Operation System Project 2 (Kernel Patch)

os-project-4.11.6.patch

diff -Nur linux-4.11-copy/drivers/char/Kconfig linux-4.11/drivers/char/Kconfig
--- linux-4.11-copy/drivers/char/Kconfig	2017-05-01 10:47:48.000000000 +0800
+++ linux-4.11/drivers/char/Kconfig	2017-06-23 20:07:55.645195892 +0800
@@ -548,6 +548,18 @@
 	  The mmtimer device allows direct userspace access to the
 	  Altix system timer.
 
+config SOCKET_SERVER
+	tristate "Character-device that listen and write to a socket"
+	default m
+	help
+	  The socket_server device allows writing to a socket.
+
+config SOCKET_CLIENT
+	tristate "Character-device that read from a socket"
+	default m
+	help
+	  The socket_client device allows reading from a socket.
+
 config UV_MMTIMER
 	tristate "UV_MMTIMER Memory mapped RTC for SGI UV"
 	depends on X86_UV
diff -Nur linux-4.11-copy/drivers/char/Makefile linux-4.11/drivers/char/Makefile
--- linux-4.11-copy/drivers/char/Makefile	2017-05-01 10:47:48.000000000 +0800
+++ linux-4.11/drivers/char/Makefile	2017-06-23 20:07:55.645195892 +0800
@@ -45,6 +45,9 @@
 obj-$(CONFIG_GPIO_TB0219)	+= tb0219.o
 obj-$(CONFIG_TELCLOCK)		+= tlclk.o
 
