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authorLennart Poettering <lennart@poettering.net>2012-01-23 23:34:36 +0100
committerLennart Poettering <lennart@poettering.net>2012-01-23 23:34:36 +0100
commit36db9a8d5b36173daf1f622fb544f4c90cfddb67 (patch)
tree3c03fb457b1ae276952db3758731f575859898f9 /src/login/multi-seat-x.c
parent36e43bddd0a4526e77cdae2c922bb29f67bd74ad (diff)
login: add multi-session X wrapper
In preparation for https://bugzilla.gnome.org/show_bug.cgi?id=655380 we decided it's better to include the multi-seat X wrapper in systemd, rather than gdm. (Side effect: this makes this accessible for other DMs) This is a stop-gap for now, until X gins proper multi-seat graphics support at which point this code will go away without replacement.
Diffstat (limited to 'src/login/multi-seat-x.c')
-rw-r--r--src/login/multi-seat-x.c187
1 files changed, 187 insertions, 0 deletions
diff --git a/src/login/multi-seat-x.c b/src/login/multi-seat-x.c
new file mode 100644
index 0000000000..8f3aacdd3a
--- /dev/null
+++ b/src/login/multi-seat-x.c
@@ -0,0 +1,187 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+ This file is part of systemd.
+
+ Copyright 2011 Lennart Poettering
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ systemd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <string.h>
+#include <unistd.h>
+
+#include <libudev.h>
+
+#include "util.h"
+
+int main(int argc, char *argv[]) {
+
+ struct udev *udev = NULL;
+ struct udev_enumerate *enumerator = NULL;
+ struct udev_list_entry *first, *item;
+ int i;
+ const char *seat = NULL;
+ char **new_argv;
+ char *path = NULL, *device_node = NULL;
+ int r;
+ FILE *f = NULL;
+
+ /* This binary will go away as soon as X natively supports
+ * display enumeration with udev in a way that covers both PCI
+ * and USB. */
+
+ /* This will simply determine the fb device id of the graphics
+ * device assigned to a seat and write a configuration file
+ * from it and then spawn the real X server. */
+
+ for (i = 1; i < argc; i++)
+ if (streq(argv[i], "-seat"))
+ seat = argv[i+1];
+
+ if (isempty(seat) || streq(seat, "seat0")) {
+ argv[0] = (char*) X_SERVER;
+ execv(X_SERVER, argv);
+ log_error("Failed to execute real X server: %m");
+ goto fail;
+ }
+
+ udev = udev_new();
+ if (!udev) {
+ log_error("Failed to allocate udev environment.");
+ goto fail;
+ }
+
+ enumerator = udev_enumerate_new(udev);
+ if (!enumerator) {
+ log_error("Failed to allocate udev enumerator.");
+ goto fail;
+ }
+
+ udev_enumerate_add_match_subsystem(enumerator, "graphics");
+ udev_enumerate_add_match_tag(enumerator, seat);
+
+ r = udev_enumerate_scan_devices(enumerator);
+ if (r < 0) {
+ log_error("Failed to enumerate devices.");
+ goto fail;
+ }
+
+ first = udev_enumerate_get_list_entry(enumerator);
+ udev_list_entry_foreach(item, first) {
+ struct udev_device *d;
+ const char *dn;
+
+ d = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item));
+ if (!d)
+ continue;
+
+ dn = udev_device_get_devnode(d);
+
+ if (!dn) {
+ device_node = strdup(dn);
+ if (!device_node) {
+ udev_device_unref(d);
+ log_error("Out of memory.");
+ goto fail;
+ }
+ }
+
+ udev_device_unref(d);
+
+ if (device_node)
+ break;
+ }
+
+ if (!device_node) {
+ log_error("Failed to find device node for seat %s.", seat);
+ goto fail;
+ }
+
+ r = safe_mkdir("/run/systemd/multi-session-x", 0755, 0, 0);
+ if (r < 0) {
+ log_error("Failed to create directory: %s", strerror(-r));
+ goto fail;
+ }
+
+ path = strappend("/run/systemd/multi-session-x/", seat);
+ if (!path) {
+ log_error("Out of memory");
+ goto fail;
+ }
+
+ f = fopen(path, "we");
+ if (!f) {
+ log_error("Failed to write configuration file: %m");
+ goto fail;
+ }
+
+ fprintf(f,
+ "Section \"Device\"\n"
+ " Identifier \"udev\"\n"
+ " Driver \"fbdev\"\n"
+ " Option \"fbdev\" \"%s\"\n"
+ "EndSection\n"
+ "Section \"ServerFlags\"\n"
+ " Option \"AutoAddDevices\" \"True\"\n"
+ " Option \"AllowEmptyInput\" \"True\"\n"
+ "EndSection\n",
+ device_node);
+
+ fflush(f);
+
+ if (ferror(f)) {
+ log_error("Failed to write configuration file: %m");
+ goto fail;
+ }
+
+ fclose(f);
+ f = NULL;
+
+ new_argv = alloca(sizeof(char*) * (argc + 3 + 1));
+ memcpy(new_argv, argv, sizeof(char*) * (argc + 2 + 1));
+
+ new_argv[0] = (char*) X_SERVER;
+ new_argv[argc+0] = (char*) "-config";
+ new_argv[argc+1] = path;
+ new_argv[argc+2] = (char*) "-sharevts";
+ new_argv[argc+3] = NULL;
+
+ udev_enumerate_unref(enumerator);
+ enumerator = NULL;
+
+ udev_unref(udev);
+ udev = NULL;
+
+ free(device_node);
+ device_node = NULL;
+
+ execv(X_SERVER, new_argv);
+ log_error("Failed to execute real X server: %m");
+
+fail:
+ if (enumerator)
+ udev_enumerate_unref(enumerator);
+
+ if (udev)
+ udev_unref(udev);
+
+ free(path);
+ free(device_node);
+
+ if (f)
+ fclose(f);
+
+ return EXIT_FAILURE;
+}