.
*/
mon->cb = NULL;
qemuAgentClose(mon);
return NULL;
}
void qemuAgentClose(qemuAgentPtr mon)
{
if (!mon)
return;
VIR_DEBUG("mon=%p", mon);
virObjectLock(mon);
if (mon->fd >= 0) {
if (mon->watch)
virEventRemoveHandle(mon->watch);
VIR_FORCE_CLOSE(mon->fd);
}
/* If there is somebody waiting for a message
* wake him up. No message will arrive anyway. */
if (mon->msg && !mon->msg->finished) {
mon->msg->finished = 1;
virCondSignal(&mon->notify);
}
virObjectUnlock(mon);
virObjectUnref(mon);
}
#define QEMU_AGENT_WAIT_TIME 5
/**
* qemuAgentSend:
* @mon: Monitor
* @msg: Message
* @seconds: number of seconds to wait for the result, it can be either
* -2, -1, 0 or positive.
*
* Send @msg to agent @mon. If @seconds is equal to
* VIR_DOMAIN_QEMU_AGENT_COMMAND_BLOCK(-2), this function will block forever
* waiting for the result. The value of
* VIR_DOMAIN_QEMU_AGENT_COMMAND_DEFAULT(-1) means use default timeout value
* and VIR_DOMAIN_QEMU_AGENT_COMMAND_NOWAIT(0) makes this this function return
* immediately without waiting. Any positive value means the number of seconds
* to wait for the result.
*
* Returns: 0 on success,
* -2 on timeout,
* -1 otherwise
*/
static int qemuAgentSend(qemuAgentPtr mon,
qemuAgentMessagePtr msg,
int seconds)
{
int ret = -1;
unsigned long long then = 0;
/* Check whether qemu quit unexpectedly */
if (mon->lastError.code != VIR_ERR_OK) {
VIR_DEBUG("Attempt to send command while error is set %s",
NULLSTR(mon->lastError.message));
virSetError(&mon->lastError);
return -1;
}
if (seconds > VIR_DOMAIN_QEMU_AGENT_COMMAND_BLOCK) {
unsigned long long now;
if (virTimeMillisNow(&now) < 0)
return -1;
if (seconds == VIR_DOMAIN_QEMU_AGENT_COMMAND_DEFAULT)
seconds = QEMU_AGENT_WAIT_TIME;
then = now + seconds * 1000ull;
}
mon->msg = msg;
qemuAgentUpdateWatch(mon);
while (!mon->msg->finished) {
if ((then && virCondWaitUntil(&mon->notify, &mon->parent.lock, then) < 0) ||
(!then && virCondWait(&mon->notify, &mon->parent.lock) < 0)) {
if (errno == ETIMEDOUT) {
virReportError(VIR_ERR_AGENT_UNRESPONSIVE, "%s",
_("Guest agent not available for now"));
ret = -2;
} else {
virReportSystemError(errno, "%s",
_("Unable to wait on agent monitor "
"condition"));
}
goto cleanup;
}
}
if (mon->lastError.code != VIR_ERR_OK) {
VIR_DEBUG("Send command resulted in error %s",
NULLSTR(mon->lastError.message));
virSetError(&mon->lastError);
goto cleanup;
}
ret = 0;
cleanup:
mon->msg = NULL;
qemuAgentUpdateWatch(mon);
return ret;
}
/**
* qemuAgentGuestSync:
* @mon: Monitor
*
* Send guest-sync with unique ID
* and wait for reply. If we get one, check if
* received ID is equal to given.
