sheepdog: reorganize coroutine flow
[qemu/ar7.git] / qga / main.c
blob538e4ee299715bf2d0d204cca1e68fb79e74fa39
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.
13 #include "qemu/osdep.h"
14 #include <getopt.h>
15 #include <glib/gstdio.h>
16 #ifndef _WIN32
17 #include <syslog.h>
18 #include <sys/wait.h>
19 #endif
20 #include "qapi/qmp/json-streamer.h"
21 #include "qapi/qmp/json-parser.h"
22 #include "qapi/qmp/qint.h"
23 #include "qapi/qmp/qjson.h"
24 #include "qga/guest-agent-core.h"
25 #include "qemu/module.h"
26 #include "qapi/qmp/qerror.h"
27 #include "qapi/qmp/dispatch.h"
28 #include "qga/channel.h"
29 #include "qemu/bswap.h"
30 #include "qemu/help_option.h"
31 #ifdef _WIN32
32 #include "qga/service-win32.h"
33 #include "qga/vss-win32.h"
34 #endif
35 #ifdef __linux__
36 #include <linux/fs.h>
37 #ifdef FIFREEZE
38 #define CONFIG_FSFREEZE
39 #endif
40 #endif
42 #ifndef _WIN32
43 #define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0"
44 #define QGA_STATE_RELATIVE_DIR "run"
45 #define QGA_SERIAL_PATH_DEFAULT "/dev/ttyS0"
46 #else
47 #define QGA_VIRTIO_PATH_DEFAULT "\\\\.\\Global\\org.qemu.guest_agent.0"
48 #define QGA_STATE_RELATIVE_DIR "qemu-ga"
49 #define QGA_SERIAL_PATH_DEFAULT "COM1"
50 #endif
51 #ifdef CONFIG_FSFREEZE
52 #define QGA_FSFREEZE_HOOK_DEFAULT CONFIG_QEMU_CONFDIR "/fsfreeze-hook"
53 #endif
54 #define QGA_SENTINEL_BYTE 0xFF
55 #define QGA_CONF_DEFAULT CONFIG_QEMU_CONFDIR G_DIR_SEPARATOR_S "qemu-ga.conf"
57 static struct {
58 const char *state_dir;
59 const char *pidfile;
60 } dfl_pathnames;
62 typedef struct GAPersistentState {
63 #define QGA_PSTATE_DEFAULT_FD_COUNTER 1000
64 int64_t fd_counter;
65 } GAPersistentState;
67 struct GAState {
68 JSONMessageParser parser;
69 GMainLoop *main_loop;
70 GAChannel *channel;
71 bool virtio; /* fastpath to check for virtio to deal with poll() quirks */
72 GACommandState *command_state;
73 GLogLevelFlags log_level;
74 FILE *log_file;
75 bool logging_enabled;
76 #ifdef _WIN32
77 GAService service;
78 #endif
79 bool delimit_response;
80 bool frozen;
81 GList *blacklist;
82 char *state_filepath_isfrozen;
83 struct {
84 const char *log_filepath;
85 const char *pid_filepath;
86 } deferred_options;
87 #ifdef CONFIG_FSFREEZE
88 const char *fsfreeze_hook;
89 #endif
90 gchar *pstate_filepath;
91 GAPersistentState pstate;
94 struct GAState *ga_state;
96 /* commands that are safe to issue while filesystems are frozen */
97 static const char *ga_freeze_whitelist[] = {
98 "guest-ping",
99 "guest-info",
100 "guest-sync",
101 "guest-sync-delimited",
102 "guest-fsfreeze-status",
103 "guest-fsfreeze-thaw",
104 NULL
107 #ifdef _WIN32
108 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
109 LPVOID ctx);
110 VOID WINAPI service_main(DWORD argc, TCHAR *argv[]);
111 #endif
113 static void
114 init_dfl_pathnames(void)
116 g_assert(dfl_pathnames.state_dir == NULL);
117 g_assert(dfl_pathnames.pidfile == NULL);
118 dfl_pathnames.state_dir = qemu_get_local_state_pathname(
119 QGA_STATE_RELATIVE_DIR);
120 dfl_pathnames.pidfile = qemu_get_local_state_pathname(
121 QGA_STATE_RELATIVE_DIR G_DIR_SEPARATOR_S "qemu-ga.pid");
124 static void quit_handler(int sig)
126 /* if we're frozen, don't exit unless we're absolutely forced to,
127 * because it's basically impossible for graceful exit to complete
128 * unless all log/pid files are on unfreezable filesystems. there's
129 * also a very likely chance killing the agent before unfreezing
130 * the filesystems is a mistake (or will be viewed as one later).
