monitor: Fix tracepoint crash on JSON syntax error
[qemu/armbru.git] / qga / main.c
blob537cc0e162f563d63adbea888216a42e83914e6b
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 "guest-agent-core.h"
27 #include "qemu/module.h"
28 #include "qga-qapi-commands.h"
29 #include "qapi/qmp/qerror.h"
30 #include "qapi/error.h"
31 #include "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_FULL_VERSION "\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, QDict *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(QOBJECT(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 qobject_unref(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 qobject_unref(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 QDict *rsp;
585 int ret;
587 g_assert(req);
588 g_debug("processing command");
589 rsp = qmp_dispatch(&ga_commands, QOBJECT(req), false);
590 if (rsp) {
591 ret = send_response(s, rsp);
592 if (ret < 0) {
593 g_warning("error sending response: %s", strerror(-ret));
595 qobject_unref(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 qobject_unref(qdict);
613 if (!err) {
614 g_warning("failed to parse event: unknown error");
615 error_setg(&err, QERR_JSON_PARSING);
616 } else {
617 g_warning("failed to parse event: %s", error_get_pretty(err));
619 qdict = qmp_error_response(err);
622 /* handle host->guest commands */
623 if (qdict_haskey(qdict, "execute")) {
624 process_command(s, qdict);
625 } else {
626 if (!qdict_haskey(qdict, "error")) {
627 qobject_unref(qdict);
628 g_warning("unrecognized payload format");
629 error_setg(&err, QERR_UNSUPPORTED);
630 qdict = qmp_error_response(err);
632 ret = send_response(s, qdict);
633 if (ret < 0) {
634 g_warning("error sending error response: %s", strerror(-ret));
638 qobject_unref(qdict);
641 /* false return signals GAChannel to close the current client connection */
642 static gboolean channel_event_cb(GIOCondition condition, gpointer data)
644 GAState *s = data;
645 gchar buf[QGA_READ_COUNT_DEFAULT+1];
646 gsize count;
647 GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
648 switch (status) {
649 case G_IO_STATUS_ERROR:
650 g_warning("error reading channel");
651 return false;
652 case G_IO_STATUS_NORMAL:
653 buf[count] = 0;
654 g_debug("read data, count: %d, data: %s", (int)count, buf);
655 json_message_parser_feed(&s->parser, (char *)buf, (int)count);
656 break;
657 case G_IO_STATUS_EOF:
658 g_debug("received EOF");
659 if (!s->virtio) {
660 return false;
662 /* fall through */
663 case G_IO_STATUS_AGAIN:
664 /* virtio causes us to spin here when no process is attached to
665 * host-side chardev. sleep a bit to mitigate this
667 if (s->virtio) {
668 usleep(100*1000);
670 return true;
671 default:
672 g_warning("unknown channel read status, closing");
673 return false;
675 return true;
678 static gboolean channel_init(GAState *s, const gchar *method, const gchar *path,
679 int listen_fd)
681 GAChannelMethod channel_method;
683 if (strcmp(method, "virtio-serial") == 0) {
684 s->virtio = true; /* virtio requires special handling in some cases */
685 channel_method = GA_CHANNEL_VIRTIO_SERIAL;
686 } else if (strcmp(method, "isa-serial") == 0) {
687 channel_method = GA_CHANNEL_ISA_SERIAL;
688 } else if (strcmp(method, "unix-listen") == 0) {
689 channel_method = GA_CHANNEL_UNIX_LISTEN;
690 } else if (strcmp(method, "vsock-listen") == 0) {
691 channel_method = GA_CHANNEL_VSOCK_LISTEN;
692 } else {
693 g_critical("unsupported channel method/type: %s", method);
694 return false;
697 s->channel = ga_channel_new(channel_method, path, listen_fd,
698 channel_event_cb, s);
699 if (!s->channel) {
700 g_critical("failed to create guest agent channel");
701 return false;
704 return true;
707 #ifdef _WIN32
708 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
709 LPVOID ctx)
711 DWORD ret = NO_ERROR;
712 GAService *service = &ga_state->service;
714 switch (ctrl)
716 case SERVICE_CONTROL_STOP:
717 case SERVICE_CONTROL_SHUTDOWN:
718 quit_handler(SIGTERM);
719 service->status.dwCurrentState = SERVICE_STOP_PENDING;
720 SetServiceStatus(service->status_handle, &service->status);
721 break;
723 default:
