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1da177e4 LT |
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> | |
1da177e4 LT |
14 | #include <linux/poll.h> |
15 | #include <linux/proc_fs.h> | |
d43c36dc | 16 | #include <linux/sched.h> |
5a0e3ad6 | 17 | #include <linux/slab.h> |
76a64921 | 18 | #include <linux/mutex.h> |
3944ad68 | 19 | #include <linux/kernel.h> |
1da177e4 LT |
20 | |
21 | #include "hysdn_defs.h" | |
22 | ||
23 | /* the proc subdir for the interface is defined in the procconf module */ | |
24 | extern struct proc_dir_entry *hysdn_proc_entry; | |
25 | ||
76a64921 | 26 | static DEFINE_MUTEX(hysdn_log_mutex); |
475be4d8 | 27 | static void put_log_buffer(hysdn_card *card, char *cp); |
aade0e82 | 28 | |
1da177e4 LT |
29 | /*************************************************/ |
30 | /* structure keeping ascii log for device output */ | |
31 | /*************************************************/ | |
32 | struct log_data { | |
33 | struct log_data *next; | |
c721bcce | 34 | unsigned long usage_cnt;/* number of files still to work */ |
1da177e4 LT |
35 | void *proc_ctrl; /* pointer to own control procdata structure */ |
36 | char log_start[2]; /* log string start (final len aligned by size) */ | |
37 | }; | |
38 | ||
39 | /**********************************************/ | |
40 | /* structure holding proc entrys for one card */ | |
41 | /**********************************************/ | |
42 | struct procdata { | |
43 | struct proc_dir_entry *log; /* log entry */ | |
44 | char log_name[15]; /* log filename */ | |
45 | struct log_data *log_head, *log_tail; /* head and tail for queue */ | |
46 | int if_used; /* open count for interface */ | |
47 | int volatile del_lock; /* lock for delete operations */ | |
c721bcce | 48 | unsigned char logtmp[LOG_MAX_LINELEN]; |
1da177e4 LT |
49 | wait_queue_head_t rd_queue; |
50 | }; | |
51 | ||
52 | ||
53 | /**********************************************/ | |
54 | /* log function for cards error log interface */ | |
55 | /**********************************************/ | |
56 | void | |
475be4d8 | 57 | hysdn_card_errlog(hysdn_card *card, tErrLogEntry *logp, int maxsize) |
1da177e4 LT |
58 | { |
59 | char buf[ERRLOG_TEXT_SIZE + 40]; | |
60 | ||
61 | sprintf(buf, "LOG 0x%08lX 0x%08lX : %s\n", logp->ulErrType, logp->ulErrSubtype, logp->ucText); | |
62 | put_log_buffer(card, buf); /* output the string */ | |
63 | } /* hysdn_card_errlog */ | |
64 | ||
65 | /***************************************************/ | |
66 | /* Log function using format specifiers for output */ | |
67 | /***************************************************/ | |
68 | void | |
475be4d8 | 69 | hysdn_addlog(hysdn_card *card, char *fmt, ...) |
1da177e4 LT |
70 | { |
71 | struct procdata *pd = card->proclog; | |
72 | char *cp; | |
73 | va_list args; | |
74 | ||
75 | if (!pd) | |
76 | return; /* log structure non existent */ | |
77 | ||
78 | cp = pd->logtmp; | |
79 | cp += sprintf(cp, "HYSDN: card %d ", card->myid); | |
80 | ||
81 | va_start(args, fmt); | |
82 | cp += vsprintf(cp, fmt, args); | |
83 | va_end(args); | |
84 | *cp++ = '\n'; | |
85 | *cp = 0; | |
86 | ||
87 | if (card->debug_flags & DEB_OUT_SYSLOG) | |
88 | printk(KERN_INFO "%s", pd->logtmp); | |
89 | else | |
90 | put_log_buffer(card, pd->logtmp); | |
91 | ||
92 | } /* hysdn_addlog */ | |
93 | ||
94 | /********************************************/ | |
95 | /* put an log buffer into the log queue. */ | |
96 | /* This buffer will be kept until all files */ | |
97 | /* opened for read got the contents. */ | |
98 | /* Flushes buffers not longer in use. */ | |
99 | /********************************************/ | |
aade0e82 | 100 | static void |
475be4d8 | 101 | put_log_buffer(hysdn_card *card, char *cp) |
1da177e4 LT |
102 | { |
103 | struct log_data *ib; | |
104 | struct procdata *pd = card->proclog; | |
105 | int i; | |