132 if (ga_is_frozen(ga_state)) {
133 return;
135 g_debug("received signal num %d, quitting", sig);
137 if (g_main_loop_is_running(ga_state->main_loop)) {
138 g_main_loop_quit(ga_state->main_loop);
142 #ifndef _WIN32
143 static gboolean register_signal_handlers(void)
145 struct sigaction sigact;
146 int ret;
148 memset(&sigact, 0, sizeof(struct sigaction));
149 sigact.sa_handler = quit_handler;
151 ret = sigaction(SIGINT, &sigact, NULL);
152 if (ret == -1) {
153 g_error("error configuring signal handler: %s", strerror(errno));
155 ret = sigaction(SIGTERM, &sigact, NULL);
156 if (ret == -1) {
157 g_error("error configuring signal handler: %s", strerror(errno));
160 sigact.sa_handler = SIG_IGN;
161 if (sigaction(SIGPIPE, &sigact, NULL) != 0) {
162 g_error("error configuring SIGPIPE signal handler: %s",
163 strerror(errno));
166 return true;
169 /* TODO: use this in place of all post-fork() fclose(std*) callers */
170 void reopen_fd_to_null(int fd)
172 int nullfd;
174 nullfd = open("/dev/null", O_RDWR);
175 if (nullfd < 0) {
176 return;
179 dup2(nullfd, fd);
181 if (nullfd != fd) {
182 close(nullfd);
185 #endif
187 static void usage(const char *cmd)
189 printf(
190 "Usage: %s [-m <method> -p <path>] [<options>]\n"
191 "QEMU Guest Agent %s\n"
192 "\n"
193 " -m, --method transport method: one of unix-listen, virtio-serial,\n"
194 " isa-serial, or vsock-listen (virtio-serial is the default)\n"
195 " -p, --path device/socket path (the default for virtio-serial is:\n"
196 " %s,\n"
197 " the default for isa-serial is:\n"
198 " %s)\n"
199 " -l, --logfile set logfile path, logs to stderr by default\n"
200 " -f, --pidfile specify pidfile (default is %s)\n"
201 #ifdef CONFIG_FSFREEZE
202 " -F, --fsfreeze-hook\n"
203 " enable fsfreeze hook. Accepts an optional argument that\n"
204 " specifies script to run on freeze/thaw. Script will be\n"
205 " called with 'freeze'/'thaw' arguments accordingly.\n"
206 " (default is %s)\n"
207 " If using -F with an argument, do not follow -F with a\n"
208 " space.\n"
209 " (for example: -F/var/run/fsfreezehook.sh)\n"
210 #endif
211 " -t, --statedir specify dir to store state information (absolute paths\n"
212 " only, default is %s)\n"
213 " -v, --verbose log extra debugging information\n"
214 " -V, --version print version information and exit\n"
215 " -d, --daemonize become a daemon\n"
216 #ifdef _WIN32
217 " -s, --service service commands: install, uninstall, vss-install, vss-uninstall\n"
218 #endif
219 " -b, --blacklist comma-separated list of RPCs to disable (no spaces, \"?\"\n"
220 " to list available RPCs)\n"
221 " -D, --dump-conf dump a qemu-ga config file based on current config\n"
222 " options / command-line parameters to stdout\n"
223 " -h, --help display this help and exit\n"
224 "\n"
225 "Report bugs to <mdroth@linux.vnet.ibm.com>\n"
226 , cmd, QEMU_VERSION, QGA_VIRTIO_PATH_DEFAULT, QGA_SERIAL_PATH_DEFAULT,
227 dfl_pathnames.pidfile,
228 #ifdef CONFIG_FSFREEZE
229 QGA_FSFREEZE_HOOK_DEFAULT,
230 #endif
231 dfl_pathnames.state_dir);
234 static const char *ga_log_level_str(GLogLevelFlags level)
236 switch (level & G_LOG_LEVEL_MASK) {
237 case G_LOG_LEVEL_ERROR:
238 return "error";
239 case G_LOG_LEVEL_CRITICAL:
240 return "critical";
241 case G_LOG_LEVEL_WARNING:
242 return "warning";
243 case G_LOG_LEVEL_MESSAGE:
244 return "message";
245 case G_LOG_LEVEL_INFO:
246 return "info";
247 case G_LOG_LEVEL_DEBUG:
248 return "debug";
249 default:
250 return "user";
254 bool ga_logging_enabled(GAState *s)
256 return s->logging_enabled;
259 void ga_disable_logging(GAState *s)
261 s->logging_enabled = false;
264 void ga_enable_logging(GAState *s)
266 s->logging_enabled = true;
269 static void ga_log(const gchar *domain, GLogLevelFlags level,
270 const gchar *msg, gpointer opaque)
272 GAState *s = opaque;
273 GTimeVal time;
274 const char *level_str = ga_log_level_str(level);
276 if (!ga_logging_enabled(s)) {
277 return;
280 level &= G_LOG_LEVEL_MASK;
281 #ifndef _WIN32
282 if (g_strcmp0(domain, "syslog") == 0) {
283 syslog(LOG_INFO, "%s: %s", level_str, msg);
284 } else if (level & s->log_level) {
285 #else
286 if (level & s->log_level) {
287 #endif
288 g_get_current_time(&time);
289 fprintf(s->log_file,
290 "%lu.%lu: %s: %s\n", time.tv_sec, time.tv_usec, level_str, msg);
291 fflush(s->log_file);
295 void ga_set_response_delimited(GAState *s)
297 s->delimit_response = true;
300 static FILE *ga_open_logfile(const char *logfile)
302 FILE *f;
304 f = fopen(logfile, "a");
305 if (!f) {
306 return NULL;
309 qemu_set_cloexec(fileno(f));
310 return f;
313 #ifndef _WIN32
314 static bool ga_open_pidfile(const char *pidfile)
316 int pidfd;
317 char pidstr[32];
319 pidfd = qemu_open(pidfile, O_CREAT|O_WRONLY, S_IRUSR|S_IWUSR);
320 if (pidfd == -1 || lockf(pidfd, F_TLOCK, 0)) {
321 g_critical("Cannot lock pid file, %s", strerror(errno));
322 if (pidfd != -1) {
