net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)

High-availability Seamless Redundancy ("HSR") provides instant failover
redundancy for Ethernet networks. It requires a special network topology where
all nodes are connected in a ring (each node having two physical network
interfaces). It is suited for applications that demand high availability and
very short reaction time.

HSR acts on the Ethernet layer, using a registered Ethernet protocol type to
send special HSR frames in both directions over the ring. The driver creates
virtual network interfaces that can be used just like any ordinary Linux
network interface, for IP/TCP/UDP traffic etc. All nodes in the network ring
must be HSR capable.

This code is a "best effort" to comply with the HSR standard as described in
IEC 62439-3:2010 (HSRv0).

Signed-off-by: Arvid Brodin <arvid.brodin@xdin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 457 insertions, 0 deletions

diff --git a/net/hsr/hsr_netlink.c b/net/hsr/hsr_netlink.c
new file mode 100644
index 000000000000..4e66bf61f585
--- /dev/null
+++ b/net/hsr/hsr_netlink.c
@@ -0,0 +1,457 @@
+/* Copyright 2011-2013 Autronica Fire and Security AS
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * Author(s):
+ *	2011-2013 Arvid Brodin, arvid.brodin@xdin.com
+ *
+ * Routines for handling Netlink messages for HSR.
+ */
+
+#include "hsr_netlink.h"
+#include <linux/kernel.h>
+#include <net/rtnetlink.h>
+#include <net/genetlink.h>
+#include "hsr_main.h"
+#include "hsr_device.h"
+#include "hsr_framereg.h"
+
+static const struct nla_policy hsr_policy[IFLA_HSR_MAX + 1] = {
+	[IFLA_HSR_SLAVE1]		= { .type = NLA_U32 },
+	[IFLA_HSR_SLAVE2]		= { .type = NLA_U32 },
+	[IFLA_HSR_MULTICAST_SPEC]	= { .type = NLA_U8 },
+};
+
+
+/* Here, it seems a netdevice has already been allocated for us, and the
+ * hsr_dev_setup routine has been executed. Nice!
+ */
+static int hsr_newlink(struct net *src_net, struct net_device *dev,
+		       struct nlattr *tb[], struct nlattr *data[])
+{
+	struct net_device *link[2];
+	unsigned char multicast_spec;
+
+	if (!data[IFLA_HSR_SLAVE1]) {
+		netdev_info(dev, "IFLA_HSR_SLAVE1 missing!\n");
+		return -EINVAL;
+	}
+	link[0] = __dev_get_by_index(src_net, nla_get_u32(data[IFLA_HSR_SLAVE1]));
+	if (!data[IFLA_HSR_SLAVE2]) {
+		netdev_info(dev, "IFLA_HSR_SLAVE2 missing!\n");
+		return -EINVAL;
+	}
+	link[1] = __dev_get_by_index(src_net, nla_get_u32(data[IFLA_HSR_SLAVE2]));
+
+	if (!link[0] || !link[1])
+		return -ENODEV;
+	if (link[0] == link[1])
+		return -EINVAL;
+
+	if (!data[IFLA_HSR_MULTICAST_SPEC])
+		multicast_spec = 0;
+	else
+		multicast_spec = nla_get_u8(data[IFLA_HSR_MULTICAST_SPEC]);
+
+	return hsr_dev_finalize(dev, link, multicast_spec);
+}
+
+static struct rtnl_link_ops hsr_link_ops __read_mostly = {
+	.kind		= "hsr",
+	.maxtype	= IFLA_HSR_MAX,
+	.policy		= hsr_policy,
+	.priv_size	= sizeof(struct hsr_priv),
+	.setup		= hsr_dev_setup,
+	.newlink	= hsr_newlink,
+};
+
+
+
+/* attribute policy */
+/* NLA_BINARY missing in libnl; use NLA_UNSPEC in userspace instead. */
+static const struct nla_policy hsr_genl_policy[HSR_A_MAX + 1] = {
+	[HSR_A_NODE_ADDR] = { .type = NLA_BINARY, .len = ETH_ALEN },
+	[HSR_A_NODE_ADDR_B] = { .type = NLA_BINARY, .len = ETH_ALEN },
+	[HSR_A_IFINDEX] = { .type = NLA_U32 },
+	[HSR_A_IF1_AGE] = { .type = NLA_U32 },
+	[HSR_A_IF2_AGE] = { .type = NLA_U32 },
+	[HSR_A_IF1_SEQ] = { .type = NLA_U16 },
+	[HSR_A_IF2_SEQ] = { .type = NLA_U16 },
+};
+
+static struct genl_family hsr_genl_family = {
+	.id = GENL_ID_GENERATE,
+	.hdrsize = 0,
+	.name = "HSR",
+	.version = 1,
+	.maxattr = HSR_A_MAX,
+};
+
+static struct genl_multicast_group hsr_network_genl_mcgrp = {
+	.name = "hsr-network",
+};
+
+
+
+/* This is called if for some node with MAC address addr, we only get frames
+ * over one of the slave interfaces. This would indicate an open network ring
+ * (i.e. a link has failed somewhere).
