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 (!*((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 */