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-rw-r--r--sys/kern/kern_prot.c898
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diff --git a/sys/kern/kern_prot.c b/sys/kern/kern_prot.c
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+++ b/sys/kern/kern_prot.c
@@ -0,0 +1,898 @@
+/*
+ * 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
+ * $Id: kern_prot.c,v 1.42 1998/11/10 09:16:29 peter Exp $
+ */
+
+/*
+ * System calls related to processes and protection
+ */
+
+#include "opt_compat.h"
+
+#include <sys/param.h>
+#include <sys/acct.h>
+#include <sys/systm.h>
+#include <sys/sysproto.h>
+#include <sys/kernel.h>
+#include <sys/proc.h>
+#include <sys/malloc.h>
+#include <sys/unistd.h>
+#include <sys/pioctl.h>
+
+static MALLOC_DEFINE(M_CRED, "cred", "credentials");
+
+#ifndef _SYS_SYSPROTO_H_
+struct getpid_args {
+ int dummy;
+};
+#endif
+
+/* ARGSUSED */
+int
+getpid(p, uap)
+ struct proc *p;
+ struct getpid_args *uap;
+{
+
+ p->p_retval[0] = p->p_pid;
+#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
+ p->p_retval[1] = p->p_pptr->p_pid;
+#endif
+ return (0);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct getppid_args {
+ int dummy;
+};
+#endif
+/* ARGSUSED */
+int
+getppid(p, uap)
+ struct proc *p;
+ struct getppid_args *uap;
+{
+
+ p->p_retval[0] = p->p_pptr->p_pid;
+ return (0);
+}
+
+/* Get process group ID; note that POSIX getpgrp takes no parameter */
+#ifndef _SYS_SYSPROTO_H_
+struct getpgrp_args {
+ int dummy;
+};
+#endif
+
+int
+getpgrp(p, uap)
+ struct proc *p;
+ struct getpgrp_args *uap;
+{
+
+ p->p_retval[0] = p->p_pgrp->pg_id;
+ return (0);
+}
+
+/* Get an arbitary pid's process group id */
+#ifndef _SYS_SYSPROTO_H_
+struct getpgid_args {
+ pid_t pid;
+};
+#endif
+
+int
+getpgid(p, uap)
+ struct proc *p;
+ struct getpgid_args *uap;
+{
+ struct proc *pt;
+
+ pt = p;
+ if (uap->pid == 0)
+ goto found;
+
+ if ((pt = pfind(uap->pid)) == 0)
+ return ESRCH;
+found:
+ p->p_retval[0] = pt->p_pgrp->pg_id;
+ return 0;
+}
+
+/*
+ * Get an arbitary pid's session id.
+ */
+#ifndef _SYS_SYSPROTO_H_
+struct getsid_args {
+ pid_t pid;
+};
+#endif
+
+int
+getsid(p, uap)
+ struct proc *p;
+ struct getsid_args *uap;
+{
+ struct proc *pt;
+
+ pt = p;
+ if (uap->pid == 0)
+ goto found;
+
+ if ((pt == pfind(uap->pid)) == 0)
+ return ESRCH;
+found:
+ p->p_retval[0] = pt->p_session->s_sid;
+ return 0;
+}
+
+
+#ifndef _SYS_SYSPROTO_H_
+struct getuid_args {
+ int dummy;
+};
+#endif
+
+/* ARGSUSED */
+int
+getuid(p, uap)
+ struct proc *p;
+ struct getuid_args *uap;
+{
+
+ p->p_retval[0] = p->p_cred->p_ruid;
+#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
+ p->p_retval[1] = p->p_ucred->cr_uid;
+#endif
+ return (0);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct geteuid_args {
+ int dummy;
+};
+#endif
+
+/* ARGSUSED */
+int
+geteuid(p, uap)
+ struct proc *p;
+ struct geteuid_args *uap;
+{
+
+ p->p_retval[0] = p->p_ucred->cr_uid;
+ return (0);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct getgid_args {
+ int dummy;
+};
+#endif
+
+/* ARGSUSED */
+int
+getgid(p, uap)
+ struct proc *p;
+ struct getgid_args *uap;
+{
+
+ p->p_retval[0] = p->p_cred->p_rgid;
+#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
+ p->p_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.
