Annotation of qemu/qga/guest-agent-commands.c, revision 1.1.1.2

1.1       root        1: /*
                      2:  * QEMU Guest Agent commands
                      3:  *
                      4:  * Copyright IBM Corp. 2011
                      5:  *
                      6:  * Authors:
                      7:  *  Michael Roth      <[email protected]>
                      8:  *
                      9:  * This work is licensed under the terms of the GNU GPL, version 2 or later.
                     10:  * See the COPYING file in the top-level directory.
                     11:  */
                     12: 
                     13: #include <glib.h>
                     14: 
                     15: #if defined(__linux__)
                     16: #include <mntent.h>
                     17: #include <linux/fs.h>
                     18: 
                     19: #if defined(__linux__) && defined(FIFREEZE)
                     20: #define CONFIG_FSFREEZE
                     21: #endif
                     22: #endif
                     23: 
                     24: #include <sys/types.h>
                     25: #include <sys/ioctl.h>
                     26: #include "qga/guest-agent-core.h"
                     27: #include "qga-qmp-commands.h"
                     28: #include "qerror.h"
                     29: #include "qemu-queue.h"
                     30: 
                     31: static GAState *ga_state;
                     32: 
                     33: /* Note: in some situations, like with the fsfreeze, logging may be
                     34:  * temporarilly disabled. if it is necessary that a command be able
                     35:  * to log for accounting purposes, check ga_logging_enabled() beforehand,
                     36:  * and use the QERR_QGA_LOGGING_DISABLED to generate an error
                     37:  */
                     38: static void slog(const char *fmt, ...)
                     39: {
                     40:     va_list ap;
                     41: 
                     42:     va_start(ap, fmt);
                     43:     g_logv("syslog", G_LOG_LEVEL_INFO, fmt, ap);
                     44:     va_end(ap);
                     45: }
                     46: 
                     47: int64_t qmp_guest_sync(int64_t id, Error **errp)
                     48: {
                     49:     return id;
                     50: }
                     51: 
                     52: void qmp_guest_ping(Error **err)
                     53: {
                     54:     slog("guest-ping called");
                     55: }
                     56: 
                     57: struct GuestAgentInfo *qmp_guest_info(Error **err)
                     58: {
1.1.1.2 ! root       59:     GuestAgentInfo *info = g_malloc0(sizeof(GuestAgentInfo));
1.1       root       60: 
                     61:     info->version = g_strdup(QGA_VERSION);
                     62: 
                     63:     return info;
                     64: }
                     65: 
                     66: void qmp_guest_shutdown(bool has_mode, const char *mode, Error **err)
                     67: {
                     68:     int ret;
                     69:     const char *shutdown_flag;
                     70: 
                     71:     slog("guest-shutdown called, mode: %s", mode);
                     72:     if (!has_mode || strcmp(mode, "powerdown") == 0) {
                     73:         shutdown_flag = "-P";
                     74:     } else if (strcmp(mode, "halt") == 0) {
                     75:         shutdown_flag = "-H";
                     76:     } else if (strcmp(mode, "reboot") == 0) {
                     77:         shutdown_flag = "-r";
                     78:     } else {
                     79:         error_set(err, QERR_INVALID_PARAMETER_VALUE, "mode",
                     80:                   "halt|powerdown|reboot");
                     81:         return;
                     82:     }
                     83: 
                     84:     ret = fork();
                     85:     if (ret == 0) {
                     86:         /* child, start the shutdown */
                     87:         setsid();
                     88:         fclose(stdin);
                     89:         fclose(stdout);
                     90:         fclose(stderr);
                     91: 
                     92:         ret = execl("/sbin/shutdown", "shutdown", shutdown_flag, "+0",
                     93:                     "hypervisor initiated shutdown", (char*)NULL);
                     94:         if (ret) {
                     95:             slog("guest-shutdown failed: %s", strerror(errno));
                     96:         }
                     97:         exit(!!ret);
                     98:     } else if (ret < 0) {
                     99:         error_set(err, QERR_UNDEFINED_ERROR);
                    100:     }
                    101: }
                    102: 
                    103: typedef struct GuestFileHandle {
                    104:     uint64_t id;
                    105:     FILE *fh;
                    106:     QTAILQ_ENTRY(GuestFileHandle) next;
                    107: } GuestFileHandle;
                    108: 
                    109: static struct {
                    110:     QTAILQ_HEAD(, GuestFileHandle) filehandles;
                    111: } guest_file_state;
