aboutsummaryrefslogtreecommitdiff
path: root/qemu-ga.c
blob: d6f786e50d7e2b4bec864feebbd63a20514ea650 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
/*
 * QEMU Guest Agent
 *
 * Copyright IBM Corp. 2011
 *
 * Authors:
 *  Adam Litke        <aglitke@linux.vnet.ibm.com>
 *  Michael Roth      <mdroth@linux.vnet.ibm.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or later.
 * See the COPYING file in the top-level directory.
 */
#include <stdlib.h>
#include <stdio.h>
#include <stdbool.h>
#include <glib.h>
#include <getopt.h>
#ifndef _WIN32
#include <syslog.h>
#include <sys/wait.h>
#endif
#include "json-streamer.h"
#include "json-parser.h"
#include "qint.h"
#include "qjson.h"
#include "qga/guest-agent-core.h"
#include "module.h"
#include "signal.h"
#include "qerror.h"
#include "error_int.h"
#include "qapi/qmp-core.h"
#include "qga/channel.h"
#ifdef _WIN32
#include "qga/service-win32.h"
#include <windows.h>
#endif

#ifndef _WIN32
#define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0"
#else
#define QGA_VIRTIO_PATH_DEFAULT "\\\\.\\Global\\org.qemu.guest_agent.0"
#endif
#define QGA_PIDFILE_DEFAULT "/var/run/qemu-ga.pid"
#define QGA_SENTINEL_BYTE 0xFF

struct GAState {
    JSONMessageParser parser;
    GMainLoop *main_loop;
    GAChannel *channel;
    bool virtio; /* fastpath to check for virtio to deal with poll() quirks */
    GACommandState *command_state;
    GLogLevelFlags log_level;
    FILE *log_file;
    bool logging_enabled;
#ifdef _WIN32
    GAService service;
#endif
    bool delimit_response;
};

struct GAState *ga_state;

#ifdef _WIN32
DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
                                  LPVOID ctx);
VOID WINAPI service_main(DWORD argc, TCHAR *argv[]);
#endif

static void quit_handler(int sig)
{
    g_debug("received signal num %d, quitting", sig);

    if (g_main_loop_is_running(ga_state->main_loop)) {
        g_main_loop_quit(ga_state->main_loop);
    }
}

#ifndef _WIN32
/* reap _all_ terminated children */
static void child_handler(int sig)
{
    int status;
    while (waitpid(-1, &status, WNOHANG) > 0) /* NOTHING */;
}

static gboolean register_signal_handlers(void)
{
    struct sigaction sigact, sigact_chld;
    int ret;

    memset(&sigact, 0, sizeof(struct sigaction));
    sigact.sa_handler = quit_handler;

    ret = sigaction(SIGINT, &sigact, NULL);
    if (ret == -1) {
        g_error("error configuring signal handler: %s", strerror(errno));
        return false;
    }
    ret = sigaction(SIGTERM, &sigact, NULL);
    if (ret == -1) {
        g_error("error configuring signal handler: %s", strerror(errno));
        return false;
    }

    memset(&sigact_chld, 0, sizeof(struct sigaction));
    sigact_chld.sa_handler = child_handler;
    sigact_chld.sa_flags = SA_NOCLDSTOP;
    ret = sigaction(SIGCHLD, &sigact_chld, NULL);
    if (ret == -1) {
        g_error("error configuring signal handler: %s", strerror(errno));
    }