323 close(pidfd);
325 return false;
328 if (ftruncate(pidfd, 0)) {
329 g_critical("Failed to truncate pid file");
330 goto fail;
332 snprintf(pidstr, sizeof(pidstr), "%d\n", getpid());
333 if (write(pidfd, pidstr, strlen(pidstr)) != strlen(pidstr)) {
334 g_critical("Failed to write pid file");
335 goto fail;
338 /* keep pidfile open & locked forever */
339 return true;
341 fail:
342 unlink(pidfile);
343 close(pidfd);
344 return false;
346 #else /* _WIN32 */
347 static bool ga_open_pidfile(const char *pidfile)
349 return true;
351 #endif
353 static gint ga_strcmp(gconstpointer str1, gconstpointer str2)
355 return strcmp(str1, str2);
358 /* disable commands that aren't safe for fsfreeze */
359 static void ga_disable_non_whitelisted(QmpCommand *cmd, void *opaque)
361 bool whitelisted = false;
362 int i = 0;
363 const char *name = qmp_command_name(cmd);
365 while (ga_freeze_whitelist[i] != NULL) {
366 if (strcmp(name, ga_freeze_whitelist[i]) == 0) {
367 whitelisted = true;
369 i++;
371 if (!whitelisted) {
372 g_debug("disabling command: %s", name);
373 qmp_disable_command(name);
377 /* [re-]enable all commands, except those explicitly blacklisted by user */
378 static void ga_enable_non_blacklisted(QmpCommand *cmd, void *opaque)
380 GList *blacklist = opaque;
381 const char *name = qmp_command_name(cmd);
383 if (g_list_find_custom(blacklist, name, ga_strcmp) == NULL &&
384 !qmp_command_is_enabled(cmd)) {
385 g_debug("enabling command: %s", name);
386 qmp_enable_command(name);
390 static bool ga_create_file(const char *path)
392 int fd = open(path, O_CREAT | O_WRONLY, S_IWUSR | S_IRUSR);
393 if (fd == -1) {
394 g_warning("unable to open/create file %s: %s", path, strerror(errno));
395 return false;
397 close(fd);
398 return true;
401 static bool ga_delete_file(const char *path)
403 int ret = unlink(path);
404 if (ret == -1) {
405 g_warning("unable to delete file: %s: %s", path, strerror(errno));
406 return false;
409 return true;
412 bool ga_is_frozen(GAState *s)
414 return s->frozen;
417 void ga_set_frozen(GAState *s)
419 if (ga_is_frozen(s)) {
420 return;
422 /* disable all non-whitelisted (for frozen state) commands */
423 qmp_for_each_command(ga_disable_non_whitelisted, NULL);
424 g_warning("disabling logging due to filesystem freeze");
425 ga_disable_logging(s);
426 s->frozen = true;
427 if (!ga_create_file(s->state_filepath_isfrozen)) {
428 g_warning("unable to create %s, fsfreeze may not function properly",
429 s->state_filepath_isfrozen);
433 void ga_unset_frozen(GAState *s)
435 if (!ga_is_frozen(s)) {
436 return;
439 /* if we delayed creation/opening of pid/log files due to being
440 * in a frozen state at start up, do it now
442 if (s->deferred_options.log_filepath) {
443 s->log_file = ga_open_logfile(s->deferred_options.log_filepath);
444 if (!s->log_file) {
445 s->log_file = stderr;
447 s->deferred_options.log_filepath = NULL;
449 ga_enable_logging(s);
450 g_warning("logging re-enabled due to filesystem unfreeze");
451 if (s->deferred_options.pid_filepath) {
452 if (!ga_open_pidfile(s->deferred_options.pid_filepath)) {
453 g_warning("failed to create/open pid file");
455 s->deferred_options.pid_filepath = NULL;
458 /* enable all disabled, non-blacklisted commands */
459 qmp_for_each_command(ga_enable_non_blacklisted, s->blacklist);
460 s->frozen = false;
461 if (!ga_delete_file(s->state_filepath_isfrozen)) {
462 g_warning("unable to delete %s, fsfreeze may not function properly",
463 s->state_filepath_isfrozen);
467 #ifdef CONFIG_FSFREEZE
468 const char *ga_fsfreeze_hook(GAState *s)
470 return s->fsfreeze_hook;
472 #endif
474 static void become_daemon(const char *pidfile)
476 #ifndef _WIN32
477 pid_t pid, sid;
479 pid = fork();
480 if (pid < 0) {
481 exit(EXIT_FAILURE);
483 if (pid > 0) {
484 exit(EXIT_SUCCESS);
487 if (pidfile) {
488 if (!ga_open_pidfile(pidfile)) {
489 g_critical("failed to create pidfile");
490 exit(EXIT_FAILURE);
494 umask(S_IRWXG | S_IRWXO);
495 sid = setsid();
496 if (sid < 0) {
497 goto fail;
499 if ((chdir("/")) < 0) {
500 goto fail;
503 reopen_fd_to_null(STDIN_FILENO);
504 reopen_fd_to_null(STDOUT_FILENO);
505 reopen_fd_to_null(STDERR_FILENO);
506 return;
508 fail:
509 if (pidfile) {
510 unlink(pidfile);
512 g_critical("failed to daemonize");
513 exit(EXIT_FAILURE);
514 #endif
517 static int send_response(GAState *s, QObject *payload)
519 const char *buf;
520 QString *payload_qstr, *response_qstr;
521 GIOStatus status;
523 g_assert(payload && s->channel);
525 payload_qstr = qobject_to_json(payload);
526 if (!payload_qstr) {
527 return -EINVAL;
530 if (s->delimit_response) {
531 s->delimit_response = false;
532 response_qstr = qstring_new();
533 qstring_append_chr(response_qstr, QGA_SENTINEL_BYTE);
534 qstring_append(response_qstr, qstring_get_str(payload_qstr));
535 QDECREF(payload_qstr);
536 } else {
537 response_qstr = payload_qstr;
