diff options
| author | Lennert Buytenhek <buytenh@wantstofly.org> | 2015-05-28 15:38:32 +0300 |
|---|---|---|
| committer | Marcel Holtmann <marcel@holtmann.org> | 2015-05-31 13:40:53 +0200 |
| commit | 3b369bd212d5cabb46cff0e863298971b382bbd6 (patch) | |
| tree | 250dc9be6bfaa82e624626d4b70e60e3333716cf | |
| parent | a9ab2184f451ec78af245ebb8b663d8700d44672 (diff) | |
ieee802154: Fix generation of random EUI-64 addresses.
Currently, ieee802154_random_extended_addr() has a 50% chance of
generating a group (multicast) address, while this function is used
for generating station addresses (which can't be group addresses)
for interfaces that don't have a hardware-provided address.
Also, in case get_random_bytes() generates the EUI-64 address
00:00:00:00:00:00:00:00 (extremely unlikely), which is an invalid
address, ieee802154_random_extended_addr() reacts by changing it
to 01:00:00:00:00:00:00:00, which is an invalid station address as
well, as it is a group address.
This patch changes the address generation procedure to grab eight
random bytes, treat that as an EUI-64, and then clear the Group
address bit and set the Locally Administered bit, which is in
line with how eth_random_addr() generates random EUI-48s.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Acked-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
| -rw-r--r-- | include/linux/ieee802154.h | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/include/linux/ieee802154.h b/include/linux/ieee802154.h index 8872ca103d06..552210d0a46f 100644 --- a/include/linux/ieee802154.h +++ b/include/linux/ieee802154.h @@ -244,9 +244,9 @@ static inline void ieee802154_random_extended_addr(__le64 *addr) { get_random_bytes(addr, IEEE802154_EXTENDED_ADDR_LEN); - /* toggle some bit if we hit an invalid extended addr */ - if (!ieee802154_is_valid_extended_addr(*addr)) - ((u8 *)addr)[IEEE802154_EXTENDED_ADDR_LEN - 1] ^= 0x01; + /* clear the group bit, and set the locally administered bit */ + ((u8 *)addr)[IEEE802154_EXTENDED_ADDR_LEN - 1] &= ~0x01; + ((u8 *)addr)[IEEE802154_EXTENDED_ADDR_LEN - 1] |= 0x02; } #endif /* LINUX_IEEE802154_H */ |