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3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
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7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
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11 * modification, are permitted provided that the following conditions
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35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * @(#)kern_prot.c 8.6 (Berkeley) 1/21/94
39 * $FreeBSD: src/sys/kern/kern_prot.c,v 1.53.2.9 2002/03/09 05:20:26 dd Exp $
40 * $DragonFly: src/sys/kern/kern_prot.c,v 1.29 2008/02/16 15:53:39 matthias Exp $
44 * System calls related to processes and protection
47 #include "opt_compat.h"
49 #include <sys/param.h>
51 #include <sys/systm.h>
52 #include <sys/sysproto.h>
53 #include <sys/kernel.h>
57 #include <sys/malloc.h>
58 #include <sys/pioctl.h>
59 #include <sys/resourcevar.h>
61 #include <sys/lockf.h>
62 #include <sys/spinlock.h>
64 #include <sys/thread2.h>
65 #include <sys/spinlock2.h>
67 static MALLOC_DEFINE(M_CRED
, "cred", "credentials");
70 sys_getpid(struct getpid_args
*uap
)
72 struct proc
*p
= curproc
;
74 uap
->sysmsg_fds
[0] = p
->p_pid
;
75 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
76 lwkt_gettoken(&proc_token
);
77 uap
->sysmsg_fds
[1] = p
->p_pptr
->p_pid
;
78 lwkt_reltoken(&proc_token
);
84 sys_getppid(struct getppid_args
*uap
)
86 struct proc
*p
= curproc
;
88 lwkt_gettoken(&proc_token
);
89 uap
->sysmsg_result
= p
->p_pptr
->p_pid
;
90 lwkt_reltoken(&proc_token
);
99 sys_lwp_gettid(struct lwp_gettid_args
*uap
)
101 struct lwp
*lp
= curthread
->td_lwp
;
103 uap
->sysmsg_result
= lp
->lwp_tid
;
108 * Get process group ID; note that POSIX getpgrp takes no parameter
113 sys_getpgrp(struct getpgrp_args
*uap
)
115 struct proc
*p
= curproc
;
117 uap
->sysmsg_result
= p
->p_pgrp
->pg_id
;
122 * Get an arbitrary pid's process group id
125 sys_getpgid(struct getpgid_args
*uap
)
127 struct proc
*p
= curproc
;
137 pt
= pfind(uap
->pid
);
141 /* XXX MPSAFE on pgrp? */
143 uap
->sysmsg_result
= pt
->p_pgrp
->pg_id
;
150 * Get an arbitrary pid's session id.
153 sys_getsid(struct getsid_args
*uap
)
155 struct proc
*p
= curproc
;
165 pt
= pfind(uap
->pid
);
170 uap
->sysmsg_result
= pt
->p_session
->s_sid
;
183 sys_getuid(struct getuid_args
*uap
)
185 struct ucred
*cred
= curthread
->td_ucred
;
187 uap
->sysmsg_fds
[0] = cred
->cr_ruid
;
188 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
189 uap
->sysmsg_fds
[1] = cred
->cr_uid
;
200 sys_geteuid(struct geteuid_args
*uap
)
202 struct ucred
*cred
= curthread
->td_ucred
;
204 uap
->sysmsg_result
= cred
->cr_uid
;
214 sys_getgid(struct getgid_args
*uap
)
216 struct ucred
*cred
= curthread
->td_ucred
;
218 uap
->sysmsg_fds
[0] = cred
->cr_rgid
;
219 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
220 uap
->sysmsg_fds
[1] = cred
->cr_groups
[0];
226 * Get effective group ID. The "egid" is groups[0], and could be obtained
227 * via getgroups. This syscall exists because it is somewhat painful to do
228 * correctly in a library function.
