1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2023 Klara, Inc.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28#include <sys/stat.h>
29#include <sys/wait.h>
30
31#include <err.h>
32#include <fcntl.h>
33#include <paths.h>
34#include <stdarg.h>
35#include <stdbool.h>
36#include <stdlib.h>
37#include <stdio.h>
38#include <string.h>
39#include <unistd.h>
40
41#define PROGNAME	"mktar"
42
43#define SUBDIRNAME	"directory"
44#define NORMALFILENAME	"file"
45#define SPARSEFILENAME	"sparse_file"
46#define HARDLINKNAME	"hard_link"
47#define SHORTLINKNAME	"short_link"
48#define LONGLINKNAME	"long_link"
49
50static bool opt_g;
51static bool opt_v;
52
53static void verbose(const char *fmt, ...)
54{
55	va_list ap;
56
57	if (!opt_v)
58		return;
59	fprintf(stderr, "%s: ", PROGNAME);
60	va_start(ap, fmt);
61	vfprintf(stderr, fmt, ap);
62	va_end(ap);
63	fprintf(stderr, "\n");
64}
65
66static void
67mknormalfile(const char *filename, mode_t mode)
68{
69	char buf[512];
70	ssize_t res;
71	int fd;
72
73	if ((fd = open(filename, O_RDWR|O_CREAT|O_EXCL, mode)) < 0)
74		err(1, "%s", filename);
75	for (unsigned int i = 0; i < sizeof(buf); i++)
76		buf[i] = 32 + i % 64;
77	res = write(fd, buf, sizeof(buf));
78	if (res < 0)
79		err(1, "%s", filename);
80	if (res != sizeof(buf))
81		errx(1, "%s: short write", filename);
82	close(fd);
83}
84
85static void
86mksparsefile(const char *filename, mode_t mode)
87{
88	char buf[511];
89	ssize_t res;
90	int fd;
91
92	if ((fd = open(filename, O_RDWR|O_CREAT|O_EXCL, mode)) < 0)
93		err(1, "%s", filename);
94	for (unsigned int i = 33; i <= 126; i++) {
95		memset(buf, i, sizeof(buf));
96		if (lseek(fd, 1048576LU * (i - 32), SEEK_SET) < 0)
97			err(1, "%s", filename);
98		res = write(fd, buf, sizeof(buf));
99		if (res < 0)
100			err(1, "%s", filename);
101		if (res != sizeof(buf))
102			errx(1, "%s: short write", filename);
103	}
104	close(fd);
105}
106
107static char *
108mklonglinktarget(const char *dirname, const char *filename)
109{
110	char *piece, *target;
111
112	if (asprintf(&piece, "%1$s/../%1$s/../%1$s/../%1$s/../", dirname) < 0)
113		err(1, "asprintf()");
114	if (asprintf(&target, "%1$s%1$s%1$s%1$s%1$s%1$s%1$s%1$s%2$s", piece, filename) < 0)
115		err(1, "asprintf()");
116	free(piece);
117	return target;
118}
119
120static void
121mktar(void)
122{
123	char *linktarget;
124
125	/* create a subdirectory */
126	verbose("mkdir %s", SUBDIRNAME);
127	if (mkdir(SUBDIRNAME, 0755) != 0)
128		err(1, "%s", SUBDIRNAME);
129
130	/* create a normal file */
131	verbose("creating %s", NORMALFILENAME);
132	mknormalfile(NORMALFILENAME, 0644);
133
134	/* create a sparse file */
135	verbose("creating %s", SPARSEFILENAME);
136	mksparsefile(SPARSEFILENAME, 0644);
137	chflags(SPARSEFILENAME, UF_NODUMP);
138
139	/* create a hard link */
140	verbose("link %s %s", SPARSEFILENAME, HARDLINKNAME);
141	if (link(SPARSEFILENAME, HARDLINKNAME) != 0)
142		err(1, "%s", HARDLINKNAME);
143
144	/* create a symbolic link with a short target */
145	verbose("symlink %s %s", SPARSEFILENAME, SHORTLINKNAME);
146	if (symlink(SPARSEFILENAME, SHORTLINKNAME) != 0)
147		err(1, "%s", SHORTLINKNAME);
