xref: /qemu/qga/commands-posix.c (revision e3a6e0da)
1 /*
2  * QEMU Guest Agent POSIX-specific command implementations
3  *
4  * Copyright IBM Corp. 2011
5  *
6  * Authors:
7  *  Michael Roth      <mdroth@linux.vnet.ibm.com>
8  *  Michal Privoznik  <mprivozn@redhat.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 
14 #include "qemu/osdep.h"
15 #include <sys/ioctl.h>
16 #include <sys/utsname.h>
17 #include <sys/wait.h>
18 #include <dirent.h>
19 #include "qemu-common.h"
20 #include "guest-agent-core.h"
21 #include "qga-qapi-commands.h"
22 #include "qapi/error.h"
23 #include "qapi/qmp/qerror.h"
24 #include "qemu/queue.h"
25 #include "qemu/host-utils.h"
26 #include "qemu/sockets.h"
27 #include "qemu/base64.h"
28 #include "qemu/cutils.h"
29 #include "commands-common.h"
30 
31 #ifdef HAVE_UTMPX
32 #include <utmpx.h>
33 #endif
34 
35 #ifndef CONFIG_HAS_ENVIRON
36 #ifdef __APPLE__
37 #include <crt_externs.h>
38 #define environ (*_NSGetEnviron())
39 #else
40 extern char **environ;
41 #endif
42 #endif
43 
44 #if defined(__linux__)
45 #include <mntent.h>
46 #include <linux/fs.h>
47 #include <ifaddrs.h>
48 #include <arpa/inet.h>
49 #include <sys/socket.h>
50 #include <net/if.h>
51 #include <sys/statvfs.h>
52 
53 #ifdef CONFIG_LIBUDEV
54 #include <libudev.h>
55 #endif
56 
57 #ifdef FIFREEZE
58 #define CONFIG_FSFREEZE
59 #endif
60 #ifdef FITRIM
61 #define CONFIG_FSTRIM
62 #endif
63 #endif
64 
65 static void ga_wait_child(pid_t pid, int *status, Error **errp)
66 {
67     pid_t rpid;
68 
69     *status = 0;
70 
71     do {
72         rpid = waitpid(pid, status, 0);
73     } while (rpid == -1 && errno == EINTR);
74 
75     if (rpid == -1) {
76         error_setg_errno(errp, errno, "failed to wait for child (pid: %d)",
77                          pid);
78         return;
79     }
80 
81     g_assert(rpid == pid);
82 }
83 
84 void qmp_guest_shutdown(bool has_mode, const char *mode, Error **errp)
85 {
86     const char *shutdown_flag;
87     Error *local_err = NULL;
88     pid_t pid;
89     int status;
90 
91     slog("guest-shutdown called, mode: %s", mode);
92     if (!has_mode || strcmp(mode, "powerdown") == 0) {
93         shutdown_flag = "-P";
94     } else if (strcmp(mode, "halt") == 0) {
95         shutdown_flag = "-H";
96     } else if (strcmp(mode, "reboot") == 0) {
97         shutdown_flag = "-r";
98     } else {
99         error_setg(errp,
100                    "mode is invalid (valid values are: halt|powerdown|reboot");
101         return;
102     }
103 
104     pid = fork();
105     if (pid == 0) {
106         /* child, start the shutdown */
107         setsid();
108         reopen_fd_to_null(0);
109         reopen_fd_to_null(1);
110         reopen_fd_to_null(2);
111 
112         execle("/sbin/shutdown", "shutdown", "-h", shutdown_flag, "+0",
113                "hypervisor initiated shutdown", (char*)NULL, environ);
114         _exit(EXIT_FAILURE);
115     } else if (pid < 0) {
116         error_setg_errno(errp, errno, "failed to create child process");
117         return;
118     }
119 
120     ga_wait_child(pid, &status, &local_err);
121     if (local_err) {
122         error_propagate(errp, local_err);
123         return;
124     }
125 
126     if (!WIFEXITED(status)) {
127         error_setg(errp, "child process has terminated abnormally");
128         return;
129     }
130 
131     if (WEXITSTATUS(status)) {
132         error_setg(errp, "child process has failed to shutdown");
133         return;
134     }
135 
136     /* succeeded */
137 }
138 
139 int64_t qmp_guest_get_time(Error **errp)
140 {
141    int ret;
142    qemu_timeval tq;
143 
144    ret = qemu_gettimeofday(&tq);
145    if (ret < 0) {
146        error_setg_errno(errp, errno, "Failed to get time");
147        return -1;
148    }
149 
150    return tq.tv_sec * 1000000000LL + tq.tv_usec * 1000;
151 }
152 
153 void qmp_guest_set_time(bool has_time, int64_t time_ns, Error **errp)
154 {
155     int ret;
156     int status;
157     pid_t pid;
158     Error *local_err = NULL;
159     struct timeval tv;
160     static const char hwclock_path[] = "/sbin/hwclock";
161     static int hwclock_available = -1;
162 
163     if (hwclock_available < 0) {
164         hwclock_available = (access(hwclock_path, X_OK) == 0);
165     }
166 
167     if (!hwclock_available) {
168         error_setg(errp, QERR_UNSUPPORTED);
169         return;
170     }
171 
172     /* If user has passed a time, validate and set it. */
173     if (has_time) {
174         GDate date = { 0, };
175 
176         /* year-2038 will overflow in case time_t is 32bit */
177         if (time_ns / 1000000000 != (time_t)(time_ns / 1000000000)) {
178             error_setg(errp, "Time %" PRId64 " is too large", time_ns);
179             return;
180         }
181 
182         tv.tv_sec = time_ns / 1000000000;
183         tv.tv_usec = (time_ns % 1000000000) / 1000;
184         g_date_set_time_t(&date, tv.tv_sec);
185         if (date.year < 1970 || date.year >= 2070) {
186             error_setg_errno(errp, errno, "Invalid time");
187             return;
188         }
189 
190         ret = settimeofday(&tv, NULL);
191         if (ret < 0) {
192             error_setg_errno(errp, errno, "Failed to set time to guest");
193             return;
194         }
195     }
196 
197     /* Now, if user has passed a time to set and the system time is set, we
198      * just need to synchronize the hardware clock. However, if no time was
199      * passed, user is requesting the opposite: set the system time from the
200      * hardware clock (RTC). */
201     pid = fork();
202     if (pid == 0) {
203         setsid();
204         reopen_fd_to_null(0);
205         reopen_fd_to_null(1);
206         reopen_fd_to_null(2);
207 
208         /* Use '/sbin/hwclock -w' to set RTC from the system time,
209          * or '/sbin/hwclock -s' to set the system time from RTC. */
210         execle(hwclock_path, "hwclock", has_time ? "-w" : "-s",
211                NULL, environ);
212         _exit(EXIT_FAILURE);
213     } else if (pid < 0) {
214         error_setg_errno(errp, errno, "failed to create child process");
215         return;
216     }
217 
218     ga_wait_child(pid, &status, &local_err);
219     if (local_err) {
220         error_propagate(errp, local_err);
221         return;
222     }
223 
224     if (!WIFEXITED(status)) {
225         error_setg(errp, "child process has terminated abnormally");
226         return;
227     }
228 
229     if (WEXITSTATUS(status)) {
230         error_setg(errp, "hwclock failed to set hardware clock to system time");
231         return;
232     }
233 }
234 
235 typedef enum {
236     RW_STATE_NEW,
237     RW_STATE_READING,
238     RW_STATE_WRITING,
239 } RwState;
240 
241 struct GuestFileHandle {
242     uint64_t id;
243     FILE *fh;
244     RwState state;
245     QTAILQ_ENTRY(GuestFileHandle) next;
246 };
247 
248 static struct {
249     QTAILQ_HEAD(, GuestFileHandle) filehandles;
250 } guest_file_state = {
251     .filehandles = QTAILQ_HEAD_INITIALIZER(guest_file_state.filehandles),
252 };
253 
254 static int64_t guest_file_handle_add(FILE *fh, Error **errp)
255 {
256     GuestFileHandle *gfh;
257     int64_t handle;
258 
259     handle = ga_get_fd_handle(ga_state, errp);
260     if (handle < 0) {
261         return -1;
262     }
263 
264     gfh = g_new0(GuestFileHandle, 1);
265     gfh->id = handle;
266     gfh->fh = fh;
267     QTAILQ_INSERT_TAIL(&guest_file_state.filehandles, gfh, next);
268 
269     return handle;
270 }
271 
272 GuestFileHandle *guest_file_handle_find(int64_t id, Error **errp)
273 {
274     GuestFileHandle *gfh;
275 
276     QTAILQ_FOREACH(gfh, &guest_file_state.filehandles, next)
277     {
278         if (gfh->id == id) {
279             return gfh;
280         }
281     }
282 
283     error_setg(errp, "handle '%" PRId64 "' has not been found", id);
284     return NULL;
285 }
286 
287 typedef const char * const ccpc;
288 
289 #ifndef O_BINARY
290 #define O_BINARY 0
291 #endif
292 
293 /* http://pubs.opengroup.org/onlinepubs/9699919799/functions/fopen.html */
294 static const struct {
295     ccpc *forms;
296     int oflag_base;
297 } guest_file_open_modes[] = {
298     { (ccpc[]){ "r",          NULL }, O_RDONLY                                 },
299     { (ccpc[]){ "rb",         NULL }, O_RDONLY                      | O_BINARY },
300     { (ccpc[]){ "w",          NULL }, O_WRONLY | O_CREAT | O_TRUNC             },
301     { (ccpc[]){ "wb",         NULL }, O_WRONLY | O_CREAT | O_TRUNC  | O_BINARY },
302     { (ccpc[]){ "a",          NULL }, O_WRONLY | O_CREAT | O_APPEND            },
303     { (ccpc[]){ "ab",         NULL }, O_WRONLY | O_CREAT | O_APPEND | O_BINARY },
304     { (ccpc[]){ "r+",         NULL }, O_RDWR                                   },
305     { (ccpc[]){ "rb+", "r+b", NULL }, O_RDWR                        | O_BINARY },
306     { (ccpc[]){ "w+",         NULL }, O_RDWR   | O_CREAT | O_TRUNC             },
307     { (ccpc[]){ "wb+", "w+b", NULL }, O_RDWR   | O_CREAT | O_TRUNC  | O_BINARY },
308     { (ccpc[]){ "a+",         NULL }, O_RDWR   | O_CREAT | O_APPEND            },
309     { (ccpc[]){ "ab+", "a+b", NULL }, O_RDWR   | O_CREAT | O_APPEND | O_BINARY }
310 };
311 
312 static int
313 find_open_flag(const char *mode_str, Error **errp)
314 {
315     unsigned mode;
316 
317     for (mode = 0; mode < ARRAY_SIZE(guest_file_open_modes); ++mode) {
318         ccpc *form;
319 
320         form = guest_file_open_modes[mode].forms;
321         while (*form != NULL && strcmp(*form, mode_str) != 0) {
322             ++form;
323         }
324         if (*form != NULL) {
325             break;
326         }
327     }
328 
329     if (mode == ARRAY_SIZE(guest_file_open_modes)) {
330         error_setg(errp, "invalid file open mode '%s'", mode_str);
331         return -1;
332     }
333     return guest_file_open_modes[mode].oflag_base | O_NOCTTY | O_NONBLOCK;
334 }
335 
336 #define DEFAULT_NEW_FILE_MODE (S_IRUSR | S_IWUSR | \
337                                S_IRGRP | S_IWGRP | \
338                                S_IROTH | S_IWOTH)
339 
340 static FILE *
341 safe_open_or_create(const char *path, const char *mode, Error **errp)
342 {
343     Error *local_err = NULL;
344     int oflag;
345 
346     oflag = find_open_flag(mode, &local_err);
347     if (local_err == NULL) {
348         int fd;
349 
350         /* If the caller wants / allows creation of a new file, we implement it
351          * with a two step process: open() + (open() / fchmod()).
352          *
353          * First we insist on creating the file exclusively as a new file. If
354          * that succeeds, we're free to set any file-mode bits on it. (The
355          * motivation is that we want to set those file-mode bits independently
356          * of the current umask.)
357          *
358          * If the exclusive creation fails because the file already exists
359          * (EEXIST is not possible for any other reason), we just attempt to
360          * open the file, but in this case we won't be allowed to change the
361          * file-mode bits on the preexistent file.
362          *
363          * The pathname should never disappear between the two open()s in
364          * practice. If it happens, then someone very likely tried to race us.
365          * In this case just go ahead and report the ENOENT from the second
366          * open() to the caller.
367          *
368          * If the caller wants to open a preexistent file, then the first
369          * open() is decisive and its third argument is ignored, and the second
370          * open() and the fchmod() are never called.
