1/*
2 * Check decoding of process_vm_readv/process_vm_writev syscall.
3 *
4 * Copyright (c) 2016 Eugene Syromyatnikov <evgsyr@gmail.com>
5 * Copyright (c) 2016-2017 The strace developers.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. The name of the author may not be used to endorse or promote products
17 *    derived from this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include <inttypes.h>
32#include <stdio.h>
33#include <unistd.h>
34#include <sys/uio.h>
35
36#if OP_WR
37# define in_iovec  rmt_iovec
38# define out_iovec lcl_iovec
39# define in_iov    rmt_iov
40# define out_iov   lcl_iov
41#else
42# define in_iovec  lcl_iovec
43# define out_iovec rmt_iovec
44# define in_iov    lcl_iov
45# define out_iov   rmt_iov
46#endif
47
48typedef void (*iov_print_fn)(const struct iovec *, const void *, long);
49
50enum { MAX_SEGM_COUNT = 2, MAX_STR_LEN = 5 };
51
52struct print_iov_arg {
53	uint32_t count;
54	uint32_t valid    :1,
55		 string   :1,
56		 addr_term:1,
57		 check_rc :1;
58	uint32_t str_segms;
59	uint8_t  str_base[MAX_SEGM_COUNT];
60	uint8_t  str_size[MAX_SEGM_COUNT];
61};
62
63static void
64print_iov(const struct iovec *iov, const void *arg_ptr, long rc)
65{
66	const struct print_iov_arg *arg = arg_ptr;
67	uint32_t i;
68	uint32_t num_segm = 0;
69	uint64_t segm_offs = 0;
70
71	if (!arg || !arg->valid) {
72		if (iov)
73			printf("%p", iov);
74		else
75			printf("NULL");
76
77		return;
78	}
79
80	printf("[");
81
82	for (i = 0; i < arg->count; i++) {
83		if (i)
84			printf(", ");
85
86		if (i >= MAX_STR_LEN) {
87			printf("...");
88			break;
89		}
90
91		printf("{iov_base=");
92		if (arg->string && (!arg->check_rc || (rc != -1))) {
93			uint64_t str_left = iov[i].iov_len;
94			uint64_t pr_count = 0;
95
96			printf("\"");
97
98			while (str_left--) {
99				static const char oct_str[] = "01234567";
100				uint8_t c = arg->str_base[num_segm] + segm_offs;
101
102				if ((num_segm >= arg->str_segms) ||
103				    (num_segm >= MAX_SEGM_COUNT))
104					error_msg_and_fail("print_iov: segment "
105							   "count overrun");
106
107				if (pr_count++ < MAX_STR_LEN)
108					printf("\\%.1s%.1s%d",
109					       (c >> 6) ?
110					       oct_str + (c >> 6) : "",
111					       (c >> 3) ?
