path: root/net/packet
diff options
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/packet
parentMerge branch 'net-tls-small-code-cleanup' (diff)
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/packet')
1 files changed, 1 insertions, 1 deletions
diff --git a/net/packet/diag.c b/net/packet/diag.c
index 7ef1c881ae74..98abfd8644a4 100644
--- a/net/packet/diag.c
+++ b/net/packet/diag.c
@@ -39,7 +39,7 @@ static int pdiag_put_mclist(const struct packet_sock *po, struct sk_buff *nlskb)
struct nlattr *mca;
struct packet_mclist *ml;
- mca = nla_nest_start(nlskb, PACKET_DIAG_MCLIST);
+ mca = nla_nest_start_noflag(nlskb, PACKET_DIAG_MCLIST);
if (!mca)
return -EMSGSIZE;