1 /* $OpenBSD: ktrace.c,v 1.40 2023/03/08 04:43:11 guenther 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/types.h>
34 #include <sys/signal.h>
35 #include <sys/stat.h>
36 #include <sys/time.h>
37 #include <sys/uio.h>
38 #include <sys/ktrace.h>
39
40 #include <err.h>
41 #include <errno.h>
42 #include <fcntl.h>
43 #include <stdlib.h>
44 #include <limits.h>
45 #include <stdio.h>
46 #include <string.h>
47 #include <unistd.h>
48
49 #include "ktrace.h"
50 #include "extern.h"
51
52 extern char *__progname;
53
54 static int rpid(const char *);
55 static void no_ktrace(int);
56 static void usage(void);
57
58 int is_ltrace;
59
60 int
main(int argc,char * argv[])61 main(int argc, char *argv[])
62 {
63 enum { NOTSET, CLEAR, CLEARALL } clear;
64 int append, ch, fd, inherit, ops, pidset, trpoints;
65 pid_t pid;
66 char *tracefile, *tracespec;
67 mode_t omask;
68 struct stat sb;
69
70 is_ltrace = strcmp(__progname, "ltrace") == 0;
71
72 clear = NOTSET;
73 append = ops = pidset = inherit = pid = 0;
74 trpoints = is_ltrace ? KTRFAC_USER : DEF_POINTS;
75 tracefile = DEF_TRACEFILE;
76 tracespec = NULL;
77
78 if (is_ltrace) {
79 while ((ch = getopt(argc, argv, "af:it:u:")) != -1)
80 switch ((char)ch) {
81 case 'a':
82 append = 1;
83 break;
84 case 'f':
85 tracefile = optarg;
86 break;
87 case 'i':
88 inherit = 1;
89 break;
90 case 't':
91 trpoints = getpoints(optarg, KTRFAC_USER);
92 if (trpoints < 0) {
93 warnx("unknown facility in %s", optarg);
94 usage();
95 }
96 break;
97 case 'u':
98 tracespec = optarg;
99 break;
100 default:
101 usage();
102 }
103 } else {
104 while ((ch = getopt(argc, argv, "aBCcdf:g:ip:t:T")) != -1)
105 switch ((char)ch) {
106 case 'a':
107 append = 1;
108 break;
109 case 'B':
110 putenv("LD_BIND_NOW=");
111 break;
112 case 'C':
113 clear = CLEARALL;
114 tracefile = NULL;
115 pidset = 1;
116 break;
117 case 'c':
118 clear = CLEAR;
119 break;
120 case 'd':
121 ops |= KTRFLAG_DESCEND;
122 break;
123 case 'f':
124 tracefile = optarg;
125 break;
126 case 'g':
127 pid = -rpid(optarg);
128 pidset = 1;
129 break;
130 case 'i':
131 inherit = 1;
132 break;
133 case 'p':
134 pid = rpid(optarg);
135 pidset = 1;
136 break;
137 case 't':
138 trpoints = getpoints(optarg, DEF_POINTS);
139 if (trpoints < 0) {
140 warnx("unknown facility in %s", optarg);
141 usage();
142 }
143 break;
144 case 'T':
145 putenv("LIBC_NOUSERTC=");
146 break;
147 default:
148 usage();
149 }
150 }
151
152 argv += optind;
153 argc -= optind;
154
155 if ((pidset && *argv) || (!pidset && !*argv && clear != CLEAR))
156 usage();
157
158 if (inherit)
159 trpoints |= KTRFAC_INHERIT;
160
161 (void)signal(SIGSYS, no_ktrace);
162 if (clear != NOTSET) {
163 if (clear == CLEARALL) {
164 ops = KTROP_CLEAR | KTRFLAG_DESCEND;
165 trpoints = ALL_POINTS;
166 pid = 1;
167 } else
168 ops |= pid ? KTROP_CLEAR : KTROP_CLEARFILE;
169
170 if (ktrace(tracefile, ops, trpoints, pid) == -1) {
171 if (errno == ESRCH)
172 err(1, "%d", pid);
173 err(1, "%s", tracefile);
174 }
175 exit(0);
176 }
177
178 omask = umask(S_IRWXG|S_IRWXO);
179 if (append) {
180 if ((fd = open(tracefile, O_CREAT | O_WRONLY, DEFFILEMODE)) == -1)
181 err(1, "%s", tracefile);
182 if (fstat(fd, &sb) != 0 || sb.st_uid != getuid())
183 errx(1, "Refuse to append to %s: not owned by you.",
184 tracefile);
185 } else {
186 if (unlink(tracefile) == -1 && errno != ENOENT)
187 err(1, "unlink %s", tracefile);
188 if ((fd = open(tracefile, O_CREAT | O_EXCL | O_WRONLY,
189 DEFFILEMODE)) == -1)
190 err(1, "%s", tracefile);
191 }
192 (void)umask(omask);
193 (void)close(fd);
194
195 if (*argv) {
196 if (is_ltrace) {
197 if (setenv("LD_TRACE_PLT", inherit ? "i" : "", 1) < 0)
198 err(1, "setenv(LD_TRACE_PLT)");
199 if (tracespec &&
200 setenv("LD_TRACE_PLTSPEC", tracespec, 1) < 0)
201 err(1, "setenv(LD_TRACE_PLTSPEC)");
202 }
203 if (ktrace(tracefile, ops, trpoints, getpid()) == -1)
204 err(1, "%s", tracefile);
205 execvp(argv[0], &argv[0]);
206 err(1, "exec of '%s' failed", argv[0]);
207 }
208 else if (ktrace(tracefile, ops, trpoints, pid) == -1) {
209 if (errno == ESRCH)
210 err(1, "%d", pid);
211 err(1, "%s", tracefile);
212 }
213 exit(0);
214 }
215
216 static int
rpid(const char * p)217 rpid(const char *p)
218 {
219 const char *errstr;
220 static int first;
221 pid_t pid;
222
223 if (first++) {
224 warnx("only one -g or -p flag is permitted.");
225 usage();
226 }
227 if (!*p) {
228 warnx("illegal process id.");
229 usage();
230 }
231 pid = strtonum(p, 1, INT_MAX, &errstr);
232 if (errstr) {
233 warnx("illegal process id: %s", errstr);
234 usage();
235 }
236 return pid;
237 }
238
239 static void
usage(void)240 usage(void)
241 {
242 if (is_ltrace)
243 fprintf(stderr, "usage: %s [-ai] [-f trfile] [-t trstr]"
244 " [-u trspec] command\n",
245 __progname);
246 else
247 fprintf(stderr, "usage: %s [-aCcdi] [-f trfile] [-g pgid]"
248 " [-p pid] [-t trstr]\n"
249 " %s [-aBdiT] [-f trfile] [-t trstr] command\n",
250 __progname, __progname);
251 exit(1);
252 }
253
254 static void
no_ktrace(int signo)255 no_ktrace(int signo)
256 {
257 dprintf(STDERR_FILENO,
258 "error:\tktrace() system call not supported in the running kernel\n\tre-compile kernel with 'option KTRACE'\n");
259 _exit(1);
260 }
261