xref: /linux/net/atm/mpoa_caches.c (revision 4b4193256c8d3bc3a5397b5cd9494c2ad386317d)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/types.h>
3 #include <linux/atmmpc.h>
4 #include <linux/slab.h>
5 #include <linux/time.h>
6 
7 #include "mpoa_caches.h"
8 #include "mpc.h"
9 
10 /*
11  * mpoa_caches.c: Implementation of ingress and egress cache
12  * handling functions
13  */
14 
15 #if 0
16 #define dprintk(format, args...)					\
17 	printk(KERN_DEBUG "mpoa:%s: " format, __FILE__, ##args)  /* debug */
18 #else
19 #define dprintk(format, args...)					\
20 	do { if (0)							\
21 		printk(KERN_DEBUG "mpoa:%s: " format, __FILE__, ##args);\
22 	} while (0)
23 #endif
24 
25 #if 0
26 #define ddprintk(format, args...)					\
27 	printk(KERN_DEBUG "mpoa:%s: " format, __FILE__, ##args)  /* debug */
28 #else
29 #define ddprintk(format, args...)					\
30 	do { if (0)							\
31 		printk(KERN_DEBUG "mpoa:%s: " format, __FILE__, ##args);\
32 	} while (0)
33 #endif
34 
in_cache_get(__be32 dst_ip,struct mpoa_client * client)35 static in_cache_entry *in_cache_get(__be32 dst_ip,
36 				    struct mpoa_client *client)
37 {
38 	in_cache_entry *entry;
39 
40 	read_lock_bh(&client->ingress_lock);
41 	entry = client->in_cache;
42 	while (entry != NULL) {
43 		if (entry->ctrl_info.in_dst_ip == dst_ip) {
44 			refcount_inc(&entry->use);
45 			read_unlock_bh(&client->ingress_lock);
46 			return entry;
47 		}
48 		entry = entry->next;
49 	}
50 	read_unlock_bh(&client->ingress_lock);
51 
52 	return NULL;
53 }
54 
in_cache_get_with_mask(__be32 dst_ip,struct mpoa_client * client,__be32 mask)55 static in_cache_entry *in_cache_get_with_mask(__be32 dst_ip,
56 					      struct mpoa_client *client,
57 					      __be32 mask)
58 {
59 	in_cache_entry *entry;
60 
61 	read_lock_bh(&client->ingress_lock);
62 	entry = client->in_cache;
63 	while (entry != NULL) {
64 		if ((entry->ctrl_info.in_dst_ip & mask) == (dst_ip & mask)) {
65 			refcount_inc(&entry->use);
66 			read_unlock_bh(&client->ingress_lock);
67 			return entry;
68 		}
69 		entry = entry->next;
70 	}
71 	read_unlock_bh(&client->ingress_lock);
72 
73 	return NULL;
74 
75 }
76 
in_cache_get_by_vcc(struct atm_vcc * vcc,struct mpoa_client * client)77 static in_cache_entry *in_cache_get_by_vcc(struct atm_vcc *vcc,
78 					   struct mpoa_client *client)
79 {
80 	in_cache_entry *entry;
81 
82 	read_lock_bh(&client->ingress_lock);
83 	entry = client->in_cache;
84 	while (entry != NULL) {
85 		if (entry->shortcut == vcc) {
86 			refcount_inc(&entry->use);
87 			read_unlock_bh(&client->ingress_lock);
88 			return entry;
89 		}
90 		entry = entry->next;
91 	}
92 	read_unlock_bh(&client->ingress_lock);
93 
94 	return NULL;
95 }
96 
in_cache_add_entry(__be32 dst_ip,struct mpoa_client * client)97 static in_cache_entry *in_cache_add_entry(__be32 dst_ip,
98 					  struct mpoa_client *client)
99 {
100 	in_cache_entry *entry = kzalloc(sizeof(in_cache_entry), GFP_KERNEL);
101 
102 	if (entry == NULL) {
103 		pr_info("mpoa: mpoa_caches.c: new_in_cache_entry: out of memory\n");
104 		return NULL;
105 	}
106 
107 	dprintk("adding an ingress entry, ip = %pI4\n", &dst_ip);
108 
109 	refcount_set(&entry->use, 1);
110 	dprintk("new_in_cache_entry: about to lock\n");
111 	write_lock_bh(&client->ingress_lock);
112 	entry->next = client->in_cache;
113 	entry->prev = NULL;
114 	if (client->in_cache != NULL)
115 		client->in_cache->prev = entry;
116 	client->in_cache = entry;
117 
118 	memcpy(entry->MPS_ctrl_ATM_addr, client->mps_ctrl_addr, ATM_ESA_LEN);
119 	entry->ctrl_info.in_dst_ip = dst_ip;
120 	entry->time = ktime_get_seconds();
121 	entry->retry_time = client->parameters.mpc_p4;
122 	entry->count = 1;
123 	entry->entry_state = INGRESS_INVALID;
