ktrace.c revision 1.22 
1/*	$OpenBSD: ktrace.c,v 1.22 2009/10/27 23:59:39 deraadt Exp $	*/
2/*	$NetBSD: ktrace.c,v 1.4 1995/08/31 23:01:44 jtc Exp $	*/
3
4/*-
5 * Copyright (c) 1988, 1993
6 *	The Regents of the University of California.  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 * 3. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#include <sys/param.h>
34#include <sys/stat.h>
35#include <sys/time.h>
36#include <sys/uio.h>
37#include <sys/ktrace.h>
38
39#include <err.h>
40#include <errno.h>
41#include <fcntl.h>
42#include <stdlib.h>
43#include <stdio.h>
44#include <string.h>
45#include <unistd.h>
46
47#include "ktrace.h"
48#include "extern.h"
49
50static int rpid(const char *);
51static void no_ktrace(int);
52static void usage(void);
53
54int
55main(int argc, char *argv[])
56{
57	enum { NOTSET, CLEAR, CLEARALL } clear;
58	int append, ch, fd, inherit, ops, pidset, trpoints;
59	pid_t pid;
60	char *tracefile;
61	mode_t omask;
62	struct stat sb;
63
64	clear = NOTSET;
65	append = ops = pidset = inherit = pid = 0;
66	trpoints = DEF_POINTS;
67	tracefile = DEF_TRACEFILE;
68	while ((ch = getopt(argc,argv,"aCcdf:g:ip:t:")) != -1)
69		switch((char)ch) {
70		case 'a':
71			append = 1;
72			break;
73		case 'C':
74			clear = CLEARALL;
75			pidset = 1;
76			break;
77		case 'c':
78			clear = CLEAR;
79			break;
80		case 'd':
81			ops |= KTRFLAG_DESCEND;
82			break;
83		case 'f':
84			tracefile = optarg;
85			break;
86		case 'g':
87			pid = -rpid(optarg);
88			pidset = 1;
89			break;
90		case 'i':
91			inherit = 1;
92			break;
93		case 'p':
94			pid = rpid(optarg);
95			pidset = 1;
96			break;
97		case 't':
98			trpoints = getpoints(optarg);
99			if (trpoints < 0) {
100				warnx("unknown facility in %s", optarg);
101				usage();
102			}
103			break;
104		default:
105			usage();
106		}
107	argv += optind;
108	argc -= optind;
109
110	if ((pidset && *argv) || (!pidset && !*argv && clear != CLEAR))
111		usage();
112
113	if (inherit)
114		trpoints |= KTRFAC_INHERIT;
115
116	(void)signal(SIGSYS, no_ktrace);
117	if (clear != NOTSET) {
118		if (clear == CLEARALL) {
119			ops = KTROP_CLEAR | KTRFLAG_DESCEND;
120			trpoints = ALL_POINTS;
121			pid = 1;
122		} else
123			ops |= pid ? KTROP_CLEAR : KTROP_CLEARFILE;
124
125		if (ktrace(tracefile, ops, trpoints, pid) < 0)
126			err(1, "%s", tracefile);
127		exit(0);
128	}
129
130	omask = umask(S_IRWXG|S_IRWXO);
131	if (append) {
132		if ((fd = open(tracefile, O_CREAT | O_WRONLY, DEFFILEMODE)) < 0)
133			err(1, "%s", tracefile);
134		if (fstat(fd, &sb) != 0 || sb.st_uid != getuid())
135			errx(1, "Refuse to append to %s: not owned by you.",
136			    tracefile);
137	} else {
138		if (unlink(tracefile) == -1 && errno != ENOENT)
139			err(1, "unlink %s", tracefile);
140		if ((fd = open(tracefile, O_CREAT | O_EXCL | O_WRONLY,
141		    DEFFILEMODE)) < 0)
142			err(1, "%s", tracefile);
143	}
144	(void)umask(omask);
145	(void)close(fd);
146
147	if (*argv) {
148		if (ktrace(tracefile, ops, trpoints, getpid()) < 0)
149			err(1, "%s", tracefile);
150		execvp(argv[0], &argv[0]);
151		err(1, "exec of '%s' failed", argv[0]);
152	}
153	else if (ktrace(tracefile, ops, trpoints, pid) < 0)
154		err(1, "%s", tracefile);
155	exit(0);
156}
157
158static int
159rpid(const char *p)
160{
161	static int first;
162
163	if (first++) {
164		warnx("only one -g or -p flag is permitted.");
165		usage();
166	}
167	if (!*p) {
168		warnx("illegal process id.");
169		usage();
170	}
171	return(atoi(p));
172}
173
174static void
175usage(void)
176{
177	(void)fprintf(stderr,
178	    "usage: ktrace [-aCcdi] [-f trfile] [-g pgid] [-p pid] [-t trstr]\n"
179	    "       ktrace [-adi] [-f trfile] [-t trstr] command\n");
180	exit(1);
181}
182
183/* ARGSUSED */
184static void
185no_ktrace(int signo)
186{
187	char buf[8192];
188
189	snprintf(buf, sizeof(buf),
190"error:\tktrace() system call not supported in the running kernel\n\tre-compile kernel with 'option KTRACE'\n");
191	write(STDERR_FILENO, buf, strlen(buf));
192	_exit(1);
193}
194