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 = %u.%u.%u.%u\n", NIPQUAD(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 %u.%u.%u.%u, sending MPOA res req\n", mpc->dev->name, NIPQUAD(entry->ctrl_info.in_dst_ip));
 154                 entry->entry_state = INGRESS_RESOLVING;
 155                 msg.type =  SND_MPOA_RES_RQST;
 156                 memcpy(msg.MPS_ctrl, mpc->mps_ctrl_addr, ATM_ESA_LEN );
 157                 msg.content.in_info = entry->ctrl_info;
 158                 qos = atm_mpoa_search_qos(entry->ctrl_info.in_dst_ip);
 159                 if (qos != NULL) msg.qos = qos->qos;
 160                 msg_to_mpoad( &msg, mpc);
 161                 do_gettimeofday(&(entry->reply_wait));
 162         }
 163
 164         return CLOSED;
 165 }
 166
 167 static void in_cache_put(in_cache_entry *entry)
 168 {
 169         if (atomic_dec_and_test(&entry->use)) {
 170                 memset(entry, 0, sizeof(in_cache_entry));
 171                 kfree(entry);
 172         }
 173
 174         return;
 175 }
 176
 177 /*
 178  * This should be called with write lock on
 179  */
 180 static void in_cache_remove_entry(in_cache_entry *entry,
 181                                   struct mpoa_client *client)
 182 {
 183         struct atm_vcc *vcc;
 184         struct k_message msg;
 185
 186         vcc = entry->shortcut;
 187         dprintk("mpoa: mpoa_caches.c: removing an ingress entry, ip = %u.%u.%u.%u\n",NIPQUAD(entry->ctrl_info.in_dst_ip));
 188
 189         if (entry->prev != NULL)
 190                 entry->prev->next = entry->next;
 191         else
 192                 client->in_cache = entry->next;
 193         if (entry->next != NULL)
 194                 entry->next->prev = entry->prev;
 195         client->in_ops->put(entry);
 196         if(client->in_cache == NULL && client->eg_cache == NULL){
 197                 msg.type = STOP_KEEP_ALIVE_SM;
 198                 msg_to_mpoad(&msg,client);
 199         }
 200
 201         /* Check if the egress side still uses this VCC */
 202         if (vcc != NULL) {
 203                 eg_cache_entry *eg_entry = client->eg_ops->get_by_vcc(vcc, client);
 204                 if (eg_entry != NULL) {
 205                         client->eg_ops->put(eg_entry);
 206                         return;
 207                 }
 208                 vcc_release_async(vcc, -EPIPE);
 209         }
 210
 211         return;
 212 }
 213
 214
 215 /* Call this every MPC-p2 seconds... Not exactly correct solution,
 216    but an easy one... */
 217 static void clear_count_and_expired(struct mpoa_client *client)
 218 {
 219         in_cache_entry *entry, *next_entry;
 220         struct timeval now;
 221
 222         do_gettimeofday(&now);
 223
 224         write_lock_bh(&client->ingress_lock);
 225         entry = client->in_cache;
 226         while(entry != NULL){
 227                 entry->count=0;
 228                 next_entry = entry->next;
 229                 if((now.tv_sec - entry->tv.tv_sec)
 230                    > entry->ctrl_info.holding_time){
 231                         dprintk("mpoa: mpoa_caches.c: holding time expired, ip = %u.%u.%u.%u\n", NIPQUAD(entry->ctrl_info.in_dst_ip));
 232                         client->in_ops->remove_entry(entry, client);
 233                 }
 234                 entry = next_entry;
 235         }
 236         write_unlock_bh(&client->ingress_lock);
 237
 238         return;
 239 }
 240
 241 /* Call this every MPC-p4 seconds. */
 242 static void check_resolving_entries(struct mpoa_client *client)
 243 {
 244
 245         struct atm_mpoa_qos *qos;
 246         in_cache_entry *entry;
 247         struct timeval now;
 248         struct k_message msg;
 249
 250         do_gettimeofday( &now );
 251
 252         read_lock_bh(&client->ingress_lock);
 253         entry = client->in_cache;
 254         while( entry != NULL ){
 255                 if(entry->entry_state == INGRESS_RESOLVING){
 256                         if(now.tv_sec - entry->hold_down.tv_sec < client->parameters.mpc_p6){
 257                                 entry = entry->next;                      /* Entry in hold down */
