main.c revision 171055 
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 171055 2007-06-26 22:42:37Z delphij $");
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
47#include <ctype.h>
48#include <err.h>
49#include <errno.h>
50#include <fcntl.h>
51#include <signal.h>
52#include <stdio.h>
53#include <stdlib.h>
54#include <string.h>
55#include <time.h>
56#include <unistd.h>
57
58#include "truss.h"
59#include "extern.h"
60
61#define MAXARGS 5
62
63static void
64usage(void)
65{
66	fprintf(stderr, "%s\n%s\n",
67	    "usage: truss [-faedDS] [-o file] [-s strsize] -p pid",
68	    "       truss [-faedDS] [-o file] [-s strsize] command [args]");
69	exit(1);
70}
71
72/*
73 * WARNING! "FreeBSD a.out" must be first, or set_etype will not
74 * work correctly.
75 */
76struct ex_types {
77	const char *type;
78	void (*enter_syscall)(struct trussinfo *, int);
79	long (*exit_syscall)(struct trussinfo *, int);
80} ex_types[] = {
81#ifdef __alpha__
82	{ "FreeBSD ELF", alpha_syscall_entry, alpha_syscall_exit },
83#endif
84#ifdef __amd64__
85	{ "FreeBSD ELF64", amd64_syscall_entry, amd64_syscall_exit },
86#endif
87#ifdef __i386__
88	{ "FreeBSD a.out", i386_syscall_entry, i386_syscall_exit },
89	{ "FreeBSD ELF", i386_syscall_entry, i386_syscall_exit },
90	{ "FreeBSD ELF32", i386_syscall_entry, i386_syscall_exit },
91	{ "Linux ELF", i386_linux_syscall_entry, i386_linux_syscall_exit },
92#endif
93#ifdef __ia64__
94	{ "FreeBSD ELF64", ia64_syscall_entry, ia64_syscall_exit },
95#endif
96#ifdef __powerpc__
97	{ "FreeBSD ELF", powerpc_syscall_entry, powerpc_syscall_exit },
98	{ "FreeBSD ELF32", powerpc_syscall_entry, powerpc_syscall_exit },
99#endif
100#ifdef __sparc64__
101	{ "FreeBSD ELF64", sparc64_syscall_entry, sparc64_syscall_exit },
102#endif
103	{ 0, 0, 0 },
104};
105
106/*
107 * Set the execution type.  This is called after every exec, and when
108 * a process is first monitored.
109 */
110
111static struct ex_types *
112set_etype(struct trussinfo *trussinfo)
113{
114	struct ex_types *funcs;
115	char progt[32];
116
117	size_t len = sizeof(progt);
118	int mib[4];
119	int error;
120
121	mib[0] = CTL_KERN;
122	mib[1] = KERN_PROC;
123	mib[2] = KERN_PROC_SV_NAME;
124	mib[3] = trussinfo->pid;
125	error = sysctl(mib, 4, progt, &len, NULL, 0);
126	if (error != 0)
127		err(2, "can not get etype");
128
129	for (funcs = ex_types; funcs->type; funcs++)
130		if (!strcmp(funcs->type, progt))
131			break;
132
133	if (funcs->type == NULL) {
134		funcs = &ex_types[0];
135		warn("execution type %s is not supported -- using %s",
136		    progt, funcs->type);
137	}
138	return (funcs);
139}
140
141char *
142strsig(int sig)
143{
144	char *ret;
145
146	ret = NULL;
147	if (sig > 0 && sig < NSIG) {
148		int i;
149		asprintf(&ret, "sig%s", sys_signame[sig]);
150		if (ret == NULL)
151			return (NULL);
152		for (i = 0; ret[i] != '\0'; ++i)
153			ret[i] = toupper(ret[i]);
154	}
155	return (ret);
156}
157
158int
159main(int ac, char **av)
160{
161	int c;
162	int i;
163	char **command;
164	struct ex_types *funcs;
165	int initial_open;
166	char *fname;
167	struct trussinfo *trussinfo;
168	char *signame;
169
170	fname = NULL;
171	initial_open = 1;
172
173	/* Initialize the trussinfo struct */
174	trussinfo = (struct trussinfo *)malloc(sizeof(struct trussinfo));
175	if (trussinfo == NULL)
176		errx(1, "malloc() failed");
177	bzero(trussinfo, sizeof(struct trussinfo));
178
179	trussinfo->outfile = stderr;
180	trussinfo->strsize = 32;
181	trussinfo->pr_why = S_NONE;
182	trussinfo->curthread = NULL;
183	SLIST_INIT(&trussinfo->threadlist);
184	while ((c = getopt(ac, av, "p:o:faedDs:S")) != -1) {
185		switch (c) {
186		case 'p':	/* specified pid */
187			trussinfo->pid = atoi(optarg);
188			/* make sure i don't trace me */
189			if(trussinfo->pid == getpid()) {
190				fprintf(stderr, "attempt to grab self.\n");
191				exit(2);
192			}
193			break;
194		case 'f': /* Follow fork()'s */
195			trussinfo->flags |= FOLLOWFORKS;
196			break;
197		case 'a': /* Print execve() argument strings. */
198			trussinfo->flags |= EXECVEARGS;
199			break;
200		case 'e': /* Print execve() environment strings. */
201			trussinfo->flags |= EXECVEENVS;
202			break;
203		case 'd': /* Absolute timestamps */
204			trussinfo->flags |= ABSOLUTETIMESTAMPS;
205			break;
206		case 'D': /* Relative timestamps */
207			trussinfo->flags |= RELATIVETIMESTAMPS;
208			break;
209		case 'o':	/* Specified output file */
210			fname = optarg;
211			break;
212		case 's':	/* Specified string size */
213			trussinfo->strsize = atoi(optarg);
214			break;
215		case 'S':	/* Don't trace signals */
216			trussinfo->flags |= NOSIGS;
217			break;
218		default:
219			usage();
220		}
221	}
222
223	ac -= optind; av += optind;
224	if ((trussinfo->pid == 0 && ac == 0) ||
225	    (trussinfo->pid != 0 && ac != 0))
226		usage();
227
228	if (fname != NULL) { /* Use output file */
229		if ((trussinfo->outfile = fopen(fname, "w")) == NULL)
230			errx(1, "cannot open %s", fname);
231	}
232
233	/*
234	 * If truss starts the process itself, it will ignore some signals --
235	 * they should be passed off to the process, which may or may not
236	 * exit.  If, however, we are examining an already-running process,
237	 * then we restore the event mask on these same signals.
