[NET]: Passcred cleanup in struct sock

struct socket uses a 'bool' (unsigned char) to
'flag' the pass-credential option for sockets
(which can be easily replaced by a flag)
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/net.h

@@ -61,6 +61,7 @@ typedef enum {
 #define SOCK_ASYNC_NOSPACE	0
 #define SOCK_ASYNC_WAITDATA	1
 #define SOCK_NOSPACE		2
+#define SOCK_PASSCRED		3
 
 #ifndef ARCH_HAS_SOCKET_TYPES
 /** sock_type - Socket types
@@ -111,7 +112,6 @@ struct socket {
 	struct sock		*sk;
 	wait_queue_head_t	wait;
 	short			type;
-	unsigned char		passcred;
 };
 
 struct vm_area_struct;

include/net/scm.h

@@ -51,13 +51,13 @@ static __inline__ void scm_recv(struct socket *sock, struct msghdr *msg,
 {
 	if (!msg->msg_control)
 	{
-		if (sock->passcred || scm->fp)
+		if (test_bit(SOCK_PASSCRED, &sock->flags) || scm->fp)
 			msg->msg_flags |= MSG_CTRUNC;
 		scm_destroy(scm);
 		return;
 	}
 
-	if (sock->passcred)
+	if (test_bit(SOCK_PASSCRED, &sock->flags))
 		put_cmsg(msg, SOL_SOCKET, SCM_CREDENTIALS, sizeof(scm->creds), &scm->creds);
 
 	if (!scm->fp)

net/core/sock.c

@@ -333,7 +333,10 @@ int sock_setsockopt(struct socket *sock, int level, int optname,
 			break;
 
 		case SO_PASSCRED:
-			sock->passcred = valbool;
+			if (valbool)
+				set_bit(SOCK_PASSCRED, &sock->flags);
+			else
+				clear_bit(SOCK_PASSCRED, &sock->flags);
 			break;
 
 		case SO_TIMESTAMP:
@@ -557,7 +560,7 @@ int sock_getsockopt(struct socket *sock, int level, int optname,
 			break; 
 
 		case SO_PASSCRED:
-			v.val = sock->passcred;
+			v.val = test_bit(SOCK_PASSCRED, &sock->flags) ? 1 : 0;
 			break;
 
 		case SO_PEERCRED:

net/socket.c

@@ -287,7 +287,7 @@ static struct inode *sock_alloc_inode(struct super_block *sb)
 	ei->socket.ops = NULL;
 	ei->socket.sk = NULL;
 	ei->socket.file = NULL;
-	ei->socket.passcred = 0;
+	ei->socket.flags = 0;
 
 	return &ei->vfs_inode;
 }

net/unix/af_unix.c

@@ -861,8 +861,8 @@ static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr,
 			goto out;
 		alen = err;
 
-		if (sock->passcred && !unix_sk(sk)->addr &&
-		    (err = unix_autobind(sock)) != 0)
+		if (test_bit(SOCK_PASSCRED, &sock->flags) &&
+		    !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0)
 			goto out;
 
 		other=unix_find_other(sunaddr, alen, sock->type, hash, &err);
@@ -952,7 +952,8 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 		goto out;
 	addr_len = err;
 
-	if (sock->passcred && !u->addr && (err = unix_autobind(sock)) != 0)
+	if (test_bit(SOCK_PASSCRED, &sock->flags)
+		&& !u->addr && (err = unix_autobind(sock)) != 0)
 		goto out;
 
 	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
@@ -1286,7 +1287,8 @@ static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
 			goto out;
 	}
 
-	if (sock->passcred && !u->addr && (err = unix_autobind(sock)) != 0)
+	if (test_bit(SOCK_PASSCRED, &sock->flags)
+		&& !u->addr && (err = unix_autobind(sock)) != 0)
 		goto out;
 
 	err = -EMSGSIZE;