xref: /linux/net/atm/mpoa_caches.c (revision 6ee738610f41b59733f63718f0bdbcba7d3a3f12)
1 #include <linux/types.h>
2 #include <linux/atmmpc.h>
3 #include <linux/time.h>
4 
5 #include "mpoa_caches.h"
6 #include "mpc.h"
7 
8 /*
9  * mpoa_caches.c: Implementation of ingress and egress cache
10  * handling functions
11  */
12 
13 #if 0
14 #define dprintk printk    /* debug */
15 #else
16 #define dprintk(format,args...)
17 #endif
18 
19 #if 0
20 #define ddprintk printk  /* more debug */
21 #else
22 #define ddprintk(format,args...)
23 #endif
24 
25 static in_cache_entry *in_cache_get(__be32 dst_ip,
26 				    struct mpoa_client *client)
27 {
28 	in_cache_entry *entry;
29 
30 	read_lock_bh(&client->ingress_lock);
31 	entry = client->in_cache;
32 	while(entry != NULL){
33 		if( entry->ctrl_info.in_dst_ip == dst_ip ){
34 			atomic_inc(&entry->use);
35 			read_unlock_bh(&client->ingress_lock);
36 			return entry;
37 		}
38 		entry = entry->next;
39 	}
40 	read_unlock_bh(&client->ingress_lock);
41 
42 	return NULL;
43 }
44 
45 static in_cache_entry *in_cache_get_with_mask(__be32 dst_ip,
46 					      struct mpoa_client *client,
47 					      __be32 mask)
48 {
49 	in_cache_entry *entry;
50 
51 	read_lock_bh(&client->ingress_lock);
52 	entry = client->in_cache;
53 	while(entry != NULL){
54 		if((entry->ctrl_info.in_dst_ip & mask)  == (dst_ip & mask )){
55 			atomic_inc(&entry->use);
56 			read_unlock_bh(&client->ingress_lock);
57 			return entry;
58 		}
59 		entry = entry->next;
60 	}
61 	read_unlock_bh(&client->ingress_lock);
62 
63 	return NULL;
64 
65 }
66 
67 static in_cache_entry *in_cache_get_by_vcc(struct atm_vcc *vcc,
68 					   struct mpoa_client *client )
69 {
70 	in_cache_entry *entry;
71 
72 	read_lock_bh(&client->ingress_lock);
73 	entry = client->in_cache;
74 	while(entry != NULL){
75 		if(entry->shortcut == vcc) {
76 			atomic_inc(&entry->use);
77 			read_unlock_bh(&client->ingress_lock);
78 			return entry;
79 		}
80 		entry = entry->next;
81 	}
82 	read_unlock_bh(&client->ingress_lock);
83 
84 	return NULL;
85 }
86 
87 static in_cache_entry *in_cache_add_entry(__be32 dst_ip,
88 					  struct mpoa_client *client)
89 {
90 	in_cache_entry *entry = kzalloc(sizeof(in_cache_entry), GFP_KERNEL);
91 
92 	if (entry == NULL) {
93 		printk("mpoa: mpoa_caches.c: new_in_cache_entry: out of memory\n");
94 		return NULL;
95 	}
96 
97 	dprintk("mpoa: mpoa_caches.c: adding an ingress entry, ip = %pI4\n", &dst_ip);
98 
99 	atomic_set(&entry->use, 1);
100 	dprintk("mpoa: mpoa_caches.c: new_in_cache_entry: about to lock\n");
101 	write_lock_bh(&client->ingress_lock);
102 	entry->next = client->in_cache;
103 	entry->prev = NULL;
104 	if (client->in_cache != NULL)
105 		client->in_cache->prev = entry;
106 	client->in_cache = entry;
107 
108 	memcpy(entry->MPS_ctrl_ATM_addr, client->mps_ctrl_addr, ATM_ESA_LEN);
109 	entry->ctrl_info.in_dst_ip = dst_ip;
110 	do_gettimeofday(&(entry->tv));
111 	entry->retry_time = client->parameters.mpc_p4;
112 	entry->count = 1;
113 	entry->entry_state = INGRESS_INVALID;
114 	entry->ctrl_info.holding_time = HOLDING_TIME_DEFAULT;
115 	atomic_inc(&entry->use);
116 
117 	write_unlock_bh(&client->ingress_lock);
118 	dprintk("mpoa: mpoa_caches.c: new_in_cache_entry: unlocked\n");
119 
120 	return entry;
121 }
122 
123 static int cache_hit(in_cache_entry *entry, struct mpoa_client *mpc)
124 {
125 	struct atm_mpoa_qos *qos;
126 	struct k_message msg;
127 
128 	entry->count++;
