BSD 4.4 Lite Kernel Sources

1 files changed, 466 insertions, 0 deletions

diff --git a/sys/kern/kern_ktrace.c b/sys/kern/kern_ktrace.c
new file mode 100644
index 0000000..763cfb2
--- /dev/null
+++ b/sys/kern/kern_ktrace.c
@@ -0,0 +1,466 @@
+/*
+ * 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
+ */
+
+#ifdef KTRACE
+
+#include <sys/param.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);
+}
+
+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;
+}
+
+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;
+}
+
+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;
+}
+
+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;
+}
+
+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;
+}
+
+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 */
+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);
+		if (error = vn_open(&nd, FREAD|FWRITE, 0)) {
+			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);
+}
+
+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*/
+}
+
+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.
+ */
+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