Introduce weston-launch

weston-launch starts weston and provides mechanism
for weston to set/drop drm master, open a tty,
and read input devices without being root.

Execution is allowed for local-active sessions
or users in the group weston-launch.
dev
Benjamin Franzke 13 years ago
parent 1a36156972
commit bfeda130de
  1. 16
      configure.ac
  2. 1
      src/.gitignore
  3. 24
      src/Makefile.am
  4. 8
      src/compositor-drm.c
  5. 1
      src/compositor.c
  6. 4
      src/compositor.h
  7. 3
      src/evdev.c
  8. 156
      src/launcher-util.c
  9. 35
      src/launcher-util.h
  10. 37
      src/tty.c
  11. 26
      src/util.c
  12. 639
      src/weston-launch.c
  13. 46
      src/weston-launch.h

@ -151,6 +151,22 @@ if test x$enable_clients = xyes; then
[AC_MSG_WARN([Cairo-EGL not found - clients will use cairo image])])
fi
AC_ARG_ENABLE(weston-launch, [ --enable-weston-launch],, enable_weston_launch=yes)
AM_CONDITIONAL(BUILD_WESTON_LAUNCH, test x$enable_weston_launch == xyes)
if test x$enable_weston_launch == xyes; then
PKG_CHECK_MODULES(WESTON_LAUNCH, [libdrm])
PKG_CHECK_MODULES(SYSTEMD_LOGIN, [libsystemd-login],
[have_systemd_login=yes], [have_systemd_login=no])
AS_IF([test "x$have_systemd_login" = "xyes"],
[AC_DEFINE([HAVE_SYSTEMD_LOGIN], [1], [Have systemd-login])])
AC_CHECK_LIB([pam], [pam_open_session], [have_pam=yes], [have_pam=no])
if test x$have_pam == xno; then
AC_ERROR([weston-launch requires pam])
fi
WESTON_LAUNCH_LIBS="$WESTON_LAUNCH_LIBS -lpam"
fi
AM_CONDITIONAL(HAVE_POPPLER, test "x$have_poppler" = "xyes")
AM_CONDITIONAL(BUILD_FULL_GL_CLIENTS,

1
src/.gitignore vendored

@ -1,4 +1,5 @@
weston
weston-launch
screenshooter-protocol.c
screenshooter-server-protocol.h
tablet-shell-protocol.c

@ -1,4 +1,5 @@
bin_PROGRAMS = weston
bin_PROGRAMS = weston \
$(weston_launch)
AM_CPPFLAGS = \
-DDATADIR='"$(datadir)"' \
@ -22,14 +23,33 @@ weston_SOURCES = \
util.c \
matrix.c \
matrix.h \
weston-launch.h \
$(xserver_launcher_sources)
if BUILD_WESTON_LAUNCH
weston_launch = weston-launch
weston_launch_SOURCES = weston-launch.c weston-launch.h
weston_launch_CFLAGS= $(GCC_CFLAGS)
weston_launch_CPPFLAGS = $(WESTON_LAUNCH_CFLAGS) $(SYSTEMD_LOGIN_CFLAGS) \
-DBINDIR='"$(bindir)"'
weston_launch_LDADD = $(WESTON_LAUNCH_LIBS) $(SYSTEMD_LOGIN_LIBS)
if ENABLE_SETUID_INSTALL
install-exec-hook:
chown root $(DESTDIR)$(bindir)/weston-launch
chmod u+s $(DESTDIR)$(bindir)/weston-launch
endif
else # BUILD_WESTON_LAUNCH
if ENABLE_SETUID_INSTALL
install-exec-hook:
chown root $(DESTDIR)$(bindir)/weston
chmod u+s $(DESTDIR)$(bindir)/weston
endif
endif # BUILD_WESTON_LAUNCH
if ENABLE_XSERVER_LAUNCHER
xserver_launcher_sources = \
xserver-launcher.c \
@ -67,6 +87,8 @@ drm_backend_la_SOURCES = \
tty.c \
evdev.c \
evdev.h \
launcher-util.c \
launcher-util.h \
libbacklight.c \
libbacklight.h
endif

