freebsd-dev/sys/kern/p1003_1b.c
Robert Watson b1fc0ec1a7 o Merge contents of struct pcred into struct ucred. Specifically, add the
real uid, saved uid, real gid, and saved gid to ucred, as well as the
  pcred->pc_uidinfo, which was associated with the real uid, only rename
  it to cr_ruidinfo so as not to conflict with cr_uidinfo, which
  corresponds to the effective uid.
o Remove p_cred from struct proc; add p_ucred to struct proc, replacing
  original macro that pointed.
  p->p_ucred to p->p_cred->pc_ucred.
o Universally update code so that it makes use of ucred instead of pcred,
  p->p_ucred instead of p->p_pcred, cr_ruidinfo instead of p_uidinfo,
  cr_{r,sv}{u,g}id instead of p_*, etc.
o Remove pcred0 and its initialization from init_main.c; initialize
  cr_ruidinfo there.
o Restruction many credential modification chunks to always crdup while
  we figure out locking and optimizations; generally speaking, this
  means moving to a structure like this:
        newcred = crdup(oldcred);
        ...
        p->p_ucred = newcred;
        crfree(oldcred);
  It's not race-free, but better than nothing.  There are also races
  in sys_process.c, all inter-process authorization, fork, exec, and
  exit.
o Remove sigio->sio_ruid since sigio->sio_ucred now contains the ruid;
  remove comments indicating that the old arrangement was a problem.
o Restructure exec1() a little to use newcred/oldcred arrangement, and
  use improved uid management primitives.
o Clean up exit1() so as to do less work in credential cleanup due to
  pcred removal.
o Clean up fork1() so as to do less work in credential cleanup and
  allocation.
o Clean up ktrcanset() to take into account changes, and move to using
  suser_xxx() instead of performing a direct uid==0 comparision.
o Improve commenting in various kern_prot.c credential modification
  calls to better document current behavior.  In a couple of places,
  current behavior is a little questionable and we need to check
  POSIX.1 to make sure it's "right".  More commenting work still
  remains to be done.
o Update credential management calls, such as crfree(), to take into
  account new ruidinfo reference.
o Modify or add the following uid and gid helper routines:
      change_euid()
      change_egid()
      change_ruid()
      change_rgid()
      change_svuid()
      change_svgid()
  In each case, the call now acts on a credential not a process, and as
  such no longer requires more complicated process locking/etc.  They
  now assume the caller will do any necessary allocation of an
  exclusive credential reference.  Each is commented to document its
  reference requirements.
o CANSIGIO() is simplified to require only credentials, not processes
  and pcreds.
o Remove lots of (p_pcred==NULL) checks.
o Add an XXX to authorization code in nfs_lock.c, since it's
  questionable, and needs to be considered carefully.
o Simplify posix4 authorization code to require only credentials, not
  processes and pcreds.  Note that this authorization, as well as
  CANSIGIO(), needs to be updated to use the p_cansignal() and
  p_cansched() centralized authorization routines, as they currently
  do not take into account some desirable restrictions that are handled
  by the centralized routines, as well as being inconsistent with other
  similar authorization instances.
o Update libkvm to take these changes into account.

Obtained from:	TrustedBSD Project
Reviewed by:	green, bde, jhb, freebsd-arch, freebsd-audit
2001-05-25 16:59:11 +00:00

