src/shared/spawn-polkit-agent.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2011 Lennart Poettering
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <errno.h>
  21 #include <poll.h>
  22 #include <signal.h>
  23 #include <stdlib.h>
  24 #include <unistd.h>
  25
  26 #include "fd-util.h"
  27 #include "io-util.h"
  28 #include "log.h"
  29 #include "macro.h"
  30 #include "process-util.h"
  31 #include "spawn-polkit-agent.h"
  32 #include "stdio-util.h"
  33 #include "time-util.h"
  34 #include "util.h"
  35
  36 #ifdef ENABLE_POLKIT
  37 static pid_t agent_pid = 0;
  38
  39 int polkit_agent_open(void) {
  40         int r;
  41         int pipe_fd[2];
  42         char notify_fd[DECIMAL_STR_MAX(int) + 1];
  43
  44         if (agent_pid > 0)
  45                 return 0;
  46
  47         /* We check STDIN here, not STDOUT, since this is about input,
  48          * not output */
  49         if (!isatty(STDIN_FILENO))
  50                 return 0;
  51
  52         if (pipe2(pipe_fd, 0) < 0)
  53                 return -errno;
  54
  55         xsprintf(notify_fd, "%i", pipe_fd[1]);
  56
  57         r = fork_agent(&agent_pid,
  58                        &pipe_fd[1], 1,
  59                        POLKIT_AGENT_BINARY_PATH,
  60                        POLKIT_AGENT_BINARY_PATH, "--notify-fd", notify_fd, "--fallback", NULL);
  61
  62         /* Close the writing side, because that's the one for the agent */
  63         safe_close(pipe_fd[1]);
  64
  65         if (r < 0)
  66                 log_error_errno(r, "Failed to fork TTY ask password agent: %m");
  67         else
  68                 /* Wait until the agent closes the fd */
  69                 fd_wait_for_event(pipe_fd[0], POLLHUP, USEC_INFINITY);
  70
  71         safe_close(pipe_fd[0]);
  72
  73         return r;
  74 }
  75
  76 void polkit_agent_close(void) {
  77
  78         if (agent_pid <= 0)
  79                 return;
  80
  81         /* Inform agent that we are done */
  82         (void) kill(agent_pid, SIGTERM);
  83         (void) kill(agent_pid, SIGCONT);
  84
  85         (void) wait_for_terminate(agent_pid, NULL);
  86         agent_pid = 0;
  87 }
  88
  89 #else
  90
  91 int polkit_agent_open(void) {
  92         return 0;
  93 }
  94
  95 void polkit_agent_close(void) {
  96 }
  97
  98 #endif