[ovs-dev,05/11] datapath: Use nla_nest_start_noflag()
diff mbox series

Message ID 1571074671-31834-6-git-send-email-yihung.wei@gmail.com
State New
Headers show
Series
  • Backport upstream conntrack related patches
Related show

Commit Message

Yi-Hung Wei Oct. 14, 2019, 5:37 p.m. UTC
This patch backports the openvswitch changes and update the compat layer
for the following upstream patch.

commit ae0be8de9a53cda3505865c11826d8ff0640237c
Author: Michal Kubecek <mkubecek@suse.cz>
Date:   Fri Apr 26 11:13:06 2019 +0200

    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>

Signed-off-by: Yi-Hung Wei <yihung.wei@gmail.com>
---
 acinclude.m4                                |  1 +
 datapath/conntrack.c                        |  6 +++---
 datapath/datapath.c                         |  7 +++---
 datapath/flow_netlink.c                     | 33 +++++++++++++++--------------
 datapath/linux/compat/include/net/netlink.h |  9 ++++++++
 datapath/meter.c                            |  8 +++----
 datapath/vport-vxlan.c                      |  2 +-
 datapath/vport.c                            |  2 +-
 8 files changed, 40 insertions(+), 28 deletions(-)

Comments

Yifeng Sun Oct. 14, 2019, 11:35 p.m. UTC | #1
LGTM, thanks.

