diff options
| author | Maciej Żenczykowski | 2023-12-06 09:36:12 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2023-12-20 17:00:15 +0100 |
| commit | 0da41ddfb2913ab03429725d940b3b1eaded6c6a (patch) | |
| tree | 675d52824b0027b0798290efdb28c9b2f67db2d0 | |
| parent | 514232495aa523641febaa58b687fe6df1cd0b73 (diff) | |
net: ipv6: support reporting otherwise unknown prefix flags in RTM_NEWPREFIX
[ Upstream commit bd4a816752bab609dd6d65ae021387beb9e2ddbd ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | include/net/addrconf.h | 12 | ||||
| -rw-r--r-- | include/net/if_inet6.h | 4 | ||||
| -rw-r--r-- | net/ipv6/addrconf.c | 6 |
3 files changed, 11 insertions, 11 deletions
diff --git a/include/net/addrconf.h b/include/net/addrconf.h index c04f359655b8..86eb2aba1479 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> diff --git a/include/net/if_inet6.h b/include/net/if_inet6.h index c8490729b4ae..31bf475eca76 100644 --- a/include/net/if_inet6.h +++ b/include/net/if_inet6.h @@ -22,10 +22,6 @@ #define IF_RS_SENT 0x10 #define IF_READY 0x80000000 -/* prefix flags */ -#define IF_PREFIX_ONLINK 0x01 -#define IF_PREFIX_AUTOCONF 0x02 - enum { INET6_IFADDR_STATE_PREDAD, INET6_IFADDR_STATE_DAD, diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index c63ccd39fc55..b8dc20fe7a4e 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -6105,11 +6105,7 @@ static int inet6_fill_prefix(struct sk_buff *skb, struct inet6_dev *idev, pmsg->prefix_len = pinfo->prefix_len; pmsg->prefix_type = pinfo->type; pmsg->prefix_pad3 = 0; - pmsg->prefix_flags = 0; - if (pinfo->onlink) - pmsg->prefix_flags |= IF_PREFIX_ONLINK; - if (pinfo->autoconf) - pmsg->prefix_flags |= IF_PREFIX_AUTOCONF; + pmsg->prefix_flags = pinfo->flags; if (nla_put(skb, PREFIX_ADDRESS, sizeof(pinfo->prefix), &pinfo->prefix)) goto nla_put_failure; |