scsi: esp: check buffer length before reading scsi command
[qemu.git] / qga / main.c
1 /*
2 * QEMU Guest Agent
3 *
4 * Copyright IBM Corp. 2011
5 *
6 * Authors:
7 * Adam Litke <aglitke@linux.vnet.ibm.com>
8 * Michael Roth <mdroth@linux.vnet.ibm.com>
9 *
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.
12 */
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
41
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"
56
57 static struct {
58 const char *state_dir;
59 const char *pidfile;
60 } dfl_pathnames;
61
62 typedef struct GAPersistentState {
63 #define QGA_PSTATE_DEFAULT_FD_COUNTER 1000
64 int64_t fd_counter;
65 } GAPersistentState;
66
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;
92 };
93
94 struct GAState *ga_state;
95
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
105 };
106
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
112
113 static void
114 init_dfl_pathnames(void)
115 {
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");
122 }
123
124 static void quit_handler(int sig)
125 {
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).
131 */
132 if (ga_is_frozen(ga_state)) {
133 return;
134 }
135 g_debug("received signal num %d, quitting", sig);
136
137 if (g_main_loop_is_running(ga_state->main_loop)) {
138 g_main_loop_quit(ga_state->main_loop);
139 }
140 }
141
142 #ifndef _WIN32
143 static gboolean register_signal_handlers(void)
144 {
145 struct sigaction sigact;
146 int ret;
147
148 memset(&sigact, 0, sizeof(struct sigaction));
149 sigact.sa_handler = quit_handler;
150
151 ret = sigaction(SIGINT, &sigact, NULL);
152 if (ret == -1) {
153 g_error("error configuring signal handler: %s", strerror(errno));
154 }
155 ret = sigaction(SIGTERM, &sigact, NULL);
156 if (ret == -1) {
157 g_error("error configuring signal handler: %s", strerror(errno));
158 }
159
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));
164 }
165
166 return true;
167 }
168
169 /* TODO: use this in place of all post-fork() fclose(std*) callers */
170 void reopen_fd_to_null(int fd)
171 {
172 int nullfd;
173
174 nullfd = open("/dev/null", O_RDWR);
175 if (nullfd < 0) {
176 return;
177 }
178
179 dup2(nullfd, fd);
180
181 if (nullfd != fd) {
182 close(nullfd);
183 }
184 }
185 #endif
186
187 static void usage(const char *cmd)
188 {
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, or\n"
194 " isa-serial (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);
232 }
233
234 static const char *ga_log_level_str(GLogLevelFlags level)
235 {
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";
251 }
252 }
253
254 bool ga_logging_enabled(GAState *s)
255 {
256 return s->logging_enabled;
257 }
258
259 void ga_disable_logging(GAState *s)
260 {
261 s->logging_enabled = false;
262 }
263
264 void ga_enable_logging(GAState *s)
265 {
266 s->logging_enabled = true;
267 }
268
269 static void ga_log(const gchar *domain, GLogLevelFlags level,
270 const gchar *msg, gpointer opaque)
271 {
272 GAState *s = opaque;
273 GTimeVal time;
274 const char *level_str = ga_log_level_str(level);
275
276 if (!ga_logging_enabled(s)) {
277 return;
278 }
279
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);
292 }
293 }
294
295 void ga_set_response_delimited(GAState *s)
296 {
297 s->delimit_response = true;
298 }
299
300 static FILE *ga_open_logfile(const char *logfile)
301 {
302 FILE *f;
303
304 f = fopen(logfile, "a");
305 if (!f) {
306 return NULL;
307 }
308
309 qemu_set_cloexec(fileno(f));
310 return f;
311 }
312
313 #ifndef _WIN32
314 static bool ga_open_pidfile(const char *pidfile)
315 {
316 int pidfd;
317 char pidstr[32];
318
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);
324 }
325 return false;
326 }
327
328 if (ftruncate(pidfd, 0)) {
329 g_critical("Failed to truncate pid file");
330 goto fail;
331 }
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;
336 }
337
338 /* keep pidfile open & locked forever */
339 return true;
340
341 fail:
342 unlink(pidfile);
343 close(pidfd);
344 return false;
345 }
346 #else /* _WIN32 */
347 static bool ga_open_pidfile(const char *pidfile)
348 {
349 return true;
350 }
351 #endif
352
353 static gint ga_strcmp(gconstpointer str1, gconstpointer str2)
354 {
355 return strcmp(str1, str2);
356 }
357
358 /* disable commands that aren't safe for fsfreeze */
359 static void ga_disable_non_whitelisted(QmpCommand *cmd, void *opaque)
360 {
361 bool whitelisted = false;
362 int i = 0;
363 const char *name = qmp_command_name(cmd);
364
