summaryrefslogtreecommitdiffstats
path: root/qga/guest-agent-commands.c
blob: a09c8ca2307bf65add6588d4258ae8fbd2957640 (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
/*
 * QEMU Guest Agent commands
 *
 * Copyright IBM Corp. 2011
 *
 * Authors:
 *  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 <glib.h>

#if defined(__linux__)
#include <mntent.h>
#include <linux/fs.h>

#if defined(__linux__) && defined(FIFREEZE)
#define CONFIG_FSFREEZE
#endif
#endif

#include <sys/types.h>
#include <sys/ioctl.h>
#include "qga/guest-agent-core.h"
#include "qga-qmp-commands.h"
#include "qerror.h"
#include "qemu-queue.h"

static GAState *ga_state;

/* Note: in some situations, like with the fsfreeze, logging may be
 * temporarilly disabled. if it is necessary that a command be able
 * to log for accounting purposes, check ga_logging_enabled() beforehand,
 * and use the QERR_QGA_LOGGING_DISABLED to generate an error
 */
static void slog(const char *fmt, ...)
{
    va_list ap;

    va_start(ap, fmt);
    g_logv("syslog", G_LOG_LEVEL_INFO, fmt, ap);
    va_end(ap);
}

int64_t qmp_guest_sync(int64_t id, Error **errp)
{
    return id;
}

void qmp_guest_ping(Error **err)
{
    slog("guest-ping called");
}

struct GuestAgentInfo *qmp_guest_info(Error **err)
{
    GuestAgentInfo *info = g_malloc0(sizeof(GuestAgentInfo));
    GuestAgentCommandInfo *cmd_info;
    GuestAgentCommandInfoList *cmd_info_list;
    char **cmd_list_head, **cmd_list;

    info->version = g_strdup(QGA_VERSION);

    cmd_list_head = cmd_list = qmp_get_command_list();
    if (*cmd_list_head == NULL) {
        goto out;
    }

    while (*cmd_list) {
        cmd_info = g_malloc0(sizeof(GuestAgentCommandInfo));
        cmd_info->name = strdup(*cmd_list);
        cmd_info->enabled = qmp_command_is_enabled(cmd_info->name);

        cmd_info_list = g_malloc0(sizeof(GuestAgentCommandInfoList));
        cmd_info_list->value = cmd_info;
        cmd_info_list->next = info->supported_commands;
        info->supported_commands = cmd_info_list;

        g_free(*cmd_list);
        cmd_list++;
    }

out:
    g_free(cmd_list_head);
    return info;
}

void qmp_guest_shutdown(bool has_mode, const char *mode, Error **err)
{
    int ret;
    const char *shutdown_flag;

    slog("guest-shutdown called, mode: %s", mode);
    if (!has_mode || strcmp(mode, "powerdown") == 0) {
        shutdown_flag = "-P";
    } else if (strcmp(mode, "halt") == 0) {
        shutdown_flag = "-H";
    } else if (strcmp(mode, "reboot") == 0) {
        shutdown_flag = "-r";
    } else {
        error_set(err, QERR_INVALID_PARAMETER_VALUE, "mode",
                  "halt|powerdown|reboot");
        return;
    }

    ret = fork();
    if (ret == 0) {
        /* child, start the shutdown */
        setsid();
        fclose(stdin);
        fclose(stdout);
        fclose(stderr);

        ret = execl("/sbin/shutdown", "shutdown", shutdown_flag, "+0",
                    "hypervisor initiated shutdown", (char*)NULL);
        if (ret) {
            slog("guest-shutdown failed: %s", strerror(errno));
        }
        exit(!!ret);
    } else if (ret < 0) {
        error_set(err, QERR_UNDEFINED_ERROR);
    }
}

typedef struct GuestFileHandle {
    uint64_t id;
    FILE *fh;
    QTAILQ_ENTRY(GuestFileHandle) next;
} GuestFileHandle;

static struct {
    QTAILQ_HEAD(, GuestFileHandle) filehandles;
} guest_file_state;

static void guest_file_handle_add(FILE *fh)
{
    GuestFileHandle *gfh;

    gfh = g_malloc0(sizeof(GuestFileHandle));
    gfh->id = fileno(fh);
    gfh->fh = fh;
    QTAILQ_INSERT_TAIL(&guest_file_state.filehandles, gfh, next);
}

static GuestFileHandle *guest_file_handle_find(int64_t id)
{
    GuestFileHandle *gfh;