+ */
+#ifndef _SYS_SYSPROTO_H_
+struct getegid_args {
+ int dummy;
+};
+#endif
+
+/* ARGSUSED */
+int
+getegid(p, uap)
+ struct proc *p;
+ struct getegid_args *uap;
+{
+
+ p->p_retval[0] = p->p_ucred->cr_groups[0];
+ return (0);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct getgroups_args {
+ u_int gidsetsize;
+ gid_t *gidset;
+};
+#endif
+int
+getgroups(p, uap)
+ struct proc *p;
+ register struct getgroups_args *uap;
+{
+ register struct pcred *pc = p->p_cred;
+ register u_int ngrp;
+ int error;
+
+ if ((ngrp = uap->gidsetsize) == 0) {
+ p->p_retval[0] = 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);
+ p->p_retval[0] = ngrp;
+ return (0);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct setsid_args {
+ int dummy;
+};
+#endif
+
+/* ARGSUSED */
+int
+setsid(p, uap)
+ register struct proc *p;
+ struct setsid_args *uap;
+{
+
+ if (p->p_pgid == p->p_pid || pgfind(p->p_pid)) {
+ return (EPERM);
+ } else {
+ (void)enterpgrp(p, p->p_pid, 1);
+ p->p_retval[0] = 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)
+ */
+#ifndef _SYS_SYSPROTO_H_
+struct setpgid_args {
+ int pid; /* target process id */
+ int pgid; /* target pgrp id */
+};
+#endif
+/* ARGSUSED */
+int
+setpgid(curp, uap)
+ struct proc *curp;
+ register struct setpgid_args *uap;
+{
+ register struct proc *targp; /* target process */
+ register struct pgrp *pgrp; /* target pgrp */
+
+ if (uap->pgid < 0)
+ return (EINVAL);
+ if (uap->pid != 0 && uap->pid != curp->p_pid) {
+ if ((targp = pfind(uap->pid)) == 0 || !inferior(targp))
+ return (ESRCH);
+ if (targp->p_pgrp == NULL || 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));
+}
+
+/*
+ * Use the clause in B.4.2.2 that allows setuid/setgid to be 4.2/4.3BSD
+ * compatable. It says that setting the uid/gid to euid/egid is a special
+ * case of "appropriate privilege". Once the rules are expanded out, this
+ * basically means that setuid(nnn) sets all three id's, in all permitted
+ * cases unless _POSIX_SAVED_IDS is enabled. In that case, setuid(getuid())
+ * does not set the saved id - this is dangerous for traditional BSD
+ * programs. For this reason, we *really* do not want to set
+ * _POSIX_SAVED_IDS and do not want to clear POSIX_APPENDIX_B_4_2_2.
+ */
+#define POSIX_APPENDIX_B_4_2_2
+
+#ifndef _SYS_SYSPROTO_H_
+struct setuid_args {
+ uid_t uid;
+};
+#endif
+/* ARGSUSED */
+int
+setuid(p, uap)
+ struct proc *p;
+ struct setuid_args *uap;
+{
+ register struct pcred *pc = p->p_cred;
+ register uid_t uid;
+ int error;
+
+ /*
+ * See if we have "permission" by POSIX 1003.1 rules.
+ *
+ * Note that setuid(geteuid()) is a special case of
+ * "appropriate privileges" in appendix B.4.2.2. We need
+ * to use this clause to be compatable with traditional BSD
+ * semantics. Basically, it means that "setuid(xx)" sets all
+ * three id's (assuming you have privs).
+ *
+ * Notes on the logic. We do things in three steps.
+ * 1: We determine if the euid is going to change, and do EPERM
+ * right away. We unconditionally change the euid later if this
+ * test is satisfied, simplifying that part of the logic.
+ * 2: We determine if the real and/or saved uid's are going to
+ * change. Determined by compile options.
+ * 3: Change euid last. (after tests in #2 for "appropriate privs")
+ */
+ uid = uap->uid;
+ if (uid != pc->p_ruid && /* allow setuid(getuid()) */
+#ifdef _POSIX_SAVED_IDS
+ uid != pc->p_svuid && /* allow setuid(saved gid) */
+#endif
+#ifdef POSIX_APPENDIX_B_4_2_2 /* Use BSD-compat clause from B.4.2.2 */
+ uid != pc->pc_ucred->cr_uid && /* allow setuid(geteuid()) */
+#endif
+ (error = suser(pc->pc_ucred, &p->p_acflag)))
+ return (error);
+
+#ifdef _POSIX_SAVED_IDS
+ /*
+ * Do we have "appropriate privileges" (are we root or uid == euid)
+ * If so, we are changing the real uid and/or saved uid.
