1/*
2 *   Copyright (c) International Business Machines  Corp., 2001
3 *
4 *   This program is free software;  you can redistribute it and/or modify
5 *   it under the terms of the GNU General Public License as published by
6 *   the Free Software Foundation; either version 2 of the License, or
7 *   (at your option) any later version.
8 *
9 *   This program is distributed in the hope that it will be useful,
10 *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
11 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
12 *   the GNU General Public License for more details.
13 *
14 *   You should have received a copy of the GNU General Public License
15 *   along with this program;  if not, write to the Free Software
16 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 *
18 * NAME
19 *	fork09.c
20 *
21 * DESCRIPTION
22 *	Check that child has access to a full set of files.
23 *
24 * ALGORITHM
25 *	Parent opens a maximum number of files
26 *	Child closes one and attempts to open another, it should be
27 *	available
28 *
29 * USAGE
30 *	fork09
31 *
32 * HISTORY
33 *	07/2001 Ported by Wayne Boyer
34 *
35 *	10/2008 Suzuki K P <suzuki@in.ibm.com>
36 *		Fix maximum number of files open logic.
37 *
38 * RESTRICTIONS
39 *	None
40 */
41
42#include <sys/types.h>
43#include <sys/wait.h>
44#include <sys/stat.h>
45#include <fcntl.h>
46#include <stdio.h>
47#include <errno.h>
48#include <unistd.h>		/* for _SC_OPEN_MAX */
49#include "test.h"
50#include "safe_macros.h"
51
52char *TCID = "fork09";
53int TST_TOTAL = 1;
54
55static void setup(void);
56static void cleanup(void);
57
58static char filname[40], childfile[40];
59static int first;
60static FILE **fildeses;		/* file streams */
61static int mypid, nfiles;
62
63#define OPEN_MAX (sysconf(_SC_OPEN_MAX))
64
65int main(int ac, char **av)
66{
67	int pid, status, nf;
68
69	int lc;
70
71	tst_parse_opts(ac, av, NULL, NULL);
72
73	setup();
74
75	fildeses = malloc((OPEN_MAX + 10) * sizeof(FILE *));
76	if (fildeses == NULL)
77		tst_brkm(TBROK, cleanup, "malloc failed");
78
79	for (lc = 0; TEST_LOOPING(lc); lc++) {
80		tst_count = 0;
81		mypid = getpid();
82
83		tst_resm(TINFO, "OPEN_MAX is %ld", OPEN_MAX);
84
85		/* establish first free file */
86		sprintf(filname, "fork09.%d", mypid);
87		first = SAFE_CREAT(cleanup, filname, 0660);
88		close(first);
89
90		tst_resm(TINFO, "first file descriptor is %d ", first);
91
92		SAFE_UNLINK(cleanup, filname);
93
94		/*
95		 * now open all the files for the test
96		 */
97		for (nfiles = first; nfiles < OPEN_MAX; nfiles++) {
98			sprintf(filname, "file%d.%d", nfiles, mypid);
99			fildeses[nfiles] = fopen(filname, "a");
100			if (fildeses[nfiles] == NULL) {
101				/* Did we already reach OPEN_MAX ? */
102				if (errno == EMFILE)
103					break;
104				tst_brkm(TBROK, cleanup, "Parent: cannot open "
105					 "file %d %s errno = %d", nfiles,
106					 filname, errno);
107			}
108#ifdef DEBUG
109			tst_resm(TINFO, "filname: %s", filname);
110#endif
111		}
112
113		tst_resm(TINFO, "Parent reporting %d files open", nfiles - 1);
114
115		pid = fork();
116		if (pid == -1)
117			tst_brkm(TBROK, cleanup, "Fork failed");
118
119		if (pid == 0) {	/* child */
120			nfiles--;
121			if (fclose(fildeses[nfiles]) == -1) {
122				tst_resm(TINFO, "Child could not close file "
123					 "#%d, errno = %d", nfiles, errno);
124				exit(1);
125			} else {
126				sprintf(childfile, "cfile.%d", getpid());
127				fildeses[nfiles] = fopen(childfile, "a");
128				if (fildeses[nfiles] == NULL) {
129					tst_resm(TINFO, "Child could not open "
130						 "file %s, errno = %d",
131						 childfile, errno);
132					exit(1);
133				} else {
134					tst_resm(TINFO, "Child opened new "
135						 "file #%d", nfiles);
136					unlink(childfile);
137					exit(0);
138				}
139			}
140		} else {	/* parent */
141			wait(&status);
142			if (status >> 8 != 0)
143				tst_resm(TFAIL, "test 1 FAILED");
144			else
145				tst_resm(TPASS, "test 1 PASSED");
146		}
147
148		/* clean up things in case we are looping */
149		for (nf = first; nf < nfiles; nf++) {
150			fclose(fildeses[nf]);
151			sprintf(filname, "file%d.%d", nf, mypid);
152			unlink(filname);
153		}
154	}
155
156	cleanup();
157	tst_exit();
158}
159
160static void setup(void)
161{
162	tst_sig(FORK, DEF_HANDLER, cleanup);
163	umask(0);
164
165	TEST_PAUSE;
166	tst_tmpdir();
167}
168
169static void cleanup(void)
170{
171	tst_rmdir();
172}
173