Merge pull request #173 from gicmo/pidfds

Introduce a new pidfd based set of D-Bus APIs

common/common-helpers.c

@@ -39,3 +39,4 @@ POSSIBILITY OF SUCH DAMAGE.
  * a specific call to the function the linker will expect an definition.
  */
 extern inline void cleanup_close(int *fd);
+extern inline void cleanup_free(void *ptr);

common/common-helpers.h

@@ -31,6 +31,7 @@ POSSIBILITY OF SUCH DAMAGE.
 
 #pragma once
 
+#include <stdlib.h>
 #include <string.h>
 #include <sys/param.h>
 #include <unistd.h>
@@ -80,3 +81,23 @@ inline void cleanup_close(int *fd_ptr)
  * like "autoclose_fd int fd = -1;".
  */
 #define autoclose_fd __attribute__((cleanup(cleanup_close)))
+
+/**
+ * Helper function for auto-freeing dynamically allocated memory. Does nothing
+ * if *ptr is NULL (ptr must not be NULL).
+ */
+inline void cleanup_free(void *ptr)
+{
+	/* The function is defined to work with 'void *' because
+	 * that will make sure it compiles without warning also
+	 * for all types; what we are getting passed into is a
+	 * pointer to a pointer though, so we need to cast */
+	void *target = *(void **)ptr;
+	free(target); /* free can deal with NULL */
+}
+
+/**
+ * Helper macro for auto-freeing dynamically allocated memory: use by
+ * prefixing the variable, like "autofree char *data = NULL;".
+ */
+#define autofree __attribute__((cleanup(cleanup_free)))

common/common-pidfds.c

@@ -0,0 +1,207 @@
+/*
+
+Copyright (c) 2017-2019, Feral Interactive
+Copyright (c) 2019, Red Hat
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+ * Redistributions of source code must retain the above copyright notice,
+   this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution.
+ * Neither the name of Feral Interactive nor the names of its contributors
+   may be used to endorse or promote products derived from this software
+   without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+
+*/
+#define _GNU_SOURCE
+#include <build-config.h>
+
+#include "common-helpers.h"
+#include "common-pidfds.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#if !HAVE_FN_PIDFD_OPEN
+#include <sys/syscall.h>
+
+#ifndef __NR_pidfd_open
+#define __NR_pidfd_open 434
+#endif
+
+static int pidfd_open(pid_t pid, unsigned int flags)
+{
+	return (int)syscall(__NR_pidfd_open, pid, flags);
+}
+#endif
+
+/* pidfd functions */
+int open_pidfds(pid_t *pids, int *fds, int count)
+{
+	int i = 0;
+
+	for (i = 0; i < count; i++) {
+		int pid = pids[i];
+		int fd = pidfd_open(pid, 0);
+
+		if (fd < 0)
+			break;
+
+		fds[i] = fd;
+	}
+
+	return i;
+}
+
+static int parse_pid(const char *str, pid_t *pid)
+{
+	unsigned long long int v;
+	char *end;
+	pid_t p;
+
+	errno = 0;
+	v = strtoull(str, &end, 0);
+	if (end == str)
+		return -ENOENT;
+	else if (errno != 0)
+		return -errno;
+
+	p = (pid_t)v;
+
+	if (p < 1 || (unsigned long long int)p != v)
+		return -ERANGE;
+
+	if (pid)
+		*pid = p;
+
+	return 0;
+}
+
+static int parse_status_field_pid(const char *val, pid_t *pid)
+{
+	const char *t;
+
+	t = strrchr(val, '\t');
+	if (t == NULL)
+		return -ENOENT;
+
+	return parse_pid(t, pid);
+}
+
+static int pidfd_to_pid(int fdinfo, int pidfd, pid_t *pid)
+{
+	autofree char *key = NULL;
+	autofree char *val = NULL;
+	char name[256] = {
+		0,
+	};
+	bool found = false;
+	FILE *f = NULL;
+	size_t keylen = 0;
+	size_t vallen = 0;
+	ssize_t n;
+	int fd;
+	int r = 0;
+
+	*pid = 0;
+
+	buffered_snprintf(name, "%d", pidfd);
+
+	fd = openat(fdinfo, name, O_RDONLY | O_CLOEXEC | O_NOCTTY);
+
+	if (fd != -1)
+		f = fdopen(fd, "r");
+
+	if (f == NULL)
+		return -errno;
+
+	do {
+		n = getdelim(&key, &keylen, ':', f);
+		if (n == -1) {
+			r = errno;
+			break;
+		}
+
+		n = getdelim(&val, &vallen, '\n', f);
+		if (n == -1) {
+			r = errno;
+			break;
+		}
+
+		// TODO: strstrip (key);
+
+		if (!strncmp(key, "Pid", 3)) {
+			r = parse_status_field_pid(val, pid);
+			found = r > -1;
+		}
+
+	} while (r == 0 && !found);
+
+	fclose(f);
+
+	if (r < 0)
+		return r;
+	else if (!found)
+		return -ENOENT;
+
+	return 0;
+}
+
+int pidfds_to_pids(int *fds, pid_t *pids, int count)
+{
+	int fdinfo = -1;
+	int r = 0;
+	int i;
+
+	fdinfo = open_fdinfo_dir();
+	if (fdinfo == -1)
+		return -1;
+
+	for (i = 0; i < count && r == 0; i++)
+		r = pidfd_to_pid(fdinfo, fds[i], &pids[i]);
+
+	(void)close(fdinfo);
+
+	if (r != 0)
+		errno = -r;
+
+	return i;
+}
+
+/* misc directory helpers */
+int open_fdinfo_dir(void)
+{
+	int fd;
+
+	fd = open("/proc/self/fdinfo", O_RDONLY | O_NONBLOCK | O_DIRECTORY | O_CLOEXEC | O_NOCTTY);
+
+	if (fd == -1)
+		return errno;
+
+	return fd;
+}

