1/*-
2 * Copyright (c) 2009 David Schultz <das@FreeBSD.org>
3 * Copyright (c) 2023 The FreeBSD Foundation
4 * All rights reserved.
5 *
6 * Portions of this software were developed by Robert Clausecker
7 * <fuz@FreeBSD.org> under sponsorship from the FreeBSD Foundation.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31#include <sys/cdefs.h>
32#include <sys/param.h>
33#include <sys/mman.h>
34#include <assert.h>
35#include <dlfcn.h>
36#include <limits.h>
37#include <stdio.h>
38#include <stdlib.h>
39#include <string.h>
40
41#include <atf-c.h>
42
43void *(*memccpy_fn)(void *restrict, const void *restrict, int, size_t);
44
45static char *
46makebuf(size_t len, int guard_at_end)
47{
48	char *buf;
49	size_t alloc_size, page_size;
50
51	page_size = getpagesize();
52	alloc_size = roundup2(len, page_size) + page_size;
53
54	buf = mmap(NULL, alloc_size, PROT_READ | PROT_WRITE, MAP_ANON, -1, 0);
55	assert(buf);
56	if (guard_at_end) {
57		assert(munmap(buf + alloc_size - page_size, page_size) == 0);
58		return (buf + alloc_size - page_size - len);
59	} else {
60		assert(munmap(buf, page_size) == 0);
61		return (buf + page_size);
62	}
63}
64
65static void
66test_memccpy(const char *s)
67{
68	char *src, *dst, *expected;
69	size_t size, bufsize, x;
70	int i, j;
71
72	size = strlen(s) + 1;
73	for (i = 0; i <= 1; i++) {
74		for (j = 0; j <= 1; j++) {
75			for (bufsize = 0; bufsize <= size + 10; bufsize++) {
76				src = makebuf(size, i);
77				memcpy(src, s, size);
78				dst = makebuf(bufsize, j);
79				memset(dst, 'X', bufsize);
80				expected = bufsize >= size ? dst + size : NULL;
81				assert(memccpy_fn(dst, src, src[size-1], bufsize) == expected);
82				assert(bufsize == 0 || strncmp(src, dst, bufsize - 1) == 0);
83				for (x = size; x < bufsize; x++)
84					assert(dst[x] == 'X');
85			}
86		}
87	}
88}
89
90static void
91test_sentinel(char *dest, char *src, size_t destlen, size_t srclen)
92{
93	size_t i, effective_len;
94	void *res, *wantres;
95	const char *fail = NULL;
96	char terminator;
97
98	for (i = 0; i < srclen; i++)
99		/* src will never include (){} */
100		src[i] = '0' + i;
101
102	/* source sentinels: not to be copied */
103	src[-1] = '(';
104	src[srclen] = ')';
105
106	memset(dest, '\xee', destlen);
107
108	/* destination sentinels: not to be touched */
109	dest[-1] = '{';
110	dest[destlen] = '}';
111
112	effective_len = srclen < destlen ? srclen : destlen;
113	wantres = srclen <= destlen ? dest + srclen : NULL;
114	terminator = src[srclen-1];
115	res = memccpy_fn(dest, src, terminator, destlen);
116
117	if (dest[-1] != '{')
118		fail = "start sentinel overwritten";
119	else if (dest[destlen] != '}')
120		fail = "end sentinel overwritten";
121	else if (res != wantres)
122		fail = "incorrect return value";
123	else if (destlen > 0 && memcmp(src, dest, effective_len) != 0)
124		fail = "string not copied correctly";
125	else for (i = srclen; i < destlen; i++)
126		if (dest[i] != '\xee') {
127			fail = "buffer mutilated behind string";
128			break;
129		}
130
131	if (fail)
132		atf_tc_fail_nonfatal("%s\n"
133		    "memccpy(%p \"%s\", %p \"%s\", %u '%c', %zu) = %p (want %p)\n",
134		    fail, dest, dest, src, src, terminator, terminator, destlen, res, wantres);
135}
136
137ATF_TC_WITHOUT_HEAD(null);
138ATF_TC_BODY(null, tc)
139{
140	ATF_CHECK_EQ(memccpy_fn(NULL, "foo", 42, 0), NULL);
141}
142
143ATF_TC(zero_extension);
144ATF_TC_HEAD(zero_extension, tc)
145{
146	atf_tc_set_md_var(tc, "descr",
147	    "Ensure the upper bits of the terminator are ignored");
148}
149ATF_TC_BODY(zero_extension, tc)
150{
151	int mask = -1 & ~UCHAR_MAX;
152	char buf[16];
153
154	memset(buf, 0xcc, sizeof(buf));
155	ATF_CHECK_EQ(memccpy(buf, "foobar", 'r', sizeof(buf)), buf + sizeof("foobar") - 1);
156	ATF_CHECK_EQ(memcmp(buf, "foobar", sizeof("foobar") - 1), 0);
157
158	memset(buf, 0xcc, sizeof(buf));
159	ATF_CHECK_EQ(memccpy(buf, "foobar", mask | 'r', sizeof(buf)), buf + sizeof("foobar") - 1);
160	ATF_CHECK_EQ(memcmp(buf, "foobar", sizeof("foobar") - 1), 0);
161}
162
163ATF_TC_WITHOUT_HEAD(bounds);
164ATF_TC_BODY(bounds, tc)
165{
166	size_t i;
167	char buf[64];
168
169	for (i = 0; i < sizeof(buf) - 1; i++) {
170		buf[i] = ' ' + i;
171		test_memccpy(buf);
172	}
173}
174
175ATF_TC_WITHOUT_HEAD(alignments);
176ATF_TC_BODY(alignments, tc)
177{
178	size_t srcalign, destalign, srclen, destlen;
179	char src[15+2+64]; /* 15 offsets + 64 max length + sentinels */
180	char dest[15+2+64]; /* 15 offsets + 64 max length + sentinels */
181
182	for (srcalign = 0; srcalign < 16; srcalign++)
183		for (destalign = 0; destalign < 16; destalign++)
184			for (srclen = 1; srclen < 64; srclen++)
185				for (destlen = 0; destlen < 64; destlen++)
186					test_sentinel(dest+destalign+1,
187					    src+srcalign+1, destlen, srclen);
188}
189
190ATF_TP_ADD_TCS(tp)
191{
192	void *dl_handle;
193
194	dl_handle = dlopen(NULL, RTLD_LAZY);
195	memccpy_fn = dlsym(dl_handle, "test_memccpy");
196	if (memccpy_fn == NULL)
197		memccpy_fn = memccpy;
198
199	ATF_TP_ADD_TC(tp, null);
200	ATF_TP_ADD_TC(tp, zero_extension);
201	ATF_TP_ADD_TC(tp, bounds);
202	ATF_TP_ADD_TC(tp, alignments);
203
204	return (atf_no_error());
205}
206