drivers/isdn/hysdn/hysdn_proclog.c

   1 /* $Id: hysdn_proclog.c,v 1.9.6.3 2001/09/23 22:24:54 kai Exp $
   2  *
   3  * Linux driver for HYSDN cards, /proc/net filesystem log functions.
   4  *
   5  * Author    Werner Cornelius (werner@titro.de) for Hypercope GmbH
   6  * Copyright 1999 by Werner Cornelius (werner@titro.de)
   7  *
   8  * This software may be used and distributed according to the terms
   9  * of the GNU General Public License, incorporated herein by reference.
  10  *
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/poll.h>
  15 #include <linux/proc_fs.h>
  16 #include <linux/sched.h>
  17 #include <linux/smp_lock.h>
  18
  19 #include "hysdn_defs.h"
  20
  21 /* the proc subdir for the interface is defined in the procconf module */
  22 extern struct proc_dir_entry *hysdn_proc_entry;
  23
  24 static void put_log_buffer(hysdn_card * card, char *cp);
  25
  26 /*************************************************/
  27 /* structure keeping ascii log for device output */
  28 /*************************************************/
  29 struct log_data {
  30         struct log_data *next;
  31         unsigned long usage_cnt;/* number of files still to work */
  32         void *proc_ctrl;        /* pointer to own control procdata structure */
  33         char log_start[2];      /* log string start (final len aligned by size) */
  34 };
  35
  36 /**********************************************/
  37 /* structure holding proc entrys for one card */
  38 /**********************************************/
  39 struct procdata {
  40         struct proc_dir_entry *log;     /* log entry */
  41         char log_name[15];      /* log filename */
  42         struct log_data *log_head, *log_tail;   /* head and tail for queue */
  43         int if_used;            /* open count for interface */
  44         int volatile del_lock;  /* lock for delete operations */
  45         unsigned char logtmp[LOG_MAX_LINELEN];
  46         wait_queue_head_t rd_queue;
  47 };
  48
  49
  50 /**********************************************/
  51 /* log function for cards error log interface */
  52 /**********************************************/
  53 void
  54 hysdn_card_errlog(hysdn_card * card, tErrLogEntry * logp, int maxsize)
  55 {
  56         char buf[ERRLOG_TEXT_SIZE + 40];
  57
  58         sprintf(buf, "LOG 0x%08lX 0x%08lX : %s\n", logp->ulErrType, logp->ulErrSubtype, logp->ucText);
  59         put_log_buffer(card, buf);      /* output the string */
  60 }                               /* hysdn_card_errlog */
  61
  62 /***************************************************/
  63 /* Log function using format specifiers for output */
  64 /***************************************************/
  65 void
  66 hysdn_addlog(hysdn_card * card, char *fmt,...)
  67 {
  68         struct procdata *pd = card->proclog;
  69         char *cp;
  70         va_list args;
  71
  72         if (!pd)
  73                 return;         /* log structure non existent */
  74
  75         cp = pd->logtmp;
  76         cp += sprintf(cp, "HYSDN: card %d ", card->myid);
  77
  78         va_start(args, fmt);
  79         cp += vsprintf(cp, fmt, args);
  80         va_end(args);
  81         *cp++ = '\n';
  82         *cp = 0;
  83
  84         if (card->debug_flags & DEB_OUT_SYSLOG)
  85                 printk(KERN_INFO "%s", pd->logtmp);
  86         else
  87                 put_log_buffer(card, pd->logtmp);
  88
  89 }                               /* hysdn_addlog */
  90
  91 /********************************************/
  92 /* put an log buffer into the log queue.    */
  93 /* This buffer will be kept until all files */
  94 /* opened for read got the contents.        */
  95 /* Flushes buffers not longer in use.       */
  96 /********************************************/
  97 static void
  98 put_log_buffer(hysdn_card * card, char *cp)
  99 {
 100         struct log_data *ib;
 101         struct procdata *pd = card->proclog;
 102         int i;
 103         unsigned long flags;
 104
 105         if (!pd)
 106                 return;
 107         if (!cp)
 108                 return;
 109         if (!*cp)
 110                 return;
 111         if (pd->if_used <= 0)
 112                 return;         /* no open file for read */
 113
 114         if (!(ib = kmalloc(sizeof(struct log_data) + strlen(cp), GFP_ATOMIC)))
 115                  return;        /* no memory */
 116         strcpy(ib->log_start, cp);      /* set output string */
 117         ib->next = NULL;
 118         ib->proc_ctrl = pd;     /* point to own control structure */
