[unix-history] / usr / src / sys / kern / kern_ktrace.c

/*
 * Copyright (c) 1989 The Regents of the University of California.
 * All rights reserved.
 *
 * %sccs.include.redist.c%
 *
 *	@(#)kern_ktrace.c	7.12 (Berkeley) %G%
 */

#ifdef KTRACE

#include "param.h"
#include "proc.h"
#include "file.h"
#include "vnode.h"
#include "ktrace.h"
#include "malloc.h"
#include "syslog.h"

struct ktr_header *
ktrgetheader(type)
{
	register struct ktr_header *kth;
	struct proc *p = curproc;

	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);
}

ktrsyscall(vp, code, narg, args)
	struct vnode *vp;
	int code, narg, args[];
{
	struct	ktr_header *kth = ktrgetheader(KTR_SYSCALL);
	struct	ktr_syscall *ktp;
	register len = sizeof(struct ktr_syscall) + (narg * sizeof(int));
	int 	*argp, i;

	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);
}

ktrsysret(vp, code, error, retval)
	struct vnode *vp;
	int code, error, retval;
{
	struct ktr_header *kth = ktrgetheader(KTR_SYSRET);
	struct ktr_sysret ktp;

	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);
}

ktrnamei(vp, path)
	struct vnode *vp;
	char *path;
{
	struct ktr_header *kth = ktrgetheader(KTR_NAMEI);

	kth->ktr_len = strlen(path);
	kth->ktr_buf = path;

	ktrwrite(vp, kth);
	FREE(kth, M_TEMP);
}

ktrgenio(vp, fd, rw, iov, len, error)
	struct vnode *vp;
	int fd;
	enum uio_rw rw;
	register struct iovec *iov;
{
	struct ktr_header *kth = ktrgetheader(KTR_GENIO);
	register struct ktr_genio *ktp;
	register caddr_t cp;
	register int resid = len, cnt;
	
	if (error)
		return;
	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);
}

ktrpsig(vp, sig, action, mask, code)
	struct	vnode *vp;
	sig_t	action;
{
	struct ktr_header *kth = ktrgetheader(KTR_PSIG);
	struct ktr_psig	kp;

	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);
}

/* Interface and common routines */

/*
 * ktrace system call
 */
/* ARGSUSED */
ktrace(curp, uap, retval)
	struct proc *curp;
	register struct args {
		char	*fname;
		int	ops;
		int	facs;
		int	pid;
	} *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;

	if (ops != KTROP_CLEAR) {
		/*
		 * an operation which requires a file argument.
		 */
		nd.ni_segflg = UIO_USERSPACE;
		nd.ni_dirp = uap->fname;
		if (error = vn_open(&nd, curp, FREAD|FWRITE, 0))
			return (error);
		vp = nd.ni_vp;
		if (vp->v_type != VREG) {
			vrele(vp);
			return (EACCES);
		}
	}
	/*
	 * Clear all uses of the tracefile
	 */
	if (ops == KTROP_CLEARFILE) {
		for (p = allproc; p != NULL; p = p->p_nxt) {
			if (p->p_tracep == vp) {
				if (ktrcanset(curp, p)) {
					p->p_tracep = NULL;
					p->p_traceflag = 0;
					vrele(vp);
				} 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)
		vrele(vp);
	return (error);
}

ktrops(curp, p, ops, facs, vp)
	struct proc *curp, *p;
	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);
}

ktrsetchildren(curp, top, ops, facs, vp)
	struct proc *curp, *top;
	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*/
}

