net/atm/mpoa_caches.c

   1 #include <linux/types.h>
   2 #include <linux/atmmpc.h>
   3 #include <linux/time.h>
   4
   5 #include "mpoa_caches.h"
   6 #include "mpc.h"
   7
   8 /*
   9  * mpoa_caches.c: Implementation of ingress and egress cache
  10  * handling functions
  11  */
  12
  13 #if 0
  14 #define dprintk printk    /* debug */
  15 #else
  16 #define dprintk(format,args...)
  17 #endif
  18
  19 #if 0
  20 #define ddprintk printk  /* more debug */
  21 #else
  22 #define ddprintk(format,args...)
  23 #endif
  24
  25 static in_cache_entry *in_cache_get(__be32 dst_ip,
  26                                     struct mpoa_client *client)
  27 {
  28         in_cache_entry *entry;
  29
  30         read_lock_bh(&client->ingress_lock);
  31         entry = client->in_cache;
  32         while(entry != NULL){
  33                 if( entry->ctrl_info.in_dst_ip == dst_ip ){
  34                         atomic_inc(&entry->use);
  35                         read_unlock_bh(&client->ingress_lock);
  36                         return entry;
  37                 }
  38                 entry = entry->next;
  39         }
  40         read_unlock_bh(&client->ingress_lock);
  41
  42         return NULL;
  43 }
  44
  45 static in_cache_entry *in_cache_get_with_mask(__be32 dst_ip,
  46                                               struct mpoa_client *client,
  47                                               __be32 mask)
  48 {
  49         in_cache_entry *entry;
  50
  51         read_lock_bh(&client->ingress_lock);
  52         entry = client->in_cache;
  53         while(entry != NULL){
  54                 if((entry->ctrl_info.in_dst_ip & mask)  == (dst_ip & mask )){
  55                         atomic_inc(&entry->use);
  56                         read_unlock_bh(&client->ingress_lock);
  57                         return entry;
  58                 }
  59                 entry = entry->next;
  60         }
  61         read_unlock_bh(&client->ingress_lock);
  62
  63         return NULL;
  64
  65 }
  66
  67 static in_cache_entry *in_cache_get_by_vcc(struct atm_vcc *vcc,
  68                                            struct mpoa_client *client )
  69 {
  70         in_cache_entry *entry;
  71
  72         read_lock_bh(&client->ingress_lock);
  73         entry = client->in_cache;
  74         while(entry != NULL){
  75                 if(entry->shortcut == vcc) {
  76                         atomic_inc(&entry->use);
  77                         read_unlock_bh(&client->ingress_lock);
  78                         return entry;
  79                 }
  80                 entry = entry->next;
  81         }
  82         read_unlock_bh(&client->ingress_lock);
  83
  84         return NULL;
  85 }
  86
  87 static in_cache_entry *in_cache_add_entry(__be32 dst_ip,
  88                                           struct mpoa_client *client)
  89 {
  90         in_cache_entry *entry = kzalloc(sizeof(in_cache_entry), GFP_KERNEL);
  91
  92         if (entry == NULL) {
  93                 printk("mpoa: mpoa_caches.c: new_in_cache_entry: out of memory\n");
  94                 return NULL;
  95         }
  96
  97         dprintk("mpoa: mpoa_caches.c: adding an ingress entry, ip = %pI4\n", &dst_ip);
  98
  99         atomic_set(&entry->use, 1);
 100         dprintk("mpoa: mpoa_caches.c: new_in_cache_entry: about to lock\n");
 101         write_lock_bh(&client->ingress_lock);
 102         entry->next = client->in_cache;
 103         entry->prev = NULL;
 104         if (client->in_cache != NULL)
 105                 client->in_cache->prev = entry;
 106         client->in_cache = entry;
 107
 108         memcpy(entry->MPS_ctrl_ATM_addr, client->mps_ctrl_addr, ATM_ESA_LEN);
