内核sk_buff工作线程总结

对skb采用异步序列操作的一个总结, 写成一系列函数. 将skb出队列作为一个线程调用, skb处理则采用回调函数, 在线程里直接调用, 提高了通用性. 也可以将一个skb_task定义为PER_CPU变量, 达到并行处理目的. :)

#include <linux/kthread.h>struct skb_task{struct task_struct *task;struct completion start_done;struct completion end_done;volatile u32 stop;u32 state;struct sk_buff_head pkt_list;int(*skb_callback)(struct sk_buff*);};enum {SKB_TASK_STOP,SKB_TASK_IDLE,SKB_TASK_RUNNING,};/*** skb_task工作线程*/static int _skb_task_worker(void *arg){struct sk_buff *skb = NULL;struct skb_task *task = (struct skb_task*)arg;if ( NULL == task ) {return 0;}pr_emerg( "%s begin./n", __func__ );set_current_state(TASK_INTERRUPTIBLE);complete( &task->start_done );while( task->stop == 0 ) {task->state = SKB_TASK_IDLE;//schedule_timeout_interruptible(2);schedule();__set_current_state(TASK_RUNNING);task->state = SKB_TASK_RUNNING;do {#if 1spin_lock(&task->pkt_list.lock);skb = __skb_dequeue(&task->pkt_list);spin_unlock(&task->pkt_list.lock);#elseskb = skb_dequeue( &task->pkt_list );#endifif ( NULL != skb ) {// 调用skb回调函数if ( NULL == task->skb_callback ) {kfree_skb( skb );}else {task->skb_callback( skb );}}if ( task->stop != 0 ) {goto _out;}}while( NULL != skb );};_out:pr_emerg( "%s end./n", __func__ );task->state = SKB_TASK_STOP;complete( &task->end_done );return 0;}/*** 初始化skb_task, callback为skb处理回调函数*/int _skb_task_init(struct skb_task *task, int (*callback)(struct sk_buff*) ){skb_queue_head_init( &task->pkt_list );init_completion( &task->start_done );init_completion( &task->end_done );task->skb_callback = callback;task->state = 0x0;task->stop = 0x0;return 0;} /*** 创建skb_task线程*/int _skb_task_create(struct skb_task *task){int rc = 0;task->task = kthread_create( _skb_task_worker, task, "skb_task");if ( IS_ERR( task->task ) ) {task->task = NULL;dbg_err( "kthread_create occur error./n" );rc = -1;}else {dbg_info( "kthread_create success./n" );wake_up_process( task->task );wait_for_completion( &task->start_done );dbg_info( "skb task worker run success./n" );}return rc;}/*** 终止skb_task线程*/void _skb_task_stop(struct skb_task *task){if ( NULL == task->task ){return ;}pr_emerg( "wait for skb task done/n" );task->stop = 0x1;if (task->state == SKB_TASK_IDLE ) {if ( !task_is_stopped(task->task)&& TASK_DEAD != task->task->state ) {wake_up_process(task->task);}}wait_for_completion( &task->end_done );printk( "taask->state = %d/n", task->task->state );}/*** 清除释放skb_task所属skb队列*/void _skb_task_clean(struct skb_task *task){struct sk_buff *skb = NULL;pr_emerg( "clean skb task queue/n" );do {skb = __skb_dequeue( &task->pkt_list );if ( NULL != skb ) {kfree_skb( skb );}}while( NULL != skb );}/*** 将skb加入skb_task所属skb队列*/int _skb_task_enqueue(struct skb_task *task, struct sk_buff *skb ){#if 1spin_lock(&task->pkt_list.lock);__skb_queue_tail(&task->pkt_list, skb );spin_unlock(&task->pkt_list.lock);#elseskb_queue_tail(&task->pkt_list, skb );#endifif ( NULL == task->task ){return -1;}if (task->state == SKB_TASK_IDLE ) {wake_up_process(task->task);}return 0;}/*****************************************************************************/// skb local_out 输出示例static struct skb_task skb_local_out;int local_out_init(void){_skb_task_init( &skb_local_out, ip_local_out );_skb_task_create( &skb_local_out );}void local_out_fini(void){_skb_task_stop( &skb_local_out );_skb_task_clean( &skb_local_out );}int local_out_enqueue( struct sk_buff *skb ){return _skb_task_enqueue( &skb_local_out, skb );}