/*** 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; }