mac处理是通过eth_type_trans函数进行处理: __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev) { unsigned short _service_access_point; const unsigned short *sap; const struct ethhdr *eth; skb->dev = dev; /* 校正skb中mac头的指针 */ skb_reset_mac_header(skb); eth =...
典型的就是“如何让skb记住IP层协议头,传输层协议头,mac头的位置”,接口是: skb_reset_mac_header skb_reset_network_header skb_reset_transport_header 调用时机为skb_push返回的当时。曾几何时,我按照下面的方式设置了协议头的位置: 构造IP头 p = skb_push(skb, sizeof(struct iphdr)); iphdr = (struct...
{ 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。
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, ...
saddr:源MAC地址 len :一般可为0 1inteth_header(structsk_buff *skb,structnet_device *dev, u16 type,void*daddr,void*saddr,intlen)2{3//将skb->data = skb->data + ETH_ALEN;4structethhdr *eth = (structethhdr*)skb_push(skb, ETH_ALEN);56if(type !=ETH_P_802_3)7eth->proto = htons...
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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。
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(nskb); //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
skb->mac_header = ~0U; #endif /* make sure we initialize shinfo sequentially */ shinfo = skb_shinfo(skb); memset(shinfo, 0, offsetof(struct skb_shared_info, dataref)); atomic_set(&shinfo->dataref, 1); if (fclone) { /* 如果是fclone cache的话,那么skb的下一个buf,也将被分配*/ ...