540 qstring_append_chr(response_qstr, '\n');
541 buf = qstring_get_str(response_qstr);
542 status = ga_channel_write_all(s->channel, buf, strlen(buf));
543 QDECREF(response_qstr);
544 if (status != G_IO_STATUS_NORMAL) {
545 return -EIO;
548 return 0;
551 static void process_command(GAState *s, QDict *req)
553 QObject *rsp = NULL;
554 int ret;
556 g_assert(req);
557 g_debug("processing command");
558 rsp = qmp_dispatch(QOBJECT(req));
559 if (rsp) {
560 ret = send_response(s, rsp);
561 if (ret < 0) {
562 g_warning("error sending response: %s", strerror(-ret));
564 qobject_decref(rsp);
568 /* handle requests/control events coming in over the channel */
569 static void process_event(JSONMessageParser *parser, GQueue *tokens)
571 GAState *s = container_of(parser, GAState, parser);
572 QDict *qdict;
573 Error *err = NULL;
574 int ret;
576 g_assert(s && parser);
578 g_debug("process_event: called");
579 qdict = qobject_to_qdict(json_parser_parse_err(tokens, NULL, &err));
580 if (err || !qdict) {
581 QDECREF(qdict);
582 qdict = qdict_new();
583 if (!err) {
584 g_warning("failed to parse event: unknown error");
585 error_setg(&err, QERR_JSON_PARSING);
586 } else {
587 g_warning("failed to parse event: %s", error_get_pretty(err));
589 qdict_put_obj(qdict, "error", qmp_build_error_object(err));
590 error_free(err);
593 /* handle host->guest commands */
594 if (qdict_haskey(qdict, "execute")) {
595 process_command(s, qdict);
596 } else {
597 if (!qdict_haskey(qdict, "error")) {
598 QDECREF(qdict);
599 qdict = qdict_new();
600 g_warning("unrecognized payload format");
601 error_setg(&err, QERR_UNSUPPORTED);
602 qdict_put_obj(qdict, "error", qmp_build_error_object(err));
603 error_free(err);
605 ret = send_response(s, QOBJECT(qdict));
606 if (ret < 0) {
607 g_warning("error sending error response: %s", strerror(-ret));
611 QDECREF(qdict);
614 /* false return signals GAChannel to close the current client connection */
615 static gboolean channel_event_cb(GIOCondition condition, gpointer data)
617 GAState *s = data;
618 gchar buf[QGA_READ_COUNT_DEFAULT+1];
619 gsize count;
620 GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
621 switch (status) {
622 case G_IO_STATUS_ERROR:
623 g_warning("error reading channel");
624 return false;
625 case G_IO_STATUS_NORMAL:
626 buf[count] = 0;
627 g_debug("read data, count: %d, data: %s", (int)count, buf);
628 json_message_parser_feed(&s->parser, (char *)buf, (int)count);
629 break;
630 case G_IO_STATUS_EOF:
631 g_debug("received EOF");
632 if (!s->virtio) {
633 return false;
635 /* fall through */
636 case G_IO_STATUS_AGAIN:
637 /* virtio causes us to spin here when no process is attached to
638 * host-side chardev. sleep a bit to mitigate this
640 if (s->virtio) {
641 usleep(100*1000);
643 return true;
644 default:
645 g_warning("unknown channel read status, closing");
646 return false;
648 return true;
651 static gboolean channel_init(GAState *s, const gchar *method, const gchar *path)
653 GAChannelMethod channel_method;
655 if (strcmp(method, "virtio-serial") == 0) {
656 s->virtio = true; /* virtio requires special handling in some cases */
657 channel_method = GA_CHANNEL_VIRTIO_SERIAL;
658 } else if (strcmp(method, "isa-serial") == 0) {
659 channel_method = GA_CHANNEL_ISA_SERIAL;
660 } else if (strcmp(method, "unix-listen") == 0) {
661 channel_method = GA_CHANNEL_UNIX_LISTEN;
662 } else if (strcmp(method, "vsock-listen") == 0) {
663 channel_method = GA_CHANNEL_VSOCK_LISTEN;
664 } else {
665 g_critical("unsupported channel method/type: %s", method);
666 return false;
669 s->channel = ga_channel_new(channel_method, path, channel_event_cb, s);
670 if (!s->channel) {
671 g_critical("failed to create guest agent channel");
672 return false;
675 return true;
678 #ifdef _WIN32
679 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
680 LPVOID ctx)
682 DWORD ret = NO_ERROR;
683 GAService *service = &ga_state->service;
685 switch (ctrl)
687 case SERVICE_CONTROL_STOP:
688 case SERVICE_CONTROL_SHUTDOWN:
689 quit_handler(SIGTERM);
690 service->status.dwCurrentState = SERVICE_STOP_PENDING;
691 SetServiceStatus(service->status_handle, &service->status);
692 break;
694 default:
695 ret = ERROR_CALL_NOT_IMPLEMENTED;
697 return ret;
700 VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
702 GAService *service = &ga_state->service;
704 service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME,
705 service_ctrl_handler, NULL);
707 if (service->status_handle == 0) {
708 g_critical("Failed to register extended requests function!\n");
709 return;
712 service->status.dwServiceType = SERVICE_WIN32;
713 service->status.dwCurrentState = SERVICE_RUNNING;
714 service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
715 service->status.dwWin32ExitCode = NO_ERROR;
716 service->status.dwServiceSpecificExitCode = NO_ERROR;
717 service->status.dwCheckPoint = 0;
