[PATCH] Introduce weston-launch
Tiago Vignatti
tiago.vignatti at linux.intel.com
Wed Feb 1 05:52:54 PST 2012
Cool, looks great at first! Thanks for taking over this work. I have
some comments bellow.
On 01/31/2012 09:22 PM, Benjamin Franzke wrote:
> 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.
you can put this description on the beginning of weston-launch.c.
BTW, weston-launch might be not the best name for it cause the program
is more than just a launcher; it gives the right permissions, launches
the compositor and is then kept alive all the time checking whether drm
or evdev needs some care. Maybe weston-daemon? or something more creative?
> ---
> configure.ac | 16 ++
> src/.gitignore | 1 +
> src/Makefile.am | 25 ++-
> src/compositor-drm.c | 8 +-
> src/compositor.c | 1 +
> src/compositor.h | 4 +
> src/evdev.c | 3 +-
> src/launcher_util.c | 164 +++++++++++++
> src/launcher_util.h | 35 +++
> src/tty.c | 37 ++-
> src/util.c | 26 ++
> src/weston-launch.c | 644 ++++++++++++++++++++++++++++++++++++++++++++++++++
> src/weston-launch.h | 31 +++
> 13 files changed, 975 insertions(+), 20 deletions(-)
> create mode 100644 src/launcher_util.c
> create mode 100644 src/launcher_util.h
> create mode 100644 src/weston-launch.c
> create mode 100644 src/weston-launch.h
>
> diff --git a/configure.ac b/configure.ac
> index 62d36eb..d5d8313 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -139,6 +139,22 @@ if test x$enable_clients == xyes; then
>
> fi
>
> +AC_ARG_ENABLE(weston-launch, [ --enable-weston-launch],, enable_weston_launch=yes)
> +AM_CONDITIONAL(BUILD_WESTON_LAUNCH, test x$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_misc], [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_misc"
> +fi
> +
another thing is the dependency chain we're creating. I already dislike
the fact that I'm not able to start weston without desktop shell and now
we would be adding one more program. Debugging cries. I haven't though
much, but can we have a disjoint solution instead?
> AM_CONDITIONAL(HAVE_POPPLER, test "x$have_poppler" = "xyes")
>
> AM_CONDITIONAL(ENABLE_DESKTOP_SHELL, true)
> diff --git a/src/.gitignore b/src/.gitignore
> index c53b402..56fc1ae 100644
> --- a/src/.gitignore
> +++ b/src/.gitignore
> @@ -1,4 +1,5 @@
> weston
> +weston-launch
> screenshooter-protocol.c
> screenshooter-server-protocol.h
> tablet-shell-protocol.c
> diff --git a/src/Makefile.am b/src/Makefile.am
> index 2c91abc..b1598e9 100644
> --- a/src/Makefile.am
> +++ b/src/Makefile.am
> @@ -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 \
> @@ -61,7 +81,8 @@ drm_backend = drm-backend.la
> drm_backend_la_LDFLAGS = -module -avoid-version
> drm_backend_la_LIBADD = $(COMPOSITOR_LIBS) $(DRM_COMPOSITOR_LIBS)
> drm_backend_la_CFLAGS = $(DRM_COMPOSITOR_CFLAGS) $(GCC_CFLAGS)
> -drm_backend_la_SOURCES = compositor-drm.c tty.c evdev.c evdev.h
> +drm_backend_la_SOURCES = compositor-drm.c tty.c evdev.c evdev.h \
> + launcher_util.c launcher_util.h
> endif
>
> if ENABLE_WAYLAND_COMPOSITOR
> diff --git a/src/compositor-drm.c b/src/compositor-drm.c
> index de6feb4..3b00f48 100644
> --- a/src/compositor-drm.c
> +++ b/src/compositor-drm.c
> @@ -36,6 +36,7 @@
>
> #include "compositor.h"
> #include "evdev.h"
> +#include "launcher_util.h"
>
> struct drm_compositor {
> struct weston_compositor base;
> @@ -841,7 +842,8 @@ drm_destroy(struct weston_compositor *ec)
>
> weston_compositor_shutdown(ec);
> gbm_device_destroy(d->gbm);
> - 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);
>
> wl_list_for_each_safe(input, next,&ec->input_device_list, link)
> @@ -882,7 +884,7 @@ 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);
> }
> @@ -913,7 +915,7 @@ 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;
> diff --git a/src/compositor.c b/src/compositor.c
> index ab184ac..c6a1d2d 100644
> --- a/src/compositor.c
> +++ b/src/compositor.c
> @@ -1991,6 +1991,7 @@ 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))
> diff --git a/src/compositor.h b/src/compositor.h
> index 4bc4ba2..1fca9b6 100644
> --- a/src/compositor.h
> +++ b/src/compositor.h
> @@ -199,6 +199,7 @@ struct weston_compositor {
> int32_t *width, int32_t *height);
>
> struct screenshooter *screenshooter;
> + int launcher_sock;
> };
these two chunks are drm compositor specific. So we have to squash
somewhere in compositor-drm.c.