233 sys_getegid(struct getegid_args
*uap
)
235 struct ucred
*cred
= curthread
->td_ucred
;
237 uap
->sysmsg_result
= cred
->cr_groups
[0];
245 sys_getgroups(struct getgroups_args
*uap
)
251 cr
= curthread
->td_ucred
;
252 if ((ngrp
= uap
->gidsetsize
) == 0) {
253 uap
->sysmsg_result
= cr
->cr_ngroups
;
256 if (ngrp
< cr
->cr_ngroups
)
258 ngrp
= cr
->cr_ngroups
;
259 error
= copyout((caddr_t
)cr
->cr_groups
,
260 (caddr_t
)uap
->gidset
, ngrp
* sizeof(gid_t
));
262 uap
->sysmsg_result
= ngrp
;
267 sys_setsid(struct setsid_args
*uap
)
269 struct proc
*p
= curproc
;
270 struct pgrp
*pg
= NULL
;
273 lwkt_gettoken(&p
->p_token
);
274 if (p
->p_pgid
== p
->p_pid
|| (pg
= pgfind(p
->p_pid
)) != NULL
) {
279 enterpgrp(p
, p
->p_pid
, 1);
280 uap
->sysmsg_result
= p
->p_pid
;
283 lwkt_reltoken(&p
->p_token
);
288 * set process group (setpgid/old setpgrp)
290 * caller does setpgid(targpid, targpgid)
292 * pid must be caller or child of caller (ESRCH)
294 * pid must be in same session (EPERM)
295 * pid can't have done an exec (EACCES)
297 * there must exist some pid in same session having pgid (EPERM)
298 * pid must not be session leader (EPERM)
301 sys_setpgid(struct setpgid_args
*uap
)
303 struct proc
*curp
= curproc
;
304 struct proc
*targp
; /* target process */
305 struct pgrp
*pgrp
= NULL
; /* target pgrp */
311 if (uap
->pid
!= 0 && uap
->pid
!= curp
->p_pid
) {
312 if ((targp
= pfind(uap
->pid
)) == NULL
|| !inferior(targp
)) {
319 lwkt_gettoken(&targp
->p_token
);
320 /* targp now referenced and its token is held */
322 if (targp
->p_pgrp
== NULL
||
323 targp
->p_session
!= curp
->p_session
) {
327 if (targp
->p_flag
& P_EXEC
) {
334 lwkt_gettoken(&targp
->p_token
);
336 if (SESS_LEADER(targp
)) {
340 if (uap
->pgid
== 0) {
341 uap
->pgid
= targp
->p_pid
;
342 } else if (uap
->pgid
!= targp
->p_pid
) {
343 if ((pgrp
= pgfind(uap
->pgid
)) == NULL
||
344 pgrp
->pg_session
!= curp
->p_session
) {
349 error
= enterpgrp(targp
, uap
->pgid
, 0);
354 lwkt_reltoken(&targp
->p_token
);
361 * Use the clause in B.4.2.2 that allows setuid/setgid to be 4.2/4.3BSD
362 * compatible. It says that setting the uid/gid to euid/egid is a special
363 * case of "appropriate privilege". Once the rules are expanded out, this
364 * basically means that setuid(nnn) sets all three id's, in all permitted
365 * cases unless _POSIX_SAVED_IDS is enabled. In that case, setuid(getuid())
366 * does not set the saved id - this is dangerous for traditional BSD
367 * programs. For this reason, we *really* do not want to set
368 * _POSIX_SAVED_IDS and do not want to clear POSIX_APPENDIX_B_4_2_2.
370 #define POSIX_APPENDIX_B_4_2_2
373 sys_setuid(struct setuid_args
*uap
)
375 struct proc
*p
= curproc
;
380 lwkt_gettoken(&proc_token
);
384 * See if we have "permission" by POSIX 1003.1 rules.
386 * Note that setuid(geteuid()) is a special case of
387 * "appropriate privileges" in appendix B.4.2.2. We need
388 * to use this clause to be compatible with traditional BSD
389 * semantics. Basically, it means that "setuid(xx)" sets all
390 * three id's (assuming you have privs).
