Implement setresuid(2), getresuid(2), setresgid(2), getresgid(2), based

partly on the Linux emul code and FreeBSD versions.
We need these for Linux, FreeBSD, and HP-UX emulation.
Also change sys_setreuid() and sys_setregid() to use uid_t and gid_t
respectively.

2 files changed, 218 insertions, 4 deletions

diff --git a/sys/kern/kern_prot.c b/sys/kern/kern_prot.c
index 45ddf7f7c31..69b0fc2d62e 100644
--- a/sys/kern/kern_prot.c
+++ b/sys/kern/kern_prot.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_prot.c,v 1.21 2002/10/15 01:27:31 nordin Exp $	*/
+/*	$OpenBSD: kern_prot.c,v 1.22 2002/10/30 20:02:58 millert Exp $	*/
 /*	$NetBSD: kern_prot.c,v 1.33 1996/02/09 18:59:42 christos Exp $	*/
 
 /*
@@ -326,6 +326,212 @@ sys_setpgid(curp, v, retval)
 
 /* ARGSUSED */
 int
+sys_getresuid(p, v, retval)
+	struct proc *p;
+	void *v;
+	register_t *retval;
+{
+	struct sys_getresuid_args /* {
+		syscallarg(uid_t *) ruid;
+		syscallarg(uid_t *) euid;
+		syscallarg(uid_t *) suid;
+	} */ *uap = v;
+	struct pcred *pc = p->p_cred;
+	uid_t *ruid, *euid, *suid;
+	int error1 = 0, error2 = 0, error3 = 0;
+
+	ruid = SCARG(uap, ruid);
+	euid = SCARG(uap, euid);
+	suid = SCARG(uap, suid);
+
+	if (ruid != NULL)
+		error1 = copyout(&pc->p_ruid, ruid, sizeof(*ruid));
+	if (euid != NULL)
+		error2 = copyout(&pc->pc_ucred->cr_uid, euid, sizeof(*euid));
+	if (suid != NULL)
+		error3 = copyout(&pc->p_svuid, suid, sizeof(*suid));
+
+	return (error1 ? error1 : error2 ? error2 : error3);
+}
+
+/* ARGSUSED */
+int
+sys_setresuid(p, v, retval)
+	struct proc *p;
+	void *v;
+	register_t *retval;
+{
+	struct sys_setresuid_args /* {
+		syscallarg(uid_t) ruid;
+		syscallarg(uid_t) euid;
+		syscallarg(uid_t) suid;
+	} */ *uap = v;
+	struct pcred *pc = p->p_cred;
+	uid_t ruid, euid, suid;
+	int error;
+
+	ruid = SCARG(uap, ruid);
+	euid = SCARG(uap, euid);
+	suid = SCARG(uap, suid);
+
+	if ((ruid == -1 || ruid == pc->p_ruid) &&
+	    (euid == -1 || euid == pc->pc_ucred->cr_uid) &&
+	    (suid == -1 || suid == pc->p_svuid))
+		return (0);			/* no change */
+
+	/*
+	 * Any of the real, effective, and saved uids may be changed
+	 * to the current value of one of the three (root is not limited).
+	 */
+	if (ruid != (uid_t)-1 &&
+	    ruid != pc->p_ruid &&
+	    ruid != pc->pc_ucred->cr_uid &&
+	    ruid != pc->p_svuid &&
+	    (error = suser(pc->pc_ucred, &p->p_acflag)))
+		return (error);
+
+	if (euid != (uid_t)-1 &&
+	    euid != pc->p_ruid &&
+	    euid != pc->pc_ucred->cr_uid &&
+	    euid != pc->p_svuid &&
+	    (error = suser(pc->pc_ucred, &p->p_acflag)))
+		return (error);
+
+	if (suid != (uid_t)-1 &&
+	    suid != pc->p_ruid &&
+	    suid != pc->pc_ucred->cr_uid &&
+	    suid != pc->p_svuid &&
+	    (error = suser(pc->pc_ucred, &p->p_acflag)))
+		return (error);
+
+	/*
+	 * Note that unlike the other set*uid() calls, each
+	 * uid type is set independently of the others.
+	 */
+	if (ruid != (uid_t)-1 && ruid != pc->p_ruid) {
+		/*
+		 * Transfer proc count to new user.
+		 */
+		(void)chgproccnt(pc->p_ruid, -1);
+		(void)chgproccnt(ruid, 1);
+		pc->p_ruid = ruid;
+	}
+	if (euid != (uid_t)-1 && euid != pc->pc_ucred->cr_uid) {
+		/*
+		 * Copy credentials so other references do not see our changes.
+		 */
+		pc->pc_ucred = crcopy(pc->pc_ucred);
+		pc->pc_ucred->cr_uid = euid;
+	}
+	if (suid != (uid_t)-1 && suid != pc->p_svuid)
+		pc->p_svuid = suid;
+
+	p->p_flag |= P_SUGID;
+	return (0);
+}
+
+/* ARGSUSED */
+int
+sys_getresgid(p, v, retval)
+	struct proc *p;
+	void *v;
+	register_t *retval;
+{
+	struct sys_getresgid_args /* {
+		syscallarg(gid_t *) rgid;
+		syscallarg(gid_t *) egid;
+		syscallarg(gid_t *) sgid;
+	} */ *uap = v;
+	struct pcred *pc = p->p_cred;
+	gid_t *rgid, *egid, *sgid;
+	int error1 = 0, error2 = 0, error3 = 0;
+
+	rgid = SCARG(uap, rgid);
+	egid = SCARG(uap, egid);
+	sgid = SCARG(uap, sgid);
+
+	if (rgid != NULL)
+		error1 = copyout(&pc->p_rgid, rgid, sizeof(*rgid));
+	if (egid != NULL)
+		error2 = copyout(&pc->pc_ucred->cr_gid, egid, sizeof(*egid));
+	if (sgid != NULL)
+		error3 = copyout(&pc->p_svgid, sgid, sizeof(*sgid));
+
+	return (error1 ? error1 : error2 ? error2 : error3);
+}
+
+/* ARGSUSED */
+int
+sys_setresgid(p, v, retval)
+	struct proc *p;
+	void *v;
+	register_t *retval;
+{
+	struct sys_setresgid_args /* {
+		syscallarg(gid_t) rgid;
+		syscallarg(gid_t) egid;
+		syscallarg(gid_t) sgid;
+	} */ *uap = v;
+	struct pcred *pc = p->p_cred;
+	gid_t rgid, egid, sgid;
+	int error;
+
+	rgid = SCARG(uap, rgid);
+	egid = SCARG(uap, egid);
+	sgid = SCARG(uap, sgid);
+
+	if ((rgid == -1 || rgid == pc->p_rgid) &&
+	    (egid == -1 || egid == pc->pc_ucred->cr_gid) &&
+	    (sgid == -1 || sgid == pc->p_svgid))
+		return (0);			/* no change */
+
+	/*
+	 * Any of the real, effective, and saved gids may be changed
+	 * to the current value of one of the three (root is not limited).
+	 */
+	if (rgid != (gid_t)-1 &&
+	    rgid != pc->p_rgid &&
+	    rgid != pc->pc_ucred->cr_gid &&
+	    rgid != pc->p_svgid &&
+	    (error = suser(pc->pc_ucred, &p->p_acflag)))
+		return (error);
+
+	if (egid != (gid_t)-1 &&
+	    egid != pc->p_rgid &&
+	    egid != pc->pc_ucred->cr_gid &&
+	    egid != pc->p_svgid &&
+	    (error = suser(pc->pc_ucred, &p->p_acflag)))
+		return (error);
+
+	if (sgid != (gid_t)-1 &&
+	    sgid != pc->p_rgid &&
+	    sgid != pc->pc_ucred->cr_gid &&
+	    sgid != pc->p_svgid &&
+	    (error = suser(pc->pc_ucred, &p->p_acflag)))
+		return (error);
+
+	/*
+	 * Note that unlike the other set*gid() calls, each
+	 * gid type is set independently of the others.
+	 */
+	if (rgid != (gid_t)-1)
+		pc->p_rgid = rgid;
+	if (egid != (gid_t)-1) {
+		/*
+		 * Copy credentials so other references do not see our changes.
+		 */
+		pc->pc_ucred = crcopy(pc->pc_ucred);
+		pc->pc_ucred->cr_gid = egid;
+	}
+	if (sgid != (gid_t)-1)
+		pc->p_svgid = sgid;
+
+	p->p_flag |= P_SUGID;
+	return (0);
+}
+
+/* ARGSUSED */
+int
 sys_setuid(p, v, retval)
 	struct proc *p;
 	void *v;
diff --git a/sys/kern/syscalls.master b/sys/kern/syscalls.master
index 8cc3c18b4df..4fd3d529f45 100644
--- a/sys/kern/syscalls.master
+++ b/sys/kern/syscalls.master
@@ -1,4 +1,4 @@
-;	$OpenBSD: syscalls.master,v 1.50 2002/07/06 19:14:20 nordin Exp $
+;	$OpenBSD: syscalls.master,v 1.51 2002/10/30 20:02:58 millert Exp $
 ;	$NetBSD: syscalls.master,v 1.32 1996/04/23 10:24:21 mycroft Exp $
 