 109         entry->ctrl_info.in_dst_ip = dst_ip;
 110         do_gettimeofday(&(entry->tv));
 111         entry->retry_time = client->parameters.mpc_p4;
 112         entry->count = 1;
 113         entry->entry_state = INGRESS_INVALID;
 114         entry->ctrl_info.holding_time = HOLDING_TIME_DEFAULT;
 115         atomic_inc(&entry->use);
 116
 117         write_unlock_bh(&client->ingress_lock);
 118         dprintk("mpoa: mpoa_caches.c: new_in_cache_entry: unlocked\n");
 119
 120         return entry;
 121 }
 122
 123 static int cache_hit(in_cache_entry *entry, struct mpoa_client *mpc)
 124 {
 125         struct atm_mpoa_qos *qos;
 126         struct k_message msg;
 127
 128         entry->count++;
 129         if(entry->entry_state == INGRESS_RESOLVED && entry->shortcut != NULL)
 130                 return OPEN;
 131
 132         if(entry->entry_state == INGRESS_REFRESHING){
 133                 if(entry->count > mpc->parameters.mpc_p1){
 134                         msg.type = SND_MPOA_RES_RQST;
 135                         msg.content.in_info = entry->ctrl_info;
 136                         memcpy(msg.MPS_ctrl, mpc->mps_ctrl_addr, ATM_ESA_LEN);
 137                         qos = atm_mpoa_search_qos(entry->ctrl_info.in_dst_ip);
 138                         if (qos != NULL) msg.qos = qos->qos;
 139                         msg_to_mpoad(&msg, mpc);
 140                         do_gettimeofday(&(entry->reply_wait));
 141                         entry->entry_state = INGRESS_RESOLVING;
 142                 }
 143                 if(entry->shortcut != NULL)
 144                         return OPEN;
 145                 return CLOSED;
 146         }
 147
 148         if(entry->entry_state == INGRESS_RESOLVING && entry->shortcut != NULL)
 149                 return OPEN;
 150
 151         if( entry->count > mpc->parameters.mpc_p1 &&
 152             entry->entry_state == INGRESS_INVALID){
 153                 dprintk("mpoa: (%s) mpoa_caches.c: threshold exceeded for ip %pI4, sending MPOA res req\n",
 154                         mpc->dev->name, &entry->ctrl_info.in_dst_ip);
 155                 entry->entry_state = INGRESS_RESOLVING;
 156                 msg.type =  SND_MPOA_RES_RQST;
 157                 memcpy(msg.MPS_ctrl, mpc->mps_ctrl_addr, ATM_ESA_LEN );
 158                 msg.content.in_info = entry->ctrl_info;
 159                 qos = atm_mpoa_search_qos(entry->ctrl_info.in_dst_ip);
 160                 if (qos != NULL) msg.qos = qos->qos;
 161                 msg_to_mpoad( &msg, mpc);
 162                 do_gettimeofday(&(entry->reply_wait));
 163         }
 164
 165         return CLOSED;
 166 }
 167
 168 static void in_cache_put(in_cache_entry *entry)
 169 {
 170         if (atomic_dec_and_test(&entry->use)) {
 171                 memset(entry, 0, sizeof(in_cache_entry));
 172                 kfree(entry);
 173         }
 174
 175         return;
 176 }
 177
 178 /*
 179  * This should be called with write lock on
 180  */
 181 static void in_cache_remove_entry(in_cache_entry *entry,
 182                                   struct mpoa_client *client)
 183 {
 184         struct atm_vcc *vcc;
 185         struct k_message msg;
 186
 187         vcc = entry->shortcut;
 188         dprintk("mpoa: mpoa_caches.c: removing an ingress entry, ip = %pI4\n",
 189                 &entry->ctrl_info.in_dst_ip);
 190
 191         if (entry->prev != NULL)
 192                 entry->prev->next = entry->next;
 193         else
 194                 client->in_cache = entry->next;
 195         if (entry->next != NULL)
 196                 entry->next->prev = entry->prev;
 197         client->in_ops->put(entry);
 198         if(client->in_cache == NULL && client->eg_cache == NULL){
