1/* $Id: divert_procfs.c,v 1.11.6.2 2001/09/23 22:24:36 kai Exp $
2 *
3 * Filesystem handling for the diversion supplementary services.
4 *
5 * Copyright 1998       by Werner Cornelius (werner@isdn4linux.de)
6 *
7 * This software may be used and distributed according to the terms
8 * of the GNU General Public License, incorporated herein by reference.
9 *
10 */
11
12#include <linux/module.h>
13#include <linux/poll.h>
14#include <linux/slab.h>
15#ifdef CONFIG_PROC_FS
16#include <linux/proc_fs.h>
17#else
18#include <linux/fs.h>
19#endif
20#include <linux/sched.h>
21#include <linux/isdnif.h>
22#include <net/net_namespace.h>
23#include <linux/mutex.h>
24#include "isdn_divert.h"
25
26
27/*********************************/
28/* Variables for interface queue */
29/*********************************/
30ulong if_used = 0;		/* number of interface users */
31static DEFINE_MUTEX(isdn_divert_mutex);
32static struct divert_info *divert_info_head = NULL;	/* head of queue */
33static struct divert_info *divert_info_tail = NULL;	/* pointer to last entry */
34static DEFINE_SPINLOCK(divert_info_lock);/* lock for queue */
35static wait_queue_head_t rd_queue;
36
37/*********************************/
38/* put an info buffer into queue */
39/*********************************/
40void
41put_info_buffer(char *cp)
42{
43	struct divert_info *ib;
44	unsigned long flags;
45
46	if (if_used <= 0)
47		return;
48	if (!cp)
49		return;
50	if (!*cp)
51		return;
52	if (!(ib = kmalloc(sizeof(struct divert_info) + strlen(cp), GFP_ATOMIC)))
53		return;	/* no memory */
54	strcpy(ib->info_start, cp);	/* set output string */
55	ib->next = NULL;
56	spin_lock_irqsave(&divert_info_lock, flags);
57	ib->usage_cnt = if_used;
58	if (!divert_info_head)
59		divert_info_head = ib;	/* new head */
60	else
61		divert_info_tail->next = ib;	/* follows existing messages */
62	divert_info_tail = ib;	/* new tail */
63
64	/* delete old entrys */
65	while (divert_info_head->next) {
66		if ((divert_info_head->usage_cnt <= 0) &&
67		    (divert_info_head->next->usage_cnt <= 0)) {
68			ib = divert_info_head;
69			divert_info_head = divert_info_head->next;
70			kfree(ib);
71		} else
72			break;
73	}			/* divert_info_head->next */
74	spin_unlock_irqrestore(&divert_info_lock, flags);
75	wake_up_interruptible(&(rd_queue));
76}				/* put_info_buffer */
77
78#ifdef CONFIG_PROC_FS
79
80/**********************************/
81/* deflection device read routine */
82/**********************************/
83static ssize_t
84isdn_divert_read(struct file *file, char __user *buf, size_t count, loff_t *off)
85{
86	struct divert_info *inf;
87	int len;
88
89	if (!(inf = *((struct divert_info **) file->private_data))) {
90		if (file->f_flags & O_NONBLOCK)
91			return -EAGAIN;
92		wait_event_interruptible(rd_queue, (inf =
93			*((struct divert_info **) file->private_data)));
94	}
95	if (!inf)
96		return (0);
97
98	inf->usage_cnt--;	/* new usage count */
99	file->private_data = &inf->next;	/* next structure */
100	if ((len = strlen(inf->info_start)) <= count) {
101		if (copy_to_user(buf, inf->info_start, len))
102			return -EFAULT;
103		*off += len;
104		return (len);
105	}
106	return (0);
107}				/* isdn_divert_read */
108
109/**********************************/
110/* deflection device write routine */
111/**********************************/
