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qemu-e2k/qga/main.c
Mark Wu 8dc4d915dd qemu-ga: Add interface to traverse the qmp command list by QmpCommand 
In the original code, qmp_get_command_list is used to construct
a list of all commands' name. To get the information of all qga
commands, it traverses the name list and search the command info
with its name.  So it can cause O(n^2) in the number of commands.

This patch adds an interface to traverse the qmp command list by
QmpCommand to replace qmp_get_command_list. It can decrease the
complexity from O(n^2) to O(n).

Signed-off-by: Mark Wu <wudxw@linux.vnet.ibm.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
*fix up commit subject
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2013-10-10 14:52:37 -05:00

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/*
* QEMU Guest Agent
*
* Copyright IBM Corp. 2011
*
* Authors:
* Adam Litke <aglitke@linux.vnet.ibm.com>
* Michael Roth <mdroth@linux.vnet.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include <stdlib.h>
#include <stdio.h>
#include <stdbool.h>
#include <glib.h>
#include <getopt.h>
#include <glib/gstdio.h>
#ifndef _WIN32
#include <syslog.h>
#include <sys/wait.h>
#include <sys/stat.h>
#endif
#include "qapi/qmp/json-streamer.h"
#include "qapi/qmp/json-parser.h"
#include "qapi/qmp/qint.h"
#include "qapi/qmp/qjson.h"
#include "qga/guest-agent-core.h"
#include "qemu/module.h"
#include "signal.h"
#include "qapi/qmp/qerror.h"
#include "qapi/qmp/dispatch.h"
#include "qga/channel.h"
#include "qemu/bswap.h"
#ifdef _WIN32
#include "qga/service-win32.h"
#include "qga/vss-win32.h"
#include <windows.h>
#endif
#ifdef __linux__
#include <linux/fs.h>
#ifdef FIFREEZE
#define CONFIG_FSFREEZE
#endif
#endif
#ifndef _WIN32
#define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0"
#define QGA_STATE_RELATIVE_DIR "run"
#else
#define QGA_VIRTIO_PATH_DEFAULT "\\\\.\\Global\\org.qemu.guest_agent.0"
#define QGA_STATE_RELATIVE_DIR "qemu-ga"
#endif
#ifdef CONFIG_FSFREEZE
#define QGA_FSFREEZE_HOOK_DEFAULT CONFIG_QEMU_CONFDIR "/fsfreeze-hook"
#endif
#define QGA_SENTINEL_BYTE 0xFF
static struct {
const char *state_dir;
const char *pidfile;
} dfl_pathnames;
typedef struct GAPersistentState {
#define QGA_PSTATE_DEFAULT_FD_COUNTER 1000
int64_t fd_counter;
} GAPersistentState;
struct GAState {
JSONMessageParser parser;
GMainLoop *main_loop;
GAChannel *channel;
bool virtio; /* fastpath to check for virtio to deal with poll() quirks */
GACommandState *command_state;
GLogLevelFlags log_level;
FILE *log_file;
bool logging_enabled;
#ifdef _WIN32
GAService service;
#endif
bool delimit_response;
bool frozen;
GList *blacklist;
const char *state_filepath_isfrozen;
struct {
const char *log_filepath;
const char *pid_filepath;
} deferred_options;
#ifdef CONFIG_FSFREEZE
const char *fsfreeze_hook;
#endif
const gchar *pstate_filepath;
GAPersistentState pstate;
};
struct GAState *ga_state;
/* commands that are safe to issue while filesystems are frozen */
static const char *ga_freeze_whitelist[] = {
"guest-ping",
"guest-info",
"guest-sync",
"guest-sync-delimited",
"guest-fsfreeze-status",
"guest-fsfreeze-thaw",
NULL
};
#ifdef _WIN32
DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
LPVOID ctx);
VOID WINAPI service_main(DWORD argc, TCHAR *argv[]);
#endif
static void
init_dfl_pathnames(void)
{
g_assert(dfl_pathnames.state_dir == NULL);
g_assert(dfl_pathnames.pidfile == NULL);
dfl_pathnames.state_dir = qemu_get_local_state_pathname(
QGA_STATE_RELATIVE_DIR);
dfl_pathnames.pidfile = qemu_get_local_state_pathname(
QGA_STATE_RELATIVE_DIR G_DIR_SEPARATOR_S "qemu-ga.pid");
}
static void quit_handler(int sig)
{
/* if we're frozen, don't exit unless we're absolutely forced to,
* because it's basically impossible for graceful exit to complete
* unless all log/pid files are on unfreezable filesystems. there's
* also a very likely chance killing the agent before unfreezing
* the filesystems is a mistake (or will be viewed as one later).
