main.c revision 168569 
1/*
2 * Copryight 1997 Sean Eric Fagan
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 * 3. All advertising materials mentioning features or use of this software
13 *    must display the following acknowledgement:
14 *	This product includes software developed by Sean Eric Fagan
15 * 4. Neither the name of the author may be used to endorse or promote
16 *    products derived from this software without specific prior written
17 *    permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33__FBSDID("$FreeBSD: head/usr.bin/truss/main.c 168569 2007-04-10 04:03:34Z delphij $");
34
35/*
36 * The main module for truss.  Suprisingly simple, but, then, the other
37 * files handle the bulk of the work.  And, of course, the kernel has to
38 * do a lot of the work :).
39 */
40
41#include <sys/param.h>
42#include <sys/types.h>
43#include <sys/time.h>
44#include <sys/resource.h>
45#include <sys/sysctl.h>
46
47#include <ctype.h>
48#include <err.h>
49#include <errno.h>
50#include <fcntl.h>
51#include <signal.h>
52#include <stdio.h>
53#include <stdlib.h>
54#include <string.h>
55#include <time.h>
56#include <unistd.h>
57
58#include "truss.h"
59#include "extern.h"
60
61#define MAXARGS 5
62
63static void
64usage(void)
65{
66	fprintf(stderr, "%s\n%s\n",
67	    "usage: truss [-faedDS] [-o file] [-s strsize] -p pid",
68	    "       truss [-faedDS] [-o file] [-s strsize] command [args]");
69	exit(1);
70}
71
72/*
73 * WARNING! "FreeBSD a.out" must be first, or set_etype will not
74 * work correctly.
75 */
76struct ex_types {
77	const char *type;
78	void (*enter_syscall)(struct trussinfo *, int);
79	long (*exit_syscall)(struct trussinfo *, int);
80} ex_types[] = {
81#ifdef __alpha__
82	{ "FreeBSD ELF", alpha_syscall_entry, alpha_syscall_exit },
83#endif
84#ifdef __amd64__
85	{ "FreeBSD ELF64", amd64_syscall_entry, amd64_syscall_exit },
86#endif
87#ifdef __i386__
88	{ "FreeBSD a.out", i386_syscall_entry, i386_syscall_exit },
89	{ "FreeBSD ELF", i386_syscall_entry, i386_syscall_exit },
90	{ "FreeBSD ELF32", i386_syscall_entry, i386_syscall_exit },
91	{ "Linux ELF", i386_linux_syscall_entry, i386_linux_syscall_exit },
92#endif
93#ifdef __ia64__
94	{ "FreeBSD ELF64", ia64_syscall_entry, ia64_syscall_exit },
95#endif
96#ifdef __powerpc__
97	{ "FreeBSD ELF", powerpc_syscall_entry, powerpc_syscall_exit },
98	{ "FreeBSD ELF32", powerpc_syscall_entry, powerpc_syscall_exit },
99#endif
100#ifdef __sparc64__
101	{ "FreeBSD ELF64", sparc64_syscall_entry, sparc64_syscall_exit },
102#endif
103	{ 0, 0, 0 },
104};
105
106/*
107 * Set the execution type.  This is called after every exec, and when
108 * a process is first monitored.
