First version

4 files changed, 537 insertions, 0 deletions

diff --git a/Makefile.am b/Makefile.am
new file mode 100644
index 0000000..697f89c
--- /dev/null
+++ b/Makefile.am
@@ -0,0 +1,41 @@
+#
+# Copyright © 2018 Keith Packard
+#
+# 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.
+#
+
+bin_PROGRAMS = xlease
+
+AM_CFLAGS = $(XLEASE_CFLAGS)
+xlease_LDADD = $(XLEASE_LIBS)
+
+xlease_SOURCES =	\
+        xlease.c
+
+MAINTAINERCLEANFILES = ChangeLog INSTALL
+
+.PHONY: ChangeLog INSTALL
+
+INSTALL:
+	$(INSTALL_CMD)
+
+ChangeLog:
+	$(CHANGELOG_CMD)
+
+dist-hook: ChangeLog INSTALL
diff --git a/autogen.sh b/autogen.sh
new file mode 100755
index 0000000..fc34bd5
--- /dev/null
+++ b/autogen.sh
@@ -0,0 +1,14 @@
+#! /bin/sh
+
+srcdir=`dirname $0`
+test -z "$srcdir" && srcdir=.
+
+ORIGDIR=`pwd`
+cd $srcdir
+
+autoreconf -v --install || exit 1
+cd $ORIGDIR || exit $?
+
+if test -z "$NOCONFIGURE"; then
+    $srcdir/configure "$@"
+fi
diff --git a/configure.ac b/configure.ac
new file mode 100644
index 0000000..783531e
--- /dev/null
+++ b/configure.ac
@@ -0,0 +1,48 @@
+dnl
+dnl Copyright © 2018 Keith Packard
+dnl
+dnl Permission to use, copy, modify, distribute, and sell this software and its
+dnl documentation for any purpose is hereby granted without fee, provided that
+dnl the above copyright notice appear in all copies and that both that copyright
+dnl notice and this permission notice appear in supporting documentation, and
+dnl that the name of the copyright holders not be used in advertising or
+dnl publicity pertaining to distribution of the software without specific,
+dnl written prior permission.  The copyright holders make no representations
+dnl about the suitability of this software for any purpose.  It is provided "as
+dnl is" without express or implied warranty.
+dnl
+dnl THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+dnl INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+dnl EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+dnl CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+dnl DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+dnl TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+dnl OF THIS SOFTWARE.
+dnl
+dnl Process this file with autoconf to create configure.
+
+# Initialize Autoconf
+AC_PREREQ([2.60])
+AC_INIT([xlease], [1.0],
+        [https://bugs.freedesktop.org/enter_bug.cgi?product=xorg], [xlease])
+AC_CONFIG_SRCDIR([Makefile.am])
+AC_CONFIG_HEADERS([config.h])
+
+# Initialize Automake
+AM_INIT_AUTOMAKE([foreign dist-bzip2])
+
+# Require X.Org macros 1.8 or later for MAN_SUBSTS set by XORG_MANPAGE_SECTIONS
+m4_ifndef([XORG_MACROS_VERSION],
+          [m4_fatal([must install xorg-macros 1.8 or later before running autoconf/autogen])])
+XORG_MACROS_VERSION(1.8)
+XORG_DEFAULT_OPTIONS
+
+# Checks for pkg-config packages
+PKG_CHECK_MODULES(XLEASE, [randrproto >= 1.6.0] xcb xcb-randr)
+
+AC_CONFIG_FILES([
+	Makefile
+	])
+
+AC_OUTPUT
+
diff --git a/xlease.c b/xlease.c
new file mode 100644
index 0000000..79c48ec
--- /dev/null
+++ b/xlease.c
@@ -0,0 +1,434 @@
+/*
+ * Copyright © 2018 Keith Packard
+ *
+ * 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 <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <limits.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <getopt.h>
+#include <xcb/randr.h>
+
+char *default_x_server[] = {
+	"X",
+	NULL
+};
+
+#define DEFAULT_ENV		"XF86_VIDEO_MODESETTING_FD"
+
+/* Lease an output from X and start an X server running on it */
+
+/* Information about one lease */
+typedef struct {
+	int fd;
+
+	/* X resources */
+	xcb_randr_output_t randr_output;
+	xcb_randr_crtc_t randr_crtc;
+	xcb_randr_lease_t randr_lease;
+	xcb_randr_mode_info_t randr_mode;
+
+} lease_t;
+
+/* Global information */
+typedef struct {
+	char *display;
+	char *output_name;
+	char **xserver;
+	char *env;
+	char *shell;
+	int verbose;
+	xcb_connection_t *conn;
+	xcb_window_t root;
+	xcb_timestamp_t config_timestamp;
+	uint8_t event_base;
+	uint8_t error_base;
+	xcb_randr_get_screen_resources_reply_t *gsr_r;
+} app_t;
+
+/*
+ * Create a lease for the desired output, select a crtc if none was
+ * provided.
