/* * 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 "qemu/osdep.h" #include <getopt.h> #include <glib/gstdio.h> #ifndef _WIN32 #include <syslog.h> #include <sys/wait.h> #endif #include "qemu/help-texts.h" #include "qapi/qmp/json-parser.h" #include "qapi/qmp/qdict.h" #include "qapi/qmp/qjson.h" #include "guest-agent-core.h" #include "qga-qapi-init-commands.h" #include "qapi/error.h" #include "channel.h" #include "qemu/cutils.h" #include "qemu/help_option.h" #include "qemu/sockets.h" #include "qemu/systemd.h" #include "qemu-version.h" #ifdef _WIN32 #include <dbt.h> #include "qga/service-win32.h" #include "qga/vss-win32.h" #endif #include "commands-common.h" #ifndef _WIN32 #ifdef CONFIG_BSD #define QGA_VIRTIO_PATH_DEFAULT "/dev/vtcon/org.qemu.guest_agent.0" #else /* CONFIG_BSD */ #define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0" #endif /* CONFIG_BSD */ #define QGA_SERIAL_PATH_DEFAULT "/dev/ttyS0" #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" #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 #define QGA_CONF_DEFAULT CONFIG_QEMU_CONFDIR G_DIR_SEPARATOR_S "qemu-ga.conf" #define QGA_RETRY_INTERVAL 5 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; typedef struct GAConfig GAConfig; 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; HANDLE wakeup_event; HANDLE event_log; #endif bool delimit_response; bool frozen; GList *blockedrpcs; GList *allowedrpcs; char *state_filepath_isfrozen; struct { const char *log_filepath; const char *pid_filepath; } deferred_options; #ifdef CONFIG_FSFREEZE const char *fsfreeze_hook; #endif gchar *pstate_filepath; GAPersistentState pstate; GAConfig *config; int socket_activation; bool force_exit; }; struct GAState *ga_state; QmpCommandList ga_commands; /* commands that are safe to issue while filesystems are frozen */ static const char *ga_freeze_allowlist[] = { "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); DWORD WINAPI handle_serial_device_events(DWORD type, LPVOID data); VOID WINAPI service_main(DWORD argc, TCHAR *argv[]); #endif static int run_agent(GAState *s); static void stop_agent(GAState *s, bool requested); static void init_dfl_pathnames(void) { g_autofree char *state = qemu_get_local_state_dir(); g_assert(dfl_pathnames.state_dir == NULL); g_assert(dfl_pathnames.pidfile == NULL); dfl_pathnames.state_dir = g_build_filename(state, QGA_STATE_RELATIVE_DIR, NULL); dfl_pathnames.pidfile = g_build_filename(state, QGA_STATE_RELATIVE_DIR, "qemu-ga.pid", NULL); } 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). * On Windows the freeze interval is limited to 10 seconds, so * we should quit, but first we should wait for the timeout, thaw * the filesystem and quit. */ if (ga_is_frozen(ga_state)) { #ifdef _WIN32 int i = 0; Error *err = NULL; HANDLE hEventTimeout; g_debug("Thawing filesystems before exiting"); hEventTimeout = OpenEvent(EVENT_ALL_ACCESS, FALSE, EVENT_NAME_TIMEOUT); if (hEventTimeout) { WaitForSingleObject(hEventTimeout, 0); CloseHandle(hEventTimeout); } qga_vss_fsfreeze(&i, false, NULL, &err); if (err) { g_debug("Error unfreezing filesystems prior to exiting: %s", error_get_pretty(err)); error_free(err); } #else return; #endif } g_debug("received signal num %d, quitting", sig); stop_agent(ga_state, true); } #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)); } sigact.sa_handler = SIG_IGN; if (sigaction(SIGPIPE, &sigact, NULL) != 0) { g_error("error configuring SIGPIPE 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) { #ifdef CONFIG_FSFREEZE g_autofree char *fsfreeze_hook = get_relocated_path(QGA_FSFREEZE_HOOK_DEFAULT); #endif printf( "Usage: %s [-m <method> -p <path>] [<options>]\n" "QEMU Guest Agent " QEMU_FULL_VERSION "\n" QEMU_COPYRIGHT "\n" "\n" " -m, --method transport method: one of unix-listen, virtio-serial,\n" " isa-serial, or vsock-listen (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" " Socket addresses for vsock-listen are written as\n" " <cid>:<port>.