Merge remote-tracking branch 'remotes/dgilbert/tags/pull-migration-20180214a' into...
[qemu.git] / qga / main.c
blobcb434d8c464a4433ea6c2211887d8148e5fa1479
1 /*
2 * QEMU Guest Agent
4 * Copyright IBM Corp. 2011
6 * Authors:
7 * Adam Litke <aglitke@linux.vnet.ibm.com>
8 * Michael Roth <mdroth@linux.vnet.ibm.com>
10 * This work is licensed under the terms of the GNU GPL, version 2 or later.
11 * See the COPYING file in the top-level directory.
14 #include "qemu/osdep.h"
15 #include <getopt.h>
16 #include <glib/gstdio.h>
17 #ifndef _WIN32
18 #include <syslog.h>
19 #include <sys/wait.h>
20 #endif
21 #include "qapi/qmp/json-streamer.h"
22 #include "qapi/qmp/json-parser.h"
23 #include "qapi/qmp/qdict.h"
24 #include "qapi/qmp/qjson.h"
25 #include "qapi/qmp/qstring.h"
26 #include "qga/guest-agent-core.h"
27 #include "qemu/module.h"
28 #include "qga-qmp-commands.h"
29 #include "qapi/qmp/qerror.h"
30 #include "qapi/error.h"
31 #include "qga/channel.h"
32 #include "qemu/bswap.h"
33 #include "qemu/help_option.h"
34 #include "qemu/sockets.h"
35 #include "qemu/systemd.h"
36 #include "qemu-version.h"
37 #ifdef _WIN32
38 #include "qga/service-win32.h"
39 #include "qga/vss-win32.h"
40 #endif
41 #ifdef __linux__
42 #include <linux/fs.h>
43 #ifdef FIFREEZE
44 #define CONFIG_FSFREEZE
45 #endif
46 #endif
48 #ifndef _WIN32
49 #define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0"
50 #define QGA_STATE_RELATIVE_DIR "run"
51 #define QGA_SERIAL_PATH_DEFAULT "/dev/ttyS0"
52 #else
53 #define QGA_VIRTIO_PATH_DEFAULT "\\\\.\\Global\\org.qemu.guest_agent.0"
54 #define QGA_STATE_RELATIVE_DIR "qemu-ga"
55 #define QGA_SERIAL_PATH_DEFAULT "COM1"
56 #endif
57 #ifdef CONFIG_FSFREEZE
58 #define QGA_FSFREEZE_HOOK_DEFAULT CONFIG_QEMU_CONFDIR "/fsfreeze-hook"
59 #endif
60 #define QGA_SENTINEL_BYTE 0xFF
61 #define QGA_CONF_DEFAULT CONFIG_QEMU_CONFDIR G_DIR_SEPARATOR_S "qemu-ga.conf"
63 static struct {
64 const char *state_dir;
65 const char *pidfile;
66 } dfl_pathnames;
68 typedef struct GAPersistentState {
69 #define QGA_PSTATE_DEFAULT_FD_COUNTER 1000
70 int64_t fd_counter;
71 } GAPersistentState;
73 struct GAState {
74 JSONMessageParser parser;
75 GMainLoop *main_loop;
76 GAChannel *channel;
77 bool virtio; /* fastpath to check for virtio to deal with poll() quirks */
78 GACommandState *command_state;
79 GLogLevelFlags log_level;
80 FILE *log_file;
81 bool logging_enabled;
82 #ifdef _WIN32
83 GAService service;
84 #endif
85 bool delimit_response;
86 bool frozen;
87 GList *blacklist;
88 char *state_filepath_isfrozen;
89 struct {
90 const char *log_filepath;
91 const char *pid_filepath;
92 } deferred_options;
93 #ifdef CONFIG_FSFREEZE
94 const char *fsfreeze_hook;
95 #endif
96 gchar *pstate_filepath;
97 GAPersistentState pstate;
100 struct GAState *ga_state;
101 QmpCommandList ga_commands;
103 /* commands that are safe to issue while filesystems are frozen */
104 static const char *ga_freeze_whitelist[] = {
105 "guest-ping",
106 "guest-info",
107 "guest-sync",
108 "guest-sync-delimited",
109 "guest-fsfreeze-status",
110 "guest-fsfreeze-thaw",
111 NULL
114 #ifdef _WIN32
115 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
116 LPVOID ctx);
117 VOID WINAPI service_main(DWORD argc, TCHAR *argv[]);
118 #endif
120 static void
121 init_dfl_pathnames(void)
123 g_assert(dfl_pathnames.state_dir == NULL);
124 g_assert(dfl_pathnames.pidfile == NULL);
125 dfl_pathnames.state_dir = qemu_get_local_state_pathname(
126 QGA_STATE_RELATIVE_DIR);
127 dfl_pathnames.pidfile = qemu_get_local_state_pathname(
128 QGA_STATE_RELATIVE_DIR G_DIR_SEPARATOR_S "qemu-ga.pid");
131 static void quit_handler(int sig)
133 /* if we're frozen, don't exit unless we're absolutely forced to,
134 * because it's basically impossible for graceful exit to complete
135 * unless all log/pid files are on unfreezable filesystems. there's
136 * also a very likely chance killing the agent before unfreezing
137 * the filesystems is a mistake (or will be viewed as one later).
138 * On Windows the freeze interval is limited to 10 seconds, so
139 * we should quit, but first we should wait for the timeout, thaw
140 * the filesystem and quit.