112					       oct_str + ((c >> 3) & 7) : "",
113					       c & 7);
114
115				segm_offs++;
116
117				if (segm_offs >= arg->str_size[num_segm]) {
118					num_segm++;
119					segm_offs = 0;
120				}
121			}
122
123			printf("\"");
124
125			if (pr_count > MAX_STR_LEN)
126				printf("...");
127		} else {
128			if (iov[i].iov_base)
129				printf("%p", iov[i].iov_base);
130			else
131				printf("NULL");
132		}
133
134		printf(", iov_len=%zu}", iov[i].iov_len);
135	}
136
137	if (arg->addr_term)
138		printf(", %p", iov + arg->count);
139
140	printf("]");
141}
142
143static void
144do_call(kernel_ulong_t pid,
145	kernel_ulong_t local_iov, const char *local_arg,
146	kernel_ulong_t liovcnt,
147	kernel_ulong_t remote_iov, const char *remote_arg,
148	kernel_ulong_t riovcnt,
149	kernel_ulong_t flags, iov_print_fn pr_iov)
150{
151	long rc;
152	const char *errstr;
153
154	rc = syscall(OP_NR, pid, local_iov, liovcnt, remote_iov, riovcnt,
155		flags);
156	errstr = sprintrc(rc);
157
158	printf("%s(%d, ", OP_STR, (int) pid);
159
160	if (pr_iov)
161		pr_iov((const struct iovec *) (uintptr_t) local_iov, local_arg,
162			rc);
163	else
164		printf("%s", local_arg);
165
166	printf(", %lu, ", (unsigned long) liovcnt);
167
168	if (pr_iov)
169		pr_iov((const struct iovec *) (uintptr_t) remote_iov,
170		       remote_arg, rc);
171	else
172		printf("%s", remote_arg);
173
174	printf(", %lu, %lu) = %s\n", (unsigned long) riovcnt,
175		(unsigned long) flags, errstr);
176}
177
178kernel_ulong_t
179ptr_cast(void *ptr)
180{
181	return (kernel_ulong_t) (uintptr_t) ptr;
182}
183
184int
185main(void)
186{
187	enum {
188		SIZE_11 = 2,
189		SIZE_12 = 3,
190		SIZE_13 = 4,
191		SIZE_1 = SIZE_11 + SIZE_12 + SIZE_13,
192		SIZE_21 = 5,
193		SIZE_22 = 6,
194		SIZE_23 = 7,
195		SIZE_2 = SIZE_21 + SIZE_22 + SIZE_23,
196	};
197
198	enum {
199		SEGM1_BASE = 0x80,
200		SEGM2_BASE = 0xA0,
201	};
202
203	static const kernel_ulong_t bogus_pid =
204		(kernel_ulong_t) 0xbadfaceddeadca57ULL;
205	static const kernel_ulong_t bogus_iovcnt1 =
206		(kernel_ulong_t) 0xdec0ded1defaced2ULL;
207	static const kernel_ulong_t bogus_iovcnt2 =
208		(kernel_ulong_t) 0xdec0ded3defaced4ULL;
209	static const kernel_ulong_t bogus_flags =
210		(kernel_ulong_t) 0xdeadc0deda7adeadULL;
211
212	pid_t my_pid = getpid();
213	char *data1_out = tail_alloc(SIZE_1);
214	char *data2_out = tail_alloc(SIZE_2);
215	char *data1_in  = tail_alloc(SIZE_2);
216	char *data2_in  = tail_alloc(SIZE_1);
217
218	struct iovec bogus_iovec[] = {
219		{ data1_out + SIZE_1, (size_t) 0xdeadfaceca57beefULL },
220		{ data1_in  + SIZE_2, (size_t) 0xbadc0dedda7adeadULL },
221		{ data2_out + SIZE_2, (size_t) 0xf157facedec0ded1ULL },
222		{ data2_in  + SIZE_1, (size_t) 0xdefaced2bea7be57ULL },
223	};
224
225	struct iovec out_iovec[] = {
226		{ data1_out,  SIZE_11 },
227		{ data1_out + SIZE_11,  SIZE_12 },
228		{ data1_out + SIZE_11 + SIZE_12,  SIZE_13 },