+ */
+static int
+make_randr_lease(app_t *app, lease_t *lease, xcb_randr_output_t output, xcb_randr_crtc_t crtc, bool whinge, xcb_generic_error_t **error)
+{
+	/* Pick a crtc if none was provided */
+	if (crtc == XCB_NONE) {
+		xcb_randr_crtc_t    *rc = xcb_randr_get_screen_resources_crtcs(app->gsr_r);
+
+		xcb_randr_crtc_t    idle_crtc = XCB_NONE;
+		xcb_randr_crtc_t    active_crtc = XCB_NONE;
+
+		/* Find either a crtc already connected to the desired output or idle */
+		for (int c = 0; active_crtc == XCB_NONE && c < app->gsr_r->num_crtcs; c++) {
+			xcb_randr_get_crtc_info_cookie_t gci_c = xcb_randr_get_crtc_info(app->conn, rc[c], app->gsr_r->config_timestamp);
+
+			xcb_randr_get_crtc_info_reply_t *gci_r = xcb_randr_get_crtc_info_reply(app->conn, gci_c, NULL);
+
+			if (gci_r->mode) {
+				int num_outputs = xcb_randr_get_crtc_info_outputs_length(gci_r);
+				xcb_randr_output_t *outputs = xcb_randr_get_crtc_info_outputs(gci_r);
+				for (int o = 0; o < num_outputs; o++)
+					if (outputs[o] == output && num_outputs == 1) {
+						active_crtc = rc[c];
+						break;
+					}
+
+			} else if (idle_crtc == 0) {
+				int num_possible = xcb_randr_get_crtc_info_possible_length(gci_r);
+				xcb_randr_output_t *possible = xcb_randr_get_crtc_info_possible(gci_r);
+				for (int p = 0; p < num_possible; p++)
+					if (possible[p] == output) {
+						idle_crtc = rc[c];
+						break;
+					}
+			}
+
+			free(gci_r);
+		}
+		if (active_crtc)
+			crtc = active_crtc;
+		else
+			crtc = idle_crtc;
+
+	}
+
+	if (crtc == XCB_NONE) {
+		if (whinge)
+			printf("\t\tcannot find usable CRTC\n");
+		return 0;
+	}
+
+	/*
+	 * Create a RandR lease
+	 */
+
+	xcb_randr_lease_t                   randr_lease = xcb_generate_id(app->conn);
+
+	xcb_randr_create_lease_cookie_t     cl_c = xcb_randr_create_lease(app->conn,
+									  app->root,
+									  randr_lease,
+									  1,
+									  1,
+									  &crtc,
+									  &output);
+	xcb_randr_create_lease_reply_t      *cl_r = xcb_randr_create_lease_reply(app->conn, cl_c, error);
+	if (!cl_r) {
+		if (whinge)
+			printf ("create lease failed\n");
+		return 0;
+	}
+
+	int fd = -1;
+	if (cl_r->nfd > 0) {
+		int *rcl_f = xcb_randr_create_lease_reply_fds(app->conn, cl_r);
+
+		fd = rcl_f[0];
+	}
+	free (cl_r);
+	if (fd < 0) {
+		if (whinge)
+			printf("\t\tLease returned invalid fd\n");
+		return 0;
+	}
+
+	lease->fd = fd;
+	lease->randr_output = output;
+	lease->randr_crtc = crtc;
+	lease->randr_lease = randr_lease;
+
+	return 1;
+}
+
+static void
+init_lease(lease_t *lease)
+{
+	memset(lease, 0, sizeof (*lease));
+	lease->fd = -1;
+}
+
+static void
+init_app(app_t *app)
+{
+	memset(app, 0, sizeof (*app));
+}
+
+static int
+make_lease(app_t *app, lease_t *lease, xcb_randr_output_t output)
+{
+	init_lease(lease);