365 while (ga_freeze_whitelist[i] != NULL) {
366 if (strcmp(name, ga_freeze_whitelist[i]) == 0) {
367 whitelisted = true;
368 }
369 i++;
370 }
371 if (!whitelisted) {
372 g_debug("disabling command: %s", name);
373 qmp_disable_command(name);
374 }
375 }
376
377 /* [re-]enable all commands, except those explicitly blacklisted by user */
378 static void ga_enable_non_blacklisted(QmpCommand *cmd, void *opaque)
379 {
380 GList *blacklist = opaque;
381 const char *name = qmp_command_name(cmd);
382
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);
387 }
388 }
389
390 static bool ga_create_file(const char *path)
391 {
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;
396 }
397 close(fd);
398 return true;
399 }
400
401 static bool ga_delete_file(const char *path)
402 {
403 int ret = unlink(path);
404 if (ret == -1) {
405 g_warning("unable to delete file: %s: %s", path, strerror(errno));
406 return false;
407 }
408
409 return true;
410 }
411
412 bool ga_is_frozen(GAState *s)
413 {
414 return s->frozen;
415 }
416
417 void ga_set_frozen(GAState *s)
418 {
419 if (ga_is_frozen(s)) {
420 return;
421 }
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);
430 }
431 }
432
433 void ga_unset_frozen(GAState *s)
434 {
435 if (!ga_is_frozen(s)) {
436 return;
437 }
438
439 /* if we delayed creation/opening of pid/log files due to being
440 * in a frozen state at start up, do it now
441 */
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;
446 }
447 s->deferred_options.log_filepath = NULL;
448 }
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");
454 }
455 s->deferred_options.pid_filepath = NULL;
456 }
457
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);
464 }
465 }
466
467 #ifdef CONFIG_FSFREEZE
468 const char *ga_fsfreeze_hook(GAState *s)
469 {
470 return s->fsfreeze_hook;
471 }
472 #endif
473
474 static void become_daemon(const char *pidfile)
475 {
476 #ifndef _WIN32
477 pid_t pid, sid;
478
479 pid = fork();
480 if (pid < 0) {
481 exit(EXIT_FAILURE);
482 }
483 if (pid > 0) {
484 exit(EXIT_SUCCESS);
485 }
486
487 if (pidfile) {
488 if (!ga_open_pidfile(pidfile)) {
489 g_critical("failed to create pidfile");
490 exit(EXIT_FAILURE);
491 }
492 }
493
494 umask(S_IRWXG | S_IRWXO);
495 sid = setsid();
496 if (sid < 0) {
497 goto fail;
498 }
499 if ((chdir("/")) < 0) {
500 goto fail;
501 }
502
503 reopen_fd_to_null(STDIN_FILENO);
504 reopen_fd_to_null(STDOUT_FILENO);
505 reopen_fd_to_null(STDERR_FILENO);
506 return;
507
508 fail:
509 if (pidfile) {
510 unlink(pidfile);
511 }
512 g_critical("failed to daemonize");
513 exit(EXIT_FAILURE);
514 #endif
515 }
516
517 static int send_response(GAState *s, QObject *payload)
518 {
519 const char *buf;
520 QString *payload_qstr, *response_qstr;
521 GIOStatus status;
522
523 g_assert(payload && s->channel);
524
525 payload_qstr = qobject_to_json(payload);
526 if (!payload_qstr) {
527 return -EINVAL;
528 }
529
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;
538 }
539
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;
546 }
547
548 return 0;
549 }
550
551 static void process_command(GAState *s, QDict *req)
552 {
553 QObject *rsp = NULL;
554 int ret;
555
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) {
562 g_warning("error sending response: %s", strerror(ret));
563 }
564 qobject_decref(rsp);
565 }
566 }
567
568 /* handle requests/control events coming in over the channel */
569 static void process_event(JSONMessageParser *parser, GQueue *tokens)
570 {
571 GAState *s = container_of(parser, GAState, parser);
572 QDict *qdict;
573 Error *err = NULL;
574 int ret;
575
576 g_assert(s && parser);
577
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));
588 }
589 qdict_put_obj(qdict, "error", qmp_build_error_object(err));
590 error_free(err);
591 }
592
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);
604 }
605 ret = send_response(s, QOBJECT(qdict));
606 if (ret < 0) {
607 g_warning("error sending error response: %s", strerror(-ret));
608 }
609 }
610
611 QDECREF(qdict);
612 }
613
614 /* false return signals GAChannel to close the current client connection */
615 static gboolean channel_event_cb(GIOCondition condition, gpointer data)
616 {
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;
634 }
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
639 */
640 if (s->virtio) {
641 usleep(100*1000);
642 }
643 return true;
644 default:
645 g_warning("unknown channel read status, closing");
646 return false;