724 ret = ERROR_CALL_NOT_IMPLEMENTED;
726 return ret;
729 VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
731 GAService *service = &ga_state->service;
733 service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME,
734 service_ctrl_handler, NULL);
736 if (service->status_handle == 0) {
737 g_critical("Failed to register extended requests function!\n");
738 return;
741 service->status.dwServiceType = SERVICE_WIN32;
742 service->status.dwCurrentState = SERVICE_RUNNING;
743 service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
744 service->status.dwWin32ExitCode = NO_ERROR;
745 service->status.dwServiceSpecificExitCode = NO_ERROR;
746 service->status.dwCheckPoint = 0;
747 service->status.dwWaitHint = 0;
748 SetServiceStatus(service->status_handle, &service->status);
750 g_main_loop_run(ga_state->main_loop);
752 service->status.dwCurrentState = SERVICE_STOPPED;
753 SetServiceStatus(service->status_handle, &service->status);
755 #endif
757 static void set_persistent_state_defaults(GAPersistentState *pstate)
759 g_assert(pstate);
760 pstate->fd_counter = QGA_PSTATE_DEFAULT_FD_COUNTER;
763 static void persistent_state_from_keyfile(GAPersistentState *pstate,
764 GKeyFile *keyfile)
766 g_assert(pstate);
767 g_assert(keyfile);
768 /* if any fields are missing, either because the file was tampered with
769 * by agents of chaos, or because the field wasn't present at the time the
770 * file was created, the best we can ever do is start over with the default
771 * values. so load them now, and ignore any errors in accessing key-value
772 * pairs
774 set_persistent_state_defaults(pstate);
776 if (g_key_file_has_key(keyfile, "global", "fd_counter", NULL)) {
777 pstate->fd_counter =
778 g_key_file_get_integer(keyfile, "global", "fd_counter", NULL);
782 static void persistent_state_to_keyfile(const GAPersistentState *pstate,
783 GKeyFile *keyfile)
785 g_assert(pstate);
786 g_assert(keyfile);
788 g_key_file_set_integer(keyfile, "global", "fd_counter", pstate->fd_counter);
791 static gboolean write_persistent_state(const GAPersistentState *pstate,
792 const gchar *path)
794 GKeyFile *keyfile = g_key_file_new();
795 GError *gerr = NULL;
796 gboolean ret = true;
797 gchar *data = NULL;
798 gsize data_len;
800 g_assert(pstate);
802 persistent_state_to_keyfile(pstate, keyfile);
803 data = g_key_file_to_data(keyfile, &data_len, &gerr);
804 if (gerr) {
805 g_critical("failed to convert persistent state to string: %s",
806 gerr->message);
807 ret = false;
808 goto out;
811 g_file_set_contents(path, data, data_len, &gerr);
812 if (gerr) {
813 g_critical("failed to write persistent state to %s: %s",
814 path, gerr->message);
815 ret = false;
816 goto out;
819 out:
820 if (gerr) {
821 g_error_free(gerr);
823 if (keyfile) {
824 g_key_file_free(keyfile);
826 g_free(data);
827 return ret;
830 static gboolean read_persistent_state(GAPersistentState *pstate,
831 const gchar *path, gboolean frozen)
833 GKeyFile *keyfile = NULL;
834 GError *gerr = NULL;
835 struct stat st;
836 gboolean ret = true;
838 g_assert(pstate);
840 if (stat(path, &st) == -1) {
841 /* it's okay if state file doesn't exist, but any other error
842 * indicates a permissions issue or some other misconfiguration
843 * that we likely won't be able to recover from.
845 if (errno != ENOENT) {
846 g_critical("unable to access state file at path %s: %s",
847 path, strerror(errno));
848 ret = false;
849 goto out;
852 /* file doesn't exist. initialize state to default values and
853 * attempt to save now. (we could wait till later when we have
854 * modified state we need to commit, but if there's a problem,
855 * such as a missing parent directory, we want to catch it now)
857 * there is a potential scenario where someone either managed to
858 * update the agent from a version that didn't use a key store
859 * while qemu-ga thought the filesystem was frozen, or
860 * deleted the key store prior to issuing a fsfreeze, prior
861 * to restarting the agent. in this case we go ahead and defer
862 * initial creation till we actually have modified state to
863 * write, otherwise fail to recover from freeze.