+ */
+void hsr_nl_ringerror(struct hsr_priv *hsr_priv, unsigned char addr[ETH_ALEN],
+		      enum hsr_dev_idx dev_idx)
+{
+	struct sk_buff *skb;
+	void *msg_head;
+	int res;
+	int ifindex;
+
+	skb = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
+	if (!skb)
+		goto fail;
+
+	msg_head = genlmsg_put(skb, 0, 0, &hsr_genl_family, 0, HSR_C_RING_ERROR);
+	if (!msg_head)
+		goto nla_put_failure;
+
+	res = nla_put(skb, HSR_A_NODE_ADDR, ETH_ALEN, addr);
+	if (res < 0)
+		goto nla_put_failure;
+
+	if (hsr_priv->slave[dev_idx])
+		ifindex = hsr_priv->slave[dev_idx]->ifindex;
+	else
+		ifindex = -1;
+	res = nla_put_u32(skb, HSR_A_IFINDEX, ifindex);
+	if (res < 0)
+		goto nla_put_failure;
+
+	genlmsg_end(skb, msg_head);
+	genlmsg_multicast(skb, 0, hsr_network_genl_mcgrp.id, GFP_ATOMIC);
+
+	return;
+
+nla_put_failure:
+	kfree_skb(skb);
+
+fail:
+	netdev_warn(hsr_priv->dev, "Could not send HSR ring error message\n");
+}
+
+/* This is called when we haven't heard from the node with MAC address addr for
+ * some time (just before the node is removed from the node table/list).
+ */
+void hsr_nl_nodedown(struct hsr_priv *hsr_priv, unsigned char addr[ETH_ALEN])
+{
+	struct sk_buff *skb;
+	void *msg_head;
+	int res;
+
+	skb = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
+	if (!skb)
+		goto fail;
+
+	msg_head = genlmsg_put(skb, 0, 0, &hsr_genl_family, 0, HSR_C_NODE_DOWN);
+	if (!msg_head)
+		goto nla_put_failure;
+
+
+	res = nla_put(skb, HSR_A_NODE_ADDR, ETH_ALEN, addr);
+	if (res < 0)
+		goto nla_put_failure;
+
+	genlmsg_end(skb, msg_head);
+	genlmsg_multicast(skb, 0, hsr_network_genl_mcgrp.id, GFP_ATOMIC);
+
+	return;
+
+nla_put_failure:
+	kfree_skb(skb);
+
+fail:
+	netdev_warn(hsr_priv->dev, "Could not send HSR node down\n");
+}
+
+
+/* HSR_C_GET_NODE_STATUS lets userspace query the internal HSR node table
+ * about the status of a specific node in the network, defined by its MAC
+ * address.
