1#include <linux/types.h>
2#include <linux/atmmpc.h>
3#include <linux/slab.h>
4#include <linux/time.h>
5
6#include "mpoa_caches.h"
7#include "mpc.h"
8
9/*
10 * mpoa_caches.c: Implementation of ingress and egress cache
11 * handling functions
12 */
13
14#if 0
15#define dprintk(format, args...)					\
16	printk(KERN_DEBUG "mpoa:%s: " format, __FILE__, ##args)  /* debug */
17#else
18#define dprintk(format, args...)					\
19	do { if (0)							\
20		printk(KERN_DEBUG "mpoa:%s: " format, __FILE__, ##args);\
21	} while (0)
22#endif
23
24#if 0
25#define ddprintk(format, args...)					\
26	printk(KERN_DEBUG "mpoa:%s: " format, __FILE__, ##args)  /* debug */
27#else
28#define ddprintk(format, args...)					\
29	do { if (0)							\
30		printk(KERN_DEBUG "mpoa:%s: " format, __FILE__, ##args);\
31	} while (0)
32#endif
33
34static in_cache_entry *in_cache_get(__be32 dst_ip,
35				    struct mpoa_client *client)
36{
37	in_cache_entry *entry;
38
39	read_lock_bh(&client->ingress_lock);
40	entry = client->in_cache;
41	while (entry != NULL) {
42		if (entry->ctrl_info.in_dst_ip == dst_ip) {
43			atomic_inc(&entry->use);
44			read_unlock_bh(&client->ingress_lock);
45			return entry;
46		}
47		entry = entry->next;
48	}
49	read_unlock_bh(&client->ingress_lock);
50
51	return NULL;
52}
53
54static in_cache_entry *in_cache_get_with_mask(__be32 dst_ip,
55					      struct mpoa_client *client,
56					      __be32 mask)
57{
58	in_cache_entry *entry;
59
60	read_lock_bh(&client->ingress_lock);
61	entry = client->in_cache;
62	while (entry != NULL) {
63		if ((entry->ctrl_info.in_dst_ip & mask) == (dst_ip & mask)) {
64			atomic_inc(&entry->use);
65			read_unlock_bh(&client->ingress_lock);
66			return entry;
67		}
68		entry = entry->next;
69	}
70	read_unlock_bh(&client->ingress_lock);
71
72	return NULL;
73
74}
75
76static in_cache_entry *in_cache_get_by_vcc(struct atm_vcc *vcc,
77					   struct mpoa_client *client)
78{
79	in_cache_entry *entry;
80
81	read_lock_bh(&client->ingress_lock);
82	entry = client->in_cache;
83	while (entry != NULL) {
84		if (entry->shortcut == vcc) {
85			atomic_inc(&entry->use);
86			read_unlock_bh(&client->ingress_lock);
87			return entry;
88		}
89		entry = entry->next;
90	}
91	read_unlock_bh(&client->ingress_lock);
92
93	return NULL;
94}
95
96static in_cache_entry *in_cache_add_entry(__be32 dst_ip,
97					  struct mpoa_client *client)
98{
99	in_cache_entry *entry = kzalloc(sizeof(in_cache_entry), GFP_KERNEL);
100
101	if (entry == NULL) {
102		pr_info("mpoa: mpoa_caches.c: new_in_cache_entry: out of memory\n");
103		return NULL;
104	}
105
106	dprintk("adding an ingress entry, ip = %pI4\n", &dst_ip);
107
108	atomic_set(&entry->use, 1);
109	dprintk("new_in_cache_entry: about to lock\n");
110	write_lock_bh(&client->ingress_lock);
111	entry->next = client->in_cache;
112	entry->prev = NULL;
113	if (client->in_cache != NULL)
114		client->in_cache->prev = entry;
115	client->in_cache = entry;
116
117	memcpy(entry->MPS_ctrl_ATM_addr, client->mps_ctrl_addr, ATM_ESA_LEN);
118	entry->ctrl_info.in_dst_ip = dst_ip;
119	do_gettimeofday(&(entry->tv));
120	entry->retry_time = client->parameters.mpc_p4;
121	entry->count = 1;
122	entry->entry_state = INGRESS_INVALID;
123	entry->ctrl_info.holding_time = HOLDING_TIME_DEFAULT;
124	atomic_inc(&entry->use);
125
126	write_unlock_bh(&client->ingress_lock);
