This defines SELinux enforcement of the 2 new LSM hooks as well
as related changes elsewhere in the SELinux code.

This also now keeps track of the peersid thru the establishment
of a connection on the server (tracking peersid on the client
is covered later in this patch set).

Signed-off-by: Venkat Yekkirala <[EMAIL PROTECTED]>
---
 security/selinux/hooks.c        |  148 +++++++++++++++++++++++-------
 security/selinux/include/xfrm.h |   11 +-
 security/selinux/xfrm.c         |   66 +++++--------
 3 files changed, 150 insertions(+), 75 deletions(-)

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 5a66c4c..fc65cc7 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -3449,8 +3449,12 @@ static int selinux_sock_rcv_skb_compat(s
 
                err = avc_has_perm(sock_sid, port_sid,
                                   sock_class, recv_perm, ad);
+               if (err)
+                       goto out;
        }
 
+       err = selinux_xfrm_sock_rcv_skb(sock_sid, skb, ad);
+
 out:
        return err;
 }
@@ -3489,10 +3493,6 @@ static int selinux_socket_sock_rcv_skb(s
                goto out;
 
        err = selinux_netlbl_sock_rcv_skb(sksec, skb, &ad);
-       if (err)
-               goto out;
-
-       err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad);
 out:   
        return err;
 }
@@ -3505,7 +3505,7 @@ static int selinux_socket_getpeersec_str
        u32 scontext_len;
        struct sk_security_struct *ssec;
        struct inode_security_struct *isec;
-       u32 peer_sid = 0;
+       u32 peer_sid;
 
        isec = SOCK_INODE(sock)->i_security;
 
@@ -3516,8 +3516,10 @@ static int selinux_socket_getpeersec_str
        }
        else if (isec->sclass == SECCLASS_TCP_SOCKET) {
                peer_sid = selinux_netlbl_socket_getpeersec_stream(sock);
-               if (peer_sid == SECSID_NULL)
-                       peer_sid = selinux_socket_getpeer_stream(sock->sk);
+               if (peer_sid == SECSID_NULL) {
+                       ssec = sock->sk->sk_security;
+                       peer_sid = ssec->peer_sid;
+               }
                if (peer_sid == SECSID_NULL) {
                        err = -ENOPROTOOPT;
                        goto out;
@@ -3550,7 +3552,8 @@ out:      
        return err;
 }
 
-static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff 
*skb, u32 *secid)
+static int selinux_socket_getpeersec_dgram(struct socket *sock,
+                               struct sk_buff *skb, u32 *secid)
 {
        u32 peer_secid = SECSID_NULL;
        int err = 0;
@@ -3559,8 +3562,12 @@ static int selinux_socket_getpeersec_dgr
                selinux_get_inode_sid(SOCK_INODE(sock), &peer_secid);
        else if (skb) {
                peer_secid = selinux_netlbl_socket_getpeersec_dgram(skb);
-               if (peer_secid == SECSID_NULL)
-                       peer_secid = selinux_socket_getpeer_dgram(skb);
+               if (peer_secid == SECSID_NULL) {
+                       if (selinux_compat_net)
+                               peer_secid = selinux_socket_getpeer_dgram(skb);
+                       else
+                               peer_secid = skb->secmark;
+               }
        }
 
        if (peer_secid == SECSID_NULL)
@@ -3626,19 +3633,24 @@ static int selinux_inet_conn_request(str
                return 0;
        }
 
-       err = selinux_xfrm_decode_session(skb, &peersid, 0);
-       BUG_ON(err);
+       if (selinux_compat_net) {
+               err = selinux_xfrm_decode_session(skb, &peersid, 0);
+               BUG_ON(err);
 
-       if (peersid == SECSID_NULL) {
-               req->secid = sksec->sid;
-               return 0;
-       }
+               if (peersid == SECSID_NULL) {
+                       req->secid = sksec->sid;
+                       req->peer_secid = 0;
+                       return 0;
+               }
+       } else
+               peersid = skb->secmark;
 
        err = security_sid_mls_copy(sksec->sid, peersid, &newsid);
        if (err)
                return err;
 
        req->secid = newsid;
+       req->peer_secid = peersid;
        return 0;
 }
 
@@ -3648,6 +3660,7 @@ static void selinux_inet_csk_clone(struc
        struct sk_security_struct *newsksec = newsk->sk_security;
 
        newsksec->sid = req->secid;
+       newsksec->peer_sid = req->peer_secid;
        /* NOTE: Ideally, we should also get the isec->sid for the
           new socket in sync, but we don't have the isec available yet.
           So we will wait until sock_graft to do it, by which
@@ -3662,6 +3675,66 @@ static void selinux_req_classify_flow(co
        fl->secid = req->secid;
 }
 