129 	if(entry->entry_state == INGRESS_RESOLVED && entry->shortcut != NULL)
130 		return OPEN;
131 
132 	if(entry->entry_state == INGRESS_REFRESHING){
133 		if(entry->count > mpc->parameters.mpc_p1){
134 			msg.type = SND_MPOA_RES_RQST;
135 			msg.content.in_info = entry->ctrl_info;
136 			memcpy(msg.MPS_ctrl, mpc->mps_ctrl_addr, ATM_ESA_LEN);
137 			qos = atm_mpoa_search_qos(entry->ctrl_info.in_dst_ip);
138 			if (qos != NULL) msg.qos = qos->qos;
139 			msg_to_mpoad(&msg, mpc);
140 			do_gettimeofday(&(entry->reply_wait));
141 			entry->entry_state = INGRESS_RESOLVING;
142 		}
143 		if(entry->shortcut != NULL)
144 			return OPEN;
145 		return CLOSED;
146 	}
147 
148 	if(entry->entry_state == INGRESS_RESOLVING && entry->shortcut != NULL)
149 		return OPEN;
150 
151 	if( entry->count > mpc->parameters.mpc_p1 &&
152 	    entry->entry_state == INGRESS_INVALID){
153 		dprintk("mpoa: (%s) mpoa_caches.c: threshold exceeded for ip %pI4, sending MPOA res req\n",
154 			mpc->dev->name, &entry->ctrl_info.in_dst_ip);
155 		entry->entry_state = INGRESS_RESOLVING;
156 		msg.type =  SND_MPOA_RES_RQST;
157 		memcpy(msg.MPS_ctrl, mpc->mps_ctrl_addr, ATM_ESA_LEN );
158 		msg.content.in_info = entry->ctrl_info;
159 		qos = atm_mpoa_search_qos(entry->ctrl_info.in_dst_ip);
160 		if (qos != NULL) msg.qos = qos->qos;
161 		msg_to_mpoad( &msg, mpc);
162 		do_gettimeofday(&(entry->reply_wait));
163 	}
164 
165 	return CLOSED;
166 }
167 
168 static void in_cache_put(in_cache_entry *entry)
169 {
170 	if (atomic_dec_and_test(&entry->use)) {
171 		memset(entry, 0, sizeof(in_cache_entry));
172 		kfree(entry);
173 	}
174 
175 	return;
176 }
177 
178 /*
179  * This should be called with write lock on
180  */
181 static void in_cache_remove_entry(in_cache_entry *entry,
182 				  struct mpoa_client *client)
183 {
184 	struct atm_vcc *vcc;
185 	struct k_message msg;
186 
187 	vcc = entry->shortcut;
188 	dprintk("mpoa: mpoa_caches.c: removing an ingress entry, ip = %pI4\n",
189 		&entry->ctrl_info.in_dst_ip);
190 
191 	if (entry->prev != NULL)
192 		entry->prev->next = entry->next;
193 	else
194 		client->in_cache = entry->next;
195 	if (entry->next != NULL)
196 		entry->next->prev = entry->prev;
197 	client->in_ops->put(entry);
198 	if(client->in_cache == NULL && client->eg_cache == NULL){
199 		msg.type = STOP_KEEP_ALIVE_SM;
200 		msg_to_mpoad(&msg,client);
201 	}
202 
203 	/* Check if the egress side still uses this VCC */
204 	if (vcc != NULL) {
205 		eg_cache_entry *eg_entry = client->eg_ops->get_by_vcc(vcc, client);
206 		if (eg_entry != NULL) {
207 			client->eg_ops->put(eg_entry);
208 			return;
209 		}
210 		vcc_release_async(vcc, -EPIPE);
211 	}
212 
213 	return;
214 }
215 
216 
217 /* Call this every MPC-p2 seconds... Not exactly correct solution,
218    but an easy one... */
219 static void clear_count_and_expired(struct mpoa_client *client)
220 {
221 	in_cache_entry *entry, *next_entry;
222 	struct timeval now;
223 
224 	do_gettimeofday(&now);
225 
226 	write_lock_bh(&client->ingress_lock);
227 	entry = client->in_cache;
228 	while(entry != NULL){
229 		entry->count=0;
230 		next_entry = entry->next;
231 		if((now.tv_sec - entry->tv.tv_sec)
232 		   > entry->ctrl_info.holding_time){
233 			dprintk("mpoa: mpoa_caches.c: holding time expired, ip = %pI4\n",
234 				&entry->ctrl_info.in_dst_ip);
235 			client->in_ops->remove_entry(entry, client);
236 		}
237 		entry = next_entry;
238 	}
239 	write_unlock_bh(&client->ingress_lock);