647 }
648 return true;
649 }
650
651 static gboolean channel_init(GAState *s, const gchar *method, const gchar *path)
652 {
653 GAChannelMethod channel_method;
654
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 {
663 g_critical("unsupported channel method/type: %s", method);
664 return false;
665 }
666
667 s->channel = ga_channel_new(channel_method, path, channel_event_cb, s);
668 if (!s->channel) {
669 g_critical("failed to create guest agent channel");
670 return false;
671 }
672
673 return true;
674 }
675
676 #ifdef _WIN32
677 DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
678 LPVOID ctx)
679 {
680 DWORD ret = NO_ERROR;
681 GAService *service = &ga_state->service;
682
683 switch (ctrl)
684 {
685 case SERVICE_CONTROL_STOP:
686 case SERVICE_CONTROL_SHUTDOWN:
687 quit_handler(SIGTERM);
688 service->status.dwCurrentState = SERVICE_STOP_PENDING;
689 SetServiceStatus(service->status_handle, &service->status);
690 break;
691
692 default:
693 ret = ERROR_CALL_NOT_IMPLEMENTED;
694 }
695 return ret;
696 }
697
698 VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
699 {
700 GAService *service = &ga_state->service;
701
702 service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME,
703 service_ctrl_handler, NULL);
704
705 if (service->status_handle == 0) {
706 g_critical("Failed to register extended requests function!\n");
707 return;
708 }
709
710 service->status.dwServiceType = SERVICE_WIN32;
711 service->status.dwCurrentState = SERVICE_RUNNING;
712 service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
713 service->status.dwWin32ExitCode = NO_ERROR;
714 service->status.dwServiceSpecificExitCode = NO_ERROR;
715 service->status.dwCheckPoint = 0;
716 service->status.dwWaitHint = 0;
717 SetServiceStatus(service->status_handle, &service->status);
718
719 g_main_loop_run(ga_state->main_loop);
720
721 service->status.dwCurrentState = SERVICE_STOPPED;
722 SetServiceStatus(service->status_handle, &service->status);
723 }
724 #endif
725
726 static void set_persistent_state_defaults(GAPersistentState *pstate)
727 {
728 g_assert(pstate);
729 pstate->fd_counter = QGA_PSTATE_DEFAULT_FD_COUNTER;
730 }
731
732 static void persistent_state_from_keyfile(GAPersistentState *pstate,
733 GKeyFile *keyfile)
734 {
735 g_assert(pstate);
736 g_assert(keyfile);
737 /* if any fields are missing, either because the file was tampered with
738 * by agents of chaos, or because the field wasn't present at the time the
739 * file was created, the best we can ever do is start over with the default
740 * values. so load them now, and ignore any errors in accessing key-value
741 * pairs
742 */
743 set_persistent_state_defaults(pstate);
744
745 if (g_key_file_has_key(keyfile, "global", "fd_counter", NULL)) {
746 pstate->fd_counter =
747 g_key_file_get_integer(keyfile, "global", "fd_counter", NULL);
748 }
749 }
750
751 static void persistent_state_to_keyfile(const GAPersistentState *pstate,
752 GKeyFile *keyfile)
753 {
754 g_assert(pstate);
755 g_assert(keyfile);
756
757 g_key_file_set_integer(keyfile, "global", "fd_counter", pstate->fd_counter);
758 }
759
760 static gboolean write_persistent_state(const GAPersistentState *pstate,
761 const gchar *path)
762 {
763 GKeyFile *keyfile = g_key_file_new();
764 GError *gerr = NULL;
765 gboolean ret = true;
766 gchar *data = NULL;
767 gsize data_len;
768
769 g_assert(pstate);
770
771 persistent_state_to_keyfile(pstate, keyfile);
772 data = g_key_file_to_data(keyfile, &data_len, &gerr);
773 if (gerr) {
774 g_critical("failed to convert persistent state to string: %s",
775 gerr->message);
776 ret = false;
777 goto out;
778 }
779
780 g_file_set_contents(path, data, data_len, &gerr);
781 if (gerr) {
782 g_critical("failed to write persistent state to %s: %s",
783 path, gerr->message);
784 ret = false;
785 goto out;
786 }
787
788 out:
789 if (gerr) {
790 g_error_free(gerr);
791 }
792 if (keyfile) {
793 g_key_file_free(keyfile);
794 }
795 g_free(data);
796 return ret;
797 }
798
799 static gboolean read_persistent_state(GAPersistentState *pstate,
800 const gchar *path, gboolean frozen)
801 {
802 GKeyFile *keyfile = NULL;
803 GError *gerr = NULL;
804 struct stat st;
805 gboolean ret = true;
806
807 g_assert(pstate);
808
809 if (stat(path, &st) == -1) {
810 /* it's okay if state file doesn't exist, but any other error
811 * indicates a permissions issue or some other misconfiguration
812 * that we likely won't be able to recover from.