@ -39,6 +39,7 @@
#include "compositor.h"
#include "evdev.h"
#include "launcher-util.h"
struct drm_compositor {
struct weston_compositor base;
@ -1449,7 +1450,8 @@ drm_destroy(struct weston_compositor *ec)
gbm_device_destroy(d->gbm);
destroy_sprites(d);
drmDropMaster(d->drm.fd);
if (weston_launcher_drm_set_master(&d->base, d->drm.fd, 0) < 0)
fprintf(stderr, "failed to drop master: %m\n");
tty_destroy(d->tty);
free(d);
@ -1489,7 +1491,7 @@ vt_func(struct weston_compositor *compositor, int event)
switch (event) {
case TTY_ENTER_VT:
compositor->focus = 1;
if (drmSetMaster(ec->drm.fd)) {
if (weston_launcher_drm_set_master(&ec->base, ec->drm.fd, 1)) {
fprintf(stderr, "failed to set master: %m\n");
wl_display_terminate(compositor->wl_display);
}
@ -1529,7 +1531,7 @@ vt_func(struct weston_compositor *compositor, int event)
wl_list_for_each(input, &compositor->input_device_list, link)
evdev_remove_devices(input);
if (drmDropMaster(ec->drm.fd) < 0)
if (weston_launcher_drm_set_master(&ec->base, ec->drm.fd, 0) < 0)
fprintf(stderr, "failed to drop master: %m\n");
break;

@ -2331,6 +2331,7 @@ weston_compositor_init(struct weston_compositor *ec, struct wl_display *display)
const char *extensions;
ec->wl_display = display;
ec->launcher_sock = weston_environment_get_fd("WESTON_LAUNCHER_SOCK");
if (!wl_display_add_global(display, &wl_compositor_interface,
ec, compositor_bind))

@ -231,6 +231,7 @@ struct weston_compositor {
int (*authenticate)(struct weston_compositor *c, uint32_t id);
struct screenshooter *screenshooter;
int launcher_sock;
};
#define MODIFIER_CTRL (1 << 8)
@ -443,6 +444,9 @@ weston_compositor_run_binding(struct weston_compositor *compositor,
struct weston_input_device *device,
uint32_t time,
uint32_t key, uint32_t button, uint32_t axis, int32_t state);
int
weston_environment_get_fd(const char *env);
struct wl_list *
weston_compositor_top(struct weston_compositor *compositor);

@ -30,6 +30,7 @@
#include "compositor.h"
#include "evdev.h"
#include "launcher-util.h"
struct evdev_input {
struct weston_input_device base;
@ -492,7 +493,7 @@ evdev_input_device_create(struct evdev_input *master,
/* Use non-blocking mode so that we can loop on read on
* evdev_input_device_data() until all events on the fd are
* read. mtdev_get() also expects this. */
device->fd = open(path, O_RDONLY | O_NONBLOCK);
device->fd = weston_launcher_open(ec, path, O_RDONLY | O_NONBLOCK);
if (device->fd < 0)
goto err0;