*/
if (ga_is_frozen(ga_state)) {
return;
}
g_debug("received signal num %d, quitting", sig);
if (g_main_loop_is_running(ga_state->main_loop)) {
g_main_loop_quit(ga_state->main_loop);
}
}
#ifndef _WIN32
static gboolean register_signal_handlers(void)
{
struct sigaction sigact;
int ret;
memset(&sigact, 0, sizeof(struct sigaction));
sigact.sa_handler = quit_handler;
ret = sigaction(SIGINT, &sigact, NULL);
if (ret == -1) {
g_error("error configuring signal handler: %s", strerror(errno));
}
ret = sigaction(SIGTERM, &sigact, NULL);
if (ret == -1) {
g_error("error configuring signal handler: %s", strerror(errno));
}
return true;
}
/* TODO: use this in place of all post-fork() fclose(std*) callers */
void reopen_fd_to_null(int fd)
{
int nullfd;
nullfd = open("/dev/null", O_RDWR);
if (nullfd < 0) {
return;
}
dup2(nullfd, fd);
if (nullfd != fd) {
close(nullfd);
}
}
#endif
static void usage(const char *cmd)
{
printf(
"Usage: %s [-m <method> -p <path>] [<options>]\n"
"QEMU Guest Agent %s\n"
"\n"
" -m, --method transport method: one of unix-listen, virtio-serial, or\n"
" isa-serial (virtio-serial is the default)\n"
" -p, --path device/socket path (the default for virtio-serial is:\n"
" %s)\n"
" -l, --logfile set logfile path, logs to stderr by default\n"
" -f, --pidfile specify pidfile (default is %s)\n"
#ifdef CONFIG_FSFREEZE
" -F, --fsfreeze-hook\n"
" enable fsfreeze hook. Accepts an optional argument that\n"
" specifies script to run on freeze/thaw. Script will be\n"
" called with 'freeze'/'thaw' arguments accordingly.\n"
" (default is %s)\n"
" If using -F with an argument, do not follow -F with a\n"
" space.\n"
" (for example: -F/var/run/fsfreezehook.sh)\n"
#endif
" -t, --statedir specify dir to store state information (absolute paths\n"
" only, default is %s)\n"
" -v, --verbose log extra debugging information\n"
" -V, --version print version information and exit\n"
" -d, --daemonize become a daemon\n"
#ifdef _WIN32
" -s, --service service commands: install, uninstall\n"
#endif
" -b, --blacklist comma-separated list of RPCs to disable (no spaces, \"?\"\n"
" to list available RPCs)\n"
" -h, --help display this help and exit\n"
"\n"
"Report bugs to <mdroth@linux.vnet.ibm.com>\n"
, cmd, QEMU_VERSION, QGA_VIRTIO_PATH_DEFAULT, dfl_pathnames.pidfile,
#ifdef CONFIG_FSFREEZE
QGA_FSFREEZE_HOOK_DEFAULT,
#endif
dfl_pathnames.state_dir);
}
static const char *ga_log_level_str(GLogLevelFlags level)
{
switch (level & G_LOG_LEVEL_MASK) {
case G_LOG_LEVEL_ERROR:
return "error";
case G_LOG_LEVEL_CRITICAL:
return "critical";
case G_LOG_LEVEL_WARNING:
return "warning";
case G_LOG_LEVEL_MESSAGE:
return "message";
case G_LOG_LEVEL_INFO:
return "info";
case G_LOG_LEVEL_DEBUG:
return "debug";
default:
return "user";
}
}
bool ga_logging_enabled(GAState *s)
{
return s->logging_enabled;
}
void ga_disable_logging(GAState *s)
{
s->logging_enabled = false;
}
void ga_enable_logging(GAState *s)
{
s->logging_enabled = true;
}
static void ga_log(const gchar *domain, GLogLevelFlags level,
const gchar *msg, gpointer opaque)
{
GAState *s = opaque;
GTimeVal time;
const char *level_str = ga_log_level_str(level);
if (!ga_logging_enabled(s)) {
return;
}
level &= G_LOG_LEVEL_MASK;
#ifndef _WIN32
if (domain && strcmp(domain, "syslog") == 0) {
syslog(LOG_INFO, "%s: %s", level_str, msg);