+ */
+ if (
+#ifdef POSIX_APPENDIX_B_4_2_2 /* Use the clause from B.4.2.2 */
+ uid == pc->pc_ucred->cr_uid ||
+#endif
+ suser(pc->pc_ucred, &p->p_acflag) == 0) /* we are using privs */
+#endif
+ {
+ /*
+ * Transfer proc count to new user.
+ */
+ if (uid != pc->p_ruid) {
+ (void)chgproccnt(pc->p_ruid, -1);
+ (void)chgproccnt(uid, 1);
+ }
+ /*
+ * Set real uid
+ */
+ if (uid != pc->p_ruid) {
+ pc->p_ruid = uid;
+ setsugid(p);
+ }
+ /*
+ * Set saved uid
+ *
+ * XXX always set saved uid even if not _POSIX_SAVED_IDS, as
+ * the security of seteuid() depends on it. B.4.2.2 says it
+ * is important that we should do this.
+ */
+ if (pc->p_svuid != uid) {
+ pc->p_svuid = uid;
+ setsugid(p);
+ }
+ }
+
+ /*
+ * In all permitted cases, we are changing the euid.
+ * Copy credentials so other references do not see our changes.
+ */
+ if (pc->pc_ucred->cr_uid != uid) {
+ pc->pc_ucred = crcopy(pc->pc_ucred);
+ pc->pc_ucred->cr_uid = uid;
+ setsugid(p);
+ }
+ return (0);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct seteuid_args {
+ uid_t euid;
+};
+#endif
+/* ARGSUSED */
+int
+seteuid(p, uap)
+ struct proc *p;
+ struct seteuid_args *uap;
+{
+ register struct pcred *pc = p->p_cred;
+ register uid_t euid;
+ int error;
+
+ euid = uap->euid;
+ if (euid != pc->p_ruid && /* allow seteuid(getuid()) */
+ euid != pc->p_svuid && /* allow seteuid(saved uid) */
+ (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.
+ */
+ if (pc->pc_ucred->cr_uid != euid) {
+ pc->pc_ucred = crcopy(pc->pc_ucred);
+ pc->pc_ucred->cr_uid = euid;
+ setsugid(p);
+ }
+ return (0);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct setgid_args {
+ gid_t gid;
+};
+#endif
+/* ARGSUSED */
+int
+setgid(p, uap)
+ struct proc *p;
+ struct setgid_args *uap;
+{
+ register struct pcred *pc = p->p_cred;
+ register gid_t gid;
+ int error;
+
+ /*
+ * See if we have "permission" by POSIX 1003.1 rules.
+ *
+ * Note that setgid(getegid()) is a special case of
+ * "appropriate privileges" in appendix B.4.2.2. We need
+ * to use this clause to be compatable with traditional BSD
+ * semantics. Basically, it means that "setgid(xx)" sets all
+ * three id's (assuming you have privs).
+ *
+ * For notes on the logic here, see setuid() above.
+ */
+ gid = uap->gid;
+ if (gid != pc->p_rgid && /* allow setgid(getgid()) */
+#ifdef _POSIX_SAVED_IDS
+ gid != pc->p_svgid && /* allow setgid(saved gid) */
+#endif
+#ifdef POSIX_APPENDIX_B_4_2_2 /* Use BSD-compat clause from B.4.2.2 */
+ gid != pc->pc_ucred->cr_groups[0] && /* allow setgid(getegid()) */
+#endif
+ (error = suser(pc->pc_ucred, &p->p_acflag)))
+ return (error);
+
+#ifdef _POSIX_SAVED_IDS
+ /*
+ * Do we have "appropriate privileges" (are we root or gid == egid)
+ * If so, we are changing the real uid and saved gid.
+ */
+ if (
+#ifdef POSIX_APPENDIX_B_4_2_2 /* use the clause from B.4.2.2 */
+ gid == pc->pc_ucred->cr_groups[0] ||
+#endif
+ suser(pc->pc_ucred, &p->p_acflag) == 0) /* we are using privs */
+#endif
+ {
+ /*
+ * Set real gid
+ */
+ if (pc->p_rgid != gid) {
+ pc->p_rgid = gid;
+ setsugid(p);
+ }
+ /*
+ * Set saved gid
+ *
+ * XXX always set saved gid even if not _POSIX_SAVED_IDS, as
+ * the security of setegid() depends on it. B.4.2.2 says it
+ * is important that we should do this.