@ -0,0 +1,156 @@
/*
* Copyright © 2012 Benjamin Franzke
*
* 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 name of the copyright holders not be used in
* advertising or publicity pertaining to distribution of the software
* without specific, written prior permission. The copyright holders make
* no representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*
* THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
* SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS 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.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/uio.h>
#include <fcntl.h>
#include <xf86drm.h>
#include "compositor.h"
#include "launcher-util.h"
#include "weston-launch.h"
int
weston_launcher_open(struct weston_compositor *compositor,
const char *path, int flags)
{
int sock = compositor->launcher_sock;
int fd, n, ret = -1;
struct msghdr msg;
struct cmsghdr *cmsg;
struct iovec iov;
char control[CMSG_SPACE(sizeof fd)];
ssize_t len;
struct weston_launcher_open *message;
if (sock == -1)
return open(path, flags);
n = sizeof(*message) + strlen(path) + 1;
message = malloc(n);
if (!message)
return -1;
message->header.opcode = WESTON_LAUNCHER_OPEN;
message->flags = flags;
strcpy(message->path, path);
do {
len = send(sock, message, n, 0);
} while (len < 0 && errno == EINTR);
memset(&msg, 0, sizeof msg);
iov.iov_base = &ret;
iov.iov_len = sizeof ret;
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_control = control;
msg.msg_controllen = sizeof control;
do {
len = recvmsg(sock, &msg, MSG_CMSG_CLOEXEC);
} while (len < 0 && errno == EINTR);
if (len != sizeof ret ||
ret < 0)
goto out;
cmsg = CMSG_FIRSTHDR(&msg);
if (!cmsg ||
cmsg->cmsg_level != SOL_SOCKET ||
cmsg->cmsg_type != SCM_RIGHTS) {
fprintf(stderr, "invalid control message\n");
goto out;
}
fd = *(int *) CMSG_DATA(cmsg);
if (fd == -1) {
fprintf(stderr, "missing drm fd in socket request");
return -1;
}
out:
free(message);
return ret < 0 ? ret : fd;
}
int
weston_launcher_drm_set_master(struct weston_compositor *compositor,
int drm_fd, char master)
{
struct msghdr msg;
struct cmsghdr *cmsg;
struct iovec iov;
char control[CMSG_SPACE(sizeof(drm_fd))];
int ret;
ssize_t len;
struct weston_launcher_set_master message;
if (compositor->launcher_sock == -1) {
if (master)
return drmSetMaster(drm_fd);
else
return drmDropMaster(drm_fd);
}
memset(&msg, 0, sizeof msg);
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_control = control;
msg.msg_controllen = sizeof control;
cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
cmsg->cmsg_len = CMSG_LEN(sizeof(drm_fd));
*(int *) CMSG_DATA(cmsg) = drm_fd;
msg.msg_controllen = cmsg->cmsg_len;
iov.iov_base = &message;
iov.iov_len = sizeof message;
message.header.opcode = WESTON_LAUNCHER_DRM_SET_MASTER;
message.set_master = master;
do {
len = sendmsg(compositor->launcher_sock, &msg, 0);
} while (len < 0 && errno == EINTR);
if (len < 0)
return -1;
do {
len = recv(compositor->launcher_sock, &ret, sizeof ret, 0);
} while (len < 0 && errno == EINTR);
if (len < 0)
return -1;
return ret;
}

@ -0,0 +1,35 @@
/*
* Copyright © 2012 Benjamin Franzke
*
* 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 name of the copyright holders not be used in
* advertising or publicity pertaining to distribution of the software
* without specific, written prior permission. The copyright holders make
* no representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*
* THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
* SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS 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.
*/
#ifndef _WESTON_LAUNCHER_UTIL_H_
#define _WESTON_LAUNCHER_UTIL_H_
#include "compositor.h"
int
weston_launcher_open(struct weston_compositor *compositor,
const char *path, int flags);
int
weston_launcher_drm_set_master(struct weston_compositor *compositor,
int drm_fd, char master);
#endif