813 */
814 if (errno != ENOENT) {
815 g_critical("unable to access state file at path %s: %s",
816 path, strerror(errno));
817 ret = false;
818 goto out;
819 }
820
821 /* file doesn't exist. initialize state to default values and
822 * attempt to save now. (we could wait till later when we have
823 * modified state we need to commit, but if there's a problem,
824 * such as a missing parent directory, we want to catch it now)
825 *
826 * there is a potential scenario where someone either managed to
827 * update the agent from a version that didn't use a key store
828 * while qemu-ga thought the filesystem was frozen, or
829 * deleted the key store prior to issuing a fsfreeze, prior
830 * to restarting the agent. in this case we go ahead and defer
831 * initial creation till we actually have modified state to
832 * write, otherwise fail to recover from freeze.
833 */
834 set_persistent_state_defaults(pstate);
835 if (!frozen) {
836 ret = write_persistent_state(pstate, path);
837 if (!ret) {
838 g_critical("unable to create state file at path %s", path);
839 ret = false;
840 goto out;
841 }
842 }
843 ret = true;
844 goto out;
845 }
846
847 keyfile = g_key_file_new();
848 g_key_file_load_from_file(keyfile, path, 0, &gerr);
849 if (gerr) {
850 g_critical("error loading persistent state from path: %s, %s",
851 path, gerr->message);
852 ret = false;
853 goto out;
854 }
855
856 persistent_state_from_keyfile(pstate, keyfile);
857
858 out:
859 if (keyfile) {
860 g_key_file_free(keyfile);
861 }
862 if (gerr) {
863 g_error_free(gerr);
864 }
865
866 return ret;
867 }
868
869 int64_t ga_get_fd_handle(GAState *s, Error **errp)
870 {
871 int64_t handle;
872
873 g_assert(s->pstate_filepath);
874 /* we blacklist commands and avoid operations that potentially require
875 * writing to disk when we're in a frozen state. this includes opening
876 * new files, so we should never get here in that situation
877 */
878 g_assert(!ga_is_frozen(s));
879
880 handle = s->pstate.fd_counter++;
881
882 /* This should never happen on a reasonable timeframe, as guest-file-open
883 * would have to be issued 2^63 times */
884 if (s->pstate.fd_counter == INT64_MAX) {
885 abort();
886 }
887
888 if (!write_persistent_state(&s->pstate, s->pstate_filepath)) {
889 error_setg(errp, "failed to commit persistent state to disk");
890 return -1;
891 }
892
893 return handle;
894 }
895
896 static void ga_print_cmd(QmpCommand *cmd, void *opaque)
897 {
898 printf("%s\n", qmp_command_name(cmd));
899 }
900
901 static GList *split_list(const gchar *str, const gchar *delim)
902 {
903 GList *list = NULL;
904 int i;
905 gchar **strv;
906
907 strv = g_strsplit(str, delim, -1);
908 for (i = 0; strv[i]; i++) {
909 list = g_list_prepend(list, strv[i]);
910 }
911 g_free(strv);
912
913 return list;
914 }
915
916 typedef struct GAConfig {
917 char *channel_path;
918 char *method;
919 char *log_filepath;
920 char *pid_filepath;
921 #ifdef CONFIG_FSFREEZE
922 char *fsfreeze_hook;
923 #endif
924 char *state_dir;
925 #ifdef _WIN32
926 const char *service;
927 #endif
928 gchar *bliststr; /* blacklist may point to this string */
929 GList *blacklist;
930 int daemonize;
931 GLogLevelFlags log_level;
932 int dumpconf;
933 } GAConfig;
934
935 static void config_load(GAConfig *config)
936 {
937 GError *gerr = NULL;
938 GKeyFile *keyfile;
939 const char *conf = g_getenv("QGA_CONF") ?: QGA_CONF_DEFAULT;
940
941 /* read system config */
942 keyfile = g_key_file_new();
