diff options
Diffstat (limited to 'net/atm/mpoa_caches.c')
| -rw-r--r-- | net/atm/mpoa_caches.c | 567 |
1 files changed, 567 insertions, 0 deletions
diff --git a/net/atm/mpoa_caches.c b/net/atm/mpoa_caches.c new file mode 100644 index 000000000..4bb418313 --- /dev/null +++ b/net/atm/mpoa_caches.c @@ -0,0 +1,567 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/types.h> +#include <linux/atmmpc.h> +#include <linux/slab.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(format, args...) \ + printk(KERN_DEBUG "mpoa:%s: " format, __FILE__, ##args) /* debug */ +#else +#define dprintk(format, args...) \ + do { if (0) \ + printk(KERN_DEBUG "mpoa:%s: " format, __FILE__, ##args);\ + } while (0) +#endif + +#if 0 +#define ddprintk(format, args...) \ + printk(KERN_DEBUG "mpoa:%s: " format, __FILE__, ##args) /* debug */ +#else +#define ddprintk(format, args...) \ + do { if (0) \ + printk(KERN_DEBUG "mpoa:%s: " format, __FILE__, ##args);\ + } while (0) +#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) { + refcount_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)) { + refcount_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) { + refcount_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) { + pr_info("mpoa: mpoa_caches.c: new_in_cache_entry: out of memory\n"); + return NULL; + } + + dprintk("adding an ingress entry, ip = %pI4\n", &dst_ip); + + refcount_set(&entry->use, 1); + dprintk("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; + entry->time = ktime_get_seconds(); + entry->retry_time = client->parameters.mpc_p4; + entry->count = 1; + entry->entry_state = INGRESS_INVALID; + entry->ctrl_info.holding_time = HOLDING_TIME_DEFAULT; + refcount_inc(&entry->use); + + write_unlock_bh(&client->ingress_lock); + dprintk("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); + entry->reply_wait = ktime_get_seconds(); + 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("(%s) threshold exceeded for ip %pI4, sending MPOA res req\n", + mpc->dev->name, &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); + entry->reply_wait = ktime_get_seconds(); + } + + return CLOSED; +} + +static void in_cache_put(in_cache_entry *entry) +{ + if (refcount_dec_and_test(&entry->use)) { + memset(entry, 0, sizeof(in_cache_entry)); + kfree(entry); + } +} + +/* + * 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("removing an ingress entry, ip = %pI4\n", + &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); + } +} + +/* 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; + time64_t now; + + now = ktime_get_seconds(); + + write_lock_bh(&client->ingress_lock); + entry = client->in_cache; + while (entry != NULL) { + entry->count = 0; + next_entry = entry->next; + if ((now - entry->time) > entry->ctrl_info.holding_time) { + dprintk("holding time expired, ip = %pI4\n", + &entry->ctrl_info.in_dst_ip); + client->in_ops->remove_entry(entry, client); + } + entry = next_entry; + } + write_unlock_bh(&client->ingress_lock); +} + +/* Call this every MPC-p4 seconds. */ +static void check_resolving_entries(struct mpoa_client *client) +{ + + struct atm_mpoa_qos *qos; + in_cache_entry *entry; + time64_t now; + struct k_message msg; + + now = ktime_get_seconds(); + + read_lock_bh(&client->ingress_lock); + entry = client->in_cache; + while (entry != NULL) { + if (entry->entry_state == INGRESS_RESOLVING) { + + if ((now - entry->hold_down) + < client->parameters.mpc_p6) { + entry = entry->next; /* Entry in hold down */ + continue; + } + if ((now - entry->reply_wait) > entry->retry_time) { + entry->retry_time = MPC_C1 * (entry->retry_time); + /* + * Retry time maximum exceeded, + * put entry in hold down. + */ + if (entry->retry_time > client->parameters.mpc_p5) { + entry->hold_down = ktime_get_seconds(); + entry->retry_time = client->parameters.mpc_p4; + entry = entry->next; + continue; + } + /* Ask daemon to send a resolution request. */ + memset(&entry->hold_down, 0, sizeof(time64_t)); + 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); + entry->reply_wait = ktime_get_seconds(); + } + } + entry = entry->next; + } + read_unlock_bh(&client->ingress_lock); +} + +/* Call this every MPC-p5 seconds. */ +static void refresh_entries(struct mpoa_client *client) +{ + time64_t now; + struct in_cache_entry *entry = client->in_cache; + + ddprintk("refresh_entries\n"); + now = ktime_get_seconds(); + + 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 - entry->reply_wait) > + entry->refresh_time) { + dprintk("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); +} + +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) { + refcount_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) { + refcount_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) { + refcount_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) { + refcount_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 (refcount_dec_and_test(&entry->use)) { + memset(entry, 0, sizeof(eg_cache_entry)); + kfree(entry); + } +} + +/* + * 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("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); + } +} + +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) { + pr_info("out of memory\n"); + return NULL; + } + + dprintk("adding an egress entry, ip = %pI4, this should be our IP\n", + &msg->content.eg_info.eg_dst_ip); + + refcount_set(&entry->use, 1); + dprintk("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; + entry->time = ktime_get_seconds(); + entry->entry_state = EGRESS_RESOLVED; + dprintk("new_eg_cache_entry cache_id %u\n", + ntohl(entry->ctrl_info.cache_id)); + dprintk("mps_ip = %pI4\n", &entry->ctrl_info.mps_ip); + refcount_inc(&entry->use); + + write_unlock_irq(&client->egress_lock); + dprintk("new_eg_cache_entry: unlocked\n"); + + return entry; +} + +static void update_eg_cache_entry(eg_cache_entry *entry, uint16_t holding_time) +{ + entry->time = ktime_get_seconds(); + entry->entry_state = EGRESS_RESOLVED; + entry->ctrl_info.holding_time = holding_time; +} + +static void clear_expired(struct mpoa_client *client) +{ + eg_cache_entry *entry, *next_entry; + time64_t now; + struct k_message msg; + + now = ktime_get_seconds(); + + write_lock_irq(&client->egress_lock); + entry = client->eg_cache; + while (entry != NULL) { + next_entry = entry->next; + if ((now - entry->time) > entry->ctrl_info.holding_time) { + msg.type = SND_EGRESS_PURGE; + msg.content.eg_info = entry->ctrl_info; + dprintk("egress_cache: holding time expired, cache_id = %u.\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); +} + +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); +} + + +static const struct in_cache_ops ingress_ops = { + .add_entry = in_cache_add_entry, + .get = in_cache_get, + .get_with_mask = in_cache_get_with_mask, + .get_by_vcc = in_cache_get_by_vcc, + .put = in_cache_put, + .remove_entry = in_cache_remove_entry, + .cache_hit = cache_hit, + .clear_count = clear_count_and_expired, + .check_resolving = check_resolving_entries, + .refresh = refresh_entries, + .destroy_cache = in_destroy_cache +}; + +static const struct eg_cache_ops egress_ops = { + .add_entry = eg_cache_add_entry, + .get_by_cache_id = eg_cache_get_by_cache_id, + .get_by_tag = eg_cache_get_by_tag, + .get_by_vcc = eg_cache_get_by_vcc, + .get_by_src_ip = eg_cache_get_by_src_ip, + .put = eg_cache_put, + .remove_entry = eg_cache_remove_entry, + .update = update_eg_cache_entry, + .clear_expired = clear_expired, + .destroy_cache = eg_destroy_cache +}; + +void atm_mpoa_init_cache(struct mpoa_client *mpc) +{ + mpc->in_ops = &ingress_ops; + mpc->eg_ops = &egress_ops; +} |