267 lines
6.6 KiB
C

/*
* Copyright (c) 1996, 1997, 1998
* HD Associates, Inc. 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 HD Associates, Inc
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY HD ASSOCIATES 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 HD ASSOCIATES 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.
*
* $FreeBSD$
*/
/* p1003_1b: Real Time common code.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/sysctl.h>
#include <sys/sysent.h>
#include <sys/syslog.h>
#include <sys/sysproto.h>
#include <posix4/posix4.h>
MALLOC_DEFINE(M_P31B, "p1003.1b", "Posix 1003.1B");
/* p31b_proc: Return a proc struct corresponding to a pid to operate on.
*
* Enforce permission policy.
*
* The policy is the same as for sending signals except there
* is no notion of process groups.
*
* pid == 0 means my process.
*
* This is disabled until I've got a permission gate in again:
* only root can do this.
*/
#if 0
/*
* This is stolen from CANSIGNAL in kern_sig:
*
* Can process with credential cr1 do "write flavor" operations to credential
* cr2. This check needs to use generalized checks.
*/
#define CAN_AFFECT(cr1, cr2) \
(!suser_xxx(cr1, NULL, PRISON_ROOT) || \
(c1)->cr_ruid == (cr2)->cr_ruid || \
(c1)->cr_uid == (cr2)->cr_ruid || \
(c1)->cr_ruid == (cr2)->cr_uid || \
(c1)->cr_uid == (cr2)->cr_uid)
#else
#define CAN_AFFECT(cr1, cr2) (!suser_xxx(cr1, NULL, PRISON_ROOT))
#endif
/*
* p31b_proc: Look up a proc from a PID. If proc is 0 it is
* my own proc.
*/
int p31b_proc(struct proc *p, pid_t pid, struct proc **pp)
{
int ret = 0;
struct proc *other_proc = 0;
if (pid == 0) {
other_proc = p;
PROC_LOCK(p);
} else
other_proc = pfind(pid);
if (other_proc)
{
/* Enforce permission policy.
*/
if (CAN_AFFECT(p->p_ucred, other_proc->p_ucred))
*pp = other_proc;
else
ret = EPERM;
PROC_UNLOCK(other_proc);
}
else
ret = ESRCH;
return ret;
}
/* The system calls return ENOSYS if an entry is called that is
* not run-time supported. I am also logging since some programs
* start to use this when they shouldn't. That will be removed if annoying.
*/
int
syscall_not_present(struct proc *p, const char *s, struct nosys_args *uap)
{
log(LOG_ERR, "cmd %s pid %d tried to use non-present %s\n",
p->p_comm, p->p_pid, s);
/* a " return nosys(p, uap); " here causes a core dump.
*/
return ENOSYS;
}
#if !defined(_KPOSIX_PRIORITY_SCHEDULING)
/* Not configured but loadable via a module:
*/
static int sched_attach(void)
{
return 0;
}
SYSCALL_NOT_PRESENT_GEN(sched_setparam)
SYSCALL_NOT_PRESENT_GEN(sched_getparam)
SYSCALL_NOT_PRESENT_GEN(sched_setscheduler)
SYSCALL_NOT_PRESENT_GEN(sched_getscheduler)
SYSCALL_NOT_PRESENT_GEN(sched_yield)
SYSCALL_NOT_PRESENT_GEN(sched_get_priority_max)
SYSCALL_NOT_PRESENT_GEN(sched_get_priority_min)
SYSCALL_NOT_PRESENT_GEN(sched_rr_get_interval)
#else
/* Configured in kernel version:
*/
static struct ksched *ksched;
static int sched_attach(void)
{
int ret = ksched_attach(&ksched);
if (ret == 0)
p31b_setcfg(CTL_P1003_1B_PRIORITY_SCHEDULING, 1);
return ret;
}
int sched_setparam(struct proc *p,
struct sched_setparam_args *uap)
{
int e;
struct sched_param sched_param;
copyin(uap->param, &sched_param, sizeof(sched_param));
(void) (0
|| (e = p31b_proc(p, uap->pid, &p))
|| (e = ksched_setparam(&p->p_retval[0], ksched, p,
(const struct sched_param *)&sched_param))
);
return e;
}
int sched_getparam(struct proc *p,
struct sched_getparam_args *uap)
{
int e;
struct sched_param sched_param;
(void) (0
|| (e = p31b_proc(p, uap->pid, &p))
|| (e = ksched_getparam(&p->p_retval[0], ksched, p, &sched_param))
);
if (!e)
copyout(&sched_param, uap->param, sizeof(sched_param));
return e;
}
int sched_setscheduler(struct proc *p,
struct sched_setscheduler_args *uap)
{
int e;
struct sched_param sched_param;
copyin(uap->param, &sched_param, sizeof(sched_param));
(void) (0
|| (e = p31b_proc(p, uap->pid, &p))
|| (e = ksched_setscheduler(&p->p_retval[0],
ksched, p, uap->policy,
(const struct sched_param *)&sched_param))
);
return e;
}
int sched_getscheduler(struct proc *p,
struct sched_getscheduler_args *uap)
{
int e;
(void) (0
|| (e = p31b_proc(p, uap->pid, &p))
|| (e = ksched_getscheduler(&p->p_retval[0], ksched, p))
);
return e;
}
int sched_yield(struct proc *p,
struct sched_yield_args *uap)
{
return ksched_yield(&p->p_retval[0], ksched);
}
int sched_get_priority_max(struct proc *p,
struct sched_get_priority_max_args *uap)
{
return ksched_get_priority_max(&p->p_retval[0],
ksched, uap->policy);
}
int sched_get_priority_min(struct proc *p,
struct sched_get_priority_min_args *uap)
{
return ksched_get_priority_min(&p->p_retval[0],
ksched, uap->policy);
}
int sched_rr_get_interval(struct proc *p,
struct sched_rr_get_interval_args *uap)
{
int e;
(void) (0
|| (e = p31b_proc(p, uap->pid, &p))
|| (e = ksched_rr_get_interval(&p->p_retval[0], ksched,
p, uap->interval))
);
return e;
}
#endif
static void p31binit(void *notused)
{
(void) sched_attach();
p31b_setcfg(CTL_P1003_1B_PAGESIZE, PAGE_SIZE);
}
SYSINIT(p31b, SI_SUB_P1003_1B, SI_ORDER_FIRST, p31binit, NULL);