|  | /* $Id: hysdn_proclog.c,v 1.9.6.3 2001/09/23 22:24:54 kai Exp $ | 
|  | * | 
|  | * Linux driver for HYSDN cards, /proc/net filesystem log functions. | 
|  | * | 
|  | * Author    Werner Cornelius (werner@titro.de) for Hypercope GmbH | 
|  | * Copyright 1999 by Werner Cornelius (werner@titro.de) | 
|  | * | 
|  | * This software may be used and distributed according to the terms | 
|  | * of the GNU General Public License, incorporated herein by reference. | 
|  | * | 
|  | */ | 
|  |  | 
|  | #include <linux/module.h> | 
|  | #include <linux/poll.h> | 
|  | #include <linux/proc_fs.h> | 
|  | #include <linux/sched.h> | 
|  | #include <linux/slab.h> | 
|  | #include <linux/mutex.h> | 
|  | #include <linux/kernel.h> | 
|  |  | 
|  | #include "hysdn_defs.h" | 
|  |  | 
|  | /* the proc subdir for the interface is defined in the procconf module */ | 
|  | extern struct proc_dir_entry *hysdn_proc_entry; | 
|  |  | 
|  | static DEFINE_MUTEX(hysdn_log_mutex); | 
|  | static void put_log_buffer(hysdn_card * card, char *cp); | 
|  |  | 
|  | /*************************************************/ | 
|  | /* structure keeping ascii log for device output */ | 
|  | /*************************************************/ | 
|  | struct log_data { | 
|  | struct log_data *next; | 
|  | unsigned long usage_cnt;/* number of files still to work */ | 
|  | void *proc_ctrl;	/* pointer to own control procdata structure */ | 
|  | char log_start[2];	/* log string start (final len aligned by size) */ | 
|  | }; | 
|  |  | 
|  | /**********************************************/ | 
|  | /* structure holding proc entrys for one card */ | 
|  | /**********************************************/ | 
|  | struct procdata { | 
|  | struct proc_dir_entry *log;	/* log entry */ | 
|  | char log_name[15];	/* log filename */ | 
|  | struct log_data *log_head, *log_tail;	/* head and tail for queue */ | 
|  | int if_used;		/* open count for interface */ | 
|  | int volatile del_lock;	/* lock for delete operations */ | 
|  | unsigned char logtmp[LOG_MAX_LINELEN]; | 
|  | wait_queue_head_t rd_queue; | 
|  | }; | 
|  |  | 
|  |  | 
|  | /**********************************************/ | 
|  | /* log function for cards error log interface */ | 
|  | /**********************************************/ | 
|  | void | 
|  | hysdn_card_errlog(hysdn_card * card, tErrLogEntry * logp, int maxsize) | 
|  | { | 
|  | char buf[ERRLOG_TEXT_SIZE + 40]; | 
|  |  | 
|  | sprintf(buf, "LOG 0x%08lX 0x%08lX : %s\n", logp->ulErrType, logp->ulErrSubtype, logp->ucText); | 
|  | put_log_buffer(card, buf);	/* output the string */ | 
|  | }				/* hysdn_card_errlog */ | 
|  |  | 
|  | /***************************************************/ | 
|  | /* Log function using format specifiers for output */ | 
|  | /***************************************************/ | 
|  | void | 
|  | hysdn_addlog(hysdn_card * card, char *fmt,...) | 
|  | { | 
|  | struct procdata *pd = card->proclog; | 
|  | char *cp; | 
|  | va_list args; | 
|  |  | 
|  | if (!pd) | 
|  | return;		/* log structure non existent */ | 
|  |  | 
|  | cp = pd->logtmp; | 
|  | cp += sprintf(cp, "HYSDN: card %d ", card->myid); | 
|  |  | 
|  | va_start(args, fmt); | 
|  | cp += vsprintf(cp, fmt, args); | 
|  | va_end(args); | 
|  | *cp++ = '\n'; | 
|  | *cp = 0; | 
|  |  | 
|  | if (card->debug_flags & DEB_OUT_SYSLOG) | 
|  | printk(KERN_INFO "%s", pd->logtmp); | 
|  | else | 
|  | put_log_buffer(card, pd->logtmp); | 
|  |  | 
|  | }				/* hysdn_addlog */ | 
|  |  | 
|  | /********************************************/ | 
|  | /* put an log buffer into the log queue.    */ | 
|  | /* This buffer will be kept until all files */ | 
|  | /* opened for read got the contents.        */ | 
|  | /* Flushes buffers not longer in use.       */ | 
