main.c revision 246142 
1/*-
2 * Copyright 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: stable/9/usr.bin/truss/main.c 246142 2013-01-31 01:15:12Z mjg $");
34
35/*
36 * The main module for truss.  Surprisingly 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#include <sys/wait.h>
47
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#include "syscall.h"
61
62#define	MAXARGS	6
63
64static void
65usage(void)
66{
67	fprintf(stderr, "%s\n%s\n",
68	    "usage: truss [-cfaedDS] [-o file] [-s strsize] -p pid",
69	    "       truss [-cfaedDS] [-o file] [-s strsize] command [args]");
70	exit(1);
71}
72
73/*
74 * WARNING! "FreeBSD a.out" must be first, or set_etype will not
75 * work correctly.
76 */
77struct ex_types {
78	const char *type;
79	void (*enter_syscall)(struct trussinfo *, int);
80	long (*exit_syscall)(struct trussinfo *, int);
81} ex_types[] = {
82#ifdef __amd64__
83	{ "FreeBSD ELF64", amd64_syscall_entry, amd64_syscall_exit },
84	{ "FreeBSD ELF32", amd64_fbsd32_syscall_entry, amd64_fbsd32_syscall_exit },
85	{ "Linux ELF32", amd64_linux32_syscall_entry, amd64_linux32_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#ifdef __powerpc64__
100	{ "FreeBSD ELF64", powerpc64_syscall_entry, powerpc64_syscall_exit },
101#endif
102#endif
103#ifdef __sparc64__
104	{ "FreeBSD ELF64", sparc64_syscall_entry, sparc64_syscall_exit },
105#endif
106#ifdef __mips__
107	{ "FreeBSD ELF", mips_syscall_entry, mips_syscall_exit },
108	{ "FreeBSD ELF32", mips_syscall_entry, mips_syscall_exit },
109	{ "FreeBSD ELF64", mips_syscall_entry, mips_syscall_exit }, // XXX
110#endif
111	{ 0, 0, 0 },
112};
113
114/*
115 * Set the execution type.  This is called after every exec, and when
116 * a process is first monitored.
117 */
118
119static struct ex_types *
120set_etype(struct trussinfo *trussinfo)
121{
122	struct ex_types *funcs;
123	size_t len;
124	int error;
125	int mib[4];
126	char progt[32];
127
128	len = sizeof(progt);
129	mib[0] = CTL_KERN;
130	mib[1] = KERN_PROC;
131	mib[2] = KERN_PROC_SV_NAME;
132	mib[3] = trussinfo->pid;
133	error = sysctl(mib, 4, progt, &len, NULL, 0);
134	if (error != 0)
135		err(2, "can not get etype");
136
137	for (funcs = ex_types; funcs->type; funcs++)
138		if (strcmp(funcs->type, progt) == 0)
139			break;
140
141	if (funcs->type == NULL) {
142		funcs = &ex_types[0];
143		warn("execution type %s is not supported -- using %s",
144		    progt, funcs->type);
145	}
146	return (funcs);
147}
148
149char *
150strsig(int sig)
151{
152	char *ret;
153
154	ret = NULL;
155	if (sig > 0 && sig < NSIG) {
156		asprintf(&ret, "SIG%s", sys_signame[sig]);
157		if (ret == NULL)
158			return (NULL);
159	}
160	return (ret);
161}
162
163int
164main(int ac, char **av)
165{
166	struct timespec timediff;
167	struct sigaction sa;
168	struct ex_types *funcs;
169	struct trussinfo *trussinfo;
170	char *fname;
171	char *signame;
172	char **command;
173	pid_t childpid;
174	int c, initial_open, status;
175
176	fname = NULL;
177	initial_open = 1;
178
179	/* Initialize the trussinfo struct */
180	trussinfo = (struct trussinfo *)calloc(1, sizeof(struct trussinfo));
181	if (trussinfo == NULL)
