weston/libweston/launcher-direct.c
nerdopolis 72db3ac694 launcher-direct: handle seat0 without VTs
This allows launcher-direct to run when seat0 has no TTYs
This checks for a proper /dev/tty0 device as /dev/tty0
does not get created by kernels compiled with CONFIG_VT=n
2021-01-21 09:02:26 +00:00

371 lines
9.1 KiB
C

/*
* Copyright © 2012 Benjamin Franzke
* Copyright © 2013 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial
* portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include "config.h"
#include <libweston/libweston.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <signal.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <linux/vt.h>
#include <linux/kd.h>
#include <linux/major.h>
#include "launcher-impl.h"
#define DRM_MAJOR 226
#ifndef KDSKBMUTE
#define KDSKBMUTE 0x4B51
#endif
/* major()/minor() */
#ifdef MAJOR_IN_MKDEV
#include <sys/mkdev.h>
#endif
#ifdef MAJOR_IN_SYSMACROS
#include <sys/sysmacros.h>
#endif
#ifdef BUILD_DRM_COMPOSITOR
#include <xf86drm.h>
static inline int
is_drm_master(int drm_fd)
{
drm_magic_t magic;
return drmGetMagic(drm_fd, &magic) == 0 &&
drmAuthMagic(drm_fd, magic) == 0;
}
#else
static inline int
drmDropMaster(int drm_fd)
{
return 0;
}
static inline int
drmSetMaster(int drm_fd)
{
return 0;
}
static inline int
is_drm_master(int drm_fd)
{
return 0;
}
#endif
struct launcher_direct {
struct weston_launcher base;
struct weston_compositor *compositor;
int kb_mode, tty, drm_fd;
struct wl_event_source *vt_source;
};
static int
vt_handler(int signal_number, void *data)
{
struct launcher_direct *launcher = data;
struct weston_compositor *compositor = launcher->compositor;
if (compositor->session_active) {
compositor->session_active = false;
wl_signal_emit(&compositor->session_signal, compositor);
drmDropMaster(launcher->drm_fd);
ioctl(launcher->tty, VT_RELDISP, 1);
} else {
ioctl(launcher->tty, VT_RELDISP, VT_ACKACQ);
drmSetMaster(launcher->drm_fd);
compositor->session_active = true;
wl_signal_emit(&compositor->session_signal, compositor);
}
return 1;
}
static int
setup_tty(struct launcher_direct *launcher, int tty)
{
struct wl_event_loop *loop;
struct vt_mode mode = { 0 };
struct stat buf;
char tty_device[32] ="<stdin>";
int ret, kd_mode;
if (geteuid() != 0)
return -1;
if (tty == 0) {
launcher->tty = dup(tty);
if (launcher->tty == -1) {
weston_log("couldn't dup stdin: %s\n",
strerror(errno));
return -1;
}
} else {
snprintf(tty_device, sizeof tty_device, "/dev/tty%d", tty);
launcher->tty = open(tty_device, O_RDWR | O_CLOEXEC);
if (launcher->tty == -1) {
weston_log("couldn't open tty %s: %s\n", tty_device,
strerror(errno));
return -1;
}
}
if (fstat(launcher->tty, &buf) == -1 ||
major(buf.st_rdev) != TTY_MAJOR || minor(buf.st_rdev) == 0) {
weston_log("%s not a vt\n", tty_device);
weston_log("if running weston from ssh, "
"use --tty to specify a tty\n");
goto err_close;
}
ret = ioctl(launcher->tty, KDGETMODE, &kd_mode);
if (ret) {
weston_log("failed to get VT mode: %s\n", strerror(errno));
return -1;
}
if (kd_mode != KD_TEXT) {
weston_log("%s is already in graphics mode, "
"is another display server running?\n", tty_device);
}
ioctl(launcher->tty, VT_ACTIVATE, minor(buf.st_rdev));
ioctl(launcher->tty, VT_WAITACTIVE, minor(buf.st_rdev));
if (ioctl(launcher->tty, KDGKBMODE, &launcher->kb_mode)) {
weston_log("failed to read keyboard mode: %s\n",
strerror(errno));
goto err_close;
}
if (ioctl(launcher->tty, KDSKBMUTE, 1) &&
ioctl(launcher->tty, KDSKBMODE, K_OFF)) {
weston_log("failed to set K_OFF keyboard mode: %s\n",
strerror(errno));
goto err_close;
}
ret = ioctl(launcher->tty, KDSETMODE, KD_GRAPHICS);
if (ret) {
weston_log("failed to set KD_GRAPHICS mode on tty: %s\n",
strerror(errno));
goto err_close;
}
/*
* SIGRTMIN is used as global VT-acquire+release signal. Note that
* SIGRT* must be tested on runtime, as their exact values are not
* known at compile-time. POSIX requires 32 of them to be available.