Reviewed-by: Yifeng Sun <pkusunyifeng@gmail.com>

On Mon, Oct 14, 2019 at 10:53 AM Yi-Hung Wei <yihung.wei@gmail.com> wrote:
>
> This patch backports the openvswitch changes and update the compat layer
> for the following upstream patch.
>
> commit ae0be8de9a53cda3505865c11826d8ff0640237c
> Author: Michal Kubecek <mkubecek@suse.cz>
> Date:   Fri Apr 26 11:13:06 2019 +0200
>
>     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>
>
> Signed-off-by: Yi-Hung Wei <yihung.wei@gmail.com>
> ---
>  acinclude.m4                                |  1 +
>  datapath/conntrack.c                        |  6 +++---
>  datapath/datapath.c                         |  7 +++---
>  datapath/flow_netlink.c                     | 33 +++++++++++++++--------------
>  datapath/linux/compat/include/net/netlink.h |  9 ++++++++
>  datapath/meter.c                            |  8 +++----
>  datapath/vport-vxlan.c                      |  2 +-
>  datapath/vport.c                            |  2 +-
>  8 files changed, 40 insertions(+), 28 deletions(-)
>
> diff --git a/acinclude.m4 b/acinclude.m4
> index dca09abefa96..fe121ab9126d 100644
> --- a/acinclude.m4
> +++ b/acinclude.m4
> @@ -844,6 +844,7 @@ AC_DEFUN([OVS_CHECK_LINUX_COMPAT], [
>    OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_put_in_addr])
>    OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_find_nested])
>    OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_is_last])
> +  OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_nest_start_noflag])
>    OVS_GREP_IFELSE([$KSRC/include/linux/netlink.h], [void.*netlink_set_err],
>                    [OVS_DEFINE([HAVE_VOID_NETLINK_SET_ERR])])
>    OVS_FIND_PARAM_IFELSE([$KSRC/include/net/netlink.h],
> diff --git a/datapath/conntrack.c b/datapath/conntrack.c
> index 010f9af5ffd2..b11a30965147 100644
> --- a/datapath/conntrack.c
> +++ b/datapath/conntrack.c
> @@ -1776,7 +1776,7 @@ static bool ovs_ct_nat_to_attr(const struct ovs_conntrack_info *info,
>  {
>         struct nlattr *start;
>
> -       start = nla_nest_start(skb, OVS_CT_ATTR_NAT);
> +       start = nla_nest_start_noflag(skb, OVS_CT_ATTR_NAT);
>         if (!start)
>                 return false;
>
> @@ -1847,7 +1847,7 @@ int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
>  {
>         struct nlattr *start;
>
> -       start = nla_nest_start(skb, OVS_ACTION_ATTR_CT);
> +       start = nla_nest_start_noflag(skb, OVS_ACTION_ATTR_CT);
>         if (!start)
>                 return -EMSGSIZE;
>
> @@ -2257,7 +2257,7 @@ static int ovs_ct_limit_cmd_get(struct sk_buff *skb, struct genl_info *info)
>         if (IS_ERR(reply))
>                 return PTR_ERR(reply);
>
> -       nla_reply = nla_nest_start(reply, OVS_CT_LIMIT_ATTR_ZONE_LIMIT);
> +       nla_reply = nla_nest_start_noflag(reply, OVS_CT_LIMIT_ATTR_ZONE_LIMIT);
>
>         if (a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
>                 err = ovs_ct_limit_get_zone_limit(
> diff --git a/datapath/datapath.c b/datapath/datapath.c
> index 94e4f6ffd6e9..78e2e6310529 100644
> --- a/datapath/datapath.c
> +++ b/datapath/datapath.c
> @@ -475,7 +475,8 @@ static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb,
>
>
>         if (upcall_info->egress_tun_info) {
> -               nla = nla_nest_start(user_skb, OVS_PACKET_ATTR_EGRESS_TUN_KEY);
> +               nla = nla_nest_start_noflag(user_skb,
> +                                           OVS_PACKET_ATTR_EGRESS_TUN_KEY);
>                 if (!nla) {
>                         err = -EMSGSIZE;
>                         goto out;
> @@ -487,7 +488,7 @@ static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb,
>         }
>
>         if (upcall_info->actions_len) {
> -               nla = nla_nest_start(user_skb, OVS_PACKET_ATTR_ACTIONS);
> +               nla = nla_nest_start_noflag(user_skb, OVS_PACKET_ATTR_ACTIONS);
>                 if (!nla) {
>                         err = -EMSGSIZE;
>                         goto out;
> @@ -789,7 +790,7 @@ static int ovs_flow_cmd_fill_actions(const struct sw_flow *flow,
>          * This can only fail for dump operations because the skb is always
>          * properly sized for single flows.
>          */
> -       start = nla_nest_start(skb, OVS_FLOW_ATTR_ACTIONS);
> +       start = nla_nest_start_noflag(skb, OVS_FLOW_ATTR_ACTIONS);
>         if (start) {
>                 const struct sw_flow_actions *sf_acts;
>
> diff --git a/datapath/flow_netlink.c b/datapath/flow_netlink.c
> index 0f7ab53fc141..35f13d753cec 100644
> --- a/datapath/flow_netlink.c
> +++ b/datapath/flow_netlink.c
> @@ -839,7 +839,7 @@ static int vxlan_opt_to_nlattr(struct sk_buff *skb,
>         const struct vxlan_metadata *opts = tun_opts;
>         struct nlattr *nla;
>