127	dprintk("new_in_cache_entry: unlocked\n");
128
129	return entry;
130}
131
132static int cache_hit(in_cache_entry *entry, struct mpoa_client *mpc)
133{
134	struct atm_mpoa_qos *qos;
135	struct k_message msg;
136
137	entry->count++;
138	if (entry->entry_state == INGRESS_RESOLVED && entry->shortcut != NULL)
139		return OPEN;
140
141	if (entry->entry_state == INGRESS_REFRESHING) {
142		if (entry->count > mpc->parameters.mpc_p1) {
143			msg.type = SND_MPOA_RES_RQST;
144			msg.content.in_info = entry->ctrl_info;
145			memcpy(msg.MPS_ctrl, mpc->mps_ctrl_addr, ATM_ESA_LEN);
146			qos = atm_mpoa_search_qos(entry->ctrl_info.in_dst_ip);
147			if (qos != NULL)
148				msg.qos = qos->qos;
149			msg_to_mpoad(&msg, mpc);
150			do_gettimeofday(&(entry->reply_wait));
151			entry->entry_state = INGRESS_RESOLVING;
152		}
153		if (entry->shortcut != NULL)
154			return OPEN;
155		return CLOSED;
156	}
157
158	if (entry->entry_state == INGRESS_RESOLVING && entry->shortcut != NULL)
159		return OPEN;
160
161	if (entry->count > mpc->parameters.mpc_p1 &&
162	    entry->entry_state == INGRESS_INVALID) {
163		dprintk("(%s) threshold exceeded for ip %pI4, sending MPOA res req\n",
164			mpc->dev->name, &entry->ctrl_info.in_dst_ip);
165		entry->entry_state = INGRESS_RESOLVING;
166		msg.type = SND_MPOA_RES_RQST;
167		memcpy(msg.MPS_ctrl, mpc->mps_ctrl_addr, ATM_ESA_LEN);
168		msg.content.in_info = entry->ctrl_info;
169		qos = atm_mpoa_search_qos(entry->ctrl_info.in_dst_ip);
170		if (qos != NULL)
171			msg.qos = qos->qos;
172		msg_to_mpoad(&msg, mpc);
173		do_gettimeofday(&(entry->reply_wait));
174	}
175
176	return CLOSED;
177}
178
179static void in_cache_put(in_cache_entry *entry)
180{
181	if (atomic_dec_and_test(&entry->use)) {
182		memset(entry, 0, sizeof(in_cache_entry));
183		kfree(entry);
184	}
185}
186
187/*
188 * This should be called with write lock on
189 */
190static void in_cache_remove_entry(in_cache_entry *entry,
191				  struct mpoa_client *client)
192{
193	struct atm_vcc *vcc;
194	struct k_message msg;
195
196	vcc = entry->shortcut;
197	dprintk("removing an ingress entry, ip = %pI4\n",
198		&entry->ctrl_info.in_dst_ip);
199
200	if (entry->prev != NULL)
201		entry->prev->next = entry->next;
202	else
203		client->in_cache = entry->next;
204	if (entry->next != NULL)
205		entry->next->prev = entry->prev;
206	client->in_ops->put(entry);
207	if (client->in_cache == NULL && client->eg_cache == NULL) {
208		msg.type = STOP_KEEP_ALIVE_SM;
209		msg_to_mpoad(&msg, client);
210	}
211
212	/* Check if the egress side still uses this VCC */
213	if (vcc != NULL) {
214		eg_cache_entry *eg_entry = client->eg_ops->get_by_vcc(vcc,
215								      client);
216		if (eg_entry != NULL) {
217			client->eg_ops->put(eg_entry);
218			return;
219		}
220		vcc_release_async(vcc, -EPIPE);
221	}
222}
223
224/* Call this every MPC-p2 seconds... Not exactly correct solution,
225   but an easy one... */
226static void clear_count_and_expired(struct mpoa_client *client)
227{
228	in_cache_entry *entry, *next_entry;
229	struct timeval now;
230
231	do_gettimeofday(&now);
232
233	write_lock_bh(&client->ingress_lock);
234	entry = client->in_cache;
235	while (entry != NULL) {
236		entry->count = 0;
237		next_entry = entry->next;
238		if ((now.tv_sec - entry->tv.tv_sec)
239		   > entry->ctrl_info.holding_time) {
