1 /*
2  * Copyright (c) International Business Machines  Corp., 2001
3  * 06/2017 modified by Xiao Yang <yangx.jy@cn.fujitsu.com>
4  *
5  * This program is free software;  you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; either version 2 of the License, or
8  * (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY;  without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
13  * the GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program;  if not, see <http://www.gnu.org/licenses/>.
17  */
18 
19 /*
20  * Description:
21  *  lseek() succeeds to set the specified offset according to whence
22  *  and read valid data from this location.
23  */
24 
25 #include <errno.h>
26 #include <string.h>
27 #include <sys/types.h>
28 #include <unistd.h>
29 #include "tst_test.h"
30 
31 #define WRITE_STR "abcdefg"
32 #define TFILE "tfile"
33 
34 static int fd;
35 static struct tcase {
36 	off_t off;
37 	int whence;
38 	char *wname;
39 	off_t exp_off;
40 	ssize_t exp_size;
41 	char *exp_data;
42 } tcases[] = {
43 	{4, SEEK_SET, "SEEK_SET", 4, 3, "efg"},
44 	{-2, SEEK_CUR, "SEEK_CUR", 5, 2, "fg"},
45 	{-4, SEEK_END, "SEEK_END", 3, 4, "defg"},
46 	{0, SEEK_END, "SEEK_END", 7, 0, NULL},
47 };
48 
49 static void verify_lseek(unsigned int n)
50 {
51 	char read_buf[64];
52 	struct tcase *tc = &tcases[n];
53 
54 	// reset the offset to end of file
55 	SAFE_READ(0, fd, read_buf, sizeof(read_buf));
56 
57 	memset(read_buf, 0, sizeof(read_buf));
58 
59 	TEST(lseek(fd, tc->off, tc->whence));
60 	if (TEST_RETURN == (off_t) -1) {
61 		tst_res(TFAIL | TTERRNO, "lseek(%s, %ld, %s) failed", TFILE,
62 			tc->off, tc->wname);
63 		return;
64 	}
65 
66 	if (TEST_RETURN != tc->exp_off) {
67 		tst_res(TFAIL, "lseek(%s, %ld, %s) returned %ld, expected %ld",
68 			TFILE, tc->off, tc->wname, TEST_RETURN, tc->exp_off);
69 		return;
70 	}
71 
72 	SAFE_READ(1, fd, read_buf, tc->exp_size);
73 
74 	if (tc->exp_data && strcmp(read_buf, tc->exp_data)) {
75 		tst_res(TFAIL, "lseek(%s, %ld, %s) read incorrect data",
76 			TFILE, tc->off, tc->wname);
77 	} else {
78 		tst_res(TPASS, "lseek(%s, %ld, %s) read correct data",
79 			TFILE, tc->off, tc->wname);
80 	}
81 }
82 
83 static void setup(void)
84 {
85 	fd = SAFE_OPEN(TFILE, O_RDWR | O_CREAT, 0644);
86 
87 	SAFE_WRITE(1, fd, WRITE_STR, sizeof(WRITE_STR) - 1);
88 }
89 
90 static void cleanup(void)
91 {
92 	if (fd > 0)
93 		SAFE_CLOSE(fd);
94 }
95 
96 static struct tst_test test = {
97 	.setup = setup,
98 	.cleanup = cleanup,
99 	.tcnt = ARRAY_SIZE(tcases),
100 	.test = verify_lseek,
101 	.needs_tmpdir = 1,
102 };
103