 119         spin_lock_irqsave(&card->hysdn_lock, flags);
 120         ib->usage_cnt = pd->if_used;
 121         if (!pd->log_head)
 122                 pd->log_head = ib;      /* new head */
 123         else
 124                 pd->log_tail->next = ib;        /* follows existing messages */
 125         pd->log_tail = ib;      /* new tail */
 126         i = pd->del_lock++;     /* get lock state */
 127         spin_unlock_irqrestore(&card->hysdn_lock, flags);
 128
 129         /* delete old entrys */
 130         if (!i)
 131                 while (pd->log_head->next) {
 132                         if ((pd->log_head->usage_cnt <= 0) &&
 133                             (pd->log_head->next->usage_cnt <= 0)) {
 134                                 ib = pd->log_head;
 135                                 pd->log_head = pd->log_head->next;
 136                                 kfree(ib);
 137                         } else
 138                                 break;
 139                 }               /* pd->log_head->next */
 140         pd->del_lock--;         /* release lock level */
 141         wake_up_interruptible(&(pd->rd_queue));         /* announce new entry */
 142 }                               /* put_log_buffer */
 143
 144
 145 /******************************/
 146 /* file operations and tables */
 147 /******************************/
 148
 149 /****************************************/
 150 /* write log file -> set log level bits */
 151 /****************************************/
 152 static ssize_t
 153 hysdn_log_write(struct file *file, const char __user *buf, size_t count, loff_t * off)
 154 {
 155         unsigned long u = 0;
 156         int found = 0;
 157         unsigned char *cp, valbuf[128];
 158         long base = 10;
 159         hysdn_card *card = (hysdn_card *) file->private_data;
 160
 161         if (count > (sizeof(valbuf) - 1))
 162                 count = sizeof(valbuf) - 1;     /* limit length */
 163         if (copy_from_user(valbuf, buf, count))
 164                 return (-EFAULT);       /* copy failed */
 165
 166         valbuf[count] = 0;      /* terminating 0 */
 167         cp = valbuf;
 168         if ((count > 2) && (valbuf[0] == '0') && (valbuf[1] == 'x')) {
 169                 cp += 2;        /* pointer after hex modifier */
 170                 base = 16;
 171         }
 172         /* scan the input for debug flags */
 173         while (*cp) {
 174                 if ((*cp >= '0') && (*cp <= '9')) {
 175                         found = 1;
 176                         u *= base;      /* adjust to next digit */
 177                         u += *cp++ - '0';
 178                         continue;
 179                 }
 180                 if (base != 16)
 181                         break;  /* end of number */
 182
 183                 if ((*cp >= 'a') && (*cp <= 'f')) {
 184                         found = 1;
 185                         u *= base;      /* adjust to next digit */
 186                         u += *cp++ - 'a' + 10;
 187                         continue;
 188                 }
 189                 break;          /* terminated */
 190         }
 191
 192         if (found) {
 193                 card->debug_flags = u;  /* remember debug flags */
 194                 hysdn_addlog(card, "debug set to 0x%lx", card->debug_flags);
 195         }
 196         return (count);
 197 }                               /* hysdn_log_write */
 198
 199 /******************/
 200 /* read log file */
 201 /******************/
 202 static ssize_t
 203 hysdn_log_read(struct file *file, char __user *buf, size_t count, loff_t * off)
 204 {
 205         struct log_data *inf;
 206         int len;
 207         struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
 208         struct procdata *pd = NULL;
 209         hysdn_card *card;
 210
 211         if (!*((struct log_data **) file->private_data)) {
 212                 if (file->f_flags & O_NONBLOCK)
 213                         return (-EAGAIN);
 214
 215                 /* sorry, but we need to search the card */
 216                 card = card_root;
 217                 while (card) {
 218                         pd = card->proclog;
 219                         if (pd->log == pde)
 220                                 break;
 221                         card = card->next;      /* search next entry */
 222                 }
 223                 if (card)
 224                         interruptible_sleep_on(&(pd->rd_queue));
 225                 else
 226                         return (-EAGAIN);
 227
 228         }
 229         if (!(inf = *((struct log_data **) file->private_data)))