240			dprintk("holding time expired, ip = %pI4\n",
241				&entry->ctrl_info.in_dst_ip);
242			client->in_ops->remove_entry(entry, client);
243		}
244		entry = next_entry;
245	}
246	write_unlock_bh(&client->ingress_lock);
247}
248
249/* Call this every MPC-p4 seconds. */
250static void check_resolving_entries(struct mpoa_client *client)
251{
252
253	struct atm_mpoa_qos *qos;
254	in_cache_entry *entry;
255	struct timeval now;
256	struct k_message msg;
257
258	do_gettimeofday(&now);
259
260	read_lock_bh(&client->ingress_lock);
261	entry = client->in_cache;
262	while (entry != NULL) {
263		if (entry->entry_state == INGRESS_RESOLVING) {
264			if ((now.tv_sec - entry->hold_down.tv_sec) <
265			    client->parameters.mpc_p6) {
266				entry = entry->next;	/* Entry in hold down */
267				continue;
268			}
269			if ((now.tv_sec - entry->reply_wait.tv_sec) >
270			    entry->retry_time) {
271				entry->retry_time = MPC_C1 * (entry->retry_time);
272				/*
273				 * Retry time maximum exceeded,
274				 * put entry in hold down.
275				 */
276				if (entry->retry_time > client->parameters.mpc_p5) {
277					do_gettimeofday(&(entry->hold_down));
278					entry->retry_time = client->parameters.mpc_p4;
279					entry = entry->next;
280					continue;
281				}
282				/* Ask daemon to send a resolution request. */
283				memset(&(entry->hold_down), 0, sizeof(struct timeval));
284				msg.type = SND_MPOA_RES_RTRY;
285				memcpy(msg.MPS_ctrl, client->mps_ctrl_addr, ATM_ESA_LEN);
286				msg.content.in_info = entry->ctrl_info;
287				qos = atm_mpoa_search_qos(entry->ctrl_info.in_dst_ip);
288				if (qos != NULL)
289					msg.qos = qos->qos;
290				msg_to_mpoad(&msg, client);
291				do_gettimeofday(&(entry->reply_wait));
292			}
293		}
294		entry = entry->next;
295	}
296	read_unlock_bh(&client->ingress_lock);
297}
298
299/* Call this every MPC-p5 seconds. */
300static void refresh_entries(struct mpoa_client *client)
301{
302	struct timeval now;
303	struct in_cache_entry *entry = client->in_cache;
304
305	ddprintk("refresh_entries\n");
306	do_gettimeofday(&now);
307
308	read_lock_bh(&client->ingress_lock);
309	while (entry != NULL) {
310		if (entry->entry_state == INGRESS_RESOLVED) {
311			if (!(entry->refresh_time))
312				entry->refresh_time = (2 * (entry->ctrl_info.holding_time))/3;
313			if ((now.tv_sec - entry->reply_wait.tv_sec) >
314			    entry->refresh_time) {
315				dprintk("refreshing an entry.\n");
316				entry->entry_state = INGRESS_REFRESHING;
317
318			}
319		}
320		entry = entry->next;
321	}
322	read_unlock_bh(&client->ingress_lock);
323}
324
325static void in_destroy_cache(struct mpoa_client *mpc)
326{
327	write_lock_irq(&mpc->ingress_lock);
328	while (mpc->in_cache != NULL)
329		mpc->in_ops->remove_entry(mpc->in_cache, mpc);
330	write_unlock_irq(&mpc->ingress_lock);
331}
332
333static eg_cache_entry *eg_cache_get_by_cache_id(__be32 cache_id,
334						struct mpoa_client *mpc)
335{
336	eg_cache_entry *entry;
337
338	read_lock_irq(&mpc->egress_lock);
339	entry = mpc->eg_cache;
340	while (entry != NULL) {
341		if (entry->ctrl_info.cache_id == cache_id) {
342			atomic_inc(&entry->use);
343			read_unlock_irq(&mpc->egress_lock);
344			return entry;
345		}
346		entry = entry->next;
347	}
348	read_unlock_irq(&mpc->egress_lock);
349
350	return NULL;
351}
352
353/* This can be called from any context since it saves CPU flags */