 258                                 continue;
 259                         }
 260                         if( (now.tv_sec - entry->reply_wait.tv_sec) >
 261                             entry->retry_time ){
 262                                 entry->retry_time = MPC_C1*( entry->retry_time );
 263                                 if(entry->retry_time > client->parameters.mpc_p5){
 264                                         /* Retry time maximum exceeded, put entry in hold down. */
 265                                         do_gettimeofday(&(entry->hold_down));
 266                                         entry->retry_time = client->parameters.mpc_p4;
 267                                         entry = entry->next;
 268                                         continue;
 269                                 }
 270                                 /* Ask daemon to send a resolution request. */
 271                                 memset(&(entry->hold_down),0,sizeof(struct timeval));
 272                                 msg.type = SND_MPOA_RES_RTRY;
 273                                 memcpy(msg.MPS_ctrl, client->mps_ctrl_addr, ATM_ESA_LEN);
 274                                 msg.content.in_info = entry->ctrl_info;
 275                                 qos = atm_mpoa_search_qos(entry->ctrl_info.in_dst_ip);
 276                                 if (qos != NULL) msg.qos = qos->qos;
 277                                 msg_to_mpoad(&msg, client);
 278                                 do_gettimeofday(&(entry->reply_wait));
 279                         }
 280                 }
 281                 entry = entry->next;
 282         }
 283         read_unlock_bh(&client->ingress_lock);
 284 }
 285
 286 /* Call this every MPC-p5 seconds. */
 287 static void refresh_entries(struct mpoa_client *client)
 288 {
 289         struct timeval now;
 290         struct in_cache_entry *entry = client->in_cache;
 291
 292         ddprintk("mpoa: mpoa_caches.c: refresh_entries\n");
 293         do_gettimeofday(&now);
 294
 295         read_lock_bh(&client->ingress_lock);
 296         while( entry != NULL ){
 297                 if( entry->entry_state == INGRESS_RESOLVED ){
 298                         if(!(entry->refresh_time))
 299                                 entry->refresh_time = (2*(entry->ctrl_info.holding_time))/3;
 300                         if( (now.tv_sec - entry->reply_wait.tv_sec) > entry->refresh_time ){
 301                                 dprintk("mpoa: mpoa_caches.c: refreshing an entry.\n");
 302                                 entry->entry_state = INGRESS_REFRESHING;
 303
 304                         }
 305                 }
 306                 entry = entry->next;
 307         }
 308         read_unlock_bh(&client->ingress_lock);
 309 }
 310
 311 static void in_destroy_cache(struct mpoa_client *mpc)
 312 {
 313         write_lock_irq(&mpc->ingress_lock);
 314         while(mpc->in_cache != NULL)
 315                 mpc->in_ops->remove_entry(mpc->in_cache, mpc);
 316         write_unlock_irq(&mpc->ingress_lock);
 317
 318         return;
 319 }
 320
 321 static eg_cache_entry *eg_cache_get_by_cache_id(__be32 cache_id, struct mpoa_client *mpc)
 322 {
 323         eg_cache_entry *entry;
 324
 325         read_lock_irq(&mpc->egress_lock);
 326         entry = mpc->eg_cache;
 327         while(entry != NULL){
 328                 if(entry->ctrl_info.cache_id == cache_id){
 329                         atomic_inc(&entry->use);
 330                         read_unlock_irq(&mpc->egress_lock);
 331                         return entry;
 332                 }
 333                 entry = entry->next;
 334         }
 335         read_unlock_irq(&mpc->egress_lock);
 336
 337         return NULL;
 338 }
 339
 340 /* This can be called from any context since it saves CPU flags */
 341 static eg_cache_entry *eg_cache_get_by_tag(__be32 tag, struct mpoa_client *mpc)
 342 {
 343         unsigned long flags;
 344         eg_cache_entry *entry;
 345
 346         read_lock_irqsave(&mpc->egress_lock, flags);
 347         entry = mpc->eg_cache;
 348         while (entry != NULL){
 349                 if (entry->ctrl_info.tag == tag) {