*
* Returns: 0 on success,
* -1 otherwise
*/
static int
qemuAgentGuestSync(qemuAgentPtr mon)
{
int ret = -1;
int send_ret;
unsigned long long id, id_ret;
qemuAgentMessage sync_msg;
memset(&sync_msg, 0, sizeof(sync_msg));
if (virTimeMillisNow(&id) < 0)
return -1;
if (virAsprintf(&sync_msg.txBuffer,
"{\"execute\":\"guest-sync\", "
"\"arguments\":{\"id\":%llu}}\n", id) < 0)
return -1;
sync_msg.txLength = strlen(sync_msg.txBuffer);
VIR_DEBUG("Sending guest-sync command with ID: %llu", id);
send_ret = qemuAgentSend(mon, &sync_msg,
VIR_DOMAIN_QEMU_AGENT_COMMAND_DEFAULT);
VIR_DEBUG("qemuAgentSend returned: %d", send_ret);
if (send_ret < 0)
goto cleanup;
if (!sync_msg.rxObject) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("Missing monitor reply object"));
goto cleanup;
}
if (virJSONValueObjectGetNumberUlong(sync_msg.rxObject,
"return", &id_ret) < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("Malformed return value"));
goto cleanup;
}
VIR_DEBUG("Guest returned ID: %llu", id_ret);
if (id_ret != id) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Guest agent returned ID: %llu instead of %llu"),
id_ret, id);
goto cleanup;
}
ret = 0;
cleanup:
virJSONValueFree(sync_msg.rxObject);
VIR_FREE(sync_msg.txBuffer);
return ret;
}
static int
qemuAgentCommand(qemuAgentPtr mon,
virJSONValuePtr cmd,
virJSONValuePtr *reply,
int seconds)
{
int ret = -1;
qemuAgentMessage msg;
char *cmdstr = NULL;
int await_event = mon->await_event;
*reply = NULL;
if (qemuAgentGuestSync(mon) < 0)
return -1;
memset(&msg, 0, sizeof(msg));
if (!(cmdstr = virJSONValueToString(cmd, false)))
goto cleanup;
if (virAsprintf(&msg.txBuffer, "%s" LINE_ENDING, cmdstr) < 0)
goto cleanup;
msg.txLength = strlen(msg.txBuffer);
VIR_DEBUG("Send command '%s' for write, seconds = %d", cmdstr, seconds);
ret = qemuAgentSend(mon, &msg, seconds);
VIR_DEBUG("Receive command reply ret=%d rxObject=%p",
ret, msg.rxObject);
if (ret == 0) {
/* If we haven't obtained any reply but we wait for an
* event, then don't report this as error */
if (!msg.rxObject) {
if (await_event) {
VIR_DEBUG("Woken up by event %d", await_event);
} else {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("Missing monitor reply object"));
ret = -1;
}
} else {
*reply = msg.rxObject;
}
}
cleanup:
VIR_FREE(cmdstr);
VIR_FREE(msg.txBuffer);
return ret;
}
static const char *
qemuAgentStringifyErrorClass(const char *klass)
{
if (STREQ_NULLABLE(klass, "BufferOverrun"))
return "Buffer overrun";
else if (STREQ_NULLABLE(klass, "CommandDisabled"))
return "The command has been disabled for this instance";
else if (STREQ_NULLABLE(klass, "CommandNotFound"))
return "The command has not been found";
else if (STREQ_NULLABLE(klass, "FdNotFound"))
return "File descriptor not found";
else if (STREQ_NULLABLE(klass, "InvalidParameter"))
return "Invalid parameter";
else if (STREQ_NULLABLE(klass, "InvalidParameterType"))
return "Invalid parameter type";
else if (STREQ_NULLABLE(klass, "InvalidParameterValue"))
return "Invalid parameter value";
else if (STREQ_NULLABLE(klass, "OpenFileFailed"))
return "Cannot open file";
else if (STREQ_NULLABLE(klass, "QgaCommandFailed"))
return "Guest agent command failed";
else if (STREQ_NULLABLE(klass, "QMPBadInputObjectMember"))
return "Bad QMP input object member";
else if (STREQ_NULLABLE(klass, "QMPExtraInputObjectMember"))
return "Unexpected extra object member";
else if (STREQ_NULLABLE(klass, "UndefinedError"))
return "An undefined error has occurred";
else if (STREQ_NULLABLE(klass, "Unsupported"))
return "this feature or command is not currently supported";
else if (klass)
return klass;
else
return "unknown QEMU command error";
}
/* Ignoring OOM in this method, since we're already reporting
* a more important error
*
* XXX see qerror.h for different klasses & fill out useful params
*/
static const char *
qemuAgentStringifyError(virJSONValuePtr error)
{
const char *klass = virJSONValueObjectGetString(error, "class");
const char *detail = NULL;
/* The QMP 'desc' field is usually sufficient for our generic
* error reporting needs.