718 service->status.dwWaitHint = 0;
719 SetServiceStatus(service->status_handle, &service->status);
721 g_main_loop_run(ga_state->main_loop);
723 service->status.dwCurrentState = SERVICE_STOPPED;
724 SetServiceStatus(service->status_handle, &service->status);
726 #endif
728 static void set_persistent_state_defaults(GAPersistentState *pstate)
730 g_assert(pstate);
731 pstate->fd_counter = QGA_PSTATE_DEFAULT_FD_COUNTER;
734 static void persistent_state_from_keyfile(GAPersistentState *pstate,
735 GKeyFile *keyfile)
737 g_assert(pstate);
738 g_assert(keyfile);
739 /* if any fields are missing, either because the file was tampered with
740 * by agents of chaos, or because the field wasn't present at the time the
741 * file was created, the best we can ever do is start over with the default
742 * values. so load them now, and ignore any errors in accessing key-value
743 * pairs
745 set_persistent_state_defaults(pstate);
747 if (g_key_file_has_key(keyfile, "global", "fd_counter", NULL)) {
748 pstate->fd_counter =
749 g_key_file_get_integer(keyfile, "global", "fd_counter", NULL);
753 static void persistent_state_to_keyfile(const GAPersistentState *pstate,
754 GKeyFile *keyfile)
756 g_assert(pstate);
757 g_assert(keyfile);
759 g_key_file_set_integer(keyfile, "global", "fd_counter", pstate->fd_counter);
762 static gboolean write_persistent_state(const GAPersistentState *pstate,
763 const gchar *path)
765 GKeyFile *keyfile = g_key_file_new();
766 GError *gerr = NULL;
767 gboolean ret = true;
768 gchar *data = NULL;
769 gsize data_len;
771 g_assert(pstate);
773 persistent_state_to_keyfile(pstate, keyfile);
774 data = g_key_file_to_data(keyfile, &data_len, &gerr);
775 if (gerr) {
776 g_critical("failed to convert persistent state to string: %s",
777 gerr->message);
778 ret = false;
779 goto out;
782 g_file_set_contents(path, data, data_len, &gerr);
783 if (gerr) {
784 g_critical("failed to write persistent state to %s: %s",
785 path, gerr->message);
786 ret = false;
787 goto out;
790 out:
791 if (gerr) {
792 g_error_free(gerr);
794 if (keyfile) {
795 g_key_file_free(keyfile);
797 g_free(data);
798 return ret;
801 static gboolean read_persistent_state(GAPersistentState *pstate,
802 const gchar *path, gboolean frozen)
804 GKeyFile *keyfile = NULL;
805 GError *gerr = NULL;
806 struct stat st;
807 gboolean ret = true;
809 g_assert(pstate);
811 if (stat(path, &st) == -1) {
812 /* it's okay if state file doesn't exist, but any other error
813 * indicates a permissions issue or some other misconfiguration
814 * that we likely won't be able to recover from.
816 if (errno != ENOENT) {
817 g_critical("unable to access state file at path %s: %s",
818 path, strerror(errno));
819 ret = false;
820 goto out;
823 /* file doesn't exist. initialize state to default values and
824 * attempt to save now. (we could wait till later when we have
825 * modified state we need to commit, but if there's a problem,
826 * such as a missing parent directory, we want to catch it now)
828 * there is a potential scenario where someone either managed to
829 * update the agent from a version that didn't use a key store
830 * while qemu-ga thought the filesystem was frozen, or
831 * deleted the key store prior to issuing a fsfreeze, prior
832 * to restarting the agent. in this case we go ahead and defer
833 * initial creation till we actually have modified state to
834 * write, otherwise fail to recover from freeze.
836 set_persistent_state_defaults(pstate);
837 if (!frozen) {
838 ret = write_persistent_state(pstate, path);
839 if (!ret) {
840 g_critical("unable to create state file at path %s", path);
841 ret = false;
842 goto out;
845 ret = true;
846 goto out;
849 keyfile = g_key_file_new();
850 g_key_file_load_from_file(keyfile, path, 0, &gerr);
851 if (gerr) {
852 g_critical("error loading persistent state from path: %s, %s",
853 path, gerr->message);
854 ret = false;
855 goto out;
858 persistent_state_from_keyfile(pstate, keyfile);
860 out:
861 if (keyfile) {
862 g_key_file_free(keyfile);
864 if (gerr) {
865 g_error_free(gerr);
868 return ret;
871 int64_t ga_get_fd_handle(GAState *s, Error **errp)
873 int64_t handle;
875 g_assert(s->pstate_filepath);
876 /* we blacklist commands and avoid operations that potentially require
877 * writing to disk when we're in a frozen state. this includes opening
878 * new files, so we should never get here in that situation
880 g_assert(!ga_is_frozen(s));
882 handle = s->pstate.fd_counter++;
884 /* This should never happen on a reasonable timeframe, as guest-file-open
885 * would have to be issued 2^63 times */
886 if (s->pstate.fd_counter == INT64_MAX) {
887 abort();
890 if (!write_persistent_state(&s->pstate, s->pstate_filepath)) {
891 error_setg(errp, "failed to commit persistent state to disk");
892 return -1;
895 return handle;
898 static void ga_print_cmd(QmpCommand *cmd, void *opaque)
