/***************************************************************************

brk_list.h - description

-------------------

begin : Thu May 15 2014

copyright : (C) 2014 by Cai Bingying

email :

***************************************************************************/

//#ifdef RECOVERYPATH

//manage the brk_list

//处理断路表，添加条目，删除条目，寻找指定条目等

#include "brk_list.h"

brk_link *brk_list;

extern u_int32_t g_broadcast_ip;

extern u_int32_t g_mesh_ip;

extern u_int8_t g_routing_metric;

extern aodv_dev *g_mesh_dev;

DEFINE_RWLOCK(brk_list_lock);

//read & write lock & unlock -- 读写锁

inline void brk_list_read_lock(void) {

read_lock_bh(&brk_list_lock);

}

inline void brk_list_read_unlock(void) {

read_unlock_bh(&brk_list_lock);

}

inline void brk_list_write_lock(void) {

write_lock_bh(&brk_list_lock);

}

inline void brk_list_write_unlock(void) {

write_unlock_bh(&brk_list_lock);

}

//find first brk entry

brk_link *first_brk_link(void) {

return brk_list;

}

//initiate the brk list--empty

void init_brk_list(void) {

brk_list = NULL;

}

//expire some brk link -- 使某个断路条目过期

void expire_brk_link(brk_link * tmp_link) {

brk_list_write_lock();

tmp_link->lifetime = (getcurrtime() + DELETE_PERIOD);

tmp_link->state = INVALID;

brk_list_write_unlock();

}

//remove brk link -- 删除某个断路条目

void remove_brk_link(brk_link *dead_link) {

brk_list_write_lock(); //to avoid conflicts

//对此有疑问，dead_link的后继与表中的是一致的么？奇怪

if (brk_list == dead_link) {

brk_list = dead_link->next;

}

if (dead_link->prev != NULL) {

dead_link->prev->next = dead_link->next;

}

if (dead_link->next!=NULL) {

dead_link->next->prev = dead_link->prev;

}

brk_list_write_unlock();

kfree(dead_link);

}

//find brk link by dst--记得测试一下返回后其下一跳长什么样

brk_link *find_first_brk_link_with_dst(u_int32_t dst_ip){

brk_link *tmp_link;

brk_list_read_lock();

tmp_link = brk_list;

while((tmp_link != NULL) && (tmp_link->dst_ip < dst_ip)){

tmp_link = tmp_link->next;

}

if((tmp_link == NULL) || (tmp_link->dst_ip != dst_ip) ){//not found

brk_list_read_unlock();

return NULL;

}

else

{

brk_list_read_unlock();

return tmp_link;

}

}

//find brk link by src & dst -- 寻找指定的断路条目

brk_link *find_brk_link(u_int32_t src_ip, u_int32_t dst_ip) {

brk_link *tmp_link;

/*lock list */

brk_list_read_lock();

tmp_link = brk_list;

while ((tmp_link != NULL) && (tmp_link->dst_ip < dst_ip)) { //serching(sorted by dst_ip in insert)

tmp_link = tmp_link->next;

}

if ((tmp_link == NULL) || (tmp_link->dst_ip != dst_ip)) { //not found!

brk_list_read_unlock();

return NULL;

}

else {

while ((tmp_link != NULL) && (tmp_link->dst_ip == dst_ip)) {

if (tmp_link->src_ip == src_ip) {

brk_list_read_unlock();

//found it

return tmp_link;

}

tmp_link = tmp_link->next;

}

}

brk_list_read_unlock();

return NULL;//not found

}

/*

int is_overlapped_with_brk_link(aodv_route *tmp_route){

brk_link *tmp_link;

brk_list_read_lock();

tmp_link = brk_list;

while(tmp_link != NULL){

if( (tmp_link->src_ip==tmp_route->src_ip)

&& (tmp_link->last_avail_ip==tmp_route->dst_ip) ){

//data link has overlap part

break;

}

tmp_link = tmp_link->next;

}

if(tmp_link){

brk_list_read_unlock();

return 1;

}

brk_list_read_unlock();

return 0;//no overlap

}

*/

//clean up the brk list -- 此功能保留，brk_list的清空应无需与内核交互

int cleanup_brk_list(void) {

brk_link *dead_link, *tmp_link;

int error;

tmp_link = brk_list;

//如果断路表不为空，直接一个一个删除，无需像路由表一样跟内核交互

while (tmp_link != NULL) {

dead_link = tmp_link;

tmp_link = tmp_link->next;

kfree(dead_link);

