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root/net/atm/mpoa_caches.c

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DEFINITIONS

This source file includes following definitions.
  1. in_cache_get
  2. in_cache_get_with_mask
  3. in_cache_get_by_vcc
  4. in_cache_add_entry
  5. cache_hit
  6. in_cache_put
  7. in_cache_remove_entry
  8. clear_count_and_expired
  9. check_resolving_entries
  10. refresh_entries
  11. in_destroy_cache
  12. eg_cache_get_by_cache_id
  13. eg_cache_get_by_tag
  14. eg_cache_get_by_vcc
  15. eg_cache_get_by_src_ip
  16. eg_cache_put
  17. eg_cache_remove_entry
  18. eg_cache_add_entry
  19. update_eg_cache_entry
  20. clear_expired
  21. eg_destroy_cache
  22. atm_mpoa_init_cache

#include <linux/types.h>
#include <linux/atmmpc.h>
#include <linux/time.h>

#include "mpoa_caches.h"
#include "mpc.h"

/*
 * mpoa_caches.c: Implementation of ingress and egress cache
 * handling functions
 */

#if 0
#define dprintk printk    /* debug */
#else
#define dprintk(format,args...)
#endif

#if 0
#define ddprintk printk  /* more debug */
#else
#define ddprintk(format,args...)
#endif

static in_cache_entry *in_cache_get(__be32 dst_ip,
                                    struct mpoa_client *client)
{
        in_cache_entry *entry;

        read_lock_bh(&client->ingress_lock);
        entry = client->in_cache;
        while(entry != NULL){
                if( entry->ctrl_info.in_dst_ip == dst_ip ){
                        atomic_inc(&entry->use);
                        read_unlock_bh(&client->ingress_lock);
                        return entry;
                }
                entry = entry->next;
        }
        read_unlock_bh(&client->ingress_lock);

        return NULL;
}

static in_cache_entry *in_cache_get_with_mask(__be32 dst_ip,
                                              struct mpoa_client *client,
                                              __be32 mask)
{
        in_cache_entry *entry;

        read_lock_bh(&client->ingress_lock);
        entry = client->in_cache;
        while(entry != NULL){
                if((entry->ctrl_info.in_dst_ip & mask)  == (dst_ip & mask )){
                        atomic_inc(&entry->use);
                        read_unlock_bh(&client->ingress_lock);
                        return entry;
                }
                entry = entry->next;
        }
        read_unlock_bh(&client->ingress_lock);

        return NULL;

}

static in_cache_entry *in_cache_get_by_vcc(struct atm_vcc *vcc,
                                           struct mpoa_client *client )
{
        in_cache_entry *entry;

        read_lock_bh(&client->ingress_lock);
        entry = client->in_cache;
        while(entry != NULL){
                if(entry->shortcut == vcc) {
                        atomic_inc(&entry->use);
                        read_unlock_bh(&client->ingress_lock);
                        return entry;
                }
                entry = entry->next;
        }
        read_unlock_bh(&client->ingress_lock);

        return NULL;
}

static in_cache_entry *in_cache_add_entry(__be32 dst_ip,
                                          struct mpoa_client *client)
{
        in_cache_entry *entry = kzalloc(sizeof(in_cache_entry), GFP_KERNEL);

        if (entry == NULL) {
                printk("mpoa: mpoa_caches.c: new_in_cache_entry: out of memory\n");
                return NULL;
        }

        dprintk("mpoa: mpoa_caches.c: adding an ingress entry, ip = %u.%u.%u.%u\n", NIPQUAD(dst_ip));

        atomic_set(&entry->use, 1);
        dprintk("mpoa: mpoa_caches.c: new_in_cache_entry: about to lock\n");
        write_lock_bh(&client->ingress_lock);
        entry->next = client->in_cache;
        entry->prev = NULL;
        if (client->in_cache != NULL)
                client->in_cache->prev = entry;
        client->in_cache = entry;

