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-rw-r--r--qemu/qga/main.c1206
1 files changed, 1206 insertions, 0 deletions
diff --git a/qemu/qga/main.c b/qemu/qga/main.c
new file mode 100644
index 000000000..791982ef0
--- /dev/null
+++ b/qemu/qga/main.c
@@ -0,0 +1,1206 @@
+/*
+ * 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"
+#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"
+#define QGA_SERIAL_PATH_DEFAULT "/dev/ttyS0"
+#else
+#define QGA_VIRTIO_PATH_DEFAULT "\\\\.\\Global\\org.qemu.guest_agent.0"
+#define QGA_STATE_RELATIVE_DIR "qemu-ga"
+#define QGA_SERIAL_PATH_DEFAULT "COM1"
+#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"
+" the default for isa-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, vss-install, vss-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, QGA_SERIAL_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 (g_strcmp0(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_setg(&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_setg(&err, QERR_UNSUPPORTED);
+ qdict_put_obj(qdict, "error", qmp_build_error_object(err));
+ error_free(err);
+ }
+ ret = send_response(s, QOBJECT(qdict));
+ if (ret < 0) {
+ 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 ) {
+ /* try the default path for the virtio-serial port */
+ path = QGA_VIRTIO_PATH_DEFAULT;
+ } else if (strcmp(method, "isa-serial") == 0){
+ /* try the default path for the serial port - COM1 */
+ path = QGA_SERIAL_PATH_DEFAULT;
+ } else {
+ g_critical("must specify a path for this channel");
+ return false;
+ }
+ }
+
+ 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 -1;
+ }
+
+ 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 if (strcmp(service, "vss-install") == 0) {
+ if (ga_install_vss_provider()) {
+ return EXIT_FAILURE;
+ }
+ return EXIT_SUCCESS;
+ } else if (strcmp(service, "vss-uninstall") == 0) {
+ ga_uninstall_vss_provider();
+ return EXIT_SUCCESS;
+ } 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 filesystems 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;
+ }
+
+ blacklist = ga_command_blacklist_init(blacklist);
+ 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;
+}