ktrwrite(vp, kth)
	struct vnode *vp;
	register struct ktr_header *kth;
{
	struct uio auio;
	struct iovec aiov[2];
	struct proc *p;
	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;
	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, curproc->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 = allproc; p != NULL; p = p->p_nxt) {
		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.
 */
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
Commit	Line	Data
2d68027d MT	1	/*
	2	* Copyright (c) 1989 The Regents of the University of California.
	3	* All rights reserved.
	4	*
dbf0c423	5	* %sccs.include.redist.c%
2d68027d	6	*
98e7d0c1	7	* @(#)kern_ktrace.c 7.12 (Berkeley) %G%
2d68027d MT	8	*/
	9
	10	#ifdef KTRACE
	11
	12	#include "param.h"
2d68027d	13	#include "proc.h"
c4ec2128 KM	14	#include "file.h"
c4ec2128 KM	15	#include "vnode.h"
2d68027d MT	16	#include "ktrace.h"
2d68027d MT	17	#include "malloc.h"
9db11bbb	18	#include "syslog.h"
2d68027d MT	19
	20	struct ktr_header *
	21	ktrgetheader(type)
	22	{
	23	register struct ktr_header *kth;
b98b2de8	24	struct proc *p = curproc;
2d68027d MT	25
	26	MALLOC(kth, struct ktr_header *, sizeof (struct ktr_header),
	27	M_TEMP, M_WAITOK);
2d68027d	28	kth->ktr_type = type;
f73d8bd6	29	microtime(&kth->ktr_time);
b98b2de8 MK	30	kth->ktr_pid = p->p_pid;
b98b2de8 MK	31	bcopy(p->p_comm, kth->ktr_comm, MAXCOMLEN);
2d68027d MT	32	return (kth);
	33	}
	34
8b24ca5d	35	ktrsyscall(vp, code, narg, args)
c4ec2128	36	struct vnode *vp;
8b24ca5d	37	int code, narg, args[];
2d68027d MT	38	{
	39	struct ktr_header *kth = ktrgetheader(KTR_SYSCALL);
	40	struct ktr_syscall *ktp;
	41	register len = sizeof(struct ktr_syscall) + (narg * sizeof(int));
	42	int *argp, i;
	43
2d68027d	44	MALLOC(ktp, struct ktr_syscall *, len, M_TEMP, M_WAITOK);
2d68027d MT	45	ktp->ktr_code = code;
	46	ktp->ktr_narg = narg;
	47	argp = (int )((char )ktp + sizeof(struct ktr_syscall));
	48	for (i = 0; i < narg; i++)
8b24ca5d	49	*argp++ = args[i];
2d68027d MT	50	kth->ktr_buf = (caddr_t)ktp;
2d68027d MT	51	kth->ktr_len = len;
c4ec2128	52	ktrwrite(vp, kth);
2d68027d MT	53	FREE(ktp, M_TEMP);
	54	FREE(kth, M_TEMP);
	55	}
	56
8b24ca5d	57	ktrsysret(vp, code, error, retval)
c4ec2128	58	struct vnode *vp;
8b24ca5d	59	int code, error, retval;
2d68027d MT	60	{
2d68027d MT	61	struct ktr_header *kth = ktrgetheader(KTR_SYSRET);
a97cc92e	62	struct ktr_sysret ktp;
2d68027d	63
a97cc92e	64	ktp.ktr_code = code;
8b24ca5d KM	65	ktp.ktr_error = error;
8b24ca5d KM	66	ktp.ktr_retval = retval; /* what about val2 ? */
2d68027d	67
a97cc92e	68	kth->ktr_buf = (caddr_t)&ktp;
2d68027d MT	69	kth->ktr_len = sizeof(struct ktr_sysret);
2d68027d MT	70
c4ec2128	71	ktrwrite(vp, kth);
2d68027d MT	72	FREE(kth, M_TEMP);
	73	}
	74
c4ec2128 KM	75	ktrnamei(vp, path)
c4ec2128 KM	76	struct vnode *vp;
2d68027d MT	77	char *path;
	78	{
	79	struct ktr_header *kth = ktrgetheader(KTR_NAMEI);
	80