\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, --block-rpcs comma-separated list of RPCs to disable (no spaces,\n" " use \"help\" to list available RPCs)\n" " -a, --allow-rpcs comma-separated list of RPCs to enable (no spaces,\n" " use \"help\" to list available RPCs)\n" " -D, --dump-conf dump a qemu-ga config file based on current config\n" " options / command-line parameters to stdout\n" " -r, --retry-path attempt re-opening path if it's unavailable or closed\n" " due to an error which may be recoverable in the future\n" " (virtio-serial driver re-install, serial device hot\n" " plug/unplug, etc.)\n" " -h, --help display this help and exit\n" "\n" QEMU_HELP_BOTTOM "\n" , cmd, QGA_VIRTIO_PATH_DEFAULT, QGA_SERIAL_PATH_DEFAULT, dfl_pathnames.pidfile, #ifdef CONFIG_FSFREEZE fsfreeze_hook, #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 int glib_log_level_to_system(int level) { switch (level) { #ifndef _WIN32 case G_LOG_LEVEL_ERROR: return LOG_ERR; case G_LOG_LEVEL_CRITICAL: return LOG_CRIT; case G_LOG_LEVEL_WARNING: return LOG_WARNING; case G_LOG_LEVEL_MESSAGE: return LOG_NOTICE; case G_LOG_LEVEL_DEBUG: return LOG_DEBUG; case G_LOG_LEVEL_INFO: default: return LOG_INFO; #else case G_LOG_LEVEL_ERROR: case G_LOG_LEVEL_CRITICAL: return EVENTLOG_ERROR_TYPE; case G_LOG_LEVEL_WARNING: return EVENTLOG_WARNING_TYPE; case G_LOG_LEVEL_MESSAGE: case G_LOG_LEVEL_INFO: case G_LOG_LEVEL_DEBUG: default: return EVENTLOG_INFORMATION_TYPE; #endif } } static void ga_log(const gchar *domain, GLogLevelFlags level, const gchar *msg, gpointer opaque) { GAState *s = opaque; const char *level_str = ga_log_level_str(level); if (!ga_logging_enabled(s)) { return; } level &= G_LOG_LEVEL_MASK; if (g_strcmp0(domain, "syslog") == 0) { #ifndef _WIN32 syslog(glib_log_level_to_system(level), "%s: %s", level_str, msg); #else ReportEvent(s->event_log, glib_log_level_to_system(level), 0, 1, NULL, 1, 0, &msg, NULL); #endif } else if (level & s->log_level) { g_autoptr(GDateTime) now = g_date_time_new_now_utc(); g_autofree char *nowstr = g_date_time_format(now, "%s.%f"); fprintf(s->log_file, "%s: %s: %s\n", nowstr, 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; } static gint ga_strcmp(gconstpointer str1, gconstpointer str2) { return strcmp(str1, str2); } /* disable commands that aren't safe for fsfreeze */ static void ga_disable_not_allowed_freeze(const QmpCommand *cmd, void *opaque) { bool allowed = false; int i = 0; const char *name = qmp_command_name(cmd); while (ga_freeze_allowlist[i] != NULL) { if (strcmp(name, ga_freeze_allowlist[i]) == 0) { allowed = true; } i++; } if (!allowed) { g_debug("disabling command: %s", name); qmp_disable_command(&ga_commands, name, "the agent is in frozen state"); } } /* [re-]enable all commands, except those explicitly blocked by user */ static void ga_enable_non_blocked(const QmpCommand *cmd, void *opaque) { GAState *s = opaque; GList *blockedrpcs = s->blockedrpcs; GList *allowedrpcs = s->allowedrpcs; const char *name = qmp_command_name(cmd); if (g_list_find_custom(blockedrpcs, name, ga_strcmp) == NULL) { if (qmp_command_is_enabled(cmd)) { return; } if (allowedrpcs && g_list_find_custom(allowedrpcs, name, ga_strcmp) == NULL) { return; } g_debug("enabling command: %s", name); qmp_enable_command(&ga_commands, name); } } /* disable commands that aren't allowed */ static void ga_disable_not_allowed(const QmpCommand *cmd, void *opaque) { GList *allowedrpcs = opaque; const char *name = qmp_command_name(cmd); if (g_list_find_custom(allowedrpcs, name, ga_strcmp) == NULL) { g_debug("disabling command: %s", name); qmp_disable_command(&ga_commands, name, "the command is not allowed"); } } 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 forbidden (for frozen state) commands */ qmp_for_each_command(&ga_commands, ga_disable_not_allowed_freeze, 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) { Error *err = NULL; if (!qemu_write_pidfile(s->deferred_options.pid_filepath, &err)) { g_warning("%s", error_get_pretty(err)); error_free(err); } s->deferred_options.pid_filepath = NULL; } /* enable all disabled, non-blocked and allowed commands */ qmp_for_each_command(&ga_commands, ga_enable_non_blocked, s); 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) { Error *err = NULL; if (!qemu_write_pidfile(pidfile, &err)) { g_critical("%s", error_get_pretty(err)); error_free(err); 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, const QDict *rsp) { GString *response; GIOStatus status; g_assert(s->channel); if (!rsp) { return 0; } response = qobject_to_json(QOBJECT(rsp)); if (!response) { return -EINVAL; } if (s->delimit_response) { s->delimit_response = false; g_string_prepend_c(response, QGA_SENTINEL_BYTE); } g_string_append_c(response, '\n'); status = ga_channel_write_all(s->channel, response->str, response->len); g_string_free(response, true); if (status != G_IO_STATUS_NORMAL) { return -EIO; } return 0; } /* handle requests/control events coming in over the channel */ static void process_event(void *opaque, QObject *obj, Error *err) { GAState *s = opaque; QDict *rsp; int ret; g_debug("process_event: called"); assert(!obj != !err); if (err) { rsp = qmp_error_response(err); goto end; } g_debug("processing command"); rsp = qmp_dispatch(&ga_commands, obj, false, NULL); end: ret = send_response(s, rsp); if (ret < 0) { g_warning("error sending error response: %s", strerror(-ret)); } qobject_unref(rsp); qobject_unref(obj); } /* 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; GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count); switch (status) { case G_IO_STATUS_ERROR: g_warning("error reading channel"); stop_agent(s, false); 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) { g_usleep(G_USEC_PER_SEC / 10); } 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, int listen_fd) { GAChannelMethod channel_method; 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 if (strcmp(method, "vsock-listen") == 0) { channel_method = GA_CHANNEL_VSOCK_LISTEN; } else { g_critical("unsupported channel method/type: %s", method); return false; } s->channel = ga_channel_new(channel_method, path, listen_fd, channel_event_cb, s); if (!s->channel) { g_critical("failed to create guest agent channel"); return false; } return true; } #ifdef _WIN32 DWORD WINAPI handle_serial_device_events(DWORD type, LPVOID data) { DWORD ret = NO_ERROR; PDEV_BROADCAST_HDR broadcast_header = (PDEV_BROADCAST_HDR)data; if (broadcast_header->dbch_devicetype == DBT_DEVTYP_DEVICEINTERFACE) { switch (type) { /* Device inserted */ case DBT_DEVICEARRIVAL: /* Start QEMU-ga's