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