SELinux: Add a network node caching mechanism similar to the sel_neti…

…f_*() functions

This patch adds a SELinux IP address/node SID caching mechanism similar to the
sel_netif_*() functions.  The node SID queries in the SELinux hooks files are
also modified to take advantage of this new functionality.  In addition, remove
the address length information from the sk_buff parsing routines as it is
redundant since we already have the address family.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>

security/selinux/Makefile

@@ -4,7 +4,14 @@
 
 obj-$(CONFIG_SECURITY_SELINUX) := selinux.o ss/
 
-selinux-y := avc.o hooks.o selinuxfs.o netlink.o nlmsgtab.o netif.o exports.o
+selinux-y := avc.o \
+	     hooks.o \
+	     selinuxfs.o \
+	     netlink.o \
+	     nlmsgtab.o \
+	     netif.o \
+	     netnode.o \
+	     exports.o
 
 selinux-$(CONFIG_SECURITY_NETWORK_XFRM) += xfrm.o
 

security/selinux/hooks.c

@@ -76,6 +76,7 @@
 #include "avc.h"
 #include "objsec.h"
 #include "netif.h"
+#include "netnode.h"
 #include "xfrm.h"
 #include "netlabel.h"
 
@@ -3395,7 +3396,7 @@ static int selinux_parse_skb_ipv6(struct sk_buff *skb,
 #endif /* IPV6 */
 
 static int selinux_parse_skb(struct sk_buff *skb, struct avc_audit_data *ad,
-			     char **addrp, int *len, int src, u8 *proto)
+			     char **addrp, int src, u8 *proto)
 {
 	int ret = 0;
 
@@ -3404,7 +3405,6 @@ static int selinux_parse_skb(struct sk_buff *skb, struct avc_audit_data *ad,
 		ret = selinux_parse_skb_ipv4(skb, ad, proto);
 		if (ret || !addrp)
 			break;
-		*len = 4;
 		*addrp = (char *)(src ? &ad->u.net.v4info.saddr :
 					&ad->u.net.v4info.daddr);
 		break;
@@ -3414,7 +3414,6 @@ static int selinux_parse_skb(struct sk_buff *skb, struct avc_audit_data *ad,
 		ret = selinux_parse_skb_ipv6(skb, ad, proto);
 		if (ret || !addrp)
 			break;
-		*len = 16;
 		*addrp = (char *)(src ? &ad->u.net.v6info.saddr :
 					&ad->u.net.v6info.daddr);
 		break;
@@ -3614,7 +3613,7 @@ static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, in
 			break;
 		}
 
-		err = security_node_sid(family, addrp, addrlen, &sid);
+		err = sel_netnode_sid(addrp, family, &sid);
 		if (err)
 			goto out;
 
@@ -3826,7 +3825,8 @@ static int selinux_socket_unix_may_send(struct socket *sock,
 }
 
 static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
-		struct avc_audit_data *ad, u16 family, char *addrp, int len)
+				       struct avc_audit_data *ad,
+				       u16 family, char *addrp)
 {
 	int err = 0;
 	u32 netif_perm, node_perm, node_sid, if_sid, recv_perm = 0;
@@ -3886,7 +3886,7 @@ static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
 	if (err)
 		goto out;
 
-	err = security_node_sid(family, addrp, len, &node_sid);
+	err = sel_netnode_sid(addrp, family, &node_sid);
 	if (err)
 		goto out;
 
@@ -3915,7 +3915,7 @@ static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
 {
 	u16 family;
 	char *addrp;
-	int len, err = 0;
+	int err = 0;
 	struct avc_audit_data ad;
 	struct sk_security_struct *sksec = sk->sk_security;
 
@@ -3931,13 +3931,12 @@ static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
 	ad.u.net.netif = skb->iif;
 	ad.u.net.family = family;
 
-	err = selinux_parse_skb(skb, &ad, &addrp, &len, 1, NULL);
+	err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
 	if (err)
 		goto out;
 
 	if (selinux_compat_net)
-		err = selinux_sock_rcv_skb_compat(sk, skb, &ad, family,
-						  addrp, len);
+		err = selinux_sock_rcv_skb_compat(sk, skb, &ad, family, addrp);
 	else
 		err = avc_has_perm(sksec->sid, skb->secmark, SECCLASS_PACKET,
 				   PACKET__RECV, &ad);
@@ -4158,9 +4157,11 @@ static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
 
 #ifdef CONFIG_NETFILTER
 
-static int selinux_ip_postroute_last_compat(struct sock *sk, struct net_device *dev,
+static int selinux_ip_postroute_last_compat(struct sock *sk,
+					    struct net_device *dev,
 					    struct avc_audit_data *ad,
-					    u16 family, char *addrp, int len)
+					    u16 family,
+					    char *addrp)
 {
 	int err = 0;
 	u32 netif_perm, node_perm, node_sid, if_sid, send_perm = 0;
@@ -4211,7 +4212,7 @@ static int selinux_ip_postroute_last_compat(struct sock *sk, struct net_device *
 	if (err)
 		goto out;
 
-	err = security_node_sid(family, addrp, len, &node_sid);
+	err = sel_netnode_sid(addrp, family, &node_sid);
 	if (err)
 		goto out;
 
@@ -4245,7 +4246,7 @@ static unsigned int selinux_ip_postroute_last(unsigned int hooknum,
                                               u16 family)
 {
 	char *addrp;
-	int len, err = 0;
+	int err = 0;
 	struct sock *sk;
 	struct avc_audit_data ad;
 	struct net_device *dev = (struct net_device *)out;
@@ -4262,13 +4263,13 @@ static unsigned int selinux_ip_postroute_last(unsigned int hooknum,
 	ad.u.net.netif = dev->ifindex;
 	ad.u.net.family = family;
 
-	err = selinux_parse_skb(skb, &ad, &addrp, &len, 0, &proto);
+	err = selinux_parse_skb(skb, &ad, &addrp, 0, &proto);
 	if (err)
 		goto out;
 
 	if (selinux_compat_net)
 		err = selinux_ip_postroute_last_compat(sk, dev, &ad,
-						       family, addrp, len);
+						       family, addrp);
 	else
 		err = avc_has_perm(sksec->sid, skb->secmark, SECCLASS_PACKET,
 				   PACKET__SEND, &ad);

security/selinux/include/netnode.h

@@ -0,0 +1,32 @@
+/*
+ * Network node table
+ *
+ * SELinux must keep a mapping of network nodes to labels/SIDs.  This
+ * mapping is maintained as part of the normal policy but a fast cache is
+ * needed to reduce the lookup overhead since most of these queries happen on
+ * a per-packet basis.
+ *
+ * Author: Paul Moore <paul.moore@hp.com>
+ *
+ */
+
+/*
+ * (c) Copyright Hewlett-Packard Development Company, L.P., 2007
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef _SELINUX_NETNODE_H
+#define _SELINUX_NETNODE_H
+
+int sel_netnode_sid(void *addr, u16 family, u32 *sid);
+
+#endif

security/selinux/include/objsec.h

@@ -100,6 +100,15 @@ struct netif_security_struct {
 	u32 sid;			/* SID for this interface */
 };
 
+struct netnode_security_struct {
+	union {
+		__be32 ipv4;		/* IPv4 node address */
+		struct in6_addr ipv6;	/* IPv6 node address */
+	} addr;
+	u32 sid;			/* SID for this node */
+	u16 family;			/* address family */
+};
+
 struct sk_security_struct {
 	struct sock *sk;		/* back pointer to sk object */
 	u32 sid;			/* SID of this object */