 350                         atomic_inc(&entry->use);
 351                         read_unlock_irqrestore(&mpc->egress_lock, flags);
 352                         return entry;
 353                 }
 354                 entry = entry->next;
 355         }
 356         read_unlock_irqrestore(&mpc->egress_lock, flags);
 357
 358         return NULL;
 359 }
 360
 361 /* This can be called from any context since it saves CPU flags */
 362 static eg_cache_entry *eg_cache_get_by_vcc(struct atm_vcc *vcc, struct mpoa_client *mpc)
 363 {
 364         unsigned long flags;
 365         eg_cache_entry *entry;
 366
 367         read_lock_irqsave(&mpc->egress_lock, flags);
 368         entry = mpc->eg_cache;
 369         while (entry != NULL){
 370                 if (entry->shortcut == vcc) {
 371                         atomic_inc(&entry->use);
 372                         read_unlock_irqrestore(&mpc->egress_lock, flags);
 373                         return entry;
 374                 }
 375                 entry = entry->next;
 376         }
 377         read_unlock_irqrestore(&mpc->egress_lock, flags);
 378
 379         return NULL;
 380 }
 381
 382 static eg_cache_entry *eg_cache_get_by_src_ip(__be32 ipaddr, struct mpoa_client *mpc)
 383 {
 384         eg_cache_entry *entry;
 385
 386         read_lock_irq(&mpc->egress_lock);
 387         entry = mpc->eg_cache;
 388         while(entry != NULL){
 389                 if(entry->latest_ip_addr == ipaddr) {
 390                         atomic_inc(&entry->use);
 391                         read_unlock_irq(&mpc->egress_lock);
 392                         return entry;
 393                 }
 394                 entry = entry->next;
 395         }
 396         read_unlock_irq(&mpc->egress_lock);
 397
 398         return NULL;
 399 }
 400
 401 static void eg_cache_put(eg_cache_entry *entry)
 402 {
 403         if (atomic_dec_and_test(&entry->use)) {
 404                 memset(entry, 0, sizeof(eg_cache_entry));
 405                 kfree(entry);
 406         }
 407
 408         return;
 409 }
 410
 411 /*
 412  * This should be called with write lock on
 413  */
 414 static void eg_cache_remove_entry(eg_cache_entry *entry,
 415                                   struct mpoa_client *client)
 416 {
 417         struct atm_vcc *vcc;
 418         struct k_message msg;
 419
 420         vcc = entry->shortcut;
 421         dprintk("mpoa: mpoa_caches.c: removing an egress entry.\n");
 422         if (entry->prev != NULL)
 423                 entry->prev->next = entry->next;
 424         else
 425                 client->eg_cache = entry->next;
 426         if (entry->next != NULL)
 427                 entry->next->prev = entry->prev;
 428         client->eg_ops->put(entry);
 429         if(client->in_cache == NULL && client->eg_cache == NULL){
 430                 msg.type = STOP_KEEP_ALIVE_SM;
 431                 msg_to_mpoad(&msg,client);
 432         }
 433
 434         /* Check if the ingress side still uses this VCC */
 435         if (vcc != NULL) {
 436                 in_cache_entry *in_entry = client->in_ops->get_by_vcc(vcc, client);
 437                 if (in_entry != NULL) {
 438                         client->in_ops->put(in_entry);
 439                         return;
 440                 }
 441                 vcc_release_async(vcc, -EPIPE);
 442         }
 443
 444         return;
 445 }
 446
 447 static eg_cache_entry *eg_cache_add_entry(struct k_message *msg, struct mpoa_client *client)
 448 {
 449         eg_cache_entry *entry = kzalloc(sizeof(eg_cache_entry), GFP_KERNEL);
 450
 451         if (entry == NULL) {
 452                 printk("mpoa: mpoa_caches.c: new_eg_cache_entry: out of memory\n");
 453                 return NULL;
 454         }
 455
 456         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));
 457
 458         atomic_set(&entry->use, 1);
 459         dprintk("mpoa: mpoa_caches.c: new_eg_cache_entry: about to lock\n");
 460         write_lock_irq(&client->egress_lock);
 461         entry->next = client->eg_cache;
 462         entry->prev = NULL;
 463         if (client->eg_cache != NULL)
 464                 client->eg_cache->prev = entry;
