unit: Add basic unit test for l_sysctl_get/set

3 files changed, 83 insertions, 1 deletions

diff --git a/.gitignore b/.gitignore
index 1540012b..31ef6686 100644
--- a/.gitignore
+++ b/.gitignore
@@ -62,6 +62,7 @@ unit/test-ecdh
 unit/test-time
 unit/test-path
 unit/test-net
+unit/test-sysctl
 unit/cert-*.pem
 unit/cert-*.csr
 unit/cert-*.srl
diff --git a/Makefile.am b/Makefile.am
index 738aa75a..cc68b246 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -201,7 +201,8 @@ unit_tests = unit/test-unit \
 			unit/test-ecdh \
 			unit/test-time \
 			unit/test-path \
-			unit/test-net
+			unit/test-net \
+			unit/test-sysctl
 
 dbus_tests = unit/test-hwdb \
 			unit/test-dbus \
@@ -350,6 +351,8 @@ unit_test_path_LDADD = ell/libell-private.la
 
 unit_test_net_LDADD = ell/libell-private.la
 
+unit_test_sysctl_LDADD = ell/libell-private.la
+
 unit_test_data_files = unit/settings.test unit/dbus.conf
 
 if EXAMPLES
diff --git a/unit/test-sysctl.c b/unit/test-sysctl.c
new file mode 100644
index 00000000..820c7079
--- /dev/null
+++ b/unit/test-sysctl.c
@@ -0,0 +1,78 @@
+/*
+ *
+ *  Embedded Linux library
+ *
+ *  Copyright (C) 2023  Cruise LLC. All rights reserved.
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public
+ *  License as published by the Free Software Foundation; either
+ *  version 2.1 of the License, or (at your option) any later version.
+ *
+ *  This library 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
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#define _GNU_SOURCE
+#include <assert.h>
+#include <errno.h>
+#include <stdio.h>
+
+#include <ell/ell.h>
+
+static void test_sysctl_get_set(const void *data)
+{
+	FILE *f;
+	uint32_t n;
+	uint32_t expected;
+	int r;
+
+	/* Grab the setting via sysctl */
+	f = popen("sysctl -n net.core.somaxconn", "r");
+	assert(f);
+
+	assert(fscanf(f, "%u", &expected) == 1);
+	pclose(f);
+
+	/* Now check against what we get */
+	assert(l_sysctl_get_u32(&n, "/proc/sys/%s/%s/%s",
+					"net", "core", "somaxconn") == 0);
+	assert(n == expected);
+
+	/*
+	 * Attempt to change the setting, if we get an -EPERM, then we're
+	 * most likely not running as root, so succeed silently.  Any other
+	 * error is treated as a unit test failure
+	 */
+
+	r = l_sysctl_set_u32(5000, "/proc/sys/net/core/%s", "somaxconn");
+	if (r == -EACCES)
+		return;
+
+	assert(!r);
+	assert(!l_sysctl_get_u32(&n, "/proc/sys/net/core/somaxconn"));
+	assert(n == 5000);
+
+	/* Set it back to original */
+	assert(!l_sysctl_set_u32(expected, "/proc/sys/net/core/somaxconn"));
+}
+
+int main(int argc, char *argv[])
+{
+	l_test_init(&argc, &argv);
+
+	l_test_add("sysctl/get_set", test_sysctl_get_set, NULL);
+
+	return l_test_run();
+}