net/atm/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         do_gettimeofday(&(entry->tv));
 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                         do_gettimeofday(&(entry->reply_wait));
 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                 do_gettimeofday(&(entry->reply_wait));
 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         struct timeval now;
 231
 232         do_gettimeofday(&now);
 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.tv_sec - entry->tv.tv_sec)
 240                    > entry->ctrl_info.holding_time) {
 241                         dprintk("holding time expired, ip = %pI4\n",
 242                                 &entry->ctrl_info.in_dst_ip);
 243                         client->in_ops->remove_entry(entry, client);
 244                 }
 245                 entry = next_entry;
 246         }
 247         write_unlock_bh(&client->ingress_lock);
 248 }
 249
 250 /* Call this every MPC-p4 seconds. */
 251 static void check_resolving_entries(struct mpoa_client *client)
 252 {
 253
 254         struct atm_mpoa_qos *qos;
 255         in_cache_entry *entry;
 256         struct timeval now;
 257         struct k_message msg;
 258
 259         do_gettimeofday(&now);
 260
 261         read_lock_bh(&client->ingress_lock);
 262         entry = client->in_cache;
 263         while (entry != NULL) {
 264                 if (entry->entry_state == INGRESS_RESOLVING) {
 265                         if ((now.tv_sec - entry->hold_down.tv_sec) <
 266                             client->parameters.mpc_p6) {
 267                                 entry = entry->next;    /* Entry in hold down */
 268                                 continue;
 269                         }
 270                         if ((now.tv_sec - entry->reply_wait.tv_sec) >
 271                             entry->retry_time) {
 272                                 entry->retry_time = MPC_C1 * (entry->retry_time);
 273                                 /*
 274                                  * Retry time maximum exceeded,
 275                                  * put entry in hold down.
 276                                  */
 277                                 if (entry->retry_time > client->parameters.mpc_p5) {
 278                                         do_gettimeofday(&(entry->hold_down));
 279                                         entry->retry_time = client->parameters.mpc_p4;
 280                                         entry = entry->next;
 281                                         continue;
 282                                 }
 283                                 /* Ask daemon to send a resolution request. */
 284                                 memset(&(entry->hold_down), 0, sizeof(struct timeval));
 285                                 msg.type = SND_MPOA_RES_RTRY;
 286                                 memcpy(msg.MPS_ctrl, client->mps_ctrl_addr, ATM_ESA_LEN);
 287                                 msg.content.in_info = entry->ctrl_info;
 288                                 qos = atm_mpoa_search_qos(entry->ctrl_info.in_dst_ip);
 289                                 if (qos != NULL)
 290                                         msg.qos = qos->qos;
 291                                 msg_to_mpoad(&msg, client);
 292                                 do_gettimeofday(&(entry->reply_wait));
 293                         }
 294                 }
 295                 entry = entry->next;
 296         }
 297         read_unlock_bh(&client->ingress_lock);
 298 }
 299
 300 /* Call this every MPC-p5 seconds. */
 301 static void refresh_entries(struct mpoa_client *client)
 302 {
 303         struct timeval now;
 304         struct in_cache_entry *entry = client->in_cache;
 305
 306         ddprintk("refresh_entries\n");
 307         do_gettimeofday(&now);
 308
 309         read_lock_bh(&client->ingress_lock);
 310         while (entry != NULL) {
 311                 if (entry->entry_state == INGRESS_RESOLVED) {
 312                         if (!(entry->refresh_time))
 313                                 entry->refresh_time = (2 * (entry->ctrl_info.holding_time))/3;
 314                         if ((now.tv_sec - entry->reply_wait.tv_sec) >
 315                             entry->refresh_time) {
 316                                 dprintk("refreshing an entry.\n");
 317                                 entry->entry_state = INGRESS_REFRESHING;
 318
 319                         }
 320                 }
 321                 entry = entry->next;
 322         }
 323         read_unlock_bh(&client->ingress_lock);
 324 }
 325