240 
241 	return;
242 }
243 
244 /* Call this every MPC-p4 seconds. */
245 static void check_resolving_entries(struct mpoa_client *client)
246 {
247 
248 	struct atm_mpoa_qos *qos;
249 	in_cache_entry *entry;
250 	struct timeval now;
251 	struct k_message msg;
252 
253 	do_gettimeofday( &now );
254 
255 	read_lock_bh(&client->ingress_lock);
256 	entry = client->in_cache;
257 	while( entry != NULL ){
258 		if(entry->entry_state == INGRESS_RESOLVING){
259 			if(now.tv_sec - entry->hold_down.tv_sec < client->parameters.mpc_p6){
260 				entry = entry->next;                      /* Entry in hold down */
261 				continue;
262 			}
263 			if( (now.tv_sec - entry->reply_wait.tv_sec) >
264 			    entry->retry_time ){
265 				entry->retry_time = MPC_C1*( entry->retry_time );
266 				if(entry->retry_time > client->parameters.mpc_p5){
267 					/* Retry time maximum exceeded, put entry in hold down. */
268 					do_gettimeofday(&(entry->hold_down));
269 					entry->retry_time = client->parameters.mpc_p4;
270 					entry = entry->next;
271 					continue;
272 				}
273 				/* Ask daemon to send a resolution request. */
274 				memset(&(entry->hold_down),0,sizeof(struct timeval));
275 				msg.type = SND_MPOA_RES_RTRY;
276 				memcpy(msg.MPS_ctrl, client->mps_ctrl_addr, ATM_ESA_LEN);
277 				msg.content.in_info = entry->ctrl_info;
278 				qos = atm_mpoa_search_qos(entry->ctrl_info.in_dst_ip);
279 				if (qos != NULL) msg.qos = qos->qos;
280 				msg_to_mpoad(&msg, client);
281 				do_gettimeofday(&(entry->reply_wait));
282 			}
283 		}
284 		entry = entry->next;
285 	}
286 	read_unlock_bh(&client->ingress_lock);
287 }
288 
289 /* Call this every MPC-p5 seconds. */
290 static void refresh_entries(struct mpoa_client *client)
291 {
292 	struct timeval now;
293 	struct in_cache_entry *entry = client->in_cache;
294 
295 	ddprintk("mpoa: mpoa_caches.c: refresh_entries\n");
296 	do_gettimeofday(&now);
297 
298 	read_lock_bh(&client->ingress_lock);
299 	while( entry != NULL ){
300 		if( entry->entry_state == INGRESS_RESOLVED ){
301 			if(!(entry->refresh_time))
302 				entry->refresh_time = (2*(entry->ctrl_info.holding_time))/3;
303 			if( (now.tv_sec - entry->reply_wait.tv_sec) > entry->refresh_time ){
304 				dprintk("mpoa: mpoa_caches.c: refreshing an entry.\n");
305 				entry->entry_state = INGRESS_REFRESHING;
306 
307 			}
308 		}
309 		entry = entry->next;
310 	}
311 	read_unlock_bh(&client->ingress_lock);
312 }
313 
314 static void in_destroy_cache(struct mpoa_client *mpc)
315 {
316 	write_lock_irq(&mpc->ingress_lock);
317 	while(mpc->in_cache != NULL)
318 		mpc->in_ops->remove_entry(mpc->in_cache, mpc);
319 	write_unlock_irq(&mpc->ingress_lock);
320 
321 	return;
322 }
323 
324 static eg_cache_entry *eg_cache_get_by_cache_id(__be32 cache_id, struct mpoa_client *mpc)
325 {
326 	eg_cache_entry *entry;
327 
328 	read_lock_irq(&mpc->egress_lock);
329 	entry = mpc->eg_cache;
330 	while(entry != NULL){
331 		if(entry->ctrl_info.cache_id == cache_id){
332 			atomic_inc(&entry->use);
333 			read_unlock_irq(&mpc->egress_lock);
334 			return entry;
335 		}
336 		entry = entry->next;
337 	}
338 	read_unlock_irq(&mpc->egress_lock);
339 
340 	return NULL;
341 }
342 
343 /* This can be called from any context since it saves CPU flags */
344 static eg_cache_entry *eg_cache_get_by_tag(__be32 tag, struct mpoa_client *mpc)
345 {
346 	unsigned long flags;
347 	eg_cache_entry *entry;
348 
349 	read_lock_irqsave(&mpc->egress_lock, flags);
