Systemd/src/shared/cgroup-util.c
Zbigniew Jędrzejewski-Szmek a2a5291b3f Reject invalid quoted strings
String which ended in an unfinished quote were accepted, potentially
with bad memory accesses.

Reject anything which ends in a unfished quote, or contains
non-whitespace characters right after the closing quote.

_FOREACH_WORD now returns the invalid character in *state. But this return
value is not checked anywhere yet.

Also, make 'word' and 'state' variables const pointers, and rename 'w'
to 'word' in various places. Things are easier to read if the same name
is used consistently.

mbiebl_> am I correct that something like this doesn't work
mbiebl_> ExecStart=/usr/bin/encfs --extpass='/bin/systemd-ask-passwd "Unlock EncFS"'
mbiebl_> systemd seems to strip of the quotes
mbiebl_> systemctl status shows
mbiebl_> ExecStart=/usr/bin/encfs --extpass='/bin/systemd-ask-password Unlock EncFS  $RootDir $MountPoint
mbiebl_> which is pretty weird
2014-07-31 04:00:31 -04:00

1729 lines
43 KiB
C

/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2010 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <errno.h>
#include <unistd.h>
#include <signal.h>
#include <string.h>
#include <stdlib.h>
#include <dirent.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <ftw.h>
#include "cgroup-util.h"
#include "log.h"
#include "set.h"
#include "macro.h"
#include "util.h"
#include "path-util.h"
#include "strv.h"
#include "unit-name.h"
#include "fileio.h"
#include "special.h"
#include "mkdir.h"
int cg_enumerate_processes(const char *controller, const char *path, FILE **_f) {
_cleanup_free_ char *fs = NULL;
FILE *f;
int r;
assert(_f);
r = cg_get_path(controller, path, "cgroup.procs", &fs);
if (r < 0)
return r;
f = fopen(fs, "re");
if (!f)
return -errno;
*_f = f;
return 0;
}
int cg_read_pid(FILE *f, pid_t *_pid) {
unsigned long ul;
/* Note that the cgroup.procs might contain duplicates! See
* cgroups.txt for details. */
assert(f);
assert(_pid);
errno = 0;
if (fscanf(f, "%lu", &ul) != 1) {
if (feof(f))
return 0;
return errno ? -errno : -EIO;
}
if (ul <= 0)
return -EIO;
*_pid = (pid_t) ul;
return 1;
}
int cg_enumerate_subgroups(const char *controller, const char *path, DIR **_d) {
_cleanup_free_ char *fs = NULL;
int r;
DIR *d;
assert(_d);
/* This is not recursive! */
r = cg_get_path(controller, path, NULL, &fs);
if (r < 0)
return r;
d = opendir(fs);
if (!d)
return -errno;
*_d = d;
return 0;
}
int cg_read_subgroup(DIR *d, char **fn) {
struct dirent *de;
assert(d);
assert(fn);
FOREACH_DIRENT(de, d, return -errno) {
char *b;
if (de->d_type != DT_DIR)
continue;
if (streq(de->d_name, ".") ||
streq(de->d_name, ".."))
continue;
b = strdup(de->d_name);
if (!b)
return -ENOMEM;
*fn = b;
return 1;
}
return 0;
}
int cg_rmdir(const char *controller, const char *path) {
_cleanup_free_ char *p = NULL;
int r;
r = cg_get_path(controller, path, NULL, &p);
if (r < 0)
return r;
r = rmdir(p);
if (r < 0 && errno != ENOENT)
return -errno;
return 0;
}
int cg_kill(const char *controller, const char *path, int sig, bool sigcont, bool ignore_self, Set *s) {
_cleanup_set_free_ Set *allocated_set = NULL;
bool done = false;
int r, ret = 0;
pid_t my_pid;
assert(sig >= 0);
/* This goes through the tasks list and kills them all. This
* is repeated until no further processes are added to the
* tasks list, to properly handle forking processes */
if (!s) {
s = allocated_set = set_new(trivial_hash_func, trivial_compare_func);
if (!s)
return -ENOMEM;
}
my_pid = getpid();
do {
_cleanup_fclose_ FILE *f = NULL;
pid_t pid = 0;
done = true;
r = cg_enumerate_processes(controller, path, &f);
if (r < 0) {
