--- /dev/null
+/* $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)
+{
+ int rc;
+ hysdn_card *card = file->private_data;
+
+ rc = kstrtoul_from_user(buf, count, 0, &card->debug_flags);
+ if (rc < 0)
+ return rc;
+ 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;
+ hysdn_card *card = PDE_DATA(file_inode(file));
+
+ if (!(inf = *((struct log_data **) file->private_data))) {
+ struct procdata *pd = card->proclog;
+ if (file->f_flags & O_NONBLOCK)
+ return (-EAGAIN);
+
+ wait_event_interruptible(pd->rd_queue, (inf =
+ *((struct log_data **) file->private_data)));
+ }
+ if (!inf)
+ 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 = PDE_DATA(ino);
+
+ mutex_lock(&hysdn_log_mutex);
+ if ((filep->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_WRITE) {
+ /* write only access -> write log level only */
+ filep->private_data = card; /* remember our own card */
+ } else if ((filep->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) {
+ struct procdata *pd = card->proclog;
+ unsigned long flags;
+
+ /* 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 */
+
+ 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 = PDE_DATA(file_inode(filep));
+ 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;
+ hysdn_card *card = PDE_DATA(file_inode(file));
+ struct procdata *pd = card->proclog;
+
+ if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_WRITE)
+ return (mask); /* no polling for write supported */
+
+ 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_data(pd->log_name,
+ S_IFREG | S_IRUGO | S_IWUSR, hysdn_proc_entry,
+ &log_fops, card);
+
+ 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 */
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