371          */
372         fd = open(path, oflag | ((oflag & O_CREAT) ? O_EXCL : 0), 0);
373         if (fd == -1 && errno == EEXIST) {
374             oflag &= ~(unsigned)O_CREAT;
375             fd = open(path, oflag);
376         }
377 
378         if (fd == -1) {
379             error_setg_errno(&local_err, errno, "failed to open file '%s' "
380                              "(mode: '%s')", path, mode);
381         } else {
382             qemu_set_cloexec(fd);
383 
384             if ((oflag & O_CREAT) && fchmod(fd, DEFAULT_NEW_FILE_MODE) == -1) {
385                 error_setg_errno(&local_err, errno, "failed to set permission "
386                                  "0%03o on new file '%s' (mode: '%s')",
387                                  (unsigned)DEFAULT_NEW_FILE_MODE, path, mode);
388             } else {
389                 FILE *f;
390 
391                 f = fdopen(fd, mode);
392                 if (f == NULL) {
393                     error_setg_errno(&local_err, errno, "failed to associate "
394                                      "stdio stream with file descriptor %d, "
395                                      "file '%s' (mode: '%s')", fd, path, mode);
396                 } else {
397                     return f;
398                 }
399             }
400 
401             close(fd);
402             if (oflag & O_CREAT) {
403                 unlink(path);
404             }
405         }
406     }
407 
408     error_propagate(errp, local_err);
409     return NULL;
410 }
411 
412 int64_t qmp_guest_file_open(const char *path, bool has_mode, const char *mode,
413                             Error **errp)
414 {
415     FILE *fh;
416     Error *local_err = NULL;
417     int64_t handle;
418 
419     if (!has_mode) {
420         mode = "r";
421     }
422     slog("guest-file-open called, filepath: %s, mode: %s", path, mode);
423     fh = safe_open_or_create(path, mode, &local_err);
424     if (local_err != NULL) {
425         error_propagate(errp, local_err);
426         return -1;
427     }
428 
429     /* set fd non-blocking to avoid common use cases (like reading from a
430      * named pipe) from hanging the agent
431      */
432     qemu_set_nonblock(fileno(fh));
433 
434     handle = guest_file_handle_add(fh, errp);
435     if (handle < 0) {
436         fclose(fh);
437         return -1;
438     }
439 
440     slog("guest-file-open, handle: %" PRId64, handle);
441     return handle;
442 }
443 
444 void qmp_guest_file_close(int64_t handle, Error **errp)
445 {
446     GuestFileHandle *gfh = guest_file_handle_find(handle, errp);
447     int ret;
448 
449     slog("guest-file-close called, handle: %" PRId64, handle);
450     if (!gfh) {
451         return;
452     }
453 
454     ret = fclose(gfh->fh);
455     if (ret == EOF) {
456         error_setg_errno(errp, errno, "failed to close handle");
457         return;
458     }
459 
460     QTAILQ_REMOVE(&guest_file_state.filehandles, gfh, next);
461     g_free(gfh);
462 }
463 
464 GuestFileRead *guest_file_read_unsafe(GuestFileHandle *gfh,
465                                       int64_t count, Error **errp)
466 {
467     GuestFileRead *read_data = NULL;
468     guchar *buf;
469     FILE *fh = gfh->fh;
470     size_t read_count;
471 
472     /* explicitly flush when switching from writing to reading */
473     if (gfh->state == RW_STATE_WRITING) {
474         int ret = fflush(fh);
475         if (ret == EOF) {
476             error_setg_errno(errp, errno, "failed to flush file");
477             return NULL;
478         }
479         gfh->state = RW_STATE_NEW;
480     }
481 
482     buf = g_malloc0(count+1);
483     read_count = fread(buf, 1, count, fh);
484     if (ferror(fh)) {
485         error_setg_errno(errp, errno, "failed to read file");
486     } else {
487         buf[read_count] = 0;
488         read_data = g_new0(GuestFileRead, 1);
489         read_data->count = read_count;
490         read_data->eof = feof(fh);
491         if (read_count) {
492             read_data->buf_b64 = g_base64_encode(buf, read_count);
493         }
494         gfh->state = RW_STATE_READING;
495     }
496     g_free(buf);
497     clearerr(fh);
498 
499     return read_data;
500 }
501 
502 GuestFileWrite *qmp_guest_file_write(int64_t handle, const char *buf_b64,
503                                      bool has_count, int64_t count,
504                                      Error **errp)
505 {
506     GuestFileWrite *write_data = NULL;
507     guchar *buf;
508     gsize buf_len;
509     int write_count;
510     GuestFileHandle *gfh = guest_file_handle_find(handle, errp);
511     FILE *fh;
512 
513     if (!gfh) {
514         return NULL;
515     }
516 
517     fh = gfh->fh;
518 
519     if (gfh->state == RW_STATE_READING) {
520         int ret = fseek(fh, 0, SEEK_CUR);
521         if (ret == -1) {
522             error_setg_errno(errp, errno, "failed to seek file");
523             return NULL;
524         }
525         gfh->state = RW_STATE_NEW;
526     }
527 
528     buf = qbase64_decode(buf_b64, -1, &buf_len, errp);
529     if (!buf) {
530         return NULL;
531     }
532 
533     if (!has_count) {
534         count = buf_len;
535     } else if (count < 0 || count > buf_len) {
536         error_setg(errp, "value '%" PRId64 "' is invalid for argument count",
537                    count);
538         g_free(buf);
539         return NULL;
540     }
541 
542     write_count = fwrite(buf, 1, count, fh);
543     if (ferror(fh)) {
544         error_setg_errno(errp, errno, "failed to write to file");
545         slog("guest-file-write failed, handle: %" PRId64, handle);
546     } else {
547         write_data = g_new0(GuestFileWrite, 1);
548         write_data->count = write_count;
549         write_data->eof = feof(fh);
550         gfh->state = RW_STATE_WRITING;
551     }
552     g_free(buf);
553     clearerr(fh);
554 
555     return write_data;
556 }
557 
558 struct GuestFileSeek *qmp_guest_file_seek(int64_t handle, int64_t offset,
559                                           GuestFileWhence *whence_code,
560                                           Error **errp)
561 {
562     GuestFileHandle *gfh = guest_file_handle_find(handle, errp);
563     GuestFileSeek *seek_data = NULL;
564     FILE *fh;
565     int ret;
566     int whence;
567     Error *err = NULL;
568 
569     if (!gfh) {
570         return NULL;
571     }
572 
573     /* We stupidly exposed 'whence':'int' in our qapi */
574     whence = ga_parse_whence(whence_code, &err);
575     if (err) {
576         error_propagate(errp, err);
577         return NULL;
578     }
579 
580     fh = gfh->fh;
581     ret = fseek(fh, offset, whence);
582     if (ret == -1) {
583         error_setg_errno(errp, errno, "failed to seek file");
584         if (errno == ESPIPE) {
585             /* file is non-seekable, stdio shouldn't be buffering anyways */
586             gfh->state = RW_STATE_NEW;
587         }
588     } else {
589         seek_data = g_new0(GuestFileSeek, 1);
590         seek_data->position = ftell(fh);
591         seek_data->eof = feof(fh);
592         gfh->state = RW_STATE_NEW;
593     }
594     clearerr(fh);
595 
596     return seek_data;
597 }
598 
599 void qmp_guest_file_flush(int64_t handle, Error **errp)
600 {
601     GuestFileHandle *gfh = guest_file_handle_find(handle, errp);
602     FILE *fh;
603     int ret;
604 
605     if (!gfh) {
606         return;
607     }
608 
609     fh = gfh->fh;
610     ret = fflush(fh);
611     if (ret == EOF) {
612         error_setg_errno(errp, errno, "failed to flush file");
613     } else {
614         gfh->state = RW_STATE_NEW;
615     }
616 }
617 
618 /* linux-specific implementations. avoid this if at all possible. */
619 #if defined(__linux__)
620 
621 #if defined(CONFIG_FSFREEZE) || defined(CONFIG_FSTRIM)
622 typedef struct FsMount {
623     char *dirname;
624     char *devtype;
625     unsigned int devmajor, devminor;
626     QTAILQ_ENTRY(FsMount) next;
627 } FsMount;
628 
629 typedef QTAILQ_HEAD(FsMountList, FsMount) FsMountList;
630 
631 static void free_fs_mount_list(FsMountList *mounts)
632 {
633      FsMount *mount, *temp;
634 
635      if (!mounts) {
636          return;
637      }
638 
639      QTAILQ_FOREACH_SAFE(mount, mounts, next, temp) {
640          QTAILQ_REMOVE(mounts, mount, next);
641          g_free(mount->dirname);
642          g_free(mount->devtype);
643          g_free(mount);
644      }
645 }
646 
647 static int dev_major_minor(const char *devpath,
648                            unsigned int *devmajor, unsigned int *devminor)
649 {
650     struct stat st;
651 
652     *devmajor = 0;
653     *devminor = 0;
654 
655     if (stat(devpath, &st) < 0) {
656         slog("failed to stat device file '%s': %s", devpath, strerror(errno));
657         return -1;
658     }
659     if (S_ISDIR(st.st_mode)) {
660         /* It is bind mount */
661         return -2;
662     }
663     if (S_ISBLK(st.st_mode)) {
664         *devmajor = major(st.st_rdev);
665         *devminor = minor(st.st_rdev);
666         return 0;
667     }
668     return -1;
669 }
670 
671 /*
672  * Walk the mount table and build a list of local file systems
673  */
674 static void build_fs_mount_list_from_mtab(FsMountList *mounts, Error **errp)
675 {
676     struct mntent *ment;
677     FsMount *mount;
678     char const *mtab = "/proc/self/mounts";
679     FILE *fp;
680     unsigned int devmajor, devminor;
681 
682     fp = setmntent(mtab, "r");
683     if (!fp) {
684         error_setg(errp, "failed to open mtab file: '%s'", mtab);
685         return;
686     }
687 
688     while ((ment = getmntent(fp))) {
689         /*
690          * An entry which device name doesn't start with a '/' is
691          * either a dummy file system or a network file system.
692          * Add special handling for smbfs and cifs as is done by
693          * coreutils as well.
694          */
695         if ((ment->mnt_fsname[0] != '/') ||
696             (strcmp(ment->mnt_type, "smbfs") == 0) ||
697             (strcmp(ment->mnt_type, "cifs") == 0)) {
698             continue;
699         }
700         if (dev_major_minor(ment->mnt_fsname, &devmajor, &devminor) == -2) {
701             /* Skip bind mounts */
702             continue;
703         }
704 
705         mount = g_new0(FsMount, 1);
706         mount->dirname = g_strdup(ment->mnt_dir);
707         mount->devtype = g_strdup(ment->mnt_type);
708         mount->devmajor = devmajor;
709         mount->devminor = devminor;
710 
711         QTAILQ_INSERT_TAIL(mounts, mount, next);
712     }
713 
714     endmntent(fp);
715 }
716 
717 static void decode_mntname(char *name, int len)
718 {
719     int i, j = 0;
720     for (i = 0; i <= len; i++) {
721         if (name[i] != '\\') {
722             name[j++] = name[i];
723         } else if (name[i + 1] == '\\') {
724             name[j++] = '\\';
725             i++;
726         } else if (name[i + 1] >= '0' && name[i + 1] <= '3' &&
727                    name[i + 2] >= '0' && name[i + 2] <= '7' &&
728                    name[i + 3] >= '0' && name[i + 3] <= '7') {
729             name[j++] = (name[i + 1] - '0') * 64 +
730                         (name[i + 2] - '0') * 8 +
731                         (name[i + 3] - '0');
732             i += 3;
733         } else {
734             name[j++] = name[i];
735         }
736     }
737 }
738 
739 static void build_fs_mount_list(FsMountList *mounts, Error **errp)
740 {
741     FsMount *mount;
742     char const *mountinfo = "/proc/self/mountinfo";
743     FILE *fp;
744     char *line = NULL, *dash;
745     size_t n;
746     char check;
747     unsigned int devmajor, devminor;
748     int ret, dir_s, dir_e, type_s, type_e, dev_s, dev_e;
749 
750     fp = fopen(mountinfo, "r");
751     if (!fp) {
752         build_fs_mount_list_from_mtab(mounts, errp);
753         return;
754     }
755 
756     while (getline(&line, &n, fp) != -1) {
757         ret = sscanf(line, "%*u %*u %u:%u %*s %n%*s%n%c",
758                      &devmajor, &devminor, &dir_s, &dir_e, &check);
759         if (ret < 3) {
760             continue;
761         }
762         dash = strstr(line + dir_e, " - ");
763         if (!dash) {
764             continue;
765         }
766         ret = sscanf(dash, " - %n%*s%n %n%*s%n%c",
767                      &type_s, &type_e, &dev_s, &dev_e, &check);
768         if (ret < 1) {
769             continue;
770         }
771         line[dir_e] = 0;
772         dash[type_e] = 0;
773         dash[dev_e] = 0;
774         decode_mntname(line + dir_s, dir_e - dir_s);
775         decode_mntname(dash + dev_s, dev_e - dev_s);
776         if (devmajor == 0) {
777             /* btrfs reports major number = 0 */
778             if (strcmp("btrfs", dash + type_s) != 0 ||
779                 dev_major_minor(dash + dev_s, &devmajor, &devminor) < 0) {
780                 continue;
781             }
782         }
783 
784         mount = g_new0(FsMount, 1);
785         mount->dirname = g_strdup(line + dir_s);
786         mount->devtype = g_strdup(dash + type_s);
787         mount->devmajor = devmajor;
788         mount->devminor = devminor;
789 
790         QTAILQ_INSERT_TAIL(mounts, mount, next);
791     }
792     free(line);
793 
794     fclose(fp);
795 }
796 #endif
797 
798 #if defined(CONFIG_FSFREEZE)
799 
800 static char *get_pci_driver(char const *syspath, int pathlen, Error **errp)
801 {
802     char *path;
803     char *dpath;
804     char *driver = NULL;
805     char buf[PATH_MAX];
806     ssize_t len;
807 
808     path = g_strndup(syspath, pathlen);
809     dpath = g_strdup_printf("%s/driver", path);
810     len = readlink(dpath, buf, sizeof(buf) - 1);
811     if (len != -1) {
812         buf[len] = 0;
813         driver = g_path_get_basename(buf);
814     }
815     g_free(dpath);
816     g_free(path);
817     return driver;
818 }
819 
820 static int compare_uint(const void *_a, const void *_b)
821 {
822     unsigned int a = *(unsigned int *)_a;
823     unsigned int b = *(unsigned int *)_b;
824 
825     return a < b ? -1 : a > b ? 1 : 0;
826 }
827 
828 /* Walk the specified sysfs and build a sorted list of host or ata numbers */
829 static int build_hosts(char const *syspath, char const *host, bool ata,
830                        unsigned int *hosts, int hosts_max, Error **errp)
831 {
832     char *path;
833     DIR *dir;
834     struct dirent *entry;
835     int i = 0;
836 
837     path = g_strndup(syspath, host - syspath);
838     dir = opendir(path);
839     if (!dir) {
840         error_setg_errno(errp, errno, "opendir(\"%s\")", path);
841         g_free(path);
842         return -1;
843     }
844 
845     while (i < hosts_max) {
846         entry = readdir(dir);
847         if (!entry) {
848             break;
849         }
850         if (ata && sscanf(entry->d_name, "ata%d", hosts + i) == 1) {
851             ++i;
852         } else if (!ata && sscanf(entry->d_name, "host%d", hosts + i) == 1) {
853             ++i;
854         }
855     }
856 
857     qsort(hosts, i, sizeof(hosts[0]), compare_uint);
858 
859     g_free(path);
860     closedir(dir);
861     return i;
862 }
863 
864 /*
865  * Store disk device info for devices on the PCI bus.