> -       nla = nla_nest_start(skb, OVS_TUNNEL_KEY_ATTR_VXLAN_OPTS);
> +       nla = nla_nest_start_noflag(skb, OVS_TUNNEL_KEY_ATTR_VXLAN_OPTS);
>         if (!nla)
>                 return -EMSGSIZE;
>
> @@ -926,7 +926,7 @@ static int ip_tun_to_nlattr(struct sk_buff *skb,
>         struct nlattr *nla;
>         int err;
>
> -       nla = nla_nest_start(skb, OVS_KEY_ATTR_TUNNEL);
> +       nla = nla_nest_start_noflag(skb, OVS_KEY_ATTR_TUNNEL);
>         if (!nla)
>                 return -EMSGSIZE;
>
> @@ -1934,7 +1934,7 @@ static int nsh_key_to_nlattr(const struct ovs_key_nsh *nsh, bool is_mask,
>  {
>         struct nlattr *start;
>
> -       start = nla_nest_start(skb, OVS_KEY_ATTR_NSH);
> +       start = nla_nest_start_noflag(skb, OVS_KEY_ATTR_NSH);
>         if (!start)
>                 return -EMSGSIZE;
>
> @@ -2017,14 +2017,15 @@ static int __ovs_nla_put_key(const struct sw_flow_key *swkey,
>                 if (swkey->eth.vlan.tci || eth_type_vlan(swkey->eth.type)) {
>                         if (ovs_nla_put_vlan(skb, &output->eth.vlan, is_mask))
>                                 goto nla_put_failure;
> -                       encap = nla_nest_start(skb, OVS_KEY_ATTR_ENCAP);
> +                       encap = nla_nest_start_noflag(skb, OVS_KEY_ATTR_ENCAP);
>                         if (!swkey->eth.vlan.tci)
>                                 goto unencap;
>
>                         if (swkey->eth.cvlan.tci || eth_type_vlan(swkey->eth.type)) {
>                                 if (ovs_nla_put_vlan(skb, &output->eth.cvlan, is_mask))
>                                         goto nla_put_failure;
> -                               in_encap = nla_nest_start(skb, OVS_KEY_ATTR_ENCAP);
> +                               in_encap = nla_nest_start_noflag(skb,
> +                                                                OVS_KEY_ATTR_ENCAP);
>                                 if (!swkey->eth.cvlan.tci)
>                                         goto unencap;
>                         }
> @@ -2203,7 +2204,7 @@ int ovs_nla_put_key(const struct sw_flow_key *swkey,
>         int err;
>         struct nlattr *nla;
>
> -       nla = nla_nest_start(skb, attr);
> +       nla = nla_nest_start_noflag(skb, attr);
>         if (!nla)
>                 return -EMSGSIZE;
>         err = __ovs_nla_put_key(swkey, output, is_mask, skb);
> @@ -3234,7 +3235,7 @@ static int sample_action_to_attr(const struct nlattr *attr,
>         const struct sample_arg *arg;
>         struct nlattr *actions;
>
> -       start = nla_nest_start(skb, OVS_ACTION_ATTR_SAMPLE);
> +       start = nla_nest_start_noflag(skb, OVS_ACTION_ATTR_SAMPLE);
>         if (!start)
>                 return -EMSGSIZE;
>
> @@ -3247,7 +3248,7 @@ static int sample_action_to_attr(const struct nlattr *attr,
>                 goto out;
>         }
>
> -       ac_start = nla_nest_start(skb, OVS_SAMPLE_ATTR_ACTIONS);
> +       ac_start = nla_nest_start_noflag(skb, OVS_SAMPLE_ATTR_ACTIONS);
>         if (!ac_start) {
>                 err = -EMSGSIZE;
>                 goto out;
> @@ -3273,7 +3274,7 @@ static int clone_action_to_attr(const struct nlattr *attr,
>         struct nlattr *start;
>         int err = 0, rem = nla_len(attr);
>
> -       start = nla_nest_start(skb, OVS_ACTION_ATTR_CLONE);
> +       start = nla_nest_start_noflag(skb, OVS_ACTION_ATTR_CLONE);
>         if (!start)
>                 return -EMSGSIZE;
>
> @@ -3295,7 +3296,7 @@ static int check_pkt_len_action_to_attr(const struct nlattr *attr,
>         const struct nlattr *a, *cpl_arg;
>         int err = 0, rem = nla_len(attr);
>
> -       start = nla_nest_start(skb, OVS_ACTION_ATTR_CHECK_PKT_LEN);
> +       start = nla_nest_start_noflag(skb, OVS_ACTION_ATTR_CHECK_PKT_LEN);
>         if (!start)
>                 return -EMSGSIZE;
>
> @@ -3314,8 +3315,8 @@ static int check_pkt_len_action_to_attr(const struct nlattr *attr,
>          * 'OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_LESS_EQUAL'.
>          */
>         a = nla_next(cpl_arg, &rem);
> -       ac_start =  nla_nest_start(skb,
> -               OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_LESS_EQUAL);
> +       ac_start =  nla_nest_start_noflag(skb,
> +                                         OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_LESS_EQUAL);
>         if (!ac_start) {
>                 err = -EMSGSIZE;
>                 goto out;
> @@ -3333,8 +3334,8 @@ static int check_pkt_len_action_to_attr(const struct nlattr *attr,
>          * OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_GREATER.
>          */
>         a = nla_next(a, &rem);
> -       ac_start =  nla_nest_start(skb,
> -                                  OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_GREATER);