                    112: 
                    113: static void guest_file_handle_add(FILE *fh)
                    114: {
                    115:     GuestFileHandle *gfh;
                    116: 
1.1.1.2 ! root      117:     gfh = g_malloc0(sizeof(GuestFileHandle));
1.1       root      118:     gfh->id = fileno(fh);
                    119:     gfh->fh = fh;
                    120:     QTAILQ_INSERT_TAIL(&guest_file_state.filehandles, gfh, next);
                    121: }
                    122: 
                    123: static GuestFileHandle *guest_file_handle_find(int64_t id)
                    124: {
                    125:     GuestFileHandle *gfh;
                    126: 
                    127:     QTAILQ_FOREACH(gfh, &guest_file_state.filehandles, next)
                    128:     {
                    129:         if (gfh->id == id) {
                    130:             return gfh;
                    131:         }
                    132:     }
                    133: 
                    134:     return NULL;
                    135: }
                    136: 
                    137: int64_t qmp_guest_file_open(const char *path, bool has_mode, const char *mode, Error **err)
                    138: {
                    139:     FILE *fh;
                    140:     int fd;
                    141:     int64_t ret = -1;
                    142: 
                    143:     if (!has_mode) {
                    144:         mode = "r";
                    145:     }
                    146:     slog("guest-file-open called, filepath: %s, mode: %s", path, mode);
                    147:     fh = fopen(path, mode);
                    148:     if (!fh) {
                    149:         error_set(err, QERR_OPEN_FILE_FAILED, path);
                    150:         return -1;
                    151:     }
                    152: 
                    153:     /* set fd non-blocking to avoid common use cases (like reading from a
                    154:      * named pipe) from hanging the agent
                    155:      */
                    156:     fd = fileno(fh);
                    157:     ret = fcntl(fd, F_GETFL);
                    158:     ret = fcntl(fd, F_SETFL, ret | O_NONBLOCK);
                    159:     if (ret == -1) {
                    160:         error_set(err, QERR_QGA_COMMAND_FAILED, "fcntl() failed");
                    161:         fclose(fh);
                    162:         return -1;
                    163:     }
                    164: 
                    165:     guest_file_handle_add(fh);
                    166:     slog("guest-file-open, handle: %d", fd);
                    167:     return fd;
                    168: }
                    169: 
                    170: void qmp_guest_file_close(int64_t handle, Error **err)
                    171: {
                    172:     GuestFileHandle *gfh = guest_file_handle_find(handle);
                    173:     int ret;
                    174: 
                    175:     slog("guest-file-close called, handle: %ld", handle);
                    176:     if (!gfh) {
                    177:         error_set(err, QERR_FD_NOT_FOUND, "handle");
                    178:         return;
                    179:     }
                    180: 
                    181:     ret = fclose(gfh->fh);
                    182:     if (ret == -1) {
                    183:         error_set(err, QERR_QGA_COMMAND_FAILED, "fclose() failed");
                    184:         return;
                    185:     }
                    186: 
                    187:     QTAILQ_REMOVE(&guest_file_state.filehandles, gfh, next);
1.1.1.2 ! root      188:     g_free(gfh);
1.1       root      189: }
                    190: 
                    191: struct GuestFileRead *qmp_guest_file_read(int64_t handle, bool has_count,
                    192:                                           int64_t count, Error **err)
                    193: {
                    194:     GuestFileHandle *gfh = guest_file_handle_find(handle);
                    195:     GuestFileRead *read_data = NULL;
                    196:     guchar *buf;
                    197:     FILE *fh;
                    198:     size_t read_count;
                    199: 
                    200:     if (!gfh) {
                    201:         error_set(err, QERR_FD_NOT_FOUND, "handle");
                    202:         return NULL;
                    203:     }
                    204: 
                    205:     if (!has_count) {
                    206:         count = QGA_READ_COUNT_DEFAULT;
                    207:     } else if (count < 0) {
                    208:         error_set(err, QERR_INVALID_PARAMETER, "count");
                    209:         return NULL;
                    210:     }
                    211: 
                    212:     fh = gfh->fh;
1.1.1.2 ! root      213:     buf = g_malloc0(count+1);
1.1       root      214:     read_count = fread(buf, 1, count, fh);
                    215:     if (ferror(fh)) {
                    216:         slog("guest-file-read failed, handle: %ld", handle);
                    217:         error_set(err, QERR_QGA_COMMAND_FAILED, "fread() failed");
                    218:     } else {
                    219:         buf[read_count] = 0;
1.1.1.2 ! root      220:         read_data = g_malloc0(sizeof(GuestFileRead));
