namespace-util: add in_same_namespace()

Add a helper for the canonical way to determine whether two namespaces
are identical.
This commit is contained in:
Christian Brauner
2022-09-30 15:02:52 +02:00
committed by Christian Brauner (Microsoft)
parent 241b15779b
commit 2fe299a320
2 changed files with 25 additions and 0 deletions

View File

@@ -236,3 +236,27 @@ int userns_acquire(const char *uid_map, const char *gid_map) {
return TAKE_FD(userns_fd);
}
int in_same_namespace(pid_t pid1, pid_t pid2, NamespaceType type) {
const char *ns_path;
struct stat ns_st1, ns_st2;
if (pid1 == 0)
pid1 = getpid_cached();
if (pid2 == 0)
pid2 = getpid_cached();
if (pid1 == pid2)
return 1;
ns_path = pid_namespace_path(pid1, type);
if (stat(ns_path, &ns_st1) < 0)
return -errno;
ns_path = pid_namespace_path(pid2, type);
if (stat(ns_path, &ns_st2) < 0)
return -errno;
return stat_inode_same(&ns_st1, &ns_st2);
}

View File

@@ -45,3 +45,4 @@ static inline bool userns_shift_range_valid(uid_t shift, uid_t range) {
}
int userns_acquire(const char *uid_map, const char *gid_map);
int in_same_namespace(pid_t pid1, pid_t pid2, NamespaceType type);