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 1 spin_lock(&task->pkt_list.lock); skb = __skb_dequeue(&task->pkt_list); spin_unlock(&task->pkt_list.lock); #else skb = skb_dequeue( &task->pkt_list ); #endif if ( 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 1 spin_lock(&task->pkt_list.lock); __skb_queue_tail(&task->pkt_list, skb ); spin_unlock(&task->pkt_list.lock); #else skb_queue_tail(&task->pkt_list, skb ); #endif if ( 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 ); }