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/version.h>
  15 #include <linux/poll.h>
  16 #include <linux/proc_fs.h>
  17 #include <linux/pci.h>
  18 #include <linux/smp_lock.h>
  19
  20 #include "hysdn_defs.h"
  21
  22 /* the proc subdir for the interface is defined in the procconf module */
  23 extern struct proc_dir_entry *hysdn_proc_entry;
  24
  25 static void put_log_buffer(hysdn_card * card, char *cp);
  26
  27 /*************************************************/
  28 /* structure keeping ascii log for device output */
  29 /*************************************************/
  30 struct log_data {
  31         struct log_data *next;
  32         ulong usage_cnt;        /* number of files still to work */
  33         void *proc_ctrl;        /* pointer to own control procdata structure */
  34         char log_start[2];      /* log string start (final len aligned by size) */
  35 };
  36
  37 /**********************************************/
  38 /* structure holding proc entrys for one card */
  39 /**********************************************/
  40 struct procdata {
  41         struct proc_dir_entry *log;     /* log entry */
  42         char log_name[15];      /* log filename */
  43         struct log_data *log_head, *log_tail;   /* head and tail for queue */
  44         int if_used;            /* open count for interface */
  45         int volatile del_lock;  /* lock for delete operations */
  46         uchar logtmp[LOG_MAX_LINELEN];
  47         wait_queue_head_t rd_queue;
  48 };
  49
  50
  51 /**********************************************/
  52 /* log function for cards error log interface */
  53 /**********************************************/
  54 void
  55 hysdn_card_errlog(hysdn_card * card, tErrLogEntry * logp, int maxsize)
  56 {
  57         char buf[ERRLOG_TEXT_SIZE + 40];
  58
  59         sprintf(buf, "LOG 0x%08lX 0x%08lX : %s\n", logp->ulErrType, logp->ulErrSubtype, logp->ucText);
  60         put_log_buffer(card, buf);      /* output the string */
  61 }                               /* hysdn_card_errlog */
  62
  63 /***************************************************/
  64 /* Log function using format specifiers for output */
  65 /***************************************************/
  66 void
  67 hysdn_addlog(hysdn_card * card, char *fmt,...)
  68 {
  69         struct procdata *pd = card->proclog;
  70         char *cp;
  71         va_list args;
  72
  73         if (!pd)
  74                 return;         /* log structure non existent */
  75
  76         cp = pd->logtmp;
  77         cp += sprintf(cp, "HYSDN: card %d ", card->myid);
  78
  79         va_start(args, fmt);
  80         cp += vsprintf(cp, fmt, args);
  81         va_end(args);
  82         *cp++ = '\n';
  83         *cp = 0;
  84
  85         if (card->debug_flags & DEB_OUT_SYSLOG)
  86                 printk(KERN_INFO "%s", pd->logtmp);
  87         else
  88                 put_log_buffer(card, pd->logtmp);
  89
  90 }                               /* hysdn_addlog */
  91
  92 /********************************************/
  93 /* put an log buffer into the log queue.    */
  94 /* This buffer will be kept until all files */
  95 /* opened for read got the contents.        */
  96 /* Flushes buffers not longer in use.       */
  97 /********************************************/
  98 static void
  99 put_log_buffer(hysdn_card * card, char *cp)
 100 {
 101         struct log_data *ib;
 102         struct procdata *pd = card->proclog;
 103         int i;
 104         unsigned long flags;
 105
 106         if (!pd)
 107                 return;
 108         if (!cp)
 109                 return;
 110         if (!*cp)
 111                 return;
 112         if (pd->if_used <= 0)
 113                 return;         /* no open file for read */
 114
 115         if (!(ib = (struct log_data *) kmalloc(sizeof(struct log_data) + strlen(cp), GFP_ATOMIC)))
 116                  return;        /* no memory */
 117         strcpy(ib->log_start, cp);      /* set output string */
 118         ib->next = NULL;
 119         ib->proc_ctrl = pd;     /* point to own control structure */
 120         save_flags(flags);
 121         cli();
 122         ib->usage_cnt = pd->if_used;
 123         if (!pd->log_head)
 124                 pd->log_head = ib;      /* new head */
 125         else
 126                 pd->log_tail->next = ib;        /* follows existing messages */
 127         pd->log_tail = ib;      /* new tail */
 128         i = pd->del_lock++;     /* get lock state */
