[mirror_ubuntu-bionic-kernel.git] / drivers / staging / dgrp / dgrp_mon_ops.c

/*****************************************************************************
 *
 * Copyright 1999 Digi International (www.digi.com)
 *     James Puzzo <jamesp at digi dot com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED; without even the
 * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 * PURPOSE.  See the GNU General Public License for more details.
 *
 */

/*
 *
 *  Filename:
 *
 *     dgrp_mon_ops.c
 *
 *  Description:
 *
 *     Handle the file operations required for the "monitor" devices.
 *     Includes those functions required to register the "mon" devices
 *     in "/proc".
 *
 *  Author:
 *
 *     James A. Puzzo
 *
 */

#include <linux/module.h>
#include <linux/tty.h>
#include <linux/sched.h>
#include <asm/unaligned.h>
#include <linux/proc_fs.h>

#include "dgrp_common.h"

/* File operation declarations */
static int dgrp_mon_open(struct inode *, struct file *);
static int dgrp_mon_release(struct inode *, struct file *);
static ssize_t dgrp_mon_read(struct file *, char __user *, size_t, loff_t *);
static long dgrp_mon_ioctl(struct file *file, unsigned int cmd,
			   unsigned long arg);

static const struct file_operations mon_ops = {
	.owner   = THIS_MODULE,
	.read    = dgrp_mon_read,
	.unlocked_ioctl = dgrp_mon_ioctl,
	.open    = dgrp_mon_open,
	.release = dgrp_mon_release,
};

static struct inode_operations mon_inode_ops = {
	.permission = dgrp_inode_permission
};

void dgrp_register_mon_hook(struct proc_dir_entry *de)
{
	struct nd_struct *node = de->data;

	de->proc_iops = &mon_inode_ops;
	de->proc_fops = &mon_ops;
	node->nd_mon_de = de;
	sema_init(&node->nd_mon_semaphore, 1);
}

/**
 * dgrp_mon_open() -- open /proc/dgrp/ports device for a PortServer
 * @inode: struct inode *
 * @file: struct file *
 *
 * Open function to open the /proc/dgrp/ports device for a PortServer.
 */
static int dgrp_mon_open(struct inode *inode, struct file *file)
{
	struct nd_struct *nd;
	struct proc_dir_entry *de;
	struct timeval tv;
	uint32_t time;
	u8 *buf;
	int rtn;

	rtn = try_module_get(THIS_MODULE);
	if (!rtn)
		return -ENXIO;

	rtn = 0;

	if (!capable(CAP_SYS_ADMIN)) {
		rtn = -EPERM;
		goto done;
	}

	/*
	 *  Make sure that the "private_data" field hasn't already been used.
	 */
	if (file->private_data) {
		rtn = -EINVAL;
		goto done;
	}

	/*
	 *  Get the node pointer, and fail if it doesn't exist.
	 */
	de = PDE(inode);
	if (!de) {
		rtn = -ENXIO;
		goto done;
	}

	nd = (struct nd_struct *)de->data;
	if (!nd) {
		rtn = -ENXIO;
		goto done;
	}

	file->private_data = (void *) nd;

	/*
	 * Allocate the monitor buffer.
	 */

	/*
	 *  Grab the MON lock.
	 */
	down(&nd->nd_mon_semaphore);

	if (nd->nd_mon_buf) {
		rtn = -EBUSY;
		goto done_up;
	}

	nd->nd_mon_buf = kmalloc(MON_MAX, GFP_KERNEL);

	if (!nd->nd_mon_buf) {
		rtn = -ENOMEM;
		goto done_up;
	}

	/*
	 *  Enter an RPDUMP file header into the buffer.
	 */

	buf = nd->nd_mon_buf;

	strcpy(buf, RPDUMP_MAGIC);
	buf += strlen(buf) + 1;

	do_gettimeofday(&tv);

	/*
	 *  tv.tv_sec might be a 64 bit quantity.  Pare
	 *  it down to 32 bits before attempting to encode
	 *  it.
	 */
	time = (uint32_t) (tv.tv_sec & 0xffffffff);

	put_unaligned_be32(time, buf);
	put_unaligned_be16(0, buf + 4);
	buf += 6;

	if (nd->nd_tx_module) {
		buf[0] = RPDUMP_CLIENT;
		put_unaligned_be32(0, buf + 1);
		put_unaligned_be16(1, buf + 5);
		buf[7] = 0xf0 + nd->nd_tx_module;
		buf += 8;
	}

	if (nd->nd_rx_module) {
		buf[0] = RPDUMP_SERVER;
		put_unaligned_be32(0, buf + 1);
		put_unaligned_be16(1, buf + 5);
		buf[7] = 0xf0 + nd->nd_rx_module;
		buf += 8;
	}

	nd->nd_mon_out = 0;
	nd->nd_mon_in  = buf - nd->nd_mon_buf;
	nd->nd_mon_lbolt = jiffies;

done_up:
	up(&nd->nd_mon_semaphore);

done:
	if (rtn)
		module_put(THIS_MODULE);
	return rtn;
}


/**
 * dgrp_mon_release() - Close the MON device for a particular PortServer
 * @inode: struct inode *
 * @file: struct file *
 */
static int dgrp_mon_release(struct inode *inode, struct file *file)
{
	struct nd_struct *nd;

