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 }