FreeBSD-5.3/usr.bin/truss/main.c
/*
* Copryight 1997 Sean Eric Fagan
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Sean Eric Fagan
* 4. Neither the name of the author may be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/usr.bin/truss/main.c,v 1.38 2004/07/17 19:19:36 alfred Exp $");
/*
* The main module for truss. Suprisingly simple, but, then, the other
* files handle the bulk of the work. And, of course, the kernel has to
* do a lot of the work :).
*/
#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/pioctl.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include "truss.h"
#include "extern.h"
/*
* It's difficult to parameterize this because it must be
* accessible in a signal handler.
*/
int Procfd;
static __inline void
usage(void)
{
fprintf(stderr, "%s\n%s\n",
"usage: truss [-faedDS] [-o file] -p pid",
" truss [-faedDS] [-o file] command [args]");
exit(1);
}
/*
* WARNING! "FreeBSD a.out" must be first, or set_etype will not
* work correctly.
*/
struct ex_types {
const char *type;
void (*enter_syscall)(struct trussinfo *, int);
long (*exit_syscall)(struct trussinfo *, int);
} ex_types[] = {
#ifdef __alpha__
{ "FreeBSD ELF", alpha_syscall_entry, alpha_syscall_exit },
#endif
#ifdef __amd64__
{ "FreeBSD ELF64", amd64_syscall_entry, amd64_syscall_exit },
#endif
#ifdef __i386__
{ "FreeBSD a.out", i386_syscall_entry, i386_syscall_exit },
{ "FreeBSD ELF", i386_syscall_entry, i386_syscall_exit },
{ "FreeBSD ELF32", i386_syscall_entry, i386_syscall_exit },
{ "Linux ELF", i386_linux_syscall_entry, i386_linux_syscall_exit },
#endif
#ifdef __ia64__
{ "FreeBSD ELF64", ia64_syscall_entry, ia64_syscall_exit },
#endif
#ifdef __sparc64__
{ "FreeBSD ELF64", sparc64_syscall_entry, sparc64_syscall_exit },
#endif
{ 0, 0, 0 },
};
/*
* Set the execution type. This is called after every exec, and when
* a process is first monitored. The procfs pseudo-file "etype" has
* the execution module type -- see /proc/curproc/etype for an example.
*/
static struct ex_types *
set_etype(struct trussinfo *trussinfo) {
struct ex_types *funcs;
char etype[24];
char progt[32];
int fd;
sprintf(etype, "/proc/%d/etype", trussinfo->pid);
if ((fd = open(etype, O_RDONLY)) == -1) {
strcpy(progt, "FreeBSD a.out");
} else {
int len = read(fd, progt, sizeof(progt));
progt[len-1] = '\0';
close(fd);
}
for (funcs = ex_types; funcs->type; funcs++)
if (!strcmp(funcs->type, progt))
break;
if (funcs->type == NULL) {
funcs = &ex_types[0];
warn("execution type %s is not supported -- using %s",
progt, funcs->type);
}
return funcs;
}
char *
strsig(int sig)
{
char *ret;
ret = NULL;
if (sig > 0 && sig < NSIG) {
int i;
asprintf(&ret, "sig%s", sys_signame[sig]);
if (ret == NULL)
return (NULL);
for (i = 0; ret[i] != '\0'; ++i)
ret[i] = toupper(ret[i]);
}
return (ret);
}
int
main(int ac, char **av) {
int c;
int i;
char **command;
struct procfs_status pfs;
struct ex_types *funcs;
int in_exec = 0;
char *fname = NULL;
int sigexit = 0;
struct trussinfo *trussinfo;
char *signame;
/* Initialize the trussinfo struct */
trussinfo = (struct trussinfo *)malloc(sizeof(struct trussinfo));
if (trussinfo == NULL)
errx(1, "malloc() failed");
bzero(trussinfo, sizeof(struct trussinfo));
trussinfo->outfile = stderr;
while ((c = getopt(ac, av, "p:o:faedDS")) != -1) {
switch (c) {
case 'p': /* specified pid */
trussinfo->pid = atoi(optarg);
break;
case 'f': /* Follow fork()'s */
trussinfo->flags |= FOLLOWFORKS;
break;
case 'a': /* Print execve() argument strings. */
trussinfo->flags |= EXECVEARGS;
break;
case 'e': /* Print execve() environment strings. */
trussinfo->flags |= EXECVEENVS;
break;
case 'd': /* Absolute timestamps */
trussinfo->flags |= ABSOLUTETIMESTAMPS;
break;
case 'D': /* Relative timestamps */
trussinfo->flags |= RELATIVETIMESTAMPS;
break;
case 'o': /* Specified output file */
fname = optarg;
break;
case 'S': /* Don't trace signals */
trussinfo->flags |= NOSIGS;
break;
default:
usage();
}
}
ac -= optind; av += optind;
if ((trussinfo->pid == 0 && ac == 0) || (trussinfo->pid != 0 && ac != 0))
usage();
if (fname != NULL) { /* Use output file */
if ((trussinfo->outfile = fopen(fname, "w")) == NULL)
errx(1, "cannot open %s", fname);
}
/*
* If truss starts the process itself, it will ignore some signals --
* they should be passed off to the process, which may or may not
* exit. If, however, we are examining an already-running process,
* then we restore the event mask on these same signals.