866  * Returns true if information has been stored, or false for failure.
867  */
868 static bool build_guest_fsinfo_for_pci_dev(char const *syspath,
869                                            GuestDiskAddress *disk,
870                                            Error **errp)
871 {
872     unsigned int pci[4], host, hosts[8], tgt[3];
873     int i, nhosts = 0, pcilen;
874     GuestPCIAddress *pciaddr = disk->pci_controller;
875     bool has_ata = false, has_host = false, has_tgt = false;
876     char *p, *q, *driver = NULL;
877     bool ret = false;
878 
879     p = strstr(syspath, "/devices/pci");
880     if (!p || sscanf(p + 12, "%*x:%*x/%x:%x:%x.%x%n",
881                      pci, pci + 1, pci + 2, pci + 3, &pcilen) < 4) {
882         g_debug("only pci device is supported: sysfs path '%s'", syspath);
883         return false;
884     }
885 
886     p += 12 + pcilen;
887     while (true) {
888         driver = get_pci_driver(syspath, p - syspath, errp);
889         if (driver && (g_str_equal(driver, "ata_piix") ||
890                        g_str_equal(driver, "sym53c8xx") ||
891                        g_str_equal(driver, "virtio-pci") ||
892                        g_str_equal(driver, "ahci"))) {
893             break;
894         }
895 
896         g_free(driver);
897         if (sscanf(p, "/%x:%x:%x.%x%n",
898                           pci, pci + 1, pci + 2, pci + 3, &pcilen) == 4) {
899             p += pcilen;
900             continue;
901         }
902 
903         g_debug("unsupported driver or sysfs path '%s'", syspath);
904         return false;
905     }
906 
907     p = strstr(syspath, "/target");
908     if (p && sscanf(p + 7, "%*u:%*u:%*u/%*u:%u:%u:%u",
909                     tgt, tgt + 1, tgt + 2) == 3) {
910         has_tgt = true;
911     }
912 
913     p = strstr(syspath, "/ata");
914     if (p) {
915         q = p + 4;
916         has_ata = true;
917     } else {
918         p = strstr(syspath, "/host");
919         q = p + 5;
920     }
921     if (p && sscanf(q, "%u", &host) == 1) {
922         has_host = true;
923         nhosts = build_hosts(syspath, p, has_ata, hosts,
924                              ARRAY_SIZE(hosts), errp);
925         if (nhosts < 0) {
926             goto cleanup;
927         }
928     }
929 
930     pciaddr->domain = pci[0];
931     pciaddr->bus = pci[1];
932     pciaddr->slot = pci[2];
933     pciaddr->function = pci[3];
934 
935     if (strcmp(driver, "ata_piix") == 0) {
936         /* a host per ide bus, target*:0:<unit>:0 */
937         if (!has_host || !has_tgt) {
938             g_debug("invalid sysfs path '%s' (driver '%s')", syspath, driver);
939             goto cleanup;
940         }
941         for (i = 0; i < nhosts; i++) {
942             if (host == hosts[i]) {
943                 disk->bus_type = GUEST_DISK_BUS_TYPE_IDE;
944                 disk->bus = i;
945                 disk->unit = tgt[1];
946                 break;
947             }
948         }
949         if (i >= nhosts) {
950             g_debug("no host for '%s' (driver '%s')", syspath, driver);
951             goto cleanup;
952         }
953     } else if (strcmp(driver, "sym53c8xx") == 0) {
954         /* scsi(LSI Logic): target*:0:<unit>:0 */
955         if (!has_tgt) {
956             g_debug("invalid sysfs path '%s' (driver '%s')", syspath, driver);
957             goto cleanup;
958         }
959         disk->bus_type = GUEST_DISK_BUS_TYPE_SCSI;
960         disk->unit = tgt[1];
961     } else if (strcmp(driver, "virtio-pci") == 0) {
962         if (has_tgt) {
963             /* virtio-scsi: target*:0:0:<unit> */
964             disk->bus_type = GUEST_DISK_BUS_TYPE_SCSI;
965             disk->unit = tgt[2];
966         } else {
967             /* virtio-blk: 1 disk per 1 device */
968             disk->bus_type = GUEST_DISK_BUS_TYPE_VIRTIO;
969         }
970     } else if (strcmp(driver, "ahci") == 0) {
971         /* ahci: 1 host per 1 unit */
972         if (!has_host || !has_tgt) {
973             g_debug("invalid sysfs path '%s' (driver '%s')", syspath, driver);
974             goto cleanup;
975         }
976         for (i = 0; i < nhosts; i++) {
977             if (host == hosts[i]) {
978                 disk->unit = i;
979                 disk->bus_type = GUEST_DISK_BUS_TYPE_SATA;
980                 break;
981             }
982         }
983         if (i >= nhosts) {
984             g_debug("no host for '%s' (driver '%s')", syspath, driver);
985             goto cleanup;
986         }
987     } else {
988         g_debug("unknown driver '%s' (sysfs path '%s')", driver, syspath);
989         goto cleanup;
990     }
991 
992     ret = true;
993 
994 cleanup:
995     g_free(driver);
996     return ret;
997 }
998 
999 /*
1000  * Store disk device info for non-PCI virtio devices (for example s390x
1001  * channel I/O devices). Returns true if information has been stored, or
1002  * false for failure.
1003  */
1004 static bool build_guest_fsinfo_for_nonpci_virtio(char const *syspath,
1005                                                  GuestDiskAddress *disk,
1006                                                  Error **errp)
1007 {
1008     unsigned int tgt[3];
1009     char *p;
1010 
1011     if (!strstr(syspath, "/virtio") || !strstr(syspath, "/block")) {
1012         g_debug("Unsupported virtio device '%s'", syspath);
1013         return false;
1014     }
1015 
1016     p = strstr(syspath, "/target");
1017     if (p && sscanf(p + 7, "%*u:%*u:%*u/%*u:%u:%u:%u",
1018                     &tgt[0], &tgt[1], &tgt[2]) == 3) {
1019         /* virtio-scsi: target*:0:<target>:<unit> */
1020         disk->bus_type = GUEST_DISK_BUS_TYPE_SCSI;
1021         disk->bus = tgt[0];
1022         disk->target = tgt[1];
1023         disk->unit = tgt[2];
1024     } else {
1025         /* virtio-blk: 1 disk per 1 device */
1026         disk->bus_type = GUEST_DISK_BUS_TYPE_VIRTIO;
1027     }
1028 
1029     return true;
1030 }
1031 
1032 /* Store disk device info specified by @sysfs into @fs */
1033 static void build_guest_fsinfo_for_real_device(char const *syspath,
1034                                                GuestFilesystemInfo *fs,
1035                                                Error **errp)
1036 {
1037     GuestDiskAddress *disk;
1038     GuestPCIAddress *pciaddr;
1039     GuestDiskAddressList *list = NULL;
1040     bool has_hwinf;
1041 #ifdef CONFIG_LIBUDEV
1042     struct udev *udev = NULL;
1043     struct udev_device *udevice = NULL;
1044 #endif
1045 
1046     pciaddr = g_new0(GuestPCIAddress, 1);
1047     pciaddr->domain = -1;                       /* -1 means field is invalid */
1048     pciaddr->bus = -1;
1049     pciaddr->slot = -1;
1050     pciaddr->function = -1;
1051 
1052     disk = g_new0(GuestDiskAddress, 1);
1053     disk->pci_controller = pciaddr;
1054     disk->bus_type = GUEST_DISK_BUS_TYPE_UNKNOWN;
1055 
1056     list = g_new0(GuestDiskAddressList, 1);
1057     list->value = disk;
1058 
1059 #ifdef CONFIG_LIBUDEV
1060     udev = udev_new();
1061     udevice = udev_device_new_from_syspath(udev, syspath);
1062     if (udev == NULL || udevice == NULL) {
1063         g_debug("failed to query udev");
1064     } else {
1065         const char *devnode, *serial;
1066         devnode = udev_device_get_devnode(udevice);
1067         if (devnode != NULL) {
1068             disk->dev = g_strdup(devnode);
1069             disk->has_dev = true;
1070         }
1071         serial = udev_device_get_property_value(udevice, "ID_SERIAL");
1072         if (serial != NULL && *serial != 0) {
1073             disk->serial = g_strdup(serial);
1074             disk->has_serial = true;
1075         }
1076     }
1077 
1078     udev_unref(udev);
1079     udev_device_unref(udevice);
1080 #endif
1081 
1082     if (strstr(syspath, "/devices/pci")) {
1083         has_hwinf = build_guest_fsinfo_for_pci_dev(syspath, disk, errp);
1084     } else if (strstr(syspath, "/virtio")) {
1085         has_hwinf = build_guest_fsinfo_for_nonpci_virtio(syspath, disk, errp);
1086     } else {
1087         g_debug("Unsupported device type for '%s'", syspath);
1088         has_hwinf = false;
1089     }
1090 
1091     if (has_hwinf || disk->has_dev || disk->has_serial) {
1092         list->next = fs->disk;
1093         fs->disk = list;
1094     } else {
1095         qapi_free_GuestDiskAddressList(list);
1096     }
1097 }
1098 
1099 static void build_guest_fsinfo_for_device(char const *devpath,
1100                                           GuestFilesystemInfo *fs,
1101                                           Error **errp);
1102 
1103 /* Store a list of slave devices of virtual volume specified by @syspath into
1104  * @fs */
1105 static void build_guest_fsinfo_for_virtual_device(char const *syspath,
1106                                                   GuestFilesystemInfo *fs,
1107                                                   Error **errp)
1108 {
1109     Error *err = NULL;
1110     DIR *dir;
1111     char *dirpath;
1112     struct dirent *entry;
1113 
1114     dirpath = g_strdup_printf("%s/slaves", syspath);
1115     dir = opendir(dirpath);
1116     if (!dir) {
1117         if (errno != ENOENT) {
1118             error_setg_errno(errp, errno, "opendir(\"%s\")", dirpath);
1119         }
1120         g_free(dirpath);
1121         return;
1122     }
1123 
1124     for (;;) {
1125         errno = 0;
1126         entry = readdir(dir);
1127         if (entry == NULL) {
1128             if (errno) {
1129                 error_setg_errno(errp, errno, "readdir(\"%s\")", dirpath);
1130             }
1131             break;
1132         }
1133 
1134         if (entry->d_type == DT_LNK) {
1135             char *path;
1136 
1137             g_debug(" slave device '%s'", entry->d_name);
1138             path = g_strdup_printf("%s/slaves/%s", syspath, entry->d_name);
1139             build_guest_fsinfo_for_device(path, fs, &err);
1140             g_free(path);
1141 
1142             if (err) {
1143                 error_propagate(errp, err);
1144                 break;
1145             }
1146         }
1147     }
1148 
1149     g_free(dirpath);
1150     closedir(dir);
1151 }
1152 
1153 /* Dispatch to functions for virtual/real device */
1154 static void build_guest_fsinfo_for_device(char const *devpath,
1155                                           GuestFilesystemInfo *fs,
1156                                           Error **errp)
1157 {
1158     char *syspath = realpath(devpath, NULL);
1159 
1160     if (!syspath) {
1161         error_setg_errno(errp, errno, "realpath(\"%s\")", devpath);
1162         return;
1163     }
1164 
1165     if (!fs->name) {
1166         fs->name = g_path_get_basename(syspath);
1167     }
1168 
1169     g_debug("  parse sysfs path '%s'", syspath);
1170 
1171     if (strstr(syspath, "/devices/virtual/block/")) {
1172         build_guest_fsinfo_for_virtual_device(syspath, fs, errp);
1173     } else {
1174         build_guest_fsinfo_for_real_device(syspath, fs, errp);
1175     }
1176 
1177     free(syspath);
1178 }
1179 
1180 /* Return a list of the disk device(s)' info which @mount lies on */
1181 static GuestFilesystemInfo *build_guest_fsinfo(struct FsMount *mount,
1182                                                Error **errp)
1183 {
1184     GuestFilesystemInfo *fs = g_malloc0(sizeof(*fs));
1185     struct statvfs buf;
1186     unsigned long used, nonroot_total, fr_size;
1187     char *devpath = g_strdup_printf("/sys/dev/block/%u:%u",
1188                                     mount->devmajor, mount->devminor);
1189 