} else if (level & s->log_level) {
#else
if (level & s->log_level) {
#endif
g_get_current_time(&time);
fprintf(s->log_file,
"%lu.%lu: %s: %s\n", time.tv_sec, time.tv_usec, level_str, msg);
fflush(s->log_file);
}
}
void ga_set_response_delimited(GAState *s)
{
s->delimit_response = true;
}
static FILE *ga_open_logfile(const char *logfile)
{
FILE *f;
f = fopen(logfile, "a");
if (!f) {
return NULL;
}
qemu_set_cloexec(fileno(f));
return f;
}
#ifndef _WIN32
static bool ga_open_pidfile(const char *pidfile)
{
int pidfd;
char pidstr[32];
pidfd = qemu_open(pidfile, O_CREAT|O_WRONLY, S_IRUSR|S_IWUSR);
if (pidfd == -1 || lockf(pidfd, F_TLOCK, 0)) {
g_critical("Cannot lock pid file, %s", strerror(errno));
if (pidfd != -1) {
close(pidfd);
}
return false;
}
if (ftruncate(pidfd, 0)) {
g_critical("Failed to truncate pid file");
goto fail;
}
snprintf(pidstr, sizeof(pidstr), "%d\n", getpid());
if (write(pidfd, pidstr, strlen(pidstr)) != strlen(pidstr)) {
g_critical("Failed to write pid file");
goto fail;
}
/* keep pidfile open & locked forever */
return true;
fail:
unlink(pidfile);
close(pidfd);
return false;
}
#else /* _WIN32 */
static bool ga_open_pidfile(const char *pidfile)
{
return true;
}
#endif
static gint ga_strcmp(gconstpointer str1, gconstpointer str2)
{
return strcmp(str1, str2);
}
/* disable commands that aren't safe for fsfreeze */
static void ga_disable_non_whitelisted(QmpCommand *cmd, void *opaque)
{
bool whitelisted = false;
int i = 0;
const char *name = qmp_command_name(cmd);
while (ga_freeze_whitelist[i] != NULL) {
if (strcmp(name, ga_freeze_whitelist[i]) == 0) {
whitelisted = true;
}
i++;
}
if (!whitelisted) {
g_debug("disabling command: %s", name);
qmp_disable_command(name);
}
}
/* [re-]enable all commands, except those explicitly blacklisted by user */
static void ga_enable_non_blacklisted(QmpCommand *cmd, void *opaque)
{
GList *blacklist = opaque;
const char *name = qmp_command_name(cmd);
if (g_list_find_custom(blacklist, name, ga_strcmp) == NULL &&
!qmp_command_is_enabled(cmd)) {
g_debug("enabling command: %s", name);
qmp_enable_command(name);
}
}
static bool ga_create_file(const char *path)
{
int fd = open(path, O_CREAT | O_WRONLY, S_IWUSR | S_IRUSR);
if (fd == -1) {
g_warning("unable to open/create file %s: %s", path, strerror(errno));
return false;
}
close(fd);
return true;
}
static bool ga_delete_file(const char *path)
{
int ret = unlink(path);
if (ret == -1) {
g_warning("unable to delete file: %s: %s", path, strerror(errno));
return false;
}
return true;
}
bool ga_is_frozen(GAState *s)
{
return s->frozen;
}
void ga_set_frozen(GAState *s)
{
if (ga_is_frozen(s)) {
return;
}
/* disable all non-whitelisted (for frozen state) commands */
qmp_for_each_command(ga_disable_non_whitelisted, NULL);
g_warning("disabling logging due to filesystem freeze");
ga_disable_logging(s);
s->frozen = true;
if (!ga_create_file(s->state_filepath_isfrozen)) {
g_warning("unable to create %s, fsfreeze may not function properly",
s->state_filepath_isfrozen);
}
}
void ga_unset_frozen(GAState *s)
{
if (!ga_is_frozen(s)) {
return;
}
/* if we delayed creation/opening of pid/log files due to being
* in a frozen state at start up, do it now
*/
if (s->deferred_options.log_filepath) {
s->log_file = ga_open_logfile(s->deferred_options.log_filepath);
