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(uint32_t 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(uint32_t dst_ip,
  46                                               struct mpoa_client *client,
  47                                               uint32_t 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(uint32_t dst_ip,
  88                                           struct mpoa_client *client)
  89 {
  90         in_cache_entry* entry = kmalloc(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 = %u.%u.%u.%u\n", NIPQUAD(dst_ip));
  98         memset(entry,0,sizeof(in_cache_entry));
  99
 100         atomic_set(&entry->use, 1);
 101         dprintk("mpoa: mpoa_caches.c: new_in_cache_entry: about to lock\n");
 102         write_lock_bh(&client->ingress_lock);
 103         entry->next = client->in_cache;
 104         entry->prev = NULL;
 105         if (client->in_cache != NULL)
 106                 client->in_cache->prev = entry;
 107         client->in_cache = entry;
 108
 109         memcpy(entry->MPS_ctrl_ATM_addr, client->mps_ctrl_addr, ATM_ESA_LEN);
 110         entry->ctrl_info.in_dst_ip = dst_ip;
 111         do_gettimeofday(&(entry->tv));
 112         entry->retry_time = client->parameters.mpc_p4;
 113         entry->count = 1;
 114         entry->entry_state = INGRESS_INVALID;
 115         entry->ctrl_info.holding_time = HOLDING_TIME_DEFAULT;
 116         atomic_inc(&entry->use);
 117
 118         write_unlock_bh(&client->ingress_lock);
 119         dprintk("mpoa: mpoa_caches.c: new_in_cache_entry: unlocked\n");
 120
 121         return entry;
 122 }
 123
 124 static int cache_hit(in_cache_entry *entry, struct mpoa_client *mpc)
 125 {
 126         struct atm_mpoa_qos *qos;
 127         struct k_message msg;
 128
 129         entry->count++;
 130         if(entry->entry_state == INGRESS_RESOLVED && entry->shortcut != NULL)
 131                 return OPEN;
 132
 133         if(entry->entry_state == INGRESS_REFRESHING){
 134                 if(entry->count > mpc->parameters.mpc_p1){
 135                         msg.type = SND_MPOA_RES_RQST;
 136                         msg.content.in_info = entry->ctrl_info;
 137                         memcpy(msg.MPS_ctrl, mpc->mps_ctrl_addr, ATM_ESA_LEN);
 138                         qos = atm_mpoa_search_qos(entry->ctrl_info.in_dst_ip);
 139                         if (qos != NULL) msg.qos = qos->qos;
 140                         msg_to_mpoad(&msg, mpc);
 141                         do_gettimeofday(&(entry->reply_wait));
 142                         entry->entry_state = INGRESS_RESOLVING;
 143                 }
 144                 if(entry->shortcut != NULL)
 145                         return OPEN;
 146                 return CLOSED;
 147         }
 148
 149         if(entry->entry_state == INGRESS_RESOLVING && entry->shortcut != NULL)
 150                 return OPEN;
 151
 152         if( entry->count > mpc->parameters.mpc_p1 &&
 153             entry->entry_state == INGRESS_INVALID){
 154                 dprintk("mpoa: (%s) mpoa_caches.c: threshold exceeded for ip %u.%u.%u.%u, sending MPOA res req\n", mpc->dev->name, NIPQUAD(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 = %u.%u.%u.%u\n",NIPQUAD(entry->ctrl_info.in_dst_ip));
 189
 190         if (entry->prev != NULL)
 191                 entry->prev->next = entry->next;
 192         else
 193                 client->in_cache = entry->next;
 194         if (entry->next != NULL)
 195                 entry->next->prev = entry->prev;
 196         client->in_ops->put(entry);
 197         if(client->in_cache == NULL && client->eg_cache == NULL){
 198                 msg.type = STOP_KEEP_ALIVE_SM;
 199                 msg_to_mpoad(&msg,client);
 200         }
 201
 202         /* Check if the egress side still uses this VCC */
 203         if (vcc != NULL) {
 204                 eg_cache_entry *eg_entry = client->eg_ops->get_by_vcc(vcc, client);
 205                 if (eg_entry != NULL) {
 206                         client->eg_ops->put(eg_entry);
 207                         return;
 208                 }
 209                 vcc_release_async(vcc, -EPIPE);
 210         }
 211
 212         return;
 213 }
 214
 215
 216 /* Call this every MPC-p2 seconds... Not exactly correct solution,
 217    but an easy one... */
 218 static void clear_count_and_expired(struct mpoa_client *client)
 219 {
 220         in_cache_entry *entry, *next_entry;
 221         struct timeval now;
 222
 223         do_gettimeofday(&now);
 224
 225         write_lock_bh(&client->ingress_lock);
 226         entry = client->in_cache;
 227         while(entry != NULL){