if (ret >= 0 && r != -ENOENT)
return r;
return ret;
}
while ((r = cg_read_pid(f, &pid)) > 0) {
if (ignore_self && pid == my_pid)
continue;
if (set_get(s, LONG_TO_PTR(pid)) == LONG_TO_PTR(pid))
continue;
/* If we haven't killed this process yet, kill
* it */
if (kill(pid, sig) < 0) {
if (ret >= 0 && errno != ESRCH)
ret = -errno;
} else {
if (sigcont)
kill(pid, SIGCONT);
if (ret == 0)
ret = 1;
}
done = false;
r = set_put(s, LONG_TO_PTR(pid));
if (r < 0) {
if (ret >= 0)
return r;
return ret;
}
}
if (r < 0) {
if (ret >= 0)
return r;
return ret;
}
/* To avoid racing against processes which fork
* quicker than we can kill them we repeat this until
* no new pids need to be killed. */
} while (!done);
return ret;
}
int cg_kill_recursive(const char *controller, const char *path, int sig, bool sigcont, bool ignore_self, bool rem, Set *s) {
_cleanup_set_free_ Set *allocated_set = NULL;
_cleanup_closedir_ DIR *d = NULL;
int r, ret = 0;
char *fn;
assert(path);
assert(sig >= 0);
if (!s) {
s = allocated_set = set_new(trivial_hash_func, trivial_compare_func);
if (!s)
return -ENOMEM;
}
ret = cg_kill(controller, path, sig, sigcont, ignore_self, s);
r = cg_enumerate_subgroups(controller, path, &d);
if (r < 0) {
if (ret >= 0 && r != -ENOENT)
return r;
return ret;
}
while ((r = cg_read_subgroup(d, &fn)) > 0) {
_cleanup_free_ char *p = NULL;
p = strjoin(path, "/", fn, NULL);
free(fn);
if (!p)
return -ENOMEM;
r = cg_kill_recursive(controller, p, sig, sigcont, ignore_self, rem, s);
if (ret >= 0 && r != 0)
ret = r;
}
if (ret >= 0 && r < 0)
ret = r;
if (rem) {
r = cg_rmdir(controller, path);
if (r < 0 && ret >= 0 && r != -ENOENT && r != -EBUSY)
return r;
}
return ret;
}
int cg_migrate(const char *cfrom, const char *pfrom, const char *cto, const char *pto, bool ignore_self) {
bool done = false;
_cleanup_set_free_ Set *s = NULL;
int r, ret = 0;
pid_t my_pid;
assert(cfrom);
assert(pfrom);
assert(cto);
assert(pto);
s = set_new(trivial_hash_func, trivial_compare_func);
if (!s)
return -ENOMEM;
my_pid = getpid();
do {
_cleanup_fclose_ FILE *f = NULL;
pid_t pid = 0;
done = true;
r = cg_enumerate_processes(cfrom, pfrom, &f);
if (r < 0) {
if (ret >= 0 && r != -ENOENT)
return r;
return ret;
}
while ((r = cg_read_pid(f, &pid)) > 0) {
/* This might do weird stuff if we aren't a
* single-threaded program. However, we
* luckily know we are not */
if (ignore_self && pid == my_pid)
continue;
if (set_get(s, LONG_TO_PTR(pid)) == LONG_TO_PTR(pid))
continue;
r = cg_attach(cto, pto, pid);
if (r < 0) {
if (ret >= 0 && r != -ESRCH)
ret = r;
} else if (ret == 0)
ret = 1;
done = false;
r = set_put(s, LONG_TO_PTR(pid));
if (r < 0) {
if (ret >= 0)
return r;
return ret;
}
}
if (r < 0) {
if (ret >= 0)
return r;
return ret;
}
} while (!done);
return ret;
}
int cg_migrate_recursive(
const char *cfrom,
const char *pfrom,
const char *cto,
const char *pto,
bool ignore_self,
bool rem) {
_cleanup_closedir_ DIR *d = NULL;
int r, ret = 0;
char *fn;
assert(cfrom);
assert(pfrom);
assert(cto);
assert(pto);
ret = cg_migrate(cfrom, pfrom, cto, pto, ignore_self);
r = cg_enumerate_subgroups(cfrom, pfrom, &d);
if (r < 0) {
if (ret >= 0 && r != -ENOENT)
return r;
return ret;
}
while ((r = cg_read_subgroup(d, &fn)) > 0) {
_cleanup_free_ char *p = NULL;
p = strjoin(pfrom, "/", fn, NULL);
free(fn);
if (!p) {
if (ret >= 0)
return -ENOMEM;
return ret;
}
r = cg_migrate_recursive(cfrom, p, cto, pto, ignore_self, rem);
if (r != 0 && ret >= 0)
ret = r;
}
if (r < 0 && ret >= 0)
ret = r;
if (rem) {
r = cg_rmdir(cfrom, pfrom);
if (r < 0 && ret >= 0 && r != -ENOENT && r != -EBUSY)
return r;
}
return ret;
}
int cg_migrate_recursive_fallback(
