diff options
| author | Maciej Żenczykowski <maze@google.com> | 2023-12-06 18:36:12 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2023-12-08 11:40:51 +0100 |
| commit | bd4a816752bab609dd6d65ae021387beb9e2ddbd (patch) | |
| tree | 95e81b5605988babb87fe1ecbbe9fe5032124555 /include/net/addrconf.h | |
| parent | neighbour: Don't let neigh_forced_gc() disable preemption for long (diff) | |
| download | linux-bd4a816752bab609dd6d65ae021387beb9e2ddbd.tar.xz linux-bd4a816752bab609dd6d65ae021387beb9e2ddbd.zip | |
net: ipv6: support reporting otherwise unknown prefix flags in RTM_NEWPREFIX
Lorenzo points out that we effectively clear all unknown
flags from PIO when copying them to userspace in the netlink
RTM_NEWPREFIX notification.
We could fix this one at a time as new flags are defined,
or in one fell swoop - I choose the latter.
We could either define 6 new reserved flags (reserved1..6) and handle
them individually (and rename them as new flags are defined), or we
could simply copy the entire unmodified byte over - I choose the latter.
This unfortunately requires some anonymous union/struct magic,
so we add a static assert on the struct size for a little extra safety.
Cc: David Ahern <dsahern@kernel.org>
Cc: Lorenzo Colitti <lorenzo@google.com>
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/addrconf.h')
| -rw-r--r-- | include/net/addrconf.h | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/include/net/addrconf.h b/include/net/addrconf.h index 82da55101b5a..61ebe723ee4d 100644 --- a/include/net/addrconf.h +++ b/include/net/addrconf.h @@ -31,17 +31,22 @@ struct prefix_info { __u8 length; __u8 prefix_len; + union __packed { + __u8 flags; + struct __packed { #if defined(__BIG_ENDIAN_BITFIELD) - __u8 onlink : 1, + __u8 onlink : 1, autoconf : 1, reserved : 6; #elif defined(__LITTLE_ENDIAN_BITFIELD) - __u8 reserved : 6, + __u8 reserved : 6, autoconf : 1, onlink : 1; #else #error "Please fix <asm/byteorder.h>" #endif + }; + }; __be32 valid; __be32 prefered; __be32 reserved2; @@ -49,6 +54,9 @@ struct prefix_info { struct in6_addr prefix; }; +/* rfc4861 4.6.2: IPv6 PIO is 32 bytes in size */ +static_assert(sizeof(struct prefix_info) == 32); + #include <linux/ipv6.h> #include <linux/netdevice.h> #include <net/if_inet6.h> |