+ *
+ * Input: hsr ifindex, node mac address
+ * Output: hsr ifindex, node mac address (copied from request),
+ *	   age of latest frame from node over slave 1, slave 2 [ms]
+ */
+static int hsr_get_node_status(struct sk_buff *skb_in, struct genl_info *info)
+{
+	/* For receiving */
+	struct nlattr *na;
+	struct net_device *hsr_dev;
+
+	/* For sending */
+	struct sk_buff *skb_out;
+	void *msg_head;
+	struct hsr_priv *hsr_priv;
+	unsigned char hsr_node_addr_b[ETH_ALEN];
+	int hsr_node_if1_age;
+	u16 hsr_node_if1_seq;
+	int hsr_node_if2_age;
+	u16 hsr_node_if2_seq;
+	int addr_b_ifindex;
+	int res;
+
+	if (!info)
+		goto invalid;
+
+	na = info->attrs[HSR_A_IFINDEX];
+	if (!na)
+		goto invalid;
+	na = info->attrs[HSR_A_NODE_ADDR];
+	if (!na)
+		goto invalid;
+
+	hsr_dev = __dev_get_by_index(genl_info_net(info),
+					nla_get_u32(info->attrs[HSR_A_IFINDEX]));
+	if (!hsr_dev)
+		goto invalid;
+	if (!is_hsr_master(hsr_dev))
+		goto invalid;
+
+
+	/* Send reply */
+
+	skb_out = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+	if (!skb_out) {
+		res = -ENOMEM;
+		goto fail;
+	}
+
+	msg_head = genlmsg_put(skb_out, NETLINK_CB(skb_in).portid,
+				info->snd_seq, &hsr_genl_family, 0,
+				HSR_C_SET_NODE_STATUS);
+	if (!msg_head) {
+		res = -ENOMEM;
+		goto nla_put_failure;
+	}
+
+	res = nla_put_u32(skb_out, HSR_A_IFINDEX, hsr_dev->ifindex);
+	if (res < 0)
+		goto nla_put_failure;
+
+	hsr_priv = netdev_priv(hsr_dev);
+	res = hsr_get_node_data(hsr_priv,
+			(unsigned char *) nla_data(info->attrs[HSR_A_NODE_ADDR]),
+			hsr_node_addr_b,
+			&addr_b_ifindex,
+			&hsr_node_if1_age,
+			&hsr_node_if1_seq,
+			&hsr_node_if2_age,
+			&hsr_node_if2_seq);
+	if (res < 0)
+		goto fail;
+
+	res = nla_put(skb_out, HSR_A_NODE_ADDR, ETH_ALEN,
+					nla_data(info->attrs[HSR_A_NODE_ADDR]));
+	if (res < 0)
+		goto nla_put_failure;
+
+	if (addr_b_ifindex > -1) {
+		res = nla_put(skb_out, HSR_A_NODE_ADDR_B, ETH_ALEN,
+								hsr_node_addr_b);
+		if (res < 0)
+			goto nla_put_failure;
+
+		res = nla_put_u32(skb_out, HSR_A_ADDR_B_IFINDEX, addr_b_ifindex);
+		if (res < 0)
+			goto nla_put_failure;
+	}
+
+	res = nla_put_u32(skb_out, HSR_A_IF1_AGE, hsr_node_if1_age);
+	if (res < 0)
+		goto nla_put_failure;
+	res = nla_put_u16(skb_out, HSR_A_IF1_SEQ, hsr_node_if1_seq);
+	if (res < 0)
+		goto nla_put_failure;
+	if (hsr_priv->slave[0])
+		res = nla_put_u32(skb_out, HSR_A_IF1_IFINDEX,
+						hsr_priv->slave[0]->ifindex);
+	if (res < 0)
+		goto nla_put_failure;
+
+	res = nla_put_u32(skb_out, HSR_A_IF2_AGE, hsr_node_if2_age);
+	if (res < 0)
+		goto nla_put_failure;
+	res = nla_put_u16(skb_out, HSR_A_IF2_SEQ, hsr_node_if2_seq);
+	if (res < 0)
+		goto nla_put_failure;
+	if (hsr_priv->slave[1])
+		res = nla_put_u32(skb_out, HSR_A_IF2_IFINDEX,
+						hsr_priv->slave[1]->ifindex);
+
+	genlmsg_end(skb_out, msg_head);
+	genlmsg_unicast(genl_info_net(info), skb_out, info->snd_portid);
+
+	return 0;
+
+invalid:
+	netlink_ack(skb_in, nlmsg_hdr(skb_in), -EINVAL);
+	return 0;
+
+nla_put_failure:
+	kfree_skb(skb_out);
+	/* Fall through */
+
+fail:
+	return res;
+}
+
+static struct genl_ops hsr_ops_get_node_status = {
+	.cmd = HSR_C_GET_NODE_STATUS,
+	.flags = 0,
+	.policy = hsr_genl_policy,
+	.doit = hsr_get_node_status,
+	.dumpit = NULL,
+};
+
+
+/* Get a list of MacAddressA of all nodes known to this node (other than self).