 199                 msg.type = STOP_KEEP_ALIVE_SM;
 200                 msg_to_mpoad(&msg,client);
 201         }
 202
 203         /* Check if the egress side still uses this VCC */
 204         if (vcc != NULL) {
 205                 eg_cache_entry *eg_entry = client->eg_ops->get_by_vcc(vcc, client);
 206                 if (eg_entry != NULL) {
 207                         client->eg_ops->put(eg_entry);
 208                         return;
 209                 }
 210                 vcc_release_async(vcc, -EPIPE);
 211         }
 212
 213         return;
 214 }
 215
 216
 217 /* Call this every MPC-p2 seconds... Not exactly correct solution,
 218    but an easy one... */
 219 static void clear_count_and_expired(struct mpoa_client *client)
 220 {
 221         in_cache_entry *entry, *next_entry;
 222         struct timeval now;
 223
 224         do_gettimeofday(&now);
 225
 226         write_lock_bh(&client->ingress_lock);
 227         entry = client->in_cache;
 228         while(entry != NULL){
 229                 entry->count=0;
 230                 next_entry = entry->next;
 231                 if((now.tv_sec - entry->tv.tv_sec)
 232                    > entry->ctrl_info.holding_time){
 233                         dprintk("mpoa: mpoa_caches.c: holding time expired, ip = %pI4\n",
 234                                 &entry->ctrl_info.in_dst_ip);
 235                         client->in_ops->remove_entry(entry, client);
 236                 }
 237                 entry = next_entry;
 238         }
 239         write_unlock_bh(&client->ingress_lock);
 240
 241         return;
 242 }
 243
 244 /* Call this every MPC-p4 seconds. */
 245 static void check_resolving_entries(struct mpoa_client *client)
 246 {
 247
 248         struct atm_mpoa_qos *qos;
 249         in_cache_entry *entry;
 250         struct timeval now;
 251         struct k_message msg;
 252
 253         do_gettimeofday( &now );
 254
 255         read_lock_bh(&client->ingress_lock);
 256         entry = client->in_cache;
 257         while( entry != NULL ){
 258                 if(entry->entry_state == INGRESS_RESOLVING){
 259                         if(now.tv_sec - entry->hold_down.tv_sec < client->parameters.mpc_p6){
 260                                 entry = entry->next;                      /* Entry in hold down */
 261                                 continue;
 262                         }
 263                         if( (now.tv_sec - entry->reply_wait.tv_sec) >
 264                             entry->retry_time ){
 265                                 entry->retry_time = MPC_C1*( entry->retry_time );
 266                                 if(entry->retry_time > client->parameters.mpc_p5){
 267                                         /* Retry time maximum exceeded, put entry in hold down. */
 268                                         do_gettimeofday(&(entry->hold_down));
 269                                         entry->retry_time = client->parameters.mpc_p4;
 270                                         entry = entry->next;
 271                                         continue;
 272                                 }
 273                                 /* Ask daemon to send a resolution request. */
 274                                 memset(&(entry->hold_down),0,sizeof(struct timeval));
 275                                 msg.type = SND_MPOA_RES_RTRY;
 276                                 memcpy(msg.MPS_ctrl, client->mps_ctrl_addr, ATM_ESA_LEN);
 277                                 msg.content.in_info = entry->ctrl_info;
 278                                 qos = atm_mpoa_search_qos(entry->ctrl_info.in_dst_ip);
 279                                 if (qos != NULL) msg.qos = qos->qos;