> +       ac_start =  nla_nest_start_noflag(skb,
> +                                         OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_GREATER);
>         if (!ac_start) {
>                 err = -EMSGSIZE;
>                 goto out;
> @@ -3368,7 +3369,7 @@ static int set_action_to_attr(const struct nlattr *a, struct sk_buff *skb)
>                 struct ovs_tunnel_info *ovs_tun = nla_data(ovs_key);
>                 struct ip_tunnel_info *tun_info = &ovs_tun->tun_dst->u.tun_info;
>
> -               start = nla_nest_start(skb, OVS_ACTION_ATTR_SET);
> +               start = nla_nest_start_noflag(skb, OVS_ACTION_ATTR_SET);
>                 if (!start)
>                         return -EMSGSIZE;
>
> @@ -3400,7 +3401,7 @@ static int masked_set_action_to_set_action_attr(const struct nlattr *a,
>         /* Revert the conversion we did from a non-masked set action to
>          * masked set action.
>          */
> -       nla = nla_nest_start(skb, OVS_ACTION_ATTR_SET);
> +       nla = nla_nest_start_noflag(skb, OVS_ACTION_ATTR_SET);
>         if (!nla)
>                 return -EMSGSIZE;
>
> diff --git a/datapath/linux/compat/include/net/netlink.h b/datapath/linux/compat/include/net/netlink.h
> index d42bf108b417..34fc3460dc81 100644
> --- a/datapath/linux/compat/include/net/netlink.h
> +++ b/datapath/linux/compat/include/net/netlink.h
> @@ -165,4 +165,13 @@ static inline int rpl_nla_parse(struct nlattr **tb, int maxtype,
>  #define nla_parse rpl_nla_parse
>  #endif
>
> +#ifndef HAVE_NLA_NEST_START_NOFLAG
> +static inline struct nlattr *rpl_nla_nest_start_noflag(struct sk_buff *skb,
> +                                                      int attrtype)
> +{
> +       return nla_nest_start(skb, attrtype);
> +}
> +#define nla_nest_start_noflag rpl_nla_nest_start_noflag
> +#endif
> +
>  #endif /* net/netlink.h */
> diff --git a/datapath/meter.c b/datapath/meter.c
> index eda14682fb96..b0a92891c7c0 100644
> --- a/datapath/meter.c
> +++ b/datapath/meter.c
> @@ -129,7 +129,7 @@ static int ovs_meter_cmd_reply_stats(struct sk_buff *reply, u32 meter_id,
>                               OVS_METER_ATTR_PAD))
>                 goto error;
>
> -       nla = nla_nest_start(reply, OVS_METER_ATTR_BANDS);
> +       nla = nla_nest_start_noflag(reply, OVS_METER_ATTR_BANDS);
>         if (!nla)
>                 goto error;
>
> @@ -138,7 +138,7 @@ static int ovs_meter_cmd_reply_stats(struct sk_buff *reply, u32 meter_id,
>         for (i = 0; i < meter->n_bands; ++i, ++band) {
>                 struct nlattr *band_nla;
>
> -               band_nla = nla_nest_start(reply, OVS_BAND_ATTR_UNSPEC);
> +               band_nla = nla_nest_start_noflag(reply, OVS_BAND_ATTR_UNSPEC);
>                 if (!band_nla || nla_put(reply, OVS_BAND_ATTR_STATS,
>                                          sizeof(struct ovs_flow_stats),
>                                          &band->stats))
> @@ -168,11 +168,11 @@ static int ovs_meter_cmd_features(struct sk_buff *skb, struct genl_info *info)
>             nla_put_u32(reply, OVS_METER_ATTR_MAX_BANDS, DP_MAX_BANDS))
>                 goto nla_put_failure;
>
> -       nla = nla_nest_start(reply, OVS_METER_ATTR_BANDS);
> +       nla = nla_nest_start_noflag(reply, OVS_METER_ATTR_BANDS);
>         if (!nla)
>                 goto nla_put_failure;
>
> -       band_nla = nla_nest_start(reply, OVS_BAND_ATTR_UNSPEC);
> +       band_nla = nla_nest_start_noflag(reply, OVS_BAND_ATTR_UNSPEC);
>         if (!band_nla)
>                 goto nla_put_failure;
>         /* Currently only DROP band type is supported. */
> diff --git a/datapath/vport-vxlan.c b/datapath/vport-vxlan.c
> index 05764467a687..70ed376e3869 100644
> --- a/datapath/vport-vxlan.c
> +++ b/datapath/vport-vxlan.c
> @@ -47,7 +47,7 @@ static int vxlan_get_options(const struct vport *vport, struct sk_buff *skb)
>  #endif
>                 struct nlattr *exts;
>
> -               exts = nla_nest_start(skb, OVS_TUNNEL_ATTR_EXTENSION);
> +               exts = nla_nest_start_noflag(skb, OVS_TUNNEL_ATTR_EXTENSION);
>                 if (!exts)
>                         return -EMSGSIZE;
>
> diff --git a/datapath/vport.c b/datapath/vport.c
> index ed7f23ec8933..f929282dcec1 100644
> --- a/datapath/vport.c
> +++ b/datapath/vport.c
> @@ -408,7 +408,7 @@ int ovs_vport_get_options(const struct vport *vport, struct sk_buff *skb)
>         if (!vport->ops->get_options)
>                 return 0;
>
> -       nla = nla_nest_start(skb, OVS_VPORT_ATTR_OPTIONS);
> +       nla = nla_nest_start_noflag(skb, OVS_VPORT_ATTR_OPTIONS);
>         if (!nla)
>                 return -EMSGSIZE;
>
> --
> 2.7.4
>
> _______________________________________________
> dev mailing list
> dev@openvswitch.org
> https://mail.openvswitch.org/mailman/listinfo/ovs-dev