1190     fs->mountpoint = g_strdup(mount->dirname);
1191     fs->type = g_strdup(mount->devtype);
1192     build_guest_fsinfo_for_device(devpath, fs, errp);
1193 
1194     if (statvfs(fs->mountpoint, &buf) == 0) {
1195         fr_size = buf.f_frsize;
1196         used = buf.f_blocks - buf.f_bfree;
1197         nonroot_total = used + buf.f_bavail;
1198         fs->used_bytes = used * fr_size;
1199         fs->total_bytes = nonroot_total * fr_size;
1200 
1201         fs->has_total_bytes = true;
1202         fs->has_used_bytes = true;
1203     }
1204 
1205     g_free(devpath);
1206 
1207     return fs;
1208 }
1209 
1210 GuestFilesystemInfoList *qmp_guest_get_fsinfo(Error **errp)
1211 {
1212     FsMountList mounts;
1213     struct FsMount *mount;
1214     GuestFilesystemInfoList *new, *ret = NULL;
1215     Error *local_err = NULL;
1216 
1217     QTAILQ_INIT(&mounts);
1218     build_fs_mount_list(&mounts, &local_err);
1219     if (local_err) {
1220         error_propagate(errp, local_err);
1221         return NULL;
1222     }
1223 
1224     QTAILQ_FOREACH(mount, &mounts, next) {
1225         g_debug("Building guest fsinfo for '%s'", mount->dirname);
1226 
1227         new = g_malloc0(sizeof(*ret));
1228         new->value = build_guest_fsinfo(mount, &local_err);
1229         new->next = ret;
1230         ret = new;
1231         if (local_err) {
1232             error_propagate(errp, local_err);
1233             qapi_free_GuestFilesystemInfoList(ret);
1234             ret = NULL;
1235             break;
1236         }
1237     }
1238 
1239     free_fs_mount_list(&mounts);
1240     return ret;
1241 }
1242 
1243 
1244 typedef enum {
1245     FSFREEZE_HOOK_THAW = 0,
1246     FSFREEZE_HOOK_FREEZE,
1247 } FsfreezeHookArg;
1248 
1249 static const char *fsfreeze_hook_arg_string[] = {
1250     "thaw",
1251     "freeze",
1252 };
1253 
1254 static void execute_fsfreeze_hook(FsfreezeHookArg arg, Error **errp)
1255 {
1256     int status;
1257     pid_t pid;
1258     const char *hook;
1259     const char *arg_str = fsfreeze_hook_arg_string[arg];
1260     Error *local_err = NULL;
1261 
1262     hook = ga_fsfreeze_hook(ga_state);
1263     if (!hook) {
1264         return;
1265     }
1266     if (access(hook, X_OK) != 0) {
1267         error_setg_errno(errp, errno, "can't access fsfreeze hook '%s'", hook);
1268         return;
1269     }
1270 
1271     slog("executing fsfreeze hook with arg '%s'", arg_str);
1272     pid = fork();
1273     if (pid == 0) {
1274         setsid();
1275         reopen_fd_to_null(0);
1276         reopen_fd_to_null(1);
1277         reopen_fd_to_null(2);
1278 
1279         execle(hook, hook, arg_str, NULL, environ);
1280         _exit(EXIT_FAILURE);
1281     } else if (pid < 0) {
1282         error_setg_errno(errp, errno, "failed to create child process");
1283         return;
1284     }
1285 
1286     ga_wait_child(pid, &status, &local_err);
1287     if (local_err) {
1288         error_propagate(errp, local_err);
1289         return;
1290     }
1291 
1292     if (!WIFEXITED(status)) {
1293         error_setg(errp, "fsfreeze hook has terminated abnormally");
1294         return;
1295     }
1296 
1297     status = WEXITSTATUS(status);
1298     if (status) {
1299         error_setg(errp, "fsfreeze hook has failed with status %d", status);
1300         return;
1301     }
1302 }
1303 
1304 /*
1305  * Return status of freeze/thaw
1306  */
1307 GuestFsfreezeStatus qmp_guest_fsfreeze_status(Error **errp)
1308 {
1309     if (ga_is_frozen(ga_state)) {
1310         return GUEST_FSFREEZE_STATUS_FROZEN;
1311     }
1312 
1313     return GUEST_FSFREEZE_STATUS_THAWED;
1314 }
1315 
1316 int64_t qmp_guest_fsfreeze_freeze(Error **errp)
1317 {
1318     return qmp_guest_fsfreeze_freeze_list(false, NULL, errp);
1319 }
1320 
1321 /*
1322  * Walk list of mounted file systems in the guest, and freeze the ones which
1323  * are real local file systems.
1324  */
1325 int64_t qmp_guest_fsfreeze_freeze_list(bool has_mountpoints,
1326                                        strList *mountpoints,
1327                                        Error **errp)
1328 {
1329     int ret = 0, i = 0;
1330     strList *list;
1331     FsMountList mounts;
1332     struct FsMount *mount;
1333     Error *local_err = NULL;
1334     int fd;
1335 
1336     slog("guest-fsfreeze called");
1337 
1338     execute_fsfreeze_hook(FSFREEZE_HOOK_FREEZE, &local_err);
1339     if (local_err) {
1340         error_propagate(errp, local_err);
1341         return -1;
1342     }
1343 
1344     QTAILQ_INIT(&mounts);
1345     build_fs_mount_list(&mounts, &local_err);
1346     if (local_err) {
1347         error_propagate(errp, local_err);
1348         return -1;
1349     }
1350 
1351     /* cannot risk guest agent blocking itself on a write in this state */
1352     ga_set_frozen(ga_state);
1353 
1354     QTAILQ_FOREACH_REVERSE(mount, &mounts, next) {
1355         /* To issue fsfreeze in the reverse order of mounts, check if the
1356          * mount is listed in the list here */
1357         if (has_mountpoints) {
1358             for (list = mountpoints; list; list = list->next) {
1359                 if (strcmp(list->value, mount->dirname) == 0) {
1360                     break;
1361                 }
1362             }
1363             if (!list) {
1364                 continue;
1365             }
1366         }
1367 
1368         fd = qemu_open(mount->dirname, O_RDONLY);
1369         if (fd == -1) {
1370             error_setg_errno(errp, errno, "failed to open %s", mount->dirname);
1371             goto error;
1372         }
1373 
1374         /* we try to cull filesystems we know won't work in advance, but other
1375          * filesystems may not implement fsfreeze for less obvious reasons.
1376          * these will report EOPNOTSUPP. we simply ignore these when tallying
1377          * the number of frozen filesystems.
1378          * if a filesystem is mounted more than once (aka bind mount) a
1379          * consecutive attempt to freeze an already frozen filesystem will
1380          * return EBUSY.
1381          *
1382          * any other error means a failure to freeze a filesystem we
1383          * expect to be freezable, so return an error in those cases
1384          * and return system to thawed state.
1385          */
1386         ret = ioctl(fd, FIFREEZE);
1387         if (ret == -1) {
1388             if (errno != EOPNOTSUPP && errno != EBUSY) {
1389                 error_setg_errno(errp, errno, "failed to freeze %s",
1390                                  mount->dirname);
1391                 close(fd);
1392                 goto error;
1393             }
1394         } else {
1395             i++;
1396         }
1397         close(fd);
1398     }
1399 
1400     free_fs_mount_list(&mounts);
1401     /* We may not issue any FIFREEZE here.
1402      * Just unset ga_state here and ready for the next call.
1403      */
1404     if (i == 0) {
1405         ga_unset_frozen(ga_state);
1406     }
1407     return i;
1408 
1409 error:
1410     free_fs_mount_list(&mounts);
1411     qmp_guest_fsfreeze_thaw(NULL);
1412     return 0;
1413 }
1414 
1415 /*
1416  * Walk list of frozen file systems in the guest, and thaw them.
1417  */
1418 int64_t qmp_guest_fsfreeze_thaw(Error **errp)
1419 {
1420     int ret;
1421     FsMountList mounts;
1422     FsMount *mount;
1423     int fd, i = 0, logged;
1424     Error *local_err = NULL;
1425 
1426     QTAILQ_INIT(&mounts);
1427     build_fs_mount_list(&mounts, &local_err);
1428     if (local_err) {
1429         error_propagate(errp, local_err);
1430         return 0;
1431     }
1432 
1433     QTAILQ_FOREACH(mount, &mounts, next) {
1434         logged = false;
1435         fd = qemu_open(mount->dirname, O_RDONLY);
1436         if (fd == -1) {
1437             continue;
1438         }
1439         /* we have no way of knowing whether a filesystem was actually unfrozen
1440          * as a result of a successful call to FITHAW, only that if an error
1441          * was returned the filesystem was *not* unfrozen by that particular
1442          * call.
1443          *
1444          * since multiple preceding FIFREEZEs require multiple calls to FITHAW
1445          * to unfreeze, continuing issuing FITHAW until an error is returned,
1446          * in which case either the filesystem is in an unfreezable state, or,
1447          * more likely, it was thawed previously (and remains so afterward).
1448          *
1449          * also, since the most recent successful call is the one that did
1450          * the actual unfreeze, we can use this to provide an accurate count
1451          * of the number of filesystems unfrozen by guest-fsfreeze-thaw, which
1452          * may * be useful for determining whether a filesystem was unfrozen
1453          * during the freeze/thaw phase by a process other than qemu-ga.
1454          */
1455         do {
1456             ret = ioctl(fd, FITHAW);
1457             if (ret == 0 && !logged) {
1458                 i++;
1459                 logged = true;
1460             }
1461         } while (ret == 0);
1462         close(fd);
1463     }
1464 
1465     ga_unset_frozen(ga_state);
1466     free_fs_mount_list(&mounts);
1467 
1468     execute_fsfreeze_hook(FSFREEZE_HOOK_THAW, errp);
1469 
1470     return i;
1471 }
1472 
1473 static void guest_fsfreeze_cleanup(void)
1474 {
1475     Error *err = NULL;
1476 
1477     if (ga_is_frozen(ga_state) == GUEST_FSFREEZE_STATUS_FROZEN) {
1478         qmp_guest_fsfreeze_thaw(&err);
1479         if (err) {
1480             slog("failed to clean up frozen filesystems: %s",
1481                  error_get_pretty(err));
1482             error_free(err);
1483         }
1484     }
1485 }
1486 #endif /* CONFIG_FSFREEZE */
1487 
1488 #if defined(CONFIG_FSTRIM)
1489 /*
1490  * Walk list of mounted file systems in the guest, and trim them.
1491  */
1492 GuestFilesystemTrimResponse *
1493 qmp_guest_fstrim(bool has_minimum, int64_t minimum, Error **errp)
1494 {
1495     GuestFilesystemTrimResponse *response;
1496     GuestFilesystemTrimResultList *list;
1497     GuestFilesystemTrimResult *result;
1498     int ret = 0;
1499     FsMountList mounts;
1500     struct FsMount *mount;
1501     int fd;
1502     Error *local_err = NULL;
1503     struct fstrim_range r;
1504 
1505     slog("guest-fstrim called");
1506 
1507     QTAILQ_INIT(&mounts);
1508     build_fs_mount_list(&mounts, &local_err);
1509     if (local_err) {
1510         error_propagate(errp, local_err);
1511         return NULL;
1512     }
1513 
1514     response = g_malloc0(sizeof(*response));
1515 
1516     QTAILQ_FOREACH(mount, &mounts, next) {
1517         result = g_malloc0(sizeof(*result));
1518         result->path = g_strdup(mount->dirname);
1519 
1520         list = g_malloc0(sizeof(*list));
1521         list->value = result;
1522         list->next = response->paths;
1523         response->paths = list;
1524 
1525         fd = qemu_open(mount->dirname, O_RDONLY);
1526         if (fd == -1) {
1527             result->error = g_strdup_printf("failed to open: %s",
1528                                             strerror(errno));
1529             result->has_error = true;
1530             continue;
1531         }
1532 
1533         /* We try to cull filesystems we know won't work in advance, but other
1534          * filesystems may not implement fstrim for less obvious reasons.
1535          * These will report EOPNOTSUPP; while in some other cases ENOTTY
1536          * will be reported (e.g. CD-ROMs).
1537          * Any other error means an unexpected error.