        memcpy(entry->MPS_ctrl_ATM_addr, client->mps_ctrl_addr, ATM_ESA_LEN);
        entry->ctrl_info.in_dst_ip = dst_ip;
        do_gettimeofday(&(entry->tv));
        entry->retry_time = client->parameters.mpc_p4;
        entry->count = 1;
        entry->entry_state = INGRESS_INVALID;
        entry->ctrl_info.holding_time = HOLDING_TIME_DEFAULT;
        atomic_inc(&entry->use);

        write_unlock_bh(&client->ingress_lock);
        dprintk("mpoa: mpoa_caches.c: new_in_cache_entry: unlocked\n");

        return entry;
}

static int cache_hit(in_cache_entry *entry, struct mpoa_client *mpc)
{
        struct atm_mpoa_qos *qos;
        struct k_message msg;

        entry->count++;
        if(entry->entry_state == INGRESS_RESOLVED && entry->shortcut != NULL)
                return OPEN;

        if(entry->entry_state == INGRESS_REFRESHING){
                if(entry->count > mpc->parameters.mpc_p1){
                        msg.type = SND_MPOA_RES_RQST;
                        msg.content.in_info = entry->ctrl_info;
                        memcpy(msg.MPS_ctrl, mpc->mps_ctrl_addr, ATM_ESA_LEN);
                        qos = atm_mpoa_search_qos(entry->ctrl_info.in_dst_ip);
                        if (qos != NULL) msg.qos = qos->qos;
                        msg_to_mpoad(&msg, mpc);
                        do_gettimeofday(&(entry->reply_wait));
                        entry->entry_state = INGRESS_RESOLVING;
                }
                if(entry->shortcut != NULL)
                        return OPEN;
                return CLOSED;
        }

        if(entry->entry_state == INGRESS_RESOLVING && entry->shortcut != NULL)
                return OPEN;

        if( entry->count > mpc->parameters.mpc_p1 &&
            entry->entry_state == INGRESS_INVALID){
                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));
                entry->entry_state = INGRESS_RESOLVING;
                msg.type =  SND_MPOA_RES_RQST;
                memcpy(msg.MPS_ctrl, mpc->mps_ctrl_addr, ATM_ESA_LEN );
                msg.content.in_info = entry->ctrl_info;
                qos = atm_mpoa_search_qos(entry->ctrl_info.in_dst_ip);
                if (qos != NULL) msg.qos = qos->qos;
                msg_to_mpoad( &msg, mpc);
                do_gettimeofday(&(entry->reply_wait));
        }

        return CLOSED;
}

static void in_cache_put(in_cache_entry *entry)
{
        if (atomic_dec_and_test(&entry->use)) {
                memset(entry, 0, sizeof(in_cache_entry));
                kfree(entry);
        }

        return;
}

/*
 * This should be called with write lock on
 */
static void in_cache_remove_entry(in_cache_entry *entry,
                                  struct mpoa_client *client)
{
        struct atm_vcc *vcc;
        struct k_message msg;

        vcc = entry->shortcut;
        dprintk("mpoa: mpoa_caches.c: removing an ingress entry, ip = %u.%u.%u.%u\n",NIPQUAD(entry->ctrl_info.in_dst_ip));

        if (entry->prev != NULL)
                entry->prev->next = entry->next;
        else
                client->in_cache = entry->next;
        if (entry->next != NULL)
                entry->next->prev = entry->prev;
        client->in_ops->put(entry);
        if(client->in_cache == NULL && client->eg_cache == NULL){
                msg.type = STOP_KEEP_ALIVE_SM;
                msg_to_mpoad(&msg,client);
        }