109 */
110
111static struct ex_types *
112set_etype(struct trussinfo *trussinfo)
113{
114	struct ex_types *funcs;
115	char progt[32];
116
117	size_t len = sizeof(progt);
118	int mib[4];
119	int error;
120
121	mib[0] = CTL_KERN;
122	mib[1] = KERN_PROC;
123	mib[2] = KERN_PROC_SV_NAME;
124	mib[3] = trussinfo->pid;
125	error = sysctl(mib, 4, progt, &len, NULL, 0);
126	if (error != 0)
127		err(2, "can not get etype");
128
129	for (funcs = ex_types; funcs->type; funcs++)
130		if (!strcmp(funcs->type, progt))
131			break;
132
133	if (funcs->type == NULL) {
134		funcs = &ex_types[0];
135		warn("execution type %s is not supported -- using %s",
136		    progt, funcs->type);
137	}
138	return (funcs);
139}
140
141char *
142strsig(int sig)
143{
144	char *ret;
145
146	ret = NULL;
147	if (sig > 0 && sig < NSIG) {
148		int i;
149		asprintf(&ret, "sig%s", sys_signame[sig]);
150		if (ret == NULL)
151			return (NULL);
152		for (i = 0; ret[i] != '\0'; ++i)
153			ret[i] = toupper(ret[i]);
154	}
155	return (ret);
156}
157
158int
159main(int ac, char **av)
160{
161	int c;
162	int i;
163	char **command;
164	struct ex_types *funcs;
165	int sigexit, initial_open;
166	char *fname;
167	struct trussinfo *trussinfo;
168	char *signame;
169
170	sigexit = 0;
171	fname = NULL;
172	initial_open = 1;
173
174	/* Initialize the trussinfo struct */
175	trussinfo = (struct trussinfo *)malloc(sizeof(struct trussinfo));
176	if (trussinfo == NULL)
177		errx(1, "malloc() failed");
178	bzero(trussinfo, sizeof(struct trussinfo));
179
180	trussinfo->outfile = stderr;
181	trussinfo->strsize = 32;
182	trussinfo->pr_why = S_NONE;
183	trussinfo->curthread = NULL;
184	SLIST_INIT(&trussinfo->threadlist);
185	while ((c = getopt(ac, av, "p:o:faedDs:S")) != -1) {
186		switch (c) {
187		case 'p':	/* specified pid */
188			trussinfo->pid = atoi(optarg);
189			break;
190		case 'f': /* Follow fork()'s */
191			trussinfo->flags |= FOLLOWFORKS;
192			break;
193		case 'a': /* Print execve() argument strings. */
194			trussinfo->flags |= EXECVEARGS;
195			break;
196		case 'e': /* Print execve() environment strings. */
197			trussinfo->flags |= EXECVEENVS;
198			break;
199		case 'd': /* Absolute timestamps */
200			trussinfo->flags |= ABSOLUTETIMESTAMPS;
201			break;
202		case 'D': /* Relative timestamps */
203			trussinfo->flags |= RELATIVETIMESTAMPS;
204			break;
205		case 'o':	/* Specified output file */
206			fname = optarg;
207			break;
208		case 's':	/* Specified string size */
209			trussinfo->strsize = atoi(optarg);
210			break;
211		case 'S':	/* Don't trace signals */
212			trussinfo->flags |= NOSIGS;
213			break;
214		default:
215			usage();
216		}
217	}
218
219	ac -= optind; av += optind;
220	if ((trussinfo->pid == 0 && ac == 0) ||
221	    (trussinfo->pid != 0 && ac != 0))
222		usage();
223
224	if (fname != NULL) { /* Use output file */
225		if ((trussinfo->outfile = fopen(fname, "w")) == NULL)
226			errx(1, "cannot open %s", fname);
227	}
228
229	/*
230	 * If truss starts the process itself, it will ignore some signals --
231	 * they should be passed off to the process, which may or may not
232	 * exit.  If, however, we are examining an already-running process,
233	 * then we restore the event mask on these same signals.
234	 */
235
236	if (trussinfo->pid == 0) {	/* Start a command ourselves */
237		command = av;
238		trussinfo->pid = setup_and_wait(command);
239		signal(SIGINT, SIG_IGN);
240		signal(SIGTERM, SIG_IGN);
241		signal(SIGQUIT, SIG_IGN);
242	} else {
243		start_tracing(trussinfo->pid);
244		signal(SIGINT, restore_proc);
245		signal(SIGTERM, restore_proc);
246		signal(SIGQUIT, restore_proc);
247	}
248
249
250	/*
251	 * At this point, if we started the process, it is stopped waiting to
252	 * be woken up, either in exit() or in execve().
253	 */
254
255START_TRACE:
256	funcs = set_etype(trussinfo);
257
258	initial_open = 0;
259	/*
260	 * At this point, it's a simple loop, waiting for the process to
261	 * stop, finding out why, printing out why, and then continuing it.