@ -81,7 +81,6 @@ try_open_vt(struct tty *tty)
{
int tty0, fd;
char filename[16];
struct vt_stat vts;
tty0 = open("/dev/tty0", O_WRONLY | O_CLOEXEC);
if (tty0 < 0) {
@ -102,18 +101,6 @@ try_open_vt(struct tty *tty)
if (fd < 0)
return fd;
if (ioctl(fd, VT_GETSTATE, &vts) == 0)
tty->starting_vt = vts.v_active;
else
tty->starting_vt = tty->vt;
if (ioctl(fd, VT_ACTIVATE, tty->vt) < 0 ||
ioctl(fd, VT_WAITACTIVE, tty->vt) < 0) {
fprintf(stderr, "failed to swtich to new vt\n");
close(fd);
return -1;
}
return fd;
}
@ -128,6 +115,7 @@ tty_create(struct weston_compositor *compositor, tty_vt_func_t vt_func,
struct wl_event_loop *loop;
struct stat buf;
char filename[16];
struct vt_stat vts;
tty = malloc(sizeof *tty);
if (tty == NULL)
@ -136,14 +124,22 @@ tty_create(struct weston_compositor *compositor, tty_vt_func_t vt_func,
memset(tty, 0, sizeof *tty);
tty->compositor = compositor;
tty->vt_func = vt_func;
tty->fd = weston_environment_get_fd("WESTON_TTY_FD");
if (tty->fd < 0)
tty->fd = STDIN_FILENO;
if (tty_nr > 0) {
snprintf(filename, sizeof filename, "/dev/tty%d", tty_nr);
fprintf(stderr, "compositor: using %s\n", filename);
tty->fd = open(filename, O_RDWR | O_NOCTTY | O_CLOEXEC);
tty->vt = tty_nr;
} else if (fstat(tty->fd, &buf) == 0 &&
major(buf.st_rdev) == TTY_MAJOR &&
minor(buf.st_rdev) > 0) {
tty->fd = fcntl(0, F_DUPFD_CLOEXEC, 0);
if (tty->fd == STDIN_FILENO)
tty->fd = fcntl(STDIN_FILENO, F_DUPFD_CLOEXEC, 0);
tty->vt = minor(buf.st_rdev);
} else {
/* Fall back to try opening a new VT. This typically
* requires root. */
@ -156,6 +152,19 @@ tty_create(struct weston_compositor *compositor, tty_vt_func_t vt_func,
return NULL;
}
if (ioctl(tty->fd, VT_GETSTATE, &vts) == 0)
tty->starting_vt = vts.v_active;
else
tty->starting_vt = tty->vt;
if (tty->starting_vt != tty->vt) {
if (ioctl(tty->fd, VT_ACTIVATE, tty->vt) < 0 ||
ioctl(tty->fd, VT_WAITACTIVE, tty->vt) < 0) {
fprintf(stderr, "failed to swtich to new vt\n");
return NULL;
}
}
if (tcgetattr(tty->fd, &tty->terminal_attributes) < 0) {
fprintf(stderr, "could not get terminal attributes: %m\n");
goto err;

@ -25,6 +25,9 @@
#include <stdio.h>
#include <math.h>
#include <unistd.h>
#include <fcntl.h>
#include "compositor.h"
WL_EXPORT void
@ -296,3 +299,26 @@ weston_compositor_run_binding(struct weston_compositor *compositor,
}
}
}
WL_EXPORT int
weston_environment_get_fd(const char *env)
{
char *e, *end;
int fd, flags;
e = getenv(env);
if (!e)
return -1;
fd = strtol(e, &end, 0);
if (*end != '\0')
return -1;
flags = fcntl(fd, F_GETFD);
if (flags == -1)
return -1;
fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
unsetenv(env);
return fd;
}

