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

/* SPDX-License-Identifier: LGPL-2.1+ */

#include <signal.h>
#include <stdlib.h>
#include <unistd.h>

#include "log.h"
#include "process-util.h"
#include "spawn-ask-password-agent.h"
#include "util.h"

static pid_t agent_pid = 0;

int ask_password_agent_open(void) {
        int r;

        if (agent_pid > 0)
                return 0;

        /* We check STDIN here, not STDOUT, since this is about input,
         * not output */
        if (!isatty(STDIN_FILENO))
                return 0;

        if (!is_main_thread())
                return -EPERM;

        r = fork_agent("(sd-askpwagent)",
                       NULL, 0,
                       &agent_pid,
                       SYSTEMD_TTY_ASK_PASSWORD_AGENT_BINARY_PATH,
                       SYSTEMD_TTY_ASK_PASSWORD_AGENT_BINARY_PATH, "--watch", NULL);
        if (r < 0)
                return log_error_errno(r, "Failed to fork TTY ask password agent: %m");

        return 1;
}

void ask_password_agent_close(void) {

        if (agent_pid <= 0)
                return;

        /* Inform agent that we are done */
        (void) kill_and_sigcont(agent_pid, SIGTERM);
        (void) wait_for_terminate(agent_pid, NULL);
        agent_pid = 0;
}