262	 * All of the grunt work is done in the support routines.
263	 */
264
265	clock_gettime(CLOCK_REALTIME, &trussinfo->start_time);
266
267	do {
268		struct timespec timediff;
269		waitevent(trussinfo);
270
271		switch(i = trussinfo->pr_why) {
272		case S_SCE:
273			funcs->enter_syscall(trussinfo, MAXARGS);
274			clock_gettime(CLOCK_REALTIME,
275			    &trussinfo->before);
276			break;
277		case S_SCX:
278			clock_gettime(CLOCK_REALTIME,
279			    &trussinfo->after);
280
281			if (trussinfo->curthread->in_fork &&
282			    (trussinfo->flags & FOLLOWFORKS)) {
283				int childpid;
284
285				trussinfo->curthread->in_fork = 0;
286				childpid =
287				    funcs->exit_syscall(trussinfo,
288					trussinfo->pr_data);
289
290				/*
291				 * Fork a new copy of ourself to trace
292				 * the child of the original traced
293				 * process.
294				 */
295				if (fork() == 0) {
296					trussinfo->pid = childpid;
297					start_tracing(trussinfo->pid);
298					goto START_TRACE;
299				}
300				break;
301			}
302			funcs->exit_syscall(trussinfo, MAXARGS);
303			break;
304		case S_SIG:
305			if (trussinfo->flags & NOSIGS)
306				break;
307			if (trussinfo->flags & FOLLOWFORKS)
308				fprintf(trussinfo->outfile, "%5d: ",
309				    trussinfo->pid);
310			if (trussinfo->flags & ABSOLUTETIMESTAMPS) {
311				timespecsubt(&trussinfo->after,
312				    &trussinfo->start_time, &timediff);
313				fprintf(trussinfo->outfile, "%ld.%09ld ",
314				    (long)timediff.tv_sec,
315				    timediff.tv_nsec);
316			}
317			if (trussinfo->flags & RELATIVETIMESTAMPS) {
318				timespecsubt(&trussinfo->after,
319				    &trussinfo->before, &timediff);
320				fprintf(trussinfo->outfile, "%ld.%09ld ",
321				    (long)timediff.tv_sec,
322				    timediff.tv_nsec);
323			}
324			signame = strsig(trussinfo->pr_data);
325			fprintf(trussinfo->outfile,
326			    "SIGNAL %u (%s)\n", trussinfo->pr_data,
327			    signame == NULL ? "?" : signame);
328			free(signame);
329			break;
330		case S_EXIT:
331			if (trussinfo->flags & FOLLOWFORKS)
332				fprintf(trussinfo->outfile, "%5d: ",
333				    trussinfo->pid);
334			if (trussinfo->flags & ABSOLUTETIMESTAMPS) {
335				timespecsubt(&trussinfo->after,
336				    &trussinfo->start_time, &timediff);
337				fprintf(trussinfo->outfile, "%ld.%09ld ",
338				    (long)timediff.tv_sec,
339				    timediff.tv_nsec);
340			}
341			if (trussinfo->flags & RELATIVETIMESTAMPS) {
342			  timespecsubt(&trussinfo->after,
343			      &trussinfo->before, &timediff);
344			  fprintf(trussinfo->outfile, "%ld.%09ld ",
345			    (long)timediff.tv_sec, timediff.tv_nsec);
346			}
347			fprintf(trussinfo->outfile,
348			    "process exit, rval = %u\n", trussinfo->pr_data);
349			break;
350		default:
351			break;
352		}
353	} while (trussinfo->pr_why != S_EXIT);
354	fflush(trussinfo->outfile);
355	if (sigexit) {
356		struct rlimit rlp;
357
358		rlp.rlim_cur = 0;
359		rlp.rlim_max = 0;
360		setrlimit(RLIMIT_CORE, &rlp);
361		(void) signal(sigexit, SIG_DFL);
362		(void) kill(getpid(), sigexit);
363	}
364
365	return (0);
366}
367