4.4BSD/usr/src/sys/kern/kern_prot.c
/*
* Copyright (c) 1982, 1986, 1989, 1990, 1991, 1993
* 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_prot.c 8.1 (Berkeley) 6/10/93
*/
/*
* 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&SEXEC)
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 |= 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 |= 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 |= 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 |= 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 |= 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 != -1 && uap->ruid != pc->p_ruid &&
uap->ruid != pc->p_svuid)
return (EPERM);
if (uap->euid == -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 != -1 && uap->rgid != pc->p_rgid &&
uap->rgid != pc->p_svgid)
return (EPERM);
if (uap->egid == -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 = splimp(); /* ??? */
if (--cr->cr_ref != 0) {
(void) splx(s);
return;
}
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);
}