[NET]: Optimize handling of CONFIG_NET=n.

kernel/sys.c

@@ -209,6 +209,23 @@ cond_syscall(sys_swapon)
 cond_syscall(sys_swapoff)
 cond_syscall(sys_init_module)
 cond_syscall(sys_delete_module)
+cond_syscall(sys_socketpair)
+cond_syscall(sys_bind)
+cond_syscall(sys_listen)
+cond_syscall(sys_accept)
+cond_syscall(sys_connect)
+cond_syscall(sys_getsockname)
+cond_syscall(sys_getpeername)
+cond_syscall(sys_sendto)
+cond_syscall(sys_send)
+cond_syscall(sys_recvfrom)
+cond_syscall(sys_recv)
+cond_syscall(sys_setsockopt)
+cond_syscall(sys_getsockopt)
+cond_syscall(sys_shutdown)
+cond_syscall(sys_sendmsg)
+cond_syscall(sys_recvmsg)
+cond_syscall(sys_socketcall)
 
 static int set_one_prio(struct task_struct *p, int niceval, int error)
 {

net/Makefile

@@ -5,7 +5,9 @@
 # Rewritten to use lists instead of if-statements.
 #
 
-obj-y	:= socket.o core/
+obj-y	:= nonet.o
+
+obj-$(CONFIG_NET)		:= socket.o core/
 
 obj-$(CONFIG_COMPAT)		+= compat.o
 

net/nonet.c

+/*
+ * net/nonet.c
+ *
+ * Dummy functions to allow us to configure network support entirely
+ * out of the kernel.
+ *
+ * Distributed under the terms of the GNU GPL version 2.
+ * Copyright (c) Matthew Wilcox 2003
+ */
+
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+
+void __init sock_init(void)
+{
+	printk(KERN_INFO "Linux NoNET1.0 for Linux 2.6\n");
+}
+
+static int sock_no_open(struct inode *irrelevant, struct file *dontcare)
+{
+	return -ENXIO;
+}
+
+struct file_operations bad_sock_fops = {
+	.open = sock_no_open,
+};