 465         client->eg_cache = entry;
 466
 467         memcpy(entry->MPS_ctrl_ATM_addr, client->mps_ctrl_addr, ATM_ESA_LEN);
 468         entry->ctrl_info = msg->content.eg_info;
 469         do_gettimeofday(&(entry->tv));
 470         entry->entry_state = EGRESS_RESOLVED;
 471         dprintk("mpoa: mpoa_caches.c: new_eg_cache_entry cache_id %lu\n", ntohl(entry->ctrl_info.cache_id));
 472         dprintk("mpoa: mpoa_caches.c: mps_ip = %u.%u.%u.%u\n",
 473                 NIPQUAD(entry->ctrl_info.mps_ip));
 474         atomic_inc(&entry->use);
 475
 476         write_unlock_irq(&client->egress_lock);
 477         dprintk("mpoa: mpoa_caches.c: new_eg_cache_entry: unlocked\n");
 478
 479         return entry;
 480 }
 481
 482 static void update_eg_cache_entry(eg_cache_entry * entry, uint16_t holding_time)
 483 {
 484         do_gettimeofday(&(entry->tv));
 485         entry->entry_state = EGRESS_RESOLVED;
 486         entry->ctrl_info.holding_time = holding_time;
 487
 488         return;
 489 }
 490
 491 static void clear_expired(struct mpoa_client *client)
 492 {
 493         eg_cache_entry *entry, *next_entry;
 494         struct timeval now;
 495         struct k_message msg;
 496
 497         do_gettimeofday(&now);
 498
 499         write_lock_irq(&client->egress_lock);
 500         entry = client->eg_cache;
 501         while(entry != NULL){
 502                 next_entry = entry->next;
 503                 if((now.tv_sec - entry->tv.tv_sec)
 504                    > entry->ctrl_info.holding_time){
 505                         msg.type = SND_EGRESS_PURGE;
 506                         msg.content.eg_info = entry->ctrl_info;
 507                         dprintk("mpoa: mpoa_caches.c: egress_cache: holding time expired, cache_id = %lu.\n",ntohl(entry->ctrl_info.cache_id));
 508                         msg_to_mpoad(&msg, client);
 509                         client->eg_ops->remove_entry(entry, client);
 510                 }
 511                 entry = next_entry;
 512         }
 513         write_unlock_irq(&client->egress_lock);
 514
 515         return;
 516 }
 517
 518 static void eg_destroy_cache(struct mpoa_client *mpc)
 519 {
 520         write_lock_irq(&mpc->egress_lock);
 521         while(mpc->eg_cache != NULL)
 522                 mpc->eg_ops->remove_entry(mpc->eg_cache, mpc);
 523         write_unlock_irq(&mpc->egress_lock);
 524
 525         return;
 526 }
 527
 528
 529
 530 static struct in_cache_ops ingress_ops = {
 531         in_cache_add_entry,               /* add_entry       */
 532         in_cache_get,                     /* get             */
 533         in_cache_get_with_mask,           /* get_with_mask   */
 534         in_cache_get_by_vcc,              /* get_by_vcc      */
 535         in_cache_put,                     /* put             */
 536         in_cache_remove_entry,            /* remove_entry    */
 537         cache_hit,                        /* cache_hit       */
 538         clear_count_and_expired,          /* clear_count     */
 539         check_resolving_entries,          /* check_resolving */
 540         refresh_entries,                  /* refresh         */
 541         in_destroy_cache                  /* destroy_cache   */
 542 };
 543
 544 static struct eg_cache_ops egress_ops = {
 545         eg_cache_add_entry,               /* add_entry        */
 546         eg_cache_get_by_cache_id,         /* get_by_cache_id  */
 547         eg_cache_get_by_tag,              /* get_by_tag       */
 548         eg_cache_get_by_vcc,              /* get_by_vcc       */
 549         eg_cache_get_by_src_ip,           /* get_by_src_ip    */
 550         eg_cache_put,                     /* put              */
 551         eg_cache_remove_entry,            /* remove_entry     */
 552         update_eg_cache_entry,            /* update           */
 553         clear_expired,                    /* clear_expired    */
 554         eg_destroy_cache                  /* destroy_cache    */
 555 };
 556
 557
 558 void atm_mpoa_init_cache(struct mpoa_client *mpc)
 559 {
 560         mpc->in_ops = &ingress_ops;
 561         mpc->eg_ops = &egress_ops;
 562
 563         return;
 564 }