slirp: check len against dhcp options array end
[qemu/ar7.git] / qga / main.c
blob1b381d0bf3547a32c9295f71da135ff00daa298b
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/qjson.h"
23 #include "qga/guest-agent-core.h"
24 #include "qemu/module.h"
25 #include "qapi/qmp/qerror.h"
26 #include "qapi/qmp/dispatch.h"
27 #include "qga/channel.h"
28 #include "qemu/bswap.h"
29 #include "qemu/help_option.h"
30 #include "qemu/sockets.h"
31 #include "qemu/systemd.h"
32 #ifdef _WIN32
33 #include "qga/service-win32.h"
34 #include "qga/vss-win32.h"
35 #endif
36 #ifdef __linux__
37 #include <linux/fs.h>
38 #ifdef FIFREEZE
39 #define CONFIG_FSFREEZE
40 #endif
41 #endif
43 #ifndef _WIN32
44 #define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0"
45 #define QGA_STATE_RELATIVE_DIR "run"
46 #define QGA_SERIAL_PATH_DEFAULT "/dev/ttyS0"
47 #else
48 #define QGA_VIRTIO_PATH_DEFAULT "\\\\.\\Global\\org.qemu.guest_agent.0"
49 #define QGA_STATE_RELATIVE_DIR "qemu-ga"
50 #define QGA_SERIAL_PATH_DEFAULT "COM1"
51 #endif
52 #ifdef CONFIG_FSFREEZE
53 #define QGA_FSFREEZE_HOOK_DEFAULT CONFIG_QEMU_CONFDIR "/fsfreeze-hook"
54 #endif
55 #define QGA_SENTINEL_BYTE 0xFF
56 #define QGA_CONF_DEFAULT CONFIG_QEMU_CONFDIR G_DIR_SEPARATOR_S "qemu-ga.conf"
58 static struct {
59 const char *state_dir;
60 const char *pidfile;
61 } dfl_pathnames;
63 typedef struct GAPersistentState {
64 #define QGA_PSTATE_DEFAULT_FD_COUNTER 1000
65 int64_t fd_counter;
66 } GAPersistentState;
68 struct GAState {
69 JSONMessageParser parser;
70 GMainLoop *main_loop;
71 GAChannel *channel;
72 bool virtio; /* fastpath to check for virtio to deal with poll() quirks */
73 GACommandState *command_state;
74 GLogLevelFlags log_level;
75 FILE *log_file;
76 bool logging_enabled;
77 #ifdef _WIN32
78 GAService service;
79 #endif
80 bool delimit_response;
81 bool frozen;
82 GList *blacklist;
83 char *state_filepath_isfrozen;
84 struct {
85 const char *log_filepath;
86 const char *pid_filepath;
87 } deferred_options;
88 #ifdef CONFIG_FSFREEZE
89 const char *fsfreeze_hook;
90 #endif
91 gchar *pstate_filepath;
92 GAPersistentState pstate;
95 struct GAState *ga_state;
96 QmpCommandList ga_commands;
98 /* commands that are safe to issue while filesystems are frozen */
99 static const char *ga_freeze_whitelist[] = {
100 "guest-ping",
101 "guest-info",
102 "guest-sync",
103 "guest-sync-delimited",
104 "guest-fsfreeze-status",
105 "guest-fsfreeze-thaw",
106 NULL
109 #ifdef _WIN32
110 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
111 LPVOID ctx);
112 VOID WINAPI service_main(DWORD argc, TCHAR *argv[]);
113 #endif
115 static void
116 init_dfl_pathnames(void)
118 g_assert(dfl_pathnames.state_dir == NULL);
119 g_assert(dfl_pathnames.pidfile == NULL);
120 dfl_pathnames.state_dir = qemu_get_local_state_pathname(
121 QGA_STATE_RELATIVE_DIR);
122 dfl_pathnames.pidfile = qemu_get_local_state_pathname(
123 QGA_STATE_RELATIVE_DIR G_DIR_SEPARATOR_S "qemu-ga.pid");
126 static void quit_handler(int sig)
128 /* if we're frozen, don't exit unless we're absolutely forced to,
129 * because it's basically impossible for graceful exit to complete
130 * unless all log/pid files are on unfreezable filesystems. there's
131 * also a very likely chance killing the agent before unfreezing
132 * the filesystems is a mistake (or will be viewed as one later).
133 * On Windows the freeze interval is limited to 10 seconds, so
134 * we should quit, but first we should wait for the timeout, thaw
135 * the filesystem and quit.
