[MLSXFRM]: Default labeling of socket specific IPSec policies

This defaults the label of socket-specific IPSec policies to be the
same as the socket they are set on.

Signed-off-by: Venkat Yekkirala <vyekkirala@TrustedCS.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

8 files changed, 66 insertions, 24 deletions

diff --git a/include/linux/security.h b/include/linux/security.h
index f3909d189fe0..8e3dc6c51a6d 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -827,8 +827,10 @@ struct swap_info_struct;
  *      used by the XFRM system.
  *      @sec_ctx contains the security context information being provided by
  *      the user-level policy update program (e.g., setkey).
+ *      @sk refers to the sock from which to derive the security context.
  *      Allocate a security structure to the xp->security field; the security
- *      field is initialized to NULL when the xfrm_policy is allocated.
+ *      field is initialized to NULL when the xfrm_policy is allocated. Only
+ *      one of sec_ctx or sock can be specified.
  *      Return 0 if operation was successful (memory to allocate, legal context)
  * @xfrm_policy_clone_security:
  *      @old contains an existing xfrm_policy in the SPD.
@@ -1359,7 +1361,8 @@ struct security_operations {
 #endif  /* CONFIG_SECURITY_NETWORK */
 
 #ifdef CONFIG_SECURITY_NETWORK_XFRM
-        int (*xfrm_policy_alloc_security) (struct xfrm_policy *xp, struct xfrm_user_sec_ctx *sec_ctx);
+        int (*xfrm_policy_alloc_security) (struct xfrm_policy *xp,
+                        struct xfrm_user_sec_ctx *sec_ctx, struct sock *sk);
         int (*xfrm_policy_clone_security) (struct xfrm_policy *old, struct xfrm_policy *new);
         void (*xfrm_policy_free_security) (struct xfrm_policy *xp);
         int (*xfrm_policy_delete_security) (struct xfrm_policy *xp);
@@ -3057,7 +3060,12 @@ static inline void security_sk_classify_flow(struct sock *sk, struct flowi *fl)
 #ifdef CONFIG_SECURITY_NETWORK_XFRM
 static inline int security_xfrm_policy_alloc(struct xfrm_policy *xp, struct xfrm_user_sec_ctx *sec_ctx)
 {
-        return security_ops->xfrm_policy_alloc_security(xp, sec_ctx);
+        return security_ops->xfrm_policy_alloc_security(xp, sec_ctx, NULL);
+}
+
+static inline int security_xfrm_sock_policy_alloc(struct xfrm_policy *xp, struct sock *sk)
+{
+        return security_ops->xfrm_policy_alloc_security(xp, NULL, sk);
 }
 
 static inline int security_xfrm_policy_clone(struct xfrm_policy *old, struct xfrm_policy *new)
@@ -3132,6 +3140,11 @@ static inline int security_xfrm_policy_alloc(struct xfrm_policy *xp, struct xfrm
         return 0;
 }
 
+static inline int security_xfrm_sock_policy_alloc(struct xfrm_policy *xp, struct sock *sk)
+{
+        return 0;
+}
+
 static inline int security_xfrm_policy_clone(struct xfrm_policy *old, struct xfrm_policy *new)
 {
         return 0;
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 3ecd9fa1ed4b..00bf86e6e82b 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -362,7 +362,7 @@ struct xfrm_mgr
         char                    *id;
         int                     (*notify)(struct xfrm_state *x, struct km_event *c);
         int                     (*acquire)(struct xfrm_state *x, struct xfrm_tmpl *, struct xfrm_policy *xp, int dir);
-        struct xfrm_policy      *(*compile_policy)(u16 family, int opt, u8 *data, int len, int *dir);
+        struct xfrm_policy      *(*compile_policy)(struct sock *sk, int opt, u8 *data, int len, int *dir);
         int                     (*new_mapping)(struct xfrm_state *x, xfrm_address_t *ipaddr, u16 sport);
         int                     (*notify_policy)(struct xfrm_policy *x, int dir, struct km_event *c);
 };
diff --git a/net/key/af_key.c b/net/key/af_key.c
index a065e1a67773..797c744a8438 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -2843,14 +2843,14 @@ static int pfkey_send_acquire(struct xfrm_state *x, struct xfrm_tmpl *t, struct
         return pfkey_broadcast(skb, GFP_ATOMIC, BROADCAST_REGISTERED, NULL);
 }
 
