main.c revision 204977 
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 204977 2010-03-10 20:31:30Z imp $");
34
35/*
36 * The main module for truss.  Suprisingly 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 <ctype.h>
49#include <err.h>
50#include <errno.h>
51#include <fcntl.h>
52#include <signal.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 */
78struct 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 __amd64__
84	{ "FreeBSD ELF64", amd64_syscall_entry, amd64_syscall_exit },
85	{ "FreeBSD ELF32", amd64_fbsd32_syscall_entry, amd64_fbsd32_syscall_exit },
86	{ "Linux ELF32", amd64_linux32_syscall_entry, amd64_linux32_syscall_exit },
87#endif
88#ifdef __i386__
89	{ "FreeBSD a.out", i386_syscall_entry, i386_syscall_exit },
90	{ "FreeBSD ELF", i386_syscall_entry, i386_syscall_exit },
91	{ "FreeBSD ELF32", i386_syscall_entry, i386_syscall_exit },
92	{ "Linux ELF", i386_linux_syscall_entry, i386_linux_syscall_exit },
93#endif
94#ifdef __ia64__
95	{ "FreeBSD ELF64", ia64_syscall_entry, ia64_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#endif
101#ifdef __sparc64__
102	{ "FreeBSD ELF64", sparc64_syscall_entry, sparc64_syscall_exit },
103#endif
104#ifdef __mips__
105	{ "FreeBSD ELF", mips_syscall_entry, mips_syscall_exit },
106	{ "FreeBSD ELF32", mips_syscall_entry, mips_syscall_exit },
107	{ "FreeBSD ELF64", mips_syscall_entry, mips_syscall_exit }, // XXX
108#endif
109	{ 0, 0, 0 },
110};
111
112/*
113 * Set the execution type.  This is called after every exec, and when
114 * a process is first monitored.
115 */
116
117static struct ex_types *
118set_etype(struct trussinfo *trussinfo)
119{
120	struct ex_types *funcs;
121	char progt[32];
122
123	size_t len = sizeof(progt);
124	int mib[4];
125	int error;
126
127	mib[0] = CTL_KERN;
128	mib[1] = KERN_PROC;
129	mib[2] = KERN_PROC_SV_NAME;
130	mib[3] = trussinfo->pid;
131	error = sysctl(mib, 4, progt, &len, NULL, 0);
132	if (error != 0)
133		err(2, "can not get etype");
134
135	for (funcs = ex_types; funcs->type; funcs++)
136		if (!strcmp(funcs->type, progt))
137			break;
138
139	if (funcs->type == NULL) {
140		funcs = &ex_types[0];
141		warn("execution type %s is not supported -- using %s",
142		    progt, funcs->type);
143	}
144	return (funcs);
145}
146
147char *
148strsig(int sig)
149{
150	char *ret;
151
152	ret = NULL;
153	if (sig > 0 && sig < NSIG) {
154		int i;
155		asprintf(&ret, "sig%s", sys_signame[sig]);
156		if (ret == NULL)
157			return (NULL);
158		for (i = 0; ret[i] != '\0'; ++i)
159			ret[i] = toupper(ret[i]);
160	}
161	return (ret);
162}
163
164int
165main(int ac, char **av)
166{
167	int c;
168	int i;
169	pid_t childpid;
170	int status;
171	char **command;
172	struct ex_types *funcs;
173	int initial_open;
174	char *fname;
175	struct trussinfo *trussinfo;
176	char *signame;
177
178	fname = NULL;
179	initial_open = 1;
180
181	/* Initialize the trussinfo struct */
182	trussinfo = (struct trussinfo *)calloc(1, sizeof(struct trussinfo));
183	if (trussinfo == NULL)
184		errx(1, "calloc() failed");
185
186	trussinfo->outfile = stderr;
187	trussinfo->strsize = 32;
188	trussinfo->pr_why = S_NONE;
189	trussinfo->curthread = NULL;
190	SLIST_INIT(&trussinfo->threadlist);
191	while ((c = getopt(ac, av, "p:o:facedDs:S")) != -1) {
192		switch (c) {
193		case 'p':	/* specified pid */
194			trussinfo->pid = atoi(optarg);
195			/* make sure i don't trace me */
196			if(trussinfo->pid == getpid()) {
197				fprintf(stderr, "attempt to grab self.\n");
198				exit(2);
199			}
200			break;
201		case 'f': /* Follow fork()'s */
202			trussinfo->flags |= FOLLOWFORKS;
203			break;
204		case 'a': /* Print execve() argument strings. */
205			trussinfo->flags |= EXECVEARGS;
206			break;
207		case 'c': /* Count number of system calls and time. */
208			trussinfo->flags |= COUNTONLY;
209			break;
210		case 'e': /* Print execve() environment strings. */
211			trussinfo->flags |= EXECVEENVS;
212			break;
213		case 'd': /* Absolute timestamps */
214			trussinfo->flags |= ABSOLUTETIMESTAMPS;
215			break;
216		case 'D': /* Relative timestamps */
217			trussinfo->flags |= RELATIVETIMESTAMPS;
218			break;
219		case 'o':	/* Specified output file */
220			fname = optarg;
221			break;
222		case 's':	/* Specified string size */
223			trussinfo->strsize = atoi(optarg);
224			break;
225		case 'S':	/* Don't trace signals */
226			trussinfo->flags |= NOSIGS;
227			break;
228		default:
229			usage();
230		}
231	}
232
233	ac -= optind; av += optind;
234	if ((trussinfo->pid == 0 && ac == 0) ||
235	    (trussinfo->pid != 0 && ac != 0))
236		usage();
237
238	if (fname != NULL) { /* Use output file */
239		if ((trussinfo->outfile = fopen(fname, "w")) == NULL)
240			errx(1, "cannot open %s", fname);
241	}
242	/*
243	 * Set FD_CLOEXEC, so that the output file is not shared with
244	 * the traced process.