service */ if (!SetEvent(ga_state->wakeup_event)) { ret = GetLastError(); } break; /* Device removed */ case DBT_DEVICEQUERYREMOVE: case DBT_DEVICEREMOVEPENDING: case DBT_DEVICEREMOVECOMPLETE: /* Stop QEMU-ga's service */ if (!ResetEvent(ga_state->wakeup_event)) { ret = GetLastError(); } break; default: ret = ERROR_CALL_NOT_IMPLEMENTED; } } return ret; } 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); SetEvent(ga_state->wakeup_event); service->status.dwCurrentState = SERVICE_STOP_PENDING; SetServiceStatus(service->status_handle, &service->status); break; case SERVICE_CONTROL_DEVICEEVENT: handle_serial_device_events(type, data); 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; DEV_BROADCAST_DEVICEINTERFACE notification_filter; ZeroMemory(¬ification_filter, sizeof(notification_filter)); notification_filter.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE; notification_filter.dbcc_size = sizeof(DEV_BROADCAST_DEVICEINTERFACE); notification_filter.dbcc_classguid = GUID_VIOSERIAL_PORT; service->device_notification_handle = RegisterDeviceNotification(service->status_handle, ¬ification_filter, DEVICE_NOTIFY_SERVICE_HANDLE); if (!service->device_notification_handle) { g_critical("Failed to register device notification handle!\n"); return; } SetServiceStatus(service->status_handle, &service->status); run_agent(ga_state); UnregisterDeviceNotification(service->device_notification_handle); 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 block 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(const QmpCommand *cmd, void *opaque) { printf("%s\n", qmp_command_name(cmd)); } static GList *split_list(const gchar *str, const gchar *delim) { GList *list = NULL; int i; gchar **strv; strv = g_strsplit(str, delim, -1); for (i = 0; strv[i]; i++) { list = g_list_prepend(list, strv[i]); } g_free(strv); return list; } struct GAConfig { char *channel_path; char *method; char *log_filepath; char *pid_filepath; #ifdef CONFIG_FSFREEZE char *fsfreeze_hook; #endif char *state_dir; #ifdef _WIN32 const char *service; #endif gchar *bliststr; /* blockedrpcs may point to this string */ gchar *aliststr; /* allowedrpcs may point to this string */ GList *blockedrpcs; GList *allowedrpcs; int daemonize; GLogLevelFlags log_level; int dumpconf; bool retry_path; }; static void config_load(GAConfig *config) { GError *gerr = NULL; GKeyFile *keyfile; g_autofree char *conf = g_strdup(g_getenv("QGA_CONF")) ?: get_relocated_path(QGA_CONF_DEFAULT); const gchar *blockrpcs_key = "block-rpcs"; /* read system config */ keyfile = g_key_file_new(); if (!g_key_file_load_from_file(keyfile, conf, 0, &gerr)) { goto end; } if (g_key_file_has_key(keyfile, "general", "daemon", NULL)) { config->daemonize = g_key_file_get_boolean(keyfile, "general", "daemon", &gerr); } if (g_key_file_has_key(keyfile, "general", "method", NULL)) { config->method = g_key_file_get_string(keyfile, "general", "method", &gerr); } if (g_key_file_has_key(keyfile, "general", "path", NULL)) { config->channel_path = g_key_file_get_string(keyfile, "general", "path", &gerr); } if (g_key_file_has_key(keyfile, "general", "logfile", NULL)) { config->log_filepath = g_key_file_get_string(keyfile, "general", "logfile", &gerr); } if (g_key_file_has_key(keyfile, "general", "pidfile", NULL)) { config->pid_filepath = g_key_file_get_string(keyfile, "general", "pidfile", &gerr); } #ifdef CONFIG_FSFREEZE if (g_key_file_has_key(keyfile, "general", "fsfreeze-hook", NULL)) { config->fsfreeze_hook = g_key_file_get_string(keyfile, "general", "fsfreeze-hook", &gerr); } #endif if (g_key_file_has_key(keyfile, "general", "statedir", NULL)) { config->state_dir = g_key_file_get_string(keyfile, "general", "statedir", &gerr); } if (g_key_file_has_key(keyfile, "general", "verbose", NULL) && g_key_file_get_boolean(keyfile, "general", "verbose", &gerr)) { /* enable all log levels */ config->log_level = G_LOG_LEVEL_MASK; } if (g_key_file_has_key(keyfile, "general", "retry-path", NULL)) { config->retry_path = g_key_file_get_boolean(keyfile, "general", "retry-path", &gerr); } if (g_key_file_has_key(keyfile, "general", "blacklist", NULL)) { g_warning("config using deprecated 'blacklist' key, should be replaced" " with the 'block-rpcs' key."); blockrpcs_key = "blacklist"; } if (g_key_file_has_key(keyfile, "general", blockrpcs_key, NULL)) { config->bliststr = g_key_file_get_string(keyfile, "general", blockrpcs_key, &gerr); config->blockedrpcs = g_list_concat(config->blockedrpcs, split_list(config->bliststr, ",")); } if (g_key_file_has_key(keyfile, "general", "allow-rpcs", NULL)) { config->aliststr = g_key_file_get_string(keyfile, "general", "allow-rpcs", &gerr); config->allowedrpcs = g_list_concat(config->allowedrpcs, split_list(config->aliststr, ",")); } if (g_key_file_has_key(keyfile, "general", blockrpcs_key, NULL) && g_key_file_has_key(keyfile, "general", "allow-rpcs", NULL)) { g_critical("wrong config, using 'block-rpcs' and 'allow-rpcs' keys at" " the same time is not allowed"); exit(EXIT_FAILURE); } end: g_key_file_free(keyfile); if (gerr && !(gerr->domain == G_FILE_ERROR && gerr->code == G_FILE_ERROR_NOENT)) { g_critical("error loading configuration from path: %s, %s", conf, gerr->message); exit(EXIT_FAILURE); } g_clear_error(&gerr); } static gchar *list_join(GList *list, const gchar separator) { GString *str = g_string_new(""); while (list) { str = g_string_append(str, (gchar *)list->data); list = g_list_next(list); if (list) { str = g_string_append_c(str, separator); } } return g_string_free(str, FALSE); } static void config_dump(GAConfig *config) { GError *error = NULL; GKeyFile *keyfile; gchar *tmp; keyfile = g_key_file_new(); g_assert(keyfile); g_key_file_set_boolean(keyfile, "general", "daemon", config->daemonize); g_key_file_set_string(keyfile, "general", "method", config->method); if (config->channel_path) { g_key_file_set_string(keyfile, "general", "path", config->channel_path); } if (config->log_filepath) { g_key_file_set_string(keyfile, "general", "logfile", config->log_filepath); } g_key_file_set_string(keyfile, "general", "pidfile", config->pid_filepath); #ifdef CONFIG_FSFREEZE if (config->fsfreeze_hook) { g_key_file_set_string(keyfile, "general", "fsfreeze-hook", config->fsfreeze_hook); } #endif g_key_file_set_string(keyfile, "general", "statedir", config->state_dir); g_key_file_set_boolean(keyfile, "general", "verbose", config->log_level == G_LOG_LEVEL_MASK); g_key_file_set_boolean(keyfile, "general", "retry-path", config->retry_path); tmp = list_join(config->blockedrpcs, ','); g_key_file_set_string(keyfile, "general", "block-rpcs", tmp); g_free(tmp); tmp = list_join(config->allowedrpcs, ','); g_key_file_set_string(keyfile, "general", "allow-rpcs", tmp); g_free(tmp); tmp = g_key_file_to_data(keyfile, NULL, &error); if (error) { g_critical("Failed to dump keyfile: %s", error->message); g_clear_error(&error); } else { printf("%s", tmp); } g_free(tmp); g_key_file_free(keyfile); } static void config_parse(GAConfig *config, int argc, char **argv) { const char *sopt = "hVvdm:p:l:f:F::b:a:s:t:Dr"; int opt_ind = 0, ch; bool block_rpcs = false, allow_rpcs = false; const struct option lopt[] = { { "help", 0, NULL, 'h' }, { "version", 0, NULL, 'V' }, { "dump-conf", 0, NULL, 'D' }, { "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' }, { "block-rpcs", 1, NULL, 'b' }, { "blacklist", 1, NULL, 'b' }, /* deprecated alias for 'block-rpcs' */ { "allow-rpcs", 1, NULL, 'a' }, #ifdef _WIN32 { "service", 1, NULL, 's' }, #endif { "statedir", 1, NULL, 't' }, { "retry-path", 0, NULL, 'r' }, { NULL, 0, NULL, 0 } }; while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) { switch (ch) { case 'm': g_free(config->method); config->method = g_strdup(optarg); break; case 'p': g_free(config->channel_path); config->channel_path = g_strdup(optarg); break; case 'l': g_free(config->log_filepath); config->log_filepath = g_strdup(optarg); break; case 'f': g_free(config->pid_filepath); config->pid_filepath = g_strdup(optarg); break; #ifdef CONFIG_FSFREEZE case 'F': g_free(config->fsfreeze_hook); config->fsfreeze_hook = optarg ? g_strdup(optarg) : get_relocated_path(QGA_FSFREEZE_HOOK_DEFAULT); break; #endif case 't': g_free(config->state_dir); config->state_dir = g_strdup(optarg); break; case 'v': /* enable all log levels */ config->log_level = G_LOG_LEVEL_MASK; break; case 'V': printf("QEMU Guest Agent %s\n", QEMU_VERSION); exit(EXIT_SUCCESS); case 'd': config->daemonize = 1; break; case 'D': config->dumpconf = 1; break; case 'r': config->retry_path = true; break; case 'b': { if (is_help_option(optarg)) { qmp_for_each_command(&ga_commands, ga_print_cmd, NULL); exit(EXIT_SUCCESS); } config->blockedrpcs = g_list_concat(config->blockedrpcs, split_list(optarg, ",")); block_rpcs = true; break; } case 'a': { if (is_help_option(optarg)) { qmp_for_each_command(&ga_commands, ga_print_cmd, NULL); exit(EXIT_SUCCESS); } config->allowedrpcs = g_list_concat(config->allowedrpcs, split_list(optarg, ",")); allow_rpcs = true; break; } #ifdef _WIN32 case 's': config->service = optarg; if (strcmp(config->service, "install") == 0) { if (ga_install_vss_provider()) { exit(EXIT_FAILURE); } if (ga_install_service(config->channel_path, config->log_filepath, config->state_dir)) { exit(EXIT_FAILURE); } exit(EXIT_SUCCESS); } else if (strcmp(config->service, "uninstall") == 0) { ga_uninstall_vss_provider(); exit(ga_uninstall_service()); } else if (strcmp(config->service, "vss-install") == 0) { if (ga_install_vss_provider()) { exit(EXIT_FAILURE); } exit(EXIT_SUCCESS); } else if (strcmp(config->service, "vss-uninstall") == 0) { ga_uninstall_vss_provider(); exit(EXIT_SUCCESS); } else { printf("Unknown service command.\n"); exit(EXIT_FAILURE); } break; #endif case 'h': usage(argv[0]); exit(EXIT_SUCCESS); case '?': g_print("Unknown option, try '%s --help' for more information.\n", argv[0]); exit(EXIT_FAILURE); } } if (block_rpcs && allow_rpcs) { g_critical("wrong commandline, using --block-rpcs and --allow-rpcs at the" " same time is not allowed"); exit(EXIT_FAILURE); } } static void config_free(GAConfig *config) { g_free(config->method); g_free(config->log_filepath); g_free(config->pid_filepath); g_free(config->state_dir); g_free(config->channel_path); g_free(config->bliststr); g_free(config->aliststr); #ifdef CONFIG_FSFREEZE g_free(config->fsfreeze_hook); #endif g_list_free_full(config->blockedrpcs, g_free); g_list_free_full(config->allowedrpcs, g_free); g_free(config); } static bool check_is_frozen(GAState *s) { #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 * unneeded 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); return true; } #endif return false; } static GAState *initialize_agent(GAConfig *config, int socket_activation) { GAState *s = g_new0(GAState, 1); g_assert(ga_state == NULL); s->log_level = config->log_level; s->log_file = stderr; #ifdef CONFIG_FSFREEZE s->fsfreeze_hook = config->fsfreeze_hook; #endif s->pstate_filepath = g_strdup_printf("%s/qga.state", config->state_dir); s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen", config->state_dir); s->frozen = check_is_frozen(s); g_log_set_default_handler(ga_log, s); g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR); ga_enable_logging(s); g_debug("Guest agent version %s started", QEMU_FULL_VERSION); #ifdef _WIN32 s->event_log = RegisterEventSource(NULL, "qemu-ga"); if (!s->event_log) { g_autofree gchar *errmsg = g_win32_error_message(GetLastError()); g_critical("unable to register event source: %s", errmsg); return NULL; } /* 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(config->state_dir, S_IRWXU) == -1) { g_critical("unable to create (an ancestor of) the state directory" " '%s': %s", config->state_dir, strerror(errno)); return NULL; } #endif if (ga_is_frozen(s)) { if (config->daemonize) { /* delay opening/locking of pidfile till filesystems are unfrozen */ s->deferred_options.pid_filepath = config->pid_filepath; become_daemon(NULL); } if (config->log_filepath) { /* delay opening the log file till filesystems are unfrozen */ s->deferred_options.log_filepath = config->log_filepath; } ga_disable_logging(s); qmp_for_each_command(&ga_commands, ga_disable_not_allowed_freeze, NULL); } else { if (config->daemonize) { become_daemon(config->pid_filepath); } if (config->log_filepath) { FILE *log_file = ga_open_logfile(config->log_filepath); if (!log_file) { g_critical("unable to open specified log file: %s", strerror(errno)); return NULL; } 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"); return NULL; } if (config->allowedrpcs) { qmp_for_each_command(&ga_commands, ga_disable_not_allowed, config->allowedrpcs); s->allowedrpcs = config->allowedrpcs; } /* * Some commands can be blocked due to system limitation. * Initialize blockedrpcs list even if allowedrpcs specified. */ config->blockedrpcs = ga_command_init_blockedrpcs(config->blockedrpcs); if (config->blockedrpcs) { GList *l = config->blockedrpcs; s->blockedrpcs = config->blockedrpcs; do { g_debug("disabling command: %s", (char *)l->data); qmp_disable_command(&ga_commands, l->data, NULL); l = g_list_next(l); } while (l); } 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, s, NULL); #ifndef _WIN32 if (!register_signal_handlers()) { g_critical("failed to register signal handlers"); return NULL; } #endif s->main_loop = g_main_loop_new(NULL, false); s->config = config; s->socket_activation = socket_activation; #ifdef _WIN32 s->wakeup_event = CreateEvent(NULL, TRUE, FALSE, TEXT("WakeUp")); if (s->wakeup_event == NULL) { g_critical("CreateEvent failed"); return NULL; } #endif ga_state = s; return s; } static void cleanup_agent(GAState *s) { #ifdef _WIN32 CloseHandle(s->wakeup_event); CloseHandle(s->event_log); #endif if (s->command_state) { ga_command_state_cleanup_all(s->command_state); ga_command_state_free(s->command_state); json_message_parser_destroy(&s->parser); } g_free(s->pstate_filepath); g_free(s->state_filepath_isfrozen); if (s->main_loop) { g_main_loop_unref(s->main_loop); } g_free(s); ga_state = NULL; } static int run_agent_once(GAState *s) { if (!channel_init(s, s->config->method, s->config->channel_path, s->socket_activation ? FIRST_SOCKET_ACTIVATION_FD : -1)) { g_critical("failed to initialize guest agent channel"); return EXIT_FAILURE; } g_main_loop_run(ga_state->main_loop); if (s->channel) { ga_channel_free(s->channel); } return EXIT_SUCCESS; } static void wait_for_channel_availability(GAState *s) { g_warning("waiting for channel path..."); #ifndef _WIN32 sleep(QGA_RETRY_INTERVAL); #else DWORD dwWaitResult; dwWaitResult = WaitForSingleObject(s->wakeup_event, INFINITE); switch (dwWaitResult) { case WAIT_OBJECT_0: break; case WAIT_TIMEOUT: break; default: g_critical("WaitForSingleObject failed"); } #endif } static int run_agent(GAState *s) { int ret = EXIT_SUCCESS; s->force_exit = false; do { ret = run_agent_once(s); if (s->config->retry_path && !s->force_exit) { g_warning("agent stopped unexpectedly, restarting..."); wait_for_channel_availability(s); } } while (s->config->retry_path && !s->force_exit); return ret; } static void stop_agent(GAState *s, bool requested) { if (!s->force_exit) { s->force_exit = requested; } if (g_main_loop_is_running(s->main_loop)) { g_main_loop_quit(s->main_loop); } } int main(int argc, char **argv) { int ret = EXIT_SUCCESS; GAState *s; GAConfig *config = g_new0(GAConfig, 1); int socket_activation; config->log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL; qemu_init_exec_dir(argv[0]); qga_qmp_init_marshal(&ga_commands); init_dfl_pathnames(); config_load(config); config_parse(config, argc, argv); if (config->pid_filepath == NULL) { config->pid_filepath = g_strdup(dfl_pathnames.pidfile); } if (config->state_dir == NULL) { config->state_dir = g_strdup(dfl_pathnames.state_dir); } if (config->method == NULL) { config->method = g_strdup("virtio-serial"); } socket_activation = check_socket_activation(); if (socket_activation > 1) { g_critical("qemu-ga only supports listening on one socket"); ret = EXIT_FAILURE; goto end; } if (socket_activation) { SocketAddress *addr; g_free(config->method); g_free(config->channel_path); config->method = NULL; config->channel_path = NULL; addr = socket_local_address(FIRST_SOCKET_ACTIVATION_FD, NULL); if (addr) { if (addr->type == SOCKET_ADDRESS_TYPE_UNIX) { config->method = g_strdup("unix-listen"); } else if (addr->type == SOCKET_ADDRESS_TYPE_VSOCK) { config->method = g_strdup("vsock-listen"); } qapi_free_SocketAddress(addr); } if (!config->method) { g_critical("unsupported listen fd type"); ret = EXIT_FAILURE; goto end; } } else if (config->channel_path == NULL) { if (strcmp(config->method, "virtio-serial") == 0) { /* try the default path for the virtio-serial port */ config->channel_path = g_strdup(QGA_VIRTIO_PATH_DEFAULT); } else if (strcmp(config->method, "isa-serial") == 0) { /* try the default path for the serial port - COM1 */ config->channel_path = g_strdup(QGA_SERIAL_PATH_DEFAULT); } else { g_critical("must specify a path for this channel"); ret = EXIT_FAILURE; goto end; } } if (config->dumpconf) { config_dump(config); goto end; } s = initialize_agent(config, socket_activation); if (!s) { g_critical("error initializing guest agent"); goto end; } #ifdef _WIN32 if (config->daemonize) { SERVICE_TABLE_ENTRY service_table[] = { { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } }; StartServiceCtrlDispatcher(service_table); } else { ret = run_agent(s); } #else ret = run_agent(s); #endif cleanup_agent(s); end: if (config->daemonize) { unlink(config->pid_filepath); } config_free(config); return ret; }