@ -0,0 +1,639 @@
/*
* Copyright © 2012 Benjamin Franzke
*
* 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 name of the copyright holders not be used in
* advertising or publicity pertaining to distribution of the software
* without specific, written prior permission. The copyright holders make
* no representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*
* THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
* SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS 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.
*/
#define _GNU_SOURCE
#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <error.h>
#include <getopt.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <sys/socket.h>
#include <sys/epoll.h>
#include <sys/signalfd.h>
#include <signal.h>
#include <unistd.h>
#include <fcntl.h>
#include <termios.h>
#include <linux/vt.h>
#include <linux/major.h>
#include <pwd.h>
#include <grp.h>
#include <security/pam_appl.h>
#include <xf86drm.h>
#ifdef HAVE_SYSTEMD_LOGIN
#include <systemd/sd-login.h>
#endif
#include "weston-launch.h"
struct weston_launch {
struct pam_conv pc;
pam_handle_t *ph;
int tty;
int ttynr;
int sock[2];
struct passwd *pw;
int epollfd;
int signalfd;
pid_t child;
int verbose;
};
static gid_t *
read_groups(void)
{
int n;
gid_t *groups;
n = getgroups(0, NULL);
groups = malloc(n * sizeof(gid_t));
if (!groups)
return NULL;
if (getgroups(n, groups) < 0) {
free(groups);
return NULL;
}
return groups;
}
static int
weston_launch_allowed(struct weston_launch *wl)
{
struct group *gr;
gid_t *groups;
int i;
#ifdef HAVE_SYSTEMD_LOGIN
char *session, *seat;
int err;
#endif
if (getuid() == 0)
return 1;
gr = getgrnam("weston-launch");
if (gr) {
groups = read_groups();
if (groups) {
for (i = 0; groups[i]; ++i) {
if (groups[i] == gr->gr_gid) {
free(groups);
return 1;
}
}
free(groups);
}
}
#ifdef HAVE_SYSTEMD_LOGIN
err = sd_pid_get_session(getpid(), &session);
if (err == 0 && session) {
if (sd_session_is_active(session) &&
sd_session_get_seat(session, &seat) == 0) {
free(seat);
free(session);
return 1;
}
free(session);
}
#endif
return 0;
}
static int
pam_conversation_fn(int msg_count,
const struct pam_message **messages,
struct pam_response **responses,
void *user_data)
{
return PAM_SUCCESS;
}
static int
setup_pam(struct weston_launch *wl)
{
int err;
wl->pc.conv = pam_conversation_fn;
wl->pc.appdata_ptr = wl;
err = pam_start("login", wl->pw->pw_name, &wl->pc, &wl->ph);
err = pam_set_item(wl->ph, PAM_TTY, ttyname(wl->tty));
if (err != PAM_SUCCESS) {
fprintf(stderr, "failed to set PAM_TTY item: %d: %s\n",
err, pam_strerror(wl->ph, err));
return -1;
}
err = pam_open_session(wl->ph, 0);
if (err != PAM_SUCCESS) {
fprintf(stderr, "failed to open pam session: %d: %s\n",
err, pam_strerror(wl->ph, err));
return -1;
}
return 0;
}
static int
setup_launcher_socket(struct weston_launch *wl)
{
struct epoll_event ev;
if (socketpair(AF_LOCAL, SOCK_DGRAM, 0, wl->sock) < 0)
error(1, errno, "socketpair failed");
fcntl(wl->sock[0], F_SETFD, O_CLOEXEC);
memset(&ev, 0, sizeof ev);
ev.events = EPOLLIN;
ev.data.fd = wl->sock[0];
if (epoll_ctl(wl->epollfd, EPOLL_CTL_ADD, ev.data.fd, &ev) < 0)
return -errno;
return 0;
}
static int
setup_signals(struct weston_launch *wl)