+ */
+ if (pc->p_svgid != gid) {
+ pc->p_svgid = gid;
+ setsugid(p);
+ }
+ }
+ /*
+ * In all cases permitted cases, we are changing the egid.
+ * Copy credentials so other references do not see our changes.
+ */
+ if (pc->pc_ucred->cr_groups[0] != gid) {
+ pc->pc_ucred = crcopy(pc->pc_ucred);
+ pc->pc_ucred->cr_groups[0] = gid;
+ setsugid(p);
+ }
+ return (0);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct setegid_args {
+ gid_t egid;
+};
+#endif
+/* ARGSUSED */
+int
+setegid(p, uap)
+ struct proc *p;
+ struct setegid_args *uap;
+{
+ register struct pcred *pc = p->p_cred;
+ register gid_t egid;
+ int error;
+
+ egid = uap->egid;
+ if (egid != pc->p_rgid && /* allow setegid(getgid()) */
+ egid != pc->p_svgid && /* allow setegid(saved gid) */
+ (error = suser(pc->pc_ucred, &p->p_acflag)))
+ return (error);
+ if (pc->pc_ucred->cr_groups[0] != egid) {
+ pc->pc_ucred = crcopy(pc->pc_ucred);
+ pc->pc_ucred->cr_groups[0] = egid;
+ setsugid(p);
+ }
+ return (0);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct setgroups_args {
+ u_int gidsetsize;
+ gid_t *gidset;
+};
+#endif
+/* ARGSUSED */
+int
+setgroups(p, uap)
+ struct proc *p;
+ struct setgroups_args *uap;
+{
+ register struct pcred *pc = p->p_cred;
+ register u_int ngrp;
+ int error;
+
+ if ((error = suser(pc->pc_ucred, &p->p_acflag)))
+ return (error);
+ ngrp = uap->gidsetsize;
+ if (ngrp > NGROUPS)
+ return (EINVAL);
+ /*
+ * XXX A little bit lazy here. We could test if anything has
+ * changed before crcopy() and setting P_SUGID.
+ */
+ pc->pc_ucred = crcopy(pc->pc_ucred);
+ if (ngrp < 1) {
+ /*
+ * setgroups(0, NULL) is a legitimate way of clearing the
+ * groups vector on non-BSD systems (which generally do not
+ * have the egid in the groups[0]). We risk security holes
+ * when running non-BSD software if we do not do the same.
+ */
+ pc->pc_ucred->cr_ngroups = 1;
+ } else {
+ 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;
+ }
+ setsugid(p);
+ return (0);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct setreuid_args {
+ uid_t ruid;
+ uid_t euid;
+};
+#endif
+/* ARGSUSED */
+int
+setreuid(p, uap)
+ register struct proc *p;
+ struct setreuid_args *uap;
+{
+ register struct pcred *pc = p->p_cred;
+ register uid_t ruid, euid;
+ int error;
+
+ ruid = uap->ruid;
+ euid = uap->euid;
+ if ((ruid != (uid_t)-1 && ruid != pc->p_ruid && ruid != pc->p_svuid ||
+ euid != (uid_t)-1 && euid != pc->pc_ucred->cr_uid &&
+ euid != pc->p_ruid && euid != pc->p_svuid) &&
+ (error = suser(pc->pc_ucred, &p->p_acflag)))
+ return (error);
+
+ if (euid != (uid_t)-1 && pc->pc_ucred->cr_uid != euid) {
+ pc->pc_ucred = crcopy(pc->pc_ucred);
+ pc->pc_ucred->cr_uid = euid;
+ setsugid(p);
+ }
+ if (ruid != (uid_t)-1 && pc->p_ruid != ruid) {
+ (void)chgproccnt(pc->p_ruid, -1);
+ (void)chgproccnt(ruid, 1);
+ pc->p_ruid = ruid;
+ setsugid(p);
+ }
+ if ((ruid != (uid_t)-1 || pc->pc_ucred->cr_uid != pc->p_ruid) &&
+ pc->p_svuid != pc->pc_ucred->cr_uid) {
+ pc->p_svuid = pc->pc_ucred->cr_uid;
+ setsugid(p);
+ }
+ return (0);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct setregid_args {