1538          */
1539         r.start = 0;
1540         r.len = -1;
1541         r.minlen = has_minimum ? minimum : 0;
1542         ret = ioctl(fd, FITRIM, &r);
1543         if (ret == -1) {
1544             result->has_error = true;
1545             if (errno == ENOTTY || errno == EOPNOTSUPP) {
1546                 result->error = g_strdup("trim not supported");
1547             } else {
1548                 result->error = g_strdup_printf("failed to trim: %s",
1549                                                 strerror(errno));
1550             }
1551             close(fd);
1552             continue;
1553         }
1554 
1555         result->has_minimum = true;
1556         result->minimum = r.minlen;
1557         result->has_trimmed = true;
1558         result->trimmed = r.len;
1559         close(fd);
1560     }
1561 
1562     free_fs_mount_list(&mounts);
1563     return response;
1564 }
1565 #endif /* CONFIG_FSTRIM */
1566 
1567 
1568 #define LINUX_SYS_STATE_FILE "/sys/power/state"
1569 #define SUSPEND_SUPPORTED 0
1570 #define SUSPEND_NOT_SUPPORTED 1
1571 
1572 typedef enum {
1573     SUSPEND_MODE_DISK = 0,
1574     SUSPEND_MODE_RAM = 1,
1575     SUSPEND_MODE_HYBRID = 2,
1576 } SuspendMode;
1577 
1578 /*
1579  * Executes a command in a child process using g_spawn_sync,
1580  * returning an int >= 0 representing the exit status of the
1581  * process.
1582  *
1583  * If the program wasn't found in path, returns -1.
1584  *
1585  * If a problem happened when creating the child process,
1586  * returns -1 and errp is set.
1587  */
1588 static int run_process_child(const char *command[], Error **errp)
1589 {
1590     int exit_status, spawn_flag;
1591     GError *g_err = NULL;
1592     bool success;
1593 
1594     spawn_flag = G_SPAWN_SEARCH_PATH | G_SPAWN_STDOUT_TO_DEV_NULL |
1595                  G_SPAWN_STDERR_TO_DEV_NULL;
1596 
1597     success =  g_spawn_sync(NULL, (char **)command, environ, spawn_flag,
1598                             NULL, NULL, NULL, NULL,
1599                             &exit_status, &g_err);
1600 
1601     if (success) {
1602         return WEXITSTATUS(exit_status);
1603     }
1604 
1605     if (g_err && (g_err->code != G_SPAWN_ERROR_NOENT)) {
1606         error_setg(errp, "failed to create child process, error '%s'",
1607                    g_err->message);
1608     }
1609 
1610     g_error_free(g_err);
1611     return -1;
1612 }
1613 
1614 static bool systemd_supports_mode(SuspendMode mode, Error **errp)
1615 {
1616     const char *systemctl_args[3] = {"systemd-hibernate", "systemd-suspend",
1617                                      "systemd-hybrid-sleep"};
1618     const char *cmd[4] = {"systemctl", "status", systemctl_args[mode], NULL};
1619     int status;
1620 
1621     status = run_process_child(cmd, errp);
1622 
1623     /*
1624      * systemctl status uses LSB return codes so we can expect
1625      * status > 0 and be ok. To assert if the guest has support
1626      * for the selected suspend mode, status should be < 4. 4 is
1627      * the code for unknown service status, the return value when
1628      * the service does not exist. A common value is status = 3
1629      * (program is not running).
1630      */
1631     if (status > 0 && status < 4) {
1632         return true;
1633     }
1634 
1635     return false;
1636 }
1637 
1638 static void systemd_suspend(SuspendMode mode, Error **errp)
1639 {
1640     Error *local_err = NULL;
1641     const char *systemctl_args[3] = {"hibernate", "suspend", "hybrid-sleep"};
1642     const char *cmd[3] = {"systemctl", systemctl_args[mode], NULL};
1643     int status;
1644 
1645     status = run_process_child(cmd, &local_err);
1646 
1647     if (status == 0) {
1648         return;
1649     }
1650 
1651     if ((status == -1) && !local_err) {
1652         error_setg(errp, "the helper program 'systemctl %s' was not found",
1653                    systemctl_args[mode]);
1654         return;
1655     }
1656 
1657     if (local_err) {
1658         error_propagate(errp, local_err);
1659     } else {
1660         error_setg(errp, "the helper program 'systemctl %s' returned an "
1661                    "unexpected exit status code (%d)",
1662                    systemctl_args[mode], status);
1663     }
1664 }
1665 
1666 static bool pmutils_supports_mode(SuspendMode mode, Error **errp)
1667 {
1668     Error *local_err = NULL;
1669     const char *pmutils_args[3] = {"--hibernate", "--suspend",
1670                                    "--suspend-hybrid"};
1671     const char *cmd[3] = {"pm-is-supported", pmutils_args[mode], NULL};
1672     int status;
1673 
1674     status = run_process_child(cmd, &local_err);
1675 
1676     if (status == SUSPEND_SUPPORTED) {
1677         return true;
1678     }
1679 
1680     if ((status == -1) && !local_err) {
1681         return false;
1682     }
1683 
1684     if (local_err) {
1685         error_propagate(errp, local_err);
1686     } else {
1687         error_setg(errp,
1688                    "the helper program '%s' returned an unexpected exit"
1689                    " status code (%d)", "pm-is-supported", status);
1690     }
1691 
1692     return false;
1693 }
1694 
1695 static void pmutils_suspend(SuspendMode mode, Error **errp)
1696 {
1697     Error *local_err = NULL;
1698     const char *pmutils_binaries[3] = {"pm-hibernate", "pm-suspend",
1699                                        "pm-suspend-hybrid"};
1700     const char *cmd[2] = {pmutils_binaries[mode], NULL};
1701     int status;
1702 
1703     status = run_process_child(cmd, &local_err);
1704 
1705     if (status == 0) {
1706         return;
1707     }
1708 
1709     if ((status == -1) && !local_err) {
1710         error_setg(errp, "the helper program '%s' was not found",
1711                    pmutils_binaries[mode]);
1712         return;
1713     }
1714 
1715     if (local_err) {
1716         error_propagate(errp, local_err);
1717     } else {
1718         error_setg(errp,
1719                    "the helper program '%s' returned an unexpected exit"
1720                    " status code (%d)", pmutils_binaries[mode], status);
1721     }
1722 }
1723 
1724 static bool linux_sys_state_supports_mode(SuspendMode mode, Error **errp)
1725 {
1726     const char *sysfile_strs[3] = {"disk", "mem", NULL};
1727     const char *sysfile_str = sysfile_strs[mode];
1728     char buf[32]; /* hopefully big enough */
1729     int fd;
1730     ssize_t ret;
1731 
1732     if (!sysfile_str) {
1733         error_setg(errp, "unknown guest suspend mode");
1734         return false;
1735     }
1736 
1737     fd = open(LINUX_SYS_STATE_FILE, O_RDONLY);
1738     if (fd < 0) {
1739         return false;
1740     }
1741 
1742     ret = read(fd, buf, sizeof(buf) - 1);
1743     close(fd);
1744     if (ret <= 0) {
1745         return false;
1746     }
1747     buf[ret] = '\0';
1748 
1749     if (strstr(buf, sysfile_str)) {
1750         return true;
1751     }
1752     return false;
1753 }
1754 
1755 static void linux_sys_state_suspend(SuspendMode mode, Error **errp)
1756 {
1757     Error *local_err = NULL;
1758     const char *sysfile_strs[3] = {"disk", "mem", NULL};
1759     const char *sysfile_str = sysfile_strs[mode];
1760     pid_t pid;
1761     int status;
1762 
1763     if (!sysfile_str) {
1764         error_setg(errp, "unknown guest suspend mode");
1765         return;
1766     }
1767 
1768     pid = fork();
1769     if (!pid) {
1770         /* child */
1771         int fd;
1772 
1773         setsid();
1774         reopen_fd_to_null(0);
1775         reopen_fd_to_null(1);
1776         reopen_fd_to_null(2);
1777 
1778         fd = open(LINUX_SYS_STATE_FILE, O_WRONLY);
1779         if (fd < 0) {
1780             _exit(EXIT_FAILURE);
1781         }
1782 
1783         if (write(fd, sysfile_str, strlen(sysfile_str)) < 0) {
1784             _exit(EXIT_FAILURE);
1785         }
1786 
1787         _exit(EXIT_SUCCESS);
1788     } else if (pid < 0) {
1789         error_setg_errno(errp, errno, "failed to create child process");
1790         return;
1791     }
1792 
1793     ga_wait_child(pid, &status, &local_err);
1794     if (local_err) {
1795         error_propagate(errp, local_err);
1796         return;
1797     }
1798 
1799     if (WEXITSTATUS(status)) {
1800         error_setg(errp, "child process has failed to suspend");
1801     }
1802 
1803 }
1804 
1805 static void guest_suspend(SuspendMode mode, Error **errp)
1806 {
1807     Error *local_err = NULL;
1808     bool mode_supported = false;
1809 
1810     if (systemd_supports_mode(mode, &local_err)) {
1811         mode_supported = true;
1812         systemd_suspend(mode, &local_err);
1813     }
1814 
1815     if (!local_err) {
1816         return;
1817     }
1818 
1819     error_free(local_err);
1820     local_err = NULL;
1821 
1822     if (pmutils_supports_mode(mode, &local_err)) {
1823         mode_supported = true;
1824         pmutils_suspend(mode, &local_err);
1825     }
1826 
1827     if (!local_err) {
1828         return;
1829     }
1830 
1831     error_free(local_err);
1832     local_err = NULL;
1833 
1834     if (linux_sys_state_supports_mode(mode, &local_err)) {
1835         mode_supported = true;
1836         linux_sys_state_suspend(mode, &local_err);
1837     }
1838 
1839     if (!mode_supported) {
1840         error_free(local_err);
1841         error_setg(errp,
1842                    "the requested suspend mode is not supported by the guest");
1843     } else {
1844         error_propagate(errp, local_err);
1845     }
1846 }
1847 
1848 void qmp_guest_suspend_disk(Error **errp)
1849 {
1850     guest_suspend(SUSPEND_MODE_DISK, errp);
1851 }
1852 
1853 void qmp_guest_suspend_ram(Error **errp)
1854 {
1855     guest_suspend(SUSPEND_MODE_RAM, errp);
1856 }
1857 
1858 void qmp_guest_suspend_hybrid(Error **errp)
1859 {
1860     guest_suspend(SUSPEND_MODE_HYBRID, errp);
1861 }
1862 
1863 static GuestNetworkInterfaceList *
1864 guest_find_interface(GuestNetworkInterfaceList *head,
1865                      const char *name)
1866 {
1867     for (; head; head = head->next) {
1868         if (strcmp(head->value->name, name) == 0) {
1869             break;
1870         }
1871     }
1872 
1873     return head;
1874 }
1875 
1876 static int guest_get_network_stats(const char *name,
1877                        GuestNetworkInterfaceStat *stats)
1878 {
1879     int name_len;
1880     char const *devinfo = "/proc/net/dev";
1881     FILE *fp;
1882     char *line = NULL, *colon;
1883     size_t n = 0;
1884     fp = fopen(devinfo, "r");
1885     if (!fp) {
1886         return -1;
1887     }
1888     name_len = strlen(name);
1889     while (getline(&line, &n, fp) != -1) {
1890         long long dummy;
1891         long long rx_bytes;
1892         long long rx_packets;
1893         long long rx_errs;
1894         long long rx_dropped;
1895         long long tx_bytes;
1896         long long tx_packets;
1897         long long tx_errs;
1898         long long tx_dropped;
1899         char *trim_line;
1900         trim_line = g_strchug(line);
1901         if (trim_line[0] == '\0') {
1902             continue;
1903         }
1904         colon = strchr(trim_line, ':');
1905         if (!colon) {
1906             continue;
1907         }
1908         if (colon - name_len  == trim_line &&
1909            strncmp(trim_line, name, name_len) == 0) {
1910             if (sscanf(colon + 1,
1911                 "%lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld %lld",
1912                   &rx_bytes, &rx_packets, &rx_errs, &rx_dropped,
1913                   &dummy, &dummy, &dummy, &dummy,
1914                   &tx_bytes, &tx_packets, &tx_errs, &tx_dropped,
1915                   &dummy, &dummy, &dummy, &dummy) != 16) {
1916                 continue;
1917             }
1918             stats->rx_bytes = rx_bytes;
1919             stats->rx_packets = rx_packets;
1920             stats->rx_errs = rx_errs;
1921             stats->rx_dropped = rx_dropped;
1922             stats->tx_bytes = tx_bytes;
1923             stats->tx_packets = tx_packets;
1924             stats->tx_errs = tx_errs;
1925             stats->tx_dropped = tx_dropped;
1926             fclose(fp);
1927             g_free(line);
1928             return 0;
1929         }
1930     }
1931     fclose(fp);
1932     g_free(line);
1933     g_debug("/proc/net/dev: Interface '%s' not found", name);
1934     return -1;
1935 }
1936 
1937 /*
1938  * Build information about guest interfaces
1939  */
1940 GuestNetworkInterfaceList *qmp_guest_network_get_interfaces(Error **errp)
1941 {
1942     GuestNetworkInterfaceList *head = NULL, *cur_item = NULL;
1943     struct ifaddrs *ifap, *ifa;
1944 
1945     if (getifaddrs(&ifap) < 0) {
1946         error_setg_errno(errp, errno, "getifaddrs failed");
1947         goto error;
1948     }
1949 
1950     for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
1951         GuestNetworkInterfaceList *info;
1952         GuestIpAddressList **address_list = NULL, *address_item = NULL;
1953         GuestNetworkInterfaceStat  *interface_stat = NULL;
1954         char addr4[INET_ADDRSTRLEN];
1955         char addr6[INET6_ADDRSTRLEN];
1956         int sock;
1957         struct ifreq ifr;
1958         unsigned char *mac_addr;
1959         void *p;
1960 
1961         g_debug("Processing %s interface", ifa->ifa_name);
1962 
1963         info = guest_find_interface(head, ifa->ifa_name);
1964 
1965         if (!info) {
1966             info = g_malloc0(sizeof(*info));
1967             info->value = g_malloc0(sizeof(*info->value));
1968             info->value->name = g_strdup(ifa->ifa_name);
1969 
1970             if (!cur_item) {
1971                 head = cur_item = info;
1972             } else {
1973                 cur_item->next = info;
1974                 cur_item = info;
1975             }
1976         }
1977 
1978         if (!info->value->has_hardware_address &&
1979             ifa->ifa_flags & SIOCGIFHWADDR) {
1980             /* we haven't obtained HW address yet */
1981             sock = socket(PF_INET, SOCK_STREAM, 0);
1982             if (sock == -1) {
1983                 error_setg_errno(errp, errno, "failed to create socket");
1984                 goto error;
1985             }
1986 
1987             memset(&ifr, 0, sizeof(ifr));
1988             pstrcpy(ifr.ifr_name, IF_NAMESIZE, info->value->name);
1989             if (ioctl(sock, SIOCGIFHWADDR, &ifr) == -1) {
1990                 error_setg_errno(errp, errno,
1991                                  "failed to get MAC address of %s",
1992                                  ifa->ifa_name);
1993                 close(sock);
1994                 goto error;
1995             }
1996 
1997             close(sock);
1998             mac_addr = (unsigned char *) &ifr.ifr_hwaddr.sa_data;
1999 
2000             info->value->hardware_address =
2001                 g_strdup_printf("%02x:%02x:%02x:%02x:%02x:%02x",
2002                                 (int) mac_addr[0], (int) mac_addr[1],
2003                                 (int) mac_addr[2], (int) mac_addr[3],
2004                                 (int) mac_addr[4], (int) mac_addr[5]);
2005 
2006             info->value->has_hardware_address = true;
2007         }
2008 
2009         if (ifa->ifa_addr &&
2010             ifa->ifa_addr->sa_family == AF_INET) {
2011             /* interface with IPv4 address */
2012             p = &((struct sockaddr_in *)ifa->ifa_addr)->sin_addr;
2013             if (!inet_ntop(AF_INET, p, addr4, sizeof(addr4))) {
2014                 error_setg_errno(errp, errno, "inet_ntop failed");
2015                 goto error;
2016             }
2017 
2018             address_item = g_malloc0(sizeof(*address_item));
2019             address_item->value = g_malloc0(sizeof(*address_item->value));
2020             address_item->value->ip_address = g_strdup(addr4);
2021             address_item->value->ip_address_type = GUEST_IP_ADDRESS_TYPE_IPV4;
2022 
2023             if (ifa->ifa_netmask) {
2024                 /* Count the number of set bits in netmask.