 228                 entry->count=0;
 229                 next_entry = entry->next;
 230                 if((now.tv_sec - entry->tv.tv_sec)
 231                    > entry->ctrl_info.holding_time){
 232                         dprintk("mpoa: mpoa_caches.c: holding time expired, ip = %u.%u.%u.%u\n", NIPQUAD(entry->ctrl_info.in_dst_ip));
 233                         client->in_ops->remove_entry(entry, client);
 234                 }
 235                 entry = next_entry;
 236         }
 237         write_unlock_bh(&client->ingress_lock);
 238
 239         return;
 240 }
 241
 242 /* Call this every MPC-p4 seconds. */
 243 static void check_resolving_entries(struct mpoa_client *client)
 244 {
 245
 246         struct atm_mpoa_qos *qos;
 247         in_cache_entry *entry;
 248         struct timeval now;
 249         struct k_message msg;
 250
 251         do_gettimeofday( &now );
 252
 253         read_lock_bh(&client->ingress_lock);
 254         entry = client->in_cache;
 255         while( entry != NULL ){
 256                 if(entry->entry_state == INGRESS_RESOLVING){
 257                         if(now.tv_sec - entry->hold_down.tv_sec < client->parameters.mpc_p6){
 258                                 entry = entry->next;                      /* Entry in hold down */
 259                                 continue;
 260                         }
 261                         if( (now.tv_sec - entry->reply_wait.tv_sec) >
 262                             entry->retry_time ){
 263                                 entry->retry_time = MPC_C1*( entry->retry_time );
 264                                 if(entry->retry_time > client->parameters.mpc_p5){
 265                                         /* Retry time maximum exceeded, put entry in hold down. */
 266                                         do_gettimeofday(&(entry->hold_down));
 267                                         entry->retry_time = client->parameters.mpc_p4;
 268                                         entry = entry->next;
 269                                         continue;
 270                                 }
 271                                 /* Ask daemon to send a resolution request. */
 272                                 memset(&(entry->hold_down),0,sizeof(struct timeval));
 273                                 msg.type = SND_MPOA_RES_RTRY;
 274                                 memcpy(msg.MPS_ctrl, client->mps_ctrl_addr, ATM_ESA_LEN);
 275                                 msg.content.in_info = entry->ctrl_info;
 276                                 qos = atm_mpoa_search_qos(entry->ctrl_info.in_dst_ip);
 277                                 if (qos != NULL) msg.qos = qos->qos;
 278                                 msg_to_mpoad(&msg, client);
 279                                 do_gettimeofday(&(entry->reply_wait));
 280                         }
 281                 }
 282                 entry = entry->next;
 283         }
 284         read_unlock_bh(&client->ingress_lock);
 285 }
 286
 287 /* Call this every MPC-p5 seconds. */
 288 static void refresh_entries(struct mpoa_client *client)
 289 {
 290         struct timeval now;
 291         struct in_cache_entry *entry = client->in_cache;
 292
 293         ddprintk("mpoa: mpoa_caches.c: refresh_entries\n");
 294         do_gettimeofday(&now);
 295
 296         read_lock_bh(&client->ingress_lock);
 297         while( entry != NULL ){
 298                 if( entry->entry_state == INGRESS_RESOLVED ){
 299                         if(!(entry->refresh_time))
 300                                 entry->refresh_time = (2*(entry->ctrl_info.holding_time))/3;
 301                         if( (now.tv_sec - entry->reply_wait.tv_sec) > entry->refresh_time ){
 302                                 dprintk("mpoa: mpoa_caches.c: refreshing an entry.\n");
 303                                 entry->entry_state = INGRESS_REFRESHING;
 304
 305                         }
 306                 }
 307                 entry = entry->next;
 308         }
 309         read_unlock_bh(&client->ingress_lock);
 310 }
 311
 312 static void in_destroy_cache(struct mpoa_client *mpc)
 313 {
 314         write_lock_irq(&mpc->ingress_lock);
 315         while(mpc->in_cache != NULL)
 316                 mpc->in_ops->remove_entry(mpc->in_cache, mpc);
 317         write_unlock_irq(&mpc->ingress_lock);
 318
 319         return;
 320 }
 321
 322 static eg_cache_entry *eg_cache_get_by_cache_id(uint32_t cache_id, struct mpoa_client *mpc)
 323 {
 324         eg_cache_entry *entry;
 325
 326         read_lock_irq(&mpc->egress_lock);
 327         entry = mpc->eg_cache;
 328         while(entry != NULL){
