hostapd的问题1

struct ieee8023_hdr {
u8 dest[6];
u8 src[6];
u16 ethertype;
} STRUCT_PACKED;


struct ieee80211_hdr {
le16 frame_control;
le16 duration_id;
u8 addr1[6];
u8 addr2[6];
u8 addr3[6];
le16 seq_ctrl;
/* followed by 'u8 addr4[6];' if ToDS and FromDS is set in data frame
*/
} STRUCT_PACKED;

这两个结构体该如何理解啊？