common/common-pidfds.h

@@ -0,0 +1,53 @@
+/*
+
+Copyright (c) 2017-2019, Feral Interactive
+Copyright (c) 2019, Red Hat
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+ * Redistributions of source code must retain the above copyright notice,
+   this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution.
+ * Neither the name of Feral Interactive nor the names of its contributors
+   may be used to endorse or promote products derived from this software
+   without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+
+*/
+
+#include <sys/types.h>
+
+/* Open pidfds for up to count process ids specified in pids. The
+ * pointer fds needs to point to an array with at least count
+ * entries. Will stop when it encounters an error (and sets errno).
+ * Returns the number of successfully opened pidfds (or -1 in case
+ * of other errors. */
+int open_pidfds(pid_t *pids, int *fds, int count);
+
+/* Translate up to count process ids to the corresponding process ids.
+ * The pointer pids needs to point to an array with at least count
+ * entries. Will stop when it encounters an error (and sets errno).
+ * Returns the number of successfully translated pidfds (or -1 in
+ * case of other errors. */
+int pidfds_to_pids(int *fds, pid_t *pids, int count);
+
+/* Helper to open the fdinfo directory for the current process, i.e.
+ * does open("/proc/self/fdinfo", ...). Returns the file descriptor
+ * for the directory, ownership is transferred and caller needs to
+ * call close on it. */
+int open_fdinfo_dir(void);

common/meson.build

@@ -5,16 +5,32 @@ common_sources = [
     'common-external.c',
     'common-helpers.c',
     'common-gpu.c',
+    'common-pidfds.c',
 ]
 
 daemon_common = static_library(
     'daemon-common',
     sources: common_sources,
     install: false,
+    include_directories: [config_h_dir]
 )
 
 link_daemon_common = declare_dependency(
     link_with: daemon_common,
+    include_directories: [include_directories('.')]
 )
 
-include_daemon_common = include_directories('.')
+lib_common = static_library(
+    'lib-common',
+    sources: [
+        'common-helpers.c',
+        'common-pidfds.c'
+    ],
+    install: false,
+    include_directories: [config_h_dir]
+)
+
+link_lib_common = declare_dependency(
+    link_with: lib_common,
+    include_directories: [include_directories('.')]
+)

daemon/gamemode-dbus.c

@@ -32,7 +32,9 @@ POSSIBILITY OF SUCH DAMAGE.
 #define _GNU_SOURCE
 
 #include "gamemode.h"
+#include "common-helpers.h"
 #include "common-logging.h"
+#include "common-pidfds.h"
 