 329                 if(entry->ctrl_info.cache_id == cache_id){
 330                         atomic_inc(&entry->use);
 331                         read_unlock_irq(&mpc->egress_lock);
 332                         return entry;
 333                 }
 334                 entry = entry->next;
 335         }
 336         read_unlock_irq(&mpc->egress_lock);
 337
 338         return NULL;
 339 }
 340
 341 /* This can be called from any context since it saves CPU flags */
 342 static eg_cache_entry *eg_cache_get_by_tag(uint32_t tag, struct mpoa_client *mpc)
 343 {
 344         unsigned long flags;
 345         eg_cache_entry *entry;
 346
 347         read_lock_irqsave(&mpc->egress_lock, flags);
 348         entry = mpc->eg_cache;
 349         while (entry != NULL){
 350                 if (entry->ctrl_info.tag == tag) {
 351                         atomic_inc(&entry->use);
 352                         read_unlock_irqrestore(&mpc->egress_lock, flags);
 353                         return entry;
 354                 }
 355                 entry = entry->next;
 356         }
 357         read_unlock_irqrestore(&mpc->egress_lock, flags);
 358
 359         return NULL;
 360 }
 361
 362 /* This can be called from any context since it saves CPU flags */
 363 static eg_cache_entry *eg_cache_get_by_vcc(struct atm_vcc *vcc, struct mpoa_client *mpc)
 364 {
 365         unsigned long flags;
 366         eg_cache_entry *entry;
 367
 368         read_lock_irqsave(&mpc->egress_lock, flags);
 369         entry = mpc->eg_cache;
 370         while (entry != NULL){
 371                 if (entry->shortcut == vcc) {
 372                         atomic_inc(&entry->use);
 373                         read_unlock_irqrestore(&mpc->egress_lock, flags);
 374                         return entry;
 375                 }
 376                 entry = entry->next;
 377         }
 378         read_unlock_irqrestore(&mpc->egress_lock, flags);
 379
 380         return NULL;
 381 }
 382
 383 static eg_cache_entry *eg_cache_get_by_src_ip(uint32_t ipaddr, struct mpoa_client *mpc)
 384 {
 385         eg_cache_entry *entry;
 386
 387         read_lock_irq(&mpc->egress_lock);
 388         entry = mpc->eg_cache;
 389         while(entry != NULL){
 390                 if(entry->latest_ip_addr == ipaddr) {
 391                         atomic_inc(&entry->use);
 392                         read_unlock_irq(&mpc->egress_lock);
 393                         return entry;
 394                 }
 395                 entry = entry->next;
 396         }
 397         read_unlock_irq(&mpc->egress_lock);
 398
 399         return NULL;
 400 }
 401
 402 static void eg_cache_put(eg_cache_entry *entry)
 403 {
 404         if (atomic_dec_and_test(&entry->use)) {
 405                 memset(entry, 0, sizeof(eg_cache_entry));
 406                 kfree(entry);
 407         }
 408
 409         return;
 410 }
 411
 412 /*
 413  * This should be called with write lock on
 414  */
 415 static void eg_cache_remove_entry(eg_cache_entry *entry,
 416                                   struct mpoa_client *client)
 417 {
 418         struct atm_vcc *vcc;
 419         struct k_message msg;
 420
 421         vcc = entry->shortcut;
 422         dprintk("mpoa: mpoa_caches.c: removing an egress entry.\n");
 423         if (entry->prev != NULL)
 424                 entry->prev->next = entry->next;
 425         else
 426                 client->eg_cache = entry->next;
 427         if (entry->next != NULL)
 428                 entry->next->prev = entry->prev;
 429         client->eg_ops->put(entry);
 430         if(client->in_cache == NULL && client->eg_cache == NULL){
 431                 msg.type = STOP_KEEP_ALIVE_SM;
 432                 msg_to_mpoad(&msg,client);
 433         }
 434
 435         /* Check if the ingress side still uses this VCC */
 436         if (vcc != NULL) {
 437                 in_cache_entry *in_entry = client->in_ops->get_by_vcc(vcc, client);
 438                 if (in_entry != NULL) {
 439                         client->in_ops->put(in_entry);
 440                         return;
 441                 }
 442                 vcc_release_async(vcc, -EPIPE);
 443         }
 444
 445         return;
 446 }
 447
 448 static eg_cache_entry *eg_cache_add_entry(struct k_message *msg, struct mpoa_client *client)
 449 {
 450         eg_cache_entry *entry = kmalloc(sizeof(eg_cache_entry), GFP_KERNEL);
 451
 452         if (entry == NULL) {
 453                 printk("mpoa: mpoa_caches.c: new_eg_cache_entry: out of memory\n");
 454                 return NULL;
 455         }
 456
 457         dprintk("mpoa: mpoa_caches.c: adding an egress entry, ip = %u.%u.%u.%u, this should be our IP\n", NIPQUAD(msg->content.eg_info.eg_dst_ip));
