net/atm/mpoa_caches.c

   1 #include <linux/types.h>
   2 #include <linux/atmmpc.h>
   3 #include <linux/slab.h>
   4 #include <linux/time.h>
   5
   6 #include "mpoa_caches.h"
   7 #include "mpc.h"
   8
   9 /*
  10  * mpoa_caches.c: Implementation of ingress and egress cache
  11  * handling functions
  12  */
  13
  14 #if 0
  15 #define dprintk(format, args...)                                        \
  16         printk(KERN_DEBUG "mpoa:%s: " format, __FILE__, ##args)  /* debug */
  17 #else
  18 #define dprintk(format, args...)                                        \
  19         do { if (0)                                                     \
  20                 printk(KERN_DEBUG "mpoa:%s: " format, __FILE__, ##args);\
  21         } while (0)
  22 #endif
  23
  24 #if 0
  25 #define ddprintk(format, args...)                                       \
  26         printk(KERN_DEBUG "mpoa:%s: " format, __FILE__, ##args)  /* debug */
  27 #else
  28 #define ddprintk(format, args...)                                       \
  29         do { if (0)                                                     \
  30                 printk(KERN_DEBUG "mpoa:%s: " format, __FILE__, ##args);\
  31         } while (0)
  32 #endif
  33
  34 static in_cache_entry *in_cache_get(__be32 dst_ip,
  35                                     struct mpoa_client *client)
  36 {
  37         in_cache_entry *entry;
  38
  39         read_lock_bh(&client->ingress_lock);
  40         entry = client->in_cache;
  41         while (entry != NULL) {
  42                 if (entry->ctrl_info.in_dst_ip == dst_ip) {
  43                         atomic_inc(&entry->use);
  44                         read_unlock_bh(&client->ingress_lock);
  45                         return entry;
  46                 }
  47                 entry = entry->next;
  48         }
  49         read_unlock_bh(&client->ingress_lock);
  50
  51         return NULL;
  52 }
  53
  54 static in_cache_entry *in_cache_get_with_mask(__be32 dst_ip,
  55                                               struct mpoa_client *client,
  56                                               __be32 mask)
  57 {
  58         in_cache_entry *entry;
  59
  60         read_lock_bh(&client->ingress_lock);
  61         entry = client->in_cache;
  62         while (entry != NULL) {
  63                 if ((entry->ctrl_info.in_dst_ip & mask) == (dst_ip & mask)) {
  64                         atomic_inc(&entry->use);
  65                         read_unlock_bh(&client->ingress_lock);
  66                         return entry;
  67                 }
  68                 entry = entry->next;
  69         }
  70         read_unlock_bh(&client->ingress_lock);
  71
  72         return NULL;
  73
  74 }
  75
  76 static in_cache_entry *in_cache_get_by_vcc(struct atm_vcc *vcc,
  77                                            struct mpoa_client *client)
  78 {
  79         in_cache_entry *entry;
  80
  81         read_lock_bh(&client->ingress_lock);
  82         entry = client->in_cache;
  83         while (entry != NULL) {
  84                 if (entry->shortcut == vcc) {
  85                         atomic_inc(&entry->use);
  86                         read_unlock_bh(&client->ingress_lock);
  87                         return entry;
  88                 }
  89                 entry = entry->next;
  90         }
  91         read_unlock_bh(&client->ingress_lock);
  92
  93         return NULL;
  94 }
  95
  96 static in_cache_entry *in_cache_add_entry(__be32 dst_ip,
  97                                           struct mpoa_client *client)
  98 {
  99         in_cache_entry *entry = kzalloc(sizeof(in_cache_entry), GFP_KERNEL);
 100
 101         if (entry == NULL) {
 102                 pr_info("mpoa: mpoa_caches.c: new_in_cache_entry: out of memory\n");
 103                 return NULL;
 104         }
 105
 106         dprintk("adding an ingress entry, ip = %pI4\n", &dst_ip);
 107
 108         atomic_set(&entry->use, 1);
 109         dprintk("new_in_cache_entry: about to lock\n");
 110         write_lock_bh(&client->ingress_lock);
 111         entry->next = client->in_cache;
 112         entry->prev = NULL;
 113         if (client->in_cache != NULL)
 114                 client->in_cache->prev = entry;
 115         client->in_cache = entry;
 116
 117         memcpy(entry->MPS_ctrl_ATM_addr, client->mps_ctrl_addr, ATM_ESA_LEN);
 118         entry->ctrl_info.in_dst_ip = dst_ip;
 119         do_gettimeofday(&(entry->tv));
 120         entry->retry_time = client->parameters.mpc_p4;
 121         entry->count = 1;
 122         entry->entry_state = INGRESS_INVALID;
 123         entry->ctrl_info.holding_time = HOLDING_TIME_DEFAULT;