148
149	/* create a symbolic link with a long target */
150	linktarget = mklonglinktarget(SUBDIRNAME, SPARSEFILENAME);
151	verbose("symlink %s %s", linktarget, LONGLINKNAME);
152	if (symlink(linktarget, LONGLINKNAME) != 0)
153		err(1, "%s", LONGLINKNAME);
154	free(linktarget);
155}
156
157static void
158usage(void)
159{
160
161	fprintf(stderr, "usage: %s [-gv] tarfile\n", PROGNAME);
162	exit(EXIT_FAILURE);
163}
164
165int
166main(int argc, char *argv[])
167{
168	const char *tarfilename;
169	char *dirname;
170	int opt, wstatus;
171	pid_t pid;
172
173	while ((opt = getopt(argc, argv, "gv")) != -1)
174		switch (opt) {
175		case 'g':
176			opt_g = true;
177			break;
178		case 'v':
179			opt_v = true;
180			break;
181		default:
182			usage();
183		}
184
185	argc -= optind;
186	argv += optind;
187
188	if (argc != 1)
189		usage();
190	tarfilename = *argv;
191
192	if (asprintf(&dirname, "%s%s.XXXXXXXX", _PATH_TMP, PROGNAME) < 0)
193		err(1, "asprintf()");
194	if (mkdtemp(dirname) == NULL)
195		err(1, "%s", dirname);
196	verbose("mkdir %s", dirname);
197
198	/* fork a child to create the files */
199	if ((pid = fork()) < 0)
200		err(1, "fork()");
201	if (pid == 0) {
202		verbose("cd %s", dirname);
203		if (chdir(dirname) != 0)
204			err(1, "%s", dirname);
205		verbose("umask 022");
206		umask(022);
207		mktar();
208		verbose("cd -");
209		exit(0);
210	}
211	if (waitpid(pid, &wstatus, 0) < 0)
212		err(1, "waitpid()");
213	if (!WIFEXITED(wstatus) || WEXITSTATUS(wstatus) != 0)
214		errx(1, "child failed");
215
216	/* fork a child to create the tarball */
217	if ((pid = fork()) < 0)
218		err(1, "fork()");
219	if (pid == 0) {
220		verbose("creating tarball");
221		execlp(opt_g ? "gtar" : "tar",
222		    "tar",
223		    "-c",
224		    "-f", tarfilename,
225		    "-C", dirname,
226		    "--posix",
227		    "--zstd",
228#if 0
229		    "--options", "zstd:frame-per-file",
230#endif
231		    "./" SUBDIRNAME "/../" NORMALFILENAME,
232		    "./" SPARSEFILENAME,
233		    "./" HARDLINKNAME,
234		    "./" SHORTLINKNAME,
235		    "./" SUBDIRNAME,
236		    "./" LONGLINKNAME,
237		    NULL);
238		err(1, "execlp()");
239	}
240	if (waitpid(pid, &wstatus, 0) < 0)
241		err(1, "waitpid()");
242	if (!WIFEXITED(wstatus) || WEXITSTATUS(wstatus) != 0)
243		errx(1, "child failed");
244
245	/* fork a child to delete everything */
246	if ((pid = fork()) < 0)
247		err(1, "fork()");
248	if (pid == 0) {
249		verbose("cd %s", dirname);
250		if (chdir(dirname) != 0)
251			err(1, "%s", dirname);
252		verbose("rm %s", LONGLINKNAME);
253		(void)unlink(LONGLINKNAME);
254		verbose("rm %s", SHORTLINKNAME);
255		(void)unlink(SHORTLINKNAME);
256		verbose("rm %s", HARDLINKNAME);
257		(void)unlink(HARDLINKNAME);
258		verbose("rm %s", SPARSEFILENAME);
259		(void)unlink(SPARSEFILENAME);
260		verbose("rmdir %s", SUBDIRNAME);
261		(void)rmdir(SUBDIRNAME);
262		verbose("cd -");
263		exit(0);
264	}
265	if (waitpid(pid, &wstatus, 0) < 0)
266		err(1, "waitpid()");
267	if (!WIFEXITED(wstatus) || WEXITSTATUS(wstatus) != 0)
268		errx(1, "child failed");
269	verbose("rmdir %s", dirname);
270	(void)rmdir(dirname);
271
272	exit(0);
273}
274