    QTAILQ_FOREACH(gfh, &guest_file_state.filehandles, next)
    {
        if (gfh->id == id) {
            return gfh;
        }
    }

    return NULL;
}

int64_t qmp_guest_file_open(const char *path, bool has_mode, const char *mode, Error **err)
{
    FILE *fh;
    int fd;
    int64_t ret = -1;

    if (!has_mode) {
        mode = "r";
    }
    slog("guest-file-open called, filepath: %s, mode: %s", path, mode);
    fh = fopen(path, mode);
    if (!fh) {
        error_set(err, QERR_OPEN_FILE_FAILED, path);
        return -1;
    }

    /* set fd non-blocking to avoid common use cases (like reading from a
     * named pipe) from hanging the agent
     */
    fd = fileno(fh);
    ret = fcntl(fd, F_GETFL);
    ret = fcntl(fd, F_SETFL, ret | O_NONBLOCK);
    if (ret == -1) {
        error_set(err, QERR_QGA_COMMAND_FAILED, "fcntl() failed");
        fclose(fh);
        return -1;
    }

    guest_file_handle_add(fh);
    slog("guest-file-open, handle: %d", fd);
    return fd;
}

void qmp_guest_file_close(int64_t handle, Error **err)
{
    GuestFileHandle *gfh = guest_file_handle_find(handle);
    int ret;

    slog("guest-file-close called, handle: %ld", handle);
    if (!gfh) {
        error_set(err, QERR_FD_NOT_FOUND, "handle");
        return;
    }

    ret = fclose(gfh->fh);
    if (ret == -1) {
        error_set(err, QERR_QGA_COMMAND_FAILED, "fclose() failed");
        return;
    }

    QTAILQ_REMOVE(&guest_file_state.filehandles, gfh, next);
    g_free(gfh);
}

struct GuestFileRead *qmp_guest_file_read(int64_t handle, bool has_count,
                                          int64_t count, Error **err)
{
    GuestFileHandle *gfh = guest_file_handle_find(handle);
    GuestFileRead *read_data = NULL;
    guchar *buf;
    FILE *fh;
    size_t read_count;

    if (!gfh) {
        error_set(err, QERR_FD_NOT_FOUND, "handle");
        return NULL;
    }

    if (!has_count) {
        count = QGA_READ_COUNT_DEFAULT;
    } else if (count < 0) {
        error_set(err, QERR_INVALID_PARAMETER, "count");
        return NULL;
    }

    fh = gfh->fh;
    buf = g_malloc0(count+1);
    read_count = fread(buf, 1, count, fh);
    if (ferror(fh)) {
        slog("guest-file-read failed, handle: %ld", handle);
        error_set(err, QERR_QGA_COMMAND_FAILED, "fread() failed");
    } else {
        buf[read_count] = 0;
        read_data = g_malloc0(sizeof(GuestFileRead));
        read_data->count = read_count;
        read_data->eof = feof(fh);
        if (read_count) {
            read_data->buf_b64 = g_base64_encode(buf, read_count);
        }
    }
    g_free(buf);
    clearerr(fh);

    return read_data;
}

GuestFileWrite *qmp_guest_file_write(int64_t handle, const char *buf_b64,
                                     bool has_count, int64_t count, Error **err)
{
    GuestFileWrite *write_data = NULL;
    guchar *buf;
    gsize buf_len;
    int write_count;
    GuestFileHandle *gfh = guest_file_handle_find(handle);
    FILE *fh;

    if (!gfh) {
        error_set(err, QERR_FD_NOT_FOUND, "handle");
        return NULL;
    }

    fh = gfh->fh;
    buf = g_base64_decode(buf_b64, &buf_len);

    if (!has_count) {
        count = buf_len;
    } else if (count < 0 || count > buf_len) {
        g_free(buf);
        error_set(err, QERR_INVALID_PARAMETER, "count");
        return NULL;
    }

    write_count = fwrite(buf, 1, count, fh);
    if (ferror(fh)) {
        slog("guest-file-write failed, handle: %ld", handle);
        error_set(err, QERR_QGA_COMMAND_FAILED, "fwrite() error");
    } else {
        write_data = g_malloc0(sizeof(GuestFileWrite));
        write_data->count = write_count;
        write_data->eof = feof(fh);
    }
    g_free(buf);
    clearerr(fh);