{
sigset_t mask;
struct sigaction sa;
struct epoll_event ev;
memset(&sa, 0, sizeof sa);
sa.sa_handler = SIG_DFL;
sa.sa_flags = SA_NOCLDSTOP | SA_RESTART;
assert(sigaction(SIGCHLD, &sa, NULL) == 0);
assert(sigemptyset(&mask) == 0);
sigaddset(&mask, SIGCHLD);
sigaddset(&mask, SIGINT);
sigaddset(&mask, SIGTERM);
assert(sigprocmask(SIG_BLOCK, &mask, NULL) == 0);
wl->signalfd = signalfd(-1, &mask, SFD_NONBLOCK | SFD_CLOEXEC);
if (wl->signalfd < 0)
return -errno;
memset(&ev, 0, sizeof ev);
ev.events = EPOLLIN;
ev.data.fd = wl->signalfd;
if (epoll_ctl(wl->epollfd, EPOLL_CTL_ADD, ev.data.fd, &ev) < 0)
return -errno;
return 0;
}
static void
setenv_fd(const char *env, int fd)
{
char buf[32];
snprintf(buf, sizeof buf, "%d", fd);
setenv(env, buf, 1);
}
static int
handle_setmaster(struct weston_launch *wl, struct msghdr *msg, ssize_t len)
{
int drm_fd = -1, ret = -1;
struct cmsghdr *cmsg;
struct weston_launcher_set_master *message;
if (len != sizeof(*message)) {
error(0, 0, "missing value in setmaster request");
goto out;
}
message = msg->msg_iov->iov_base;
cmsg = CMSG_FIRSTHDR(msg);
if (!cmsg ||
cmsg->cmsg_level != SOL_SOCKET ||
cmsg->cmsg_type != SCM_RIGHTS) {
error(0, 0, "invalid control message");
goto out;
}
drm_fd = *(int *) CMSG_DATA(cmsg);
if (drm_fd == -1) {
error(0, 0, "missing drm fd in socket request");
goto out;
}
if (message->set_master)
ret = drmSetMaster(drm_fd);
else
ret = drmDropMaster(drm_fd);
close(drm_fd);
out:
do {
len = send(wl->sock[0], &ret, sizeof ret, 0);
} while (len < 0 && errno == EINTR);
if (len < 0)
return -1;
return 0;
}
static int
handle_open(struct weston_launch *wl, struct msghdr *msg, ssize_t len)
{
int fd = -1, ret = -1;
char control[CMSG_SPACE(sizeof(fd))];
struct cmsghdr *cmsg;
struct stat s;
struct msghdr nmsg;
struct iovec iov;
struct weston_launcher_open *message;
message = msg->msg_iov->iov_base;
if ((size_t)len < sizeof(*message))
goto err0;
/* Ensure path is null-terminated */
((char *) message)[len-1] = '\0';
if (stat(message->path, &s) < 0)
goto err0;
fd = open(message->path, message->flags);
if (fd < 0)
goto err0;
if (major(s.st_rdev) != INPUT_MAJOR) {
close(fd);
fd = -1;
goto err0;
}
err0:
memset(&nmsg, 0, sizeof nmsg);
nmsg.msg_iov = &iov;
nmsg.msg_iovlen = 1;
if (fd != -1) {
nmsg.msg_control = control;
nmsg.msg_controllen = sizeof control;
cmsg = CMSG_FIRSTHDR(&nmsg);
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
cmsg->cmsg_len = CMSG_LEN(sizeof(fd));
*(int *) CMSG_DATA(cmsg) = fd;
nmsg.msg_controllen = cmsg->cmsg_len;
ret = 0;
}
iov.iov_base = &ret;
iov.iov_len = sizeof ret;
if (wl->verbose)
fprintf(stderr, "weston-launch: opened %s: ret: %d, fd: %d\n",
message->path, ret, fd);
do {
len = sendmsg(wl->sock[0], &nmsg, 0);
} while (len < 0 && errno == EINTR);
if (len < 0)
return -1;
return 0;
}
static int
handle_socket_msg(struct weston_launch *wl)
{
char control[CMSG_SPACE(sizeof(int))];
char buf[BUFSIZ];
struct msghdr msg;
struct iovec iov;
int ret = -1;
ssize_t len;
struct weston_launcher_message *message;
memset(&msg, 0, sizeof(msg));
iov.iov_base = buf;
iov.iov_len = sizeof buf;
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_control = control;
msg.msg_controllen = sizeof control;
do {
