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-rw-r--r--src/shared/util.c73
1 files changed, 73 insertions, 0 deletions
diff --git a/src/shared/util.c b/src/shared/util.c
index 1c35edfbb1..66276aa54e 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -5951,3 +5951,76 @@ int proc_cmdline(char **ret) {
return 1;
}
+
+int container_get_leader(const char *machine, pid_t *pid) {
+ _cleanup_free_ char *s = NULL, *class = NULL;
+ const char *p;
+ pid_t leader;
+ int r;
+
+ assert(machine);
+ assert(pid);
+
+ p = strappenda("/run/systemd/machines/", machine);
+ r = parse_env_file(p, NEWLINE, "LEADER", &s, "CLASS", &class, NULL);
+ if (r == -ENOENT)
+ return -EHOSTDOWN;
+ if (r < 0)
+ return r;
+ if (!s)
+ return -EIO;
+
+ if (!streq_ptr(class, "container"))
+ return -EIO;
+
+ r = parse_pid(s, &leader);
+ if (r < 0)
+ return r;
+ if (leader <= 1)
+ return -EIO;
+
+ *pid = leader;
+ return 0;
+}
+
+int namespace_open(pid_t pid, int *namespace_fd, int *root_fd) {
+ _cleanup_close_ int nsfd = -1;
+ const char *ns, *root;
+ int rfd;
+
+ assert(pid >= 0);
+ assert(namespace_fd);
+ assert(root_fd);
+
+ ns = procfs_file_alloca(pid, "ns/mnt");
+ nsfd = open(ns, O_RDONLY|O_NOCTTY|O_CLOEXEC);
+ if (nsfd < 0)
+ return -errno;
+
+ root = procfs_file_alloca(pid, "root");
+ rfd = open(root, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY);
+ if (rfd < 0)
+ return -errno;
+
+ *namespace_fd = nsfd;
+ *root_fd = rfd;
+ nsfd = -1;
+
+ return 0;
+}
+
+int namespace_enter(int namespace_fd, int root_fd) {
+ assert(namespace_fd >= 0);
+ assert(root_fd >= 0);
+
+ if (setns(namespace_fd, CLONE_NEWNS) < 0)
+ return -errno;
+
+ if (fchdir(root_fd) < 0)
+ return -errno;
+
+ if (chroot(".") < 0)
+ return -errno;
+
+ return 0;
+}