943 if (!g_key_file_load_from_file(keyfile, conf, 0, &gerr)) {
944 goto end;
945 }
946 if (g_key_file_has_key(keyfile, "general", "daemon", NULL)) {
947 config->daemonize =
948 g_key_file_get_boolean(keyfile, "general", "daemon", &gerr);
949 }
950 if (g_key_file_has_key(keyfile, "general", "method", NULL)) {
951 config->method =
952 g_key_file_get_string(keyfile, "general", "method", &gerr);
953 }
954 if (g_key_file_has_key(keyfile, "general", "path", NULL)) {
955 config->channel_path =
956 g_key_file_get_string(keyfile, "general", "path", &gerr);
957 }
958 if (g_key_file_has_key(keyfile, "general", "logfile", NULL)) {
959 config->log_filepath =
960 g_key_file_get_string(keyfile, "general", "logfile", &gerr);
961 }
962 if (g_key_file_has_key(keyfile, "general", "pidfile", NULL)) {
963 config->pid_filepath =
964 g_key_file_get_string(keyfile, "general", "pidfile", &gerr);
965 }
966 #ifdef CONFIG_FSFREEZE
967 if (g_key_file_has_key(keyfile, "general", "fsfreeze-hook", NULL)) {
968 config->fsfreeze_hook =
969 g_key_file_get_string(keyfile,
970 "general", "fsfreeze-hook", &gerr);
971 }
972 #endif
973 if (g_key_file_has_key(keyfile, "general", "statedir", NULL)) {
974 config->state_dir =
975 g_key_file_get_string(keyfile, "general", "statedir", &gerr);
976 }
977 if (g_key_file_has_key(keyfile, "general", "verbose", NULL) &&
978 g_key_file_get_boolean(keyfile, "general", "verbose", &gerr)) {
979 /* enable all log levels */
980 config->log_level = G_LOG_LEVEL_MASK;
981 }
982 if (g_key_file_has_key(keyfile, "general", "blacklist", NULL)) {
983 config->bliststr =
984 g_key_file_get_string(keyfile, "general", "blacklist", &gerr);
985 config->blacklist = g_list_concat(config->blacklist,
986 split_list(config->bliststr, ","));
987 }
988
989 end:
990 g_key_file_free(keyfile);
991 if (gerr &&
992 !(gerr->domain == G_FILE_ERROR && gerr->code == G_FILE_ERROR_NOENT)) {
993 g_critical("error loading configuration from path: %s, %s",
994 QGA_CONF_DEFAULT, gerr->message);
995 exit(EXIT_FAILURE);
996 }
997 g_clear_error(&gerr);
998 }
999
1000 static gchar *list_join(GList *list, const gchar separator)
1001 {
1002 GString *str = g_string_new("");
1003
1004 while (list) {
1005 str = g_string_append(str, (gchar *)list->data);
1006 list = g_list_next(list);
1007 if (list) {
1008 str = g_string_append_c(str, separator);
1009 }
1010 }
1011
1012 return g_string_free(str, FALSE);
1013 }
1014
1015 static void config_dump(GAConfig *config)
1016 {
1017 GError *error = NULL;
1018 GKeyFile *keyfile;
1019 gchar *tmp;
1020
1021 keyfile = g_key_file_new();
1022 g_assert(keyfile);
1023
1024 g_key_file_set_boolean(keyfile, "general", "daemon", config->daemonize);
1025 g_key_file_set_string(keyfile, "general", "method", config->method);
1026 g_key_file_set_string(keyfile, "general", "path", config->channel_path);
1027 if (config->log_filepath) {
1028 g_key_file_set_string(keyfile, "general", "logfile",
1029 config->log_filepath);
1030 }
1031 g_key_file_set_string(keyfile, "general", "pidfile", config->pid_filepath);
1032 #ifdef CONFIG_FSFREEZE
1033 if (config->fsfreeze_hook) {
1034 g_key_file_set_string(keyfile, "general", "fsfreeze-hook",
1035 config->fsfreeze_hook);
1036 }
1037 #endif
1038 g_key_file_set_string(keyfile, "general", "statedir", config->state_dir);
1039 g_key_file_set_boolean(keyfile, "general", "verbose",
1040 config->log_level == G_LOG_LEVEL_MASK);
1041 tmp = list_join(config->blacklist, ',');
1042 g_key_file_set_string(keyfile, "general", "blacklist", tmp);
