+ *ret = unit;
+ return 0;
+}
+
+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;
+
+ if (isempty(p))
+ return NULL;
+
+ p += strspn(p, "/");
+
+ n = strcspn(p, "/");
+ if (n < strlen("session-x.scope"))
+ return NULL;
+
+ if (memcmp(p, "session-", 8) == 0 && memcmp(p + n - 6, ".scope", 6) == 0) {
+ char buf[n - 8 - 6 + 1];
+
+ memcpy(buf, p + 8, n - 8 - 6);
+ buf[n - 8 - 6] = 0;
+
+ /* Note that session scopes never need unescaping,
+ * since they cannot conflict with the kernel's own
+ * names, hence we don't need to call cg_unescape()
+ * here. */
+
+ if (!session_id_valid(buf))
+ return false;
+
+ p += n;
+ p += strspn(p, "/");
+ return p;
+ }
+
+ return NULL;
+}
+
+/**
+ * Skip user@*.service, but require it to be there.
+ */
+static const char *skip_user_manager(const char *p) {
+ size_t n;
+
+ if (isempty(p))
+ return NULL;
+
+ p += strspn(p, "/");
+
+ n = strcspn(p, "/");
+ if (n < strlen("user@x.service"))
+ return NULL;
+
+ if (memcmp(p, "user@", 5) == 0 && memcmp(p + n - 8, ".service", 8) == 0) {
+ char buf[n - 5 - 8 + 1];
+
+ memcpy(buf, p + 5, n - 5 - 8);
+ buf[n - 5 - 8] = 0;
+
+ /* Note that user manager services never need unescaping,
+ * since they cannot conflict with the kernel's own
+ * names, hence we don't need to call cg_unescape()
+ * here. */
+
+ if (parse_uid(buf, NULL) < 0)
+ return NULL;
+
+ p += n;
+ p += strspn(p, "/");
+
+ return p;
+ }
+
+ return NULL;
+}
+
+static const char *skip_user_prefix(const char *path) {
+ const char *e, *t;
+
+ assert(path);
+
+ /* Skip slices, if there are any */
+ e = skip_slices(path);
+
+ /* Skip the user manager, if it's in the path now... */
+ t = skip_user_manager(e);
+ if (t)
+ return t;
+
+ /* Alternatively skip the user session if it is in the path... */
+ return skip_session(e);
+}
+
+int cg_path_get_user_unit(const char *path, char **ret) {
+ const char *t;
+
+ assert(path);
+ assert(ret);
+
+ t = skip_user_prefix(path);
+ if (!t)
+ return -ENXIO;
+
+ /* And from here on it looks pretty much the same as for a
+ * system unit, hence let's use the same parser from here
+ * on. */
+ return cg_path_get_unit(t, ret);
+}
+
+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) {
+ _cleanup_free_ char *unit = NULL;
+ char *start, *end;
+ int r;
+
+ assert(path);
+
+ r = cg_path_get_unit(path, &unit);
+ if (r < 0)
+ return r;
+
+ start = startswith(unit, "session-");
+ if (!start)
+ return -ENXIO;
+ end = endswith(start, ".scope");
+ if (!end)
+ return -ENXIO;
+
+ *end = 0;
+ if (!session_id_valid(start))
+ return -ENXIO;
+
+ if (session) {
+ char *rr;
+
+ rr = strdup(start);
+ if (!rr)
+ return -ENOMEM;
+
+ *session = rr;
+ }
+
+ 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;
+ char *start, *end;
+ int r;
+
+ assert(path);
+
+ r = cg_path_get_slice(path, &slice);
+ if (r < 0)
+ return r;
+
+ start = startswith(slice, "user-");
+ if (!start)
+ return -ENXIO;
+ end = endswith(start, ".slice");
+ if (!end)
+ return -ENXIO;
+
+ *end = 0;
+ if (parse_uid(start, uid) < 0)
+ return -ENXIO;
+
+ 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;
+
+ assert(p);
+ assert(slice);
+
+ /* Finds the right-most slice unit from the beginning, but
+ * stops before we come to the first non-slice unit. */
+
+ for (;;) {
+ size_t n;
+
+ p += strspn(p, "/");
+
+ n = strcspn(p, "/");
+ if (!valid_slice_name(p, n)) {
+
+ if (!e) {
+ char *s;
+
+ s = strdup("-.slice");
+ if (!s)
+ return -ENOMEM;
+
+ *slice = s;
+ return 0;
+ }
+
+ return cg_path_decode_unit(e, slice);
+ }
+
+ e = p;
+ 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);
+}
+
+int cg_path_get_user_slice(const char *p, char **slice) {
+ const char *t;
+ assert(p);
+ assert(slice);
+
+ t = skip_user_prefix(p);
+ if (!t)
+ return -ENXIO;
+
+ /* And now it looks pretty much the same as for a system
+ * slice, so let's just use the same parser from here on. */
+ return cg_path_get_slice(t, slice);
+}
+
+int cg_pid_get_user_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_user_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 (streq(unit, "-.slice")) {
+ char *x;
+
+ x = strdup("");
+ if (!x)
+ return -ENOMEM;
+ *ret = x;
+ return 0;
+ }
+
+ 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")];
+
+ if (isempty(dash + 1))
+ return -EINVAL;
+
+ 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_no_create(p, value);
+}
+
+int cg_get_attribute(const char *controller, const char *path, const char *attribute, char **ret) {
+ _cleanup_free_ char *p = NULL;
+ int r;
+
+ r = cg_get_path(controller, path, attribute, &p);
+ if (r < 0)
+ return r;
+
+ return read_one_line_file(p, ret);
+}
+
+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, cg_migrate_callback_t path_callback, void *userdata) {
+ 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) {
+ const char *p = NULL;
+
+ if (path_callback)
+ p = path_callback(bit, userdata);
+
+ if (!p)
+ p = path;
+
+ cg_attach_fallback(n, path, pid);
+ }
+
+ bit <<= 1;
+ }
+
+ return 0;
+}
+
+int cg_attach_many_everywhere(CGroupControllerMask supported, const char *path, Set* pids, cg_migrate_callback_t path_callback, void *userdata) {
+ 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, path_callback, userdata);
+ 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;
+}
+
+int cg_kernel_controllers(Set *controllers) {
+ _cleanup_fclose_ FILE *f = NULL;
+ char buf[LINE_MAX];
+ int r;
+
+ assert(controllers);
+
+ f = fopen("/proc/cgroups", "re");
+ if (!f) {
+ if (errno == ENOENT)
+ return 0;
+ return -errno;
+ }
+
+ /* Ignore the header line */
+ (void) fgets(buf, sizeof(buf), f);
+
+ for (;;) {
+ char *controller;
+ int enabled = 0;
+
+ errno = 0;
+ if (fscanf(f, "%ms %*i %*i %i", &controller, &enabled) != 2) {
+
+ if (feof(f))
+ break;
+
+ if (ferror(f) && errno)
+ return -errno;
+
+ return -EBADMSG;
+ }
+
+ if (!enabled) {
+ free(controller);
+ continue;
+ }
+
+ if (!filename_is_valid(controller)) {
+ free(controller);
+ return -EBADMSG;
+ }
+
+ r = set_consume(controllers, controller);
+ if (r < 0)
+ return r;
+ }