src/shared/spawn-ask-password-agent.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <signal.h>
   4 #include <stdlib.h>
   5 #include <unistd.h>
   6
   7 #include "exec-util.h"
   8 #include "log.h"
   9 #include "process-util.h"
  10 #include "spawn-ask-password-agent.h"
  11
  12 static pid_t agent_pid = 0;
  13
  14 int ask_password_agent_open(void) {
  15         int r;
  16
  17         if (agent_pid > 0)
  18                 return 0;
  19
  20         /* We check STDIN here, not STDOUT, since this is about input,
  21          * not output */
  22         if (!isatty(STDIN_FILENO))
  23                 return 0;
  24
  25         if (!is_main_thread())
  26                 return -EPERM;
  27
  28         r = fork_agent("(sd-askpwagent)",
  29                        NULL, 0,
  30                        &agent_pid,
  31                        SYSTEMD_TTY_ASK_PASSWORD_AGENT_BINARY_PATH,
  32                        SYSTEMD_TTY_ASK_PASSWORD_AGENT_BINARY_PATH, "--watch", NULL);
  33         if (r < 0)
  34                 return log_error_errno(r, "Failed to fork TTY ask password agent: %m");
  35
  36         return 1;
  37 }
  38
  39 void ask_password_agent_close(void) {
  40
  41         if (agent_pid <= 0)
  42                 return;
  43
  44         /* Inform agent that we are done */
  45         sigterm_wait(TAKE_PID(agent_pid));
  46 }
  47
  48 int ask_password_agent_open_if_enabled(BusTransport transport, bool ask_password) {
  49
  50         /* Open the ask password agent as a child process if necessary */
  51
  52         if (transport != BUS_TRANSPORT_LOCAL)
  53                 return 0;
  54
  55         if (!ask_password)
  56                 return 0;
  57
  58         return ask_password_agent_open();
  59 }