*/
if (klass)
detail = virJSONValueObjectGetString(error, "desc");
if (!detail)
detail = qemuAgentStringifyErrorClass(klass);
return detail;
}
static const char *
qemuAgentCommandName(virJSONValuePtr cmd)
{
const char *name = virJSONValueObjectGetString(cmd, "execute");
if (name)
return name;
else
return "<unknown>";
}
static int
qemuAgentCheckError(virJSONValuePtr cmd,
virJSONValuePtr reply)
{
if (virJSONValueObjectHasKey(reply, "error")) {
virJSONValuePtr error = virJSONValueObjectGet(reply, "error");
char *cmdstr = virJSONValueToString(cmd, false);
char *replystr = virJSONValueToString(reply, false);
/* Log the full JSON formatted command & error */
VIR_DEBUG("unable to execute QEMU agent command %s: %s",
NULLSTR(cmdstr), NULLSTR(replystr));
/* Only send the user the command name + friendly error */
if (!error)
virReportError(VIR_ERR_INTERNAL_ERROR,
_("unable to execute QEMU agent command '%s'"),
qemuAgentCommandName(cmd));
else
virReportError(VIR_ERR_INTERNAL_ERROR,
_("unable to execute QEMU agent command '%s': %s"),
qemuAgentCommandName(cmd),
qemuAgentStringifyError(error));
VIR_FREE(cmdstr);
VIR_FREE(replystr);
return -1;
} else if (!virJSONValueObjectHasKey(reply, "return")) {
char *cmdstr = virJSONValueToString(cmd, false);
char *replystr = virJSONValueToString(reply, false);
VIR_DEBUG("Neither 'return' nor 'error' is set in the JSON reply %s: %s",
NULLSTR(cmdstr), NULLSTR(replystr));
virReportError(VIR_ERR_INTERNAL_ERROR,
_("unable to execute QEMU agent command '%s'"),
qemuAgentCommandName(cmd));
VIR_FREE(cmdstr);
VIR_FREE(replystr);
return -1;
}
return 0;
}
static virJSONValuePtr ATTRIBUTE_SENTINEL
qemuAgentMakeCommand(const char *cmdname,
...)
{
virJSONValuePtr obj;
virJSONValuePtr jargs = NULL;
va_list args;
char *key;
va_start(args, cmdname);
if (!(obj = virJSONValueNewObject()))
goto error;
if (virJSONValueObjectAppendString(obj, "execute", cmdname) < 0)
goto error;
while ((key = va_arg(args, char *)) != NULL) {
int ret;
char type;
if (strlen(key) < 3) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("argument key '%s' is too short, missing type prefix"),
key);
goto error;
}
/* Keys look like s:name the first letter is a type code */
type = key[0];
key += 2;
if (!jargs &&
!(jargs = virJSONValueNewObject()))
goto error;
/* This doesn't support maps/arrays. This hasn't
* proved to be a problem..... yet :-) */
switch (type) {
case 's': {
char *val = va_arg(args, char *);
ret = virJSONValueObjectAppendString(jargs, key, val);
} break;
case 'i': {
int val = va_arg(args, int);
ret = virJSONValueObjectAppendNumberInt(jargs, key, val);
} break;
case 'u': {
unsigned int val = va_arg(args, unsigned int);
ret = virJSONValueObjectAppendNumberUint(jargs, key, val);
} break;
case 'I': {
long long val = va_arg(args, long long);
ret = virJSONValueObjectAppendNumberLong(jargs, key, val);
} break;
case 'U': {
/* qemu silently truncates numbers larger than LLONG_MAX,
* so passing the full range of unsigned 64 bit integers
* is not safe here. Pass them as signed 64 bit integers
* instead.