142 if (ga_is_frozen(ga_state)) {
143 #ifdef _WIN32
144 int i = 0;
145 Error *err = NULL;
146 HANDLE hEventTimeout;
148 g_debug("Thawing filesystems before exiting");
150 hEventTimeout = OpenEvent(EVENT_ALL_ACCESS, FALSE, EVENT_NAME_TIMEOUT);
151 if (hEventTimeout) {
152 WaitForSingleObject(hEventTimeout, 0);
153 CloseHandle(hEventTimeout);
155 qga_vss_fsfreeze(&i, false, &err);
156 if (err) {
157 g_debug("Error unfreezing filesystems prior to exiting: %s",
158 error_get_pretty(err));
159 error_free(err);
161 #else
162 return;
163 #endif
165 g_debug("received signal num %d, quitting", sig);
167 if (g_main_loop_is_running(ga_state->main_loop)) {
168 g_main_loop_quit(ga_state->main_loop);
172 #ifndef _WIN32
173 static gboolean register_signal_handlers(void)
175 struct sigaction sigact;
176 int ret;
178 memset(&sigact, 0, sizeof(struct sigaction));
179 sigact.sa_handler = quit_handler;
181 ret = sigaction(SIGINT, &sigact, NULL);
182 if (ret == -1) {
183 g_error("error configuring signal handler: %s", strerror(errno));
185 ret = sigaction(SIGTERM, &sigact, NULL);
186 if (ret == -1) {
187 g_error("error configuring signal handler: %s", strerror(errno));
190 sigact.sa_handler = SIG_IGN;
191 if (sigaction(SIGPIPE, &sigact, NULL) != 0) {
192 g_error("error configuring SIGPIPE signal handler: %s",
193 strerror(errno));
196 return true;
199 /* TODO: use this in place of all post-fork() fclose(std*) callers */
200 void reopen_fd_to_null(int fd)
202 int nullfd;
204 nullfd = open("/dev/null", O_RDWR);
205 if (nullfd < 0) {
206 return;
209 dup2(nullfd, fd);
211 if (nullfd != fd) {
212 close(nullfd);
215 #endif
217 static void usage(const char *cmd)
219 printf(
220 "Usage: %s [-m <method> -p <path>] [<options>]\n"
221 "QEMU Guest Agent " QEMU_VERSION QEMU_PKGVERSION "\n"
222 QEMU_COPYRIGHT "\n"
223 "\n"
224 " -m, --method transport method: one of unix-listen, virtio-serial,\n"
225 " isa-serial, or vsock-listen (virtio-serial is the default)\n"
226 " -p, --path device/socket path (the default for virtio-serial is:\n"
227 " %s,\n"
228 " the default for isa-serial is:\n"
229 " %s)\n"
230 " -l, --logfile set logfile path, logs to stderr by default\n"
231 " -f, --pidfile specify pidfile (default is %s)\n"
232 #ifdef CONFIG_FSFREEZE
233 " -F, --fsfreeze-hook\n"
234 " enable fsfreeze hook. Accepts an optional argument that\n"
235 " specifies script to run on freeze/thaw. Script will be\n"
236 " called with 'freeze'/'thaw' arguments accordingly.\n"
237 " (default is %s)\n"
238 " If using -F with an argument, do not follow -F with a\n"
239 " space.\n"
240 " (for example: -F/var/run/fsfreezehook.sh)\n"
241 #endif
242 " -t, --statedir specify dir to store state information (absolute paths\n"
243 " only, default is %s)\n"
244 " -v, --verbose log extra debugging information\n"
245 " -V, --version print version information and exit\n"
246 " -d, --daemonize become a daemon\n"
247 #ifdef _WIN32
248 " -s, --service service commands: install, uninstall, vss-install, vss-uninstall\n"
249 #endif
250 " -b, --blacklist comma-separated list of RPCs to disable (no spaces, \"?\"\n"
251 " to list available RPCs)\n"
252 " -D, --dump-conf dump a qemu-ga config file based on current config\n"
253 " options / command-line parameters to stdout\n"
254 " -h, --help display this help and exit\n"
255 "\n"
256 QEMU_HELP_BOTTOM "\n"
257 , cmd, QGA_VIRTIO_PATH_DEFAULT, QGA_SERIAL_PATH_DEFAULT,
258 dfl_pathnames.pidfile,
259 #ifdef CONFIG_FSFREEZE
260 QGA_FSFREEZE_HOOK_DEFAULT,
261 #endif
262 dfl_pathnames.state_dir);
265 static const char *ga_log_level_str(GLogLevelFlags level)
267 switch (level & G_LOG_LEVEL_MASK) {
268 case G_LOG_LEVEL_ERROR:
269 return "error";
270 case G_LOG_LEVEL_CRITICAL:
271 return "critical";
272 case G_LOG_LEVEL_WARNING:
273 return "warning";
274 case G_LOG_LEVEL_MESSAGE:
275 return "message";
276 case G_LOG_LEVEL_INFO:
277 return "info";
278 case G_LOG_LEVEL_DEBUG:
279 return "debug";
280 default:
281 return "user";
285 bool ga_logging_enabled(GAState *s)
287 return s->logging_enabled;
290 void ga_disable_logging(GAState *s)
292 s->logging_enabled = false;
295 void ga_enable_logging(GAState *s)
297 s->logging_enabled = true;
300 static void ga_log(const gchar *domain, GLogLevelFlags level,
301 const gchar *msg, gpointer opaque)
303 GAState *s = opaque;
304 GTimeVal time;
305 const char *level_str = ga_log_level_str(level);
307 if (!ga_logging_enabled(s)) {
308 return;
311 level &= G_LOG_LEVEL_MASK;
312 #ifndef _WIN32
313 if (g_strcmp0(domain, "syslog") == 0) {
314 syslog(LOG_INFO, "%s: %s", level_str, msg);
315 } else if (level & s->log_level) {
316 #else
317 if (level & s->log_level) {
318 #endif
319 g_get_current_time(&time);
320 fprintf(s->log_file,
321 "%lu.%lu: %s: %s\n", time.tv_sec, time.tv_usec, level_str, msg);
322 fflush(s->log_file);
326 void ga_set_response_delimited(GAState *s)
328 s->delimit_response = true;
331 static FILE *ga_open_logfile(const char *logfile)
333 FILE *f;
335 f = fopen(logfile, "a");
336 if (!f) {
