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From:   Fabrice Fontaine <fontaine.fabrice@gmail.com>
To:     linux-bluetooth@vger.kernel.org
Cc:     Fabrice Fontaine <fontaine.fabrice@gmail.com>
Subject: [PATCH BlueZ v2] fix build with glibc < 2.25
Date:   Mon, 14 Feb 2022 16:31:05 +0100
Message-Id: <20220214153105.2862331-1-fontaine.fabrice@gmail.com>
MIME-Version: 1.0
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getrandom and sys/random.h are only available since glibc 2.25:
https://www.gnu.org/software/gnulib/manual/html_node/sys_002frandom_002eh.html
resulting in the following build failures since version 5.63 and
https://git.kernel.org/pub/scm/bluetooth/bluez.git/log/?qt=grep&q=getrandom:

plugins/autopair.c:20:24: fatal error: sys/random.h: No such file or directory
 #include <sys/random.h>
                        ^

To fix this build failure, add a getrandom fallback borrowed from
pipewire and licensed under MIT:
https://gitlab.freedesktop.org/pipewire/pipewire/-/blob/master/src/pipewire/utils.c

Fixes:
 - http://autobuild.buildroot.org/results/6b8870d12e0804d6154230a7322c49416c1dc0e2

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
---
Changes v1 -> v2 (after review of Marcel Holtmann):
 - Add a getrandom fallback in src/missing.h instead of adding ifdef

 Makefile.am            |  1 +
 configure.ac           |  4 +++-
 emulator/le.c          |  3 +++
 emulator/phy.c         |  3 +++
 peripheral/main.c      |  3 +++
 plugins/autopair.c     |  3 +++
 profiles/health/hdp.c  |  3 +++
 profiles/health/mcap.c |  3 +++
 src/missing.h          | 30 ++++++++++++++++++++++++++++++
 tools/btgatt-server.c  |  3 +++
 10 files changed, 55 insertions(+), 1 deletion(-)
 create mode 100644 src/missing.h

diff --git a/Makefile.am b/Makefile.am
index 82125c482..d6c18fe0d 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -299,6 +299,7 @@ pkglibexec_PROGRAMS += src/bluetoothd
 src_bluetoothd_SOURCES = $(builtin_sources) \
 			$(attrib_sources) $(btio_sources) \
 			src/bluetooth.ver \
+			src/missing.h \
 			src/main.c src/log.h src/log.c \
 			src/backtrace.h src/backtrace.c \
 			src/rfkill.c src/btd.h src/sdpd.h \
diff --git a/configure.ac b/configure.ac
index 07d068a4d..441bd5f29 100644
--- a/configure.ac
+++ b/configure.ac
@@ -54,6 +54,8 @@ AC_ARG_ENABLE(threads, AS_HELP_STRING([--enable-threads],
 
 AC_CHECK_FUNCS(explicit_bzero)
 
+AC_CHECK_FUNCS(getrandom)
+
 AC_CHECK_FUNCS(rawmemchr)
 
 AC_CHECK_FUNC(signalfd, dummy=yes,
@@ -68,7 +70,7 @@ AC_CHECK_LIB(pthread, pthread_create, dummy=yes,
 AC_CHECK_LIB(dl, dlopen, dummy=yes,
 			AC_MSG_ERROR(dynamic linking loader is required))
 
-AC_CHECK_HEADERS(linux/types.h linux/if_alg.h linux/uinput.h linux/uhid.h)
+AC_CHECK_HEADERS(linux/types.h linux/if_alg.h linux/uinput.h linux/uhid.h sys/random.h)
 
 PKG_CHECK_MODULES(GLIB, glib-2.0 >= 2.28, dummy=yes,
 				AC_MSG_ERROR(GLib >= 2.28 is required))
diff --git a/emulator/le.c b/emulator/le.c
index f8f313f2c..b3916d49b 100644
--- a/emulator/le.c
+++ b/emulator/le.c
@@ -20,12 +20,15 @@
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <sys/uio.h>
+#ifdef HAVE_SYS_RANDOM_H
 #include <sys/random.h>
+#endif
 #include <time.h>
 
 #include "lib/bluetooth.h"
 #include "lib/hci.h"
 
+#include "src/missing.h"
 #include "src/shared/util.h"
 #include "src/shared/crypto.h"
 #include "src/shared/ecc.h"
diff --git a/emulator/phy.c b/emulator/phy.c
index 44cace438..9cb6460d7 100644
--- a/emulator/phy.c
+++ b/emulator/phy.c
@@ -19,11 +19,14 @@
 #include <stdlib.h>
 #include <string.h>
 #include <sys/socket.h>
+#ifdef HAVE_SYS_RANDOM_H
 #include <sys/random.h>
+#endif
 #include <netinet/in.h>
 #include <netinet/ip.h>
 #include <time.h>
 