*/
long long val = va_arg(args, long long);
ret = virJSONValueObjectAppendNumberLong(jargs, key, val);
} break;
case 'd': {
double val = va_arg(args, double);
ret = virJSONValueObjectAppendNumberDouble(jargs, key, val);
} break;
case 'b': {
int val = va_arg(args, int);
ret = virJSONValueObjectAppendBoolean(jargs, key, val);
} break;
case 'n': {
ret = virJSONValueObjectAppendNull(jargs, key);
} break;
case 'a': {
virJSONValuePtr val = va_arg(args, virJSONValuePtr);
ret = virJSONValueObjectAppend(jargs, key, val);
} break;
default:
virReportError(VIR_ERR_INTERNAL_ERROR,
_("unsupported data type '%c' for arg '%s'"), type, key - 2);
goto error;
}
if (ret < 0)
goto error;
}
if (jargs &&
virJSONValueObjectAppend(obj, "arguments", jargs) < 0)
goto error;
va_end(args);
return obj;
error:
virJSONValueFree(obj);
virJSONValueFree(jargs);
va_end(args);
return NULL;
}
void qemuAgentNotifyEvent(qemuAgentPtr mon,
qemuAgentEvent event)
{
VIR_DEBUG("mon=%p event=%d", mon, event);
if (mon->await_event == event) {
VIR_DEBUG("Waking up a tragedian");
mon->await_event = QEMU_AGENT_EVENT_NONE;
/* somebody waiting for this event, wake him up. */
if (mon->msg && !mon->msg->finished) {
mon->msg->finished = 1;
virCondSignal(&mon->notify);
}
} else {
/* shouldn't happen but one never knows */
VIR_WARN("Received unexpected event %d", event);
}
}
VIR_ENUM_DECL(qemuAgentShutdownMode);
VIR_ENUM_IMPL(qemuAgentShutdownMode,
QEMU_AGENT_SHUTDOWN_LAST,
"powerdown", "reboot", "halt");
int qemuAgentShutdown(qemuAgentPtr mon,
qemuAgentShutdownMode mode)
{
int ret = -1;
virJSONValuePtr cmd;
virJSONValuePtr reply = NULL;
cmd = qemuAgentMakeCommand("guest-shutdown",
"s:mode", qemuAgentShutdownModeTypeToString(mode),
NULL);
if (!cmd)
return -1;
if (mode == QEMU_AGENT_SHUTDOWN_REBOOT)
mon->await_event = QEMU_AGENT_EVENT_RESET;
else
mon->await_event = QEMU_AGENT_EVENT_SHUTDOWN;
ret = qemuAgentCommand(mon, cmd, &reply,
VIR_DOMAIN_QEMU_AGENT_COMMAND_BLOCK);
if (reply && ret == 0)
ret = qemuAgentCheckError(cmd, reply);
virJSONValueFree(cmd);
virJSONValueFree(reply);
return ret;
}
/*
* qemuAgentFSFreeze:
* @mon: Agent
*
* Issue guest-fsfreeze-freeze command to guest agent,
* which freezes all mounted file systems and returns
* number of frozen file systems on success.
*
* Returns: number of file system frozen on success,
* -1 on error.
*/
int qemuAgentFSFreeze(qemuAgentPtr mon)
{
int ret = -1;
virJSONValuePtr cmd;
virJSONValuePtr reply = NULL;
cmd = qemuAgentMakeCommand("guest-fsfreeze-freeze", NULL);
if (!cmd)
return -1;
if (qemuAgentCommand(mon, cmd, &reply,
VIR_DOMAIN_QEMU_AGENT_COMMAND_BLOCK) < 0 ||
qemuAgentCheckError(cmd, reply) < 0)
goto cleanup;
if (virJSONValueObjectGetNumberInt(reply, "return", &ret) < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("malformed return value"));
}
cleanup:
virJSONValueFree(cmd);
virJSONValueFree(reply);
return ret;
}
/*
* qemuAgentFSThaw:
* @mon: Agent
*
* Issue guest-fsfreeze-thaw command to guest agent,
* which unfreezes all mounted file systems and returns
* number of thawed file systems on success.
*
* Returns: number of file system thawed on success,
* -1 on error.