2025                  * This is safe as '1' and '0' cannot be shuffled in netmask. */
2026                 p = &((struct sockaddr_in *)ifa->ifa_netmask)->sin_addr;
2027                 address_item->value->prefix = ctpop32(((uint32_t *) p)[0]);
2028             }
2029         } else if (ifa->ifa_addr &&
2030                    ifa->ifa_addr->sa_family == AF_INET6) {
2031             /* interface with IPv6 address */
2032             p = &((struct sockaddr_in6 *)ifa->ifa_addr)->sin6_addr;
2033             if (!inet_ntop(AF_INET6, p, addr6, sizeof(addr6))) {
2034                 error_setg_errno(errp, errno, "inet_ntop failed");
2035                 goto error;
2036             }
2037 
2038             address_item = g_malloc0(sizeof(*address_item));
2039             address_item->value = g_malloc0(sizeof(*address_item->value));
2040             address_item->value->ip_address = g_strdup(addr6);
2041             address_item->value->ip_address_type = GUEST_IP_ADDRESS_TYPE_IPV6;
2042 
2043             if (ifa->ifa_netmask) {
2044                 /* Count the number of set bits in netmask.
2045                  * This is safe as '1' and '0' cannot be shuffled in netmask. */
2046                 p = &((struct sockaddr_in6 *)ifa->ifa_netmask)->sin6_addr;
2047                 address_item->value->prefix =
2048                     ctpop32(((uint32_t *) p)[0]) +
2049                     ctpop32(((uint32_t *) p)[1]) +
2050                     ctpop32(((uint32_t *) p)[2]) +
2051                     ctpop32(((uint32_t *) p)[3]);
2052             }
2053         }
2054 
2055         if (!address_item) {
2056             continue;
2057         }
2058 
2059         address_list = &info->value->ip_addresses;
2060 
2061         while (*address_list && (*address_list)->next) {
2062             address_list = &(*address_list)->next;
2063         }
2064 
2065         if (!*address_list) {
2066             *address_list = address_item;
2067         } else {
2068             (*address_list)->next = address_item;
2069         }
2070 
2071         info->value->has_ip_addresses = true;
2072 
2073         if (!info->value->has_statistics) {
2074             interface_stat = g_malloc0(sizeof(*interface_stat));
2075             if (guest_get_network_stats(info->value->name,
2076                 interface_stat) == -1) {
2077                 info->value->has_statistics = false;
2078                 g_free(interface_stat);
2079             } else {
2080                 info->value->statistics = interface_stat;
2081                 info->value->has_statistics = true;
2082             }
2083         }
2084     }
2085 
2086     freeifaddrs(ifap);
2087     return head;
2088 
2089 error:
2090     freeifaddrs(ifap);
2091     qapi_free_GuestNetworkInterfaceList(head);
2092     return NULL;
2093 }
2094 
2095 #define SYSCONF_EXACT(name, errp) sysconf_exact((name), #name, (errp))
2096 
2097 static long sysconf_exact(int name, const char *name_str, Error **errp)
2098 {
2099     long ret;
2100 
2101     errno = 0;
2102     ret = sysconf(name);
2103     if (ret == -1) {
2104         if (errno == 0) {
2105             error_setg(errp, "sysconf(%s): value indefinite", name_str);
2106         } else {
2107             error_setg_errno(errp, errno, "sysconf(%s)", name_str);
2108         }
2109     }
2110     return ret;
2111 }
2112 
2113 /* Transfer online/offline status between @vcpu and the guest system.
2114  *
2115  * On input either @errp or *@errp must be NULL.
2116  *
2117  * In system-to-@vcpu direction, the following @vcpu fields are accessed:
2118  * - R: vcpu->logical_id
2119  * - W: vcpu->online
2120  * - W: vcpu->can_offline
2121  *
2122  * In @vcpu-to-system direction, the following @vcpu fields are accessed:
2123  * - R: vcpu->logical_id
2124  * - R: vcpu->online
2125  *
2126  * Written members remain unmodified on error.
2127  */
2128 static void transfer_vcpu(GuestLogicalProcessor *vcpu, bool sys2vcpu,
2129                           char *dirpath, Error **errp)
2130 {
2131     int fd;
2132     int res;
2133     int dirfd;
2134     static const char fn[] = "online";
2135 
2136     dirfd = open(dirpath, O_RDONLY | O_DIRECTORY);
2137     if (dirfd == -1) {
2138         error_setg_errno(errp, errno, "open(\"%s\")", dirpath);
2139         return;
2140     }
2141 
2142     fd = openat(dirfd, fn, sys2vcpu ? O_RDONLY : O_RDWR);
2143     if (fd == -1) {
2144         if (errno != ENOENT) {
2145             error_setg_errno(errp, errno, "open(\"%s/%s\")", dirpath, fn);
2146         } else if (sys2vcpu) {
2147             vcpu->online = true;
2148             vcpu->can_offline = false;
2149         } else if (!vcpu->online) {
2150             error_setg(errp, "logical processor #%" PRId64 " can't be "
2151                        "offlined", vcpu->logical_id);
2152         } /* otherwise pretend successful re-onlining */
2153     } else {
2154         unsigned char status;
2155 
2156         res = pread(fd, &status, 1, 0);
2157         if (res == -1) {
2158             error_setg_errno(errp, errno, "pread(\"%s/%s\")", dirpath, fn);
2159         } else if (res == 0) {
2160             error_setg(errp, "pread(\"%s/%s\"): unexpected EOF", dirpath,
2161                        fn);
2162         } else if (sys2vcpu) {
2163             vcpu->online = (status != '0');
2164             vcpu->can_offline = true;
2165         } else if (vcpu->online != (status != '0')) {
2166             status = '0' + vcpu->online;
2167             if (pwrite(fd, &status, 1, 0) == -1) {
2168                 error_setg_errno(errp, errno, "pwrite(\"%s/%s\")", dirpath,
2169                                  fn);
2170             }
2171         } /* otherwise pretend successful re-(on|off)-lining */
2172 
2173         res = close(fd);
2174         g_assert(res == 0);
2175     }
2176 
2177     res = close(dirfd);
2178     g_assert(res == 0);
2179 }
2180 
2181 GuestLogicalProcessorList *qmp_guest_get_vcpus(Error **errp)
2182 {
2183     int64_t current;
2184     GuestLogicalProcessorList *head, **link;
2185     long sc_max;
2186     Error *local_err = NULL;
2187 
2188     current = 0;
2189     head = NULL;
2190     link = &head;
2191     sc_max = SYSCONF_EXACT(_SC_NPROCESSORS_CONF, &local_err);
2192 
2193     while (local_err == NULL && current < sc_max) {
2194         GuestLogicalProcessor *vcpu;
2195         GuestLogicalProcessorList *entry;
2196         int64_t id = current++;
2197         char *path = g_strdup_printf("/sys/devices/system/cpu/cpu%" PRId64 "/",
2198                                      id);
2199 
2200         if (g_file_test(path, G_FILE_TEST_EXISTS)) {
2201             vcpu = g_malloc0(sizeof *vcpu);
2202             vcpu->logical_id = id;
2203             vcpu->has_can_offline = true; /* lolspeak ftw */
2204             transfer_vcpu(vcpu, true, path, &local_err);
2205             entry = g_malloc0(sizeof *entry);
2206             entry->value = vcpu;
2207             *link = entry;
2208             link = &entry->next;
2209         }
2210         g_free(path);
2211     }
2212 
2213     if (local_err == NULL) {
2214         /* there's no guest with zero VCPUs */
2215         g_assert(head != NULL);
2216         return head;
2217     }
2218 
2219     qapi_free_GuestLogicalProcessorList(head);
2220     error_propagate(errp, local_err);
2221     return NULL;
2222 }
2223 
2224 int64_t qmp_guest_set_vcpus(GuestLogicalProcessorList *vcpus, Error **errp)
2225 {
2226     int64_t processed;
2227     Error *local_err = NULL;
2228 
2229     processed = 0;
2230     while (vcpus != NULL) {
2231         char *path = g_strdup_printf("/sys/devices/system/cpu/cpu%" PRId64 "/",
2232                                      vcpus->value->logical_id);
2233 
2234         transfer_vcpu(vcpus->value, false, path, &local_err);
2235         g_free(path);
2236         if (local_err != NULL) {
2237             break;
2238         }
2239         ++processed;
2240         vcpus = vcpus->next;
2241     }
2242 
2243     if (local_err != NULL) {
2244         if (processed == 0) {
2245             error_propagate(errp, local_err);
2246         } else {
2247             error_free(local_err);
2248         }
2249     }
2250 
2251     return processed;
2252 }
2253 
2254 void qmp_guest_set_user_password(const char *username,
2255                                  const char *password,
2256                                  bool crypted,
2257                                  Error **errp)
2258 {
2259     Error *local_err = NULL;
2260     char *passwd_path = NULL;
2261     pid_t pid;
2262     int status;
2263     int datafd[2] = { -1, -1 };
2264     char *rawpasswddata = NULL;
2265     size_t rawpasswdlen;
2266     char *chpasswddata = NULL;
2267     size_t chpasswdlen;
2268 
2269     rawpasswddata = (char *)qbase64_decode(password, -1, &rawpasswdlen, errp);
2270     if (!rawpasswddata) {
2271         return;
2272     }
2273     rawpasswddata = g_renew(char, rawpasswddata, rawpasswdlen + 1);
2274     rawpasswddata[rawpasswdlen] = '\0';
2275 
2276     if (strchr(rawpasswddata, '\n')) {
2277         error_setg(errp, "forbidden characters in raw password");
2278         goto out;
2279     }
2280 
2281     if (strchr(username, '\n') ||
2282         strchr(username, ':')) {
2283         error_setg(errp, "forbidden characters in username");
2284         goto out;
2285     }
2286 
2287     chpasswddata = g_strdup_printf("%s:%s\n", username, rawpasswddata);
2288     chpasswdlen = strlen(chpasswddata);
2289 
2290     passwd_path = g_find_program_in_path("chpasswd");
2291 
2292     if (!passwd_path) {
2293         error_setg(errp, "cannot find 'passwd' program in PATH");
2294         goto out;
2295     }
2296 
2297     if (pipe(datafd) < 0) {
2298         error_setg(errp, "cannot create pipe FDs");
2299         goto out;
2300     }
2301 
2302     pid = fork();
2303     if (pid == 0) {
2304         close(datafd[1]);
2305         /* child */
2306         setsid();
2307         dup2(datafd[0], 0);
2308         reopen_fd_to_null(1);
2309         reopen_fd_to_null(2);
2310 
2311         if (crypted) {
2312             execle(passwd_path, "chpasswd", "-e", NULL, environ);
2313         } else {
2314             execle(passwd_path, "chpasswd", NULL, environ);
2315         }
2316         _exit(EXIT_FAILURE);
2317     } else if (pid < 0) {
2318         error_setg_errno(errp, errno, "failed to create child process");
2319         goto out;
2320     }
2321     close(datafd[0]);
2322     datafd[0] = -1;
2323 
2324     if (qemu_write_full(datafd[1], chpasswddata, chpasswdlen) != chpasswdlen) {
2325         error_setg_errno(errp, errno, "cannot write new account password");
2326         goto out;
2327     }
2328     close(datafd[1]);
2329     datafd[1] = -1;
2330 
2331     ga_wait_child(pid, &status, &local_err);
2332     if (local_err) {
2333         error_propagate(errp, local_err);
2334         goto out;
2335     }
2336 
2337     if (!WIFEXITED(status)) {
2338         error_setg(errp, "child process has terminated abnormally");
2339         goto out;
2340     }
2341 
2342     if (WEXITSTATUS(status)) {
2343         error_setg(errp, "child process has failed to set user password");
2344         goto out;
2345     }
2346 
2347 out:
2348     g_free(chpasswddata);
2349     g_free(rawpasswddata);
2350     g_free(passwd_path);
2351     if (datafd[0] != -1) {
2352         close(datafd[0]);
2353     }
2354     if (datafd[1] != -1) {
2355         close(datafd[1]);
2356     }
2357 }
2358 
2359 static void ga_read_sysfs_file(int dirfd, const char *pathname, char *buf,
2360                                int size, Error **errp)
2361 {
2362     int fd;
2363     int res;
2364 
2365     errno = 0;
2366     fd = openat(dirfd, pathname, O_RDONLY);
2367     if (fd == -1) {
2368         error_setg_errno(errp, errno, "open sysfs file \"%s\"", pathname);
2369         return;
2370     }
2371 
2372     res = pread(fd, buf, size, 0);
2373     if (res == -1) {
2374         error_setg_errno(errp, errno, "pread sysfs file \"%s\"", pathname);
2375     } else if (res == 0) {
2376         error_setg(errp, "pread sysfs file \"%s\": unexpected EOF", pathname);
2377     }
2378     close(fd);
2379 }
2380 
2381 static void ga_write_sysfs_file(int dirfd, const char *pathname,
2382                                 const char *buf, int size, Error **errp)
2383 {
2384     int fd;
2385 
2386     errno = 0;
2387     fd = openat(dirfd, pathname, O_WRONLY);
2388     if (fd == -1) {
2389         error_setg_errno(errp, errno, "open sysfs file \"%s\"", pathname);
2390         return;
2391     }
2392 
2393     if (pwrite(fd, buf, size, 0) == -1) {
2394         error_setg_errno(errp, errno, "pwrite sysfs file \"%s\"", pathname);
2395     }
2396 
2397     close(fd);
2398 }
2399 
2400 /* Transfer online/offline status between @mem_blk and the guest system.