182		errx(1, "calloc() failed");
183
184	trussinfo->outfile = stderr;
185	trussinfo->strsize = 32;
186	trussinfo->pr_why = S_NONE;
187	trussinfo->curthread = NULL;
188	SLIST_INIT(&trussinfo->threadlist);
189	while ((c = getopt(ac, av, "p:o:facedDs:S")) != -1) {
190		switch (c) {
191		case 'p':	/* specified pid */
192			trussinfo->pid = atoi(optarg);
193			/* make sure i don't trace me */
194			if (trussinfo->pid == getpid()) {
195				fprintf(stderr, "attempt to grab self.\n");
196				exit(2);
197			}
198			break;
199		case 'f': /* Follow fork()'s */
200			trussinfo->flags |= FOLLOWFORKS;
201			break;
202		case 'a': /* Print execve() argument strings. */
203			trussinfo->flags |= EXECVEARGS;
204			break;
205		case 'c': /* Count number of system calls and time. */
206			trussinfo->flags |= COUNTONLY;
207			break;
208		case 'e': /* Print execve() environment strings. */
209			trussinfo->flags |= EXECVEENVS;
210			break;
211		case 'd': /* Absolute timestamps */
212			trussinfo->flags |= ABSOLUTETIMESTAMPS;
213			break;
214		case 'D': /* Relative timestamps */
215			trussinfo->flags |= RELATIVETIMESTAMPS;
216			break;
217		case 'o':	/* Specified output file */
218			fname = optarg;
219			break;
220		case 's':	/* Specified string size */
221			trussinfo->strsize = atoi(optarg);
222			break;
223		case 'S':	/* Don't trace signals */
224			trussinfo->flags |= NOSIGS;
225			break;
226		default:
227			usage();
228		}
229	}
230
231	ac -= optind; av += optind;
232	if ((trussinfo->pid == 0 && ac == 0) ||
233	    (trussinfo->pid != 0 && ac != 0))
234		usage();
235
236	if (fname != NULL) { /* Use output file */
237		if ((trussinfo->outfile = fopen(fname, "w")) == NULL)
238			err(1, "cannot open %s", fname);
239		/*
240		 * Set FD_CLOEXEC, so that the output file is not shared with
241		 * the traced process.
242		 */
243		if (fcntl(fileno(trussinfo->outfile), F_SETFD, FD_CLOEXEC) ==
244		    -1)
245			warn("fcntl()");
246	}
247
248	/*
249	 * If truss starts the process itself, it will ignore some signals --
250	 * they should be passed off to the process, which may or may not
251	 * exit.  If, however, we are examining an already-running process,
252	 * then we restore the event mask on these same signals.
253	 */
254
255	if (trussinfo->pid == 0) {	/* Start a command ourselves */
256		command = av;
257		trussinfo->pid = setup_and_wait(command);
258		signal(SIGINT, SIG_IGN);
259		signal(SIGTERM, SIG_IGN);
260		signal(SIGQUIT, SIG_IGN);
261	} else {
262		sa.sa_handler = restore_proc;
263		sa.sa_flags = 0;
264		sigemptyset(&sa.sa_mask);
265		sigaction(SIGINT, &sa, NULL);
266		sigaction(SIGQUIT, &sa, NULL);
267		sigaction(SIGTERM, &sa, NULL);
268		start_tracing(trussinfo->pid);
269	}
270
271
272	/*
273	 * At this point, if we started the process, it is stopped waiting to
274	 * be woken up, either in exit() or in execve().
275	 */
276
277START_TRACE:
278	funcs = set_etype(trussinfo);
279
280	initial_open = 0;
281	/*
282	 * At this point, it's a simple loop, waiting for the process to
283	 * stop, finding out why, printing out why, and then continuing it.
284	 * All of the grunt work is done in the support routines.