337 return NULL;
340 qemu_set_cloexec(fileno(f));
341 return f;
344 #ifndef _WIN32
345 static bool ga_open_pidfile(const char *pidfile)
347 int pidfd;
348 char pidstr[32];
350 pidfd = qemu_open(pidfile, O_CREAT|O_WRONLY, S_IRUSR|S_IWUSR);
351 if (pidfd == -1 || lockf(pidfd, F_TLOCK, 0)) {
352 g_critical("Cannot lock pid file, %s", strerror(errno));
353 if (pidfd != -1) {
354 close(pidfd);
356 return false;
359 if (ftruncate(pidfd, 0)) {
360 g_critical("Failed to truncate pid file");
361 goto fail;
363 snprintf(pidstr, sizeof(pidstr), "%d\n", getpid());
364 if (write(pidfd, pidstr, strlen(pidstr)) != strlen(pidstr)) {
365 g_critical("Failed to write pid file");
366 goto fail;
369 /* keep pidfile open & locked forever */
370 return true;
372 fail:
373 unlink(pidfile);
374 close(pidfd);
375 return false;
377 #else /* _WIN32 */
378 static bool ga_open_pidfile(const char *pidfile)
380 return true;
382 #endif
384 static gint ga_strcmp(gconstpointer str1, gconstpointer str2)
386 return strcmp(str1, str2);
389 /* disable commands that aren't safe for fsfreeze */
390 static void ga_disable_non_whitelisted(QmpCommand *cmd, void *opaque)
392 bool whitelisted = false;
393 int i = 0;
394 const char *name = qmp_command_name(cmd);
396 while (ga_freeze_whitelist[i] != NULL) {
397 if (strcmp(name, ga_freeze_whitelist[i]) == 0) {
398 whitelisted = true;
400 i++;
402 if (!whitelisted) {
403 g_debug("disabling command: %s", name);
404 qmp_disable_command(&ga_commands, name);
408 /* [re-]enable all commands, except those explicitly blacklisted by user */
409 static void ga_enable_non_blacklisted(QmpCommand *cmd, void *opaque)
411 GList *blacklist = opaque;
412 const char *name = qmp_command_name(cmd);
414 if (g_list_find_custom(blacklist, name, ga_strcmp) == NULL &&
415 !qmp_command_is_enabled(cmd)) {
416 g_debug("enabling command: %s", name);
417 qmp_enable_command(&ga_commands, name);
421 static bool ga_create_file(const char *path)
423 int fd = open(path, O_CREAT | O_WRONLY, S_IWUSR | S_IRUSR);
424 if (fd == -1) {
425 g_warning("unable to open/create file %s: %s", path, strerror(errno));
426 return false;
428 close(fd);
429 return true;
432 static bool ga_delete_file(const char *path)
434 int ret = unlink(path);
435 if (ret == -1) {
436 g_warning("unable to delete file: %s: %s", path, strerror(errno));
437 return false;
440 return true;
443 bool ga_is_frozen(GAState *s)
445 return s->frozen;
448 void ga_set_frozen(GAState *s)
450 if (ga_is_frozen(s)) {
451 return;
453 /* disable all non-whitelisted (for frozen state) commands */
454 qmp_for_each_command(&ga_commands, ga_disable_non_whitelisted, NULL);
455 g_warning("disabling logging due to filesystem freeze");
456 ga_disable_logging(s);
457 s->frozen = true;
458 if (!ga_create_file(s->state_filepath_isfrozen)) {
459 g_warning("unable to create %s, fsfreeze may not function properly",
460 s->state_filepath_isfrozen);
464 void ga_unset_frozen(GAState *s)
466 if (!ga_is_frozen(s)) {
467 return;
470 /* if we delayed creation/opening of pid/log files due to being
471 * in a frozen state at start up, do it now
473 if (s->deferred_options.log_filepath) {
474 s->log_file = ga_open_logfile(s->deferred_options.log_filepath);
475 if (!s->log_file) {
476 s->log_file = stderr;
478 s->deferred_options.log_filepath = NULL;
480 ga_enable_logging(s);
481 g_warning("logging re-enabled due to filesystem unfreeze");
482 if (s->deferred_options.pid_filepath) {
483 if (!ga_open_pidfile(s->deferred_options.pid_filepath)) {
484 g_warning("failed to create/open pid file");
486 s->deferred_options.pid_filepath = NULL;
489 /* enable all disabled, non-blacklisted commands */
490 qmp_for_each_command(&ga_commands, ga_enable_non_blacklisted, s->blacklist);
491 s->frozen = false;
492 if (!ga_delete_file(s->state_filepath_isfrozen)) {
493 g_warning("unable to delete %s, fsfreeze may not function properly",
494 s->state_filepath_isfrozen);
498 #ifdef CONFIG_FSFREEZE
499 const char *ga_fsfreeze_hook(GAState *s)
501 return s->fsfreeze_hook;
503 #endif
505 static void become_daemon(const char *pidfile)
507 #ifndef _WIN32
508 pid_t pid, sid;
510 pid = fork();
511 if (pid < 0) {
512 exit(EXIT_FAILURE);
514 if (pid > 0) {
515 exit(EXIT_SUCCESS);
518 if (pidfile) {
519 if (!ga_open_pidfile(pidfile)) {
520 g_critical("failed to create pidfile");
521 exit(EXIT_FAILURE);
525 umask(S_IRWXG | S_IRWXO);
526 sid = setsid();
527 if (sid < 0) {
528 goto fail;
530 if ((chdir("/")) < 0) {
531 goto fail;
534 reopen_fd_to_null(STDIN_FILENO);
535 reopen_fd_to_null(STDOUT_FILENO);
536 reopen_fd_to_null(STDERR_FILENO);
537 return;
539 fail:
540 if (pidfile) {
541 unlink(pidfile);
543 g_critical("failed to daemonize");
544 exit(EXIT_FAILURE);
545 #endif
548 static int send_response(GAState *s, QObject *payload)
550 const char *buf;
551 QString *payload_qstr, *response_qstr;
552 GIOStatus status;
554 g_assert(payload && s->channel);
556 payload_qstr = qobject_to_json(payload);
557 if (!payload_qstr) {
558 return -EINVAL;
