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 (!(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