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   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 "isdn_divert.h"
  24
  25
  26 /*********************************/
  27 /* Variables for interface queue */
  28 /*********************************/
  29 ulong if_used = 0;              /* number of interface users */
  30 static struct divert_info *divert_info_head = NULL;     /* head of queue */
  31 static struct divert_info *divert_info_tail = NULL;     /* pointer to last entry */
  32 static DEFINE_SPINLOCK(divert_info_lock);/* lock for queue */
  33 static wait_queue_head_t rd_queue;
  34
  35 /*********************************/
  36 /* put an info buffer into queue */
  37 /*********************************/
  38 void
  39 put_info_buffer(char *cp)
  40 {
  41         struct divert_info *ib;
  42         unsigned long flags;
  43
  44         if (if_used <= 0)
  45                 return;
  46         if (!cp)
  47                 return;
  48         if (!*cp)
  49                 return;
  50         if (!(ib = kmalloc(sizeof(struct divert_info) + strlen(cp), GFP_ATOMIC)))
  51                  return;        /* no memory */
  52         strcpy(ib->info_start, cp);     /* set output string */
  53         ib->next = NULL;
  54         spin_lock_irqsave( &divert_info_lock, flags );
  55         ib->usage_cnt = if_used;
  56         if (!divert_info_head)
  57                 divert_info_head = ib;  /* new head */
  58         else
  59                 divert_info_tail->next = ib;    /* follows existing messages */
  60         divert_info_tail = ib;  /* new tail */
  61
  62         /* delete old entrys */
  63         while (divert_info_head->next) {
  64                 if ((divert_info_head->usage_cnt <= 0) &&
  65                     (divert_info_head->next->usage_cnt <= 0)) {
  66                         ib = divert_info_head;
  67                         divert_info_head = divert_info_head->next;
  68                         kfree(ib);
  69                 } else
  70                         break;
  71         }                       /* divert_info_head->next */
  72         spin_unlock_irqrestore( &divert_info_lock, flags );
  73         wake_up_interruptible(&(rd_queue));
  74 }                               /* put_info_buffer */
  75
  76 #ifdef CONFIG_PROC_FS
  77
  78 /**********************************/
  79 /* deflection device read routine */
  80 /**********************************/
  81 static ssize_t
  82 isdn_divert_read(struct file *file, char __user *buf, size_t count, loff_t * off)
  83 {
  84         struct divert_info *inf;
  85         int len;
  86
  87         if (!*((struct divert_info **) file->private_data)) {
  88                 if (file->f_flags & O_NONBLOCK)
  89                         return -EAGAIN;
  90                 interruptible_sleep_on(&(rd_queue));
  91         }
  92         if (!(inf = *((struct divert_info **) file->private_data)))
  93                 return (0);
  94
  95         inf->usage_cnt--;       /* new usage count */
  96         file->private_data = &inf->next;        /* next structure */
  97         if ((len = strlen(inf->info_start)) <= count) {
  98                 if (copy_to_user(buf, inf->info_start, len))
  99                         return -EFAULT;
 100                 *off += len;
 101                 return (len);
 102         }
 103         return (0);
 104 }                               /* isdn_divert_read */
 105
 106 /**********************************/
 107 /* deflection device write routine */
 108 /**********************************/
 109 static ssize_t
 110 isdn_divert_write(struct file *file, const char __user *buf, size_t count, loff_t * off)
 111 {
 112         return (-ENODEV);
 113 }                               /* isdn_divert_write */
 114
 115
 116 /***************************************/
 117 /* select routines for various kernels */
 118 /***************************************/
 119 static unsigned int
 120 isdn_divert_poll(struct file *file, poll_table * wait)
 121 {
 122         unsigned int mask = 0;
 123
 124         poll_wait(file, &(rd_queue), wait);
 125         /* mask = POLLOUT | POLLWRNORM; */
 126         if (*((struct divert_info **) file->private_data)) {
