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/smp_lock.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 struct divert_info *divert_info_head = NULL;     /* head of queue */
  32 static struct divert_info *divert_info_tail = NULL;     /* pointer to last entry */
  33 static DEFINE_SPINLOCK(divert_info_lock);/* lock for queue */
  34 static wait_queue_head_t rd_queue;
  35
  36 /*********************************/
  37 /* put an info buffer into queue */
  38 /*********************************/
  39 void
  40 put_info_buffer(char *cp)
  41 {
  42         struct divert_info *ib;
  43         unsigned long flags;
  44
  45         if (if_used <= 0)
  46                 return;
  47         if (!cp)
  48                 return;
  49         if (!*cp)
  50                 return;
  51         if (!(ib = kmalloc(sizeof(struct divert_info) + strlen(cp), GFP_ATOMIC)))
  52                  return;        /* no memory */
  53         strcpy(ib->info_start, cp);     /* set output string */
  54         ib->next = NULL;
  55         spin_lock_irqsave( &divert_info_lock, flags );
  56         ib->usage_cnt = if_used;
  57         if (!divert_info_head)
  58                 divert_info_head = ib;  /* new head */
  59         else
  60                 divert_info_tail->next = ib;    /* follows existing messages */
  61         divert_info_tail = ib;  /* new tail */
  62
  63         /* delete old entrys */
  64         while (divert_info_head->next) {
  65                 if ((divert_info_head->usage_cnt <= 0) &&
  66                     (divert_info_head->next->usage_cnt <= 0)) {
  67                         ib = divert_info_head;
  68                         divert_info_head = divert_info_head->next;
  69                         kfree(ib);
  70                 } else
  71                         break;
  72         }                       /* divert_info_head->next */
  73         spin_unlock_irqrestore( &divert_info_lock, flags );
  74         wake_up_interruptible(&(rd_queue));
  75 }                               /* put_info_buffer */
  76
  77 #ifdef CONFIG_PROC_FS
  78
  79 /**********************************/
  80 /* deflection device read routine */
  81 /**********************************/
  82 static ssize_t
  83 isdn_divert_read(struct file *file, char __user *buf, size_t count, loff_t * off)
  84 {
  85         struct divert_info *inf;
  86         int len;
  87
  88         if (!*((struct divert_info **) file->private_data)) {
  89                 if (file->f_flags & O_NONBLOCK)
  90                         return -EAGAIN;
  91                 interruptible_sleep_on(&(rd_queue));
  92         }
  93         if (!(inf = *((struct divert_info **) file->private_data)))
  94                 return (0);
  95
  96         inf->usage_cnt--;       /* new usage count */
  97         file->private_data = &inf->next;        /* next structure */
  98         if ((len = strlen(inf->info_start)) <= count) {
  99                 if (copy_to_user(buf, inf->info_start, len))
 100                         return -EFAULT;
 101                 *off += len;
 102                 return (len);
 103         }
 104         return (0);
 105 }                               /* isdn_divert_read */
 106
 107 /**********************************/
 108 /* deflection device write routine */
 109 /**********************************/
 110 static ssize_t
 111 isdn_divert_write(struct file *file, const char __user *buf, size_t count, loff_t * off)
 112 {
 113         return (-ENODEV);
 114 }                               /* isdn_divert_write */
 115
 116
 117 /***************************************/
 118 /* select routines for various kernels */
 119 /***************************************/
 120 static unsigned int
 121 isdn_divert_poll(struct file *file, poll_table * wait)
 122 {
 123         unsigned int mask = 0;
 124
 125         poll_wait(file, &(rd_queue), wait);
 126         /* mask = POLLOUT | POLLWRNORM; */
 127         if (*((struct divert_info **) file->private_data)) {
 128                 mask |= POLLIN | POLLRDNORM;
 129         }