        /* Check if the egress side still uses this VCC */
        if (vcc != NULL) {
                eg_cache_entry *eg_entry = client->eg_ops->get_by_vcc(vcc, client);
                if (eg_entry != NULL) {
                        client->eg_ops->put(eg_entry);
                        return;
                }
                vcc_release_async(vcc, -EPIPE);
        }

        return;
}


/* Call this every MPC-p2 seconds... Not exactly correct solution,
   but an easy one... */
static void clear_count_and_expired(struct mpoa_client *client)
{
        in_cache_entry *entry, *next_entry;
        struct timeval now;

        do_gettimeofday(&now);

        write_lock_bh(&client->ingress_lock);
        entry = client->in_cache;
        while(entry != NULL){
                entry->count=0;
                next_entry = entry->next;
                if((now.tv_sec - entry->tv.tv_sec)
                   > entry->ctrl_info.holding_time){
                        dprintk("mpoa: mpoa_caches.c: holding time expired, ip = %u.%u.%u.%u\n", NIPQUAD(entry->ctrl_info.in_dst_ip));
                        client->in_ops->remove_entry(entry, client);
                }
                entry = next_entry;
        }
        write_unlock_bh(&client->ingress_lock);

        return;
}

/* Call this every MPC-p4 seconds. */
static void check_resolving_entries(struct mpoa_client *client)
{

        struct atm_mpoa_qos *qos;
        in_cache_entry *entry;
        struct timeval now;
        struct k_message msg;

        do_gettimeofday( &now );

        read_lock_bh(&client->ingress_lock);
        entry = client->in_cache;
        while( entry != NULL ){
                if(entry->entry_state == INGRESS_RESOLVING){
                        if(now.tv_sec - entry->hold_down.tv_sec < client->parameters.mpc_p6){
                                entry = entry->next;                      /* Entry in hold down */
                                continue;
                        }
                        if( (now.tv_sec - entry->reply_wait.tv_sec) >
                            entry->retry_time ){
                                entry->retry_time = MPC_C1*( entry->retry_time );
                                if(entry->retry_time > client->parameters.mpc_p5){
                                        /* Retry time maximum exceeded, put entry in hold down. */
                                        do_gettimeofday(&(entry->hold_down));
                                        entry->retry_time = client->parameters.mpc_p4;
                                        entry = entry->next;
                                        continue;
                                }
                                /* Ask daemon to send a resolution request. */
                                memset(&(entry->hold_down),0,sizeof(struct timeval));
                                msg.type = SND_MPOA_RES_RTRY;
                                memcpy(msg.MPS_ctrl, client->mps_ctrl_addr, ATM_ESA_LEN);
                                msg.content.in_info = entry->ctrl_info;
                                qos = atm_mpoa_search_qos(entry->ctrl_info.in_dst_ip);
                                if (qos != NULL) msg.qos = qos->qos;
                                msg_to_mpoad(&msg, client);
                                do_gettimeofday(&(entry->reply_wait));
                        }
                }
                entry = entry->next;
        }
        read_unlock_bh(&client->ingress_lock);
}

/* Call this every MPC-p5 seconds. */
static void refresh_entries(struct mpoa_client *client)
{
        struct timeval now;
        struct in_cache_entry *entry = client->in_cache;

        ddprintk("mpoa: mpoa_caches.c: refresh_entries\n");
        do_gettimeofday(&now);

        read_lock_bh(&client->ingress_lock);
        while( entry != NULL ){
                if( entry->entry_state == INGRESS_RESOLVED ){
                        if(!(entry->refresh_time))
                                entry->refresh_time = (2*(entry->ctrl_info.holding_time))/3;
                        if( (now.tv_sec - entry->reply_wait.tv_sec) > entry->refresh_time ){
                                dprintk("mpoa: mpoa_caches.c: refreshing an entry.\n");
                                entry->entry_state = INGRESS_REFRESHING;

                        }
                }
                entry = entry->next;
        }
        read_unlock_bh(&client->ingress_lock);
}

static void in_destroy_cache(struct mpoa_client *mpc)
{
        write_lock_irq(&mpc->ingress_lock);
        while(mpc->in_cache != NULL)
                mpc->in_ops->remove_entry(mpc->in_cache, mpc);
        write_unlock_irq(&mpc->ingress_lock);

        return;
}

static eg_cache_entry *eg_cache_get_by_cache_id(__be32 cache_id, struct mpoa_client *mpc)
{
        eg_cache_entry *entry;