|  | /********************************************/ | 
|  | static void | 
|  | put_log_buffer(hysdn_card * card, char *cp) | 
|  | { | 
|  | struct log_data *ib; | 
|  | struct procdata *pd = card->proclog; | 
|  | int i; | 
|  | unsigned long flags; | 
|  |  | 
|  | if (!pd) | 
|  | return; | 
|  | if (!cp) | 
|  | return; | 
|  | if (!*cp) | 
|  | return; | 
|  | if (pd->if_used <= 0) | 
|  | return;		/* no open file for read */ | 
|  |  | 
|  | if (!(ib = kmalloc(sizeof(struct log_data) + strlen(cp), GFP_ATOMIC))) | 
|  | return;	/* no memory */ | 
|  | strcpy(ib->log_start, cp);	/* set output string */ | 
|  | ib->next = NULL; | 
|  | ib->proc_ctrl = pd;	/* point to own control structure */ | 
|  | spin_lock_irqsave(&card->hysdn_lock, flags); | 
|  | ib->usage_cnt = pd->if_used; | 
|  | if (!pd->log_head) | 
|  | pd->log_head = ib;	/* new head */ | 
|  | else | 
|  | pd->log_tail->next = ib;	/* follows existing messages */ | 
|  | pd->log_tail = ib;	/* new tail */ | 
|  | i = pd->del_lock++;	/* get lock state */ | 
|  | spin_unlock_irqrestore(&card->hysdn_lock, flags); | 
|  |  | 
|  | /* delete old entrys */ | 
|  | if (!i) | 
|  | while (pd->log_head->next) { | 
|  | if ((pd->log_head->usage_cnt <= 0) && | 
|  | (pd->log_head->next->usage_cnt <= 0)) { | 
|  | ib = pd->log_head; | 
|  | pd->log_head = pd->log_head->next; | 
|  | kfree(ib); | 
|  | } else | 
|  | break; | 
|  | }		/* pd->log_head->next */ | 
|  | pd->del_lock--;		/* release lock level */ | 
|  | wake_up_interruptible(&(pd->rd_queue));		/* announce new entry */ | 
|  | }				/* put_log_buffer */ | 
|  |  | 
|  |  | 
|  | /******************************/ | 
|  | /* file operations and tables */ | 
|  | /******************************/ | 
|  |  | 
|  | /****************************************/ | 
|  | /* write log file -> set log level bits */ | 
|  | /****************************************/ | 
|  | static ssize_t | 
|  | hysdn_log_write(struct file *file, const char __user *buf, size_t count, loff_t * off) | 
|  | { | 
|  | unsigned long u = 0; | 
|  | int rc; | 
|  | unsigned char valbuf[128]; | 
|  | hysdn_card *card = file->private_data; | 
|  |  | 
|  | if (count > (sizeof(valbuf) - 1)) | 
|  | count = sizeof(valbuf) - 1;	/* limit length */ | 
|  | if (copy_from_user(valbuf, buf, count)) | 
|  | return (-EFAULT);	/* copy failed */ | 
|  |  | 
|  | valbuf[count] = 0;	/* terminating 0 */ | 
|  |  | 
|  | rc = strict_strtoul(valbuf, 0, &u); | 
|  |  | 
|  | if (rc == 0) { | 
|  | card->debug_flags = u;	/* remember debug flags */ | 
|  | hysdn_addlog(card, "debug set to 0x%lx", card->debug_flags); | 
|  | } | 
|  | return (count); | 
|  | }				/* hysdn_log_write */ | 
|  |  | 
|  | /******************/ | 
|  | /* read log file */ | 
|  | /******************/ | 
|  | static ssize_t | 
|  | hysdn_log_read(struct file *file, char __user *buf, size_t count, loff_t * off) | 
|  | { | 
|  | struct log_data *inf; | 
|  | int len; | 
|  | struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); | 
|  | struct procdata *pd = NULL; | 
|  | hysdn_card *card; | 
|  |  | 
|  | if (!*((struct log_data **) file->private_data)) { | 
|  | if (file->f_flags & O_NONBLOCK) | 
|  | return (-EAGAIN); | 
|  |  | 
|  | /* sorry, but we need to search the card */ | 
|  | card = card_root; | 
|  | while (card) { | 
|  | pd = card->proclog; | 
|  | if (pd->log == pde) | 
|  | break; | 
|  | card = card->next;	/* search next entry */ | 
|  | } | 
|  | if (card) | 
|  | interruptible_sleep_on(&(pd->rd_queue)); | 
|  | else | 
|  | return (-EAGAIN); | 
|  |  | 
|  | } | 
|  | if (!(inf = *((struct log_data **) file->private_data))) | 
|  | return (0); | 
|  |  | 
|  | inf->usage_cnt--;	/* new usage count */ | 
|  | file->private_data = &inf->next;	/* next structure */ | 