1043 g_free(tmp);
1044
1045 tmp = g_key_file_to_data(keyfile, NULL, &error);
1046 printf("%s", tmp);
1047
1048 g_free(tmp);
1049 g_key_file_free(keyfile);
1050 }
1051
1052 static void config_parse(GAConfig *config, int argc, char **argv)
1053 {
1054 const char *sopt = "hVvdm:p:l:f:F::b:s:t:D";
1055 int opt_ind = 0, ch;
1056 const struct option lopt[] = {
1057 { "help", 0, NULL, 'h' },
1058 { "version", 0, NULL, 'V' },
1059 { "dump-conf", 0, NULL, 'D' },
1060 { "logfile", 1, NULL, 'l' },
1061 { "pidfile", 1, NULL, 'f' },
1062 #ifdef CONFIG_FSFREEZE
1063 { "fsfreeze-hook", 2, NULL, 'F' },
1064 #endif
1065 { "verbose", 0, NULL, 'v' },
1066 { "method", 1, NULL, 'm' },
1067 { "path", 1, NULL, 'p' },
1068 { "daemonize", 0, NULL, 'd' },
1069 { "blacklist", 1, NULL, 'b' },
1070 #ifdef _WIN32
1071 { "service", 1, NULL, 's' },
1072 #endif
1073 { "statedir", 1, NULL, 't' },
1074 { NULL, 0, NULL, 0 }
1075 };
1076
1077 while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
1078 switch (ch) {
1079 case 'm':
1080 g_free(config->method);
1081 config->method = g_strdup(optarg);
1082 break;
1083 case 'p':
1084 g_free(config->channel_path);
1085 config->channel_path = g_strdup(optarg);
1086 break;
1087 case 'l':
1088 g_free(config->log_filepath);
1089 config->log_filepath = g_strdup(optarg);
1090 break;
1091 case 'f':
1092 g_free(config->pid_filepath);
1093 config->pid_filepath = g_strdup(optarg);
1094 break;
1095 #ifdef CONFIG_FSFREEZE
1096 case 'F':
1097 g_free(config->fsfreeze_hook);
1098 config->fsfreeze_hook = g_strdup(optarg ?: QGA_FSFREEZE_HOOK_DEFAULT);
1099 break;
1100 #endif
1101 case 't':
1102 g_free(config->state_dir);
1103 config->state_dir = g_strdup(optarg);
1104 break;
1105 case 'v':
1106 /* enable all log levels */
1107 config->log_level = G_LOG_LEVEL_MASK;
1108 break;
1109 case 'V':
1110 printf("QEMU Guest Agent %s\n", QEMU_VERSION);
1111 exit(EXIT_SUCCESS);
1112 case 'd':
1113 config->daemonize = 1;
1114 break;
1115 case 'D':
1116 config->dumpconf = 1;
1117 break;
1118 case 'b': {
1119 if (is_help_option(optarg)) {
1120 qmp_for_each_command(ga_print_cmd, NULL);
1121 exit(EXIT_SUCCESS);
1122 }
1123 config->blacklist = g_list_concat(config->blacklist,
1124 split_list(optarg, ","));
1125 break;
1126 }
1127 #ifdef _WIN32
1128 case 's':
1129 config->service = optarg;
1130 if (strcmp(config->service, "install") == 0) {
1131 if (ga_install_vss_provider()) {
1132 exit(EXIT_FAILURE);
1133 }
1134 if (ga_install_service(config->channel_path,
1135 config->log_filepath, config->state_dir)) {
1136 exit(EXIT_FAILURE);
1137 }
1138 exit(EXIT_SUCCESS);
1139 } else if (strcmp(config->service, "uninstall") == 0) {
1140 ga_uninstall_vss_provider();
1141 exit(ga_uninstall_service());
1142 } else if (strcmp(config->service, "vss-install") == 0) {
1143 if (ga_install_vss_provider()) {
1144 exit(EXIT_FAILURE);
1145 }
1146 exit(EXIT_SUCCESS);
1147 } else if (strcmp(config->service, "vss-uninstall") == 0) {
1148 ga_uninstall_vss_provider();
1149 exit(EXIT_SUCCESS);
1150 } else {
1151 printf("Unknown service command.\n");
1152 exit(EXIT_FAILURE);
1153 }
1154 break;
1155 #endif
1156 case 'h':
1157 usage(argv[0]);
1158 exit(EXIT_SUCCESS);
1159 case '?':
1160 g_print("Unknown option, try '%s --help' for more information.\n",
1161 argv[0]);
1162 exit(EXIT_FAILURE);
1163 }
1164 }
1165 }
1166
1167 static void config_free(GAConfig *config)
1168 {
1169 g_free(config->method);
1170 g_free(config->log_filepath);
1171 g_free(config->pid_filepath);