    return true;
}
#endif

static void usage(const char *cmd)
{
    printf(
"Usage: %s -c <channel_opts>\n"
"QEMU Guest Agent %s\n"
"\n"
"  -m, --method      transport method: one of unix-listen, virtio-serial, or\n"
"                    isa-serial (virtio-serial is the default)\n"
"  -p, --path        device/socket path (%s is the default for virtio-serial)\n"
"  -l, --logfile     set logfile path, logs to stderr by default\n"
"  -f, --pidfile     specify pidfile (default is %s)\n"
"  -v, --verbose     log extra debugging information\n"
"  -V, --version     print version information and exit\n"
"  -d, --daemonize   become a daemon\n"
#ifdef _WIN32
"  -s, --service     service commands: install, uninstall\n"
#endif
"  -b, --blacklist   comma-separated list of RPCs to disable (no spaces, \"?\""
"                    to list available RPCs)\n"
"  -h, --help        display this help and exit\n"
"\n"
"Report bugs to <mdroth@linux.vnet.ibm.com>\n"
    , cmd, QGA_VERSION, QGA_VIRTIO_PATH_DEFAULT, QGA_PIDFILE_DEFAULT);
}

static const char *ga_log_level_str(GLogLevelFlags level)
{
    switch (level & G_LOG_LEVEL_MASK) {
        case G_LOG_LEVEL_ERROR:
            return "error";
        case G_LOG_LEVEL_CRITICAL:
            return "critical";
        case G_LOG_LEVEL_WARNING:
            return "warning";
        case G_LOG_LEVEL_MESSAGE:
            return "message";
        case G_LOG_LEVEL_INFO:
            return "info";
        case G_LOG_LEVEL_DEBUG:
            return "debug";
        default:
            return "user";
    }
}

bool ga_logging_enabled(GAState *s)
{
    return s->logging_enabled;
}

void ga_disable_logging(GAState *s)
{
    s->logging_enabled = false;
}

void ga_enable_logging(GAState *s)
{
    s->logging_enabled = true;
}

static void ga_log(const gchar *domain, GLogLevelFlags level,
                   const gchar *msg, gpointer opaque)
{
    GAState *s = opaque;
    GTimeVal time;
    const char *level_str = ga_log_level_str(level);

    if (!ga_logging_enabled(s)) {
        return;
    }

    level &= G_LOG_LEVEL_MASK;
#ifndef _WIN32
    if (domain && strcmp(domain, "syslog") == 0) {
        syslog(LOG_INFO, "%s: %s", level_str, msg);
    } else if (level & s->log_level) {
#else
    if (level & s->log_level) {
#endif
        g_get_current_time(&time);
        fprintf(s->log_file,
                "%lu.%lu: %s: %s\n", time.tv_sec, time.tv_usec, level_str, msg);
        fflush(s->log_file);
    }
}

void ga_set_response_delimited(GAState *s)
{
    s->delimit_response = true;
}

#ifndef _WIN32
static void become_daemon(const char *pidfile)
{
    pid_t pid, sid;
    int pidfd;
    char *pidstr = NULL;

    pid = fork();
    if (pid < 0) {
        exit(EXIT_FAILURE);
    }
    if (pid > 0) {
        exit(EXIT_SUCCESS);
    }

    pidfd = open(pidfile, O_CREAT|O_WRONLY|O_EXCL, S_IRUSR|S_IWUSR);
    if (pidfd == -1) {
        g_critical("Cannot create pid file, %s", strerror(errno));
        exit(EXIT_FAILURE);
    }

    if (asprintf(&pidstr, "%d", getpid()) == -1) {
        g_critical("Cannot allocate memory");
        goto fail;
    }
    if (write(pidfd, pidstr, strlen(pidstr)) != strlen(pidstr)) {
        free(pidstr);
        g_critical("Failed to write pid file");
        goto fail;
    }

    umask(0);
    sid = setsid();
    if (sid < 0) {
        goto fail;
    }
    if ((chdir("/")) < 0) {
        goto fail;
    }

    close(STDIN_FILENO);
    close(STDOUT_FILENO);
    close(STDERR_FILENO);
    free(pidstr);
    return;

fail:
    unlink(pidfile);
    g_critical("failed to daemonize");
    exit(EXIT_FAILURE);
}
#endif

static int send_response(GAState *s, QObject *payload)
{
    const char *buf;
    QString *payload_qstr, *response_qstr;
    GIOStatus status;

    g_assert(payload && s->channel);