392 * Notes on the logic. We do things in three steps.
393 * 1: We determine if the euid is going to change, and do EPERM
394 * right away. We unconditionally change the euid later if this
395 * test is satisfied, simplifying that part of the logic.
396 * 2: We determine if the real and/or saved uid's are going to
397 * change. Determined by compile options.
398 * 3: Change euid last. (after tests in #2 for "appropriate privs")
401 if (uid
!= cr
->cr_ruid
&& /* allow setuid(getuid()) */
402 #ifdef _POSIX_SAVED_IDS
403 uid
!= crc
->cr_svuid
&& /* allow setuid(saved gid) */
405 #ifdef POSIX_APPENDIX_B_4_2_2 /* Use BSD-compat clause from B.4.2.2 */
406 uid
!= cr
->cr_uid
&& /* allow setuid(geteuid()) */
408 (error
= priv_check_cred(cr
, PRIV_CRED_SETUID
, 0)))
411 #ifdef _POSIX_SAVED_IDS
413 * Do we have "appropriate privileges" (are we root or uid == euid)
414 * If so, we are changing the real uid and/or saved uid.
417 #ifdef POSIX_APPENDIX_B_4_2_2 /* Use the clause from B.4.2.2 */
420 priv_check_cred(cr
, PRIV_CRED_SETUID
, 0) == 0) /* we are using privs */
424 * Set the real uid and transfer proc count to new user.
426 if (uid
!= cr
->cr_ruid
) {
427 cr
= change_ruid(uid
);
433 * XXX always set saved uid even if not _POSIX_SAVED_IDS, as
434 * the security of seteuid() depends on it. B.4.2.2 says it
435 * is important that we should do this.
437 if (cr
->cr_svuid
!= uid
) {
438 cr
= cratom(&p
->p_ucred
);
445 * In all permitted cases, we are changing the euid.
446 * Copy credentials so other references do not see our changes.
448 if (cr
->cr_uid
!= uid
) {
454 lwkt_reltoken(&proc_token
);
459 sys_seteuid(struct seteuid_args
*uap
)
461 struct proc
*p
= curproc
;
466 lwkt_gettoken(&proc_token
);
469 if (euid
!= cr
->cr_ruid
&& /* allow seteuid(getuid()) */
470 euid
!= cr
->cr_svuid
&& /* allow seteuid(saved uid) */
471 (error
= priv_check_cred(cr
, PRIV_CRED_SETEUID
, 0))) {
472 lwkt_reltoken(&proc_token
);
477 * Everything's okay, do it. Copy credentials so other references do
478 * not see our changes.
480 if (cr
->cr_uid
!= euid
) {
484 lwkt_reltoken(&proc_token
);
489 sys_setgid(struct setgid_args
*uap
)
491 struct proc
*p
= curproc
;
496 lwkt_gettoken(&proc_token
);
500 * See if we have "permission" by POSIX 1003.1 rules.
502 * Note that setgid(getegid()) is a special case of
503 * "appropriate privileges" in appendix B.4.2.2. We need
504 * to use this clause to be compatible with traditional BSD
505 * semantics. Basically, it means that "setgid(xx)" sets all
506 * three id's (assuming you have privs).
508 * For notes on the logic here, see setuid() above.
511 if (gid
!= cr
->cr_rgid
&& /* allow setgid(getgid()) */
512 #ifdef _POSIX_SAVED_IDS
513 gid
!= cr
->cr_svgid
&& /* allow setgid(saved gid) */
515 #ifdef POSIX_APPENDIX_B_4_2_2 /* Use BSD-compat clause from B.4.2.2 */
516 gid
!= cr
->cr_groups
[0] && /* allow setgid(getegid()) */
518 (error
= priv_check_cred(cr
, PRIV_CRED_SETGID
, 0))) {
522 #ifdef _POSIX_SAVED_IDS
524 * Do we have "appropriate privileges" (are we root or gid == egid)
525 * If so, we are changing the real uid and saved gid.
