1 files changed, 566 insertions, 0 deletions

diff --git a/sys/kern/kern_prot.c b/sys/kern/kern_prot.c
new file mode 100644
index 0000000..ef40077
--- /dev/null
+++ b/sys/kern/kern_prot.c
@@ -0,0 +1,566 @@
+/*
+ * Copyright (c) 1982, 1986, 1989, 1990, 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * (c) UNIX System Laboratories, Inc.
+ * All or some portions of this file are derived from material licensed
+ * to the University of California by American Telephone and Telegraph
+ * Co. or Unix System Laboratories, Inc. and are reproduced herein with
+ * the permission of UNIX System Laboratories, Inc.
+ *
+ * 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_prot.c	8.6 (Berkeley) 1/21/94
+ */
+
+/*
+ * System calls related to processes and protection
+ */
+
+#include <sys/param.h>
+#include <sys/acct.h>
+#include <sys/systm.h>
+#include <sys/ucred.h>
+#include <sys/proc.h>
+#include <sys/timeb.h>
+#include <sys/times.h>
+#include <sys/malloc.h>
+
+struct args {
+	int	dummy;
+};
+
+/* ARGSUSED */
+getpid(p, uap, retval)
+	struct proc *p;
+	struct args *uap;
+	int *retval;
+{
+
+	*retval = p->p_pid;
+#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
+	retval[1] = p->p_pptr->p_pid;
+#endif
+	return (0);
+}
+
+/* ARGSUSED */
+getppid(p, uap, retval)
+	struct proc *p;
+	struct args *uap;
+	int *retval;
+{
+
+	*retval = p->p_pptr->p_pid;
+	return (0);
+}
+
+/* Get process group ID; note that POSIX getpgrp takes no parameter */
+getpgrp(p, uap, retval)
+	struct proc *p;
+	struct args *uap;
+	int *retval;
+{
+
+	*retval = p->p_pgrp->pg_id;
+	return (0);
+}
+
+/* ARGSUSED */
+getuid(p, uap, retval)
+	struct proc *p;
+	struct args *uap;
+	int *retval;
+{
+
+	*retval = p->p_cred->p_ruid;
+#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
+	retval[1] = p->p_ucred->cr_uid;
+#endif
+	return (0);
+}
+
+/* ARGSUSED */
+geteuid(p, uap, retval)
+	struct proc *p;
+	struct args *uap;
+	int *retval;
+{
+
+	*retval = p->p_ucred->cr_uid;
+	return (0);
+}
+
+/* ARGSUSED */
+getgid(p, uap, retval)
+	struct proc *p;
+	struct args *uap;
+	int *retval;
+{
+
+	*retval = p->p_cred->p_rgid;
+#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
+	retval[1] = p->p_ucred->cr_groups[0];
+#endif
+	return (0);
+}
+
+/*
+ * Get effective group ID.  The "egid" is groups[0], and could be obtained
+ * via getgroups.  This syscall exists because it is somewhat painful to do
+ * correctly in a library function.
