LXR linux/drivers/isdn/divert/divert

   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 (!*((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/**********************************/
 111static ssize_t
 112isdn_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/***************************************/
 121static unsigned int
 122isdn_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/****************/
 137static int
 138isdn_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/*******************/
 156static int
 157isdn_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/*********/
 182static 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 ((i = cf_command(dioctl.cf_ctrl.drvid,
 246                                            (cmd == IIOCDOCFACT) ? 1 : (cmd == IIOCDOCFDIS) ? 0 : 2,
 247                                            dioctl.cf_ctrl.cfproc,
 248                                            dioctl.cf_ctrl.msn,
 249                                            dioctl.cf_ctrl.service,
 250                                            dioctl.cf_ctrl.fwd_nr,
 251                                            &dioctl.cf_ctrl.procid)))
 252                                return (i);
 253                        break;
 254
 255                default:
 256                        return (-EINVAL);
 257        }                       /* switch cmd */
 258        return copy_to_user((void __user *)arg, &dioctl, sizeof(dioctl)) ? -EFAULT : 0;
 259}                               /* isdn_divert_ioctl */
 260
 261static long isdn_divert_ioctl(struct file *file, uint cmd, ulong arg)
 262{
 263        long ret;
 264
 265        mutex_lock(&isdn_divert_mutex);
 266        ret = isdn_divert_ioctl_unlocked(file, cmd, arg);
 267        mutex_unlock(&isdn_divert_mutex);
 268
 269        return ret;
 270}
 271
 272static const struct file_operations isdn_fops =
 273{
 274        .owner          = THIS_MODULE,
 275        .llseek         = no_llseek,
 276        .read           = isdn_divert_read,
 277        .write          = isdn_divert_write,
 278        .poll           = isdn_divert_poll,
 279        .unlocked_ioctl = isdn_divert_ioctl,
 280        .open           = isdn_divert_open,
 281        .release        = isdn_divert_close,                                      
 282};
 283
 284/****************************/
 285/* isdn subdir in /proc/net */
 286/****************************/
 287static struct proc_dir_entry *isdn_proc_entry = NULL;
 288static struct proc_dir_entry *isdn_divert_entry = NULL;
 289#endif  /* CONFIG_PROC_FS */
 290
 291/***************************************************************************/
 292/* divert_dev_init must be called before the proc filesystem may be used   */
 293/***************************************************************************/
 294int
 295divert_dev_init(void)
 296{
 297
 298        init_waitqueue_head(&rd_queue);
 299
 300#ifdef CONFIG_PROC_FS
 301        isdn_proc_entry = proc_mkdir("isdn", init_net.proc_net);
 302        if (!isdn_proc_entry)
 303                return (-1);
 304        isdn_divert_entry = proc_create("divert", S_IFREG | S_IRUGO,
 305                                        isdn_proc_entry, &isdn_fops);
 306        if (!isdn_divert_entry) {
 307                remove_proc_entry("isdn", init_net.proc_net);
 308                return (-1);
 309        }
 310#endif  /* CONFIG_PROC_FS */
 311
 312        return (0);
 313}                               /* divert_dev_init */
 314
 315/***************************************************************************/
 316/* divert_dev_deinit must be called before leaving isdn when included as   */
 317/* a module.                                                               */
 318/***************************************************************************/
 319int
 320divert_dev_deinit(void)
 321{
 322
 323#ifdef CONFIG_PROC_FS
 324        remove_proc_entry("divert", isdn_proc_entry);
 325        remove_proc_entry("isdn", init_net.proc_net);
 326#endif  /* CONFIG_PROC_FS */
 327
 328        return (0);
 329}                               /* divert_dev_deinit */
 330