*/
int qemuAgentFSThaw(qemuAgentPtr mon)
{
int ret = -1;
virJSONValuePtr cmd;
virJSONValuePtr reply = NULL;
cmd = qemuAgentMakeCommand("guest-fsfreeze-thaw", NULL);
if (!cmd)
return -1;
if (qemuAgentCommand(mon, cmd, &reply,
VIR_DOMAIN_QEMU_AGENT_COMMAND_BLOCK) < 0 ||
qemuAgentCheckError(cmd, reply) < 0)
goto cleanup;
if (virJSONValueObjectGetNumberInt(reply, "return", &ret) < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("malformed return value"));
}
cleanup:
virJSONValueFree(cmd);
virJSONValueFree(reply);
return ret;
}
VIR_ENUM_DECL(qemuAgentSuspendMode);
VIR_ENUM_IMPL(qemuAgentSuspendMode,
VIR_NODE_SUSPEND_TARGET_LAST,
"guest-suspend-ram",
"guest-suspend-disk",
"guest-suspend-hybrid");
int
qemuAgentSuspend(qemuAgentPtr mon,
unsigned int target)
{
int ret = -1;
virJSONValuePtr cmd;
virJSONValuePtr reply = NULL;
cmd = qemuAgentMakeCommand(qemuAgentSuspendModeTypeToString(target),
NULL);
if (!cmd)
return -1;
mon->await_event = QEMU_AGENT_EVENT_SUSPEND;
ret = qemuAgentCommand(mon, cmd, &reply,
VIR_DOMAIN_QEMU_AGENT_COMMAND_BLOCK);
if (reply && ret == 0)
ret = qemuAgentCheckError(cmd, reply);
virJSONValueFree(cmd);
virJSONValueFree(reply);
return ret;
}
int
qemuAgentArbitraryCommand(qemuAgentPtr mon,
const char *cmd_str,
char **result,
int timeout)
{
int ret = -1;
virJSONValuePtr cmd = NULL;
virJSONValuePtr reply = NULL;
*result = NULL;
if (timeout < VIR_DOMAIN_QEMU_AGENT_COMMAND_MIN) {
virReportError(VIR_ERR_INVALID_ARG,
_("guest agent timeout '%d' is "
"less than the minimum '%d'"),
timeout, VIR_DOMAIN_QEMU_AGENT_COMMAND_MIN);
goto cleanup;
}
if (!(cmd = virJSONValueFromString(cmd_str)))
goto cleanup;
if ((ret = qemuAgentCommand(mon, cmd, &reply, timeout)) < 0)
goto cleanup;
if ((ret = qemuAgentCheckError(cmd, reply)) < 0)
goto cleanup;
if (!(*result = virJSONValueToString(reply, false)))
ret = -1;
cleanup:
virJSONValueFree(cmd);
virJSONValueFree(reply);
return ret;
}
int
qemuAgentFSTrim(qemuAgentPtr mon,
unsigned long long minimum)
{
int ret = -1;
virJSONValuePtr cmd;
virJSONValuePtr reply = NULL;
cmd = qemuAgentMakeCommand("guest-fstrim",
"U:minimum", minimum,
NULL);
if (!cmd)
return ret;
ret = qemuAgentCommand(mon, cmd, &reply,
VIR_DOMAIN_QEMU_AGENT_COMMAND_BLOCK);
if (reply && ret == 0)
ret = qemuAgentCheckError(cmd, reply);
virJSONValueFree(cmd);
virJSONValueFree(reply);
return ret;
}
int
qemuAgentGetVCPUs(qemuAgentPtr mon,
qemuAgentCPUInfoPtr *info)
{
int ret = -1;
size_t i;
virJSONValuePtr cmd;
virJSONValuePtr reply = NULL;
virJSONValuePtr data = NULL;
int ndata;
if (!(cmd = qemuAgentMakeCommand("guest-get-vcpus", NULL)))
return -1;
if (qemuAgentCommand(mon, cmd, &reply,
VIR_DOMAIN_QEMU_AGENT_COMMAND_BLOCK) < 0 ||
qemuAgentCheckError(cmd, reply) < 0)
goto cleanup;
if (!(data = virJSONValueObjectGet(reply, "return"))) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("guest-get-vcpus reply was missing return data"));
goto cleanup;
}
if (data->type != VIR_JSON_TYPE_ARRAY) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("guest-get-vcpus return information was not an array"));
goto cleanup;
}
ndata = virJSONValueArraySize(data);
if (VIR_ALLOC_N(*info, ndata) < 0)
goto cleanup;
for (i = 0; i < ndata; i++) {
virJSONValuePtr entry = virJSONValueArrayGet(data, i);
qemuAgentCPUInfoPtr in = *info + i;
if (!entry) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("array element missing in guest-get-vcpus return "
"value"));
goto cleanup;
}
if (virJSONValueObjectGetNumberUint(entry, "logical-id", &in->id) < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("'logical-id' missing in reply of guest-get-vcpus"));
goto cleanup;
}
if (virJSONValueObjectGetBoolean(entry, "online", &in->online) < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("'online' missing in reply of guest-get-vcpus"));
goto cleanup;
}
if (virJSONValueObjectGetBoolean(entry, "can-offline",
&in->offlinable) < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("'can-offline' missing in reply of guest-get-vcpus"));
goto cleanup;
}
}
ret = ndata;
cleanup:
virJSONValueFree(cmd);
virJSONValueFree(reply);
return ret;
}
/**
* Set the VCPU state using guest agent.