-static struct xfrm_policy *pfkey_compile_policy(u16 family, int opt,
+static struct xfrm_policy *pfkey_compile_policy(struct sock *sk, int opt,
                                                 u8 *data, int len, int *dir)
 {
         struct xfrm_policy *xp;
         struct sadb_x_policy *pol = (struct sadb_x_policy*)data;
         struct sadb_x_sec_ctx *sec_ctx;
 
-        switch (family) {
+        switch (sk->sk_family) {
         case AF_INET:
                 if (opt != IP_IPSEC_POLICY) {
                         *dir = -EOPNOTSUPP;
@@ -2891,7 +2891,7 @@ static struct xfrm_policy *pfkey_compile_policy(u16 family, int opt,
         xp->lft.hard_byte_limit = XFRM_INF;
         xp->lft.soft_packet_limit = XFRM_INF;
         xp->lft.hard_packet_limit = XFRM_INF;
-        xp->family = family;
+        xp->family = sk->sk_family;
 
         xp->xfrm_nr = 0;
         if (pol->sadb_x_policy_type == IPSEC_POLICY_IPSEC &&
@@ -2907,8 +2907,10 @@ static struct xfrm_policy *pfkey_compile_policy(u16 family, int opt,
                 p += pol->sadb_x_policy_len*8;
                 sec_ctx = (struct sadb_x_sec_ctx *)p;
                 if (len < pol->sadb_x_policy_len*8 +
-                    sec_ctx->sadb_x_sec_len)
+                    sec_ctx->sadb_x_sec_len) {
+                        *dir = -EINVAL;
                         goto out;
+                }
                 if ((*dir = verify_sec_ctx_len(p)))
                         goto out;
                 uctx = pfkey_sadb2xfrm_user_sec_ctx(sec_ctx);
@@ -2918,6 +2920,11 @@ static struct xfrm_policy *pfkey_compile_policy(u16 family, int opt,
                 if (*dir)
                         goto out;
         }
+        else {
+                *dir = security_xfrm_sock_policy_alloc(xp, sk);
+                if (*dir)
+                        goto out;
+        }
 
         *dir = pol->sadb_x_policy_dir-1;
         return xp;
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index be02bd981d12..1c796087ee78 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -1026,7 +1026,7 @@ int xfrm_user_policy(struct sock *sk, int optname, u8 __user *optval, int optlen
         err = -EINVAL;
         read_lock(&xfrm_km_lock);
         list_for_each_entry(km, &xfrm_km_list, list) {
-                pol = km->compile_policy(sk->sk_family, optname, data,
+                pol = km->compile_policy(sk, optname, data,
                                          optlen, &err);
                 if (err >= 0)
                         break;
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index dac8db1088bc..f70e158874d2 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1757,7 +1757,7 @@ static int xfrm_send_acquire(struct xfrm_state *x, struct xfrm_tmpl *xt,
 /* User gives us xfrm_user_policy_info followed by an array of 0
  * or more templates.
  */
-static struct xfrm_policy *xfrm_compile_policy(u16 family, int opt,
+static struct xfrm_policy *xfrm_compile_policy(struct sock *sk, int opt,
                                                u8 *data, int len, int *dir)
 {
         struct xfrm_userpolicy_info *p = (struct xfrm_userpolicy_info *)data;
@@ -1765,7 +1765,7 @@ static struct xfrm_policy *xfrm_compile_policy(u16 family, int opt,
         struct xfrm_policy *xp;
         int nr;
 
-        switch (family) {
+        switch (sk->sk_family) {
         case AF_INET:
                 if (opt != IP_XFRM_POLICY) {
                         *dir = -EOPNOTSUPP;
@@ -1807,6 +1807,15 @@ static struct xfrm_policy *xfrm_compile_policy(u16 family, int opt,
         copy_from_user_policy(xp, p);
         copy_templates(xp, ut, nr);
 