*/
if (SIGRTMIN > SIGRTMAX) {
weston_log("not enough RT signals available: %u-%u\n",
SIGRTMIN, SIGRTMAX);
ret = -EINVAL;
goto err_close;
}
mode.mode = VT_PROCESS;
mode.relsig = SIGRTMIN;
mode.acqsig = SIGRTMIN;
if (ioctl(launcher->tty, VT_SETMODE, &mode) < 0) {
weston_log("failed to take control of vt handling\n");
goto err_close;
}
loop = wl_display_get_event_loop(launcher->compositor->wl_display);
launcher->vt_source =
wl_event_loop_add_signal(loop, SIGRTMIN, vt_handler, launcher);
if (!launcher->vt_source) {
weston_log("failed to add SIGRTMIN signal\n");
goto err_close;
}
return 0;
err_close:
close(launcher->tty);
return -1;
}
static int
launcher_direct_open(struct weston_launcher *launcher_base, const char *path, int flags)
{
struct launcher_direct *launcher = wl_container_of(launcher_base, launcher, base);
struct stat s;
int fd;
fd = open(path, flags | O_CLOEXEC);
if (fd == -1) {
weston_log("couldn't open: %s! error=%s\n", path, strerror(errno));
return -1;
}
if (geteuid() != 0) {
weston_log("WARNING! Succeeded opening %s as non-root user."
" This implies your device can be spied on.\n",
path);
}
if (fstat(fd, &s) == -1) {
weston_log("couldn't fstat: %s! error=%s\n", path, strerror(errno));
close(fd);
return -1;
}
if (major(s.st_rdev) == DRM_MAJOR) {
launcher->drm_fd = fd;
if (!is_drm_master(fd)) {
weston_log("drm fd not master\n");
close(fd);
return -1;
}
}
return fd;
}
static void
launcher_direct_close(struct weston_launcher *launcher_base, int fd)
{
close(fd);
}
static void
launcher_direct_restore(struct weston_launcher *launcher_base)
{
struct launcher_direct *launcher = wl_container_of(launcher_base, launcher, base);
struct vt_mode mode = { 0 };
if (ioctl(launcher->tty, KDSKBMUTE, 0) &&
ioctl(launcher->tty, KDSKBMODE, launcher->kb_mode))
weston_log("failed to restore kb mode: %s\n",
strerror(errno));
if (ioctl(launcher->tty, KDSETMODE, KD_TEXT))
weston_log("failed to set KD_TEXT mode on tty: %s\n",
strerror(errno));
/* We have to drop master before we switch the VT back in
* VT_AUTO, so we don't risk switching to a VT with another
* display server, that will then fail to set drm master. */
drmDropMaster(launcher->drm_fd);
mode.mode = VT_AUTO;
if (ioctl(launcher->tty, VT_SETMODE, &mode) < 0)
weston_log("could not reset vt handling! error=%s\n",
strerror(errno));
}
static int
launcher_direct_activate_vt(struct weston_launcher *launcher_base, int vt)
{
struct launcher_direct *launcher = wl_container_of(launcher_base, launcher, base);
return ioctl(launcher->tty, VT_ACTIVATE, vt);
}
static int
launcher_direct_connect(struct weston_launcher **out, struct weston_compositor *compositor,
int tty, const char *seat_id, bool sync_drm)
{
struct launcher_direct *launcher;
struct stat buf;
launcher = zalloc(sizeof(*launcher));
if (launcher == NULL) {
weston_log("failed to alloc for launcher\n");
return -ENOMEM;
}
launcher->base.iface = &launcher_direct_iface;
launcher->compositor = compositor;
/* Checking the existance of /dev/tty0 and verifying it's a TTY
* device, as kernels compiled with CONFIG_VT=0 do not create these
* devices. */
if (stat("/dev/tty0", &buf) == 0 &&
strcmp("seat0", seat_id) == 0 && major(buf.st_rdev) == TTY_MAJOR) {
if (setup_tty(launcher, tty) == -1) {
free(launcher);
return -1;
}
} else {
launcher->tty = -1;
}
* (struct launcher_direct **) out = launcher;
return 0;
}
static void
launcher_direct_destroy(struct weston_launcher *launcher_base)
{
struct launcher_direct *launcher = wl_container_of(launcher_base, launcher, base);
if (launcher->tty >= 0) {
launcher_direct_restore(&launcher->base);
wl_event_source_remove(launcher->vt_source);
close(launcher->tty);
}
free(launcher);
}
static int
launcher_direct_get_vt(struct weston_launcher *base)
{
struct launcher_direct *launcher = wl_container_of(base, launcher, base);
struct stat s;
if (fstat(launcher->tty, &s) < 0) {
weston_log("couldn't fstat launcher tty: %s\n", strerror(errno));
return -1;
}
return minor(s.st_rdev);
}
const struct launcher_interface launcher_direct_iface = {
.name = "direct",
.connect = launcher_direct_connect,
.destroy = launcher_direct_destroy,
.open = launcher_direct_open,
.close = launcher_direct_close,
.activate_vt = launcher_direct_activate_vt,
.get_vt = launcher_direct_get_vt,
};