 129         restore_flags(flags);
 130
 131         /* delete old entrys */
 132         if (!i)
 133                 while (pd->log_head->next) {
 134                         if ((pd->log_head->usage_cnt <= 0) &&
 135                             (pd->log_head->next->usage_cnt <= 0)) {
 136                                 ib = pd->log_head;
 137                                 pd->log_head = pd->log_head->next;
 138                                 kfree(ib);
 139                         } else
 140                                 break;
 141                 }               /* pd->log_head->next */
 142         pd->del_lock--;         /* release lock level */
 143         wake_up_interruptible(&(pd->rd_queue));         /* announce new entry */
 144 }                               /* put_log_buffer */
 145
 146
 147 /******************************/
 148 /* file operations and tables */
 149 /******************************/
 150
 151 /****************************************/
 152 /* write log file -> set log level bits */
 153 /****************************************/
 154 static ssize_t
 155 hysdn_log_write(struct file *file, const char __user *buf, size_t count, loff_t * off)
 156 {
 157         ulong u = 0;
 158         int found = 0;
 159         uchar *cp, valbuf[128];
 160         long base = 10;
 161         hysdn_card *card = (hysdn_card *) file->private_data;
 162
 163         if (count > (sizeof(valbuf) - 1))
 164                 count = sizeof(valbuf) - 1;     /* limit length */
 165         if (copy_from_user(valbuf, buf, count))
 166                 return (-EFAULT);       /* copy failed */
 167
 168         valbuf[count] = 0;      /* terminating 0 */
 169         cp = valbuf;
 170         if ((count > 2) && (valbuf[0] == '0') && (valbuf[1] == 'x')) {
 171                 cp += 2;        /* pointer after hex modifier */
 172                 base = 16;
 173         }
 174         /* scan the input for debug flags */
 175         while (*cp) {
 176                 if ((*cp >= '0') && (*cp <= '9')) {
 177                         found = 1;
 178                         u *= base;      /* adjust to next digit */
 179                         u += *cp++ - '0';
 180                         continue;
 181                 }
 182                 if (base != 16)
 183                         break;  /* end of number */
 184
 185                 if ((*cp >= 'a') && (*cp <= 'f')) {
 186                         found = 1;
 187                         u *= base;      /* adjust to next digit */
 188                         u += *cp++ - 'a' + 10;
 189                         continue;
 190                 }
 191                 break;          /* terminated */
 192         }
 193
 194         if (found) {
 195                 card->debug_flags = u;  /* remember debug flags */
 196                 hysdn_addlog(card, "debug set to 0x%lx", card->debug_flags);
 197         }
 198         return (count);
 199 }                               /* hysdn_log_write */
 200
 201 /******************/
 202 /* read log file */
 203 /******************/
 204 static ssize_t
 205 hysdn_log_read(struct file *file, char __user *buf, size_t count, loff_t * off)
 206 {
 207         struct log_data *inf;
 208         int len;
 209         struct proc_dir_entry *pde = PDE(file->f_dentry->d_inode);
 210         struct procdata *pd = NULL;
 211         hysdn_card *card;
 212
 213         if (!*((struct log_data **) file->private_data)) {
 214                 if (file->f_flags & O_NONBLOCK)
 215                         return (-EAGAIN);
 216
 217                 /* sorry, but we need to search the card */
 218                 card = card_root;
 219                 while (card) {
 220                         pd = card->proclog;
 221                         if (pd->log == pde)
 222                                 break;
 223                         card = card->next;      /* search next entry */
 224                 }
 225                 if (card)
 226                         interruptible_sleep_on(&(pd->rd_queue));
 227                 else
 228                         return (-EAGAIN);
 229
 230         }
 231         if (!(inf = *((struct log_data **) file->private_data)))
 232                 return (0);
 233
 234         inf->usage_cnt--;       /* new usage count */
 235         file->private_data = &inf->next;        /* next structure */
 236         if ((len = strlen(inf->log_start)) <= count) {
 237                 if (copy_to_user(buf, inf->log_start, len))
 238                         return -EFAULT;