528 #ifdef POSIX_APPENDIX_B_4_2_2 /* use the clause from B.4.2.2 */
529 gid
== cr
->cr_groups
[0] ||
531 priv_check_cred(cr
, PRIV_CRED_SETGID
, 0) == 0) /* we are using privs */
537 if (cr
->cr_rgid
!= gid
) {
538 cr
= cratom(&p
->p_ucred
);
545 * XXX always set saved gid even if not _POSIX_SAVED_IDS, as
546 * the security of setegid() depends on it. B.4.2.2 says it
547 * is important that we should do this.
549 if (cr
->cr_svgid
!= gid
) {
550 cr
= cratom(&p
->p_ucred
);
556 * In all cases permitted cases, we are changing the egid.
557 * Copy credentials so other references do not see our changes.
559 if (cr
->cr_groups
[0] != gid
) {
560 cr
= cratom(&p
->p_ucred
);
561 cr
->cr_groups
[0] = gid
;
566 lwkt_reltoken(&proc_token
);
571 sys_setegid(struct setegid_args
*uap
)
573 struct proc
*p
= curproc
;
578 lwkt_gettoken(&proc_token
);
581 if (egid
!= cr
->cr_rgid
&& /* allow setegid(getgid()) */
582 egid
!= cr
->cr_svgid
&& /* allow setegid(saved gid) */
583 (error
= priv_check_cred(cr
, PRIV_CRED_SETEGID
, 0))) {
586 if (cr
->cr_groups
[0] != egid
) {
587 cr
= cratom(&p
->p_ucred
);
588 cr
->cr_groups
[0] = egid
;
593 lwkt_reltoken(&proc_token
);
598 sys_setgroups(struct setgroups_args
*uap
)
600 struct proc
*p
= curproc
;
605 lwkt_gettoken(&proc_token
);
608 if ((error
= priv_check_cred(cr
, PRIV_CRED_SETGROUPS
, 0)))
610 ngrp
= uap
->gidsetsize
;
611 if (ngrp
> NGROUPS
) {
616 * XXX A little bit lazy here. We could test if anything has
617 * changed before cratom() and setting P_SUGID.
619 cr
= cratom(&p
->p_ucred
);
622 * setgroups(0, NULL) is a legitimate way of clearing the
623 * groups vector on non-BSD systems (which generally do not
624 * have the egid in the groups[0]). We risk security holes
625 * when running non-BSD software if we do not do the same.
629 error
= copyin(uap
->gidset
, cr
->cr_groups
,
630 ngrp
* sizeof(gid_t
));
633 cr
->cr_ngroups
= ngrp
;
638 lwkt_reltoken(&proc_token
);
643 sys_setreuid(struct setreuid_args
*uap
)
645 struct proc
*p
= curproc
;
650 lwkt_gettoken(&proc_token
);
655 if (((ruid
!= (uid_t
)-1 && ruid
!= cr
->cr_ruid
&& ruid
!= cr
->cr_svuid
) ||
656 (euid
!= (uid_t
)-1 && euid
!= cr
->cr_uid
&&
657 euid
!= cr
->cr_ruid
&& euid
!= cr
->cr_svuid
)) &&
658 (error
