NetBSD/sys/kern/kern_prot.c

812 lines
17 KiB
C

/* $NetBSD: kern_prot.c,v 1.70 2003/01/18 10:06:29 thorpej Exp $ */
/*
* 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 8.9 (Berkeley) 2/14/95
*/
/*
* System calls related to processes and protection
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: kern_prot.c,v 1.70 2003/01/18 10:06:29 thorpej Exp $");
#include "opt_compat_43.h"
#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>
#include <sys/mount.h>
#include <sys/sa.h>
#include <sys/syscallargs.h>
int sys_getpid(struct lwp *, void *, register_t *);
int sys_getpid_with_ppid(struct lwp *, void *, register_t *);
int sys_getuid(struct lwp *, void *, register_t *);
int sys_getuid_with_euid(struct lwp *, void *, register_t *);
int sys_getgid(struct lwp *, void *, register_t *);
int sys_getgid_with_egid(struct lwp *, void *, register_t *);
/* ARGSUSED */
int
sys_getpid(l, v, retval)
struct lwp *l;
void *v;
register_t *retval;
{
struct proc *p = l->l_proc;
*retval = p->p_pid;
return (0);
}
/* ARGSUSED */
int
sys_getpid_with_ppid(l, v, retval)
struct lwp *l;
void *v;
register_t *retval;
{
struct proc *p = l->l_proc;
retval[0] = p->p_pid;
retval[1] = p->p_pptr->p_pid;
return (0);
}
/* ARGSUSED */
int
sys_getppid(l, v, retval)
struct lwp *l;
void *v;
register_t *retval;
{
struct proc *p = l->l_proc;
*retval = p->p_pptr->p_pid;
return (0);
}
/* Get process group ID; note that POSIX getpgrp takes no parameter */
int
sys_getpgrp(l, v, retval)
struct lwp *l;
void *v;
register_t *retval;
{
struct proc *p = l->l_proc;
*retval = p->p_pgrp->pg_id;
return (0);
}
/*
* Return the process group ID of the session leader (session ID)
* for the specified process.
*/
int
sys_getsid(l, v, retval)
struct lwp *l;
void *v;
register_t *retval;
{
struct sys_getsid_args /* {
syscalldarg(pid_t) pid;
} */ *uap = v;
struct proc *p = l->l_proc;
if (SCARG(uap, pid) == 0)
goto found;
if ((p = pfind(SCARG(uap, pid))) == 0)
return (ESRCH);
found:
*retval = p->p_session->s_sid;
return (0);
}
int
sys_getpgid(l, v, retval)
struct lwp *l;
void *v;
register_t *retval;
{
struct sys_getpgid_args /* {
syscallarg(pid_t) pid;
} */ *uap = v;
struct proc *p = l->l_proc;
if (SCARG(uap, pid) == 0)
goto found;
if ((p = pfind(SCARG(uap, pid))) == 0)
return (ESRCH);
found:
*retval = p->p_pgid;
return (0);
}
/* ARGSUSED */
int
sys_getuid(l, v, retval)
struct lwp *l;
void *v;
register_t *retval;
{
struct proc *p = l->l_proc;
*retval = p->p_cred->p_ruid;
return (0);
}
/* ARGSUSED */
int
sys_getuid_with_euid(l, v, retval)
struct lwp *l;
void *v;
register_t *retval;
{
struct proc *p = l->l_proc;
retval[0] = p->p_cred->p_ruid;
retval[1] = p->p_ucred->cr_uid;
return (0);
}
/* ARGSUSED */
int
sys_geteuid(l, v, retval)
struct lwp *l;
void *v;
register_t *retval;
{
struct proc *p = l->l_proc;
*retval = p->p_ucred->cr_uid;
return (0);
}
/* ARGSUSED */
int
sys_getgid(l, v, retval)
struct lwp *l;
void *v;
register_t *retval;
{
struct proc *p = l->l_proc;
*retval = p->p_cred->p_rgid;
return (0);
}
/* ARGSUSED */
int
sys_getgid_with_egid(l, v, retval)