561 if (s->delimit_response) {
562 s->delimit_response = false;
563 response_qstr = qstring_new();
564 qstring_append_chr(response_qstr, QGA_SENTINEL_BYTE);
565 qstring_append(response_qstr, qstring_get_str(payload_qstr));
566 QDECREF(payload_qstr);
567 } else {
568 response_qstr = payload_qstr;
571 qstring_append_chr(response_qstr, '\n');
572 buf = qstring_get_str(response_qstr);
573 status = ga_channel_write_all(s->channel, buf, strlen(buf));
574 QDECREF(response_qstr);
575 if (status != G_IO_STATUS_NORMAL) {
576 return -EIO;
579 return 0;
582 static void process_command(GAState *s, QDict *req)
584 QObject *rsp = NULL;
585 int ret;
587 g_assert(req);
588 g_debug("processing command");
589 rsp = qmp_dispatch(&ga_commands, QOBJECT(req));
590 if (rsp) {
591 ret = send_response(s, rsp);
592 if (ret < 0) {
593 g_warning("error sending response: %s", strerror(-ret));
595 qobject_decref(rsp);
599 /* handle requests/control events coming in over the channel */
600 static void process_event(JSONMessageParser *parser, GQueue *tokens)
602 GAState *s = container_of(parser, GAState, parser);
603 QDict *qdict;
604 Error *err = NULL;
605 int ret;
607 g_assert(s && parser);
609 g_debug("process_event: called");
610 qdict = qobject_to_qdict(json_parser_parse_err(tokens, NULL, &err));
611 if (err || !qdict) {
612 QDECREF(qdict);
613 qdict = qdict_new();
614 if (!err) {
615 g_warning("failed to parse event: unknown error");
616 error_setg(&err, QERR_JSON_PARSING);
617 } else {
618 g_warning("failed to parse event: %s", error_get_pretty(err));
620 qdict_put_obj(qdict, "error", qmp_build_error_object(err));
621 error_free(err);
624 /* handle host->guest commands */
625 if (qdict_haskey(qdict, "execute")) {
626 process_command(s, qdict);
627 } else {
628 if (!qdict_haskey(qdict, "error")) {
629 QDECREF(qdict);
630 qdict = qdict_new();
631 g_warning("unrecognized payload format");
632 error_setg(&err, QERR_UNSUPPORTED);
633 qdict_put_obj(qdict, "error", qmp_build_error_object(err));
634 error_free(err);
636 ret = send_response(s, QOBJECT(qdict));
637 if (ret < 0) {
638 g_warning("error sending error response: %s", strerror(-ret));
642 QDECREF(qdict);
645 /* false return signals GAChannel to close the current client connection */
646 static gboolean channel_event_cb(GIOCondition condition, gpointer data)
648 GAState *s = data;
649 gchar buf[QGA_READ_COUNT_DEFAULT+1];
650 gsize count;
651 GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
652 switch (status) {
653 case G_IO_STATUS_ERROR:
654 g_warning("error reading channel");
655 return false;
656 case G_IO_STATUS_NORMAL:
657 buf[count] = 0;
658 g_debug("read data, count: %d, data: %s", (int)count, buf);
659 json_message_parser_feed(&s->parser, (char *)buf, (int)count);
660 break;
661 case G_IO_STATUS_EOF:
662 g_debug("received EOF");
663 if (!s->virtio) {
664 return false;
666 /* fall through */
667 case G_IO_STATUS_AGAIN:
668 /* virtio causes us to spin here when no process is attached to
669 * host-side chardev. sleep a bit to mitigate this
671 if (s->virtio) {
672 usleep(100*1000);
674 return true;
675 default:
676 g_warning("unknown channel read status, closing");
677 return false;
679 return true;
682 static gboolean channel_init(GAState *s, const gchar *method, const gchar *path,
683 int listen_fd)
685 GAChannelMethod channel_method;
687 if (strcmp(method, "virtio-serial") == 0) {
688 s->virtio = true; /* virtio requires special handling in some cases */
689 channel_method = GA_CHANNEL_VIRTIO_SERIAL;
690 } else if (strcmp(method, "isa-serial") == 0) {
691 channel_method = GA_CHANNEL_ISA_SERIAL;
692 } else if (strcmp(method, "unix-listen") == 0) {
693 channel_method = GA_CHANNEL_UNIX_LISTEN;
694 } else if (strcmp(method, "vsock-listen") == 0) {
695 channel_method = GA_CHANNEL_VSOCK_LISTEN;
696 } else {
697 g_critical("unsupported channel method/type: %s", method);
698 return false;
701 s->channel = ga_channel_new(channel_method, path, listen_fd,
702 channel_event_cb, s);
703 if (!s->channel) {
704 g_critical("failed to create guest agent channel");
705 return false;
708 return true;
711 #ifdef _WIN32
712 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
713 LPVOID ctx)
715 DWORD ret = NO_ERROR;
716 GAService *service = &ga_state->service;
718 switch (ctrl)
720 case SERVICE_CONTROL_STOP:
721 case SERVICE_CONTROL_SHUTDOWN:
722 quit_handler(SIGTERM);
723 service->status.dwCurrentState = SERVICE_STOP_PENDING;
724 SetServiceStatus(service->status_handle, &service->status);
725 break;
727 default:
728 ret = ERROR_CALL_NOT_IMPLEMENTED;
730 return ret;
733 VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
735 GAService *service = &ga_state->service;
737 service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME,
738 service_ctrl_handler, NULL);
740 if (service->status_handle == 0) {
741 g_critical("Failed to register extended requests function!\n");
742 return;
745 service->status.dwServiceType = SERVICE_WIN32;
746 service->status.dwCurrentState = SERVICE_RUNNING;