 #include <systemd/sd-bus.h>
 #include <systemd/sd-daemon.h>
@@ -169,7 +171,7 @@ static int method_unregister_game_by_pid(sd_bus_message *m, void *userdata,
 }
 
 /**
- * Handles the QueryStatus D-BUS Method
+ * Handles the QueryStatusByPID D-BUS Method
  */
 static int method_query_status_by_pid(sd_bus_message *m, void *userdata,
                                       __attribute__((unused)) sd_bus_error *ret_error)
@@ -188,8 +190,87 @@ static int method_query_status_by_pid(sd_bus_message *m, void *userdata,
 
 	return sd_bus_reply_method_return(m, "i", status);
 }
+
+/**
+ * Handles the RegisterGameByPIDFd D-BUS Method
+ */
+static int method_register_game_by_pidfd(sd_bus_message *m, void *userdata,
+                                         __attribute__((unused)) sd_bus_error *ret_error)
+{
+	int fds[2] = { -1, -1 };
+	pid_t pids[2] = { 0, 0 };
+	GameModeContext *context = userdata;
+
+	int ret = sd_bus_message_read(m, "hh", &fds[0], &fds[1]);
+	if (ret < 0) {
+		LOG_ERROR("Failed to parse input parameters: %s\n", strerror(-ret));
+		return ret;
+	}
+
+	int reply = pidfds_to_pids(fds, pids, 2);
+
+	if (reply == 2)
+		reply = game_mode_context_register(context, pids[0], pids[1]);
+	else
+		reply = -1;
+
+	return sd_bus_reply_method_return(m, "i", reply);
+}
+
 /**
- * Handles the Active D-BUS Method
+ * Handles the UnregisterGameByPIDFd D-BUS Method
+ */
+static int method_unregister_game_by_pidfd(sd_bus_message *m, void *userdata,
+                                           __attribute__((unused)) sd_bus_error *ret_error)
+{
+	int fds[2] = { -1, -1 };
+	pid_t pids[2] = { 0, 0 };
+	GameModeContext *context = userdata;
+
+	int ret = sd_bus_message_read(m, "hh", &fds[0], &fds[1]);
+	if (ret < 0) {
+		LOG_ERROR("Failed to parse input parameters: %s\n", strerror(-ret));
+		return ret;
+	}
+
+	int reply = pidfds_to_pids(fds, pids, 2);
+
+	if (reply == 2)
+		reply = game_mode_context_unregister(context, pids[0], pids[1]);
+	else
+		reply = -1;
+
+	return sd_bus_reply_method_return(m, "i", reply);
+}
+
+/**
+ * Handles the QueryStatusByPIDFd D-BUS Method
+ */
+static int method_query_status_by_pidfd(sd_bus_message *m, void *userdata,
+                                        __attribute__((unused)) sd_bus_error *ret_error)
+{
+	int fds[2] = { -1, -1 };
+	pid_t pids[2] = { 0, 0 };
+	GameModeContext *context = userdata;
+
+	int ret = sd_bus_message_read(m, "hh", &fds[0], &fds[1]);
+	if (ret < 0) {
+		LOG_ERROR("Failed to parse input parameters: %s\n", strerror(-ret));
+		return ret;
+	}
+
+	int reply = pidfds_to_pids(fds, pids, 2);
+
+	if (reply == 2)
+		reply = game_mode_context_query_status(context, pids[0], pids[1]);
+	else
+		reply = -1;
+
+	return sd_bus_reply_method_return(m, "i", reply);
+}
+
+/**
+ * Handles the ClientCount D-BUS Property
  */
 static int property_get_client_count(sd_bus *local_bus, const char *path, const char *interface,
                                      const char *property, sd_bus_message *reply, void *userdata,
@@ -322,6 +403,12 @@ static const sd_bus_vtable gamemode_vtable[] = {
 	              SD_BUS_VTABLE_UNPRIVILEGED),
 	SD_BUS_METHOD("QueryStatusByPID", "ii", "i", method_query_status_by_pid,
 	              SD_BUS_VTABLE_UNPRIVILEGED),
+	SD_BUS_METHOD("RegisterGameByPIDFd", "hh", "i", method_register_game_by_pidfd,
+	              SD_BUS_VTABLE_UNPRIVILEGED),
+	SD_BUS_METHOD("UnregisterGameByPIDFd", "hh", "i", method_unregister_game_by_pidfd,
+	              SD_BUS_VTABLE_UNPRIVILEGED),
+	SD_BUS_METHOD("QueryStatusByPIDFd", "hh", "i", method_query_status_by_pidfd,
+	              SD_BUS_VTABLE_UNPRIVILEGED),
 	SD_BUS_METHOD("RefreshConfig", "", "i", method_refresh_config, SD_BUS_VTABLE_UNPRIVILEGED),
 	SD_BUS_METHOD("ListGames", "", "a(io)", method_list_games, SD_BUS_VTABLE_UNPRIVILEGED),
 

