1/*
2 *
3 *   Copyright (c) International Business Machines  Corp., 2002
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, write to the Free Software
17 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18 */
19
20/*
21 * NAME
22 *	pipe04.c
23 *
24 * DESCRIPTION
25 * 	Check that processes are killable, even when they are still writing
26 * 	data to a pipe.
27 *
28 * ALGORITHM
29 * 	1. Open a pipe
30 * 	2. fork a two children that will write to the pipe
31 * 	3. read a bit from both children
32 * 	3. kill both children and wait to make sure they die
33 *
34 * USAGE:  <for command-line>
35 *  pipe04 [-c n] [-f] [-i n] [-I x] [-P x] [-t]
36 *     where,  -c n : Run n copies concurrently.
37 *             -f   : Turn off functionality Testing.
38 *             -i n : Execute test n times.
39 *             -I x : Execute test for x seconds.
40 *             -P x : Pause for x seconds between iterations.
41 *             -t   : Turn on syscall timing.
42 *
43 * HISTORY
44 *	11/2002 Ported by Paul Larson
45 */
46#include <unistd.h>
47#include <errno.h>
48#include <signal.h>
49#include <sys/types.h>
50#include <sys/wait.h>
51#include "test.h"
52#include "safe_macros.h"
53
54char *TCID = "pipe04";
55int TST_TOTAL = 1;
56
57int fildes[2];			/* fds for pipe read and write */
58
59void setup(void);
60void cleanup(void);
61void c1func(void);
62void c2func(void);
63void alarmfunc(int);
64
65ssize_t do_read(int fd, void *buf, size_t count)
66{
67	ssize_t n;
68
69	do {
70		n = read(fd, buf, count);
71	} while (n < 0 && errno == EINTR);
72
73	return n;
74}
75
76int main(int ac, char **av)
77{
78	int lc;
79	pid_t c1pid, c2pid;
80	int wtstatus;
81	int bytesread;
82	int acnt = 0, bcnt = 0;
83
84	char rbuf[BUFSIZ];
85
86	tst_parse_opts(ac, av, NULL, NULL);
87#ifdef UCLINUX
88	maybe_run_child(&c1func, "ndd", 1, &fildes[0], &fildes[1]);
89	maybe_run_child(&c2func, "ndd", 2, &fildes[0], &fildes[1]);
90#endif
91
92	setup();
93
94	for (lc = 0; TEST_LOOPING(lc); lc++) {
95
96		/* reset tst_count in case we are looping */
97		tst_count = 0;
98
99		SAFE_PIPE(cleanup, fildes);
100
101		if ((c1pid = FORK_OR_VFORK()) == -1)
102			tst_brkm(TBROK, cleanup, "fork() failed - "
103				 "errno %d", errno);
104		if (c1pid == 0)
105#ifdef UCLINUX
106			if (self_exec(av[0], "ndd", 1, fildes[0], fildes[1]) <
107			    0) {
108				tst_brkm(TBROK, cleanup, "self_exec failed");
109			}
110#else
111			c1func();
112#endif
113		if ((c2pid = FORK_OR_VFORK()) == -1)
114			tst_brkm(TBROK, cleanup, "fork() failed - "
115				 "errno %d", errno);
116		if (c2pid == 0)
117#ifdef UCLINUX
118			if (self_exec(av[0], "ndd", 2, fildes[0], fildes[1]) <
119			    0) {
120				tst_brkm(TBROK, cleanup, "self_exec failed");
121			}
122#else
123			c2func();
124#endif
125
126		/* PARENT */
127		if (close(fildes[1]) == -1)
128			tst_resm(TWARN, "Could not close fildes[1] - errno %d",
129				 errno);
130		/*
131		 * Read a bit from the children first
132		 */
133		while ((acnt < 100) && (bcnt < 100)) {
134			bytesread = do_read(fildes[0], rbuf, sizeof(rbuf));
135			if (bytesread < 0) {
136				tst_resm(TFAIL, "Unable to read from pipe, "
137					 "errno=%d", errno);
138				break;
139			}
140			switch (rbuf[1]) {
141			case 'A':
142				acnt++;
143				break;
144			case 'b':
145				bcnt++;
146				break;
147			default:
148				tst_resm(TFAIL, "Got bogus '%c' "
149					 "character", rbuf[1]);
150				break;
151			}
152		}
153
154		/*
155		 * Try to kill the children
156		 */
157		if (kill(c1pid, SIGKILL) == -1)
158			tst_resm(TFAIL, "failed to kill child 1, errno=%d",
159				 errno);
160		if (kill(c2pid, SIGKILL) == -1)
161			tst_resm(TFAIL, "failed to kill child 1, errno=%d",
162				 errno);
163
164		/*
165		 * Set action for the alarm
166		 */
167		if (signal(SIGALRM, alarmfunc) == SIG_ERR)
168			tst_resm(TWARN | TERRNO, "call to signal failed");
169		/*
170		 * Set an alarm for 60 seconds just in case the child
171		 * processes don't die
172		 */
173		alarm(60);
174		if (waitpid(c1pid, &wtstatus, 0) != -1) {
175			if (wtstatus != SIGKILL)
176				tst_resm(TFAIL | TERRNO,
177					 "unexpected wait status " "%d",
178					 wtstatus);
179			else
180				tst_resm(TPASS, "Child 1 killed while "
181					 "writing to a pipe");
182		}
183		if (waitpid(c2pid, &wtstatus, 0) != -1) {
184			if (!WIFSIGNALED(wtstatus) ||
185			    WTERMSIG(wtstatus) != SIGKILL)
186				tst_resm(TFAIL | TERRNO,
187					 "unexpected wait status " "%d",
188					 wtstatus);
189			else
190				tst_resm(TPASS, "Child 2 killed while "
191					 "writing to a pipe");
192		}
193		if (alarm(0) <= 0)
194			tst_resm(TWARN, "call to alarm(0) failed");
195	}
196	cleanup();
197
198	tst_exit();
199}
200
201/*
202 * setup() - performs all ONE TIME setup for this test.
203 */
204void setup(void)
205{
206
207	tst_sig(FORK, DEF_HANDLER, cleanup);
208
209	TEST_PAUSE;
210}
211
212/*
213 * cleanup() - performs all ONE TIME cleanup for this test at
214 *	       completion or premature exit.
215 */
216void cleanup(void)
217{
218}
219
220void c1func(void)
221{
222	if (close(fildes[0]) == -1)
223		tst_resm(TWARN, "Could not close fildes[0] - errno %d", errno);
224	while (1)
225		if (write(fildes[1], "bbbbbbbbbbbbbbbbbbbbbbbbb", 25) == -1)
226			tst_resm(TBROK | TERRNO, "[child 1] pipe write failed");
227}
228
229void c2func(void)
230{
231	if (close(fildes[0]) == -1)
232		tst_resm(TWARN, "Could not close fildes[0] - errno %d", errno);
233	while (1)
234		if (write(fildes[1], "AAAAAAAAAAAAAAAAAAAAAAAAA", 25) == -1)
235			tst_resm(TBROK | TERRNO, "[child 2] pipe write failed");
236}
237
238void alarmfunc(int sig)
239{
240	/* for some reason tst_brkm doesn't seem to work in a signal handler */
241	tst_brkm(TFAIL, cleanup, "one or more children did't die in 60 second "
242		 "time limit");
243}
244