xref: /linux/net/hsr/hsr_slave.c (revision 9e9f60108423f18a99c9cc93ef7f23490ecc709b)
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 
21 static 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 
47 finish_consume:
48 	rcu_read_unlock(); /* hsr->node_db, hsr->ports */
49 	return RX_HANDLER_CONSUMED;
50 
51 finish_pass:
52 	rcu_read_unlock(); /* hsr->node_db, hsr->ports */
53 	return RX_HANDLER_PASS;
54 }
55 
56 bool hsr_port_exists(const struct net_device *dev)
57 {
58 	return rcu_access_pointer(dev->rx_handler) == hsr_handle_frame;
59 }
60 
61 
62 static 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. */
101 static 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 
122 fail_rx_handler:
123 	dev_set_promiscuity(dev, -1);
124 fail_promiscuity:
125 	dev_put(dev);
126 
127 	return res;
128 }
129 
130 int 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 
169 fail_dev_setup:
170 	kfree(port);
171 	return res;
172 }
173 
174 void 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 		netdev_update_features(master->dev);
185 		dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
186 		netdev_rx_handler_unregister(port->dev);
187 		dev_set_promiscuity(port->dev, -1);
188 	}
189 
190 	/* FIXME?
191 	 * netdev_upper_dev_unlink(port->dev, port->hsr->dev);
192 	 */
193 
194 	synchronize_rcu();
195 	dev_put(port->dev);
196 }
197