diff options
| -rw-r--r-- | net/batman-adv/packet.h | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/net/batman-adv/packet.h b/net/batman-adv/packet.h index df548ed196d3..1c5454d33f67 100644 --- a/net/batman-adv/packet.h +++ b/net/batman-adv/packet.h @@ -173,6 +173,18 @@ struct batadv_icmp_packet_rr { uint8_t rr[BATADV_RR_LEN][ETH_ALEN]; }; +/* All packet headers in front of an ethernet header have to be completely + * divisible by 2 but not by 4 to make the payload after the ethernet + * header again 4 bytes boundary aligned. + * + * A packing of 2 is necessary to avoid extra padding at the end of the struct + * caused by a structure member which is larger than two bytes. Otherwise + * the structure would not fulfill the previously mentioned rule to avoid the + * misalignment of the payload after the ethernet header. It may also lead to + * leakage of information when the padding it not initialized before sending. + */ +#pragma pack(2) + struct batadv_unicast_packet { struct batadv_header header; uint8_t ttvn; /* destination translation table version number */ @@ -216,7 +228,9 @@ struct batadv_bcast_packet { /* "4 bytes boundary + 2 bytes" long to make the payload after the * following ethernet header again 4 bytes boundary aligned */ -} __packed; +}; + +#pragma pack() struct batadv_vis_packet { struct batadv_header header; |