ktrace.c revision 1.24 
1/*	$OpenBSD: ktrace.c,v 1.24 2012/07/12 18:03:29 jmc 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,"aBCcdf:g:ip:t:")) != -1)
69		switch((char)ch) {
70		case 'a':
71			append = 1;
72			break;
73		case 'B':
74			putenv("LD_BIND_NOW=");
75			break;
76		case 'C':
77			clear = CLEARALL;
78			pidset = 1;
79			break;
80		case 'c':
81			clear = CLEAR;
82			break;
83		case 'd':
84			ops |= KTRFLAG_DESCEND;
85			break;
86		case 'f':
87			tracefile = optarg;
88			break;
89		case 'g':
90			pid = -rpid(optarg);
91			pidset = 1;
92			break;
93		case 'i':
94			inherit = 1;
95			break;
96		case 'p':
97			pid = rpid(optarg);
98			pidset = 1;
99			break;
100		case 't':
101			trpoints = getpoints(optarg);
102			if (trpoints < 0) {
103				warnx("unknown facility in %s", optarg);
104				usage();
105			}
106			break;
107		default:
108			usage();
109		}
110	argv += optind;
111	argc -= optind;
112
113	if ((pidset && *argv) || (!pidset && !*argv && clear != CLEAR))
114		usage();
115
116	if (inherit)
117		trpoints |= KTRFAC_INHERIT;
118
119	(void)signal(SIGSYS, no_ktrace);
120	if (clear != NOTSET) {
121		if (clear == CLEARALL) {
122			ops = KTROP_CLEAR | KTRFLAG_DESCEND;
123			trpoints = ALL_POINTS;
124			pid = 1;
125		} else
126			ops |= pid ? KTROP_CLEAR : KTROP_CLEARFILE;
127
128		if (ktrace(tracefile, ops, trpoints, pid) < 0)
129			err(1, "%s", tracefile);
130		exit(0);
131	}
132
133	omask = umask(S_IRWXG|S_IRWXO);
134	if (append) {
135		if ((fd = open(tracefile, O_CREAT | O_WRONLY, DEFFILEMODE)) < 0)
136			err(1, "%s", tracefile);
137		if (fstat(fd, &sb) != 0 || sb.st_uid != getuid())
138			errx(1, "Refuse to append to %s: not owned by you.",
139			    tracefile);
140	} else {
141		if (unlink(tracefile) == -1 && errno != ENOENT)
142			err(1, "unlink %s", tracefile);
143		if ((fd = open(tracefile, O_CREAT | O_EXCL | O_WRONLY,
144		    DEFFILEMODE)) < 0)
145			err(1, "%s", tracefile);
146	}
147	(void)umask(omask);
148	(void)close(fd);
149
150	if (*argv) {
151		if (ktrace(tracefile, ops, trpoints, getpid()) < 0)
152			err(1, "%s", tracefile);
153		execvp(argv[0], &argv[0]);
154		err(1, "exec of '%s' failed", argv[0]);
155	}
156	else if (ktrace(tracefile, ops, trpoints, pid) < 0)
157		err(1, "%s", tracefile);
158	exit(0);
159}
160
161static int
162rpid(const char *p)
163{
164	static int first;
165
166	if (first++) {
167		warnx("only one -g or -p flag is permitted.");
168		usage();
169	}
170	if (!*p) {
171		warnx("illegal process id.");
172		usage();
173	}
174	return(atoi(p));
175}
176
177static void
178usage(void)
179{
180	(void)fprintf(stderr,
181	    "usage: ktrace [-aBCcdi] [-f trfile] [-g pgid] [-p pid] [-t trstr]\n"
182	    "       ktrace [-adi] [-f trfile] [-t trstr] command\n");
183	exit(1);
184}
185
186/* ARGSUSED */
187static void
188no_ktrace(int signo)
189{
190	char buf[8192];
191
192	snprintf(buf, sizeof(buf),
193"error:\tktrace() system call not supported in the running kernel\n\tre-compile kernel with 'option KTRACE'\n");
194	write(STDERR_FILENO, buf, strlen(buf));
195	_exit(1);
196}
197