4bb4183137203a013b1b5f2e3111fd1ac4721ffa
[releases.git] / mpoa_caches.c
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                 memset(entry, 0, sizeof(in_cache_entry));
184                 kfree(entry);
185         }
186 }
187
188 /*
189  * This should be called with write lock on
190  */
191 static void in_cache_remove_entry(in_cache_entry *entry,
192                                   struct mpoa_client *client)
193 {
194         struct atm_vcc *vcc;
195         struct k_message msg;
196
197         vcc = entry->shortcut;
198         dprintk("removing an ingress entry, ip = %pI4\n",
199                 &entry->ctrl_info.in_dst_ip);
200
201         if (entry->prev != NULL)
202                 entry->prev->next = entry->next;
203         else
204                 client->in_cache = entry->next;
205         if (entry->next != NULL)
206                 entry->next->prev = entry->prev;
207         client->in_ops->put(entry);
208         if (client->in_cache == NULL && client->eg_cache == NULL) {
209                 msg.type = STOP_KEEP_ALIVE_SM;
210                 msg_to_mpoad(&msg, client);
211         }
212
213         /* Check if the egress side still uses this VCC */
214         if (vcc != NULL) {
215                 eg_cache_entry *eg_entry = client->eg_ops->get_by_vcc(vcc,
216                                                                       client);
217                 if (eg_entry != NULL) {
218                         client->eg_ops->put(eg_entry);
219                         return;
220                 }
221                 vcc_release_async(vcc, -EPIPE);
222         }
223 }
224
225 /* Call this every MPC-p2 seconds... Not exactly correct solution,
226    but an easy one... */
227 static void clear_count_and_expired(struct mpoa_client *client)
228 {
229         in_cache_entry *entry, *next_entry;
230         time64_t now;
231
232         now = ktime_get_seconds();
233
234         write_lock_bh(&client->ingress_lock);
235         entry = client->in_cache;
236         while (entry != NULL) {
237                 entry->count = 0;
238                 next_entry = entry->next;
239                 if ((now - entry->time) > 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. */
250 static void check_resolving_entries(struct mpoa_client *client)
251 {
252
253         struct atm_mpoa_qos *qos;
254         in_cache_entry *entry;
255         time64_t now;
256         struct k_message msg;
257
258         now = ktime_get_seconds();
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
265                         if ((now - entry->hold_down)
266                                         < client->parameters.mpc_p6) {
267                                 entry = entry->next;    /* Entry in hold down */
268                                 continue;
269                         }
270                         if ((now - entry->reply_wait) > 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                                         entry->hold_down = ktime_get_seconds();
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(time64_t));
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                                 entry->reply_wait = ktime_get_seconds();
292                         }
293                 }
294                 entry = entry->next;
295         }
296         read_unlock_bh(&client->ingress_lock);
297 }
298
299 /* Call this every MPC-p5 seconds. */
300 static void refresh_entries(struct mpoa_client *client)
301 {
302         time64_t now;
303         struct in_cache_entry *entry = client->in_cache;
304
305         ddprintk("refresh_entries\n");
306         now = ktime_get_seconds();
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 - entry->reply_wait) >
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
325 static 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
333 static 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                         refcount_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 */
354 static 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                         refcount_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 */
375 static 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                         refcount_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
396 static 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                         refcount_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
416 static void eg_cache_put(eg_cache_entry *entry)
417 {
418         if (refcount_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  */
427 static 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
458 static 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         refcount_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         entry->time = ktime_get_seconds();
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         refcount_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
495 static void update_eg_cache_entry(eg_cache_entry *entry, uint16_t holding_time)
496 {
497         entry->time = ktime_get_seconds();
498         entry->entry_state = EGRESS_RESOLVED;
499         entry->ctrl_info.holding_time = holding_time;
500 }
501
502 static void clear_expired(struct mpoa_client *client)
503 {
504         eg_cache_entry *entry, *next_entry;
505         time64_t now;
506         struct k_message msg;
507
508         now = ktime_get_seconds();
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 - entry->time) > entry->ctrl_info.holding_time) {
515                         msg.type = SND_EGRESS_PURGE;
516                         msg.content.eg_info = entry->ctrl_info;
517                         dprintk("egress_cache: holding time expired, cache_id = %u.\n",
518                                 ntohl(entry->ctrl_info.cache_id));
519                         msg_to_mpoad(&msg, client);
520                         client->eg_ops->remove_entry(entry, client);
521                 }
522                 entry = next_entry;
523         }
524         write_unlock_irq(&client->egress_lock);
525 }
526
527 static void eg_destroy_cache(struct mpoa_client *mpc)
528 {
529         write_lock_irq(&mpc->egress_lock);
530         while (mpc->eg_cache != NULL)
531                 mpc->eg_ops->remove_entry(mpc->eg_cache, mpc);
532         write_unlock_irq(&mpc->egress_lock);
533 }
534
535
536 static const struct in_cache_ops ingress_ops = {
537         .add_entry = in_cache_add_entry,
538         .get = in_cache_get,
539         .get_with_mask = in_cache_get_with_mask,
540         .get_by_vcc = in_cache_get_by_vcc,
541         .put = in_cache_put,
542         .remove_entry = in_cache_remove_entry,
543         .cache_hit = cache_hit,
544         .clear_count = clear_count_and_expired,
545         .check_resolving = check_resolving_entries,
546         .refresh = refresh_entries,
547         .destroy_cache = in_destroy_cache
548 };
549
550 static const struct eg_cache_ops egress_ops = {
551         .add_entry = eg_cache_add_entry,
552         .get_by_cache_id = eg_cache_get_by_cache_id,
553         .get_by_tag = eg_cache_get_by_tag,
554         .get_by_vcc = eg_cache_get_by_vcc,
555         .get_by_src_ip = eg_cache_get_by_src_ip,
556         .put = eg_cache_put,
557         .remove_entry = eg_cache_remove_entry,
558         .update = update_eg_cache_entry,
559         .clear_expired = clear_expired,
560         .destroy_cache = eg_destroy_cache
561 };
562
563 void atm_mpoa_init_cache(struct mpoa_client *mpc)
564 {
565         mpc->in_ops = &ingress_ops;
566         mpc->eg_ops = &egress_ops;
567 }