Re: [RFC net-next v4 4/9] bridge: mrp: Implement netlink interface to configure MRP

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

The 03/30/2020 18:30, Nikolay Aleksandrov wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> 
> On 27/03/2020 11:21, 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 | 176 ++++++++++++++++++++++++++++++++++++
> >  1 file changed, 176 insertions(+)
> >  create mode 100644 net/bridge/br_mrp_netlink.c
> >
> 
> Hi Horatiu,

Hi Nik,

Thanks for the feedback, I will update all this in the new patch series.

> 
> > diff --git a/net/bridge/br_mrp_netlink.c b/net/bridge/br_mrp_netlink.c
> > new file mode 100644
> > index 000000000000..043b7f6cddbe
> > --- /dev/null
> > +++ b/net/bridge/br_mrp_netlink.c
> > @@ -0,0 +1,176 @@
> > +// 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 int br_mrp_parse_instance(struct net_bridge *br, struct nlattr *attr,
> > +                              int cmd)
> > +{
> > +     struct br_mrp_instance *instance;
> > +
> > +     if (nla_len(attr) != sizeof(*instance))
> > +             return -EINVAL;
> > +
> > +     instance = nla_data(attr);
> > +
> > +     if (cmd == RTM_SETLINK)
> > +             return br_mrp_add(br, instance);
> > +     else
> > +             return br_mrp_del(br, instance);
> > +}
> > +
> > +static int br_mrp_parse_port_state(struct net_bridge *br,
> > +                                struct net_bridge_port *p,
> > +                                struct nlattr *attr)
> > +{
> > +     enum br_mrp_port_state_type state;
> > +
> > +     if (nla_len(attr) != sizeof(u32) || !p)
> > +             return -EINVAL;
> > +
> > +     state = nla_get_u32(attr);
> > +
> > +     return br_mrp_set_port_state(p, state);
> > +}
> > +
> > +static int br_mrp_parse_port_role(struct net_bridge *br,
> > +                               struct net_bridge_port *p,
> > +                               struct nlattr *attr)
> > +{
> > +     struct br_mrp_port_role *role;
> > +
> > +     if (nla_len(attr) != sizeof(*role) || !p)
> > +             return -EINVAL;
> > +
> > +     role = nla_data(attr);
> > +
> > +     return br_mrp_set_port_role(p, role->ring_id, role->role);
> > +}
> > +
> > +static int br_mrp_parse_ring_state(struct net_bridge *br, struct nlattr *attr)
> > +{
> > +     struct br_mrp_ring_state *state;
> > +
> > +     if (nla_len(attr) != sizeof(*state))
> > +             return -EINVAL;
> > +
> > +     state = nla_data(attr);
> > +
> > +     return br_mrp_set_ring_state(br, state->ring_id, state->ring_state);
> > +}
> > +
> > +static int br_mrp_parse_ring_role(struct net_bridge *br, struct nlattr *attr)
> > +{
> > +     struct br_mrp_ring_role *role;
> > +
> > +     if (nla_len(attr) != sizeof(*role))
> > +             return -EINVAL;
> > +
> > +     role = nla_data(attr);
> > +
> > +     return br_mrp_set_ring_role(br, role->ring_id, role->ring_role);
> > +}
> > +
> > +static int br_mrp_parse_start_test(struct net_bridge *br, struct nlattr *attr)
> > +{
> > +     struct br_mrp_start_test *test;
> > +
> > +     if (nla_len(attr) != sizeof(*test))
> > +             return -EINVAL;
> > +
> > +     test = nla_data(attr);
> > +
> > +     return br_mrp_start_test(br, test->ring_id, test->interval,
> > +                              test->max_miss, test->period);
> > +}
> > +
> > +int br_mrp_parse(struct net_bridge *br, struct net_bridge_port *p,
> > +              struct nlattr *attr, int cmd)
> > +{