354static eg_cache_entry *eg_cache_get_by_tag(__be32 tag, struct mpoa_client *mpc)
355{
356	unsigned long flags;
357	eg_cache_entry *entry;
358
359	read_lock_irqsave(&mpc->egress_lock, flags);
360	entry = mpc->eg_cache;
361	while (entry != NULL) {
362		if (entry->ctrl_info.tag == tag) {
363			atomic_inc(&entry->use);
364			read_unlock_irqrestore(&mpc->egress_lock, flags);
365			return entry;
366		}
367		entry = entry->next;
368	}
369	read_unlock_irqrestore(&mpc->egress_lock, flags);
370
371	return NULL;
372}
373
374/* This can be called from any context since it saves CPU flags */
375static eg_cache_entry *eg_cache_get_by_vcc(struct atm_vcc *vcc,
376					   struct mpoa_client *mpc)
377{
378	unsigned long flags;
379	eg_cache_entry *entry;
380
381	read_lock_irqsave(&mpc->egress_lock, flags);
382	entry = mpc->eg_cache;
383	while (entry != NULL) {
384		if (entry->shortcut == vcc) {
385			atomic_inc(&entry->use);
386			read_unlock_irqrestore(&mpc->egress_lock, flags);
387			return entry;
388		}
389		entry = entry->next;
390	}
391	read_unlock_irqrestore(&mpc->egress_lock, flags);
392
393	return NULL;
394}
395
396static eg_cache_entry *eg_cache_get_by_src_ip(__be32 ipaddr,
397					      struct mpoa_client *mpc)
398{
399	eg_cache_entry *entry;
400
401	read_lock_irq(&mpc->egress_lock);
402	entry = mpc->eg_cache;
403	while (entry != NULL) {
404		if (entry->latest_ip_addr == ipaddr) {
405			atomic_inc(&entry->use);
406			read_unlock_irq(&mpc->egress_lock);
407			return entry;
408		}
409		entry = entry->next;
410	}
411	read_unlock_irq(&mpc->egress_lock);
412
413	return NULL;
414}
415
416static void eg_cache_put(eg_cache_entry *entry)
417{
418	if (atomic_dec_and_test(&entry->use)) {
419		memset(entry, 0, sizeof(eg_cache_entry));
420		kfree(entry);
421	}
422}
423
424/*
425 * This should be called with write lock on
426 */
427static void eg_cache_remove_entry(eg_cache_entry *entry,
428				  struct mpoa_client *client)
429{
430	struct atm_vcc *vcc;
431	struct k_message msg;
432
433	vcc = entry->shortcut;
434	dprintk("removing an egress entry.\n");
435	if (entry->prev != NULL)
436		entry->prev->next = entry->next;
437	else
438		client->eg_cache = entry->next;
439	if (entry->next != NULL)
440		entry->next->prev = entry->prev;
441	client->eg_ops->put(entry);
442	if (client->in_cache == NULL && client->eg_cache == NULL) {
443		msg.type = STOP_KEEP_ALIVE_SM;
444		msg_to_mpoad(&msg, client);
445	}
446
447	/* Check if the ingress side still uses this VCC */
448	if (vcc != NULL) {
449		in_cache_entry *in_entry = client->in_ops->get_by_vcc(vcc, client);
450		if (in_entry != NULL) {
451			client->in_ops->put(in_entry);
452			return;
453		}
454		vcc_release_async(vcc, -EPIPE);
455	}
456}
457
458static eg_cache_entry *eg_cache_add_entry(struct k_message *msg,
459					  struct mpoa_client *client)
460{
461	eg_cache_entry *entry = kzalloc(sizeof(eg_cache_entry), GFP_KERNEL);
462
463	if (entry == NULL) {
464		pr_info("out of memory\n");
465		return NULL;
466	}
467
468	dprintk("adding an egress entry, ip = %pI4, this should be our IP\n",
469		&msg->content.eg_info.eg_dst_ip);
470
471	atomic_set(&entry->use, 1);
472	dprintk("new_eg_cache_entry: about to lock\n");
473	write_lock_irq(&client->egress_lock);
474	entry->next = client->eg_cache;
475	entry->prev = NULL;
476	if (client->eg_cache != NULL)