124 	entry->ctrl_info.holding_time = HOLDING_TIME_DEFAULT;
125 	refcount_inc(&entry->use);
126 
127 	write_unlock_bh(&client->ingress_lock);
128 	dprintk("new_in_cache_entry: unlocked\n");
129 
130 	return entry;
131 }
132 
cache_hit(in_cache_entry * entry,struct mpoa_client * mpc)133 static int cache_hit(in_cache_entry *entry, struct mpoa_client *mpc)
134 {
135 	struct atm_mpoa_qos *qos;
136 	struct k_message msg;
137 
138 	entry->count++;
139 	if (entry->entry_state == INGRESS_RESOLVED && entry->shortcut != NULL)
140 		return OPEN;
141 
142 	if (entry->entry_state == INGRESS_REFRESHING) {
143 		if (entry->count > mpc->parameters.mpc_p1) {
144 			msg.type = SND_MPOA_RES_RQST;
145 			msg.content.in_info = entry->ctrl_info;
146 			memcpy(msg.MPS_ctrl, mpc->mps_ctrl_addr, ATM_ESA_LEN);
147 			qos = atm_mpoa_search_qos(entry->ctrl_info.in_dst_ip);
148 			if (qos != NULL)
149 				msg.qos = qos->qos;
150 			msg_to_mpoad(&msg, mpc);
151 			entry->reply_wait = ktime_get_seconds();
152 			entry->entry_state = INGRESS_RESOLVING;
153 		}
154 		if (entry->shortcut != NULL)
155 			return OPEN;
156 		return CLOSED;
157 	}
158 
159 	if (entry->entry_state == INGRESS_RESOLVING && entry->shortcut != NULL)
160 		return OPEN;
161 
162 	if (entry->count > mpc->parameters.mpc_p1 &&
163 	    entry->entry_state == INGRESS_INVALID) {
164 		dprintk("(%s) threshold exceeded for ip %pI4, sending MPOA res req\n",
165 			mpc->dev->name, &entry->ctrl_info.in_dst_ip);
166 		entry->entry_state = INGRESS_RESOLVING;
167 		msg.type = SND_MPOA_RES_RQST;
168 		memcpy(msg.MPS_ctrl, mpc->mps_ctrl_addr, ATM_ESA_LEN);
169 		msg.content.in_info = entry->ctrl_info;
170 		qos = atm_mpoa_search_qos(entry->ctrl_info.in_dst_ip);
171 		if (qos != NULL)
172 			msg.qos = qos->qos;
173 		msg_to_mpoad(&msg, mpc);
174 		entry->reply_wait = ktime_get_seconds();
175 	}
176 
177 	return CLOSED;
178 }
179 
in_cache_put(in_cache_entry * entry)180 static void in_cache_put(in_cache_entry *entry)
181 {
182 	if (refcount_dec_and_test(&entry->use)) {
183 		kfree_sensitive(entry);
184 	}
185 }
186 
187 /*
188  * This should be called with write lock on
189  */
in_cache_remove_entry(in_cache_entry * entry,struct mpoa_client * client)190 static 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... */
clear_count_and_expired(struct mpoa_client * client)226 static void clear_count_and_expired(struct mpoa_client *client)
227 {
228 	in_cache_entry *entry, *next_entry;
229 	time64_t now;
230 
231 	now = ktime_get_seconds();
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 - entry->time) > entry->ctrl_info.holding_time) {
239 			dprintk("holding time expired, ip = %pI4\n",
240 				&entry->ctrl_info.in_dst_ip);
241 			client->in_ops->remove_entry(entry, client);
242 		}
243 		entry = next_entry;
244 	}
245 	write_unlock_bh(&client->ingress_lock);
246 }
247 
248 /* Call this every MPC-p4 seconds. */
check_resolving_entries(struct mpoa_client * client)249 static void check_resolving_entries(struct mpoa_client *client)
250 {
251 
252 	struct atm_mpoa_qos *qos;
253 	in_cache_entry *entry;
254 	time64_t now;
255 	struct k_message msg;
256 
257 	now = ktime_get_seconds();
258 
259 	read_lock_bh(&client->ingress_lock);
260 	entry = client->in_cache;
261 	while (entry != NULL) {
262 		if (entry->entry_state == INGRESS_RESOLVING) {
263 
264 			if ((now - entry->hold_down)
265 					< client->parameters.mpc_p6) {
266 				entry = entry->next;	/* Entry in hold down */
267 				continue;
268 			}
269 			if ((now - entry->reply_wait) > entry->retry_time) {
270 				entry->retry_time = MPC_C1 * (entry->retry_time);
271 				/*
272 				 * Retry time maximum exceeded,
273 				 * put entry in hold down.