137 if (ga_is_frozen(ga_state)) {
138 #ifdef _WIN32
139 int i = 0;
140 Error *err = NULL;
141 HANDLE hEventTimeout;
143 g_debug("Thawing filesystems before exiting");
145 hEventTimeout = OpenEvent(EVENT_ALL_ACCESS, FALSE, EVENT_NAME_TIMEOUT);
146 if (hEventTimeout) {
147 WaitForSingleObject(hEventTimeout, 0);
148 CloseHandle(hEventTimeout);
150 qga_vss_fsfreeze(&i, false, &err);
151 if (err) {
152 g_debug("Error unfreezing filesystems prior to exiting: %s",
153 error_get_pretty(err));
154 error_free(err);
156 #else
157 return;
158 #endif
160 g_debug("received signal num %d, quitting", sig);
162 if (g_main_loop_is_running(ga_state->main_loop)) {
163 g_main_loop_quit(ga_state->main_loop);
167 #ifndef _WIN32
168 static gboolean register_signal_handlers(void)
170 struct sigaction sigact;
171 int ret;
173 memset(&sigact, 0, sizeof(struct sigaction));
174 sigact.sa_handler = quit_handler;
176 ret = sigaction(SIGINT, &sigact, NULL);
177 if (ret == -1) {
178 g_error("error configuring signal handler: %s", strerror(errno));
180 ret = sigaction(SIGTERM, &sigact, NULL);
181 if (ret == -1) {
182 g_error("error configuring signal handler: %s", strerror(errno));
185 sigact.sa_handler = SIG_IGN;
186 if (sigaction(SIGPIPE, &sigact, NULL) != 0) {
187 g_error("error configuring SIGPIPE signal handler: %s",
188 strerror(errno));
191 return true;
194 /* TODO: use this in place of all post-fork() fclose(std*) callers */
195 void reopen_fd_to_null(int fd)
197 int nullfd;
199 nullfd = open("/dev/null", O_RDWR);
200 if (nullfd < 0) {
201 return;
204 dup2(nullfd, fd);
206 if (nullfd != fd) {
207 close(nullfd);
210 #endif
212 static void usage(const char *cmd)
214 printf(
215 "Usage: %s [-m <method> -p <path>] [<options>]\n"
216 "QEMU Guest Agent %s\n"
217 "\n"
218 " -m, --method transport method: one of unix-listen, virtio-serial,\n"
219 " isa-serial, or vsock-listen (virtio-serial is the default)\n"
220 " -p, --path device/socket path (the default for virtio-serial is:\n"
221 " %s,\n"
222 " the default for isa-serial is:\n"
223 " %s)\n"
224 " -l, --logfile set logfile path, logs to stderr by default\n"
225 " -f, --pidfile specify pidfile (default is %s)\n"
226 #ifdef CONFIG_FSFREEZE
227 " -F, --fsfreeze-hook\n"
228 " enable fsfreeze hook. Accepts an optional argument that\n"
229 " specifies script to run on freeze/thaw. Script will be\n"
230 " called with 'freeze'/'thaw' arguments accordingly.\n"
231 " (default is %s)\n"
232 " If using -F with an argument, do not follow -F with a\n"
233 " space.\n"
234 " (for example: -F/var/run/fsfreezehook.sh)\n"
235 #endif
236 " -t, --statedir specify dir to store state information (absolute paths\n"
237 " only, default is %s)\n"
238 " -v, --verbose log extra debugging information\n"
239 " -V, --version print version information and exit\n"
240 " -d, --daemonize become a daemon\n"
241 #ifdef _WIN32
242 " -s, --service service commands: install, uninstall, vss-install, vss-uninstall\n"
243 #endif
244 " -b, --blacklist comma-separated list of RPCs to disable (no spaces, \"?\"\n"
245 " to list available RPCs)\n"
246 " -D, --dump-conf dump a qemu-ga config file based on current config\n"
247 " options / command-line parameters to stdout\n"
248 " -h, --help display this help and exit\n"
249 "\n"
250 "Report bugs to <mdroth@linux.vnet.ibm.com>\n"
251 , cmd, QEMU_VERSION, QGA_VIRTIO_PATH_DEFAULT, QGA_SERIAL_PATH_DEFAULT,
252 dfl_pathnames.pidfile,
253 #ifdef CONFIG_FSFREEZE
254 QGA_FSFREEZE_HOOK_DEFAULT,
255 #endif
256 dfl_pathnames.state_dir);
259 static const char *ga_log_level_str(GLogLevelFlags level)
261 switch (level & G_LOG_LEVEL_MASK) {
262 case G_LOG_LEVEL_ERROR:
263 return "error";
264 case G_LOG_LEVEL_CRITICAL:
265 return "critical";
266 case G_LOG_LEVEL_WARNING:
267 return "warning";
268 case G_LOG_LEVEL_MESSAGE:
269 return "message";
270 case G_LOG_LEVEL_INFO:
271 return "info";
272 case G_LOG_LEVEL_DEBUG:
273 return "debug";
274 default:
275 return "user";
279 bool ga_logging_enabled(GAState *s)
281 return s->logging_enabled;
284 void ga_disable_logging(GAState *s)
286 s->logging_enabled = false;
289 void ga_enable_logging(GAState *s)
291 s->logging_enabled = true;
294 static void ga_log(const gchar *domain, GLogLevelFlags level,
295 const gchar *msg, gpointer opaque)
297 GAState *s = opaque;
298 GTimeVal time;
299 const char *level_str = ga_log_level_str(level);
301 if (!ga_logging_enabled(s)) {
302 return;
305 level &= G_LOG_LEVEL_MASK;
306 #ifndef _WIN32
307 if (g_strcmp0(domain, "syslog") == 0) {
308 syslog(LOG_INFO, "%s: %s", level_str, msg);
309 } else if (level & s->log_level) {
310 #else
311 if (level & s->log_level) {
312 #endif
313 g_get_current_time(&time);
314 fprintf(s->log_file,
315 "%lu.%lu: %s: %s\n", time.tv_sec, time.tv_usec, level_str, msg);
316 fflush(s->log_file);
320 void ga_set_response_delimited(GAState *s)
322 s->delimit_response = true;
325 static FILE *ga_open_logfile(const char *logfile)
327 FILE *f;
329 f = fopen(logfile, "a");
330 if (!f) {
331 return NULL;
