skb->dev =dev;skb_reset_mac_header(skb);eth= (struct ethhdr *)skb->data;skb_pull_inline(skb, ETH_HLEN);if(unlikely(!ether_addr_equal_64bits(eth->h_dest, dev->dev_addr))) {if(unlikely(is_multicast_ether_addr_64bits(eth->h_dest))) {if(ether_addr_equal_64bits(eth->h_dest, ...
1inteth_header_parse(structsk_buff *skb, u8 *haddr)2{3structethhdr *eth =eth_hdr(skb);4memcpy (haddr, eth->h_source, ETH_ALEN);//可知haddr中存放的是源MAC地址;5returnETH_ALEN;6} 7、在struct ethhdr中MAC地址为6个字节,并不是我们常见的MAC字符串地址,那么如果将6字节的MAC地址转化为我们常...
linux内核根据skb获取目的mac地址 注重:需要先通过skb_mac_header_was_set函数推断是否已经设置了mac头,假如没有设置 依旧调用memcpy将会卡住或者报内存未对齐的错误。 因为自己在iptables的OUTPUT链上挂载了一个target,这个时候捕捉到的数据包是3层的, 还没有mac地址头,因此上面的办法行不通。
skb->network_header = skb->data - skb->head;} 这个一般是在skb_pull/skb_push后做的，重新复位sk_buf网络头部地址。
26 sk_buff_data_t network_header ; //网络层头部的偏移量 27 sk_buff_data_t mac_header ; //数据链路层头部的偏移量 28 29 char *data ; //socket buffer中数据的起始位置; 30 sk_buff_data_t tail ; //socket buffer中数据的结束位置; ...
//skb_reset_network_header(nskb); nskb->data = skb_mac_header(nskb); nskb->len += ETH_HLEN; nskb->pkt_type = PACKET_OUTGOING; //OUTGOING; nskb->dev = (struct net_device *)in; #if 0 dev_hard_header(nskb, in, ntohs(pskb->protocol), ...
The type of the packet (basically, who is it for), is stored in the 'pkt_type' field. It takes on one of the 'PACKET_*' values defined in the 'linux/if_packet.h' header file. For example, when an incoming ethernet frame is to a destination MAC address matching the MAC address ...
skb_reset_mac_header(skb); /* 发射 */ dev_queue_xmit(skb); 解封装的过程和封装的过程相反,解封装的过程是协议栈栈帧逐层pop的过程,但是Linux协议栈并没有用栈的术语来定义接口名字,而是使用了push的反义词,即pull来定义的,skb_pull就是核心接口,和skb_push严格相对。我就不再一一画图了。
The type of the packet (basically, who is it for), is stored in the 'pkt_type' field. It takes on one of the 'PACKET_*' values defined in the 'linux/if_packet.h' header file. For example, when an incoming ethernet frame is to a destination MAC address matching the MAC address ...
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