struct lwp *l;
void *v;
register_t *retval;
{
struct proc *p = l->l_proc;
retval[0] = p->p_cred->p_rgid;
retval[1] = p->p_ucred->cr_gid;
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 */
int
sys_getegid(l, v, retval)
struct lwp *l;
void *v;
register_t *retval;
{
struct proc *p = l->l_proc;
*retval = p->p_ucred->cr_gid;
return (0);
}
int
sys_getgroups(l, v, retval)
struct lwp *l;
void *v;
register_t *retval;
{
struct sys_getgroups_args /* {
syscallarg(int) gidsetsize;
syscallarg(gid_t *) gidset;
} */ *uap = v;
struct proc *p = l->l_proc;
struct pcred *pc = p->p_cred;
u_int ngrp;
int error;
if (SCARG(uap, gidsetsize) == 0) {
*retval = pc->pc_ucred->cr_ngroups;
return (0);
} else if (SCARG(uap, gidsetsize) < 0)
return (EINVAL);
ngrp = SCARG(uap, gidsetsize);
if (ngrp < pc->pc_ucred->cr_ngroups)
return (EINVAL);
ngrp = pc->pc_ucred->cr_ngroups;
error = copyout((caddr_t)pc->pc_ucred->cr_groups,
(caddr_t)SCARG(uap, gidset), ngrp * sizeof(gid_t));
if (error)
return (error);
*retval = ngrp;
return (0);
}
/* ARGSUSED */
int
sys_setsid(l, v, retval)
struct lwp *l;
void *v;
register_t *retval;
{
struct proc *p = l->l_proc;
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)
*
* pgid must be in valid range (EINVAL)
* 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)
*/
/* ARGSUSED */
int
sys_setpgid(l, v, retval)
struct lwp *l;
void *v;
register_t *retval;
{
struct sys_setpgid_args /* {
syscallarg(int) pid;
syscallarg(int) pgid;
} */ *uap = v;
struct proc *curp = l->l_proc;
struct proc *targp; /* target process */
struct pgrp *pgrp; /* target pgrp */
if (SCARG(uap, pgid) < 0)
return (EINVAL);
if (SCARG(uap, pid) != 0 && SCARG(uap, pid) != curp->p_pid) {
if ((targp = pfind(SCARG(uap, pid))) == 0
|| !inferior(targp, curp))
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 (SCARG(uap, pgid) == 0)
SCARG(uap, pgid) = targp->p_pid;
else if (SCARG(uap, pgid) != targp->p_pid)
if ((pgrp = pgfind(SCARG(uap, pgid))) == 0 ||
pgrp->pg_session != curp->p_session)
return (EPERM);
return (enterpgrp(targp, SCARG(uap, pgid), 0));
}
/* ARGSUSED */
int
sys_setuid(l, v, retval)
struct lwp *l;
void *v;
register_t *retval;
{
struct sys_setuid_args /* {
syscallarg(uid_t) uid;
} */ *uap = v;
struct proc *p = l->l_proc;
struct pcred *pc = p->p_cred;
uid_t uid;
int error;
uid = SCARG(uap, uid);
if (uid != pc->p_ruid &&
(error = suser(pc->pc_ucred, &p->p_acflag)))
return (error);
/*
* Check if we are all set, and this is a no-op.
*/
if (pc->p_ruid == uid && pc->p_svuid == uid &&
pc->pc_ucred->cr_uid == uid)
return (0);
/*
* 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_sugid(p);
return (0);
}
/* ARGSUSED */
int
sys_seteuid(l, v, retval)
struct lwp *l;
void *v;
register_t *retval;
{
struct sys_seteuid_args /* {
syscallarg(uid_t) euid;
} */ *uap = v;
struct proc *p = l->l_proc;
struct pcred *pc = p->p_cred;
uid_t euid;
int error;
euid = SCARG(uap, euid);
if (euid != pc->p_ruid && euid != pc->p_svuid &&
(error = suser(pc->pc_ucred, &p->p_acflag)))
return (error);
/*
* Check if we are all set, and this is a no-op.