        read_lock_irq(&mpc->egress_lock);
        entry = mpc->eg_cache;
        while(entry != NULL){
                if(entry->ctrl_info.cache_id == cache_id){
                        atomic_inc(&entry->use);
                        read_unlock_irq(&mpc->egress_lock);
                        return entry;
                }
                entry = entry->next;
        }
        read_unlock_irq(&mpc->egress_lock);

        return NULL;
}

/* This can be called from any context since it saves CPU flags */
static eg_cache_entry *eg_cache_get_by_tag(__be32 tag, struct mpoa_client *mpc)
{
        unsigned long flags;
        eg_cache_entry *entry;

        read_lock_irqsave(&mpc->egress_lock, flags);
        entry = mpc->eg_cache;
        while (entry != NULL){
                if (entry->ctrl_info.tag == tag) {
                        atomic_inc(&entry->use);
                        read_unlock_irqrestore(&mpc->egress_lock, flags);
                        return entry;
                }
                entry = entry->next;
        }
        read_unlock_irqrestore(&mpc->egress_lock, flags);

        return NULL;
}

/* This can be called from any context since it saves CPU flags */
static eg_cache_entry *eg_cache_get_by_vcc(struct atm_vcc *vcc, struct mpoa_client *mpc)
{
        unsigned long flags;
        eg_cache_entry *entry;

        read_lock_irqsave(&mpc->egress_lock, flags);
        entry = mpc->eg_cache;
        while (entry != NULL){
                if (entry->shortcut == vcc) {
                        atomic_inc(&entry->use);
                        read_unlock_irqrestore(&mpc->egress_lock, flags);
                        return entry;
                }
                entry = entry->next;
        }
        read_unlock_irqrestore(&mpc->egress_lock, flags);

        return NULL;
}

static eg_cache_entry *eg_cache_get_by_src_ip(__be32 ipaddr, struct mpoa_client *mpc)
{
        eg_cache_entry *entry;

        read_lock_irq(&mpc->egress_lock);
        entry = mpc->eg_cache;
        while(entry != NULL){
                if(entry->latest_ip_addr == ipaddr) {
                        atomic_inc(&entry->use);
                        read_unlock_irq(&mpc->egress_lock);
                        return entry;
                }
                entry = entry->next;
        }
        read_unlock_irq(&mpc->egress_lock);

        return NULL;
}

static void eg_cache_put(eg_cache_entry *entry)
{
        if (atomic_dec_and_test(&entry->use)) {
                memset(entry, 0, sizeof(eg_cache_entry));
                kfree(entry);
        }

        return;
}

/*
 * This should be called with write lock on
 */
static void eg_cache_remove_entry(eg_cache_entry *entry,
                                  struct mpoa_client *client)
{
        struct atm_vcc *vcc;
        struct k_message msg;

        vcc = entry->shortcut;
        dprintk("mpoa: mpoa_caches.c: removing an egress entry.\n");
        if (entry->prev != NULL)
                entry->prev->next = entry->next;
        else
                client->eg_cache = entry->next;
        if (entry->next != NULL)
                entry->next->prev = entry->prev;
        client->eg_ops->put(entry);
        if(client->in_cache == NULL && client->eg_cache == NULL){
                msg.type = STOP_KEEP_ALIVE_SM;
                msg_to_mpoad(&msg,client);
        }

        /* Check if the ingress side still uses this VCC */
        if (vcc != NULL) {
                in_cache_entry *in_entry = client->in_ops->get_by_vcc(vcc, client);
                if (in_entry != NULL) {
                        client->in_ops->put(in_entry);
                        return;
                }
                vcc_release_async(vcc, -EPIPE);
        }

        return;
}

static eg_cache_entry *eg_cache_add_entry(struct k_message *msg, struct mpoa_client *client)
{
        eg_cache_entry *entry = kzalloc(sizeof(eg_cache_entry), GFP_KERNEL);

        if (entry == NULL) {
                printk("mpoa: mpoa_caches.c: new_eg_cache_entry: out of memory\n");
                return NULL;
        }