900 printf("%s\n", qmp_command_name(cmd));
903 static GList *split_list(const gchar *str, const gchar *delim)
905 GList *list = NULL;
906 int i;
907 gchar **strv;
909 strv = g_strsplit(str, delim, -1);
910 for (i = 0; strv[i]; i++) {
911 list = g_list_prepend(list, strv[i]);
913 g_free(strv);
915 return list;
918 typedef struct GAConfig {
919 char *channel_path;
920 char *method;
921 char *log_filepath;
922 char *pid_filepath;
923 #ifdef CONFIG_FSFREEZE
924 char *fsfreeze_hook;
925 #endif
926 char *state_dir;
927 #ifdef _WIN32
928 const char *service;
929 #endif
930 gchar *bliststr; /* blacklist may point to this string */
931 GList *blacklist;
932 int daemonize;
933 GLogLevelFlags log_level;
934 int dumpconf;
935 } GAConfig;
937 static void config_load(GAConfig *config)
939 GError *gerr = NULL;
940 GKeyFile *keyfile;
941 const char *conf = g_getenv("QGA_CONF") ?: QGA_CONF_DEFAULT;
943 /* read system config */
944 keyfile = g_key_file_new();
945 if (!g_key_file_load_from_file(keyfile, conf, 0, &gerr)) {
946 goto end;
948 if (g_key_file_has_key(keyfile, "general", "daemon", NULL)) {
949 config->daemonize =
950 g_key_file_get_boolean(keyfile, "general", "daemon", &gerr);
952 if (g_key_file_has_key(keyfile, "general", "method", NULL)) {
953 config->method =
954 g_key_file_get_string(keyfile, "general", "method", &gerr);
956 if (g_key_file_has_key(keyfile, "general", "path", NULL)) {
957 config->channel_path =
958 g_key_file_get_string(keyfile, "general", "path", &gerr);
960 if (g_key_file_has_key(keyfile, "general", "logfile", NULL)) {
961 config->log_filepath =
962 g_key_file_get_string(keyfile, "general", "logfile", &gerr);
964 if (g_key_file_has_key(keyfile, "general", "pidfile", NULL)) {
965 config->pid_filepath =
966 g_key_file_get_string(keyfile, "general", "pidfile", &gerr);
968 #ifdef CONFIG_FSFREEZE
969 if (g_key_file_has_key(keyfile, "general", "fsfreeze-hook", NULL)) {
970 config->fsfreeze_hook =
971 g_key_file_get_string(keyfile,
972 "general", "fsfreeze-hook", &gerr);
974 #endif
975 if (g_key_file_has_key(keyfile, "general", "statedir", NULL)) {
976 config->state_dir =
977 g_key_file_get_string(keyfile, "general", "statedir", &gerr);
979 if (g_key_file_has_key(keyfile, "general", "verbose", NULL) &&
980 g_key_file_get_boolean(keyfile, "general", "verbose", &gerr)) {
981 /* enable all log levels */
982 config->log_level = G_LOG_LEVEL_MASK;
984 if (g_key_file_has_key(keyfile, "general", "blacklist", NULL)) {
985 config->bliststr =
986 g_key_file_get_string(keyfile, "general", "blacklist", &gerr);
987 config->blacklist = g_list_concat(config->blacklist,
988 split_list(config->bliststr, ","));
991 end:
992 g_key_file_free(keyfile);
993 if (gerr &&
994 !(gerr->domain == G_FILE_ERROR && gerr->code == G_FILE_ERROR_NOENT)) {
995 g_critical("error loading configuration from path: %s, %s",
996 QGA_CONF_DEFAULT, gerr->message);
997 exit(EXIT_FAILURE);
999 g_clear_error(&gerr);
1002 static gchar *list_join(GList *list, const gchar separator)
1004 GString *str = g_string_new("");
1006 while (list) {
1007 str = g_string_append(str, (gchar *)list->data);
1008 list = g_list_next(list);
1009 if (list) {
1010 str = g_string_append_c(str, separator);
1014 return g_string_free(str, FALSE);
1017 static void config_dump(GAConfig *config)
1019 GError *error = NULL;
1020 GKeyFile *keyfile;
1021 gchar *tmp;
1023 keyfile = g_key_file_new();
1024 g_assert(keyfile);
1026 g_key_file_set_boolean(keyfile, "general", "daemon", config->daemonize);
1027 g_key_file_set_string(keyfile, "general", "method", config->method);
1028 g_key_file_set_string(keyfile, "general", "path", config->channel_path);
1029 if (config->log_filepath) {
1030 g_key_file_set_string(keyfile, "general", "logfile",
1031 config->log_filepath);
1033 g_key_file_set_string(keyfile, "general", "pidfile", config->pid_filepath);
1034 #ifdef CONFIG_FSFREEZE
1035 if (config->fsfreeze_hook) {
1036 g_key_file_set_string(keyfile, "general", "fsfreeze-hook",
1037 config->fsfreeze_hook);
1039 #endif
1040 g_key_file_set_string(keyfile, "general", "statedir", config->state_dir);
1041 g_key_file_set_boolean(keyfile, "general", "verbose",
1042 config->log_level == G_LOG_LEVEL_MASK);
1043 tmp = list_join(config->blacklist, ',');
1044 g_key_file_set_string(keyfile, "general", "blacklist", tmp);
1045 g_free(tmp);
1047 tmp = g_key_file_to_data(keyfile, NULL, &error);
1048 printf("%s", tmp);
1050 g_free(tmp);
1051 g_key_file_free(keyfile);
1054 static void config_parse(GAConfig *config, int argc, char **argv)
1056 const char *sopt = "hVvdm:p:l:f:F::b:s:t:D";
1057 int opt_ind = 0, ch;
1058 const struct option lopt[] = {
1059 { "help", 0, NULL, 'h' },
1060 { "version", 0, NULL, 'V' },
1061 { "dump-conf", 0, NULL, 'D' },
1062 { "logfile", 1, NULL, 'l' },
1063 { "pidfile", 1, NULL, 'f' },
1064 #ifdef CONFIG_FSFREEZE