Patch
diff mbox series

diff --git a/acinclude.m4 b/acinclude.m4
index dca09abefa96..fe121ab9126d 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -844,6 +844,7 @@  AC_DEFUN([OVS_CHECK_LINUX_COMPAT], [
   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_put_in_addr])
   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_find_nested])
   OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_is_last])
+  OVS_GREP_IFELSE([$KSRC/include/net/netlink.h], [nla_nest_start_noflag])
   OVS_GREP_IFELSE([$KSRC/include/linux/netlink.h], [void.*netlink_set_err],
                   [OVS_DEFINE([HAVE_VOID_NETLINK_SET_ERR])])
   OVS_FIND_PARAM_IFELSE([$KSRC/include/net/netlink.h],
diff --git a/datapath/conntrack.c b/datapath/conntrack.c
index 010f9af5ffd2..b11a30965147 100644
--- a/datapath/conntrack.c
+++ b/datapath/conntrack.c
@@ -1776,7 +1776,7 @@  static bool ovs_ct_nat_to_attr(const struct ovs_conntrack_info *info,
 {
 	struct nlattr *start;
 
-	start = nla_nest_start(skb, OVS_CT_ATTR_NAT);
+	start = nla_nest_start_noflag(skb, OVS_CT_ATTR_NAT);
 	if (!start)
 		return false;
 
@@ -1847,7 +1847,7 @@  int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
 {
 	struct nlattr *start;
 
-	start = nla_nest_start(skb, OVS_ACTION_ATTR_CT);
+	start = nla_nest_start_noflag(skb, OVS_ACTION_ATTR_CT);
 	if (!start)
 		return -EMSGSIZE;
 
@@ -2257,7 +2257,7 @@  static int ovs_ct_limit_cmd_get(struct sk_buff *skb, struct genl_info *info)
 	if (IS_ERR(reply))
 		return PTR_ERR(reply);
 
-	nla_reply = nla_nest_start(reply, OVS_CT_LIMIT_ATTR_ZONE_LIMIT);
+	nla_reply = nla_nest_start_noflag(reply, OVS_CT_LIMIT_ATTR_ZONE_LIMIT);
 
 	if (a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
 		err = ovs_ct_limit_get_zone_limit(
diff --git a/datapath/datapath.c b/datapath/datapath.c
index 94e4f6ffd6e9..78e2e6310529 100644
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -475,7 +475,8 @@  static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb,
 