477		client->eg_cache->prev = entry;
478	client->eg_cache = entry;
479
480	memcpy(entry->MPS_ctrl_ATM_addr, client->mps_ctrl_addr, ATM_ESA_LEN);
481	entry->ctrl_info = msg->content.eg_info;
482	do_gettimeofday(&(entry->tv));
483	entry->entry_state = EGRESS_RESOLVED;
484	dprintk("new_eg_cache_entry cache_id %u\n",
485		ntohl(entry->ctrl_info.cache_id));
486	dprintk("mps_ip = %pI4\n", &entry->ctrl_info.mps_ip);
487	atomic_inc(&entry->use);
488
489	write_unlock_irq(&client->egress_lock);
490	dprintk("new_eg_cache_entry: unlocked\n");
491
492	return entry;
493}
494
495static void update_eg_cache_entry(eg_cache_entry *entry, uint16_t holding_time)
496{
497	do_gettimeofday(&(entry->tv));
498	entry->entry_state = EGRESS_RESOLVED;
499	entry->ctrl_info.holding_time = holding_time;
500}
501
502static void clear_expired(struct mpoa_client *client)
503{
504	eg_cache_entry *entry, *next_entry;
505	struct timeval now;
506	struct k_message msg;
507
508	do_gettimeofday(&now);
509
510	write_lock_irq(&client->egress_lock);
511	entry = client->eg_cache;
512	while (entry != NULL) {
513		next_entry = entry->next;
514		if ((now.tv_sec - entry->tv.tv_sec)
515		   > entry->ctrl_info.holding_time) {
516			msg.type = SND_EGRESS_PURGE;
517			msg.content.eg_info = entry->ctrl_info;
518			dprintk("egress_cache: holding time expired, cache_id = %u.\n",
519				ntohl(entry->ctrl_info.cache_id));
520			msg_to_mpoad(&msg, client);
521			client->eg_ops->remove_entry(entry, client);
522		}
523		entry = next_entry;
524	}
525	write_unlock_irq(&client->egress_lock);
526}
527
528static void eg_destroy_cache(struct mpoa_client *mpc)
529{
530	write_lock_irq(&mpc->egress_lock);
531	while (mpc->eg_cache != NULL)
532		mpc->eg_ops->remove_entry(mpc->eg_cache, mpc);
533	write_unlock_irq(&mpc->egress_lock);
534}
535
536
537static struct in_cache_ops ingress_ops = {
538	in_cache_add_entry,               /* add_entry       */
539	in_cache_get,                     /* get             */
540	in_cache_get_with_mask,           /* get_with_mask   */
541	in_cache_get_by_vcc,              /* get_by_vcc      */
542	in_cache_put,                     /* put             */
543	in_cache_remove_entry,            /* remove_entry    */
544	cache_hit,                        /* cache_hit       */
545	clear_count_and_expired,          /* clear_count     */
546	check_resolving_entries,          /* check_resolving */
547	refresh_entries,                  /* refresh         */
548	in_destroy_cache                  /* destroy_cache   */
549};
550
551static struct eg_cache_ops egress_ops = {
552	eg_cache_add_entry,               /* add_entry        */
553	eg_cache_get_by_cache_id,         /* get_by_cache_id  */
554	eg_cache_get_by_tag,              /* get_by_tag       */
555	eg_cache_get_by_vcc,              /* get_by_vcc       */
556	eg_cache_get_by_src_ip,           /* get_by_src_ip    */
557	eg_cache_put,                     /* put              */
558	eg_cache_remove_entry,            /* remove_entry     */
559	update_eg_cache_entry,            /* update           */
560	clear_expired,                    /* clear_expired    */
561	eg_destroy_cache                  /* destroy_cache    */
562};
563
564
565void atm_mpoa_init_cache(struct mpoa_client *mpc)
566{
567	mpc->in_ops = &ingress_ops;
568	mpc->eg_ops = &egress_ops;
569}
570