/*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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 8.2 (Berkeley) 9/23/93
* $Id: kern_ktrace.c,v 1.4 1994/08/18 22:35:01 wollman Exp $
*/
#ifdef KTRACE
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/file.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/ktrace.h>
#include <sys/malloc.h>
#include <sys/syslog.h>
struct ktr_header *
ktrgetheader(type)
int type;
{
register struct ktr_header *kth;
struct proc *p = curproc; /* XXX */
MALLOC(kth, struct ktr_header *, sizeof (struct ktr_header),
M_TEMP, M_WAITOK);
kth->ktr_type = type;
microtime(&kth->ktr_time);
kth->ktr_pid = p->p_pid;
bcopy(p->p_comm, kth->ktr_comm, MAXCOMLEN);
return (kth);
}
void
ktrsyscall(vp, code, narg, args)
struct vnode *vp;
int code, narg, args[];
{
struct ktr_header *kth;
struct ktr_syscall *ktp;
register len = sizeof(struct ktr_syscall) + (narg * sizeof(int));
struct proc *p = curproc; /* XXX */
int *argp, i;
p->p_traceflag |= KTRFAC_ACTIVE;
kth = ktrgetheader(KTR_SYSCALL);
MALLOC(ktp, struct ktr_syscall *, len, M_TEMP, M_WAITOK);
ktp->ktr_code = code;
ktp->ktr_narg = narg;
argp = (int *)((char *)ktp + sizeof(struct ktr_syscall));
for (i = 0; i < narg; i++)
*argp++ = args[i];
kth->ktr_buf = (caddr_t)ktp;
kth->ktr_len = len;
ktrwrite(vp, kth);
FREE(ktp, M_TEMP);
FREE(kth, M_TEMP);
p->p_traceflag &= ~KTRFAC_ACTIVE;
}
void
ktrsysret(vp, code, error, retval)
struct vnode *vp;
int code, error, retval;
{
struct ktr_header *kth;
struct ktr_sysret ktp;
struct proc *p = curproc; /* XXX */
p->p_traceflag |= KTRFAC_ACTIVE;
kth = ktrgetheader(KTR_SYSRET);
ktp.ktr_code = code;
ktp.ktr_error = error;
ktp.ktr_retval = retval; /* what about val2 ? */
kth->ktr_buf = (caddr_t)&ktp;
kth->ktr_len = sizeof(struct ktr_sysret);
ktrwrite(vp, kth);
FREE(kth, M_TEMP);
p->p_traceflag &= ~KTRFAC_ACTIVE;
}
void
ktrnamei(vp, path)
struct vnode *vp;
char *path;
{
struct ktr_header *kth;
struct proc *p = curproc; /* XXX */
p->p_traceflag |= KTRFAC_ACTIVE;
kth = ktrgetheader(KTR_NAMEI);
kth->ktr_len = strlen(path);
kth->ktr_buf = path;
ktrwrite(vp, kth);
FREE(kth, M_TEMP);
p->p_traceflag &= ~KTRFAC_ACTIVE;
}
void
ktrgenio(vp, fd, rw, iov, len, error)
struct vnode *vp;
int fd;
enum uio_rw rw;
register struct iovec *iov;
int len, error;
{
struct ktr_header *kth;
register struct ktr_genio *ktp;
register caddr_t cp;
register int resid = len, cnt;
struct proc *p = curproc; /* XXX */
if (error)
return;
p->p_traceflag |= KTRFAC_ACTIVE;
kth = ktrgetheader(KTR_GENIO);
MALLOC(ktp, struct ktr_genio *, sizeof(struct ktr_genio) + len,
M_TEMP, M_WAITOK);