 
 	if (upcall_info->egress_tun_info) {
-		nla = nla_nest_start(user_skb, OVS_PACKET_ATTR_EGRESS_TUN_KEY);
+		nla = nla_nest_start_noflag(user_skb,
+					    OVS_PACKET_ATTR_EGRESS_TUN_KEY);
 		if (!nla) {
 			err = -EMSGSIZE;
 			goto out;
@@ -487,7 +488,7 @@  static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb,
 	}
 
 	if (upcall_info->actions_len) {
-		nla = nla_nest_start(user_skb, OVS_PACKET_ATTR_ACTIONS);
+		nla = nla_nest_start_noflag(user_skb, OVS_PACKET_ATTR_ACTIONS);
 		if (!nla) {
 			err = -EMSGSIZE;
 			goto out;
@@ -789,7 +790,7 @@  static int ovs_flow_cmd_fill_actions(const struct sw_flow *flow,
 	 * This can only fail for dump operations because the skb is always
 	 * properly sized for single flows.
 	 */
-	start = nla_nest_start(skb, OVS_FLOW_ATTR_ACTIONS);
+	start = nla_nest_start_noflag(skb, OVS_FLOW_ATTR_ACTIONS);
 	if (start) {
 		const struct sw_flow_actions *sf_acts;
 
diff --git a/datapath/flow_netlink.c b/datapath/flow_netlink.c
index 0f7ab53fc141..35f13d753cec 100644
--- a/datapath/flow_netlink.c
+++ b/datapath/flow_netlink.c
@@ -839,7 +839,7 @@  static int vxlan_opt_to_nlattr(struct sk_buff *skb,
 	const struct vxlan_metadata *opts = tun_opts;
 	struct nlattr *nla;
 
-	nla = nla_nest_start(skb, OVS_TUNNEL_KEY_ATTR_VXLAN_OPTS);
+	nla = nla_nest_start_noflag(skb, OVS_TUNNEL_KEY_ATTR_VXLAN_OPTS);
 	if (!nla)
 		return -EMSGSIZE;
 
@@ -926,7 +926,7 @@  static int ip_tun_to_nlattr(struct sk_buff *skb,
 	struct nlattr *nla;
 	int err;
 
-	nla = nla_nest_start(skb, OVS_KEY_ATTR_TUNNEL);
+	nla = nla_nest_start_noflag(skb, OVS_KEY_ATTR_TUNNEL);
 	if (!nla)
 		return -EMSGSIZE;
 
@@ -1934,7 +1934,7 @@  static int nsh_key_to_nlattr(const struct ovs_key_nsh *nsh, bool is_mask,
 {
 	struct nlattr *start;
 
-	start = nla_nest_start(skb, OVS_KEY_ATTR_NSH);
+	start = nla_nest_start_noflag(skb, OVS_KEY_ATTR_NSH);
 	if (!start)
 		return -EMSGSIZE;
 
@@ -2017,14 +2017,15 @@  static int __ovs_nla_put_key(const struct sw_flow_key *swkey,
 		if (swkey->eth.vlan.tci || eth_type_vlan(swkey->eth.type)) {
 			if (ovs_nla_put_vlan(skb, &output->eth.vlan, is_mask))
 				goto nla_put_failure;
-			encap = nla_nest_start(skb, OVS_KEY_ATTR_ENCAP);
+			encap = nla_nest_start_noflag(skb, OVS_KEY_ATTR_ENCAP);
 			if (!swkey->eth.vlan.tci)
 				goto unencap;
 
 			if (swkey->eth.cvlan.tci || eth_type_vlan(swkey->eth.type)) {
 				if (ovs_nla_put_vlan(skb, &output->eth.cvlan, is_mask))
 					goto nla_put_failure;
-				in_encap = nla_nest_start(skb, OVS_KEY_ATTR_ENCAP);
+				in_encap = nla_nest_start_noflag(skb,
+								 OVS_KEY_ATTR_ENCAP);
 				if (!swkey->eth.cvlan.tci)
 					goto unencap;
 			}
@@ -2203,7 +2204,7 @@  int ovs_nla_put_key(const struct sw_flow_key *swkey,
 	int err;
 	struct nlattr *nla;
 