274 				 */
275 				if (entry->retry_time > client->parameters.mpc_p5) {
276 					entry->hold_down = ktime_get_seconds();
277 					entry->retry_time = client->parameters.mpc_p4;
278 					entry = entry->next;
279 					continue;
280 				}
281 				/* Ask daemon to send a resolution request. */
282 				memset(&entry->hold_down, 0, sizeof(time64_t));
283 				msg.type = SND_MPOA_RES_RTRY;
284 				memcpy(msg.MPS_ctrl, client->mps_ctrl_addr, ATM_ESA_LEN);
285 				msg.content.in_info = entry->ctrl_info;
286 				qos = atm_mpoa_search_qos(entry->ctrl_info.in_dst_ip);
287 				if (qos != NULL)
288 					msg.qos = qos->qos;
289 				msg_to_mpoad(&msg, client);
290 				entry->reply_wait = ktime_get_seconds();
291 			}
292 		}
293 		entry = entry->next;
294 	}
295 	read_unlock_bh(&client->ingress_lock);
296 }
297 
298 /* Call this every MPC-p5 seconds. */
refresh_entries(struct mpoa_client * client)299 static void refresh_entries(struct mpoa_client *client)
300 {
301 	time64_t now;
302 	struct in_cache_entry *entry = client->in_cache;
303 
304 	ddprintk("refresh_entries\n");
305 	now = ktime_get_seconds();
306 
307 	read_lock_bh(&client->ingress_lock);
308 	while (entry != NULL) {
309 		if (entry->entry_state == INGRESS_RESOLVED) {
310 			if (!(entry->refresh_time))
311 				entry->refresh_time = (2 * (entry->ctrl_info.holding_time))/3;
312 			if ((now - entry->reply_wait) >
313 			    entry->refresh_time) {
314 				dprintk("refreshing an entry.\n");
315 				entry->entry_state = INGRESS_REFRESHING;
316 
317 			}
318 		}
319 		entry = entry->next;
320 	}
321 	read_unlock_bh(&client->ingress_lock);
322 }
323 
in_destroy_cache(struct mpoa_client * mpc)324 static void in_destroy_cache(struct mpoa_client *mpc)
325 {
326 	write_lock_irq(&mpc->ingress_lock);
327 	while (mpc->in_cache != NULL)
328 		mpc->in_ops->remove_entry(mpc->in_cache, mpc);
329 	write_unlock_irq(&mpc->ingress_lock);
330 }
331 
eg_cache_get_by_cache_id(__be32 cache_id,struct mpoa_client * mpc)332 static eg_cache_entry *eg_cache_get_by_cache_id(__be32 cache_id,
333 						struct mpoa_client *mpc)
334 {
335 	eg_cache_entry *entry;
336 
337 	read_lock_irq(&mpc->egress_lock);
338 	entry = mpc->eg_cache;
339 	while (entry != NULL) {
340 		if (entry->ctrl_info.cache_id == cache_id) {
341 			refcount_inc(&entry->use);
342 			read_unlock_irq(&mpc->egress_lock);
343 			return entry;
344 		}
345 		entry = entry->next;
346 	}
347 	read_unlock_irq(&mpc->egress_lock);
348 
349 	return NULL;
350 }
351 
352 /* This can be called from any context since it saves CPU flags */
eg_cache_get_by_tag(__be32 tag,struct mpoa_client * mpc)353 static eg_cache_entry *eg_cache_get_by_tag(__be32 tag, struct mpoa_client *mpc)
354 {
355 	unsigned long flags;
356 	eg_cache_entry *entry;
357 
358 	read_lock_irqsave(&mpc->egress_lock, flags);
359 	entry = mpc->eg_cache;
360 	while (entry != NULL) {
361 		if (entry->ctrl_info.tag == tag) {
362 			refcount_inc(&entry->use);
363 			read_unlock_irqrestore(&mpc->egress_lock, flags);
364 			return entry;
365 		}
366 		entry = entry->next;
367 	}
368 	read_unlock_irqrestore(&mpc->egress_lock, flags);
369 
370 	return NULL;
371 }
372 