+
+	if (!make_randr_lease(app, lease, output, XCB_NONE, true, NULL))
+		return 0;
+
+	return 1;
+}
+
+static void
+free_randr_lease(app_t *app, lease_t *lease)
+{
+	if (lease->randr_lease) {
+		xcb_randr_free_lease(app->conn, lease->randr_lease, 0);
+		free(xcb_get_input_focus_reply(app->conn, xcb_get_input_focus(app->conn), NULL));
+		lease->randr_lease = 0;
+	}
+}
+
+static void
+close_kernel_lease(app_t *app, lease_t *lease)
+{
+	if (lease->fd >= 0) {
+		close(lease->fd);
+		lease->fd = -1;
+	}
+}
+
+static void
+close_lease(app_t *app, lease_t *lease)
+{
+	close_kernel_lease(app, lease);
+	free_randr_lease(app, lease);
+}
+
+static void
+describe_error(app_t *app, xcb_generic_error_t *error)
+{
+	if (error->error_code <= XCB_IMPLEMENTATION) {
+		fprintf(stderr, "Core error %d\n", error->error_code);
+	} else {
+		switch (error->error_code - app->error_base) {
+		case XCB_RANDR_BAD_OUTPUT:
+			fprintf(stderr, "bad output\n"); break;
+		case XCB_RANDR_BAD_CRTC:
+			fprintf(stderr, "bad crtc\n"); break;
+		case XCB_RANDR_BAD_MODE:
+			fprintf(stderr, "bad mode\n"); break;
+		case XCB_RANDR_BAD_PROVIDER:
+			fprintf(stderr, "bad provider\n"); break;
+		default:
+			fprintf(stderr, "error code %d\n", error->error_code);
+		}
+	}
+}
+
+static int
+app_setup(app_t *app)
+{
+	int screen;
+
+	app->conn = xcb_connect(app->display, &screen);
+
+	if (!app->conn) {
+		fprintf(stderr, "Cannot connect to X server\n");
+		return 0;
+	}
+
+	const xcb_setup_t                    *setup = xcb_get_setup(app->conn);
+
+	/*
+	 * Find our root window
+	 */
+	xcb_screen_iterator_t iter;
+	for (iter = xcb_setup_roots_iterator(setup); iter.rem; xcb_screen_next(&iter)) {
+		if (screen == 0) {
+			app->root = iter.data->root;
+			break;
+		}
+		--screen;
+	}
+
+	const xcb_query_extension_reply_t     *qer = xcb_get_extension_data(app->conn, &xcb_randr_id);
+
+	if (!qer) {
+		fprintf(stderr, "Cannot get randr extension data\n");
+		xcb_disconnect(app->conn);
+		return 0;
+	}
+
+	app->error_base = qer->first_error;
+	app->event_base = qer->first_event;
+
+	return 1;
+}
+
+static int
+app_get_randr_resources(app_t *app)
+{
+    if (app->gsr_r) {
+        free(app->gsr_r);
+        app->gsr_r = NULL;
+    }
+
+    xcb_randr_get_screen_resources_cookie_t gsr_c = xcb_randr_get_screen_resources(app->conn, app->root);
+
+    xcb_generic_error_t *error;
+
+    app->gsr_r = xcb_randr_get_screen_resources_reply(app->conn, gsr_c, &error);
+
+    if (!app->gsr_r) {
+        printf("\t\tget_screen_resources failed\n");
+        if (error)
+            describe_error(app, error);
+        return 0;
+    }
+
+    app->config_timestamp = app->gsr_r->config_timestamp;
+
+    return 1;
+}
+
+static void
+app_fini(app_t *app)
+{
+    free(app->gsr_r);
+    app->gsr_r = NULL;