112static ssize_t
113isdn_divert_write(struct file *file, const char __user *buf, size_t count, loff_t *off)
114{
115	return (-ENODEV);
116}				/* isdn_divert_write */
117
118
119/***************************************/
120/* select routines for various kernels */
121/***************************************/
122static unsigned int
123isdn_divert_poll(struct file *file, poll_table *wait)
124{
125	unsigned int mask = 0;
126
127	poll_wait(file, &(rd_queue), wait);
128	/* mask = POLLOUT | POLLWRNORM; */
129	if (*((struct divert_info **) file->private_data)) {
130		mask |= POLLIN | POLLRDNORM;
131	}
132	return mask;
133}				/* isdn_divert_poll */
134
135/****************/
136/* Open routine */
137/****************/
138static int
139isdn_divert_open(struct inode *ino, struct file *filep)
140{
141	unsigned long flags;
142
143	spin_lock_irqsave(&divert_info_lock, flags);
144	if_used++;
145	if (divert_info_head)
146		filep->private_data = &(divert_info_tail->next);
147	else
148		filep->private_data = &divert_info_head;
149	spin_unlock_irqrestore(&divert_info_lock, flags);
150	/*  start_divert(); */
151	return nonseekable_open(ino, filep);
152}				/* isdn_divert_open */
153
154/*******************/
155/* close routine   */
156/*******************/
157static int
158isdn_divert_close(struct inode *ino, struct file *filep)
159{
160	struct divert_info *inf;
161	unsigned long flags;
162
163	spin_lock_irqsave(&divert_info_lock, flags);
164	if_used--;
165	inf = *((struct divert_info **) filep->private_data);
166	while (inf) {
167		inf->usage_cnt--;
168		inf = inf->next;
169	}
170	if (if_used <= 0)
171		while (divert_info_head) {
172			inf = divert_info_head;
173			divert_info_head = divert_info_head->next;
174			kfree(inf);
175		}
176	spin_unlock_irqrestore(&divert_info_lock, flags);
177	return (0);
178}				/* isdn_divert_close */
179
180/*********/
181/* IOCTL */
182/*********/
183static int isdn_divert_ioctl_unlocked(struct file *file, uint cmd, ulong arg)
184{
185	divert_ioctl dioctl;
186	int i;
187	unsigned long flags;
188	divert_rule *rulep;
189	char *cp;
190
191	if (copy_from_user(&dioctl, (void __user *) arg, sizeof(dioctl)))
192		return -EFAULT;
193
194	switch (cmd) {
195	case IIOCGETVER:
196		dioctl.drv_version = DIVERT_IIOC_VERSION;	/* set version */
197		break;
198
199	case IIOCGETDRV:
200		if ((dioctl.getid.drvid = divert_if.name_to_drv(dioctl.getid.drvnam)) < 0)
201			return (-EINVAL);
202		break;
203
204	case IIOCGETNAM:
205		cp = divert_if.drv_to_name(dioctl.getid.drvid);
206		if (!cp)
207			return (-EINVAL);
208		if (!*cp)
209			return (-EINVAL);
210		strcpy(dioctl.getid.drvnam, cp);
211		break;
212
213	case IIOCGETRULE:
214		if (!(rulep = getruleptr(dioctl.getsetrule.ruleidx)))
215			return (-EINVAL);
216		dioctl.getsetrule.rule = *rulep;	/* copy data */
217		break;
218
219	case IIOCMODRULE:
220		if (!(rulep = getruleptr(dioctl.getsetrule.ruleidx)))
221			return (-EINVAL);
222		spin_lock_irqsave(&divert_lock, flags);
223		*rulep = dioctl.getsetrule.rule;	/* copy data */
224		spin_unlock_irqrestore(&divert_lock, flags);
225		return (0);	/* no copy required */
226		break;
227
228	case IIOCINSRULE:
229		return (insertrule(dioctl.getsetrule.ruleidx, &dioctl.getsetrule.rule));
230		break;
231
232	case IIOCDELRULE:
233		return (deleterule(dioctl.getsetrule.ruleidx));
