1 /* Copyright 2011-2014 Autronica Fire and Security AS
3 * This program is free software; you can redistribute it and/or modify it
4 * under the terms of the GNU General Public License as published by the Free
5 * Software Foundation; either version 2 of the License, or (at your option)
9 * 2011-2014 Arvid Brodin, arvid.brodin@alten.se
12 #include "hsr_slave.h"
13 #include <linux/etherdevice.h>
14 #include <linux/if_arp.h>
16 #include "hsr_device.h"
17 #include "hsr_framereg.h"
20 static int hsr_check_dev_ok(struct net_device *dev)
22 /* Don't allow HSR on non-ethernet like devices */
23 if ((dev->flags & IFF_LOOPBACK) || (dev->type != ARPHRD_ETHER) ||
24 (dev->addr_len != ETH_ALEN)) {
25 netdev_info(dev, "Cannot use loopback or non-ethernet device as HSR slave.\n");
29 /* Don't allow enslaving hsr devices */
30 if (is_hsr_master(dev)) {
31 netdev_info(dev, "Cannot create trees of HSR devices.\n");
35 if (hsr_port_exists(dev)) {
36 netdev_info(dev, "This device is already a HSR slave.\n");
40 if (dev->priv_flags & IFF_802_1Q_VLAN) {
41 netdev_info(dev, "HSR on top of VLAN is not yet supported in this driver.\n");
45 /* HSR over bonded devices has not been tested, but I'm not sure it
53 static struct sk_buff *hsr_pull_tag(struct sk_buff *skb)
55 struct hsr_tag *hsr_tag;
58 skb2 = skb_share_check(skb, GFP_ATOMIC);
63 if (unlikely(!pskb_may_pull(skb, HSR_HLEN)))
66 hsr_tag = (struct hsr_tag *) skb->data;
67 skb->protocol = hsr_tag->encap_proto;
68 skb_pull(skb, HSR_HLEN);
78 /* The uses I can see for these HSR supervision frames are:
79 * 1) Use the frames that are sent after node initialization ("HSR_TLV.Type =
80 * 22") to reset any sequence_nr counters belonging to that node. Useful if
81 * the other node's counter has been reset for some reason.
83 * Or not - resetting the counter and bridging the frame would create a
84 * loop, unfortunately.
86 * 2) Use the LifeCheck frames to detect ring breaks. I.e. if no LifeCheck
87 * frame is received from a particular node, we know something is wrong.
88 * We just register these (as with normal frames) and throw them away.
90 * 3) Allow different MAC addresses for the two slave interfaces, using the
93 static bool is_supervision_frame(struct hsr_priv *hsr, struct sk_buff *skb)
95 struct hsr_sup_tag *hsr_stag;
97 if (!ether_addr_equal(eth_hdr(skb)->h_dest,
98 hsr->sup_multicast_addr))
101 hsr_stag = (struct hsr_sup_tag *) skb->data;
102 if (get_hsr_stag_path(hsr_stag) != 0x0f)
104 if ((hsr_stag->HSR_TLV_Type != HSR_TLV_ANNOUNCE) &&
105 (hsr_stag->HSR_TLV_Type != HSR_TLV_LIFE_CHECK))
107 if (hsr_stag->HSR_TLV_Length != 12)
114 /* Implementation somewhat according to IEC-62439-3, p. 43
116 rx_handler_result_t hsr_handle_frame(struct sk_buff **pskb)
118 struct sk_buff *skb = *pskb;
119 struct hsr_port *port, *other_port, *master;
120 struct hsr_priv *hsr;
121 struct hsr_node *node;
122 bool deliver_to_self;
123 struct sk_buff *skb_deliver;
127 if (eth_hdr(skb)->h_proto != htons(ETH_P_PRP))
128 return RX_HANDLER_PASS;
130 rcu_read_lock(); /* ports & node */
132 port = hsr_port_get_rcu(skb->dev);
134 master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
136 node = hsr_find_node(&hsr->self_node_db, skb);
138 /* Always kill frames sent by ourselves */
140 ret = RX_HANDLER_CONSUMED;
144 /* Is this frame a candidate for local reception? */
145 deliver_to_self = false;
146 if ((skb->pkt_type == PACKET_HOST) ||
147 (skb->pkt_type == PACKET_MULTICAST) ||
148 (skb->pkt_type == PACKET_BROADCAST))
149 deliver_to_self = true;
150 else if (ether_addr_equal(eth_hdr(skb)->h_dest,
151 master->dev->dev_addr)) {
152 skb->pkt_type = PACKET_HOST;
153 deliver_to_self = true;
156 node = hsr_find_node(&hsr->node_db, skb);
158 if (is_supervision_frame(hsr, skb)) {
159 skb_pull(skb, sizeof(struct hsr_sup_tag));
160 node = hsr_merge_node(node, skb, port);
163 master->dev->stats.rx_dropped++;
164 ret = RX_HANDLER_CONSUMED;
167 skb_push(skb, sizeof(struct hsr_sup_tag));
168 deliver_to_self = false;
172 /* Source node unknown; this might be a HSR frame from
173 * another net (different multicast address). Ignore it.
