]> git.ipfire.org Git - thirdparty/systemd.git/blobdiff - src/shared/clean-ipc.c
Add SPDX license identifiers to source files under the LGPL
[thirdparty/systemd.git] / src / shared / clean-ipc.c
index 95686348c1b9ee6952a572187b12fa2ef72d643a..7e2ef4a8eb7130664064bc2838f31c79af17ba87 100644 (file)
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
 /***
   This file is part of systemd.
 
 #include "dirent-util.h"
 #include "fd-util.h"
 #include "fileio.h"
-#include "formats-util.h"
+#include "format-util.h"
 #include "log.h"
 #include "macro.h"
 #include "string-util.h"
 #include "strv.h"
+#include "user-util.h"
 
-static int clean_sysvipc_shm(uid_t delete_uid) {
+static bool match_uid_gid(uid_t subject_uid, gid_t subject_gid, uid_t delete_uid, gid_t delete_gid) {
+
+        if (uid_is_valid(delete_uid) && subject_uid == delete_uid)
+                return true;
+
+        if (gid_is_valid(delete_gid) && subject_gid == delete_gid)
+                return true;
+
+        return false;
+}
+
+static int clean_sysvipc_shm(uid_t delete_uid, gid_t delete_gid, bool rm) {
         _cleanup_fclose_ FILE *f = NULL;
         char line[LINE_MAX];
         bool first = true;
@@ -77,18 +90,25 @@ static int clean_sysvipc_shm(uid_t delete_uid) {
                 if (n_attached > 0)
                         continue;
 
-                if (uid != delete_uid)
+                if (!match_uid_gid(uid, gid, delete_uid, delete_gid))
                         continue;
 
+                if (!rm)
+                        return 1;
+
                 if (shmctl(shmid, IPC_RMID, NULL) < 0) {
 
                         /* Ignore entries that are already deleted */
-                        if (errno == EIDRM || errno == EINVAL)
+                        if (IN_SET(errno, EIDRM, EINVAL))
                                 continue;
 
                         ret = log_warning_errno(errno,
                                                 "Failed to remove SysV shared memory segment %i: %m",
                                                 shmid);
+                } else {
+                        log_debug("Removed SysV shared memory segment %i.", shmid);
+                        if (ret == 0)
+                                ret = 1;
                 }
         }
 
@@ -98,7 +118,7 @@ fail:
         return log_warning_errno(errno, "Failed to read /proc/sysvipc/shm: %m");
 }
 
-static int clean_sysvipc_sem(uid_t delete_uid) {
+static int clean_sysvipc_sem(uid_t delete_uid, gid_t delete_gid, bool rm) {
         _cleanup_fclose_ FILE *f = NULL;
         char line[LINE_MAX];
         bool first = true;
@@ -128,18 +148,25 @@ static int clean_sysvipc_sem(uid_t delete_uid) {
                            &semid, &uid, &gid, &cuid, &cgid) != 5)
                         continue;
 
-                if (uid != delete_uid)
+                if (!match_uid_gid(uid, gid, delete_uid, delete_gid))
                         continue;
 
+                if (!rm)
+                        return 1;
+
                 if (semctl(semid, 0, IPC_RMID) < 0) {
 
                         /* Ignore entries that are already deleted */
-                        if (errno == EIDRM || errno == EINVAL)
+                        if (IN_SET(errno, EIDRM, EINVAL))
                                 continue;
 
                         ret = log_warning_errno(errno,
                                                 "Failed to remove SysV semaphores object %i: %m",
                                                 semid);
+                } else {
+                        log_debug("Removed SysV semaphore %i.", semid);
+                        if (ret == 0)
+                                ret = 1;
                 }
         }
 
@@ -149,7 +176,7 @@ fail:
         return log_warning_errno(errno, "Failed to read /proc/sysvipc/sem: %m");
 }
 
-static int clean_sysvipc_msg(uid_t delete_uid) {
+static int clean_sysvipc_msg(uid_t delete_uid, gid_t delete_gid, bool rm) {
         _cleanup_fclose_ FILE *f = NULL;
         char line[LINE_MAX];
         bool first = true;
@@ -180,18 +207,25 @@ static int clean_sysvipc_msg(uid_t delete_uid) {
                            &msgid, &cpid, &lpid, &uid, &gid, &cuid, &cgid) != 7)
                         continue;
 
