Remove the suser(9) interface from the kernel. It has been replaced from

years by the priv_check(9) interface and just very few places are left.
Note that compatibility stub with older FreeBSD version
(all above the 8 limit though) are left in order to reduce diffs against
old versions. It is responsibility of the maintainers for any module, if
they think it is the case, to axe out such cases.

This patch breaks KPI so __FreeBSD_version will be bumped into a later
commit.

This patch needs to be credited 50-50 with rwatson@ as he found time to
explain me how the priv_check() works in detail and to review patches.

Tested by:      Giovanni Trematerra <giovanni dot trematerra at gmail dot com>
Reviewed by:    rwatson

6 files changed, 41 insertions, 43 deletions

diff --git a/sys/dev/cxgb/ulp/tom/cxgb_cpl_io.c b/sys/dev/cxgb/ulp/tom/cxgb_cpl_io.c
index 952a05b..b12c367 100644
--- a/sys/dev/cxgb/ulp/tom/cxgb_cpl_io.c
+++ b/sys/dev/cxgb/ulp/tom/cxgb_cpl_io.c
@@ -1663,8 +1663,8 @@ t3_ip_ctloutput(struct socket *so, struct sockopt *sopt)
 	if (error)
 		return (error);
 
-	if (optval > IPTOS_PREC_CRITIC_ECP && !suser(curthread))
-		return (EPERM);
+	if (optval > IPTOS_PREC_CRITIC_ECP)
+		return (EINVAL);
 
 	inp = so_sotoinpcb(so);
 	inp_wlock(inp);
diff --git a/sys/kern/kern_priv.c b/sys/kern/kern_priv.c
index 87cce77..100f6d4 100644
--- a/sys/kern/kern_priv.c
+++ b/sys/kern/kern_priv.c
@@ -133,24 +133,3 @@ priv_check(struct thread *td, int priv)
 
 	return (priv_check_cred(td->td_ucred, priv, 0));
 }
-
-/*
- * Historical suser() wrapper functions, which now simply request PRIV_ROOT.
- * These will be removed in the near future, and exist solely because
- * the kernel and modules are not yet fully adapted to the new model.
- */
-int
-suser_cred(struct ucred *cred, int flags)
-{
-
-	return (priv_check_cred(cred, PRIV_ROOT, flags));
-}
-
-int
-suser(struct thread *td)
-{
-
-	KASSERT(td == curthread, ("suser: td != curthread"));
-
-	return (suser_cred(td->td_ucred, 0));
-}
diff --git a/sys/netipx/ipx.c b/sys/netipx/ipx.c
index 5ae0d4b..5761636 100644
--- a/sys/netipx/ipx.c
+++ b/sys/netipx/ipx.c
@@ -99,7 +99,7 @@ ipx_control(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
 	struct ifaddr *ifa;
 	struct ipx_ifaddr *oia;
 	int dstIsNew, hostIsNew;
-	int error = 0;
+	int error = 0, priv;
 
 	/*
 	 * Find address for this interface, if it exists.
@@ -135,12 +135,13 @@ ipx_control(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
 		return (0);
 	}
 
-	if (td && (error = suser(td)) != 0)
-		return (error);
-
 	switch (cmd) {
 	case SIOCAIFADDR:
 	case SIOCDIFADDR:
+		priv = (cmd == SIOCAIFADDR) ? PRIV_NET_ADDIFADDR :
+		    PRIV_NET_DELIFADDR;
+		if (td && (error = priv_check(td, priv)) != 0)
+			return (error);
 		if (ifra->ifra_addr.sipx_family == AF_IPX)
 		    for (oia = ia; ia != NULL; ia = ia->ia_next) {
 			if (ia->ia_ifp == ifp  &&
@@ -154,6 +155,8 @@ ipx_control(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
 
 	case SIOCSIFADDR:
 	case SIOCSIFDSTADDR:
+		if (td && (error = priv_check(td, PRIV_NET_SETLLADDR)) != 0)
+			return (error);
 		if (ia == NULL) {
 			oia = (struct ipx_ifaddr *)
 				malloc(sizeof(*ia), M_IFADDR,
@@ -183,6 +186,10 @@ ipx_control(struct socket *so, u_long cmd, caddr_t data, struct ifnet *ifp,
 				ia->ia_broadaddr.sipx_addr.x_host = ipx_broadhost;
 			}
 		}
+		break;
+	default:
+		if (td && (error = priv_check(td, PRIV_NET_HWIOCTL)) != 0)
+			return (error);
 	}
 