747 service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
748 service->status.dwWin32ExitCode = NO_ERROR;
749 service->status.dwServiceSpecificExitCode = NO_ERROR;
750 service->status.dwCheckPoint = 0;
751 service->status.dwWaitHint = 0;
752 SetServiceStatus(service->status_handle, &service->status);
754 g_main_loop_run(ga_state->main_loop);
756 service->status.dwCurrentState = SERVICE_STOPPED;
757 SetServiceStatus(service->status_handle, &service->status);
759 #endif
761 static void set_persistent_state_defaults(GAPersistentState *pstate)
763 g_assert(pstate);
764 pstate->fd_counter = QGA_PSTATE_DEFAULT_FD_COUNTER;
767 static void persistent_state_from_keyfile(GAPersistentState *pstate,
768 GKeyFile *keyfile)
770 g_assert(pstate);
771 g_assert(keyfile);
772 /* if any fields are missing, either because the file was tampered with
773 * by agents of chaos, or because the field wasn't present at the time the
774 * file was created, the best we can ever do is start over with the default
775 * values. so load them now, and ignore any errors in accessing key-value
776 * pairs
778 set_persistent_state_defaults(pstate);
780 if (g_key_file_has_key(keyfile, "global", "fd_counter", NULL)) {
781 pstate->fd_counter =
782 g_key_file_get_integer(keyfile, "global", "fd_counter", NULL);
786 static void persistent_state_to_keyfile(const GAPersistentState *pstate,
787 GKeyFile *keyfile)
789 g_assert(pstate);
790 g_assert(keyfile);
792 g_key_file_set_integer(keyfile, "global", "fd_counter", pstate->fd_counter);
795 static gboolean write_persistent_state(const GAPersistentState *pstate,
796 const gchar *path)
798 GKeyFile *keyfile = g_key_file_new();
799 GError *gerr = NULL;
800 gboolean ret = true;
801 gchar *data = NULL;
802 gsize data_len;
804 g_assert(pstate);
806 persistent_state_to_keyfile(pstate, keyfile);
807 data = g_key_file_to_data(keyfile, &data_len, &gerr);
808 if (gerr) {
809 g_critical("failed to convert persistent state to string: %s",
810 gerr->message);
811 ret = false;
812 goto out;
815 g_file_set_contents(path, data, data_len, &gerr);
816 if (gerr) {
817 g_critical("failed to write persistent state to %s: %s",
818 path, gerr->message);
819 ret = false;
820 goto out;
823 out:
824 if (gerr) {
825 g_error_free(gerr);
827 if (keyfile) {
828 g_key_file_free(keyfile);
830 g_free(data);
831 return ret;
834 static gboolean read_persistent_state(GAPersistentState *pstate,
835 const gchar *path, gboolean frozen)
837 GKeyFile *keyfile = NULL;
838 GError *gerr = NULL;
839 struct stat st;
840 gboolean ret = true;
842 g_assert(pstate);
844 if (stat(path, &st) == -1) {
845 /* it's okay if state file doesn't exist, but any other error
846 * indicates a permissions issue or some other misconfiguration
847 * that we likely won't be able to recover from.
849 if (errno != ENOENT) {
850 g_critical("unable to access state file at path %s: %s",
851 path, strerror(errno));
852 ret = false;
853 goto out;
856 /* file doesn't exist. initialize state to default values and
857 * attempt to save now. (we could wait till later when we have
858 * modified state we need to commit, but if there's a problem,
859 * such as a missing parent directory, we want to catch it now)
861 * there is a potential scenario where someone either managed to
862 * update the agent from a version that didn't use a key store
863 * while qemu-ga thought the filesystem was frozen, or
864 * deleted the key store prior to issuing a fsfreeze, prior
865 * to restarting the agent. in this case we go ahead and defer
866 * initial creation till we actually have modified state to
867 * write, otherwise fail to recover from freeze.
869 set_persistent_state_defaults(pstate);
870 if (!frozen) {
871 ret = write_persistent_state(pstate, path);
872 if (!ret) {
873 g_critical("unable to create state file at path %s", path);
874 ret = false;
875 goto out;
878 ret = true;
879 goto out;
882 keyfile = g_key_file_new();
883 g_key_file_load_from_file(keyfile, path, 0, &gerr);
884 if (gerr) {
885 g_critical("error loading persistent state from path: %s, %s",
886 path, gerr->message);
887 ret = false;
888 goto out;
891 persistent_state_from_keyfile(pstate, keyfile);
893 out:
894 if (keyfile) {
895 g_key_file_free(keyfile);
897 if (gerr) {
898 g_error_free(gerr);
901 return ret;
904 int64_t ga_get_fd_handle(GAState *s, Error **errp)
906 int64_t handle;
908 g_assert(s->pstate_filepath);
909 /* we blacklist commands and avoid operations that potentially require
910 * writing to disk when we're in a frozen state. this includes opening
911 * new files, so we should never get here in that situation
913 g_assert(!ga_is_frozen(s));
915 handle = s->pstate.fd_counter++;
917 /* This should never happen on a reasonable timeframe, as guest-file-open
918 * would have to be issued 2^63 times */
919 if (s->pstate.fd_counter == INT64_MAX) {
920 abort();
923 if (!write_persistent_state(&s->pstate, s->pstate_filepath)) {
924 error_setg(errp, "failed to commit persistent state to disk");
925 return -1;
