main.c revision 290052 
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/10/usr.bin/truss/main.c 290052 2015-10-27 17:00:04Z 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/ptrace.h>
42
43#include <err.h>
44#include <signal.h>
45#include <stdio.h>
46#include <stdlib.h>
47#include <time.h>
48#include <unistd.h>
49
50#include "truss.h"
51#include "extern.h"
52#include "syscall.h"
53
54static void
55usage(void)
56{
57	fprintf(stderr, "%s\n%s\n",
58	    "usage: truss [-cfaedDS] [-o file] [-s strsize] -p pid",
59	    "       truss [-cfaedDS] [-o file] [-s strsize] command [args]");
60	exit(1);
61}
62
63char *
64strsig(int sig)
65{
66	static char tmp[64];
67
68	if (sig > 0 && sig < NSIG) {
69		snprintf(tmp, sizeof(tmp), "SIG%s", sys_signame[sig]);
70		return (tmp);
71	}
72	return (NULL);
73}
74
75int
76main(int ac, char **av)
77{
78	struct sigaction sa;
79	struct trussinfo *trussinfo;
80	char *fname;
81	char **command;
82	pid_t pid;
83	int c;
84
85	fname = NULL;
86
87	/* Initialize the trussinfo struct */
88	trussinfo = (struct trussinfo *)calloc(1, sizeof(struct trussinfo));
89	if (trussinfo == NULL)
90		errx(1, "calloc() failed");
91
92	pid = 0;
93	trussinfo->outfile = stderr;
94	trussinfo->strsize = 32;
95	trussinfo->curthread = NULL;
96	LIST_INIT(&trussinfo->proclist);
97	init_syscalls();
98	while ((c = getopt(ac, av, "p:o:facedDs:S")) != -1) {
99		switch (c) {
100		case 'p':	/* specified pid */
101			pid = atoi(optarg);
102			/* make sure i don't trace me */
103			if (pid == getpid()) {
104				errx(2, "attempt to grab self.");
105			}
106			break;
107		case 'f': /* Follow fork()'s */
108			trussinfo->flags |= FOLLOWFORKS;
109			break;
110		case 'a': /* Print execve() argument strings. */
111			trussinfo->flags |= EXECVEARGS;
112			break;
113		case 'c': /* Count number of system calls and time. */
114			trussinfo->flags |= (COUNTONLY | NOSIGS);
115			break;
116		case 'e': /* Print execve() environment strings. */
117			trussinfo->flags |= EXECVEENVS;
118			break;
119		case 'd': /* Absolute timestamps */
120			trussinfo->flags |= ABSOLUTETIMESTAMPS;
121			break;
122		case 'D': /* Relative timestamps */
123			trussinfo->flags |= RELATIVETIMESTAMPS;
124			break;
125		case 'o':	/* Specified output file */
126			fname = optarg;
127			break;
128		case 's':	/* Specified string size */
129			trussinfo->strsize = atoi(optarg);
130			break;
131		case 'S':	/* Don't trace signals */
132			trussinfo->flags |= NOSIGS;
133			break;
134		default:
135			usage();
136		}
137	}
138
139	ac -= optind; av += optind;
140	if ((pid == 0 && ac == 0) ||
141	    (pid != 0 && ac != 0))
142		usage();
143
144	if (fname != NULL) { /* Use output file */
145		/*
146		 * Set close-on-exec ('e'), so that the output file is not
147		 * shared with the traced process.
148		 */
149		if ((trussinfo->outfile = fopen(fname, "we")) == NULL)
150			err(1, "cannot open %s", fname);
151	}
152
153	/*
154	 * If truss starts the process itself, it will ignore some signals --
155	 * they should be passed off to the process, which may or may not
156	 * exit.  If, however, we are examining an already-running process,
157	 * then we restore the event mask on these same signals.
158	 */
159	if (pid == 0) {
160		/* Start a command ourselves */
161		command = av;
162		setup_and_wait(trussinfo, command);
163		signal(SIGINT, SIG_IGN);
164		signal(SIGTERM, SIG_IGN);
165		signal(SIGQUIT, SIG_IGN);
166	} else {
167		sa.sa_handler = restore_proc;
168		sa.sa_flags = 0;
169		sigemptyset(&sa.sa_mask);
170		sigaction(SIGINT, &sa, NULL);
171		sigaction(SIGQUIT, &sa, NULL);
172		sigaction(SIGTERM, &sa, NULL);
173		start_tracing(trussinfo, pid);
174	}
175
176	/*
177	 * At this point, if we started the process, it is stopped waiting to
178	 * be woken up, either in exit() or in execve().
179	 */
180	if (LIST_FIRST(&trussinfo->proclist)->abi == NULL) {
181		/*
182		 * If we are not able to handle this ABI, detach from the
183		 * process and exit.  If we just created a new process to
184		 * run a command, kill the new process rather than letting
185		 * it run untraced.
186		 */
187		if (pid == 0)
188			kill(LIST_FIRST(&trussinfo->proclist)->pid, SIGKILL);
189		ptrace(PT_DETACH, LIST_FIRST(&trussinfo->proclist)->pid, NULL,
190		    0);
191		return (1);
192	}
193	ptrace(PT_SYSCALL, LIST_FIRST(&trussinfo->proclist)->pid, (caddr_t)1,
194	    0);
195
196	/*
197	 * At this point, it's a simple loop, waiting for the process to
198	 * stop, finding out why, printing out why, and then continuing it.
199	 * All of the grunt work is done in the support routines.
200	 */
201	clock_gettime(CLOCK_REALTIME, &trussinfo->start_time);
202
203	eventloop(trussinfo);
204
205	if (trussinfo->flags & COUNTONLY)
206		print_summary(trussinfo);
207
208	fflush(trussinfo->outfile);
209
210	return (0);
211}
212