if (!s->log_file) {
s->log_file = stderr;
}
s->deferred_options.log_filepath = NULL;
}
ga_enable_logging(s);
g_warning("logging re-enabled due to filesystem unfreeze");
if (s->deferred_options.pid_filepath) {
if (!ga_open_pidfile(s->deferred_options.pid_filepath)) {
g_warning("failed to create/open pid file");
}
s->deferred_options.pid_filepath = NULL;
}
/* enable all disabled, non-blacklisted commands */
qmp_for_each_command(ga_enable_non_blacklisted, s->blacklist);
s->frozen = false;
if (!ga_delete_file(s->state_filepath_isfrozen)) {
g_warning("unable to delete %s, fsfreeze may not function properly",
s->state_filepath_isfrozen);
}
}
#ifdef CONFIG_FSFREEZE
const char *ga_fsfreeze_hook(GAState *s)
{
return s->fsfreeze_hook;
}
#endif
static void become_daemon(const char *pidfile)
{
#ifndef _WIN32
pid_t pid, sid;
pid = fork();
if (pid < 0) {
exit(EXIT_FAILURE);
}
if (pid > 0) {
exit(EXIT_SUCCESS);
}
if (pidfile) {
if (!ga_open_pidfile(pidfile)) {
g_critical("failed to create pidfile");
exit(EXIT_FAILURE);
}
}
umask(S_IRWXG | S_IRWXO);
sid = setsid();
if (sid < 0) {
goto fail;
}
if ((chdir("/")) < 0) {
goto fail;
}
reopen_fd_to_null(STDIN_FILENO);
reopen_fd_to_null(STDOUT_FILENO);
reopen_fd_to_null(STDERR_FILENO);
return;
fail:
if (pidfile) {
unlink(pidfile);
}
g_critical("failed to daemonize");
exit(EXIT_FAILURE);
#endif
}
static int send_response(GAState *s, QObject *payload)
{
const char *buf;
QString *payload_qstr, *response_qstr;
GIOStatus status;
g_assert(payload && s->channel);
payload_qstr = qobject_to_json(payload);
if (!payload_qstr) {
return -EINVAL;
}
if (s->delimit_response) {
s->delimit_response = false;
response_qstr = qstring_new();
qstring_append_chr(response_qstr, QGA_SENTINEL_BYTE);
qstring_append(response_qstr, qstring_get_str(payload_qstr));
QDECREF(payload_qstr);
} else {
response_qstr = payload_qstr;
}
qstring_append_chr(response_qstr, '\n');
buf = qstring_get_str(response_qstr);
status = ga_channel_write_all(s->channel, buf, strlen(buf));
QDECREF(response_qstr);
if (status != G_IO_STATUS_NORMAL) {
return -EIO;
}
return 0;
}
static void process_command(GAState *s, QDict *req)
{
QObject *rsp = NULL;
int ret;
g_assert(req);
g_debug("processing command");
rsp = qmp_dispatch(QOBJECT(req));
if (rsp) {
ret = send_response(s, rsp);
if (ret) {
g_warning("error sending response: %s", strerror(ret));
}
qobject_decref(rsp);
}
}
/* handle requests/control events coming in over the channel */
static void process_event(JSONMessageParser *parser, QList *tokens)
{
GAState *s = container_of(parser, GAState, parser);
QObject *obj;
QDict *qdict;
Error *err = NULL;
int ret;
g_assert(s && parser);
g_debug("process_event: called");
obj = json_parser_parse_err(tokens, NULL, &err);
if (err || !obj || qobject_type(obj) != QTYPE_QDICT) {
qobject_decref(obj);
qdict = qdict_new();
if (!err) {
g_warning("failed to parse event: unknown error");
error_set(&err, QERR_JSON_PARSING);
} else {
g_warning("failed to parse event: %s", error_get_pretty(err));
}
qdict_put_obj(qdict, "error", qmp_build_error_object(err));
error_free(err);
} else {
qdict = qobject_to_qdict(obj);
}
g_assert(qdict);
/* handle host->guest commands */
if (qdict_haskey(qdict, "execute")) {
process_command(s, qdict);
} else {