+        if (!xp->security) {
+                int err = security_xfrm_sock_policy_alloc(xp, sk);
+                if (err) {
+                        kfree(xp);
+                        *dir = err;
+                        return NULL;
+                }
+        }
+
         *dir = p->dir;
 
         return xp;
diff --git a/security/dummy.c b/security/dummy.c
index c0ff6b9bfd7d..66cc06404930 100644
--- a/security/dummy.c
+++ b/security/dummy.c
@@ -815,7 +815,8 @@ static inline void dummy_sk_getsecid(struct sock *sk, u32 *secid)
 #endif  /* CONFIG_SECURITY_NETWORK */
 
 #ifdef CONFIG_SECURITY_NETWORK_XFRM
-static int dummy_xfrm_policy_alloc_security(struct xfrm_policy *xp, struct xfrm_user_sec_ctx *sec_ctx)
+static int dummy_xfrm_policy_alloc_security(struct xfrm_policy *xp,
+                struct xfrm_user_sec_ctx *sec_ctx, struct sock *sk)
 {
         return 0;
 }
diff --git a/security/selinux/include/xfrm.h b/security/selinux/include/xfrm.h
index 8e45c1d588a8..1822c73e5085 100644
--- a/security/selinux/include/xfrm.h
+++ b/security/selinux/include/xfrm.h
@@ -7,7 +7,8 @@
 #ifndef _SELINUX_XFRM_H_
 #define _SELINUX_XFRM_H_
 
-int selinux_xfrm_policy_alloc(struct xfrm_policy *xp, struct xfrm_user_sec_ctx *sec_ctx);
+int selinux_xfrm_policy_alloc(struct xfrm_policy *xp,
+                struct xfrm_user_sec_ctx *sec_ctx, struct sock *sk);
 int selinux_xfrm_policy_clone(struct xfrm_policy *old, struct xfrm_policy *new);
 void selinux_xfrm_policy_free(struct xfrm_policy *xp);
 int selinux_xfrm_policy_delete(struct xfrm_policy *xp);
diff --git a/security/selinux/xfrm.c b/security/selinux/xfrm.c
index c750ef7af66f..d3690f985135 100644
--- a/security/selinux/xfrm.c
+++ b/security/selinux/xfrm.c
@@ -208,10 +208,8 @@ static int selinux_xfrm_sec_ctx_alloc(struct xfrm_sec_ctx **ctxp,
 
         BUG_ON(uctx && pol);
 
-        if (pol)
-                goto from_policy;
-
-        BUG_ON(!uctx);
+        if (!uctx)
+                goto not_from_user;
 
         if (uctx->ctx_doi != XFRM_SC_ALG_SELINUX)
                 return -EINVAL;
@@ -251,11 +249,14 @@ static int selinux_xfrm_sec_ctx_alloc(struct xfrm_sec_ctx **ctxp,
 
         return rc;
 
-from_policy:
-        BUG_ON(!pol);
-        rc = security_sid_mls_copy(pol->ctx_sid, sid, &ctx_sid);
-        if (rc)
-                goto out;
+not_from_user:
+        if (pol) {
+                rc = security_sid_mls_copy(pol->ctx_sid, sid, &ctx_sid);
+                if (rc)
+                        goto out;
+        }
+        else
+                ctx_sid = sid;
 
         rc = security_sid_to_context(ctx_sid, &ctx_str, &str_len);
         if (rc)
@@ -293,13 +294,23 @@ out2:
  * LSM hook implementation that allocs and transfers uctx spec to
  * xfrm_policy.
  */
-int selinux_xfrm_policy_alloc(struct xfrm_policy *xp, struct xfrm_user_sec_ctx *uctx)
+int selinux_xfrm_policy_alloc(struct xfrm_policy *xp,
+                struct xfrm_user_sec_ctx *uctx, struct sock *sk)
 {
         int err;
+        u32 sid;
 
         BUG_ON(!xp);
+        BUG_ON(uctx && sk);
+
+        if (sk) {
+                struct sk_security_struct *ssec = sk->sk_security;
+                sid = ssec->sid;
+        }
+        else
+                sid = SECSID_NULL;
 
-        err = selinux_xfrm_sec_ctx_alloc(&xp->security, uctx, NULL, 0);
+        err = selinux_xfrm_sec_ctx_alloc(&xp->security, uctx, NULL, sid);
         return err;
 }