 130         return mask;
 131 }                               /* isdn_divert_poll */
 132
 133 /****************/
 134 /* Open routine */
 135 /****************/
 136 static int
 137 isdn_divert_open(struct inode *ino, struct file *filep)
 138 {
 139         unsigned long flags;
 140
 141         spin_lock_irqsave( &divert_info_lock, flags );
 142         if_used++;
 143         if (divert_info_head)
 144                 filep->private_data = &(divert_info_tail->next);
 145         else
 146                 filep->private_data = &divert_info_head;
 147         spin_unlock_irqrestore( &divert_info_lock, flags );
 148         /*  start_divert(); */
 149         return nonseekable_open(ino, filep);
 150 }                               /* isdn_divert_open */
 151
 152 /*******************/
 153 /* close routine   */
 154 /*******************/
 155 static int
 156 isdn_divert_close(struct inode *ino, struct file *filep)
 157 {
 158         struct divert_info *inf;
 159         unsigned long flags;
 160
 161         spin_lock_irqsave( &divert_info_lock, flags );
 162         if_used--;
 163         inf = *((struct divert_info **) filep->private_data);
 164         while (inf) {
 165                 inf->usage_cnt--;
 166                 inf = inf->next;
 167         }
 168         if (if_used <= 0)
 169                 while (divert_info_head) {
 170                         inf = divert_info_head;
 171                         divert_info_head = divert_info_head->next;
 172                         kfree(inf);
 173                 }
 174         spin_unlock_irqrestore( &divert_info_lock, flags );
 175         return (0);
 176 }                               /* isdn_divert_close */
 177
 178 /*********/
 179 /* IOCTL */
 180 /*********/
 181 static int isdn_divert_ioctl_unlocked(struct file *file, uint cmd, ulong arg)
 182 {
 183         divert_ioctl dioctl;
 184         int i;
 185         unsigned long flags;
 186         divert_rule *rulep;
 187         char *cp;
 188
 189         if (copy_from_user(&dioctl, (void __user *) arg, sizeof(dioctl)))
 190                 return -EFAULT;
 191
 192         switch (cmd) {
 193                 case IIOCGETVER:
 194                         dioctl.drv_version = DIVERT_IIOC_VERSION;       /* set version */
 195                         break;
 196
 197                 case IIOCGETDRV:
 198                         if ((dioctl.getid.drvid = divert_if.name_to_drv(dioctl.getid.drvnam)) < 0)
 199                                 return (-EINVAL);
 200                         break;
 201
 202                 case IIOCGETNAM:
 203                         cp = divert_if.drv_to_name(dioctl.getid.drvid);
 204                         if (!cp)
 205                                 return (-EINVAL);
 206                         if (!*cp)
 207                                 return (-EINVAL);
 208                         strcpy(dioctl.getid.drvnam, cp);
 209                         break;
 210
 211                 case IIOCGETRULE:
 212                         if (!(rulep = getruleptr(dioctl.getsetrule.ruleidx)))
 213                                 return (-EINVAL);
 214                         dioctl.getsetrule.rule = *rulep;        /* copy data */
 215                         break;
 216
 217                 case IIOCMODRULE:
 218                         if (!(rulep = getruleptr(dioctl.getsetrule.ruleidx)))
 219                                 return (-EINVAL);
 220             spin_lock_irqsave(&divert_lock, flags);
 221                         *rulep = dioctl.getsetrule.rule;        /* copy data */
 222                         spin_unlock_irqrestore(&divert_lock, flags);
 223                         return (0);     /* no copy required */
 224                         break;
 225
 226                 case IIOCINSRULE:
 227                         return (insertrule(dioctl.getsetrule.ruleidx, &dioctl.getsetrule.rule));
 228                         break;
 229
 230                 case IIOCDELRULE:
 231                         return (deleterule(dioctl.getsetrule.ruleidx));
 232                         break;