    return write_data;
}

struct GuestFileSeek *qmp_guest_file_seek(int64_t handle, int64_t offset,
                                          int64_t whence, Error **err)
{
    GuestFileHandle *gfh = guest_file_handle_find(handle);
    GuestFileSeek *seek_data = NULL;
    FILE *fh;
    int ret;

    if (!gfh) {
        error_set(err, QERR_FD_NOT_FOUND, "handle");
        return NULL;
    }

    fh = gfh->fh;
    ret = fseek(fh, offset, whence);
    if (ret == -1) {
        error_set(err, QERR_QGA_COMMAND_FAILED, strerror(errno));
    } else {
        seek_data = g_malloc0(sizeof(GuestFileRead));
        seek_data->position = ftell(fh);
        seek_data->eof = feof(fh);
    }
    clearerr(fh);

    return seek_data;
}

void qmp_guest_file_flush(int64_t handle, Error **err)
{
    GuestFileHandle *gfh = guest_file_handle_find(handle);
    FILE *fh;
    int ret;

    if (!gfh) {
        error_set(err, QERR_FD_NOT_FOUND, "handle");
        return;
    }

    fh = gfh->fh;
    ret = fflush(fh);
    if (ret == EOF) {
        error_set(err, QERR_QGA_COMMAND_FAILED, strerror(errno));
    }
}

static void guest_file_init(void)
{
    QTAILQ_INIT(&guest_file_state.filehandles);
}

#if defined(CONFIG_FSFREEZE)
static void disable_logging(void)
{
    ga_disable_logging(ga_state);
}

static void enable_logging(void)
{
    ga_enable_logging(ga_state);
}

typedef struct GuestFsfreezeMount {
    char *dirname;
    char *devtype;
    QTAILQ_ENTRY(GuestFsfreezeMount) next;
} GuestFsfreezeMount;

struct {
    GuestFsfreezeStatus status;
    QTAILQ_HEAD(, GuestFsfreezeMount) mount_list;
} guest_fsfreeze_state;

/*
 * Walk the mount table and build a list of local file systems
 */
static int guest_fsfreeze_build_mount_list(void)
{
    struct mntent *ment;
    GuestFsfreezeMount *mount, *temp;
    char const *mtab = MOUNTED;
    FILE *fp;

    QTAILQ_FOREACH_SAFE(mount, &guest_fsfreeze_state.mount_list, next, temp) {
        QTAILQ_REMOVE(&guest_fsfreeze_state.mount_list, mount, next);
        g_free(mount->dirname);
        g_free(mount->devtype);
        g_free(mount);
    }

    fp = setmntent(mtab, "r");
    if (!fp) {
        g_warning("fsfreeze: unable to read mtab");
        return -1;
    }

    while ((ment = getmntent(fp))) {
        /*
         * An entry which device name doesn't start with a '/' is
         * either a dummy file system or a network file system.
         * Add special handling for smbfs and cifs as is done by
         * coreutils as well.
         */
        if ((ment->mnt_fsname[0] != '/') ||
            (strcmp(ment->mnt_type, "smbfs") == 0) ||
            (strcmp(ment->mnt_type, "cifs") == 0)) {
            continue;
        }

        mount = g_malloc0(sizeof(GuestFsfreezeMount));
        mount->dirname = g_strdup(ment->mnt_dir);
        mount->devtype = g_strdup(ment->mnt_type);

        QTAILQ_INSERT_TAIL(&guest_fsfreeze_state.mount_list, mount, next);
    }

    endmntent(fp);

    return 0;
}

/*
 * Return status of freeze/thaw
 */
GuestFsfreezeStatus qmp_guest_fsfreeze_status(Error **err)
{
    return guest_fsfreeze_state.status;
}

/*
 * Walk list of mounted file systems in the guest, and freeze the ones which
 * are real local file systems.
 */
int64_t qmp_guest_fsfreeze_freeze(Error **err)
{
    int ret = 0, i = 0;
    struct GuestFsfreezeMount *mount, *temp;
    int fd;
    char err_msg[512];

    slog("guest-fsfreeze called");

    if (guest_fsfreeze_state.status == GUEST_FSFREEZE_STATUS_FROZEN) {
        return 0;
    }

    ret = guest_fsfreeze_build_mount_list();
    if (ret < 0) {
        return ret;
    }