234		break;
235
236	case IIOCDODFACT:
237		return (deflect_extern_action(dioctl.fwd_ctrl.subcmd,
238					      dioctl.fwd_ctrl.callid,
239					      dioctl.fwd_ctrl.to_nr));
240
241	case IIOCDOCFACT:
242	case IIOCDOCFDIS:
243	case IIOCDOCFINT:
244		if (!divert_if.drv_to_name(dioctl.cf_ctrl.drvid))
245			return (-EINVAL);	/* invalid driver */
246		if (strnlen(dioctl.cf_ctrl.msn, sizeof(dioctl.cf_ctrl.msn)) ==
247		    sizeof(dioctl.cf_ctrl.msn))
248			return -EINVAL;
249		if (strnlen(dioctl.cf_ctrl.fwd_nr, sizeof(dioctl.cf_ctrl.fwd_nr)) ==
250		    sizeof(dioctl.cf_ctrl.fwd_nr))
251			return -EINVAL;
252		if ((i = cf_command(dioctl.cf_ctrl.drvid,
253				    (cmd == IIOCDOCFACT) ? 1 : (cmd == IIOCDOCFDIS) ? 0 : 2,
254				    dioctl.cf_ctrl.cfproc,
255				    dioctl.cf_ctrl.msn,
256				    dioctl.cf_ctrl.service,
257				    dioctl.cf_ctrl.fwd_nr,
258				    &dioctl.cf_ctrl.procid)))
259			return (i);
260		break;
261
262	default:
263		return (-EINVAL);
264	}			/* switch cmd */
265	return copy_to_user((void __user *)arg, &dioctl, sizeof(dioctl)) ? -EFAULT : 0;
266}				/* isdn_divert_ioctl */
267
268static long isdn_divert_ioctl(struct file *file, uint cmd, ulong arg)
269{
270	long ret;
271
272	mutex_lock(&isdn_divert_mutex);
273	ret = isdn_divert_ioctl_unlocked(file, cmd, arg);
274	mutex_unlock(&isdn_divert_mutex);
275
276	return ret;
277}
278
279static const struct file_operations isdn_fops =
280{
281	.owner          = THIS_MODULE,
282	.llseek         = no_llseek,
283	.read           = isdn_divert_read,
284	.write          = isdn_divert_write,
285	.poll           = isdn_divert_poll,
286	.unlocked_ioctl = isdn_divert_ioctl,
287	.open           = isdn_divert_open,
288	.release        = isdn_divert_close,
289};
290
291/****************************/
292/* isdn subdir in /proc/net */
293/****************************/
294static struct proc_dir_entry *isdn_proc_entry = NULL;
295static struct proc_dir_entry *isdn_divert_entry = NULL;
296#endif	/* CONFIG_PROC_FS */
297
298/***************************************************************************/
299/* divert_dev_init must be called before the proc filesystem may be used   */
300/***************************************************************************/
301int
302divert_dev_init(void)
303{
304
305	init_waitqueue_head(&rd_queue);
306
307#ifdef CONFIG_PROC_FS
308	isdn_proc_entry = proc_mkdir("isdn", init_net.proc_net);
309	if (!isdn_proc_entry)
310		return (-1);
311	isdn_divert_entry = proc_create("divert", S_IFREG | S_IRUGO,
312					isdn_proc_entry, &isdn_fops);
313	if (!isdn_divert_entry) {
314		remove_proc_entry("isdn", init_net.proc_net);
315		return (-1);
316	}
317#endif	/* CONFIG_PROC_FS */
318
319	return (0);
320}				/* divert_dev_init */
321
322/***************************************************************************/
323/* divert_dev_deinit must be called before leaving isdn when included as   */
324/* a module.                                                               */
325/***************************************************************************/
326int
327divert_dev_deinit(void)
328{
329
330#ifdef CONFIG_PROC_FS
331	remove_proc_entry("divert", isdn_proc_entry);
332	remove_proc_entry("isdn", init_net.proc_net);
333#endif	/* CONFIG_PROC_FS */
334
335	return (0);
336}				/* divert_dev_deinit */
337