drivers/isdn/divert/divert_procfs.c

   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 /*********************************/
  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 (!(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 /**********************************/
 112 static ssize_t
 113 isdn_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 /***************************************/
 122 static __poll_t
 123 isdn_divert_poll(struct file *file, poll_table *wait)
 124 {
 125         __poll_t mask = 0;
 126
 127         poll_wait(file, &(rd_queue), wait);
 128         /* mask = EPOLLOUT | EPOLLWRNORM; */
 129         if (*((struct divert_info **) file->private_data)) {
 130                 mask |= EPOLLIN | EPOLLRDNORM;
 131         }
 132         return mask;
 133 }                               /* isdn_divert_poll */
 134
 135 /****************/
 136 /* Open routine */
 137 /****************/
 138 static int
 139 isdn_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 /*******************/
 157 static int
 158 isdn_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 /*********/
 183 static 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
 268 static 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
 279 static 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 /****************************/
 294 static struct proc_dir_entry *isdn_proc_entry = NULL;
 295 static 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 /***************************************************************************/
 301 int
 302 divert_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 /***************************************************************************/
 326 int
 327 divert_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 */