+
+    xcb_disconnect(app->conn);
+    app->conn = NULL;
+}
+
+static const struct option options[] = {
+	{ .name = "output", .has_arg = 1, .val = 'o' },
+	{ .name = "display", .has_arg = 1, .val = 'd' },
+	{ .name = "help", .has_arg = 0, .val = '?' },
+	{ .name = "verbose", .has_arg = 0, .val = 'v' },
+	{ .name = "env", .has_arg = 1, .val = 'e' },
+	{ 0 },
+};
+
+static void usage(char *program, int code)
+{
+	fprintf(stderr, "usage: %s [--display=<display>] [--output=<output>] [--env=<name>] [--verbose] [--help] {X server ...}\n", program);
+	exit(code);
+}
+
+int main (int argc, char **argv)
+{
+	app_t app;
+	int c;
+
+	init_app(&app);
+
+	app.xserver = default_x_server;
+	app.env = DEFAULT_ENV;
+
+	while ((c = getopt_long(argc, argv, "?vo:d:x:s:", options, NULL)) != -1) {
+		switch (c) {
+		case 'v':
+			app.verbose++;
+			break;
+		case 'd':
+			app.display = optarg;
+			break;
+		case 'o':
+			app.output_name = optarg;
+			break;
+		case 'e':
+			app.env = optarg;
+			break;
+		case '?':
+			usage(argv[0], 0);
+			break;
+		default:
+			usage(argv[0], 1);
+			break;
+		}
+	}
+
+	if (optind < argc)
+		app.xserver = &argv[optind];
+
+	if (!app.output_name) {
+		fprintf(stderr, "No output specified\n");
+		exit(1);
+	}
+
+        if (!app_setup(&app))
+		exit(1);
+
+	if (!app_get_randr_resources(&app))
+                exit(1);
+
+	xcb_randr_output_t	*ro = xcb_randr_get_screen_resources_outputs(app.gsr_r);
+	int			num_outputs = app.gsr_r->num_outputs;
+
+	int			o;
+
+	xcb_randr_output_t	output = XCB_NONE;
+
+	for (o = 0; o < num_outputs; o++) {
+
+		xcb_randr_get_output_info_cookie_t  goi_c = xcb_randr_get_output_info(app.conn, ro[o], app.config_timestamp);
+
+		xcb_randr_get_output_info_reply_t   *goi_r = xcb_randr_get_output_info_reply(app.conn, goi_c, NULL);
+
+		uint8_t                             *output_name = xcb_randr_get_output_info_name(goi_r);
+		int                                 output_name_length = xcb_randr_get_output_info_name_length(goi_r);
+
+		if (output_name_length == strlen(app.output_name) &&
+		    memcmp(output_name, app.output_name, output_name_length) == 0)
+		{
+			output = ro[o];
+			break;
+		}
+	}
+
+	if (!output) {
+		fprintf(stderr, "%s: no such output\n", app.output_name);
+		exit(1);
+	}
+
+	lease_t	lease;
+
+	init_lease(&lease);
+
+	if (!make_lease(&app, &lease, output)) {
+		fprintf(stderr, "%s: lease create failed\n", app.output_name);
+		exit(1);
+	}
+
+	xcb_disconnect(app.conn);
+
+	char *fd_string;
+
+	if (asprintf(&fd_string, "%d", lease.fd) <= 0) {
+		perror("asprintf");
+		exit(1);
+	}
+
+	if (setenv(app.env, fd_string, 1) < 0) {
+		perror("setenv");
+		exit(1);
+	}
+
+	if (execvp(app.xserver[0], app.xserver)) {
+		perror(app.xserver[0]);
+		exit(1);
+	}
+
+	exit(0);
+}