len = recvmsg(wl->sock[0], &msg, 0);
} while (len < 0 && errno == EINTR);
if (len < 1)
return -1;
message = (void *) buf;
switch (message->opcode) {
case WESTON_LAUNCHER_OPEN:
ret = handle_open(wl, &msg, len);
break;
case WESTON_LAUNCHER_DRM_SET_MASTER:
ret = handle_setmaster(wl, &msg, len);
break;
}
return ret;
}
static void
quit(struct weston_launch *wl, int status)
{
int err;
close(wl->epollfd);
close(wl->signalfd);
close(wl->sock[0]);
err = pam_close_session(wl->ph, 0);
if (err)
fprintf(stderr, "pam_close_session failed: %d: %s\n",
err, pam_strerror(wl->ph, err));
pam_end(wl->ph, err);
exit(status);
}
static int
handle_signal(struct weston_launch *wl)
{
struct signalfd_siginfo sig;
int pid, status;
if (read(wl->signalfd, &sig, sizeof sig) != sizeof sig) {
error(0, errno, "reading signalfd failed");
return -1;
}
switch (sig.ssi_signo) {
case SIGCHLD:
pid = waitpid(-1, &status, 0);
if (pid == wl->child) {
wl->child = 0;
quit(wl, WIFEXITED(status) ? WEXITSTATUS(status) : 0);
}
break;
case SIGTERM:
if (wl->child)
kill(wl->child, SIGTERM);
quit(wl, 0);
break;
case SIGINT:
if (wl->child)
kill(wl->child, SIGTERM);
break;
default:
return -1;
}
return 0;
}
static int
setup_tty(struct weston_launch *wl, const char *tty)
{
struct stat buf;
char *t;
if (tty) {
t = ttyname(STDIN_FILENO);
if (t && strcmp(t, tty) == 0)
wl->tty = STDIN_FILENO;
else
wl->tty = open(tty, O_RDWR | O_NOCTTY);
} else {
int tty0 = open("/dev/tty0", O_WRONLY | O_CLOEXEC);
char filename[16];
if (tty0 < 0)
error(1, errno, "count not open tty0");
if (ioctl(tty0, VT_OPENQRY, &wl->ttynr) < 0 || wl->ttynr == -1)
error(1, errno, "failed to find non-opened console");
snprintf(filename, sizeof filename, "/dev/tty%d", wl->ttynr);
wl->tty = open(filename, O_RDWR | O_NOCTTY);
close(tty0);
}
if (wl->tty < 0)
error(1, errno, "failed to open tty");
if (tty) {
if (fstat(wl->tty, &buf) < 0)
error(1, errno, "stat %s failed", tty);
if (major(buf.st_rdev) != TTY_MAJOR)
error(1, 0, "invalid tty device: %s", tty);
wl->ttynr = minor(buf.st_rdev);
}
return 0;
}
static void
help(const char *name)
{
fprintf(stderr, "Usage: %s [args...] [-- [weston args..]]\n", name);
fprintf(stderr, " -u, --user Start session as specified username\n");
fprintf(stderr, " -t, --tty Start session on alternative tty device\n");
fprintf(stderr, " -v, --verbose Be verbose\n");
fprintf(stderr, " -s, --sleep Sleep specified amount of time before exec\n");
fprintf(stderr, " -h, --help Display this help message\n");
}
int
main(int argc, char *argv[])
{
struct weston_launch wl;
char **env;
int i, c;
char **child_argv;
char *tty = NULL, *new_user = NULL;
int sleep_fork = 0;
struct option opts[] = {
{ "user", required_argument, NULL, 'u' },
{ "tty", required_argument, NULL, 't' },
{ "verbose", no_argument, NULL, 'v' },
{ "sleep", optional_argument, NULL, 's' },
{ "help", no_argument, NULL, 'h' },
{ 0, 0, NULL, 0 }
};
memset(&wl, 0, sizeof wl);
while ((c = getopt_long(argc, argv, "u:t:s::vh", opts, &i)) != -1) {
switch (c) {
case 'u':
new_user = optarg;
if (getuid() != 0)
error(1, 0, "Permission denied. -u allowed for root only");
break;
case 't':
tty = optarg;
break;
case 'v':
wl.verbose = 1;
break;
case 's':
if (optarg)
sleep_fork = atoi(optarg);
else
