main.c revision 192025 
1/*-
2 * Copryight 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 192025 2009-05-12 20:42:12Z dds $");
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 *)malloc(sizeof(struct trussinfo));
183	if (trussinfo == NULL)
184		errx(1, "malloc() failed");
185	bzero(trussinfo, sizeof(struct trussinfo));
186
187	trussinfo->outfile = stderr;
188	trussinfo->strsize = 32;
189	trussinfo->pr_why = S_NONE;
190	trussinfo->curthread = NULL;
191	SLIST_INIT(&trussinfo->threadlist);
192	while ((c = getopt(ac, av, "p:o:facedDs:S")) != -1) {
193		switch (c) {
194		case 'p':	/* specified pid */
195			trussinfo->pid = atoi(optarg);
196			/* make sure i don't trace me */
197			if(trussinfo->pid == getpid()) {
198				fprintf(stderr, "attempt to grab self.\n");
199				exit(2);
200			}
201			break;
202		case 'f': /* Follow fork()'s */
203			trussinfo->flags |= FOLLOWFORKS;
204			break;
205		case 'a': /* Print execve() argument strings. */
206			trussinfo->flags |= EXECVEARGS;
207			break;
208		case 'c': /* Count number of system calls and time. */
209			trussinfo->flags |= COUNTONLY;
210			break;
211		case 'e': /* Print execve() environment strings. */
212			trussinfo->flags |= EXECVEENVS;
213			break;
214		case 'd': /* Absolute timestamps */
215			trussinfo->flags |= ABSOLUTETIMESTAMPS;
216			break;
217		case 'D': /* Relative timestamps */
218			trussinfo->flags |= RELATIVETIMESTAMPS;
219			break;
220		case 'o':	/* Specified output file */
221			fname = optarg;
222			break;
223		case 's':	/* Specified string size */
224			trussinfo->strsize = atoi(optarg);
225			break;
226		case 'S':	/* Don't trace signals */
227			trussinfo->flags |= NOSIGS;
228			break;
229		default:
230			usage();
231		}
232	}
233
234	ac -= optind; av += optind;
235	if ((trussinfo->pid == 0 && ac == 0) ||
236	    (trussinfo->pid != 0 && ac != 0))
237		usage();
238
239	if (fname != NULL) { /* Use output file */
240		if ((trussinfo->outfile = fopen(fname, "w")) == NULL)
241			errx(1, "cannot open %s", fname);
242	}
243
244	/*
245	 * If truss starts the process itself, it will ignore some signals --
246	 * they should be passed off to the process, which may or may not
247	 * exit.  If, however, we are examining an already-running process,
248	 * then we restore the event mask on these same signals.
249	 */
250
251	if (trussinfo->pid == 0) {	/* Start a command ourselves */
252		command = av;
253		trussinfo->pid = setup_and_wait(command);
254		signal(SIGINT, SIG_IGN);
255		signal(SIGTERM, SIG_IGN);
256		signal(SIGQUIT, SIG_IGN);
257	} else {
258		start_tracing(trussinfo->pid);
259		signal(SIGINT, restore_proc);
260		signal(SIGTERM, restore_proc);
261		signal(SIGQUIT, restore_proc);
262	}
263
264
265	/*
266	 * At this point, if we started the process, it is stopped waiting to
267	 * be woken up, either in exit() or in execve().
268	 */
269
270START_TRACE:
271	funcs = set_etype(trussinfo);
272
273	initial_open = 0;
274	/*
275	 * At this point, it's a simple loop, waiting for the process to
276	 * stop, finding out why, printing out why, and then continuing it.
277	 * All of the grunt work is done in the support routines.
278	 */
279
280	clock_gettime(CLOCK_REALTIME, &trussinfo->start_time);
281
282	do {
283		struct timespec timediff;
284		waitevent(trussinfo);
285
286		switch(i = trussinfo->pr_why) {
287		case S_SCE:
288			funcs->enter_syscall(trussinfo, MAXARGS);
289			clock_gettime(CLOCK_REALTIME,
290			    &trussinfo->before);
291			break;
292		case S_SCX:
293			clock_gettime(CLOCK_REALTIME,
294			    &trussinfo->after);
295
296			if (trussinfo->curthread->in_fork &&
297			    (trussinfo->flags & FOLLOWFORKS)) {
298				trussinfo->curthread->in_fork = 0;
299				childpid =
300				    funcs->exit_syscall(trussinfo,
301					trussinfo->pr_data);
302
303				/*
304				 * Fork a new copy of ourself to trace
305				 * the child of the original traced
306				 * process.
307				 */
308				if (fork() == 0) {
309					trussinfo->pid = childpid;
310					start_tracing(trussinfo->pid);
311					goto START_TRACE;
312				}
313				break;
314			}
315			funcs->exit_syscall(trussinfo, MAXARGS);
316			break;
317		case S_SIG:
318			if (trussinfo->flags & NOSIGS)
319				break;
320			if (trussinfo->flags & FOLLOWFORKS)
321				fprintf(trussinfo->outfile, "%5d: ",
322				    trussinfo->pid);
323			if (trussinfo->flags & ABSOLUTETIMESTAMPS) {
324				timespecsubt(&trussinfo->after,
325				    &trussinfo->start_time, &timediff);
326				fprintf(trussinfo->outfile, "%ld.%09ld ",
327				    (long)timediff.tv_sec,
328				    timediff.tv_nsec);
329			}
330			if (trussinfo->flags & RELATIVETIMESTAMPS) {
331				timespecsubt(&trussinfo->after,
332				    &trussinfo->before, &timediff);
333				fprintf(trussinfo->outfile, "%ld.%09ld ",
334				    (long)timediff.tv_sec,
335				    timediff.tv_nsec);
336			}
337			signame = strsig(trussinfo->pr_data);
338			fprintf(trussinfo->outfile,
339			    "SIGNAL %u (%s)\n", trussinfo->pr_data,
340			    signame == NULL ? "?" : signame);
341			free(signame);
342			break;
343		case S_EXIT:
344			if (trussinfo->flags & COUNTONLY)
345				break;
346			if (trussinfo->flags & FOLLOWFORKS)
347				fprintf(trussinfo->outfile, "%5d: ",
348				    trussinfo->pid);
349			if (trussinfo->flags & ABSOLUTETIMESTAMPS) {
350				timespecsubt(&trussinfo->after,
351				    &trussinfo->start_time, &timediff);
352				fprintf(trussinfo->outfile, "%ld.%09ld ",
353				    (long)timediff.tv_sec,
354				    timediff.tv_nsec);
355			}
356			if (trussinfo->flags & RELATIVETIMESTAMPS) {
357			  timespecsubt(&trussinfo->after,
358			      &trussinfo->before, &timediff);
359			  fprintf(trussinfo->outfile, "%ld.%09ld ",
360			    (long)timediff.tv_sec, timediff.tv_nsec);
361			}
362			fprintf(trussinfo->outfile,
363			    "process exit, rval = %u\n", trussinfo->pr_data);
364			break;
365		default:
366			break;
367		}
368	} while (trussinfo->pr_why != S_EXIT);
369
370	if (trussinfo->flags & FOLLOWFORKS)
371		do {
372			childpid = wait(&status);
373		} while (childpid != -1);
374
375 	if (trussinfo->flags & COUNTONLY)
376 		print_summary(trussinfo);
377
378	fflush(trussinfo->outfile);
379
380	return (0);
381}
382