sctp: refactor sctp_setsockopt_bindx

Split out a sctp_setsockopt_bindx_kernel that takes a kernel pointer
to the sockaddr and make sctp_setsockopt_bindx a small wrapper around
it.  This prepares for adding a new bind_add proto op.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 827a9903ee288f69d37dd663a180d2c3eb3efacb..6e745ac3c4a596e1b614922d4b890e8e208d63c3 100644 (file)
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -972,23 +972,22 @@ int sctp_asconf_mgmt(struct sctp_sock *sp, struct sctp_sockaddr_entry *addrw)
  * it.
  *
  * sk        The sk of the socket
- * addrs     The pointer to the addresses in user land
+ * addrs     The pointer to the addresses
  * addrssize Size of the addrs buffer
  * op        Operation to perform (add or remove, see the flags of
  *           sctp_bindx)
  *
  * Returns 0 if ok, <0 errno code on error.
  */
-static int sctp_setsockopt_bindx(struct sock *sk,
-                                struct sockaddr __user *addrs,
-                                int addrs_size, int op)
+static int sctp_setsockopt_bindx_kernel(struct sock *sk,
+                                       struct sockaddr *addrs, int addrs_size,
+                                       int op)
 {
-       struct sockaddr *kaddrs;
        int err;
        int addrcnt = 0;
        int walk_size = 0;
        struct sockaddr *sa_addr;
-       void *addr_buf;
+       void *addr_buf = addrs;
        struct sctp_af *af;
 
        pr_debug("%s: sk:%p addrs:%p addrs_size:%d opt:%d\n",
@@ -997,17 +996,10 @@ static int sctp_setsockopt_bindx(struct sock *sk,
        if (unlikely(addrs_size <= 0))
                return -EINVAL;
 
-       kaddrs = memdup_user(addrs, addrs_size);
-       if (IS_ERR(kaddrs))
-               return PTR_ERR(kaddrs);
-
        /* Walk through the addrs buffer and count the number of addresses. */
-       addr_buf = kaddrs;
        while (walk_size < addrs_size) {
-               if (walk_size + sizeof(sa_family_t) > addrs_size) {
-                       kfree(kaddrs);
+               if (walk_size + sizeof(sa_family_t) > addrs_size)
                        return -EINVAL;
-               }
 
                sa_addr = addr_buf;
                af = sctp_get_af_specific(sa_addr->sa_family);
@@ -1015,10 +1007,8 @@ static int sctp_setsockopt_bindx(struct sock *sk,
                /* If the address family is not supported or if this address
                 * causes the address buffer to overflow return EINVAL.
                 */
-               if (!af || (walk_size + af->sockaddr_len) > addrs_size) {
-                       kfree(kaddrs);
+               if (!af || (walk_size + af->sockaddr_len) > addrs_size)
                        return -EINVAL;
-               }
                addrcnt++;
                addr_buf += af->sockaddr_len;
                walk_size += af->sockaddr_len;
@@ -1029,31 +1019,36 @@ static int sctp_setsockopt_bindx(struct sock *sk,
        case SCTP_BINDX_ADD_ADDR:
                /* Allow security module to validate bindx addresses. */
                err = security_sctp_bind_connect(sk, SCTP_SOCKOPT_BINDX_ADD,
-                                                (struct sockaddr *)kaddrs,
-                                                addrs_size);
+                                                addrs, addrs_size);
                if (err)
-                       goto out;
-               err = sctp_bindx_add(sk, kaddrs, addrcnt);
+                       return err;
+               err = sctp_bindx_add(sk, addrs, addrcnt);
                if (err)
-                       goto out;
-               err = sctp_send_asconf_add_ip(sk, kaddrs, addrcnt);
-               break;
-
+                       return err;
+               return sctp_send_asconf_add_ip(sk, addrs, addrcnt);
        case SCTP_BINDX_REM_ADDR:
-               err = sctp_bindx_rem(sk, kaddrs, addrcnt);
+               err = sctp_bindx_rem(sk, addrs, addrcnt);
                if (err)
-                       goto out;
-               err = sctp_send_asconf_del_ip(sk, kaddrs, addrcnt);
-               break;
+                       return err;
+               return sctp_send_asconf_del_ip(sk, addrs, addrcnt);
 
        default:
-               err = -EINVAL;
-               break;
+               return -EINVAL;
        }
+}
 
-out:
-       kfree(kaddrs);
+static int sctp_setsockopt_bindx(struct sock *sk,
+                                struct sockaddr __user *addrs,
+                                int addrs_size, int op)
+{
+       struct sockaddr *kaddrs;
+       int err;
 
+       kaddrs = memdup_user(addrs, addrs_size);
+       if (IS_ERR(kaddrs))
+               return PTR_ERR(kaddrs);
+       err = sctp_setsockopt_bindx_kernel(sk, kaddrs, addrs_size, op);
+       kfree(kaddrs);
        return err;
 }