/* $NetBSD: kern_prot.c,v 1.32 1996/02/04 02:15:57 christos 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 8.6 (Berkeley) 1/21/94 */ /* * System calls related to processes and protection */ #include #include #include #include #include #include #include #include #include #include #include /* ARGSUSED */ int sys_getpid(p, v, retval) struct proc *p; void *v; register_t *retval; { *retval = p->p_pid; #if defined(COMPAT_43) || defined(COMPAT_SUNOS) || defined(COMPAT_IBCS2) || \ defined(COMPAT_FREEBSD) retval[1] = p->p_pptr->p_pid; #endif return (0); } /* ARGSUSED */ int sys_getppid(p, v, retval) struct proc *p; void *v; register_t *retval; { *retval = p->p_pptr->p_pid; return (0); } /* Get process group ID; note that POSIX getpgrp takes no parameter */ int sys_getpgrp(p, v, retval) struct proc *p; void *v; register_t *retval; { *retval = p->p_pgrp->pg_id; return (0); } /* ARGSUSED */ int sys_getuid(p, v, retval) struct proc *p; void *v; register_t *retval; { *retval = p->p_cred->p_ruid; #if defined(COMPAT_43) || defined(COMPAT_SUNOS) || defined(COMPAT_IBCS2) || \ defined(COMPAT_FREEBSD) retval[1] = p->p_ucred->cr_uid; #endif return (0); } /* ARGSUSED */ int sys_geteuid(p, v, retval) struct proc *p; void *v; register_t *retval; { *retval = p->p_ucred->cr_uid; return (0); } /* ARGSUSED */ int sys_getgid(p, v, retval) struct proc *p; void *v; register_t *retval; { *retval = p->p_cred->p_rgid; #if defined(COMPAT_43) || defined(COMPAT_SUNOS) || defined(COMPAT_FREEBSD) retval[1] = p->p_ucred->cr_gid; #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 */ int sys_getegid(p, v, retval) struct proc *p; void *v; register_t *retval; { *retval = p->p_ucred->cr_gid; return (0); } int sys_getgroups(p, v, retval) struct proc *p; void *v; register_t *retval; { register struct sys_getgroups_args /* { syscallarg(u_int) gidsetsize; syscallarg(gid_t *) gidset; } */ *uap = v; register struct pcred *pc = p->p_cred; register u_int ngrp; int error; if ((ngrp = SCARG(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; 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(p, v, retval) register struct proc *p; void *v; register_t *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) */ /* ARGSUSED */ int sys_setpgid(curp, v, retval) struct proc *curp; void *v; register_t *retval; { register struct sys_setpgid_args /* { syscallarg(int) pid; syscallarg(int) pgid; } */ *uap = v; register struct proc *targp; /* target process */ register struct pgrp *pgrp; /* target pgrp */ #ifdef COMPAT_09 SCARG(uap, pid) = (short) SCARG(uap, pid); /* XXX */ SCARG(uap, pgid) = (short) SCARG(uap, pgid); /* XXX */ #endif if (SCARG(uap, pid) != 0 && SCARG(uap, pid) != curp->p_pid) { if ((targp = pfind(SCARG(uap, pid))) == 0 || !inferior(targp)) 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(p, v, retval) struct proc *p; void *v; register_t *retval; { struct sys_setuid_args /* { syscallarg(uid_t) uid; } */ *uap = v; register struct pcred *pc = p->p_cred; register uid_t uid; int error; #ifdef COMPAT_09 /* XXX */ uid = (u_short)SCARG(uap, uid); #else uid = SCARG(uap, uid); #endif 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 |= P_SUGID; return (0); } /* ARGSUSED */ int sys_seteuid(p, v, retval) struct proc *p; void *v; register_t *retval; { struct sys_seteuid_args /* { syscallarg(uid_t) euid; } */ *uap = v; register struct pcred *pc = p->p_cred; register uid_t euid; int error; #ifdef COMPAT_09 /* XXX */ euid = (u_short)SCARG(uap, euid); #else euid = SCARG(uap, euid); #endif 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 |= P_SUGID; return (0); } /* ARGSUSED */ int sys_setgid(p, v, retval) struct proc *p; void *v; register_t *retval; { struct sys_setgid_args /* { syscallarg(gid_t) gid; } */ *uap = v; register struct pcred *pc = p->p_cred; register gid_t gid; int error; #ifdef COMPAT_09 /* XXX */ gid = (u_short)SCARG(uap, gid); #else gid = SCARG(uap, gid); #endif 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_gid = gid; pc->p_rgid = gid; pc->p_svgid = gid; /* ??? */ p->p_flag |= P_SUGID; return (0); } /* ARGSUSED */ int sys_setegid(p, v, retval) struct proc *p; void *v; register_t *retval; { struct sys_setegid_args /* { syscallarg(gid_t) egid; } */ *uap = v; register struct pcred *pc = p->p_cred; register gid_t egid; int error; #ifdef COMPAT_09 /* XXX */ egid = (u_short)SCARG(uap, egid); #else egid = SCARG(uap, egid); #endif 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_gid = egid; p->p_flag |= P_SUGID; return (0); } /* ARGSUSED */ int sys_setgroups(p, v, retval) struct proc *p; void *v; register_t *retval; { struct sys_setgroups_args /* { syscallarg(u_int) gidsetsize; syscallarg(gid_t *) gidset; } */ *uap = v; register struct pcred *pc = p->p_cred; register u_int ngrp; int error; if ((error = suser(pc->pc_ucred, &p->p_acflag)) != 0) return (error); ngrp = SCARG(uap, gidsetsize); if (ngrp > NGROUPS) return (EINVAL); pc->pc_ucred = crcopy(pc->pc_ucred); error = copyin((caddr_t)SCARG(uap, gidset), (caddr_t)pc->pc_ucred->cr_groups, ngrp * sizeof(gid_t)); if (error) return (error); pc->pc_ucred->cr_ngroups = ngrp; p->p_flag |= P_SUGID; return (0); } /* * Check if gid is a member of the group set. */ int 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. */ 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() { 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. */ void crfree(cr) struct ucred *cr; { int s; s = splimp(); /* ??? */ if (--cr->cr_ref == 0) 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. */ /* ARGSUSED */ int sys_getlogin(p, v, retval) struct proc *p; void *v; register_t *retval; { struct sys_getlogin_args /* { syscallarg(char *) namebuf; syscallarg(u_int) namelen; } */ *uap = v; 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(p, v, retval) struct proc *p; void *v; register_t *retval; { struct sys_setlogin_args /* { syscallarg(char *) namebuf; } */ *uap = v; int error; if ((error = suser(p->p_ucred, &p->p_acflag)) != 0) return (error); error = copyinstr((caddr_t) SCARG(uap, namebuf), (caddr_t) 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); }