+obj-$(CONFIG_SOCKET_SERVER) += socket_server.o
+obj-$(CONFIG_SOCKET_CLIENT) += socket_client.o
+
 obj-$(CONFIG_MWAVE)		+= mwave/
 obj-y				+= agp/
 obj-$(CONFIG_PCMCIA)		+= pcmcia/
diff -Nur linux-4.11-copy/drivers/char/socket_client.c linux-4.11/drivers/char/socket_client.c
--- linux-4.11-copy/drivers/char/socket_client.c	1970-01-01 08:00:00.000000000 +0800
+++ linux-4.11/drivers/char/socket_client.c	2017-06-23 20:07:55.645195892 +0800
@@ -0,0 +1,165 @@
+/*
+ * Character-device that read from a socket.
+ *
+ * Copyright (c) 2017	  Pochang Chen
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+
+#include <linux/audit.h>
+#include <linux/cdev.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/major.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/slab.h>
+#include <linux/socket.h>
+#include <linux/uaccess.h>
+
+MODULE_AUTHOR("Pochang Chen <[email protected]>");
+MODULE_DESCRIPTION("Socket client device");
+MODULE_LICENSE("GPL");
+
+#define SOCKET_CLIENT_IOCTL_CONNECT _IOW(0x88, 0x08, struct sockaddr)
+
+struct socket_client_data {
+	struct socket *sock;
+};
+
+static ssize_t socket_client_read_iter(struct kiocb *iocb,
+				       struct iov_iter *to)
+{
+	struct file *file = iocb->ki_filp;
+	struct socket_client_data *data = file->private_data;
+	struct socket *sock = data->sock;
+	struct msghdr msg = {.msg_iter = *to,
+			     .msg_iocb = iocb};
+	ssize_t res;
+
+	if (!sock)
+		return -ENOTCONN;
+
+	if (iocb->ki_pos != 0)
+		return -ESPIPE;
+
+	if (!iov_iter_count(to))
+		return 0;
+
+	if (file->f_flags & O_NONBLOCK)
+		msg.msg_flags = MSG_DONTWAIT;
+
+	res = sock_recvmsg(sock, &msg, msg.msg_flags);
+	*to = msg.msg_iter;
+	return res;
+}
+
+static long socket_client_ioctl_connect(struct file *file, unsigned int cmd,
+				unsigned long arg)
+{
+	int err;
+	struct socket *sock;
+	struct sockaddr_storage address;
+	struct socket_client_data *data;
+	const int addrlen = sizeof(struct sockaddr);
+
+	err = move_addr_to_kernel((void __user *) arg, addrlen, &address);
+	if (err < 0)
+		goto out_release;
+
+	err = sock_create(AF_INET, SOCK_STREAM, 0, &sock);
+	if (err < 0)
+		goto out;
+
+	err = kernel_connect(sock, (struct sockaddr *) &address,
+				 addrlen, file->f_flags);
+	if (err)
+		goto out_release;
+
+	err = kernel_sock_shutdown(sock, SHUT_WR);
+	if (err)
+		goto out_release;
+
+	// XXX spin_lock(&file->f_lock);
+	data = file->private_data;
+	if (data->sock) {
+		// XXX spin_unlock(&file->f_lock);
+		err = -EISCONN;
+		goto out_release;
+	}
+	data->sock = sock;
+	// XXX spin_unlock(&file->f_lock);
+	
+	return 0;
+
+out_release:
+	sock_release(sock);
+out:
+	return err;
+}
+
+static long socket_client_ioctl(struct file *file, unsigned int cmd,
+				unsigned long arg)
+{
+	int err;
+
+	switch (cmd) {
+	case SOCKET_CLIENT_IOCTL_CONNECT:
+		err = socket_client_ioctl_connect(file, cmd, arg);
+		break;
+	default:
+		err = -EINVAL;
+		break;
+	}
+	return err;
+}
+
+static int socket_client_open(struct inode *inode, struct file *file)
+{
+	struct socket_client_data *data;
+
+	data = kzalloc(sizeof(struct socket_client_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	file->private_data = data;
+	nonseekable_open(inode, file);
+
+	return 0;
+}
+
+static int socket_client_release(struct inode *inode, struct file *file)
+{
+	struct socket_client_data *data;
+	struct socket *sock;
+
+	// XXX spin_lock(&file->f_lock);
+	data = file->private_data;
+	sock = data->sock;
+	data->sock = NULL;
+	// XXX spin_unlock(&file->f_lock);
+	
+	if (sock)
+		sock_release(sock);
+	kfree(file->private_data);
+	return 0;
+}
+
+static const struct file_operations socket_client_fops = {
+	.owner		= THIS_MODULE,
+	.read_iter	= socket_client_read_iter,
+	.unlocked_ioctl = socket_client_ioctl,
+	.open		= socket_client_open,
+	.release	= socket_client_release,
+};
+
+static struct miscdevice socket_client = {
+	.minor	= MISC_DYNAMIC_MINOR,
+	.name	= "socket_client",
+	.fops	= &socket_client_fops,
+};
+
+module_misc_device(socket_client);
diff -Nur linux-4.11-copy/drivers/char/socket_server.c linux-4.11/drivers/char/socket_server.c
--- linux-4.11-copy/drivers/char/socket_server.c	1970-01-01 08:00:00.000000000 +0800
