main.c revision 324779 
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 324779 2017-10-20 00:33:49Z emaste $");
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 [-cfaedDHS] [-o file] [-s strsize] -p pid",
59	    "       truss [-cfaedDHS] [-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:SH")) != -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		case 'H':
135			trussinfo->flags |= DISPLAYTIDS;
136			break;
137		default:
138			usage();
139		}
140	}
141
142	ac -= optind; av += optind;
143	if ((pid == 0 && ac == 0) ||
144	    (pid != 0 && ac != 0))
145		usage();
146
147	if (fname != NULL) { /* Use output file */
148		/*
149		 * Set close-on-exec ('e'), so that the output file is not
150		 * shared with the traced process.
151		 */
152		if ((trussinfo->outfile = fopen(fname, "we")) == NULL)
153			err(1, "cannot open %s", fname);
154	}
155
156	/*
157	 * If truss starts the process itself, it will ignore some signals --
158	 * they should be passed off to the process, which may or may not
159	 * exit.  If, however, we are examining an already-running process,
160	 * then we restore the event mask on these same signals.
161	 */
162	if (pid == 0) {
163		/* Start a command ourselves */
164		command = av;
165		setup_and_wait(trussinfo, command);
166		signal(SIGINT, SIG_IGN);
167		signal(SIGTERM, SIG_IGN);
168		signal(SIGQUIT, SIG_IGN);
169	} else {
170		sa.sa_handler = restore_proc;
171		sa.sa_flags = 0;
172		sigemptyset(&sa.sa_mask);
173		sigaction(SIGINT, &sa, NULL);
174		sigaction(SIGQUIT, &sa, NULL);
175		sigaction(SIGTERM, &sa, NULL);
176		start_tracing(trussinfo, pid);
177	}
178
179	/*
180	 * At this point, if we started the process, it is stopped waiting to
181	 * be woken up, either in exit() or in execve().
182	 */
183	if (LIST_FIRST(&trussinfo->proclist)->abi == NULL) {
184		/*
185		 * If we are not able to handle this ABI, detach from the
186		 * process and exit.  If we just created a new process to
187		 * run a command, kill the new process rather than letting
188		 * it run untraced.
189		 */
190		if (pid == 0)
191			kill(LIST_FIRST(&trussinfo->proclist)->pid, SIGKILL);
192		ptrace(PT_DETACH, LIST_FIRST(&trussinfo->proclist)->pid, NULL,
193		    0);
194		return (1);
195	}
196	ptrace(PT_SYSCALL, LIST_FIRST(&trussinfo->proclist)->pid, (caddr_t)1,
197	    0);
198
199	/*
200	 * At this point, it's a simple loop, waiting for the process to
201	 * stop, finding out why, printing out why, and then continuing it.
202	 * All of the grunt work is done in the support routines.
203	 */
204	clock_gettime(CLOCK_REALTIME, &trussinfo->start_time);
205
206	eventloop(trussinfo);
207
208	if (trussinfo->flags & COUNTONLY)
209		print_summary(trussinfo);
210
211	fflush(trussinfo->outfile);
212
213	return (0);
214}
215