229		{ data2_out,  SIZE_21 },
230		{ data2_out + SIZE_21,  SIZE_22 },
231		{ data2_out + SIZE_21 + SIZE_22,  SIZE_23 },
232	};
233	struct iovec in_iovec[] = {
234		{ data1_in,  SIZE_23 },
235		{ data1_in + SIZE_23,  SIZE_22 },
236		{ data1_in + SIZE_23 + SIZE_22,  SIZE_21 },
237		{ data2_in,  SIZE_13 },
238		{ data2_in + SIZE_13,  SIZE_12 },
239		{ data2_in + SIZE_13 + SIZE_12,  SIZE_11 },
240	};
241
242	struct iovec *bogus_iov = tail_memdup(bogus_iovec, sizeof(bogus_iovec));
243	struct iovec *lcl_iov   = tail_memdup(lcl_iovec,   sizeof(lcl_iovec));
244	struct iovec *rmt_iov   = tail_memdup(rmt_iovec,   sizeof(rmt_iovec));
245
246	struct print_iov_arg bogus_arg   = { ARRAY_SIZE(bogus_iovec), 1 };
247	struct print_iov_arg lcl_arg     = { ARRAY_SIZE(lcl_iovec), 1, 1, 0, 0,
248		2, {SEGM1_BASE, SEGM2_BASE}, {SIZE_1, SIZE_2} };
249	struct print_iov_arg rmt_arg     = { ARRAY_SIZE(rmt_iovec), 1 };
250
251	struct print_iov_arg bogus_arg_cut = {
252		ARRAY_SIZE(bogus_iovec) - 2, 1, 0, 1
253	};
254	struct print_iov_arg lcl_arg_cut = {
255		ARRAY_SIZE(lcl_iovec) - 2, 1, 1, 1, 0, 2,
256		{ SEGM1_BASE + SIZE_11 + SIZE_12, SEGM2_BASE },
257		{SIZE_13, SIZE_2}
258	};
259	struct print_iov_arg rmt_arg_cut = { ARRAY_SIZE(rmt_iovec) - 2, 1 };
260
261
262	fill_memory_ex(data1_out, SIZE_1, SEGM1_BASE, SIZE_1);
263	fill_memory_ex(data2_out, SIZE_2, SEGM2_BASE, SIZE_2);
264
265
266	do_call(bogus_pid, (kernel_ulong_t) (uintptr_t) ARG_STR(NULL),
267		bogus_iovcnt1, (kernel_ulong_t) (uintptr_t) ARG_STR(NULL),
268		bogus_iovcnt2, bogus_flags, NULL);
269
270	do_call(my_pid, ptr_cast(bogus_iov + ARRAY_SIZE(bogus_iovec)),
271		"[]", 0, ptr_cast(in_iov + ARRAY_SIZE(in_iovec)), "[]",
272		0, 0, NULL);
273	do_call(my_pid, ptr_cast(bogus_iov + ARRAY_SIZE(bogus_iovec)), NULL,
274		bogus_iovcnt1, ptr_cast(in_iov + ARRAY_SIZE(in_iovec)), NULL,
275		bogus_iovcnt2, 0, print_iov);
276
277	do_call(my_pid, ptr_cast(bogus_iov), (char *) &bogus_arg,
278		ARRAY_SIZE(bogus_iovec), ptr_cast(rmt_iov + 2),
279		(char *) &rmt_arg_cut, ARRAY_SIZE(rmt_iovec) - 2, 0, print_iov);
280
281#if !OP_WR
282	lcl_arg.check_rc = 1;
283	lcl_arg_cut.check_rc = 1;
284#endif
285
286	do_call(my_pid, ptr_cast(lcl_iov + 2), (char *) &lcl_arg_cut,
287		ARRAY_SIZE(lcl_iovec) - 1, ptr_cast(bogus_iov + 2),
288		(char *) &bogus_arg_cut, ARRAY_SIZE(bogus_iovec) - 1, 0,
289		print_iov);
290
291	lcl_arg_cut.addr_term = 0;
292
293	rmt_arg_cut.addr_term = 1;
294	rmt_arg_cut.count = 5;
295
296	do_call(my_pid, ptr_cast(lcl_iov + 2), (char *) &lcl_arg_cut,
297		ARRAY_SIZE(lcl_iovec) - 2, ptr_cast(rmt_iov + 1),
298		(char *) &rmt_arg_cut, ARRAY_SIZE(rmt_iovec), 0, print_iov);
299
300	/* Correct call */
301	do_call(my_pid, ptr_cast(lcl_iov), (char *) &lcl_arg,
302		ARRAY_SIZE(lcl_iovec), ptr_cast(rmt_iov), (char *) &rmt_arg,
303		ARRAY_SIZE(rmt_iovec), 0, print_iov);
304
305	puts("+++ exited with 0 +++");
306
307	return 0;
308}
309