928 return handle;
931 static void ga_print_cmd(QmpCommand *cmd, void *opaque)
933 printf("%s\n", qmp_command_name(cmd));
936 static GList *split_list(const gchar *str, const gchar *delim)
938 GList *list = NULL;
939 int i;
940 gchar **strv;
942 strv = g_strsplit(str, delim, -1);
943 for (i = 0; strv[i]; i++) {
944 list = g_list_prepend(list, strv[i]);
946 g_free(strv);
948 return list;
951 typedef struct GAConfig {
952 char *channel_path;
953 char *method;
954 char *log_filepath;
955 char *pid_filepath;
956 #ifdef CONFIG_FSFREEZE
957 char *fsfreeze_hook;
958 #endif
959 char *state_dir;
960 #ifdef _WIN32
961 const char *service;
962 #endif
963 gchar *bliststr; /* blacklist may point to this string */
964 GList *blacklist;
965 int daemonize;
966 GLogLevelFlags log_level;
967 int dumpconf;
968 } GAConfig;
970 static void config_load(GAConfig *config)
972 GError *gerr = NULL;
973 GKeyFile *keyfile;
974 const char *conf = g_getenv("QGA_CONF") ?: QGA_CONF_DEFAULT;
976 /* read system config */
977 keyfile = g_key_file_new();
978 if (!g_key_file_load_from_file(keyfile, conf, 0, &gerr)) {
979 goto end;
981 if (g_key_file_has_key(keyfile, "general", "daemon", NULL)) {
982 config->daemonize =
983 g_key_file_get_boolean(keyfile, "general", "daemon", &gerr);
985 if (g_key_file_has_key(keyfile, "general", "method", NULL)) {
986 config->method =
987 g_key_file_get_string(keyfile, "general", "method", &gerr);
989 if (g_key_file_has_key(keyfile, "general", "path", NULL)) {
990 config->channel_path =
991 g_key_file_get_string(keyfile, "general", "path", &gerr);
993 if (g_key_file_has_key(keyfile, "general", "logfile", NULL)) {
994 config->log_filepath =
995 g_key_file_get_string(keyfile, "general", "logfile", &gerr);
997 if (g_key_file_has_key(keyfile, "general", "pidfile", NULL)) {
998 config->pid_filepath =
999 g_key_file_get_string(keyfile, "general", "pidfile", &gerr);
1001 #ifdef CONFIG_FSFREEZE
1002 if (g_key_file_has_key(keyfile, "general", "fsfreeze-hook", NULL)) {
1003 config->fsfreeze_hook =
1004 g_key_file_get_string(keyfile,
1005 "general", "fsfreeze-hook", &gerr);
1007 #endif
1008 if (g_key_file_has_key(keyfile, "general", "statedir", NULL)) {
1009 config->state_dir =
1010 g_key_file_get_string(keyfile, "general", "statedir", &gerr);
1012 if (g_key_file_has_key(keyfile, "general", "verbose", NULL) &&
1013 g_key_file_get_boolean(keyfile, "general", "verbose", &gerr)) {
1014 /* enable all log levels */
1015 config->log_level = G_LOG_LEVEL_MASK;
1017 if (g_key_file_has_key(keyfile, "general", "blacklist", NULL)) {
1018 config->bliststr =
1019 g_key_file_get_string(keyfile, "general", "blacklist", &gerr);
1020 config->blacklist = g_list_concat(config->blacklist,
1021 split_list(config->bliststr, ","));
1024 end:
1025 g_key_file_free(keyfile);
1026 if (gerr &&
1027 !(gerr->domain == G_FILE_ERROR && gerr->code == G_FILE_ERROR_NOENT)) {
1028 g_critical("error loading configuration from path: %s, %s",
1029 QGA_CONF_DEFAULT, gerr->message);
1030 exit(EXIT_FAILURE);
1032 g_clear_error(&gerr);
1035 static gchar *list_join(GList *list, const gchar separator)
1037 GString *str = g_string_new("");
1039 while (list) {
1040 str = g_string_append(str, (gchar *)list->data);
1041 list = g_list_next(list);
1042 if (list) {
1043 str = g_string_append_c(str, separator);
1047 return g_string_free(str, FALSE);
1050 static void config_dump(GAConfig *config)
1052 GError *error = NULL;
1053 GKeyFile *keyfile;
1054 gchar *tmp;
1056 keyfile = g_key_file_new();
1057 g_assert(keyfile);
1059 g_key_file_set_boolean(keyfile, "general", "daemon", config->daemonize);
1060 g_key_file_set_string(keyfile, "general", "method", config->method);
1061 if (config->channel_path) {
1062 g_key_file_set_string(keyfile, "general", "path", config->channel_path);
1064 if (config->log_filepath) {
1065 g_key_file_set_string(keyfile, "general", "logfile",
1066 config->log_filepath);
1068 g_key_file_set_string(keyfile, "general", "pidfile", config->pid_filepath);
1069 #ifdef CONFIG_FSFREEZE
1070 if (config->fsfreeze_hook) {
1071 g_key_file_set_string(keyfile, "general", "fsfreeze-hook",
1072 config->fsfreeze_hook);
1074 #endif
1075 g_key_file_set_string(keyfile, "general", "statedir", config->state_dir);
1076 g_key_file_set_boolean(keyfile, "general", "verbose",
1077 config->log_level == G_LOG_LEVEL_MASK);
1078 tmp = list_join(config->blacklist, ',');
1079 g_key_file_set_string(keyfile, "general", "blacklist", tmp);
1080 g_free(tmp);
1082 tmp = g_key_file_to_data(keyfile, NULL, &error);
1083 if (error) {
1084 g_critical("Failed to dump keyfile: %s", error->message);
1085 g_clear_error(&error);
1086 } else {
1087 printf("%s", tmp);
1090 g_free(tmp);
1091 g_key_file_free(keyfile);
1094 static void config_parse(GAConfig *config, int argc, char **argv)
1096 const char *sopt = "hVvdm:p:l:f:F::b:s:t:D";
1097 int opt_ind = 0, ch;
1098 const struct option lopt[] = {
1099 { "help", 0, NULL, 'h' },
1100 { "version", 0, NULL, 'V' },
1101 { "dump-conf", 0, NULL, 'D' },
