main.c revision 294849 
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 294849 2016-01-26 19:07:09Z 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 <sysdecode.h>
48#include <time.h>
49#include <unistd.h>
50
51#include "truss.h"
52#include "extern.h"
53#include "syscall.h"
54
55static void
56usage(void)
57{
58	fprintf(stderr, "%s\n%s\n",
59	    "usage: truss [-cfaedDS] [-o file] [-s strsize] -p pid",
60	    "       truss [-cfaedDS] [-o file] [-s strsize] command [args]");
61	exit(1);
62}
63
64char *
65strsig(int sig)
66{
67	static char tmp[64];
68
69	if (sig > 0 && sig < NSIG) {
70		snprintf(tmp, sizeof(tmp), "SIG%s", sys_signame[sig]);
71		return (tmp);
72	}
73	return (NULL);
74}
75
76int
77main(int ac, char **av)
78{
79	struct sigaction sa;
80	struct trussinfo *trussinfo;
81	char *fname;
82	char **command;
83	pid_t pid;
84	int c;
85
86	fname = NULL;
87
88	/* Initialize the trussinfo struct */
89	trussinfo = (struct trussinfo *)calloc(1, sizeof(struct trussinfo));
90	if (trussinfo == NULL)
91		errx(1, "calloc() failed");
92
93	pid = 0;
94	trussinfo->outfile = stderr;
95	trussinfo->strsize = 32;
96	trussinfo->curthread = NULL;
97	LIST_INIT(&trussinfo->proclist);
98	init_syscalls();
99	while ((c = getopt(ac, av, "p:o:facedDs:S")) != -1) {
100		switch (c) {
101		case 'p':	/* specified pid */
102			pid = atoi(optarg);
103			/* make sure i don't trace me */
104			if (pid == getpid()) {
105				errx(2, "attempt to grab self.");
106			}
107			break;
108		case 'f': /* Follow fork()'s */
109			trussinfo->flags |= FOLLOWFORKS;
110			break;
111		case 'a': /* Print execve() argument strings. */
112			trussinfo->flags |= EXECVEARGS;
113			break;
114		case 'c': /* Count number of system calls and time. */
115			trussinfo->flags |= (COUNTONLY | NOSIGS);
116			break;
117		case 'e': /* Print execve() environment strings. */
118			trussinfo->flags |= EXECVEENVS;
119			break;
120		case 'd': /* Absolute timestamps */
121			trussinfo->flags |= ABSOLUTETIMESTAMPS;
122			break;
123		case 'D': /* Relative timestamps */
124			trussinfo->flags |= RELATIVETIMESTAMPS;
125			break;
126		case 'o':	/* Specified output file */
127			fname = optarg;
128			break;
129		case 's':	/* Specified string size */
130			trussinfo->strsize = atoi(optarg);
131			break;
132		case 'S':	/* Don't trace signals */
133			trussinfo->flags |= NOSIGS;
134			break;
135		default:
136			usage();
137		}
138	}
139
140	ac -= optind; av += optind;
141	if ((pid == 0 && ac == 0) ||
142	    (pid != 0 && ac != 0))
143		usage();
144
145	if (fname != NULL) { /* Use output file */
146		/*
147		 * Set close-on-exec ('e'), so that the output file is not
148		 * shared with the traced process.
149		 */
150		if ((trussinfo->outfile = fopen(fname, "we")) == NULL)
151			err(1, "cannot open %s", fname);
152	}
153
154	/*
155	 * If truss starts the process itself, it will ignore some signals --
156	 * they should be passed off to the process, which may or may not
157	 * exit.  If, however, we are examining an already-running process,
158	 * then we restore the event mask on these same signals.
159	 */
160	if (pid == 0) {
161		/* Start a command ourselves */
162		command = av;
163		setup_and_wait(trussinfo, command);
164		signal(SIGINT, SIG_IGN);
165		signal(SIGTERM, SIG_IGN);
166		signal(SIGQUIT, SIG_IGN);
167	} else {
168		sa.sa_handler = restore_proc;
169		sa.sa_flags = 0;
170		sigemptyset(&sa.sa_mask);
171		sigaction(SIGINT, &sa, NULL);
172		sigaction(SIGQUIT, &sa, NULL);
173		sigaction(SIGTERM, &sa, NULL);
174		start_tracing(trussinfo, pid);
175	}
176
177	/*
178	 * At this point, if we started the process, it is stopped waiting to
179	 * be woken up, either in exit() or in execve().
180	 */
181	if (LIST_FIRST(&trussinfo->proclist)->abi == NULL) {
182		/*
183		 * If we are not able to handle this ABI, detach from the
184		 * process and exit.  If we just created a new process to
185		 * run a command, kill the new process rather than letting
186		 * it run untraced.
187		 */
188		if (pid == 0)
189			kill(LIST_FIRST(&trussinfo->proclist)->pid, SIGKILL);
190		ptrace(PT_DETACH, LIST_FIRST(&trussinfo->proclist)->pid, NULL,
191		    0);
192		return (1);
193	}
194	ptrace(PT_SYSCALL, LIST_FIRST(&trussinfo->proclist)->pid, (caddr_t)1,
195	    0);
196
197	/*
198	 * At this point, it's a simple loop, waiting for the process to
199	 * stop, finding out why, printing out why, and then continuing it.
200	 * All of the grunt work is done in the support routines.
201	 */
202	clock_gettime(CLOCK_REALTIME, &trussinfo->start_time);
203
204	eventloop(trussinfo);
205
206	if (trussinfo->flags & COUNTONLY)
207		print_summary(trussinfo);
208
209	fflush(trussinfo->outfile);
210
211	return (0);
212}
213