= priv_check_cred(cr
, PRIV_CRED_SETREUID
, 0)) != 0) {
662 if (euid
!= (uid_t
)-1 && cr
->cr_uid
!= euid
) {
663 cr
= change_euid(euid
);
666 if (ruid
!= (uid_t
)-1 && cr
->cr_ruid
!= ruid
) {
667 cr
= change_ruid(ruid
);
670 if ((ruid
!= (uid_t
)-1 || cr
->cr_uid
!= cr
->cr_ruid
) &&
671 cr
->cr_svuid
!= cr
->cr_uid
) {
672 cr
= cratom(&p
->p_ucred
);
673 cr
->cr_svuid
= cr
->cr_uid
;
678 lwkt_reltoken(&proc_token
);
683 sys_setregid(struct setregid_args
*uap
)
685 struct proc
*p
= curproc
;
690 lwkt_gettoken(&proc_token
);
695 if (((rgid
!= (gid_t
)-1 && rgid
!= cr
->cr_rgid
&& rgid
!= cr
->cr_svgid
) ||
696 (egid
!= (gid_t
)-1 && egid
!= cr
->cr_groups
[0] &&
697 egid
!= cr
->cr_rgid
&& egid
!= cr
->cr_svgid
)) &&
698 (error
= priv_check_cred(cr
, PRIV_CRED_SETREGID
, 0)) != 0) {
702 if (egid
!= (gid_t
)-1 && cr
->cr_groups
[0] != egid
) {
703 cr
= cratom(&p
->p_ucred
);
704 cr
->cr_groups
[0] = egid
;
707 if (rgid
!= (gid_t
)-1 && cr
->cr_rgid
!= rgid
) {
708 cr
= cratom(&p
->p_ucred
);
712 if ((rgid
!= (gid_t
)-1 || cr
->cr_groups
[0] != cr
->cr_rgid
) &&
713 cr
->cr_svgid
!= cr
->cr_groups
[0]) {
714 cr
= cratom(&p
->p_ucred
);
715 cr
->cr_svgid
= cr
->cr_groups
[0];
720 lwkt_reltoken(&proc_token
);
725 * setresuid(ruid, euid, suid) is like setreuid except control over the
726 * saved uid is explicit.
729 sys_setresuid(struct setresuid_args
*uap
)
731 struct proc
*p
= curproc
;
733 uid_t ruid
, euid
, suid
;
736 lwkt_gettoken(&proc_token
);
742 if (((ruid
!= (uid_t
)-1 && ruid
!= cr
->cr_ruid
&& ruid
!= cr
->cr_svuid
&&
743 ruid
!= cr
->cr_uid
) ||
744 (euid
!= (uid_t
)-1 && euid
!= cr
->cr_ruid
&& euid
!= cr
->cr_svuid
&&
745 euid
!= cr
->cr_uid
) ||
746 (suid
!= (uid_t
)-1 && suid
!= cr
->cr_ruid
&& suid
!= cr
->cr_svuid
&&
747 suid
!= cr
->cr_uid
)) &&
748 (error
= priv_check_cred(cr
, PRIV_CRED_SETRESUID
, 0)) != 0) {
751 if (euid
!= (uid_t
)-1 && cr
->cr_uid
!= euid
) {
752 cr
= change_euid(euid
);
755 if (ruid
!= (uid_t
)-1 && cr
->cr_ruid
!= ruid
) {
756 cr
= change_ruid(ruid
);
759 if (suid
!= (uid_t
)-1 && cr
->cr_svuid
!= suid
) {
760 cr
= cratom(&p
->p_ucred
);
766 lwkt_reltoken(&proc_token
);
771 * setresgid(rgid, egid, sgid) is like setregid except control over the
772 * saved gid is explicit.