106 | unsigned long flags; | |
107 | ||
108 | if (!pd) | |
109 | return; | |
110 | if (!cp) | |
111 | return; | |
112 | if (!*cp) | |
113 | return; | |
114 | if (pd->if_used <= 0) | |
115 | return; /* no open file for read */ | |
116 | ||
5cbded58 | 117 | if (!(ib = kmalloc(sizeof(struct log_data) + strlen(cp), GFP_ATOMIC))) |
475be4d8 | 118 | return; /* no memory */ |
1da177e4 LT |
119 | strcpy(ib->log_start, cp); /* set output string */ |
120 | ib->next = NULL; | |
121 | ib->proc_ctrl = pd; /* point to own control structure */ | |
0d9ba869 | 122 | spin_lock_irqsave(&card->hysdn_lock, flags); |
1da177e4 LT |
123 | ib->usage_cnt = pd->if_used; |
124 | if (!pd->log_head) | |
125 | pd->log_head = ib; /* new head */ | |
126 | else | |
127 | pd->log_tail->next = ib; /* follows existing messages */ | |
128 | pd->log_tail = ib; /* new tail */ | |
129 | i = pd->del_lock++; /* get lock state */ | |
0d9ba869 | 130 | spin_unlock_irqrestore(&card->hysdn_lock, flags); |
1da177e4 LT |
131 | |
132 | /* delete old entrys */ | |
133 | if (!i) | |
134 | while (pd->log_head->next) { | |
135 | if ((pd->log_head->usage_cnt <= 0) && | |
136 | (pd->log_head->next->usage_cnt <= 0)) { | |
137 | ib = pd->log_head; | |
138 | pd->log_head = pd->log_head->next; | |
139 | kfree(ib); | |
140 | } else | |
141 | break; | |
142 | } /* pd->log_head->next */ | |
143 | pd->del_lock--; /* release lock level */ | |
144 | wake_up_interruptible(&(pd->rd_queue)); /* announce new entry */ | |
145 | } /* put_log_buffer */ | |
146 | ||
147 | ||
148 | /******************************/ | |
149 | /* file operations and tables */ | |
150 | /******************************/ | |
151 | ||
152 | /****************************************/ | |
153 | /* write log file -> set log level bits */ | |
154 | /****************************************/ | |
155 | static ssize_t | |
475be4d8 | 156 | hysdn_log_write(struct file *file, const char __user *buf, size_t count, loff_t *off) |
1da177e4 | 157 | { |
3944ad68 | 158 | int rc; |
54cbb1ca | 159 | hysdn_card *card = file->private_data; |
1da177e4 | 160 | |
8831a3f2 | 161 | rc = kstrtoul_from_user(buf, count, 0, &card->debug_flags); |
19eccc2b AD |
162 | if (rc < 0) |
163 | return rc; | |
164 | hysdn_addlog(card, "debug set to 0x%lx", card->debug_flags); | |
1da177e4 LT |
165 | return (count); |
166 | } /* hysdn_log_write */ | |
167 | ||
168 | /******************/ | |
169 | /* read log file */ | |
170 | /******************/ | |
171 | static ssize_t | |
475be4d8 | 172 | hysdn_log_read(struct file *file, char __user *buf, size_t count, loff_t *off) |
1da177e4 LT |
173 | { |
174 | struct log_data *inf; | |
175 | int len; | |
4482dfad | 176 | struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); |
1da177e4 LT |
177 | struct procdata *pd = NULL; |
178 | hysdn_card *card; | |
179 | ||
180 | if (!*((struct log_data **) file->private_data)) { | |
181 | if (file->f_flags & O_NONBLOCK) | |
182 | return (-EAGAIN); | |
183 | ||
184 | /* sorry, but we need to search the card */ | |
185 | card = card_root; | |
186 | while (card) { | |
187 | pd = card->proclog; | |
188 | if (pd->log == pde) | |
189 | break; | |
190 | card = card->next; /* search next entry */ | |
191 | } | |
192 | if (card) | |
193 | interruptible_sleep_on(&(pd->rd_queue)); | |
194 | else | |
195 | return (-EAGAIN); | |
196 | ||
197 | } | |
198 | if (!(inf = *((struct log_data **) file->private_data))) | |
199 | return (0); | |
200 | ||
201 | inf->usage_cnt--; /* new usage count */ | |
202 | file->private_data = &inf->next; /* next structure */ | |
203 | if ((len = strlen(inf->log_start)) <= count) { | |
204 | if (copy_to_user(buf, inf->log_start, len)) | |
205 | return -EFAULT; | |
206 | *off += len; | |
207 | return (len); | |
208 | } | |
209 | return (0); | |
210 | } /* hysdn_log_read */ | |
211 | ||
212 | /******************/ | |
213 | /* open log file */ | |