+ */
+/* ARGSUSED */
+getegid(p, uap, retval)
+	struct proc *p;
+	struct args *uap;
+	int *retval;
+{
+
+	*retval = p->p_ucred->cr_groups[0];
+	return (0);
+}
+
+struct getgroups_args {
+	u_int	gidsetsize;
+	gid_t	*gidset;
+};
+getgroups(p, uap, retval)
+	struct proc *p;
+	register struct	getgroups_args *uap;
+	int *retval;
+{
+	register struct pcred *pc = p->p_cred;
+	register u_int ngrp;
+	int error;
+
+	if ((ngrp = uap->gidsetsize) == 0) {
+		*retval = pc->pc_ucred->cr_ngroups;
+		return (0);
+	}
+	if (ngrp < pc->pc_ucred->cr_ngroups)
+		return (EINVAL);
+	ngrp = pc->pc_ucred->cr_ngroups;
+	if (error = copyout((caddr_t)pc->pc_ucred->cr_groups,
+	    (caddr_t)uap->gidset, ngrp * sizeof(gid_t)))
+		return (error);
+	*retval = ngrp;
+	return (0);
+}
+
+/* ARGSUSED */
+setsid(p, uap, retval)
+	register struct proc *p;
+	struct args *uap;
+	int *retval;
+{
+
+	if (p->p_pgid == p->p_pid || pgfind(p->p_pid)) {
+		return (EPERM);
+	} else {
+		(void)enterpgrp(p, p->p_pid, 1);
+		*retval = p->p_pid;
+		return (0);
+	}
+}
+
+/*
+ * set process group (setpgid/old setpgrp)
+ *
+ * caller does setpgid(targpid, targpgid)
+ *
+ * pid must be caller or child of caller (ESRCH)
+ * if a child
+ *	pid must be in same session (EPERM)
+ *	pid can't have done an exec (EACCES)
+ * if pgid != pid
+ * 	there must exist some pid in same session having pgid (EPERM)
+ * pid must not be session leader (EPERM)
+ */
+struct setpgid_args {
+	int	pid;	/* target process id */
+	int	pgid;	/* target pgrp id */
+};
+/* ARGSUSED */
+setpgid(curp, uap, retval)
+	struct proc *curp;
+	register struct setpgid_args *uap;
+	int *retval;
+{
+	register struct proc *targp;		/* target process */
+	register struct pgrp *pgrp;		/* target pgrp */
+
+	if (uap->pid != 0 && uap->pid != curp->p_pid) {
+		if ((targp = pfind(uap->pid)) == 0 || !inferior(targp))
+			return (ESRCH);
+		if (targp->p_session != curp->p_session)
+			return (EPERM);
+		if (targp->p_flag & P_EXEC)
+			return (EACCES);
+	} else
+		targp = curp;
+	if (SESS_LEADER(targp))
+		return (EPERM);
+	if (uap->pgid == 0)
+		uap->pgid = targp->p_pid;
+	else if (uap->pgid != targp->p_pid)
+		if ((pgrp = pgfind(uap->pgid)) == 0 ||
+	            pgrp->pg_session != curp->p_session)
+			return (EPERM);
+	return (enterpgrp(targp, uap->pgid, 0));
+}
+
+struct setuid_args {
+	uid_t	uid;
+};
+/* ARGSUSED */
+setuid(p, uap, retval)
+	struct proc *p;
+	struct setuid_args *uap;
+	int *retval;
+{
+	register struct pcred *pc = p->p_cred;
+	register uid_t uid;
+	int error;
+
+	uid = uap->uid;
+	if (uid != pc->p_ruid &&
+	    (error = suser(pc->pc_ucred, &p->p_acflag)))
+		return (error);
+	/*
+	 * Everything's okay, do it.
+	 * Transfer proc count to new user.
+	 * Copy credentials so other references do not see our changes.
+	 */
+	(void)chgproccnt(pc->p_ruid, -1);
+	(void)chgproccnt(uid, 1);
+	pc->pc_ucred = crcopy(pc->pc_ucred);
+	pc->pc_ucred->cr_uid = uid;
+	pc->p_ruid = uid;
+	pc->p_svuid = uid;
+	p->p_flag |= P_SUGID;
+	return (0);
+}
+
+struct seteuid_args {
+	uid_t	euid;
+};
+/* ARGSUSED */
+seteuid(p, uap, retval)
+	struct proc *p;
+	struct seteuid_args *uap;
+	int *retval;
+{
+	register struct pcred *pc = p->p_cred;
+	register uid_t euid;
+	int error;
+
+	euid = uap->euid;
+	if (euid != pc->p_ruid && euid != pc->p_svuid &&
+	    (error = suser(pc->pc_ucred, &p->p_acflag)))
+		return (error);
+	/*
+	 * Everything's okay, do it.  Copy credentials so other references do
+	 * not see our changes.