if (!qdict_haskey(qdict, "error")) {
QDECREF(qdict);
qdict = qdict_new();
g_warning("unrecognized payload format");
error_set(&err, QERR_UNSUPPORTED);
qdict_put_obj(qdict, "error", qmp_build_error_object(err));
error_free(err);
}
ret = send_response(s, QOBJECT(qdict));
if (ret) {
g_warning("error sending error response: %s", strerror(ret));
}
}
QDECREF(qdict);
}
/* false return signals GAChannel to close the current client connection */
static gboolean channel_event_cb(GIOCondition condition, gpointer data)
{
GAState *s = data;
gchar buf[QGA_READ_COUNT_DEFAULT+1];
gsize count;
GError *err = NULL;
GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
if (err != NULL) {
g_warning("error reading channel: %s", err->message);
g_error_free(err);
return false;
}
switch (status) {
case G_IO_STATUS_ERROR:
g_warning("error reading channel");
return false;
case G_IO_STATUS_NORMAL:
buf[count] = 0;
g_debug("read data, count: %d, data: %s", (int)count, buf);
json_message_parser_feed(&s->parser, (char *)buf, (int)count);
break;
case G_IO_STATUS_EOF:
g_debug("received EOF");
if (!s->virtio) {
return false;
}
/* fall through */
case G_IO_STATUS_AGAIN:
/* virtio causes us to spin here when no process is attached to
* host-side chardev. sleep a bit to mitigate this
*/
if (s->virtio) {
usleep(100*1000);
}
return true;
default:
g_warning("unknown channel read status, closing");
return false;
}
return true;
}
static gboolean channel_init(GAState *s, const gchar *method, const gchar *path)
{
GAChannelMethod channel_method;
if (method == NULL) {
method = "virtio-serial";
}
if (path == NULL) {
if (strcmp(method, "virtio-serial") != 0) {
g_critical("must specify a path for this channel");
return false;
}
/* try the default path for the virtio-serial port */
path = QGA_VIRTIO_PATH_DEFAULT;
}
if (strcmp(method, "virtio-serial") == 0) {
s->virtio = true; /* virtio requires special handling in some cases */
channel_method = GA_CHANNEL_VIRTIO_SERIAL;
} else if (strcmp(method, "isa-serial") == 0) {
channel_method = GA_CHANNEL_ISA_SERIAL;
} else if (strcmp(method, "unix-listen") == 0) {
channel_method = GA_CHANNEL_UNIX_LISTEN;
} else {
g_critical("unsupported channel method/type: %s", method);
return false;
}
s->channel = ga_channel_new(channel_method, path, channel_event_cb, s);
if (!s->channel) {
g_critical("failed to create guest agent channel");
return false;
}
return true;
}
#ifdef _WIN32
DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
LPVOID ctx)
{
DWORD ret = NO_ERROR;
GAService *service = &ga_state->service;
switch (ctrl)
{
case SERVICE_CONTROL_STOP:
case SERVICE_CONTROL_SHUTDOWN:
quit_handler(SIGTERM);
service->status.dwCurrentState = SERVICE_STOP_PENDING;
SetServiceStatus(service->status_handle, &service->status);
break;
default:
ret = ERROR_CALL_NOT_IMPLEMENTED;
}
return ret;
}
VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
{
GAService *service = &ga_state->service;
service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME,
service_ctrl_handler, NULL);
if (service->status_handle == 0) {
g_critical("Failed to register extended requests function!\n");
return;
}
service->status.dwServiceType = SERVICE_WIN32;
service->status.dwCurrentState = SERVICE_RUNNING;
service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