334 qemu_set_cloexec(fileno(f));
335 return f;
338 #ifndef _WIN32
339 static bool ga_open_pidfile(const char *pidfile)
341 int pidfd;
342 char pidstr[32];
344 pidfd = qemu_open(pidfile, O_CREAT|O_WRONLY, S_IRUSR|S_IWUSR);
345 if (pidfd == -1 || lockf(pidfd, F_TLOCK, 0)) {
346 g_critical("Cannot lock pid file, %s", strerror(errno));
347 if (pidfd != -1) {
348 close(pidfd);
350 return false;
353 if (ftruncate(pidfd, 0)) {
354 g_critical("Failed to truncate pid file");
355 goto fail;
357 snprintf(pidstr, sizeof(pidstr), "%d\n", getpid());
358 if (write(pidfd, pidstr, strlen(pidstr)) != strlen(pidstr)) {
359 g_critical("Failed to write pid file");
360 goto fail;
363 /* keep pidfile open & locked forever */
364 return true;
366 fail:
367 unlink(pidfile);
368 close(pidfd);
369 return false;
371 #else /* _WIN32 */
372 static bool ga_open_pidfile(const char *pidfile)
374 return true;
376 #endif
378 static gint ga_strcmp(gconstpointer str1, gconstpointer str2)
380 return strcmp(str1, str2);
383 /* disable commands that aren't safe for fsfreeze */
384 static void ga_disable_non_whitelisted(QmpCommand *cmd, void *opaque)
386 bool whitelisted = false;
387 int i = 0;
388 const char *name = qmp_command_name(cmd);
390 while (ga_freeze_whitelist[i] != NULL) {
391 if (strcmp(name, ga_freeze_whitelist[i]) == 0) {
392 whitelisted = true;
394 i++;
396 if (!whitelisted) {
397 g_debug("disabling command: %s", name);
398 qmp_disable_command(&ga_commands, name);
402 /* [re-]enable all commands, except those explicitly blacklisted by user */
403 static void ga_enable_non_blacklisted(QmpCommand *cmd, void *opaque)
405 GList *blacklist = opaque;
406 const char *name = qmp_command_name(cmd);
408 if (g_list_find_custom(blacklist, name, ga_strcmp) == NULL &&
409 !qmp_command_is_enabled(cmd)) {
410 g_debug("enabling command: %s", name);
411 qmp_enable_command(&ga_commands, name);
415 static bool ga_create_file(const char *path)
417 int fd = open(path, O_CREAT | O_WRONLY, S_IWUSR | S_IRUSR);
418 if (fd == -1) {
419 g_warning("unable to open/create file %s: %s", path, strerror(errno));
420 return false;
422 close(fd);
423 return true;
426 static bool ga_delete_file(const char *path)
428 int ret = unlink(path);
429 if (ret == -1) {
430 g_warning("unable to delete file: %s: %s", path, strerror(errno));
431 return false;
434 return true;
437 bool ga_is_frozen(GAState *s)
439 return s->frozen;
442 void ga_set_frozen(GAState *s)
444 if (ga_is_frozen(s)) {
445 return;
447 /* disable all non-whitelisted (for frozen state) commands */
448 qmp_for_each_command(&ga_commands, ga_disable_non_whitelisted, NULL);
449 g_warning("disabling logging due to filesystem freeze");
450 ga_disable_logging(s);
451 s->frozen = true;
452 if (!ga_create_file(s->state_filepath_isfrozen)) {
453 g_warning("unable to create %s, fsfreeze may not function properly",
454 s->state_filepath_isfrozen);
458 void ga_unset_frozen(GAState *s)
460 if (!ga_is_frozen(s)) {
461 return;
464 /* if we delayed creation/opening of pid/log files due to being
465 * in a frozen state at start up, do it now
467 if (s->deferred_options.log_filepath) {
468 s->log_file = ga_open_logfile(s->deferred_options.log_filepath);
469 if (!s->log_file) {
470 s->log_file = stderr;
472 s->deferred_options.log_filepath = NULL;
474 ga_enable_logging(s);
475 g_warning("logging re-enabled due to filesystem unfreeze");
476 if (s->deferred_options.pid_filepath) {
477 if (!ga_open_pidfile(s->deferred_options.pid_filepath)) {
478 g_warning("failed to create/open pid file");
480 s->deferred_options.pid_filepath = NULL;
483 /* enable all disabled, non-blacklisted commands */
484 qmp_for_each_command(&ga_commands, ga_enable_non_blacklisted, s->blacklist);
485 s->frozen = false;
486 if (!ga_delete_file(s->state_filepath_isfrozen)) {
487 g_warning("unable to delete %s, fsfreeze may not function properly",
488 s->state_filepath_isfrozen);
492 #ifdef CONFIG_FSFREEZE
493 const char *ga_fsfreeze_hook(GAState *s)
495 return s->fsfreeze_hook;
497 #endif
499 static void become_daemon(const char *pidfile)
501 #ifndef _WIN32
502 pid_t pid, sid;
504 pid = fork();
505 if (pid < 0) {
506 exit(EXIT_FAILURE);
508 if (pid > 0) {
509 exit(EXIT_SUCCESS);
512 if (pidfile) {
513 if (!ga_open_pidfile(pidfile)) {
514 g_critical("failed to create pidfile");
515 exit(EXIT_FAILURE);
519 umask(S_IRWXG | S_IRWXO);
520 sid = setsid();
521 if (sid < 0) {
522 goto fail;
524 if ((chdir("/")) < 0) {
525 goto fail;
528 reopen_fd_to_null(STDIN_FILENO);
529 reopen_fd_to_null(STDOUT_FILENO);
530 reopen_fd_to_null(STDERR_FILENO);
531 return;
533 fail:
534 if (pidfile) {
535 unlink(pidfile);
537 g_critical("failed to daemonize");
538 exit(EXIT_FAILURE);
539 #endif
542 static int send_response(GAState *s, QObject *payload)
544 const char *buf;
545 QString *payload_qstr, *response_qstr;
546 GIOStatus status;
548 g_assert(payload && s->channel);
550 payload_qstr = qobject_to_json(payload);
551 if (!payload_qstr) {
552 return -EINVAL;