176 ret = RX_HANDLER_CONSUMED;
180 if (port->type == HSR_PT_SLAVE_A)
181 other_port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_B);
183 other_port = hsr_port_get_hsr(hsr, HSR_PT_SLAVE_A);
185 /* Register ALL incoming frames as outgoing through the other interface.
186 * This allows us to register frames as incoming only if they are valid
187 * for the receiving interface, without using a specific counter for
191 dup_out = hsr_register_frame_out(node, other_port, skb);
195 hsr_register_frame_in(node, port);
197 /* Forward this frame? */
198 if (dup_out || (skb->pkt_type == PACKET_HOST))
201 if (hsr_register_frame_out(node, master, skb))
202 deliver_to_self = false;
204 if (!deliver_to_self && !other_port) {
206 /* Circulated frame; silently remove it. */
207 ret = RX_HANDLER_CONSUMED;
212 if (deliver_to_self && other_port) {
213 /* skb_clone() is not enough since we will strip the hsr tag
214 * and do address substitution below
216 skb_deliver = pskb_copy(skb, GFP_ATOMIC);
218 deliver_to_self = false;
219 master->dev->stats.rx_dropped++;
223 if (deliver_to_self) {
224 bool multicast_frame;
226 skb_deliver = hsr_pull_tag(skb_deliver);
228 master->dev->stats.rx_dropped++;
231 #if !defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
232 /* Move everything in the header that is after the HSR tag,
233 * to work around alignment problems caused by the 6-byte HSR
234 * tag. In practice, this removes/overwrites the HSR tag in
235 * the header and restores a "standard" packet.
237 memmove(skb_deliver->data - HSR_HLEN, skb_deliver->data,
238 skb_headlen(skb_deliver));
240 /* Adjust skb members so they correspond with the move above.
241 * This cannot possibly underflow skb->data since hsr_pull_tag()
243 * At this point in the protocol stack, the transport and
244 * network headers have not been set yet, and we haven't touched
245 * the mac header nor the head. So we only need to adjust data
248 skb_deliver->data -= HSR_HLEN;
249 skb_deliver->tail -= HSR_HLEN;
251 skb_deliver->dev = master->dev;
252 hsr_addr_subst_source(hsr, skb_deliver);
253 multicast_frame = (skb_deliver->pkt_type == PACKET_MULTICAST);
254 ret = netif_rx(skb_deliver);
255 if (ret == NET_RX_DROP) {
256 master->dev->stats.rx_dropped++;
258 master->dev->stats.rx_packets++;
259 master->dev->stats.rx_bytes += skb->len;
261 master->dev->stats.multicast++;
267 skb_push(skb, ETH_HLEN);
268 skb->dev = other_port->dev;
272 ret = RX_HANDLER_CONSUMED;
279 /* Setup device to be added to the HSR bridge. */
280 static int hsr_portdev_setup(struct net_device *dev, struct hsr_port *port)
285 res = dev_set_promiscuity(dev, 1);
287 goto fail_promiscuity;
288 res = netdev_rx_handler_register(dev, hsr_handle_frame, port);
290 goto fail_rx_handler;
291 dev_disable_lro(dev);
294 * What does net device "adjacency" mean? Should we do
295 * res = netdev_master_upper_dev_link(port->dev, port->hsr->dev); ?
301 dev_set_promiscuity(dev, -1);
308 int hsr_add_port(struct hsr_priv *hsr, struct net_device *dev,
309 enum hsr_port_type type)
311 struct hsr_port *port, *master;
314 if (type != HSR_PT_MASTER) {
315 res = hsr_check_dev_ok(dev);
320 port = hsr_port_get_hsr(hsr, type);
322 return -EBUSY; /* This port already exists */
324 port = kzalloc(sizeof(*port), GFP_KERNEL);
328 if (type != HSR_PT_MASTER) {
329 res = hsr_portdev_setup(dev, port);
338 list_add_tail_rcu(&port->port_list, &hsr->ports);
341 master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
343 /* Set required header length */
344 if (dev->hard_header_len + HSR_HLEN > master->dev->hard_header_len)
345 master->dev->hard_header_len = dev->hard_header_len + HSR_HLEN;
347 netdev_update_features(master->dev);
348 dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
357 void hsr_del_port(struct hsr_port *port)
359 struct hsr_priv *hsr;
360 struct hsr_port *master;
363 master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
364 list_del_rcu(&port->port_list);
366 if (port != master) {
367 netdev_update_features(master->dev);
368 dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
369 netdev_rx_handler_unregister(port->dev);
370 dev_set_promiscuity(port->dev, -1);
374 * netdev_upper_dev_unlink(port->dev, port->hsr->dev);