+ gid_t rgid;
+ gid_t egid;
+};
+#endif
+/* ARGSUSED */
+int
+setregid(p, uap)
+ register struct proc *p;
+ struct setregid_args *uap;
+{
+ register struct pcred *pc = p->p_cred;
+ register gid_t rgid, egid;
+ int error;
+
+ rgid = uap->rgid;
+ egid = uap->egid;
+ if ((rgid != (gid_t)-1 && rgid != pc->p_rgid && rgid != pc->p_svgid ||
+ egid != (gid_t)-1 && egid != pc->pc_ucred->cr_groups[0] &&
+ egid != pc->p_rgid && egid != pc->p_svgid) &&
+ (error = suser(pc->pc_ucred, &p->p_acflag)))
+ return (error);
+
+ if (egid != (gid_t)-1 && pc->pc_ucred->cr_groups[0] != egid) {
+ pc->pc_ucred = crcopy(pc->pc_ucred);
+ pc->pc_ucred->cr_groups[0] = egid;
+ setsugid(p);
+ }
+ if (rgid != (gid_t)-1 && pc->p_rgid != rgid) {
+ pc->p_rgid = rgid;
+ setsugid(p);
+ }
+ if ((rgid != (gid_t)-1 || pc->pc_ucred->cr_groups[0] != pc->p_rgid) &&
+ pc->p_svgid != pc->pc_ucred->cr_groups[0]) {
+ pc->p_svgid = pc->pc_ucred->cr_groups[0];
+ setsugid(p);
+ }
+ return (0);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct issetugid_args {
+ int dummy;
+};
+#endif
+/* ARGSUSED */
+int
+issetugid(p, uap)
+ register struct proc *p;
+ struct issetugid_args *uap;
+{
+ /*
+ * Note: OpenBSD sets a P_SUGIDEXEC flag set at execve() time,
+ * we use P_SUGID because we consider changing the owners as
+ * "tainting" as well.
+ * This is significant for procs that start as root and "become"
+ * a user without an exec - programs cannot know *everything*
+ * that libc *might* have put in their data segment.
+ */
+ if (p->p_flag & P_SUGID)
+ return (1);
+ return (0);
+}
+
+/*
+ * Check if gid is a member of the group set.
+ */
+int
+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.
+ */
+int
+suser(cred, acflag)
+ struct ucred *cred;
+ u_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.
+ */
+void
+crfree(cr)
+ struct ucred *cr;
+{
+ if (--cr->cr_ref == 0)
+ FREE((caddr_t)cr, M_CRED);
+}
+
+/*
+ * 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.
+ */
+#ifndef _SYS_SYSPROTO_H_
+struct getlogin_args {
+ char *namebuf;
+ u_int namelen;
+};
+#endif
+/* ARGSUSED */
+int
+getlogin(p, uap)
+ struct proc *p;
+ struct getlogin_args *uap;
+{
+
+ if (uap->namelen > MAXLOGNAME)
+ uap->namelen = MAXLOGNAME;
+ return (copyout((caddr_t) p->p_pgrp->pg_session->s_login,
+ (caddr_t) uap->namebuf, uap->namelen));
+}
+
+/*
+ * Set login name.
+ */
+#ifndef _SYS_SYSPROTO_H_
+struct setlogin_args {
+ char *namebuf;
+};
+#endif
+/* ARGSUSED */
+int
+setlogin(p, uap)
+ struct proc *p;
+ struct setlogin_args *uap;
+{
+ int error;
+ char logintmp[MAXLOGNAME];
+
+ if ((error = suser(p->p_ucred, &p->p_acflag)))
+ return (error);
+ error = copyinstr((caddr_t) uap->namebuf, (caddr_t) logintmp,
+ sizeof(logintmp), (size_t *)0);
+ if (error == ENAMETOOLONG)
+ error = EINVAL;
+ else if (!error)
+ (void) memcpy(p->p_pgrp->pg_session->s_login, logintmp,
+ sizeof(logintmp));
+ return (error);
+}
+
+void
+setsugid(p)
+ struct proc *p;
+{
+ p->p_flag |= P_SUGID;
+ if (!(p->p_pfsflags & PF_ISUGID))
+ p->p_stops = 0;
+}
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