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authorMaciej Żenczykowski <maze@google.com>2023-12-06 20:36:12 +0300
committerDavid S. Miller <davem@davemloft.net>2023-12-08 13:40:51 +0300
commitbd4a816752bab609dd6d65ae021387beb9e2ddbd (patch)
tree95e81b5605988babb87fe1ecbbe9fe5032124555 /include/net/addrconf.h
parente5dc5afff62f3e97e86c3643ec9fcad23de4f2d3 (diff)
downloadlinux-bd4a816752bab609dd6d65ae021387beb9e2ddbd.tar.xz
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.h12
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>