865 set_persistent_state_defaults(pstate);
866 if (!frozen) {
867 ret = write_persistent_state(pstate, path);
868 if (!ret) {
869 g_critical("unable to create state file at path %s", path);
870 ret = false;
871 goto out;
874 ret = true;
875 goto out;
878 keyfile = g_key_file_new();
879 g_key_file_load_from_file(keyfile, path, 0, &gerr);
880 if (gerr) {
881 g_critical("error loading persistent state from path: %s, %s",
882 path, gerr->message);
883 ret = false;
884 goto out;
887 persistent_state_from_keyfile(pstate, keyfile);
889 out:
890 if (keyfile) {
891 g_key_file_free(keyfile);
893 if (gerr) {
894 g_error_free(gerr);
897 return ret;
900 int64_t ga_get_fd_handle(GAState *s, Error **errp)
902 int64_t handle;
904 g_assert(s->pstate_filepath);
905 /* we blacklist commands and avoid operations that potentially require
906 * writing to disk when we're in a frozen state. this includes opening
907 * new files, so we should never get here in that situation
909 g_assert(!ga_is_frozen(s));
911 handle = s->pstate.fd_counter++;
913 /* This should never happen on a reasonable timeframe, as guest-file-open
914 * would have to be issued 2^63 times */
915 if (s->pstate.fd_counter == INT64_MAX) {
916 abort();
919 if (!write_persistent_state(&s->pstate, s->pstate_filepath)) {
920 error_setg(errp, "failed to commit persistent state to disk");
921 return -1;
924 return handle;
927 static void ga_print_cmd(QmpCommand *cmd, void *opaque)
929 printf("%s\n", qmp_command_name(cmd));
932 static GList *split_list(const gchar *str, const gchar *delim)
934 GList *list = NULL;
935 int i;
936 gchar **strv;
938 strv = g_strsplit(str, delim, -1);
939 for (i = 0; strv[i]; i++) {
940 list = g_list_prepend(list, strv[i]);
942 g_free(strv);
944 return list;
947 typedef struct GAConfig {
948 char *channel_path;
949 char *method;
950 char *log_filepath;
951 char *pid_filepath;
952 #ifdef CONFIG_FSFREEZE
953 char *fsfreeze_hook;
954 #endif
955 char *state_dir;
956 #ifdef _WIN32
957 const char *service;
958 #endif
959 gchar *bliststr; /* blacklist may point to this string */
960 GList *blacklist;
961 int daemonize;
962 GLogLevelFlags log_level;
963 int dumpconf;
964 } GAConfig;
966 static void config_load(GAConfig *config)
968 GError *gerr = NULL;
969 GKeyFile *keyfile;
970 const char *conf = g_getenv("QGA_CONF") ?: QGA_CONF_DEFAULT;
972 /* read system config */
973 keyfile = g_key_file_new();
974 if (!g_key_file_load_from_file(keyfile, conf, 0, &gerr)) {
975 goto end;
977 if (g_key_file_has_key(keyfile, "general", "daemon", NULL)) {
978 config->daemonize =
979 g_key_file_get_boolean(keyfile, "general", "daemon", &gerr);
981 if (g_key_file_has_key(keyfile, "general", "method", NULL)) {
982 config->method =
983 g_key_file_get_string(keyfile, "general", "method", &gerr);
985 if (g_key_file_has_key(keyfile, "general", "path", NULL)) {
986 config->channel_path =
987 g_key_file_get_string(keyfile, "general", "path", &gerr);
989 if (g_key_file_has_key(keyfile, "general", "logfile", NULL)) {
990 config->log_filepath =
991 g_key_file_get_string(keyfile, "general", "logfile", &gerr);
993 if (g_key_file_has_key(keyfile, "general", "pidfile", NULL)) {
994 config->pid_filepath =
995 g_key_file_get_string(keyfile, "general", "pidfile", &gerr);
997 #ifdef CONFIG_FSFREEZE
998 if (g_key_file_has_key(keyfile, "general", "fsfreeze-hook", NULL)) {
999 config->fsfreeze_hook =