	/*
	 *  Get the node pointer, and quit if it doesn't exist.
	 */
	nd = (struct nd_struct *)(file->private_data);
	if (!nd)
		goto done;

	/*
	 *  Free the monitor buffer.
	 */

	down(&nd->nd_mon_semaphore);

	kfree(nd->nd_mon_buf);
	nd->nd_mon_buf = NULL;
	nd->nd_mon_out = nd->nd_mon_in;

	/*
	 *  Wakeup any thread waiting for buffer space.
	 */

	if (nd->nd_mon_flag & MON_WAIT_SPACE) {
		nd->nd_mon_flag &= ~MON_WAIT_SPACE;
		wake_up_interruptible(&nd->nd_mon_wqueue);
	}

	up(&nd->nd_mon_semaphore);

	/*
	 *  Make sure there is no thread in the middle of writing a packet.
	 */
	down(&nd->nd_net_semaphore);
	up(&nd->nd_net_semaphore);

done:
	module_put(THIS_MODULE);
	file->private_data = NULL;
	return 0;
}

/**
 * dgrp_mon_read() -- Copy data from the monitoring buffer to the user
 */
static ssize_t dgrp_mon_read(struct file *file, char __user *buf, size_t count,
			     loff_t *ppos)
{
	struct nd_struct *nd;
	int r;
	int offset = 0;
	int res = 0;
	ssize_t rtn;

	/*
	 *  Get the node pointer, and quit if it doesn't exist.
	 */
	nd = (struct nd_struct *)(file->private_data);
	if (!nd)
		return -ENXIO;

	/*
	 *  Wait for some data to appear in the buffer.
	 */

	down(&nd->nd_mon_semaphore);

	for (;;) {
		res = (nd->nd_mon_in - nd->nd_mon_out) & MON_MASK;

		if (res)
			break;

		nd->nd_mon_flag |= MON_WAIT_DATA;

		up(&nd->nd_mon_semaphore);

		/*
		 * Go to sleep waiting until the condition becomes true.
		 */
		rtn = wait_event_interruptible(nd->nd_mon_wqueue,
					       ((nd->nd_mon_flag & MON_WAIT_DATA) == 0));

		if (rtn)
			return rtn;

		down(&nd->nd_mon_semaphore);
	}

	/*
	 *  Read whatever is there.
	 */

	if (res > count)
		res = count;

	r = MON_MAX - nd->nd_mon_out;

	if (r <= res) {
		rtn = copy_to_user((void __user *)buf,
				   nd->nd_mon_buf + nd->nd_mon_out, r);
		if (rtn) {
			up(&nd->nd_mon_semaphore);
			return -EFAULT;
		}

		nd->nd_mon_out = 0;
		res -= r;
		offset = r;
	}

	rtn = copy_to_user((void __user *) buf + offset,
			   nd->nd_mon_buf + nd->nd_mon_out, res);
	if (rtn) {
		up(&nd->nd_mon_semaphore);
		return -EFAULT;
	}

	nd->nd_mon_out += res;

	*ppos += res;

	up(&nd->nd_mon_semaphore);

	/*
	 *  Wakeup any thread waiting for buffer space.
	 */

	if (nd->nd_mon_flag & MON_WAIT_SPACE) {
		nd->nd_mon_flag &= ~MON_WAIT_SPACE;
		wake_up_interruptible(&nd->nd_mon_wqueue);
	}