2d68027d MT	81	kth->ktr_len = strlen(path);
	82	kth->ktr_buf = path;
	83
c4ec2128	84	ktrwrite(vp, kth);
2d68027d MT	85	FREE(kth, M_TEMP);
	86	}
	87
8b24ca5d	88	ktrgenio(vp, fd, rw, iov, len, error)
c4ec2128	89	struct vnode *vp;
8b24ca5d	90	int fd;
f73d8bd6 MT	91	enum uio_rw rw;
	92	register struct iovec *iov;
	93	{
	94	struct ktr_header *kth = ktrgetheader(KTR_GENIO);
	95	register struct ktr_genio *ktp;
	96	register caddr_t cp;
	97	register int resid = len, cnt;
	98
9db11bbb	99	if (error)
f73d8bd6 MT	100	return;
	101	MALLOC(ktp, struct ktr_genio *, sizeof(struct ktr_genio) + len,
	102	M_TEMP, M_WAITOK);
f73d8bd6 MT	103	ktp->ktr_fd = fd;
	104	ktp->ktr_rw = rw;
	105	cp = (caddr_t)((char *)ktp + sizeof (struct ktr_genio));
	106	while (resid > 0) {
	107	if ((cnt = iov->iov_len) > resid)
	108	cnt = resid;
e5e5e641	109	if (copyin(iov->iov_base, cp, (unsigned)cnt))
f73d8bd6 MT	110	goto done;
	111	cp += cnt;
	112	resid -= cnt;
	113	iov++;
	114	}
	115	kth->ktr_buf = (caddr_t)ktp;
	116	kth->ktr_len = sizeof (struct ktr_genio) + len;
	117
c4ec2128	118	ktrwrite(vp, kth);
f73d8bd6 MT	119	done:
	120	FREE(kth, M_TEMP);
	121	FREE(ktp, M_TEMP);
	122	}
	123
a97cc92e MT	124	ktrpsig(vp, sig, action, mask, code)
	125	struct vnode *vp;
	126	sig_t action;
	127	{
	128	struct ktr_header *kth = ktrgetheader(KTR_PSIG);
	129	struct ktr_psig kp;
	130
a97cc92e MT	131	kp.signo = (char)sig;
	132	kp.action = action;
	133	kp.mask = mask;
	134	kp.code = code;
	135	kth->ktr_buf = (caddr_t)&kp;
	136	kth->ktr_len = sizeof (struct ktr_psig);
	137
	138	ktrwrite(vp, kth);
	139	FREE(kth, M_TEMP);
	140	}
	141
	142	/* Interface and common routines */
	143
2d68027d MT	144	/*
	145	* ktrace system call
	146	*/
8b24ca5d KM	147	/* ARGSUSED */
	148	ktrace(curp, uap, retval)
	149	struct proc *curp;
	150	register struct args {
2d68027d MT	151	char *fname;
	152	int ops;
	153	int facs;
f73d8bd6	154	int pid;
8b24ca5d KM	155	} *uap;
	156	int *retval;
	157	{
c4ec2128	158	register struct vnode *vp = NULL;
2d68027d MT	159	register struct proc *p;
2d68027d MT	160	struct pgrp *pg;
9db11bbb MT	161	int facs = uap->facs & ~KTRFAC_ROOT;
	162	int ops = KTROP(uap->ops);
	163	int descend = uap->ops & KTRFLAG_DESCEND;
	164	int ret = 0;
8b24ca5d	165	int error = 0;
b98b2de8	166	struct nameidata nd;
2d68027d	167
2d68027d MT	168	if (ops != KTROP_CLEAR) {
	169	/*
	170	* an operation which requires a file argument.
	171	*/
b98b2de8 MK	172	nd.ni_segflg = UIO_USERSPACE;
	173	nd.ni_dirp = uap->fname;
	174	if (error = vn_open(&nd, curp, FREAD\|FWRITE, 0))
d9c2f47f	175	return (error);
b98b2de8	176	vp = nd.ni_vp;
c4ec2128	177	if (vp->v_type != VREG) {
c4ec2128	178	vrele(vp);
d9c2f47f	179	return (EACCES);
2d68027d	180	}
2d68027d MT	181	}
	182	/*
	183	* Clear all uses of the tracefile
	184	*/
	185	if (ops == KTROP_CLEARFILE) {
	186	for (p = allproc; p != NULL; p = p->p_nxt) {
c4ec2128	187	if (p->p_tracep == vp) {
9db11bbb MT	188	if (ktrcanset(curp, p)) {
