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divert_procfs.c
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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 ([email protected])
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 /*********************************/
30 ulong if_used = 0; /* number of interface users */
31 static DEFINE_MUTEX(isdn_divert_mutex);
32 static struct divert_info *divert_info_head = NULL; /* head of queue */
33 static struct divert_info *divert_info_tail = NULL; /* pointer to last entry */
34 static DEFINE_SPINLOCK(divert_info_lock);/* lock for queue */
35 static wait_queue_head_t rd_queue;
36 
37 /*********************************/
38 /* put an info buffer into queue */
39 /*********************************/
40 void
41 put_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 /**********************************/
83 static ssize_t
84 isdn_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 (!*((struct divert_info **) file->private_data)) {
90  if (file->f_flags & O_NONBLOCK)
91  return -EAGAIN;
92  interruptible_sleep_on(&(rd_queue));
93  }
94  if (!(inf = *((struct divert_info **) file->private_data)))
95  return (0);
96 
97  inf->usage_cnt--; /* new usage count */
98  file->private_data = &inf->next; /* next structure */
99  if ((len = strlen(inf->info_start)) <= count) {
100  if (copy_to_user(buf, inf->info_start, len))
101  return -EFAULT;
102  *off += len;
103  return (len);
104  }
105  return (0);
106 } /* isdn_divert_read */
107 
108 /**********************************/
109 /* deflection device write routine */
110 /**********************************/
111 static ssize_t
112 isdn_divert_write(struct file *file, const char __user *buf, size_t count, loff_t *off)
113 {
114  return (-ENODEV);
115 } /* isdn_divert_write */
116 
117 
118 /***************************************/
119 /* select routines for various kernels */
120 /***************************************/
121 static unsigned int
122 isdn_divert_poll(struct file *file, poll_table *wait)
123 {
124  unsigned int mask = 0;
125 
126  poll_wait(file, &(rd_queue), wait);
127  /* mask = POLLOUT | POLLWRNORM; */
128  if (*((struct divert_info **) file->private_data)) {
129  mask |= POLLIN | POLLRDNORM;
130  }
131  return mask;
132 } /* isdn_divert_poll */
133 
134 /****************/
135 /* Open routine */
136 /****************/
137 static int
138 isdn_divert_open(struct inode *ino, struct file *filep)
139 {
140  unsigned long flags;
141 
142  spin_lock_irqsave(&divert_info_lock, flags);
143  if_used++;
144  if (divert_info_head)
145  filep->private_data = &(divert_info_tail->next);
146  else
147  filep->private_data = &divert_info_head;
148  spin_unlock_irqrestore(&divert_info_lock, flags);
149  /* start_divert(); */
150  return nonseekable_open(ino, filep);
151 } /* isdn_divert_open */
152 
153 /*******************/
154 /* close routine */
155 /*******************/
156 static int
157 isdn_divert_close(struct inode *ino, struct file *filep)
158 {
159  struct divert_info *inf;
160  unsigned long flags;
161 
162  spin_lock_irqsave(&divert_info_lock, flags);
163  if_used--;
164  inf = *((struct divert_info **) filep->private_data);
165  while (inf) {
166  inf->usage_cnt--;
167  inf = inf->next;
168  }
169  if (if_used <= 0)
170  while (divert_info_head) {
171  inf = divert_info_head;
172  divert_info_head = divert_info_head->next;
173  kfree(inf);
174  }
175  spin_unlock_irqrestore(&divert_info_lock, flags);
176  return (0);
177 } /* isdn_divert_close */
178 
179 /*********/
180 /* IOCTL */
181 /*********/
182 static int isdn_divert_ioctl_unlocked(struct file *file, uint cmd, ulong arg)
183 {
184  divert_ioctl dioctl;
185  int i;
186  unsigned long flags;
187  divert_rule *rulep;
188  char *cp;
189 
190  if (copy_from_user(&dioctl, (void __user *) arg, sizeof(dioctl)))
191  return -EFAULT;
192 
193  switch (cmd) {
194  case IIOCGETVER:
195  dioctl.drv_version = DIVERT_IIOC_VERSION; /* set version */
196  break;
197 
198  case IIOCGETDRV:
199  if ((dioctl.getid.drvid = divert_if.name_to_drv(dioctl.getid.drvnam)) < 0)
200  return (-EINVAL);
201  break;
