/*
* 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.
*/
#ifndef lint
static const char rcsid[] =
"$FreeBSD$";
#endif /* not lint */
/*
* 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 <err.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/pioctl.h>
extern int setup_and_wait(char **);
extern int start_tracing(int, int);
#ifdef __alpha__
extern void alpha_syscall_entry(int, int);
extern void alpha_syscall_exit(int, int);
#endif
#ifdef __i386__
extern void i386_syscall_entry(int, int);
extern void i386_syscall_exit(int, int);
extern void i386_linux_syscall_entry(int, int);
extern void i386_linux_syscall_exit(int, int);
#endif
/*
* These should really be parameterized -- I don't like having globals,
* but this is the easiest way, right now, to deal with them.
*/
int pid = 0;
int nosigs = 0;
FILE *outfile = stderr;
int Procfd;
char progtype[50]; /* OS and type of executable */
static inline void
usage(void)
{
fprintf(stderr, "%s\n%s\n",
"usage: truss [-S] [-o file] -p pid",
" truss [-S] [-o file] command [args]");
exit(1);
}
/*
* WARNING! "FreeBSD a.out" must be first, or set_etype will not
* work correctly.
*/
struct ex_types {
char *type;
void (*enter_syscall)(int, int);
void (*exit_syscall)(int, int);
} ex_types[] = {
#ifdef __alpha__
{ "FreeBSD ELF", alpha_syscall_entry, alpha_syscall_exit },
#endif
#ifdef __i386__
{ "FreeBSD a.out", i386_syscall_entry, i386_syscall_exit },
{ "FreeBSD ELF", i386_syscall_entry, i386_syscall_exit },
{ "Linux ELF", i386_linux_syscall_entry, i386_linux_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 ex_types *funcs;
char etype[24];
char progtype[32];
int fd;
sprintf(etype, "/proc/%d/etype", pid);
if ((fd = open(etype, O_RDONLY)) == -1) {
strcpy(progtype, "FreeBSD a.out");
} else {
int len = read(fd, progtype, sizeof(progtype));
progtype[len-1] = '\0';
close(fd);
}
for (funcs = ex_types; funcs->type; funcs++)
if (!strcmp(funcs->type, progtype))
break;
if (funcs == NULL) {
warn("Execution type %s is not supported -- using FreeBSD a.out\n",
progtype);
funcs = &ex_types[0];
}
return funcs;
}
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;
while ((c = getopt(ac, av, "p:o:S")) != -1) {
switch (c) {
case 'p': /* specified pid */
pid = atoi(optarg);
break;
case 'o': /* Specified output file */
fname = optarg;
break;
case 'S': /* Don't trace signals */
nosigs = 1;
break;
default:
usage();
}
}
ac -= optind; av += optind;
if ((pid == 0 && ac == 0) || (pid != 0 && ac != 0))
usage();
if (fname != NULL) { /* Use output file */
if ((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 (pid == 0) { /* Start a command ourselves */
command = av;
pid = setup_and_wait(command);
signal(SIGINT, SIG_IGN);
signal(SIGTERM, SIG_IGN);
signal(SIGQUIT, SIG_IGN);
} else {
extern void restore_proc(int);
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().
*/
Procfd = start_tracing(pid, S_EXEC | S_SCE | S_SCX | S_CORE | S_EXIT |
(nosigs ? 0 : S_SIG));
pfs.why = 0;
funcs = set_etype();
/*
* 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.
*/
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(pid, pfs.val);
break;
case S_SCX:
/*
* 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;
}
funcs->exit_syscall(pid, pfs.val);
break;
case S_SIG:
fprintf(outfile, "SIGNAL %lu\n", pfs.val);
sigexit = pfs.val;
break;
case S_EXIT:
fprintf (outfile, "process exit, rval = %lu\n", pfs.val);
break;
case S_EXEC:
funcs = set_etype();
in_exec = 1;
break;
default:
fprintf (outfile, "Process stopped because of: %d\n", i);
break;
}
}
if (ioctl(Procfd, PIOCCONT, val) == -1)
warn("PIOCCONT");
} while (pfs.why != S_EXIT);
fflush(outfile);
if (sigexit) {
if (sigexit == SIGQUIT)
exit(sigexit);
(void) signal(sigexit, SIG_DFL);
(void) kill(getpid(), sigexit);
}
return 0;
}
