selinux: Add new NetLabel glue code to handle labeling of connection requests

[NOTE: based on 389fb800ac8be2832efedd19978a2b8ced37eb61]

This patch provides the missing functions to properly handle the labeling of
responses to incoming connection requests within SELinux.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index e210b212da7f2465150f98afff3d6b8840f12877..5f740cceb2566c38de2ab766561d7dd5927aeaee 100644 (file)
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -3799,7 +3799,7 @@ static int selinux_socket_post_create(struct socket *sock, int family,
                sksec = sock->sk->sk_security;
                sksec->sid = isec->sid;
                sksec->sclass = isec->sclass;
-               err = selinux_netlbl_socket_post_create(sock);
+               err = selinux_netlbl_socket_post_create(sock->sk, family);
        }
 
        return err;
@@ -4467,8 +4467,6 @@ static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
                family = PF_INET;
 
        selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid);
-
-       selinux_netlbl_inet_conn_established(sk, family);
 }
 
 static void selinux_req_classify_flow(const struct request_sock *req,

diff --git a/security/selinux/include/netlabel.h b/security/selinux/include/netlabel.h
index b913c8d060386728bfe0bc68441a56b4ad3f012f..9fca7b5069e82b5aa97bd5a34925f469492434d3 100644 (file)
--- a/security/selinux/include/netlabel.h
+++ b/security/selinux/include/netlabel.h
@@ -32,6 +32,7 @@
 #include <linux/net.h>
 #include <linux/skbuff.h>
 #include <net/sock.h>
+#include <net/request_sock.h>
 
 #include "avc.h"
 #include "objsec.h"
@@ -53,8 +54,9 @@ int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
                                 u16 family,
                                 u32 sid);
 
-void selinux_netlbl_inet_conn_established(struct sock *sk, u16 family);
-int selinux_netlbl_socket_post_create(struct socket *sock);
+int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family);
+void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family);
+int selinux_netlbl_socket_post_create(struct sock *sk, u16 family);
 int selinux_netlbl_inode_permission(struct inode *inode, int mask);
 int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
                                struct sk_buff *skb,
@@ -113,12 +115,17 @@ static inline int selinux_netlbl_conn_setsid(struct sock *sk,
        return 0;
 }
 
-static inline void selinux_netlbl_inet_conn_established(struct sock *sk,
-                                                       u16 family)
+static inline int selinux_netlbl_inet_conn_request(struct request_sock *req,
+                                                  u16 family)
+{
+       return 0;
+}
+static inline void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
 {
        return;
 }
-static inline int selinux_netlbl_socket_post_create(struct socket *sock)
+static inline int selinux_netlbl_socket_post_create(struct sock *sk,
+                                                   u16 family)
 {
        return 0;
 }

diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c
index 350794ab9b4212d7e50b07f3c778bb42bb81aa3a..8fcb2d56bdcf95b0e5f318ccf90294ba70df375a 100644 (file)
--- a/security/selinux/netlabel.c
+++ b/security/selinux/netlabel.c
@@ -281,73 +281,52 @@ skbuff_setsid_return:
 }
 
 /**
- * selinux_netlbl_inet_conn_established - Netlabel the newly accepted connection
- * @sk: the new connection
+ * selinux_netlbl_inet_conn_request - Label an incoming stream connection
+ * @req: incoming connection request socket
  *
  * Description:
- * A new connection has been established on @sk so make sure it is labeled
- * correctly with the NetLabel susbsystem.
+ * A new incoming connection request is represented by @req, we need to label
+ * the new request_sock here and the stack will ensure the on-the-wire label
+ * will get preserved when a full sock is created once the connection handshake
+ * is complete.  Returns zero on success, negative values on failure.
  *
  */
-void selinux_netlbl_inet_conn_established(struct sock *sk, u16 family)
+int selinux_netlbl_inet_conn_request(struct request_sock *req, u16 family)
 {
        int rc;
-       struct sk_security_struct *sksec = sk->sk_security;
-       struct netlbl_lsm_secattr *secattr;
-       struct inet_sock *sk_inet = inet_sk(sk);
-       struct sockaddr_in addr;
+       struct netlbl_lsm_secattr secattr;
 
