#include <dirent.h>

#include <fcntl.h>

#include <mqueue.h>

#include <sys/ipc.h>

#include <sys/msg.h>

#include <sys/sem.h>

#include <sys/shm.h>

#include <sys/stat.h>

#include "clean-ipc.h"

#include "dirent-util.h"

#include "fd-util.h"

#include "fileio.h"

#include "formats-util.h"

#include "string-util.h"

#include "strv.h"

#include "util.h"

static int clean_sysvipc_shm(uid_t delete_uid) {

_cleanup_fclose_ FILE *f = NULL;

char line[LINE_MAX];

bool first = true;

int ret = 0;

f = fopen("/proc/sysvipc/shm", "re");

if (!f) {

if (errno == ENOENT)

return 0;

return log_warning_errno(errno, "Failed to open /proc/sysvipc/shm: %m");

}

FOREACH_LINE(line, f, goto fail) {

unsigned n_attached;

pid_t cpid, lpid;

uid_t uid, cuid;

gid_t gid, cgid;

int shmid;

if (first) {

first = false;

continue;

}

truncate_nl(line);

if (sscanf(line, "%*i %i %*o %*u " PID_FMT " " PID_FMT " %u " UID_FMT " " GID_FMT " " UID_FMT " " GID_FMT,

&shmid, &cpid, &lpid, &n_attached, &uid, &gid, &cuid, &cgid) != 8)

continue;

if (n_attached > 0)

continue;

if (uid != delete_uid)

continue;

if (shmctl(shmid, IPC_RMID, NULL) < 0) {

/* Ignore entries that are already deleted */

if (errno == EIDRM || errno == EINVAL)

continue;

ret = log_warning_errno(errno,

"Failed to remove SysV shared memory segment %i: %m",

shmid);

}

}

return ret;

fail:

return log_warning_errno(errno, "Failed to read /proc/sysvipc/shm: %m");

}

static int clean_sysvipc_sem(uid_t delete_uid) {

_cleanup_fclose_ FILE *f = NULL;

char line[LINE_MAX];

bool first = true;

int ret = 0;

f = fopen("/proc/sysvipc/sem", "re");

if (!f) {

if (errno == ENOENT)

return 0;

return log_warning_errno(errno, "Failed to open /proc/sysvipc/sem: %m");

}

FOREACH_LINE(line, f, goto fail) {

uid_t uid, cuid;

gid_t gid, cgid;

int semid;

if (first) {

first = false;

continue;

}

truncate_nl(line);

if (sscanf(line, "%*i %i %*o %*u " UID_FMT " " GID_FMT " " UID_FMT " " GID_FMT,

&semid, &uid, &gid, &cuid, &cgid) != 5)

continue;

if (uid != delete_uid)

continue;

if (semctl(semid, 0, IPC_RMID) < 0) {

/* Ignore entries that are already deleted */

if (errno == EIDRM || errno == EINVAL)

continue;

ret = log_warning_errno(errno,

"Failed to remove SysV semaphores object %i: %m",

semid);

}

}

return ret;

fail:

return log_warning_errno(errno, "Failed to read /proc/sysvipc/sem: %m");

}

static int clean_sysvipc_msg(uid_t delete_uid) {

_cleanup_fclose_ FILE *f = NULL;

char line[LINE_MAX];

bool first = true;

int ret = 0;

f = fopen("/proc/sysvipc/msg", "re");

if (!f) {

if (errno == ENOENT)

return 0;

return log_warning_errno(errno, "Failed to open /proc/sysvipc/msg: %m");

}

FOREACH_LINE(line, f, goto fail) {

uid_t uid, cuid;

gid_t gid, cgid;

pid_t cpid, lpid;

int msgid;

if (first) {

first = false;

continue;

}

truncate_nl(line);

if (sscanf(line, "%*i %i %*o %*u %*u " PID_FMT " " PID_FMT " " UID_FMT " " GID_FMT " " UID_FMT " " GID_FMT,