1000 g_key_file_get_string(keyfile,
1001 "general", "fsfreeze-hook", &gerr);
1003 #endif
1004 if (g_key_file_has_key(keyfile, "general", "statedir", NULL)) {
1005 config->state_dir =
1006 g_key_file_get_string(keyfile, "general", "statedir", &gerr);
1008 if (g_key_file_has_key(keyfile, "general", "verbose", NULL) &&
1009 g_key_file_get_boolean(keyfile, "general", "verbose", &gerr)) {
1010 /* enable all log levels */
1011 config->log_level = G_LOG_LEVEL_MASK;
1013 if (g_key_file_has_key(keyfile, "general", "blacklist", NULL)) {
1014 config->bliststr =
1015 g_key_file_get_string(keyfile, "general", "blacklist", &gerr);
1016 config->blacklist = g_list_concat(config->blacklist,
1017 split_list(config->bliststr, ","));
1020 end:
1021 g_key_file_free(keyfile);
1022 if (gerr &&
1023 !(gerr->domain == G_FILE_ERROR && gerr->code == G_FILE_ERROR_NOENT)) {
1024 g_critical("error loading configuration from path: %s, %s",
1025 QGA_CONF_DEFAULT, gerr->message);
1026 exit(EXIT_FAILURE);
1028 g_clear_error(&gerr);
1031 static gchar *list_join(GList *list, const gchar separator)
1033 GString *str = g_string_new("");
1035 while (list) {
1036 str = g_string_append(str, (gchar *)list->data);
1037 list = g_list_next(list);
1038 if (list) {
1039 str = g_string_append_c(str, separator);
1043 return g_string_free(str, FALSE);
1046 static void config_dump(GAConfig *config)
1048 GError *error = NULL;
1049 GKeyFile *keyfile;
1050 gchar *tmp;
1052 keyfile = g_key_file_new();
1053 g_assert(keyfile);
1055 g_key_file_set_boolean(keyfile, "general", "daemon", config->daemonize);
1056 g_key_file_set_string(keyfile, "general", "method", config->method);
1057 if (config->channel_path) {
1058 g_key_file_set_string(keyfile, "general", "path", config->channel_path);
1060 if (config->log_filepath) {
1061 g_key_file_set_string(keyfile, "general", "logfile",
1062 config->log_filepath);
1064 g_key_file_set_string(keyfile, "general", "pidfile", config->pid_filepath);
1065 #ifdef CONFIG_FSFREEZE
1066 if (config->fsfreeze_hook) {
1067 g_key_file_set_string(keyfile, "general", "fsfreeze-hook",
1068 config->fsfreeze_hook);
1070 #endif
1071 g_key_file_set_string(keyfile, "general", "statedir", config->state_dir);
1072 g_key_file_set_boolean(keyfile, "general", "verbose",
1073 config->log_level == G_LOG_LEVEL_MASK);
1074 tmp = list_join(config->blacklist, ',');
1075 g_key_file_set_string(keyfile, "general", "blacklist", tmp);
1076 g_free(tmp);
1078 tmp = g_key_file_to_data(keyfile, NULL, &error);
1079 if (error) {
1080 g_critical("Failed to dump keyfile: %s", error->message);
1081 g_clear_error(&error);
1082 } else {
1083 printf("%s", tmp);
1086 g_free(tmp);
1087 g_key_file_free(keyfile);
1090 static void config_parse(GAConfig *config, int argc, char **argv)
1092 const char *sopt = "hVvdm:p:l:f:F::b:s:t:D";
1093 int opt_ind = 0, ch;
1094 const struct option lopt[] = {
1095 { "help", 0, NULL, 'h' },
1096 { "version", 0, NULL, 'V' },
1097 { "dump-conf", 0, NULL, 'D' },
1098 { "logfile", 1, NULL, 'l' },
1099 { "pidfile", 1, NULL, 'f' },
1100 #ifdef CONFIG_FSFREEZE
1101 { "fsfreeze-hook", 2, NULL, 'F' },
1102 #endif
1103 { "verbose", 0, NULL, 'v' },
1104 { "method", 1, NULL, 'm' },
1105 { "path", 1, NULL, 'p' },
1106 { "daemonize", 0, NULL, 'd' },
1107 { "blacklist", 1, NULL, 'b' },
1108 #ifdef _WIN32
1109 { "service", 1, NULL, 's' },
1110 #endif
1111 { "statedir", 1, NULL, 't' },