+	 */
+	pc->pc_ucred = crcopy(pc->pc_ucred);
+	pc->pc_ucred->cr_uid = euid;
+	p->p_flag |= P_SUGID;
+	return (0);
+}
+
+struct setgid_args {
+	gid_t	gid;
+};
+/* ARGSUSED */
+setgid(p, uap, retval)
+	struct proc *p;
+	struct setgid_args *uap;
+	int *retval;
+{
+	register struct pcred *pc = p->p_cred;
+	register gid_t gid;
+	int error;
+
+	gid = uap->gid;
+	if (gid != pc->p_rgid && (error = suser(pc->pc_ucred, &p->p_acflag)))
+		return (error);
+	pc->pc_ucred = crcopy(pc->pc_ucred);
+	pc->pc_ucred->cr_groups[0] = gid;
+	pc->p_rgid = gid;
+	pc->p_svgid = gid;		/* ??? */
+	p->p_flag |= P_SUGID;
+	return (0);
+}
+
+struct setegid_args {
+	gid_t	egid;
+};
+/* ARGSUSED */
+setegid(p, uap, retval)
+	struct proc *p;
+	struct setegid_args *uap;
+	int *retval;
+{
+	register struct pcred *pc = p->p_cred;
+	register gid_t egid;
+	int error;
+
+	egid = uap->egid;
+	if (egid != pc->p_rgid && egid != pc->p_svgid &&
+	    (error = suser(pc->pc_ucred, &p->p_acflag)))
+		return (error);
+	pc->pc_ucred = crcopy(pc->pc_ucred);
+	pc->pc_ucred->cr_groups[0] = egid;
+	p->p_flag |= P_SUGID;
+	return (0);
+}
+
+struct setgroups_args {
+	u_int	gidsetsize;
+	gid_t	*gidset;
+};
+/* ARGSUSED */
+setgroups(p, uap, retval)
+	struct proc *p;
+	struct setgroups_args *uap;
+	int *retval;
+{
+	register struct pcred *pc = p->p_cred;
+	register u_int ngrp;
+	int error;
+
+	if (error = suser(pc->pc_ucred, &p->p_acflag))
+		return (error);
+	if ((ngrp = uap->gidsetsize) > NGROUPS)
+		return (EINVAL);
+	pc->pc_ucred = crcopy(pc->pc_ucred);
+	if (error = copyin((caddr_t)uap->gidset,
+	    (caddr_t)pc->pc_ucred->cr_groups, ngrp * sizeof(gid_t)))
+		return (error);
+	pc->pc_ucred->cr_ngroups = ngrp;
+	p->p_flag |= P_SUGID;
+	return (0);
+}
+
+#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
+struct setreuid_args {
+	int	ruid;
+	int	euid;
+};
+/* ARGSUSED */
+osetreuid(p, uap, retval)
+	register struct proc *p;
+	struct setreuid_args *uap;
+	int *retval;
+{
+	register struct pcred *pc = p->p_cred;
+	struct seteuid_args args;
+
+	/*
+	 * we assume that the intent of setting ruid is to be able to get
+	 * back ruid priviledge. So we make sure that we will be able to
+	 * do so, but do not actually set the ruid.
+	 */
+	if (uap->ruid != (uid_t)-1 && uap->ruid != pc->p_ruid &&
+	    uap->ruid != pc->p_svuid)
+		return (EPERM);
+	if (uap->euid == (uid_t)-1)
+		return (0);
+	args.euid = uap->euid;
+	return (seteuid(p, &args, retval));
+}
+
+struct setregid_args {
+	int	rgid;
+	int	egid;
+};
+/* ARGSUSED */
+osetregid(p, uap, retval)
+	register struct proc *p;
+	struct setregid_args *uap;
+	int *retval;
+{
+	register struct pcred *pc = p->p_cred;
+	struct setegid_args args;
+
+	/*
+	 * we assume that the intent of setting rgid is to be able to get
+	 * back rgid priviledge. So we make sure that we will be able to
+	 * do so, but do not actually set the rgid.