 233
 234                 case IIOCDODFACT:
 235                         return (deflect_extern_action(dioctl.fwd_ctrl.subcmd,
 236                                                   dioctl.fwd_ctrl.callid,
 237                                                  dioctl.fwd_ctrl.to_nr));
 238
 239                 case IIOCDOCFACT:
 240                 case IIOCDOCFDIS:
 241                 case IIOCDOCFINT:
 242                         if (!divert_if.drv_to_name(dioctl.cf_ctrl.drvid))
 243                                 return (-EINVAL);       /* invalid driver */
 244                         if ((i = cf_command(dioctl.cf_ctrl.drvid,
 245                                             (cmd == IIOCDOCFACT) ? 1 : (cmd == IIOCDOCFDIS) ? 0 : 2,
 246                                             dioctl.cf_ctrl.cfproc,
 247                                             dioctl.cf_ctrl.msn,
 248                                             dioctl.cf_ctrl.service,
 249                                             dioctl.cf_ctrl.fwd_nr,
 250                                             &dioctl.cf_ctrl.procid)))
 251                                 return (i);
 252                         break;
 253
 254                 default:
 255                         return (-EINVAL);
 256         }                       /* switch cmd */
 257         return copy_to_user((void __user *)arg, &dioctl, sizeof(dioctl)) ? -EFAULT : 0;
 258 }                               /* isdn_divert_ioctl */
 259
 260 static long isdn_divert_ioctl(struct file *file, uint cmd, ulong arg)
 261 {
 262         long ret;
 263
 264         lock_kernel();
 265         ret = isdn_divert_ioctl_unlocked(file, cmd, arg);
 266         unlock_kernel();
 267
 268         return ret;
 269 }
 270
 271 static const struct file_operations isdn_fops =
 272 {
 273         .owner          = THIS_MODULE,
 274         .llseek         = no_llseek,
 275         .read           = isdn_divert_read,
 276         .write          = isdn_divert_write,
 277         .poll           = isdn_divert_poll,
 278         .unlocked_ioctl = isdn_divert_ioctl,
 279         .open           = isdn_divert_open,
 280         .release        = isdn_divert_close,
 281 };
 282
 283 /****************************/
 284 /* isdn subdir in /proc/net */
 285 /****************************/
 286 static struct proc_dir_entry *isdn_proc_entry = NULL;
 287 static struct proc_dir_entry *isdn_divert_entry = NULL;
 288 #endif  /* CONFIG_PROC_FS */
 289
 290 /***************************************************************************/
 291 /* divert_dev_init must be called before the proc filesystem may be used   */
 292 /***************************************************************************/
 293 int
 294 divert_dev_init(void)
 295 {
 296
 297         init_waitqueue_head(&rd_queue);
 298
 299 #ifdef CONFIG_PROC_FS
 300         isdn_proc_entry = proc_mkdir("isdn", init_net.proc_net);
 301         if (!isdn_proc_entry)
 302                 return (-1);
 303         isdn_divert_entry = proc_create("divert", S_IFREG | S_IRUGO,
 304                                         isdn_proc_entry, &isdn_fops);
 305         if (!isdn_divert_entry) {
 306                 remove_proc_entry("isdn", init_net.proc_net);
 307                 return (-1);
 308         }
 309 #endif  /* CONFIG_PROC_FS */
 310
 311         return (0);
 312 }                               /* divert_dev_init */
 313
 314 /***************************************************************************/
 315 /* divert_dev_deinit must be called before leaving isdn when included as   */
 316 /* a module.                                                               */
 317 /***************************************************************************/
 318 int
 319 divert_dev_deinit(void)
 320 {
 321
 322 #ifdef CONFIG_PROC_FS
 323         remove_proc_entry("divert", isdn_proc_entry);
 324         remove_proc_entry("isdn", init_net.proc_net);
 325 #endif  /* CONFIG_PROC_FS */
 326
 327         return (0);
 328 }                               /* divert_dev_deinit */