-                if (uid != delete_uid)
+                if (!match_uid_gid(uid, gid, delete_uid, delete_gid))
                         continue;
 
+                if (!rm)
+                        return 1;
+
                 if (msgctl(msgid, IPC_RMID, NULL) < 0) {
 
                         /* Ignore entries that are already deleted */
-                        if (errno == EIDRM || errno == EINVAL)
+                        if (IN_SET(errno, EIDRM, EINVAL))
                                 continue;
 
                         ret = log_warning_errno(errno,
                                                 "Failed to remove SysV message queue %i: %m",
                                                 msgid);
+                } else {
+                        log_debug("Removed SysV message queue %i.", msgid);
+                        if (ret == 0)
+                                ret = 1;
                 }
         }
 
@@ -201,7 +235,7 @@ fail:
         return log_warning_errno(errno, "Failed to read /proc/sysvipc/msg: %m");
 }
 
-static int clean_posix_shm_internal(DIR *dir, uid_t uid) {
+static int clean_posix_shm_internal(DIR *dir, uid_t uid, gid_t gid, bool rm) {
         struct dirent *de;
         int ret = 0, r;
 
@@ -210,7 +244,7 @@ static int clean_posix_shm_internal(DIR *dir, uid_t uid) {
         FOREACH_DIRENT_ALL(de, dir, goto fail) {
                 struct stat st;
 
-                if (STR_IN_SET(de->d_name, "..", "."))
+                if (dot_or_dot_dot(de->d_name))
                         continue;
 
                 if (fstatat(dirfd(dir), de->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0) {
@@ -221,9 +255,6 @@ static int clean_posix_shm_internal(DIR *dir, uid_t uid) {
                         continue;
                 }
 
-                if (st.st_uid != uid)
-                        continue;
-
                 if (S_ISDIR(st.st_mode)) {
                         _cleanup_closedir_ DIR *kid;
 
@@ -232,26 +263,46 @@ static int clean_posix_shm_internal(DIR *dir, uid_t uid) {
                                 if (errno != ENOENT)
                                         ret = log_warning_errno(errno, "Failed to enter shared memory directory %s: %m", de->d_name);
                         } else {
-                                r = clean_posix_shm_internal(kid, uid);
+                                r = clean_posix_shm_internal(kid, uid, gid, rm);
                                 if (r < 0)
                                         ret = r;
                         }
 
+                        if (!match_uid_gid(st.st_uid, st.st_gid, uid, gid))
+                                continue;
+
+                        if (!rm)
+                                return 1;
+
                         if (unlinkat(dirfd(dir), de->d_name, AT_REMOVEDIR) < 0) {
 
                                 if (errno == ENOENT)
                                         continue;
 
                                 ret = log_warning_errno(errno, "Failed to remove POSIX shared memory directory %s: %m", de->d_name);
+                        } else {
+                                log_debug("Removed POSIX shared memory directory %s", de->d_name);
+                                if (ret == 0)
+                                        ret = 1;
                         }
                 } else {
 
+                        if (!match_uid_gid(st.st_uid, st.st_gid, uid, gid))
+                                continue;
+
+                        if (!rm)
+                                return 1;
+
                         if (unlinkat(dirfd(dir), de->d_name, 0) < 0) {
 
                                 if (errno == ENOENT)
                                         continue;
 
                                 ret = log_warning_errno(errno, "Failed to remove POSIX shared memory segment %s: %m", de->d_name);
+                        } else {
+                                log_debug("Removed POSIX shared memory segment %s", de->d_name);
+                                if (ret == 0)
+                                        ret = 1;
                         }
                 }
         }
@@ -262,7 +313,7 @@ fail:
         return log_warning_errno(errno, "Failed to read /dev/shm: %m");
 }
 
-static int clean_posix_shm(uid_t uid) {
+static int clean_posix_shm(uid_t uid, gid_t gid, bool rm) {
         _cleanup_closedir_ DIR *dir = NULL;
 
         dir = opendir("/dev/shm");
@@ -273,10 +324,10 @@ static int clean_posix_shm(uid_t uid) {
                 return log_warning_errno(errno, "Failed to open /dev/shm: %m");
         }
 
-        return clean_posix_shm_internal(dir, uid);
+        return clean_posix_shm_internal(dir, uid, gid, rm);
 }
 