555 if (s->delimit_response) {
556 s->delimit_response = false;
557 response_qstr = qstring_new();
558 qstring_append_chr(response_qstr, QGA_SENTINEL_BYTE);
559 qstring_append(response_qstr, qstring_get_str(payload_qstr));
560 QDECREF(payload_qstr);
561 } else {
562 response_qstr = payload_qstr;
565 qstring_append_chr(response_qstr, '\n');
566 buf = qstring_get_str(response_qstr);
567 status = ga_channel_write_all(s->channel, buf, strlen(buf));
568 QDECREF(response_qstr);
569 if (status != G_IO_STATUS_NORMAL) {
570 return -EIO;
573 return 0;
576 static void process_command(GAState *s, QDict *req)
578 QObject *rsp = NULL;
579 int ret;
581 g_assert(req);
582 g_debug("processing command");
583 rsp = qmp_dispatch(&ga_commands, QOBJECT(req));
584 if (rsp) {
585 ret = send_response(s, rsp);
586 if (ret < 0) {
587 g_warning("error sending response: %s", strerror(-ret));
589 qobject_decref(rsp);
593 /* handle requests/control events coming in over the channel */
594 static void process_event(JSONMessageParser *parser, GQueue *tokens)
596 GAState *s = container_of(parser, GAState, parser);
597 QDict *qdict;
598 Error *err = NULL;
599 int ret;
601 g_assert(s && parser);
603 g_debug("process_event: called");
604 qdict = qobject_to_qdict(json_parser_parse_err(tokens, NULL, &err));
605 if (err || !qdict) {
606 QDECREF(qdict);
607 qdict = qdict_new();
608 if (!err) {
609 g_warning("failed to parse event: unknown error");
610 error_setg(&err, QERR_JSON_PARSING);
611 } else {
612 g_warning("failed to parse event: %s", error_get_pretty(err));
614 qdict_put_obj(qdict, "error", qmp_build_error_object(err));
615 error_free(err);
618 /* handle host->guest commands */
619 if (qdict_haskey(qdict, "execute")) {
620 process_command(s, qdict);
621 } else {
622 if (!qdict_haskey(qdict, "error")) {
623 QDECREF(qdict);
624 qdict = qdict_new();
625 g_warning("unrecognized payload format");
626 error_setg(&err, QERR_UNSUPPORTED);
627 qdict_put_obj(qdict, "error", qmp_build_error_object(err));
628 error_free(err);
630 ret = send_response(s, QOBJECT(qdict));
631 if (ret < 0) {
632 g_warning("error sending error response: %s", strerror(-ret));
636 QDECREF(qdict);
639 /* false return signals GAChannel to close the current client connection */
640 static gboolean channel_event_cb(GIOCondition condition, gpointer data)
642 GAState *s = data;
643 gchar buf[QGA_READ_COUNT_DEFAULT+1];
644 gsize count;
645 GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
646 switch (status) {
647 case G_IO_STATUS_ERROR:
648 g_warning("error reading channel");
649 return false;
650 case G_IO_STATUS_NORMAL:
651 buf[count] = 0;
652 g_debug("read data, count: %d, data: %s", (int)count, buf);
653 json_message_parser_feed(&s->parser, (char *)buf, (int)count);
654 break;
655 case G_IO_STATUS_EOF:
656 g_debug("received EOF");
657 if (!s->virtio) {
658 return false;
660 /* fall through */
661 case G_IO_STATUS_AGAIN:
662 /* virtio causes us to spin here when no process is attached to
663 * host-side chardev. sleep a bit to mitigate this
665 if (s->virtio) {
666 usleep(100*1000);
668 return true;
669 default:
670 g_warning("unknown channel read status, closing");
671 return false;
673 return true;
676 static gboolean channel_init(GAState *s, const gchar *method, const gchar *path,
677 int listen_fd)
679 GAChannelMethod channel_method;
681 if (strcmp(method, "virtio-serial") == 0) {
682 s->virtio = true; /* virtio requires special handling in some cases */
683 channel_method = GA_CHANNEL_VIRTIO_SERIAL;
684 } else if (strcmp(method, "isa-serial") == 0) {
685 channel_method = GA_CHANNEL_ISA_SERIAL;
686 } else if (strcmp(method, "unix-listen") == 0) {
687 channel_method = GA_CHANNEL_UNIX_LISTEN;
688 } else if (strcmp(method, "vsock-listen") == 0) {
689 channel_method = GA_CHANNEL_VSOCK_LISTEN;
690 } else {
691 g_critical("unsupported channel method/type: %s", method);
692 return false;
695 s->channel = ga_channel_new(channel_method, path, listen_fd,
696 channel_event_cb, s);
697 if (!s->channel) {
698 g_critical("failed to create guest agent channel");
699 return false;
702 return true;
705 #ifdef _WIN32
706 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
707 LPVOID ctx)
709 DWORD ret = NO_ERROR;
710 GAService *service = &ga_state->service;
712 switch (ctrl)
714 case SERVICE_CONTROL_STOP:
715 case SERVICE_CONTROL_SHUTDOWN:
716 quit_handler(SIGTERM);
717 service->status.dwCurrentState = SERVICE_STOP_PENDING;
718 SetServiceStatus(service->status_handle, &service->status);
719 break;
721 default:
722 ret = ERROR_CALL_NOT_IMPLEMENTED;
724 return ret;
727 VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
729 GAService *service = &ga_state->service;
731 service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME,
732 service_ctrl_handler, NULL);
734 if (service->status_handle == 0) {
735 g_critical("Failed to register extended requests function!\n");
736 return;
739 service->status.dwServiceType = SERVICE_WIN32;
740 service->status.dwCurrentState = SERVICE_RUNNING;