service->status.dwWin32ExitCode = NO_ERROR;
service->status.dwServiceSpecificExitCode = NO_ERROR;
service->status.dwCheckPoint = 0;
service->status.dwWaitHint = 0;
SetServiceStatus(service->status_handle, &service->status);
g_main_loop_run(ga_state->main_loop);
service->status.dwCurrentState = SERVICE_STOPPED;
SetServiceStatus(service->status_handle, &service->status);
}
#endif
static void set_persistent_state_defaults(GAPersistentState *pstate)
{
g_assert(pstate);
pstate->fd_counter = QGA_PSTATE_DEFAULT_FD_COUNTER;
}
static void persistent_state_from_keyfile(GAPersistentState *pstate,
GKeyFile *keyfile)
{
g_assert(pstate);
g_assert(keyfile);
/* if any fields are missing, either because the file was tampered with
* by agents of chaos, or because the field wasn't present at the time the
* file was created, the best we can ever do is start over with the default
* values. so load them now, and ignore any errors in accessing key-value
* pairs
*/
set_persistent_state_defaults(pstate);
if (g_key_file_has_key(keyfile, "global", "fd_counter", NULL)) {
pstate->fd_counter =
g_key_file_get_integer(keyfile, "global", "fd_counter", NULL);
}
}
static void persistent_state_to_keyfile(const GAPersistentState *pstate,
GKeyFile *keyfile)
{
g_assert(pstate);
g_assert(keyfile);
g_key_file_set_integer(keyfile, "global", "fd_counter", pstate->fd_counter);
}
static gboolean write_persistent_state(const GAPersistentState *pstate,
const gchar *path)
{
GKeyFile *keyfile = g_key_file_new();
GError *gerr = NULL;
gboolean ret = true;
gchar *data = NULL;
gsize data_len;
g_assert(pstate);
persistent_state_to_keyfile(pstate, keyfile);
data = g_key_file_to_data(keyfile, &data_len, &gerr);
if (gerr) {
g_critical("failed to convert persistent state to string: %s",
gerr->message);
ret = false;
goto out;
}
g_file_set_contents(path, data, data_len, &gerr);
if (gerr) {
g_critical("failed to write persistent state to %s: %s",
path, gerr->message);
ret = false;
goto out;
}
out:
if (gerr) {
g_error_free(gerr);
}
if (keyfile) {
g_key_file_free(keyfile);
}
g_free(data);
return ret;
}
static gboolean read_persistent_state(GAPersistentState *pstate,
const gchar *path, gboolean frozen)
{
GKeyFile *keyfile = NULL;
GError *gerr = NULL;
struct stat st;
gboolean ret = true;
g_assert(pstate);
if (stat(path, &st) == -1) {
/* it's okay if state file doesn't exist, but any other error
* indicates a permissions issue or some other misconfiguration
* that we likely won't be able to recover from.
*/
if (errno != ENOENT) {
g_critical("unable to access state file at path %s: %s",
path, strerror(errno));
ret = false;
goto out;
}
/* file doesn't exist. initialize state to default values and
* attempt to save now. (we could wait till later when we have
* modified state we need to commit, but if there's a problem,
* such as a missing parent directory, we want to catch it now)
*
* there is a potential scenario where someone either managed to
* update the agent from a version that didn't use a key store
* while qemu-ga thought the filesystem was frozen, or
* deleted the key store prior to issuing a fsfreeze, prior
* to restarting the agent. in this case we go ahead and defer
* initial creation till we actually have modified state to
* write, otherwise fail to recover from freeze.
