xref: /freebsd/usr.bin/ktrace/ktrace.c (revision da647ae946a00482f69900a49b0f1c4d5912abf2)
1 /*-
2  * Copyright (c) 1988, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 static const char copyright[] =
36 "@(#) Copyright (c) 1988, 1993\n\
37 	The Regents of the University of California.  All rights reserved.\n";
38 #endif /* not lint */
39 
40 #if 0
41 #ifndef lint
42 static char sccsid[] = "@(#)ktrace.c	8.1 (Berkeley) 6/6/93";
43 #endif /* not lint */
44 #endif
45 
46 #include <sys/cdefs.h>
47 __FBSDID("$FreeBSD$");
48 
49 #include <sys/param.h>
50 #include <sys/stat.h>
51 #include <sys/file.h>
52 #include <sys/time.h>
53 #include <sys/errno.h>
54 #include <sys/uio.h>
55 #include <sys/ktrace.h>
56 
57 #include <err.h>
58 #include <stdlib.h>
59 #include <stdio.h>
60 #include <stdlib.h>
61 #include <unistd.h>
62 
63 #include "ktrace.h"
64 
65 static char def_tracefile[] = DEF_TRACEFILE;
66 
67 static void no_ktrace(int);
68 static int rpid(char *);
69 static void usage(void);
70 
71 int
72 main(int argc, char *argv[])
73 {
74 	enum { NOTSET, CLEAR, CLEARALL } clear;
75 	int append, ch, fd, inherit, ops, pid, pidset, trpoints;
76 	const char *tracefile;
77 	mode_t omask;
78 	struct stat sb;
79 
80 	clear = NOTSET;
81 	append = ops = pidset = inherit = 0;
82 	trpoints = DEF_POINTS;
83 	tracefile = def_tracefile;
84 	while ((ch = getopt(argc,argv,"aCcdf:g:ip:t:")) != -1)
85 		switch((char)ch) {
86 		case 'a':
87 			append = 1;
88 			break;
89 		case 'C':
90 			clear = CLEARALL;
91 			pidset = 1;
92 			break;
93 		case 'c':
94 			clear = CLEAR;
95 			break;
96 		case 'd':
97 			ops |= KTRFLAG_DESCEND;
98 			break;
99 		case 'f':
100 			tracefile = optarg;
101 			break;
102 		case 'g':
103 			pid = -rpid(optarg);
104 			pidset = 1;
105 			break;
106 		case 'i':
107 			inherit = 1;
108 			break;
109 		case 'p':
110 			pid = rpid(optarg);
111 			pidset = 1;
112 			break;
113 		case 't':
114 			trpoints = getpoints(optarg);
115 			if (trpoints < 0) {
116 				warnx("unknown facility in %s", optarg);
117 				usage();
118 			}
119 			break;
120 		default:
121 			usage();
122 		}
123 	argv += optind;
124 	argc -= optind;
125 
126 	if ((pidset && *argv) || (!pidset && clear == NOTSET && !*argv))
127 		usage();
128 
129 	if (inherit)
130 		trpoints |= KTRFAC_INHERIT;
131 
132 	(void)signal(SIGSYS, no_ktrace);
133 	if (clear != NOTSET) {
134 		if (clear == CLEARALL) {
135 			ops = KTROP_CLEAR | KTRFLAG_DESCEND;
136 			trpoints = ALL_POINTS;
137 			pid = 1;
138 		} else
139 			ops |= pidset ? KTROP_CLEAR : KTROP_CLEARFILE;
140 
141 		if (ktrace(tracefile, ops, trpoints, pid) < 0)
142 			err(1, "%s", tracefile);
143 		exit(0);
144 	}
145 
146 	omask = umask(S_IRWXG|S_IRWXO);
147 	if (append) {
148 		if ((fd = open(tracefile, O_CREAT | O_WRONLY | O_NONBLOCK,
149 		    DEFFILEMODE)) < 0)
150 			err(1, "%s", tracefile);
151 		if (fstat(fd, &sb) != 0 || sb.st_uid != getuid())
152 			errx(1, "refuse to append to %s not owned by you",
153 			    tracefile);
154 		if (!(S_ISREG(sb.st_mode)))
155 			errx(1, "%s not regular file", tracefile);
156 	} else {
157 		if (unlink(tracefile) == -1 && errno != ENOENT)
158 			err(1, "unlink %s", tracefile);
159 		if ((fd = open(tracefile, O_CREAT | O_EXCL | O_WRONLY,
160 		    DEFFILEMODE)) < 0)
161 			err(1, "%s", tracefile);
162 	}
163 	(void)umask(omask);
164 	(void)close(fd);
165 
166 	if (*argv) {
167 		if (ktrace(tracefile, ops, trpoints, getpid()) < 0)
168 			err(1, "%s", tracefile);
169 		execvp(argv[0], &argv[0]);
170 		err(1, "exec of '%s' failed", argv[0]);
171 	}
172 	else if (ktrace(tracefile, ops, trpoints, pid) < 0)
173 		err(1, "%s", tracefile);
174 	exit(0);
175 }
176 
177 static int
178 rpid(char *p)
179 {
180 	static int first;
181 
182 	if (first++) {
183 		warnx("only one -g or -p flag is permitted");
184 		usage();
185 	}
186 	if (!*p) {
187 		warnx("illegal process id");
188 		usage();
189 	}
190 	return(atoi(p));
191 }
192 
193 static void
194 usage(void)
195 {
196 	(void)fprintf(stderr, "%s\n%s\n",
197 "usage: ktrace [-aCcdi] [-f trfile] [-g pgrp | -p pid] [-t trstr]",
198 "       ktrace [-adi] [-f trfile] [-t trstr] command");
199 	exit(1);
200 }
201 
202 static void
203 no_ktrace(int sig __unused)
204 {
205         (void)fprintf(stderr,
206 "error:\tktrace() system call not supported in the running kernel\n\tre-compile kernel with 'options KTRACE'\n");
207         exit(1);
208 }
209