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
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
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
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
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
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
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 */
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... */
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. */
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. */
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
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
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 */
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 */
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
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
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 */
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
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
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
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
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
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
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