350 	entry = mpc->eg_cache;
351 	while (entry != NULL){
352 		if (entry->ctrl_info.tag == tag) {
353 			atomic_inc(&entry->use);
354 			read_unlock_irqrestore(&mpc->egress_lock, flags);
355 			return entry;
356 		}
357 		entry = entry->next;
358 	}
359 	read_unlock_irqrestore(&mpc->egress_lock, flags);
360 
361 	return NULL;
362 }
363 
364 /* This can be called from any context since it saves CPU flags */
365 static eg_cache_entry *eg_cache_get_by_vcc(struct atm_vcc *vcc, struct mpoa_client *mpc)
366 {
367 	unsigned long flags;
368 	eg_cache_entry *entry;
369 
370 	read_lock_irqsave(&mpc->egress_lock, flags);
371 	entry = mpc->eg_cache;
372 	while (entry != NULL){
373 		if (entry->shortcut == vcc) {
374 			atomic_inc(&entry->use);
375 			read_unlock_irqrestore(&mpc->egress_lock, flags);
376 			return entry;
377 		}
378 		entry = entry->next;
379 	}
380 	read_unlock_irqrestore(&mpc->egress_lock, flags);
381 
382 	return NULL;
383 }
384 
385 static eg_cache_entry *eg_cache_get_by_src_ip(__be32 ipaddr, struct mpoa_client *mpc)
386 {
387 	eg_cache_entry *entry;
388 
389 	read_lock_irq(&mpc->egress_lock);
390 	entry = mpc->eg_cache;
391 	while(entry != NULL){
392 		if(entry->latest_ip_addr == ipaddr) {
393 			atomic_inc(&entry->use);
394 			read_unlock_irq(&mpc->egress_lock);
395 			return entry;
396 		}
397 		entry = entry->next;
398 	}
399 	read_unlock_irq(&mpc->egress_lock);
400 
401 	return NULL;
402 }
403 
404 static void eg_cache_put(eg_cache_entry *entry)
405 {
406 	if (atomic_dec_and_test(&entry->use)) {
407 		memset(entry, 0, sizeof(eg_cache_entry));
408 		kfree(entry);
409 	}
410 
411 	return;
412 }
413 
414 /*
415  * This should be called with write lock on
416  */
417 static void eg_cache_remove_entry(eg_cache_entry *entry,
418 				  struct mpoa_client *client)
419 {
420 	struct atm_vcc *vcc;
421 	struct k_message msg;
422 
423 	vcc = entry->shortcut;
424 	dprintk("mpoa: mpoa_caches.c: removing an egress entry.\n");
425 	if (entry->prev != NULL)
426 		entry->prev->next = entry->next;
427 	else
428 		client->eg_cache = entry->next;
429 	if (entry->next != NULL)
430 		entry->next->prev = entry->prev;
431 	client->eg_ops->put(entry);
432 	if(client->in_cache == NULL && client->eg_cache == NULL){
433 		msg.type = STOP_KEEP_ALIVE_SM;
434 		msg_to_mpoad(&msg,client);
435 	}
436 
437 	/* Check if the ingress side still uses this VCC */
438 	if (vcc != NULL) {
439 		in_cache_entry *in_entry = client->in_ops->get_by_vcc(vcc, client);
440 		if (in_entry != NULL) {
441 			client->in_ops->put(in_entry);
442 			return;
443 		}
444 		vcc_release_async(vcc, -EPIPE);
445 	}
446 
447 	return;
448 }
449 
450 static eg_cache_entry *eg_cache_add_entry(struct k_message *msg, struct mpoa_client *client)
451 {
452 	eg_cache_entry *entry = kzalloc(sizeof(eg_cache_entry), GFP_KERNEL);
453 
454 	if (entry == NULL) {
455 		printk("mpoa: mpoa_caches.c: new_eg_cache_entry: out of memory\n");
456 		return NULL;
457 	}
458 
459 	dprintk("mpoa: mpoa_caches.c: adding an egress entry, ip = %pI4, this should be our IP\n",
460 		&msg->content.eg_info.eg_dst_ip);
461 
462 	atomic_set(&entry->use, 1);
463 	dprintk("mpoa: mpoa_caches.c: new_eg_cache_entry: about to lock\n");
464 	write_lock_irq(&client->egress_lock);
465 	entry->next = client->eg_cache;
466 	entry->prev = NULL;
467 	if (client->eg_cache != NULL)
468 		client->eg_cache->prev = entry;
469 	client->eg_cache = entry;
470 