741 service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
742 service->status.dwWin32ExitCode = NO_ERROR;
743 service->status.dwServiceSpecificExitCode = NO_ERROR;
744 service->status.dwCheckPoint = 0;
745 service->status.dwWaitHint = 0;
746 SetServiceStatus(service->status_handle, &service->status);
748 g_main_loop_run(ga_state->main_loop);
750 service->status.dwCurrentState = SERVICE_STOPPED;
751 SetServiceStatus(service->status_handle, &service->status);
753 #endif
755 static void set_persistent_state_defaults(GAPersistentState *pstate)
757 g_assert(pstate);
758 pstate->fd_counter = QGA_PSTATE_DEFAULT_FD_COUNTER;
761 static void persistent_state_from_keyfile(GAPersistentState *pstate,
762 GKeyFile *keyfile)
764 g_assert(pstate);
765 g_assert(keyfile);
766 /* if any fields are missing, either because the file was tampered with
767 * by agents of chaos, or because the field wasn't present at the time the
768 * file was created, the best we can ever do is start over with the default
769 * values. so load them now, and ignore any errors in accessing key-value
770 * pairs
772 set_persistent_state_defaults(pstate);
774 if (g_key_file_has_key(keyfile, "global", "fd_counter", NULL)) {
775 pstate->fd_counter =
776 g_key_file_get_integer(keyfile, "global", "fd_counter", NULL);
780 static void persistent_state_to_keyfile(const GAPersistentState *pstate,
781 GKeyFile *keyfile)
783 g_assert(pstate);
784 g_assert(keyfile);
786 g_key_file_set_integer(keyfile, "global", "fd_counter", pstate->fd_counter);
789 static gboolean write_persistent_state(const GAPersistentState *pstate,
790 const gchar *path)
792 GKeyFile *keyfile = g_key_file_new();
793 GError *gerr = NULL;
794 gboolean ret = true;
795 gchar *data = NULL;
796 gsize data_len;
798 g_assert(pstate);
800 persistent_state_to_keyfile(pstate, keyfile);
801 data = g_key_file_to_data(keyfile, &data_len, &gerr);
802 if (gerr) {
803 g_critical("failed to convert persistent state to string: %s",
804 gerr->message);
805 ret = false;
806 goto out;
809 g_file_set_contents(path, data, data_len, &gerr);
810 if (gerr) {
811 g_critical("failed to write persistent state to %s: %s",
812 path, gerr->message);
813 ret = false;
814 goto out;
817 out:
818 if (gerr) {
819 g_error_free(gerr);
821 if (keyfile) {
822 g_key_file_free(keyfile);
824 g_free(data);
825 return ret;
828 static gboolean read_persistent_state(GAPersistentState *pstate,
829 const gchar *path, gboolean frozen)
831 GKeyFile *keyfile = NULL;
832 GError *gerr = NULL;
833 struct stat st;
834 gboolean ret = true;
836 g_assert(pstate);
838 if (stat(path, &st) == -1) {
839 /* it's okay if state file doesn't exist, but any other error
840 * indicates a permissions issue or some other misconfiguration
841 * that we likely won't be able to recover from.
843 if (errno != ENOENT) {
844 g_critical("unable to access state file at path %s: %s",
845 path, strerror(errno));
846 ret = false;
847 goto out;
850 /* file doesn't exist. initialize state to default values and
851 * attempt to save now. (we could wait till later when we have
852 * modified state we need to commit, but if there's a problem,
853 * such as a missing parent directory, we want to catch it now)
855 * there is a potential scenario where someone either managed to
856 * update the agent from a version that didn't use a key store
857 * while qemu-ga thought the filesystem was frozen, or
858 * deleted the key store prior to issuing a fsfreeze, prior
859 * to restarting the agent. in this case we go ahead and defer
860 * initial creation till we actually have modified state to
861 * write, otherwise fail to recover from freeze.
863 set_persistent_state_defaults(pstate);
864 if (!frozen) {
865 ret = write_persistent_state(pstate, path);
866 if (!ret) {
867 g_critical("unable to create state file at path %s", path);
868 ret = false;
869 goto out;
872 ret = true;
873 goto out;
876 keyfile = g_key_file_new();
877 g_key_file_load_from_file(keyfile, path, 0, &gerr);
878 if (gerr) {
879 g_critical("error loading persistent state from path: %s, %s",
880 path, gerr->message);
881 ret = false;
882 goto out;
885 persistent_state_from_keyfile(pstate, keyfile);
887 out:
888 if (keyfile) {
889 g_key_file_free(keyfile);
891 if (gerr) {
892 g_error_free(gerr);
895 return ret;
898 int64_t ga_get_fd_handle(GAState *s, Error **errp)
900 int64_t handle;
902 g_assert(s->pstate_filepath);
903 /* we blacklist commands and avoid operations that potentially require
904 * writing to disk when we're in a frozen state. this includes opening
905 * new files, so we should never get here in that situation
907 g_assert(!ga_is_frozen(s));
909 handle = s->pstate.fd_counter++;
911 /* This should never happen on a reasonable timeframe, as guest-file-open
912 * would have to be issued 2^63 times */
913 if (s->pstate.fd_counter == INT64_MAX) {
914 abort();
917 if (!write_persistent_state(&s->pstate, s->pstate_filepath)) {
918 error_setg(errp, "failed to commit persistent state to disk");
919 return -1;
