xref: /openbmc/linux/net/hsr/hsr_slave.c (revision bb3982b4)
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 
31 	if (hsr_addr_is_self(port->hsr, eth_hdr(skb)->h_source)) {
32 		/* Directly kill frames sent by ourselves */
33 		kfree_skb(skb);
34 		goto finish_consume;
35 	}
36 
37 	protocol = eth_hdr(skb)->h_proto;
38 	if (protocol != htons(ETH_P_PRP) && protocol != htons(ETH_P_HSR))
39 		goto finish_pass;
40 
41 	skb_push(skb, ETH_HLEN);
42 
43 	hsr_forward_skb(skb, port);
44 
45 finish_consume:
46 	rcu_read_unlock(); /* hsr->node_db, hsr->ports */
47 	return RX_HANDLER_CONSUMED;
48 
49 finish_pass:
50 	rcu_read_unlock(); /* hsr->node_db, hsr->ports */
51 	return RX_HANDLER_PASS;
52 }
53 
54 bool hsr_port_exists(const struct net_device *dev)
55 {
56 	return rcu_access_pointer(dev->rx_handler) == hsr_handle_frame;
57 }
58 
59 static int hsr_check_dev_ok(struct net_device *dev)
60 {
61 	/* Don't allow HSR on non-ethernet like devices */
62 	if ((dev->flags & IFF_LOOPBACK) || dev->type != ARPHRD_ETHER ||
63 	    dev->addr_len != ETH_ALEN) {
64 		netdev_info(dev, "Cannot use loopback or non-ethernet device as HSR slave.\n");
65 		return -EINVAL;
66 	}
67 
68 	/* Don't allow enslaving hsr devices */
69 	if (is_hsr_master(dev)) {
70 		netdev_info(dev, "Cannot create trees of HSR devices.\n");
71 		return -EINVAL;
72 	}
73 
74 	if (hsr_port_exists(dev)) {
75 		netdev_info(dev, "This device is already a HSR slave.\n");
76 		return -EINVAL;
77 	}
78 
79 	if (is_vlan_dev(dev)) {
80 		netdev_info(dev, "HSR on top of VLAN is not yet supported in this driver.\n");
81 		return -EINVAL;
82 	}
83 
84 	if (dev->priv_flags & IFF_DONT_BRIDGE) {
85 		netdev_info(dev, "This device does not support bridging.\n");
86 		return -EOPNOTSUPP;
87 	}
88 
89 	/* HSR over bonded devices has not been tested, but I'm not sure it
90 	 * won't work...
91 	 */
92 
93 	return 0;
94 }
95 
96 /* Setup device to be added to the HSR bridge. */
97 static int hsr_portdev_setup(struct net_device *dev, struct hsr_port *port)
98 {
99 	int res;
100 
101 	dev_hold(dev);
102 	res = dev_set_promiscuity(dev, 1);
103 	if (res)
104 		goto fail_promiscuity;
105 
106 	/* FIXME:
107 	 * What does net device "adjacency" mean? Should we do
108 	 * res = netdev_master_upper_dev_link(port->dev, port->hsr->dev); ?
109 	 */
110 
111 	res = netdev_rx_handler_register(dev, hsr_handle_frame, port);
112 	if (res)
113 		goto fail_rx_handler;
114 	dev_disable_lro(dev);
115 
116 	return 0;
117 
118 fail_rx_handler:
119 	dev_set_promiscuity(dev, -1);
120 fail_promiscuity:
121 	dev_put(dev);
122 
123 	return res;
124 }
125 
126 int hsr_add_port(struct hsr_priv *hsr, struct net_device *dev,
127 		 enum hsr_port_type type)
128 {
129 	struct hsr_port *port, *master;
130 	int res;
131 
132 	if (type != HSR_PT_MASTER) {
133 		res = hsr_check_dev_ok(dev);
134 		if (res)
135 			return res;
136 	}
137 
138 	port = hsr_port_get_hsr(hsr, type);
139 	if (port)
140 		return -EBUSY;	/* This port already exists */
141 
142 	port = kzalloc(sizeof(*port), GFP_KERNEL);
143 	if (!port)
144 		return -ENOMEM;
145 
146 	if (type != HSR_PT_MASTER) {
147 		res = hsr_portdev_setup(dev, port);
148 		if (res)
149 			goto fail_dev_setup;
150 	}
151 
152 	port->hsr = hsr;
153 	port->dev = dev;
154 	port->type = type;
155 
156 	list_add_tail_rcu(&port->port_list, &hsr->ports);
157 	synchronize_rcu();
158 
159 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
160 	netdev_update_features(master->dev);
161 	dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
162 
163 	return 0;
164 
165 fail_dev_setup:
166 	kfree(port);
167 	return res;
168 }
169 
170 void hsr_del_port(struct hsr_port *port)
171 {
172 	struct hsr_priv *hsr;
173 	struct hsr_port *master;
174 
175 	hsr = port->hsr;
176 	master = hsr_port_get_hsr(hsr, HSR_PT_MASTER);
177 	list_del_rcu(&port->port_list);
178 
179 	if (port != master) {
180 		if (master) {
181 			netdev_update_features(master->dev);
182 			dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
183 		}
184 		netdev_rx_handler_unregister(port->dev);
185 		dev_set_promiscuity(port->dev, -1);
186 	}
187 
188 	/* FIXME?
189 	 * netdev_upper_dev_unlink(port->dev, port->hsr->dev);
190 	 */
191 
192 	synchronize_rcu();
193 
194 	if (port != master)
195 		dev_put(port->dev);
196 }
197