hsr_slave.c

  1// SPDX-License-Identifier: GPL-2.0
  2/* Copyright 2011-2014 Autronica Fire and Security AS
  3 *
  4 * Author(s):
  5 *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
  6 *
  7 * Frame handler other utility functions for HSR and PRP.
  8 */
  9
 10#include "hsr_slave.h"
 11#include <linux/etherdevice.h>
 12#include <linux/if_arp.h>
 13#include <linux/if_vlan.h>
 14#include "hsr_main.h"
 15#include "hsr_device.h"
 16#include "hsr_forward.h"
 17#include "hsr_framereg.h"
 18
 19bool hsr_invalid_dan_ingress_frame(__be16 protocol)
 20{
 21	return (protocol != htons(ETH_P_PRP) && protocol != htons(ETH_P_HSR));
 22}
 23
 24static rx_handler_result_t hsr_handle_frame(struct sk_buff **pskb)
 25{
 26	struct sk_buff *skb = *pskb;
 27	struct hsr_port *port;
 28	struct hsr_priv *hsr;
 29	__be16 protocol;
 30
 31	/* Packets from dev_loopback_xmit() do not have L2 header, bail out */
 32	if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
 33		return RX_HANDLER_PASS;
 34
 35	if (!skb_mac_header_was_set(skb)) {
 36		WARN_ONCE(1, "%s: skb invalid", __func__);
 37		return RX_HANDLER_PASS;
 38	}
 39
 40	port = hsr_port_get_rcu(skb->dev);
 41	if (!port)
 42		goto finish_pass;
 43	hsr = port->hsr;
 44
 45	if (hsr_addr_is_self(port->hsr, eth_hdr(skb)->h_source)) {
 46		/* Directly kill frames sent by ourselves */
 47		kfree_skb(skb);
 48		goto finish_consume;
 49	}
 50
 51	/* For HSR, only tagged frames are expected (unless the device offloads
 52	 * HSR tag removal), but for PRP there could be non tagged frames as
 53	 * well from Single attached nodes (SANs).
 54	 */
 55	protocol = eth_hdr(skb)->h_proto;
 56
 57	if (!(port->dev->features & NETIF_F_HW_HSR_TAG_RM) &&
 58	    port->type != HSR_PT_INTERLINK &&
 59	    hsr->proto_ops->invalid_dan_ingress_frame &&
 60	    hsr->proto_ops->invalid_dan_ingress_frame(protocol))
 61		goto finish_pass;
 62
 63	skb_push(skb, ETH_HLEN);
 64	skb_reset_mac_header(skb);
 65	if ((!hsr->prot_version && protocol == htons(ETH_P_PRP)) ||
 66	    protocol == htons(ETH_P_HSR)) {
 67		if (!pskb_may_pull(skb, ETH_HLEN + HSR_HLEN)) {
 68			kfree_skb(skb);
 69			goto finish_consume;
 70		}
 71
 72		skb_set_network_header(skb, ETH_HLEN + HSR_HLEN);
 73	}
 74	skb_reset_mac_len(skb);
 75
 76	/* Only the frames received over the interlink port will assign a
 77	 * sequence number and require synchronisation vs other sender.
 78	 */
 79	if (port->type == HSR_PT_INTERLINK) {
 80		spin_lock_bh(&hsr->seqnr_lock);
 81		hsr_forward_skb(skb, port);
 82		spin_unlock_bh(&hsr->seqnr_lock);
 83	} else {
 84		hsr_forward_skb(skb, port);
 85	}
 86
 87finish_consume:
 88	return RX_HANDLER_CONSUMED;
 89
 90finish_pass:
 91	return RX_HANDLER_PASS;
 92}
 93
 94bool hsr_port_exists(const struct net_device *dev)
 95{
 96	return rcu_access_pointer(dev->rx_handler) == hsr_handle_frame;
 97}
 98
 99static int hsr_check_dev_ok(struct net_device *dev,
100			    struct netlink_ext_ack *extack)
101{
102	/* Don't allow HSR on non-ethernet like devices */
103	if ((dev->flags & IFF_LOOPBACK) || dev->type != ARPHRD_ETHER ||
104	    dev->addr_len != ETH_ALEN) {
105		NL_SET_ERR_MSG_MOD(extack, "Cannot use loopback or non-ethernet device as HSR slave.");
106		return -EINVAL;
107	}
108
109	/* Don't allow enslaving hsr devices */
110	if (is_hsr_master(dev)) {
111		NL_SET_ERR_MSG_MOD(extack,
112				   "Cannot create trees of HSR devices.");
113		return -EINVAL;
114	}
115
116	if (hsr_port_exists(dev)) {
117		NL_SET_ERR_MSG_MOD(extack,
118				   "This device is already a HSR slave.");
119		return -EINVAL;
120	}
121
122	if (is_vlan_dev(dev)) {
123		NL_SET_ERR_MSG_MOD(extack, "HSR on top of VLAN is not yet supported in this driver.");
124		return -EINVAL;
125	}
126
127	if (dev->priv_flags & IFF_DONT_BRIDGE) {
128		NL_SET_ERR_MSG_MOD(extack,
129				   "This device does not support bridging.");
130		return -EOPNOTSUPP;
131	}
132
133	/* HSR over bonded devices has not been tested, but I'm not sure it
134	 * won't work...