    payload_qstr = qobject_to_json(payload);
    if (!payload_qstr) {
        return -EINVAL;
    }

    if (s->delimit_response) {
        s->delimit_response = false;
        response_qstr = qstring_new();
        qstring_append_chr(response_qstr, QGA_SENTINEL_BYTE);
        qstring_append(response_qstr, qstring_get_str(payload_qstr));
        QDECREF(payload_qstr);
    } else {
        response_qstr = payload_qstr;
    }

    qstring_append_chr(response_qstr, '\n');
    buf = qstring_get_str(response_qstr);
    status = ga_channel_write_all(s->channel, buf, strlen(buf));
    QDECREF(response_qstr);
    if (status != G_IO_STATUS_NORMAL) {
        return -EIO;
    }

    return 0;
}

static void process_command(GAState *s, QDict *req)
{
    QObject *rsp = NULL;
    int ret;

    g_assert(req);
    g_debug("processing command");
    rsp = qmp_dispatch(QOBJECT(req));
    if (rsp) {
        ret = send_response(s, rsp);
        if (ret) {
            g_warning("error sending response: %s", strerror(ret));
        }
        qobject_decref(rsp);
    } else {
        g_warning("error getting response");
    }
}

/* handle requests/control events coming in over the channel */
static void process_event(JSONMessageParser *parser, QList *tokens)
{
    GAState *s = container_of(parser, GAState, parser);
    QObject *obj;
    QDict *qdict;
    Error *err = NULL;
    int ret;

    g_assert(s && parser);

    g_debug("process_event: called");
    obj = json_parser_parse_err(tokens, NULL, &err);
    if (err || !obj || qobject_type(obj) != QTYPE_QDICT) {
        qobject_decref(obj);
        qdict = qdict_new();
        if (!err) {
            g_warning("failed to parse event: unknown error");
            error_set(&err, QERR_JSON_PARSING);
        } else {
            g_warning("failed to parse event: %s", error_get_pretty(err));
        }
        qdict_put_obj(qdict, "error", error_get_qobject(err));
        error_free(err);
    } else {
        qdict = qobject_to_qdict(obj);
    }

    g_assert(qdict);

    /* handle host->guest commands */
    if (qdict_haskey(qdict, "execute")) {
        process_command(s, qdict);
    } else {
        if (!qdict_haskey(qdict, "error")) {
            QDECREF(qdict);
            qdict = qdict_new();
            g_warning("unrecognized payload format");
            error_set(&err, QERR_UNSUPPORTED);
            qdict_put_obj(qdict, "error", error_get_qobject(err));
            error_free(err);
        }
        ret = send_response(s, QOBJECT(qdict));
        if (ret) {
            g_warning("error sending error response: %s", strerror(ret));
        }
    }

    QDECREF(qdict);
}

/* false return signals GAChannel to close the current client connection */
static gboolean channel_event_cb(GIOCondition condition, gpointer data)
{
    GAState *s = data;
    gchar buf[QGA_READ_COUNT_DEFAULT+1];
    gsize count;
    GError *err = NULL;
    GIOStatus status = ga_channel_read(s->channel, buf, QGA_READ_COUNT_DEFAULT, &count);
    if (err != NULL) {
        g_warning("error reading channel: %s", err->message);
        g_error_free(err);
        return false;
    }
    switch (status) {
    case G_IO_STATUS_ERROR:
        g_warning("error reading channel");
        return false;
    case G_IO_STATUS_NORMAL:
        buf[count] = 0;
        g_debug("read data, count: %d, data: %s", (int)count, buf);
        json_message_parser_feed(&s->parser, (char *)buf, (int)count);
        break;
    case G_IO_STATUS_EOF:
        g_debug("received EOF");
        if (!s->virtio) {
            return false;
        }
    case G_IO_STATUS_AGAIN:
        /* virtio causes us to spin here when no process is attached to
         * host-side chardev. sleep a bit to mitigate this
         */
        if (s->virtio) {
            usleep(100*1000);
        }
        return true;
    default:
        g_warning("unknown channel read status, closing");
        return false;
    }
    return true;
}

