xref: /freebsd/usr.bin/ktrace/ktrace.c (revision 10b9d77bf1ccf2f3affafa6261692cb92cf7e992)
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  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 #ifndef lint
31 static const char copyright[] =
32 "@(#) Copyright (c) 1988, 1993\n\
33 	The Regents of the University of California.  All rights reserved.\n";
34 #endif /* not lint */
35 
36 #if 0
37 #ifndef lint
38 static char sccsid[] = "@(#)ktrace.c	8.1 (Berkeley) 6/6/93";
39 #endif /* not lint */
40 #endif
41 
42 #include <sys/cdefs.h>
43 __FBSDID("$FreeBSD$");
44 
45 #include <sys/param.h>
46 #include <sys/stat.h>
47 #include <sys/file.h>
48 #include <sys/time.h>
49 #include <sys/errno.h>
50 #include <sys/uio.h>
51 #include <sys/ktrace.h>
52 
53 #include <err.h>
54 #include <stdlib.h>
55 #include <stdio.h>
56 #include <stdlib.h>
57 #include <unistd.h>
58 
59 #include "ktrace.h"
60 
61 static char def_tracefile[] = DEF_TRACEFILE;
62 
63 static void no_ktrace(int);
64 static int rpid(char *);
65 static void usage(void);
66 
67 int
68 main(int argc, char *argv[])
69 {
70 	enum { NOTSET, CLEAR, CLEARALL } clear;
71 	int append, ch, fd, inherit, ops, pid, pidset, trpoints;
72 	const char *tracefile;
73 	mode_t omask;
74 	struct stat sb;
75 
76 	clear = NOTSET;
77 	append = ops = pidset = inherit = 0;
78 	trpoints = DEF_POINTS;
79 	tracefile = def_tracefile;
80 	while ((ch = getopt(argc,argv,"aCcdf:g:ip:t:")) != -1)
81 		switch((char)ch) {
82 		case 'a':
83 			append = 1;
84 			break;
85 		case 'C':
86 			clear = CLEARALL;
87 			pidset = 1;
88 			break;
89 		case 'c':
90 			clear = CLEAR;
91 			break;
92 		case 'd':
93 			ops |= KTRFLAG_DESCEND;
94 			break;
95 		case 'f':
96 			tracefile = optarg;
97 			break;
98 		case 'g':
99 			pid = -rpid(optarg);
100 			pidset = 1;
101 			break;
102 		case 'i':
103 			inherit = 1;
104 			break;
105 		case 'p':
106 			pid = rpid(optarg);
107 			pidset = 1;
108 			break;
109 		case 't':
110 			trpoints = getpoints(optarg);
111 			if (trpoints < 0) {
112 				warnx("unknown facility in %s", optarg);
113 				usage();
114 			}
115 			break;
116 		default:
117 			usage();
118 		}
119 	argv += optind;
120 	argc -= optind;
121 
122 	if ((pidset && *argv) || (!pidset && clear == NOTSET && !*argv))
123 		usage();
124 
125 	if (inherit)
126 		trpoints |= KTRFAC_INHERIT;
127 
128 	(void)signal(SIGSYS, no_ktrace);
129 	if (clear != NOTSET) {
130 		if (clear == CLEARALL) {
131 			ops = KTROP_CLEAR | KTRFLAG_DESCEND;
132 			trpoints = ALL_POINTS;
133 			pid = 1;
134 		} else
135 			ops |= pidset ? KTROP_CLEAR : KTROP_CLEARFILE;
136 
137 		if (ktrace(tracefile, ops, trpoints, pid) < 0)
138 			err(1, "%s", tracefile);
139 		exit(0);
140 	}
141 
142 	omask = umask(S_IRWXG|S_IRWXO);
143 	if (append) {
144 		if ((fd = open(tracefile, O_CREAT | O_WRONLY | O_NONBLOCK,
145 		    DEFFILEMODE)) < 0)
146 			err(1, "%s", tracefile);
147 		if (fstat(fd, &sb) != 0 || sb.st_uid != getuid())
148 			errx(1, "refuse to append to %s not owned by you",
149 			    tracefile);
150 		if (!(S_ISREG(sb.st_mode)))
151 			errx(1, "%s not regular file", tracefile);
152 	} else {
153 		if (unlink(tracefile) == -1 && errno != ENOENT)
154 			err(1, "unlink %s", tracefile);
155 		if ((fd = open(tracefile, O_CREAT | O_EXCL | O_WRONLY,
156 		    DEFFILEMODE)) < 0)
157 			err(1, "%s", tracefile);
158 	}
159 	(void)umask(omask);
160 	(void)close(fd);
161 
162 	trpoints |= PROC_ABI_POINTS;
163 
164 	if (*argv) {
165 		if (ktrace(tracefile, ops, trpoints, getpid()) < 0)
166 			err(1, "%s", tracefile);
167 		execvp(argv[0], &argv[0]);
168 		err(1, "exec of '%s' failed", argv[0]);
169 	}
170 	else if (ktrace(tracefile, ops, trpoints, pid) < 0)
171 		err(1, "%s", tracefile);
172 	exit(0);
173 }
174 
175 static int
176 rpid(char *p)
177 {
178 	static int first;
179 
180 	if (first++) {
181 		warnx("only one -g or -p flag is permitted");
182 		usage();
183 	}
184 	if (!*p) {
185 		warnx("illegal process id");
186 		usage();
187 	}
188 	return(atoi(p));
189 }
190 
191 static void
192 usage(void)
193 {
194 	(void)fprintf(stderr, "%s\n%s\n",
195 "usage: ktrace [-aCcdi] [-f trfile] [-g pgrp | -p pid] [-t trstr]",
196 "       ktrace [-adi] [-f trfile] [-t trstr] command");
197 	exit(1);
198 }
199 
200 static void
201 no_ktrace(int sig __unused)
202 {
203         (void)fprintf(stderr,
204 "error:\tktrace() system call not supported in the running kernel\n\tre-compile kernel with 'options KTRACE'\n");
205         exit(1);
206 }
207