1102 { "logfile", 1, NULL, 'l' },
1103 { "pidfile", 1, NULL, 'f' },
1104 #ifdef CONFIG_FSFREEZE
1105 { "fsfreeze-hook", 2, NULL, 'F' },
1106 #endif
1107 { "verbose", 0, NULL, 'v' },
1108 { "method", 1, NULL, 'm' },
1109 { "path", 1, NULL, 'p' },
1110 { "daemonize", 0, NULL, 'd' },
1111 { "blacklist", 1, NULL, 'b' },
1112 #ifdef _WIN32
1113 { "service", 1, NULL, 's' },
1114 #endif
1115 { "statedir", 1, NULL, 't' },
1116 { NULL, 0, NULL, 0 }
1119 while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
1120 switch (ch) {
1121 case 'm':
1122 g_free(config->method);
1123 config->method = g_strdup(optarg);
1124 break;
1125 case 'p':
1126 g_free(config->channel_path);
1127 config->channel_path = g_strdup(optarg);
1128 break;
1129 case 'l':
1130 g_free(config->log_filepath);
1131 config->log_filepath = g_strdup(optarg);
1132 break;
1133 case 'f':
1134 g_free(config->pid_filepath);
1135 config->pid_filepath = g_strdup(optarg);
1136 break;
1137 #ifdef CONFIG_FSFREEZE
1138 case 'F':
1139 g_free(config->fsfreeze_hook);
1140 config->fsfreeze_hook = g_strdup(optarg ?: QGA_FSFREEZE_HOOK_DEFAULT);
1141 break;
1142 #endif
1143 case 't':
1144 g_free(config->state_dir);
1145 config->state_dir = g_strdup(optarg);
1146 break;
1147 case 'v':
1148 /* enable all log levels */
1149 config->log_level = G_LOG_LEVEL_MASK;
1150 break;
1151 case 'V':
1152 printf("QEMU Guest Agent %s\n", QEMU_VERSION);
1153 exit(EXIT_SUCCESS);
1154 case 'd':
1155 config->daemonize = 1;
1156 break;
1157 case 'D':
1158 config->dumpconf = 1;
1159 break;
1160 case 'b': {
1161 if (is_help_option(optarg)) {
1162 qmp_for_each_command(&ga_commands, ga_print_cmd, NULL);
1163 exit(EXIT_SUCCESS);
1165 config->blacklist = g_list_concat(config->blacklist,
1166 split_list(optarg, ","));
1167 break;
1169 #ifdef _WIN32
1170 case 's':
1171 config->service = optarg;
1172 if (strcmp(config->service, "install") == 0) {
1173 if (ga_install_vss_provider()) {
1174 exit(EXIT_FAILURE);
1176 if (ga_install_service(config->channel_path,
1177 config->log_filepath, config->state_dir)) {
1178 exit(EXIT_FAILURE);
1180 exit(EXIT_SUCCESS);
1181 } else if (strcmp(config->service, "uninstall") == 0) {
1182 ga_uninstall_vss_provider();
1183 exit(ga_uninstall_service());
1184 } else if (strcmp(config->service, "vss-install") == 0) {
1185 if (ga_install_vss_provider()) {
1186 exit(EXIT_FAILURE);
1188 exit(EXIT_SUCCESS);
1189 } else if (strcmp(config->service, "vss-uninstall") == 0) {
1190 ga_uninstall_vss_provider();
1191 exit(EXIT_SUCCESS);
1192 } else {
1193 printf("Unknown service command.\n");
1194 exit(EXIT_FAILURE);
1196 break;
1197 #endif
1198 case 'h':
1199 usage(argv[0]);
1200 exit(EXIT_SUCCESS);
1201 case '?':
1202 g_print("Unknown option, try '%s --help' for more information.\n",
1203 argv[0]);
1204 exit(EXIT_FAILURE);
1209 static void config_free(GAConfig *config)
1211 g_free(config->method);
1212 g_free(config->log_filepath);
1213 g_free(config->pid_filepath);
1214 g_free(config->state_dir);
1215 g_free(config->channel_path);
1216 g_free(config->bliststr);
1217 #ifdef CONFIG_FSFREEZE
1218 g_free(config->fsfreeze_hook);
1219 #endif
1220 g_list_free_full(config->blacklist, g_free);
1221 g_free(config);
1224 static bool check_is_frozen(GAState *s)
1226 #ifndef _WIN32
1227 /* check if a previous instance of qemu-ga exited with filesystems' state
1228 * marked as frozen. this could be a stale value (a non-qemu-ga process
1229 * or reboot may have since unfrozen them), but better to require an
1230 * uneeded unfreeze than to risk hanging on start-up
1232 struct stat st;
1233 if (stat(s->state_filepath_isfrozen, &st) == -1) {
1234 /* it's okay if the file doesn't exist, but if we can't access for
1235 * some other reason, such as permissions, there's a configuration
1236 * that needs to be addressed. so just bail now before we get into
1237 * more trouble later
1239 if (errno != ENOENT) {
1240 g_critical("unable to access state file at path %s: %s",
1241 s->state_filepath_isfrozen, strerror(errno));
1242 return EXIT_FAILURE;
1244 } else {
1245 g_warning("previous instance appears to have exited with frozen"
1246 " filesystems. deferring logging/pidfile creation and"
1247 " disabling non-fsfreeze-safe commands until"
1248 " guest-fsfreeze-thaw is issued, or filesystems are"
1249 " manually unfrozen and the file %s is removed",
1250 s->state_filepath_isfrozen);
1251 return true;
1253 #endif
1254 return false;
1257 static int run_agent(GAState *s, GAConfig *config, int socket_activation)
1259 ga_state = s;
1261 g_log_set_default_handler(ga_log, s);
1262 g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
1263 ga_enable_logging(s);
1265 #ifdef _WIN32
1266 /* On win32 the state directory is application specific (be it the default
1267 * or a user override). We got past the command line parsing; let's create
1268 * the directory (with any intermediate directories). If we run into an
1269 * error later on, we won't try to clean up the directory, it is considered
1270 * persistent.