214 | /******************/ | |
215 | static int | |
216 | hysdn_log_open(struct inode *ino, struct file *filep) | |
217 | { | |
218 | hysdn_card *card; | |
219 | struct procdata *pd = NULL; | |
c721bcce | 220 | unsigned long flags; |
1da177e4 | 221 | |
76a64921 | 222 | mutex_lock(&hysdn_log_mutex); |
1da177e4 LT |
223 | card = card_root; |
224 | while (card) { | |
225 | pd = card->proclog; | |
226 | if (pd->log == PDE(ino)) | |
227 | break; | |
228 | card = card->next; /* search next entry */ | |
229 | } | |
230 | if (!card) { | |
76a64921 | 231 | mutex_unlock(&hysdn_log_mutex); |
1da177e4 LT |
232 | return (-ENODEV); /* device is unknown/invalid */ |
233 | } | |
234 | filep->private_data = card; /* remember our own card */ | |
235 | ||
236 | if ((filep->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_WRITE) { | |
237 | /* write only access -> write log level only */ | |
238 | } else if ((filep->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) { | |
239 | ||
240 | /* read access -> log/debug read */ | |
0d9ba869 | 241 | spin_lock_irqsave(&card->hysdn_lock, flags); |
1da177e4 LT |
242 | pd->if_used++; |
243 | if (pd->log_head) | |
244 | filep->private_data = &pd->log_tail->next; | |
245 | else | |
246 | filep->private_data = &pd->log_head; | |
0d9ba869 | 247 | spin_unlock_irqrestore(&card->hysdn_lock, flags); |
1da177e4 | 248 | } else { /* simultaneous read/write access forbidden ! */ |
76a64921 | 249 | mutex_unlock(&hysdn_log_mutex); |
1da177e4 LT |
250 | return (-EPERM); /* no permission this time */ |
251 | } | |
76a64921 | 252 | mutex_unlock(&hysdn_log_mutex); |
1da177e4 LT |
253 | return nonseekable_open(ino, filep); |
254 | } /* hysdn_log_open */ | |
255 | ||
256 | /*******************************************************************************/ | |
257 | /* close a cardlog file. If the file has been opened for exclusive write it is */ | |
258 | /* assumed as pof data input and the pof loader is noticed about. */ | |
259 | /* Otherwise file is handled as log output. In this case the interface usage */ | |
260 | /* count is decremented and all buffers are noticed of closing. If this file */ | |
261 | /* was the last one to be closed, all buffers are freed. */ | |
262 | /*******************************************************************************/ | |
263 | static int | |
264 | hysdn_log_close(struct inode *ino, struct file *filep) | |
265 | { | |
266 | struct log_data *inf; | |
267 | struct procdata *pd; | |
268 | hysdn_card *card; | |
269 | int retval = 0; | |
1da177e4 | 270 | |
76a64921 | 271 | mutex_lock(&hysdn_log_mutex); |
1da177e4 LT |
272 | if ((filep->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_WRITE) { |
273 | /* write only access -> write debug level written */ | |
274 | retval = 0; /* success */ | |
275 | } else { | |
276 | /* read access -> log/debug read, mark one further file as closed */ | |
277 | ||
278 | pd = NULL; | |
1da177e4 LT |
279 | inf = *((struct log_data **) filep->private_data); /* get first log entry */ |
280 | if (inf) | |
281 | pd = (struct procdata *) inf->proc_ctrl; /* still entries there */ | |
282 | else { | |
283 | /* no info available -> search card */ | |
284 | card = card_root; | |
285 | while (card) { | |
286 | pd = card->proclog; | |
287 | if (pd->log == PDE(ino)) | |
288 | break; | |
289 | card = card->next; /* search next entry */ | |
290 | } | |
291 | if (card) | |
292 | pd = card->proclog; /* pointer to procfs log */ | |
293 | } | |
294 | if (pd) | |
295 | pd->if_used--; /* decrement interface usage count by one */ | |
296 | ||
297 | while (inf) { | |
298 | inf->usage_cnt--; /* decrement usage count for buffers */ | |
299 | inf = inf->next; | |
300 | } | |
1da177e4 LT |
301 | |
302 | if (pd) | |
303 | if (pd->if_used <= 0) /* delete buffers if last file closed */ | |
304 | while (pd->log_head) { | |
305 | inf = pd->log_head; | |
