xref: /aosp_15_r20/external/ltp/testcases/kernel/syscalls/lseek/lseek01.c (revision 49cdfc7efb34551c7342be41a7384b9c40d7cab7)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (c) International Business Machines Corp., 2001
4  * 06/2017 modified by Xiao Yang <[email protected]>
5  */
6 
7 /*
8  * Description:
9  *  lseek() succeeds to set the specified offset according to whence
10  *  and read valid data from this location.
11  */
12 
13 #include <errno.h>
14 #include <string.h>
15 #include <sys/types.h>
16 #include <unistd.h>
17 #include "tst_test.h"
18 
19 #define WRITE_STR "abcdefg"
20 #define TFILE "tfile"
21 
22 static int fd;
23 static struct tcase {
24 	off_t off;
25 	int whence;
26 	char *wname;
27 	off_t exp_off;
28 	ssize_t exp_size;
29 	char *exp_data;
30 } tcases[] = {
31 	{4, SEEK_SET, "SEEK_SET", 4, 3, "efg"},
32 	{-2, SEEK_CUR, "SEEK_CUR", 5, 2, "fg"},
33 	{-4, SEEK_END, "SEEK_END", 3, 4, "defg"},
34 	{0, SEEK_END, "SEEK_END", 7, 0, NULL},
35 };
36 
verify_lseek(unsigned int n)37 static void verify_lseek(unsigned int n)
38 {
39 	char read_buf[64];
40 	struct tcase *tc = &tcases[n];
41 
42 	// reset the offset to end of file
43 	SAFE_READ(0, fd, read_buf, sizeof(read_buf));
44 
45 	memset(read_buf, 0, sizeof(read_buf));
46 
47 	TEST(lseek(fd, tc->off, tc->whence));
48 	if (TST_RET == (off_t) -1) {
49 		tst_res(TFAIL | TTERRNO, "lseek(%s, %lld, %s) failed", TFILE,
50 			(long long int)tc->off, tc->wname);
51 		return;
52 	}
53 
54 	if (TST_RET != tc->exp_off) {
55 		tst_res(TFAIL, "lseek(%s, %lld, %s) returned %ld, expected %lld",
56 			TFILE, (long long int)tc->off, tc->wname, TST_RET,
57 			(long long int)tc->exp_off);
58 		return;
59 	}
60 
61 	SAFE_READ(1, fd, read_buf, tc->exp_size);
62 
63 	if (tc->exp_data && strcmp(read_buf, tc->exp_data)) {
64 		tst_res(TFAIL, "lseek(%s, %lld, %s) read incorrect data",
65 			TFILE, (long long int)tc->off, tc->wname);
66 	} else {
67 		tst_res(TPASS, "lseek(%s, %lld, %s) read correct data",
68 			TFILE, (long long int)tc->off, tc->wname);
69 	}
70 }
71 
setup(void)72 static void setup(void)
73 {
74 	fd = SAFE_OPEN(TFILE, O_RDWR | O_CREAT, 0644);
75 
76 	SAFE_WRITE(SAFE_WRITE_ALL, fd, WRITE_STR, sizeof(WRITE_STR) - 1);
77 }
78 
cleanup(void)79 static void cleanup(void)
80 {
81 	if (fd > 0)
82 		SAFE_CLOSE(fd);
83 }
84 
85 static struct tst_test test = {
86 	.setup = setup,
87 	.cleanup = cleanup,
88 	.tcnt = ARRAY_SIZE(tcases),
89 	.test = verify_lseek,
90 	.needs_tmpdir = 1,
91 };
92