Johannes Nixdorf
2023-Sep-21 07:23 UTC
[Bridge] [PATCH net-next v4 2/6] net: bridge: Set strict_start_type for br_policy
On Wed, Sep 20, 2023 at 01:46:02PM +0300, Nikolay Aleksandrov wrote:> On 9/19/23 11:12, Johannes Nixdorf wrote: > > Set any new attributes added to br_policy to be parsed strictly, to > > prevent userspace from passing garbage. > > > > Signed-off-by: Johannes Nixdorf <jnixdorf-oss at avm.de> > > --- > > net/bridge/br_netlink.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c > > index 10f0d33d8ccf..505683ef9a26 100644 > > --- a/net/bridge/br_netlink.c > > +++ b/net/bridge/br_netlink.c > > @@ -1229,6 +1229,8 @@ static size_t br_port_get_slave_size(const struct net_device *brdev, > > } > > static const struct nla_policy br_policy[IFLA_BR_MAX + 1] = { > > + [IFLA_BR_UNSPEC] = { .strict_start_type > > + IFLA_BR_MCAST_QUERIER_STATE + 1 }, > > [IFLA_BR_FORWARD_DELAY] = { .type = NLA_U32 }, > > [IFLA_BR_HELLO_TIME] = { .type = NLA_U32 }, > > [IFLA_BR_MAX_AGE] = { .type = NLA_U32 }, > > > > instead of IFLA_BR_MCAST_QUERIER_STATE + 1, why not move around the patch > and just use the new attribute name? > These are uapi, they won't change.I wanted to avoid having a state between the two commits where the new attributes are already added, but not yet strictly verified. Otherwise they would present a slightly different UAPI at that one commit boundary than after this commit. This is also not the only place in the kernel where strict_start_type is specified that way. See e.g. commit c00041cf1cb8 ("net: bridge: Set strict_start_type at two policies"), even though that seems mostly be done to turn on strict_start_type preemtively, not in the same series that adds the new attribute.
Nikolay Aleksandrov
2023-Sep-21 10:14 UTC
[Bridge] [PATCH net-next v4 2/6] net: bridge: Set strict_start_type for br_policy
On 9/21/23 10:23, Johannes Nixdorf wrote:> On Wed, Sep 20, 2023 at 01:46:02PM +0300, Nikolay Aleksandrov wrote: >> On 9/19/23 11:12, Johannes Nixdorf wrote: >>> Set any new attributes added to br_policy to be parsed strictly, to >>> prevent userspace from passing garbage. >>> >>> Signed-off-by: Johannes Nixdorf <jnixdorf-oss at avm.de> >>> --- >>> net/bridge/br_netlink.c | 2 ++ >>> 1 file changed, 2 insertions(+) >>> >>> diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c >>> index 10f0d33d8ccf..505683ef9a26 100644 >>> --- a/net/bridge/br_netlink.c >>> +++ b/net/bridge/br_netlink.c >>> @@ -1229,6 +1229,8 @@ static size_t br_port_get_slave_size(const struct net_device *brdev, >>> } >>> static const struct nla_policy br_policy[IFLA_BR_MAX + 1] = { >>> + [IFLA_BR_UNSPEC] = { .strict_start_type >>> + IFLA_BR_MCAST_QUERIER_STATE + 1 }, >>> [IFLA_BR_FORWARD_DELAY] = { .type = NLA_U32 }, >>> [IFLA_BR_HELLO_TIME] = { .type = NLA_U32 }, >>> [IFLA_BR_MAX_AGE] = { .type = NLA_U32 }, >>> >> >> instead of IFLA_BR_MCAST_QUERIER_STATE + 1, why not move around the patch >> and just use the new attribute name? >> These are uapi, they won't change. > > I wanted to avoid having a state between the two commits where the new > attributes are already added, but not yet strictly verified. Otherwise > they would present a slightly different UAPI at that one commit boundary > than after this commit. >That's not really a problem, the attribute is the same.> This is also not the only place in the kernel where strict_start_type > is specified that way. See e.g. commit c00041cf1cb8 ("net: bridge: Set > strict_start_type at two policies"), even though that seems mostly be > done to turn on strict_start_type preemtively, not in the same series > that adds the new attribute.Please, just use the new attribute to be more explicit where the strict parsing starts. Thanks, Nik