daemon/meson.build

@@ -26,7 +26,6 @@ executable(
     ],
     include_directories: [
         gamemoded_includes,
-        include_daemon_common,
     ],
     install: true,
 )

lib/client_impl.c

@@ -31,8 +31,14 @@ POSSIBILITY OF SUCH DAMAGE.
 
 #define _GNU_SOURCE
 
+#include <common-helpers.h>
+#include <common-pidfds.h>
+
 #include <dbus/dbus.h>
+#include <errno.h>
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
@@ -54,6 +60,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #define _cleanup_bus_ _cleanup_(hop_off_the_bus)
 #define _cleanup_msg_ _cleanup_(cleanup_msg)
 #define _cleanup_dpc_ _cleanup_(cleanup_pending_call)
+#define _cleanup_fds_ _cleanup_(cleanup_fd_array)
 
 #ifdef NDEBUG
 #define DEBUG(...)
@@ -73,15 +80,49 @@ static int log_error(const char *fmt, ...) __attribute__((format(printf, 1, 2)))
 // Storage for error strings
 static char error_string[512] = { 0 };
 
+// memory helpers
+static void cleanup_fd_array(int **fdlist)
+{
+	if (fdlist == NULL || *fdlist == NULL)
+		return;
+
+	int errsave = errno;
+	for (int *fd = *fdlist; *fd != -1; fd++) {
+		TRACE("GM Closing fd %d\n", *fd);
+		(void)close(*fd);
+	}
+
+	errno = errsave;
+	free(*fdlist);
+}
+
+// Allocate a -1 termianted array of ints
+static inline int *alloc_fd_array(int n)
+{
+	int *fds;
+
+	size_t count = (size_t)n + 1; /* -1, terminated */
+	fds = (int *)malloc(sizeof(int) * count);
+	for (size_t i = 0; i < count; i++)
+		fds[i] = -1;
+
+	return fds;
+}
+
 // Helper to check if we are running inside a flatpak
 static int in_flatpak(void)
 {
-	struct stat sb;
-	int r;
+	static int status = -1;
 
-	r = lstat("/.flatpak-info", &sb);
+	if (status == -1) {
+		struct stat sb;
+		int r;
 
-	return r == 0 && sb.st_size > 0;
+		r = lstat("/.flatpak-info", &sb);
+		status = r == 0 && sb.st_size > 0;
+	}
+
+	return status;
 }
 
 static int log_error(const char *fmt, ...)
@@ -131,7 +172,7 @@ static DBusConnection *hop_on_the_bus(void)
 /* cleanup functions */
 static void cleanup_msg(DBusMessage **msg)
 {
-	if (msg == NULL)
+	if (msg == NULL || *msg == NULL)
 		return;
 
 	dbus_message_unref(*msg);
@@ -139,37 +180,53 @@ static void cleanup_msg(DBusMessage **msg)
 
 static void cleanup_pending_call(DBusPendingCall **call)
 {
-	if (call == NULL)
+	if (call == NULL || *call == NULL)
 		return;
 
 	dbus_pending_call_unref(*call);
 }
 
 /* internal API */
-static int gamemode_request(const char *method, pid_t for_pid)
+static int make_request(DBusConnection *bus, int native, int use_pidfds, const char *method,
+                        pid_t *pids, int npids, DBusError *error)
 {
-	_cleanup_bus_ DBusConnection *bus = NULL;
 	_cleanup_msg_ DBusMessage *msg = NULL;
 	_cleanup_dpc_ DBusPendingCall *call = NULL;
-	DBusMessageIter iter;
+	_cleanup_fds_ int *fds = NULL;
+	char action[256] = {
+		0,
+	};
 	DBusError err;
-	dbus_int32_t pid;
-	int native;
+	DBusMessageIter iter;
 	int res = -1;
 