775 sys_setresgid(struct setresgid_args
*uap
)
777 struct proc
*p
= curproc
;
779 gid_t rgid
, egid
, sgid
;
782 lwkt_gettoken(&proc_token
);
787 if (((rgid
!= (gid_t
)-1 && rgid
!= cr
->cr_rgid
&& rgid
!= cr
->cr_svgid
&&
788 rgid
!= cr
->cr_groups
[0]) ||
789 (egid
!= (gid_t
)-1 && egid
!= cr
->cr_rgid
&& egid
!= cr
->cr_svgid
&&
790 egid
!= cr
->cr_groups
[0]) ||
791 (sgid
!= (gid_t
)-1 && sgid
!= cr
->cr_rgid
&& sgid
!= cr
->cr_svgid
&&
792 sgid
!= cr
->cr_groups
[0])) &&
793 (error
= priv_check_cred(cr
, PRIV_CRED_SETRESGID
, 0)) != 0) {
797 if (egid
!= (gid_t
)-1 && cr
->cr_groups
[0] != egid
) {
798 cr
= cratom(&p
->p_ucred
);
799 cr
->cr_groups
[0] = egid
;
802 if (rgid
!= (gid_t
)-1 && cr
->cr_rgid
!= rgid
) {
803 cr
= cratom(&p
->p_ucred
);
807 if (sgid
!= (gid_t
)-1 && cr
->cr_svgid
!= sgid
) {
808 cr
= cratom(&p
->p_ucred
);
814 lwkt_reltoken(&proc_token
);
819 sys_getresuid(struct getresuid_args
*uap
)
821 struct proc
*p
= curproc
;
823 int error1
= 0, error2
= 0, error3
= 0;
825 lwkt_gettoken(&proc_token
);
828 error1
= copyout((caddr_t
)&cr
->cr_ruid
,
829 (caddr_t
)uap
->ruid
, sizeof(cr
->cr_ruid
));
831 error2
= copyout((caddr_t
)&cr
->cr_uid
,
832 (caddr_t
)uap
->euid
, sizeof(cr
->cr_uid
));
834 error3
= copyout((caddr_t
)&cr
->cr_svuid
,
835 (caddr_t
)uap
->suid
, sizeof(cr
->cr_svuid
));
836 lwkt_reltoken(&proc_token
);
837 return error1
? error1
: (error2
? error2
: error3
);
844 sys_getresgid(struct getresgid_args
*uap
)
847 int error1
= 0, error2
= 0, error3
= 0;
849 cr
= curthread
->td_ucred
;
851 error1
= copyout(&cr
->cr_rgid
, uap
->rgid
,
852 sizeof(cr
->cr_rgid
));
854 error2
= copyout(&cr
->cr_groups
[0], uap
->egid
,
855 sizeof(cr
->cr_groups
[0]));
857 error3
= copyout(&cr
->cr_svgid
, uap
->sgid
,
858 sizeof(cr
->cr_svgid
));
859 return error1
? error1
: (error2
? error2
: error3
);
864 * NOTE: OpenBSD sets a P_SUGIDEXEC flag set at execve() time,
865 * we use P_SUGID because we consider changing the owners as
866 * "tainting" as well.
867 * This is significant for procs that start as root and "become"
868 * a user without an exec - programs cannot know *everything*
869 * that libc *might* have put in their data segment.
874 sys_issetugid(struct issetugid_args
*uap
)
876 uap
->sysmsg_result
= (curproc
->p_flag
& P_SUGID
) ? 1 : 0;
881 * Check if gid is a member of the group set.
884 groupmember(gid_t gid
, struct ucred
*cred
)
889 egp
= &(cred
->cr_groups
[cred
->cr_ngroups
]);
890 for (gp
= cred
->cr_groups
; gp
< egp
; gp
++) {
898 * Test whether the specified credentials have the privilege
901 * A kernel thread without a process context is assumed to have
902 * the privilege in question. In situations where the caller always
903 * expect a cred to exist, the cred should be passed separately and
904 * priv_check_cred() should be used instead of priv_check().
906 * Returns 0 or error.
911 priv_check(struct thread
*td
, int priv
)
913 if (td
->td_lwp
!= NULL
)
914 return priv_check_cred(td
->td_ucred
, priv
, 0);
919 * Check a credential for privilege.
921 * A non-null credential is expected unless NULL_CRED_OKAY is set.