const char *cfrom,
const char *pfrom,
const char *cto,
const char *pto,
bool ignore_self,
bool rem) {
int r;
assert(cfrom);
assert(pfrom);
assert(cto);
assert(pto);
r = cg_migrate_recursive(cfrom, pfrom, cto, pto, ignore_self, rem);
if (r < 0) {
char prefix[strlen(pto) + 1];
/* This didn't work? Then let's try all prefixes of the destination */
PATH_FOREACH_PREFIX(prefix, pto) {
r = cg_migrate_recursive(cfrom, pfrom, cto, prefix, ignore_self, rem);
if (r >= 0)
break;
}
}
return 0;
}
static const char *normalize_controller(const char *controller) {
assert(controller);
if (streq(controller, SYSTEMD_CGROUP_CONTROLLER))
return "systemd";
else if (startswith(controller, "name="))
return controller + 5;
else
return controller;
}
static int join_path(const char *controller, const char *path, const char *suffix, char **fs) {
char *t = NULL;
if (!isempty(controller)) {
if (!isempty(path) && !isempty(suffix))
t = strjoin("/sys/fs/cgroup/", controller, "/", path, "/", suffix, NULL);
else if (!isempty(path))
t = strjoin("/sys/fs/cgroup/", controller, "/", path, NULL);
else if (!isempty(suffix))
t = strjoin("/sys/fs/cgroup/", controller, "/", suffix, NULL);
else
t = strappend("/sys/fs/cgroup/", controller);
} else {
if (!isempty(path) && !isempty(suffix))
t = strjoin(path, "/", suffix, NULL);
else if (!isempty(path))
t = strdup(path);
else
return -EINVAL;
}
if (!t)
return -ENOMEM;
*fs = path_kill_slashes(t);
return 0;
}
int cg_get_path(const char *controller, const char *path, const char *suffix, char **fs) {
const char *p;
static thread_local bool good = false;
assert(fs);
if (controller && !cg_controller_is_valid(controller, true))
return -EINVAL;
if (_unlikely_(!good)) {
int r;
r = path_is_mount_point("/sys/fs/cgroup", false);
if (r <= 0)
return r < 0 ? r : -ENOENT;
/* Cache this to save a few stat()s */
good = true;
}
p = controller ? normalize_controller(controller) : NULL;
return join_path(p, path, suffix, fs);
}
static int check_hierarchy(const char *p) {
char *cc;
assert(p);
/* Check if this controller actually really exists */
cc = alloca(strlen("/sys/fs/cgroup/") + strlen(p) + 1);
strcpy(stpcpy(cc, "/sys/fs/cgroup/"), p);
if (access(cc, F_OK) < 0)
return -errno;
return 0;
}
int cg_get_path_and_check(const char *controller, const char *path, const char *suffix, char **fs) {
const char *p;
int r;
assert(fs);
if (!cg_controller_is_valid(controller, true))
return -EINVAL;
/* Normalize the controller syntax */
p = normalize_controller(controller);
/* Check if this controller actually really exists */
r = check_hierarchy(p);
if (r < 0)
return r;
return join_path(p, path, suffix, fs);
}
static int trim_cb(const char *path, const struct stat *sb, int typeflag, struct FTW *ftwbuf) {
assert(path);
assert(sb);
assert(ftwbuf);
if (typeflag != FTW_DP)
return 0;
if (ftwbuf->level < 1)
return 0;
rmdir(path);
return 0;
}
int cg_trim(const char *controller, const char *path, bool delete_root) {
_cleanup_free_ char *fs = NULL;
int r = 0;
assert(path);
r = cg_get_path(controller, path, NULL, &fs);
if (r < 0)
return r;
errno = 0;
if (nftw(fs, trim_cb, 64, FTW_DEPTH|FTW_MOUNT|FTW_PHYS) != 0)
r = errno ? -errno : -EIO;
if (delete_root) {
if (rmdir(fs) < 0 && errno != ENOENT)
return -errno;
}
return r;
}
int cg_delete(const char *controller, const char *path) {
_cleanup_free_ char *parent = NULL;
int r;
assert(path);
r = path_get_parent(path, &parent);
if (r < 0)
return r;
r = cg_migrate_recursive(controller, path, controller, parent, false, true);
return r == -ENOENT ? 0 : r;
}
int cg_create(const char *controller, const char *path) {
_cleanup_free_ char *fs = NULL;