135	 */
136
137	return 0;
138}
139
140/* Setup device to be added to the HSR bridge. */
141static int hsr_portdev_setup(struct hsr_priv *hsr, struct net_device *dev,
142			     struct hsr_port *port,
143			     struct netlink_ext_ack *extack)
144
145{
146	struct netdev_lag_upper_info lag_upper_info;
147	struct net_device *hsr_dev;
148	struct hsr_port *master;
149	int res;
150
151	/* Don't use promiscuous mode for offload since L2 frame forward
152	 * happens at the offloaded hardware.
153	 */
154	if (!port->hsr->fwd_offloaded) {
155		res = dev_set_promiscuity(dev, 1);
156		if (res)
157			return res;
158	}
159
160	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
161	hsr_dev = master->dev;
162
163	lag_upper_info.tx_type = NETDEV_LAG_TX_TYPE_BROADCAST;
164	lag_upper_info.hash_type = NETDEV_LAG_HASH_UNKNOWN;
165	res = netdev_master_upper_dev_link(dev, hsr_dev, NULL, &lag_upper_info, extack);
166	if (res)
167		goto fail_upper_dev_link;
168
169	res = netdev_rx_handler_register(dev, hsr_handle_frame, port);
170	if (res)
171		goto fail_rx_handler;
172	dev_disable_lro(dev);
173
174	return 0;
175
176fail_rx_handler:
177	netdev_upper_dev_unlink(dev, hsr_dev);
178fail_upper_dev_link:
179	if (!port->hsr->fwd_offloaded)
180		dev_set_promiscuity(dev, -1);
181
182	return res;
183}
184
185int hsr_add_port(struct hsr_priv *hsr, struct net_device *dev,
186		 enum hsr_port_type type, struct netlink_ext_ack *extack)
187{
188	struct hsr_port *port, *master;
189	int res;
190
191	if (type != HSR_PT_MASTER) {
192		res = hsr_check_dev_ok(dev, extack);
193		if (res)
194			return res;
195	}
196
197	port = hsr_port_get_hsr(hsr, type);
198	if (port)
199		return -EBUSY;	/* This port already exists */
200
201	port = kzalloc(sizeof(*port), GFP_KERNEL);
202	if (!port)
203		return -ENOMEM;
204
205	port->hsr = hsr;
206	port->dev = dev;
207	port->type = type;
208	ether_addr_copy(port->original_macaddress, dev->dev_addr);
209
210	list_add_tail_rcu(&port->port_list, &hsr->ports);
211
212	if (type != HSR_PT_MASTER) {
213		res = hsr_portdev_setup(hsr, dev, port, extack);
214		if (res)
215			goto fail_dev_setup;
216	}
217
218	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
219	netdev_update_features(master->dev);
220	dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
221
222	return 0;
223
224fail_dev_setup:
225	list_del_rcu(&port->port_list);
226	kfree_rcu(port, rcu);
227	return res;
228}
229
230void hsr_del_port(struct hsr_port *port)
231{
232	struct hsr_priv *hsr;
233	struct hsr_port *master;
234
235	hsr = port->hsr;
236	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
237	list_del_rcu(&port->port_list);
238
239	if (port != master) {
240		netdev_update_features(master->dev);
241		dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
242		netdev_rx_handler_unregister(port->dev);
243		if (!port->hsr->fwd_offloaded)
244			dev_set_promiscuity(port->dev, -1);
245		netdev_upper_dev_unlink(port->dev, master->dev);
246		eth_hw_addr_set(port->dev, port->original_macaddress);
247	}
248
249	kfree_rcu(port, rcu);
250}