 ;	@(#)syscalls.master	8.2 (Berkeley) 1/13/94
@@ -238,8 +238,8 @@
 125	COMPAT_43	{ int sys_recvfrom(int s, caddr_t buf, size_t len, \
 			    int flags, caddr_t from, int *fromlenaddr); } \
 			    orecvfrom
-126	COMPAT_43	{ int sys_setreuid(int ruid, int euid); } osetreuid
-127	COMPAT_43	{ int sys_setregid(int rgid, int egid); } osetregid
+126	COMPAT_43	{ int sys_setreuid(uid_t ruid, uid_t euid); } osetreuid
+127	COMPAT_43	{ int sys_setregid(gid_t rgid, gid_t egid); } osetregid
 128	STD		{ int sys_rename(const char *from, const char *to); }
 129	COMPAT_43	{ int sys_truncate(const char *path, long length); } \
 			    otruncate
@@ -562,3 +562,11 @@
 279	UNIMPL		sys_extattr_get_fd
 280	UNIMPL		sys_extattr_delete_fd
 #endif
+281	STD		{ int sys_getresuid(uid_t *ruid, uid_t *euid, \
+			    uid_t *suid); }
+282	STD		{ int sys_setresuid(uid_t ruid, uid_t euid, \
+			    uid_t suid); }
+283	STD		{ int sys_getresgid(gid_t *rgid, gid_t *egid, \
+			    gid_t *sgid); }
+284	STD		{ int sys_setresgid(gid_t rgid, gid_t egid, \
+			    gid_t sgid); }