1272 if (g_mkdir_with_parents(config->state_dir, S_IRWXU) == -1) {
1273 g_critical("unable to create (an ancestor of) the state directory"
1274 " '%s': %s", config->state_dir, strerror(errno));
1275 return EXIT_FAILURE;
1277 #endif
1279 if (ga_is_frozen(s)) {
1280 if (config->daemonize) {
1281 /* delay opening/locking of pidfile till filesystems are unfrozen */
1282 s->deferred_options.pid_filepath = config->pid_filepath;
1283 become_daemon(NULL);
1285 if (config->log_filepath) {
1286 /* delay opening the log file till filesystems are unfrozen */
1287 s->deferred_options.log_filepath = config->log_filepath;
1289 ga_disable_logging(s);
1290 qmp_for_each_command(&ga_commands, ga_disable_non_whitelisted, NULL);
1291 } else {
1292 if (config->daemonize) {
1293 become_daemon(config->pid_filepath);
1295 if (config->log_filepath) {
1296 FILE *log_file = ga_open_logfile(config->log_filepath);
1297 if (!log_file) {
1298 g_critical("unable to open specified log file: %s",
1299 strerror(errno));
1300 return EXIT_FAILURE;
1302 s->log_file = log_file;
1306 /* load persistent state from disk */
1307 if (!read_persistent_state(&s->pstate,
1308 s->pstate_filepath,
1309 ga_is_frozen(s))) {
1310 g_critical("failed to load persistent state");
1311 return EXIT_FAILURE;
1314 config->blacklist = ga_command_blacklist_init(config->blacklist);
1315 if (config->blacklist) {
1316 GList *l = config->blacklist;
1317 s->blacklist = config->blacklist;
1318 do {
1319 g_debug("disabling command: %s", (char *)l->data);
1320 qmp_disable_command(&ga_commands, l->data);
1321 l = g_list_next(l);
1322 } while (l);
1324 s->command_state = ga_command_state_new();
1325 ga_command_state_init(s, s->command_state);
1326 ga_command_state_init_all(s->command_state);
1327 json_message_parser_init(&s->parser, process_event);
1329 #ifndef _WIN32
1330 if (!register_signal_handlers()) {
1331 g_critical("failed to register signal handlers");
1332 return EXIT_FAILURE;
1334 #endif
1336 s->main_loop = g_main_loop_new(NULL, false);
1338 if (!channel_init(ga_state, config->method, config->channel_path,
1339 socket_activation ? FIRST_SOCKET_ACTIVATION_FD : -1)) {
1340 g_critical("failed to initialize guest agent channel");
1341 return EXIT_FAILURE;
1343 #ifndef _WIN32
1344 g_main_loop_run(ga_state->main_loop);
1345 #else
1346 if (config->daemonize) {
1347 SERVICE_TABLE_ENTRY service_table[] = {
1348 { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
1349 StartServiceCtrlDispatcher(service_table);
1350 } else {
1351 g_main_loop_run(ga_state->main_loop);
1353 #endif
1355 return EXIT_SUCCESS;
1358 int main(int argc, char **argv)
1360 int ret = EXIT_SUCCESS;
1361 GAState *s = g_new0(GAState, 1);
1362 GAConfig *config = g_new0(GAConfig, 1);
1363 int socket_activation;
1365 config->log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
1367 qga_qmp_init_marshal(&ga_commands);
1369 init_dfl_pathnames();
1370 config_load(config);
1371 config_parse(config, argc, argv);
1373 if (config->pid_filepath == NULL) {
1374 config->pid_filepath = g_strdup(dfl_pathnames.pidfile);
1377 if (config->state_dir == NULL) {
1378 config->state_dir = g_strdup(dfl_pathnames.state_dir);
1381 if (config->method == NULL) {
1382 config->method = g_strdup("virtio-serial");
1385 socket_activation = check_socket_activation();
1386 if (socket_activation > 1) {
1387 g_critical("qemu-ga only supports listening on one socket");
1388 ret = EXIT_FAILURE;
1389 goto end;
1391 if (socket_activation) {
1392 SocketAddress *addr;
1394 g_free(config->method);
1395 g_free(config->channel_path);
1396 config->method = NULL;
1397 config->channel_path = NULL;
1399 addr = socket_local_address(FIRST_SOCKET_ACTIVATION_FD, NULL);
1400 if (addr) {
1401 if (addr->type == SOCKET_ADDRESS_TYPE_UNIX) {
1402 config->method = g_strdup("unix-listen");
1403 } else if (addr->type == SOCKET_ADDRESS_TYPE_VSOCK) {
1404 config->method = g_strdup("vsock-listen");
1407 qapi_free_SocketAddress(addr);
1410 if (!config->method) {
1411 g_critical("unsupported listen fd type");
1412 ret = EXIT_FAILURE;
1413 goto end;
1415 } else if (config->channel_path == NULL) {
1416 if (strcmp(config->method, "virtio-serial") == 0) {
1417 /* try the default path for the virtio-serial port */
1418 config->channel_path = g_strdup(QGA_VIRTIO_PATH_DEFAULT);
1419 } else if (strcmp(config->method, "isa-serial") == 0) {
1420 /* try the default path for the serial port - COM1 */
1421 config->channel_path = g_strdup(QGA_SERIAL_PATH_DEFAULT);
1422 } else {
1423 g_critical("must specify a path for this channel");
1424 ret = EXIT_FAILURE;
1425 goto end;
1429 s->log_level = config->log_level;
1430 s->log_file = stderr;
1431 #ifdef CONFIG_FSFREEZE
1432 s->fsfreeze_hook = config->fsfreeze_hook;
1433 #endif
1434 s->pstate_filepath = g_strdup_printf("%s/qga.state", config->state_dir);
1435 s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen",
1436 config->state_dir);
1437 s->frozen = check_is_frozen(s);
1439 if (config->dumpconf) {
1440 config_dump(config);
1441 goto end;
1444 ret = run_agent(s, config, socket_activation);
1446 end:
1447 if (s->command_state) {
1448 ga_command_state_cleanup_all(s->command_state);
1449 ga_command_state_free(s->command_state);
1450 json_message_parser_destroy(&s->parser);
1452 if (s->channel) {
1453 ga_channel_free(s->channel);
1455 g_free(s->pstate_filepath);
1456 g_free(s->state_filepath_isfrozen);
1458 if (config->daemonize) {
1459 unlink(config->pid_filepath);
1462 config_free(config);
1463 if (s->main_loop) {
1464 g_main_loop_unref(s->main_loop);
1466 g_free(s);
1468 return ret;