471 	memcpy(entry->MPS_ctrl_ATM_addr, client->mps_ctrl_addr, ATM_ESA_LEN);
472 	entry->ctrl_info = msg->content.eg_info;
473 	do_gettimeofday(&(entry->tv));
474 	entry->entry_state = EGRESS_RESOLVED;
475 	dprintk("mpoa: mpoa_caches.c: new_eg_cache_entry cache_id %lu\n", ntohl(entry->ctrl_info.cache_id));
476 	dprintk("mpoa: mpoa_caches.c: mps_ip = %pI4\n",
477 		&entry->ctrl_info.mps_ip);
478 	atomic_inc(&entry->use);
479 
480 	write_unlock_irq(&client->egress_lock);
481 	dprintk("mpoa: mpoa_caches.c: new_eg_cache_entry: unlocked\n");
482 
483 	return entry;
484 }
485 
486 static void update_eg_cache_entry(eg_cache_entry * entry, uint16_t holding_time)
487 {
488 	do_gettimeofday(&(entry->tv));
489 	entry->entry_state = EGRESS_RESOLVED;
490 	entry->ctrl_info.holding_time = holding_time;
491 
492 	return;
493 }
494 
495 static void clear_expired(struct mpoa_client *client)
496 {
497 	eg_cache_entry *entry, *next_entry;
498 	struct timeval now;
499 	struct k_message msg;
500 
501 	do_gettimeofday(&now);
502 
503 	write_lock_irq(&client->egress_lock);
504 	entry = client->eg_cache;
505 	while(entry != NULL){
506 		next_entry = entry->next;
507 		if((now.tv_sec - entry->tv.tv_sec)
508 		   > entry->ctrl_info.holding_time){
509 			msg.type = SND_EGRESS_PURGE;
510 			msg.content.eg_info = entry->ctrl_info;
511 			dprintk("mpoa: mpoa_caches.c: egress_cache: holding time expired, cache_id = %lu.\n",ntohl(entry->ctrl_info.cache_id));
512 			msg_to_mpoad(&msg, client);
513 			client->eg_ops->remove_entry(entry, client);
514 		}
515 		entry = next_entry;
516 	}
517 	write_unlock_irq(&client->egress_lock);
518 
519 	return;
520 }
521 
522 static void eg_destroy_cache(struct mpoa_client *mpc)
523 {
524 	write_lock_irq(&mpc->egress_lock);
525 	while(mpc->eg_cache != NULL)
526 		mpc->eg_ops->remove_entry(mpc->eg_cache, mpc);
527 	write_unlock_irq(&mpc->egress_lock);
528 
529 	return;
530 }
531 
532 
533 
534 static struct in_cache_ops ingress_ops = {
535 	in_cache_add_entry,               /* add_entry       */
536 	in_cache_get,                     /* get             */
537 	in_cache_get_with_mask,           /* get_with_mask   */
538 	in_cache_get_by_vcc,              /* get_by_vcc      */
539 	in_cache_put,                     /* put             */
540 	in_cache_remove_entry,            /* remove_entry    */
541 	cache_hit,                        /* cache_hit       */
542 	clear_count_and_expired,          /* clear_count     */
543 	check_resolving_entries,          /* check_resolving */
544 	refresh_entries,                  /* refresh         */
545 	in_destroy_cache                  /* destroy_cache   */
546 };
547 
548 static struct eg_cache_ops egress_ops = {
549 	eg_cache_add_entry,               /* add_entry        */
550 	eg_cache_get_by_cache_id,         /* get_by_cache_id  */
551 	eg_cache_get_by_tag,              /* get_by_tag       */
552 	eg_cache_get_by_vcc,              /* get_by_vcc       */
553 	eg_cache_get_by_src_ip,           /* get_by_src_ip    */
554 	eg_cache_put,                     /* put              */
555 	eg_cache_remove_entry,            /* remove_entry     */
556 	update_eg_cache_entry,            /* update           */
557 	clear_expired,                    /* clear_expired    */
558 	eg_destroy_cache                  /* destroy_cache    */
559 };
560 
561 
562 void atm_mpoa_init_cache(struct mpoa_client *mpc)
563 {
564 	mpc->in_ops = &ingress_ops;
565 	mpc->eg_ops = &egress_ops;
566 
567 	return;
568 }
569