int r;
r = cg_get_path_and_check(controller, path, NULL, &fs);
if (r < 0)
return r;
r = mkdir_parents(fs, 0755);
if (r < 0)
return r;
if (mkdir(fs, 0755) < 0) {
if (errno == EEXIST)
return 0;
return -errno;
}
return 1;
}
int cg_create_and_attach(const char *controller, const char *path, pid_t pid) {
int r, q;
assert(pid >= 0);
r = cg_create(controller, path);
if (r < 0)
return r;
q = cg_attach(controller, path, pid);
if (q < 0)
return q;
/* This does not remove the cgroup on failure */
return r;
}
int cg_attach(const char *controller, const char *path, pid_t pid) {
_cleanup_free_ char *fs = NULL;
char c[DECIMAL_STR_MAX(pid_t) + 2];
int r;
assert(path);
assert(pid >= 0);
r = cg_get_path_and_check(controller, path, "cgroup.procs", &fs);
if (r < 0)
return r;
if (pid == 0)
pid = getpid();
snprintf(c, sizeof(c), PID_FMT"\n", pid);
return write_string_file(fs, c);
}
int cg_attach_fallback(const char *controller, const char *path, pid_t pid) {
int r;
assert(controller);
assert(path);
assert(pid >= 0);
r = cg_attach(controller, path, pid);
if (r < 0) {
char prefix[strlen(path) + 1];
/* This didn't work? Then let's try all prefixes of
* the destination */
PATH_FOREACH_PREFIX(prefix, path) {
r = cg_attach(controller, prefix, pid);
if (r >= 0)
break;
}
}
return 0;
}
int cg_set_group_access(
const char *controller,
const char *path,
mode_t mode,
uid_t uid,
gid_t gid) {
_cleanup_free_ char *fs = NULL;
int r;
assert(path);
if (mode != (mode_t) -1)
mode &= 0777;
r = cg_get_path(controller, path, NULL, &fs);
if (r < 0)
return r;
return chmod_and_chown(fs, mode, uid, gid);
}
int cg_set_task_access(
const char *controller,
const char *path,
mode_t mode,
uid_t uid,
gid_t gid) {
_cleanup_free_ char *fs = NULL, *procs = NULL;
int r;
assert(path);
if (mode == (mode_t) -1 && uid == (uid_t) -1 && gid == (gid_t) -1)
return 0;
if (mode != (mode_t) -1)
mode &= 0666;
r = cg_get_path(controller, path, "cgroup.procs", &fs);
if (r < 0)
return r;
r = chmod_and_chown(fs, mode, uid, gid);
if (r < 0)
return r;
/* Compatibility, Always keep values for "tasks" in sync with
* "cgroup.procs" */
r = cg_get_path(controller, path, "tasks", &procs);
if (r < 0)
return r;
return chmod_and_chown(procs, mode, uid, gid);
}
int cg_pid_get_path(const char *controller, pid_t pid, char **path) {
_cleanup_fclose_ FILE *f = NULL;
char line[LINE_MAX];
const char *fs;
size_t cs;
assert(path);
assert(pid >= 0);
if (controller) {
if (!cg_controller_is_valid(controller, true))
return -EINVAL;
controller = normalize_controller(controller);
} else
controller = SYSTEMD_CGROUP_CONTROLLER;
fs = procfs_file_alloca(pid, "cgroup");
f = fopen(fs, "re");
if (!f)
return errno == ENOENT ? -ESRCH : -errno;
cs = strlen(controller);
FOREACH_LINE(line, f, return -errno) {
char *l, *p, *e;
size_t k;
const char *word, *state;
bool found = false;
truncate_nl(line);
l = strchr(line, ':');
if (!l)
continue;
l++;
e = strchr(l, ':');
if (!e)
continue;
*e = 0;
FOREACH_WORD_SEPARATOR(word, k, l, ",", state) {
if (k == cs && memcmp(word, controller, cs) == 0) {
found = true;
break;
}
if (k == 5 + cs &&
memcmp(word, "name=", 5) == 0 &&
memcmp(word+5, controller, cs) == 0) {
found = true;
break;
}
}
if (!found)
continue;
p = strdup(e + 1);
if (!p)
return -ENOMEM;
*path = p;
return 0;
}
return -ENOENT;
}
int cg_install_release_agent(const char *controller, const char *agent) {
_cleanup_free_ char *fs = NULL, *contents = NULL;
char *sc;
int r;
assert(agent);
r = cg_get_path(controller, NULL, "release_agent", &fs);
if (r < 0)
return r;
r = read_one_line_file(fs, &contents);
if (r < 0)
return r;
sc = strstrip(contents);