|  | if ((len = strlen(inf->log_start)) <= count) { | 
|  | if (copy_to_user(buf, inf->log_start, len)) | 
|  | return -EFAULT; | 
|  | *off += len; | 
|  | return (len); | 
|  | } | 
|  | return (0); | 
|  | }				/* hysdn_log_read */ | 
|  |  | 
|  | /******************/ | 
|  | /* open log file */ | 
|  | /******************/ | 
|  | static int | 
|  | hysdn_log_open(struct inode *ino, struct file *filep) | 
|  | { | 
|  | hysdn_card *card; | 
|  | struct procdata *pd = NULL; | 
|  | unsigned long flags; | 
|  |  | 
|  | mutex_lock(&hysdn_log_mutex); | 
|  | card = card_root; | 
|  | while (card) { | 
|  | pd = card->proclog; | 
|  | if (pd->log == PDE(ino)) | 
|  | break; | 
|  | card = card->next;	/* search next entry */ | 
|  | } | 
|  | if (!card) { | 
|  | mutex_unlock(&hysdn_log_mutex); | 
|  | return (-ENODEV);	/* device is unknown/invalid */ | 
|  | } | 
|  | filep->private_data = card;	/* remember our own card */ | 
|  |  | 
|  | if ((filep->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_WRITE) { | 
|  | /* write only access -> write log level only */ | 
|  | } else if ((filep->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) { | 
|  |  | 
|  | /* read access -> log/debug read */ | 
|  | spin_lock_irqsave(&card->hysdn_lock, flags); | 
|  | pd->if_used++; | 
|  | if (pd->log_head) | 
|  | filep->private_data = &pd->log_tail->next; | 
|  | else | 
|  | filep->private_data = &pd->log_head; | 
|  | spin_unlock_irqrestore(&card->hysdn_lock, flags); | 
|  | } else {		/* simultaneous read/write access forbidden ! */ | 
|  | mutex_unlock(&hysdn_log_mutex); | 
|  | return (-EPERM);	/* no permission this time */ | 
|  | } | 
|  | mutex_unlock(&hysdn_log_mutex); | 
|  | return nonseekable_open(ino, filep); | 
|  | }				/* hysdn_log_open */ | 
|  |  | 
|  | /*******************************************************************************/ | 
|  | /* close a cardlog file. If the file has been opened for exclusive write it is */ | 
|  | /* assumed as pof data input and the pof loader is noticed about.              */ | 
|  | /* Otherwise file is handled as log output. In this case the interface usage   */ | 
|  | /* count is decremented and all buffers are noticed of closing. If this file   */ | 
|  | /* was the last one to be closed, all buffers are freed.                       */ | 
|  | /*******************************************************************************/ | 
|  | static int | 
|  | hysdn_log_close(struct inode *ino, struct file *filep) | 
|  | { | 
|  | struct log_data *inf; | 
|  | struct procdata *pd; | 
|  | hysdn_card *card; | 
|  | int retval = 0; | 
|  |  | 
|  | mutex_lock(&hysdn_log_mutex); | 
|  | if ((filep->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_WRITE) { | 
|  | /* write only access -> write debug level written */ | 
|  | retval = 0;	/* success */ | 
|  | } else { | 
|  | /* read access -> log/debug read, mark one further file as closed */ | 
|  |  | 
|  | pd = NULL; | 
|  | inf = *((struct log_data **) filep->private_data);	/* get first log entry */ | 
|  | if (inf) | 
|  | pd = (struct procdata *) inf->proc_ctrl;	/* still entries there */ | 
|  | else { | 
|  | /* no info available -> search card */ | 
|  | card = card_root; | 
|  | while (card) { | 
|  | pd = card->proclog; | 
|  | if (pd->log == PDE(ino)) | 
|  | break; | 
|  | card = card->next;	/* search next entry */ | 
|  | } | 
|  | if (card) | 
|  | pd = card->proclog;	/* pointer to procfs log */ | 
|  | } | 
|  | if (pd) | 
|  | pd->if_used--;	/* decrement interface usage count by one */ | 
|  |  | 
|  | while (inf) { | 
|  | inf->usage_cnt--;	/* decrement usage count for buffers */ | 
|  | inf = inf->next; | 
|  | } | 
|  |  | 
|  | if (pd) | 
|  | if (pd->if_used <= 0)	/* delete buffers if last file closed */ | 
