1// SPDX-License-Identifier: GPL-2.0
  2
  3/*
  4 * Copyright (C) 2020 Google LLC.
  5 */
  6
  7#include <test_progs.h>
  8#include <sys/mman.h>
  9#include <sys/wait.h>
 10#include <unistd.h>
 11#include <malloc.h>
 12#include <stdlib.h>
 13
 14#include "lsm.skel.h"
 15#include "lsm_tailcall.skel.h"
 16
 17char *CMD_ARGS[] = {"true", NULL};
 18
 19#define GET_PAGE_ADDR(ADDR, PAGE_SIZE)					\
 20	(char *)(((unsigned long) (ADDR + PAGE_SIZE)) & ~(PAGE_SIZE-1))
 21
 22int stack_mprotect(void)
 23{
 24	void *buf;
 25	long sz;
 26	int ret;
 27
 28	sz = sysconf(_SC_PAGESIZE);
 29	if (sz < 0)
 30		return sz;
 31
 32	buf = alloca(sz * 3);
 33	ret = mprotect(GET_PAGE_ADDR(buf, sz), sz,
 34		       PROT_READ | PROT_WRITE | PROT_EXEC);
 35	return ret;
 36}
 37
 38int exec_cmd(int *monitored_pid)
 39{
 40	int child_pid, child_status;
 41
 42	child_pid = fork();
 43	if (child_pid == 0) {
 44		*monitored_pid = getpid();
 45		execvp(CMD_ARGS[0], CMD_ARGS);
 46		return -EINVAL;
 47	} else if (child_pid > 0) {
 48		waitpid(child_pid, &child_status, 0);
 49		return child_status;
 50	}
 51
 52	return -EINVAL;
 53}
 54
 55static int test_lsm(struct lsm *skel)
 56{
 57	struct bpf_link *link;
 58	int buf = 1234;
 59	int err;
 60
 61	err = lsm__attach(skel);
 62	if (!ASSERT_OK(err, "attach"))
 63		return err;
 64
 65	/* Check that already linked program can't be attached again. */
 66	link = bpf_program__attach(skel->progs.test_int_hook);
 67	if (!ASSERT_ERR_PTR(link, "attach_link"))
 68		return -1;
 69
 70	err = exec_cmd(&skel->bss->monitored_pid);
 71	if (!ASSERT_OK(err, "exec_cmd"))
 72		return err;
 73
 74	ASSERT_EQ(skel->bss->bprm_count, 1, "bprm_count");
 75
 76	skel->bss->monitored_pid = getpid();
 77
 78	err = stack_mprotect();
 79	if (!ASSERT_EQ(err, -1, "stack_mprotect") ||
 80	    !ASSERT_EQ(errno, EPERM, "stack_mprotect"))
 81		return err;
 82
 83	ASSERT_EQ(skel->bss->mprotect_count, 1, "mprotect_count");
 84
 85	syscall(__NR_setdomainname, &buf, -2L);
 86	syscall(__NR_setdomainname, 0, -3L);
 87	syscall(__NR_setdomainname, ~0L, -4L);
 88
 89	ASSERT_EQ(skel->bss->copy_test, 3, "copy_test");
 90
 91	lsm__detach(skel);
 92
 93	skel->bss->copy_test = 0;
 94	skel->bss->bprm_count = 0;
 95	skel->bss->mprotect_count = 0;
 96	return 0;
 97}
 98
 99static void test_lsm_basic(void)
100{
101	struct lsm *skel = NULL;
102	int err;
103
104	skel = lsm__open_and_load();
105	if (!ASSERT_OK_PTR(skel, "lsm_skel_load"))
106		goto close_prog;
107
108	err = test_lsm(skel);
109	if (!ASSERT_OK(err, "test_lsm_first_attach"))
110		goto close_prog;
111
112	err = test_lsm(skel);
113	ASSERT_OK(err, "test_lsm_second_attach");
114
115close_prog:
116	lsm__destroy(skel);
117}
118
119static void test_lsm_tailcall(void)
120{
121	struct lsm_tailcall *skel = NULL;
122	int map_fd, prog_fd;
123	int err, key;
124
125	skel = lsm_tailcall__open_and_load();
126	if (!ASSERT_OK_PTR(skel, "lsm_tailcall__skel_load"))
127		goto close_prog;
128
129	map_fd = bpf_map__fd(skel->maps.jmp_table);
130	if (CHECK_FAIL(map_fd < 0))
131		goto close_prog;
132
133	prog_fd = bpf_program__fd(skel->progs.lsm_file_permission_prog);
134	if (CHECK_FAIL(prog_fd < 0))
135		goto close_prog;
136
137	key = 0;
138	err = bpf_map_update_elem(map_fd, &key, &prog_fd, BPF_ANY);
139	if (CHECK_FAIL(!err))
140		goto close_prog;
141
142	prog_fd = bpf_program__fd(skel->progs.lsm_file_alloc_security_prog);
143	if (CHECK_FAIL(prog_fd < 0))
144		goto close_prog;
145
146	err = bpf_map_update_elem(map_fd, &key, &prog_fd, BPF_ANY);
147	if (CHECK_FAIL(err))
148		goto close_prog;
149
150close_prog:
151	lsm_tailcall__destroy(skel);
152}
153
154void test_test_lsm(void)
155{
156	if (test__start_subtest("lsm_basic"))
157		test_lsm_basic();
158	if (test__start_subtest("lsm_tailcall"))
159		test_lsm_tailcall();
160}