*/
set_persistent_state_defaults(pstate);
if (!frozen) {
ret = write_persistent_state(pstate, path);
if (!ret) {
g_critical("unable to create state file at path %s", path);
ret = false;
goto out;
}
}
ret = true;
goto out;
}
keyfile = g_key_file_new();
g_key_file_load_from_file(keyfile, path, 0, &gerr);
if (gerr) {
g_critical("error loading persistent state from path: %s, %s",
path, gerr->message);
ret = false;
goto out;
}
persistent_state_from_keyfile(pstate, keyfile);
out:
if (keyfile) {
g_key_file_free(keyfile);
}
if (gerr) {
g_error_free(gerr);
}
return ret;
}
int64_t ga_get_fd_handle(GAState *s, Error **errp)
{
int64_t handle;
g_assert(s->pstate_filepath);
/* we blacklist commands and avoid operations that potentially require
* writing to disk when we're in a frozen state. this includes opening
* new files, so we should never get here in that situation
*/
g_assert(!ga_is_frozen(s));
handle = s->pstate.fd_counter++;
/* This should never happen on a reasonable timeframe, as guest-file-open
* would have to be issued 2^63 times */
if (s->pstate.fd_counter == INT64_MAX) {
abort();
}
if (!write_persistent_state(&s->pstate, s->pstate_filepath)) {
error_setg(errp, "failed to commit persistent state to disk");
}
return handle;
}
static void ga_print_cmd(QmpCommand *cmd, void *opaque)
{
printf("%s\n", qmp_command_name(cmd));
}
int main(int argc, char **argv)
{
const char *sopt = "hVvdm:p:l:f:F::b:s:t:";
const char *method = NULL, *path = NULL;
const char *log_filepath = NULL;
const char *pid_filepath;
#ifdef CONFIG_FSFREEZE
const char *fsfreeze_hook = NULL;
#endif
const char *state_dir;
#ifdef _WIN32
const char *service = NULL;
#endif
const struct option lopt[] = {
{ "help", 0, NULL, 'h' },
{ "version", 0, NULL, 'V' },
{ "logfile", 1, NULL, 'l' },
{ "pidfile", 1, NULL, 'f' },
#ifdef CONFIG_FSFREEZE
{ "fsfreeze-hook", 2, NULL, 'F' },
#endif
{ "verbose", 0, NULL, 'v' },
{ "method", 1, NULL, 'm' },
{ "path", 1, NULL, 'p' },
{ "daemonize", 0, NULL, 'd' },
{ "blacklist", 1, NULL, 'b' },
#ifdef _WIN32
{ "service", 1, NULL, 's' },
#endif
{ "statedir", 1, NULL, 't' },
{ NULL, 0, NULL, 0 }
};
int opt_ind = 0, ch, daemonize = 0, i, j, len;
GLogLevelFlags log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
GList *blacklist = NULL;
GAState *s;
module_call_init(MODULE_INIT_QAPI);
init_dfl_pathnames();
pid_filepath = dfl_pathnames.pidfile;
state_dir = dfl_pathnames.state_dir;
while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
switch (ch) {
case 'm':
method = optarg;
break;
case 'p':
path = optarg;
break;
case 'l':
log_filepath = optarg;
break;
case 'f':
pid_filepath = optarg;
break;
#ifdef CONFIG_FSFREEZE
case 'F':
fsfreeze_hook = optarg ? optarg : QGA_FSFREEZE_HOOK_DEFAULT;
break;
#endif
case 't':
state_dir = optarg;
break;
case 'v':
/* enable all log levels */
log_level = G_LOG_LEVEL_MASK;
break;
case 'V':
printf("QEMU Guest Agent %s\n", QEMU_VERSION);
return 0;
case 'd':
daemonize = 1;
break;
case 'b': {
if (is_help_option(optarg)) {
qmp_for_each_command(ga_print_cmd, NULL);
return 0;
}
for (j = 0, i = 0, len = strlen(optarg); i < len; i++) {
if (optarg[i] == ',') {
optarg[i] = 0;
blacklist = g_list_append(blacklist, &optarg[j]);
j = i + 1;
}
}
if (j < i) {
blacklist = g_list_append(blacklist, &optarg[j]);
}
break;
}
#ifdef _WIN32
case 's':
service = optarg;
if (strcmp(service, "install") == 0) {
const char *fixed_state_dir;
/* If the user passed the "-t" option, we save that state dir
* in the service. Otherwise we let the service fetch the state
* dir from the environment when it starts.
*/
fixed_state_dir = (state_dir == dfl_pathnames.state_dir) ?
NULL :
state_dir;
if (ga_install_vss_provider()) {
return EXIT_FAILURE;
}
if (ga_install_service(path, log_filepath, fixed_state_dir)) {
return EXIT_FAILURE;
}
return 0;
} else if (strcmp(service, "uninstall") == 0) {
ga_uninstall_vss_provider();
return ga_uninstall_service();
} else {
printf("Unknown service command.\n");
return EXIT_FAILURE;
}
break;
#endif
case 'h':
usage(argv[0]);
return 0;
case '?':
g_print("Unknown option, try '%s --help' for more information.\n",
argv[0]);
return EXIT_FAILURE;
}
}
#ifdef _WIN32
/* On win32 the state directory is application specific (be it the default
* or a user override). We got past the command line parsing; let's create
* the directory (with any intermediate directories). If we run into an
* error later on, we won't try to clean up the directory, it is considered
* persistent.