sleep_fork = 10;
break;
case 'h':
help("weston");
exit(1);
}
}
child_argv = &argv[optind-1];
child_argv[0] = BINDIR "/weston";
if (new_user)
wl.pw = getpwnam(new_user);
else
wl.pw = getpwuid(getuid());
if (wl.pw == NULL)
error(1, errno, "failed to get username");
if (!weston_launch_allowed(&wl))
error(1, 0, "Permission denied. You should..\n"
#ifdef HAVE_SYSTEMD_LOGIN
" - run from an active and local (systemd) session.\n"
#else
" - enable systemd session support for weston-launch.\n"
#endif
" - add yourself to the 'weston-launch' group.");
if (setup_tty(&wl, tty) < 0)
return 1;
if (setup_pam(&wl) < 0)
return 1;
wl.epollfd = epoll_create1(EPOLL_CLOEXEC);
if (wl.epollfd < 0)
error(1, errno, "epoll create failed");
if (setup_launcher_socket(&wl) < 0)
return 1;
if (setup_signals(&wl) < 0)
return 1;
switch ((wl.child = fork())) {
case -1:
error(1, errno, "fork failed");
break;
case 0:
if (wl.verbose)
printf("weston-launch: spawned weston with pid: %d\n", getpid());
if (wl.tty != STDIN_FILENO) {
if (setsid() < 0)
error(1, errno, "setsid failed");
if (ioctl(wl.tty, TIOCSCTTY, 0) < 0)
error(1, errno, "TIOCSCTTY failed - tty is in use");
}
if (setgid(wl.pw->pw_gid) < 0 ||
setuid(wl.pw->pw_uid) < 0)
error(1, errno, "dropping privilidges failed");
if (sleep_fork) {
if (wl.verbose)
printf("weston-launch: waiting %d seconds\n", sleep_fork);
sleep(sleep_fork);
}
if (new_user) {
setenv("USER", wl.pw->pw_name, 1);
setenv("LOGNAME", wl.pw->pw_name, 1);
setenv("HOME", wl.pw->pw_dir, 1);
setenv("SHELL", wl.pw->pw_shell, 1);
}
env = pam_getenvlist(wl.ph);
if (env) {
for (i = 0; env[i]; ++i) {
if (putenv(env[i]) < 0)
error(0, 0, "putenv %s failed", env[i]);
}
free(env);
}
if (wl.tty != STDIN_FILENO)
setenv_fd("WESTON_TTY_FD", wl.tty);
setenv_fd("WESTON_LAUNCHER_SOCK", wl.sock[1]);
unsetenv("DISPLAY");
execv(child_argv[0], child_argv);
error(1, errno, "exec failed");
break;
default:
close(wl.sock[1]);
if (wl.tty != STDIN_FILENO)
close(wl.tty);
while (1) {
struct epoll_event ev;
int n;
n = epoll_wait(wl.epollfd, &ev, 1, -1);
if (n < 0)
error(0, errno, "epoll_wait failed");
if (n != 1)
continue;
if (ev.data.fd == wl.sock[0])
handle_socket_msg(&wl);
else if (ev.data.fd == wl.signalfd)
handle_signal(&wl);
}
break;
}
return 0;
}

@ -0,0 +1,46 @@
/*
* Copyright © 2012 Benjamin Franzke
*
* 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 name of the copyright holders not be used in
* advertising or publicity pertaining to distribution of the software
* without specific, written prior permission. The copyright holders make
* no representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*
* THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
* SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS 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.
*/
#ifndef _WESTON_LAUNCH_H_
#define _WESTON_LAUNCH_H_
enum weston_launcher_opcode {
WESTON_LAUNCHER_OPEN,
WESTON_LAUNCHER_DRM_SET_MASTER
};
struct weston_launcher_message {
int opcode;
};
struct weston_launcher_open {
struct weston_launcher_message header;
int flags;
char path[0];
};
struct weston_launcher_set_master {
struct weston_launcher_message header;
int set_master;
};
#endif
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