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#include <stdio.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <systemd/sd-bus.h>
#include <systemd/sd-login.h>
#include <unistd.h>
#include <sys/sysmacros.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "session.h"
#include "otd.h"
int take_device(struct otd *restrict otd,
const char *restrict path,
bool *restrict paused_out)
{
int ret;
int fd = -1;
sd_bus_message *msg = NULL;
sd_bus_error error = SD_BUS_ERROR_NULL;
struct otd_session *s = &otd->session;
struct stat st;
if (stat(path, &st) < 0) {
fprintf(stderr, "Failed to stat '%s'\n", path);
return -1;
}
ret = sd_bus_call_method(s->bus,
"org.freedesktop.login1",
s->path,
"org.freedesktop.login1.Session",
"TakeDevice",
&error, &msg,
"uu", major(st.st_rdev), minor(st.st_rdev));
if (ret < 0) {
fprintf(stderr, "%s\n", error.message);
goto error;
}
int paused = 0;
ret = sd_bus_message_read(msg, "hb", &fd, &paused);
if (ret < 0) {
fprintf(stderr, "%s\n", strerror(-ret));
goto error;
}
// The original fd seem to be closed when the message is freed
// so we just clone it.
fd = fcntl(fd, F_DUPFD_CLOEXEC, 0);
if (paused_out)
*paused_out = paused;
error:
sd_bus_error_free(&error);
sd_bus_message_unref(msg);
return fd;
}
void release_device(struct otd *otd, int fd)
{
int ret;
sd_bus_message *msg = NULL;
sd_bus_error error = SD_BUS_ERROR_NULL;
struct otd_session *s = &otd->session;
struct stat st;
if (fstat(fd, &st) < 0) {
fprintf(stderr, "Could not stat fd %d\n", fd);
return;
}
ret = sd_bus_call_method(s->bus,
"org.freedesktop.login1",
s->path,
"org.freedesktop.login1.Session",
"ReleaseDevice",
&error, &msg,
"uu", major(st.st_rdev), minor(st.st_rdev));
if (ret < 0) {
/* Log something */;
}
sd_bus_error_free(&error);
sd_bus_message_unref(msg);
}
static bool session_activate(struct otd *otd)
{
int ret;
sd_bus_message *msg = NULL;
sd_bus_error error = SD_BUS_ERROR_NULL;
struct otd_session *s = &otd->session;
ret = sd_bus_call_method(s->bus,
"org.freedesktop.login1",
s->path,
"org.freedesktop.login1.Session",
"Activate",
&error, &msg,
"");
if (ret < 0) {
fprintf(stderr, "%s\n", error.message);
}
sd_bus_error_free(&error);
sd_bus_message_unref(msg);
return ret >= 0;
}
static bool take_control(struct otd *otd)
{
int ret;
sd_bus_message *msg = NULL;
sd_bus_error error = SD_BUS_ERROR_NULL;
struct otd_session *s = &otd->session;
ret = sd_bus_call_method(s->bus,
"org.freedesktop.login1",
s->path,
"org.freedesktop.login1.Session",
"TakeControl",
&error, &msg,
"b", false);
if (ret < 0) {
/* Log something */;
}
sd_bus_error_free(&error);
sd_bus_message_unref(msg);
return ret >= 0;
}
static void release_control(struct otd *otd)
{
int ret;
sd_bus_message *msg = NULL;
sd_bus_error error = SD_BUS_ERROR_NULL;
struct otd_session *s = &otd->session;
ret = sd_bus_call_method(s->bus,
"org.freedesktop.login1",
s->path,
"org.freedesktop.login1.Session",
"ReleaseControl",
&error, &msg,
"");
if (ret < 0) {
/* Log something */;
}
sd_bus_error_free(&error);
sd_bus_message_unref(msg);
}
void otd_close_session(struct otd *otd)
{
release_device(otd, otd->fd);
release_control(otd);
sd_bus_unref(otd->session.bus);
free(otd->session.id);
free(otd->session.path);
free(otd->session.seat);
}
bool otd_new_session(struct otd *otd)
{
int ret;
struct otd_session *s = &otd->session;
ret = sd_pid_get_session(getpid(), &s->id);
if (ret < 0) {
fprintf(stderr, "Could not get session\n");
goto error;
}
ret = sd_session_get_seat(s->id, &s->seat);
if (ret < 0) {
fprintf(stderr, "Could not get seat\n");
goto error;
}
// This could be done using asprintf, but I don't want to define _GNU_SOURCE
const char *fmt = "/org/freedesktop/login1/session/%s";
int len = snprintf(NULL, 0, fmt, s->id);
s->path = malloc(len + 1);
if (!s->path)
goto error;
sprintf(s->path, fmt, s->id);
ret = sd_bus_open_system(&s->bus);
if (ret < 0) {
fprintf(stderr, "Could not open bus\n");
goto error;
}
if (!session_activate(otd)) {
fprintf(stderr, "Could not activate session\n");
goto error_bus;
}
if (!take_control(otd)) {
fprintf(stderr, "Could not take control of session\n");
goto error_bus;
}
return true;
error_bus:
sd_bus_unref(s->bus);
error:
free(s->path);
free(s->id);
free(s->seat);
return false;
}
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