&msgid, &cpid, &lpid, &uid, &gid, &cuid, &cgid) != 7)

continue;

if (uid != delete_uid)

continue;

if (msgctl(msgid, IPC_RMID, NULL) < 0) {

/* Ignore entries that are already deleted */

if (errno == EIDRM || errno == EINVAL)

continue;

ret = log_warning_errno(errno,

"Failed to remove SysV message queue %i: %m",

msgid);

}

}

return ret;

fail:

return log_warning_errno(errno, "Failed to read /proc/sysvipc/msg: %m");

}

static int clean_posix_shm_internal(DIR *dir, uid_t uid) {

struct dirent *de;

int ret = 0, r;

assert(dir);

FOREACH_DIRENT(de, dir, goto fail) {

struct stat st;

if (STR_IN_SET(de->d_name, "..", "."))

continue;

if (fstatat(dirfd(dir), de->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0) {

if (errno == ENOENT)

continue;

log_warning_errno(errno, "Failed to stat() POSIX shared memory segment %s: %m", de->d_name);

ret = -errno;

continue;

}

if (st.st_uid != uid)

continue;

if (S_ISDIR(st.st_mode)) {

_cleanup_closedir_ DIR *kid;

kid = xopendirat(dirfd(dir), de->d_name, O_NOFOLLOW|O_NOATIME);

if (!kid) {

if (errno != ENOENT) {

log_warning_errno(errno, "Failed to enter shared memory directory %s: %m", de->d_name);

ret = -errno;

}

} else {

r = clean_posix_shm_internal(kid, uid);

if (r < 0)

ret = r;

}

if (unlinkat(dirfd(dir), de->d_name, AT_REMOVEDIR) < 0) {

if (errno == ENOENT)

continue;

log_warning_errno(errno, "Failed to remove POSIX shared memory directory %s: %m", de->d_name);

ret = -errno;

}

} else {

if (unlinkat(dirfd(dir), de->d_name, 0) < 0) {

if (errno == ENOENT)

continue;

log_warning_errno(errno, "Failed to remove POSIX shared memory segment %s: %m", de->d_name);

ret = -errno;

}

}

}

return ret;

fail:

log_warning_errno(errno, "Failed to read /dev/shm: %m");

return -errno;

}

static int clean_posix_shm(uid_t uid) {

_cleanup_closedir_ DIR *dir = NULL;

dir = opendir("/dev/shm");

if (!dir) {

if (errno == ENOENT)

return 0;

return log_warning_errno(errno, "Failed to open /dev/shm: %m");

}

return clean_posix_shm_internal(dir, uid);

}

static int clean_posix_mq(uid_t uid) {

_cleanup_closedir_ DIR *dir = NULL;

struct dirent *de;

int ret = 0;

dir = opendir("/dev/mqueue");

if (!dir) {

if (errno == ENOENT)

return 0;

return log_warning_errno(errno, "Failed to open /dev/mqueue: %m");

}

FOREACH_DIRENT(de, dir, goto fail) {

struct stat st;

char fn[1+strlen(de->d_name)+1];

if (STR_IN_SET(de->d_name, "..", "."))

continue;

if (fstatat(dirfd(dir), de->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0) {

if (errno == ENOENT)

continue;

ret = log_warning_errno(errno,

"Failed to stat() MQ segment %s: %m",

de->d_name);

continue;

}

if (st.st_uid != uid)

continue;

fn[0] = '/';

strcpy(fn+1, de->d_name);

if (mq_unlink(fn) < 0) {

if (errno == ENOENT)

continue;

ret = log_warning_errno(errno,

"Failed to unlink POSIX message queue %s: %m",

fn);

}

}

return ret;

fail:

return log_warning_errno(errno, "Failed to read /dev/mqueue: %m");

}

int clean_ipc(uid_t uid) {

int ret = 0, r;

/* Refuse to clean IPC of the root and system users */

if (uid <= SYSTEM_UID_MAX)

return 0;

r = clean_sysvipc_shm(uid);

if (r < 0)

ret = r;

r = clean_sysvipc_sem(uid);

if (r < 0)

ret = r;

r = clean_sysvipc_msg(uid);

if (r < 0)

ret = r;

r = clean_posix_shm(uid);

if (r < 0)

ret = r;

r = clean_posix_mq(uid);

if (r < 0)

ret = r;

return ret;

}