summaryrefslogtreecommitdiff
path: root/usr.bin/sudo/find_path.c
blob: 8bb2c140cc35dbfe6f860cacd99ae81d2d0994e7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
/*
 * Copyright (c) 1996, 1998-2003 Todd C. Miller <Todd.Miller@courtesan.com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * 4. Products derived from this software may not be called "Sudo" nor
 *    may "Sudo" appear in their names without specific prior written
 *    permission from the author.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Sponsored in part by the Defense Advanced Research Projects
 * Agency (DARPA) and Air Force Research Laboratory, Air Force
 * Materiel Command, USAF, under agreement number F39502-99-1-0512.
 */

#include "config.h"

#include <sys/types.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <stdio.h>
#ifdef STDC_HEADERS
# include <stdlib.h>
# include <stddef.h>
#else
# ifdef HAVE_STDLIB_H
#  include <stdlib.h>
# endif
#endif /* STDC_HEADERS */
#ifdef HAVE_STRING_H
# include <string.h>
#else
# ifdef HAVE_STRINGS_H
#  include <strings.h>
# endif
#endif /* HAVE_STRING_H */
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif /* HAVE_UNISTD_H */
#ifdef HAVE_ERR_H
# include <err.h>
#else
# include "emul/err.h"
#endif /* HAVE_ERR_H */

#include "sudo.h"

#ifndef lint
static const char rcsid[] = "$Sudo: find_path.c,v 1.103 2003/04/16 00:42:10 millert Exp $";
#endif /* lint */

/*
 * This function finds the full pathname for a command and
 * stores it in a statically allocated array, filling in a pointer
 * to the array.  Returns FOUND if the command was found, NOT_FOUND
 * if it was not found, or NOT_FOUND_DOT if it would have been found
 * but it is in '.' and IGNORE_DOT is set.
 */
int
find_path(infile, outfile, path)
    char *infile;		/* file to find */
    char **outfile;		/* result parameter */
    char *path;			/* path to search */
{
    static char command[MAXPATHLEN]; /* qualified filename */
    char *n;			/* for traversing path */
    char *origpath;		/* so we can free path later */
    char *result = NULL;	/* result of path/file lookup */
    int checkdot = 0;		/* check current dir? */
    int len;			/* length parameter */

    if (strlen(infile) >= MAXPATHLEN)
	errx(1, "%s: File name too long", infile);

    /*
     * If we were given a fully qualified or relative path
     * there is no need to look at $PATH.
     */
    if (strchr(infile, '/')) {
	strlcpy(command, infile, sizeof(command));	/* paranoia */
	if (sudo_goodpath(command)) {
	    *outfile = command;
	    return(FOUND);
	} else
	    return(NOT_FOUND);
    }

    /* Use PATH passed in unless SECURE_PATH is in effect.  */
#ifdef SECURE_PATH
    if (!user_is_exempt())
	path = SECURE_PATH;
#endif /* SECURE_PATH */
    if (path == NULL)
	return(NOT_FOUND);
    path = estrdup(path);
    origpath = path;

    do {
	if ((n = strchr(path, ':')))
	    *n = '\0';

	/*
	 * Search current dir last if it is in PATH This will miss sneaky
	 * things like using './' or './/' 
	 */
	if (*path == '\0' || (*path == '.' && *(path + 1) == '\0')) {
	    checkdot = 1;
	    path = n + 1;
	    continue;
	}

	/*
	 * Resolve the path and exit the loop if found.
	 */
	len = snprintf(command, sizeof(command), "%s/%s", path, infile);
	if (len <= 0 || len >= sizeof(command))
	    errx(1, "%s: File name too long", infile);
	if ((result = sudo_goodpath(command)))
	    break;

	path = n + 1;

    } while (n);
    free(origpath);

    /*
     * Check current dir if dot was in the PATH
     */
    if (!result && checkdot) {
	result = sudo_goodpath(infile);
	if (result && def_flag(I_IGNORE_DOT))
	    return(NOT_FOUND_DOT);
    }

    if (result) {
	*outfile = result;
	return(FOUND);
    } else
	return(NOT_FOUND);
}