*
* Returns -1 on error, ninfo in case everything was successful and less than
* ninfo on a partial failure.
*/
int
qemuAgentSetVCPUs(qemuAgentPtr mon,
qemuAgentCPUInfoPtr info,
size_t ninfo)
{
int ret = -1;
virJSONValuePtr cmd = NULL;
virJSONValuePtr reply = NULL;
virJSONValuePtr cpus = NULL;
virJSONValuePtr cpu = NULL;
size_t i;
/* create the key data array */
if (!(cpus = virJSONValueNewArray()))
goto cleanup;
for (i = 0; i < ninfo; i++) {
qemuAgentCPUInfoPtr in = &info[i];
/* create single cpu object */
if (!(cpu = virJSONValueNewObject()))
goto cleanup;
if (virJSONValueObjectAppendNumberInt(cpu, "logical-id", in->id) < 0)
goto cleanup;
if (virJSONValueObjectAppendBoolean(cpu, "online", in->online) < 0)
goto cleanup;
if (virJSONValueArrayAppend(cpus, cpu) < 0)
goto cleanup;
cpu = NULL;
}
if (!(cmd = qemuAgentMakeCommand("guest-set-vcpus",
"a:vcpus", cpus,
NULL)))
goto cleanup;
cpus = NULL;
if (qemuAgentCommand(mon, cmd, &reply,
VIR_DOMAIN_QEMU_AGENT_COMMAND_BLOCK) < 0 ||
qemuAgentCheckError(cmd, reply) < 0)
goto cleanup;
if (virJSONValueObjectGetNumberInt(reply, "return", &ret) < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("malformed return value"));
}
cleanup:
virJSONValueFree(cmd);
virJSONValueFree(reply);
virJSONValueFree(cpu);
virJSONValueFree(cpus);
return ret;
}
/* modify the cpu info structure to set the correct amount of cpus */
int
qemuAgentUpdateCPUInfo(unsigned int nvcpus,
qemuAgentCPUInfoPtr cpuinfo,
int ncpuinfo)
{
size_t i;
int nonline = 0;
int nofflinable = 0;
/* count the active and offlinable cpus */
for (i = 0; i < ncpuinfo; i++) {
if (cpuinfo[i].online)
nonline++;
if (cpuinfo[i].offlinable && cpuinfo[i].online)
nofflinable++;
/* This shouldn't happen, but we can't trust the guest agent */
if (!cpuinfo[i].online && !cpuinfo[i].offlinable) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("Invalid data provided by guest agent"));
return -1;
}
}
/* the guest agent reported less cpus than requested */
if (nvcpus > ncpuinfo) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("guest agent reports less cpu than requested"));
return -1;
}
/* not enough offlinable CPUs to support the request */
if (nvcpus < nonline - nofflinable) {
virReportError(VIR_ERR_INVALID_ARG, "%s",
_("Cannot offline enough CPUs"));
return -1;
}
for (i = 0; i < ncpuinfo; i++) {
if (nvcpus < nonline) {
/* unplug */
if (cpuinfo[i].offlinable && cpuinfo[i].online) {
cpuinfo[i].online = false;
nonline--;
}
} else if (nvcpus > nonline) {
/* plug */
if (!cpuinfo[i].online) {
cpuinfo[i].online = true;
nonline++;
}
} else {
/* done */
break;
}
}
return 0;
}