285	 */
286
287	clock_gettime(CLOCK_REALTIME, &trussinfo->start_time);
288
289	do {
290		waitevent(trussinfo);
291
292		switch (trussinfo->pr_why) {
293		case S_SCE:
294			funcs->enter_syscall(trussinfo, MAXARGS);
295			clock_gettime(CLOCK_REALTIME,
296			    &trussinfo->curthread->before);
297			break;
298		case S_SCX:
299			clock_gettime(CLOCK_REALTIME,
300			    &trussinfo->curthread->after);
301
302			if (trussinfo->curthread->in_fork &&
303			    (trussinfo->flags & FOLLOWFORKS)) {
304				trussinfo->curthread->in_fork = 0;
305				childpid = funcs->exit_syscall(trussinfo,
306				    trussinfo->pr_data);
307
308				/*
309				 * Fork a new copy of ourself to trace
310				 * the child of the original traced
311				 * process.
312				 */
313				if (fork() == 0) {
314					trussinfo->pid = childpid;
315					start_tracing(trussinfo->pid);
316					goto START_TRACE;
317				}
318				break;
319			}
320			funcs->exit_syscall(trussinfo, MAXARGS);
321			break;
322		case S_SIG:
323			if (trussinfo->flags & NOSIGS)
324				break;
325			if (trussinfo->flags & FOLLOWFORKS)
326				fprintf(trussinfo->outfile, "%5d: ",
327				    trussinfo->pid);
328			if (trussinfo->flags & ABSOLUTETIMESTAMPS) {
329				timespecsubt(&trussinfo->curthread->after,
330				    &trussinfo->start_time, &timediff);
331				fprintf(trussinfo->outfile, "%ld.%09ld ",
332				    (long)timediff.tv_sec,
333				    timediff.tv_nsec);
334			}
335			if (trussinfo->flags & RELATIVETIMESTAMPS) {
336				timespecsubt(&trussinfo->curthread->after,
337				    &trussinfo->curthread->before, &timediff);
338				fprintf(trussinfo->outfile, "%ld.%09ld ",
339				    (long)timediff.tv_sec,
340				    timediff.tv_nsec);
341			}
342			signame = strsig(trussinfo->pr_data);
343			fprintf(trussinfo->outfile,
344			    "SIGNAL %u (%s)\n", trussinfo->pr_data,
345			    signame == NULL ? "?" : signame);
346			free(signame);
347			break;
348		case S_EXIT:
349			if (trussinfo->flags & COUNTONLY)
350				break;
351			if (trussinfo->flags & FOLLOWFORKS)
352				fprintf(trussinfo->outfile, "%5d: ",
353				    trussinfo->pid);
354			if (trussinfo->flags & ABSOLUTETIMESTAMPS) {
355				timespecsubt(&trussinfo->curthread->after,
356				    &trussinfo->start_time, &timediff);
357				fprintf(trussinfo->outfile, "%ld.%09ld ",
358				    (long)timediff.tv_sec,
359				    timediff.tv_nsec);
360			}
361			if (trussinfo->flags & RELATIVETIMESTAMPS) {
362				timespecsubt(&trussinfo->curthread->after,
363				    &trussinfo->curthread->before, &timediff);
364				fprintf(trussinfo->outfile, "%ld.%09ld ",
365				    (long)timediff.tv_sec, timediff.tv_nsec);
366			}
367			fprintf(trussinfo->outfile,
368			    "process exit, rval = %u\n", trussinfo->pr_data);
369			break;
370		default:
371			break;
372		}
373	} while (trussinfo->pr_why != S_EXIT &&
374	    trussinfo->pr_why != S_DETACHED);
375
376	if (trussinfo->flags & FOLLOWFORKS) {
377		do {
378			childpid = wait(&status);
379		} while (childpid != -1);
380	}
381
382	if (trussinfo->flags & COUNTONLY)
383		print_summary(trussinfo);
384
385	fflush(trussinfo->outfile);
386
387	return (0);
388}
389