1065 { "fsfreeze-hook", 2, NULL, 'F' },
1066 #endif
1067 { "verbose", 0, NULL, 'v' },
1068 { "method", 1, NULL, 'm' },
1069 { "path", 1, NULL, 'p' },
1070 { "daemonize", 0, NULL, 'd' },
1071 { "blacklist", 1, NULL, 'b' },
1072 #ifdef _WIN32
1073 { "service", 1, NULL, 's' },
1074 #endif
1075 { "statedir", 1, NULL, 't' },
1076 { NULL, 0, NULL, 0 }
1079 while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
1080 switch (ch) {
1081 case 'm':
1082 g_free(config->method);
1083 config->method = g_strdup(optarg);
1084 break;
1085 case 'p':
1086 g_free(config->channel_path);
1087 config->channel_path = g_strdup(optarg);
1088 break;
1089 case 'l':
1090 g_free(config->log_filepath);
1091 config->log_filepath = g_strdup(optarg);
1092 break;
1093 case 'f':
1094 g_free(config->pid_filepath);
1095 config->pid_filepath = g_strdup(optarg);
1096 break;
1097 #ifdef CONFIG_FSFREEZE
1098 case 'F':
1099 g_free(config->fsfreeze_hook);
1100 config->fsfreeze_hook = g_strdup(optarg ?: QGA_FSFREEZE_HOOK_DEFAULT);
1101 break;
1102 #endif
1103 case 't':
1104 g_free(config->state_dir);
1105 config->state_dir = g_strdup(optarg);
1106 break;
1107 case 'v':
1108 /* enable all log levels */
1109 config->log_level = G_LOG_LEVEL_MASK;
1110 break;
1111 case 'V':
1112 printf("QEMU Guest Agent %s\n", QEMU_VERSION);
1113 exit(EXIT_SUCCESS);
1114 case 'd':
1115 config->daemonize = 1;
1116 break;
1117 case 'D':
1118 config->dumpconf = 1;
1119 break;
1120 case 'b': {
1121 if (is_help_option(optarg)) {
1122 qmp_for_each_command(ga_print_cmd, NULL);
1123 exit(EXIT_SUCCESS);
1125 config->blacklist = g_list_concat(config->blacklist,
1126 split_list(optarg, ","));
1127 break;
1129 #ifdef _WIN32
1130 case 's':
1131 config->service = optarg;
1132 if (strcmp(config->service, "install") == 0) {
1133 if (ga_install_vss_provider()) {
1134 exit(EXIT_FAILURE);
1136 if (ga_install_service(config->channel_path,
1137 config->log_filepath, config->state_dir)) {
1138 exit(EXIT_FAILURE);
1140 exit(EXIT_SUCCESS);
1141 } else if (strcmp(config->service, "uninstall") == 0) {
1142 ga_uninstall_vss_provider();
1143 exit(ga_uninstall_service());
1144 } else if (strcmp(config->service, "vss-install") == 0) {
1145 if (ga_install_vss_provider()) {
1146 exit(EXIT_FAILURE);
1148 exit(EXIT_SUCCESS);
1149 } else if (strcmp(config->service, "vss-uninstall") == 0) {
1150 ga_uninstall_vss_provider();
1151 exit(EXIT_SUCCESS);
1152 } else {
1153 printf("Unknown service command.\n");
1154 exit(EXIT_FAILURE);
1156 break;
1157 #endif
1158 case 'h':
1159 usage(argv[0]);
1160 exit(EXIT_SUCCESS);
1161 case '?':
1162 g_print("Unknown option, try '%s --help' for more information.\n",
1163 argv[0]);
1164 exit(EXIT_FAILURE);
1169 static void config_free(GAConfig *config)
1171 g_free(config->method);
1172 g_free(config->log_filepath);
1173 g_free(config->pid_filepath);
1174 g_free(config->state_dir);
1175 g_free(config->channel_path);
1176 g_free(config->bliststr);
1177 #ifdef CONFIG_FSFREEZE
1178 g_free(config->fsfreeze_hook);
1179 #endif
1180 g_list_free_full(config->blacklist, g_free);
1181 g_free(config);
1184 static bool check_is_frozen(GAState *s)
1186 #ifndef _WIN32
1187 /* check if a previous instance of qemu-ga exited with filesystems' state
1188 * marked as frozen. this could be a stale value (a non-qemu-ga process
1189 * or reboot may have since unfrozen them), but better to require an
1190 * uneeded unfreeze than to risk hanging on start-up
1192 struct stat st;
1193 if (stat(s->state_filepath_isfrozen, &st) == -1) {
1194 /* it's okay if the file doesn't exist, but if we can't access for
1195 * some other reason, such as permissions, there's a configuration
1196 * that needs to be addressed. so just bail now before we get into
1197 * more trouble later
1199 if (errno != ENOENT) {
1200 g_critical("unable to access state file at path %s: %s",
1201 s->state_filepath_isfrozen, strerror(errno));
1202 return EXIT_FAILURE;
1204 } else {
1205 g_warning("previous instance appears to have exited with frozen"
1206 " filesystems. deferring logging/pidfile creation and"
1207 " disabling non-fsfreeze-safe commands until"
1208 " guest-fsfreeze-thaw is issued, or filesystems are"
1209 " manually unfrozen and the file %s is removed",
1210 s->state_filepath_isfrozen);
1211 return true;
1213 #endif
1214 return false;
1217 static int run_agent(GAState *s, GAConfig *config)
1219 ga_state = s;
1221 g_log_set_default_handler(ga_log, s);
1222 g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
1223 ga_enable_logging(s);
1225 #ifdef _WIN32
1226 /* On win32 the state directory is application specific (be it the default
1227 * or a user override). We got past the command line parsing; let's create
1228 * the directory (with any intermediate directories). If we run into an
1229 * error later on, we won't try to clean up the directory, it is considered
1230 * persistent.