922 return handle;
925 static void ga_print_cmd(QmpCommand *cmd, void *opaque)
927 printf("%s\n", qmp_command_name(cmd));
930 static GList *split_list(const gchar *str, const gchar *delim)
932 GList *list = NULL;
933 int i;
934 gchar **strv;
936 strv = g_strsplit(str, delim, -1);
937 for (i = 0; strv[i]; i++) {
938 list = g_list_prepend(list, strv[i]);
940 g_free(strv);
942 return list;
945 typedef struct GAConfig {
946 char *channel_path;
947 char *method;
948 char *log_filepath;
949 char *pid_filepath;
950 #ifdef CONFIG_FSFREEZE
951 char *fsfreeze_hook;
952 #endif
953 char *state_dir;
954 #ifdef _WIN32
955 const char *service;
956 #endif
957 gchar *bliststr; /* blacklist may point to this string */
958 GList *blacklist;
959 int daemonize;
960 GLogLevelFlags log_level;
961 int dumpconf;
962 } GAConfig;
964 static void config_load(GAConfig *config)
966 GError *gerr = NULL;
967 GKeyFile *keyfile;
968 const char *conf = g_getenv("QGA_CONF") ?: QGA_CONF_DEFAULT;
970 /* read system config */
971 keyfile = g_key_file_new();
972 if (!g_key_file_load_from_file(keyfile, conf, 0, &gerr)) {
973 goto end;
975 if (g_key_file_has_key(keyfile, "general", "daemon", NULL)) {
976 config->daemonize =
977 g_key_file_get_boolean(keyfile, "general", "daemon", &gerr);
979 if (g_key_file_has_key(keyfile, "general", "method", NULL)) {
980 config->method =
981 g_key_file_get_string(keyfile, "general", "method", &gerr);
983 if (g_key_file_has_key(keyfile, "general", "path", NULL)) {
984 config->channel_path =
985 g_key_file_get_string(keyfile, "general", "path", &gerr);
987 if (g_key_file_has_key(keyfile, "general", "logfile", NULL)) {
988 config->log_filepath =
989 g_key_file_get_string(keyfile, "general", "logfile", &gerr);
991 if (g_key_file_has_key(keyfile, "general", "pidfile", NULL)) {
992 config->pid_filepath =
993 g_key_file_get_string(keyfile, "general", "pidfile", &gerr);
995 #ifdef CONFIG_FSFREEZE
996 if (g_key_file_has_key(keyfile, "general", "fsfreeze-hook", NULL)) {
997 config->fsfreeze_hook =
998 g_key_file_get_string(keyfile,
999 "general", "fsfreeze-hook", &gerr);
1001 #endif
1002 if (g_key_file_has_key(keyfile, "general", "statedir", NULL)) {
1003 config->state_dir =
1004 g_key_file_get_string(keyfile, "general", "statedir", &gerr);
1006 if (g_key_file_has_key(keyfile, "general", "verbose", NULL) &&
1007 g_key_file_get_boolean(keyfile, "general", "verbose", &gerr)) {
1008 /* enable all log levels */
1009 config->log_level = G_LOG_LEVEL_MASK;
1011 if (g_key_file_has_key(keyfile, "general", "blacklist", NULL)) {
1012 config->bliststr =
1013 g_key_file_get_string(keyfile, "general", "blacklist", &gerr);
1014 config->blacklist = g_list_concat(config->blacklist,
1015 split_list(config->bliststr, ","));
1018 end:
1019 g_key_file_free(keyfile);
1020 if (gerr &&
1021 !(gerr->domain == G_FILE_ERROR && gerr->code == G_FILE_ERROR_NOENT)) {
1022 g_critical("error loading configuration from path: %s, %s",
1023 QGA_CONF_DEFAULT, gerr->message);
1024 exit(EXIT_FAILURE);
1026 g_clear_error(&gerr);
1029 static gchar *list_join(GList *list, const gchar separator)
1031 GString *str = g_string_new("");
1033 while (list) {
1034 str = g_string_append(str, (gchar *)list->data);
1035 list = g_list_next(list);
1036 if (list) {
1037 str = g_string_append_c(str, separator);
1041 return g_string_free(str, FALSE);
1044 static void config_dump(GAConfig *config)
1046 GError *error = NULL;
1047 GKeyFile *keyfile;
1048 gchar *tmp;
1050 keyfile = g_key_file_new();
1051 g_assert(keyfile);
1053 g_key_file_set_boolean(keyfile, "general", "daemon", config->daemonize);
1054 g_key_file_set_string(keyfile, "general", "method", config->method);
1055 if (config->channel_path) {
1056 g_key_file_set_string(keyfile, "general", "path", config->channel_path);
1058 if (config->log_filepath) {
1059 g_key_file_set_string(keyfile, "general", "logfile",
1060 config->log_filepath);
1062 g_key_file_set_string(keyfile, "general", "pidfile", config->pid_filepath);
1063 #ifdef CONFIG_FSFREEZE
1064 if (config->fsfreeze_hook) {
1065 g_key_file_set_string(keyfile, "general", "fsfreeze-hook",
1066 config->fsfreeze_hook);
1068 #endif
1069 g_key_file_set_string(keyfile, "general", "statedir", config->state_dir);
1070 g_key_file_set_boolean(keyfile, "general", "verbose",
1071 config->log_level == G_LOG_LEVEL_MASK);
1072 tmp = list_join(config->blacklist, ',');
1073 g_key_file_set_string(keyfile, "general", "blacklist", tmp);
1074 g_free(tmp);
1076 tmp = g_key_file_to_data(keyfile, NULL, &error);
1077 if (error) {
1078 g_critical("Failed to dump keyfile: %s", error->message);
1079 g_clear_error(&error);
1080 } else {
1081 printf("%s", tmp);
1084 g_free(tmp);
1085 g_key_file_free(keyfile);
1088 static void config_parse(GAConfig *config, int argc, char **argv)
1090 const char *sopt = "hVvdm:p:l:f:F::b:s:t:D";
1091 int opt_ind = 0, ch;
1092 const struct option lopt[] = {
1093 { "help", 0, NULL, 'h' },
1094 { "version", 0, NULL, 'V' },
1095 { "dump-conf", 0, NULL, 'D' },