 127                 mask |= POLLIN | POLLRDNORM;
 128         }
 129         return mask;
 130 }                               /* isdn_divert_poll */
 131
 132 /****************/
 133 /* Open routine */
 134 /****************/
 135 static int
 136 isdn_divert_open(struct inode *ino, struct file *filep)
 137 {
 138         unsigned long flags;
 139
 140         spin_lock_irqsave( &divert_info_lock, flags );
 141         if_used++;
 142         if (divert_info_head)
 143                 filep->private_data = &(divert_info_tail->next);
 144         else
 145                 filep->private_data = &divert_info_head;
 146         spin_unlock_irqrestore( &divert_info_lock, flags );
 147         /*  start_divert(); */
 148         return nonseekable_open(ino, filep);
 149 }                               /* isdn_divert_open */
 150
 151 /*******************/
 152 /* close routine   */
 153 /*******************/
 154 static int
 155 isdn_divert_close(struct inode *ino, struct file *filep)
 156 {
 157         struct divert_info *inf;
 158         unsigned long flags;
 159
 160         spin_lock_irqsave( &divert_info_lock, flags );
 161         if_used--;
 162         inf = *((struct divert_info **) filep->private_data);
 163         while (inf) {
 164                 inf->usage_cnt--;
 165                 inf = inf->next;
 166         }
 167         if (if_used <= 0)
 168                 while (divert_info_head) {
 169                         inf = divert_info_head;
 170                         divert_info_head = divert_info_head->next;
 171                         kfree(inf);
 172                 }
 173         spin_unlock_irqrestore( &divert_info_lock, flags );
 174         return (0);
 175 }                               /* isdn_divert_close */
 176
 177 /*********/
 178 /* IOCTL */
 179 /*********/
 180 static int
 181 isdn_divert_ioctl(struct inode *inode, struct file *file,
 182                   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
 261 static const struct file_operations isdn_fops =
 262 {
 263         .owner          = THIS_MODULE,
 264         .llseek         = no_llseek,
 265         .read           = isdn_divert_read,
 266         .write          = isdn_divert_write,
 267         .poll           = isdn_divert_poll,
 268         .ioctl          = isdn_divert_ioctl,
 269         .open           = isdn_divert_open,
 270         .release        = isdn_divert_close,
 271 };
 272
 273 /****************************/
 274 /* isdn subdir in /proc/net */
 275 /****************************/
 276 static struct proc_dir_entry *isdn_proc_entry = NULL;
 277 static struct proc_dir_entry *isdn_divert_entry = NULL;
 278 #endif  /* CONFIG_PROC_FS */
 279
 280 /***************************************************************************/
 281 /* divert_dev_init must be called before the proc filesystem may be used   */
 282 /***************************************************************************/
 283 int
 284 divert_dev_init(void)
 285 {
 286
 287         init_waitqueue_head(&rd_queue);
 288
 289 #ifdef CONFIG_PROC_FS
 290         isdn_proc_entry = proc_mkdir("isdn", init_net.proc_net);
 291         if (!isdn_proc_entry)
 292                 return (-1);
 293         isdn_divert_entry = proc_create("divert", S_IFREG | S_IRUGO,
 294                                         isdn_proc_entry, &isdn_fops);
 295         if (!isdn_divert_entry) {
 296                 remove_proc_entry("isdn", init_net.proc_net);
 297                 return (-1);
 298         }
 299 #endif  /* CONFIG_PROC_FS */
 300
 301         return (0);
 302 }                               /* divert_dev_init */
 303
 304 /***************************************************************************/
 305 /* divert_dev_deinit must be called before leaving isdn when included as   */
 306 /* a module.                                                               */
 307 /***************************************************************************/
 308 int
 309 divert_dev_deinit(void)
 310 {
 311
 312 #ifdef CONFIG_PROC_FS
 313         remove_proc_entry("divert", isdn_proc_entry);
 314         remove_proc_entry("isdn", init_net.proc_net);
 315 #endif  /* CONFIG_PROC_FS */
 316
 317         return (0);
 318 }                               /* divert_dev_deinit */