        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));

        atomic_set(&entry->use, 1);
        dprintk("mpoa: mpoa_caches.c: new_eg_cache_entry: about to lock\n");
        write_lock_irq(&client->egress_lock);
        entry->next = client->eg_cache;
        entry->prev = NULL;
        if (client->eg_cache != NULL)
                client->eg_cache->prev = entry;
        client->eg_cache = entry;

        memcpy(entry->MPS_ctrl_ATM_addr, client->mps_ctrl_addr, ATM_ESA_LEN);
        entry->ctrl_info = msg->content.eg_info;
        do_gettimeofday(&(entry->tv));
        entry->entry_state = EGRESS_RESOLVED;
        dprintk("mpoa: mpoa_caches.c: new_eg_cache_entry cache_id %lu\n", ntohl(entry->ctrl_info.cache_id));
        dprintk("mpoa: mpoa_caches.c: mps_ip = %u.%u.%u.%u\n",
                NIPQUAD(entry->ctrl_info.mps_ip));
        atomic_inc(&entry->use);

        write_unlock_irq(&client->egress_lock);
        dprintk("mpoa: mpoa_caches.c: new_eg_cache_entry: unlocked\n");

        return entry;
}

static void update_eg_cache_entry(eg_cache_entry * entry, uint16_t holding_time)
{
        do_gettimeofday(&(entry->tv));
        entry->entry_state = EGRESS_RESOLVED;
        entry->ctrl_info.holding_time = holding_time;

        return;
}

static void clear_expired(struct mpoa_client *client)
{
        eg_cache_entry *entry, *next_entry;
        struct timeval now;
        struct k_message msg;

        do_gettimeofday(&now);

        write_lock_irq(&client->egress_lock);
        entry = client->eg_cache;
        while(entry != NULL){
                next_entry = entry->next;
                if((now.tv_sec - entry->tv.tv_sec)
                   > entry->ctrl_info.holding_time){
                        msg.type = SND_EGRESS_PURGE;
                        msg.content.eg_info = entry->ctrl_info;
                        dprintk("mpoa: mpoa_caches.c: egress_cache: holding time expired, cache_id = %lu.\n",ntohl(entry->ctrl_info.cache_id));
                        msg_to_mpoad(&msg, client);
                        client->eg_ops->remove_entry(entry, client);
                }
                entry = next_entry;
        }
        write_unlock_irq(&client->egress_lock);

        return;
}

static void eg_destroy_cache(struct mpoa_client *mpc)
{
        write_lock_irq(&mpc->egress_lock);
        while(mpc->eg_cache != NULL)
                mpc->eg_ops->remove_entry(mpc->eg_cache, mpc);
        write_unlock_irq(&mpc->egress_lock);

        return;
}



static struct in_cache_ops ingress_ops = {
        in_cache_add_entry,               /* add_entry       */
        in_cache_get,                     /* get             */
        in_cache_get_with_mask,           /* get_with_mask   */
        in_cache_get_by_vcc,              /* get_by_vcc      */
        in_cache_put,                     /* put             */
        in_cache_remove_entry,            /* remove_entry    */
        cache_hit,                        /* cache_hit       */
        clear_count_and_expired,          /* clear_count     */
        check_resolving_entries,          /* check_resolving */
        refresh_entries,                  /* refresh         */
        in_destroy_cache                  /* destroy_cache   */
};

static struct eg_cache_ops egress_ops = {
        eg_cache_add_entry,               /* add_entry        */
        eg_cache_get_by_cache_id,         /* get_by_cache_id  */
        eg_cache_get_by_tag,              /* get_by_tag       */
        eg_cache_get_by_vcc,              /* get_by_vcc       */
        eg_cache_get_by_src_ip,           /* get_by_src_ip    */
        eg_cache_put,                     /* put              */
        eg_cache_remove_entry,            /* remove_entry     */
        update_eg_cache_entry,            /* update           */
        clear_expired,                    /* clear_expired    */
        eg_destroy_cache                  /* destroy_cache    */
};


void atm_mpoa_init_cache(struct mpoa_client *mpc)
{
        mpc->in_ops = &ingress_ops;
        mpc->eg_ops = &egress_ops;

        return;
}

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