 326 static void in_destroy_cache(struct mpoa_client *mpc)
 327 {
 328         write_lock_irq(&mpc->ingress_lock);
 329         while (mpc->in_cache != NULL)
 330                 mpc->in_ops->remove_entry(mpc->in_cache, mpc);
 331         write_unlock_irq(&mpc->ingress_lock);
 332 }
 333
 334 static eg_cache_entry *eg_cache_get_by_cache_id(__be32 cache_id,
 335                                                 struct mpoa_client *mpc)
 336 {
 337         eg_cache_entry *entry;
 338
 339         read_lock_irq(&mpc->egress_lock);
 340         entry = mpc->eg_cache;
 341         while (entry != NULL) {
 342                 if (entry->ctrl_info.cache_id == cache_id) {
 343                         refcount_inc(&entry->use);
 344                         read_unlock_irq(&mpc->egress_lock);
 345                         return entry;
 346                 }
 347                 entry = entry->next;
 348         }
 349         read_unlock_irq(&mpc->egress_lock);
 350
 351         return NULL;
 352 }
 353
 354 /* This can be called from any context since it saves CPU flags */
 355 static eg_cache_entry *eg_cache_get_by_tag(__be32 tag, struct mpoa_client *mpc)
 356 {
 357         unsigned long flags;
 358         eg_cache_entry *entry;
 359
 360         read_lock_irqsave(&mpc->egress_lock, flags);
 361         entry = mpc->eg_cache;
 362         while (entry != NULL) {
 363                 if (entry->ctrl_info.tag == tag) {
 364                         refcount_inc(&entry->use);
 365                         read_unlock_irqrestore(&mpc->egress_lock, flags);
 366                         return entry;
 367                 }
 368                 entry = entry->next;
 369         }
 370         read_unlock_irqrestore(&mpc->egress_lock, flags);
 371
 372         return NULL;
 373 }
 374
 375 /* This can be called from any context since it saves CPU flags */
 376 static eg_cache_entry *eg_cache_get_by_vcc(struct atm_vcc *vcc,
 377                                            struct mpoa_client *mpc)
 378 {
 379         unsigned long flags;
 380         eg_cache_entry *entry;
 381
 382         read_lock_irqsave(&mpc->egress_lock, flags);
 383         entry = mpc->eg_cache;
 384         while (entry != NULL) {
 385                 if (entry->shortcut == vcc) {
 386                         refcount_inc(&entry->use);
 387                         read_unlock_irqrestore(&mpc->egress_lock, flags);
 388                         return entry;
 389                 }
 390                 entry = entry->next;
 391         }
 392         read_unlock_irqrestore(&mpc->egress_lock, flags);
 393
 394         return NULL;
 395 }
 396
 397 static eg_cache_entry *eg_cache_get_by_src_ip(__be32 ipaddr,
 398                                               struct mpoa_client *mpc)
 399 {
 400         eg_cache_entry *entry;
 401
 402         read_lock_irq(&mpc->egress_lock);
 403         entry = mpc->eg_cache;
 404         while (entry != NULL) {
 405                 if (entry->latest_ip_addr == ipaddr) {
 406                         refcount_inc(&entry->use);
 407                         read_unlock_irq(&mpc->egress_lock);
 408                         return entry;
 409                 }
 410                 entry = entry->next;
 411         }
 412         read_unlock_irq(&mpc->egress_lock);
 413
 414         return NULL;
 415 }
 416
 417 static void eg_cache_put(eg_cache_entry *entry)
 418 {
 419         if (refcount_dec_and_test(&entry->use)) {
 420                 memset(entry, 0, sizeof(eg_cache_entry));
 421                 kfree(entry);
 422         }
 423 }
 424
 425 /*
 426  * This should be called with write lock on
 427  */
 428 static void eg_cache_remove_entry(eg_cache_entry *entry,
 429                                   struct mpoa_client *client)
 430 {
 431         struct atm_vcc *vcc;
 432         struct k_message msg;
 433
 434         vcc = entry->shortcut;
 435         dprintk("removing an egress entry.\n");
 436         if (entry->prev != NULL)
 437                 entry->prev->next = entry->next;
 438         else
 439                 client->eg_cache = entry->next;
 440         if (entry->next != NULL)
 441                 entry->next->prev = entry->prev;
 442         client->eg_ops->put(entry);
 443         if (client->in_cache == NULL && client->eg_cache == NULL) {
 444                 msg.type = STOP_KEEP_ALIVE_SM;
 445                 msg_to_mpoad(&msg, client);
 446         }
 447
 448         /* Check if the ingress side still uses this VCC */
 449         if (vcc != NULL) {
 450                 in_cache_entry *in_entry = client->in_ops->get_by_vcc(vcc, client);
