diff options
Diffstat (limited to 'sys/kern/kern_prot.c')
| -rw-r--r-- | sys/kern/kern_prot.c | 1969 |
1 files changed, 1969 insertions, 0 deletions
diff --git a/sys/kern/kern_prot.c b/sys/kern/kern_prot.c new file mode 100644 index 0000000..a3e4bea --- /dev/null +++ b/sys/kern/kern_prot.c @@ -0,0 +1,1969 @@ +/* + * 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. + * Copyright (c) 2000-2001 Robert N. M. Watson. 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 8.6 (Berkeley) 1/21/94 + * $FreeBSD$ + */ + +/* + * System calls related to processes and protection + */ + +#include "opt_compat.h" + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/acct.h> +#include <sys/kernel.h> +#include <sys/lock.h> +#include <sys/malloc.h> +#include <sys/mutex.h> +#include <sys/sx.h> +#include <sys/proc.h> +#include <sys/sysproto.h> +#include <sys/jail.h> +#include <sys/pioctl.h> +#include <sys/resourcevar.h> +#include <sys/socket.h> +#include <sys/socketvar.h> +#include <sys/sysctl.h> + +static MALLOC_DEFINE(M_CRED, "cred", "credentials"); + +SYSCTL_DECL(_security); +SYSCTL_NODE(_security, OID_AUTO, bsd, CTLFLAG_RW, 0, + "BSD security policy"); + +#ifndef _SYS_SYSPROTO_H_ +struct getpid_args { + int dummy; +}; +#endif +/* + * MPSAFE + */ +/* ARGSUSED */ +int +getpid(struct thread *td, struct getpid_args *uap) +{ + struct proc *p = td->td_proc; + int s; + + s = mtx_lock_giant(kern_giant_proc); + td->td_retval[0] = p->p_pid; +#if defined(COMPAT_43) || defined(COMPAT_SUNOS) + PROC_LOCK(p); + td->td_retval[1] = p->p_pptr->p_pid; + PROC_UNLOCK(p); +#endif + mtx_unlock_giant(s); + return (0); +} + +#ifndef _SYS_SYSPROTO_H_ +struct getppid_args { + int dummy; +}; +#endif +/* + * MPSAFE + */ +/* ARGSUSED */ +int +getppid(struct thread *td, struct getppid_args *uap) +{ + struct proc *p = td->td_proc; + int s; + + s = mtx_lock_giant(kern_giant_proc); + PROC_LOCK(p); + td->td_retval[0] = p->p_pptr->p_pid; + PROC_UNLOCK(p); + mtx_unlock_giant(s); + return (0); +} + +/* + * Get process group ID; note that POSIX getpgrp takes no parameter. + */ +#ifndef _SYS_SYSPROTO_H_ +struct getpgrp_args { + int dummy; +}; +#endif +/* + * MPSAFE + */ +int +getpgrp(struct thread *td, struct getpgrp_args *uap) +{ + struct proc *p = td->td_proc; + int s; + + s = mtx_lock_giant(kern_giant_proc); + PROC_LOCK(p); + td->td_retval[0] = p->p_pgrp->pg_id; + PROC_UNLOCK(p); + mtx_unlock_giant(s); + return (0); +} + +/* Get an arbitary pid's process group id */ +#ifndef _SYS_SYSPROTO_H_ +struct getpgid_args { + pid_t pid; +}; +#endif +/* + * MPSAFE + */ +int +getpgid(struct thread *td, struct getpgid_args *uap) +{ + struct proc *p = td->td_proc; + struct proc *pt; + int error; + + mtx_lock(&Giant); + error = 0; + if (uap->pid == 0) { + PROC_LOCK(p); + td->td_retval[0] = p->p_pgrp->pg_id; + PROC_UNLOCK(p); + } else if ((pt = pfind(uap->pid)) == NULL) + error = ESRCH; + else { + error = p_cansee(td, pt); + if (error == 0) + td->td_retval[0] = pt->p_pgrp->pg_id; + PROC_UNLOCK(pt); + } + mtx_unlock(&Giant); + return (error); +} + +/* + * Get an arbitary pid's session id. + */ +#ifndef _SYS_SYSPROTO_H_ +struct getsid_args { + pid_t pid; +}; +#endif +/* + * MPSAFE + */ +int +getsid(struct thread *td, struct getsid_args *uap) +{ + struct proc *p = td->td_proc; + struct proc *pt; + int error; + + mtx_lock(&Giant); + error = 0; + if (uap->pid == 0) { + PROC_LOCK(p); + td->td_retval[0] = p->p_session->s_sid; + PROC_UNLOCK(p); + } else if ((pt = pfind(uap->pid)) == NULL) + error = ESRCH; + else { + error = p_cansee(td, pt); + if (error == 0) + td->td_retval[0] = pt->p_session->s_sid; + PROC_UNLOCK(pt); + } + mtx_unlock(&Giant); + return (error); +} + +#ifndef _SYS_SYSPROTO_H_ +struct getuid_args { + int dummy; +}; +#endif +/* + * MPSAFE + */ +/* ARGSUSED */ +int +getuid(struct thread *td, struct getuid_args *uap) +{ + + td->td_retval[0] = td->td_ucred->cr_ruid; +#if defined(COMPAT_43) || defined(COMPAT_SUNOS) + td->td_retval[1] = td->td_ucred->cr_uid; +#endif + return (0); +} + +#ifndef _SYS_SYSPROTO_H_ +struct geteuid_args { + int dummy; +}; +#endif +/* + * MPSAFE + */ +/* ARGSUSED */ +int +geteuid(struct thread *td, struct geteuid_args *uap) +{ + + td->td_retval[0] = td->td_ucred->cr_uid; + return (0); +} + +#ifndef _SYS_SYSPROTO_H_ +struct getgid_args { + int dummy; +}; +#endif +/* + * MPSAFE + */ +/* ARGSUSED */ +int +getgid(struct thread *td, struct getgid_args *uap) +{ + + td->td_retval[0] = td->td_ucred->cr_rgid; +#if defined(COMPAT_43) || defined(COMPAT_SUNOS) + td->td_retval[1] = td->td_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 +/* + * MPSAFE + */ +/* ARGSUSED */ +int +getegid(struct thread *td, struct getegid_args *uap) +{ + + td->td_retval[0] = td->td_ucred->cr_groups[0]; + return (0); +} + +#ifndef _SYS_SYSPROTO_H_ +struct getgroups_args { + u_int gidsetsize; + gid_t *gidset; +}; +#endif +/* + * MPSAFE + */ +int +getgroups(struct thread *td, register struct getgroups_args *uap) +{ + struct ucred *cred; + u_int ngrp; + int error; + + cred = td->td_ucred; + if ((ngrp = uap->gidsetsize) == 0) { + td->td_retval[0] = cred->cr_ngroups; + return (0); + } + if (ngrp < cred->cr_ngroups) + return (EINVAL); + ngrp = cred->cr_ngroups; + error = copyout((caddr_t)cred->cr_groups, (caddr_t)uap->gidset, + ngrp * sizeof(gid_t)); + if (error == 0) + td->td_retval[0] = ngrp; + return (error); +} + +#ifndef _SYS_SYSPROTO_H_ +struct setsid_args { + int dummy; +}; +#endif +/* + * MPSAFE + */ +/* ARGSUSED */ +int +setsid(register struct thread *td, struct setsid_args *uap) +{ + struct pgrp *pgrp; + int error; + struct proc *p = td->td_proc; + struct pgrp *newpgrp; + struct session *newsess; + + error = 0; + pgrp = NULL; + + MALLOC(newpgrp, struct pgrp *, sizeof(struct pgrp), M_PGRP, M_WAITOK | M_ZERO); + MALLOC(newsess, struct session *, sizeof(struct session), M_SESSION, M_WAITOK | M_ZERO); + + sx_xlock(&proctree_lock); + + if (p->p_pgid == p->p_pid || (pgrp = pgfind(p->p_pid)) != NULL) { + if (pgrp != NULL) + PGRP_UNLOCK(pgrp); + error = EPERM; + } else { + (void)enterpgrp(p, p->p_pid, newpgrp, newsess); + td->td_retval[0] = p->p_pid; + newpgrp = NULL; + newsess = NULL; + } + + sx_xunlock(&proctree_lock); + + if (newpgrp != NULL) + FREE(newpgrp, M_PGRP); + if (newsess != NULL) + FREE(newsess, M_SESSION); + + return (error); +} + +/* + * 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 +/* + * MPSAFE + */ +/* ARGSUSED */ +int +setpgid(struct thread *td, register struct setpgid_args *uap) +{ + struct proc *curp = td->td_proc; + register struct proc *targp; /* target process */ + register struct pgrp *pgrp; /* target pgrp */ + int error; + struct pgrp *newpgrp; + + if (uap->pgid < 0) + return (EINVAL); + + error = 0; + + MALLOC(newpgrp, struct pgrp *, sizeof(struct pgrp), M_PGRP, M_WAITOK | M_ZERO); + + sx_xlock(&proctree_lock); + if (uap->pid != 0 && uap->pid != curp->p_pid) { + if ((targp = pfind(uap->pid)) == NULL) { + if (targp) + PROC_UNLOCK(targp); + error = ESRCH; + goto done; + } + if (!inferior(targp)) { + PROC_UNLOCK(targp); + error = ESRCH; + goto done; + } + if ((error = p_cansee(curthread, targp))) { + PROC_UNLOCK(targp); + goto done; + } + if (targp->p_pgrp == NULL || + targp->p_session != curp->p_session) { + PROC_UNLOCK(targp); + error = EPERM; + goto done; + } + if (targp->p_flag & P_EXEC) { + PROC_UNLOCK(targp); + error = EACCES; + goto done; + } + PROC_UNLOCK(targp); + } else + targp = curp; + if (SESS_LEADER(targp)) { + error = EPERM; + goto done; + } + if (uap->pgid == 0) + uap->pgid = targp->p_pid; + if (uap->pgid == targp->p_pid) { + if (targp->p_pgid == uap->pgid) + goto done; + error = enterpgrp(targp, uap->pgid, newpgrp, NULL); + if (error == 0) + newpgrp = NULL; + } else { + if ((pgrp = pgfind(uap->pgid)) == NULL || + pgrp->pg_session != curp->p_session) { + if (pgrp != NULL) + PGRP_UNLOCK(pgrp); + error = EPERM; + goto done; + } + if (pgrp == targp->p_pgrp) { + PGRP_UNLOCK(pgrp); + goto done; + } + PGRP_UNLOCK(pgrp); + error = enterthispgrp(targp, pgrp); + } +done: + sx_xunlock(&proctree_lock); + KASSERT((error == 0) || (newpgrp != NULL), + ("setpgid failed and newpgrp is NULL")); + if (newpgrp != NULL) + FREE(newpgrp, M_PGRP); + return (error); +} + +/* + * Use the clause in B.4.2.2 that allows setuid/setgid to be 4.2/4.3BSD + * compatible. 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 +/* + * MPSAFE + */ +/* ARGSUSED */ +int +setuid(struct thread *td, struct setuid_args *uap) +{ + struct proc *p = td->td_proc; + struct ucred *newcred, *oldcred; + uid_t uid; + struct uidinfo *uip; + int error; + + mtx_lock(&Giant); + uid = uap->uid; + newcred = crget(); + uip = uifind(uid); + PROC_LOCK(p); + oldcred = p->p_ucred; + + /* + * 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 compatible 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 uids are going to + * change. Determined by compile options. + * 3: Change euid last. (after tests in #2 for "appropriate privs") + */ + if (uid != oldcred->cr_ruid && /* allow setuid(getuid()) */ +#ifdef _POSIX_SAVED_IDS + uid != oldcred->cr_svuid && /* allow setuid(saved gid) */ +#endif +#ifdef POSIX_APPENDIX_B_4_2_2 /* Use BSD-compat clause from B.4.2.2 */ + uid != oldcred->cr_uid && /* allow setuid(geteuid()) */ +#endif + (error = suser_cred(oldcred, PRISON_ROOT)) != 0) { + PROC_UNLOCK(p); + uifree(uip); + crfree(newcred); + mtx_unlock(&Giant); + return (error); + } + + /* + * Copy credentials so other references do not see our changes. + */ + crcopy(newcred, oldcred); +#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 == oldcred->cr_uid || +#endif + suser_cred(oldcred, PRISON_ROOT) == 0) /* we are using privs */ +#endif + { + /* + * Set the real uid and transfer proc count to new user. + */ + if (uid != oldcred->cr_ruid) { + change_ruid(newcred, uip); + 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 (uid != oldcred->cr_svuid) { + change_svuid(newcred, uid); + setsugid(p); + } + } + + /* + * In all permitted cases, we are changing the euid. + */ + if (uid != oldcred->cr_uid) { + change_euid(newcred, uip); + setsugid(p); + } + p->p_ucred = newcred; + PROC_UNLOCK(p); + uifree(uip); + crfree(oldcred); + mtx_unlock(&Giant); + return (0); +} + +#ifndef _SYS_SYSPROTO_H_ +struct seteuid_args { + uid_t euid; +}; +#endif +/* + * MPSAFE + */ +/* ARGSUSED */ +int +seteuid(struct thread *td, struct seteuid_args *uap) +{ + struct proc *p = td->td_proc; + struct ucred *newcred, *oldcred; + uid_t euid; + struct uidinfo *euip; + int error; + + euid = uap->euid; + mtx_lock(&Giant); + newcred = crget(); + euip = uifind(euid); + PROC_LOCK(p); + oldcred = p->p_ucred; + if (euid != oldcred->cr_ruid && /* allow seteuid(getuid()) */ + euid != oldcred->cr_svuid && /* allow seteuid(saved uid) */ + (error = suser_cred(oldcred, PRISON_ROOT)) != 0) { + PROC_UNLOCK(p); + uifree(euip); + crfree(newcred); + mtx_unlock(&Giant); + return (error); + } + /* + * Everything's okay, do it. Copy credentials so other references do + * not see our changes. + */ + crcopy(newcred, oldcred); + if (oldcred->cr_uid != euid) { + change_euid(newcred, euip); + setsugid(p); + } + p->p_ucred = newcred; + PROC_UNLOCK(p); + uifree(euip); + crfree(oldcred); + mtx_unlock(&Giant); + return (0); +} + +#ifndef _SYS_SYSPROTO_H_ +struct setgid_args { + gid_t gid; +}; +#endif +/* + * MPSAFE + */ +/* ARGSUSED */ +int +setgid(struct thread *td, struct setgid_args *uap) +{ + struct proc *p = td->td_proc; + struct ucred *newcred, *oldcred; + gid_t gid; + int error; + + gid = uap->gid; + mtx_lock(&Giant); + newcred = crget(); + PROC_LOCK(p); + oldcred = p->p_ucred; + + /* + * 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 compatible 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. + */ + if (gid != oldcred->cr_rgid && /* allow setgid(getgid()) */ +#ifdef _POSIX_SAVED_IDS + gid != oldcred->cr_svgid && /* allow setgid(saved gid) */ +#endif +#ifdef POSIX_APPENDIX_B_4_2_2 /* Use BSD-compat clause from B.4.2.2 */ + gid != oldcred->cr_groups[0] && /* allow setgid(getegid()) */ +#endif + (error = suser_cred(oldcred, PRISON_ROOT)) != 0) { + PROC_UNLOCK(p); + crfree(newcred); + mtx_unlock(&Giant); + return (error); + } + + crcopy(newcred, oldcred); +#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 == oldcred->cr_groups[0] || +#endif + suser_cred(oldcred, PRISON_ROOT) == 0) /* we are using privs */ +#endif + { + /* + * Set real gid + */ + if (oldcred->cr_rgid != gid) { + change_rgid(newcred, 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 (oldcred->cr_svgid != gid) { + change_svgid(newcred, gid); + setsugid(p); + } + } + /* + * In all cases permitted cases, we are changing the egid. + * Copy credentials so other references do not see our changes. + */ + if (oldcred->cr_groups[0] != gid) { + change_egid(newcred, gid); + setsugid(p); + } + p->p_ucred = newcred; + PROC_UNLOCK(p); + crfree(oldcred); + mtx_unlock(&Giant); + return (0); +} + +#ifndef _SYS_SYSPROTO_H_ +struct setegid_args { + gid_t egid; +}; +#endif +/* + * MPSAFE + */ +/* ARGSUSED */ +int +setegid(struct thread *td, struct setegid_args *uap) +{ + struct proc *p = td->td_proc; + struct ucred *newcred, *oldcred; + gid_t egid; + int error; + + egid = uap->egid; + mtx_lock(&Giant); + newcred = crget(); + PROC_LOCK(p); + oldcred = p->p_ucred; + if (egid != oldcred->cr_rgid && /* allow setegid(getgid()) */ + egid != oldcred->cr_svgid && /* allow setegid(saved gid) */ + (error = suser_cred(oldcred, PRISON_ROOT)) != 0) { + PROC_UNLOCK(p); + crfree(newcred); + mtx_unlock(&Giant); + return (error); + } + crcopy(newcred, oldcred); + if (oldcred->cr_groups[0] != egid) { + change_egid(newcred, egid); + setsugid(p); + } + p->p_ucred = newcred; + PROC_UNLOCK(p); + crfree(oldcred); + mtx_unlock(&Giant); + return (0); +} + +#ifndef _SYS_SYSPROTO_H_ +struct setgroups_args { + u_int gidsetsize; + gid_t *gidset; +}; +#endif +/* + * MPSAFE + */ +/* ARGSUSED */ +int +setgroups(struct thread *td, struct setgroups_args *uap) +{ + struct proc *p = td->td_proc; + struct ucred *newcred, *tempcred, *oldcred; + u_int ngrp; + int error; + + ngrp = uap->gidsetsize; + if (ngrp > NGROUPS) + return (EINVAL); + mtx_lock(&Giant); + tempcred = crget(); + error = copyin((caddr_t)uap->gidset, (caddr_t)tempcred->cr_groups, + ngrp * sizeof(gid_t)); + if (error != 0) { + crfree(tempcred); + mtx_unlock(&Giant); + return (error); + } + newcred = crget(); + PROC_LOCK(p); + oldcred = p->p_ucred; + error = suser_cred(oldcred, PRISON_ROOT); + if (error) { + PROC_UNLOCK(p); + crfree(newcred); + crfree(tempcred); + mtx_unlock(&Giant); + return (error); + } + + /* + * XXX A little bit lazy here. We could test if anything has + * changed before crcopy() and setting P_SUGID. + */ + crcopy(newcred, oldcred); + 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. + */ + newcred->cr_ngroups = 1; + } else { + bcopy(tempcred->cr_groups, newcred->cr_groups, + ngrp * sizeof(gid_t)); + newcred->cr_ngroups = ngrp; + } + setsugid(p); + p->p_ucred = newcred; + PROC_UNLOCK(p); + crfree(tempcred); + crfree(oldcred); + mtx_unlock(&Giant); + return (0); +} + +#ifndef _SYS_SYSPROTO_H_ +struct setreuid_args { + uid_t ruid; + uid_t euid; +}; +#endif +/* + * MPSAFE + */ +/* ARGSUSED */ +int +setreuid(register struct thread *td, struct setreuid_args *uap) +{ + struct proc *p = td->td_proc; + struct ucred *newcred, *oldcred; + uid_t euid, ruid; + struct uidinfo *euip, *ruip; + int error; + + euid = uap->euid; + ruid = uap->ruid; + mtx_lock(&Giant); + newcred = crget(); + euip = uifind(euid); + ruip = uifind(ruid); + PROC_LOCK(p); + oldcred = p->p_ucred; + if (((ruid != (uid_t)-1 && ruid != oldcred->cr_ruid && + ruid != oldcred->cr_svuid) || + (euid != (uid_t)-1 && euid != oldcred->cr_uid && + euid != oldcred->cr_ruid && euid != oldcred->cr_svuid)) && + (error = suser_cred(oldcred, PRISON_ROOT)) != 0) { + PROC_UNLOCK(p); + uifree(ruip); + uifree(euip); + crfree(newcred); + mtx_unlock(&Giant); + return (error); + } + crcopy(newcred, oldcred); + if (euid != (uid_t)-1 && oldcred->cr_uid != euid) { + change_euid(newcred, euip); + setsugid(p); + } + if (ruid != (uid_t)-1 && oldcred->cr_ruid != ruid) { + change_ruid(newcred, ruip); + setsugid(p); + } + if ((ruid != (uid_t)-1 || newcred->cr_uid != newcred->cr_ruid) && + newcred->cr_svuid != newcred->cr_uid) { + change_svuid(newcred, newcred->cr_uid); + setsugid(p); + } + p->p_ucred = newcred; + PROC_UNLOCK(p); + uifree(ruip); + uifree(euip); + crfree(oldcred); + mtx_unlock(&Giant); + return (0); +} + +#ifndef _SYS_SYSPROTO_H_ +struct setregid_args { + gid_t rgid; + gid_t egid; +}; +#endif +/* + * MPSAFE + */ +/* ARGSUSED */ +int +setregid(register struct thread *td, struct setregid_args *uap) +{ + struct proc *p = td->td_proc; + struct ucred *newcred, *oldcred; + gid_t egid, rgid; + int error; + + egid = uap->egid; + rgid = uap->rgid; + mtx_lock(&Giant); + newcred = crget(); + PROC_LOCK(p); + oldcred = p->p_ucred; + if (((rgid != (gid_t)-1 && rgid != oldcred->cr_rgid && + rgid != oldcred->cr_svgid) || + (egid != (gid_t)-1 && egid != oldcred->cr_groups[0] && + egid != oldcred->cr_rgid && egid != oldcred->cr_svgid)) && + (error = suser_cred(oldcred, PRISON_ROOT)) != 0) { + PROC_UNLOCK(p); + crfree(newcred); + mtx_unlock(&Giant); + return (error); + } + + crcopy(newcred, oldcred); + if (egid != (gid_t)-1 && oldcred->cr_groups[0] != egid) { + change_egid(newcred, egid); + setsugid(p); + } + if (rgid != (gid_t)-1 && oldcred->cr_rgid != rgid) { + change_rgid(newcred, rgid); + setsugid(p); + } + if ((rgid != (gid_t)-1 || newcred->cr_groups[0] != newcred->cr_rgid) && + newcred->cr_svgid != newcred->cr_groups[0]) { + change_svgid(newcred, newcred->cr_groups[0]); + setsugid(p); + } + p->p_ucred = newcred; + PROC_UNLOCK(p); + crfree(oldcred); + mtx_unlock(&Giant); + return (0); +} + +/* + * setresuid(ruid, euid, suid) is like setreuid except control over the + * saved uid is explicit. + */ + +#ifndef _SYS_SYSPROTO_H_ +struct setresuid_args { + uid_t ruid; + uid_t euid; + uid_t suid; +}; +#endif +/* + * MPSAFE + */ +/* ARGSUSED */ +int +setresuid(register struct thread *td, struct setresuid_args *uap) +{ + struct proc *p = td->td_proc; + struct ucred *newcred, *oldcred; + uid_t euid, ruid, suid; + struct uidinfo *euip, *ruip; + int error; + + euid = uap->euid; + ruid = uap->ruid; + suid = uap->suid; + mtx_lock(&Giant); + newcred = crget(); + euip = uifind(euid); + ruip = uifind(ruid); + PROC_LOCK(p); + oldcred = p->p_ucred; + if (((ruid != (uid_t)-1 && ruid != oldcred->cr_ruid && + ruid != oldcred->cr_svuid && + ruid != oldcred->cr_uid) || + (euid != (uid_t)-1 && euid != oldcred->cr_ruid && + euid != oldcred->cr_svuid && + euid != oldcred->cr_uid) || + (suid != (uid_t)-1 && suid != oldcred->cr_ruid && + suid != oldcred->cr_svuid && + suid != oldcred->cr_uid)) && + (error = suser_cred(oldcred, PRISON_ROOT)) != 0) { + PROC_UNLOCK(p); + uifree(ruip); + uifree(euip); + crfree(newcred); + mtx_unlock(&Giant); + return (error); + } + + crcopy(newcred, oldcred); + if (euid != (uid_t)-1 && oldcred->cr_uid != euid) { + change_euid(newcred, euip); + setsugid(p); + } + if (ruid != (uid_t)-1 && oldcred->cr_ruid != ruid) { + change_ruid(newcred, ruip); + setsugid(p); + } + if (suid != (uid_t)-1 && oldcred->cr_svuid != suid) { + change_svuid(newcred, suid); + setsugid(p); + } + p->p_ucred = newcred; + PROC_UNLOCK(p); + uifree(ruip); + uifree(euip); + crfree(oldcred); + mtx_unlock(&Giant); + return (0); +} + +/* + * setresgid(rgid, egid, sgid) is like setregid except control over the + * saved gid is explicit. + */ + +#ifndef _SYS_SYSPROTO_H_ +struct setresgid_args { + gid_t rgid; + gid_t egid; + gid_t sgid; +}; +#endif +/* + * MPSAFE + */ +/* ARGSUSED */ +int +setresgid(register struct thread *td, struct setresgid_args *uap) +{ + struct proc *p = td->td_proc; + struct ucred *newcred, *oldcred; + gid_t egid, rgid, sgid; + int error; + + egid = uap->egid; + rgid = uap->rgid; + sgid = uap->sgid; + mtx_lock(&Giant); + newcred = crget(); + PROC_LOCK(p); + oldcred = p->p_ucred; + if (((rgid != (gid_t)-1 && rgid != oldcred->cr_rgid && + rgid != oldcred->cr_svgid && + rgid != oldcred->cr_groups[0]) || + (egid != (gid_t)-1 && egid != oldcred->cr_rgid && + egid != oldcred->cr_svgid && + egid != oldcred->cr_groups[0]) || + (sgid != (gid_t)-1 && sgid != oldcred->cr_rgid && + sgid != oldcred->cr_svgid && + sgid != oldcred->cr_groups[0])) && + (error = suser_cred(oldcred, PRISON_ROOT)) != 0) { + PROC_UNLOCK(p); + crfree(newcred); + mtx_unlock(&Giant); + return (error); + } + + crcopy(newcred, oldcred); + if (egid != (gid_t)-1 && oldcred->cr_groups[0] != egid) { + change_egid(newcred, egid); + setsugid(p); + } + if (rgid != (gid_t)-1 && oldcred->cr_rgid != rgid) { + change_rgid(newcred, rgid); + setsugid(p); + } + if (sgid != (gid_t)-1 && oldcred->cr_svgid != sgid) { + change_svgid(newcred, sgid); + setsugid(p); + } + p->p_ucred = newcred; + PROC_UNLOCK(p); + crfree(oldcred); + mtx_unlock(&Giant); + return (0); +} + +#ifndef _SYS_SYSPROTO_H_ +struct getresuid_args { + uid_t *ruid; + uid_t *euid; + uid_t *suid; +}; +#endif +/* + * MPSAFE + */ +/* ARGSUSED */ +int +getresuid(register struct thread *td, struct getresuid_args *uap) +{ + struct ucred *cred; + int error1 = 0, error2 = 0, error3 = 0; + + cred = td->td_ucred; + if (uap->ruid) + error1 = copyout((caddr_t)&cred->cr_ruid, + (caddr_t)uap->ruid, sizeof(cred->cr_ruid)); + if (uap->euid) + error2 = copyout((caddr_t)&cred->cr_uid, + (caddr_t)uap->euid, sizeof(cred->cr_uid)); + if (uap->suid) + error3 = copyout((caddr_t)&cred->cr_svuid, + (caddr_t)uap->suid, sizeof(cred->cr_svuid)); + return (error1 ? error1 : error2 ? error2 : error3); +} + +#ifndef _SYS_SYSPROTO_H_ +struct getresgid_args { + gid_t *rgid; + gid_t *egid; + gid_t *sgid; +}; +#endif +/* + * MPSAFE + */ +/* ARGSUSED */ +int +getresgid(register struct thread *td, struct getresgid_args *uap) +{ + struct ucred *cred; + int error1 = 0, error2 = 0, error3 = 0; + + cred = td->td_ucred; + if (uap->rgid) + error1 = copyout((caddr_t)&cred->cr_rgid, + (caddr_t)uap->rgid, sizeof(cred->cr_rgid)); + if (uap->egid) + error2 = copyout((caddr_t)&cred->cr_groups[0], + (caddr_t)uap->egid, sizeof(cred->cr_groups[0])); + if (uap->sgid) + error3 = copyout((caddr_t)&cred->cr_svgid, + (caddr_t)uap->sgid, sizeof(cred->cr_svgid)); + return (error1 ? error1 : error2 ? error2 : error3); +} + +#ifndef _SYS_SYSPROTO_H_ +struct issetugid_args { + int dummy; +}; +#endif +/* + * NOT MPSAFE? + */ +/* ARGSUSED */ +int +issetugid(register struct thread *td, struct issetugid_args *uap) +{ + struct proc *p = td->td_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. + */ + PROC_LOCK(p); + td->td_retval[0] = (p->p_flag & P_SUGID) ? 1 : 0; + PROC_UNLOCK(p); + return (0); +} + +/* + * MPSAFE + */ +int +__setugid(struct thread *td, struct __setugid_args *uap) +{ +#ifdef REGRESSION + struct proc *p; + + p = td->td_proc; + switch (uap->flag) { + case 0: + mtx_lock(&Giant); + PROC_LOCK(p); + p->p_flag &= ~P_SUGID; + PROC_UNLOCK(p); + mtx_unlock(&Giant); + return (0); + case 1: + mtx_lock(&Giant); + PROC_LOCK(p); + p->p_flag |= P_SUGID; + PROC_UNLOCK(p); + mtx_unlock(&Giant); + return (0); + default: + return (EINVAL); + } +#else /* !REGRESSION */ + + return (ENOSYS); +#endif /* REGRESSION */ +} + +/* + * Check if gid is a member of the group set. + * + * MPSAFE (cred must be held) + */ +int +groupmember(gid_t gid, 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); +} + +/* + * `suser_enabled' (which can be set by the security.suser_enabled + * sysctl) determines whether the system 'super-user' policy is in effect. + * If it is nonzero, an effective uid of 0 connotes special privilege, + * overriding many mandatory and discretionary protections. If it is zero, + * uid 0 is offered no special privilege in the kernel security policy. + * Setting it to zero may seriously impact the functionality of many + * existing userland programs, and should not be done without careful + * consideration of the consequences. + */ +int suser_enabled = 1; +SYSCTL_INT(_security_bsd, OID_AUTO, suser_enabled, CTLFLAG_RW, + &suser_enabled, 0, "processes with uid 0 have privilege"); +TUNABLE_INT("security.bsd.suser_enabled", &suser_enabled); + +/* + * Test whether the specified credentials imply "super-user" privilege. + * Return 0 or EPERM. The flag argument is currently used only to + * specify jail interaction. + */ +int +suser_cred(struct ucred *cred, int flag) +{ + + if (!suser_enabled) + return (EPERM); + if (cred->cr_uid != 0) + return (EPERM); + if (jailed(cred) && !(flag & PRISON_ROOT)) + return (EPERM); + return (0); +} + +/* + * Shortcut to hide contents of struct td and struct proc from the + * caller, promoting binary compatibility. + */ +int +suser(struct thread *td) +{ + + return (suser_cred(td->td_ucred, 0)); +} + +/* + * Test the active securelevel against a given level. securelevel_gt() + * implements (securelevel > level). securelevel_ge() implements + * (securelevel >= level). Note that the logic is inverted -- these + * functions return EPERM on "success" and 0 on "failure". + * + * MPSAFE + */ +int +securelevel_gt(struct ucred *cr, int level) +{ + int active_securelevel; + + active_securelevel = securelevel; + KASSERT(cr != NULL, ("securelevel_gt: null cr")); + if (cr->cr_prison != NULL) { + mtx_lock(&cr->cr_prison->pr_mtx); + active_securelevel = imax(cr->cr_prison->pr_securelevel, + active_securelevel); + mtx_unlock(&cr->cr_prison->pr_mtx); + } + return (active_securelevel > level ? EPERM : 0); +} + +int +securelevel_ge(struct ucred *cr, int level) +{ + int active_securelevel; + + active_securelevel = securelevel; + KASSERT(cr != NULL, ("securelevel_ge: null cr")); + if (cr->cr_prison != NULL) { + mtx_lock(&cr->cr_prison->pr_mtx); + active_securelevel = imax(cr->cr_prison->pr_securelevel, + active_securelevel); + mtx_unlock(&cr->cr_prison->pr_mtx); + } + return (active_securelevel >= level ? EPERM : 0); +} + +/* + * 'see_other_uids' determines whether or not visibility of processes + * and sockets with credentials holding