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git.ipfire.org Git - thirdparty/systemd.git/blob - src/shared/clean-ipc.c
1 /* SPDX-License-Identifier: LGPL-2.1+ */
3 This file is part of systemd.
5 Copyright 2014 Lennart Poettering
23 #include "clean-ipc.h"
24 #include "dirent-util.h"
27 #include "format-util.h"
30 #include "string-util.h"
32 #include "user-util.h"
34 static bool match_uid_gid(uid_t subject_uid
, gid_t subject_gid
, uid_t delete_uid
, gid_t delete_gid
) {
36 if (uid_is_valid(delete_uid
) && subject_uid
== delete_uid
)
39 if (gid_is_valid(delete_gid
) && subject_gid
== delete_gid
)
45 static int clean_sysvipc_shm(uid_t delete_uid
, gid_t delete_gid
, bool rm
) {
46 _cleanup_fclose_
FILE *f
= NULL
;
51 f
= fopen("/proc/sysvipc/shm", "re");
56 return log_warning_errno(errno
, "Failed to open /proc/sysvipc/shm: %m");
59 FOREACH_LINE(line
, f
, goto fail
) {
73 if (sscanf(line
, "%*i %i %*o %*u " PID_FMT
" " PID_FMT
" %u " UID_FMT
" " GID_FMT
" " UID_FMT
" " GID_FMT
,
74 &shmid
, &cpid
, &lpid
, &n_attached
, &uid
, &gid
, &cuid
, &cgid
) != 8)
80 if (!match_uid_gid(uid
, gid
, delete_uid
, delete_gid
))
86 if (shmctl(shmid
, IPC_RMID
, NULL
) < 0) {
88 /* Ignore entries that are already deleted */
89 if (IN_SET(errno
, EIDRM
, EINVAL
))
92 ret
= log_warning_errno(errno
,
93 "Failed to remove SysV shared memory segment %i: %m",
96 log_debug("Removed SysV shared memory segment %i.", shmid
);
105 return log_warning_errno(errno
, "Failed to read /proc/sysvipc/shm: %m");
108 static int clean_sysvipc_sem(uid_t delete_uid
, gid_t delete_gid
, bool rm
) {
109 _cleanup_fclose_
FILE *f
= NULL
;
114 f
= fopen("/proc/sysvipc/sem", "re");
119 return log_warning_errno(errno
, "Failed to open /proc/sysvipc/sem: %m");
122 FOREACH_LINE(line
, f
, goto fail
) {
134 if (sscanf(line
, "%*i %i %*o %*u " UID_FMT
" " GID_FMT
" " UID_FMT
" " GID_FMT
,
135 &semid
, &uid
, &gid
, &cuid
, &cgid
) != 5)
138 if (!match_uid_gid(uid
, gid
, delete_uid
, delete_gid
))
144 if (semctl(semid
, 0, IPC_RMID
) < 0) {
146 /* Ignore entries that are already deleted */
147 if (IN_SET(errno
, EIDRM
, EINVAL
))
150 ret
= log_warning_errno(errno
,
151 "Failed to remove SysV semaphores object %i: %m",
154 log_debug("Removed SysV semaphore %i.", semid
);
163 return log_warning_errno(errno
, "Failed to read /proc/sysvipc/sem: %m");
166 static int clean_sysvipc_msg(uid_t delete_uid
, gid_t delete_gid
, bool rm
) {
167 _cleanup_fclose_
FILE *f
= NULL
;
172 f
= fopen("/proc/sysvipc/msg", "re");
177 return log_warning_errno(errno
, "Failed to open /proc/sysvipc/msg: %m");
180 FOREACH_LINE(line
, f
, goto fail
) {
193 if (sscanf(line
, "%*i %i %*o %*u %*u " PID_FMT
" " PID_FMT
" " UID_FMT
" " GID_FMT
" " UID_FMT
" " GID_FMT
,
194 &msgid
, &cpid
, &lpid
, &uid
, &gid
, &cuid
, &cgid
) != 7)
197 if (!match_uid_gid(uid
, gid
, delete_uid
, delete_gid
))
203 if (msgctl(msgid
, IPC_RMID
, NULL
) < 0) {
205 /* Ignore entries that are already deleted */
206 if (IN_SET(errno
, EIDRM
, EINVAL
))
209 ret
= log_warning_errno(errno
,
210 "Failed to remove SysV message queue %i: %m",
213 log_debug("Removed SysV message queue %i.", msgid
);
222 return log_warning_errno(errno
, "Failed to read /proc/sysvipc/msg: %m");
225 static int clean_posix_shm_internal(DIR *dir
, uid_t uid
, gid_t gid
, bool rm
) {
231 FOREACH_DIRENT_ALL(de
, dir
, goto fail
) {
234 if (dot_or_dot_dot(de
->d_name
))
