1/* Copyright 2011-2014 Autronica Fire and Security AS
2 *
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)
6 * any later version.
7 *
8 * Author(s):
9 *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
10 */
11
12#include "hsr_slave.h"
13#include <linux/etherdevice.h>
14#include <linux/if_arp.h>
15#include "hsr_main.h"
16#include "hsr_device.h"
17#include "hsr_forward.h"
18#include "hsr_framereg.h"
19
20
21static rx_handler_result_t hsr_handle_frame(struct sk_buff **pskb)
22{
23	struct sk_buff *skb = *pskb;
24	struct hsr_port *port;
25
26	if (!skb_mac_header_was_set(skb)) {
27		WARN_ONCE(1, "%s: skb invalid", __func__);
28		return RX_HANDLER_PASS;
29	}
30
31	rcu_read_lock(); /* hsr->node_db, hsr->ports */
32	port = hsr_port_get_rcu(skb->dev);
33
34	if (hsr_addr_is_self(port->hsr, eth_hdr(skb)->h_source)) {
35		/* Directly kill frames sent by ourselves */
36		kfree_skb(skb);
37		goto finish_consume;
38	}
39
40	if (eth_hdr(skb)->h_proto != htons(ETH_P_PRP))
41		goto finish_pass;
42
43	skb_push(skb, ETH_HLEN);
44
45	hsr_forward_skb(skb, port);
46
47finish_consume:
48	rcu_read_unlock(); /* hsr->node_db, hsr->ports */
49	return RX_HANDLER_CONSUMED;
50
51finish_pass:
52	rcu_read_unlock(); /* hsr->node_db, hsr->ports */
53	return RX_HANDLER_PASS;
54}
55
56bool hsr_port_exists(const struct net_device *dev)
57{
58	return rcu_access_pointer(dev->rx_handler) == hsr_handle_frame;
59}
60
61
62static int hsr_check_dev_ok(struct net_device *dev)
63{
64	/* Don't allow HSR on non-ethernet like devices */
65	if ((dev->flags & IFF_LOOPBACK) || (dev->type != ARPHRD_ETHER) ||
66	    (dev->addr_len != ETH_ALEN)) {
67		netdev_info(dev, "Cannot use loopback or non-ethernet device as HSR slave.\n");
68		return -EINVAL;
69	}
70
71	/* Don't allow enslaving hsr devices */
72	if (is_hsr_master(dev)) {
73		netdev_info(dev, "Cannot create trees of HSR devices.\n");
74		return -EINVAL;
75	}
76
77	if (hsr_port_exists(dev)) {
78		netdev_info(dev, "This device is already a HSR slave.\n");
79		return -EINVAL;
80	}
81
82	if (dev->priv_flags & IFF_802_1Q_VLAN) {
83		netdev_info(dev, "HSR on top of VLAN is not yet supported in this driver.\n");
84		return -EINVAL;
85	}
86
87	if (dev->priv_flags & IFF_DONT_BRIDGE) {
88		netdev_info(dev, "This device does not support bridging.\n");
89		return -EOPNOTSUPP;
90	}
91
92	/* HSR over bonded devices has not been tested, but I'm not sure it
93	 * won't work...
94	 */
95
96	return 0;
97}
98
99
100/* Setup device to be added to the HSR bridge. */
101static int hsr_portdev_setup(struct net_device *dev, struct hsr_port *port)
102{
103	int res;
104
105	dev_hold(dev);
106	res = dev_set_promiscuity(dev, 1);
107	if (res)
108		goto fail_promiscuity;
109
110	/* FIXME:
111	 * What does net device "adjacency" mean? Should we do
112	 * res = netdev_master_upper_dev_link(port->dev, port->hsr->dev); ?
113	 */
114
115	res = netdev_rx_handler_register(dev, hsr_handle_frame, port);
116	if (res)
117		goto fail_rx_handler;
118	dev_disable_lro(dev);
119
120	return 0;
121
122fail_rx_handler:
123	dev_set_promiscuity(dev, -1);
124fail_promiscuity:
125	dev_put(dev);
126
127	return res;
128}
129
130int hsr_add_port(struct hsr_priv *hsr, struct net_device *dev,
131		 enum hsr_port_type type)
132{
133	struct hsr_port *port, *master;
134	int res;
135
136	if (type != HSR_PT_MASTER) {
137		res = hsr_check_dev_ok(dev);
138		if (res)
139			return res;
140	}
141
142	port = hsr_port_get_hsr(hsr, type);
143	if (port != NULL)
144		return -EBUSY;	/* This port already exists */
145
146	port = kzalloc(sizeof(*port), GFP_KERNEL);
147	if (port == NULL)
148		return -ENOMEM;
149
150	if (type != HSR_PT_MASTER) {
151		res = hsr_portdev_setup(dev, port);
152		if (res)
153			goto fail_dev_setup;
154	}
155
156	port->hsr = hsr;
157	port->dev = dev;
158	port->type = type;
159
160	list_add_tail_rcu(&port->port_list, &hsr->ports);
161	synchronize_rcu();
162
163	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
164	netdev_update_features(master->dev);
165	dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
166
167	return 0;
168
169fail_dev_setup:
170	kfree(port);
171	return res;
172}
173
174void hsr_del_port(struct hsr_port *port)
175{
176	struct hsr_priv *hsr;
177	struct hsr_port *master;
178
179	hsr = port->hsr;
180	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
181	list_del_rcu(&port->port_list);
182
183	if (port != master) {
184		if (master != NULL) {
185			netdev_update_features(master->dev);
186			dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
187		}
188		netdev_rx_handler_unregister(port->dev);
189		dev_set_promiscuity(port->dev, -1);
190	}
191
192	/* FIXME?
193	 * netdev_upper_dev_unlink(port->dev, port->hsr->dev);
194	 */
195
196	synchronize_rcu();
197
198	if (port != master)
199		dev_put(port->dev);
200}
201