IP packet that does not need fragmentation, with IPsec 不需要分片的IP packet(IPsec)的skb的内存结构: 注意,对于IPsec,exthdrlen为IPsec header的长度,对于普通IP packet,exthdrlen为0。 Fragmentation without Scatter/Gather I/O 如果设备不支持SG(Scatter/Gather I/O),会根据是否设置MSG_MORE,情况会不一样:...