ktp->ktr_fd = fd;
ktp->ktr_rw = rw;
cp = (caddr_t)((char *)ktp + sizeof (struct ktr_genio));
while (resid > 0) {
if ((cnt = iov->iov_len) > resid)
cnt = resid;
if (copyin(iov->iov_base, cp, (unsigned)cnt))
goto done;
cp += cnt;
resid -= cnt;
iov++;
}
kth->ktr_buf = (caddr_t)ktp;
kth->ktr_len = sizeof (struct ktr_genio) + len;
ktrwrite(vp, kth);
done:
FREE(kth, M_TEMP);
FREE(ktp, M_TEMP);
p->p_traceflag &= ~KTRFAC_ACTIVE;
}
void
ktrpsig(vp, sig, action, mask, code)
struct vnode *vp;
int sig;
sig_t action;
int mask, code;
{
struct ktr_header *kth;
struct ktr_psig kp;
struct proc *p = curproc; /* XXX */
p->p_traceflag |= KTRFAC_ACTIVE;
kth = ktrgetheader(KTR_PSIG);
kp.signo = (char)sig;
kp.action = action;
kp.mask = mask;
kp.code = code;
kth->ktr_buf = (caddr_t)&kp;
kth->ktr_len = sizeof (struct ktr_psig);
ktrwrite(vp, kth);
FREE(kth, M_TEMP);
p->p_traceflag &= ~KTRFAC_ACTIVE;
}
void
ktrcsw(vp, out, user)
struct vnode *vp;
int out, user;
{
struct ktr_header *kth;
struct ktr_csw kc;
struct proc *p = curproc; /* XXX */
p->p_traceflag |= KTRFAC_ACTIVE;
kth = ktrgetheader(KTR_CSW);
kc.out = out;
kc.user = user;
kth->ktr_buf = (caddr_t)&kc;
kth->ktr_len = sizeof (struct ktr_csw);
ktrwrite(vp, kth);
FREE(kth, M_TEMP);
p->p_traceflag &= ~KTRFAC_ACTIVE;
}
/* Interface and common routines */
/*
* ktrace system call
*/
struct ktrace_args {
char *fname;
int ops;
int facs;
int pid;
};
/* ARGSUSED */
int
ktrace(curp, uap, retval)
struct proc *curp;
register struct ktrace_args *uap;
int *retval;
{
register struct vnode *vp = NULL;
register struct proc *p;
struct pgrp *pg;
int facs = uap->facs & ~KTRFAC_ROOT;
int ops = KTROP(uap->ops);
int descend = uap->ops & KTRFLAG_DESCEND;
int ret = 0;
int error = 0;
struct nameidata nd;
curp->p_traceflag |= KTRFAC_ACTIVE;
if (ops != KTROP_CLEAR) {
/*
* an operation which requires a file argument.
*/
NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, uap->fname, curp);
error = vn_open(&nd, FREAD|FWRITE, 0);
if (error) {
curp->p_traceflag &= ~KTRFAC_ACTIVE;
return (error);
}
vp = nd.ni_vp;
VOP_UNLOCK(vp);
if (vp->v_type != VREG) {
(void) vn_close(vp, FREAD|FWRITE, curp->p_ucred, curp);
curp->p_traceflag &= ~KTRFAC_ACTIVE;
return (EACCES);
}
}
/*
* Clear all uses of the tracefile
*/
if (ops == KTROP_CLEARFILE) {
for (p = (struct proc *)allproc; p != NULL; p = p->p_next) {
if (p->p_tracep == vp) {
if (ktrcanset(curp, p)) {
p->p_tracep = NULL;
p->p_traceflag = 0;
(void) vn_close(vp, FREAD|FWRITE,
p->p_ucred, p);
} else
error = EPERM;
}
}
goto done;
}
/*
* need something to (un)trace (XXX - why is this here?)