1.1       root      221:         read_data->count = read_count;
                    222:         read_data->eof = feof(fh);
                    223:         if (read_count) {
                    224:             read_data->buf_b64 = g_base64_encode(buf, read_count);
                    225:         }
                    226:     }
1.1.1.2 ! root      227:     g_free(buf);
1.1       root      228:     clearerr(fh);
                    229: 
                    230:     return read_data;
                    231: }
                    232: 
                    233: GuestFileWrite *qmp_guest_file_write(int64_t handle, const char *buf_b64,
                    234:                                      bool has_count, int64_t count, Error **err)
                    235: {
                    236:     GuestFileWrite *write_data = NULL;
                    237:     guchar *buf;
                    238:     gsize buf_len;
                    239:     int write_count;
                    240:     GuestFileHandle *gfh = guest_file_handle_find(handle);
                    241:     FILE *fh;
                    242: 
                    243:     if (!gfh) {
                    244:         error_set(err, QERR_FD_NOT_FOUND, "handle");
                    245:         return NULL;
                    246:     }
                    247: 
                    248:     fh = gfh->fh;
                    249:     buf = g_base64_decode(buf_b64, &buf_len);
                    250: 
                    251:     if (!has_count) {
                    252:         count = buf_len;
                    253:     } else if (count < 0 || count > buf_len) {
1.1.1.2 ! root      254:         g_free(buf);
1.1       root      255:         error_set(err, QERR_INVALID_PARAMETER, "count");
                    256:         return NULL;
                    257:     }
                    258: 
                    259:     write_count = fwrite(buf, 1, count, fh);
                    260:     if (ferror(fh)) {
                    261:         slog("guest-file-write failed, handle: %ld", handle);
                    262:         error_set(err, QERR_QGA_COMMAND_FAILED, "fwrite() error");
                    263:     } else {
1.1.1.2 ! root      264:         write_data = g_malloc0(sizeof(GuestFileWrite));
1.1       root      265:         write_data->count = write_count;
                    266:         write_data->eof = feof(fh);
                    267:     }
1.1.1.2 ! root      268:     g_free(buf);
1.1       root      269:     clearerr(fh);
                    270: 
                    271:     return write_data;
                    272: }
                    273: 
                    274: struct GuestFileSeek *qmp_guest_file_seek(int64_t handle, int64_t offset,
                    275:                                           int64_t whence, Error **err)
                    276: {
                    277:     GuestFileHandle *gfh = guest_file_handle_find(handle);
                    278:     GuestFileSeek *seek_data = NULL;
                    279:     FILE *fh;
                    280:     int ret;
                    281: 
                    282:     if (!gfh) {
                    283:         error_set(err, QERR_FD_NOT_FOUND, "handle");
                    284:         return NULL;
                    285:     }
                    286: 
                    287:     fh = gfh->fh;
                    288:     ret = fseek(fh, offset, whence);
                    289:     if (ret == -1) {
                    290:         error_set(err, QERR_QGA_COMMAND_FAILED, strerror(errno));
                    291:     } else {
1.1.1.2 ! root      292:         seek_data = g_malloc0(sizeof(GuestFileRead));
1.1       root      293:         seek_data->position = ftell(fh);
                    294:         seek_data->eof = feof(fh);
                    295:     }
                    296:     clearerr(fh);
                    297: 
                    298:     return seek_data;
                    299: }
                    300: 
                    301: void qmp_guest_file_flush(int64_t handle, Error **err)
                    302: {
                    303:     GuestFileHandle *gfh = guest_file_handle_find(handle);
                    304:     FILE *fh;
                    305:     int ret;
                    306: 
                    307:     if (!gfh) {
                    308:         error_set(err, QERR_FD_NOT_FOUND, "handle");
                    309:         return;
                    310:     }
                    311: 
                    312:     fh = gfh->fh;
                    313:     ret = fflush(fh);
                    314:     if (ret == EOF) {
                    315:         error_set(err, QERR_QGA_COMMAND_FAILED, strerror(errno));
                    316:     }
                    317: }
                    318: 
                    319: static void guest_file_init(void)
                    320: {
                    321:     QTAILQ_INIT(&guest_file_state.filehandles);
                    322: }
                    323: 
                    324: #if defined(CONFIG_FSFREEZE)
                    325: static void disable_logging(void)
                    326: {
                    327:     ga_disable_logging(ga_state);
                    328: }
                    329: 
                    330: static void enable_logging(void)
                    331: {
                    332:     ga_enable_logging(ga_state);
