xserver/hw/xfree86/os-support/linux/lnx_init.c
Hans de Goede 1dba5a0b19 linux: Add linux_parse_vt_settings and linux_get_keeptty helpers
systemd-logind integration does not work when starting X on a new tty, as
that detaches X from the current session and after hat systemd-logind revokes
all rights on any already open fds and refuses to open new fds for X.

This means that currently e.g. "startx -- vt7" breaks, and breaks badly,
requiring ssh access to the system to kill X.

The fix for this is easy, we must not use systemd-logind integration when
not using KeepTty, or iow we may only use systemd-logind integration together
with KeepTty.

But the final KeepTty value is not known until the code to chose which vtno to
run on has been called, which currently happens after intializing
systemd-logind.

This commit is step 1 in fixing the "startx -- vt7" breakage, it factors out
the linux xf86OpenConsole bits which set xf86Info.vtno and keepTty so that
these can be called earlier. Calling this earlier is safe as this code has
no side effects other than setting xf86Info.vtno and keepTty.

Note this basically only moves a large chunk of xf86OpenConsole() into
linux_parse_vt_settings() without changing a single line of it, this is
hard to see in the diff because the identation level has changed.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
2015-06-03 11:31:30 +02:00

372 lines
11 KiB
C

/*
* Copyright 1992 by Orest Zborowski <obz@Kodak.com>
* Copyright 1993 by David Wexelblat <dwex@goblin.org>
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that
* copyright notice and this permission notice appear in supporting
* documentation, and that the names of Orest Zborowski and David Wexelblat
* not be used in advertising or publicity pertaining to distribution of
* the software without specific, written prior permission. Orest Zborowski
* and David Wexelblat make no representations about the suitability of this
* software for any purpose. It is provided "as is" without express or
* implied warranty.
*
* OREST ZBOROWSKI AND DAVID WEXELBLAT DISCLAIMS ALL WARRANTIES WITH REGARD
* TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS, IN NO EVENT SHALL OREST ZBOROWSKI OR DAVID WEXELBLAT BE LIABLE
* FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
*/
#ifdef HAVE_XORG_CONFIG_H
#include <xorg-config.h>
#endif
#include <X11/X.h>
#include <X11/Xmd.h>
#include "compiler.h"
#include "linux.h"
#include "xf86.h"
#include "xf86Priv.h"
#include "xf86_OSlib.h"
#include <sys/stat.h>
#ifndef K_OFF
#define K_OFF 0x4
#endif
#ifndef KDSKBMUTE
#define KDSKBMUTE 0x4B51
#endif
static Bool KeepTty = FALSE;
static int activeVT = -1;
static char vtname[11];
static struct termios tty_attr; /* tty state to restore */
static int tty_mode; /* kbd mode to restore */
static void
drain_console(int fd, void *closure)
{
errno = 0;
if (tcflush(fd, TCIOFLUSH) == -1 && errno == EIO) {
xf86SetConsoleHandler(NULL, NULL);
}
}
static void
switch_to(int vt, const char *from)
{
int ret;
SYSCALL(ret = ioctl(xf86Info.consoleFd, VT_ACTIVATE, vt));
if (ret < 0)
FatalError("%s: VT_ACTIVATE failed: %s\n", from, strerror(errno));
SYSCALL(ret = ioctl(xf86Info.consoleFd, VT_WAITACTIVE, vt));
if (ret < 0)
FatalError("%s: VT_WAITACTIVE failed: %s\n", from, strerror(errno));