 280                                 msg_to_mpoad(&msg, client);
 281                                 do_gettimeofday(&(entry->reply_wait));
 282                         }
 283                 }
 284                 entry = entry->next;
 285         }
 286         read_unlock_bh(&client->ingress_lock);
 287 }
 288
 289 /* Call this every MPC-p5 seconds. */
 290 static void refresh_entries(struct mpoa_client *client)
 291 {
 292         struct timeval now;
 293         struct in_cache_entry *entry = client->in_cache;
 294
 295         ddprintk("mpoa: mpoa_caches.c: refresh_entries\n");
 296         do_gettimeofday(&now);
 297
 298         read_lock_bh(&client->ingress_lock);
 299         while( entry != NULL ){
 300                 if( entry->entry_state == INGRESS_RESOLVED ){
 301                         if(!(entry->refresh_time))
 302                                 entry->refresh_time = (2*(entry->ctrl_info.holding_time))/3;
 303                         if( (now.tv_sec - entry->reply_wait.tv_sec) > entry->refresh_time ){
 304                                 dprintk("mpoa: mpoa_caches.c: refreshing an entry.\n");
 305                                 entry->entry_state = INGRESS_REFRESHING;
 306
 307                         }
 308                 }
 309                 entry = entry->next;
 310         }
 311         read_unlock_bh(&client->ingress_lock);
 312 }
 313
 314 static void in_destroy_cache(struct mpoa_client *mpc)
 315 {
 316         write_lock_irq(&mpc->ingress_lock);
 317         while(mpc->in_cache != NULL)
 318                 mpc->in_ops->remove_entry(mpc->in_cache, mpc);
 319         write_unlock_irq(&mpc->ingress_lock);
 320
 321         return;
 322 }
 323
 324 static eg_cache_entry *eg_cache_get_by_cache_id(__be32 cache_id, struct mpoa_client *mpc)
 325 {
 326         eg_cache_entry *entry;
 327
 328         read_lock_irq(&mpc->egress_lock);
 329         entry = mpc->eg_cache;
 330         while(entry != NULL){
 331                 if(entry->ctrl_info.cache_id == cache_id){
 332                         atomic_inc(&entry->use);
 333                         read_unlock_irq(&mpc->egress_lock);
 334                         return entry;
 335                 }
 336                 entry = entry->next;
 337         }
 338         read_unlock_irq(&mpc->egress_lock);
 339
 340         return NULL;
 341 }
 342
 343 /* This can be called from any context since it saves CPU flags */
 344 static eg_cache_entry *eg_cache_get_by_tag(__be32 tag, struct mpoa_client *mpc)
 345 {
 346         unsigned long flags;
 347         eg_cache_entry *entry;
 348
 349         read_lock_irqsave(&mpc->egress_lock, flags);
 350         entry = mpc->eg_cache;
 351         while (entry != NULL){
 352                 if (entry->ctrl_info.tag == tag) {
 353                         atomic_inc(&entry->use);
 354                         read_unlock_irqrestore(&mpc->egress_lock, flags);
 355                         return entry;
 356                 }
 357                 entry = entry->next;
 358         }
 359         read_unlock_irqrestore(&mpc->egress_lock, flags);
 360
 361         return NULL;
 362 }
 363
 364 /* This can be called from any context since it saves CPU flags */
 365 static eg_cache_entry *eg_cache_get_by_vcc(struct atm_vcc *vcc, struct mpoa_client *mpc)
 366 {
 367         unsigned long flags;
 368         eg_cache_entry *entry;
 369
 370         read_lock_irqsave(&mpc->egress_lock, flags);
 371         entry = mpc->eg_cache;
 372         while (entry != NULL){
 373                 if (entry->shortcut == vcc) {
 374                         atomic_inc(&entry->use);
 375                         read_unlock_irqrestore(&mpc->egress_lock, flags);
 376                         return entry;