	189	p->p_tracep = NULL;
	190	p->p_traceflag = 0;
	191	vrele(vp);
	192	} else
	193	error = EPERM;
2d68027d MT	194	}
	195	}
	196	goto done;
	197	}
2d68027d	198	/*
9db11bbb	199	* need something to (un)trace (XXX - why is this here?)
2d68027d MT	200	*/
2d68027d MT	201	if (!facs) {
8b24ca5d	202	error = EINVAL;
2d68027d MT	203	goto done;
2d68027d MT	204	}
a97cc92e	205	/*
9db11bbb	206	* do it
a97cc92e	207	*/
2d68027d	208	if (uap->pid < 0) {
9db11bbb MT	209	/*
	210	* by process group
	211	*/
2d68027d MT	212	pg = pgfind(-uap->pid);
2d68027d MT	213	if (pg == NULL) {
8b24ca5d	214	error = ESRCH;
2d68027d MT	215	goto done;
	216	}
	217	for (p = pg->pg_mem; p != NULL; p = p->p_pgrpnxt)
9db11bbb MT	218	if (descend)
9db11bbb MT	219	ret \|= ktrsetchildren(curp, p, ops, facs, vp);
2d68027d	220	else
9db11bbb	221	ret \|= ktrops(curp, p, ops, facs, vp);
2d68027d MT	222
2d68027d MT	223	} else {
9db11bbb MT	224	/*
	225	* by pid
	226	*/
2d68027d MT	227	p = pfind(uap->pid);
2d68027d MT	228	if (p == NULL) {
8b24ca5d	229	error = ESRCH;
2d68027d MT	230	goto done;
2d68027d MT	231	}
9db11bbb MT	232	if (descend)
9db11bbb MT	233	ret \|= ktrsetchildren(curp, p, ops, facs, vp);
2d68027d	234	else
9db11bbb	235	ret \|= ktrops(curp, p, ops, facs, vp);
2d68027d	236	}
f73d8bd6	237	if (!ret)
8b24ca5d	238	error = EPERM;
2d68027d	239	done:
c4ec2128 KM	240	if (vp != NULL)
c4ec2128 KM	241	vrele(vp);
d9c2f47f	242	return (error);
2d68027d MT	243	}
2d68027d MT	244
9db11bbb MT	245	ktrops(curp, p, ops, facs, vp)
9db11bbb MT	246	struct proc curp, p;
c4ec2128	247	struct vnode *vp;
2d68027d	248	{
f73d8bd6	249
9db11bbb	250	if (!ktrcanset(curp, p))
d9c2f47f	251	return (0);
2d68027d	252	if (ops == KTROP_SET) {
a97cc92e	253	if (p->p_tracep != vp) {
2d68027d MT	254	/*
	255	* if trace file already in use, relinquish
	256	*/
	257	if (p->p_tracep != NULL)
c4ec2128	258	vrele(p->p_tracep);
2c0d2f20	259	VREF(vp);
c4ec2128	260	p->p_tracep = vp;
2d68027d MT	261	}
2d68027d MT	262	p->p_traceflag \|= facs;
b98b2de8	263	if (curp->p_ucred->cr_uid == 0)
9db11bbb	264	p->p_traceflag \|= KTRFAC_ROOT;
2d68027d MT	265	} else {
2d68027d MT	266	/* KTROP_CLEAR */
9db11bbb	267	if (((p->p_traceflag &= ~facs) & KTRFAC_MASK) == 0) {
a97cc92e MT	268	/* no more tracing */
a97cc92e MT	269	p->p_traceflag = 0;
2d68027d	270	if (p->p_tracep != NULL) {
c4ec2128	271	vrele(p->p_tracep);
2d68027d MT	272	p->p_tracep = NULL;
2d68027d MT	273	}
2d68027d MT	274	}
2d68027d MT	275	}
f73d8bd6	276
9db11bbb	277	return (1);
2d68027d	278	}
f73d8bd6	279
9db11bbb MT	280	ktrsetchildren(curp, top, ops, facs, vp)
9db11bbb MT	281	struct proc curp, top;
c4ec2128	282	struct vnode *vp;
2d68027d MT	283	{
2d68027d MT	284	register struct proc *p;
f73d8bd6	285	register int ret = 0;
2d68027d MT	286
	287	p = top;
	288	for (;;) {
9db11bbb	289	ret \|= ktrops(curp, p, ops, facs, vp);
2d68027d MT	290	/*
	291	* If this process has children, descend to them next,