*/
if (pc->pc_ucred->cr_uid == euid)
return (0);
/*
* 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_sugid(p);
return (0);
}
int
sys_setreuid(l, v, retval)
struct lwp *l;
void *v;
register_t *retval;
{
struct sys_setreuid_args /* {
syscallarg(uid_t) ruid;
syscallarg(uid_t) euid;
} */ *uap = v;
struct proc *p = l->l_proc;
struct pcred *pc = p->p_cred;
uid_t ruid, euid;
int error, changed = 0;
ruid = SCARG(uap, ruid);
euid = SCARG(uap, euid);
if (ruid != (uid_t)-1 &&
ruid != pc->p_ruid && ruid != pc->pc_ucred->cr_uid &&
(error = suser(pc->pc_ucred, &p->p_acflag)))
return (error);
if (euid != (uid_t)-1 &&
euid != pc->p_ruid && euid != pc->pc_ucred->cr_uid &&
euid != pc->p_svuid &&
(error = suser(pc->pc_ucred, &p->p_acflag)))
return (error);
if (euid != (uid_t)-1 && euid != pc->pc_ucred->cr_uid) {
pc->pc_ucred = crcopy(pc->pc_ucred);
pc->pc_ucred->cr_uid = euid;
changed++;
}
if (ruid != (uid_t)-1 &&
(pc->p_ruid != ruid || pc->p_svuid != pc->pc_ucred->cr_uid)) {
(void)chgproccnt(pc->p_ruid, -1);
(void)chgproccnt(ruid, 1);
pc->p_ruid = ruid;
pc->p_svuid = pc->pc_ucred->cr_uid;
changed++;
}
if (changed)
p_sugid(p);
return (0);
}
/* ARGSUSED */
int
sys_setgid(l, v, retval)
struct lwp *l;
void *v;
register_t *retval;
{
struct sys_setgid_args /* {
syscallarg(gid_t) gid;
} */ *uap = v;
struct proc *p = l->l_proc;
struct pcred *pc = p->p_cred;
gid_t gid;
int error;
gid = SCARG(uap, gid);
if (gid != pc->p_rgid &&
(error = suser(pc->pc_ucred, &p->p_acflag)))
return (error);
/*
* Check if we are all set, and this is a no-op.
*/
if (pc->pc_ucred->cr_gid == gid && pc->p_rgid == gid &&
pc->p_svgid == gid)
return (0);
pc->pc_ucred = crcopy(pc->pc_ucred);
pc->pc_ucred->cr_gid = gid;
pc->p_rgid = gid;
pc->p_svgid = gid;
p_sugid(p);
return (0);
}
/* ARGSUSED */
int
sys_setegid(l, v, retval)
struct lwp *l;
void *v;
register_t *retval;
{
struct sys_setegid_args /* {
syscallarg(gid_t) egid;
} */ *uap = v;
struct proc *p = l->l_proc;
struct pcred *pc = p->p_cred;
gid_t egid;
int error;
egid = SCARG(uap, egid);
if (egid != pc->p_rgid && egid != pc->p_svgid &&
(error = suser(pc->pc_ucred, &p->p_acflag)))
return (error);
/*
* Check if we are all set, and this is a no-op.
*/
if (pc->pc_ucred->cr_gid == egid)
return (0);
pc->pc_ucred = crcopy(pc->pc_ucred);
pc->pc_ucred->cr_gid = egid;
p_sugid(p);
return (0);
}
int
sys_setregid(l, v, retval)
struct lwp *l;
void *v;
register_t *retval;
{
struct sys_setregid_args /* {
syscallarg(gid_t) rgid;
syscallarg(gid_t) egid;
} */ *uap = v;
struct proc *p = l->l_proc;
struct pcred *pc = p->p_cred;
gid_t rgid, egid;
int error, changed = 0;
rgid = SCARG(uap, rgid);
egid = SCARG(uap, egid);
if (rgid != (gid_t)-1 &&
rgid != pc->p_rgid && rgid != pc->pc_ucred->cr_gid &&
(error = suser(pc->pc_ucred, &p->p_acflag)))
return (error);
if (egid != (gid_t)-1 &&
egid != pc->p_rgid && egid != pc->pc_ucred->cr_gid &&
egid != pc->p_svgid &&
(error = suser(pc->pc_ucred, &p->p_acflag)))
return (error);
if (egid != (gid_t)-1 && pc->pc_ucred->cr_gid != egid) {
pc->pc_ucred = crcopy(pc->pc_ucred);
pc->pc_ucred->cr_gid = egid;
changed++;
}
if (rgid != (gid_t)-1 &&
(pc->p_rgid != rgid || pc->p_svgid != pc->pc_ucred->cr_gid)) {
pc->p_rgid = rgid;
pc->p_svgid = pc->pc_ucred->cr_gid;
changed++;
}
if (changed)
p_sugid(p);
return (0);
}
int
sys_issetugid(l, v, retval)
struct lwp *l;
void *v;
register_t *retval;
{
struct proc *p = l->l_proc;
/*
* 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.