-	native = !in_flatpak();
-	pid = (dbus_int32_t)getpid();
-
-	TRACE("GM: [%d] request '%s' received (for pid: %d) [portal: %s]\n",
-	      (int)pid,
+	TRACE("GM: Incoming request: %s, npids: %d, native: %d pifds: %d\n",
 	      method,
-	      (int)for_pid,
-	      (native ? "n" : "y"));
-
-	bus = hop_on_the_bus();
+	      npids,
+	      native,
+	      use_pidfds);
+
+	if (use_pidfds) {
+		fds = alloc_fd_array(npids);
+
+		res = open_pidfds(pids, fds, npids);
+		if (res != npids) {
+			dbus_set_error(error, DBUS_ERROR_FAILED, "Could not open pidfd for %d", (int)pids[res]);
+			return -1;
+		}
+
+		if (strstr(method, "ByPID"))
+			snprintf(action, sizeof(action), "%sFd", method);
+		else
+			snprintf(action, sizeof(action), "%sByPIDFd", method);
+		method = action;
+	}
 
-	if (bus == NULL)
-		return -1;
+	TRACE("GM:   Making request: %s, npids: %d, native: %d pifds: %d\n",
+	      method,
+	      npids,
+	      native,
+	      use_pidfds);
 
 	// If we are inside a flatpak we need to talk to the portal instead
 	const char *dest = native ? DAEMON_DBUS_NAME : PORTAL_DBUS_NAME;
@@ -178,15 +235,25 @@ static int gamemode_request(const char *method, pid_t for_pid)
 
 	msg = dbus_message_new_method_call(dest, path, iface, method);
 
-	if (!msg)
-		return log_error("Could not create dbus message");
+	if (!msg) {
+		dbus_set_error_const(error, DBUS_ERROR_FAILED, "Could not create dbus message");
+		return -1;
+	}
 
 	dbus_message_iter_init_append(msg, &iter);
-	dbus_message_iter_append_basic(&iter, DBUS_TYPE_INT32, &pid);
 
-	if (for_pid != 0) {
-		dbus_int32_t p = (dbus_int32_t)for_pid;
-		dbus_message_iter_append_basic(&iter, DBUS_TYPE_INT32, &p);
+	for (int i = 0; i < npids; i++) {
+		dbus_int32_t p;
+		int type;
+
+		if (use_pidfds) {
+			type = DBUS_TYPE_UNIX_FD;
+			p = (dbus_int32_t)fds[i];
+		} else {
+			type = DBUS_TYPE_INT32;
+			p = (dbus_int32_t)pids[i];
+		}
+		dbus_message_iter_append_basic(&iter, type, &p);
 	}
 
 	dbus_connection_send_with_reply(bus, msg, &call, -1);
@@ -197,20 +264,87 @@ static int gamemode_request(const char *method, pid_t for_pid)
 	dbus_pending_call_block(call);
 	msg = dbus_pending_call_steal_reply(call);
 
-	if (msg == NULL)
-		return log_error("Did not receive a reply");
+	if (msg == NULL) {
+		dbus_set_error_const(error, DBUS_ERROR_FAILED, "Did not receive a reply");
+		return -1;
+	}
 