 230                 return (0);
 231
 232         inf->usage_cnt--;       /* new usage count */
 233         file->private_data = &inf->next;        /* next structure */
 234         if ((len = strlen(inf->log_start)) <= count) {
 235                 if (copy_to_user(buf, inf->log_start, len))
 236                         return -EFAULT;
 237                 *off += len;
 238                 return (len);
 239         }
 240         return (0);
 241 }                               /* hysdn_log_read */
 242
 243 /******************/
 244 /* open log file */
 245 /******************/
 246 static int
 247 hysdn_log_open(struct inode *ino, struct file *filep)
 248 {
 249         hysdn_card *card;
 250         struct procdata *pd = NULL;
 251         unsigned long flags;
 252
 253         lock_kernel();
 254         card = card_root;
 255         while (card) {
 256                 pd = card->proclog;
 257                 if (pd->log == PDE(ino))
 258                         break;
 259                 card = card->next;      /* search next entry */
 260         }
 261         if (!card) {
 262                 unlock_kernel();
 263                 return (-ENODEV);       /* device is unknown/invalid */
 264         }
 265         filep->private_data = card;     /* remember our own card */
 266
 267         if ((filep->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_WRITE) {
 268                 /* write only access -> write log level only */
 269         } else if ((filep->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) {
 270
 271                 /* read access -> log/debug read */
 272                 spin_lock_irqsave(&card->hysdn_lock, flags);
 273                 pd->if_used++;
 274                 if (pd->log_head)
 275                         filep->private_data = &pd->log_tail->next;
 276                 else
 277                         filep->private_data = &pd->log_head;
 278                 spin_unlock_irqrestore(&card->hysdn_lock, flags);
 279         } else {                /* simultaneous read/write access forbidden ! */
 280                 unlock_kernel();
 281                 return (-EPERM);        /* no permission this time */
 282         }
 283         unlock_kernel();
 284         return nonseekable_open(ino, filep);
 285 }                               /* hysdn_log_open */
 286
 287 /*******************************************************************************/
 288 /* close a cardlog file. If the file has been opened for exclusive write it is */
 289 /* assumed as pof data input and the pof loader is noticed about.              */
 290 /* Otherwise file is handled as log output. In this case the interface usage   */
 291 /* count is decremented and all buffers are noticed of closing. If this file   */
 292 /* was the last one to be closed, all buffers are freed.                       */
 293 /*******************************************************************************/
 294 static int
 295 hysdn_log_close(struct inode *ino, struct file *filep)
 296 {
 297         struct log_data *inf;
 298         struct procdata *pd;
 299         hysdn_card *card;
 300         int retval = 0;
 301
 302         lock_kernel();
 303         if ((filep->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_WRITE) {
 304                 /* write only access -> write debug level written */
 305                 retval = 0;     /* success */
 306         } else {
 307                 /* read access -> log/debug read, mark one further file as closed */
 308
 309                 pd = NULL;
 310                 inf = *((struct log_data **) filep->private_data);      /* get first log entry */
 311                 if (inf)
 312                         pd = (struct procdata *) inf->proc_ctrl;        /* still entries there */
 313                 else {
 314                         /* no info available -> search card */
 315                         card = card_root;
 316                         while (card) {
 317                                 pd = card->proclog;
 318                                 if (pd->log == PDE(ino))
 319                                         break;
 320                                 card = card->next;      /* search next entry */
 321                         }
 322                         if (card)
 323                                 pd = card->proclog;     /* pointer to procfs log */
 324                 }
 325                 if (pd)
 326                         pd->if_used--;  /* decrement interface usage count by one */
 327
 328                 while (inf) {
