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authorMichal Kubecek <mkubecek@suse.cz>2019-04-26 11:13:06 +0200
committerDavid S. Miller <davem@davemloft.net>2019-04-27 17:03:44 -0400
commitae0be8de9a53cda3505865c11826d8ff0640237c (patch)
tree43bc8a0d58965d57e4ed1bedf8d892c3fe72e8b5 /net/l2tp
parentc7881b4a97e21b617b8243094dfa4b62028b956c (diff)
downloadlinux-ae0be8de9a53cda3505865c11826d8ff0640237c.tar.bz2
netlink: make nla_nest_start() add NLA_F_NESTED flag
Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most netlink based interfaces (including recently added ones) are still not setting it in kernel generated messages. Without the flag, message parsers not aware of attribute semantics (e.g. wireshark dissector or libmnl's mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display the structure of their contents. Unfortunately we cannot just add the flag everywhere as there may be userspace applications which check nlattr::nla_type directly rather than through a helper masking out the flags. Therefore the patch renames nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start() as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually are rewritten to use nla_nest_start(). Except for changes in include/net/netlink.h, the patch was generated using this semantic patch: @@ expression E1, E2; @@ -nla_nest_start(E1, E2) +nla_nest_start_noflag(E1, E2) @@ expression E1, E2; @@ -nla_nest_start_noflag(E1, E2 | NLA_F_NESTED) +nla_nest_start(E1, E2) Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Acked-by: Jiri Pirko <jiri@mellanox.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/l2tp')
-rw-r--r--net/l2tp/l2tp_netlink.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/net/l2tp/l2tp_netlink.c b/net/l2tp/l2tp_netlink.c
index 77595fcc9f75..c31b50cc48d9 100644
--- a/net/l2tp/l2tp_netlink.c
+++ b/net/l2tp/l2tp_netlink.c
@@ -345,7 +345,7 @@ static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int fla
nla_put_u16(skb, L2TP_ATTR_ENCAP_TYPE, tunnel->encap))
goto nla_put_failure;
- nest = nla_nest_start(skb, L2TP_ATTR_STATS);
+ nest = nla_nest_start_noflag(skb, L2TP_ATTR_STATS);
if (nest == NULL)
goto nla_put_failure;
@@ -742,7 +742,7 @@ static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int fl
session->reorder_timeout, L2TP_ATTR_PAD)))
goto nla_put_failure;
- nest = nla_nest_start(skb, L2TP_ATTR_STATS);
+ nest = nla_nest_start_noflag(skb, L2TP_ATTR_STATS);
if (nest == NULL)
goto nla_put_failure;