xref: /illumos-gate/usr/src/cmd/pfexec/pfexec.c (revision 511ef1d6)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2014 Gary Mills
23  * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
24  */
25 
26 /*
27  * New implementation of pfexec(1) and all of the profile shells.
28  *
29  * The algorithm is as follows:
30  * 	first try to derive the shell's path from getexecname();
31  *	note that this requires a *hard* link to the program, so
32  *	if we find that we are actually executing pfexec, we start
33  *	looking at argv[0].
34  *	argv[0] is also our fallback in case getexecname doesn't find it.
35  */
36 #include <sys/param.h>
37 #include <alloca.h>
38 #include <errno.h>
39 #include <locale.h>
40 #include <priv.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <unistd.h>
45 
46 #define	PFEXEC	"pfexec"
47 #ifndef TEXT_DOMAIN
48 #define	TEXT_DOMAIN	"SYS_TEST"
49 #endif
50 
51 #define	RES_PFEXEC	1
52 #define	RES_OK		0
53 #define	RES_FAILURE	-1
54 
55 /*
56  * Return the shellname
57  */
58 int
shellname(const char * name,char buf[MAXPATHLEN])59 shellname(const char *name, char buf[MAXPATHLEN])
60 {
61 	const char *cmd = strrchr(name, '/');
62 
63 	if (cmd == NULL)
64 		cmd = name;
65 	else
66 		cmd++;
67 
68 	if (strncmp(cmd, "pf", 2) != 0)
69 		return (RES_FAILURE);
70 
71 	if (strcmp(cmd, PFEXEC) == 0)
72 		return (RES_PFEXEC);
73 
74 	if (strlen(name) >= MAXPATHLEN)
75 		return (RES_FAILURE);
76 
77 	if (cmd == name) {
78 		(void) strlcpy(buf, cmd + 2, MAXPATHLEN);
79 	} else {
80 		(void) strncpy(buf, name, cmd - name);
81 		(void) strcpy(buf + (cmd - name), cmd + 2);
82 	}
83 	return (RES_OK);
84 
85 }
86 
87 static void
usage(void)88 usage(void)
89 {
90 	(void) fprintf(stderr, gettext("pfexec [-P privset] cmd [arg ..]\n"));
91 	exit(EXIT_FAILURE);
92 }
93 
94 int
main(int argc,char ** argv)95 main(int argc, char **argv)
96 {
97 	char *cmd;
98 	char *pset = NULL;
99 	char pathbuf[MAXPATHLEN];
100 	int c;
101 	priv_set_t *wanted;
102 	int oflag;
103 
104 	oflag = getpflags(PRIV_PFEXEC);
105 	if (setpflags(PRIV_PFEXEC, 1) != 0) {
106 		(void) fprintf(stderr,
107 		    gettext("pfexec: unable to set PFEXEC flag: %s\n"),
108 		    strerror(errno));
109 		exit(1);
110 	}
111 
112 	if (*argv[0] == '-')
113 		cmd = argv[0] + 1;
114 	else
115 		cmd = argv[0];
116 
117 	/* Strip "pf" from argv[0], it confuses some shells. */
118 	if (strncmp(cmd, "pf", 2) == 0) {
119 		argv[0] += 2;
120 		/* argv[0] will need to start with '-' again. */
121 		if (argv[0][-2] == '-')
122 			*argv[0] = '-';
123 	}
124 
125 	/* If this fails, we just continue with plan B */
126 	if (shellname(getexecname(), pathbuf) == RES_OK)
127 		(void) execv(pathbuf, argv);
128 
129 	switch (shellname(cmd, pathbuf)) {
130 	case RES_OK:
131 		(void) execv(pathbuf, argv);
132 		(void) fprintf(stderr,
133 		    gettext("pfexec: unable to execute %s: %s\n"),
134 		    pathbuf, strerror(errno));
135 		return (1);
136 	case RES_PFEXEC:
137 	case RES_FAILURE:
138 		while ((c = getopt(argc, argv, "P:")) != EOF) {
139 			switch (c) {
140 			case 'P':
141 				if (pset == NULL) {
142 					pset = optarg;
143 					break;
144 				}
145 				/* FALLTHROUGH */
146 			default:
147 				usage();
148 			}
149 		}
150 		argc -= optind;
151 		argv += optind;
152 		if (argc < 1)
153 			usage();
154 
155 		if (pset != NULL) {
156 			if ((wanted = priv_str_to_set(pset, ",", NULL)) ==
157 			    NULL) {
158 				(void) fprintf(stderr,
159 				    gettext("pfexec: error parsing "
160 				    "privileges: %s\n"), strerror(errno));
161 				exit(EXIT_FAILURE);
162 			}
163 			if (setppriv(PRIV_ON, PRIV_INHERITABLE, wanted) != 0) {
164 				(void) fprintf(stderr,
165 				    gettext("pfexec: error setting "
166 				    "privileges: %s\n"), strerror(errno));
167 				exit(EXIT_FAILURE);
168 			}
169 			(void) setpflags(PRIV_PFEXEC, oflag);
170 		}
171 
172 		(void) execvp(argv[0], argv);
173 		(void) fprintf(stderr,
174 		    gettext("pfexec: unable to execute %s: %s\n"),
175 		    argv[0], strerror(errno));
176 		return (1);
177 	}
178 	return (1);
179 }
180