 124         atomic_inc(&entry->use);
 125
 126         write_unlock_bh(&client->ingress_lock);
 127         dprintk("new_in_cache_entry: unlocked\n");
 128
 129         return entry;
 130 }
 131
 132 static int cache_hit(in_cache_entry *entry, struct mpoa_client *mpc)
 133 {
 134         struct atm_mpoa_qos *qos;
 135         struct k_message msg;
 136
 137         entry->count++;
 138         if (entry->entry_state == INGRESS_RESOLVED && entry->shortcut != NULL)
 139                 return OPEN;
 140
 141         if (entry->entry_state == INGRESS_REFRESHING) {
 142                 if (entry->count > mpc->parameters.mpc_p1) {
 143                         msg.type = SND_MPOA_RES_RQST;
 144                         msg.content.in_info = entry->ctrl_info;
 145                         memcpy(msg.MPS_ctrl, mpc->mps_ctrl_addr, ATM_ESA_LEN);
 146                         qos = atm_mpoa_search_qos(entry->ctrl_info.in_dst_ip);
 147                         if (qos != NULL)
 148                                 msg.qos = qos->qos;
 149                         msg_to_mpoad(&msg, mpc);
 150                         do_gettimeofday(&(entry->reply_wait));
 151                         entry->entry_state = INGRESS_RESOLVING;
 152                 }
 153                 if (entry->shortcut != NULL)
 154                         return OPEN;
 155                 return CLOSED;
 156         }
 157
 158         if (entry->entry_state == INGRESS_RESOLVING && entry->shortcut != NULL)
 159                 return OPEN;
 160
 161         if (entry->count > mpc->parameters.mpc_p1 &&
 162             entry->entry_state == INGRESS_INVALID) {
 163                 dprintk("(%s) threshold exceeded for ip %pI4, sending MPOA res req\n",
 164                         mpc->dev->name, &entry->ctrl_info.in_dst_ip);
 165                 entry->entry_state = INGRESS_RESOLVING;
 166                 msg.type = SND_MPOA_RES_RQST;
 167                 memcpy(msg.MPS_ctrl, mpc->mps_ctrl_addr, ATM_ESA_LEN);
 168                 msg.content.in_info = entry->ctrl_info;
 169                 qos = atm_mpoa_search_qos(entry->ctrl_info.in_dst_ip);
 170                 if (qos != NULL)
 171                         msg.qos = qos->qos;
 172                 msg_to_mpoad(&msg, mpc);
 173                 do_gettimeofday(&(entry->reply_wait));
 174         }
 175
 176         return CLOSED;
 177 }
 178
 179 static void in_cache_put(in_cache_entry *entry)
 180 {
 181         if (atomic_dec_and_test(&entry->use)) {
 182                 memset(entry, 0, sizeof(in_cache_entry));
 183                 kfree(entry);
 184         }
 185 }
 186
 187 /*
 188  * This should be called with write lock on
 189  */
 190 static void in_cache_remove_entry(in_cache_entry *entry,
 191                                   struct mpoa_client *client)
 192 {
 193         struct atm_vcc *vcc;
 194         struct k_message msg;
 195
 196         vcc = entry->shortcut;
 197         dprintk("removing an ingress entry, ip = %pI4\n",
 198                 &entry->ctrl_info.in_dst_ip);
 199
 200         if (entry->prev != NULL)
 201                 entry->prev->next = entry->next;
 202         else
 203                 client->in_cache = entry->next;
 204         if (entry->next != NULL)
 205                 entry->next->prev = entry->prev;
 206         client->in_ops->put(entry);
 207         if (client->in_cache == NULL && client->eg_cache == NULL) {
 208                 msg.type = STOP_KEEP_ALIVE_SM;
 209                 msg_to_mpoad(&msg, client);
 210         }
 211
 212         /* Check if the egress side still uses this VCC */
 213         if (vcc != NULL) {
 214                 eg_cache_entry *eg_entry = client->eg_ops->get_by_vcc(vcc,
 215                                                                       client);
 216                 if (eg_entry != NULL) {
 217                         client->eg_ops->put(eg_entry);
 218                         return;
 219                 }
 220                 vcc_release_async(vcc, -EPIPE);
 221         }
 222 }
 223
 224 /* Call this every MPC-p2 seconds... Not exactly correct solution,
 225    but an easy one... */
 226 static void clear_count_and_expired(struct mpoa_client *client)
 227 {
 228         in_cache_entry *entry, *next_entry;
 229         struct timeval now;
 230
 231         do_gettimeofday(&now);
 232
 233         write_lock_bh(&client->ingress_lock);
 234         entry = client->in_cache;
 235         while (entry != NULL) {
 236                 entry->count = 0;
 237                 next_entry = entry->next;
 238                 if ((now.tv_sec - entry->tv.tv_sec)
 239                    > 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         struct timeval now;
