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

[Nikolay Aleksandrov <nikolay@cumulusnetworks.com>]

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@microchip.com>
> ---
>  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");

Use extack.

> +		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;
> +}
> +
> +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);
> 

Why do you need this function when you already have br_ifinfo_notify() ?