if (sc[0] == 0) {
r = write_string_file(fs, agent);
if (r < 0)
return r;
} else if (!streq(sc, agent))
return -EEXIST;
free(fs);
fs = NULL;
r = cg_get_path(controller, NULL, "notify_on_release", &fs);
if (r < 0)
return r;
free(contents);
contents = NULL;
r = read_one_line_file(fs, &contents);
if (r < 0)
return r;
sc = strstrip(contents);
if (streq(sc, "0")) {
r = write_string_file(fs, "1");
if (r < 0)
return r;
return 1;
}
if (!streq(sc, "1"))
return -EIO;
return 0;
}
int cg_uninstall_release_agent(const char *controller) {
_cleanup_free_ char *fs = NULL;
int r;
r = cg_get_path(controller, NULL, "notify_on_release", &fs);
if (r < 0)
return r;
r = write_string_file(fs, "0");
if (r < 0)
return r;
free(fs);
fs = NULL;
r = cg_get_path(controller, NULL, "release_agent", &fs);
if (r < 0)
return r;
r = write_string_file(fs, "");
if (r < 0)
return r;
return 0;
}
int cg_is_empty(const char *controller, const char *path, bool ignore_self) {
_cleanup_fclose_ FILE *f = NULL;
pid_t pid = 0, self_pid;
bool found = false;
int r;
assert(path);
r = cg_enumerate_processes(controller, path, &f);
if (r < 0)
return r == -ENOENT ? 1 : r;
self_pid = getpid();
while ((r = cg_read_pid(f, &pid)) > 0) {
if (ignore_self && pid == self_pid)
continue;
found = true;
break;
}
if (r < 0)
return r;
return !found;
}
int cg_is_empty_recursive(const char *controller, const char *path, bool ignore_self) {
_cleanup_closedir_ DIR *d = NULL;
char *fn;
int r;
assert(path);
r = cg_is_empty(controller, path, ignore_self);
if (r <= 0)
return r;
r = cg_enumerate_subgroups(controller, path, &d);
if (r < 0)
return r == -ENOENT ? 1 : r;
while ((r = cg_read_subgroup(d, &fn)) > 0) {
_cleanup_free_ char *p = NULL;
p = strjoin(path, "/", fn, NULL);
free(fn);
if (!p)
return -ENOMEM;
r = cg_is_empty_recursive(controller, p, ignore_self);
if (r <= 0)
return r;
}
if (r < 0)
return r;
return 1;
}
int cg_split_spec(const char *spec, char **controller, char **path) {
const char *e;
char *t = NULL, *u = NULL;
_cleanup_free_ char *v = NULL;
assert(spec);
if (*spec == '/') {
if (!path_is_safe(spec))
return -EINVAL;
if (path) {
t = strdup(spec);
if (!t)
return -ENOMEM;
*path = path_kill_slashes(t);
}
if (controller)
*controller = NULL;
return 0;
}
e = strchr(spec, ':');
if (!e) {
if (!cg_controller_is_valid(spec, true))
return -EINVAL;
if (controller) {
t = strdup(normalize_controller(spec));
if (!t)
return -ENOMEM;
*controller = t;
}
if (path)
*path = NULL;
return 0;
}
v = strndup(spec, e-spec);
if (!v)
return -ENOMEM;
t = strdup(normalize_controller(v));
if (!t)
return -ENOMEM;
if (!cg_controller_is_valid(t, true)) {
free(t);
return -EINVAL;
}
if (streq(e+1, "")) {
u = strdup("/");
if (!u) {
free(t);
return -ENOMEM;
}
} else {
u = strdup(e+1);
if (!u) {
free(t);
return -ENOMEM;
}
if (!path_is_safe(u) ||
!path_is_absolute(u)) {
free(t);
free(u);
return -EINVAL;
}
path_kill_slashes(u);
}
if (controller)
*controller = t;
else
free(t);
if (path)
*path = u;
else
free(u);
return 0;
}
int cg_mangle_path(const char *path, char **result) {
_cleanup_free_ char *c = NULL, *p = NULL;
char *t;
int r;
assert(path);
assert(result);
/* First, check if it already is a filesystem path */
if (path_startswith(path, "/sys/fs/cgroup")) {
t = strdup(path);
if (!t)
return -ENOMEM;
*result = path_kill_slashes(t);
return 0;
}
/* Otherwise, treat it as cg spec */
r = cg_split_spec(path, &c, &p);
if (r < 0)
return r;
return cg_get_path(c ? c : SYSTEMD_CGROUP_CONTROLLER, p ? p : "/", NULL, result);
}
int cg_get_root_path(char **path) {
char *p, *e;
int r;
assert(path);
r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 1, &p);