237 if (fstatat(dirfd(dir
), de
->d_name
, &st
, AT_SYMLINK_NOFOLLOW
) < 0) {
241 ret
= log_warning_errno(errno
, "Failed to stat() POSIX shared memory segment %s: %m", de
->d_name
);
245 if (S_ISDIR(st
.st_mode
)) {
246 _cleanup_closedir_
DIR *kid
;
248 kid
= xopendirat(dirfd(dir
), de
->d_name
, O_NOFOLLOW
|O_NOATIME
);
251 ret
= log_warning_errno(errno
, "Failed to enter shared memory directory %s: %m", de
->d_name
);
253 r
= clean_posix_shm_internal(kid
, uid
, gid
, rm
);
258 if (!match_uid_gid(st
.st_uid
, st
.st_gid
, uid
, gid
))
264 if (unlinkat(dirfd(dir
), de
->d_name
, AT_REMOVEDIR
) < 0) {
269 ret
= log_warning_errno(errno
, "Failed to remove POSIX shared memory directory %s: %m", de
->d_name
);
271 log_debug("Removed POSIX shared memory directory %s", de
->d_name
);
277 if (!match_uid_gid(st
.st_uid
, st
.st_gid
, uid
, gid
))
283 if (unlinkat(dirfd(dir
), de
->d_name
, 0) < 0) {
288 ret
= log_warning_errno(errno
, "Failed to remove POSIX shared memory segment %s: %m", de
->d_name
);
290 log_debug("Removed POSIX shared memory segment %s", de
->d_name
);
300 return log_warning_errno(errno
, "Failed to read /dev/shm: %m");
303 static int clean_posix_shm(uid_t uid
, gid_t gid
, bool rm
) {
304 _cleanup_closedir_
DIR *dir
= NULL
;
306 dir
= opendir("/dev/shm");
311 return log_warning_errno(errno
, "Failed to open /dev/shm: %m");
314 return clean_posix_shm_internal(dir
, uid
, gid
, rm
);
317 static int clean_posix_mq(uid_t uid
, gid_t gid
, bool rm
) {
318 _cleanup_closedir_
DIR *dir
= NULL
;
322 dir
= opendir("/dev/mqueue");
327 return log_warning_errno(errno
, "Failed to open /dev/mqueue: %m");
330 FOREACH_DIRENT_ALL(de
, dir
, goto fail
) {
332 char fn
[1+strlen(de
->d_name
)+1];
334 if (dot_or_dot_dot(de
->d_name
))
337 if (fstatat(dirfd(dir
), de
->d_name
, &st
, AT_SYMLINK_NOFOLLOW
) < 0) {
341 ret
= log_warning_errno(errno
,
342 "Failed to stat() MQ segment %s: %m",
347 if (!match_uid_gid(st
.st_uid
, st
.st_gid
, uid
, gid
))
354 strcpy(fn
+1, de
->d_name
);
356 if (mq_unlink(fn
) < 0) {
360 ret
= log_warning_errno(errno
,
361 "Failed to unlink POSIX message queue %s: %m",
364 log_debug("Removed POSIX message queue %s", fn
);
373 return log_warning_errno(errno
, "Failed to read /dev/mqueue: %m");
376 int clean_ipc_internal(uid_t uid
, gid_t gid
, bool rm
) {
379 /* If 'rm' is true, clean all IPC objects owned by either the specified UID or the specified GID. Return the
380 * last error encountered or == 0 if no matching IPC objects have been found or > 0 if matching IPC objects
381 * have been found and have been removed.
383 * If 'rm' is false, just search for IPC objects owned by either the specified UID or the specified GID. In
384 * this case we return < 0 on error, > 0 if we found a matching object, == 0 if we didn't.
386 * As special rule: if UID/GID is specified as root we'll silently not clean up things, and always claim that
387 * there are IPC objects for it. */
402 /* Anything to do? */
403 if (!uid_is_valid(uid
) && !gid_is_valid(gid
))
406 r
= clean_sysvipc_shm(uid
, gid
, rm
);
414 r
= clean_sysvipc_sem(uid
, gid
, rm
);
422 r
= clean_sysvipc_msg(uid
, gid
, rm
);
430 r
= clean_posix_shm(uid
, gid
, rm
);
438 r
= clean_posix_mq(uid
, gid
, rm
);
449 int clean_ipc_by_uid(uid_t uid
) {
450 return clean_ipc_internal(uid
, GID_INVALID
, true);
453 int clean_ipc_by_gid(gid_t gid
) {
454 return clean_ipc_internal(UID_INVALID
, gid
, true);