*/
if (trussinfo->pid == 0) { /* Start a command ourselves */
command = av;
trussinfo->pid = setup_and_wait(command);
signal(SIGINT, SIG_IGN);
signal(SIGTERM, SIG_IGN);
signal(SIGQUIT, SIG_IGN);
} else {
signal(SIGINT, restore_proc);
signal(SIGTERM, restore_proc);
signal(SIGQUIT, restore_proc);
}
/*
* At this point, if we started the process, it is stopped waiting to
* be woken up, either in exit() or in execve().
*/
START_TRACE:
Procfd = start_tracing(
trussinfo->pid, S_EXEC | S_SCE | S_SCX | S_CORE | S_EXIT |
((trussinfo->flags & NOSIGS) ? 0 : S_SIG),
((trussinfo->flags & FOLLOWFORKS) ? PF_FORK : 0));
if (Procfd == -1)
return 0;
pfs.why = 0;
funcs = set_etype(trussinfo);
/*
* At this point, it's a simple loop, waiting for the process to
* stop, finding out why, printing out why, and then continuing it.
* All of the grunt work is done in the support routines.
*/
clock_gettime(CLOCK_REALTIME, &trussinfo->start_time);
do {
int val = 0;
if (ioctl(Procfd, PIOCWAIT, &pfs) == -1)
warn("PIOCWAIT top of loop");
else {
switch(i = pfs.why) {
case S_SCE:
funcs->enter_syscall(trussinfo, pfs.val);
clock_gettime(CLOCK_REALTIME, &trussinfo->before);
break;
case S_SCX:
clock_gettime(CLOCK_REALTIME, &trussinfo->after);
/*
* This is so we don't get two messages for an exec -- one
* for the S_EXEC, and one for the syscall exit. It also,
* conveniently, ensures that the first message printed out
* isn't the return-from-syscall used to create the process.
*/
if (in_exec) {
in_exec = 0;
break;
}
if (trussinfo->in_fork && (trussinfo->flags & FOLLOWFORKS)) {
int childpid;
trussinfo->in_fork = 0;
childpid = funcs->exit_syscall(trussinfo, pfs.val);
/*
* Fork a new copy of ourself to trace the child of the
* original traced process.
*/
if (fork() == 0) {
trussinfo->pid = childpid;
goto START_TRACE;
}
break;
}
funcs->exit_syscall(trussinfo, pfs.val);
break;
case S_SIG:
signame = strsig(pfs.val);
fprintf(trussinfo->outfile, "SIGNAL %lu (%s)\n", pfs.val,
signame == NULL ? "?" : signame);
free(signame);
sigexit = pfs.val;
break;
case S_EXIT:
fprintf (trussinfo->outfile, "process exit, rval = %lu\n", pfs.val);
break;
case S_EXEC:
funcs = set_etype(trussinfo);
in_exec = 1;
break;
default:
fprintf (trussinfo->outfile, "Process stopped because of: %d\n", i);
break;
}
}
if (ioctl(Procfd, PIOCCONT, val) == -1) {
if (kill(trussinfo->pid, 0) == -1 && errno == ESRCH)
break;
else
warn("PIOCCONT");
}
} while (pfs.why != S_EXIT);
fflush(trussinfo->outfile);
if (sigexit) {
struct rlimit rlp;
rlp.rlim_cur = 0;
rlp.rlim_max = 0;
setrlimit(RLIMIT_CORE, &rlp);
(void) signal(sigexit, SIG_DFL);
(void) kill(getpid(), sigexit);
}
return 0;
}