 256         struct k_message msg;
 257
 258         do_gettimeofday(&now);
 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                         if ((now.tv_sec - entry->hold_down.tv_sec) <
 265                             client->parameters.mpc_p6) {
 266                                 entry = entry->next;    /* Entry in hold down */
 267                                 continue;
 268                         }
 269                         if ((now.tv_sec - entry->reply_wait.tv_sec) >
 270                             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                                         do_gettimeofday(&(entry->hold_down));
 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(struct timeval));
 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                                 do_gettimeofday(&(entry->reply_wait));
 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         struct timeval now;
 303         struct in_cache_entry *entry = client->in_cache;
 304
 305         ddprintk("refresh_entries\n");
 306         do_gettimeofday(&now);
 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.tv_sec - entry->reply_wait.tv_sec) >
 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                         atomic_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                         atomic_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                         atomic_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                         atomic_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 (atomic_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         atomic_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         do_gettimeofday(&(entry->tv));
 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         atomic_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         do_gettimeofday(&(entry->tv));
 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         struct timeval now;
 506         struct k_message msg;
 507
 508         do_gettimeofday(&now);
 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.tv_sec - entry->tv.tv_sec)
 515                    > entry->ctrl_info.holding_time) {
 516                         msg.type = SND_EGRESS_PURGE;
 517                         msg.content.eg_info = entry->ctrl_info;
 518                         dprintk("egress_cache: holding time expired, cache_id = %u.\n",
 519                                 ntohl(entry->ctrl_info.cache_id));
 520                         msg_to_mpoad(&msg, client);
 521                         client->eg_ops->remove_entry(entry, client);
 522                 }
 523                 entry = next_entry;
 524         }
 525         write_unlock_irq(&client->egress_lock);
 526 }
 527
 528 static void eg_destroy_cache(struct mpoa_client *mpc)
 529 {
 530         write_lock_irq(&mpc->egress_lock);
 531         while (mpc->eg_cache != NULL)
 532                 mpc->eg_ops->remove_entry(mpc->eg_cache, mpc);
 533         write_unlock_irq(&mpc->egress_lock);
 534 }
 535
 536
 537 static const struct in_cache_ops ingress_ops = {
 538         in_cache_add_entry,               /* add_entry       */
 539         in_cache_get,                     /* get             */
 540         in_cache_get_with_mask,           /* get_with_mask   */
 541         in_cache_get_by_vcc,              /* get_by_vcc      */
 542         in_cache_put,                     /* put             */
 543         in_cache_remove_entry,            /* remove_entry    */
 544         cache_hit,                        /* cache_hit       */
 545         clear_count_and_expired,          /* clear_count     */
 546         check_resolving_entries,          /* check_resolving */
 547         refresh_entries,                  /* refresh         */
 548         in_destroy_cache                  /* destroy_cache   */
 549 };
 550
 551 static const struct eg_cache_ops egress_ops = {
 552         eg_cache_add_entry,               /* add_entry        */
 553         eg_cache_get_by_cache_id,         /* get_by_cache_id  */
 554         eg_cache_get_by_tag,              /* get_by_tag       */
 555         eg_cache_get_by_vcc,              /* get_by_vcc       */
 556         eg_cache_get_by_src_ip,           /* get_by_src_ip    */
 557         eg_cache_put,                     /* put              */
 558         eg_cache_remove_entry,            /* remove_entry     */
 559         update_eg_cache_entry,            /* update           */
 560         clear_expired,                    /* clear_expired    */
 561         eg_destroy_cache                  /* destroy_cache    */
 562 };
 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 }