 377                 }
 378                 entry = entry->next;
 379         }
 380         read_unlock_irqrestore(&mpc->egress_lock, flags);
 381
 382         return NULL;
 383 }
 384
 385 static eg_cache_entry *eg_cache_get_by_src_ip(__be32 ipaddr, struct mpoa_client *mpc)
 386 {
 387         eg_cache_entry *entry;
 388
 389         read_lock_irq(&mpc->egress_lock);
 390         entry = mpc->eg_cache;
 391         while(entry != NULL){
 392                 if(entry->latest_ip_addr == ipaddr) {
 393                         atomic_inc(&entry->use);
 394                         read_unlock_irq(&mpc->egress_lock);
 395                         return entry;
 396                 }
 397                 entry = entry->next;
 398         }
 399         read_unlock_irq(&mpc->egress_lock);
 400
 401         return NULL;
 402 }
 403
 404 static void eg_cache_put(eg_cache_entry *entry)
 405 {
 406         if (atomic_dec_and_test(&entry->use)) {
 407                 memset(entry, 0, sizeof(eg_cache_entry));
 408                 kfree(entry);
 409         }
 410
 411         return;
 412 }
 413
 414 /*
 415  * This should be called with write lock on
 416  */
 417 static void eg_cache_remove_entry(eg_cache_entry *entry,
 418                                   struct mpoa_client *client)
 419 {
 420         struct atm_vcc *vcc;
 421         struct k_message msg;
 422
 423         vcc = entry->shortcut;
 424         dprintk("mpoa: mpoa_caches.c: removing an egress entry.\n");
 425         if (entry->prev != NULL)
 426                 entry->prev->next = entry->next;
 427         else
 428                 client->eg_cache = entry->next;
 429         if (entry->next != NULL)
 430                 entry->next->prev = entry->prev;
 431         client->eg_ops->put(entry);
 432         if(client->in_cache == NULL && client->eg_cache == NULL){
 433                 msg.type = STOP_KEEP_ALIVE_SM;
 434                 msg_to_mpoad(&msg,client);
 435         }
 436
 437         /* Check if the ingress side still uses this VCC */
 438         if (vcc != NULL) {
 439                 in_cache_entry *in_entry = client->in_ops->get_by_vcc(vcc, client);
 440                 if (in_entry != NULL) {
 441                         client->in_ops->put(in_entry);
 442                         return;
 443                 }
 444                 vcc_release_async(vcc, -EPIPE);
 445         }
 446
 447         return;
 448 }
 449
 450 static eg_cache_entry *eg_cache_add_entry(struct k_message *msg, struct mpoa_client *client)
 451 {
 452         eg_cache_entry *entry = kzalloc(sizeof(eg_cache_entry), GFP_KERNEL);
 453
 454         if (entry == NULL) {
 455                 printk("mpoa: mpoa_caches.c: new_eg_cache_entry: out of memory\n");
 456                 return NULL;
 457         }
 458
 459         dprintk("mpoa: mpoa_caches.c: adding an egress entry, ip = %pI4, this should be our IP\n",
 460                 &msg->content.eg_info.eg_dst_ip);
 461
 462         atomic_set(&entry->use, 1);
 463         dprintk("mpoa: mpoa_caches.c: new_eg_cache_entry: about to lock\n");
 464         write_lock_irq(&client->egress_lock);
 465         entry->next = client->eg_cache;
 466         entry->prev = NULL;
 467         if (client->eg_cache != NULL)
 468                 client->eg_cache->prev = entry;
 469         client->eg_cache = entry;
 470
 471         memcpy(entry->MPS_ctrl_ATM_addr, client->mps_ctrl_addr, ATM_ESA_LEN);
 472         entry->ctrl_info = msg->content.eg_info;
 473         do_gettimeofday(&(entry->tv));
 474         entry->entry_state = EGRESS_RESOLVED;
 475         dprintk("mpoa: mpoa_caches.c: new_eg_cache_entry cache_id %lu\n", ntohl(entry->ctrl_info.cache_id));
 476         dprintk("mpoa: mpoa_caches.c: mps_ip = %pI4\n",