if (r < 0)
return r;
e = endswith(p, "/" SPECIAL_SYSTEM_SLICE);
if (e)
*e = 0;
*path = p;
return 0;
}
int cg_shift_path(const char *cgroup, const char *root, const char **shifted) {
_cleanup_free_ char *rt = NULL;
char *p;
int r;
assert(cgroup);
assert(shifted);
if (!root) {
/* If the root was specified let's use that, otherwise
* let's determine it from PID 1 */
r = cg_get_root_path(&rt);
if (r < 0)
return r;
root = rt;
}
p = path_startswith(cgroup, root);
if (p)
*shifted = p - 1;
else
*shifted = cgroup;
return 0;
}
int cg_pid_get_path_shifted(pid_t pid, const char *root, char **cgroup) {
_cleanup_free_ char *raw = NULL;
const char *c;
int r;
assert(pid >= 0);
assert(cgroup);
r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &raw);
if (r < 0)
return r;
r = cg_shift_path(raw, root, &c);
if (r < 0)
return r;
if (c == raw) {
*cgroup = raw;
raw = NULL;
} else {
char *n;
n = strdup(c);
if (!n)
return -ENOMEM;
*cgroup = n;
}
return 0;
}
int cg_path_decode_unit(const char *cgroup, char **unit){
char *e, *c, *s;
assert(cgroup);
assert(unit);
e = strchrnul(cgroup, '/');
c = strndupa(cgroup, e - cgroup);
c = cg_unescape(c);
if (!unit_name_is_valid(c, TEMPLATE_INVALID))
return -EINVAL;
s = strdup(c);
if (!s)
return -ENOMEM;
*unit = s;
return 0;
}
static const char *skip_slices(const char *p) {
/* Skips over all slice assignments */
for (;;) {
size_t n;
p += strspn(p, "/");
n = strcspn(p, "/");
if (n <= 6 || memcmp(p + n - 6, ".slice", 6) != 0)
return p;
p += n;
}
}
int cg_path_get_unit(const char *path, char **unit) {
const char *e;
assert(path);
assert(unit);
e = skip_slices(path);
return cg_path_decode_unit(e, unit);
}
int cg_pid_get_unit(pid_t pid, char **unit) {
_cleanup_free_ char *cgroup = NULL;
int r;
assert(unit);
r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
if (r < 0)
return r;
return cg_path_get_unit(cgroup, unit);
}
/**
* Skip session-*.scope, but require it to be there.
*/
static const char *skip_session(const char *p) {
size_t n;
assert(p);
p += strspn(p, "/");
n = strcspn(p, "/");
if (n < strlen("session-x.scope") || memcmp(p, "session-", 8) != 0 || memcmp(p + n - 6, ".scope", 6) != 0)
return NULL;
p += n;
p += strspn(p, "/");
return p;
}
/**
* Skip user@*.service, but require it to be there.
*/
static const char *skip_user_manager(const char *p) {
size_t n;
assert(p);
p += strspn(p, "/");
n = strcspn(p, "/");
if (n < strlen("user@x.service") || memcmp(p, "user@", 5) != 0 || memcmp(p + n - 8, ".service", 8) != 0)
return NULL;
p += n;
p += strspn(p, "/");
return p;
}
int cg_path_get_user_unit(const char *path, char **unit) {
const char *e, *t;
assert(path);
assert(unit);
/* We always have to parse the path from the beginning as unit
* cgroups might have arbitrary child cgroups and we shouldn't get
* confused by those */
/* Skip slices, if there are any */
e = skip_slices(path);
/* Skip the session scope... */
t = skip_session(e);
if (t)
/* ... and skip more slices if there's one */
e = skip_slices(t);
else {
/* ... or require a user manager unit to be there */
e = skip_user_manager(e);
if (!e)
return -ENOENT;
}
return cg_path_decode_unit(e, unit);
}
int cg_pid_get_user_unit(pid_t pid, char **unit) {
_cleanup_free_ char *cgroup = NULL;
int r;
assert(unit);
r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
if (r < 0)
return r;
return cg_path_get_user_unit(cgroup, unit);
}
int cg_path_get_machine_name(const char *path, char **machine) {
_cleanup_free_ char *u = NULL, *sl = NULL;
int r;
r = cg_path_get_unit(path, &u);
if (r < 0)
return r;
sl = strjoin("/run/systemd/machines/unit:", u, NULL);
if (!sl)
return -ENOMEM;