                    333: }
                    334: 
                    335: typedef struct GuestFsfreezeMount {
                    336:     char *dirname;
                    337:     char *devtype;
                    338:     QTAILQ_ENTRY(GuestFsfreezeMount) next;
                    339: } GuestFsfreezeMount;
                    340: 
                    341: struct {
                    342:     GuestFsfreezeStatus status;
                    343:     QTAILQ_HEAD(, GuestFsfreezeMount) mount_list;
                    344: } guest_fsfreeze_state;
                    345: 
                    346: /*
                    347:  * Walk the mount table and build a list of local file systems
                    348:  */
                    349: static int guest_fsfreeze_build_mount_list(void)
                    350: {
                    351:     struct mntent *ment;
                    352:     GuestFsfreezeMount *mount, *temp;
                    353:     char const *mtab = MOUNTED;
                    354:     FILE *fp;
                    355: 
                    356:     QTAILQ_FOREACH_SAFE(mount, &guest_fsfreeze_state.mount_list, next, temp) {
                    357:         QTAILQ_REMOVE(&guest_fsfreeze_state.mount_list, mount, next);
1.1.1.2 ! root      358:         g_free(mount->dirname);
        !           359:         g_free(mount->devtype);
        !           360:         g_free(mount);
1.1       root      361:     }
                    362: 
                    363:     fp = setmntent(mtab, "r");
                    364:     if (!fp) {
                    365:         g_warning("fsfreeze: unable to read mtab");
                    366:         return -1;
                    367:     }
                    368: 
                    369:     while ((ment = getmntent(fp))) {
                    370:         /*
                    371:          * An entry which device name doesn't start with a '/' is
                    372:          * either a dummy file system or a network file system.
                    373:          * Add special handling for smbfs and cifs as is done by
                    374:          * coreutils as well.
                    375:          */
                    376:         if ((ment->mnt_fsname[0] != '/') ||
                    377:             (strcmp(ment->mnt_type, "smbfs") == 0) ||
                    378:             (strcmp(ment->mnt_type, "cifs") == 0)) {
                    379:             continue;
                    380:         }
                    381: 
1.1.1.2 ! root      382:         mount = g_malloc0(sizeof(GuestFsfreezeMount));
        !           383:         mount->dirname = g_strdup(ment->mnt_dir);
        !           384:         mount->devtype = g_strdup(ment->mnt_type);
1.1       root      385: 
                    386:         QTAILQ_INSERT_TAIL(&guest_fsfreeze_state.mount_list, mount, next);
                    387:     }
                    388: 
                    389:     endmntent(fp);
                    390: 
                    391:     return 0;
                    392: }
                    393: 
                    394: /*
                    395:  * Return status of freeze/thaw
                    396:  */
                    397: GuestFsfreezeStatus qmp_guest_fsfreeze_status(Error **err)
                    398: {
                    399:     return guest_fsfreeze_state.status;
                    400: }
                    401: 
                    402: /*
                    403:  * Walk list of mounted file systems in the guest, and freeze the ones which
                    404:  * are real local file systems.
                    405:  */
                    406: int64_t qmp_guest_fsfreeze_freeze(Error **err)
                    407: {
                    408:     int ret = 0, i = 0;
                    409:     struct GuestFsfreezeMount *mount, *temp;
                    410:     int fd;
                    411:     char err_msg[512];
                    412: 
                    413:     slog("guest-fsfreeze called");
                    414: 
                    415:     if (guest_fsfreeze_state.status == GUEST_FSFREEZE_STATUS_FROZEN) {
                    416:         return 0;
                    417:     }
                    418: 
                    419:     ret = guest_fsfreeze_build_mount_list();
                    420:     if (ret < 0) {
                    421:         return ret;
                    422:     }
                    423: 
                    424:     /* cannot risk guest agent blocking itself on a write in this state */
                    425:     disable_logging();
                    426: 
                    427:     QTAILQ_FOREACH_SAFE(mount, &guest_fsfreeze_state.mount_list, next, temp) {
                    428:         fd = qemu_open(mount->dirname, O_RDONLY);
                    429:         if (fd == -1) {
                    430:             sprintf(err_msg, "failed to open %s, %s", mount->dirname, strerror(errno));
                    431:             error_set(err, QERR_QGA_COMMAND_FAILED, err_msg);
                    432:             goto error;
                    433:         }
                    434: 
                    435:         /* we try to cull filesytems we know won't work in advance, but other
                    436:          * filesytems may not implement fsfreeze for less obvious reasons.