}
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wformat-nonliteral"
void
linux_parse_vt_settings(void)
{
int i, fd = -1, ret, current_vt = -1;
struct vt_stat vts;
struct stat st;
MessageType from = X_PROBED;
const char *tty0[] = { "/dev/tty0", "/dev/vc/0", NULL };
/* Only do this once */
static int vt_settings_parsed = 0;
if (vt_settings_parsed)
return;
/*
* setup the virtual terminal manager
*/
if (xf86Info.vtno != -1) {
from = X_CMDLINE;
}
else {
i = 0;
while (tty0[i] != NULL) {
if ((fd = open(tty0[i], O_WRONLY, 0)) >= 0)
break;
i++;
}
if (fd < 0)
FatalError("parse_vt_settings: Cannot open /dev/tty0 (%s)\n",
strerror(errno));
if (xf86Info.ShareVTs) {
SYSCALL(ret = ioctl(fd, VT_GETSTATE, &vts));
if (ret < 0)
FatalError("parse_vt_settings: Cannot find the current"
" VT (%s)\n", strerror(errno));
xf86Info.vtno = vts.v_active;
}
else {
SYSCALL(ret = ioctl(fd, VT_OPENQRY, &xf86Info.vtno));
if (ret < 0)
FatalError("parse_vt_settings: Cannot find a free VT: "
"%s\n", strerror(errno));
if (xf86Info.vtno == -1)
FatalError("parse_vt_settings: Cannot find a free VT\n");
}
close(fd);
}
xf86Msg(from, "using VT number %d\n\n", xf86Info.vtno);
/* Some of stdin / stdout / stderr maybe redirected to a file */
for (i = STDIN_FILENO; i <= STDERR_FILENO; i++) {
ret = fstat(i, &st);
if (ret == 0 && S_ISCHR(st.st_mode) && major(st.st_rdev) == 4) {
current_vt = minor(st.st_rdev);
break;
}
}
if (!KeepTty && current_vt == xf86Info.vtno) {
xf86Msg(X_PROBED,
"controlling tty is VT number %d, auto-enabling KeepTty\n",
current_vt);
KeepTty = TRUE;
}
vt_settings_parsed = 1;
}
int
linux_get_keeptty(void)
{
return KeepTty;
}
void
xf86OpenConsole(void)
{
int i, ret;
struct vt_stat vts;
struct vt_mode VT;
const char *vcs[] = { "/dev/vc/%d", "/dev/tty%d", NULL };
if (serverGeneration == 1) {
linux_parse_vt_settings();
if (!KeepTty) {
pid_t ppid = getppid();
pid_t ppgid;
ppgid = getpgid(ppid);
/*
* change to parent process group that pgid != pid so
* that setsid() doesn't fail and we become process
* group leader
*/
if (setpgid(0, ppgid) < 0)
xf86Msg(X_WARNING, "xf86OpenConsole: setpgid failed: %s\n",
strerror(errno));
/* become process group leader */
if ((setsid() < 0))
xf86Msg(X_WARNING, "xf86OpenConsole: setsid failed: %s\n",
strerror(errno));
}
i = 0;
while (vcs[i] != NULL) {
snprintf(vtname, sizeof(vtname), vcs[i], xf86Info.vtno); /* /dev/tty1-64 */
if ((xf86Info.consoleFd = open(vtname, O_RDWR | O_NDELAY, 0)) >= 0)
break;
i++;
}
if (xf86Info.consoleFd < 0)
FatalError("xf86OpenConsole: Cannot open virtual console"
" %d (%s)\n", xf86Info.vtno, strerror(errno));
/*
* Linux doesn't switch to an active vt after the last close of a vt,
* so we do this ourselves by remembering which is active now.
*/
SYSCALL(ret = ioctl(xf86Info.consoleFd, VT_GETSTATE, &vts));
if (ret < 0)
xf86Msg(X_WARNING, "xf86OpenConsole: VT_GETSTATE failed: %s\n",
strerror(errno));
else
activeVT = vts.v_active;
if (!xf86Info.ShareVTs) {
struct termios nTty;
/*
* now get the VT. This _must_ succeed, or else fail completely.
*/
switch_to(xf86Info.vtno, "xf86OpenConsole");
SYSCALL(ret = ioctl(xf86Info.consoleFd, VT_GETMODE, &VT));
if (ret < 0)
FatalError("xf86OpenConsole: VT_GETMODE failed %s\n",
strerror(errno));
signal(SIGUSR1, xf86VTRequest);
VT.mode = VT_PROCESS;