return readlink_malloc(sl, machine);
}
int cg_pid_get_machine_name(pid_t pid, char **machine) {
_cleanup_free_ char *cgroup = NULL;
int r;
assert(machine);
r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
if (r < 0)
return r;
return cg_path_get_machine_name(cgroup, machine);
}
int cg_path_get_session(const char *path, char **session) {
const char *e, *n, *x;
char *s;
size_t l;
assert(path);
/* Skip slices, if there are any */
e = skip_slices(path);
n = strchrnul(e, '/');
if (e == n)
return -ENOENT;
s = strndupa(e, n - e);
s = cg_unescape(s);
x = startswith(s, "session-");
if (!x)
return -ENOENT;
if (!endswith(x, ".scope"))
return -ENOENT;
l = strlen(x);
if (l <= 6)
return -ENOENT;
if (session) {
char *r;
r = strndup(x, l - 6);
if (!r)
return -ENOMEM;
*session = r;
}
return 0;
}
int cg_pid_get_session(pid_t pid, char **session) {
_cleanup_free_ char *cgroup = NULL;
int r;
r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
if (r < 0)
return r;
return cg_path_get_session(cgroup, session);
}
int cg_path_get_owner_uid(const char *path, uid_t *uid) {
_cleanup_free_ char *slice = NULL;
const char *start, *end;
char *s;
uid_t u;
int r;
assert(path);
r = cg_path_get_slice(path, &slice);
if (r < 0)
return r;
start = startswith(slice, "user-");
if (!start)
return -ENOENT;
end = endswith(slice, ".slice");
if (!end)
return -ENOENT;
s = strndupa(start, end - start);
if (!s)
return -ENOENT;
if (parse_uid(s, &u) < 0)
return -EIO;
if (uid)
*uid = u;
return 0;
}
int cg_pid_get_owner_uid(pid_t pid, uid_t *uid) {
_cleanup_free_ char *cgroup = NULL;
int r;
r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
if (r < 0)
return r;
return cg_path_get_owner_uid(cgroup, uid);
}
int cg_path_get_slice(const char *p, char **slice) {
const char *e = NULL;
size_t m = 0;
assert(p);
assert(slice);
for (;;) {
size_t n;
p += strspn(p, "/");
n = strcspn(p, "/");
if (n <= 6 || memcmp(p + n - 6, ".slice", 6) != 0) {
char *s;
if (!e)
return -ENOENT;
s = strndup(e, m);
if (!s)
return -ENOMEM;
*slice = s;
return 0;
}
e = p;
m = n;
p += n;
}
}
int cg_pid_get_slice(pid_t pid, char **slice) {
_cleanup_free_ char *cgroup = NULL;
int r;
assert(slice);
r = cg_pid_get_path_shifted(pid, NULL, &cgroup);
if (r < 0)
return r;
return cg_path_get_slice(cgroup, slice);
}
char *cg_escape(const char *p) {
bool need_prefix = false;
/* This implements very minimal escaping for names to be used
* as file names in the cgroup tree: any name which might
* conflict with a kernel name or is prefixed with '_' is
* prefixed with a '_'. That way, when reading cgroup names it
* is sufficient to remove a single prefixing underscore if
* there is one. */
/* The return value of this function (unlike cg_unescape())
* needs free()! */
if (p[0] == 0 ||
p[0] == '_' ||
p[0] == '.' ||
streq(p, "notify_on_release") ||
streq(p, "release_agent") ||
streq(p, "tasks"))
need_prefix = true;
else {
const char *dot;
dot = strrchr(p, '.');
if (dot) {
if (dot - p == 6 && memcmp(p, "cgroup", 6) == 0)
need_prefix = true;
else {
char *n;
n = strndupa(p, dot - p);
if (check_hierarchy(n) >= 0)
need_prefix = true;
}
}
}
if (need_prefix)
return strappend("_", p);
else
return strdup(p);
}
char *cg_unescape(const char *p) {
assert(p);
/* The return value of this function (unlike cg_escape())
* doesn't need free()! */
if (p[0] == '_')
return (char*) p+1;
return (char*) p;
}
#define CONTROLLER_VALID \
DIGITS LETTERS \
"_"
bool cg_controller_is_valid(const char *p, bool allow_named) {
const char *t, *s;
if (!p)
return false;
if (allow_named) {
s = startswith(p, "name=");
if (s)
p = s;
}
if (*p == 0 || *p == '_')
return false;