2401  *
2402  * On input either @errp or *@errp must be NULL.
2403  *
2404  * In system-to-@mem_blk direction, the following @mem_blk fields are accessed:
2405  * - R: mem_blk->phys_index
2406  * - W: mem_blk->online
2407  * - W: mem_blk->can_offline
2408  *
2409  * In @mem_blk-to-system direction, the following @mem_blk fields are accessed:
2410  * - R: mem_blk->phys_index
2411  * - R: mem_blk->online
2412  *-  R: mem_blk->can_offline
2413  * Written members remain unmodified on error.
2414  */
2415 static void transfer_memory_block(GuestMemoryBlock *mem_blk, bool sys2memblk,
2416                                   GuestMemoryBlockResponse *result,
2417                                   Error **errp)
2418 {
2419     char *dirpath;
2420     int dirfd;
2421     char *status;
2422     Error *local_err = NULL;
2423 
2424     if (!sys2memblk) {
2425         DIR *dp;
2426 
2427         if (!result) {
2428             error_setg(errp, "Internal error, 'result' should not be NULL");
2429             return;
2430         }
2431         errno = 0;
2432         dp = opendir("/sys/devices/system/memory/");
2433          /* if there is no 'memory' directory in sysfs,
2434          * we think this VM does not support online/offline memory block,
2435          * any other solution?
2436          */
2437         if (!dp) {
2438             if (errno == ENOENT) {
2439                 result->response =
2440                     GUEST_MEMORY_BLOCK_RESPONSE_TYPE_OPERATION_NOT_SUPPORTED;
2441             }
2442             goto out1;
2443         }
2444         closedir(dp);
2445     }
2446 
2447     dirpath = g_strdup_printf("/sys/devices/system/memory/memory%" PRId64 "/",
2448                               mem_blk->phys_index);
2449     dirfd = open(dirpath, O_RDONLY | O_DIRECTORY);
2450     if (dirfd == -1) {
2451         if (sys2memblk) {
2452             error_setg_errno(errp, errno, "open(\"%s\")", dirpath);
2453         } else {
2454             if (errno == ENOENT) {
2455                 result->response = GUEST_MEMORY_BLOCK_RESPONSE_TYPE_NOT_FOUND;
2456             } else {
2457                 result->response =
2458                     GUEST_MEMORY_BLOCK_RESPONSE_TYPE_OPERATION_FAILED;
2459             }
2460         }
2461         g_free(dirpath);
2462         goto out1;
2463     }
2464     g_free(dirpath);
2465 
2466     status = g_malloc0(10);
2467     ga_read_sysfs_file(dirfd, "state", status, 10, &local_err);
2468     if (local_err) {
2469         /* treat with sysfs file that not exist in old kernel */
2470         if (errno == ENOENT) {
2471             error_free(local_err);
2472             if (sys2memblk) {
2473                 mem_blk->online = true;
2474                 mem_blk->can_offline = false;
2475             } else if (!mem_blk->online) {
2476                 result->response =
2477                     GUEST_MEMORY_BLOCK_RESPONSE_TYPE_OPERATION_NOT_SUPPORTED;
2478             }
2479         } else {
2480             if (sys2memblk) {
2481                 error_propagate(errp, local_err);
2482             } else {
2483                 error_free(local_err);
2484                 result->response =
2485                     GUEST_MEMORY_BLOCK_RESPONSE_TYPE_OPERATION_FAILED;
2486             }
2487         }
2488         goto out2;
2489     }
2490 
2491     if (sys2memblk) {
2492         char removable = '0';
2493 
2494         mem_blk->online = (strncmp(status, "online", 6) == 0);
2495 
2496         ga_read_sysfs_file(dirfd, "removable", &removable, 1, &local_err);
2497         if (local_err) {
2498             /* if no 'removable' file, it doesn't support offline mem blk */
2499             if (errno == ENOENT) {
2500                 error_free(local_err);
2501                 mem_blk->can_offline = false;
2502             } else {
2503                 error_propagate(errp, local_err);
2504             }
2505         } else {
2506             mem_blk->can_offline = (removable != '0');
2507         }
2508     } else {
2509         if (mem_blk->online != (strncmp(status, "online", 6) == 0)) {
2510             const char *new_state = mem_blk->online ? "online" : "offline";
2511 
2512             ga_write_sysfs_file(dirfd, "state", new_state, strlen(new_state),
2513                                 &local_err);
2514             if (local_err) {
2515                 error_free(local_err);
2516                 result->response =
2517                     GUEST_MEMORY_BLOCK_RESPONSE_TYPE_OPERATION_FAILED;
2518                 goto out2;
2519             }
2520 
2521             result->response = GUEST_MEMORY_BLOCK_RESPONSE_TYPE_SUCCESS;
2522             result->has_error_code = false;
2523         } /* otherwise pretend successful re-(on|off)-lining */
2524     }
2525     g_free(status);
2526     close(dirfd);
2527     return;
2528 
2529 out2:
2530     g_free(status);
2531     close(dirfd);
2532 out1:
2533     if (!sys2memblk) {
2534         result->has_error_code = true;
2535         result->error_code = errno;
2536     }
2537 }
2538 
2539 GuestMemoryBlockList *qmp_guest_get_memory_blocks(Error **errp)
2540 {
2541     GuestMemoryBlockList *head, **link;
2542     Error *local_err = NULL;
2543     struct dirent *de;
2544     DIR *dp;
2545 
2546     head = NULL;
2547     link = &head;
2548 
2549     dp = opendir("/sys/devices/system/memory/");
2550     if (!dp) {
2551         /* it's ok if this happens to be a system that doesn't expose
2552          * memory blocks via sysfs, but otherwise we should report
2553          * an error
2554          */
2555         if (errno != ENOENT) {
2556             error_setg_errno(errp, errno, "Can't open directory"
2557                              "\"/sys/devices/system/memory/\"");
2558         }
2559         return NULL;
2560     }
2561 
2562     /* Note: the phys_index of memory block may be discontinuous,
2563      * this is because a memblk is the unit of the Sparse Memory design, which
2564      * allows discontinuous memory ranges (ex. NUMA), so here we should
2565      * traverse the memory block directory.
