1 files changed, 54 insertions, 5 deletions

diff --git a/net/ipv4/tcp_ulp.c b/net/ipv4/tcp_ulp.c
index 6bb9e14c710a..622caa4039e0 100644
--- a/net/ipv4/tcp_ulp.c
+++ b/net/ipv4/tcp_ulp.c
@@ -29,6 +29,18 @@ static struct tcp_ulp_ops *tcp_ulp_find(const char *name)
         return NULL;
 }
 
+static struct tcp_ulp_ops *tcp_ulp_find_id(const int ulp)
+{
+        struct tcp_ulp_ops *e;
+
+        list_for_each_entry_rcu(e, &tcp_ulp_list, list) {
+                if (e->uid == ulp)
+                        return e;
+        }
+
+        return NULL;
+}
+
 static const struct tcp_ulp_ops *__tcp_ulp_find_autoload(const char *name)
 {
         const struct tcp_ulp_ops *ulp = NULL;
@@ -51,6 +63,18 @@ static const struct tcp_ulp_ops *__tcp_ulp_find_autoload(const char *name)
         return ulp;
 }
 
+static const struct tcp_ulp_ops *__tcp_ulp_lookup(const int uid)
+{
+        const struct tcp_ulp_ops *ulp;
+
+        rcu_read_lock();
+        ulp = tcp_ulp_find_id(uid);
+        if (!ulp || !try_module_get(ulp->owner))
+                ulp = NULL;
+        rcu_read_unlock();
+        return ulp;
+}
+
 /* Attach new upper layer protocol to the list
  * of available protocols.
  */
@@ -59,13 +83,10 @@ int tcp_register_ulp(struct tcp_ulp_ops *ulp)
         int ret = 0;
 
         spin_lock(&tcp_ulp_list_lock);
-        if (tcp_ulp_find(ulp->name)) {
-                pr_notice("%s already registered or non-unique name\n",
-                          ulp->name);
+        if (tcp_ulp_find(ulp->name))
                 ret = -EEXIST;
-        } else {
+        else
                 list_add_tail_rcu(&ulp->list, &tcp_ulp_list);
-        }
         spin_unlock(&tcp_ulp_list_lock);
 
         return ret;
@@ -124,6 +145,34 @@ int tcp_set_ulp(struct sock *sk, const char *name)
         if (!ulp_ops)
                 return -ENOENT;
 
+        if (!ulp_ops->user_visible) {
+                module_put(ulp_ops->owner);
+                return -ENOENT;
+        }
+
+        err = ulp_ops->init(sk);
+        if (err) {
+                module_put(ulp_ops->owner);
+                return err;
+        }
+
+        icsk->icsk_ulp_ops = ulp_ops;
+        return 0;
+}
+
+int tcp_set_ulp_id(struct sock *sk, int ulp)
+{
+        struct inet_connection_sock *icsk = inet_csk(sk);
+        const struct tcp_ulp_ops *ulp_ops;
+        int err;
+
+        if (icsk->icsk_ulp_ops)
+                return -EEXIST;
+
+        ulp_ops = __tcp_ulp_lookup(ulp);
+        if (!ulp_ops)
+                return -ENOENT;
+
         err = ulp_ops->init(sk);
         if (err) {
                 module_put(ulp_ops->owner);