1 files changed, 96 insertions, 0 deletions
diff --git a/src/shared/spawn-polkit-agent.c b/src/shared/spawn-polkit-agent.c
new file mode 100644
index 0000000..ce3c5fb
--- /dev/null
+++ b/src/shared/spawn-polkit-agent.c
@@ -0,0 +1,96 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <errno.h>
+#include <poll.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "exec-util.h"
+#include "fd-util.h"
+#include "io-util.h"
+#include "log.h"
+#include "macro.h"
+#include "process-util.h"
+#include "spawn-polkit-agent.h"
+#include "stdio-util.h"
+#include "time-util.h"
+
+#if ENABLE_POLKIT
+static pid_t agent_pid = 0;
+
+int polkit_agent_open(void) {
+        char notify_fd[DECIMAL_STR_MAX(int) + 1];
+        int pipe_fd[2], r;
+
+        if (agent_pid > 0)
+                return 0;
+
+        /* Clients that run as root don't need to activate/query polkit */
+        if (geteuid() == 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;
+
+        if (pipe2(pipe_fd, 0) < 0)
+                return -errno;
+
+        xsprintf(notify_fd, "%i", pipe_fd[1]);
+
+        r = fork_agent("(polkit-agent)",
+                       &pipe_fd[1], 1,
+                       &agent_pid,
+                       POLKIT_AGENT_BINARY_PATH,
+                       POLKIT_AGENT_BINARY_PATH, "--notify-fd", notify_fd, "--fallback", NULL);
+
+        /* Close the writing side, because that's the one for the agent */
+        safe_close(pipe_fd[1]);
+
+        if (r < 0)
+                log_error_errno(r, "Failed to fork TTY ask password agent: %m");
+        else
+                /* Wait until the agent closes the fd */
+                (void) fd_wait_for_event(pipe_fd[0], POLLHUP, USEC_INFINITY);
+
+        safe_close(pipe_fd[0]);
+
+        return r;
+}
+
+void polkit_agent_close(void) {
+
+        if (agent_pid <= 0)
+                return;
+
+        /* Inform agent that we are done */
+        sigterm_wait(TAKE_PID(agent_pid));
+}
+
+#else
+
+int polkit_agent_open(void) {
+        return 0;
+}
+
+void polkit_agent_close(void) {
+}
+
+#endif
+
+int polkit_agent_open_if_enabled(BusTransport transport, bool ask_password) {
+
+        /* Open the polkit agent as a child process if necessary */
+
+        if (transport != BUS_TRANSPORT_LOCAL)
+                return 0;
+
+        if (!ask_password)
+                return 0;
+
+        return polkit_agent_open();
+}