	return res;
}

/*  ioctl is not valid on monitor device */
static long dgrp_mon_ioctl(struct file *file, unsigned int cmd,
			   unsigned long arg)
{
	return -EINVAL;
}
Commit	Line	Data
0b52b749 BP	1	/*****************************************************************************
	2	*
	3	* Copyright 1999 Digi International (www.digi.com)
	4	* James Puzzo <jamesp at digi dot com>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2, or (at your option)
	9	* any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED; without even the
	13	* implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
	14	* PURPOSE. See the GNU General Public License for more details.
	15	*
	16	*/
	17
	18	/*
	19	*
	20	* Filename:
	21	*
	22	* dgrp_mon_ops.c
	23	*
	24	* Description:
	25	*
	26	* Handle the file operations required for the "monitor" devices.
	27	* Includes those functions required to register the "mon" devices
	28	* in "/proc".
	29	*
	30	* Author:
	31	*
	32	* James A. Puzzo
	33	*
	34	*/
	35
	36	#include <linux/module.h>
	37	#include <linux/tty.h>
	38	#include <linux/sched.h>
	39	#include <asm/unaligned.h>
	40	#include <linux/proc_fs.h>
	41
	42	#include "dgrp_common.h"
	43
	44	/* File operation declarations */
	45	static int dgrp_mon_open(struct inode , struct file );
	46	static int dgrp_mon_release(struct inode , struct file );
	47	static ssize_t dgrp_mon_read(struct file , char __user , size_t, loff_t *);
	48	static long dgrp_mon_ioctl(struct file *file, unsigned int cmd,
	49	unsigned long arg);
	50
	51	static const struct file_operations mon_ops = {
	52	.owner = THIS_MODULE,
	53	.read = dgrp_mon_read,
	54	.unlocked_ioctl = dgrp_mon_ioctl,
	55	.open = dgrp_mon_open,
	56	.release = dgrp_mon_release,
	57	};
	58
	59	static struct inode_operations mon_inode_ops = {
	60	.permission = dgrp_inode_permission
	61	};
	62
	63	void dgrp_register_mon_hook(struct proc_dir_entry *de)
	64	{
65	struct nd_struct *node = de->data;
66
67	de->proc_iops = &mon_inode_ops;
68	de->proc_fops = &mon_ops;
69	node->nd_mon_de = de;
70	sema_init(&node->nd_mon_semaphore, 1);
71	}
72
73	/**
74	* dgrp_mon_open() -- open /proc/dgrp/ports device for a PortServer
75	* @inode: struct inode *
76	* @file: struct file *
77	*
78	* Open function to open the /proc/dgrp/ports device for a PortServer.
79	*/
80	static int dgrp_mon_open(struct inode inode, struct file file)
81	{
82	struct nd_struct *nd;
83	struct proc_dir_entry *de;
84	struct timeval tv;
85	uint32_t time;
86	u8 *buf;
87	int rtn;
88
89	rtn = try_module_get(THIS_MODULE);
90	if (!rtn)
91	return -ENXIO;
92
93	rtn = 0;
94
95	if (!capable(CAP_SYS_ADMIN)) {
96	rtn = -EPERM;
97	goto done;
98	}
99
100	/*
101	* Make sure that the "private_data" field hasn't already been used.
102	*/
103	if (file->private_data) {
104	rtn = -EINVAL;
105	goto done;
106	}
107
108	/*
109	* Get the node pointer, and fail if it doesn't exist.
110	*/
111	de = PDE(inode);
112	if (!de) {
113	rtn = -ENXIO;
114	goto done;
115	}
116
117	nd = (struct nd_struct *)de->data;
118	if (!nd) {
119	rtn = -ENXIO;
120	goto done;
121	}
122
123	file->private_data = (void *) nd;
124
125	/*
126	* Allocate the monitor buffer.
127	*/
128
129	/*
130	* Grab the MON lock.
131	*/
132	down(&nd->nd_mon_semaphore);
133
134	if (nd->nd_mon_buf) {
135	rtn = -EBUSY;
136	goto done_up;
137	}
138
139	nd->nd_mon_buf = kmalloc(MON_MAX, GFP_KERNEL);
140
141	if (!nd->nd_mon_buf) {
142	rtn = -ENOMEM;
143	goto done_up;
144	}
145
146	/*
147	* Enter an RPDUMP file header into the buffer.
148	*/
149
150	buf = nd->nd_mon_buf;
151
152	strcpy(buf, RPDUMP_MAGIC);
153	buf += strlen(buf) + 1;
154
155	do_gettimeofday(&tv);
156
157	/*
158	* tv.tv_sec might be a 64 bit quantity. Pare
159	* it down to 32 bits before attempting to encode
160	* it.
161	*/
162	time = (uint32_t) (tv.tv_sec & 0xffffffff);
163