1096 { "logfile", 1, NULL, 'l' },
1097 { "pidfile", 1, NULL, 'f' },
1098 #ifdef CONFIG_FSFREEZE
1099 { "fsfreeze-hook", 2, NULL, 'F' },
1100 #endif
1101 { "verbose", 0, NULL, 'v' },
1102 { "method", 1, NULL, 'm' },
1103 { "path", 1, NULL, 'p' },
1104 { "daemonize", 0, NULL, 'd' },
1105 { "blacklist", 1, NULL, 'b' },
1106 #ifdef _WIN32
1107 { "service", 1, NULL, 's' },
1108 #endif
1109 { "statedir", 1, NULL, 't' },
1110 { NULL, 0, NULL, 0 }
1113 while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
1114 switch (ch) {
1115 case 'm':
1116 g_free(config->method);
1117 config->method = g_strdup(optarg);
1118 break;
1119 case 'p':
1120 g_free(config->channel_path);
1121 config->channel_path = g_strdup(optarg);
1122 break;
1123 case 'l':
1124 g_free(config->log_filepath);
1125 config->log_filepath = g_strdup(optarg);
1126 break;
1127 case 'f':
1128 g_free(config->pid_filepath);
1129 config->pid_filepath = g_strdup(optarg);
1130 break;
1131 #ifdef CONFIG_FSFREEZE
1132 case 'F':
1133 g_free(config->fsfreeze_hook);
1134 config->fsfreeze_hook = g_strdup(optarg ?: QGA_FSFREEZE_HOOK_DEFAULT);
1135 break;
1136 #endif
1137 case 't':
1138 g_free(config->state_dir);
1139 config->state_dir = g_strdup(optarg);
1140 break;
1141 case 'v':
1142 /* enable all log levels */
1143 config->log_level = G_LOG_LEVEL_MASK;
1144 break;
1145 case 'V':
1146 printf("QEMU Guest Agent %s\n", QEMU_VERSION);
1147 exit(EXIT_SUCCESS);
1148 case 'd':
1149 config->daemonize = 1;
1150 break;
1151 case 'D':
1152 config->dumpconf = 1;
1153 break;
1154 case 'b': {
1155 if (is_help_option(optarg)) {
1156 qmp_for_each_command(&ga_commands, ga_print_cmd, NULL);
1157 exit(EXIT_SUCCESS);
1159 config->blacklist = g_list_concat(config->blacklist,
1160 split_list(optarg, ","));
1161 break;
1163 #ifdef _WIN32
1164 case 's':
1165 config->service = optarg;
1166 if (strcmp(config->service, "install") == 0) {
1167 if (ga_install_vss_provider()) {
1168 exit(EXIT_FAILURE);
1170 if (ga_install_service(config->channel_path,
1171 config->log_filepath, config->state_dir)) {
1172 exit(EXIT_FAILURE);
1174 exit(EXIT_SUCCESS);
1175 } else if (strcmp(config->service, "uninstall") == 0) {
1176 ga_uninstall_vss_provider();
1177 exit(ga_uninstall_service());
1178 } else if (strcmp(config->service, "vss-install") == 0) {
1179 if (ga_install_vss_provider()) {
1180 exit(EXIT_FAILURE);
1182 exit(EXIT_SUCCESS);
1183 } else if (strcmp(config->service, "vss-uninstall") == 0) {
1184 ga_uninstall_vss_provider();
1185 exit(EXIT_SUCCESS);
1186 } else {
1187 printf("Unknown service command.\n");
1188 exit(EXIT_FAILURE);
1190 break;
1191 #endif
1192 case 'h':
1193 usage(argv[0]);
1194 exit(EXIT_SUCCESS);
1195 case '?':
1196 g_print("Unknown option, try '%s --help' for more information.\n",
1197 argv[0]);
1198 exit(EXIT_FAILURE);
1203 static void config_free(GAConfig *config)
1205 g_free(config->method);
1206 g_free(config->log_filepath);
1207 g_free(config->pid_filepath);
1208 g_free(config->state_dir);
1209 g_free(config->channel_path);
1210 g_free(config->bliststr);
1211 #ifdef CONFIG_FSFREEZE
1212 g_free(config->fsfreeze_hook);
1213 #endif
1214 g_list_free_full(config->blacklist, g_free);
1215 g_free(config);
1218 static bool check_is_frozen(GAState *s)
1220 #ifndef _WIN32
1221 /* check if a previous instance of qemu-ga exited with filesystems' state
1222 * marked as frozen. this could be a stale value (a non-qemu-ga process
1223 * or reboot may have since unfrozen them), but better to require an
1224 * uneeded unfreeze than to risk hanging on start-up
1226 struct stat st;
1227 if (stat(s->state_filepath_isfrozen, &st) == -1) {
1228 /* it's okay if the file doesn't exist, but if we can't access for
1229 * some other reason, such as permissions, there's a configuration
1230 * that needs to be addressed. so just bail now before we get into
1231 * more trouble later
1233 if (errno != ENOENT) {
1234 g_critical("unable to access state file at path %s: %s",
1235 s->state_filepath_isfrozen, strerror(errno));
1236 return EXIT_FAILURE;
1238 } else {
1239 g_warning("previous instance appears to have exited with frozen"
1240 " filesystems. deferring logging/pidfile creation and"
1241 " disabling non-fsfreeze-safe commands until"
1242 " guest-fsfreeze-thaw is issued, or filesystems are"
1243 " manually unfrozen and the file %s is removed",
1244 s->state_filepath_isfrozen);
1245 return true;
1247 #endif
1248 return false;
1251 static int run_agent(GAState *s, GAConfig *config, int socket_activation)
1253 ga_state = s;
1255 g_log_set_default_handler(ga_log, s);
1256 g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
1257 ga_enable_logging(s);
1259 #ifdef _WIN32
1260 /* On win32 the state directory is application specific (be it the default
1261 * or a user override). We got past the command line parsing; let's create
1262 * the directory (with any intermediate directories). If we run into an
1263 * error later on, we won't try to clean up the directory, it is considered
1264 * persistent.
