[CIPSO]: remove duplicated code in the cipso_v4_*_getattr() functions

The bulk of the CIPSO option parsing/processing in the cipso_v4_sock_getattr()
and cipso_v4_skb_getattr() functions are identical, the only real difference
being where the functions obtain the CIPSO option itself.  This patch creates
a new function, cipso_v4_getattr(), which contains the common CIPSO option
parsing/processing code and modifies the existing functions to call this new
helper function.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 42 insertions, 73 deletions

diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index ab56a052ce31..805a78e6ed55 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -1831,68 +1831,75 @@ socket_setattr_failure:
 }
 
 /**
- * cipso_v4_sock_getattr - Get the security attributes from a sock
- * @sk: the sock
+ * cipso_v4_getattr - Helper function for the cipso_v4_*_getattr functions
+ * @cipso: the CIPSO v4 option
  * @secattr: the security attributes
  *
  * Description:
- * Query @sk to see if there is a CIPSO option attached to the sock and if
- * there is return the CIPSO security attributes in @secattr.  This function
- * requires that @sk be locked, or privately held, but it does not do any
- * locking itself.  Returns zero on success and negative values on failure.
+ * Inspect @cipso and return the security attributes in @secattr.  Returns zero
+ * on success and negative values on failure.
  *
  */
-int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr)
+static int cipso_v4_getattr(const unsigned char *cipso,
+                            struct netlbl_lsm_secattr *secattr)
 {
         int ret_val = -ENOMSG;
-        struct inet_sock *sk_inet;
-        unsigned char *cipso_ptr;
         u32 doi;
         struct cipso_v4_doi *doi_def;
 
-        sk_inet = inet_sk(sk);
-        if (sk_inet->opt == NULL || sk_inet->opt->cipso == 0)
-                return -ENOMSG;
-        cipso_ptr = sk_inet->opt->__data + sk_inet->opt->cipso -
-                sizeof(struct iphdr);
-        ret_val = cipso_v4_cache_check(cipso_ptr, cipso_ptr[1], secattr);
-        if (ret_val == 0)
-                return ret_val;
+        if (cipso_v4_cache_check(cipso, cipso[1], secattr) == 0)
+                return 0;
 
-        doi = ntohl(get_unaligned((__be32 *)&cipso_ptr[2]));
+        doi = ntohl(get_unaligned((__be32 *)&cipso[2]));
         rcu_read_lock();
         doi_def = cipso_v4_doi_search(doi);
-        if (doi_def == NULL) {
-                rcu_read_unlock();
-                return -ENOMSG;
-        }
-
+        if (doi_def == NULL)
+                goto getattr_return;
         /* XXX - This code assumes only one tag per CIPSO option which isn't
          * really a good assumption to make but since we only support the MAC
          * tags right now it is a safe assumption. */
-        switch (cipso_ptr[6]) {
+        switch (cipso[6]) {
         case CIPSO_V4_TAG_RBITMAP:
-                ret_val = cipso_v4_parsetag_rbm(doi_def,
-                                                &cipso_ptr[6],
-                                                secattr);
+                ret_val = cipso_v4_parsetag_rbm(doi_def, &cipso[6], secattr);
                 break;
         case CIPSO_V4_TAG_ENUM:
-                ret_val = cipso_v4_parsetag_enum(doi_def,
-                                                 &cipso_ptr[6],
-                                                 secattr);
+                ret_val = cipso_v4_parsetag_enum(doi_def, &cipso[6], secattr);
                 break;
         case CIPSO_V4_TAG_RANGE:
-                ret_val = cipso_v4_parsetag_rng(doi_def,
-                                                &cipso_ptr[6],
-                                                secattr);
+                ret_val = cipso_v4_parsetag_rng(doi_def, &cipso[6], secattr);
                 break;
         }
-        rcu_read_unlock();
 
+getattr_return:
+        rcu_read_unlock();
         return ret_val;
 }
 
 /**
+ * cipso_v4_sock_getattr - Get the security attributes from a sock
+ * @sk: the sock
+ * @secattr: the security attributes
+ *
+ * Description:
+ * Query @sk to see if there is a CIPSO option attached to the sock and if
+ * there is return the CIPSO security attributes in @secattr.  This function
+ * requires that @sk be locked, or privately held, but it does not do any
+ * locking itself.  Returns zero on success and negative values on failure.
+ *
+ */
+int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr)
+{
+        struct ip_options *opt;
+
+        opt = inet_sk(sk)->opt;
+        if (opt == NULL || opt->cipso == 0)
+                return -ENOMSG;
+
+        return cipso_v4_getattr(opt->__data + opt->cipso - sizeof(struct iphdr),
+                                secattr);
+}
+
+/**
  * cipso_v4_skbuff_getattr - Get the security attributes from the CIPSO option
  * @skb: the packet
  * @secattr: the security attributes
@@ -1905,45 +1912,7 @@ int cipso_v4_sock_getattr(struct sock *sk, struct netlbl_lsm_secattr *secattr)
 int cipso_v4_skbuff_getattr(const struct sk_buff *skb,
                             struct netlbl_lsm_secattr *secattr)
 {
-        int ret_val = -ENOMSG;
-        unsigned char *cipso_ptr;
-        u32 doi;
-        struct cipso_v4_doi *doi_def;
-
-        cipso_ptr = CIPSO_V4_OPTPTR(skb);
-        if (cipso_v4_cache_check(cipso_ptr, cipso_ptr[1], secattr) == 0)
-                return 0;
-
-        doi = ntohl(get_unaligned((__be32 *)&cipso_ptr[2]));
-        rcu_read_lock();
-        doi_def = cipso_v4_doi_search(doi);
-        if (doi_def == NULL)
-                goto skbuff_getattr_return;
-
-        /* XXX - This code assumes only one tag per CIPSO option which isn't
-         * really a good assumption to make but since we only support the MAC
-         * tags right now it is a safe assumption. */
-        switch (cipso_ptr[6]) {
-        case CIPSO_V4_TAG_RBITMAP:
-                ret_val = cipso_v4_parsetag_rbm(doi_def,
-                                                &cipso_ptr[6],
-                                                secattr);
-                break;
-        case CIPSO_V4_TAG_ENUM:
-                ret_val = cipso_v4_parsetag_enum(doi_def,
-                                                 &cipso_ptr[6],
-                                                 secattr);
-                break;
-        case CIPSO_V4_TAG_RANGE:
-                ret_val = cipso_v4_parsetag_rng(doi_def,
-                                                &cipso_ptr[6],
-                                                secattr);
-                break;
-        }
-
-skbuff_getattr_return:
-        rcu_read_unlock();
-        return ret_val;
+        return cipso_v4_getattr(CIPSO_V4_OPTPTR(skb), secattr);
 }
 
 /*