 	switch (cmd) {
diff --git a/sys/nfsserver/nfs_serv.c b/sys/nfsserver/nfs_serv.c
index 15c6624..901a4bd 100644
--- a/sys/nfsserver/nfs_serv.c
+++ b/sys/nfsserver/nfs_serv.c
@@ -1802,7 +1802,8 @@ nfsrv_create(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
 			if (vap->va_type == VCHR && rdev == 0xffffffff)
 				vap->va_type = VFIFO;
                         if (vap->va_type != VFIFO &&
-                            (error = suser_cred(cred, 0))) {
+			    (error = priv_check_cred(cred, PRIV_VFS_MKNOD_DEV,
+			    0))) {
 				goto ereply;
                         }
 			vap->va_rdev = rdev;
@@ -2024,7 +2025,8 @@ nfsrv_mknod(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
 		if (error)
 			NDFREE(&nd, NDF_ONLY_PNBUF);
 	} else {
-		if (vtyp != VFIFO && (error = suser_cred(cred, 0)))
+		if (vtyp != VFIFO && (error = priv_check_cred(cred,
+		    PRIV_VFS_MKNOD_DEV, 0)))
 			goto out;
 		error = VOP_MKNOD(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, vap);
 		if (error) {
diff --git a/sys/security/mac_bsdextended/mac_bsdextended.c b/sys/security/mac_bsdextended/mac_bsdextended.c
index cb993db..93befae 100644
--- a/sys/security/mac_bsdextended/mac_bsdextended.c
+++ b/sys/security/mac_bsdextended/mac_bsdextended.c
@@ -221,7 +221,7 @@ static int
 ugidfw_rulecheck(struct mac_bsdextended_rule *rule,
     struct ucred *cred, struct vnode *vp, struct vattr *vap, int acc_mode)
 {
-	int match;
+	int mac_granted, match, priv_granted;
 	int i;
 
 	/*
@@ -372,9 +372,31 @@ ugidfw_rulecheck(struct mac_bsdextended_rule *rule,
 	}
 
 	/*
+	 * MBI_APPEND should not be here as it should get converted to
+	 * MBI_WRITE.
+	 */
+	priv_granted = 0;
+	mac_granted = rule->mbr_mode;
+	if ((acc_mode & MBI_ADMIN) && (mac_granted & MBI_ADMIN) == 0 &&
+	    priv_check_cred(cred, PRIV_VFS_ADMIN, 0) == 0)
+		priv_granted |= MBI_ADMIN;
+	if ((acc_mode & MBI_EXEC) && (mac_granted & MBI_EXEC) == 0 &&
+	    priv_check_cred(cred, (vap->va_type == VDIR) ? PRIV_VFS_LOOKUP :
+	    PRIV_VFS_EXEC, 0) == 0)
+		priv_granted |= MBI_EXEC;
+	if ((acc_mode & MBI_READ) && (mac_granted & MBI_READ) == 0 &&
+	    priv_check_cred(cred, PRIV_VFS_READ, 0) == 0)
+		priv_granted |= MBI_READ;
+	if ((acc_mode & MBI_STAT) && (mac_granted & MBI_STAT) == 0 &&
+	    priv_check_cred(cred, PRIV_VFS_STAT, 0) == 0)
+		priv_granted |= MBI_STAT;
+	if ((acc_mode & MBI_WRITE) && (mac_granted & MBI_WRITE) == 0 &&
+	    priv_check_cred(cred, PRIV_VFS_WRITE, 0) == 0)
+		priv_granted |= MBI_WRITE;
+	/*
 	 * Is the access permitted?
 	 */
-	if ((rule->mbr_mode & acc_mode) != acc_mode) {
+	if (((mac_granted | priv_granted) & acc_mode) != acc_mode) {
 		if (ugidfw_logging)
 			log(LOG_AUTHPRIV, "mac_bsdextended: %d:%d request %d"
 			    " on %d:%d failed. \n", cred->cr_ruid,
@@ -400,12 +422,6 @@ ugidfw_check(struct ucred *cred, struct vnode *vp, struct vattr *vap,
 	int error, i;
 
 	/*
-	 * XXXRW: More specific privilege selection needed.
-	 */
-	if (suser_cred(cred, 0) == 0)
-		return (0);
-
-	/*
 	 * Since we do not separately handle append, map append to write.
 	 */
 	if (acc_mode & MBI_APPEND) {
diff --git a/sys/sys/priv.h b/sys/sys/priv.h
index 4c0fdca..c56c99d 100644
--- a/sys/sys/priv.h
+++ b/sys/sys/priv.h
@@ -485,12 +485,6 @@ struct thread;
 struct ucred;
 int	priv_check(struct thread *td, int priv);
 int	priv_check_cred(struct ucred *cred, int priv, int flags);
-
-/*
- * Continue to support external modules that rely on suser(9) -- for now.
- */
-int	suser(struct thread *td);
-int	suser_cred(struct ucred *cred, int flags);
 #endif
 
 #endif /* !_SYS_PRIV_H_ */