1/*-
2 * SPDX-License-Identifier: BSD-4-Clause
3 *
4 * Copyright 1997 Sean Eric Fagan
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 *    must display the following acknowledgement:
16 *	This product includes software developed by Sean Eric Fagan
17 * 4. Neither the name of the author may be used to endorse or promote
18 *    products derived from this software without specific prior written
19 *    permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#include <sys/cdefs.h>
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 <stdbool.h>
46#include <stdio.h>
47#include <stdlib.h>
48#include <sysdecode.h>
49#include <time.h>
50#include <unistd.h>
51
52#include "truss.h"
53#include "extern.h"
54#include "syscall.h"
55
56static __dead2 void
57usage(void)
58{
59	fprintf(stderr, "%s\n%s\n",
60	    "usage: truss [-cfaedDHS] [-o file] [-s strsize] -p pid",
61	    "       truss [-cfaedDHS] [-o file] [-s strsize] command [args]");
62	exit(1);
63}
64
65int
66main(int ac, char **av)
67{
68	struct sigaction sa;
69	struct trussinfo *trussinfo;
70	char *fname;
71	char **command;
72	const char *errstr;
73	pid_t pid;
74	int c;
75
76	fname = NULL;
77
78	/* Initialize the trussinfo struct */
79	trussinfo = (struct trussinfo *)calloc(1, sizeof(struct trussinfo));
80	if (trussinfo == NULL)
81		errx(1, "calloc() failed");
82
83	pid = 0;
84	trussinfo->outfile = stderr;
85	trussinfo->strsize = 32;
86	trussinfo->curthread = NULL;
87	LIST_INIT(&trussinfo->proclist);
88	while ((c = getopt(ac, av, "p:o:facedDs:SH")) != -1) {
89		switch (c) {
90		case 'p':	/* specified pid */
91			pid = atoi(optarg);
92			/* make sure i don't trace me */
93			if (pid == getpid()) {
94				errx(2, "attempt to grab self.");
95			}
96			break;
97		case 'f': /* Follow fork()'s */
98			trussinfo->flags |= FOLLOWFORKS;
99			break;
100		case 'a': /* Print execve() argument strings. */
101			trussinfo->flags |= EXECVEARGS;
102			break;
103		case 'c': /* Count number of system calls and time. */
104			trussinfo->flags |= (COUNTONLY | NOSIGS);
105			break;
106		case 'e': /* Print execve() environment strings. */
107			trussinfo->flags |= EXECVEENVS;
108			break;
109		case 'd': /* Absolute timestamps */
110			trussinfo->flags |= ABSOLUTETIMESTAMPS;
111			break;
112		case 'D': /* Relative timestamps */
113			trussinfo->flags |= RELATIVETIMESTAMPS;
114			break;
115		case 'o':	/* Specified output file */
116			fname = optarg;
117			break;
118		case 's':	/* Specified string size */
119			trussinfo->strsize = (int)strtonum(optarg, 0, INT_MAX,
120			    &errstr);
121			if (errstr)
122				errx(1, "maximum string size is %s: %s", errstr, optarg);
123			break;
124		case 'S':	/* Don't trace signals */
125			trussinfo->flags |= NOSIGS;
126			break;
127		case 'H':
128			trussinfo->flags |= DISPLAYTIDS;
129			break;
130		default:
131			usage();
132		}
133	}
134
135	ac -= optind; av += optind;
136	if ((pid == 0 && ac == 0) ||
137	    (pid != 0 && ac != 0))
138		usage();
139
140	if (fname != NULL) { /* Use output file */
141		/*
142		 * Set close-on-exec ('e'), so that the output file is not
143		 * shared with the traced process.
144		 */
145		if ((trussinfo->outfile = fopen(fname, "we")) == NULL)
146			err(1, "cannot open %s", fname);
147	}
148
149	/*
150	 * If truss starts the process itself, it will ignore some signals --
151	 * they should be passed off to the process, which may or may not
152	 * exit.  If, however, we are examining an already-running process,
153	 * then we restore the event mask on these same signals.
154	 */
155	if (pid == 0) {
156		/* Start a command ourselves */
157		command = av;
158		setup_and_wait(trussinfo, command);
159		signal(SIGINT, SIG_IGN);
160		signal(SIGTERM, SIG_IGN);
161		signal(SIGQUIT, SIG_IGN);
162	} else {
163		sa.sa_handler = restore_proc;
164		sa.sa_flags = 0;
165		sigemptyset(&sa.sa_mask);
166		sigaction(SIGINT, &sa, NULL);
167		sigaction(SIGQUIT, &sa, NULL);
168		sigaction(SIGTERM, &sa, NULL);
169		start_tracing(trussinfo, pid);
170	}
171
172	/*
173	 * At this point, if we started the process, it is stopped waiting to
174	 * be woken up, either in exit() or in execve().
175	 */
176	if (LIST_FIRST(&trussinfo->proclist)->abi == NULL) {
177		/*
178		 * If we are not able to handle this ABI, detach from the
179		 * process and exit.  If we just created a new process to
180		 * run a command, kill the new process rather than letting
181		 * it run untraced.
182		 */
183		if (pid == 0)
184			kill(LIST_FIRST(&trussinfo->proclist)->pid, SIGKILL);
185		ptrace(PT_DETACH, LIST_FIRST(&trussinfo->proclist)->pid, NULL,
186		    0);
187		return (1);
188	}
189	ptrace(PT_SYSCALL, LIST_FIRST(&trussinfo->proclist)->pid, (caddr_t)1,
190	    0);
191
192	/*
193	 * At this point, it's a simple loop, waiting for the process to
194	 * stop, finding out why, printing out why, and then continuing it.
195	 * All of the grunt work is done in the support routines.
196	 */
197	clock_gettime(CLOCK_REALTIME, &trussinfo->start_time);
198
199	eventloop(trussinfo);
200
201	if (trussinfo->flags & COUNTONLY)
202		print_summary(trussinfo);
203
204	fflush(trussinfo->outfile);
205
206	return (0);
207}
208