main.c revision 286939 
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: head/usr.bin/truss/main.c 286939 2015-08-19 20:09:14Z jhb $");
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 <stdint.h>
53#include <stdio.h>
54#include <stdlib.h>
55#include <string.h>
56#include <time.h>
57#include <unistd.h>
58
59#include "truss.h"
60#include "extern.h"
61#include "syscall.h"
62
63#define	MAXARGS	6
64
65static void
66usage(void)
67{
68	fprintf(stderr, "%s\n%s\n",
69	    "usage: truss [-cfaedDS] [-o file] [-s strsize] -p pid",
70	    "       truss [-cfaedDS] [-o file] [-s strsize] command [args]");
71	exit(1);
72}
73
74/*
75 * WARNING! "FreeBSD a.out" must be first, or set_etype will not
76 * work correctly.
77 */
78static struct ex_types {
79	const char *type;
80	void (*enter_syscall)(struct trussinfo *, int);
81	long (*exit_syscall)(struct trussinfo *, int);
82} ex_types[] = {
83#ifdef __arm__
84	{ "FreeBSD ELF32", arm_syscall_entry, arm_syscall_exit },
85#endif
86#ifdef __amd64__
87	{ "FreeBSD ELF64", amd64_syscall_entry, amd64_syscall_exit },
88	{ "FreeBSD ELF32", amd64_fbsd32_syscall_entry, amd64_fbsd32_syscall_exit },
89	{ "Linux ELF32", amd64_linux32_syscall_entry, amd64_linux32_syscall_exit },
90#endif
91#ifdef __i386__
92	{ "FreeBSD a.out", i386_syscall_entry, i386_syscall_exit },
93	{ "FreeBSD ELF", i386_syscall_entry, i386_syscall_exit },
94	{ "FreeBSD ELF32", i386_syscall_entry, i386_syscall_exit },
95	{ "Linux ELF", i386_linux_syscall_entry, i386_linux_syscall_exit },
96#endif
97#ifdef __powerpc__
98	{ "FreeBSD ELF", powerpc_syscall_entry, powerpc_syscall_exit },
99	{ "FreeBSD ELF32", powerpc_syscall_entry, powerpc_syscall_exit },
100#ifdef __powerpc64__
101	{ "FreeBSD ELF64", powerpc64_syscall_entry, powerpc64_syscall_exit },
102#endif
103#endif
104#ifdef __sparc64__
105	{ "FreeBSD ELF64", sparc64_syscall_entry, sparc64_syscall_exit },
106#endif
107#ifdef __mips__
108	{ "FreeBSD ELF", mips_syscall_entry, mips_syscall_exit },
109	{ "FreeBSD ELF32", mips_syscall_entry, mips_syscall_exit },
110	{ "FreeBSD ELF64", mips_syscall_entry, mips_syscall_exit }, // XXX
111#endif
112	{ 0, 0, 0 },
113};
114
115/*
116 * Set the execution type.  This is called after every exec, and when
117 * a process is first monitored.