+#include "src/missing.h"
 #include "src/shared/util.h"
 #include "src/shared/mainloop.h"
 
diff --git a/peripheral/main.c b/peripheral/main.c
index 91adb45fc..e854bd14c 100644
--- a/peripheral/main.c
+++ b/peripheral/main.c
@@ -25,12 +25,15 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <sys/mount.h>
+#ifdef HAVE_SYS_RANDOM_H
 #include <sys/random.h>
+#endif
 
 #ifndef WAIT_ANY
 #define WAIT_ANY (-1)
 #endif
 
+#include "src/missing.h"
 #include "src/shared/mainloop.h"
 #include "peripheral/efivars.h"
 #include "peripheral/attach.h"
diff --git a/plugins/autopair.c b/plugins/autopair.c
index a75ecebe4..6ce97672b 100644
--- a/plugins/autopair.c
+++ b/plugins/autopair.c
@@ -17,13 +17,16 @@
 #include <fcntl.h>
 #include <unistd.h>
 #include <errno.h>
+#ifdef HAVE_SYS_RANDOM_H
 #include <sys/random.h>
+#endif
 
 #include <glib.h>
 
 #include "lib/bluetooth.h"
 #include "lib/sdp.h"
 
+#include "src/missing.h"
 #include "src/plugin.h"
 #include "src/adapter.h"
 #include "src/device.h"
diff --git a/profiles/health/hdp.c b/profiles/health/hdp.c
index 9d9d1e824..1e6e16fd2 100644
--- a/profiles/health/hdp.c
+++ b/profiles/health/hdp.c
@@ -16,7 +16,9 @@
 #include <stdint.h>
 #include <stdbool.h>
 #include <unistd.h>
+#ifdef HAVE_SYS_RANDOM_H
 #include <sys/random.h>
+#endif
 
 #include <glib.h>
 
@@ -26,6 +28,7 @@
 
 #include "gdbus/gdbus.h"
 
+#include "src/missing.h"
 #include "src/dbus-common.h"
 #include "src/log.h"
 #include "src/error.h"
diff --git a/profiles/health/mcap.c b/profiles/health/mcap.c
index aad0a08a3..6b779c513 100644
--- a/profiles/health/mcap.c
+++ b/profiles/health/mcap.c
@@ -19,13 +19,16 @@
 #include <errno.h>
 #include <unistd.h>
 #include <time.h>
+#ifdef HAVE_SYS_RANDOM_H
 #include <sys/random.h>
+#endif
 
 #include <glib.h>
 
 #include "lib/bluetooth.h"
 #include "bluetooth/l2cap.h"
 #include "btio/btio.h"
+#include "src/missing.h"
 #include "src/log.h"
 #include "src/shared/timeout.h"
 
diff --git a/src/missing.h b/src/missing.h
new file mode 100644
index 000000000..df8bd980a
--- /dev/null
+++ b/src/missing.h
@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: MIT
+/*
+ *
+ *  BlueZ - Bluetooth protocol stack for Linux
+ *
+ *  Copyright (C) 2018 Wim Taymans
+ *
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#ifndef HAVE_GETRANDOM
+ssize_t getrandom(void *buf, size_t buflen, unsigned int flags)
+{
+	ssize_t bytes;
+	int fd;
+
+	fd = open("/dev/urandom", O_CLOEXEC);
+	if (fd < 0)
+		return -1;
+
+	bytes = read(fd, buf, buflen);
+	close(fd);
+
+	return bytes;
+}
+#endif
diff --git a/tools/btgatt-server.c b/tools/btgatt-server.c
index 15d49a464..30314f4ac 100644
--- a/tools/btgatt-server.c
+++ b/tools/btgatt-server.c
@@ -20,7 +20,9 @@
 #include <getopt.h>
 #include <unistd.h>
 #include <errno.h>
+#ifdef HAVE_SYS_RANDOM_H
 #include <sys/random.h>
+#endif
 
 #include "lib/bluetooth.h"
 #include "lib/hci.h"
@@ -28,6 +30,7 @@
 #include "lib/l2cap.h"
 #include "lib/uuid.h"
 
+#include "src/missing.h"
 #include "src/shared/mainloop.h"
 #include "src/shared/util.h"
 #include "src/shared/att.h"
-- 
2.34.1