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authorEric Dumazet <edumazet@google.com>2023-07-20 11:09:01 +0000
committerDavid S. Miller <davem@davemloft.net>2023-07-24 09:39:31 +0100
commitf5f80e32de12fad2813d37270e8364a03e6d3ef0 (patch)
tree40646cf495a3ae868afc96d9d63fba08834be509 /net/l2tp/l2tp_ip6.c
parent1671bcfd76fdc0b9e65153cf759153083755fe4c (diff)
ipv6: remove hard coded limitation on ipv6_pinfo
IPv6 inet sockets are supposed to have a "struct ipv6_pinfo" field at the end of their definition, so that inet6_sk_generic() can derive from socket size the offset of the "struct ipv6_pinfo". This is very fragile, and prevents adding bigger alignment in sockets, because inet6_sk_generic() does not work if the compiler adds padding after the ipv6_pinfo component. We are currently working on a patch series to reorganize TCP structures for better data locality and found issues similar to the one fixed in commit f5d547676ca0 ("tcp: fix tcp_inet6_sk() for 32bit kernels") Alternative would be to force an alignment on "struct ipv6_pinfo", greater or equal to __alignof__(any ipv6 sock) to ensure there is no padding. This does not look great. v2: fix typo in mptcp_proto_v6_init() (Paolo) Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Chao Wu <wwchao@google.com> Cc: Wei Wang <weiwan@google.com> Cc: Coco Li <lixiaoyan@google.com> Cc: YiFei Zhu <zhuyifei@google.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/l2tp/l2tp_ip6.c')
-rw-r--r--net/l2tp/l2tp_ip6.c4
1 files changed, 1 insertions, 3 deletions
diff --git a/net/l2tp/l2tp_ip6.c b/net/l2tp/l2tp_ip6.c
index b1623f9c4f92..2eee95a00c05 100644
--- a/net/l2tp/l2tp_ip6.c
+++ b/net/l2tp/l2tp_ip6.c
@@ -36,9 +36,6 @@ struct l2tp_ip6_sock {
u32 conn_id;
u32 peer_conn_id;
- /* ipv6_pinfo has to be the last member of l2tp_ip6_sock, see
- * inet6_sk_generic
- */
struct ipv6_pinfo inet6;
};
@@ -730,6 +727,7 @@ static struct proto l2tp_ip6_prot = {
.hash = l2tp_ip6_hash,
.unhash = l2tp_ip6_unhash,
.obj_size = sizeof(struct l2tp_ip6_sock),
+ .ipv6_pinfo_offset = offsetof(struct l2tp_ip6_sock, inet6),
};
static const struct proto_ops l2tp_ip6_ops = {