*/
*retval = (p->p_flag & P_SUGID) != 0;
return (0);
}
/* ARGSUSED */
int
sys_setgroups(l, v, retval)
struct lwp *l;
void *v;
register_t *retval;
{
struct sys_setgroups_args /* {
syscallarg(int) gidsetsize;
syscallarg(const gid_t *) gidset;
} */ *uap = v;
struct proc *p = l->l_proc;
struct pcred *pc = p->p_cred;
int ngrp;
int error;
gid_t grp[NGROUPS];
size_t grsize;
if ((error = suser(pc->pc_ucred, &p->p_acflag)) != 0)
return (error);
ngrp = SCARG(uap, gidsetsize);
if ((u_int)ngrp > NGROUPS)
return (EINVAL);
grsize = ngrp * sizeof(gid_t);
error = copyin(SCARG(uap, gidset), grp, grsize);
if (error)
return (error);
/*
* Check if this is a no-op.
*/
if (pc->pc_ucred->cr_ngroups == (u_int) ngrp &&
memcmp(grp, pc->pc_ucred->cr_groups, grsize) == 0)
return (0);
pc->pc_ucred = crcopy(pc->pc_ucred);
(void)memcpy(pc->pc_ucred->cr_groups, grp, grsize);
pc->pc_ucred->cr_ngroups = ngrp;
p_sugid(p);
return (0);
}
/*
* Check if gid is a member of the group set.
*/
int
groupmember(gid, cred)
gid_t gid;
struct ucred *cred;
{
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()
{
struct ucred *cr;
MALLOC(cr, struct ucred *, sizeof(*cr), M_CRED, M_WAITOK);
memset((caddr_t)cr, 0, 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);
}
/*
* convert from userland credentials to kernel one
*/
void
crcvt(uc, uuc)
struct ucred *uc;
const struct uucred *uuc;
{
uc->cr_ref = 0;
uc->cr_uid = uuc->cr_uid;
uc->cr_gid = uuc->cr_gid;
uc->cr_ngroups = uuc->cr_ngroups;
(void)memcpy(uc->cr_groups, uuc->cr_groups, sizeof(uuc->cr_groups));
}
/*
* Get login name, if available.
*/
/* ARGSUSED */
int
sys___getlogin(l, v, retval)
struct lwp *l;
void *v;
register_t *retval;
{
struct sys___getlogin_args /* {
syscallarg(char *) namebuf;
syscallarg(size_t) namelen;
} */ *uap = v;
struct proc *p = l->l_proc;
if (SCARG(uap, namelen) > sizeof(p->p_pgrp->pg_session->s_login))
SCARG(uap, namelen) = sizeof(p->p_pgrp->pg_session->s_login);
return (copyout((caddr_t) p->p_pgrp->pg_session->s_login,
(caddr_t) SCARG(uap, namebuf), SCARG(uap, namelen)));
}
/*
* Set login name.
*/
/* ARGSUSED */
int
sys___setlogin(l, v, retval)
struct lwp *l;
void *v;
register_t *retval;
{
struct sys___setlogin_args /* {
syscallarg(const char *) namebuf;
} */ *uap = v;
struct proc *p = l->l_proc;
int error;
if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
return (error);
error = copyinstr(SCARG(uap, namebuf), p->p_pgrp->pg_session->s_login,
sizeof(p->p_pgrp->pg_session->s_login) - 1, (size_t *)0);
if (error == ENAMETOOLONG)
error = EINVAL;
return (error);
}