Re: [PATCH net-next 10/13] bridge: mrp: Implement netlink interface to configure MRP

[Horatiu Vultur <horatiu.vultur@microchip.com>]

The 04/21/2020 11:47, Nikolay Aleksandrov wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> 
> On 20/04/2020 18:09, Horatiu Vultur wrote:
> > Implement netlink interface to configure MRP. The implementation
> > will do sanity checks over the attributes and then eventually call the MRP
> > interface.
> >
> > Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
> > ---
> >  net/bridge/br_mrp_netlink.c | 117 ++++++++++++++++++++++++++++++++++++
> >  1 file changed, 117 insertions(+)
> >  create mode 100644 net/bridge/br_mrp_netlink.c
> >
> > diff --git a/net/bridge/br_mrp_netlink.c b/net/bridge/br_mrp_netlink.c
> > new file mode 100644
> > index 000000000000..0ff42e7c7f57
> > --- /dev/null
> > +++ b/net/bridge/br_mrp_netlink.c
> > @@ -0,0 +1,117 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +
> > +#include <net/genetlink.h>
> > +
> > +#include <uapi/linux/mrp_bridge.h>
> > +#include "br_private.h"
> > +#include "br_private_mrp.h"
> > +
> > +static const struct nla_policy br_mrp_policy[IFLA_BRIDGE_MRP_MAX + 1] = {
> > +     [IFLA_BRIDGE_MRP_UNSPEC]        = { .type = NLA_REJECT },
> > +     [IFLA_BRIDGE_MRP_INSTANCE]      = { .type = NLA_EXACT_LEN,
> > +                                         .len = sizeof(struct br_mrp_instance)},
> > +     [IFLA_BRIDGE_MRP_PORT_STATE]    = { .type = NLA_U32 },
> > +     [IFLA_BRIDGE_MRP_PORT_ROLE]     = { .type = NLA_EXACT_LEN,
> > +                                         .len = sizeof(struct br_mrp_port_role)},
> > +     [IFLA_BRIDGE_MRP_RING_STATE]    = { .type = NLA_EXACT_LEN,
> > +                                         .len = sizeof(struct br_mrp_ring_state)},
> > +     [IFLA_BRIDGE_MRP_RING_ROLE]     = { .type = NLA_EXACT_LEN,
> > +                                         .len = sizeof(struct br_mrp_ring_role)},
> > +     [IFLA_BRIDGE_MRP_START_TEST]    = { .type = NLA_EXACT_LEN,
> > +                                         .len = sizeof(struct br_mrp_start_test)},
> > +};
> > +
> > +int br_mrp_parse(struct net_bridge *br, struct net_bridge_port *p,
> > +              struct nlattr *attr, int cmd, struct netlink_ext_ack *extack)
> > +{
> 
> Note that "p" can be NULL here if br_afspec() was called for the bridge device.
> Some of the functions below dereference it without any checks and will deref a
> null ptr.

Good check, I will update the functions br_mrp_set_port_role and
br_mrp_set_port_state to check for the null ptr.

> 
> > +     struct nlattr *tb[IFLA_BRIDGE_MRP_MAX + 1];
> > +     int err;
> > +
> > +     if (br->stp_enabled != BR_NO_STP) {
> > +             NL_SET_ERR_MSG_MOD(extack, "MRP can't be enabled if STP is already enabled\n");
> > +             return -EINVAL;
> > +     }
> > +
> > +     err = nla_parse_nested(tb, IFLA_BRIDGE_MRP_MAX, attr,
> > +                            NULL, extack);
> > +     if (err)
> > +             return err;
> > +
> > +     if (tb[IFLA_BRIDGE_MRP_INSTANCE]) {
> > +             struct br_mrp_instance *instance =
> > +                     nla_data(tb[IFLA_BRIDGE_MRP_INSTANCE]);
> > +
> > +             if (cmd == RTM_SETLINK)
> > +                     err = br_mrp_add(br, instance);
> > +             else
> > +                     err = br_mrp_del(br, instance);
> > +             if (err)
> > +                     return err;
> > +     }
> > +
> > +     if (tb[IFLA_BRIDGE_MRP_PORT_STATE]) {
> > +             enum br_mrp_port_state_type state =
> > +                     nla_get_u32(tb[IFLA_BRIDGE_MRP_PORT_STATE]);
> > +
> > +             err = br_mrp_set_port_state(p, state);
> > +             if (err)
> > +                     return err;
> > +     }
> > +
> > +     if (tb[IFLA_BRIDGE_MRP_PORT_ROLE]) {
> > +             struct br_mrp_port_role *role =
> > +                     nla_data(tb[IFLA_BRIDGE_MRP_PORT_ROLE]);
> > +
> > +             err = br_mrp_set_port_role(p, role);
> > +             if (err)
> > +                     return err;
> > +     }
> > +
> > +     if (tb[IFLA_BRIDGE_MRP_RING_STATE]) {
> > +             struct br_mrp_ring_state *state =
> > +                     nla_data(tb[IFLA_BRIDGE_MRP_RING_STATE]);
> > +
> > +             err = br_mrp_set_ring_state(br, state);
> > +             if (err)
> > +                     return err;
> > +     }
> > +
> > +     if (tb[IFLA_BRIDGE_MRP_RING_ROLE]) {
> > +             struct br_mrp_ring_role *role =
> > +                     nla_data(tb[IFLA_BRIDGE_MRP_RING_ROLE]);
> > +
> > +             err = br_mrp_set_ring_role(br, role);
> > +             if (err)
> > +                     return err;
> > +     }
> > +
> > +     if (tb[IFLA_BRIDGE_MRP_START_TEST]) {
> > +             struct br_mrp_start_test *test =
> > +                     nla_data(tb[IFLA_BRIDGE_MRP_START_TEST]);
> > +
> > +             err = br_mrp_start_test(br, test);
> > +             if (err)
> > +                     return err;
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +int br_mrp_port_open(struct net_device *dev, u8 loc)
> > +{
> > +     struct net_bridge_port *p;
> > +     int err = 0;
> > +
> > +     p = br_port_get_rcu(dev);
> > +     if (!p) {
> > +             err = -EINVAL;
> > +             goto out;
> > +     }
> > +
> > +     p->loc = loc;
> > +     br_ifinfo_notify(RTM_NEWLINK, NULL, p);
> > +
> > +out:
> > +     return err;
> > +}
> > +EXPORT_SYMBOL(br_mrp_port_open);
> >
> 

-- 
/Horatiu