 451                 if (in_entry != NULL) {
 452                         client->in_ops->put(in_entry);
 453                         return;
 454                 }
 455                 vcc_release_async(vcc, -EPIPE);
 456         }
 457 }
 458
 459 static eg_cache_entry *eg_cache_add_entry(struct k_message *msg,
 460                                           struct mpoa_client *client)
 461 {
 462         eg_cache_entry *entry = kzalloc(sizeof(eg_cache_entry), GFP_KERNEL);
 463
 464         if (entry == NULL) {
 465                 pr_info("out of memory\n");
 466                 return NULL;
 467         }
 468
 469         dprintk("adding an egress entry, ip = %pI4, this should be our IP\n",
 470                 &msg->content.eg_info.eg_dst_ip);
 471
 472         refcount_set(&entry->use, 1);
 473         dprintk("new_eg_cache_entry: about to lock\n");
 474         write_lock_irq(&client->egress_lock);
 475         entry->next = client->eg_cache;
 476         entry->prev = NULL;
 477         if (client->eg_cache != NULL)
 478                 client->eg_cache->prev = entry;
 479         client->eg_cache = entry;
 480
 481         memcpy(entry->MPS_ctrl_ATM_addr, client->mps_ctrl_addr, ATM_ESA_LEN);
 482         entry->ctrl_info = msg->content.eg_info;
 483         do_gettimeofday(&(entry->tv));
 484         entry->entry_state = EGRESS_RESOLVED;
 485         dprintk("new_eg_cache_entry cache_id %u\n",
 486                 ntohl(entry->ctrl_info.cache_id));
 487         dprintk("mps_ip = %pI4\n", &entry->ctrl_info.mps_ip);
 488         refcount_inc(&entry->use);
 489
 490         write_unlock_irq(&client->egress_lock);
 491         dprintk("new_eg_cache_entry: unlocked\n");
 492
 493         return entry;
 494 }
 495
 496 static void update_eg_cache_entry(eg_cache_entry *entry, uint16_t holding_time)
 497 {
 498         do_gettimeofday(&(entry->tv));
 499         entry->entry_state = EGRESS_RESOLVED;
 500         entry->ctrl_info.holding_time = holding_time;
 501 }
 502
 503 static void clear_expired(struct mpoa_client *client)
 504 {
 505         eg_cache_entry *entry, *next_entry;
 506         struct timeval now;
 507         struct k_message msg;
 508
 509         do_gettimeofday(&now);
 510
 511         write_lock_irq(&client->egress_lock);
 512         entry = client->eg_cache;
 513         while (entry != NULL) {
 514                 next_entry = entry->next;
 515                 if ((now.tv_sec - entry->tv.tv_sec)
 516                    > entry->ctrl_info.holding_time) {
 517                         msg.type = SND_EGRESS_PURGE;
 518                         msg.content.eg_info = entry->ctrl_info;
 519                         dprintk("egress_cache: holding time expired, cache_id = %u.\n",
 520                                 ntohl(entry->ctrl_info.cache_id));
 521                         msg_to_mpoad(&msg, client);
 522                         client->eg_ops->remove_entry(entry, client);
 523                 }
 524                 entry = next_entry;
 525         }
 526         write_unlock_irq(&client->egress_lock);
 527 }
 528
 529 static void eg_destroy_cache(struct mpoa_client *mpc)
 530 {
 531         write_lock_irq(&mpc->egress_lock);
 532         while (mpc->eg_cache != NULL)
 533                 mpc->eg_ops->remove_entry(mpc->eg_cache, mpc);
 534         write_unlock_irq(&mpc->egress_lock);
 535 }
 536
 537
 538 static const struct in_cache_ops ingress_ops = {
 539         .add_entry = in_cache_add_entry,
 540         .get = in_cache_get,
 541         .get_with_mask = in_cache_get_with_mask,
 542         .get_by_vcc = in_cache_get_by_vcc,
 543         .put = in_cache_put,
 544         .remove_entry = in_cache_remove_entry,
 545         .cache_hit = cache_hit,
 546         .clear_count = clear_count_and_expired,
 547         .check_resolving = check_resolving_entries,
 548         .refresh = refresh_entries,
 549         .destroy_cache = in_destroy_cache
 550 };
 551
 552 static const struct eg_cache_ops egress_ops = {
 553         .add_entry = eg_cache_add_entry,
 554         .get_by_cache_id = eg_cache_get_by_cache_id,
 555         .get_by_tag = eg_cache_get_by_tag,
 556         .get_by_vcc = eg_cache_get_by_vcc,
 557         .get_by_src_ip = eg_cache_get_by_src_ip,
 558         .put = eg_cache_put,
 559         .remove_entry = eg_cache_remove_entry,
 560         .update = update_eg_cache_entry,
 561         .clear_expired = clear_expired,
 562         .destroy_cache = eg_destroy_cache
 563 };
 564
 565 void atm_mpoa_init_cache(struct mpoa_client *mpc)
 566 {
 567         mpc->in_ops = &ingress_ops;
 568         mpc->eg_ops = &egress_ops;
 569 }