+	 */
+	if (uap->rgid != (gid_t)-1 && uap->rgid != pc->p_rgid &&
+	    uap->rgid != pc->p_svgid)
+		return (EPERM);
+	if (uap->egid == (gid_t)-1)
+		return (0);
+	args.egid = uap->egid;
+	return (setegid(p, &args, retval));
+}
+#endif /* defined(COMPAT_43) || defined(COMPAT_SUNOS) */
+
+/*
+ * Check if gid is a member of the group set.
+ */
+groupmember(gid, cred)
+	gid_t gid;
+	register struct ucred *cred;
+{
+	register gid_t *gp;
+	gid_t *egp;
+
+	egp = &(cred->cr_groups[cred->cr_ngroups]);
+	for (gp = cred->cr_groups; gp < egp; gp++)
+		if (*gp == gid)
+			return (1);
+	return (0);
+}
+
+/*
+ * Test whether the specified credentials imply "super-user"
+ * privilege; if so, and we have accounting info, set the flag
+ * indicating use of super-powers.
+ * Returns 0 or error.
+ */
+suser(cred, acflag)
+	struct ucred *cred;
+	short *acflag;
+{
+	if (cred->cr_uid == 0) {
+		if (acflag)
+			*acflag |= ASU;
+		return (0);
+	}
+	return (EPERM);
+}
+
+/*
+ * Allocate a zeroed cred structure.
+ */
+struct ucred *
+crget()
+{
+	register struct ucred *cr;
+
+	MALLOC(cr, struct ucred *, sizeof(*cr), M_CRED, M_WAITOK);
+	bzero((caddr_t)cr, sizeof(*cr));
+	cr->cr_ref = 1;
+	return (cr);
+}
+
+/*
+ * Free a cred structure.
+ * Throws away space when ref count gets to 0.
+ */
+crfree(cr)
+	struct ucred *cr;
+{
+	int s;
+
+	s = splimp();				/* ??? */
+	if (--cr->cr_ref == 0)
+		FREE((caddr_t)cr, M_CRED);
+	(void) splx(s);
+}
+
+/*
+ * Copy cred structure to a new one and free the old one.
+ */
+struct ucred *
+crcopy(cr)
+	struct ucred *cr;
+{
+	struct ucred *newcr;
+
+	if (cr->cr_ref == 1)
+		return (cr);
+	newcr = crget();
+	*newcr = *cr;
+	crfree(cr);
+	newcr->cr_ref = 1;
+	return (newcr);
+}
+
+/*
+ * Dup cred struct to a new held one.
+ */
+struct ucred *
+crdup(cr)
+	struct ucred *cr;
+{
+	struct ucred *newcr;
+
+	newcr = crget();
+	*newcr = *cr;
+	newcr->cr_ref = 1;
+	return (newcr);
+}
+
+/*
+ * Get login name, if available.
+ */
+struct getlogin_args {
+	char	*namebuf;
+	u_int	namelen;
+};
+/* ARGSUSED */
+getlogin(p, uap, retval)
+	struct proc *p;
+	struct getlogin_args *uap;
+	int *retval;
+{
+
+	if (uap->namelen > sizeof (p->p_pgrp->pg_session->s_login))
+		uap->namelen = sizeof (p->p_pgrp->pg_session->s_login);
+	return (copyout((caddr_t) p->p_pgrp->pg_session->s_login,
+	    (caddr_t) uap->namebuf, uap->namelen));
+}
+
+/*
+ * Set login name.
+ */
+struct setlogin_args {
+	char	*namebuf;
+};
+/* ARGSUSED */
+setlogin(p, uap, retval)
+	struct proc *p;
+	struct setlogin_args *uap;
+	int *retval;
+{
+	int error;
+
+	if (error = suser(p->p_ucred, &p->p_acflag))
+		return (error);
+	error = copyinstr((caddr_t) uap->namebuf,
+	    (caddr_t) p->p_pgrp->pg_session->s_login,
+	    sizeof (p->p_pgrp->pg_session->s_login) - 1, (u_int *)0);
+	if (error == ENAMETOOLONG)
+		error = EINVAL;
+	return (error);
+}