1232 if (g_mkdir_with_parents(config->state_dir, S_IRWXU) == -1) {
1233 g_critical("unable to create (an ancestor of) the state directory"
1234 " '%s': %s", config->state_dir, strerror(errno));
1235 return EXIT_FAILURE;
1237 #endif
1239 if (ga_is_frozen(s)) {
1240 if (config->daemonize) {
1241 /* delay opening/locking of pidfile till filesystems are unfrozen */
1242 s->deferred_options.pid_filepath = config->pid_filepath;
1243 become_daemon(NULL);
1245 if (config->log_filepath) {
1246 /* delay opening the log file till filesystems are unfrozen */
1247 s->deferred_options.log_filepath = config->log_filepath;
1249 ga_disable_logging(s);
1250 qmp_for_each_command(ga_disable_non_whitelisted, NULL);
1251 } else {
1252 if (config->daemonize) {
1253 become_daemon(config->pid_filepath);
1255 if (config->log_filepath) {
1256 FILE *log_file = ga_open_logfile(config->log_filepath);
1257 if (!log_file) {
1258 g_critical("unable to open specified log file: %s",
1259 strerror(errno));
1260 return EXIT_FAILURE;
1262 s->log_file = log_file;
1266 /* load persistent state from disk */
1267 if (!read_persistent_state(&s->pstate,
1268 s->pstate_filepath,
1269 ga_is_frozen(s))) {
1270 g_critical("failed to load persistent state");
1271 return EXIT_FAILURE;
1274 config->blacklist = ga_command_blacklist_init(config->blacklist);
1275 if (config->blacklist) {
1276 GList *l = config->blacklist;
1277 s->blacklist = config->blacklist;
1278 do {
1279 g_debug("disabling command: %s", (char *)l->data);
1280 qmp_disable_command(l->data);
1281 l = g_list_next(l);
1282 } while (l);
1284 s->command_state = ga_command_state_new();
1285 ga_command_state_init(s, s->command_state);
1286 ga_command_state_init_all(s->command_state);
1287 json_message_parser_init(&s->parser, process_event);
1288 ga_state = s;
1289 #ifndef _WIN32
1290 if (!register_signal_handlers()) {
1291 g_critical("failed to register signal handlers");
1292 return EXIT_FAILURE;
1294 #endif
1296 s->main_loop = g_main_loop_new(NULL, false);
1297 if (!channel_init(ga_state, config->method, config->channel_path)) {
1298 g_critical("failed to initialize guest agent channel");
1299 return EXIT_FAILURE;
1301 #ifndef _WIN32
1302 g_main_loop_run(ga_state->main_loop);
1303 #else
1304 if (config->daemonize) {
1305 SERVICE_TABLE_ENTRY service_table[] = {
1306 { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
1307 StartServiceCtrlDispatcher(service_table);
1308 } else {
1309 g_main_loop_run(ga_state->main_loop);
1311 #endif
1313 return EXIT_SUCCESS;
1316 int main(int argc, char **argv)
1318 int ret = EXIT_SUCCESS;
1319 GAState *s = g_new0(GAState, 1);
1320 GAConfig *config = g_new0(GAConfig, 1);
1322 config->log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
1324 module_call_init(MODULE_INIT_QAPI);
1326 init_dfl_pathnames();
1327 config_load(config);
1328 config_parse(config, argc, argv);
1330 if (config->pid_filepath == NULL) {
1331 config->pid_filepath = g_strdup(dfl_pathnames.pidfile);
1334 if (config->state_dir == NULL) {
1335 config->state_dir = g_strdup(dfl_pathnames.state_dir);
1338 if (config->method == NULL) {
1339 config->method = g_strdup("virtio-serial");
1342 if (config->channel_path == NULL) {
1343 if (strcmp(config->method, "virtio-serial") == 0) {
1344 /* try the default path for the virtio-serial port */
1345 config->channel_path = g_strdup(QGA_VIRTIO_PATH_DEFAULT);
1346 } else if (strcmp(config->method, "isa-serial") == 0) {
1347 /* try the default path for the serial port - COM1 */
1348 config->channel_path = g_strdup(QGA_SERIAL_PATH_DEFAULT);
1349 } else {
1350 g_critical("must specify a path for this channel");
1351 ret = EXIT_FAILURE;
1352 goto end;
1356 s->log_level = config->log_level;
1357 s->log_file = stderr;
1358 #ifdef CONFIG_FSFREEZE
1359 s->fsfreeze_hook = config->fsfreeze_hook;
1360 #endif
1361 s->pstate_filepath = g_strdup_printf("%s/qga.state", config->state_dir);
1362 s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen",
1363 config->state_dir);
1364 s->frozen = check_is_frozen(s);
1366 if (config->dumpconf) {
1367 config_dump(config);
1368 goto end;
1371 ret = run_agent(s, config);
1373 end:
1374 if (s->command_state) {
1375 ga_command_state_cleanup_all(s->command_state);
1376 ga_command_state_free(s->command_state);
1377 json_message_parser_destroy(&s->parser);
1379 if (s->channel) {
1380 ga_channel_free(s->channel);
1382 g_free(s->pstate_filepath);
1383 g_free(s->state_filepath_isfrozen);
1385 if (config->daemonize) {
1386 unlink(config->pid_filepath);
1389 config_free(config);
1390 if (s->main_loop) {
1391 g_main_loop_unref(s->main_loop);
1393 g_free(s);
1395 return ret;