}

brk_list = NULL;

return 0;

}

//创建新的断路条目

brk_link *create_brk_link(u_int32_t src_ip, u_int32_t dst_ip,

u_int32_t lasthop,u_int32_t lastavail) {

brk_link *tmp_entry;

#ifdef CaiDebug

char src[20];

char dst[20];

char lhop[20];

char lavail[20];

strcpy(src, inet_ntoa(src_ip));

strcpy(dst, inet_ntoa(dst_ip));

strcpy(lhop, inet_ntoa(lasthop));

strcpy(lavail, inet_ntoa(lastavail));

printk ("create_brk_link: Creating %s to %s via %s,last DTN is %s\n", src,dst,lhop,lavail);

#endif

/* Allocate memory for new entry */

if ((tmp_entry = (brk_link *) kmalloc(sizeof(brk_link), GFP_ATOMIC)) == NULL) {

printk("Error getting memory for new brk link\n");

return NULL;

}

tmp_entry->dst_ip = dst_ip;

tmp_entry->dst_id = htonl(dst_ip);

tmp_entry->src_ip = src_ip;

tmp_entry->last_hop = lasthop;

tmp_entry->state = ACTIVE;

//tmp_entry->last_avail_ip = NULL;

//#ifdef DTN

tmp_entry->last_avail_ip = lastavail;//若没有则为空，该字段不能缺少

//#endif

tmp_entry->prev = NULL;

tmp_entry->next = NULL;

tmp_entry->lifetime = getcurrtime() + BRK_LINK_TIMEOUT;//该删除时间是否应该调整到稍微大一点？？？

insert_brk_link(tmp_entry);

#ifdef CaiDebug

if (brk_list == NULL) // if the brk_list is empty

{

printk ("brk list still NULL after insert!! ");

}

#endif

return tmp_entry;

}

//insert a new brk link entry,and sort it first by dst

//插入新的断路条目，并先按dst排序

void insert_brk_link(brk_link *new_link) { //ordenamos por dst_ip

brk_link *tmp_link;

brk_link *prev_link = NULL;

brk_list_write_lock(); //to avoid conflicts

tmp_link = brk_list;

while ((tmp_link != NULL) && (tmp_link->dst_ip < new_link->dst_ip)) //entries ordered by dst_ip

{

prev_link = tmp_link;

tmp_link = tmp_link->next;

}

if (brk_list && (tmp_link == brk_list)) // if it goes in the first spot in the list

{

brk_list->prev = new_link;

new_link->next = brk_list;

brk_list = new_link;

#ifdef CaiDebug

printk("New link should be put in the head of the list in brk_list.c\n");

#endif

brk_list_write_unlock();

return ;

}

if (brk_list == NULL) // if the brk_list is empty

{

brk_list = new_link;

brk_list_write_unlock();

#ifdef CaiDebug

printk("The list is empty in brk_list.c\n");

#endif

return;

}

if (tmp_link == NULL) //i'm going in next spot in the list and it is empty

{

new_link->next = NULL;

new_link->prev = prev_link;

prev_link->next = new_link;

brk_list_write_unlock();

#ifdef CaiDebug

printk("New link should be put in the last of the list in brk_list.c\n");

#endif

return;

}

//found it in somewhere of the list

tmp_link->prev = new_link;

new_link->next = tmp_link;

new_link->prev = prev_link;

prev_link->next = new_link;

brk_list_write_unlock();

return;

}

int flush_brk_list(void) {

u_int64_t currtime = getcurrtime();

brk_link *dead_link, *tmp_link, *prev_link=NULL;

tmp_link = brk_list;

while (tmp_link!=NULL) {

prev_link = tmp_link;

if (time_before((unsigned long) tmp_link->lifetime,

(unsigned long) currtime)) {//生命周期在当前时间之前

if (tmp_link->state != INVALID) {//未过期则使其过期

expire_brk_link(tmp_link);

tmp_link = tmp_link->next;

}

else {//已标志过期，则删除。

}

dead_link = tmp_link;

prev_link = tmp_link->prev;

tmp_link = tmp_link->next;

remove_brk_link(dead_link);

}

tmp_link = tmp_link->next;

}

//insert_timer_simple(TASK_CLEANUP, HELLO_INTERVAL, g_mesh_ip);

//update_timer_queue();

return 1;

}

//#endif