-	nla = nla_nest_start(skb, attr);
+	nla = nla_nest_start_noflag(skb, attr);
 	if (!nla)
 		return -EMSGSIZE;
 	err = __ovs_nla_put_key(swkey, output, is_mask, skb);
@@ -3234,7 +3235,7 @@  static int sample_action_to_attr(const struct nlattr *attr,
 	const struct sample_arg *arg;
 	struct nlattr *actions;
 
-	start = nla_nest_start(skb, OVS_ACTION_ATTR_SAMPLE);
+	start = nla_nest_start_noflag(skb, OVS_ACTION_ATTR_SAMPLE);
 	if (!start)
 		return -EMSGSIZE;
 
@@ -3247,7 +3248,7 @@  static int sample_action_to_attr(const struct nlattr *attr,
 		goto out;
 	}
 
-	ac_start = nla_nest_start(skb, OVS_SAMPLE_ATTR_ACTIONS);
+	ac_start = nla_nest_start_noflag(skb, OVS_SAMPLE_ATTR_ACTIONS);
 	if (!ac_start) {
 		err = -EMSGSIZE;
 		goto out;
@@ -3273,7 +3274,7 @@  static int clone_action_to_attr(const struct nlattr *attr,
 	struct nlattr *start;
 	int err = 0, rem = nla_len(attr);
 
-	start = nla_nest_start(skb, OVS_ACTION_ATTR_CLONE);
+	start = nla_nest_start_noflag(skb, OVS_ACTION_ATTR_CLONE);
 	if (!start)
 		return -EMSGSIZE;
 
@@ -3295,7 +3296,7 @@  static int check_pkt_len_action_to_attr(const struct nlattr *attr,
 	const struct nlattr *a, *cpl_arg;
 	int err = 0, rem = nla_len(attr);
 
-	start = nla_nest_start(skb, OVS_ACTION_ATTR_CHECK_PKT_LEN);
+	start = nla_nest_start_noflag(skb, OVS_ACTION_ATTR_CHECK_PKT_LEN);
 	if (!start)
 		return -EMSGSIZE;
 
@@ -3314,8 +3315,8 @@  static int check_pkt_len_action_to_attr(const struct nlattr *attr,
 	 * 'OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_LESS_EQUAL'.
 	 */
 	a = nla_next(cpl_arg, &rem);
-	ac_start =  nla_nest_start(skb,
-		OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_LESS_EQUAL);
+	ac_start =  nla_nest_start_noflag(skb,
+					  OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_LESS_EQUAL);
 	if (!ac_start) {
 		err = -EMSGSIZE;
 		goto out;
@@ -3333,8 +3334,8 @@  static int check_pkt_len_action_to_attr(const struct nlattr *attr,
 	 * OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_GREATER.
 	 */
 	a = nla_next(a, &rem);
-	ac_start =  nla_nest_start(skb,
-				   OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_GREATER);
+	ac_start =  nla_nest_start_noflag(skb,
+					  OVS_CHECK_PKT_LEN_ATTR_ACTIONS_IF_GREATER);
 	if (!ac_start) {
 		err = -EMSGSIZE;
 		goto out;
@@ -3368,7 +3369,7 @@  static int set_action_to_attr(const struct nlattr *a, struct sk_buff *skb)
 		struct ovs_tunnel_info *ovs_tun = nla_data(ovs_key);
 		struct ip_tunnel_info *tun_info = &ovs_tun->tun_dst->u.tun_info;
 
-		start = nla_nest_start(skb, OVS_ACTION_ATTR_SET);
+		start = nla_nest_start_noflag(skb, OVS_ACTION_ATTR_SET);
 		if (!start)
 			return -EMSGSIZE;
 
@@ -3400,7 +3401,7 @@  static int masked_set_action_to_set_action_attr(const struct nlattr *a,
 	/* Revert the conversion we did from a non-masked set action to
 	 * masked set action.
 	 */
-	nla = nla_nest_start(skb, OVS_ACTION_ATTR_SET);
+	nla = nla_nest_start_noflag(skb, OVS_ACTION_ATTR_SET);
 	if (!nla)
 		return -EMSGSIZE;
 
diff --git a/datapath/linux/compat/include/net/netlink.h b/datapath/linux/compat/include/net/netlink.h
index d42bf108b417..34fc3460dc81 100644
--- a/datapath/linux/compat/include/net/netlink.h
+++ b/datapath/linux/compat/include/net/netlink.h
@@ -165,4 +165,13 @@  static inline int rpl_nla_parse(struct nlattr **tb, int maxtype,
 #define nla_parse rpl_nla_parse
 #endif
 