1112 { NULL, 0, NULL, 0 }
1115 while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
1116 switch (ch) {
1117 case 'm':
1118 g_free(config->method);
1119 config->method = g_strdup(optarg);
1120 break;
1121 case 'p':
1122 g_free(config->channel_path);
1123 config->channel_path = g_strdup(optarg);
1124 break;
1125 case 'l':
1126 g_free(config->log_filepath);
1127 config->log_filepath = g_strdup(optarg);
1128 break;
1129 case 'f':
1130 g_free(config->pid_filepath);
1131 config->pid_filepath = g_strdup(optarg);
1132 break;
1133 #ifdef CONFIG_FSFREEZE
1134 case 'F':
1135 g_free(config->fsfreeze_hook);
1136 config->fsfreeze_hook = g_strdup(optarg ?: QGA_FSFREEZE_HOOK_DEFAULT);
1137 break;
1138 #endif
1139 case 't':
1140 g_free(config->state_dir);
1141 config->state_dir = g_strdup(optarg);
1142 break;
1143 case 'v':
1144 /* enable all log levels */
1145 config->log_level = G_LOG_LEVEL_MASK;
1146 break;
1147 case 'V':
1148 printf("QEMU Guest Agent %s\n", QEMU_VERSION);
1149 exit(EXIT_SUCCESS);
1150 case 'd':
1151 config->daemonize = 1;
1152 break;
1153 case 'D':
1154 config->dumpconf = 1;
1155 break;
1156 case 'b': {
1157 if (is_help_option(optarg)) {
1158 qmp_for_each_command(&ga_commands, ga_print_cmd, NULL);
1159 exit(EXIT_SUCCESS);
1161 config->blacklist = g_list_concat(config->blacklist,
1162 split_list(optarg, ","));
1163 break;
1165 #ifdef _WIN32
1166 case 's':
1167 config->service = optarg;
1168 if (strcmp(config->service, "install") == 0) {
1169 if (ga_install_vss_provider()) {
1170 exit(EXIT_FAILURE);
1172 if (ga_install_service(config->channel_path,
1173 config->log_filepath, config->state_dir)) {
1174 exit(EXIT_FAILURE);
1176 exit(EXIT_SUCCESS);
1177 } else if (strcmp(config->service, "uninstall") == 0) {
1178 ga_uninstall_vss_provider();
1179 exit(ga_uninstall_service());
1180 } else if (strcmp(config->service, "vss-install") == 0) {
1181 if (ga_install_vss_provider()) {
1182 exit(EXIT_FAILURE);
1184 exit(EXIT_SUCCESS);
1185 } else if (strcmp(config->service, "vss-uninstall") == 0) {
1186 ga_uninstall_vss_provider();
1187 exit(EXIT_SUCCESS);
1188 } else {
1189 printf("Unknown service command.\n");
1190 exit(EXIT_FAILURE);
1192 break;
1193 #endif
1194 case 'h':
1195 usage(argv[0]);
1196 exit(EXIT_SUCCESS);
1197 case '?':
1198 g_print("Unknown option, try '%s --help' for more information.\n",
1199 argv[0]);
1200 exit(EXIT_FAILURE);
1205 static void config_free(GAConfig *config)
1207 g_free(config->method);
1208 g_free(config->log_filepath);
1209 g_free(config->pid_filepath);
1210 g_free(config->state_dir);
1211 g_free(config->channel_path);
1212 g_free(config->bliststr);
1213 #ifdef CONFIG_FSFREEZE
1214 g_free(config->fsfreeze_hook);
1215 #endif
1216 g_list_free_full(config->blacklist, g_free);
1217 g_free(config);
1220 static bool check_is_frozen(GAState *s)
1222 #ifndef _WIN32
1223 /* check if a previous instance of qemu-ga exited with filesystems' state
1224 * marked as frozen. this could be a stale value (a non-qemu-ga process
1225 * or reboot may have since unfrozen them), but better to require an
1226 * uneeded unfreeze than to risk hanging on start-up
1228 struct stat st;
1229 if (stat(s->state_filepath_isfrozen, &st) == -1) {
1230 /* it's okay if the file doesn't exist, but if we can't access for
1231 * some other reason, such as permissions, there's a configuration