*/
if (!facs) {
error = EINVAL;
goto done;
}
/*
* do it
*/
if (uap->pid < 0) {
/*
* by process group
*/
pg = pgfind(-uap->pid);
if (pg == NULL) {
error = ESRCH;
goto done;
}
for (p = pg->pg_mem; p != NULL; p = p->p_pgrpnxt)
if (descend)
ret |= ktrsetchildren(curp, p, ops, facs, vp);
else
ret |= ktrops(curp, p, ops, facs, vp);
} else {
/*
* by pid
*/
p = pfind(uap->pid);
if (p == NULL) {
error = ESRCH;
goto done;
}
if (descend)
ret |= ktrsetchildren(curp, p, ops, facs, vp);
else
ret |= ktrops(curp, p, ops, facs, vp);
}
if (!ret)
error = EPERM;
done:
if (vp != NULL)
(void) vn_close(vp, FWRITE, curp->p_ucred, curp);
curp->p_traceflag &= ~KTRFAC_ACTIVE;
return (error);
}
int
ktrops(curp, p, ops, facs, vp)
struct proc *p, *curp;
int ops, facs;
struct vnode *vp;
{
if (!ktrcanset(curp, p))
return (0);
if (ops == KTROP_SET) {
if (p->p_tracep != vp) {
/*
* if trace file already in use, relinquish
*/
if (p->p_tracep != NULL)
vrele(p->p_tracep);
VREF(vp);
p->p_tracep = vp;
}
p->p_traceflag |= facs;
if (curp->p_ucred->cr_uid == 0)
p->p_traceflag |= KTRFAC_ROOT;
} else {
/* KTROP_CLEAR */
if (((p->p_traceflag &= ~facs) & KTRFAC_MASK) == 0) {
/* no more tracing */
p->p_traceflag = 0;
if (p->p_tracep != NULL) {
vrele(p->p_tracep);
p->p_tracep = NULL;
}
}
}
return (1);
}
int
ktrsetchildren(curp, top, ops, facs, vp)
struct proc *curp, *top;
int ops, facs;
struct vnode *vp;
{
register struct proc *p;
register int ret = 0;
p = top;
for (;;) {
ret |= ktrops(curp, p, ops, facs, vp);
/*
* If this process has children, descend to them next,
* otherwise do any siblings, and if done with this level,
* follow back up the tree (but not past top).
*/
if (p->p_cptr)
p = p->p_cptr;
else if (p == top)
return (ret);
else if (p->p_osptr)
p = p->p_osptr;
else for (;;) {
p = p->p_pptr;
if (p == top)
return (ret);
if (p->p_osptr) {
p = p->p_osptr;
break;
}
}
}
/*NOTREACHED*/
}
void
ktrwrite(vp, kth)
struct vnode *vp;
register struct ktr_header *kth;
{
struct uio auio;
struct iovec aiov[2];
register struct proc *p = curproc; /* XXX */
int error;
if (vp == NULL)
return;
auio.uio_iov = &aiov[0];
auio.uio_offset = 0;
auio.uio_segflg = UIO_SYSSPACE;
auio.uio_rw = UIO_WRITE;
aiov[0].iov_base = (caddr_t)kth;
aiov[0].iov_len = sizeof(struct ktr_header);
auio.uio_resid = sizeof(struct ktr_header);
auio.uio_iovcnt = 1;
auio.uio_procp = (struct proc *)0;
if (kth->ktr_len > 0) {
auio.uio_iovcnt++;
aiov[1].iov_base = kth->ktr_buf;
aiov[1].iov_len = kth->ktr_len;
auio.uio_resid += kth->ktr_len;
}
VOP_LOCK(vp);
error = VOP_WRITE(vp, &auio, IO_UNIT|IO_APPEND, p->p_ucred);
VOP_UNLOCK(vp);
if (!error)
return;
/*
* If error encountered, give up tracing on this vnode.
*/
log(LOG_NOTICE, "ktrace write failed, errno %d, tracing stopped\n",
error);
for (p = (struct proc *)allproc; p != NULL; p = p->p_next) {
if (p->p_tracep == vp) {
p->p_tracep = NULL;
p->p_traceflag = 0;
vrele(vp);
}
}
}
/*
* Return true if caller has permission to set the ktracing state
* of target. Essentially, the target can't possess any
* more permissions than the caller. KTRFAC_ROOT signifies that
* root previously set the tracing status on the target process, and
* so, only root may further change it.
*
* TODO: check groups. use caller effective gid.
*/
int
ktrcanset(callp, targetp)
struct proc *callp, *targetp;
{
register struct pcred *caller = callp->p_cred;
register struct pcred *target = targetp->p_cred;
if ((caller->pc_ucred->cr_uid == target->p_ruid &&
target->p_ruid == target->p_svuid &&
caller->p_rgid == target->p_rgid && /* XXX */
target->p_rgid == target->p_svgid &&
(targetp->p_traceflag & KTRFAC_ROOT) == 0) ||
caller->pc_ucred->cr_uid == 0)
return (1);
return (0);
}
#endif