	292	* otherwise do any siblings, and if done with this level,
	293	* follow back up the tree (but not past top).
	294	*/
	295	if (p->p_cptr)
	296	p = p->p_cptr;
	297	else if (p == top)
9db11bbb	298	return (ret);
2d68027d MT	299	else if (p->p_osptr)
	300	p = p->p_osptr;
	301	else for (;;) {
	302	p = p->p_pptr;
	303	if (p == top)
9db11bbb	304	return (ret);
2d68027d MT	305	if (p->p_osptr) {
	306	p = p->p_osptr;
	307	break;
	308	}
	309	}
	310	}
f73d8bd6	311	/NOTREACHED/
2d68027d MT	312	}
2d68027d MT	313
c4ec2128 KM	314	ktrwrite(vp, kth)
	315	struct vnode *vp;
	316	register struct ktr_header *kth;
2d68027d	317	{
c4ec2128 KM	318	struct uio auio;
c4ec2128 KM	319	struct iovec aiov[2];
e5e5e641	320	struct proc *p;
aeb44310	321	int error;
c4ec2128 KM	322
c4ec2128 KM	323	if (vp == NULL)
f73d8bd6	324	return;
c4ec2128 KM	325	auio.uio_iov = &aiov[0];
	326	auio.uio_offset = 0;
	327	auio.uio_segflg = UIO_SYSSPACE;
	328	auio.uio_rw = UIO_WRITE;
	329	aiov[0].iov_base = (caddr_t)kth;
	330	aiov[0].iov_len = sizeof(struct ktr_header);
	331	auio.uio_resid = sizeof(struct ktr_header);
	332	auio.uio_iovcnt = 1;
2d68027d	333	if (kth->ktr_len > 0) {
c4ec2128 KM	334	auio.uio_iovcnt++;
	335	aiov[1].iov_base = kth->ktr_buf;
	336	aiov[1].iov_len = kth->ktr_len;
	337	auio.uio_resid += kth->ktr_len;
2d68027d	338	}
aeb44310	339	VOP_LOCK(vp);
b98b2de8	340	error = VOP_WRITE(vp, &auio, IO_UNIT\|IO_APPEND, curproc->p_ucred);
aeb44310	341	VOP_UNLOCK(vp);
e5e5e641 KM	342	if (!error)
	343	return;
	344	/*
	345	* If error encountered, give up tracing on this vnode.
	346	*/
b98b2de8 MK	347	log(LOG_NOTICE, "ktrace write failed, errno %d, tracing stopped\n",
b98b2de8 MK	348	error);
e5e5e641 KM	349	for (p = allproc; p != NULL; p = p->p_nxt) {
	350	if (p->p_tracep == vp) {
	351	p->p_tracep = NULL;
	352	p->p_traceflag = 0;
	353	vrele(vp);
	354	}
	355	}
2d68027d	356	}
9db11bbb MT	357
	358	/*
	359	* Return true if caller has permission to set the ktracing state
	360	* of target. Essentially, the target can't possess any
	361	* more permissions than the caller. KTRFAC_ROOT signifies that
	362	* root previously set the tracing status on the target process, and
	363	* so, only root may further change it.
	364	*
b98b2de8	365	* TODO: check groups. use caller effective gid.
9db11bbb	366	*/
b98b2de8 MK	367	ktrcanset(callp, targetp)
b98b2de8 MK	368	struct proc callp, targetp;
9db11bbb	369	{
b98b2de8 MK	370	register struct pcred *caller = callp->p_cred;
	371	register struct pcred *target = targetp->p_cred;
	372
	373	if ((caller->pc_ucred->cr_uid == target->p_ruid &&
9db11bbb MT	374	target->p_ruid == target->p_svuid &&
	375	caller->p_rgid == target->p_rgid && /* XXX */
	376	target->p_rgid == target->p_svgid &&
b98b2de8 MK	377	(targetp->p_traceflag & KTRFAC_ROOT) == 0) \|\|
b98b2de8 MK	378	caller->pc_ucred->cr_uid == 0)
9db11bbb MT	379	return (1);
	380
	381	return (0);
	382	}
	383
2d68027d	384	#endif