926 priv_check_cred(struct ucred
*cred
, int priv
, int flags
)
930 KASSERT(PRIV_VALID(priv
), ("priv_check_cred: invalid privilege"));
932 KASSERT(cred
!= NULL
|| flags
& NULL_CRED_OKAY
,
933 ("priv_check_cred: NULL cred!"));
936 if (flags
& NULL_CRED_OKAY
)
941 if (cred
->cr_uid
!= 0)
944 error
= prison_priv_check(cred
, priv
);
948 /* NOTE: accounting for suser access (p_acflag/ASU) removed */
953 * Return zero if p1 can fondle p2, return errno (EPERM/ESRCH) otherwise.
956 p_trespass(struct ucred
*cr1
, struct ucred
*cr2
)
960 if (!PRISON_CHECK(cr1
, cr2
))
962 if (cr1
->cr_ruid
== cr2
->cr_ruid
)
964 if (cr1
->cr_uid
== cr2
->cr_ruid
)
966 if (cr1
->cr_ruid
== cr2
->cr_uid
)
968 if (cr1
->cr_uid
== cr2
->cr_uid
)
970 if (priv_check_cred(cr1
, PRIV_PROC_TRESPASS
, 0) == 0)
979 _crinit(struct ucred
*cr
)
988 crinit(struct ucred
*cr
)
990 bzero(cr
, sizeof(*cr
));
995 * Allocate a zeroed cred structure.
1004 cr
= kmalloc(sizeof(*cr
), M_CRED
, M_WAITOK
|M_ZERO
);
1010 * Claim another reference to a ucred structure. Can be used with special
1013 * It must be possible to call this routine with spinlocks held, meaning
1014 * that this routine itself cannot obtain a spinlock.
1019 crhold(struct ucred
*cr
)
1021 if (cr
!= NOCRED
&& cr
!= FSCRED
)
1022 atomic_add_int(&cr
->cr_ref
, 1);
1027 * Drop a reference from the cred structure, free it if the reference count
1030 * NOTE: because we used atomic_add_int() above, without a spinlock, we
1031 * must also use atomic_subtract_int() below. A spinlock is required
1032 * in crfree() to handle multiple callers racing the refcount to 0.
1037 crfree(struct ucred
*cr
)
1039 if (cr
->cr_ref
<= 0)
1040 panic("Freeing already free credential! %p", cr
);
1041 if (atomic_fetchadd_int(&cr
->cr_ref
, -1) == 1) {
1043 * Some callers of crget(), such as nfs_statfs(),
1044 * allocate a temporary credential, but don't
1045 * allocate a uidinfo structure.
1047 if (cr
->cr_uidinfo
!= NULL
) {
1048 uidrop(cr
->cr_uidinfo
);
1049 cr
->cr_uidinfo
= NULL
;
1051 if (cr
->cr_ruidinfo
!= NULL
) {
1052 uidrop(cr
->cr_ruidinfo
);
1053 cr
->cr_ruidinfo
= NULL
;
1057 * Destroy empty prisons
1060 prison_free(cr
->cr_prison
);
1061 cr
->cr_prison
= NULL
; /* safety */
1063 FREE((caddr_t
)cr
, M_CRED
);
1068 * Atomize a cred structure so it can be modified without polluting
1069 * other references to it.
1071 * MPSAFE (however, *pcr must be stable)
1074 cratom(struct ucred
**pcr
)
1076 struct ucred
*oldcr
;
1077 struct ucred
*newcr
;
1080 if (oldcr
->cr_ref
== 1)
1084 if (newcr
->cr_uidinfo
)
1085 uihold(newcr
->cr_uidinfo
);
1086 if (newcr
->cr_ruidinfo
)
1087 uihold(newcr
->cr_ruidinfo
);
1089 prison_hold(newcr
->cr_prison
);
1096 #if 0 /* no longer used but keep around for a little while */
1098 * Copy cred structure to a new one and free the old one.
