diff options
Diffstat (limited to 'src/basic')
-rw-r--r-- | src/basic/cgroup-util.c | 99 | ||||
-rw-r--r-- | src/basic/cgroup-util.h | 3 |
2 files changed, 57 insertions, 45 deletions
diff --git a/src/basic/cgroup-util.c b/src/basic/cgroup-util.c index 90877c9fa1..21e2255dae 100644 --- a/src/basic/cgroup-util.c +++ b/src/basic/cgroup-util.c @@ -1554,52 +1554,64 @@ int cg_pid_get_user_slice(pid_t pid, char **slice) { 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 (IN_SET(p[0], 0, '_', '.') || - STR_IN_SET(p, "notify_on_release", "release_agent", "tasks") || - startswith(p, "cgroup.")) - need_prefix = true; - else { - const char *dot; +bool cg_needs_escape(const char *p) { - dot = strrchr(p, '.'); - if (dot) { - CGroupController c; - size_t l = dot - p; + /* Checks if the specified path is a valid cgroup name by our rules, or if it must be escaped. Note + * that we consider escaped cgroup names invalid here, as they need to be escaped a second time if + * they shall be used. Also note that various names cannot be made valid by escaping even if we + * return true here (because too long, or contain the forbidden character "/"). */ - for (c = 0; c < _CGROUP_CONTROLLER_MAX; c++) { - const char *n; + if (!filename_is_valid(p)) + return true; - n = cgroup_controller_to_string(c); + if (IN_SET(p[0], '_', '.')) + return true; - if (l != strlen(n)) - continue; + if (STR_IN_SET(p, "notify_on_release", "release_agent", "tasks")) + return true; - if (memcmp(p, n, l) != 0) - continue; + if (startswith(p, "cgroup.")) + return true; - need_prefix = true; - break; - } - } + for (CGroupController c = 0; c < _CGROUP_CONTROLLER_MAX; c++) { + const char *q; + + q = startswith(p, cgroup_controller_to_string(c)); + if (!q) + continue; + + if (q[0] == '.') + return true; } - if (need_prefix) - return strjoin("_", p); + return false; +} + +int cg_escape(const char *p, char **ret) { + _cleanup_free_ char *n = NULL; + + /* 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()! */ - return strdup(p); + if (cg_needs_escape(p)) { + n = strjoin("_", p); + if (!n) + return -ENOMEM; + + if (!filename_is_valid(n)) /* became invalid due to the prefixing? Or contained things like a slash that cannot be fixed by prefixing? */ + return -EINVAL; + } else { + n = strdup(p); + if (!n) + return -ENOMEM; + } + + *ret = TAKE_PTR(n); + return 0; } char *cg_unescape(const char *p) { @@ -1698,9 +1710,9 @@ int cg_slice_to_path(const char *unit, char **ret) { if (!unit_name_is_valid(n, UNIT_NAME_PLAIN)) return -EINVAL; - escaped = cg_escape(n); - if (!escaped) - return -ENOMEM; + r = cg_escape(n, &escaped); + if (r < 0) + return r; if (!strextend(&s, escaped, "/")) return -ENOMEM; @@ -1708,15 +1720,14 @@ int cg_slice_to_path(const char *unit, char **ret) { dash = strchr(dash+1, '-'); } - e = cg_escape(unit); - if (!e) - return -ENOMEM; + r = cg_escape(unit, &e); + if (r < 0) + return r; if (!strextend(&s, e)) return -ENOMEM; *ret = TAKE_PTR(s); - return 0; } diff --git a/src/basic/cgroup-util.h b/src/basic/cgroup-util.h index 5de000c4ce..9b30ae0396 100644 --- a/src/basic/cgroup-util.h +++ b/src/basic/cgroup-util.h @@ -279,7 +279,8 @@ int cg_pid_get_user_slice(pid_t pid, char **slice); int cg_path_decode_unit(const char *cgroup, char **unit); -char *cg_escape(const char *p); +bool cg_needs_escape(const char *p); +int cg_escape(const char *p, char **ret); char *cg_unescape(const char *p) _pure_; bool cg_controller_is_valid(const char *p); |