Re: [RFC net-next v5 8/9] bridge: mrp: Implement netlink interface to configure MRP

[Horatiu Vultur]

The 04/18/2020 11:34, Nikolay Aleksandrov wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> 
> On 14/04/2020 14:26, 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@xxxxxxxxxxxxx>
> > ---
> >  net/bridge/br_mrp_netlink.c | 164 ++++++++++++++++++++++++++++++++++++
> >  1 file changed, 164 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..0d8253311595
> > --- /dev/null
> > +++ b/net/bridge/br_mrp_netlink.c
> > @@ -0,0 +1,164 @@
> > +// 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)
> > +{
> > +     struct nlattr *tb[IFLA_BRIDGE_MRP_MAX + 1];
> > +     int err;
> > +
> > +     if (br->stp_enabled != BR_NO_STP) {
> > +             br_warn(br, "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);
> 
> This can be executed for any port, just noting it.

Yes, maybe I should add an extra check in the function
br_mrp_set_port_state, similar to the function br_mrp_set_port_role, to
allow to be executed only on MRP_AWARE ports.

> 
> > +             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);
> 
> This can be executed for any port also, shouldn't it be available only for MRP_AWARE ports?

Yes, it can be executed for any port, but it would return an error if
the port is not MRP_AWARE. Because the function br_mrp_set_port_role
will check if the port is part of a ring and if it not then return
-EINVAL.

> 
> > +             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;
> > +}
> > +
> > +static inline size_t br_mrp_nlmsg_size(void)
> > +{
> > +     return NLMSG_ALIGN(sizeof(struct ifinfomsg))
> > +             + nla_total_size(4); /* IFLA_BRIDGE_MRP_RING_OPEN */
> > +}
> > +
> > +int 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(br_mrp_nlmsg_size(), GFP_ATOMIC);
> > +     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);
> > +     if (!af) {
> > +             err = -EMSGSIZE;
> > +             goto nla_put_failure;
> > +     }
> > +
> > +     mrp = nla_nest_start_noflag(skb, IFLA_BRIDGE_MRP);
> > +     if (!mrp) {
> > +             err = -EMSGSIZE;
> > +             goto nla_put_failure;
> > +     }
> > +
> > +     err = nla_put_u32(skb, IFLA_BRIDGE_MRP_RING_OPEN, loc);
> > +     if (err)
> > +             goto nla_put_failure;
> > +
> > +     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 0;
> > +
> > +nla_put_failure:
> > +     nlmsg_cancel(skb, nlh);
> > +     kfree_skb(skb);
> > +
> > +errout:
> > +     rtnl_set_sk_err(net, RTNLGRP_LINK, err);
> > +     return err;
> > +}
> > +EXPORT_SYMBOL(br_mrp_port_open);
> >
> 

-- 
/Horatiu