 239                 *off += len;
 240                 return (len);
 241         }
 242         return (0);
 243 }                               /* hysdn_log_read */
 244
 245 /******************/
 246 /* open log file */
 247 /******************/
 248 static int
 249 hysdn_log_open(struct inode *ino, struct file *filep)
 250 {
 251         hysdn_card *card;
 252         struct procdata *pd = NULL;
 253         ulong flags;
 254
 255         lock_kernel();
 256         card = card_root;
 257         while (card) {
 258                 pd = card->proclog;
 259                 if (pd->log == PDE(ino))
 260                         break;
 261                 card = card->next;      /* search next entry */
 262         }
 263         if (!card) {
 264                 unlock_kernel();
 265                 return (-ENODEV);       /* device is unknown/invalid */
 266         }
 267         filep->private_data = card;     /* remember our own card */
 268
 269         if ((filep->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_WRITE) {
 270                 /* write only access -> write log level only */
 271         } else if ((filep->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) {
 272
 273                 /* read access -> log/debug read */
 274                 save_flags(flags);
 275                 cli();
 276                 pd->if_used++;
 277                 if (pd->log_head)
 278                         filep->private_data = &pd->log_tail->next;
 279                 else
 280                         filep->private_data = &pd->log_head;
 281                 restore_flags(flags);
 282         } else {                /* simultaneous read/write access forbidden ! */
 283                 unlock_kernel();
 284                 return (-EPERM);        /* no permission this time */
 285         }
 286         unlock_kernel();
 287         return nonseekable_open(ino, filep);
 288 }                               /* hysdn_log_open */
 289
 290 /*******************************************************************************/
 291 /* close a cardlog file. If the file has been opened for exclusive write it is */
 292 /* assumed as pof data input and the pof loader is noticed about.              */
 293 /* Otherwise file is handled as log output. In this case the interface usage   */
 294 /* count is decremented and all buffers are noticed of closing. If this file   */
 295 /* was the last one to be closed, all buffers are freed.                       */
 296 /*******************************************************************************/
 297 static int
 298 hysdn_log_close(struct inode *ino, struct file *filep)
 299 {
 300         struct log_data *inf;
 301         struct procdata *pd;
 302         hysdn_card *card;
 303         int retval = 0;
 304         unsigned long flags;
 305
 306
 307         lock_kernel();
 308         if ((filep->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_WRITE) {
 309                 /* write only access -> write debug level written */
 310                 retval = 0;     /* success */
 311         } else {
 312                 /* read access -> log/debug read, mark one further file as closed */
 313
 314                 pd = NULL;
 315                 save_flags(flags);
 316                 cli();
 317                 inf = *((struct log_data **) filep->private_data);      /* get first log entry */
 318                 if (inf)
 319                         pd = (struct procdata *) inf->proc_ctrl;        /* still entries there */
 320                 else {
 321                         /* no info available -> search card */
 322                         card = card_root;
 323                         while (card) {
 324                                 pd = card->proclog;
 325                                 if (pd->log == PDE(ino))
 326                                         break;
 327                                 card = card->next;      /* search next entry */
 328                         }
 329                         if (card)
 330                                 pd = card->proclog;     /* pointer to procfs log */
 331                 }
 332                 if (pd)
 333                         pd->if_used--;  /* decrement interface usage count by one */
 334
 335                 while (inf) {
 336                         inf->usage_cnt--;       /* decrement usage count for buffers */
 337                         inf = inf->next;
 338                 }
 339                 restore_flags(flags);
 340
 341                 if (pd)
