--- /dev/null
+/***
+ This file is part of systemd
+
+ Copyright 2014 Ronny Chevalier
+
+ systemd 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.
+
+ 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <sys/capability.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <pwd.h>
+#include <unistd.h>
+
+#include "capability.h"
+#include "util.h"
+#include "macro.h"
+
+static uid_t test_uid = -1;
+static gid_t test_gid = -1;
+// We keep CAP_DAC_OVERRIDE to avoid errors with gcov when doing test coverage
+static uint64_t test_flags = 1ULL << CAP_DAC_OVERRIDE;
+
+static void fork_test(void (*test_func)(void)) {
+ pid_t pid = 0;
+
+ pid = fork();
+ assert_se(pid >= 0);
+ if (pid == 0) {
+ test_func();
+ exit(0);
+ } else if (pid > 0) {
+ int status;
+
+ assert_se(waitpid(pid, &status, 0) > 0);
+ assert_se(WIFEXITED(status) && WEXITSTATUS(status) == 0);
+ }
+}
+
+static void show_capabilities(void) {
+ cap_t caps;
+ char *text;
+
+ caps = cap_get_proc();
+ assert_se(caps);
+
+ text = cap_to_text(caps, NULL);
+ assert_se(text);
+
+ log_info("Capabilities:%s", text);
+ cap_free(caps);
+ cap_free(text);
+}
+
+static int setup_tests(void) {
+ struct passwd *nobody;
+
+ nobody = getpwnam("nobody");
+ if (!nobody) {
+ log_error("Could not find nobody user: %m");
+ return -EXIT_TEST_SKIP;
+ }
+ test_uid = nobody->pw_uid;
+ test_gid = nobody->pw_gid;
+
+ return 0;
+}
+
+static void test_drop_privileges_keep_net_raw(void) {
+ int sock;
+
+ sock = socket(AF_INET, SOCK_RAW, IPPROTO_UDP);
+ assert_se(sock >= 0);
+ safe_close(sock);
+
+ assert_se(drop_privileges(test_uid, test_gid, test_flags | (1ULL << CAP_NET_RAW)) >= 0);
+ assert_se(getuid() == test_uid);
+ assert_se(getgid() == test_gid);
+ show_capabilities();
+
+ sock = socket(AF_INET, SOCK_RAW, IPPROTO_UDP);
+ assert_se(sock >= 0);
+ safe_close(sock);
+}
+
+static void test_drop_privileges_dontkeep_net_raw(void) {
+ int sock;
+
+ sock = socket(AF_INET, SOCK_RAW, IPPROTO_UDP);
+ assert_se(sock >= 0);
+ safe_close(sock);
+
+ assert_se(drop_privileges(test_uid, test_gid, test_flags) >= 0);
+ assert_se(getuid() == test_uid);
+ assert_se(getgid() == test_gid);
+ show_capabilities();
+
+ sock = socket(AF_INET, SOCK_RAW, IPPROTO_UDP);
+ assert_se(sock < 0);
+}
+
+static void test_drop_privileges_fail(void) {
+ assert_se(drop_privileges(test_uid, test_gid, test_flags) >= 0);
+ assert_se(getuid() == test_uid);
+ assert_se(getgid() == test_gid);
+
+ assert_se(drop_privileges(test_uid, test_gid, test_flags) < 0);
+ assert_se(drop_privileges(0, 0, test_flags) < 0);
+}
+
+static void test_drop_privileges(void) {
+ fork_test(test_drop_privileges_keep_net_raw);
+ fork_test(test_drop_privileges_dontkeep_net_raw);
+ fork_test(test_drop_privileges_fail);
+}
+
+static void test_have_effective_cap(void) {
+ assert_se(have_effective_cap(CAP_KILL));
+ assert_se(have_effective_cap(CAP_CHOWN));
+
+ assert_se(drop_privileges(test_uid, test_gid, test_flags | (1ULL << CAP_KILL)) >= 0);
+ assert_se(getuid() == test_uid);
+ assert_se(getgid() == test_gid);
+
+ assert_se(have_effective_cap(CAP_KILL));
+ assert_se(!have_effective_cap(CAP_CHOWN));
+}
+
+int main(int argc, char *argv[]) {
+ int r;
+
+ log_parse_environment();
+ log_open();
+
+ if (getuid() != 0)
+ return EXIT_TEST_SKIP;
+
+ r = setup_tests();
+ if (r < 0)
+ return -r;
+
+ show_capabilities();
+
+ test_drop_privileges();
+ fork_test(test_have_effective_cap);
+
+ return 0;
+}