373 /* This can be called from any context since it saves CPU flags */
eg_cache_get_by_vcc(struct atm_vcc * vcc,struct mpoa_client * mpc)374 static eg_cache_entry *eg_cache_get_by_vcc(struct atm_vcc *vcc,
375 					   struct mpoa_client *mpc)
376 {
377 	unsigned long flags;
378 	eg_cache_entry *entry;
379 
380 	read_lock_irqsave(&mpc->egress_lock, flags);
381 	entry = mpc->eg_cache;
382 	while (entry != NULL) {
383 		if (entry->shortcut == vcc) {
384 			refcount_inc(&entry->use);
385 			read_unlock_irqrestore(&mpc->egress_lock, flags);
386 			return entry;
387 		}
388 		entry = entry->next;
389 	}
390 	read_unlock_irqrestore(&mpc->egress_lock, flags);
391 
392 	return NULL;
393 }
394 
eg_cache_get_by_src_ip(__be32 ipaddr,struct mpoa_client * mpc)395 static eg_cache_entry *eg_cache_get_by_src_ip(__be32 ipaddr,
396 					      struct mpoa_client *mpc)
397 {
398 	eg_cache_entry *entry;
399 
400 	read_lock_irq(&mpc->egress_lock);
401 	entry = mpc->eg_cache;
402 	while (entry != NULL) {
403 		if (entry->latest_ip_addr == ipaddr) {
404 			refcount_inc(&entry->use);
405 			read_unlock_irq(&mpc->egress_lock);
406 			return entry;
407 		}
408 		entry = entry->next;
409 	}
410 	read_unlock_irq(&mpc->egress_lock);
411 
412 	return NULL;
413 }
414 
eg_cache_put(eg_cache_entry * entry)415 static void eg_cache_put(eg_cache_entry *entry)
416 {
417 	if (refcount_dec_and_test(&entry->use)) {
418 		kfree_sensitive(entry);
419 	}
420 }
421 
422 /*
423  * This should be called with write lock on
424  */
eg_cache_remove_entry(eg_cache_entry * entry,struct mpoa_client * client)425 static void eg_cache_remove_entry(eg_cache_entry *entry,
426 				  struct mpoa_client *client)
427 {
428 	struct atm_vcc *vcc;
429 	struct k_message msg;
430 
431 	vcc = entry->shortcut;
432 	dprintk("removing an egress entry.\n");
433 	if (entry->prev != NULL)
434 		entry->prev->next = entry->next;
435 	else
436 		client->eg_cache = entry->next;
437 	if (entry->next != NULL)
438 		entry->next->prev = entry->prev;
439 	client->eg_ops->put(entry);
440 	if (client->in_cache == NULL && client->eg_cache == NULL) {
441 		msg.type = STOP_KEEP_ALIVE_SM;
442 		msg_to_mpoad(&msg, client);
443 	}
444 
445 	/* Check if the ingress side still uses this VCC */
446 	if (vcc != NULL) {
447 		in_cache_entry *in_entry = client->in_ops->get_by_vcc(vcc, client);
448 		if (in_entry != NULL) {
449 			client->in_ops->put(in_entry);
450 			return;
451 		}
452 		vcc_release_async(vcc, -EPIPE);
453 	}
454 }
455 
eg_cache_add_entry(struct k_message * msg,struct mpoa_client * client)456 static eg_cache_entry *eg_cache_add_entry(struct k_message *msg,
457 					  struct mpoa_client *client)
458 {
459 	eg_cache_entry *entry = kzalloc(sizeof(eg_cache_entry), GFP_KERNEL);
460 
461 	if (entry == NULL) {
462 		pr_info("out of memory\n");
463 		return NULL;
464 	}
465 
466 	dprintk("adding an egress entry, ip = %pI4, this should be our IP\n",
467 		&msg->content.eg_info.eg_dst_ip);
468 
469 	refcount_set(&entry->use, 1);
470 	dprintk("new_eg_cache_entry: about to lock\n");
471 	write_lock_irq(&client->egress_lock);
472 	entry->next = client->eg_cache;
473 	entry->prev = NULL;