238	 */
239
240	if (trussinfo->pid == 0) {	/* Start a command ourselves */
241		command = av;
242		trussinfo->pid = setup_and_wait(command);
243		signal(SIGINT, SIG_IGN);
244		signal(SIGTERM, SIG_IGN);
245		signal(SIGQUIT, SIG_IGN);
246	} else {
247		start_tracing(trussinfo->pid);
248		signal(SIGINT, restore_proc);
249		signal(SIGTERM, restore_proc);
250		signal(SIGQUIT, restore_proc);
251	}
252
253
254	/*
255	 * At this point, if we started the process, it is stopped waiting to
256	 * be woken up, either in exit() or in execve().
257	 */
258
259START_TRACE:
260	funcs = set_etype(trussinfo);
261
262	initial_open = 0;
263	/*
264	 * At this point, it's a simple loop, waiting for the process to
265	 * stop, finding out why, printing out why, and then continuing it.
266	 * All of the grunt work is done in the support routines.
267	 */
268
269	clock_gettime(CLOCK_REALTIME, &trussinfo->start_time);
270
271	do {
272		struct timespec timediff;
273		waitevent(trussinfo);
274
275		switch(i = trussinfo->pr_why) {
276		case S_SCE:
277			funcs->enter_syscall(trussinfo, MAXARGS);
278			clock_gettime(CLOCK_REALTIME,
279			    &trussinfo->before);
280			break;
281		case S_SCX:
282			clock_gettime(CLOCK_REALTIME,
283			    &trussinfo->after);
284
285			if (trussinfo->curthread->in_fork &&
286			    (trussinfo->flags & FOLLOWFORKS)) {
287				int childpid;
288
289				trussinfo->curthread->in_fork = 0;
290				childpid =
291				    funcs->exit_syscall(trussinfo,
292					trussinfo->pr_data);
293
294				/*
295				 * Fork a new copy of ourself to trace
296				 * the child of the original traced
297				 * process.
298				 */
299				if (fork() == 0) {
300					trussinfo->pid = childpid;
301					start_tracing(trussinfo->pid);
302					goto START_TRACE;
303				}
304				break;
305			}
306			funcs->exit_syscall(trussinfo, MAXARGS);
307			break;
308		case S_SIG:
309			if (trussinfo->flags & NOSIGS)
310				break;
311			if (trussinfo->flags & FOLLOWFORKS)
312				fprintf(trussinfo->outfile, "%5d: ",
313				    trussinfo->pid);
314			if (trussinfo->flags & ABSOLUTETIMESTAMPS) {
315				timespecsubt(&trussinfo->after,
316				    &trussinfo->start_time, &timediff);
317				fprintf(trussinfo->outfile, "%ld.%09ld ",
318				    (long)timediff.tv_sec,
319				    timediff.tv_nsec);
320			}
321			if (trussinfo->flags & RELATIVETIMESTAMPS) {
322				timespecsubt(&trussinfo->after,
323				    &trussinfo->before, &timediff);
324				fprintf(trussinfo->outfile, "%ld.%09ld ",
325				    (long)timediff.tv_sec,
326				    timediff.tv_nsec);
327			}
328			signame = strsig(trussinfo->pr_data);
329			fprintf(trussinfo->outfile,
330			    "SIGNAL %u (%s)\n", trussinfo->pr_data,
331			    signame == NULL ? "?" : signame);
332			free(signame);
333			break;
334		case S_EXIT:
335			if (trussinfo->flags & FOLLOWFORKS)
336				fprintf(trussinfo->outfile, "%5d: ",
337				    trussinfo->pid);
338			if (trussinfo->flags & ABSOLUTETIMESTAMPS) {
339				timespecsubt(&trussinfo->after,
340				    &trussinfo->start_time, &timediff);
341				fprintf(trussinfo->outfile, "%ld.%09ld ",
342				    (long)timediff.tv_sec,
343				    timediff.tv_nsec);
344			}
345			if (trussinfo->flags & RELATIVETIMESTAMPS) {
346			  timespecsubt(&trussinfo->after,
347			      &trussinfo->before, &timediff);
348			  fprintf(trussinfo->outfile, "%ld.%09ld ",
349			    (long)timediff.tv_sec, timediff.tv_nsec);
350			}
351			fprintf(trussinfo->outfile,
352			    "process exit, rval = %u\n", trussinfo->pr_data);
353			break;
354		default:
355			break;
356		}
357	} while (trussinfo->pr_why != S_EXIT);
358	fflush(trussinfo->outfile);
359
360	return (0);
361}
362