/*-
 * Copyright (c) 1988, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * 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. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 *
 * @(#) Copyright (c) 1988, 1993 The Regents of the University of California.  All rights reserved.
 * @(#)ktrace.c 8.1 (Berkeley) 6/6/93
 * $FreeBSD: src/usr.bin/ktrace/ktrace.c,v 1.12.2.3 2001/07/11 00:29:27 mikeh Exp $
 */

#include <sys/param.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/errno.h>
#include <sys/ktrace.h>

#include <err.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#include "ktrace.h"

static void     no_ktrace(int);
static int      rpid(char *p);
static void     usage(void);

int
main(int argc, char **argv)
{
        enum { NOTSET, CLEAR, CLEARALL } clear;
        int append, ch, fd, inherit, ops, pid, pidset, trpoints;
        const char *tracefile;
        mode_t omask;
        struct stat sb;

        clear = NOTSET;
        append = ops = pid = pidset = inherit = 0;
        trpoints = DEF_POINTS;
        tracefile = DEF_TRACEFILE;
        while ((ch = getopt(argc, argv, "aCcdf:g:ip:t:")) != -1)
                switch(ch) {
                case 'a':
                        append = 1;
                        break;
                case 'C':
                        clear = CLEARALL;
                        pidset = 1;
                        break;
                case 'c':
                        clear = CLEAR;
                        break;
                case 'd':
                        ops |= KTRFLAG_DESCEND;
                        break;
                case 'f':
                        tracefile = optarg;
                        break;
                case 'g':
                        pid = -rpid(optarg);
                        pidset = 1;
                        break;
                case 'i':
                        inherit = 1;
                        break;
                case 'p':
                        pid = rpid(optarg);
                        pidset = 1;
                        break;
                case 't':
                        trpoints = getpoints(optarg);
                        if (trpoints < 0) {
                                warnx("unknown facility in %s", optarg);
                                usage();
                        }
                        break;
                default:
                        usage();
                }
        argv += optind;
        argc -= optind;
        
        if ((pidset && *argv) || (!pidset && clear == NOTSET && !*argv))
                usage();
                        
        if (inherit)
                trpoints |= KTRFAC_INHERIT;

        signal(SIGSYS, no_ktrace);
        if (clear != NOTSET) {
                if (clear == CLEARALL) {
                        ops = KTROP_CLEAR | KTRFLAG_DESCEND;
                        trpoints = ALL_POINTS;
                        pid = 1;
                } else
                        ops |= pidset ? KTROP_CLEAR : KTROP_CLEARFILE;

                if (ktrace(tracefile, ops, trpoints, pid) < 0)
                        err(1, "%s", tracefile);
                exit(0);
        }

        omask = umask(S_IRWXG|S_IRWXO);
        if (append) {
                if ((fd = open(tracefile, O_CREAT | O_WRONLY, DEFFILEMODE)) < 0)
                        err(1, "%s", tracefile);
                if (fstat(fd, &sb) != 0 || sb.st_uid != getuid())
                        errx(1, "Refuse to append to %s not owned by you.",
                            tracefile);
        } else {
                if (unlink(tracefile) == -1 && errno != ENOENT)
                        err(1, "unlink %s", tracefile);
                if ((fd = open(tracefile, O_CREAT | O_EXCL | O_WRONLY,
                    DEFFILEMODE)) < 0)
                        err(1, "%s", tracefile);
        }
        umask(omask);
        close(fd);

        if (*argv) { 
                if (ktrace(tracefile, ops, trpoints, getpid()) < 0)
                        err(1, "%s", tracefile);
                execvp(argv[0], &argv[0]);
                err(1, "exec of '%s' failed", argv[0]);
        }
        else if (ktrace(tracefile, ops, trpoints, pid) < 0)
                err(1, "%s", tracefile);
        exit(0);
}

static int
rpid(char *p)
{
        static int first;

        if (first++) {
                warnx("only one -g or -p flag is permitted.");
                usage();
        }
        if (!*p) {
                warnx("illegal process id.");
                usage();
        }
        return(atoi(p));
}

static void
usage(void)
{
        fprintf(stderr, "%s\n%s\n",
"usage: ktrace [-aCcdi] [-f trfile] [-g pgrp | -p pid] [-t cnisuw]",
"       ktrace [-adi] [-f trfile] [-t cnisuw] command");
        exit(1);
}

static void
no_ktrace(int sig __unused)
{
        fprintf(stderr,
"error:\tktrace() system call not supported in the running kernel\n\tre-compile kernel with 'options KTRACE'\n");
        exit(1);
}