[PATCH net-next] net: add extack arg for link ops

From: Rocco Yue
Date: Tue Aug 03 2021 - 08:19:26 EST


Pass extack arg to validate_linkmsg and validate_link_af callbacks.
If a netlink attribute has a reject_message, use the extended ack
mechanism to carry the message back to user space.

Signed-off-by: Rocco Yue <rocco.yue@xxxxxxxxxxxx>
---
include/net/rtnetlink.h | 3 ++-
net/core/rtnetlink.c | 9 +++++----
net/ipv4/devinet.c | 5 +++--
net/ipv6/addrconf.c | 5 +++--
4 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h
index 384e800665f2..9f48733bfd21 100644
--- a/include/net/rtnetlink.h
+++ b/include/net/rtnetlink.h
@@ -153,7 +153,8 @@ struct rtnl_af_ops {
u32 ext_filter_mask);

int (*validate_link_af)(const struct net_device *dev,
- const struct nlattr *attr);
+ const struct nlattr *attr,
+ struct netlink_ext_ack *extack);
int (*set_link_af)(struct net_device *dev,
const struct nlattr *attr,
struct netlink_ext_ack *extack);
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index f6af3e74fc44..8c78715338b0 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -2268,7 +2268,8 @@ static int rtnl_ensure_unique_netns(struct nlattr *tb[],
return -EINVAL;
}

-static int validate_linkmsg(struct net_device *dev, struct nlattr *tb[])
+static int validate_linkmsg(struct net_device *dev, struct nlattr *tb[],
+ struct netlink_ext_ack *extack)
{
if (dev) {
if (tb[IFLA_ADDRESS] &&
@@ -2295,7 +2296,7 @@ static int validate_linkmsg(struct net_device *dev, struct nlattr *tb[])
return -EOPNOTSUPP;

if (af_ops->validate_link_af) {
- err = af_ops->validate_link_af(dev, af);
+ err = af_ops->validate_link_af(dev, af, extack);
if (err < 0)
return err;
}
@@ -2603,7 +2604,7 @@ static int do_setlink(const struct sk_buff *skb,
const struct net_device_ops *ops = dev->netdev_ops;
int err;

- err = validate_linkmsg(dev, tb);
+ err = validate_linkmsg(dev, tb, extack);
if (err < 0)
return err;

@@ -3301,7 +3302,7 @@ static int __rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh,
m_ops = master_dev->rtnl_link_ops;
}

- err = validate_linkmsg(dev, tb);
+ err = validate_linkmsg(dev, tb, extack);
if (err < 0)
return err;

diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 73721a4448bd..26856064096a 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1950,7 +1950,8 @@ static const struct nla_policy inet_af_policy[IFLA_INET_MAX+1] = {
};

static int inet_validate_link_af(const struct net_device *dev,
- const struct nlattr *nla)
+ const struct nlattr *nla,
+ struct netlink_ext_ack *extack)
{
struct nlattr *a, *tb[IFLA_INET_MAX+1];
int err, rem;
@@ -1959,7 +1960,7 @@ static int inet_validate_link_af(const struct net_device *dev,
return -EAFNOSUPPORT;

err = nla_parse_nested_deprecated(tb, IFLA_INET_MAX, nla,
- inet_af_policy, NULL);
+ inet_af_policy, extack);
if (err < 0)
return err;

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 3bf685fe64b9..59792779551e 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -5784,7 +5784,8 @@ static int check_stable_privacy(struct inet6_dev *idev, struct net *net,
}

static int inet6_validate_link_af(const struct net_device *dev,
- const struct nlattr *nla)
+ const struct nlattr *nla,
+ struct netlink_ext_ack *extack)
{
struct nlattr *tb[IFLA_INET6_MAX + 1];
struct inet6_dev *idev = NULL;
@@ -5797,7 +5798,7 @@ static int inet6_validate_link_af(const struct net_device *dev,
}

err = nla_parse_nested_deprecated(tb, IFLA_INET6_MAX, nla,
- inet6_af_policy, NULL);
+ inet6_af_policy, extack);
if (err)
return err;

--
2.18.0