    /* cannot risk guest agent blocking itself on a write in this state */
    disable_logging();

    QTAILQ_FOREACH_SAFE(mount, &guest_fsfreeze_state.mount_list, next, temp) {
        fd = qemu_open(mount->dirname, O_RDONLY);
        if (fd == -1) {
            sprintf(err_msg, "failed to open %s, %s", mount->dirname, strerror(errno));
            error_set(err, QERR_QGA_COMMAND_FAILED, err_msg);
            goto error;
        }

        /* we try to cull filesytems we know won't work in advance, but other
         * filesytems may not implement fsfreeze for less obvious reasons.
         * these will report EOPNOTSUPP, so we simply ignore them. when
         * thawing, these filesystems will return an EINVAL instead, due to
         * not being in a frozen state. Other filesystem-specific
         * errors may result in EINVAL, however, so the user should check the
         * number * of filesystems returned here against those returned by the
         * thaw operation to determine whether everything completed
         * successfully
         */
        ret = ioctl(fd, FIFREEZE);
        if (ret < 0 && errno != EOPNOTSUPP) {
            sprintf(err_msg, "failed to freeze %s, %s", mount->dirname, strerror(errno));
            error_set(err, QERR_QGA_COMMAND_FAILED, err_msg);
            close(fd);
            goto error;
        }
        close(fd);

        i++;
    }

    guest_fsfreeze_state.status = GUEST_FSFREEZE_STATUS_FROZEN;
    return i;

error:
    if (i > 0) {
        qmp_guest_fsfreeze_thaw(NULL);
    }
    return 0;
}

/*
 * Walk list of frozen file systems in the guest, and thaw them.
 */
int64_t qmp_guest_fsfreeze_thaw(Error **err)
{
    int ret;
    GuestFsfreezeMount *mount, *temp;
    int fd, i = 0;
    bool has_error = false;

    QTAILQ_FOREACH_SAFE(mount, &guest_fsfreeze_state.mount_list, next, temp) {
        fd = qemu_open(mount->dirname, O_RDONLY);
        if (fd == -1) {
            has_error = true;
            continue;
        }
        ret = ioctl(fd, FITHAW);
        if (ret < 0 && errno != EOPNOTSUPP && errno != EINVAL) {
            has_error = true;
            close(fd);
            continue;
        }
        close(fd);
        i++;
    }

    if (has_error) {
        guest_fsfreeze_state.status = GUEST_FSFREEZE_STATUS_ERROR;
    } else {
        guest_fsfreeze_state.status = GUEST_FSFREEZE_STATUS_THAWED;
    }
    enable_logging();
    return i;
}

static void guest_fsfreeze_init(void)
{
    guest_fsfreeze_state.status = GUEST_FSFREEZE_STATUS_THAWED;
    QTAILQ_INIT(&guest_fsfreeze_state.mount_list);
}

static void guest_fsfreeze_cleanup(void)
{
    int64_t ret;
    Error *err = NULL;

    if (guest_fsfreeze_state.status == GUEST_FSFREEZE_STATUS_FROZEN) {
        ret = qmp_guest_fsfreeze_thaw(&err);
        if (ret < 0 || err) {
            slog("failed to clean up frozen filesystems");
        }
    }
}
#else
/*
 * Return status of freeze/thaw
 */
GuestFsfreezeStatus qmp_guest_fsfreeze_status(Error **err)
{
    error_set(err, QERR_UNSUPPORTED);

    return 0;
}

/*
 * Walk list of mounted file systems in the guest, and freeze the ones which
 * are real local file systems.
 */
int64_t qmp_guest_fsfreeze_freeze(Error **err)
{
    error_set(err, QERR_UNSUPPORTED);

    return 0;
}

/*
 * Walk list of frozen file systems in the guest, and thaw them.
 */
int64_t qmp_guest_fsfreeze_thaw(Error **err)
{
    error_set(err, QERR_UNSUPPORTED);

    return 0;
}
#endif

/* register init/cleanup routines for stateful command groups */
void ga_command_state_init(GAState *s, GACommandState *cs)
{
    ga_state = s;
#if defined(CONFIG_FSFREEZE)
    ga_command_state_add(cs, guest_fsfreeze_init, guest_fsfreeze_cleanup);
#endif
    ga_command_state_add(cs, guest_file_init, NULL);
}
OpenPOWER on IntegriCloud