164	put_unaligned_be32(time, buf);
165	put_unaligned_be16(0, buf + 4);
166	buf += 6;
167
168	if (nd->nd_tx_module) {
169	buf[0] = RPDUMP_CLIENT;
170	put_unaligned_be32(0, buf + 1);
171	put_unaligned_be16(1, buf + 5);
172	buf[7] = 0xf0 + nd->nd_tx_module;
173	buf += 8;
174	}
175
176	if (nd->nd_rx_module) {
177	buf[0] = RPDUMP_SERVER;
178	put_unaligned_be32(0, buf + 1);
179	put_unaligned_be16(1, buf + 5);
180	buf[7] = 0xf0 + nd->nd_rx_module;
181	buf += 8;
182	}
183
184	nd->nd_mon_out = 0;
185	nd->nd_mon_in = buf - nd->nd_mon_buf;
186	nd->nd_mon_lbolt = jiffies;
187
188	done_up:
189	up(&nd->nd_mon_semaphore);
190
191	done:
192	if (rtn)
193	module_put(THIS_MODULE);
194	return rtn;
195	}
196
197
198	/**
199	* dgrp_mon_release() - Close the MON device for a particular PortServer
200	* @inode: struct inode *
201	* @file: struct file *
202	*/
203	static int dgrp_mon_release(struct inode inode, struct file file)
204	{
205	struct nd_struct *nd;
206
207	/*
208	* Get the node pointer, and quit if it doesn't exist.
209	*/
210	nd = (struct nd_struct *)(file->private_data);
211	if (!nd)
212	goto done;
213
214	/*
215	* Free the monitor buffer.
216	*/
217
218	down(&nd->nd_mon_semaphore);
219
220	kfree(nd->nd_mon_buf);
221	nd->nd_mon_buf = NULL;
222	nd->nd_mon_out = nd->nd_mon_in;
223
224	/*
225	* Wakeup any thread waiting for buffer space.
226	*/
227
228	if (nd->nd_mon_flag & MON_WAIT_SPACE) {
229	nd->nd_mon_flag &= ~MON_WAIT_SPACE;
230	wake_up_interruptible(&nd->nd_mon_wqueue);
231	}
232
233	up(&nd->nd_mon_semaphore);
234
235	/*
236	* Make sure there is no thread in the middle of writing a packet.
237	*/
238	down(&nd->nd_net_semaphore);
239	up(&nd->nd_net_semaphore);
240
241	done:
242	module_put(THIS_MODULE);
243	file->private_data = NULL;
244	return 0;
245	}
246
247	/**
248	* dgrp_mon_read() -- Copy data from the monitoring buffer to the user
249	*/
250	static ssize_t dgrp_mon_read(struct file file, char __user buf, size_t count,
251	loff_t *ppos)
252	{
253	struct nd_struct *nd;
254	int r;
255	int offset = 0;
256	int res = 0;
257	ssize_t rtn;
258
259	/*
260	* Get the node pointer, and quit if it doesn't exist.
261	*/
262	nd = (struct nd_struct *)(file->private_data);
263	if (!nd)
264	return -ENXIO;
265
266	/*
267	* Wait for some data to appear in the buffer.
268	*/
269
270	down(&nd->nd_mon_semaphore);
271
272	for (;;) {
273	res = (nd->nd_mon_in - nd->nd_mon_out) & MON_MASK;
274
275	if (res)
276	break;
277
278	nd->nd_mon_flag \|= MON_WAIT_DATA;
279
280	up(&nd->nd_mon_semaphore);
281
282	/*
283	* Go to sleep waiting until the condition becomes true.
284	*/
285	rtn = wait_event_interruptible(nd->nd_mon_wqueue,
286	((nd->nd_mon_flag & MON_WAIT_DATA) == 0));
287
288	if (rtn)
289	return rtn;
290
291	down(&nd->nd_mon_semaphore);
292	}
293
294	/*
295	* Read whatever is there.
296	*/
297
298	if (res > count)
299	res = count;
300
301	r = MON_MAX - nd->nd_mon_out;
302
303	if (r <= res) {
304	rtn = copy_to_user((void __user *)buf,
305	nd->nd_mon_buf + nd->nd_mon_out, r);
306	if (rtn) {
307	up(&nd->nd_mon_semaphore);
308	return -EFAULT;
309	}
310
311	nd->nd_mon_out = 0;
312	res -= r;
313	offset = r;
314	}
315
316	rtn = copy_to_user((void __user *) buf + offset,
317	nd->nd_mon_buf + nd->nd_mon_out, res);
318	if (rtn) {
319	up(&nd->nd_mon_semaphore);
320	return -EFAULT;
321	}
322
323	nd->nd_mon_out += res;
324
325	*ppos += res;
326
327	up(&nd->nd_mon_semaphore);
328
329	/*
330	* Wakeup any thread waiting for buffer space.
331	*/
332
333	if (nd->nd_mon_flag & MON_WAIT_SPACE) {
334	nd->nd_mon_flag &= ~MON_WAIT_SPACE;
335	wake_up_interruptible(&nd->nd_mon_wqueue);
336	}
337
338	return res;
339	}
340
341	/* ioctl is not valid on monitor device */
342	static long dgrp_mon_ioctl(struct file *file, unsigned int cmd,
343	unsigned long arg)
344	{
345	return -EINVAL;
346	}