1232 * that needs to be addressed. so just bail now before we get into
1233 * more trouble later
1235 if (errno != ENOENT) {
1236 g_critical("unable to access state file at path %s: %s",
1237 s->state_filepath_isfrozen, strerror(errno));
1238 return EXIT_FAILURE;
1240 } else {
1241 g_warning("previous instance appears to have exited with frozen"
1242 " filesystems. deferring logging/pidfile creation and"
1243 " disabling non-fsfreeze-safe commands until"
1244 " guest-fsfreeze-thaw is issued, or filesystems are"
1245 " manually unfrozen and the file %s is removed",
1246 s->state_filepath_isfrozen);
1247 return true;
1249 #endif
1250 return false;
1253 static int run_agent(GAState *s, GAConfig *config, int socket_activation)
1255 ga_state = s;
1257 g_log_set_default_handler(ga_log, s);
1258 g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
1259 ga_enable_logging(s);
1261 #ifdef _WIN32
1262 /* On win32 the state directory is application specific (be it the default
1263 * or a user override). We got past the command line parsing; let's create
1264 * the directory (with any intermediate directories). If we run into an
1265 * error later on, we won't try to clean up the directory, it is considered
1266 * persistent.
1268 if (g_mkdir_with_parents(config->state_dir, S_IRWXU) == -1) {
1269 g_critical("unable to create (an ancestor of) the state directory"
1270 " '%s': %s", config->state_dir, strerror(errno));
1271 return EXIT_FAILURE;
1273 #endif
1275 if (ga_is_frozen(s)) {
1276 if (config->daemonize) {
1277 /* delay opening/locking of pidfile till filesystems are unfrozen */
1278 s->deferred_options.pid_filepath = config->pid_filepath;
1279 become_daemon(NULL);
1281 if (config->log_filepath) {
1282 /* delay opening the log file till filesystems are unfrozen */
1283 s->deferred_options.log_filepath = config->log_filepath;
1285 ga_disable_logging(s);
1286 qmp_for_each_command(&ga_commands, ga_disable_non_whitelisted, NULL);
1287 } else {
1288 if (config->daemonize) {
1289 become_daemon(config->pid_filepath);
1291 if (config->log_filepath) {
1292 FILE *log_file = ga_open_logfile(config->log_filepath);
1293 if (!log_file) {
1294 g_critical("unable to open specified log file: %s",
1295 strerror(errno));
1296 return EXIT_FAILURE;
1298 s->log_file = log_file;
1302 /* load persistent state from disk */
1303 if (!read_persistent_state(&s->pstate,
1304 s->pstate_filepath,
1305 ga_is_frozen(s))) {
1306 g_critical("failed to load persistent state");
1307 return EXIT_FAILURE;
1310 config->blacklist = ga_command_blacklist_init(config->blacklist);
1311 if (config->blacklist) {
1312 GList *l = config->blacklist;
1313 s->blacklist = config->blacklist;
1314 do {
1315 g_debug("disabling command: %s", (char *)l->data);
1316 qmp_disable_command(&ga_commands, l->data);
1317 l = g_list_next(l);
1318 } while (l);
1320 s->command_state = ga_command_state_new();
1321 ga_command_state_init(s, s->command_state);
1322 ga_command_state_init_all(s->command_state);
1323 json_message_parser_init(&s->parser, process_event);
1325 #ifndef _WIN32
1326 if (!register_signal_handlers()) {
1327 g_critical("failed to register signal handlers");
1328 return EXIT_FAILURE;
1330 #endif
1332 s->main_loop = g_main_loop_new(NULL, false);
1334 if (!channel_init(ga_state, config->method, config->channel_path,
1335 socket_activation ? FIRST_SOCKET_ACTIVATION_FD : -1)) {
1336 g_critical("failed to initialize guest agent channel");