1172 g_free(config->state_dir);
1173 g_free(config->channel_path);
1174 g_free(config->bliststr);
1175 #ifdef CONFIG_FSFREEZE
1176 g_free(config->fsfreeze_hook);
1177 #endif
1178 g_free(config);
1179 }
1180
1181 static bool check_is_frozen(GAState *s)
1182 {
1183 #ifndef _WIN32
1184 /* check if a previous instance of qemu-ga exited with filesystems' state
1185 * marked as frozen. this could be a stale value (a non-qemu-ga process
1186 * or reboot may have since unfrozen them), but better to require an
1187 * uneeded unfreeze than to risk hanging on start-up
1188 */
1189 struct stat st;
1190 if (stat(s->state_filepath_isfrozen, &st) == -1) {
1191 /* it's okay if the file doesn't exist, but if we can't access for
1192 * some other reason, such as permissions, there's a configuration
1193 * that needs to be addressed. so just bail now before we get into
1194 * more trouble later
1195 */
1196 if (errno != ENOENT) {
1197 g_critical("unable to access state file at path %s: %s",
1198 s->state_filepath_isfrozen, strerror(errno));
1199 return EXIT_FAILURE;
1200 }
1201 } else {
1202 g_warning("previous instance appears to have exited with frozen"
1203 " filesystems. deferring logging/pidfile creation and"
1204 " disabling non-fsfreeze-safe commands until"
1205 " guest-fsfreeze-thaw is issued, or filesystems are"
1206 " manually unfrozen and the file %s is removed",
1207 s->state_filepath_isfrozen);
1208 return true;
1209 }
1210 #endif
1211 return false;
1212 }
1213
1214 static int run_agent(GAState *s, GAConfig *config)
1215 {
1216 ga_state = s;
1217
1218 g_log_set_default_handler(ga_log, s);
1219 g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
1220 ga_enable_logging(s);
1221
1222 #ifdef _WIN32
1223 /* On win32 the state directory is application specific (be it the default
1224 * or a user override). We got past the command line parsing; let's create
1225 * the directory (with any intermediate directories). If we run into an
1226 * error later on, we won't try to clean up the directory, it is considered
1227 * persistent.
1228 */
1229 if (g_mkdir_with_parents(config->state_dir, S_IRWXU) == -1) {
1230 g_critical("unable to create (an ancestor of) the state directory"
1231 " '%s': %s", config->state_dir, strerror(errno));
1232 return EXIT_FAILURE;
1233 }
1234 #endif
1235
1236 if (ga_is_frozen(s)) {
1237 if (config->daemonize) {
1238 /* delay opening/locking of pidfile till filesystems are unfrozen */
1239 s->deferred_options.pid_filepath = config->pid_filepath;
1240 become_daemon(NULL);
1241 }
1242 if (config->log_filepath) {
1243 /* delay opening the log file till filesystems are unfrozen */
1244 s->deferred_options.log_filepath = config->log_filepath;
1245 }
1246 ga_disable_logging(s);
1247 qmp_for_each_command(ga_disable_non_whitelisted, NULL);
1248 } else {
1249 if (config->daemonize) {
1250 become_daemon(config->pid_filepath);
1251 }
1252 if (config->log_filepath) {
1253 FILE *log_file = ga_open_logfile(config->log_filepath);
1254 if (!log_file) {
1255 g_critical("unable to open specified log file: %s",
1256 strerror(errno));
1257 return EXIT_FAILURE;
1258 }
1259 s->log_file = log_file;
1260 }
1261 }
1262
1263 /* load persistent state from disk */
1264 if (!read_persistent_state(&s->pstate,
1265 s->pstate_filepath,
1266 ga_is_frozen(s))) {
1267 g_critical("failed to load persistent state");
1268 return EXIT_FAILURE;
1269 }
1270
1271 config->blacklist = ga_command_blacklist_init(config->blacklist);
1272 if (config->blacklist) {
