1 /*
2  *
3  *   Copyright (c) International Business Machines  Corp., 2001
4  *	07/2001 Ported by John George
5  *      04/2002 wjhuie sigset cleanups
6  *      08/2007 Ricardo Salveti de Araujo <rsalveti@linux.vnet.ibm.com>
7  *
8  *   This program is free software;  you can redistribute it and/or modify
9  *   it under the terms of the GNU General Public License as published by
10  *   the Free Software Foundation; either version 2 of the License, or
11  *   (at your option) any later version.
12  *
13  *   This program is distributed in the hope that it will be useful,
14  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
15  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
16  *   the GNU General Public License for more details.
17  *
18  *   You should have received a copy of the GNU General Public License
19  *   along with this program;  if not, write to the Free Software
20  *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 /*
24  * DESCRIPTION
25  *	Check the return value, and errnos of write(2)
26  *	- when the file descriptor is invalid - EBADF
27  *	- when the buf parameter is invalid - EFAULT
28  *	- on an attempt to write to a pipe that is not open for reading - EPIPE
29  */
30 #include <sys/types.h>
31 #include <sys/stat.h>
32 #include <fcntl.h>
33 #include <errno.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <sys/wait.h>
37 #include <sys/mman.h>
38 #include "tst_test.h"
39 
40 static int fd;
41 static int inv_fd = -1;
42 static char b[32];
43 static char *buf = b;
44 static char *bad_addr;
45 static int pipefd[2];
46 
47 static struct tcase {
48 	int *fd;
49 	char **buf;
50 	size_t size;
51 	int exp_errno;
52 } tcases[] = {
53 	{&inv_fd, &buf, sizeof(buf), EBADF},
54 	{&fd, &bad_addr, sizeof(buf), EFAULT},
55 	{&pipefd[1], &buf, sizeof(buf), EPIPE},
56 };
57 
58 static int sigpipe_cnt;
59 
sighandler(int sig)60 static void sighandler(int sig)
61 {
62 	if (sig == SIGPIPE)
63 		sigpipe_cnt++;
64 }
65 
verify_write(unsigned int i)66 static void verify_write(unsigned int i)
67 {
68 	struct tcase *tc = &tcases[i];
69 
70 	sigpipe_cnt = 0;
71 
72 	TEST(write(*tc->fd, *tc->buf, tc->size));
73 
74 	if (TST_RET != -1) {
75 		tst_res(TFAIL, "write() succeeded unexpectedly");
76 		return;
77 	}
78 
79 	if (TST_ERR != tc->exp_errno) {
80 		tst_res(TFAIL | TTERRNO,
81 			"write() failed unexpectedly, expected %s",
82 			tst_strerrno(tc->exp_errno));
83 		return;
84 	}
85 
86 	if (tc->exp_errno == EPIPE && sigpipe_cnt != 1) {
87 		tst_res(TFAIL, "sigpipe_cnt = %i", sigpipe_cnt);
88 		return;
89 	}
90 
91 	tst_res(TPASS | TTERRNO, "write() failed expectedly");
92 }
93 
setup(void)94 static void setup(void)
95 {
96 	fd = SAFE_OPEN("write_test", O_RDWR | O_CREAT, 0644);
97 
98 	bad_addr = SAFE_MMAP(0, 1, PROT_NONE,
99 			MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);
100 
101 	SAFE_PIPE(pipefd);
102 	SAFE_CLOSE(pipefd[0]);
103 
104 	SAFE_SIGNAL(SIGPIPE, sighandler);
105 }
106 
cleanup(void)107 static void cleanup(void)
108 {
109 	if (fd > 0)
110 		SAFE_CLOSE(fd);
111 
112 	SAFE_MUNMAP(bad_addr, 1);
113 }
114 
115 static struct tst_test test = {
116 	.needs_tmpdir = 1,
117 	.setup = setup,
118 	.cleanup = cleanup,
119 	.test = verify_write,
120 	.tcnt = ARRAY_SIZE(tcases),
121 };
122