1266 if (g_mkdir_with_parents(config->state_dir, S_IRWXU) == -1) {
1267 g_critical("unable to create (an ancestor of) the state directory"
1268 " '%s': %s", config->state_dir, strerror(errno));
1269 return EXIT_FAILURE;
1271 #endif
1273 if (ga_is_frozen(s)) {
1274 if (config->daemonize) {
1275 /* delay opening/locking of pidfile till filesystems are unfrozen */
1276 s->deferred_options.pid_filepath = config->pid_filepath;
1277 become_daemon(NULL);
1279 if (config->log_filepath) {
1280 /* delay opening the log file till filesystems are unfrozen */
1281 s->deferred_options.log_filepath = config->log_filepath;
1283 ga_disable_logging(s);
1284 qmp_for_each_command(&ga_commands, ga_disable_non_whitelisted, NULL);
1285 } else {
1286 if (config->daemonize) {
1287 become_daemon(config->pid_filepath);
1289 if (config->log_filepath) {
1290 FILE *log_file = ga_open_logfile(config->log_filepath);
1291 if (!log_file) {
1292 g_critical("unable to open specified log file: %s",
1293 strerror(errno));
1294 return EXIT_FAILURE;
1296 s->log_file = log_file;
1300 /* load persistent state from disk */
1301 if (!read_persistent_state(&s->pstate,
1302 s->pstate_filepath,
1303 ga_is_frozen(s))) {
1304 g_critical("failed to load persistent state");
1305 return EXIT_FAILURE;
1308 config->blacklist = ga_command_blacklist_init(config->blacklist);
1309 if (config->blacklist) {
1310 GList *l = config->blacklist;
1311 s->blacklist = config->blacklist;
1312 do {
1313 g_debug("disabling command: %s", (char *)l->data);
1314 qmp_disable_command(&ga_commands, l->data);
1315 l = g_list_next(l);
1316 } while (l);
1318 s->command_state = ga_command_state_new();
1319 ga_command_state_init(s, s->command_state);
1320 ga_command_state_init_all(s->command_state);
1321 json_message_parser_init(&s->parser, process_event);
1323 #ifndef _WIN32
1324 if (!register_signal_handlers()) {
1325 g_critical("failed to register signal handlers");
1326 return EXIT_FAILURE;
1328 #endif
1330 s->main_loop = g_main_loop_new(NULL, false);
1332 if (!channel_init(ga_state, config->method, config->channel_path,
1333 socket_activation ? FIRST_SOCKET_ACTIVATION_FD : -1)) {
1334 g_critical("failed to initialize guest agent channel");
1335 return EXIT_FAILURE;
1337 #ifndef _WIN32
1338 g_main_loop_run(ga_state->main_loop);
1339 #else
1340 if (config->daemonize) {
1341 SERVICE_TABLE_ENTRY service_table[] = {
1342 { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
1343 StartServiceCtrlDispatcher(service_table);
1344 } else {
1345 g_main_loop_run(ga_state->main_loop);
1347 #endif
1349 return EXIT_SUCCESS;
1352 int main(int argc, char **argv)
1354 int ret = EXIT_SUCCESS;
1355 GAState *s = g_new0(GAState, 1);
1356 GAConfig *config = g_new0(GAConfig, 1);
1357 int socket_activation;
1359 config->log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
1361 qga_qmp_init_marshal(&ga_commands);
1363 init_dfl_pathnames();
1364 config_load(config);
1365 config_parse(config, argc, argv);
1367 if (config->pid_filepath == NULL) {
1368 config->pid_filepath = g_strdup(dfl_pathnames.pidfile);
1371 if (config->state_dir == NULL) {
1372 config->state_dir = g_strdup(dfl_pathnames.state_dir);
1375 if (config->method == NULL) {
1376 config->method = g_strdup("virtio-serial");
1379 socket_activation = check_socket_activation();
1380 if (socket_activation > 1) {
1381 g_critical("qemu-ga only supports listening on one socket");
1382 ret = EXIT_FAILURE;
1383 goto end;
1385 if (socket_activation) {
1386 SocketAddress *addr;
1388 g_free(config->method);
1389 g_free(config->channel_path);
1390 config->method = NULL;
1391 config->channel_path = NULL;
1393 addr = socket_local_address(FIRST_SOCKET_ACTIVATION_FD, NULL);
1394 if (addr) {
1395 if (addr->type == SOCKET_ADDRESS_TYPE_UNIX) {
1396 config->method = g_strdup("unix-listen");
1397 } else if (addr->type == SOCKET_ADDRESS_TYPE_VSOCK) {
1398 config->method = g_strdup("vsock-listen");
1401 qapi_free_SocketAddress(addr);
1404 if (!config->method) {
1405 g_critical("unsupported listen fd type");
1406 ret = EXIT_FAILURE;
1407 goto end;
1409 } else if (config->channel_path == NULL) {
1410 if (strcmp(config->method, "virtio-serial") == 0) {
1411 /* try the default path for the virtio-serial port */
1412 config->channel_path = g_strdup(QGA_VIRTIO_PATH_DEFAULT);
1413 } else if (strcmp(config->method, "isa-serial") == 0) {
1414 /* try the default path for the serial port - COM1 */
1415 config->channel_path = g_strdup(QGA_SERIAL_PATH_DEFAULT);
1416 } else {
1417 g_critical("must specify a path for this channel");
1418 ret = EXIT_FAILURE;
1419 goto end;
1423 s->log_level = config->log_level;
1424 s->log_file = stderr;
1425 #ifdef CONFIG_FSFREEZE
1426 s->fsfreeze_hook = config->fsfreeze_hook;
1427 #endif
1428 s->pstate_filepath = g_strdup_printf("%s/qga.state", config->state_dir);
1429 s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen",
1430 config->state_dir);
1431 s->frozen = check_is_frozen(s);
1433 if (config->dumpconf) {
1434 config_dump(config);
1435 goto end;
1438 ret = run_agent(s, config, socket_activation);
1440 end:
1441 if (s->command_state) {
1442 ga_command_state_cleanup_all(s->command_state);
1443 ga_command_state_free(s->command_state);
1444 json_message_parser_destroy(&s->parser);
1446 if (s->channel) {
1447 ga_channel_free(s->channel);
1449 g_free(s->pstate_filepath);
1450 g_free(s->state_filepath_isfrozen);
1452 if (config->daemonize) {
1453 unlink(config->pid_filepath);
1456 config_free(config);
1457 if (s->main_loop) {
1458 g_main_loop_unref(s->main_loop);
1460 g_free(s);
1462 return ret;