static gboolean channel_init(GAState *s, const gchar *method, const gchar *path)
{
    GAChannelMethod channel_method;

    if (method == NULL) {
        method = "virtio-serial";
    }

    if (path == NULL) {
        if (strcmp(method, "virtio-serial") != 0) {
            g_critical("must specify a path for this channel");
            return false;
        }
        /* try the default path for the virtio-serial port */
        path = QGA_VIRTIO_PATH_DEFAULT;
    }

    if (strcmp(method, "virtio-serial") == 0) {
        s->virtio = true; /* virtio requires special handling in some cases */
        channel_method = GA_CHANNEL_VIRTIO_SERIAL;
    } else if (strcmp(method, "isa-serial") == 0) {
        channel_method = GA_CHANNEL_ISA_SERIAL;
    } else if (strcmp(method, "unix-listen") == 0) {
        channel_method = GA_CHANNEL_UNIX_LISTEN;
    } else {
        g_critical("unsupported channel method/type: %s", method);
        return false;
    }

    s->channel = ga_channel_new(channel_method, path, channel_event_cb, s);
    if (!s->channel) {
        g_critical("failed to create guest agent channel");
        return false;
    }

    return true;
}

#ifdef _WIN32
DWORD WINAPI service_ctrl_handler(DWORD ctrl, DWORD type, LPVOID data,
                                  LPVOID ctx)
{
    DWORD ret = NO_ERROR;
    GAService *service = &ga_state->service;

    switch (ctrl)
    {
        case SERVICE_CONTROL_STOP:
        case SERVICE_CONTROL_SHUTDOWN:
            quit_handler(SIGTERM);
            service->status.dwCurrentState = SERVICE_STOP_PENDING;
            SetServiceStatus(service->status_handle, &service->status);
            break;

        default:
            ret = ERROR_CALL_NOT_IMPLEMENTED;
    }
    return ret;
}

VOID WINAPI service_main(DWORD argc, TCHAR *argv[])
{
    GAService *service = &ga_state->service;

    service->status_handle = RegisterServiceCtrlHandlerEx(QGA_SERVICE_NAME,
        service_ctrl_handler, NULL);

    if (service->status_handle == 0) {
        g_critical("Failed to register extended requests function!\n");
        return;
    }

    service->status.dwServiceType = SERVICE_WIN32;
    service->status.dwCurrentState = SERVICE_RUNNING;
    service->status.dwControlsAccepted = SERVICE_ACCEPT_STOP | SERVICE_ACCEPT_SHUTDOWN;
    service->status.dwWin32ExitCode = NO_ERROR;
    service->status.dwServiceSpecificExitCode = NO_ERROR;
    service->status.dwCheckPoint = 0;
    service->status.dwWaitHint = 0;
    SetServiceStatus(service->status_handle, &service->status);

    g_main_loop_run(ga_state->main_loop);

    service->status.dwCurrentState = SERVICE_STOPPED;
    SetServiceStatus(service->status_handle, &service->status);
}
#endif

int main(int argc, char **argv)
{
    const char *sopt = "hVvdm:p:l:f:b:s:";
    const char *method = NULL, *path = NULL, *pidfile = QGA_PIDFILE_DEFAULT;
    const char *log_file_name = NULL;
#ifdef _WIN32
    const char *service = NULL;
#endif
    const struct option lopt[] = {
        { "help", 0, NULL, 'h' },
        { "version", 0, NULL, 'V' },
        { "logfile", 1, NULL, 'l' },
        { "pidfile", 1, NULL, 'f' },
        { "verbose", 0, NULL, 'v' },
        { "method", 1, NULL, 'm' },
        { "path", 1, NULL, 'p' },
        { "daemonize", 0, NULL, 'd' },
        { "blacklist", 1, NULL, 'b' },
#ifdef _WIN32
        { "service", 1, NULL, 's' },
#endif        
        { NULL, 0, NULL, 0 }
    };
    int opt_ind = 0, ch, daemonize = 0, i, j, len;
    GLogLevelFlags log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;
    FILE *log_file = stderr;
    GAState *s;