 329                         inf->usage_cnt--;       /* decrement usage count for buffers */
 330                         inf = inf->next;
 331                 }
 332
 333                 if (pd)
 334                         if (pd->if_used <= 0)   /* delete buffers if last file closed */
 335                                 while (pd->log_head) {
 336                                         inf = pd->log_head;
 337                                         pd->log_head = pd->log_head->next;
 338                                         kfree(inf);
 339                                 }
 340         }                       /* read access */
 341         unlock_kernel();
 342
 343         return (retval);
 344 }                               /* hysdn_log_close */
 345
 346 /*************************************************/
 347 /* select/poll routine to be able using select() */
 348 /*************************************************/
 349 static unsigned int
 350 hysdn_log_poll(struct file *file, poll_table * wait)
 351 {
 352         unsigned int mask = 0;
 353         struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
 354         hysdn_card *card;
 355         struct procdata *pd = NULL;
 356
 357         if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_WRITE)
 358                 return (mask);  /* no polling for write supported */
 359
 360         /* we need to search the card */
 361         card = card_root;
 362         while (card) {
 363                 pd = card->proclog;
 364                 if (pd->log == pde)
 365                         break;
 366                 card = card->next;      /* search next entry */
 367         }
 368         if (!card)
 369                 return (mask);  /* card not found */
 370
 371         poll_wait(file, &(pd->rd_queue), wait);
 372
 373         if (*((struct log_data **) file->private_data))
 374                 mask |= POLLIN | POLLRDNORM;
 375
 376         return mask;
 377 }                               /* hysdn_log_poll */
 378
 379 /**************************************************/
 380 /* table for log filesystem functions defined above. */
 381 /**************************************************/
 382 static const struct file_operations log_fops =
 383 {
 384         .owner          = THIS_MODULE,
 385         .llseek         = no_llseek,
 386         .read           = hysdn_log_read,
 387         .write          = hysdn_log_write,
 388         .poll           = hysdn_log_poll,
 389         .open           = hysdn_log_open,
 390         .release        = hysdn_log_close,
 391 };
 392
 393
 394 /***********************************************************************************/
 395 /* hysdn_proclog_init is called when the module is loaded after creating the cards */
 396 /* conf files.                                                                     */
 397 /***********************************************************************************/
 398 int
 399 hysdn_proclog_init(hysdn_card * card)
 400 {
 401         struct procdata *pd;
 402
 403         /* create a cardlog proc entry */
 404
 405         if ((pd = kzalloc(sizeof(struct procdata), GFP_KERNEL)) != NULL) {
 406                 sprintf(pd->log_name, "%s%d", PROC_LOG_BASENAME, card->myid);
 407                 pd->log = proc_create(pd->log_name,
 408                                 S_IFREG | S_IRUGO | S_IWUSR, hysdn_proc_entry,
 409                                 &log_fops);
 410
 411                 init_waitqueue_head(&(pd->rd_queue));
 412
 413                 card->proclog = (void *) pd;    /* remember procfs structure */
 414         }
 415         return (0);
 416 }                               /* hysdn_proclog_init */
 417
 418 /************************************************************************************/
 419 /* hysdn_proclog_release is called when the module is unloaded and before the cards */
 420 /* conf file is released                                                            */
 421 /* The module counter is assumed to be 0 !                                          */
 422 /************************************************************************************/
 423 void
 424 hysdn_proclog_release(hysdn_card * card)
 425 {
 426         struct procdata *pd;
 427
 428         if ((pd = (struct procdata *) card->proclog) != NULL) {
 429                 if (pd->log)
 430                         remove_proc_entry(pd->log_name, hysdn_proc_entry);
 431                 kfree(pd);      /* release memory */
 432                 card->proclog = NULL;
 433         }
 434 }                               /* hysdn_proclog_release */