different real uids is possible + * using a variety of system MIBs. + * XXX: data declarations should be together near the beginning of the file. + */ +static int see_other_uids = 1; +SYSCTL_INT(_security_bsd, OID_AUTO, see_other_uids, CTLFLAG_RW, + &see_other_uids, 0, + "Unprivileged processes may see subjects/objects with different real uid"); + +/*- + * Determine if u1 "can see" the subject specified by u2, according to the + * 'see_other_uids' policy. + * Returns: 0 for permitted, ESRCH otherwise + * Locks: none + * References: *u1 and *u2 must not change during the call + * u1 may equal u2, in which case only one reference is required + */ +static int +cr_seeotheruids(struct ucred *u1, struct ucred *u2) +{ + + if (!see_other_uids && u1->cr_ruid != u2->cr_ruid) { + if (suser_cred(u1, PRISON_ROOT) != 0) + return (ESRCH); + } + return (0); +} + +/*- + * Determine if u1 "can see" the subject specified by u2. + * Returns: 0 for permitted, an errno value otherwise + * Locks: none + * References: *u1 and *u2 must not change during the call + * u1 may equal u2, in which case only one reference is required + */ +int +cr_cansee(struct ucred *u1, struct ucred *u2) +{ + int error; + + if ((error = prison_check(u1, u2))) + return (error); + if ((error = cr_seeotheruids(u1, u2))) + return (error); + return (0); +} + +/*- + * Determine if td "can see" the subject specified by p. + * Returns: 0 for permitted, an errno value otherwise + * Locks: Sufficient locks to protect p->p_ucred must be held. td really + * should be curthread. + * References: td and p must be valid for the lifetime of the call + */ +int +p_cansee(struct thread *td, struct proc *p) +{ + + /* Wrap cr_cansee() for all functionality. */ + KASSERT(td == curthread, ("%s: td not curthread", __func__)); + PROC_LOCK_ASSERT(p, MA_OWNED); + return (cr_cansee(td->td_ucred, p->p_ucred)); +} + +/*- + * Determine whether cred may deliver the specified signal to proc. + * Returns: 0 for permitted, an errno value otherwise. + * Locks: A lock must be held for proc. + * References: cred and proc must be valid for the lifetime of the call. + */ +int +cr_cansignal(struct ucred *cred, struct proc *proc, int signum) +{ + int error; + + PROC_LOCK_ASSERT(proc, MA_OWNED); + /* + * Jail semantics limit the scope of signalling to proc in the + * same jail as cred, if cred is in jail. + */ + error = prison_check(cred, proc->p_ucred); + if (error) + return (error); + error = cr_seeotheruids(cred, proc->p_ucred); + if (error) + return (error); + + /* + * UNIX signal semantics depend on the status of the P_SUGID + * bit on the target process. If the bit is set, then additional + * restrictions are placed on the set of available signals. + */ + if (proc->p_flag & P_SUGID) { + switch (signum) { + case 0: + case SIGKILL: + case SIGINT: + case SIGTERM: + case SIGSTOP: + case SIGTTIN: + case SIGTTOU: + case SIGTSTP: + case SIGHUP: + case SIGUSR1: + case SIGUSR2: + /* + * Generally, permit job and terminal control + * signals. + */ + break; + default: + /* Not permitted without privilege. */ + error = suser_cred(cred, PRISON_ROOT); + if (error) + return (error); + } + } + + /* + * Generally, the target credential's ruid or svuid must match the + * subject credential's ruid or euid. + */ + if (cred->cr_ruid != proc->p_ucred->cr_ruid && + cred->cr_ruid != proc->p_ucred->cr_svuid && + cred->cr_uid != proc->p_ucred->cr_ruid && + cred->cr_uid != proc->p_ucred->cr_svuid) { + /* Not permitted without privilege. */ + error = suser_cred(cred, PRISON_ROOT); + if (error) + return (error); + } + + return (0); +} + + +/*- + * Determine whether td may deliver the specified signal to p. + * Returns: 0 for permitted, an errno value otherwise + * Locks: Sufficient locks to protect various components of td and p + * must be held. td must be curthread, and a lock must be + * held for p. + * References: td and p must be valid for the lifetime of the call + */ +int +p_cansignal(struct thread *td, struct proc *p, int signum) +{ + + KASSERT(td == curthread, ("%s: td not curthread", __func__)); + PROC_LOCK_ASSERT(p, MA_OWNED); + if (td->td_proc == p) + return (0); + + /* + * UNIX signalling semantics require that processes in the same + * session always be able to deliver SIGCONT to one another, + * overriding the remaining protections. + */ + /* XXX: This will require an additional lock of some sort. */ + if (signum == SIGCONT && td->td_proc->p_session == p->p_session) + return (0); + + return (cr_cansignal(td->td_ucred, p, signum)); +} + +/*- + * Determine whether td may reschedule p. + * Returns: 0 for permitted, an errno value otherwise + * Locks: Sufficient locks to protect various components of td and p + * must be held. td must be curthread, and a lock must + * be held for p. + * References: td and p must be valid for the lifetime of the call + */ +int +p_cansched(struct thread *td, struct proc *p) +{ + int error; + + KASSERT(td == curthread, ("%s: td not curthread", __func__)); + PROC_LOCK_ASSERT(p, MA_OWNED); + if (td->td_proc == p) + return (0); + if ((error = prison_check(td->td_ucred, p->p_ucred))) + return (error); + if ((error = cr_seeotheruids(td->td_ucred, p->p_ucred))) + return (error); + if (td->td_ucred->cr_ruid == p->p_ucred->cr_ruid) + return (0); + if (td->td_ucred->cr_uid == p->p_ucred->cr_ruid) + return (0); + if (suser_cred(td->td_ucred, PRISON_ROOT) == 0) + return (0); + +#ifdef CAPABILITIES + if (!cap_check(NULL, td, CAP_SYS_NICE, PRISON_ROOT)) + return (0); +#endif + + return (EPERM); +} + +/* + * The 'unprivileged_proc_debug' flag may be used to disable a variety of + * unprivileged inter-process debugging services, including some procfs + * functionality, ptrace(), and ktrace(). In the past, inter-process + * debugging has been involved in a variety of security problems, and sites + * not requiring the service might choose to disable it when hardening + * systems. + * + * XXX: Should modifying and reading this variable require locking? + * XXX: data declarations should be together near the beginning of the file. + */ +static int unprivileged_proc_debug = 1; +SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_proc_debug, CTLFLAG_RW, + &unprivileged_proc_debug, 0, + "Unprivileged processes may use process debugging facilities"); + +/*- + * Determine whether td may debug p. + * Returns: 0 for permitted, an errno value otherwise + * Locks: Sufficient locks to protect various components of td and p + * must be held. td must be curthread, and a lock must + * be held for p. + * References: td and p must be valid for the lifetime of the call + */ +int +p_candebug(struct thread *td, struct proc *p) +{ + int credentialchanged, error, grpsubset, i, uidsubset; + + KASSERT(td == curthread, ("%s: td not curthread", __func__)); + PROC_LOCK_ASSERT(p, MA_OWNED); + if (!unprivileged_proc_debug) { + error = suser_cred(td->td_ucred, PRISON_ROOT); + if (error) + return (error); + } + if (td->td_proc == p) + return (0); + if ((error = prison_check(td->td_ucred, p->p_ucred))) + return (error); + if ((error = cr_seeotheruids(td->td_ucred, p->p_ucred))) + return (error); + + /* + * Is p's group set a subset of td's effective group set? This + * includes p's egid, group access list, rgid, and svgid. + */ + grpsubset = 1; + for (i = 0; i < p->p_ucred->cr_ngroups; i++) { + if (!groupmember(p->p_ucred->cr_groups[i], td->td_ucred)) { + grpsubset = 0; + break; + } + } + grpsubset = grpsubset && + groupmember(p->p_ucred->cr_rgid, td->td_ucred) && + groupmember(p->p_ucred->cr_svgid, td->td_ucred); + + /* + * Are the uids present in p's credential equal to td's + * effective uid? This includes p's euid, svuid, and ruid. + */ + uidsubset = (td->td_ucred->cr_uid == p->p_ucred->cr_uid && + td->td_ucred->cr_uid == p->p_ucred->cr_svuid && + td->td_ucred->cr_uid == p->p_ucred->cr_ruid); + + /* + * Has the credential of the process changed since the last exec()? + */ + credentialchanged = (p->p_flag & P_SUGID); + + /* + * If p's gids aren't a subset, or the uids aren't a subset, + * or the credential has changed, require appropriate privilege + * for td to debug p. For POSIX.1e capabilities, this will + * require CAP_SYS_PTRACE. + */ + if (!grpsubset || !uidsubset || credentialchanged) { + error = suser_cred(td->td_ucred, PRISON_ROOT); + if (error) + return (error); + } + + /* Can't trace init when securelevel > 0. */ + if (p == initproc) { + error = securelevel_gt(td->td_ucred, 0); + if (error) + return (error); + } + + /* + * Can't trace a process that's currently exec'ing. + * XXX: Note, this is not a security policy decision, it's a + * basic correctness/functionality decision. Therefore, this check + * should be moved to the caller's of p_candebug(). + */ + if ((p->p_flag & P_INEXEC) != 0) + return (EAGAIN); + + return (0); +} + +/*- + * Determine whether the subject represented by cred can "see" a socket. + * Returns: 0 for permitted, ENOENT otherwise. + */ +int +cr_canseesocket(struct ucred *cred, struct socket *so) +{ + int error; + + error = prison_check(cred, so->so_cred); + if (error) + return (ENOENT); + if (cr_seeotheruids(cred, so->so_cred)) + return (ENOENT); +#ifdef MAC + /* XXX: error = mac_cred_check_seesocket() here. */ +#endif + + return (0); +} + +/* + * Allocate a zeroed cred structure. + */ +struct ucred * +crget(void) +{ + register struct ucred *cr; + + MALLOC(cr, struct ucred *, sizeof(*cr), M_CRED, M_WAITOK | M_ZERO); + cr->cr_ref = 1; + cr->cr_mtxp = mtx_pool_find(cr); + return (cr); +} + +/* + * Claim another reference to a ucred structure. + */ +struct ucred * +crhold(struct ucred *cr) +{ + + mtx_lock(cr->cr_mtxp); + cr->cr_ref++; + mtx_unlock(cr->cr_mtxp); + return (cr); +} + +/* + * Free a cred structure. + * Throws away space when ref count gets to 0. + */ +void +crfree(struct ucred *cr) +{ + struct mtx *mtxp = cr->cr_mtxp; + + mtx_lock(mtxp); + KASSERT(cr->cr_ref > 0, ("bad ucred refcount: %d", cr->cr_ref)); + if (--cr->cr_ref == 0) { + /* + * Some callers of crget(), such as nfs_statfs(), + * allocate a temporary credential, but don't + * allocate a uidinfo structure. + */ + mtx_unlock(mtxp); + mtx_lock(&Giant); + if (cr->cr_uidinfo != NULL) + uifree(cr->cr_uidinfo); + if (cr->cr_ruidinfo != NULL) + uifree(cr->cr_ruidinfo); + /* + * Free a prison, if any. + */ + if (jailed(cr)) + prison_free(cr->cr_prison); + FREE((caddr_t)cr, M_CRED); + mtx_unlock(&Giant); + } else { + mtx_unlock(mtxp); + } +} + +/* + * Check to see if this ucred is shared. + */ +int +crshared(struct ucred *cr) +{ + int shared; + + mtx_lock(cr->cr_mtxp); + shared = (cr->cr_ref > 1); + mtx_unlock(cr->cr_mtxp); + return (shared); +} + +/* + * Copy a ucred's contents from a template. Does not block. + */ +void +crcopy(struct ucred *dest, struct ucred *src) +{ + + KASSERT(crshared(dest) == 0, ("crcopy of shared ucred")); + bcopy(&src->cr_startcopy, &dest->cr_startcopy, + (unsigned)((caddr_t)&src->cr_endcopy - + (caddr_t)&src->cr_startcopy)); + uihold(dest->cr_uidinfo); + uihold(dest->cr_ruidinfo); + if (jailed(dest)) + prison_hold(dest->cr_prison); +} + +/* + * Dup cred struct to a new held one. + */ +struct ucred * +crdup(struct ucred *cr) +{ + struct ucred *newcr; + + newcr = crget(); + crcopy(newcr, cr); + return (newcr); +} + +/* + * Fill in a struct xucred based on a struct ucred. + */ +void +cru2x(struct ucred *cr, struct xucred *xcr) +{ + + bzero(xcr, sizeof(*xcr)); + xcr->cr_version = XUCRED_VERSION; + xcr->cr_uid = cr->cr_uid; + xcr->cr_ngroups = cr->cr_ngroups; + bcopy(cr->cr_groups, xcr->cr_groups, sizeof(cr->cr_groups)); +} + +/* + * small routine to swap a thread's current ucred for the correct one + * taken from the process. + */ +void +cred_update_thread(struct thread *td) +{ + struct proc *p; + struct ucred *cred; + + p = td->td_proc; + cred = td->td_ucred; + mtx_lock(&Giant); + PROC_LOCK(p); + td->td_ucred = crhold(p->p_ucred); + PROC_UNLOCK(p); + if (cred != NULL) + crfree(cred); + mtx_unlock(&Giant); +} + +/* + * Get login name, if available. + */ +#ifndef _SYS_SYSPROTO_H_ +struct getlogin_args { + char *namebuf; + u_int namelen; +}; +#endif +/* + * MPSAFE + */ +/* ARGSUSED */ +int +getlogin(struct thread *td, struct getlogin_args *uap) +{ + int error; + char login[MAXLOGNAME]; + struct proc *p = td->td_proc; + + if (uap->namelen > MAXLOGNAME) + uap->namelen = MAXLOGNAME; + PROC_LOCK(p); + SESS_LOCK(p->p_session); + bcopy(p->p_session->s_login, login, uap->namelen); + SESS_UNLOCK(p->p_session); + PROC_UNLOCK(p); + error = copyout((caddr_t) login, (caddr_t) uap->namebuf, uap->namelen); + return(error); +} + +/* + * Set login name. + */ +#ifndef _SYS_SYSPROTO_H_ +struct setlogin_args { + char *namebuf; +}; +#endif +/* + * MPSAFE + */ +/* ARGSUSED */ +int +setlogin(struct thread *td, struct setlogin_args *uap) +{ + struct proc *p = td->td_proc; + int error; + char logintmp[MAXLOGNAME]; + + error = suser_cred(td->td_ucred, PRISON_ROOT); + if (error) + return (error); + error = copyinstr((caddr_t) uap->namebuf, (caddr_t) logintmp, + sizeof(logintmp), (size_t *)0); + if (error == ENAMETOOLONG) + error = EINVAL; + else if (!error) { + PROC_LOCK(p); + SESS_LOCK(p->p_session); + (void) memcpy(p->p_session->s_login, logintmp, + sizeof(logintmp)); + SESS_UNLOCK(p->p_session); + PROC_UNLOCK(p); + } + return (error); +} + +void +setsugid(struct proc *p) +{ + + PROC_LOCK_ASSERT(p, MA_OWNED); + p->p_flag |= P_SUGID; + if (!(p->p_pfsflags & PF_ISUGID)) + p->p_stops = 0; +} + +/*- + * Change a process's effective uid. + * Side effects: newcred->cr_uid and newcred->cr_uidinfo will be modified. + * References: newcred must be an exclusive credential reference for the + * duration of the call. + */ +void +change_euid(struct ucred *newcred, struct uidinfo *euip) +{ + + newcred->cr_uid = euip->ui_uid; + uihold(euip); + uifree(newcred->cr_uidinfo); + newcred->cr_uidinfo = euip; +} + +/*- + * Change a process's effective gid. + * Side effects: newcred->cr_gid will be modified. + * References: newcred must be an exclusive credential reference for the + * duration of the call. + */ +void +change_egid(struct ucred *newcred, gid_t egid) +{ + + newcred->cr_groups[0] = egid; +} + +/*- + * Change a process's real uid. + * Side effects: newcred->cr_ruid will be updated, newcred->cr_ruidinfo + * will be updated, and the old and new cr_ruidinfo proc + * counts will be updated. + * References: newcred must be an exclusive credential reference for the + * duration of the call. + */ +void +change_ruid(struct ucred *newcred, struct uidinfo *ruip) +{ + + (void)chgproccnt(newcred->cr_ruidinfo, -1, 0); + newcred->cr_ruid = ruip->ui_uid; + uihold(ruip); + uifree(newcred->cr_ruidinfo); + newcred->cr_ruidinfo = ruip; + (void)chgproccnt(newcred->cr_ruidinfo, 1, 0); +} + +/*- + * Change a process's real gid. + * Side effects: newcred->cr_rgid will be updated. + * References: newcred must be an exclusive credential reference for the + * duration of the call. + */ +void +change_rgid(struct ucred *newcred, gid_t rgid) +{ + + newcred->cr_rgid = rgid; +} + +/*- + * Change a process's saved uid. + * Side effects: newcred->cr_svuid will be updated. + * References: newcred must be an exclusive credential reference for the + * duration of the call. + */ +void +change_svuid(struct ucred *newcred, uid_t svuid) +{ + + newcred->cr_svuid = svuid; +} + +/*- + * Change a process's saved gid. + * Side effects: newcred->cr_svgid will be updated. + * References: newcred must be an exclusive credential reference for the + * duration of the call. + */ +void +change_svgid(struct ucred *newcred, gid_t svgid) +{ + + newcred->cr_svgid = svgid; +} |
