| /* $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; |
| struct proc_dir_entry *pde = PDE(file_inode(file)); |
| 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_inode(file)); |
| 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 */ |