1 files changed, 92 insertions, 7 deletions

diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index d5fa708f037d..bd8e2cdeceef 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -2,7 +2,7 @@
  * net/tipc/socket.c: TIPC socket API
  *
  * Copyright (c) 2001-2007, 2012 Ericsson AB
- * Copyright (c) 2004-2008, 2010-2012, Wind River Systems
+ * Copyright (c) 2004-2008, 2010-2013, Wind River Systems
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -63,12 +63,15 @@ static u32 dispatch(struct tipc_port *tport, struct sk_buff *buf);
 static void wakeupdispatch(struct tipc_port *tport);
 static void tipc_data_ready(struct sock *sk, int len);
 static void tipc_write_space(struct sock *sk);
+static int release(struct socket *sock);
+static int accept(struct socket *sock, struct socket *new_sock, int flags);
 
 static const struct proto_ops packet_ops;
 static const struct proto_ops stream_ops;
 static const struct proto_ops msg_ops;
 
 static struct proto tipc_proto;
+static struct proto tipc_proto_kern;
 
 static int sockets_enabled;
 
@@ -141,7 +144,7 @@ static void reject_rx_queue(struct sock *sk)
 }
 
 /**
- * tipc_create - create a TIPC socket
+ * tipc_sk_create - create a TIPC socket
  * @net: network namespace (must be default network)
  * @sock: pre-allocated socket structure
  * @protocol: protocol indicator (must be 0)
@@ -152,8 +155,8 @@ static void reject_rx_queue(struct sock *sk)
  *
  * Returns 0 on success, errno otherwise
  */
-static int tipc_create(struct net *net, struct socket *sock, int protocol,
-                       int kern)
+static int tipc_sk_create(struct net *net, struct socket *sock, int protocol,
+                          int kern)
 {
         const struct proto_ops *ops;
         socket_state state;
@@ -183,7 +186,11 @@ static int tipc_create(struct net *net, struct socket *sock, int protocol,
         }
 
         /* Allocate socket's protocol area */
-        sk = sk_alloc(net, AF_TIPC, GFP_KERNEL, &tipc_proto);
+        if (!kern)
+                sk = sk_alloc(net, AF_TIPC, GFP_KERNEL, &tipc_proto);
+        else
+                sk = sk_alloc(net, AF_TIPC, GFP_KERNEL, &tipc_proto_kern);
+
         if (sk == NULL)
                 return -ENOMEM;
 
@@ -219,6 +226,78 @@ static int tipc_create(struct net *net, struct socket *sock, int protocol,
 }
 
 /**
+ * tipc_sock_create_local - create TIPC socket from inside TIPC module
+ * @type: socket type - SOCK_RDM or SOCK_SEQPACKET
+ *
+ * We cannot use sock_creat_kern here because it bumps module user count.
+ * Since socket owner and creator is the same module we must make sure
+ * that module count remains zero for module local sockets, otherwise
+ * we cannot do rmmod.
+ *
+ * Returns 0 on success, errno otherwise
+ */
+int tipc_sock_create_local(int type, struct socket **res)
+{
+        int rc;
+        struct sock *sk;
+
+        rc = sock_create_lite(AF_TIPC, type, 0, res);
+        if (rc < 0) {
+                pr_err("Failed to create kernel socket\n");
+                return rc;
+        }
+        tipc_sk_create(&init_net, *res, 0, 1);
+
+        sk = (*res)->sk;
+
+        return 0;
+}
+
+/**
+ * tipc_sock_release_local - release socket created by tipc_sock_create_local
+ * @sock: the socket to be released.
+ *
+ * Module reference count is not incremented when such sockets are created,
+ * so we must keep it from being decremented when they are released.
+ */
+void tipc_sock_release_local(struct socket *sock)
+{
+        release(sock);
+        sock->ops = NULL;
+        sock_release(sock);
+}
+
+/**
+ * tipc_sock_accept_local - accept a connection on a socket created
+ * with tipc_sock_create_local. Use this function to avoid that
+ * module reference count is inadvertently incremented.
+ *
+ * @sock:    the accepting socket
+ * @newsock: reference to the new socket to be created
+ * @flags:   socket flags
+ */
+
+int tipc_sock_accept_local(struct socket *sock, struct socket **newsock,
+                            int flags)
+{
+        struct sock *sk = sock->sk;
+        int ret;
+
+        ret = sock_create_lite(sk->sk_family, sk->sk_type,
+                               sk->sk_protocol, newsock);
+        if (ret < 0)
+                return ret;
+
+        ret = accept(sock, *newsock, flags);
+        if (ret < 0) {
+                sock_release(*newsock);
+                return ret;
+        }
+        (*newsock)->ops = sock->ops;
+        return ret;
+}
+
+/**
  * release - destroy a TIPC socket
  * @sock: socket to destroy
  *
@@ -1529,7 +1608,7 @@ static int accept(struct socket *sock, struct socket *new_sock, int flags)
 
         buf = skb_peek(&sk->sk_receive_queue);
 
-        res = tipc_create(sock_net(sock->sk), new_sock, 0, 0);
+        res = tipc_sk_create(sock_net(sock->sk), new_sock, 0, 1);
         if (res)
                 goto exit;
 
@@ -1839,7 +1918,7 @@ static const struct proto_ops stream_ops = {
 static const struct net_proto_family tipc_family_ops = {
         .owner          = THIS_MODULE,
         .family         = AF_TIPC,
-        .create         = tipc_create
+        .create         = tipc_sk_create
 };
 
 static struct proto tipc_proto = {
@@ -1849,6 +1928,12 @@ static struct proto tipc_proto = {
         .sysctl_rmem    = sysctl_tipc_rmem
 };
 
+static struct proto tipc_proto_kern = {
+        .name           = "TIPC",
+        .obj_size       = sizeof(struct tipc_sock),
+        .sysctl_rmem    = sysctl_tipc_rmem
+};
+
 /**
  * tipc_socket_init - initialize TIPC socket interface
  *