474 	if (client->eg_cache != NULL)
475 		client->eg_cache->prev = entry;
476 	client->eg_cache = entry;
477 
478 	memcpy(entry->MPS_ctrl_ATM_addr, client->mps_ctrl_addr, ATM_ESA_LEN);
479 	entry->ctrl_info = msg->content.eg_info;
480 	entry->time = ktime_get_seconds();
481 	entry->entry_state = EGRESS_RESOLVED;
482 	dprintk("new_eg_cache_entry cache_id %u\n",
483 		ntohl(entry->ctrl_info.cache_id));
484 	dprintk("mps_ip = %pI4\n", &entry->ctrl_info.mps_ip);
485 	refcount_inc(&entry->use);
486 
487 	write_unlock_irq(&client->egress_lock);
488 	dprintk("new_eg_cache_entry: unlocked\n");
489 
490 	return entry;
491 }
492 
update_eg_cache_entry(eg_cache_entry * entry,uint16_t holding_time)493 static void update_eg_cache_entry(eg_cache_entry *entry, uint16_t holding_time)
494 {
495 	entry->time = ktime_get_seconds();
496 	entry->entry_state = EGRESS_RESOLVED;
497 	entry->ctrl_info.holding_time = holding_time;
498 }
499 
clear_expired(struct mpoa_client * client)500 static void clear_expired(struct mpoa_client *client)
501 {
502 	eg_cache_entry *entry, *next_entry;
503 	time64_t now;
504 	struct k_message msg;
505 
506 	now = ktime_get_seconds();
507 
508 	write_lock_irq(&client->egress_lock);
509 	entry = client->eg_cache;
510 	while (entry != NULL) {
511 		next_entry = entry->next;
512 		if ((now - entry->time) > entry->ctrl_info.holding_time) {
513 			msg.type = SND_EGRESS_PURGE;
514 			msg.content.eg_info = entry->ctrl_info;
515 			dprintk("egress_cache: holding time expired, cache_id = %u.\n",
516 				ntohl(entry->ctrl_info.cache_id));
517 			msg_to_mpoad(&msg, client);
518 			client->eg_ops->remove_entry(entry, client);
519 		}
520 		entry = next_entry;
521 	}
522 	write_unlock_irq(&client->egress_lock);
523 }
524 
eg_destroy_cache(struct mpoa_client * mpc)525 static void eg_destroy_cache(struct mpoa_client *mpc)
526 {
527 	write_lock_irq(&mpc->egress_lock);
528 	while (mpc->eg_cache != NULL)
529 		mpc->eg_ops->remove_entry(mpc->eg_cache, mpc);
530 	write_unlock_irq(&mpc->egress_lock);
531 }
532 
533 
534 static const struct in_cache_ops ingress_ops = {
535 	.add_entry = in_cache_add_entry,
536 	.get = in_cache_get,
537 	.get_with_mask = in_cache_get_with_mask,
538 	.get_by_vcc = in_cache_get_by_vcc,
539 	.put = in_cache_put,
540 	.remove_entry = in_cache_remove_entry,
541 	.cache_hit = cache_hit,
542 	.clear_count = clear_count_and_expired,
543 	.check_resolving = check_resolving_entries,
544 	.refresh = refresh_entries,
545 	.destroy_cache = in_destroy_cache
546 };
547 
548 static const struct eg_cache_ops egress_ops = {
549 	.add_entry = eg_cache_add_entry,
550 	.get_by_cache_id = eg_cache_get_by_cache_id,
551 	.get_by_tag = eg_cache_get_by_tag,
552 	.get_by_vcc = eg_cache_get_by_vcc,
553 	.get_by_src_ip = eg_cache_get_by_src_ip,
554 	.put = eg_cache_put,
555 	.remove_entry = eg_cache_remove_entry,
556 	.update = update_eg_cache_entry,
557 	.clear_expired = clear_expired,
558 	.destroy_cache = eg_destroy_cache
559 };
560 
atm_mpoa_init_cache(struct mpoa_client * mpc)561 void atm_mpoa_init_cache(struct mpoa_client *mpc)
562 {
563 	mpc->in_ops = &ingress_ops;
564 	mpc->eg_ops = &egress_ops;
565 }
566