202 
203  case IIOCGETNAM:
204  cp = divert_if.drv_to_name(dioctl.getid.drvid);
205  if (!cp)
206  return (-EINVAL);
207  if (!*cp)
208  return (-EINVAL);
209  strcpy(dioctl.getid.drvnam, cp);
210  break;
211 
212  case IIOCGETRULE:
213  if (!(rulep = getruleptr(dioctl.getsetrule.ruleidx)))
214  return (-EINVAL);
215  dioctl.getsetrule.rule = *rulep; /* copy data */
216  break;
217 
218  case IIOCMODRULE:
219  if (!(rulep = getruleptr(dioctl.getsetrule.ruleidx)))
220  return (-EINVAL);
221  spin_lock_irqsave(&divert_lock, flags);
222  *rulep = dioctl.getsetrule.rule; /* copy data */
223  spin_unlock_irqrestore(&divert_lock, flags);
224  return (0); /* no copy required */
225  break;
226 
227  case IIOCINSRULE:
228  return (insertrule(dioctl.getsetrule.ruleidx, &dioctl.getsetrule.rule));
229  break;
230 
231  case IIOCDELRULE:
232  return (deleterule(dioctl.getsetrule.ruleidx));
233  break;
234 
235  case IIOCDODFACT:
236  return (deflect_extern_action(dioctl.fwd_ctrl.subcmd,
237  dioctl.fwd_ctrl.callid,
238  dioctl.fwd_ctrl.to_nr));
239 
240  case IIOCDOCFACT:
241  case IIOCDOCFDIS:
242  case IIOCDOCFINT:
243  if (!divert_if.drv_to_name(dioctl.cf_ctrl.drvid))
244  return (-EINVAL); /* invalid driver */
245  if (strnlen(dioctl.cf_ctrl.msn, sizeof(dioctl.cf_ctrl.msn)) ==
246  sizeof(dioctl.cf_ctrl.msn))
247  return -EINVAL;
248  if (strnlen(dioctl.cf_ctrl.fwd_nr, sizeof(dioctl.cf_ctrl.fwd_nr)) ==
249  sizeof(dioctl.cf_ctrl.fwd_nr))
250  return -EINVAL;
251  if ((i = cf_command(dioctl.cf_ctrl.drvid,
252  (cmd == IIOCDOCFACT) ? 1 : (cmd == IIOCDOCFDIS) ? 0 : 2,
253  dioctl.cf_ctrl.cfproc,
254  dioctl.cf_ctrl.msn,
255  dioctl.cf_ctrl.service,
256  dioctl.cf_ctrl.fwd_nr,
257  &dioctl.cf_ctrl.procid)))
258  return (i);
259  break;
260 
261  default:
262  return (-EINVAL);
263  } /* switch cmd */
264  return copy_to_user((void __user *)arg, &dioctl, sizeof(dioctl)) ? -EFAULT : 0;
265 } /* isdn_divert_ioctl */
266 
267 static long isdn_divert_ioctl(struct file *file, uint cmd, ulong arg)
268 {
269  long ret;
270 
271  mutex_lock(&isdn_divert_mutex);
272  ret = isdn_divert_ioctl_unlocked(file, cmd, arg);
273  mutex_unlock(&isdn_divert_mutex);
274 
275  return ret;
276 }
277 
278 static const struct file_operations isdn_fops =
279 {
280  .owner = THIS_MODULE,
281  .llseek = no_llseek,
282  .read = isdn_divert_read,
283  .write = isdn_divert_write,
284  .poll = isdn_divert_poll,
285  .unlocked_ioctl = isdn_divert_ioctl,
286  .open = isdn_divert_open,
287  .release = isdn_divert_close,
288 };
289 
290 /****************************/
291 /* isdn subdir in /proc/net */
292 /****************************/
293 static struct proc_dir_entry *isdn_proc_entry = NULL;
294 static struct proc_dir_entry *isdn_divert_entry = NULL;
295 #endif /* CONFIG_PROC_FS */
296 
297 /***************************************************************************/
298 /* divert_dev_init must be called before the proc filesystem may be used */
299 /***************************************************************************/
300 int
301 divert_dev_init(void)
302 {
303 
304  init_waitqueue_head(&rd_queue);
305 
306 #ifdef CONFIG_PROC_FS
307  isdn_proc_entry = proc_mkdir("isdn", init_net.proc_net);
308  if (!isdn_proc_entry)
309  return (-1);
310  isdn_divert_entry = proc_create("divert", S_IFREG | S_IRUGO,
311  isdn_proc_entry, &isdn_fops);
312  if (!isdn_divert_entry) {
313  remove_proc_entry("isdn", init_net.proc_net);
314  return (-1);
315  }
316 #endif /* CONFIG_PROC_FS */
317 
318  return (0);
319 } /* divert_dev_init */
320 
321 /***************************************************************************/
322 /* divert_dev_deinit must be called before leaving isdn when included as */
323 /* a module. */
324 /***************************************************************************/
325 int
326 divert_dev_deinit(void)
327 {
328 
329 #ifdef CONFIG_PROC_FS
330  remove_proc_entry("divert", isdn_proc_entry);
331  remove_proc_entry("isdn", init_net.proc_net);
332 #endif /* CONFIG_PROC_FS */
333 
334  return (0);
335 } /* divert_dev_deinit */
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