#include "skbuff.h"#include "utils.h"struct sk_buff skbuff[5];int skb_cur = 0;int skb_init(void){	return 0;}void skb_headerinit(struct sk_buff *skb){	memset(skb, 0, sizeof(struct sk_buff));	skb->data = skb->buf;	skb->len = 0;	skb->truesize = ETH_FRAME_LEN;}struct sk_buff *alloc_skb(unsigned int size){	struct sk_buff *skb;		skb = &skbuff[skb_cur];	skb_cur = (skb_cur + 1) % 5;	skb_headerinit(skb);	return skb;}void free_skb(struct sk_buff *skb){}unsigned char *skb_put(struct sk_buff *skb, unsigned int len){	skb->len += len;	return skb->data;}unsigned char *skb_pull(struct sk_buff *skb, unsigned int len){	skb->data += len;	skb->len -= len;	return skb->data;}unsigned char *skb_push(struct sk_buff *skb, unsigned int len){	skb->data -= len;	skb->len += len;	return skb->data;}void skb_reserve(struct sk_buff *skb, unsigned int len){	skb->data += len;}