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 #if 0 /// UNNEEDED by elogind
318 static int clean_posix_mq(uid_t uid, gid_t gid, bool rm) {
319 _cleanup_closedir_ DIR *dir = NULL;
323 dir = opendir("/dev/mqueue");
328 return log_warning_errno(errno, "Failed to open /dev/mqueue: %m");
331 FOREACH_DIRENT_ALL(de, dir, goto fail) {
333 char fn[1+strlen(de->d_name)+1];
335 if (dot_or_dot_dot(de->d_name))
338 if (fstatat(dirfd(dir), de->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0) {
342 ret = log_warning_errno(errno,
343 "Failed to stat() MQ segment %s: %m",
348 if (!match_uid_gid(st.st_uid, st.st_gid, uid, gid))
355 strcpy(fn+1, de->d_name);
357 if (mq_unlink(fn) < 0) {
361 ret = log_warning_errno(errno,
362 "Failed to unlink POSIX message queue %s: %m",
365 log_debug("Removed POSIX message queue %s", fn);
374 return log_warning_errno(errno, "Failed to read /dev/mqueue: %m");
378 int clean_ipc_internal(uid_t uid, gid_t gid, bool rm) {
381 /* If 'rm' is true, clean all IPC objects owned by either the specified UID or the specified GID. Return the
382 * last error encountered or == 0 if no matching IPC objects have been found or > 0 if matching IPC objects
383 * have been found and have been removed.
385 * If 'rm' is false, just search for IPC objects owned by either the specified UID or the specified GID. In
386 * this case we return < 0 on error, > 0 if we found a matching object, == 0 if we didn't.
388 * As special rule: if UID/GID is specified as root we'll silently not clean up things, and always claim that
389 * there are IPC objects for it. */
404 /* Anything to do? */
405 if (!uid_is_valid(uid) && !gid_is_valid(gid))
408 r = clean_sysvipc_shm(uid, gid, rm);
416 #if 0 /// elogind does not use mq_open anywhere
418 r = clean_sysvipc_sem(uid, gid, rm);
426 r = clean_sysvipc_msg(uid, gid, rm);
434 r = clean_posix_shm(uid, gid, rm);
442 #if 0 /// Nothing in elogind uses mqueues
443 r = clean_posix_mq(uid, gid, rm);
455 int clean_ipc_by_uid(uid_t uid) {
456 return clean_ipc_internal(uid, GID_INVALID, true);
459 #if 0 /// UNNEEDED by elogind
460 int clean_ipc_by_gid(gid_t gid) {
461 return clean_ipc_internal(UID_INVALID, gid, true);