> #define MODIFIER_CTRL (1<< 8)
> @@ -365,6 +366,9 @@ weston_compositor_run_binding(struct weston_compositor *compositor,
> struct weston_input_device *device,
> uint32_t time,
> uint32_t key, uint32_t button, int32_t state);
> +int
> +weston_environment_get_fd(const char *env);
> +
> struct wl_list *
> weston_compositor_top(struct weston_compositor *compositor);
>
> diff --git a/src/evdev.c b/src/evdev.c
> index f489ede..0096352 100644
> --- a/src/evdev.c
> +++ b/src/evdev.c
> @@ -29,6 +29,7 @@
>
> #include "compositor.h"
> #include "evdev.h"
> +#include "launcher_util.h"
>
> struct evdev_input {
> struct weston_input_device base;
> @@ -456,7 +457,7 @@ evdev_input_device_create(struct evdev_input *master,
> device->rel.dx = 0;
> device->rel.dy = 0;
>
> - device->fd = open(path, O_RDONLY);
> + device->fd = weston_launcher_open(ec, path, O_RDONLY);
> if (device->fd< 0)
> goto err0;
>
> diff --git a/src/launcher_util.c b/src/launcher_util.c
> new file mode 100644
> index 0000000..534203f
> --- /dev/null
> +++ b/src/launcher_util.c
> @@ -0,0 +1,164 @@
> +/*
> + * Copyright © 2011 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, char 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)];
> + char *buf;
> + ssize_t len;
> +
> + fd = open(path, flags);
> + if (fd> 0)
> + return fd;
> +
you could insert a comment right here explaning what it does when is not
possible to open the fd (for instance, I spent like 5 minutes trying to
understand the socket talk and negotiation that happens between
compositor and daemon). And "socket" is better than "sock" :)
> + if (sock == -1)
> + return -1;
> +
> + n = 2 + strlen(path) + 1;
> + buf = malloc(n);
> + if (!buf)
> + return -1;
> +
> + buf[0] = WESTON_LAUNCHER_OPEN;
> + buf[1] = flags;
> + strcpy(&buf[2], path);
> +
> + do {
> + len = send(sock, buf, 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, 0);
> + } 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;
> + }
> + fcntl(fd, F_SETFD, FD_CLOEXEC);
> +
> +out:
> + free(buf);
> + 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;
> + char buf[2];
> +
> + if (master)
> + ret = drmSetMaster(drm_fd);
> + else
> + ret = drmDropMaster(drm_fd);
> + if (ret == 0)
> + return 0;
> +
> + if (compositor->launcher_sock == -1)
> + return -1;
> +
> + 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 = buf;
> + iov.iov_len = sizeof buf;
> +
> + buf[0] = WESTON_LAUNCHER_DRM_SET_MASTER;
> + buf[1] = 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;
> +}
> +
> diff --git a/src/launcher_util.h b/src/launcher_util.h
> new file mode 100644
> index 0000000..e9ee33b
> --- /dev/null
> +++ b/src/launcher_util.h
> @@ -0,0 +1,35 @@
> +/*
> + * Copyright © 2011 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, char flags);
> +int
> +weston_launcher_drm_set_master(struct weston_compositor *compositor,
> + int drm_fd, char master);
> +
> +#endif
> diff --git a/src/tty.c b/src/tty.c
> index 249f5bb..e556fc8 100644
> --- a/src/tty.c
> +++ b/src/tty.c
> @@ -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. */
> @@ -155,6 +151,19 @@ 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");
> return NULL;
> diff --git a/src/util.c b/src/util.c
> index ee8e7cf..5704f1b 100644
> --- a/src/util.c
> +++ b/src/util.c
> @@ -25,6 +25,9 @@
> #include<stdio.h>
> #include<math.h>
>
> +#include<unistd.h>
> +#include<fcntl.h>
> +
> #include "compositor.h"
>
> WL_EXPORT void
> @@ -247,3 +250,26 @@ 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;
> +}
> diff --git a/src/weston-launch.c b/src/weston-launch.c
> new file mode 100644
> index 0000000..4e9d1c2
> --- /dev/null
> +++ b/src/weston-launch.c
> @@ -0,0 +1,644 @@
> +/*
> + * Copyright © 2011 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;
> + char set_master;
> +
> + if (len != 2) {
> + error(0, 0, "missing value in setmaster request");
> + goto out;
> + }
> +
> + set_master = ((char *)msg->msg_iov->iov_base)[1];
> +
> + 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 (set_master)
> + ret = drmSetMaster(drm_fd);
> + else
> + ret = drmDropMaster(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)
> +{
> + char flags, *path;
> + int fd = -1, ret = -1;
> + char control[CMSG_SPACE(sizeof(fd))];
> + struct cmsghdr *cmsg;
> + struct stat s;
> + struct msghdr nmsg;
> + struct iovec iov;
> + char *in;
> +
> + in = msg->msg_iov->iov_base;
> + in[len] = '\0';
> +
> + if (len< 3)
> + goto err0;
> +
> + flags = in[1];
> + path =&in[2];
> +
> + if (stat(path,&s)< 0)
> + goto err0;
> +
> + fd = open(path, 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",
> + 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;
> +
> + 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;
> +
> + switch (buf[0]) {
> + 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...] [-- [/path/to/weston] [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, *t;
> + 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];
> +
> + if ((argc - optind) == 0 ||
> + (child_argv[0][0] != '.'&& child_argv[0][0] != '/')) {
> + child_argv--;
> + child_argv[0] = BINDIR "/weston";
> + }
you can probably fold all this option getting procedure in another
function in order to make main() more light..
> + 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"
> + " - run from an active and local (systemd) session.\n"
> + " - 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");
type in "privilidges".
> +
> + if (sleep_fork) {
do we need sleep_fork really?
> + 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]);
> +
> + t = getenv("WESTON_LIBRARY_PATH");
> + if (t)
> + setenv("LD_LIBRARY_PATH", t, 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;
> +}
> diff --git a/src/weston-launch.h b/src/weston-launch.h
> new file mode 100644
> index 0000000..2544d46
> --- /dev/null
> +++ b/src/weston-launch.h
> @@ -0,0 +1,31 @@
> +/*
> + * Copyright © 2011 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
> +};
> +
> +#endif
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