-       if (sksec->nlbl_state != NLBL_REQUIRE)
-               return;
+       if (family != PF_INET)
+               return 0;
 
-       secattr = selinux_netlbl_sock_genattr(sk);
-       if (secattr == NULL)
-               return;
+       netlbl_secattr_init(&secattr);
+       rc = security_netlbl_sid_to_secattr(req->secid, &secattr);
+       if (rc != 0)
+               goto inet_conn_request_return;
+       rc = netlbl_req_setattr(req, &secattr);
+inet_conn_request_return:
+       netlbl_secattr_destroy(&secattr);
+       return rc;
+}
 
-       rc = netlbl_sock_setattr(sk, secattr);
-       switch (rc) {
-       case 0:
+/**
+ * selinux_netlbl_inet_csk_clone - Initialize the newly created sock
+ * @sk: the new sock
+ *
+ * Description:
+ * A new connection has been established using @sk, we've already labeled the
+ * socket via the request_sock struct in selinux_netlbl_inet_conn_request() but
+ * we need to set the NetLabel state here since we now have a sock structure.
+ *
+ */
+void selinux_netlbl_inet_csk_clone(struct sock *sk, u16 family)
+{
+       struct sk_security_struct *sksec = sk->sk_security;
+
+       if (family == PF_INET)
                sksec->nlbl_state = NLBL_LABELED;
-               break;
-       case -EDESTADDRREQ:
-               /* no PF_INET6 support yet because we don't support any IPv6
-                * labeling protocols */
-               if (family != PF_INET) {
-                       sksec->nlbl_state = NLBL_UNSET;
-                       return;
-               }
-
-               addr.sin_family = family;
-               addr.sin_addr.s_addr = sk_inet->daddr;
-               if (netlbl_conn_setattr(sk, (struct sockaddr *)&addr,
-                                       secattr) != 0) {
-                       /* we failed to label the connected socket (could be
-                        * for a variety of reasons, the actual "why" isn't
-                        * important here) so we have to go to our backup plan,
-                        * labeling the packets individually in the netfilter
-                        * local output hook.  this is okay but we need to
-                        * adjust the MSS of the connection to take into
-                        * account any labeling overhead, since we don't know
-                        * the exact overhead at this point we'll use the worst
-                        * case value which is 40 bytes for IPv4 */
-                       struct inet_connection_sock *sk_conn = inet_csk(sk);
-                       sk_conn->icsk_ext_hdr_len += 40 -
-                                     (sk_inet->opt ? sk_inet->opt->optlen : 0);
-                       sk_conn->icsk_sync_mss(sk, sk_conn->icsk_pmtu_cookie);
-
-                       sksec->nlbl_state = NLBL_REQSKB;
-               } else
-                       sksec->nlbl_state = NLBL_CONNLABELED;
-               break;
-       default:
-               /* note that we are failing to label the socket which could be
-                * a bad thing since it means traffic could leave the system
-                * without the desired labeling, however, all is not lost as
-                * we have a check in selinux_netlbl_inode_permission() to
-                * pick up the pieces that we might drop here because we can't
-                * return an error code */
-               break;
-       }
+       else
+               sksec->nlbl_state = NLBL_UNSET;
 }
 
 /**
@@ -359,9 +338,30 @@ void selinux_netlbl_inet_conn_established(struct sock *sk, u16 family)
  * SID.  Returns zero values on success, negative values on failure.
  *
  */
-int selinux_netlbl_socket_post_create(struct socket *sock)
+int selinux_netlbl_socket_post_create(struct sock *sk, u16 family)
 {
-       return selinux_netlbl_sock_setsid(sock->sk);
+       int rc;
+       struct sk_security_struct *sksec = sk->sk_security;
+       struct netlbl_lsm_secattr *secattr;
+
+       if (family != PF_INET)
+               return 0;
+
+       secattr = selinux_netlbl_sock_genattr(sk);
+       if (secattr == NULL)
+               return -ENOMEM;
+       rc = netlbl_sock_setattr(sk, secattr);
+       switch (rc) {
+       case 0:
+               sksec->nlbl_state = NLBL_LABELED;
+               break;
+       case -EDESTADDRREQ:
+               sksec->nlbl_state = NLBL_REQSKB;
+               rc = 0;
+               break;
+       }
+
+       return rc;
 }
 
 /**