/*      $NetBSD: kern_ktrace_vfs.c,v 1.3 2021/06/29 22:40:53 dholland Exp $     */

/*-
* Copyright (c) 2006, 2007, 2008 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Andrew Doran.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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) 1989, 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.
*
*      @(#)kern_ktrace.c       8.5 (Berkeley) 5/14/95
*/

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: kern_ktrace_vfs.c,v 1.3 2021/06/29 22:40:53 dholland Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/file.h>
#include <sys/filedesc.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/kernel.h>
#include <sys/ktrace.h>
#include <sys/kauth.h>

#include <sys/mount.h>
#include <sys/syscallargs.h>

/*
* ktrace system call, the part of the ktrace framework that
* explicitly interacts with VFS
*/
/* ARGSUSED */
int
sys_ktrace(struct lwp *l, const struct sys_ktrace_args *uap, register_t *retval)
{
       /* {
               syscallarg(const char *) fname;
               syscallarg(int) ops;
               syscallarg(int) facs;
               syscallarg(int) pid;
       } */
       struct vnode *vp = NULL;
       file_t *fp = NULL;
       struct pathbuf *pb;
       int error = 0;
       int fd;

       if (ktrenter(l))
               return EAGAIN;

       if (KTROP(SCARG(uap, ops)) != KTROP_CLEAR) {
               /*
                * an operation which requires a file argument.
                */
               error = pathbuf_copyin(SCARG(uap, fname), &pb);
               if (error) {
                       ktrexit(l);
                       return (error);
               }
               error = vn_open(NULL, pb, 0, FREAD|FWRITE, 0, &vp, NULL, NULL);
               if (error != 0) {
                       pathbuf_destroy(pb);
                       ktrexit(l);
                       return (error);
               }
               pathbuf_destroy(pb);
               VOP_UNLOCK(vp);
               if (vp->v_type != VREG) {
                       vn_close(vp, FREAD|FWRITE, l->l_cred);
                       ktrexit(l);
                       return (EACCES);
               }
               /*
                * This uses up a file descriptor slot in the
                * tracing process for the duration of this syscall.
                * This is not expected to be a problem.
                */
               if ((error = fd_allocfile(&fp, &fd)) != 0) {
                       vn_close(vp, FWRITE, l->l_cred);
                       ktrexit(l);
                       return error;
               }
               fp->f_flag = FWRITE;
               fp->f_type = DTYPE_VNODE;
               fp->f_ops = &vnops;
               fp->f_vnode = vp;
               vp = NULL;
       }
       error = ktrace_common(l, SCARG(uap, ops), SCARG(uap, facs),
           SCARG(uap, pid), &fp);
       if (KTROP(SCARG(uap, ops)) != KTROP_CLEAR)
               fd_abort(curproc, fp, fd);
       return (error);
}