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

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);
+		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);