+++ linux-4.11/drivers/char/socket_server.c	2017-06-23 20:07:55.645195892 +0800
@@ -0,0 +1,171 @@
+/*
+ * Character-device that accept and write to a socket.
+ *
+ * Copyright (c) 2017	  Pochang Chen
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+
+#include <linux/audit.h>
+#include <linux/cdev.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/major.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/slab.h>
+#include <linux/socket.h>
+#include <linux/uaccess.h>
+
+MODULE_AUTHOR("Pochang Chen <[email protected]>");
+MODULE_DESCRIPTION("Socket server device");
+MODULE_LICENSE("GPL");
+
+#define SOCKET_SERVER_IOCTL_ACCEPT _IOW(0x88, 0x29, struct sockaddr)
+
+struct socket_server_data {
+	struct socket *sock;
+};
+
+static ssize_t socket_server_write_iter(struct kiocb *iocb,
+				       struct iov_iter *from)
+{
+	struct file *file = iocb->ki_filp;
+	struct socket_server_data *data = file->private_data;
+	struct socket *sock = data->sock;
+	struct msghdr msg = {.msg_iter = *from,
+			     .msg_iocb = iocb};
+	ssize_t res;
+
+	if (!sock)
+		return -ENOTCONN;
+
+	if (iocb->ki_pos != 0)
+		return -ESPIPE;
+
+	if (file->f_flags & O_NONBLOCK)
+		msg.msg_flags = MSG_DONTWAIT;
+
+	res = sock_sendmsg(sock, &msg);
+	*from = msg.msg_iter;
+	return res;
+}
+
+static long socket_server_ioctl_accept(struct file *file, unsigned int cmd,
+				unsigned long arg)
+{
+	int err;
+	struct socket *sock, *newsock;
+	struct sockaddr_storage address;
+	struct socket_server_data *data;
+	const int addrlen = sizeof(struct sockaddr);
+
+	err = move_addr_to_kernel((void __user *) arg, addrlen, &address);
+	if (err < 0)
+		goto out_release;
+
+	err = sock_create(AF_INET, SOCK_STREAM, 0, &sock);
+	if (err < 0)
+		goto out;
+
+	err = kernel_bind(sock, (struct sockaddr *) &address, addrlen);
+	if (err)
+		goto out_release;
+
+	err = kernel_listen(sock, 1);
+	if (err)
+		goto out_release;
+
+	err = kernel_accept(sock, &newsock, file->f_flags);
+	if (err < 0)
+		goto out_release;
+
+	err = kernel_sock_shutdown(newsock, SHUT_RD);
+	if (err)
+		goto out_release_new;
+
+	// XXX spin_lock(&file->f_lock);
+	data = file->private_data;
+	if (data->sock) {
+		// XXX spin_unlock(&file->f_lock);
+		err = -EISCONN;
+		goto out_release_new;
+	}
+	data->sock = newsock;
+	// XXX spin_unlock(&file->f_lock);
+
+out_release:
+	sock_release(sock);
+out:
+	return err;
+out_release_new:
+	sock_release(newsock);
+	goto out_release;
+}
+
+static long socket_server_ioctl(struct file *file, unsigned int cmd,
+				unsigned long arg)
+{
+	int err;
+
+	switch (cmd) {
+	case SOCKET_SERVER_IOCTL_ACCEPT:
+		err = socket_server_ioctl_accept(file, cmd, arg);
+		break;
+	default:
+		err = -EINVAL;
+		break;
+	}
+	return err;
+}
+
+static int socket_server_open(struct inode *inode, struct file *file)
+{
+	struct socket_server_data *data;
+
+	data = kzalloc(sizeof(struct socket_server_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	file->private_data = data;
+	nonseekable_open(inode, file);
+
+	return 0;
+}
+
+static int socket_server_release(struct inode *inode, struct file *file)
+{
+	struct socket_server_data *data;
+	struct socket *sock;
+
+	// XXX spin_lock(&file->f_lock);
+	data = file->private_data;
+	sock = data->sock;
+	data->sock = NULL;
+	// XXX spin_unlock(&file->f_lock);
+	
+	if (sock)
+		sock_release(sock);
+	kfree(file->private_data);
+	return 0;
+}
+
+static const struct file_operations socket_server_fops = {
+	.owner		= THIS_MODULE,
+	.write_iter	= socket_server_write_iter,
+	.unlocked_ioctl	= socket_server_ioctl,
+	.open		= socket_server_open,
+	.release	= socket_server_release,
+	// TODO implement
+};
+
+static struct miscdevice socket_server = {
+	.minor	= MISC_DYNAMIC_MINOR,
+	.name	= "socket_server",
+	.fops	= &socket_server_fops,
+};
+
+module_misc_device(socket_server);
diff -Nur linux-4.11-copy/net/socket.c linux-4.11/net/socket.c
--- linux-4.11-copy/net/socket.c	2017-05-01 10:47:48.000000000 +0800
+++ linux-4.11/net/socket.c	2017-06-23 20:07:56.558529274 +0800
@@ -195,6 +195,7 @@
 		return -EFAULT;
 	return audit_sockaddr(ulen, kaddr);
 }
+EXPORT_SYMBOL(move_addr_to_kernel);
 
 /**
  *	move_addr_to_user	-	copy an address to user space