+ */
+static int hsr_get_node_list(struct sk_buff *skb_in, struct genl_info *info)
+{
+	/* For receiving */
+	struct nlattr *na;
+	struct net_device *hsr_dev;
+
+	/* For sending */
+	struct sk_buff *skb_out;
+	void *msg_head;
+	struct hsr_priv *hsr_priv;
+	void *pos;
+	unsigned char addr[ETH_ALEN];
+	int res;
+
+	if (!info)
+		goto invalid;
+
+	na = info->attrs[HSR_A_IFINDEX];
+	if (!na)
+		goto invalid;
+
+	hsr_dev = __dev_get_by_index(genl_info_net(info),
+				     nla_get_u32(info->attrs[HSR_A_IFINDEX]));
+	if (!hsr_dev)
+		goto invalid;
+	if (!is_hsr_master(hsr_dev))
+		goto invalid;
+
+
+	/* Send reply */
+
+	skb_out = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+	if (!skb_out) {
+		res = -ENOMEM;
+		goto fail;
+	}
+
+	msg_head = genlmsg_put(skb_out, NETLINK_CB(skb_in).portid,
+				info->snd_seq, &hsr_genl_family, 0,
+				HSR_C_SET_NODE_LIST);
+	if (!msg_head) {
+		res = -ENOMEM;
+		goto nla_put_failure;
+	}
+
+	res = nla_put_u32(skb_out, HSR_A_IFINDEX, hsr_dev->ifindex);
+	if (res < 0)
+		goto nla_put_failure;
+
+	hsr_priv = netdev_priv(hsr_dev);
+
+	rcu_read_lock();
+	pos = hsr_get_next_node(hsr_priv, NULL, addr);
+	while (pos) {
+		res = nla_put(skb_out, HSR_A_NODE_ADDR, ETH_ALEN, addr);
+		if (res < 0) {
+			rcu_read_unlock();
+			goto nla_put_failure;
+		}
+		pos = hsr_get_next_node(hsr_priv, pos, addr);
+	}
+	rcu_read_unlock();
+
+	genlmsg_end(skb_out, msg_head);
+	genlmsg_unicast(genl_info_net(info), skb_out, info->snd_portid);
+
+	return 0;
+
+invalid:
+	netlink_ack(skb_in, nlmsg_hdr(skb_in), -EINVAL);
+	return 0;
+
+nla_put_failure:
+	kfree_skb(skb_out);
+	/* Fall through */
+
+fail:
+	return res;
+}
+
+
+static struct genl_ops hsr_ops_get_node_list = {
+	.cmd = HSR_C_GET_NODE_LIST,
+	.flags = 0,
+	.policy = hsr_genl_policy,
+	.doit = hsr_get_node_list,
+	.dumpit = NULL,
+};
+
+int __init hsr_netlink_init(void)
+{
+	int rc;
+
+	rc = rtnl_link_register(&hsr_link_ops);
+	if (rc)
+		goto fail_rtnl_link_register;
+
+	rc = genl_register_family(&hsr_genl_family);
+	if (rc)
+		goto fail_genl_register_family;
+
+	rc = genl_register_ops(&hsr_genl_family, &hsr_ops_get_node_status);
+	if (rc)
+		goto fail_genl_register_ops;
+
+	rc = genl_register_ops(&hsr_genl_family, &hsr_ops_get_node_list);
+	if (rc)
+		goto fail_genl_register_ops_node_list;
+
+	rc = genl_register_mc_group(&hsr_genl_family, &hsr_network_genl_mcgrp);
+	if (rc)
+		goto fail_genl_register_mc_group;
+
+	return 0;
+
+fail_genl_register_mc_group:
+	genl_unregister_ops(&hsr_genl_family, &hsr_ops_get_node_list);
+fail_genl_register_ops_node_list:
+	genl_unregister_ops(&hsr_genl_family, &hsr_ops_get_node_status);
+fail_genl_register_ops:
+	genl_unregister_family(&hsr_genl_family);
+fail_genl_register_family:
+	rtnl_link_unregister(&hsr_link_ops);
+fail_rtnl_link_register:
+
+	return rc;
+}
+
+void __exit hsr_netlink_exit(void)
+{
+	genl_unregister_mc_group(&hsr_genl_family, &hsr_network_genl_mcgrp);
+	genl_unregister_ops(&hsr_genl_family, &hsr_ops_get_node_status);
+	genl_unregister_family(&hsr_genl_family);
+
+	rtnl_link_unregister(&hsr_link_ops);
+}
+
+MODULE_ALIAS_RTNL_LINK("hsr");