VT.relsig = SIGUSR1;
VT.acqsig = SIGUSR1;
SYSCALL(ret = ioctl(xf86Info.consoleFd, VT_SETMODE, &VT));
if (ret < 0)
FatalError
("xf86OpenConsole: VT_SETMODE VT_PROCESS failed: %s\n",
strerror(errno));
SYSCALL(ret = ioctl(xf86Info.consoleFd, KDSETMODE, KD_GRAPHICS));
if (ret < 0)
FatalError("xf86OpenConsole: KDSETMODE KD_GRAPHICS failed %s\n",
strerror(errno));
tcgetattr(xf86Info.consoleFd, &tty_attr);
SYSCALL(ioctl(xf86Info.consoleFd, KDGKBMODE, &tty_mode));
/* disable kernel special keys and buffering, new style */
SYSCALL(ret = ioctl(xf86Info.consoleFd, KDSKBMUTE, 1));
if (ret < 0)
{
/* disable kernel special keys and buffering, old style */
SYSCALL(ret = ioctl(xf86Info.consoleFd, KDSKBMODE, K_OFF));
if (ret < 0)
{
/* fine, just disable special keys */
SYSCALL(ret = ioctl(xf86Info.consoleFd, KDSKBMODE, K_RAW));
if (ret < 0)
FatalError("xf86OpenConsole: KDSKBMODE K_RAW failed %s\n",
strerror(errno));
/* ... and drain events, else the kernel gets angry */
xf86SetConsoleHandler(drain_console, NULL);
}
}
nTty = tty_attr;
nTty.c_iflag = (IGNPAR | IGNBRK) & (~PARMRK) & (~ISTRIP);
nTty.c_oflag = 0;
nTty.c_cflag = CREAD | CS8;
nTty.c_lflag = 0;
nTty.c_cc[VTIME] = 0;
nTty.c_cc[VMIN] = 1;
cfsetispeed(&nTty, 9600);
cfsetospeed(&nTty, 9600);
tcsetattr(xf86Info.consoleFd, TCSANOW, &nTty);
}
}
else { /* serverGeneration != 1 */
if (!xf86Info.ShareVTs && xf86Info.autoVTSwitch) {
/* now get the VT */
switch_to(xf86Info.vtno, "xf86OpenConsole");
}
}
}
#pragma GCC diagnostic pop
void
xf86CloseConsole(void)
{
struct vt_mode VT;
int ret;
if (xf86Info.ShareVTs) {
close(xf86Info.consoleFd);
return;
}
/*
* unregister the drain_console handler
* - what to do if someone else changed it in the meantime?
*/
xf86SetConsoleHandler(NULL, NULL);
/* Back to text mode ... */
SYSCALL(ret = ioctl(xf86Info.consoleFd, KDSETMODE, KD_TEXT));
if (ret < 0)
xf86Msg(X_WARNING, "xf86CloseConsole: KDSETMODE failed: %s\n",
strerror(errno));
SYSCALL(ioctl(xf86Info.consoleFd, KDSKBMUTE, 0));
SYSCALL(ioctl(xf86Info.consoleFd, KDSKBMODE, tty_mode));
tcsetattr(xf86Info.consoleFd, TCSANOW, &tty_attr);
SYSCALL(ret = ioctl(xf86Info.consoleFd, VT_GETMODE, &VT));
if (ret < 0)
xf86Msg(X_WARNING, "xf86CloseConsole: VT_GETMODE failed: %s\n",
strerror(errno));
else {
/* set dflt vt handling */
VT.mode = VT_AUTO;
SYSCALL(ret = ioctl(xf86Info.consoleFd, VT_SETMODE, &VT));
if (ret < 0)
xf86Msg(X_WARNING, "xf86CloseConsole: VT_SETMODE failed: %s\n",
strerror(errno));
}
if (xf86Info.autoVTSwitch) {
/*
* Perform a switch back to the active VT when we were started
*/
if (activeVT >= 0) {
switch_to(activeVT, "xf86CloseConsole");
activeVT = -1;
}
}
close(xf86Info.consoleFd); /* make the vt-manager happy */
}
int
xf86ProcessArgument(int argc, char *argv[], int i)
{
/*
* Keep server from detaching from controlling tty. This is useful
* when debugging (so the server can receive keyboard signals.
*/
if (!strcmp(argv[i], "-keeptty")) {
KeepTty = TRUE;
return 1;
}
if ((argv[i][0] == 'v') && (argv[i][1] == 't')) {
if (sscanf(argv[i], "vt%2d", &xf86Info.vtno) == 0) {
UseMsg();
xf86Info.vtno = -1;
return 0;
}
return 1;
}
return 0;
}
void
xf86UseMsg(void)
{
ErrorF("vtXX use the specified VT number\n");
ErrorF("-keeptty ");
ErrorF("don't detach controlling tty (for debugging only)\n");
}