|  | while (pd->log_head) { | 
|  | inf = pd->log_head; | 
|  | pd->log_head = pd->log_head->next; | 
|  | kfree(inf); | 
|  | } | 
|  | }			/* read access */ | 
|  | mutex_unlock(&hysdn_log_mutex); | 
|  |  | 
|  | return (retval); | 
|  | }				/* hysdn_log_close */ | 
|  |  | 
|  | /*************************************************/ | 
|  | /* select/poll routine to be able using select() */ | 
|  | /*************************************************/ | 
|  | static unsigned int | 
|  | hysdn_log_poll(struct file *file, poll_table * wait) | 
|  | { | 
|  | unsigned int mask = 0; | 
|  | struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); | 
|  | hysdn_card *card; | 
|  | struct procdata *pd = NULL; | 
|  |  | 
|  | if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_WRITE) | 
|  | return (mask);	/* no polling for write supported */ | 
|  |  | 
|  | /* we need to search the card */ | 
|  | card = card_root; | 
|  | while (card) { | 
|  | pd = card->proclog; | 
|  | if (pd->log == pde) | 
|  | break; | 
|  | card = card->next;	/* search next entry */ | 
|  | } | 
|  | if (!card) | 
|  | return (mask);	/* card not found */ | 
|  |  | 
|  | poll_wait(file, &(pd->rd_queue), wait); | 
|  |  | 
|  | if (*((struct log_data **) file->private_data)) | 
|  | mask |= POLLIN | POLLRDNORM; | 
|  |  | 
|  | return mask; | 
|  | }				/* hysdn_log_poll */ | 
|  |  | 
|  | /**************************************************/ | 
|  | /* table for log filesystem functions defined above. */ | 
|  | /**************************************************/ | 
|  | static const struct file_operations log_fops = | 
|  | { | 
|  | .owner		= THIS_MODULE, | 
|  | .llseek         = no_llseek, | 
|  | .read           = hysdn_log_read, | 
|  | .write          = hysdn_log_write, | 
|  | .poll           = hysdn_log_poll, | 
|  | .open           = hysdn_log_open, | 
|  | .release        = hysdn_log_close, | 
|  | }; | 
|  |  | 
|  |  | 
|  | /***********************************************************************************/ | 
|  | /* hysdn_proclog_init is called when the module is loaded after creating the cards */ | 
|  | /* conf files.                                                                     */ | 
|  | /***********************************************************************************/ | 
|  | int | 
|  | hysdn_proclog_init(hysdn_card * card) | 
|  | { | 
|  | struct procdata *pd; | 
|  |  | 
|  | /* create a cardlog proc entry */ | 
|  |  | 
|  | if ((pd = kzalloc(sizeof(struct procdata), GFP_KERNEL)) != NULL) { | 
|  | sprintf(pd->log_name, "%s%d", PROC_LOG_BASENAME, card->myid); | 
|  | pd->log = proc_create(pd->log_name, | 
|  | S_IFREG | S_IRUGO | S_IWUSR, hysdn_proc_entry, | 
|  | &log_fops); | 
|  |  | 
|  | init_waitqueue_head(&(pd->rd_queue)); | 
|  |  | 
|  | card->proclog = (void *) pd;	/* remember procfs structure */ | 
|  | } | 
|  | return (0); | 
|  | }				/* hysdn_proclog_init */ | 
|  |  | 
|  | /************************************************************************************/ | 
|  | /* hysdn_proclog_release is called when the module is unloaded and before the cards */ | 
|  | /* conf file is released                                                            */ | 
|  | /* The module counter is assumed to be 0 !                                          */ | 
|  | /************************************************************************************/ | 
|  | void | 
|  | hysdn_proclog_release(hysdn_card * card) | 
|  | { | 
|  | struct procdata *pd; | 
|  |  | 
|  | if ((pd = (struct procdata *) card->proclog) != NULL) { | 
|  | if (pd->log) | 
|  | remove_proc_entry(pd->log_name, hysdn_proc_entry); | 
|  | kfree(pd);	/* release memory */ | 
|  | card->proclog = NULL; | 
|  | } | 
|  | }				/* hysdn_proclog_release */ |