*/
if (g_mkdir_with_parents(state_dir, S_IRWXU) == -1) {
g_critical("unable to create (an ancestor of) the state directory"
" '%s': %s", state_dir, strerror(errno));
return EXIT_FAILURE;
}
#endif
s = g_malloc0(sizeof(GAState));
s->log_level = log_level;
s->log_file = stderr;
#ifdef CONFIG_FSFREEZE
s->fsfreeze_hook = fsfreeze_hook;
#endif
g_log_set_default_handler(ga_log, s);
g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
ga_enable_logging(s);
s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen",
state_dir);
s->pstate_filepath = g_strdup_printf("%s/qga.state", state_dir);
s->frozen = false;
#ifndef _WIN32
/* check if a previous instance of qemu-ga exited with filesystems' state
* marked as frozen. this could be a stale value (a non-qemu-ga process
* or reboot may have since unfrozen them), but better to require an
* uneeded unfreeze than to risk hanging on start-up
*/
struct stat st;
if (stat(s->state_filepath_isfrozen, &st) == -1) {
/* it's okay if the file doesn't exist, but if we can't access for
* some other reason, such as permissions, there's a configuration
* that needs to be addressed. so just bail now before we get into
* more trouble later
*/
if (errno != ENOENT) {
g_critical("unable to access state file at path %s: %s",
s->state_filepath_isfrozen, strerror(errno));
return EXIT_FAILURE;
}
} else {
g_warning("previous instance appears to have exited with frozen"
" filesystems. deferring logging/pidfile creation and"
" disabling non-fsfreeze-safe commands until"
" guest-fsfreeze-thaw is issued, or filesystems are"
" manually unfrozen and the file %s is removed",
s->state_filepath_isfrozen);
s->frozen = true;
}
#endif
if (ga_is_frozen(s)) {
if (daemonize) {
/* delay opening/locking of pidfile till filesystem are unfrozen */
s->deferred_options.pid_filepath = pid_filepath;
become_daemon(NULL);
}
if (log_filepath) {
/* delay opening the log file till filesystems are unfrozen */
s->deferred_options.log_filepath = log_filepath;
}
ga_disable_logging(s);
qmp_for_each_command(ga_disable_non_whitelisted, NULL);
} else {
if (daemonize) {
become_daemon(pid_filepath);
}
if (log_filepath) {
FILE *log_file = ga_open_logfile(log_filepath);
if (!log_file) {
g_critical("unable to open specified log file: %s",
strerror(errno));
goto out_bad;
}
s->log_file = log_file;
}
}
/* load persistent state from disk */
if (!read_persistent_state(&s->pstate,
s->pstate_filepath,
ga_is_frozen(s))) {
g_critical("failed to load persistent state");
goto out_bad;
}
if (blacklist) {
s->blacklist = blacklist;
do {
g_debug("disabling command: %s", (char *)blacklist->data);
qmp_disable_command(blacklist->data);
blacklist = g_list_next(blacklist);
} while (blacklist);
}
s->command_state = ga_command_state_new();
ga_command_state_init(s, s->command_state);
ga_command_state_init_all(s->command_state);
json_message_parser_init(&s->parser, process_event);
ga_state = s;
#ifndef _WIN32
if (!register_signal_handlers()) {
g_critical("failed to register signal handlers");
goto out_bad;
}
#endif
s->main_loop = g_main_loop_new(NULL, false);
if (!channel_init(ga_state, method, path)) {
g_critical("failed to initialize guest agent channel");
goto out_bad;
}
#ifndef _WIN32
g_main_loop_run(ga_state->main_loop);
#else
if (daemonize) {
SERVICE_TABLE_ENTRY service_table[] = {
{ (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
StartServiceCtrlDispatcher(service_table);
} else {
g_main_loop_run(ga_state->main_loop);
}
#endif
ga_command_state_cleanup_all(ga_state->command_state);
ga_channel_free(ga_state->channel);
if (daemonize) {
unlink(pid_filepath);
}
return 0;
out_bad:
if (daemonize) {
unlink(pid_filepath);
}
return EXIT_FAILURE;
}
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