118 */
119
120static struct ex_types *
121set_etype(struct trussinfo *trussinfo)
122{
123	struct ex_types *funcs;
124	size_t len;
125	int error;
126	int mib[4];
127	char progt[32];
128
129	len = sizeof(progt);
130	mib[0] = CTL_KERN;
131	mib[1] = KERN_PROC;
132	mib[2] = KERN_PROC_SV_NAME;
133	mib[3] = trussinfo->pid;
134	error = sysctl(mib, 4, progt, &len, NULL, 0);
135	if (error != 0)
136		err(2, "can not get etype");
137
138	for (funcs = ex_types; funcs->type; funcs++)
139		if (strcmp(funcs->type, progt) == 0)
140			break;
141
142	if (funcs->type == NULL) {
143		funcs = &ex_types[0];
144		warn("execution type %s is not supported -- using %s",
145		    progt, funcs->type);
146	}
147	return (funcs);
148}
149
150char *
151strsig(int sig)
152{
153	static char tmp[64];
154
155	if (sig > 0 && sig < NSIG) {
156		snprintf(tmp, sizeof(tmp), "SIG%s", sys_signame[sig]);
157		return (tmp);
158	}
159	return (NULL);
160}
161
162int
163main(int ac, char **av)
164{
165	struct timespec timediff;
166	struct sigaction sa;
167	struct ex_types *funcs;
168	struct trussinfo *trussinfo;
169	char *fname;
170	char *signame;
171	char **command;
172	pid_t childpid;
173	int c, initial_open, status;
174
175	fname = NULL;
176	initial_open = 1;
177
178	/* Initialize the trussinfo struct */
179	trussinfo = (struct trussinfo *)calloc(1, sizeof(struct trussinfo));
180	if (trussinfo == NULL)
181		errx(1, "calloc() failed");
182
183	trussinfo->outfile = stderr;
184	trussinfo->strsize = 32;
185	trussinfo->pr_why = S_NONE;
186	trussinfo->curthread = NULL;
187	SLIST_INIT(&trussinfo->threadlist);
188	while ((c = getopt(ac, av, "p:o:facedDs:S")) != -1) {
189		switch (c) {
190		case 'p':	/* specified pid */
191			trussinfo->pid = atoi(optarg);
192			/* make sure i don't trace me */
193			if (trussinfo->pid == getpid()) {
194				fprintf(stderr, "attempt to grab self.\n");
195				exit(2);
196			}
197			break;
198		case 'f': /* Follow fork()'s */
199			trussinfo->flags |= FOLLOWFORKS;
200			break;
201		case 'a': /* Print execve() argument strings. */
202			trussinfo->flags |= EXECVEARGS;
203			break;
204		case 'c': /* Count number of system calls and time. */
205			trussinfo->flags |= COUNTONLY;
206			break;
207		case 'e': /* Print execve() environment strings. */
208			trussinfo->flags |= EXECVEENVS;
209			break;
210		case 'd': /* Absolute timestamps */
211			trussinfo->flags |= ABSOLUTETIMESTAMPS;
212			break;
213		case 'D': /* Relative timestamps */
214			trussinfo->flags |= RELATIVETIMESTAMPS;
215			break;
216		case 'o':	/* Specified output file */
217			fname = optarg;
218			break;
219		case 's':	/* Specified string size */
220			trussinfo->strsize = atoi(optarg);
221			break;
222		case 'S':	/* Don't trace signals */
223			trussinfo->flags |= NOSIGS;
224			break;
225		default:
226			usage();
227		}
228	}
229
230	ac -= optind; av += optind;
231	if ((trussinfo->pid == 0 && ac == 0) ||
232	    (trussinfo->pid != 0 && ac != 0))
233		usage();
234
235	if (fname != NULL) { /* Use output file */
236		/*
237		 * Set close-on-exec ('e'), so that the output file is not
238		 * shared with the traced process.
239		 */
240		if ((trussinfo->outfile = fopen(fname, "we")) == NULL)
241			err(1, "cannot open %s", fname);
242	}
243
244	/*
245	 * If truss starts the process itself, it will ignore some signals --
246	 * they should be passed off to the process, which may or may not
247	 * exit.  If, however, we are examining an already-running process,
248	 * then we restore the event mask on these same signals.
249	 */
250
251	if (trussinfo->pid == 0) {	/* Start a command ourselves */
252		command = av;
253		trussinfo->pid = setup_and_wait(command);
254		signal(SIGINT, SIG_IGN);
255		signal(SIGTERM, SIG_IGN);
256		signal(SIGQUIT, SIG_IGN);
257	} else {
258		sa.sa_handler = restore_proc;
259		sa.sa_flags = 0;
260		sigemptyset(&sa.sa_mask);
261		sigaction(SIGINT, &sa, NULL);
262		sigaction(SIGQUIT, &sa, NULL);
263		sigaction(SIGTERM, &sa, NULL);
264		start_tracing(trussinfo->pid);
265	}
266
267
268	/*
269	 * At this point, if we started the process, it is stopped waiting to
270	 * be woken up, either in exit() or in execve().
271	 */
272
273START_TRACE:
274	funcs = set_etype(trussinfo);
275
276	initial_open = 0;
277	/*
278	 * At this point, it's a simple loop, waiting for the process to
279	 * stop, finding out why, printing out why, and then continuing it.