    module_call_init(MODULE_INIT_QAPI);

    while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {
        switch (ch) {
        case 'm':
            method = optarg;
            break;
        case 'p':
            path = optarg;
            break;
        case 'l':
            log_file_name = optarg;
            log_file = fopen(log_file_name, "a");
            if (!log_file) {
                g_critical("unable to open specified log file: %s",
                           strerror(errno));
                return EXIT_FAILURE;
            }
            break;
        case 'f':
            pidfile = optarg;
            break;
        case 'v':
            /* enable all log levels */
            log_level = G_LOG_LEVEL_MASK;
            break;
        case 'V':
            printf("QEMU Guest Agent %s\n", QGA_VERSION);
            return 0;
        case 'd':
            daemonize = 1;
            break;
        case 'b': {
            char **list_head, **list;
            if (*optarg == '?') {
                list_head = list = qmp_get_command_list();
                while (*list != NULL) {
                    printf("%s\n", *list);
                    g_free(*list);
                    list++;
                }
                g_free(list_head);
                return 0;
            }
            for (j = 0, i = 0, len = strlen(optarg); i < len; i++) {
                if (optarg[i] == ',') {
                    optarg[i] = 0;
                    qmp_disable_command(&optarg[j]);
                    g_debug("disabling command: %s", &optarg[j]);
                    j = i + 1;
                }
            }
            if (j < i) {
                qmp_disable_command(&optarg[j]);
                g_debug("disabling command: %s", &optarg[j]);
            }
            break;
        }
#ifdef _WIN32
        case 's':
            service = optarg;
            if (strcmp(service, "install") == 0) {
                return ga_install_service(path, log_file_name);
            } else if (strcmp(service, "uninstall") == 0) {
                return ga_uninstall_service();
            } else {
                printf("Unknown service command.\n");
                return EXIT_FAILURE;
            }
            break;
#endif
        case 'h':
            usage(argv[0]);
            return 0;
        case '?':
            g_print("Unknown option, try '%s --help' for more information.\n",
                    argv[0]);
            return EXIT_FAILURE;
        }
    }

#ifndef _WIN32
    if (daemonize) {
        g_debug("starting daemon");
        become_daemon(pidfile);
    }
#endif

    s = g_malloc0(sizeof(GAState));
    s->log_file = log_file;
    s->log_level = log_level;
    g_log_set_default_handler(ga_log, s);
    g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);
    s->logging_enabled = true;
    s->command_state = ga_command_state_new();
    ga_command_state_init(s, s->command_state);
    ga_command_state_init_all(s->command_state);
    json_message_parser_init(&s->parser, process_event);
    ga_state = s;
#ifndef _WIN32
    if (!register_signal_handlers()) {
        g_critical("failed to register signal handlers");
        goto out_bad;
    }
#endif

    s->main_loop = g_main_loop_new(NULL, false);
    if (!channel_init(ga_state, method, path)) {
        g_critical("failed to initialize guest agent channel");
        goto out_bad;
    }
#ifndef _WIN32
    g_main_loop_run(ga_state->main_loop);
#else
    if (daemonize) {
        SERVICE_TABLE_ENTRY service_table[] = {
            { (char *)QGA_SERVICE_NAME, service_main }, { NULL, NULL } };
        StartServiceCtrlDispatcher(service_table);
    } else {
        g_main_loop_run(ga_state->main_loop);
    }
#endif

    ga_command_state_cleanup_all(ga_state->command_state);
    ga_channel_free(ga_state->channel);

    if (daemonize) {
        unlink(pidfile);
    }
    return 0;

out_bad:
    if (daemonize) {
        unlink(pidfile);
    }
    return EXIT_FAILURE;
}