1273 GList *l = config->blacklist;
1274 s->blacklist = config->blacklist;
1275 do {
1276 g_debug("disabling command: %s", (char *)l->data);
1277 qmp_disable_command(l->data);
1278 l = g_list_next(l);
1279 } while (l);
1280 }
1281 s->command_state = ga_command_state_new();
1282 ga_command_state_init(s, s->command_state);
1283 ga_command_state_init_all(s->command_state);
1284 json_message_parser_init(&s->parser, process_event);
1285 ga_state = s;
1286 #ifndef _WIN32
1287 if (!register_signal_handlers()) {
1288 g_critical("failed to register signal handlers");
1289 return EXIT_FAILURE;
1290 }
1291 #endif
1292
1293 s->main_loop = g_main_loop_new(NULL, false);
1294 if (!channel_init(ga_state, config->method, config->channel_path)) {
1295 g_critical("failed to initialize guest agent channel");
1296 return EXIT_FAILURE;
1297 }
1298 #ifndef _WIN32
1299 g_main_loop_run(ga_state->main_loop);
1300 #else
1301 if (config->daemonize) {
1302 SERVICE_TABLE_ENTRY service_table[] = {
1303 { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
1304 StartServiceCtrlDispatcher(service_table);
1305 } else {
1306 g_main_loop_run(ga_state->main_loop);
1307 }
1308 #endif
1309
1310 return EXIT_SUCCESS;
1311 }
1312
1313 static void free_blacklist_entry(gpointer entry, gpointer unused)
1314 {
1315 g_free(entry);
1316 }
1317
1318 int main(int argc, char **argv)
1319 {
1320 int ret = EXIT_SUCCESS;
1321 GAState *s = g_new0(GAState, 1);
1322 GAConfig *config = g_new0(GAConfig, 1);
1323
1324 config->log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
1325
1326 module_call_init(MODULE_INIT_QAPI);
1327
1328 init_dfl_pathnames();
1329 config_load(config);
1330 config_parse(config, argc, argv);
1331
1332 if (config->pid_filepath == NULL) {
1333 config->pid_filepath = g_strdup(dfl_pathnames.pidfile);
1334 }
1335
1336 if (config->state_dir == NULL) {
1337 config->state_dir = g_strdup(dfl_pathnames.state_dir);
1338 }
1339
1340 if (config->method == NULL) {
1341 config->method = g_strdup("virtio-serial");
1342 }
1343
1344 if (config->channel_path == NULL) {
1345 if (strcmp(config->method, "virtio-serial") == 0) {
1346 /* try the default path for the virtio-serial port */
1347 config->channel_path = g_strdup(QGA_VIRTIO_PATH_DEFAULT);
1348 } else if (strcmp(config->method, "isa-serial") == 0) {
1349 /* try the default path for the serial port - COM1 */
1350 config->channel_path = g_strdup(QGA_SERIAL_PATH_DEFAULT);
1351 } else {
1352 g_critical("must specify a path for this channel");
1353 ret = EXIT_FAILURE;
1354 goto end;
1355 }
1356 }
1357
1358 s->log_level = config->log_level;
1359 s->log_file = stderr;
1360 #ifdef CONFIG_FSFREEZE
1361 s->fsfreeze_hook = config->fsfreeze_hook;
1362 #endif
1363 s->pstate_filepath = g_strdup_printf("%s/qga.state", config->state_dir);
1364 s->state_filepath_isfrozen = g_strdup_printf("%s/qga.state.isfrozen",
1365 config->state_dir);
1366 s->frozen = check_is_frozen(s);
1367
1368 if (config->dumpconf) {
1369 config_dump(config);
1370 goto end;
1371 }
1372
1373 ret = run_agent(s, config);
1374
1375 end:
1376 if (s->command_state) {
1377 ga_command_state_cleanup_all(s->command_state);
1378 }
1379 if (s->channel) {
1380 ga_channel_free(s->channel);
1381 }
1382 g_list_foreach(config->blacklist, free_blacklist_entry, NULL);
1383 g_free(s->pstate_filepath);
1384 g_free(s->state_filepath_isfrozen);
1385
1386 if (config->daemonize) {
1387 unlink(config->pid_filepath);
1388 }
1389
1390 config_free(config);
1391
1392 return ret;
1393 }