1 files changed, 48 insertions, 0 deletions
diff --git a/linger-switch.cpp b/linger-switch.cpp
new file mode 100644
index 000000000000..674201a633eb
--- /dev/null
+++ b/linger-switch.cpp
@@ -0,0 +1,48 @@
+#include <pwd.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <cstdio>
+#include <cstdlib>
+#include <string>
+
+void Help(const char* name) {
+  fprintf(stderr, "Usage: %s [enable/disable]\n", name);
+  exit(1);
+}
+void Err(const char* str) {
+  perror(str);
+  exit(1);
+}
+
+int main(int argc, char** argv) {
+  if (setgid(0) < 0) Err("setgid");
+  uid_t uid = getuid();
+  if (setresuid(uid, uid, 0) < 0) Err("setuid");
+  umask(0022);
+  bool del = false, flag = false;
+  if (argv == 0) Help("linger");
+  else if (argc != 2) Help(argv[0]);
+  try {
+    std::string mode_str(argv[1]);
+    if (mode_str == "enable") {
+      del = false;
+    } else if (mode_str == "disable") {
+      del = true;
+    } else {
+      Help(argv[0]);
+    }
+    struct passwd* pwd = getpwuid(uid);
+    if (!pwd) Err("getpwuid");
+    std::string path = std::string("/var/lib/systemd/linger/") + getpwuid(uid)->pw_name;
+    if (setresuid(uid, 0, 0) < 0) Err("setuid");
+    if (del) {
+      unlink(path.c_str());
+    } else {
+      int fd = open(path.c_str(), O_WRONLY | O_CREAT | O_NOCTTY | O_NONBLOCK, 0644);
+      if (fd >= 0) futimens(fd, nullptr);
+      close(fd);
+    }
+  } catch (...) { Err(argv[0]); }
+}