xref: /openbmc/linux/net/hsr/hsr_slave.c (revision 9bd5910d)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright 2011-2014 Autronica Fire and Security AS
3  *
4  * Author(s):
5  *	2011-2014 Arvid Brodin, arvid.brodin@alten.se
6  */
7 
8 #include "hsr_slave.h"
9 #include <linux/etherdevice.h>
10 #include <linux/if_arp.h>
11 #include <linux/if_vlan.h>
12 #include "hsr_main.h"
13 #include "hsr_device.h"
14 #include "hsr_forward.h"
15 #include "hsr_framereg.h"
16 
17 static rx_handler_result_t hsr_handle_frame(struct sk_buff **pskb)
18 {
19 	struct sk_buff *skb = *pskb;
20 	struct hsr_port *port;
21 	u16 protocol;
22 
23 	if (!skb_mac_header_was_set(skb)) {
24 		WARN_ONCE(1, "%s: skb invalid", __func__);
25 		return RX_HANDLER_PASS;
26 	}
27 
28 	rcu_read_lock(); /* hsr->node_db, hsr->ports */
29 	port = hsr_port_get_rcu(skb->dev);
30 	if (!port)
31 		goto finish_pass;
32 
33 	if (hsr_addr_is_self(port->hsr, eth_hdr(skb)->h_source)) {
34 		/* Directly kill frames sent by ourselves */
35 		kfree_skb(skb);
36 		goto finish_consume;
37 	}
38 
39 	protocol = eth_hdr(skb)->h_proto;
40 	if (protocol != htons(ETH_P_PRP) && protocol != htons(ETH_P_HSR))
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 static int hsr_check_dev_ok(struct net_device *dev)
62 {
63 	/* Don't allow HSR on non-ethernet like devices */
64 	if ((dev->flags & IFF_LOOPBACK) || dev->type != ARPHRD_ETHER ||
65 	    dev->addr_len != ETH_ALEN) {
66 		netdev_info(dev, "Cannot use loopback or non-ethernet device as HSR slave.\n");
67 		return -EINVAL;
68 	}
69 
70 	/* Don't allow enslaving hsr devices */
71 	if (is_hsr_master(dev)) {
72 		netdev_info(dev, "Cannot create trees of HSR devices.\n");
73 		return -EINVAL;
74 	}
75 
76 	if (hsr_port_exists(dev)) {
77 		netdev_info(dev, "This device is already a HSR slave.\n");
78 		return -EINVAL;
79 	}
80 
81 	if (is_vlan_dev(dev)) {
82 		netdev_info(dev, "HSR on top of VLAN is not yet supported in this driver.\n");
83 		return -EINVAL;
84 	}
85 
86 	if (dev->priv_flags & IFF_DONT_BRIDGE) {
87 		netdev_info(dev, "This device does not support bridging.\n");
88 		return -EOPNOTSUPP;
89 	}
90 
91 	/* HSR over bonded devices has not been tested, but I'm not sure it
92 	 * won't work...
93 	 */
94 
95 	return 0;
96 }
97 
98 /* Setup device to be added to the HSR bridge. */
99 static int hsr_portdev_setup(struct net_device *dev, struct hsr_port *port)
100 {
101 	int res;
102 
103 	dev_hold(dev);
104 	res = dev_set_promiscuity(dev, 1);
105 	if (res)
106 		goto fail_promiscuity;
107 
108 	/* FIXME:
109 	 * What does net device "adjacency" mean? Should we do
110 	 * res = netdev_master_upper_dev_link(port->dev, port->hsr->dev); ?
111 	 */
112 
113 	res = netdev_rx_handler_register(dev, hsr_handle_frame, port);
114 	if (res)
115 		goto fail_rx_handler;
116 	dev_disable_lro(dev);
117 
118 	return 0;
119 
120 fail_rx_handler:
121 	dev_set_promiscuity(dev, -1);
122 fail_promiscuity:
123 	dev_put(dev);
124 
125 	return res;
126 }
127 
128 int hsr_add_port(struct hsr_priv *hsr, struct net_device *dev,
129 		 enum hsr_port_type type)
130 {
131 	struct hsr_port *port, *master;
132 	int res;
133 
134 	if (type != HSR_PT_MASTER) {
135 		res = hsr_check_dev_ok(dev);
136 		if (res)
137 			return res;
138 	}
139 
140 	port = hsr_port_get_hsr(hsr, type);
141 	if (port)
142 		return -EBUSY;	/* This port already exists */
143 
144 	port = kzalloc(sizeof(*port), GFP_KERNEL);
145 	if (!port)
146 		return -ENOMEM;
147 
148 	if (type != HSR_PT_MASTER) {
149 		res = hsr_portdev_setup(dev, port);
150 		if (res)
151 			goto fail_dev_setup;
152 	}
153 
154 	port->hsr = hsr;
155 	port->dev = dev;
156 	port->type = type;
157 
158 	list_add_tail_rcu(&port->port_list, &hsr->ports);
159 	synchronize_rcu();
160 
161 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
162 	netdev_update_features(master->dev);
163 	dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
164 
165 	return 0;
166 
167 fail_dev_setup:
168 	kfree(port);
169 	return res;
170 }
171 
172 void hsr_del_port(struct hsr_port *port)
173 {
174 	struct hsr_priv *hsr;
175 	struct hsr_port *master;
176 
177 	hsr = port->hsr;
178 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
179 	list_del_rcu(&port->port_list);
180 
181 	if (port != master) {
182 		if (master) {
183 			netdev_update_features(master->dev);
184 			dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
185 		}
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 
196 	if (port != master)
197 		dev_put(port->dev);
198 	kfree(port);
199 }
200