> > +     struct nlattr *mrp;
> > +     int rem, err;
> > +
> > +     nla_for_each_nested(mrp, attr, rem) {
> > +             err = 0;
> > +             switch (nla_type(mrp)) {
> > +             case IFLA_BRIDGE_MRP_INSTANCE:
> > +                     err = br_mrp_parse_instance(br, mrp, cmd);
> > +                     if (err)
> > +                             return err;
> > +                     break;
> > +             case IFLA_BRIDGE_MRP_PORT_STATE:
> > +                     err = br_mrp_parse_port_state(br, p, mrp);
> > +                     if (err)
> > +                             return err;
> > +                     break;
> > +             case IFLA_BRIDGE_MRP_PORT_ROLE:
> > +                     err = br_mrp_parse_port_role(br, p, mrp);
> > +                     if (err)
> > +                             return err;
> > +                     break;
> > +             case IFLA_BRIDGE_MRP_RING_STATE:
> > +                     err = br_mrp_parse_ring_state(br, mrp);
> > +                     if (err)
> > +                             return err;
> > +                     break;
> > +             case IFLA_BRIDGE_MRP_RING_ROLE:
> > +                     err = br_mrp_parse_ring_role(br, mrp);
> > +                     if (err)
> > +                             return err;
> > +                     break;
> > +             case IFLA_BRIDGE_MRP_START_TEST:
> > +                     err = br_mrp_parse_start_test(br, mrp);
> > +                     if (err)
> > +                             return err;
> > +                     break;
> > +             }
> > +     }
> > +
> > +     return 0;
> > +}
> 
> All of the above can be implemented via nla_parse_nested() with a proper policy.
> You don't have to manually check for the attribute size. Then your code follows
> the netlink normal (e.g. check the bridge netlink handling) of:
>  nla_parse_nested(tb)
>  if (tb[attr])
>     do_something_with(tb[attr])
>  ...
> 
> 
> > +
> > +void br_mrp_port_open(struct net_device *dev, u8 loc)
> > +{
> > +     struct nlattr *af, *mrp;
> > +     struct ifinfomsg *hdr;
> > +     struct nlmsghdr *nlh;
> > +     struct sk_buff *skb;
> > +     int err = -ENOBUFS;
> > +     struct net *net;
> > +
> > +     net = dev_net(dev);
> > +
> > +     skb = nlmsg_new(1024, GFP_ATOMIC);
> 
> Please add a function which calculates the size based on the attribute sizes.
> 
> > +     if (!skb)
> > +             goto errout;
> > +
> > +     nlh = nlmsg_put(skb, 0, 0, RTM_NEWLINK, sizeof(*hdr), 0);
> > +     if (!nlh)
> > +             goto errout;
> > +
> > +     hdr = nlmsg_data(nlh);
> > +     hdr->ifi_family = AF_BRIDGE;
> > +     hdr->__ifi_pad = 0;
> > +     hdr->ifi_type = dev->type;
> > +     hdr->ifi_index = dev->ifindex;
> > +     hdr->ifi_flags = dev_get_flags(dev);
> > +     hdr->ifi_change = 0;
> > +
> > +     af = nla_nest_start_noflag(skb, IFLA_AF_SPEC);
> > +     mrp = nla_nest_start_noflag(skb, IFLA_BRIDGE_MRP);
> > +
> 
> These can return an error which has to be handled.
> 
> > +     nla_put_u32(skb, IFLA_BRIDGE_MRP_RING_OPEN, loc);
> > +
> 
> Same for this.
> 
> > +     nla_nest_end(skb, mrp);
> > +     nla_nest_end(skb, af);
> > +     nlmsg_end(skb, nlh);
> > +
> > +     rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, GFP_ATOMIC);
> > +     return;
> > +errout:
> > +     rtnl_set_sk_err(net, RTNLGRP_LINK, err);
> > +}
> > +EXPORT_SYMBOL(br_mrp_port_open);
> >
> 

-- 
/Horatiu