1100 * MPSAFE (*cr must be stable)
1103 crcopy(struct ucred
*cr
)
1105 struct ucred
*newcr
;
1107 if (cr
->cr_ref
== 1)
1111 if (newcr
->cr_uidinfo
)
1112 uihold(newcr
->cr_uidinfo
);
1113 if (newcr
->cr_ruidinfo
)
1114 uihold(newcr
->cr_ruidinfo
);
1116 prison_hold(newcr
->cr_prison
);
1124 * Dup cred struct to a new held one.
1127 crdup(struct ucred
*cr
)
1129 struct ucred
*newcr
;
1133 if (newcr
->cr_uidinfo
)
1134 uihold(newcr
->cr_uidinfo
);
1135 if (newcr
->cr_ruidinfo
)
1136 uihold(newcr
->cr_ruidinfo
);
1138 prison_hold(newcr
->cr_prison
);
1144 * Fill in a struct xucred based on a struct ucred.
1147 cru2x(struct ucred
*cr
, struct xucred
*xcr
)
1150 bzero(xcr
, sizeof(*xcr
));
1151 xcr
->cr_version
= XUCRED_VERSION
;
1152 xcr
->cr_uid
= cr
->cr_uid
;
1153 xcr
->cr_ngroups
= cr
->cr_ngroups
;
1154 bcopy(cr
->cr_groups
, xcr
->cr_groups
, sizeof(cr
->cr_groups
));
1158 * Get login name, if available.
1161 sys_getlogin(struct getlogin_args
*uap
)
1163 struct proc
*p
= curproc
;
1164 char buf
[MAXLOGNAME
];
1167 if (uap
->namelen
> MAXLOGNAME
) /* namelen is unsigned */
1168 uap
->namelen
= MAXLOGNAME
;
1169 bzero(buf
, sizeof(buf
));
1170 lwkt_gettoken(&proc_token
);
1171 bcopy(p
->p_pgrp
->pg_session
->s_login
, buf
, uap
->namelen
);
1172 lwkt_reltoken(&proc_token
);
1174 error
= copyout(buf
, uap
->namebuf
, uap
->namelen
);
1182 sys_setlogin(struct setlogin_args
*uap
)
1184 struct thread
*td
= curthread
;
1187 char buf
[MAXLOGNAME
];
1190 cred
= td
->td_ucred
;
1193 if ((error
= priv_check_cred(cred
, PRIV_PROC_SETLOGIN
, 0)))
1195 bzero(buf
, sizeof(buf
));
1196 error
= copyinstr(uap
->namebuf
, buf
, sizeof(buf
), NULL
);
1197 if (error
== ENAMETOOLONG
)
1200 lwkt_gettoken(&proc_token
);
1201 memcpy(p
->p_pgrp
->pg_session
->s_login
, buf
, sizeof(buf
));
1202 lwkt_reltoken(&proc_token
);
1210 struct proc
*p
= curproc
;
1212 KKASSERT(p
!= NULL
);
1213 p
->p_flag
|= P_SUGID
;
1214 if (!(p
->p_pfsflags
& PF_ISUGID
))
1219 * Helper function to change the effective uid of a process
1222 change_euid(uid_t euid
)
1224 struct proc
*p
= curproc
;
1227 KKASSERT(p
!= NULL
);
1228 lf_count_adjust(p
, 0);
1229 cr
= cratom(&p
->p_ucred
);
1231 uireplace(&cr
->cr_uidinfo
, uifind(euid
));
1232 lf_count_adjust(p
, 1);
1237 * Helper function to change the real uid of a process
1239 * The per-uid process count for this process is transfered from
1240 * the old uid to the new uid.
1243 change_ruid(uid_t ruid
)
1245 struct proc
*p
= curproc
;
1248 KKASSERT(p
!= NULL
);
1250 cr
= cratom(&p
->p_ucred
);
1251 chgproccnt(cr
->cr_ruidinfo
, -1, 0);
1253 uireplace(&cr
->cr_ruidinfo
, uifind(ruid
));
1254 chgproccnt(cr
->cr_ruidinfo
, 1, 0);