 342                         if (pd->if_used <= 0)   /* delete buffers if last file closed */
 343                                 while (pd->log_head) {
 344                                         inf = pd->log_head;
 345                                         pd->log_head = pd->log_head->next;
 346                                         kfree(inf);
 347                                 }
 348         }                       /* read access */
 349         unlock_kernel();
 350
 351         return (retval);
 352 }                               /* hysdn_log_close */
 353
 354 /*************************************************/
 355 /* select/poll routine to be able using select() */
 356 /*************************************************/
 357 static unsigned int
 358 hysdn_log_poll(struct file *file, poll_table * wait)
 359 {
 360         unsigned int mask = 0;
 361         struct proc_dir_entry *pde = PDE(file->f_dentry->d_inode);
 362         hysdn_card *card;
 363         struct procdata *pd = NULL;
 364
 365         if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_WRITE)
 366                 return (mask);  /* no polling for write supported */
 367
 368         /* we need to search the card */
 369         card = card_root;
 370         while (card) {
 371                 pd = card->proclog;
 372                 if (pd->log == pde)
 373                         break;
 374                 card = card->next;      /* search next entry */
 375         }
 376         if (!card)
 377                 return (mask);  /* card not found */
 378
 379         poll_wait(file, &(pd->rd_queue), wait);
 380
 381         if (*((struct log_data **) file->private_data))
 382                 mask |= POLLIN | POLLRDNORM;
 383
 384         return mask;
 385 }                               /* hysdn_log_poll */
 386
 387 /**************************************************/
 388 /* table for log filesystem functions defined above. */
 389 /**************************************************/
 390 static struct file_operations log_fops =
 391 {
 392         .llseek         = no_llseek,
 393         .read           = hysdn_log_read,
 394         .write          = hysdn_log_write,
 395         .poll           = hysdn_log_poll,
 396         .open           = hysdn_log_open,
 397         .release        = hysdn_log_close,
 398 };
 399
 400
 401 /***********************************************************************************/
 402 /* hysdn_proclog_init is called when the module is loaded after creating the cards */
 403 /* conf files.                                                                     */
 404 /***********************************************************************************/
 405 int
 406 hysdn_proclog_init(hysdn_card * card)
 407 {
 408         struct procdata *pd;
 409
 410         /* create a cardlog proc entry */
 411
 412         if ((pd = (struct procdata *) kmalloc(sizeof(struct procdata), GFP_KERNEL)) != NULL) {
 413                 memset(pd, 0, sizeof(struct procdata));
 414                 sprintf(pd->log_name, "%s%d", PROC_LOG_BASENAME, card->myid);
 415                 if ((pd->log = create_proc_entry(pd->log_name, S_IFREG | S_IRUGO | S_IWUSR, hysdn_proc_entry)) != NULL) {
 416                         pd->log->proc_fops = &log_fops;
 417                         pd->log->owner = THIS_MODULE;
 418                 }
 419
 420                 init_waitqueue_head(&(pd->rd_queue));
 421
 422                 card->proclog = (void *) pd;    /* remember procfs structure */
 423         }
 424         return (0);
 425 }                               /* hysdn_proclog_init */
 426
 427 /************************************************************************************/
 428 /* hysdn_proclog_release is called when the module is unloaded and before the cards */
 429 /* conf file is released                                                            */
 430 /* The module counter is assumed to be 0 !                                          */
 431 /************************************************************************************/
 432 void
 433 hysdn_proclog_release(hysdn_card * card)
 434 {
 435         struct procdata *pd;
 436
 437         if ((pd = (struct procdata *) card->proclog) != NULL) {
 438                 if (pd->log)
 439                         remove_proc_entry(pd->log_name, hysdn_proc_entry);
 440                 kfree(pd);      /* release memory */
 441                 card->proclog = NULL;
 442         }
 443 }                               /* hysdn_proclog_release */