1337 return EXIT_FAILURE;
1339 #ifndef _WIN32
1340 g_main_loop_run(ga_state->main_loop);
1341 #else
1342 if (config->daemonize) {
1343 SERVICE_TABLE_ENTRY service_table[] = {
1344 { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
1345 StartServiceCtrlDispatcher(service_table);
1346 } else {
1347 g_main_loop_run(ga_state->main_loop);
1349 #endif
1351 return EXIT_SUCCESS;
1354 int main(int argc, char **argv)
1356 int ret = EXIT_SUCCESS;
1357 GAState *s = g_new0(GAState, 1);
1358 GAConfig *config = g_new0(GAConfig, 1);
1359 int socket_activation;
1361 config->log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
1363 qga_qmp_init_marshal(&ga_commands);
1365 init_dfl_pathnames();
1366 config_load(config);
1367 config_parse(config, argc, argv);
1369 if (config->pid_filepath == NULL) {
1370 config->pid_filepath = g_strdup(dfl_pathnames.pidfile);
1373 if (config->state_dir == NULL) {
1374 config->state_dir = g_strdup(dfl_pathnames.state_dir);
1377 if (config->method == NULL) {
1378 config->method = g_strdup("virtio-serial");
1381 socket_activation = check_socket_activation();
1382 if (socket_activation > 1) {
1383 g_critical("qemu-ga only supports listening on one socket");
1384 ret = EXIT_FAILURE;
1385 goto end;
1387 if (socket_activation) {
1388 SocketAddress *addr;
1390 g_free(config->method);
1391 g_free(config->channel_path);
1392 config->method = NULL;
1393 config->channel_path = NULL;
1395 addr = socket_local_address(FIRST_SOCKET_ACTIVATION_FD, NULL);
1396 if (addr) {
1397 if (addr->type == SOCKET_ADDRESS_TYPE_UNIX) {
1398 config->method = g_strdup("unix-listen");
1399 } else if (addr->type == SOCKET_ADDRESS_TYPE_VSOCK) {
1400 config->method = g_strdup("vsock-listen");
1403 qapi_free_SocketAddress(addr);
1406 if (!config->method) {
1407 g_critical("unsupported listen fd type");
1408 ret = EXIT_FAILURE;
1409 goto end;
1411 } else if (config->channel_path == NULL) {
1412 if (strcmp(config->method, "virtio-serial") == 0) {
1413 /* try the default path for the virtio-serial port */
1414 config->channel_path = g_strdup(QGA_VIRTIO_PATH_DEFAULT);
1415 } else if (strcmp(config->method, "isa-serial") == 0) {
1416 /* try the default path for the serial port - COM1 */
1417 config->channel_path = g_strdup(QGA_SERIAL_PATH_DEFAULT);
1418 } else {
1419 g_critical("must specify a path for this channel");
1420 ret = EXIT_FAILURE;
1421 goto end;
1425 s->log_level = config->log_level;
1426 s->log_file = stderr;
1427 #ifdef CONFIG_FSFREEZE
1428 s->fsfreeze_hook = config->fsfreeze_hook;
1429 #endif
1430 s->pstate_filepath = g_strdup_printf("%s/qga.state", config->state_dir);
1431 s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen",
1432 config->state_dir);
1433 s->frozen = check_is_frozen(s);
1435 if (config->dumpconf) {
1436 config_dump(config);
1437 goto end;
1440 ret = run_agent(s, config, socket_activation);
1442 end:
1443 if (s->command_state) {
1444 ga_command_state_cleanup_all(s->command_state);
1445 ga_command_state_free(s->command_state);
1446 json_message_parser_destroy(&s->parser);
1448 if (s->channel) {
1449 ga_channel_free(s->channel);
1451 g_free(s->pstate_filepath);
1452 g_free(s->state_filepath_isfrozen);
1454 if (config->daemonize) {
1455 unlink(config->pid_filepath);
1458 config_free(config);
1459 if (s->main_loop) {
1460 g_main_loop_unref(s->main_loop);
1462 g_free(s);
1464 return ret;