xref: /openbmc/linux/net/hsr/hsr_slave.c (revision 6d99a79c)
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 <linux/if_vlan.h>
16 #include "hsr_main.h"
17 #include "hsr_device.h"
18 #include "hsr_forward.h"
19 #include "hsr_framereg.h"
20 
21 
22 static rx_handler_result_t hsr_handle_frame(struct sk_buff **pskb)
23 {
24 	struct sk_buff *skb = *pskb;
25 	struct hsr_port *port;
26 	u16 protocol;
27 
28 	if (!skb_mac_header_was_set(skb)) {
29 		WARN_ONCE(1, "%s: skb invalid", __func__);
30 		return RX_HANDLER_PASS;
31 	}
32 
33 	rcu_read_lock(); /* hsr->node_db, hsr->ports */
34 	port = hsr_port_get_rcu(skb->dev);
35 
36 	if (hsr_addr_is_self(port->hsr, eth_hdr(skb)->h_source)) {
37 		/* Directly kill frames sent by ourselves */
38 		kfree_skb(skb);
39 		goto finish_consume;
40 	}
41 
42 	protocol = eth_hdr(skb)->h_proto;
43 	if (protocol != htons(ETH_P_PRP) && protocol != htons(ETH_P_HSR))
44 		goto finish_pass;
45 
46 	skb_push(skb, ETH_HLEN);
47 
48 	hsr_forward_skb(skb, port);
49 
50 finish_consume:
51 	rcu_read_unlock(); /* hsr->node_db, hsr->ports */
52 	return RX_HANDLER_CONSUMED;
53 
54 finish_pass:
55 	rcu_read_unlock(); /* hsr->node_db, hsr->ports */
56 	return RX_HANDLER_PASS;
57 }
58 
59 bool hsr_port_exists(const struct net_device *dev)
60 {
61 	return rcu_access_pointer(dev->rx_handler) == hsr_handle_frame;
62 }
63 
64 
65 static int hsr_check_dev_ok(struct net_device *dev)
66 {
67 	/* Don't allow HSR on non-ethernet like devices */
68 	if ((dev->flags & IFF_LOOPBACK) || (dev->type != ARPHRD_ETHER) ||
69 	    (dev->addr_len != ETH_ALEN)) {
70 		netdev_info(dev, "Cannot use loopback or non-ethernet device as HSR slave.\n");
71 		return -EINVAL;
72 	}
73 
74 	/* Don't allow enslaving hsr devices */
75 	if (is_hsr_master(dev)) {
76 		netdev_info(dev, "Cannot create trees of HSR devices.\n");
77 		return -EINVAL;
78 	}
79 
80 	if (hsr_port_exists(dev)) {
81 		netdev_info(dev, "This device is already a HSR slave.\n");
82 		return -EINVAL;
83 	}
84 
85 	if (is_vlan_dev(dev)) {
86 		netdev_info(dev, "HSR on top of VLAN is not yet supported in this driver.\n");
87 		return -EINVAL;
88 	}
89 
90 	if (dev->priv_flags & IFF_DONT_BRIDGE) {
91 		netdev_info(dev, "This device does not support bridging.\n");
92 		return -EOPNOTSUPP;
93 	}
94 
95 	/* HSR over bonded devices has not been tested, but I'm not sure it
96 	 * won't work...
97 	 */
98 
99 	return 0;
100 }
101 
102 
103 /* Setup device to be added to the HSR bridge. */
104 static int hsr_portdev_setup(struct net_device *dev, struct hsr_port *port)
105 {
106 	int res;
107 
108 	dev_hold(dev);
109 	res = dev_set_promiscuity(dev, 1);
110 	if (res)
111 		goto fail_promiscuity;
112 
113 	/* FIXME:
114 	 * What does net device "adjacency" mean? Should we do
115 	 * res = netdev_master_upper_dev_link(port->dev, port->hsr->dev); ?
116 	 */
117 
118 	res = netdev_rx_handler_register(dev, hsr_handle_frame, port);
119 	if (res)
120 		goto fail_rx_handler;
121 	dev_disable_lro(dev);
122 
123 	return 0;
124 
125 fail_rx_handler:
126 	dev_set_promiscuity(dev, -1);
127 fail_promiscuity:
128 	dev_put(dev);
129 
130 	return res;
131 }
132 
133 int hsr_add_port(struct hsr_priv *hsr, struct net_device *dev,
134 		 enum hsr_port_type type)
135 {
136 	struct hsr_port *port, *master;
137 	int res;
138 
139 	if (type != HSR_PT_MASTER) {
140 		res = hsr_check_dev_ok(dev);
141 		if (res)
142 			return res;
143 	}
144 
145 	port = hsr_port_get_hsr(hsr, type);
146 	if (port != NULL)
147 		return -EBUSY;	/* This port already exists */
148 
149 	port = kzalloc(sizeof(*port), GFP_KERNEL);
150 	if (port == NULL)
151 		return -ENOMEM;
152 
153 	if (type != HSR_PT_MASTER) {
154 		res = hsr_portdev_setup(dev, port);
155 		if (res)
156 			goto fail_dev_setup;
157 	}
158 
159 	port->hsr = hsr;
160 	port->dev = dev;
161 	port->type = type;
162 
163 	list_add_tail_rcu(&port->port_list, &hsr->ports);
164 	synchronize_rcu();
165 
166 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
167 	netdev_update_features(master->dev);
168 	dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
169 
170 	return 0;
171 
172 fail_dev_setup:
173 	kfree(port);
174 	return res;
175 }
176 
177 void hsr_del_port(struct hsr_port *port)
178 {
179 	struct hsr_priv *hsr;
180 	struct hsr_port *master;
181 
182 	hsr = port->hsr;
183 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
184 	list_del_rcu(&port->port_list);
185 
186 	if (port != master) {
187 		if (master != NULL) {
188 			netdev_update_features(master->dev);
189 			dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
190 		}
191 		netdev_rx_handler_unregister(port->dev);
192 		dev_set_promiscuity(port->dev, -1);
193 	}
194 
195 	/* FIXME?
196 	 * netdev_upper_dev_unlink(port->dev, port->hsr->dev);
197 	 */
198 
199 	synchronize_rcu();
200 
201 	if (port != master)
202 		dev_put(port->dev);
203 }
204