 	dbus_error_init(&err);
+	res = -1;
+	if (dbus_set_error_from_message(&err, msg)) {
+		dbus_set_error(error,
+		               err.name,
+		               "Could not call method '%s' on '%s': %s",
+		               method,
+		               dest,
+		               err.message);
+	} else if (!dbus_message_iter_init(msg, &iter) ||
+	           dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_INT32) {
+		dbus_set_error(error, DBUS_ERROR_INVALID_SIGNATURE, "Failed to parse response");
+	} else {
+		dbus_message_iter_get_basic(&iter, &res);
+	}
+
+	/* free the local error */
+	if (dbus_error_is_set(&err))
+		dbus_error_free(&err);
+
+	return res;
+}
+
+static int gamemode_request(const char *method, pid_t for_pid)
+{
+	_cleanup_bus_ DBusConnection *bus = NULL;
+	static int use_pidfs = 1;
+	DBusError err;
+	pid_t pids[2];
+	int npids;
+	int native;
+	int res = -1;
+
+	native = !in_flatpak();
+
+	/* pid[0] is the client, i.e. the game
+	 * pid[1] is the requestor, i.e. this process
+	 *
+	 * we setup the array such that pids[1] will always be a valid
+	 * pid, because if we are going to use the pidfd based API,
+	 * both pids are being sent, even if they are the same
+	 */
+	pids[1] = getpid();
+	pids[0] = for_pid != 0 ? for_pid : pids[1];
+
+	TRACE("GM: [%d] request '%s' received (by: %d) [portal: %s]\n",
+	      (int)pids[0],
+	      method,
+	      (int)pids[1],
+	      (native ? "n" : "y"));
+
+	bus = hop_on_the_bus();
+
+	if (bus == NULL)
+		return -1;
 
-	if (dbus_set_error_from_message(&err, msg))
-		log_error("Could not call method '%s' on '%s': %s", method, dest, err.message);
-	else if (!dbus_message_iter_init(msg, &iter) ||
-	         dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_INT32)
-		log_error("Failed to parse response");
+	dbus_error_init(&err);
+retry:
+	if (for_pid != 0 || use_pidfs)
+		npids = 2;
 	else
-		dbus_message_iter_get_basic(&iter, &res);
+		npids = 1;
+
+	res = make_request(bus, native, use_pidfs, method, pids, npids, &err);
+
+	if (res == -1 && use_pidfs && dbus_error_is_set(&err)) {
+		TRACE("GM: Request with pidfds failed (%s). Retrying.\n", err.message);
+		use_pidfs = 0;
+		dbus_error_free(&err);
+		goto retry;
+	}
+
+	if (res == -1 && dbus_error_is_set(&err))
+		log_error("D-Bus error: %s", err.message);
 
-	TRACE("GM: [%d] request '%s' done: %d\n", (int)pid, method, res);
+	TRACE("GM: [%d] request '%s' done: %d\n", (int)pids[0], method, res);
 
 	if (dbus_error_is_set(&err))
 		dbus_error_free(&err);

lib/meson.build

@@ -12,6 +12,7 @@ gamemode = shared_library(
         'client_impl.c',
     ],
     dependencies: [
+        link_lib_common,
         dep_dbus,
     ],
     install: true,

meson.build

@@ -128,21 +128,25 @@ with_examples = get_option('with-examples')
 with_util = get_option('with-util')
 
 # Provide a config.h
+pidfd_open = cc.has_function('pidfd_open', args: '-D_GNU_SOURCE')
+
 cdata = configuration_data()
 cdata.set_quoted('LIBEXECDIR', path_libexecdir)
 cdata.set_quoted('GAMEMODE_VERSION', meson.project_version())
+cdata.set10('HAVE_FN_PIDFD_OPEN', pidfd_open)
+
 config_h = configure_file(
     configuration: cdata,
     output: 'build-config.h',
 )
 config_h_dir = include_directories('.')
 
-# Library is always required
-subdir('lib')
-
 # common lib is always required
 subdir('common')
 
+# Library is always required
+subdir('lib')
+
 # Utilities are always required except when having both 64 and 32 bit versions
 # of libgamemode installed
 if with_util == true

util/meson.build

@@ -11,7 +11,6 @@ cpugovctl = executable(
         link_daemon_common,
     ],
     install: true,
-    include_directories: include_daemon_common,
     install_dir: path_libexecdir,
 )
 
@@ -27,6 +26,5 @@ gpuclockctl = executable(
         link_daemon_common,
     ],
     install: true,
-    include_directories: include_daemon_common,
     install_dir: path_libexecdir,
 )