/* $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 */ 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; 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 */ /* delete old entrys */ 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 */ spin_unlock_irqrestore(&card->hysdn_lock, flags); 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 __poll_t hysdn_log_poll(struct file *file, poll_table *wait) { __poll_t 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 |= EPOLLIN | EPOLLRDNORM; 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 */