xref: /openbmc/linux/net/hsr/hsr_slave.c (revision f3539c12)
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 	u16 protocol;
26 
27 	if (!skb_mac_header_was_set(skb)) {
28 		WARN_ONCE(1, "%s: skb invalid", __func__);
29 		return RX_HANDLER_PASS;
30 	}
31 
32 	rcu_read_lock(); /* hsr->node_db, hsr->ports */
33 	port = hsr_port_get_rcu(skb->dev);
34 
35 	if (hsr_addr_is_self(port->hsr, eth_hdr(skb)->h_source)) {
36 		/* Directly kill frames sent by ourselves */
37 		kfree_skb(skb);
38 		goto finish_consume;
39 	}
40 
41 	protocol = eth_hdr(skb)->h_proto;
42 	if (protocol != htons(ETH_P_PRP) && protocol != htons(ETH_P_HSR))
43 		goto finish_pass;
44 
45 	skb_push(skb, ETH_HLEN);
46 
47 	hsr_forward_skb(skb, port);
48 
49 finish_consume:
50 	rcu_read_unlock(); /* hsr->node_db, hsr->ports */
51 	return RX_HANDLER_CONSUMED;
52 
53 finish_pass:
54 	rcu_read_unlock(); /* hsr->node_db, hsr->ports */
55 	return RX_HANDLER_PASS;
56 }
57 
58 bool hsr_port_exists(const struct net_device *dev)
59 {
60 	return rcu_access_pointer(dev->rx_handler) == hsr_handle_frame;
61 }
62 
63 
64 static int hsr_check_dev_ok(struct net_device *dev)
65 {
66 	/* Don't allow HSR on non-ethernet like devices */
67 	if ((dev->flags & IFF_LOOPBACK) || (dev->type != ARPHRD_ETHER) ||
68 	    (dev->addr_len != ETH_ALEN)) {
69 		netdev_info(dev, "Cannot use loopback or non-ethernet device as HSR slave.\n");
70 		return -EINVAL;
71 	}
72 
73 	/* Don't allow enslaving hsr devices */
74 	if (is_hsr_master(dev)) {
75 		netdev_info(dev, "Cannot create trees of HSR devices.\n");
76 		return -EINVAL;
77 	}
78 
79 	if (hsr_port_exists(dev)) {
80 		netdev_info(dev, "This device is already a HSR slave.\n");
81 		return -EINVAL;
82 	}
83 
84 	if (dev->priv_flags & IFF_802_1Q_VLAN) {
85 		netdev_info(dev, "HSR on top of VLAN is not yet supported in this driver.\n");
86 		return -EINVAL;
87 	}
88 
89 	if (dev->priv_flags & IFF_DONT_BRIDGE) {
90 		netdev_info(dev, "This device does not support bridging.\n");
91 		return -EOPNOTSUPP;
92 	}
93 
94 	/* HSR over bonded devices has not been tested, but I'm not sure it
95 	 * won't work...
96 	 */
97 
98 	return 0;
99 }
100 
101 
102 /* Setup device to be added to the HSR bridge. */
103 static int hsr_portdev_setup(struct net_device *dev, struct hsr_port *port)
104 {
105 	int res;
106 
107 	dev_hold(dev);
108 	res = dev_set_promiscuity(dev, 1);
109 	if (res)
110 		goto fail_promiscuity;
111 
112 	/* FIXME:
113 	 * What does net device "adjacency" mean? Should we do
114 	 * res = netdev_master_upper_dev_link(port->dev, port->hsr->dev); ?
115 	 */
116 
117 	res = netdev_rx_handler_register(dev, hsr_handle_frame, port);
118 	if (res)
119 		goto fail_rx_handler;
120 	dev_disable_lro(dev);
121 
122 	return 0;
123 
124 fail_rx_handler:
125 	dev_set_promiscuity(dev, -1);
126 fail_promiscuity:
127 	dev_put(dev);
128 
129 	return res;
130 }
131 
132 int hsr_add_port(struct hsr_priv *hsr, struct net_device *dev,
133 		 enum hsr_port_type type)
134 {
135 	struct hsr_port *port, *master;
136 	int res;
137 
138 	if (type != HSR_PT_MASTER) {
139 		res = hsr_check_dev_ok(dev);
140 		if (res)
141 			return res;
142 	}
143 
144 	port = hsr_port_get_hsr(hsr, type);
145 	if (port != NULL)
146 		return -EBUSY;	/* This port already exists */
147 
148 	port = kzalloc(sizeof(*port), GFP_KERNEL);
149 	if (port == NULL)
150 		return -ENOMEM;
151 
152 	if (type != HSR_PT_MASTER) {
153 		res = hsr_portdev_setup(dev, port);
154 		if (res)
155 			goto fail_dev_setup;
156 	}
157 
158 	port->hsr = hsr;
159 	port->dev = dev;
160 	port->type = type;
161 
162 	list_add_tail_rcu(&port->port_list, &hsr->ports);
163 	synchronize_rcu();
164 
165 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
166 	netdev_update_features(master->dev);
167 	dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
168 
169 	return 0;
170 
171 fail_dev_setup:
172 	kfree(port);
173 	return res;
174 }
175 
176 void hsr_del_port(struct hsr_port *port)
177 {
178 	struct hsr_priv *hsr;
179 	struct hsr_port *master;
180 
181 	hsr = port->hsr;
182 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
183 	list_del_rcu(&port->port_list);
184 
185 	if (port != master) {
186 		if (master != NULL) {
187 			netdev_update_features(master->dev);
188 			dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
189 		}
190 		netdev_rx_handler_unregister(port->dev);
191 		dev_set_promiscuity(port->dev, -1);
192 	}
193 
194 	/* FIXME?
195 	 * netdev_upper_dev_unlink(port->dev, port->hsr->dev);
196 	 */
197 
198 	synchronize_rcu();
199 
200 	if (port != master)
201 		dev_put(port->dev);
202 }
203