 458         memset(entry, 0, sizeof(eg_cache_entry));
 459
 460         atomic_set(&entry->use, 1);
 461         dprintk("mpoa: mpoa_caches.c: new_eg_cache_entry: about to lock\n");
 462         write_lock_irq(&client->egress_lock);
 463         entry->next = client->eg_cache;
 464         entry->prev = NULL;
 465         if (client->eg_cache != NULL)
 466                 client->eg_cache->prev = entry;
 467         client->eg_cache = entry;
 468
 469         memcpy(entry->MPS_ctrl_ATM_addr, client->mps_ctrl_addr, ATM_ESA_LEN);
 470         entry->ctrl_info = msg->content.eg_info;
 471         do_gettimeofday(&(entry->tv));
 472         entry->entry_state = EGRESS_RESOLVED;
 473         dprintk("mpoa: mpoa_caches.c: new_eg_cache_entry cache_id %lu\n", ntohl(entry->ctrl_info.cache_id));
 474         dprintk("mpoa: mpoa_caches.c: mps_ip = %u.%u.%u.%u\n",
 475                 NIPQUAD(entry->ctrl_info.mps_ip));
 476         atomic_inc(&entry->use);
 477
 478         write_unlock_irq(&client->egress_lock);
 479         dprintk("mpoa: mpoa_caches.c: new_eg_cache_entry: unlocked\n");
 480
 481         return entry;
 482 }
 483
 484 static void update_eg_cache_entry(eg_cache_entry * entry, uint16_t holding_time)
 485 {
 486         do_gettimeofday(&(entry->tv));
 487         entry->entry_state = EGRESS_RESOLVED;
 488         entry->ctrl_info.holding_time = holding_time;
 489
 490         return;
 491 }
 492
 493 static void clear_expired(struct mpoa_client *client)
 494 {
 495         eg_cache_entry *entry, *next_entry;
 496         struct timeval now;
 497         struct k_message msg;
 498
 499         do_gettimeofday(&now);
 500
 501         write_lock_irq(&client->egress_lock);
 502         entry = client->eg_cache;
 503         while(entry != NULL){
 504                 next_entry = entry->next;
 505                 if((now.tv_sec - entry->tv.tv_sec)
 506                    > entry->ctrl_info.holding_time){
 507                         msg.type = SND_EGRESS_PURGE;
 508                         msg.content.eg_info = entry->ctrl_info;
 509                         dprintk("mpoa: mpoa_caches.c: egress_cache: holding time expired, cache_id = %lu.\n",ntohl(entry->ctrl_info.cache_id));
 510                         msg_to_mpoad(&msg, client);
 511                         client->eg_ops->remove_entry(entry, client);
 512                 }
 513                 entry = next_entry;
 514         }
 515         write_unlock_irq(&client->egress_lock);
 516
 517         return;
 518 }
 519
 520 static void eg_destroy_cache(struct mpoa_client *mpc)
 521 {
 522         write_lock_irq(&mpc->egress_lock);
 523         while(mpc->eg_cache != NULL)
 524                 mpc->eg_ops->remove_entry(mpc->eg_cache, mpc);
 525         write_unlock_irq(&mpc->egress_lock);
 526
 527         return;
 528 }
 529
 530
 531
 532 static struct in_cache_ops ingress_ops = {
 533         in_cache_add_entry,               /* add_entry       */
 534         in_cache_get,                     /* get             */
 535         in_cache_get_with_mask,           /* get_with_mask   */
 536         in_cache_get_by_vcc,              /* get_by_vcc      */
 537         in_cache_put,                     /* put             */
 538         in_cache_remove_entry,            /* remove_entry    */
 539         cache_hit,                        /* cache_hit       */
 540         clear_count_and_expired,          /* clear_count     */
 541         check_resolving_entries,          /* check_resolving */
 542         refresh_entries,                  /* refresh         */
 543         in_destroy_cache                  /* destroy_cache   */
 544 };
 545
 546 static struct eg_cache_ops egress_ops = {
 547         eg_cache_add_entry,               /* add_entry        */
 548         eg_cache_get_by_cache_id,         /* get_by_cache_id  */
 549         eg_cache_get_by_tag,              /* get_by_tag       */
 550         eg_cache_get_by_vcc,              /* get_by_vcc       */
 551         eg_cache_get_by_src_ip,           /* get_by_src_ip    */
 552         eg_cache_put,                     /* put              */
 553         eg_cache_remove_entry,            /* remove_entry     */
 554         update_eg_cache_entry,            /* update           */
 555         clear_expired,                    /* clear_expired    */
 556         eg_destroy_cache                  /* destroy_cache    */
 557 };
 558
 559
 560 void atm_mpoa_init_cache(struct mpoa_client *mpc)
 561 {
 562         mpc->in_ops = &ingress_ops;
 563         mpc->eg_ops = &egress_ops;
 564
 565         return;
 566 }