xref: /freebsd/usr.bin/pathchk/pathchk.c (revision cd0d51baaa4509a1db83251a601d34404d20c990)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2002 Tim J. Robbins.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 /*
30  * pathchk -- check pathnames
31  *
32  * Check whether files could be created with the names specified on the
33  * command line. If -p is specified, check whether the pathname is portable
34  * to all POSIX systems.
35  */
36 
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include <sys/types.h>
41 #include <sys/stat.h>
42 
43 #include <err.h>
44 #include <errno.h>
45 #include <limits.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <unistd.h>
50 
51 static int	 check(const char *);
52 static int	 portable(const char *);
53 static void	 usage(void);
54 
55 static int	 pflag;			/* Perform portability checks */
56 static int	 Pflag;			/* Check for empty paths, leading '-' */
57 
58 int
59 main(int argc, char *argv[])
60 {
61 	int ch, rval;
62 	const char *arg;
63 
64 	while ((ch = getopt(argc, argv, "pP")) > 0) {
65 		switch (ch) {
66 		case 'p':
67 			pflag = 1;
68 			break;
69 		case 'P':
70 			Pflag = 1;
71 			break;
72 		default:
73 			usage();
74 			/*NOTREACHED*/
75 		}
76 	}
77 	argc -= optind;
78 	argv += optind;
79 
80 	if (argc == 0)
81 		usage();
82 
83 	rval = 0;
84 	while ((arg = *argv++) != NULL)
85 		rval |= check(arg);
86 
87 	exit(rval);
88 }
89 
90 static void
91 usage(void)
92 {
93 
94 	fprintf(stderr, "usage: pathchk [-Pp] pathname ...\n");
95 	exit(1);
96 }
97 
98 static int
99 check(const char *path)
100 {
101 	struct stat sb;
102 	long complen, namemax, pathmax, svnamemax;
103 	int last;
104 	char *end, *p, *pathd;
105 
106 	if ((pathd = strdup(path)) == NULL)
107 		err(1, "strdup");
108 
109 	p = pathd;
110 
111 	if (Pflag && *p == '\0') {
112 		warnx("%s: empty pathname", path);
113 		goto bad;
114 	}
115 	if ((Pflag || pflag) && (*p == '-' || strstr(p, "/-") != NULL)) {
116 		warnx("%s: contains a component starting with '-'", path);
117 		goto bad;
118 	}
119 
120 	if (!pflag) {
121 		errno = 0;
122 		namemax = pathconf(*p == '/' ? "/" : ".", _PC_NAME_MAX);
123 		if (namemax == -1 && errno != 0)
124 			namemax = NAME_MAX;
125 	} else
126 		namemax = _POSIX_NAME_MAX;
127 
128 	for (;;) {
129 		p += strspn(p, "/");
130 		complen = (long)strcspn(p, "/");
131 		end = p + complen;
132 		last = *end == '\0';
133 		*end = '\0';
134 
135 		if (namemax != -1 && complen > namemax) {
136 			warnx("%s: %s: component too long (limit %ld)", path,
137 			    p, namemax);
138 			goto bad;
139 		}
140 
141 		if (!pflag && stat(pathd, &sb) == -1 && errno != ENOENT) {
142 			warn("%s: %.*s", path, (int)(strlen(pathd) -
143 			    complen - 1), pathd);
144 			goto bad;
145 		}
146 
147 		if (pflag && !portable(p)) {
148 			warnx("%s: %s: component contains non-portable "
149 			    "character", path, p);
150 			goto bad;
151 		}
152 
153 		if (last)
154 			break;
155 
156 		if (!pflag) {
157 			errno = 0;
158 			svnamemax = namemax;
159 			namemax = pathconf(pathd, _PC_NAME_MAX);
160 			if (namemax == -1 && errno != 0)
161 				namemax = svnamemax;
162 		}
163 
164 		*end = '/';
165 		p = end + 1;
166 	}
167 
168 	if (!pflag) {
169 		errno = 0;
170 		pathmax = pathconf(path, _PC_PATH_MAX);
171 		if (pathmax == -1 && errno != 0)
172 			pathmax = PATH_MAX;
173 	} else
174 		pathmax = _POSIX_PATH_MAX;
175 	if (pathmax != -1 && strlen(path) >= (size_t)pathmax) {
176 		warnx("%s: path too long (limit %ld)", path, pathmax - 1);
177 		goto bad;
178 	}
179 
180 	free(pathd);
181 	return (0);
182 
183 bad:	free(pathd);
184 	return (1);
185 }
186 
187 /*
188  * Check whether a path component contains only portable characters.
189  */
190 static int
191 portable(const char *path)
192 {
193 	static const char charset[] =
194 	    "abcdefghijklmnopqrstuvwxyz"
195 	    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
196 	    "0123456789._-";
197 	long s;
198 
199 	s = strspn(path, charset);
200 	if (path[s] != '\0')
201 		return (0);
202 
203 	return (1);
204 }
205