+static int selinux_skb_flow_in(struct sk_buff *skb, unsigned short family)
+{
+       u32 xfrm_sid;
+       int err;
+
+       if (selinux_compat_net)
+               return 1;
+
+       /*
+        * loopback traffic already labeled and
+        * flow-controlled on outbound. We may
+        * need to flow-control on the inbound
+        * as well if there's ever a use-case for it.
+        */
+       if (skb->dev == &loopback_dev)
+               return 1;
+
+       err = selinux_xfrm_decode_session(skb, &xfrm_sid, 0);
+       BUG_ON(err);
+
+       err = avc_has_perm(xfrm_sid, skb->secmark, SECCLASS_PACKET,
+                                       PACKET__FLOW_IN, NULL);
+       if (err)
+               goto out;
+
+       if (xfrm_sid)
+               skb->secmark = xfrm_sid;
+
+       /* See if NetLabel can flow in thru the current secmark here */
+
+out:
+       return err ? 0 : 1;
+};
+
+static int selinux_skb_flow_out(struct sk_buff *skb, u32 nf_secid)
+{
+       int err;
+
+       if (selinux_compat_net)
+               return 1;
+
+       if (!skb->secmark) {
+               u32 xfrm_sid;
+
+               selinux_skb_xfrm_sid(skb, &xfrm_sid);
+
+               if (xfrm_sid)
+                       skb->secmark = xfrm_sid;
+               else if (skb->sk) {
+                       struct sk_security_struct *sksec = skb->sk->sk_security;
+                       skb->secmark = sksec->sid;
+               }
+       }
+
+       err = avc_has_perm(skb->secmark, nf_secid, SECCLASS_PACKET,
+                               PACKET__FLOW_OUT, NULL);
+
+       return err ? 0 : 1;
+}
+
 static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
 {
        int err = 0;
@@ -3700,7 +3773,8 @@ out:
 
 #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 sk_buff 
*skb,
+                                           struct net_device *dev,
                                            struct avc_audit_data *ad,
                                            u16 family, char *addrp, int len)
 {
@@ -3710,6 +3784,9 @@ static int selinux_ip_postroute_last_com
        struct inode *inode;
        struct inode_security_struct *isec;
 
+       if (!sk)
+               goto out;
+
        sock = sk->sk_socket;
        if (!sock)
                goto out;
@@ -3768,7 +3845,11 @@ static int selinux_ip_postroute_last_com
 
                err = avc_has_perm(isec->sid, port_sid, isec->sclass,
                                   send_perm, ad);
+               if (err)
+                       goto out;
        }
+
+       err = selinux_xfrm_postroute_last(isec->sid, skb, ad);
 out:
        return err;
 }
@@ -3782,17 +3863,9 @@ static unsigned int selinux_ip_postroute
 {
        char *addrp;
        int len, err = 0;
-       struct sock *sk;
        struct sk_buff *skb = *pskb;
        struct avc_audit_data ad;
        struct net_device *dev = (struct net_device *)out;
-       struct sk_security_struct *sksec;
-
-       sk = skb->sk;
-       if (!sk)
-               goto out;
-
-       sksec = sk->sk_security;
 
        AVC_AUDIT_DATA_INIT(&ad, NET);
        ad.u.net.netif = dev->name;
@@ -3803,16 +3876,25 @@ static unsigned int selinux_ip_postroute
                goto out;
 
        if (selinux_compat_net)
-               err = selinux_ip_postroute_last_compat(sk, dev, &ad,
+               err = selinux_ip_postroute_last_compat(skb->sk, skb, dev, &ad,
                                                       family, addrp, len);
-       else
-               err = avc_has_perm(sksec->sid, skb->secmark, SECCLASS_PACKET,
-                                  PACKET__SEND, &ad);
+       else {
+               if (!skb->secmark) {
+                       u32 xfrm_sid;
 
-       if (err)
-               goto out;
+                       selinux_skb_xfrm_sid(skb, &xfrm_sid);
 
-       err = selinux_xfrm_postroute_last(sksec->sid, skb, &ad);
+                       if (xfrm_sid)
+                               skb->secmark = xfrm_sid;
+                       else if (skb->sk) {
+                               struct sk_security_struct *sksec =
+                                               skb->sk->sk_security;
+                               skb->secmark = sksec->sid;
+                       }
+               }
+               err = avc_has_perm(skb->secmark, SECINITSID_UNLABELED,
+                                  SECCLASS_PACKET, PACKET__FLOW_OUT, &ad);
+       }
 out:
        return err ? NF_DROP : NF_ACCEPT;
 }
@@ -4719,6 +4801,8 @@ static struct security_operations selinu
        .inet_conn_request =            selinux_inet_conn_request,
        .inet_csk_clone =               selinux_inet_csk_clone,
        .req_classify_flow =            selinux_req_classify_flow,
+       .skb_flow_in =                  selinux_skb_flow_in,
+       .skb_flow_out =                 selinux_skb_flow_out,
 