280	 * All of the grunt work is done in the support routines.
281	 */
282
283	clock_gettime(CLOCK_REALTIME, &trussinfo->start_time);
284
285	do {
286		waitevent(trussinfo);
287
288		switch (trussinfo->pr_why) {
289		case S_SCE:
290			funcs->enter_syscall(trussinfo, MAXARGS);
291			clock_gettime(CLOCK_REALTIME,
292			    &trussinfo->curthread->before);
293			break;
294		case S_SCX:
295			clock_gettime(CLOCK_REALTIME,
296			    &trussinfo->curthread->after);
297
298			if (trussinfo->curthread->in_fork &&
299			    (trussinfo->flags & FOLLOWFORKS)) {
300				trussinfo->curthread->in_fork = 0;
301				childpid = funcs->exit_syscall(trussinfo,
302				    trussinfo->pr_data);
303
304				/*
305				 * Fork a new copy of ourself to trace
306				 * the child of the original traced
307				 * process.
308				 */
309				if (fork() == 0) {
310					trussinfo->pid = childpid;
311					start_tracing(trussinfo->pid);
312					goto START_TRACE;
313				}
314				break;
315			}
316			funcs->exit_syscall(trussinfo, MAXARGS);
317			break;
318		case S_SIG:
319			if (trussinfo->flags & NOSIGS)
320				break;
321			if (trussinfo->flags & FOLLOWFORKS)
322				fprintf(trussinfo->outfile, "%5d: ",
323				    trussinfo->pid);
324			if (trussinfo->flags & ABSOLUTETIMESTAMPS) {
325				timespecsubt(&trussinfo->curthread->after,
326				    &trussinfo->start_time, &timediff);
327				fprintf(trussinfo->outfile, "%jd.%09ld ",
328				    (intmax_t)timediff.tv_sec,
329				    timediff.tv_nsec);
330			}
331			if (trussinfo->flags & RELATIVETIMESTAMPS) {
332				timespecsubt(&trussinfo->curthread->after,
333				    &trussinfo->curthread->before, &timediff);
334				fprintf(trussinfo->outfile, "%jd.%09ld ",
335				    (intmax_t)timediff.tv_sec,
336				    timediff.tv_nsec);
337			}
338			signame = strsig(trussinfo->pr_data);
339			fprintf(trussinfo->outfile,
340			    "SIGNAL %u (%s)\n", trussinfo->pr_data,
341			    signame == NULL ? "?" : signame);
342			break;
343		case S_EXIT:
344			if (trussinfo->flags & COUNTONLY)
345				break;
346			if (trussinfo->flags & FOLLOWFORKS)
347				fprintf(trussinfo->outfile, "%5d: ",
348				    trussinfo->pid);
349			if (trussinfo->flags & ABSOLUTETIMESTAMPS) {
350				timespecsubt(&trussinfo->curthread->after,
351				    &trussinfo->start_time, &timediff);
352				fprintf(trussinfo->outfile, "%jd.%09ld ",
353				    (intmax_t)timediff.tv_sec,
354				    timediff.tv_nsec);
355			}
356			if (trussinfo->flags & RELATIVETIMESTAMPS) {
357				timespecsubt(&trussinfo->curthread->after,
358				    &trussinfo->curthread->before, &timediff);
359				fprintf(trussinfo->outfile, "%jd.%09ld ",
360				    (intmax_t)timediff.tv_sec,
361				    timediff.tv_nsec);
362			}
363			fprintf(trussinfo->outfile,
364			    "process exit, rval = %u\n", trussinfo->pr_data);
365			break;
366		default:
367			break;
368		}
369	} while (trussinfo->pr_why != S_EXIT &&
370	    trussinfo->pr_why != S_DETACHED);
371
372	if (trussinfo->flags & FOLLOWFORKS) {
373		do {
374			childpid = wait(&status);
375		} while (childpid != -1);
376	}
377
378	if (trussinfo->flags & COUNTONLY)
379		print_summary(trussinfo);
380
381	fflush(trussinfo->outfile);
382
383	return (0);
384}
385