xref: /freebsd/usr.bin/protect/protect.c (revision b9f654b163bce26de79705e77b872427c9f2afa1)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2013 Hudson River Trading LLC
5  * Written by: John H. Baldwin <jhb@FreeBSD.org>
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/procctl.h>
34 #include <sys/types.h>
35 #include <sys/mman.h>
36 #include <err.h>
37 #include <errno.h>
38 #include <stdbool.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <unistd.h>
42 
43 static void
44 usage(void)
45 {
46 
47 	fprintf(stderr, "usage: protect [-i] command\n");
48 	fprintf(stderr, "       protect [-cdi] -g pgrp | -p pid\n");
49 	exit(1);
50 }
51 
52 static id_t
53 parse_id(char *id)
54 {
55 	static bool first = true;
56 	long value;
57 	char *ch;
58 
59 	if (!first) {
60 		warnx("only one -g or -p flag is permitted");
61 		usage();
62 	}
63 	value = strtol(id, &ch, 0);
64 	if (*ch != '\0') {
65 		warnx("invalid process id");
66 		usage();
67 	}
68 	return (value);
69 }
70 
71 int
72 main(int argc, char *argv[])
73 {
74 	idtype_t idtype;
75 	id_t id;
76 	int ch, flags;
77 	bool descend, inherit, idset;
78 
79 	idtype = P_PID;
80 	id = getpid();
81 	flags = PPROT_SET;
82 	descend = inherit = idset = false;
83 	while ((ch = getopt(argc, argv, "cdig:p:")) != -1)
84 		switch (ch) {
85 		case 'c':
86 			flags = PPROT_CLEAR;
87 			break;
88 		case 'd':
89 			descend = true;
90 			break;
91 		case 'i':
92 			inherit = true;
93 			break;
94 		case 'g':
95 			idtype = P_PGID;
96 			id = parse_id(optarg);
97 			idset = true;
98 			break;
99 		case 'p':
100 			idtype = P_PID;
101 			id = parse_id(optarg);
102 			idset = true;
103 			break;
104 		}
105 	argc -= optind;
106 	argv += optind;
107 
108 	if ((idset && argc != 0) || (!idset && (argc == 0 || descend)))
109 		usage();
110 
111 	if (descend)
112 		flags |= PPROT_DESCEND;
113 	if (inherit)
114 		flags |= PPROT_INHERIT;
115 	if (procctl(idtype, id, PROC_SPROTECT, &flags) == -1)
116 		err(1, "procctl");
117 
118 	if (argc != 0) {
119 		errno = 0;
120 		execvp(*argv, argv);
121 		err(errno == ENOENT ? 127 : 126, "%s", *argv);
122 	}
123 	return (0);
124 }
125