 #ifdef CONFIG_SECURITY_NETWORK_XFRM
        .xfrm_policy_alloc_security =   selinux_xfrm_policy_alloc,
diff --git a/security/selinux/include/xfrm.h b/security/selinux/include/xfrm.h
index 81eb598..b1e8425 100644
--- a/security/selinux/include/xfrm.h
+++ b/security/selinux/include/xfrm.h
@@ -38,9 +38,9 @@ int selinux_xfrm_sock_rcv_skb(u32 sid, s
                        struct avc_audit_data *ad);
 int selinux_xfrm_postroute_last(u32 isec_sid, struct sk_buff *skb,
                        struct avc_audit_data *ad);
-u32 selinux_socket_getpeer_stream(struct sock *sk);
 u32 selinux_socket_getpeer_dgram(struct sk_buff *skb);
 int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int ckall);
+void selinux_skb_xfrm_sid(struct sk_buff *skb, u32 *sid);
 #else
 static inline int selinux_xfrm_sock_rcv_skb(u32 isec_sid, struct sk_buff *skb,
                        struct avc_audit_data *ad)
@@ -54,11 +54,6 @@ static inline int selinux_xfrm_postroute
        return 0;
 }
 
-static inline int selinux_socket_getpeer_stream(struct sock *sk)
-{
-       return SECSID_NULL;
-}
-
 static inline int selinux_socket_getpeer_dgram(struct sk_buff *skb)
 {
        return SECSID_NULL;
@@ -68,6 +63,10 @@ static inline int selinux_xfrm_decode_se
        *sid = SECSID_NULL;
        return 0;
 }
+static inline void selinux_skb_xfrm_sid(struct sk_buff *skb, u32 *sid)
+{
+       *sid = SECSID_NULL;
+}
 #endif
 
 #endif /* _SELINUX_XFRM_H_ */
diff --git a/security/selinux/xfrm.c b/security/selinux/xfrm.c
index 3e742b8..aae9f8f 100644
--- a/security/selinux/xfrm.c
+++ b/security/selinux/xfrm.c
@@ -155,7 +155,8 @@ int selinux_xfrm_flow_state_match(struct
 }
 
 /*
- * LSM hook implementation that determines the sid for the session.
+ * LSM hook implementation that checks and/or returns the xfrm sid for the
+ * incoming packet.
  */
 
 int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int ckall)
@@ -193,6 +194,32 @@ int selinux_xfrm_decode_session(struct s
 }
 
 /*
+ * LSM hook implementation that returns the xfrm sid for the outgoing packet.
+ */
+
+void selinux_skb_xfrm_sid(struct sk_buff *skb, u32 *sid)
+{
+       struct dst_entry *dst;
+
+       *sid = SECSID_NULL;
+
+       dst = skb->dst;
+       if (dst) {
+               struct dst_entry *dst_test;
+               for (dst_test = dst; dst_test != 0;
+                       dst_test = dst_test->child) {
+                       struct xfrm_state *x = dst_test->xfrm;
+
+                       if (x && selinux_authorizable_xfrm(x)) {
+                               struct xfrm_sec_ctx *ctx = x->security;
+                               *sid = ctx->ctx_sid;
+                               break;
+                       }
+               }
+       }
+}
+
+/*
  * Security blob allocation for xfrm_policy and xfrm_state
  * CTX does not have a meaningful value on input
  */
@@ -391,43 +418,8 @@ void selinux_xfrm_state_free(struct xfrm
 }
 
 /*
- * SELinux internal function to retrieve the context of a connected
- * (sk->sk_state == TCP_ESTABLISHED) TCP socket based on its security
- * association used to connect to the remote socket.
- *
- * Retrieve via getsockopt SO_PEERSEC.
- */
-u32 selinux_socket_getpeer_stream(struct sock *sk)
-{
-       struct dst_entry *dst, *dst_test;
-       u32 peer_sid = SECSID_NULL;
-
-       if (sk->sk_state != TCP_ESTABLISHED)
-               goto out;
-
-       dst = sk_dst_get(sk);
-       if (!dst)
-               goto out;
-
-       for (dst_test = dst; dst_test != 0;
-            dst_test = dst_test->child) {
-               struct xfrm_state *x = dst_test->xfrm;
-
-               if (x && selinux_authorizable_xfrm(x)) {
-                       struct xfrm_sec_ctx *ctx = x->security;
-                       peer_sid = ctx->ctx_sid;
-                       break;
-               }
-       }
-       dst_release(dst);
-
-out:
-       return peer_sid;
-}
-
-/*
  * SELinux internal function to retrieve the context of a UDP packet
- * based on its security association used to connect to the remote socket.
+ * based on its security association.
  *
  * Retrieve via setsockopt IP_PASSSEC and recvmsg with control message
  * type SCM_SECURITY.
-
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