for (t = p; *t; t++)
if (!strchr(CONTROLLER_VALID, *t))
return false;
if (t - p > FILENAME_MAX)
return false;
return true;
}
int cg_slice_to_path(const char *unit, char **ret) {
_cleanup_free_ char *p = NULL, *s = NULL, *e = NULL;
const char *dash;
assert(unit);
assert(ret);
if (!unit_name_is_valid(unit, TEMPLATE_INVALID))
return -EINVAL;
if (!endswith(unit, ".slice"))
return -EINVAL;
p = unit_name_to_prefix(unit);
if (!p)
return -ENOMEM;
dash = strchr(p, '-');
while (dash) {
_cleanup_free_ char *escaped = NULL;
char n[dash - p + sizeof(".slice")];
strcpy(stpncpy(n, p, dash - p), ".slice");
if (!unit_name_is_valid(n, TEMPLATE_INVALID))
return -EINVAL;
escaped = cg_escape(n);
if (!escaped)
return -ENOMEM;
if (!strextend(&s, escaped, "/", NULL))
return -ENOMEM;
dash = strchr(dash+1, '-');
}
e = cg_escape(unit);
if (!e)
return -ENOMEM;
if (!strextend(&s, e, NULL))
return -ENOMEM;
*ret = s;
s = NULL;
return 0;
}
int cg_set_attribute(const char *controller, const char *path, const char *attribute, const char *value) {
_cleanup_free_ char *p = NULL;
int r;
r = cg_get_path(controller, path, attribute, &p);
if (r < 0)
return r;
return write_string_file(p, value);
}
static const char mask_names[] =
"cpu\0"
"cpuacct\0"
"blkio\0"
"memory\0"
"devices\0";
int cg_create_everywhere(CGroupControllerMask supported, CGroupControllerMask mask, const char *path) {
CGroupControllerMask bit = 1;
const char *n;
int r;
/* This one will create a cgroup in our private tree, but also
* duplicate it in the trees specified in mask, and remove it
* in all others */
/* First create the cgroup in our own hierarchy. */
r = cg_create(SYSTEMD_CGROUP_CONTROLLER, path);
if (r < 0)
return r;
/* Then, do the same in the other hierarchies */
NULSTR_FOREACH(n, mask_names) {
if (mask & bit)
cg_create(n, path);
else if (supported & bit)
cg_trim(n, path, true);
bit <<= 1;
}
return 0;
}
int cg_attach_everywhere(CGroupControllerMask supported, const char *path, pid_t pid) {
CGroupControllerMask bit = 1;
const char *n;
int r;
r = cg_attach(SYSTEMD_CGROUP_CONTROLLER, path, pid);
if (r < 0)
return r;
NULSTR_FOREACH(n, mask_names) {
if (supported & bit)
cg_attach_fallback(n, path, pid);
bit <<= 1;
}
return 0;
}
int cg_attach_many_everywhere(CGroupControllerMask supported, const char *path, Set* pids) {
Iterator i;
void *pidp;
int r = 0;
SET_FOREACH(pidp, pids, i) {
pid_t pid = PTR_TO_LONG(pidp);
int q;
q = cg_attach_everywhere(supported, path, pid);
if (q < 0)
r = q;
}
return r;
}
int cg_migrate_everywhere(CGroupControllerMask supported, const char *from, const char *to, cg_migrate_callback_t to_callback, void *userdata) {
CGroupControllerMask bit = 1;
const char *n;
int r;
if (!path_equal(from, to)) {
r = cg_migrate_recursive(SYSTEMD_CGROUP_CONTROLLER, from, SYSTEMD_CGROUP_CONTROLLER, to, false, true);
if (r < 0)
return r;
}
NULSTR_FOREACH(n, mask_names) {
if (supported & bit) {
const char *p = NULL;
if (to_callback)
p = to_callback(bit, userdata);
if (!p)
p = to;
cg_migrate_recursive_fallback(SYSTEMD_CGROUP_CONTROLLER, to, n, p, false, false);
}
bit <<= 1;
}
return 0;
}
int cg_trim_everywhere(CGroupControllerMask supported, const char *path, bool delete_root) {
CGroupControllerMask bit = 1;
const char *n;
int r;
r = cg_trim(SYSTEMD_CGROUP_CONTROLLER, path, delete_root);
if (r < 0)
return r;
NULSTR_FOREACH(n, mask_names) {
if (supported & bit)
cg_trim(n, path, delete_root);
bit <<= 1;
}
return 0;
}
CGroupControllerMask cg_mask_supported(void) {
CGroupControllerMask bit = 1, mask = 0;
const char *n;
NULSTR_FOREACH(n, mask_names) {
if (check_hierarchy(n) >= 0)
mask |= bit;
bit <<= 1;
}
return mask;
}