                    437:          * these will report EOPNOTSUPP, so we simply ignore them. when
                    438:          * thawing, these filesystems will return an EINVAL instead, due to
                    439:          * not being in a frozen state. Other filesystem-specific
                    440:          * errors may result in EINVAL, however, so the user should check the
                    441:          * number * of filesystems returned here against those returned by the
                    442:          * thaw operation to determine whether everything completed
                    443:          * successfully
                    444:          */
                    445:         ret = ioctl(fd, FIFREEZE);
                    446:         if (ret < 0 && errno != EOPNOTSUPP) {
                    447:             sprintf(err_msg, "failed to freeze %s, %s", mount->dirname, strerror(errno));
                    448:             error_set(err, QERR_QGA_COMMAND_FAILED, err_msg);
                    449:             close(fd);
                    450:             goto error;
                    451:         }
                    452:         close(fd);
                    453: 
                    454:         i++;
                    455:     }
                    456: 
                    457:     guest_fsfreeze_state.status = GUEST_FSFREEZE_STATUS_FROZEN;
                    458:     return i;
                    459: 
                    460: error:
                    461:     if (i > 0) {
                    462:         qmp_guest_fsfreeze_thaw(NULL);
                    463:     }
                    464:     return 0;
                    465: }
                    466: 
                    467: /*
                    468:  * Walk list of frozen file systems in the guest, and thaw them.
                    469:  */
                    470: int64_t qmp_guest_fsfreeze_thaw(Error **err)
                    471: {
                    472:     int ret;
                    473:     GuestFsfreezeMount *mount, *temp;
                    474:     int fd, i = 0;
                    475:     bool has_error = false;
                    476: 
                    477:     QTAILQ_FOREACH_SAFE(mount, &guest_fsfreeze_state.mount_list, next, temp) {
                    478:         fd = qemu_open(mount->dirname, O_RDONLY);
                    479:         if (fd == -1) {
                    480:             has_error = true;
                    481:             continue;
                    482:         }
                    483:         ret = ioctl(fd, FITHAW);
                    484:         if (ret < 0 && errno != EOPNOTSUPP && errno != EINVAL) {
                    485:             has_error = true;
                    486:             close(fd);
                    487:             continue;
                    488:         }
                    489:         close(fd);
                    490:         i++;
                    491:     }
                    492: 
                    493:     if (has_error) {
                    494:         guest_fsfreeze_state.status = GUEST_FSFREEZE_STATUS_ERROR;
                    495:     } else {
                    496:         guest_fsfreeze_state.status = GUEST_FSFREEZE_STATUS_THAWED;
                    497:     }
                    498:     enable_logging();
                    499:     return i;
                    500: }
                    501: 
                    502: static void guest_fsfreeze_init(void)
                    503: {
                    504:     guest_fsfreeze_state.status = GUEST_FSFREEZE_STATUS_THAWED;
                    505:     QTAILQ_INIT(&guest_fsfreeze_state.mount_list);
                    506: }
                    507: 
                    508: static void guest_fsfreeze_cleanup(void)
                    509: {
                    510:     int64_t ret;
                    511:     Error *err = NULL;
                    512: 
                    513:     if (guest_fsfreeze_state.status == GUEST_FSFREEZE_STATUS_FROZEN) {
                    514:         ret = qmp_guest_fsfreeze_thaw(&err);
                    515:         if (ret < 0 || err) {
                    516:             slog("failed to clean up frozen filesystems");
                    517:         }
                    518:     }
                    519: }
                    520: #else
                    521: /*
                    522:  * Return status of freeze/thaw
                    523:  */
                    524: GuestFsfreezeStatus qmp_guest_fsfreeze_status(Error **err)
                    525: {
                    526:     error_set(err, QERR_UNSUPPORTED);
                    527: 
                    528:     return 0;
                    529: }
                    530: 
                    531: /*
                    532:  * Walk list of mounted file systems in the guest, and freeze the ones which
                    533:  * are real local file systems.
                    534:  */
                    535: int64_t qmp_guest_fsfreeze_freeze(Error **err)
                    536: {
                    537:     error_set(err, QERR_UNSUPPORTED);
                    538: 
                    539:     return 0;
                    540: }
                    541: 
                    542: /*
                    543:  * Walk list of frozen file systems in the guest, and thaw them.
                    544:  */
                    545: int64_t qmp_guest_fsfreeze_thaw(Error **err)
                    546: {
                    547:     error_set(err, QERR_UNSUPPORTED);
                    548: 
                    549:     return 0;
                    550: }
                    551: #endif
                    552: 
                    553: /* register init/cleanup routines for stateful command groups */
                    554: void ga_command_state_init(GAState *s, GACommandState *cs)
                    555: {
                    556:     ga_state = s;
                    557: #if defined(CONFIG_FSFREEZE)
                    558:     ga_command_state_add(cs, guest_fsfreeze_init, guest_fsfreeze_cleanup);
                    559: #endif
                    560:     ga_command_state_add(cs, guest_file_init, NULL);
                    561: }

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