 477                 &entry->ctrl_info.mps_ip);
 478         atomic_inc(&entry->use);
 479
 480         write_unlock_irq(&client->egress_lock);
 481         dprintk("mpoa: mpoa_caches.c: new_eg_cache_entry: unlocked\n");
 482
 483         return entry;
 484 }
 485
 486 static void update_eg_cache_entry(eg_cache_entry * entry, uint16_t holding_time)
 487 {
 488         do_gettimeofday(&(entry->tv));
 489         entry->entry_state = EGRESS_RESOLVED;
 490         entry->ctrl_info.holding_time = holding_time;
 491
 492         return;
 493 }
 494
 495 static void clear_expired(struct mpoa_client *client)
 496 {
 497         eg_cache_entry *entry, *next_entry;
 498         struct timeval now;
 499         struct k_message msg;
 500
 501         do_gettimeofday(&now);
 502
 503         write_lock_irq(&client->egress_lock);
 504         entry = client->eg_cache;
 505         while(entry != NULL){
 506                 next_entry = entry->next;
 507                 if((now.tv_sec - entry->tv.tv_sec)
 508                    > entry->ctrl_info.holding_time){
 509                         msg.type = SND_EGRESS_PURGE;
 510                         msg.content.eg_info = entry->ctrl_info;
 511                         dprintk("mpoa: mpoa_caches.c: egress_cache: holding time expired, cache_id = %lu.\n",ntohl(entry->ctrl_info.cache_id));
 512                         msg_to_mpoad(&msg, client);
 513                         client->eg_ops->remove_entry(entry, client);
 514                 }
 515                 entry = next_entry;
 516         }
 517         write_unlock_irq(&client->egress_lock);
 518
 519         return;
 520 }
 521
 522 static void eg_destroy_cache(struct mpoa_client *mpc)
 523 {
 524         write_lock_irq(&mpc->egress_lock);
 525         while(mpc->eg_cache != NULL)
 526                 mpc->eg_ops->remove_entry(mpc->eg_cache, mpc);
 527         write_unlock_irq(&mpc->egress_lock);
 528
 529         return;
 530 }
 531
 532
 533
 534 static struct in_cache_ops ingress_ops = {
 535         in_cache_add_entry,               /* add_entry       */
 536         in_cache_get,                     /* get             */
 537         in_cache_get_with_mask,           /* get_with_mask   */
 538         in_cache_get_by_vcc,              /* get_by_vcc      */
 539         in_cache_put,                     /* put             */
 540         in_cache_remove_entry,            /* remove_entry    */
 541         cache_hit,                        /* cache_hit       */
 542         clear_count_and_expired,          /* clear_count     */
 543         check_resolving_entries,          /* check_resolving */
 544         refresh_entries,                  /* refresh         */
 545         in_destroy_cache                  /* destroy_cache   */
 546 };
 547
 548 static struct eg_cache_ops egress_ops = {
 549         eg_cache_add_entry,               /* add_entry        */
 550         eg_cache_get_by_cache_id,         /* get_by_cache_id  */
 551         eg_cache_get_by_tag,              /* get_by_tag       */
 552         eg_cache_get_by_vcc,              /* get_by_vcc       */
 553         eg_cache_get_by_src_ip,           /* get_by_src_ip    */
 554         eg_cache_put,                     /* put              */
 555         eg_cache_remove_entry,            /* remove_entry     */
 556         update_eg_cache_entry,            /* update           */
 557         clear_expired,                    /* clear_expired    */
 558         eg_destroy_cache                  /* destroy_cache    */
 559 };
 560
 561
 562 void atm_mpoa_init_cache(struct mpoa_client *mpc)
 563 {
 564         mpc->in_ops = &ingress_ops;
 565         mpc->eg_ops = &egress_ops;
 566
 567         return;
 568 }