306 | pd->log_head = pd->log_head->next; | |
307 | kfree(inf); | |
308 | } | |
309 | } /* read access */ | |
76a64921 | 310 | mutex_unlock(&hysdn_log_mutex); |
1da177e4 LT |
311 | |
312 | return (retval); | |
313 | } /* hysdn_log_close */ | |
314 | ||
315 | /*************************************************/ | |
316 | /* select/poll routine to be able using select() */ | |
317 | /*************************************************/ | |
318 | static unsigned int | |
475be4d8 | 319 | hysdn_log_poll(struct file *file, poll_table *wait) |
1da177e4 LT |
320 | { |
321 | unsigned int mask = 0; | |
4482dfad | 322 | struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); |
1da177e4 LT |
323 | hysdn_card *card; |
324 | struct procdata *pd = NULL; | |
325 | ||
326 | if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_WRITE) | |
327 | return (mask); /* no polling for write supported */ | |
328 | ||
329 | /* we need to search the card */ | |
330 | card = card_root; | |
331 | while (card) { | |
332 | pd = card->proclog; | |
333 | if (pd->log == pde) | |
334 | break; | |
335 | card = card->next; /* search next entry */ | |
336 | } | |
337 | if (!card) | |
338 | return (mask); /* card not found */ | |
339 | ||
340 | poll_wait(file, &(pd->rd_queue), wait); | |
341 | ||
342 | if (*((struct log_data **) file->private_data)) | |
343 | mask |= POLLIN | POLLRDNORM; | |
344 | ||
345 | return mask; | |
346 | } /* hysdn_log_poll */ | |
347 | ||
348 | /**************************************************/ | |
349 | /* table for log filesystem functions defined above. */ | |
350 | /**************************************************/ | |
2b8693c0 | 351 | static const struct file_operations log_fops = |
1da177e4 | 352 | { |
ac41cfd1 | 353 | .owner = THIS_MODULE, |
1da177e4 LT |
354 | .llseek = no_llseek, |
355 | .read = hysdn_log_read, | |
356 | .write = hysdn_log_write, | |
357 | .poll = hysdn_log_poll, | |
358 | .open = hysdn_log_open, | |
475be4d8 | 359 | .release = hysdn_log_close, |
1da177e4 LT |
360 | }; |
361 | ||
362 | ||
363 | /***********************************************************************************/ | |
364 | /* hysdn_proclog_init is called when the module is loaded after creating the cards */ | |
365 | /* conf files. */ | |
366 | /***********************************************************************************/ | |
367 | int | |
475be4d8 | 368 | hysdn_proclog_init(hysdn_card *card) |
1da177e4 LT |
369 | { |
370 | struct procdata *pd; | |
371 | ||
372 | /* create a cardlog proc entry */ | |
373 | ||
41f96935 | 374 | if ((pd = kzalloc(sizeof(struct procdata), GFP_KERNEL)) != NULL) { |
1da177e4 | 375 | sprintf(pd->log_name, "%s%d", PROC_LOG_BASENAME, card->myid); |
ac41cfd1 | 376 | pd->log = proc_create(pd->log_name, |
475be4d8 JP |
377 | S_IFREG | S_IRUGO | S_IWUSR, hysdn_proc_entry, |
378 | &log_fops); | |
1da177e4 LT |
379 | |
380 | init_waitqueue_head(&(pd->rd_queue)); | |
381 | ||
382 | card->proclog = (void *) pd; /* remember procfs structure */ | |
383 | } | |
384 | return (0); | |
385 | } /* hysdn_proclog_init */ | |
386 | ||
387 | /************************************************************************************/ | |
388 | /* hysdn_proclog_release is called when the module is unloaded and before the cards */ | |
389 | /* conf file is released */ | |
390 | /* The module counter is assumed to be 0 ! */ | |
391 | /************************************************************************************/ | |
392 | void | |
475be4d8 | 393 | hysdn_proclog_release(hysdn_card *card) |
1da177e4 LT |
394 | { |
395 | struct procdata *pd; | |
396 | ||
397 | if ((pd = (struct procdata *) card->proclog) != NULL) { | |
398 | if (pd->log) | |
399 | remove_proc_entry(pd->log_name, hysdn_proc_entry); | |
400 | kfree(pd); /* release memory */ | |
401 | card->proclog = NULL; | |
402 | } | |
403 | } /* hysdn_proclog_release */ |