245	 */
246	if (fcntl(fileno(trussinfo->outfile), F_SETFD, FD_CLOEXEC) == -1)
247		warn("fcntl()");
248
249	/*
250	 * If truss starts the process itself, it will ignore some signals --
251	 * they should be passed off to the process, which may or may not
252	 * exit.  If, however, we are examining an already-running process,
253	 * then we restore the event mask on these same signals.
254	 */
255
256	if (trussinfo->pid == 0) {	/* Start a command ourselves */
257		command = av;
258		trussinfo->pid = setup_and_wait(command);
259		signal(SIGINT, SIG_IGN);
260		signal(SIGTERM, SIG_IGN);
261		signal(SIGQUIT, SIG_IGN);
262	} else {
263		start_tracing(trussinfo->pid);
264		signal(SIGINT, restore_proc);
265		signal(SIGTERM, restore_proc);
266		signal(SIGQUIT, restore_proc);
267	}
268
269
270	/*
271	 * At this point, if we started the process, it is stopped waiting to
272	 * be woken up, either in exit() or in execve().
273	 */
274
275START_TRACE:
276	funcs = set_etype(trussinfo);
277
278	initial_open = 0;
279	/*
280	 * At this point, it's a simple loop, waiting for the process to
281	 * stop, finding out why, printing out why, and then continuing it.
282	 * All of the grunt work is done in the support routines.
283	 */
284
285	clock_gettime(CLOCK_REALTIME, &trussinfo->start_time);
286
287	do {
288		struct timespec timediff;
289		waitevent(trussinfo);
290
291		switch(i = trussinfo->pr_why) {
292		case S_SCE:
293			funcs->enter_syscall(trussinfo, MAXARGS);
294			clock_gettime(CLOCK_REALTIME,
295			    &trussinfo->before);
296			break;
297		case S_SCX:
298			clock_gettime(CLOCK_REALTIME,
299			    &trussinfo->after);
300
301			if (trussinfo->curthread->in_fork &&
302			    (trussinfo->flags & FOLLOWFORKS)) {
303				trussinfo->curthread->in_fork = 0;
304				childpid =
305				    funcs->exit_syscall(trussinfo,
306					trussinfo->pr_data);
307
308				/*
309				 * Fork a new copy of ourself to trace
310				 * the child of the original traced
311				 * process.
312				 */
313				if (fork() == 0) {
314					trussinfo->pid = childpid;
315					start_tracing(trussinfo->pid);
316					goto START_TRACE;
317				}
318				break;
319			}
320			funcs->exit_syscall(trussinfo, MAXARGS);
321			break;
322		case S_SIG:
323			if (trussinfo->flags & NOSIGS)
324				break;
325			if (trussinfo->flags & FOLLOWFORKS)
326				fprintf(trussinfo->outfile, "%5d: ",
327				    trussinfo->pid);
328			if (trussinfo->flags & ABSOLUTETIMESTAMPS) {
329				timespecsubt(&trussinfo->after,
330				    &trussinfo->start_time, &timediff);
331				fprintf(trussinfo->outfile, "%ld.%09ld ",
332				    (long)timediff.tv_sec,
333				    timediff.tv_nsec);
334			}
335			if (trussinfo->flags & RELATIVETIMESTAMPS) {
336				timespecsubt(&trussinfo->after,
337				    &trussinfo->before, &timediff);
338				fprintf(trussinfo->outfile, "%ld.%09ld ",
339				    (long)timediff.tv_sec,
340				    timediff.tv_nsec);
341			}
342			signame = strsig(trussinfo->pr_data);
343			fprintf(trussinfo->outfile,
344			    "SIGNAL %u (%s)\n", trussinfo->pr_data,
345			    signame == NULL ? "?" : signame);
346			free(signame);
347			break;
348		case S_EXIT:
349			if (trussinfo->flags & COUNTONLY)
350				break;
351			if (trussinfo->flags & FOLLOWFORKS)
352				fprintf(trussinfo->outfile, "%5d: ",
353				    trussinfo->pid);
354			if (trussinfo->flags & ABSOLUTETIMESTAMPS) {
355				timespecsubt(&trussinfo->after,
356				    &trussinfo->start_time, &timediff);
357				fprintf(trussinfo->outfile, "%ld.%09ld ",
358				    (long)timediff.tv_sec,
359				    timediff.tv_nsec);
360			}
361			if (trussinfo->flags & RELATIVETIMESTAMPS) {
362			  timespecsubt(&trussinfo->after,
363			      &trussinfo->before, &timediff);
364			  fprintf(trussinfo->outfile, "%ld.%09ld ",
365			    (long)timediff.tv_sec, timediff.tv_nsec);
366			}
367			fprintf(trussinfo->outfile,
368			    "process exit, rval = %u\n", trussinfo->pr_data);
369			break;
370		default:
371			break;
372		}
373	} while (trussinfo->pr_why != S_EXIT);
374
375	if (trussinfo->flags & FOLLOWFORKS)
376		do {
377			childpid = wait(&status);
378		} while (childpid != -1);
379
380 	if (trussinfo->flags & COUNTONLY)
381 		print_summary(trussinfo);
382
383	fflush(trussinfo->outfile);
384
385	return (0);
386}
387