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/***
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/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_errno(errno, "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;
}
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