-static int clean_posix_mq(uid_t uid) {
+static int clean_posix_mq(uid_t uid, gid_t gid, bool rm) {
         _cleanup_closedir_ DIR *dir = NULL;
         struct dirent *de;
         int ret = 0;
@@ -293,7 +344,7 @@ static int clean_posix_mq(uid_t uid) {
                 struct stat st;
                 char fn[1+strlen(de->d_name)+1];
 
-                if (STR_IN_SET(de->d_name, "..", "."))
+                if (dot_or_dot_dot(de->d_name))
                         continue;
 
                 if (fstatat(dirfd(dir), de->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0) {
@@ -306,9 +357,12 @@ static int clean_posix_mq(uid_t uid) {
                         continue;
                 }
 
-                if (st.st_uid != uid)
+                if (!match_uid_gid(st.st_uid, st.st_gid, uid, gid))
                         continue;
 
+                if (!rm)
+                        return 1;
+
                 fn[0] = '/';
                 strcpy(fn+1, de->d_name);
 
@@ -319,6 +373,10 @@ static int clean_posix_mq(uid_t uid) {
                         ret = log_warning_errno(errno,
                                                 "Failed to unlink POSIX message queue %s: %m",
                                                 fn);
+                } else {
+                        log_debug("Removed POSIX message queue %s", fn);
+                        if (ret == 0)
+                                ret = 1;
                 }
         }
 
@@ -328,32 +386,83 @@ fail:
         return log_warning_errno(errno, "Failed to read /dev/mqueue: %m");
 }
 
-int clean_ipc(uid_t uid) {
+int clean_ipc_internal(uid_t uid, gid_t gid, bool rm) {
         int ret = 0, r;
 
-        /* Refuse to clean IPC of the root and system users */
-        if (uid <= SYSTEM_UID_MAX)
+        /* If 'rm' is true, clean all IPC objects owned by either the specified UID or the specified GID. Return the
+         * last error encountered or == 0 if no matching IPC objects have been found or > 0 if matching IPC objects
+         * have been found and have been removed.
+         *
+         * If 'rm' is false, just search for IPC objects owned by either the specified UID or the specified GID. In
+         * this case we return < 0 on error, > 0 if we found a matching object, == 0 if we didn't.
+         *
+         * As special rule: if UID/GID is specified as root we'll silently not clean up things, and always claim that
+         * there are IPC objects for it. */
+
+        if (uid == 0) {
+                if (!rm)
+                        return 1;
+
+                uid = UID_INVALID;
+        }
+        if (gid == 0) {
+                if (!rm)
+                        return 1;
+
+                gid = GID_INVALID;
+        }
+
+        /* Anything to do? */
+        if (!uid_is_valid(uid) && !gid_is_valid(gid))
                 return 0;
 
-        r = clean_sysvipc_shm(uid);
-        if (r < 0)
-                ret = r;
+        r = clean_sysvipc_shm(uid, gid, rm);
+        if (r != 0) {
+                if (!rm)
+                        return r;
+                if (ret == 0)
+                        ret = r;
+        }
 
-        r = clean_sysvipc_sem(uid);
-        if (r < 0)
-                ret = r;
+        r = clean_sysvipc_sem(uid, gid, rm);
+        if (r != 0) {
+                if (!rm)
+                        return r;
+                if (ret == 0)
+                        ret = r;
+        }
 
-        r = clean_sysvipc_msg(uid);
-        if (r < 0)
-                ret = r;
+        r = clean_sysvipc_msg(uid, gid, rm);
+        if (r != 0) {
+                if (!rm)
+                        return r;
+                if (ret == 0)
+                        ret = r;
+        }
 
-        r = clean_posix_shm(uid);
-        if (r < 0)
-                ret = r;
+        r = clean_posix_shm(uid, gid, rm);
+        if (r != 0) {
+                if (!rm)
+                        return r;
+                if (ret == 0)
+                        ret = r;
+        }
 
-        r = clean_posix_mq(uid);
-        if (r < 0)
-                ret = r;
+        r = clean_posix_mq(uid, gid, rm);
+        if (r != 0) {
+                if (!rm)
+                        return r;
+                if (ret == 0)
+                        ret = r;
+        }
 
         return ret;
 }
+
+int clean_ipc_by_uid(uid_t uid) {
+        return clean_ipc_internal(uid, GID_INVALID, true);
+}
+
+int clean_ipc_by_gid(gid_t gid) {
+        return clean_ipc_internal(UID_INVALID, gid, true);
+}