2566      */
2567     while ((de = readdir(dp)) != NULL) {
2568         GuestMemoryBlock *mem_blk;
2569         GuestMemoryBlockList *entry;
2570 
2571         if ((strncmp(de->d_name, "memory", 6) != 0) ||
2572             !(de->d_type & DT_DIR)) {
2573             continue;
2574         }
2575 
2576         mem_blk = g_malloc0(sizeof *mem_blk);
2577         /* The d_name is "memoryXXX",  phys_index is block id, same as XXX */
2578         mem_blk->phys_index = strtoul(&de->d_name[6], NULL, 10);
2579         mem_blk->has_can_offline = true; /* lolspeak ftw */
2580         transfer_memory_block(mem_blk, true, NULL, &local_err);
2581         if (local_err) {
2582             break;
2583         }
2584 
2585         entry = g_malloc0(sizeof *entry);
2586         entry->value = mem_blk;
2587 
2588         *link = entry;
2589         link = &entry->next;
2590     }
2591 
2592     closedir(dp);
2593     if (local_err == NULL) {
2594         /* there's no guest with zero memory blocks */
2595         if (head == NULL) {
2596             error_setg(errp, "guest reported zero memory blocks!");
2597         }
2598         return head;
2599     }
2600 
2601     qapi_free_GuestMemoryBlockList(head);
2602     error_propagate(errp, local_err);
2603     return NULL;
2604 }
2605 
2606 GuestMemoryBlockResponseList *
2607 qmp_guest_set_memory_blocks(GuestMemoryBlockList *mem_blks, Error **errp)
2608 {
2609     GuestMemoryBlockResponseList *head, **link;
2610     Error *local_err = NULL;
2611 
2612     head = NULL;
2613     link = &head;
2614 
2615     while (mem_blks != NULL) {
2616         GuestMemoryBlockResponse *result;
2617         GuestMemoryBlockResponseList *entry;
2618         GuestMemoryBlock *current_mem_blk = mem_blks->value;
2619 
2620         result = g_malloc0(sizeof(*result));
2621         result->phys_index = current_mem_blk->phys_index;
2622         transfer_memory_block(current_mem_blk, false, result, &local_err);
2623         if (local_err) { /* should never happen */
2624             goto err;
2625         }
2626         entry = g_malloc0(sizeof *entry);
2627         entry->value = result;
2628 
2629         *link = entry;
2630         link = &entry->next;
2631         mem_blks = mem_blks->next;
2632     }
2633 
2634     return head;
2635 err:
2636     qapi_free_GuestMemoryBlockResponseList(head);
2637     error_propagate(errp, local_err);
2638     return NULL;
2639 }
2640 
2641 GuestMemoryBlockInfo *qmp_guest_get_memory_block_info(Error **errp)
2642 {
2643     Error *local_err = NULL;
2644     char *dirpath;
2645     int dirfd;
2646     char *buf;
2647     GuestMemoryBlockInfo *info;
2648 
2649     dirpath = g_strdup_printf("/sys/devices/system/memory/");
2650     dirfd = open(dirpath, O_RDONLY | O_DIRECTORY);
2651     if (dirfd == -1) {
2652         error_setg_errno(errp, errno, "open(\"%s\")", dirpath);
2653         g_free(dirpath);
2654         return NULL;
2655     }
2656     g_free(dirpath);
2657 
2658     buf = g_malloc0(20);
2659     ga_read_sysfs_file(dirfd, "block_size_bytes", buf, 20, &local_err);
2660     close(dirfd);
2661     if (local_err) {
2662         g_free(buf);
2663         error_propagate(errp, local_err);
2664         return NULL;
2665     }
2666 
2667     info = g_new0(GuestMemoryBlockInfo, 1);
2668     info->size = strtol(buf, NULL, 16); /* the unit is bytes */
2669 
2670     g_free(buf);
2671 
2672     return info;
2673 }
2674 
2675 #else /* defined(__linux__) */
2676 
2677 void qmp_guest_suspend_disk(Error **errp)
2678 {
2679     error_setg(errp, QERR_UNSUPPORTED);
2680 }
2681 
2682 void qmp_guest_suspend_ram(Error **errp)
2683 {
2684     error_setg(errp, QERR_UNSUPPORTED);
2685 }
2686 
2687 void qmp_guest_suspend_hybrid(Error **errp)
2688 {
2689     error_setg(errp, QERR_UNSUPPORTED);
2690 }
2691 
2692 GuestNetworkInterfaceList *qmp_guest_network_get_interfaces(Error **errp)
2693 {
2694     error_setg(errp, QERR_UNSUPPORTED);
2695     return NULL;
2696 }
2697 
2698 GuestLogicalProcessorList *qmp_guest_get_vcpus(Error **errp)
2699 {
2700     error_setg(errp, QERR_UNSUPPORTED);
2701     return NULL;
2702 }
2703 
2704 int64_t qmp_guest_set_vcpus(GuestLogicalProcessorList *vcpus, Error **errp)
2705 {
2706     error_setg(errp, QERR_UNSUPPORTED);
2707     return -1;
2708 }
2709 
2710 void qmp_guest_set_user_password(const char *username,
2711                                  const char *password,
2712                                  bool crypted,
2713                                  Error **errp)
2714 {
2715     error_setg(errp, QERR_UNSUPPORTED);
2716 }
2717 
2718 GuestMemoryBlockList *qmp_guest_get_memory_blocks(Error **errp)
2719 {
2720     error_setg(errp, QERR_UNSUPPORTED);
2721     return NULL;
2722 }
2723 
2724 GuestMemoryBlockResponseList *
2725 qmp_guest_set_memory_blocks(GuestMemoryBlockList *mem_blks, Error **errp)
2726 {
2727     error_setg(errp, QERR_UNSUPPORTED);
2728     return NULL;
2729 }
2730 
2731 GuestMemoryBlockInfo *qmp_guest_get_memory_block_info(Error **errp)
2732 {
2733     error_setg(errp, QERR_UNSUPPORTED);
2734     return NULL;
2735 }
2736 
2737 #endif
2738 
2739 #if !defined(CONFIG_FSFREEZE)
2740 
2741 GuestFilesystemInfoList *qmp_guest_get_fsinfo(Error **errp)
2742 {
2743     error_setg(errp, QERR_UNSUPPORTED);
2744     return NULL;
2745 }
2746 
2747 GuestFsfreezeStatus qmp_guest_fsfreeze_status(Error **errp)
2748 {
2749     error_setg(errp, QERR_UNSUPPORTED);
2750 
2751     return 0;
2752 }
2753 
2754 int64_t qmp_guest_fsfreeze_freeze(Error **errp)
2755 {
2756     error_setg(errp, QERR_UNSUPPORTED);
2757 
2758     return 0;
2759 }
2760 
2761 int64_t qmp_guest_fsfreeze_freeze_list(bool has_mountpoints,
2762                                        strList *mountpoints,
2763                                        Error **errp)
2764 {
2765     error_setg(errp, QERR_UNSUPPORTED);
2766 
2767     return 0;
2768 }
2769 
2770 int64_t qmp_guest_fsfreeze_thaw(Error **errp)
2771 {
2772     error_setg(errp, QERR_UNSUPPORTED);
2773 
2774     return 0;
2775 }
2776 #endif /* CONFIG_FSFREEZE */
2777 
2778 #if !defined(CONFIG_FSTRIM)
2779 GuestFilesystemTrimResponse *
2780 qmp_guest_fstrim(bool has_minimum, int64_t minimum, Error **errp)
2781 {
2782     error_setg(errp, QERR_UNSUPPORTED);
2783     return NULL;
2784 }
2785 #endif
2786 
2787 /* add unsupported commands to the blacklist */
2788 GList *ga_command_blacklist_init(GList *blacklist)
2789 {
2790 #if !defined(__linux__)
2791     {
2792         const char *list[] = {
2793             "guest-suspend-disk", "guest-suspend-ram",
2794             "guest-suspend-hybrid", "guest-network-get-interfaces",
2795             "guest-get-vcpus", "guest-set-vcpus",
2796             "guest-get-memory-blocks", "guest-set-memory-blocks",
2797             "guest-get-memory-block-size", "guest-get-memory-block-info",
2798             NULL};
2799         char **p = (char **)list;
2800 
2801         while (*p) {
2802             blacklist = g_list_append(blacklist, g_strdup(*p++));
2803         }
2804     }
2805 #endif
2806 
2807 #if !defined(CONFIG_FSFREEZE)
2808     {
2809         const char *list[] = {
2810             "guest-get-fsinfo", "guest-fsfreeze-status",
2811             "guest-fsfreeze-freeze", "guest-fsfreeze-freeze-list",
2812             "guest-fsfreeze-thaw", "guest-get-fsinfo", NULL};
2813         char **p = (char **)list;
2814 
2815         while (*p) {
2816             blacklist = g_list_append(blacklist, g_strdup(*p++));
2817         }
2818     }
2819 #endif
2820 
2821 #if !defined(CONFIG_FSTRIM)
2822     blacklist = g_list_append(blacklist, g_strdup("guest-fstrim"));
2823 #endif
2824 
2825     blacklist = g_list_append(blacklist, g_strdup("guest-get-devices"));
2826 
2827     return blacklist;
2828 }
2829 
2830 /* register init/cleanup routines for stateful command groups */
2831 void ga_command_state_init(GAState *s, GACommandState *cs)
2832 {
2833 #if defined(CONFIG_FSFREEZE)
2834     ga_command_state_add(cs, NULL, guest_fsfreeze_cleanup);
2835 #endif
2836 }
2837 
2838 #ifdef HAVE_UTMPX
2839 
2840 #define QGA_MICRO_SECOND_TO_SECOND 1000000
2841 
2842 static double ga_get_login_time(struct utmpx *user_info)
2843 {
2844     double seconds = (double)user_info->ut_tv.tv_sec;
2845     double useconds = (double)user_info->ut_tv.tv_usec;
2846     useconds /= QGA_MICRO_SECOND_TO_SECOND;
2847     return seconds + useconds;
2848 }
2849 
2850 GuestUserList *qmp_guest_get_users(Error **errp)
2851 {
2852     GHashTable *cache = NULL;
2853     GuestUserList *head = NULL, *cur_item = NULL;
2854     struct utmpx *user_info = NULL;
2855     gpointer value = NULL;
2856     GuestUser *user = NULL;
2857     GuestUserList *item = NULL;
2858     double login_time = 0;
2859 
2860     cache = g_hash_table_new(g_str_hash, g_str_equal);
2861     setutxent();
2862 
2863     for (;;) {
2864         user_info = getutxent();
2865         if (user_info == NULL) {
2866             break;
2867         } else if (user_info->ut_type != USER_PROCESS) {
2868             continue;
2869         } else if (g_hash_table_contains(cache, user_info->ut_user)) {
2870             value = g_hash_table_lookup(cache, user_info->ut_user);
2871             user = (GuestUser *)value;
2872             login_time = ga_get_login_time(user_info);
2873             /* We're ensuring the earliest login time to be sent */
2874             if (login_time < user->login_time) {
2875                 user->login_time = login_time;
2876             }
2877             continue;
2878         }
2879 
2880         item = g_new0(GuestUserList, 1);
2881         item->value = g_new0(GuestUser, 1);
2882         item->value->user = g_strdup(user_info->ut_user);
2883         item->value->login_time = ga_get_login_time(user_info);
2884 
2885         g_hash_table_insert(cache, item->value->user, item->value);
2886 
2887         if (!cur_item) {
2888             head = cur_item = item;
2889         } else {
2890             cur_item->next = item;
2891             cur_item = item;
2892         }
2893     }
2894     endutxent();
2895     g_hash_table_destroy(cache);
2896     return head;
2897 }
2898 
2899 #else
2900 
2901 GuestUserList *qmp_guest_get_users(Error **errp)
2902 {
2903     error_setg(errp, QERR_UNSUPPORTED);
2904     return NULL;
2905 }
2906 
2907 #endif
2908 
2909 /* Replace escaped special characters with theire real values. The replacement
2910  * is done in place -- returned value is in the original string.
2911  */
2912 static void ga_osrelease_replace_special(gchar *value)
2913 {
2914     gchar *p, *p2, quote;
2915 
2916     /* Trim the string at first space or semicolon if it is not enclosed in
2917      * single or double quotes. */
2918     if ((value[0] != '"') || (value[0] == '\'')) {
2919         p = strchr(value, ' ');
2920         if (p != NULL) {
2921             *p = 0;
2922         }
2923         p = strchr(value, ';');
2924         if (p != NULL) {
2925             *p = 0;
2926         }
2927         return;
2928     }
2929 
2930     quote = value[0];
2931     p2 = value;
2932     p = value + 1;
2933     while (*p != 0) {
2934         if (*p == '\\') {
2935             p++;
2936             switch (*p) {
2937             case '$':
2938             case '\'':
2939             case '"':
2940             case '\\':
2941             case '`':
2942                 break;
2943             default:
2944                 /* Keep literal backslash followed by whatever is there */
2945                 p--;
2946                 break;
2947             }
2948         } else if (*p == quote) {
2949             *p2 = 0;
2950             break;
2951         }
2952         *(p2++) = *(p++);
2953     }
2954 }
2955 
2956 static GKeyFile *ga_parse_osrelease(const char *fname)
2957 {
2958     gchar *content = NULL;
2959     gchar *content2 = NULL;
2960     GError *err = NULL;
2961     GKeyFile *keys = g_key_file_new();
2962     const char *group = "[os-release]\n";
2963 
2964     if (!g_file_get_contents(fname, &content, NULL, &err)) {
2965         slog("failed to read '%s', error: %s", fname, err->message);
2966         goto fail;
2967     }
2968 
2969     if (!g_utf8_validate(content, -1, NULL)) {
2970         slog("file is not utf-8 encoded: %s", fname);
2971         goto fail;
2972     }
2973     content2 = g_strdup_printf("%s%s", group, content);
2974 
2975     if (!g_key_file_load_from_data(keys, content2, -1, G_KEY_FILE_NONE,
2976                                    &err)) {
2977         slog("failed to parse file '%s', error: %s", fname, err->message);
2978         goto fail;
2979     }
2980 
2981     g_free(content);
2982     g_free(content2);
2983     return keys;
2984 
2985 fail:
2986     g_error_free(err);
2987     g_free(content);
2988     g_free(content2);
2989     g_key_file_free(keys);
2990     return NULL;
2991 }
2992 
2993 GuestOSInfo *qmp_guest_get_osinfo(Error **errp)
2994 {
2995     GuestOSInfo *info = NULL;
2996     struct utsname kinfo;
2997     GKeyFile *osrelease = NULL;
2998     const char *qga_os_release = g_getenv("QGA_OS_RELEASE");
2999 
3000     info = g_new0(GuestOSInfo, 1);
3001 
3002     if (uname(&kinfo) != 0) {
3003         error_setg_errno(errp, errno, "uname failed");
3004     } else {
3005         info->has_kernel_version = true;
3006         info->kernel_version = g_strdup(kinfo.version);
3007         info->has_kernel_release = true;
3008         info->kernel_release = g_strdup(kinfo.release);
3009         info->has_machine = true;
3010         info->machine = g_strdup(kinfo.machine);
3011     }
3012 
3013     if (qga_os_release != NULL) {
3014         osrelease = ga_parse_osrelease(qga_os_release);
3015     } else {
3016         osrelease = ga_parse_osrelease("/etc/os-release");
3017         if (osrelease == NULL) {
3018             osrelease = ga_parse_osrelease("/usr/lib/os-release");
3019         }
3020     }
3021 
3022     if (osrelease != NULL) {
3023         char *value;
3024 
3025 #define GET_FIELD(field, osfield) do { \
3026     value = g_key_file_get_value(osrelease, "os-release", osfield, NULL); \
3027     if (value != NULL) { \
3028         ga_osrelease_replace_special(value); \
3029         info->has_ ## field = true; \
3030         info->field = value; \
3031     } \
3032 } while (0)
3033         GET_FIELD(id, "ID");
3034         GET_FIELD(name, "NAME");
3035         GET_FIELD(pretty_name, "PRETTY_NAME");
3036         GET_FIELD(version, "VERSION");
3037         GET_FIELD(version_id, "VERSION_ID");
3038         GET_FIELD(variant, "VARIANT");
3039         GET_FIELD(variant_id, "VARIANT_ID");
3040 #undef GET_FIELD
3041 
3042         g_key_file_free(osrelease);
3043     }
3044 
3045     return info;
3046 }
3047 
3048 GuestDeviceInfoList *qmp_guest_get_devices(Error **errp)
3049 {
3050     error_setg(errp, QERR_UNSUPPORTED);
3051 
3052     return NULL;
3053 }
3054