+#ifndef HAVE_NLA_NEST_START_NOFLAG
+static inline struct nlattr *rpl_nla_nest_start_noflag(struct sk_buff *skb,
+						       int attrtype)
+{
+	return nla_nest_start(skb, attrtype);
+}
+#define nla_nest_start_noflag rpl_nla_nest_start_noflag
+#endif
+
 #endif /* net/netlink.h */
diff --git a/datapath/meter.c b/datapath/meter.c
index eda14682fb96..b0a92891c7c0 100644
--- a/datapath/meter.c
+++ b/datapath/meter.c
@@ -129,7 +129,7 @@  static int ovs_meter_cmd_reply_stats(struct sk_buff *reply, u32 meter_id,
 			      OVS_METER_ATTR_PAD))
 		goto error;
 
-	nla = nla_nest_start(reply, OVS_METER_ATTR_BANDS);
+	nla = nla_nest_start_noflag(reply, OVS_METER_ATTR_BANDS);
 	if (!nla)
 		goto error;
 
@@ -138,7 +138,7 @@  static int ovs_meter_cmd_reply_stats(struct sk_buff *reply, u32 meter_id,
 	for (i = 0; i < meter->n_bands; ++i, ++band) {
 		struct nlattr *band_nla;
 
-		band_nla = nla_nest_start(reply, OVS_BAND_ATTR_UNSPEC);
+		band_nla = nla_nest_start_noflag(reply, OVS_BAND_ATTR_UNSPEC);
 		if (!band_nla || nla_put(reply, OVS_BAND_ATTR_STATS,
 					 sizeof(struct ovs_flow_stats),
 					 &band->stats))
@@ -168,11 +168,11 @@  static int ovs_meter_cmd_features(struct sk_buff *skb, struct genl_info *info)
 	    nla_put_u32(reply, OVS_METER_ATTR_MAX_BANDS, DP_MAX_BANDS))
 		goto nla_put_failure;
 
-	nla = nla_nest_start(reply, OVS_METER_ATTR_BANDS);
+	nla = nla_nest_start_noflag(reply, OVS_METER_ATTR_BANDS);
 	if (!nla)
 		goto nla_put_failure;
 
-	band_nla = nla_nest_start(reply, OVS_BAND_ATTR_UNSPEC);
+	band_nla = nla_nest_start_noflag(reply, OVS_BAND_ATTR_UNSPEC);
 	if (!band_nla)
 		goto nla_put_failure;
 	/* Currently only DROP band type is supported. */
diff --git a/datapath/vport-vxlan.c b/datapath/vport-vxlan.c
index 05764467a687..70ed376e3869 100644
--- a/datapath/vport-vxlan.c
+++ b/datapath/vport-vxlan.c
@@ -47,7 +47,7 @@  static int vxlan_get_options(const struct vport *vport, struct sk_buff *skb)
 #endif
 		struct nlattr *exts;
 
-		exts = nla_nest_start(skb, OVS_TUNNEL_ATTR_EXTENSION);
+		exts = nla_nest_start_noflag(skb, OVS_TUNNEL_ATTR_EXTENSION);
 		if (!exts)
 			return -EMSGSIZE;
 
diff --git a/datapath/vport.c b/datapath/vport.c
index ed7f23ec8933..f929282dcec1 100644
--- a/datapath/vport.c
+++ b/datapath/vport.c
@@ -408,7 +408,7 @@  int ovs_vport_get_options(const struct vport *vport, struct sk_buff *skb)
 	if (!vport->ops->get_options)
 		return 0;
 
-	nla = nla_nest_start(skb, OVS_VPORT_ATTR_OPTIONS);
+	nla = nla_nest_start_noflag(skb, OVS_VPORT_ATTR_OPTIONS);
 	if (!nla)
 		return -EMSGSIZE;